segunda-feira, 19 de maio de 2014

Why the West is anxious about China's economic slowdown

 

May 19, 2014

The recent World Bank report that "China will overtake the United States to become the largest economy" has triggered global concern. Some are taken aback by the fast-paced growth of the Chinese economy; others question the conclusion that China will become the largest economy.
In fact, in recent years there has been a constant chatter of voices talking down China's economy, especially during its economic slowdown this year.
"Before the first quarter of this year, when the National Bureau of Statistics (NBS) announced its economic growth data, Goldman Sachs had predicted China's economic growth rate would be only 6 percent for the first quarter." Economist Ma Guangyuan says that the figures released by the NBS represented a strong riposte to the international investment bank, but they did not put a stop to the questioning voices.
Asking China to engage in a blind acceleration is unreasonable
At an early stage of the G20 finance ministers and central bank governors meeting held in July last year, a number of European countries expressed the hope that China would take aggressive stimulus measures to improve its growth in order to promote the economic recovery of other countries. Today, there is still a popular sentiment in the West that China should bear the primary burden of supporting international economic growth, ignoring the fact that China's intensive economic development model has run its course.
The reality is that the West has become too dependent on China's rapid growth, and that this growth is not sustainable. Structural contradictions, resource constraints, and environmental pressures, stemming from long-term government investment, are becoming more and more serious. Internal and external demand has declined, and some developed countries are now adopting protectionist measures that have led to a new decline in Chinese exports. Competitive currency devaluation in some developed countries has caused hot money flows, the continued appreciation of the RMB, and imported inflation.
"The argument that China's economic slowdown is a drag on global growth is inconsistent with the facts”, says Xu Hongcai, director of the Information Department of the China Center for International Economic Exchanges.
China's contribution to the global economic recovery and sustainable development is remarkable. China has maintained growth at more than 7 percent, it provides more than 10 million jobs a year, and it is currently the world's biggest economy in terms of foreign trade, all of which contribute to global economic growth.
China to contribute more to the world
With the deepening of China's economic reform, Western countries should gradually adapt to the "new normal" of China's economy, under which: first, China's economy will slow down from rapid growth to moderate or high growth, second, there will be a shift in China's economic growth model from intensive growth to innovative and consumer-driven growth, and third, precautions against risk should play a more important role, according to Li Huiyong, an analyst at Shenyin Wanguo Securities.
Although in the transition process, China's economic growth will experience a slowdown, the quality and efficiency of the economy will be greatly improved, with a transition from the "world factory" to the "world market" - from "Made in China" to "Created in China". China's contribution to the world economy will continue to grow.
During the transition process the technology, capital, and experience of developed countries can be introduced to the Chinese market and they can play a positive role in China, says Xu Hongcai.
In the context of economic globalization, China has always advocated the liberalization of trade and the facilitation of investment, but it has also pursued an upgrade of the industrial structure, energy saving, and improvements to the energy structure, which have positive implications for the world economy and for ecological and environmental protection.

Why It's Hard to Stick With Rheumatoid Arthritis Treatment

 

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If dealing with rheumatoid arthritis is a full-time job, the treatment for RA is a task that requires painstaking attention to detail and a whole-hearted commitment to a long-term goal.
While the payoff can be huge—preventing or at least slowing down potentially disabling joint destruction—it's still hard for patients to stick with the treatment, whether it's pills, self-administered injections, or three-hour-long infusions given in a doctor's office.
Consider also that RA medications can be pricey and have side effects and that there's the psychological impact of having to undergo lifelong treatment, and you have a recipe for noncompliance—the medical term for people who don't take their medicine as directed.
"Compliance is a huge issue," confirms Christopher Ritchlin, MD, MPH, a rheumatologist and professor of medicine at the University of Rochester Medical Center in New York. According to a 2007 study, some people with RA missed their meds between 10% and 36% of the time, depending on the drug taken. Other studies have reported noncompliance rates as high as 70%.
"I can deal with bouts of pain, but the fact that it's chronic and never going away, that's the hardest thing to deal with," says Angela Lundberg, 32, who was diagnosed at 18.
It's especially tempting to skip medication when the beneficial effects aren't obvious unless you're looking at an X-ray showing the condition's progression (or even if they are obvious). Still, research suggests that without treatment joints will deteriorate more rapidly and the journey to disability will be quicker. Hence, it's important to find ways to stay motivated.

Next >: How treatment helps

Your Half-Marathon Training Guide

 

Ready to try a half-marathon? Try this 12-week plan for experienced runners who want to build up to running 13 miles.

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Running just might be the most convenient workout going. You don't need to be a skilled athlete, and there's no fancy equipment involved; just lace up your sneaks and go. It's also one of the most efficient ways to blast fat and burn calories—about 600 an hour.

Sure, walking has its benefits, but research shows that running kicks its butt when it comes to shedding pounds. One recent study of 47,000 runners and walkers, from the Lawrence Berkeley National Laboratory in Berkeley, Calif., found that the runners burned more calories and had a far greater decrease in BMI over a six-year period. The joggers who started out heaviest (those with a BMI over 28) lost up to 90 percent more weight than the walkers did.
Dropping pounds and toning up are hardly the only benefits of this killer cardio workout: You'll also reduce your risk of heart disease and
diabetes, boost your mood, temper stress and build muscle, especially in the lower body and core. You don't even need to dedicate a lot of time to reap these rewards; do 20 to 30 minutes, three to four days a week, and you'll see significant improvement.
Ready to hit the road? Here's a plan for experienced runners. And it's smart to add in one day of cross-training (think cycling or swimming) to rev up calorie burn and help prevent injury. Soon enough, you'll feel as if you were born to run.
Your stats: You run three to four times a week for at least five miles nonstop.
The goal: Boost your overall performance—speed, endurance and distance—over the course of 12 weeks, then challenge yourself with a half-marathon.
Your coach: Andrew Kastor is coaching director at Asics L.A. Marathon and head coach at Mammoth Track Club in Mammoth, California.
The plan: In Week 1, run three to four miles at an easy pace (think 5 on a scale of 1 to 10) on your first day; four to five miles on Days 2 and 3; and five to six on Day 4. In subsequent weeks, keep doing one easy-pace day, and vary half-mile-long to mile-long speed intervals. The detailed schedule also tells you how to add in race-pace workouts, so you can hold your speed for longer distances.
HERE'S YOUR GUIDE:
Expert Half-Marathon Training Plan
Train smarter!
1. Buddy up
Face it, sometimes you just don't feel like going for a run, especially when you've been seriously challenging yourself. Having someone by your side is a great way to make the miles more tolerable and maintain your performance. "When you train with a group or pack, you almost always run a little harder or faster," says Kastor. Grab a friend or find a new jogging pal at buddyup.com or the Road Runners Club of America (rrca.org). Choose partners who are a bit better than you; you want a challenge but don't want to get burned out or injured.
2. Take the plunge
Kastor, who works with many elite runners (including Olympian Deena Kastor, his wife), recommends a cold bath right after a hard workout. "It helps reduce inflammation by constricting the blood vessels, so there's less blood pooling through the muscle tissue, and you're not as sore the next day," he explains.
Massage can speed recovery, too: Give yourself a five-minute rubdown using a foam roller; roll slowly up and down your legs, butt, shoulders and back. You can also alleviate soreness by gently pressing into the area with your fingers.
3. Write down your goal
You're amping up your workouts—pump up your
motivation, too! Jot your goal time for the half-marathon or just 13.1 on a sticky note, and post it onto your mirror. As Kastor puts it: "Seeing that number will remind you to make the best choices for your body."
MORE: 7 Tips for Running Your First Race

Lower Cholesterol May Lessen Risk of Some Cancers

 

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THURSDAY, Nov. 5 (Health.com) — Most people know that healthy cholesterol levels can help protect your heart. But new research suggests another potential benefit: a lower risk of developing some types of cancer.
In fact, low total cholesterol is associated with about 60% less risk of the most aggressive form of prostate cancer, and higher levels of good cholesterol (HDL) may protect against lung, liver, and other cancers, according to two studies published this week in the journal Cancer Epidemiology, Biomarkers & Prevention.

