miércoles, 27 de junio de 2012

Pollution Levels in Some Kitchens Are Higher Than City-Center Hotspots

A study by the University of Sheffield has found that the air we breathe inside our own homes can have pollutant levels three times higher than the outdoor environment, in city centres and along busy roads.

Researchers from the University's Faculty of Engineering measured air quality inside and outside three residential buildings with different types of energy use (gas vs. electric cookers). They found that nitrogen dioxide (NO2) levels in the kitchen of the city centre flat with a gas cooker were three times higher than the concentrations measured outside the property and well above those recommended in UK Indoor Air Quality Guidance1. These findings are published in the Journal of Indoor and Built Environment.
"We spend 90 per cent of our time indoors and work hard to make our homes warm, secure and comfortable, but we rarely think about the pollution we might be breathing in," said Professor Vida Sharifi, who led the research. "Energy is just one source of indoor pollution, but it is a significant one. And as we make our homes more airtight to reduce heating costs, we are likely to be exposed to higher levels of indoor pollution, with potential impacts on our health."
The study, funded by the Engineering and Physical Sciences Research Council (EPSRC INTRAWISE Consortium), compared a rural house with two flats, one in Sheffield city centre and the other in an urban location next to a busy road. The rural house had an electric cooker while both flats used gas appliances. Samples were taken outside and inside the properties, from each kitchen, over a four week period.
The researchers, Professor Sharifi, Professor Jim Swithenbank and Dr Karen Finney, focused on pollutants known to have a detrimental health impact, particularly on the elderly and people with respiratory or cardiovascular problems.
These included carbon monoxide (CO), nitrogen dioxide (NO2), volatile organic compounds (VOCs) and solid particles small enough to penetrate into the lungs (2.5 microns in size or smaller, known as PM2.5).
The average particle concentrations measured by the research team in the kitchens of both flats with gas cookers were higher than the levels set by the Government as its objective for outdoor air quality in both London and England2. There are currently no set guidelines for safe levels of particles in the home.
Professor Sharifi said: "Concerns about air quality tend to focus on what we breathe in outdoors, but as we spend most of our time indoors, we need to understand more about air pollution in our homes. There is very little data on emission rates from different appliances or acceptable standards on indoor pollutants.
"Although ours was just a small study, it highlights the need for more research to determine the impact of changing housing and lifestyles on our indoor air quality."
University of Sheffield. "Pollution levels in some kitchens are higher than city-center hotspots."ScienceDaily, 14 Jun. 2012. Web. 27 Jun. 2012.

Lower coronary flow during hypoglycemia ups CV risk for type 1 diabetes


Decreased coronary flow reserve during periods of hypoglycemia may raise the risk for myocardial ischemia in patients with type 1 diabetes, a researcher said here.
“Low blood sugar provokes profound hemodynamic effects through sympathoadrenal stimulation. It is associated with an increase in heart rate and myocardial contraction and, thereby, cardiac output. Also it decreases central blood pressure and increases arterial elasticity in normal individuals, causing the heart to generate a pulse wave that bounces off the central arteries during diastole, thereby aiding coronary filling. However, in patients with type 1 diabetes, especially of longer duration, arterial stiffness causes the pulse wave to return during systole and there is suboptimal filling of the coronary flow,” Radzi M. Noh, MRCP, of the Royal Infirmary of Edinburgh, said during a presentation. “In addition to increasing myocardial workload, it increases the risk for myocardial ischemia.”
To evaluate whether periods of hypoglycemia worsened this risk, Noh and colleagues examined participants during periods of experimental hypoglycemia. They included 16 participants with type 1 diabetes of varying duration and 10 healthy, age-matched controls. These participants were aged 18 to 46 years (median, 29 years); had HbA1c ranging from 7% to 9% (median, 8.3%), no microvascular complications and were being treated with insulin only.
The researchers used a hyperinsulinemic glucose clamp to induce hypoglycemia and measured coronary flow reserve during euglycemia, defined as 4.5 mmol/L, and hypoglycemia, defined as 2.5 mmol/L. They employed transthoracic echocardiography to assess coronary blood flow velocity in the left anterior descending coronary artery before and during adenosine-induced microvascular hyperemia. Coronary flow reserve is measured as the maximum hyperemic blood flow velocity divided by baseline blood flow velocity.
Data indicated a trend toward lower coronary flow reserve in patients with diabetes vs. the control arm (3.69 vs. 4; P=.07). Further, at 3.56, patients with a longer duration of diabetes had the lowest coronary flow reserve when compared with both patients with and without diabetes. In contrast, coronary flow reserve rose slightly in the control group vs. the diabetes group (4.08 vs. 3.53; P<.05).
“During acute hypoglycemia, a modest reduction of coronary flow reserve may be well tolerated in healthy individuals, but may promote ischemia in older people with diabetes who have coronary heart disease,” Noh concluded. –
Referencia: Noh RM. Abstract #171-OR. Presented at: the American Diabetes Association’s 72nd Scientific Sessions; June 8-12; Philadelphia.
Tomado de: Endocrine today.com

