sábado, 27 de dezembro de 2014

Cholesterol: What numbers should you aim for?

 

What do your cholesterol numbers mean?

A simple blood test called a lipid profile can tell you how much good, bad and total cholesterol you have in your blood, as well as your level of triglycerides, another form of fat in your blood.

Your doctor will ask that you go without foods and liquids other than water for nine to 12 hours before the test so that you'll get accurate measurements. In the United States and some other countries, your test results will list cholesterol levels in units called milligrams per deciliter (mg/dL) of blood. Canada and most European countries measure cholesterol in millimoles per liter (mmol/L) of blood.

Here are some guidelines to help you make sense of the numbers:

Total cholesterol (U.S. and some other countries)
Total cholesterol* (Canada and most of Europe)

*Canadian and European guidelines differ slightly from U.S. guidelines. These conversions are based on U.S. guidelines.

Below 200 mg/dL
Below 5.2 mmol/L
Desirable

200-239 mg/dL
5.2-6.2 mmol/L
Borderline high

240 mg/dL and above
Above 6.2 mmol/L
High

LDL cholesterol (U.S. and some other countries)
LDL cholesterol* (Canada and most of Europe)

*Canadian and European guidelines differ slightly from U.S. guidelines. These conversions are based on U.S. guidelines.

Below 70 mg/dL
Below 1.8 mmol/L
Ideal for people at very high risk of heart disease

Below 100 mg/dL
Below 2.6 mmol/L
Ideal for people at risk of heart disease

100-129 mg/dL
2.6-3.3 mmol/L
Near ideal

130-159 mg/dL
3.4-4.1 mmol/L
Borderline high

160-189 mg/dL
4.1-4.9 mmol/L
High

190 mg/dL and above
Above 4.9 mmol/L
Very high

HDL cholesterol (U.S. and some other countries)
HDL cholesterol* (Canada and most of Europe)

*Canadian and European guidelines differ slightly from U.S. guidelines. These conversions are based on U.S. guidelines.

  1. Below 40 mg/dL (men)
  2. Below 50 mg/dL (women)
  1. Below 1 mmol/L (men)
  2. Below 1.3 mmol/L (women)

Poor
  1. 40-49 mg/dL (men)
  2. 50-59 mg/dL (women)
  1. 1-1.3 mmol/L (men)
  2. 1.3-1.5 mmol/L (women)

Better

60 mg/dL and above
Above 1.5 mmol/L
Best

If it turns out you have high cholesterol, your doctor may prescribe lifestyle changes, such as exercise and a healthy diet, as well as medication, to help control your cholesterol.

References

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Can you outgrow food allergies?

 

 

My 4-year-old son is allergic to both peanuts and eggs. Is it possible he will outgrow these allergies as he gets older?

Answers from James T C Li, M.D., Ph.D.

Eight foods trigger 90 percent of all food allergies. Peanuts and eggs are two of them. The rest are milk, fish, shellfish, tree nuts, soy and wheat.

Statistically speaking, there's a good chance he can safely eat eggs as an adult. Children usually outgrow egg and milk allergies as they get older.

Unfortunately, it's much less likely for him to outgrow his peanut allergy. By school-age, this allergy is resolved in only 20 percent of children. Peanut consumption remains a common cause of allergic reactions in adults.

Your son can outgrow his food allergies if and when his body begins to suppress the production of a protein called immunoglobulin E (IgE). The immune system releases this protein when it mistakenly identifies a food substance, such as peanuts and eggs, as something harmful. IgE suppression is key to gaining tolerance for foods that have previously caused an allergic reaction.

There are other factors that can affect the likelihood of your son outgrowing his allergies. These include the severity of his reactions, how many foods he's allergic to, and how old he was when he had his first reaction.

Mar. 04, 2014

References
  1. Zukiewicz-Sobczak W, et al. Causes, symptoms, and prevention of food allergy. Postepy Dermatologii i Alergologii. 2013;30:113.
  2. Keet C. Recognition and management of food-induced anaphylaxis. Pediatric Clinics of North America. 2011;58:377.
  3. Sheikh A, et al. Oral immunotherapy for the treatment of peanut allergy: Systematic review of six case series studies. Primary Care Respiratory Journal. 2011;21:41.
  4. Immunoglobulin E (IgE). American Academy of Allergy, Asthma and Immunology. https://www.aaaai.org/conditions-and-treatments/conditions-a-to-z-search/immunoglobulin-e-%28ige%29.aspx. Accessed Jan. 24, 2014.
  5. Yamashita H, et al. Overcoming food allergy through acquired tolerance conferred by transfer of Tregs in a murine model. Allergy. 2012;67:201.
  6. Gupta RS, et al. Factors associated with reported food allergy tolerance among US Children. Annals of Allergy, Asthma & Immunology. 2013;111:194.
  7. Sheikh SZ, et al. Recent advances in the diagnosis and therapy of peanut allergy. Expert Review of Clinical Immunology. 2013;9:551.

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Air Pollution Down Thanks to California’s Regulation of Diesel Trucks

 

 

Berkeley Lab air quality scientists measure truck emissions at Port of Oakland and Caldecott Tunnel.