Thats quite a reversal of fortune for low cholesterol, which has, in the past, been associated with a higher cancer risk. The new studies suggest that low cholesterol may not deserve its bad reputation, earned from a series of studies in the 1980s that said people with low cholesterol might be at risk of cancer.
In fact, cholesterol may drop in people with undiagnosed cancer, meaning that low cholesterol may be a result—not a cause—of cancer.
In the first study, men with HDL cholesterol above roughly 55 mg/dL had an 11% decrease in overall cancer risk, including lung and liver cancer. (HDL levels between 40 and 50 are average for men.) The study, conducted by National Cancer Institute (NCI) researchers who looked at about 29,000 male smokers in Finland over an 18-year period, is the largest to show a relationship between HDL and cancer.
"Very few studies measured [HDL], and any relationship between HDL and overall cancer risk had therefore not been adequately evaluated," the NCI's Demetrius Albanes, MD, the lead author of the study, said at a press briefing.
While the findings are new and intriguing, more research needs to be conducted to confirm a link between HDL and cancer risk reduction.
“[Its] a very new, exciting question, but we need to do a great deal more research before we have any clear answers," says Eric Jacobs, PhD, an epidemiologist with the American Cancer Society, who co-wrote an editorial accompanying the studies. For his part, Dr. Albanes stressed that the results need to be confirmed, especially in women and nonsmokers.

Next : Can cholesterol-lowering drugs help?

What Your Heart Needs Now

 

 

Things to do in your 30s, 40s, and beyond

heart-hand

(ISTOCKPHOTO)

The statistics are sobering: Heart disease is the number-one killer of women in the United States. And an estimated eight million women have it. Whats more, a new study shows that in recent years, the overall heart disease risk for Americans—especially women—hasnt continued the healthy downward trend it showed in previous decades. Ready for some good news? You can do more to prevent heart disease than almost any other serious condition. Start with these age-specific steps.

donuts-nutrition

(ISTOCKPHOTO)

Declare a trans fat–free zone
Commonly used to extend the shelf life of packaged foods like cookies and crackers, and also found in margarine, trans fats pack a double whammy: They raise bad cholesterol (LDL), while lowering good, protective HDL (your LDL should be below 100; your HDL, above 60). In a Harvard University study, women with the highest level of trans fats in their blood had triple the risk of
heart disease. Take a cue from major U.S. cities like New York and Philadelphia (which have banned trans fats from restaurants), and pitch them out of your pantry.
On ingredient lists, they show up as “hydrogenated” and “partially hydrogenated” oils. But scrutinize any product touted as “trans fat–free” at the supermarket too: Some manufacturers have replaced hydrogenated oils with tropical oils that are high in
saturated fat, which also raises LDL cholesterol. Eating out in a city where trans fats arent banned? Skip the fried stuff; many restaurants still use the oils for frying.

pregnancy-hear

(ISTOCKPHOTO)

Use your ob-gyn as a partner
During your prime reproductive years, you may visit your ob-gyn more than you go to your regular doctor. Make sure you talk to her about your heart as well as gynecological health, particularly because
blood pressure (BP) can rise if youre taking birth control pills or when youre pregnant.
Women who develop preeclampsia (pregnancy-related hypertension) are prone to heart disease later in life. And, in general, “how your heart handles pregnancy offers a snapshot of how it will look in middle age,” says Sharonne Hayes, MD, director of the Womens Heart Clinic at the Mayo Clinic, in Rochester, Minn. To keep BP from creeping up (the safe zone is lower than 120 over 80), substitute herbs and spices for salt; try cumin for a healthy twist on popcorn, for instance. Too much salt causes blood vessels to retain water, which can lead to high BP.

screaming-woman

(ISTOCKPHOTO)

Simmer down
If you boil over when the shopper in front of you has 16 grocery items in the 15-or-fewer lane, beware: Losing your temper can damage your arteries, according to research by C. Noel Bairey Merz, MD, director of the Womens Heart Center and endowed chair in Womens Health at the Cedars-Sinai Heart Institute in Los Angeles. “Raging causes your blood pressure to surge and stay up there,” Dr. Merz says. Thats why its crucial to
get a grip on anger at an early age, before it takes a toll. Instead of venting when a situation makes you furious, take a few deep breaths and describe to yourself whats making you angry. That should help you calm down.

Did you know?

 

Famous people and their drug use

Tabagismo e Alcoolismo: Tratamento

 

 

Há 1,1 bilhão de fumantes no mundo, segundo a OMS, matando mais que o álcool e drogas ilegais.
O fumo é o maior responsável pelas faringites, bronquites, falta de apetite, tremores, perturbações da visão, diversos tipos de câncer, sobretudo do pulmão e doenças cardiovasculares como a angina do peito e o enfarte do miocárdio.

Além do câncer do pulmão, de que o fumo é maior causador, produz bronquite crônica, enfisema pulmonar, coronariopatias, úlceras do estômago e do duodeno, câncer da língua, da faringe, do esôfago e da bexiga.
A ação da nicotina é exercida pelo sistema sobre o sistema parassimpático e simpático e pela liberação de adrenalina e influi na diminuição do consumo do oxigênio e, além de prejudicar o organismo em geral, vai diretamente ao cérebro, coração e circulação.

Apenas um cigarro é suficiente para contrair todos os vasos sanguíneos do corpo. E a fumaça de um cigarro, é o bastante para contrair os vasos capilares das pernas e dos pés.

O fumante sofre, em cada trago, endurecimento das artérias, fazendo o coração trabalhar mais depressa, enquanto os pulmões absorvem monóxido de carbono, amônio, ácido carbônico, piridina e substâncias alcatroadas que passam a circulação do sangue. O monóxido de carbono também origina dores de cabeça; o amônio irrita as narinas e a garganta, a piridina irrita os brônquios e as substâncias alcatroadas engrossam a língua, sujam os dentes e determinam câncer na boca e na língua.A nicotina, em si, diminui a vitalidade do fumante e de seus filhos.
A fumaça do cigarro provoca uma reação violenta nos centros nervosos, produzindo a degeneração das células do cérebro.

Uma vez que o hábito de fumar conduz o viciado a um estado de intoxicação crônica e o leva a uma dependência física e psíquica, sente o fumante dificuldade em abandoná-lo.

A nicotina é um dos venenos mais ativos. A nicotina e o alcatrão deve-se a maior soma de males acarretada aos fumantes. O fumante médio absorve nos pulmões mais de um litro de alcatrão por ano.
Os venenos do fumo agem no organismo pelas vias respiratórias e pelas vias digestivas. Pelas vias respiratórias, através da traquéia e brônquios, por onde chegam aos pulmões, onde são absorvidos e conduzidos ao sangue e, por este, a todos os demais órgãos. A nicotina, por intermédio da circulação, excita as glândulas supra-renais que segregam mais adrenalina. Conduzida ao sangue, provoca contração das paredes arteriais, ocasionando espamos das artérias. É assim que o fumo aumenta a pressão arterial, favorece problemas coronários e cardiovasculares.
Pelas vias digestivas, boca, estômago e intestinos, pois que, parte do venenos do fumo dissolve-se na saliva e é conduzida ao estômago, ocasionando a diminuição da secreção gástrica, dificultando a digestão, diminuindo o apetite e predispondo o fumante à úlcera gastroduodenal. Do aparelho digestivo os venenos do fumo são conduzidos ao sangue e aos diversos tecidos do corpo.
No fígado, grande parte da nicotina é transformada em ácido úrico, com o que ocasiona o surgimento do reumatismo e da gota.

O que está comprovado sobre a fumaça ambiental do tabaco:
- é inalada, absorvida e processada por não-fumantes
- é quimicamente similar a fumaça inalada pelo fumante, e esta é carcinogênica
- contém substâncias que causam câncer
- pode causar câncer e lesões genéticas (que originam câncer) em animais de laboratório
- está associada a problemas cardíacos
- causa problemas respiratórios em crianças de até 18 meses
- retarda o desenvolvimento fetal