jueves, 14 de junio de 2012

Coffee Linked to Lower Death Risk


     Java lovers, take heart. A large prospective study suggests that – far from being bad for your health – that steaming cuppa is actually associated with a lower risk of death.  
     Analysis of a large prospective study of more than 400,000 people found that men who drank four to five cups of coffee daily reduced their risk of death over a 13-year period by 12%, while women's risk dropped by 16%, according to Neal Freedman, PhD, of the National Cancer Institute, and colleagues.
     The inverse associations were seen for deaths due to heart disease, respiratory disease, stroke, injuries and accidents, diabetes, and infections, but not for deaths due to cancer, the researchers found. On the other hand, a suite of other behaviors that often go hand-in-hand with coffee drinking – smoking, lack of exercise, and poor diet – usually combine to mask the benefit, the researchers noted in the May 17 issue ofThe New England Journal of Medicine.
     Freedman and colleagues cautioned that the study could not prove that coffee is good for you.
"It may be that there's something that goes along with coffee-drinking that's affecting our results that we couldn't take into account in our analysis," Freedman told 
     But, together with previous research, he said, the findings provide "some reassurance that coffee drinkers don't have a higher risk of death (and suggest) that there might be some benefit from drinking coffee."
Indeed, the findings are not surprising, according to Frank Hu, MD, PhD, of the Harvard School of Public Health, who was senior author on a 2008 study that also found an apparent benefit for coffee drinking.
     "All the evidence is coming together to indicate a potential health benefit of regular coffee consumption," Hu told 
     The only way to prove the benefit exists, Hu said, would be to conduct a large randomized trial, but such a study "may not be feasible" because it would need too many participants.
     In the meantime, a large prospective cohort, such as the National Institutes of Health–AARP Diet and Health Study analyzed by Freedman and colleagues, provides the "best available evidence."
The NIH-AARP cohort has been running since 1995 and includes 229,119 men and 173,141 women who were 50 to 71 when the study started. Over the period from 1995 through 2008, Freedman and colleagues reported, 33,731 men and 18,784 women died.
      In an analysis that only took age into account, coffee consumption was associated with an increased risk of death, they reported.
      But coffee drinkers were also more likely to smoke, to eat more red meat and fewer fruits and vegetables, to drink alcohol, and to have less vigorous physical activity.
     When those factors were taken into account, Freedman and colleagues found, coffee emerged as being inversely associated with all-cause mortality, as well as a range of major causes of death.
Compared with non-drinkers, there was little effect for those who drank some coffee, but less than a cup a day. But for more coffee, the odds of death dropped significantly. Specifically:
·          - For those who drank one cup a day, the odds ratios for death were 0.94 for men and 0.95 for women (95% CI 0.90 to 0.99 and 0.90 to 1.01, respectively).
·         - For two or three cups a day, the odds ratios for death were 0.90 for men and 0.87 for women (95% CI 0.86 to 0.93 and 0.83 to 0.92, respectively).
·           - For four or five cups a day, the odds ratios for death were 0.88 for men and 0.84 for women (95% CI 0.84 to 0.93 and 0.79 to 0.90, respectively).
·          -  And for six or more cups a day, the odds ratio for death were 0.90 for men and 0.85 for women (95% CI 0.85 to 0.96 and 0.78 to 0.93, respectively).
·         For both men and women the trend was significant at P<0.001.
     While most of the outcomes showed a benefit for coffee, "the effect was modest," Freedman said.
Indeed, other experts said other behavioral changes are likely to be more useful than drinking more coffee.
"Based on this study alone, I would not tell people to start drinking more coffee to lower their risk of death," said Lona Sandon, RD, of UT Southwestern Medical Center in Dallas.
     "There are other things with bigger impact on mortality that they probably should be doing," Sandon said in an email to MedPage Today and ABC News.
Freedman told MedPage Today that people should consult their physicians before making a change - or not - in their diet.
Sandon also questioned one of the acknowledged limitations of the study -- that the coffee consumption was measured only at the beginning. "It is possible that their coffee-drinking habits changed over the 12 years of the study," she said.
Again Freedman agreed, but noted that other studies have shown that coffee drinking as a part of diet is relatively stable over time.
The bottom line, Sandon said, is to "stop smoking, be more physically active, eat your fruits, veggies, whole grains, and healthy fats, and a little coffee doesn't appear to hurt."
The study is well done and the conclusions are supported by the data, argued Peter McCullough, MD, of the St. John Providence Health System in Detroit.
In an email to MedPage Today and ABC News, McCullough noted that even decaffeinated coffee appeared to be beneficial - "good news" for people who like coffee but fear caffeine.
But he and others called for a deeper understanding of the complex mix of compounds found in coffee.
"If you are not a coffee drinker, this study is not a good enough reason to start," commented Cheryl Williams, RD, of Emory Heart & Vascular Center in Atlanta.
Williams said in an email to MedPage Today and ABC News that she's not confident coffee is truly beneficial, given that other factors might also play a role in the outcomes reported by Freedman and colleagues.
"Overall," she said, "more research needs to be done to truly understand the compounds in coffee (including those unknown) and their biological activity and effect on health."