Feature Story Julie Chao (510) 486-6491 • December 11, 2014

Chelsea Preble, Rob Harley, and Tom Kirchstetter will be presenting new results from their research on Dec. 17 at the 2014 Fall Meeting of the American Geophysical Union in San Francisco (Moscone South, 1:40 to 6 pm).

Ever wonder what’s in the black cloud that emits from some semi trucks that you pass on the freeway? Lawrence Berkeley National Laboratory (Berkeley Lab) scientist Thomas Kirchstetter knows very precisely what’s in there, having conducted detailed measurements of thousands of heavy-duty trucks over months at a time at two San Francisco Bay Area locations.

With a specially outfitted research van equipped with sophisticated monitors for several pollutant types, he and his team are studying emissions levels from diesel trucks to understand and analyze the impact of new control technologies and California air pollution regulations.

Click on photo to view a Zeega slideshow with more photos.

“We’re measuring a range of pollutants relevant to public health and the environment,” said Kirchstetter, an air quality scientist who also serves as an adjunct professor in UC Berkeley’s Department of Civil and Environmental Engineering. “Heavy-duty diesel trucks are major sources of nitrogen oxides, which are a precursor to the formation of ozone and particulate matter (PM) in the atmosphere, and of black carbon PM, which, according to climate scientists, contributes to global warming and regional changes in climate, such as precipitation and snow melting.”

Outdoor air pollution is linked to 100,000 premature deaths per year in the United States, according to published studies. While the U.S. Environmental Protection Agency (EPA) has set emissions standards for new engines, most trucks and buses run for several decades, so the California Air Resources Board (CARB) has sought to accelerate emissions reductions with aggressive new regulations in recent years. As a result growing numbers of heavy-duty diesel trucks in California are using two control technologies, a diesel particle filter, which removes most particulate matter, and selective catalytic reduction, which targets emissions of nitrogen oxides (NOx).

The good news is that these regulations are having their intended effect, Kirchstetter and his collaborators, Rob Harley, professor of civil and environmental engineering at UC Berkeley, and Phil Martien of the Bay Area Air Quality Management District (BAAQMD), have found. “At the Port of Oakland, we measured dramatic reductions of nitrogen oxides and black carbon PM, indicating a large degree of success which should translate into local improvements in air quality, especially as more trucks on the road use these technologies,” he said.

Between 2009 and 2013, the fraction of trucks at the Port of Oakland equipped with a diesel particle filter increased from 2 to 99 percent, and the median engine age fell from 11 to 6 years. During the same period, the emission factor (or average emission rate) decreased by 76 percent for black carbon and by 53 percent for NOx.

The researchers monitored drayage (short distance) trucks at the Port of Oakland in 2009, before a new emissions rule was implemented, in 2011 during the rule’s phase-in, and in 2013, after the rule was implemented.

View passing trucks at the Port of Oakland overlaid with real-time measurements of four pollutants in the truck exhaust.

California’s program of accelerated vehicle emissions reductions is especially important because fuel consumption is rising, and diesel fuel consumption is growing at an even faster rate than that of gasoline. “These new control technologies on trucks improve air quality despite increases in vehicle miles traveled and fuel consumption,” said Kirchstetter, who has been studying air pollutant emissions and controls in the transport sector for more than 20 years.

The technologies come with some trade-offs that the research team is investigating. Selective catalytic reduction can cause some trucks to have increased emissions of nitrous oxide (N2O), a potent greenhouse gas. With diesel particle filters, the catalytic oxidation process leads to increased tailpipe emission of nitrogen dioxide, NO2, which is a toxic air contaminant and is involved in the formation of ozone. While these were known side effects, the research team is measuring the amounts of these increases.

This summer Kirchstetter brought his research van to the Caldecott Tunnel, which connects Oakland to Contra Costa County, to measure emissions from a larger sampling of heavy-duty trucks. On a sunny weekday morning graduate student Chelsea Preble and undergraduate Troy Cados are in the van, having arrived at 6 a.m. to tune the instruments and catch the morning rush hour.

The equipment includes an air sampler hanging directly above the right lane, a video camera that records the truck and its license plate as it passes under the sampling location, and state-of-the-art monitors to capture several species of pollutants.

“Our measurements are very fast. We measure concentrations at a rate of one or two times a second, which is near real-time,” Preble said. “That allows us to link the emissions profile to the attributes of each passing truck, which we get from its license plate. So our methodology allows us to understand emissions changes associated with technologies.”

The team plans to return to the Caldecott next summer and again in 2017 when nearly all heavy-duty trucks will have diesel particle filters installed. CARB’s Truck and Bus Regulation applies to approximately 1 million trucks and buses operating statewide.

“Our study is an important verification of the impacts of California’s air quality regulations,” Kirchstetter said. “California tends to lead the way in air quality. The technologies we’re evaluating will eventually dominate truck fleets nationwide, so the significance of our study extends far beyond California and perhaps the USA.” 

The research was supported by the California Air Resources Board and the Bay Area Air Quality Management District.

Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov. DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

source: www.lbl.gov