Substâncias da Fumaça do Cigarro
Quando cigarros industrializados ou de fumo-de-rolo, cachimbos e charutos são acesos, algumas substâncias são inaladas pelo fumante e outras se difundem pelo ambiente. Essas substâncias são nocivas à saúde.
Todas as formas de uso do tabaco, inclusive os cigarros com mentol, filtros especiais, com baixos teores (light, exta-light) etc. tem uma composição semelhante, não havendo, portanto cigarros "saudáveis" ou cachimbos e charutos que façam menos mal. Isso ocorre porque, mesmo escolhendo produtos com menores teores de alcatrão e nicotina, os fumantes acabam compensando essa redução, fumando mais cigarros por dia e tragando mais freqüente ou profundamente, ou seja, fazendo outras modificações compensatórias em conseqüência da dependência à nicotina.
A fumaça do cigarro é uma mistura de cerca de 5 mil elementos diferentes. Ela é formada pelos seguintes componentes:
Nicotina - considerada droga pela OMS. Sua atuação no sistema nervoso central é como a da cocaína, com uma diferença: chega entre 2 e 4 segundos mais rápido ao cérebro que a própria cocaína. É uma droga psicoativa, responsável pela dependência do fumante. É por isso que o tabagismo é classificado no Código Internacional de Doenças (CID - 10) como grupo dos transtornos mentais e de comportamento decorrente do uso de substâncias psicoativas. A nicotina aumenta a liberação de catecolaminas, acelerando a freqüência cardíaca, com conseqüente vasoconstricção e hipertensão arterial. Provoca uma maior adesividade plaquetária, e juntamente com o monóxido de carbono leva à arterosclerose. Contribui assim para o surgimento de doenças cardiovasculares. No aparelho gastrointestinal, a nicotina estimula a produção de ácido clorídrico, podendo levar ao aparecimento de úlcera gástrica. Também estimula o sistema parassimpático, o que pode causar diarréia. A nicotina libera substâncias quimiotáxicas, que vão atrair para o pulmão os leucócitos neutrófilos polimorfonucleares, a maior fonte de elastase, que destrói a elastina e provoca o enfisema pulmonar (Orleans e Slade, 1993; Rosemberg, 1996).
Monóxido de Carbono (CO) - tem afinidade com a hemoglobina (HB) contida nos glóbulos vermelhos do sangue, que transportam oxigênio para os tecidos de todos os órgãos do corpo. A ligação do monóxido de carbono com a hemoglobina forma o composto chamado carboxihemoglobina, que dificulta a oxigenação do sangue, privando alguns órgãos do oxigênio e causando doenças como a arterosclerose.
Alcatrão - composto de mais de 40 substâncias comprovadamente carcinogênicas que incluem o arsênico, níquel, benzopireno e cádmio. Carcinogênicas são substâncias que provocam câncer como resíduos de agrotóxicos nos produtos agrícolas, como o DDT, e até substâncias radioativas, como é o caso do polônio 210.
Vale ressaltar que as substâncias da fumaça do cigarro tem efeitos sobre a saúde do fumante, mas também sobre a saúde do não-fumante, exposto à poluição do ambiente causada pelo cigarro.
Cigarros de Baixos Teores
O modo de fumar é determinado pela necessidade do fumante em consumir nicotina (que lhe traz a sensação de satisfação). Os fumantes utilizam artifícios para alcançar tal sensação ao fumarem cigarros com teores baixos, dando tragadas mais profundas. Assim, aumentam o número de tragadas por cigarros, aumentam o número de cigarros fumados e bloqueiam os orifícios de ventilação dos filtros para aumentar a concentração de fumaça inalada durante a tragada.
Esses artifícios são conhecidos como compensação e tem sido, extensivamente, documentados na literatura científica, sendo bem conhecidos da indústria do tabaco há mais de 20 anos. Testes demonstram que, em "condições de fumo realísticas", existe uma diferença muito pequena entre os cigarros denominados "light" e os comuns. Na verdade, eles podem até produzir quantidades maiores de alcatrão, nicotina e monóxido que os cigarros tradicionais testados.
Um estudo realizado na Inglaterra por Kozlwski et al. (1999) demonstrou que 58% dos filtros de cigarros examinados apresentavam sinais de bloqueio significativo e 19% sinais de bloqueio total. A partir dos resultados de uma pesquisa realizada em 1998, a ASH e The Observer mostraram que os cigarros com baixos teores podem propiciar os mesmos mecanismos compensatórios antes citados.
Por mais que a indústria do fumo afirme que realiza pesquisas visando ao desenvolvimento de produtos alternativos, na verdade, ela estuda produtos e formas de distribuir a nicotina em dispositivos que contenham menos teor de determinadas substâncias, como o alcatrão, por exemplo, e mantendo a nicotina, que causa a dependência.
Lutando contra o cigarro
Muitos tabagistas tentam parar de fumar sozinhos. A seguir algumas dicas possíveis de ser aplicada por qualquer pessoa para que seja obtido um melhor resultado. São para dificultar o gesto automático de fumar, tornando-o consciente:
1. Ter certeza de que quer fumar e não simplesmente acender um cigarro automaticamente, ou seja, pensar muito bem se de fato precisa fumar ou se pode deixar para mais tarde.
2. Parar de comprar cigarros.
3. Não comprar um maço de modo algum enquanto não acabar o último cigarro, mesmo que seja na boca da noite ou na véspera de uma viagem.
4. Quando não tiver cigarro, ter o brio de não ficar catando bitucas.
5. Não ter fósforo, isqueiro, fogo por perto.
6. Desfazer-se do isqueiro. O "som"(ruído) característico obtido ao se abrir um determinado isqueiro também pode ser prazeroso.
7. Jogar cinzeiro fora para dificultar o trabalho na hora de bater as cinzas em lugar adequado.
8. Colocar o maço de cigarros num lugar que lhe dê trabalho quando for pegá-lo; não andar com o maço no bolso nem deixá-lo na cabeceira, na escrivaninha, etc.
9. Se possível, colocar o maço em outro ambiente.
10. Não acender o cigarro somente porque você ficou com vontade ao ver alguém acendendo ou fumando um.
11. Demorar o máximo possível com o cigarro na mão antes de acendê-lo.
12. Dar no máximo três tragadas de cada cigarro, mesmo que o jogue fora quase inteiro (nicotina a menos).
13. Envergonhar-se de fumar.
14. Questionar se vale a pena fumar, mesmo que corra o risco de morrer como aquele parente que teve dores, permaneceu acamado, emagreceu, fez radioterapia, ficou feio, fez a família sofrer, gastou o que tinham e... acabou falecendo.
15. Lembrar que nas escolas o cigarro é proibido pela Lei 9760/97.
Se essa luta íntima contra o cigarro não der certo, ainda há muitas esperanças de cura para esse vício. Psicoterapias, grupos de auto-ajuda e recursos médicos, como nicotina em adesivos e antidepressivos, são os meios mais eficazes.
(Fonte: Anjos Caídos, Içami Tiba. Editora Gente, 6ª edição)

Dez razões para parar de fumar
1 - Após 6 horas sem fumar, a pressão e o coração se normalizam. Após 30 dias, estão completamente normais
2 - Após 1 dia sem cigarro, o pulmão funciona melhor
3 - Após 2 dias sem fumar, o olfato e o paladar sofrem uma significativa melhora
4 - Após 3 semanas, os exercícios físicos ficam mais fáceis de serem executados
5 - A circulação sanguínea melhora após 2 meses sem cigarro
6 - Após 3 meses, o número de espermatozóides normaliza e há um significativo aumento em sua qualidade
7 - Após 1 ano o risco de problemas cardíacos está reduzido
8 - Após 5 anos sem fumar, o risco de problemas no coração são iguais aos de uma pessoa que nunca tenha fumado
9 - Dentes, mãos e pele clareiam após o término do vício
10 - Aumento da qualidade de vida, disposição e humor
(Revista Cyber Mondo Ciência e Tecnologia - Ano1 nº2)

Fumo e doenças cardiovasculares
- Fumar aumenta o risco de doenças coronárias como angina no peito e infarto do miocárdio
- Triplica o risco de morte por infarto em homens com menos de 55 anos
- Aumenta em 10 vezes o risco de tromboembolia venosa e infarto em mulheres que tomam anticoncepcionais orais
- Aumenta o risco de insuficiência vascular periférica, causando má circulação nas pernas e impotência sexual
Fumo e doenças neurovasculares
- Fumar triplica o risco de derrame cerebral  (acidente vascular cerebral - AVC)
Fumo e câncer
O cigarro contém mais de 40 substâncias cancerígenas que aumentam o risco de câncer na:
- boca, faringe, laringe e traquéia
- pulmões - risco 12 a 20 vezes maior
- esôfago, estômago
- rins, bexiga, colo do útero, etc
Fumo e doenças respiratórias
Fumar aumenta a queda da capacidade respiratória com a idade e aumenta o risco de problemas respiratórios como:
- tosse, chiado e falta de ar
- bronquite crônica e enfisema
- causa 90% da doença pulmonar obstrutiva crônica (DPOC) e aumenta seu risco em 10 vezes
- laringite (rouquidão)
- infecções das vias respiratórias
- crise de asma

Fumo e pele
Fumar eleva o risco de rugas prematuras e de celulite e interfere na cicatrização de feridas cirúrgicas
Fumo e gravidez
Fumar aumenta o risco de infertilidade e de complicações da gravidez.
A gestante fumante tem maior chance de abortar, de ter filho prematuro, de baixo peso e de morte do filho no período perinatal.