Tomado de: MedPage Today.

Speedy eaters at risk for type 2 diabetes

     Patients that ate meals faster were two-and-a-half times more likely to develop type 2 diabetes than those who take their time eating, according to data presented at the Joint 15th International Congress of Endocrinology and 14th European Congress of Endocrinology Meeting.

     Lina Radzeviciene, MD, and Rytas Ostrauskas, MD, from Lithuanian University of Health Sciences developed a case-control study including 234 patients with a new diagnosis of type 2 diabetes and 468 control patients without the disease. Both groups were matched by gender and age (±5 years).
The patients completed a questionnaire which rated their eating speed compared with others, and recorded their height, weight, waist and hip circumference and risk factors for type 2 diabetes. Those who already had type 2 diabetes displayed a higher BMI and significantly lower education level, compared with the control group, researchers said.
After adjustments were made for variables like family history of diabetes, education, morning exercise, BMI, waist circumference, smoking and plasma triglycerides level, data demonstrated an increased risk for type 2 diabetes in patients who ate faster (OR=2.52; 95% CI, 1.56-4.06), compared with patients who ate at a slower pace.
“The prevalence of type 2 diabetes is increasing globally and becoming a world pandemic. It appears to involve interaction between susceptible genetic backgrounds and environmental factors. It’s important to identify modifiable risk factors that may help people reduce their chances of developing the disease,” Radzeviciene said.
Researchers said they hope to perform a larger study to examine how particular types of food, calorie intake, physical exercise, and psychological and emotional well-being affect risk for diabetes.
Tomado de: Endocrine today