Fumar reduz a expectativa de vida
A chance de viver até os 73 anos é de 42% em fumantes e 78% em não-fumantes
Fumar prejudica o tratamento de doenças
Como gastrite, úlcera péptica, esofagite de refluxo, angina, insuficiência cardíaca, bronquite, enfisema e asma
Fumar aumenta as complicações pós-operatórias
Especialmente em idosos, obesos e pacientes em tratamento de doenças cardíacas ou respiratórias

Fumo Passivo
As pessoas que estão próximas dos fumantes, especialmente em ambientes fechados, inalam mais de 400 substâncias que podem prejudicar a saúde.
O fumante passivo tem maior risco de câncer de pulmão e infarto do miocárdio.
As crianças que convivem com pais fumantes têm maior risco de infecções respiratórias, bronquiolites, asma, otites e infecções de garganta (amigdalites).

Cigarro e Gravidez: Parceria Perigosa
As mulheres têm um motivo a mais para deixar de fumar: durante a gravidez, esse hábito pode fazer imenso mal ao feto. Quando a mãe fuma durante a gestação, o bebê recebe as substâncias tóxicas do cigarro por meio da placenta. A nicotina provoca o aumento do batimento cardíaco do feto, e a criança pode nascer com peso reduzido, menor estatura e alterações neurológicas importantes. Isso sem falar que a gestante tem um risco aumentado de sofrer um aborto espontâneo, entre outras implicações ao longo dos nove meses. Para piorar o quadro, durante a amamentação, as substâncias tóxicas continuam sendo transmitidas ao bebê via leite materno.
Portanto, mulheres, procurem abandonar o cigarro logo agora, porque depois de já estarem grávidas a luta contra o tabaco fica ainda mais difícil. Porém é fundamental.
Fonte: Revista Documento Verdade, Ano1, Nº03, Pg.32. Editora Escala.
Correlatos Psicossociais do Tabagismo
Correlatos Sociais

No mundo desenvolvido, particularmente nos países onde há campanhas/políticas antifumo bem organizadas, o tabagismo é estreitamente relacionado com a situação socioeconômica, sendo mais prevalente entre pobres, trabalhadores braçais semiqualificados, desempregados, indivíduos com baixos níveis culturais e mães solteiras. Além disso, essa demarcação entre os grupos sociais está se acentuando: nas últimas 3 décadas a prevalência do tabagismo caiu mais de 50% nas classes mais elevadas da sociedade britânica, mas permaneceu imutável nos grupos mais desvalidos. De modo semelhante, os índices de cessação do tabagismo no Reino Unido mostram grande relação inversa com a privação social.
Correlatos Psiquiátricos
A depressão é um fator importante de risco de dependência de nicotina. Nos fumantes é maior a prevalência de história de depressão significativa e, nesses casos, a probabilidade de cessação do tabagismo é menor do que nos indivíduos sem história de depressão. Sugeriu-se que a associação entre depressão e tabagismo pode ser devida a uma predisposição genética comum às duas doenças. Outros fatores de risco da dependência de nicotina incluem esquizofrenia (70 a 90% dos esquizofrênicos são fumantes) e abuso de múltiplas drogas, particularmente álcool, cocaína e heroína.
Assim, é provável que a maioria que continua fumando é composta por aqueles com problemas psiquiátricos ou sociais. Além disso, é provável que esses fumantes sejam mais dependentes do tabaco e menos interessados em abandoná-lo.

Simplifying an ultrafast laser offers better control

 

 


Going back to the drawing board to find a way to overcome the technical limitations of their laser, a team led by François Légaré, professor at the INRS Énergie Matériaux Télécommunications Research Centre, developed a new concept offering a simpler laser design, control over new parameters, and excellent performance potential.

Going back to the drawing board to find a way to overcome the technical limitations of their laser, a team led by François Légaré, professor at the INRS Énergie Matériaux Télécommunications Research Centre, developed a new concept offering a simpler laser design, control over new parameters, and excellent performance potential. Called "frequency domain optical parametric amplification" (FOPA), the concept supersedes traditional time domain amplification schemes that have been the linchpin of ultrafast laser science for 20 years. The new concept is explained in detail in an open access article in Nature Communications.

For researchers, capturing images of a moving electron is the holy grail of molecular imaging. But in their efforts to generate a light pulse that is sufficiently short and powerful to capture such an image, researchers have been held back by the fundamental limitations and unsatisfactory performance of lasers. "Our goal is to capture images of a chemical reaction using high spatial and temporal resolution," explained François Légaré, speaking at the TEDxConcordia event. "I want to shoot a video where you can actually see the atoms dancing in a chemical reaction."

Amplifying laser pulses in the frequency domain rather than the time domain also overcomes certain technical constraints, among them the ability to access multiple different frequencies simultaneously and control them independently. In addition, higher light pulse energy can be achieved with the new concept. "Our approach holds promise for high-power, broad spectrum, few-cycle laser sources," said the young researcher.

In the proof of concept presented in the Nature Communications article, Professor Légaré's team demonstrated that FOPA generates pulses comparable to lasers using time domain amplification in the given conditions: 1.5 mJ, 1.8 microns, 12 fs duration corresponding to 2 optical cycles. Research associate and lead author Bruno Schmidt points out that not only does the FOPA approach open up access to parameters that could not previously be controlled, it also eliminates many complex assembly components. "The logic underpinning this concept could be applied to other types of applications," he added, "so we believe it will allow us to look at nonlinear optics in a whole new light." Optimistic and ambitious, Bruno Schmidt plans to market the innovations stemming from his work, even founding his own company, few-cycle Inc.


Story Source:

The above story is based on materials provided by INRS. The original article was written by Stéphanie Thibault. Note: Materials may be edited for content and length.


Journal Reference:

  1. Bruno E. Schmidt, Nicolas Thiré, Maxime Boivin, Antoine Laramée, François Poitras, Guy Lebrun, Tsuneyuki Ozaki, Heide Ibrahim, François Légaré. Frequency domain optical parametric amplification. Nature Communications, 2014; 5 DOI: 10.1038/ncomms4643

Unified superconductors: Single theoretical model of superconductivity for many materials

 

May 14, 2014

Sissa Medialab

Superconductors are promising materials, with applications ranging from medicine to transport. Unfortunately, though, their use is for the time being limited to the very low temperatures (close to absolute zero) necessary for superconductivity to occur. Some materials, however, could be improved so as to obtain higher and energetically less “costly” critical temperatures. Scientists have now investigated a class of conductors at high critical temperature, adding insight into the physics of these phenomena.


Superconductors are promising materials, with applications ranging from medicine to transport. Unfortunately, though, their use is for the time being limited to the very low temperatures (close to absolute zero) necessary for superconductivity to occur. Some materials, however, could be improved so as to obtain higher and energetically less "costly" critical temperatures. A team of researchers coordinated by SISSA investigated a class of conductors at high critical temperature, adding insight into the physics of these phenomena.

Leading-edge imaging and medical diagnostics, but also magnetic levitation trains: these are examples of technology relying on "superconductors." Superconductors are materials in which electrons flow without dissipation and which have very special properties such as expelling all magnetic fields. The physics underlying the phenomenon has only been explained for low-temperature superconductors, those exhibiting their properties at temperatures close to absolute zero. The so-called high-temperature superconductors remain one of the major mysteries of the physics of matter, and scientists have recently been redoubling their efforts to understand the phenomenon and improve its yield. Among them are Massimo Capone and co-workers who have just published a paper in Physical Review Letters. The study was authored by Capone, ERC SUPERBAD project leader, Gianluca Giovannetti of CNR-IOM and SISSA, and Luca de' Medici of the European Synchrotron Radiation Facility in Grenoble.

"To be able to function, classical superconductors have to reach extremely low temperatures, very close to absolute zero. This makes their use very costly and uneconomical," explains Capone. "Almost 30 years ago scientists discovered some classes of materials that worked at temperatures that were substantially higher though still quite low -- in the order of 200°C below zero. Several types of materials exist, with different characteristics and critical temperatures," continues Capone, "the most investigated family is based on copper, while another, slightly less efficient one is based on iron -- and that's precisely the family we set out to investigate."

As Capone explains, there's no agreement on how the phenomenon originates in the different materials, and according to some scientists the explanations could be different for the various families. "We carried out a study based on theory and simulations that demonstrated that this is not the case: the theoretical explanation for copper and iron superconductors could be the same, and could even apply to other materials like carbon, for example carbon fullerides, which have been extensively studied at SISSA. In practice, there could be a unified theory for these superconductors."

In their new paper, Capone and co-workers demonstrate that the explanation is the same, and they put forward some hypotheses as to the theoretical framework for this explanation, hypotheses which paradoxically liken superconductivity and very high impedance phenomena. "Clearly, we haven't yet explained the physics of these superconductors, or we would have won the Nobel prize," he jokes. "However, demonstrating that there is a single theoretical framework explaining these phenomena could be an important step forward."


Story Source:

The above story is based on materials provided by Sissa Medialab. Note: Materials may be edited for content and length.


Journal Reference:

  1. Luca de’ Medici, Gianluca Giovannetti, Massimo Capone. Selective Mott Physics as a Key to Iron Superconductors. Physical Review Letters, 2014; 112 (17) DOI: 10.1103/PhysRevLett.112.177001

Non-invasive lithotripsy leads to more treatment for kidney stones

 


When it comes to treating kidney stones, less invasive may not always be better, according to new research from Duke Medicine.

In a direct comparison of shock wave lithotripsy vs. ureteroscopy -- the two predominant methods of removing kidney stones -- researchers found that ureteroscopy resulted in fewer repeat treatments.

The findings were published May 16, 2014, in the journal JAMA Surgery, coinciding with presentation at the annual meeting of the American Urological Association.

"Nearly one out of 11 people in the United States has kidney stones, leading to more than $10 billion a year in treatment costs," said lead author Charles D. Scales Jr., M.D., assistant professor of surgery at Duke. "As we explore ways to improve value in the health care system, we need to look at the kinds of things that drive costs up; reducing the number of repeat procedures is one place to start."

Scales and colleagues analyzed data for nearly 48,000 insured patients in the United States who sought emergency room or urgent care treatment for kidney stones from 2002-10.

Roughly half the patients received shock wave lithotripsy, a non-invasive approach that focuses pressure waves on the stones to break them into tiny pieces that can then pass painlessly. The other half of patients underwent ureteroscopy, a minimally invasive procedure that uses a laser to break up the stone, and a thin scope that travels through the urethra to snare the stone in a small basket for removal.

Within 120 days of the initial procedure, approximately one in five of the patients needed a second treatment. The researchers focused their comparison on patients who were equally qualified for either procedure. Among that group, 11 percent of patients undergoing shock wave lithotripsy needed a second procedure, while less than 1 percent of ureteroscopy patients needed an additional treatment.

"Our findings add new insight, since most of published research around the effectiveness of the procedures was conducted years ago, when the technology was new," Scales said. In the past 20 years, he said, many experts believe shock wave lithotripsy has become less effective as the devices underwent design changes to improve safety. At the same time, ureteroscopy improved with better endoscopes and laser technology."

The researchers noted that the findings have important policy implications around Medicare reimbursements. For treating kidney stones, Medicare currently pays about $700 for a patient to receive lithotripsy, but only about $400 for a patient to receive the endoscopic ureteroscopy treatment, which the study found to be more effective.

The researchers suggested that differences in effectiveness, invasiveness and costs highlight important tradeoffs between the two procedures. In all cases, Scales said, the decision to undergo shock wave lithotripsy or ureteroscopy should be carefully considered by both the doctor and the patient.

"Many patients believe that because nothing is inserted into the body, shock wave lithotripsy is better, but that may not always be the case," Scales said. "There can be important tradeoffs for having the non-invasive procedure. One question to ask is about the likelihood of a second procedure, and the impact that might have on the cost of care and the time off work."


Story Source:

The above story is based on materials provided by Duke University Medical Center. Note: Materials may be edited for content and length.


Journal Reference:

  1. Charles D. Scales, Julie C. Lai, Andrew W. Dick, Jan M. Hanley, Jeroen van Meijgaard, Claude M. Setodji, Christopher S. Saigal. Comparative Effectiveness of Shock Wave Lithotripsy and Ureteroscopy for Treating Patients With Kidney Stones. JAMA Surgery, 2014; DOI: 10.1001/jamasurg.2014.336

First test of pluripotent stem cell therapy in monkeys is successful

 

May 15, 2014

 

For the first time in an animal that is more closely related to humans, researchers have demonstrated that it is possible to make new bone from stem-cell-like induced pluripotent stem cells (iPSCs) made from an individual animal's own skin cells. The study in monkeys also shows that there is some risk that those iPSCs could seed tumors, but that unfortunate outcome appears to be less likely than studies in immune-compromised mice would suggest.


Rhesus macaque (stock image). "We have been able to design an animal model for testing of pluripotent stem cell therapies using the rhesus macaque, a small monkey that is readily available and has been validated as being closely related physiologically to humans," said Cynthia Dunbar of the National Heart, Lung, and Blood Institute.

Researchers have shown for the first time in an animal that is more closely related to humans that it is possible to make new bone from stem-cell-like induced pluripotent stem cells (iPSCs) made from an individual animal's own skin cells. The study in monkeys reported in the Cell Press journal Cell Reports on May 15th also shows that there is some risk that those iPSCs could seed tumors, but that unfortunate outcome appears to be less likely than studies in immune-compromised mice would suggest.

"We have been able to design an animal model for testing of pluripotent stem cell therapies using the rhesus macaque, a small monkey that is readily available and has been validated as being closely related physiologically to humans," said Cynthia Dunbar of the National Heart, Lung, and Blood Institute. "We have used this model to demonstrate that tumor formation of a type called a 'teratoma' from undifferentiated autologous iPSCs does occur; however, tumor formation is very slow and requires large numbers of iPSCs given under very hospitable conditions. We have also shown that new bone can be produced from autologous iPSCs, as a model for their possible clinical application."

Autologous refers to the fact that the iPSCs capable of producing any tissue type—in this case bone—were derived from the very individual that later received them. That means that use of these cells in tissue repair would not require long-term or possibly toxic immune suppression drugs to prevent rejection.

The researchers first used a standard recipe to reprogram skin cells taken from rhesus macaques. They then coaxed those cells to form first pluripotent stem cells and then cells that have the potential to act more specifically as bone progenitors. Those progenitor cells were then seeded onto ceramic scaffolds that are already in use by reconstructive surgeons attempting to fill in or rebuild bone. And, it worked; the monkeys grew new bone.

Importantly, the researchers report that no teratoma structures developed in monkeys that had received the bone "stem cells." In other experiments, undifferentiated iPSCs did form teratomas in a dose-dependent manner.

The researchers say that therapies based on this approach could be particularly beneficial for people with large congenital bone defects or other traumatic injuries. Although bone replacement is an unlikely "first in human" use for stem cell therapies given that the condition it treats is not life threatening, the findings in a primate are an essential step on the path toward regenerative clinical medicine.

"A large animal preclinical model for the development of pluripotent or other high-risk/high-reward generative cell therapies is absolutely required to address issues of tissue integration or homing, risk of tumor formation, and immunogenicity," Dunbar said. "The testing of human-derived cells in vitro or in profoundly immunodeficient mice simply cannot model these crucial preclinical safety and efficiency issues."

The NIH team is now working with collaborators on differentiation of the macaque iPSCs into liver, heart, and white blood cells for eventual clinical trials in hepatitis C, heart failure, and chronic granulomatous disease, respectively.


Story Source:

The above story is based on materials provided by Cell Press. Note: Materials may be edited for content and length.


Journal Reference:

  1. So Gun Hong, Thomas Winkler, Chuanfeng Wu, Vicky Guo, Stefania Pittaluga, Alina Nicolae, Robert E. Donahue, Mark E. Metzger, Sandra D. Price, Naoya Uchida, Sergei A. Kuznetsov, Tina Kilts, Li Li, Pamela G. Robey, Cynthia E. Dunbar. Path to the Clinic: Assessment of iPSC-Based Cell Therapies In Vivo in a Nonhuman Primate Model. Cell Reports, 2014; DOI: 10.1016/j.celrep.2014.04.019

Mice with multiple sclerosis-like condition walk again after human stem cell treatment

 

May 15, 2014

University of Utah Health Sciences

Mice severely disabled by a condition similar to multiple sclerosis (MS) were able to walk less than two weeks following treatment with human neural stem cells. The finding uncovers potential new avenues for treating MS. When scientists transplanted human stem cells into MS mice, they predicted the cells would be rejected, much like rejection of an organ transplant. Expecting no benefit to the mice, they were surprised when the experiment yielded spectacular results.


1) Multiple sclerosis (MS) impairs nerve function by damaging myelin, an insulating layer that surrounds nerves. MS mice can't move well. 2) Human neural stem cells injected into MS mice stimulate the mouse's own cells to repair the damage. 3) Nerve cell function is restored. MS mice can walk and run.

Mice severely disabled by a multiple sclerosis (MS) -- like condition could walk less than two weeks following treatment with human stem cells. The finding, which uncovers new avenues for treating MS, will be published online on May 15, 2014, in the journal Stem Cell Reports.

When scientists transplanted human stem cells into MS mice, they predicted the cells would be rejected, much like rejection of an organ transplant.

Expecting no benefit to the mice, they were surprised when the experiment yielded spectacular results.