lunes, 11 de junio de 2012

Blood Test for Mom Can ID Dad Early On


     A noninvasive test, using blood samples from a pregnant woman, can accurately determine the paternity of the fetus in the first trimester, researchers found.
   The method picks out fetal DNA and allows comparison between the male-derived components of the fetal genetic material and samples from adult males, according to Ravinder Dhallan, MD, PhD, of Ravgen, in Columbia, Md., and colleagues.
     In a small sample of 30 pregnant women, the approach was completely accurate in a blinded analysis, Dhallan and colleagues reported in a letter in the May 3 issue of the New England Journal of Medicine.
     In all cases, the test identified the biological father and rejected DNA from an unrelated male, a finding that Dhallan and colleagues said was significant at P<1.86x10-9.
    The procedure was carried out within the first 8 to 14 weeks of gestation, earlier than allowed by other methods, such as amniocentesis or chorionic villi sampling, Dhallan and colleagues noted.
Those methods also carry a risk of miscarriage, which the blood test does not.
   The study was supported by Ravgen, which is developing noninvasive diagnostic methods for use during pregnancy. Dhallan and colleagues have previously reported the ability to diagnose Down syndrome early in pregnancy.
   One obstacle to noninvasive paternity testing, they noted, has been that cell-free DNA from the mother overwhelms the fetal DNA in the blood sample, making it impossible to compare with a putative paternal sample.
   That barrier, they reported in 2004, can be overcome by using formaldehyde to prevent maternal cells from breaking down.
     The method could be useful, Dhallan and colleagues argued, in cases of rape, in which a pregnancy could be the result of the crime or consensual intercourse with another man. 
     Most terminations of unintended pregnancies occur before 10 weeks gestation, they noted, but other methods of testing paternity are not used before 10 to 15 weeks gestation. Therefore, they argued "it seems likely that many rape victims terminate pregnancies before testing for paternity."
Tomado de medpagetoday.com

sábado, 9 de junio de 2012

APRENDIZAJE BASADO EN UN CASO CLINICO


A 30-year-old man with a long history of intravenous drug abuse and chronic hepatitis B presents with jaundice. Physical examination reveals a malnourished man with ascites, dependent pitting edema, spider angiomata, female secondary sex characteristics, and bilateral gynecomastia. Rectal examination reveals yellow-brown stool and a negative stool gualac. External hemorrhoids are present. The patient has poor concentration, but no asterixis is present.

He has the following biochemical profile:
-Total protein 8.3 g,d/L (normal, 6.O-7.8 g/dL)
-Serum albumin 2.5 g/dL (normal, 3.5.-5.5 g/dL)
-Serum globulins 5.8 g/dL (normal, 2.3-3.5 g/dL)
-Serum calcium 6.5 mg/dL (normal, 8.4-10.2 mg/dL)
-Serum total bilirubin 6.0 mg/dL (normal, 0.1-1.0 mg/dL)
-Urinalysis: positive for bilirubin
-Serum AST 200 U/L (normal, 8-20 U/L)
-Serum ALT 350 U/L (normal, 8-20 U/L)
-Serum AP 180 U/L (normal, 20-70 U/L)
-Serum GGT 100 U/L (normal, 6-37 U/L)
-Serum LDH 300 U/L (normal, 45-90 U/L)
-CBC: macrocytic anemia, hypersegmented neutrophils, mild neutropenia, mild
thrombocytopenla
-Coagulation: prothrombin time (PT) is prolonged and does not correct with
intramuscul& vitamin K.


1. What is the clinical significance of his abnormal liver function tests, hypoalbuminemia, and prolonged prothrombin time that does not correct with intramuscular vitamin K?