"My postdoctoral fellow Dr. Lu Chen came to me and said, 'The mice are walking.' I didn't believe her," said co-senior author, Tom Lane, Ph.D., a professor of pathology at the University of Utah, who began the work at University of California, Irvine.

Within just 10 to 14 days, the mice regained motor skills. Six months later, they still showed no signs of slowing down.

"This result opens up a whole new area of research for us," said co-senior author Jeanne Loring, Ph.D., co-senior author and professor at The Scripps Research Institute in La Jolla, Calif.

More than 2.3 million people worldwide have MS, a disease where the immune system attacks myelin, an insulation layer surrounding nerve fibers. The resulting damage inhibits nerve impulses, producing symptoms that include difficulty walking, impaired vision, fatigue and pain.

The MS mice treated with human stem cells experience a reversal of symptoms. Immune attacks are blunted, and damaged myelin is repaired, explaining their dramatic recovery. The discovery could help patients with latter, or progressive, stages of the disease, for whom there are no treatments.

Counterintuitively, the researchers' original prediction that the mice would reject the stem cells, came true. There are no signs of the cells after one week. In that short window, they send chemical signals that instruct the mouse's own cells to repair the damage caused by MS. This realization could be important for therapy development.

"Rather than having to engraft stem cells into a patient, which can be challenging, we might be able to put those chemical signals into a drug that can be used to deliver the therapy much more easily," said Lane.

With clinical trials as the long-term goal, the next steps are to assess durability and safety of the stem cell therapy in mice.

"I would love to see something that could promote repair and ease the burden that patients with MS have," said Lane.

"This result opens up a whole new area of research for us," said co-senior author Jeanne Loring, Ph.D., co-senior author and professor at The Scripps Research Institute in La Jolla, Calif.

More than 2.3 million people worldwide have MS, a disease where the immune system attacks myelin, an insulation layer surrounding nerve fibers. The resulting damage inhibits nerve impulses, producing symptoms that include difficulty walking, impaired vision, fatigue and pain.


Story Source:

The above story is based on materials provided by University of Utah Health Sciences. Note: Materials may be edited for content and length.


Journal Reference:

  1. Lu Chen, Ronald Coleman, Ronika Leang, Ha Tran, Alexandra Kopf, Craig M. Walsh, Ilse Sears-Kraxberger, Oswald Steward, Wendy B. Macklin, Jeanne F. Loring, Thomas E. Lane. Human Neural Precursor Cells Promote Neurologic Recovery in a Viral Model of Multiple Sclerosis. Stem Cell Reports, 2014; DOI: 10.1016/j.stemcr.2014.04.005

Secret of radiation vulnerability revealed by research

 

The mutant flies bred by the scientists have a number of significant peculiarities. The experiments have shown that even low doses of X-ray irradiation (not exceeding 10 R) can cause serious defects in those flies' legs.

In contrast, in the flies with normal (unchanged) genome such defects could not be caused even by doses of irradiation hundreds of times higher. What is more, the combination of the two mutations worsened the long-term memory impairment, earlier observed in the flies with only one of the mutations.

In addition, the mutant flies' cells are less resistant to the so-called superoxide radicals.

Superoxide radicals are ions which appear in cells under both normal and pathological conditions. Superoxide radicals have very high rates of reactivity, which is why their excess damages many types of bio-molecules, including DNA. The mutations in Drosophilaflies' cells lowered their ability to resist that damage.

What was already known

According to the scientists, mutations in the genome of the experimental flies affected two genes: CG5017 and spineless. Both these genes are involved in regulation of many different functions, a large number of which still remain unknown. The team of researchers from MIPT, RAS and Cold Spring Harbor Laboratory has set a goal to reduce this white spot. The scientists started with the already known facts, i.e., that the CG5017 gene mutations impair insects' memory, and that mutations in spineless bring about a number of defects in morphogenesis. In Drosophila flies, spineless mutations affect leg and eye formation and disrupt the development of neuronal dendritic structure.

The CG5017 gene encodes the proteins which belong to the Nucleosome assembly protein (NAP) super-family. These proteins are the so-called nucleotropic chaperones, i.e., they are involved in the formation of functioning chromosomes' elementary units, namely, nucleosomes.

It should also be noted that in most multicellular organisms the DNA molecules, located in the cell's nuclei, are not simply wound up double spirals, but very complex structures linked with protein molecules.

Spineless is a transcription factor, which means that this gene is involved in the process of transcribing genetic information from DNA to RNA, that is, RNA synthesis. This gene is important for cells also because it regulates the transcriptional activity of many other genes.

The protein encoded by spineless regulates the synthesis of other proteins, which, in their turn, perform many important functions. Mutationsappearing in spineless do not directly impact the structure of this or that protein. Yet, such mutations can either seriously limit, or even render impossible, the synthesis of many different protein molecules at once.

Spineless-controlled genes are responsible for the proper development of an animal. Even by the first half of the twentieth century,spineless gene mutations were ranked among the so-called homeotic mutations. Such mutations do not stop the process of the organism's formation, but direct it in the wrong way.

"Where we expected to see antennae, there emerged leg morphological structures with altered segmentation. It later turned out that the formation of eye structures and nervous cells had also been disrupted," said Boris Kuzin, the leading author of the article presenting the research. Boris Kuzin is a staff scientist of the DNBICT Brain Stem Cells Laboratory and the head of the Genetic Mechanisms of OrganogenesisResearch Group at the Institute of Developmental Biology (RAS).

What was discovered

The new research has shown the following: the spineless gene is also involved in long-term memory formation and detoxification. Spineless, and the proteins it controls, help the cell to get rid of exogenous toxins (i.e., originating outside the cell) and endogenous ones (in this case, those which were produced inside the cell following the irradiation).

According to Boris Kuzin, the combination of the weak spineless and CG5017 gene mutations in a genome has a synergistic effect and results in the weakening of spineless (ss) products' functions. The organisms of fruit flies with these particular mutations cannot manage the simultaneous processes of detoxification and morphogenesis.

"It seems that the disruption of detoxification leads to aggravation of the defects, which appear in the process of limb formation in response to even low radiation doses. It looks like these mutant flies lack the functionally active spineless (ss) products necessary for the simultaneous control of development and detoxification," said Kuzin.

It should be emphasized that many genes have functional analogues, which work as partial substitutes, i.e., if a gene cannot function properly because of a mutation, other genes can, to some extent, compensate for this disruption. Besides, gene mutations can be strong (the affected gene is fully dysfunctional) and weak (the affected gene retains some of its functions).

What is means

The discovery, as the scientists state in their article, can shed some light on the problem of individual irradiation sensitivity. It is known that low doses of radiation sometimes result in serious inborn defects, and sometimes leave no traces. In part, it is connected with thea priori random nature of ionizing radiation, but there are also a number of genetically-based molecular-biological differences, many of which have not been yet defined.

"These results may have broader implications beyond the model organism. In particular, they may indicate an increased risk of pathological response to radiation in humans carrying hypomorphic mutations of these genes in their genome (note that both genes are highly evolutionarily conserved). Such individuals may be more vulnerable than the bulk of the population to even low levels of radiation, such as those delivered during routine medical procedures, prolonged air travel, or long term residency on the premises with high levels of radon," wrote the researchers.

In the scientists' opinion, with the advent of broadly available genome sequencing it may become possible to single out the mutations linked with increased radiation sensitivity in individuals. The data can be used, for example, when choosing diagnostic procedures for such patients in order to ameliorate their increased vulnerability to radiation.

The fact that the CG5017 gene mutation effect is enhanced by a mutation in spineless (ss), and vice versa, confirms that different genes do interact with each other. The researchers suppose that the CG5017 gene product launches the process of synthesis of other proteins, which, in their turn, are necessary for the complete functioning of the spineless gene products.

A further detailed study of such interactions will help the scientists to get answers to many questions. For example, how multicellular organisms developed, how they acquired the ability to resist various toxins at different steps of evolution and how they managed to use this ability and long-term memory while adapting to a new ecological niche.

For Reference: about the researchers

The leading expert of the research project is Boris Kuzin, a staff scientist of the DNBICT Brain Stem Cells Laboratory and the head of the Genetic Mechanisms of Organogenesis Research Group at the Institute of Developmental Biology (RAS). Among Kuzin's scientific interests aregene transcription regulation processes, determination and differentiation of cells, and morphogenesis.

Grigori Enikolopov is the head of MIPT's DNBICT BrainStem Cells Laboratory. Enikopolov is among the scientists awarded with the so-called "mega-grants," i.e., target financing as part of a Russian Federation government program, aimed at inviting leading specialists to universities.

For Reference: about the genes and what comes with them

DNA is able to store the information because its component blocks, the nucleotide pairs, are joined together in a certain order, the so-called nucleic acid sequence. The DNA matrix is the basis for the synthesis of another molecule, RNA. This molecule differs fromDNA in chemical content and structure: in most cases, RNA is a single, not a double, strand.

RNA molecules serve either as the matrix for protein synthesis (every three RNA nucleotides correspond to one amino acid in the protein), or perform their own function, e.g., some RNAs act as ferments, inducing biochemical reactions.

DNA, as was mentioned above, does not appear isolated in the cell, but always comes with a complex of proteins. These proteins are responsible for selectively "switching off" a certain number of genes in the cell. This, in turn, makes the process of RNA synthesis, ortranscription, impossible. There is also a group of proteins which, on the contrary, perform the function of launching RNA synthesis. Such proteins are called transcription factors.

Studying of the transcription control mechanisms (and today we know plenty of them) is the main task of molecular biology. There are many reasons for this.

First, it is gene transcription that defines the type of cells during the organism's development. Because of the differences in the processes of transcription, some cells become neurons, and others turn into liver, or, skin.

Second, understanding the differences in gene expression can shed light on the process of aging,the mechanisms of degradation of normal cells into cancer, and on many other disease progressions.

Third, during evolution, many important characteristics linked with the emergence of a new trait did not appear because of the arrival of some absolutely new kind of protein. These characteristics were shaped by changes in the pattern of development of a certain organ. For example, our ancestors got rid of the tail obviously not because some new protein appeared, but because at a particular stage of embryonic development the group of genes responsible for tail vertebrae formation got "switched off."

Fourth, the switching "on" and "off" of the genes in a certain sequence supports many vital processes, including memory consolidation, digestion, muscle mass growth during long-term physical activity, and many others.

Many genes interact with each other, and this interaction can develop according to different scenarios. A protein encoded by one gene can engage with a protein encoded by another gene, and the resulting product, in its turn, will launch the RNA synthesis from a third, or a fourth, gene. Or, it might, on the contrary, suppress the synthesis of yet another protein.

These days the scientists are actively studying such interactions.

Gender differences stand out in measuring impact of Viagra as therapy for heart failure

 

May 16, 2014

Johns Hopkins Medicine

Sildenafil, the erectile dysfunction drug sold as Viagra and now under consideration as a treatment for heart failure, affects males and females very differently, new animal studies by cardiovascular researchers strongly suggest. In female mice modeling human heart failure, the benefits of sildenafil ranged from robust to practically nonexistent, depending on the animals' levels of the hormone estrogen, says a researcher. In male mice, sildenafil generally appears to work well, but only because it targets a different biological process independent of estrogen, he says.


New animal studies by Johns Hopkins cardiovascular researchers strongly suggest that sildenafil, the erectile dysfunction drug sold as Viagra and now under consideration as a treatment for heart failure, affects males and females very differently.

The results of their investigations in varied male and female mouse models of heart failure are so clear-cut, says lead scientist Eiki Takimoto, M.D., Ph.D., that physicians may need to take gender into consideration when prescribing certain medications and that drug developers would be wise to take them into careful account when setting protocols for clinical trials of the medication in people. An online description of the new research appears May 16 in The Journal of Clinical Investigation.

Specifically, in female mice modeling human heart failure, the benefits of sildenafil ranged from robust to practically nonexistent, depending on the animals' levels of the hormone estrogen, says Takimoto, an assistant professor of medicine and a researcher with the Heart and Vascular Institute at Johns Hopkins. In male mice, sildenafil generally appears to work well, but only because it targets a different biological process independent of estrogen, he says. Estrogen is present in both male and female mammals, although in different amounts.

"The research is especially significant," he adds, "because it offers a mechanism to explain how estrogen affects sildenafil's efficacy. That's the first time the actual pathway of a hormone's cause and effect on a drug has been mapped out."

Sildenafil, the generic compound used to initiate and strengthen male erections, works by encouraging blood vessels to dilate and increase blood flow to the penis. The effects are similar to some drugs, such as nitrates, already used to increase blood flow to failing hearts. Besides these effects, beneficial direct effects on heart muscles have been suggested by recent experimental studies, which is why researchers believe it could help patients with heart failure.

Heart failure is the most common reason for hospital admissions in the Medicare population, according to heart experts, and is the leading cause of death in Americans. Useful drugs such as beta-blockers and ACE inhibitors help to increase the blood-pumping efficiency of the heart, "yet they don't fully address the ongoing pathology," says Takimoto.

Whether due to a heart attack, hypertension, arteriosclerosis or other reasons, even moderate injury to heart muscle cells can initiate a downhill remodeling of broad areas of heart tissue, including enlargement of the heart and stiffening of heart chambers as fibrous proteins replace more flexible ones in muscle cells. The weakened and altered heart muscle compromises circulation, a hallmark of heart failure.

"Because cardiac remodeling is an underlying mechanism," Takimoto says, "we've put more than a decade of research into understanding it enough to stop or reverse it."

Key to the Johns Hopkins team's research, Takimoto says, is the molecule cyclic guanosine monophosphate (cGMP), which trips a helpful biochemical cascade that can counter effects of hypertension and other stressors. Heart cells typically maintain a strategic pool of cGMP, but heart-damaging events deplete this pool via the disabling action of an enzyme called PDE5. That's where sildenafil comes in.

As a potent inhibitor of PDE5, sildenafil increases cell levels of cGMP, which helps erectile dysfunction. More recently, research has explored the drug's ability to raise cGMP levels for cardiac disease.

In 2005, Takimoto's group studied sildenafil in mice engineered to have so-called transverse aortic constriction (TAC). A surgically-fitted band around the aorta in mice with TAC raised their internal heart pressure. The result was cardiac remodeling, and then signs of classic human heart failure. "By increasing cGMP with sildenafil, we both blocked and reversed remodeling in the animals, ameliorating heart failure," Takimoto says.

Subsequent work by other research groups with various animal models showed similar effects, laying groundwork for human heart disease studies.

The new gender-based findings are especially interesting, Takimoto says, because of contradictory results of early clinical trials with sildenafil for heart failure. Notably, he says, a small, single-center clinical study showed sildenafil's long-term positive effects against cardiac remodeling and classic human heart failure. But last year, results of the RELAX study -- a National Institutes of Health-sponsored, 26-center U.S. and Canadian study testing sildenafil against placebo for diastolic heart failure, a difficult-to-treat type of heart failure -- found essentially no benefit.

To better understand the protective effects of cGMP activity, Takimoto's team focused on the tie-in with estrogen, also known to be naturally cardioprotective. Women, for example, develop heart disease much later on average than men, usually after menopause and estrogen depletion; estrogen feeds into the cGMP pathway. But this new study by Takimoto's group used sildenafil to shed more light on the process.

The team used both the TAC model and an established, powerful, gene-based model of heart failure that together better reflected human heart failure, according to Takimoto. Half of the female mice his team tested had their ovaries removed, which meant these mice had minimal levels of estrogen. Both groups of female mice received sildenafil. As expected, all the mice developed cardiac remodeling, but those low in estrogen fared far worse. Treating the estrogen-low mice with supplements of the hormone, however, raised cGMP and reversed heart damage. "This tells us that estrogen critically impacts the response to sildenafil in heart failure treatment," Takimoto says.

Male mice, which have naturally low amounts of estrogen, fared differently. Like the females, they had cardiac remodeling. But sildenafil alone was able to stop it.

Takimoto explains the gender effect as a difference in male-female physiology: "In female mice, their normally high estrogen levels insure presence of an ongoing pool of cGMP with its protective effects. In males, however, there's no such pool of cGMP. It's synthesized only in response to stress on the heart."

"Our findings may have important clinical implications," he and study first author Hideyuki Sasaki, M.D., Ph.D., say. They cite the RELAX trial, where half of the participants were 69 or older. That's long after menopause started for women in the trials. "Knowing that sildenafil's benefits to female mice come only with higher estrogen levels offers a possible reason for RELAX's negative results," says Takimoto.

That and the ability of added estrogen to turn around a poor sildenafil response in the mice, he adds, "suggest we need to look more into female-specific strategies with these therapies."


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The above story is based on materials provided by Johns Hopkins Medicine. Note: Materials may be edited for content and length.