2. What is the clinical significance of hypocalcemia in this patient?
3. What is the most likely cause of the macrocytic anemia?



viernes, 8 de junio de 2012

Mango skin may help reduce fat


Scientists have discovered that two common mango varieties contain natural compounds that may help to fight flab...in the part that most people throw away.
     In two of three mango varieties examined in the study, scientists from The University of Queensland found it was the mango peel that demonstrated the biggest fat-reducing potential.
     The detailed analysis of three mango varieties was part of a collaborative research project between the Queensland Alliance for Agriculture and Food Innovation (QAAFI) and UQ School of Pharmacy as part of an Australian Research Council Linkage Projects grant with the Queensland Government.
     Professor Mike Gidley, who heads QAAFI's Centre for Nutrition and Food Sciences, said it was not unusual for the outer skin of a fruit to have quite a different chemical composition to the flesh.
     “We know mangoes have many excellent nutritional properties, but more work needs to done to understand the complex natural compounds found in these and other fruits,” he said.
     “This research reminds us that we should be looking at the whole fruit when considering how to take advantage of natural goodness.
     “Detailed chemical analysis of the skin and flesh is extremely valuable for mango growers and processors, who are always looking for new ways to value-add their fruit.”
      In laboratory models, the study found that the peel from 'Irwin' and 'Nam Doc Mai' mangoes contained high concentrations of bioactives that inhibit development of human fat cells.
      Professor Greg Monteith from the UQ School of Pharmacy said there were probably many reasons for this characteristic.
     “A complex interplay of bioactive compounds unique to each peel extract is likely responsible for the difference, rather than just a single component,” he said.
      The work was conducted by PhD student Mr Meng-Wong Taing and his study's results could help growers develop mango varieties that actively help reduce obesity.
     Obesity is associated with many chronic conditions such as diabetes, coronary heart disease and several cancers, including those of the breast and colon.

Tomado de sciencealert.com.au 

miércoles, 6 de junio de 2012

Female Choice Key to Evolutionary Shift to Modern Family

 It is a question that has puzzled evolutionary biologists for years: Why did we stop being promiscuous and decide to settle down to start families?

Sergey Gavrilets, professor of ecology and evolutionary biology at the University of Tennessee, Knoxville, may have found the answer, and it lies in the power of female choice. The study reveals how females chose their mates played a critical role in human evolution by leading to monogamous relationships, which laid the foundation for the institution of the modern family.
Using mathematical modeling, the associate director for scientific activities at the National Institute for Mathematical and Biological Synthesis (NIMBioS) at UT has discovered that the transformation may have occurred when early-hominid females started choosing males who were good providers.
Gavrilets' findings are published in the Proceedings of the National Academy of Sciences.
The "sexual revolution" entailed males first competing with other males for dominance, as a way to get matings. However, low-ranked males—and eventually all males except those with the highest societal stature—began supplying females with provisions in what is called "food-for-mating" to get a leg up on the competition. Females showed preference for the "provisioning" males, leading males' energy to be spent on providing for females and females becoming increasingly faithful. This spurred self-domestication and the modern family as we know it today.
"This change has confounded scientists for a long time because many species would be much better off evolutionarily if the effort spent on males competing for mates was redirected towards increasing female fertility or survivorship of their offspring," said Gavrilets.
The study demonstrates mathematically that the most commonly proposed theories for the transition to human pair bonding—or coupling—are not biologically feasible.
However, the study advances a new model showing that the transition to pair-bonding can occur when female choice and faithfulness, among other factors, are included. The result is an increased emphasis on males provisioning females over male competition for mating.
"The study reveals that female choice played a crucial role in human evolution," said Gavrilets.
According to Gavrilets, the transition to coupling has opened the path to intensified male parental investment, which was a breakthrough adaptation with multiple anatomical, behavioral and physiological consequences for early hominids and for all of their descendants. It shifted the dynamic away from males competing with each other for sex to males competing with each other to see who is a better provider to get better mates.
"Pair bonding laid the foundation for a later emergence of the institution of the modern family," said Gavrilets.

University of Tennessee. "Female choice key to evolutionary shift to modern family."ScienceDaily, 30 May 2012. Web. 6 Jun. 2012