Journal Reference:

  1. Hideyuki Sasaki, Takahiro Nagayama, Robert M. Blanton, Kinya Seo, Manling Zhang, Guangshuo Zhu, Dong I. Lee, Djahida Bedja, Steven Hsu, Osamu Tsukamoto, Seiji Takashima, Masafumi Kitakaze, Michael E. Mendelsohn, Richard H. Karas, David A. Kass, Eiki Takimoto. PDE5 inhibitor efficacy is estrogen dependent in female heart disease. Journal of Clinical Investigation, 2014; DOI: 10.1172/JCI70731

Bacteria in mouth may diagnose pancreatic cancer

 


Patients with pancreatic cancer have a different and distinct profile of specific bacteria in their saliva compared to healthy controls and even patients with other cancers or pancreatic diseases, according to research presented today at the annual meeting of the American Society for Microbiology. These findings could form the basis for a test to diagnose the disease in its early stages.

"Our studies suggest that ratios of particular types of bacteria found in saliva may be indicative of pancreatic cancer," says Pedro Torres of San Diego State University who presented the research.

In the United States, approximately 40,000 people die every year due to pancreatic adenocarcinoma, making it the fourth leading cause of cancer related death. Patients diagnosed in the early stages of pancreatic cancer have a 5-year survival rate of 21.5%. Unfortunately symptoms do not appear until after the cancer has become untreatable in the vast majority of cases, says Torres.

In the study, Torres and his colleagues compared the diversity of saliva bacteria across 131 patients, 63 female and 68 male, being treated at the University of California, San Diego (UCSD) Moores Cancer Center. Of these patients, 14 had been diagnosed with pancreatic cancer, 13 with pancreatic disease, 22 with other forms of cancer and 10 disease free. Results showed that patients diagnosed with pancreatic cancer had higher levels of two particular oral bacteria, Leptotrichia and Campylobacter, when compared to any other healthy or diseased state including non-cancerous pancreatic disease. Those with pancreatic cancer also had lower levels of Streptococcus, Treponema and Veillonella.

"Our results suggest the presence of a consistently distinct microbial profile for pancreatic cancer," says Torres. "We may be able to detect pancreatic cancer at its early stages by taking individuals' saliva and looking at the ratios of these bacteria."


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The above story is based on materials provided by American Society for Microbiology. Note: Materials may be edited for content and length.

Targeting heart failure may reduce readmissions, save lives, studies find

 

May 17, 2014

European Society of Cardiology (ESC)

Worsening symptoms and signs of heart failure (HF) in patients admitted to a hospital is a common sign of treatment failure and can lead to long-term consequences for the patient, including longer length of hospitalization and a higher risk for readmission and death, according to a recent study. Heart failure is the most common reason for admission to hospital in people over 65 years old and affects millions of people each year.


Worsening symptoms and signs of heart failure (WHF) in patients admitted to a hospital is a common sign of treatment failure and can lead to long-term consequences for the patient, including longer length of hospitalization and a higher risk for readmission and death, according to a late-breaking study (RELAX-AHF, PROTECT) presented in Athens at the ESC's Heart Failure Congress 2014.

Heart failure is the most common reason for admission to hospital in people over 65 years old and affects millions of people each year. Research has shown that the outcomes of patients admitted with Acute Heart Failure (AHF) are dire with significant time spent in the hospital and high rates of readmissions or death within 6 months. Currently available therapies such as i.v. diuretics and vasodilators, may relieve some of the symptoms of AHF including dyspnoea, but most probably do not affect short term outcomes.

"Worsening heart failure is a clinical event occurring during an admission for acute heart failure defined as worsening of the symptoms and signs that brought the patient to the hospital requiring additional intravenous or mechanical therapy," said Beth Davison, lead author on the RELAX-AHF study and vice president of Momentum Research Inc. "It prolongs the hospital stay and is associated with increased risk for heart failure readmission within 2 months and death within 6 months. Preventing this early event would not only reduce the patient's suffering during the admission but possibly also reduce its longer-term consequences." In data pooled from the PROTECT Pilot, PROTECT, Pre-RELAX-AHF, and RELAX-AHF studies the association of WHF with length of stay, mortality and HF re-hospitalization were examined. In 3691 patients, death or WHF occurred in 12.4%. WHF was associated with a mean increase in the length of hospital stay of 5.2 days (95% confidence intervals [CI] 4.6-5.8 days); a hazard ratio (HR) for 60-day HF readmission or CV death of 1.64 (CI 1.34-2.01) and a HR for 180-day mortality of 1.93 (1.55-2.41) -- all P< 0.001. WHF was also associated with larger increases in markers of renal and hepatic dysfunction during the first days of admission.

The association of WHF with these outcomes remained robust after adjustment for changes in these markers at day 2 on top of adjustment for baseline characteristics. The association of WHF with mortality was significant regardless of what therapy was given for WHF, although patients who needed IV inotropes or mechanical support had higher mortality.

"Because WHF is associated with more adverse outcome physicians should monitor closely patients who develop WHF during admission," said Dr. Davison. "As suggested by the results of the RELAX-AHF study, future therapy may reduce the occurrence of WHF and some of its downstream effects."


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The above story is based on materials provided by European Society of Cardiology (ESC). Note: Materials may be edited for content and length.

Negative iron balance predicts acute heart failure survival

 

May 17, 2014

European Society of Cardiology (ESC)

Negative iron balance predicts survival in patients with acute heart failure, according to research. “Patients with acute heart failure have a major collapse in homeostasis. Iron is a key micronutrient that is required for the maintenance of homeostasis. Iron is needed for cellular metabolism and deficiency leads to severely impaired energy metabolism and mitochondrial dysfunction,” the first author said.


Negative iron balance predicts survival in patients with acute heart failure, according to research presented for the first time today at the Heart Failure Congress 2014 in Athens, Greece. The Congress is the main annual meeting of the Heart Failure Association of the European Society of Cardiology.

Professor Ewa Jankowska, first author of the study, said: “Patients with acute heart failure have a major collapse in homeostasis. Iron is a key micronutrient that is required for the maintenance of homeostasis. Iron is needed for cellular metabolism and deficiency leads to severely impaired energy metabolism and mitochondrial dysfunction.”

She continued: “Previous studies have shown that patients at high cardiovascular risk – for example diabetics with coronary artery disease or patients with stable chronic heart failure – may develop iron deficiency which leads to recurrent hospitalisations and increased mortality.”

Professor Piotr Ponikowski, last author, said: “We have data showing that iron may be important for clinical outcomes in chronic heart failure and correction of iron deficiency in these patients is beneficial. This is the first study of iron status in acute heart failure.”

Iron deficiency has traditionally been measured using serum ferritin to track iron stores and transferrin saturation (TSAT) to assess iron utilisation in the cell. These measures cannot be reliably interpreted in acute clinical settings because they are influenced by inflammation and oxidative stress.

The researchers therefore proposed a new, more sensitive, measure for acute heart failure which can best characterise iron deficiency in these settings. This refers to both depleted iron stores, measured by circulating hepcidin, and unmet cellular iron needs, measured by soluble transferrin receptor. The receptor is expressed on all cells and enables iron to enter the cell. When there is not enough iron in the cell, the receptor is overexpressed and shed into the circulation. Concomitance of low hepcidin and high soluble transferrin receptor reflects the most severe form of iron deficiency (lack of iron in the body accompanied by iron need), which the investigators called negative iron balance (NIB).

This prospective, observational study included 165 patients hospitalized for acute heart failure. The researchers assessed the prevalence of NIB and its impact on 12 month mortality.

NIB was found in 37% of patients. Just 29% had only high soluble transferrin receptor, while 9% had only low hepcidin and 25% had none of these abnormalities. Twelve month mortality was 20% for the whole group. Patients with NIB had the highest 12 month mortality (41%) compared to those with only high soluble transferrin receptor (15%), only low hepcidin (7%) and none of these abnormalities (0%) (p<0.001). During the hospital stay 3 patients died and all had NIB.

Professor Jankowska said: “Our study shows that deranged iron status is common in acute heart failure. Mortality in the patients with NIB was high during the 12 month follow up, whereas all of the patients with no iron abnormalities survived to one year.”

NIB led to poorer survival in acute heart failure patients regardless of whether they were anaemic or not.

The researchers also measured the standard parameters of iron status, serum ferritin and TSAT, and found that they were less able to predict 12 month mortality than NIB. Levels of serum ferritin and TSAT were only weakly correlated with hepcidin and soluble transferrin receptor.

Professor Ponikowski said: “Levels of hepcidin and soluble transferrin receptor are more clinically relevant in patients with acute heart failure than traditional measures of iron status. We propose a new pathophysiological definition of iron deficiency which accurately reflects stored and utilised iron in patients with acute heart failure.”

Both concluded: “Iron supplementation may reverse NIB and improve survival in acute heart failure patients but this needs to be tested in a randomised clinical trial. We hope to initiate such trial soon.”


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The above story is based on materials provided by European Society of Cardiology (ESC). Note: Materials may be edited for content and length.