miércoles, 26 de febrero de 2014

Para los que insisten con las vitaminas...

Heartwire USPSTF: No Evidence of CVD Benefit With Multivitamins Michael O'Riordan February 24, 2014 3 commentsPrintEmailEditors' Recommendations TACT: No CVD Benefit With High-Dose MultivitaminsChelation Therapy Gets Explained in JAMADrug & Reference Information Primary and Secondary Prevention of Coronary Artery Disease Vitamin A Deficiency Common Pregnancy Complaints and Questions WASHINGTON, DC — The current clinical evidence is insufficient to assess the benefits and risks of taking multivitamins or single or paired nutrient supplements for the prevention of cardiovascular disease or cancer, according to a new statement by the United States Preventive Services Task Force (USPSTF). The evidence against the use of beta-carotene or vitamin E is stronger, however, and the agency said these supplements should not be used for preventing cardiovascular events or cancer. "A critical gap in the evidence is the lack of studies of multivitamin combinations in groups generalizable to the US population," the USPSTF concludes. "Targeting research toward individuals who can be identified as high risk for nutrient deficiency rather than the general population may be more productive." Published February 24, 2014 in the Annals of Internal Medicine and chaired by Dr Virginia Moyer (Baylor College of Medicine, Houston, TX), the vitamin review included four randomized, controlled trials and one cohort study of multivitamin supplementation. Although the trials varied with the nutrients and dosages, there was no effect on all-cause mortality and no effect on cardiovascular outcomes. One trial showed a borderline significant reduction in MI. The reviewers also analyzed 24 studies of individual vitamins, minerals, or paired nutrients. As the USPSTF notes, "There was no evidence of beneficial effect on cardiovascular disease, cancer, or all-cause mortality. However, there are only a limited number of studies for most individual nutrients, and differences in study designs make it difficult to pool effects across supplements. Therefore, the USPSTF is not able to conclude there is no effect." For beta-carotene and vitamin E, though, there is evidence sufficient to estimate the overall net benefit. Given the higher lung-cancer risk with beta-carotene in smokers, there is evidence of net harm, while "there is a large and consistent body of evidence" showing that vitamin-E supplements have no effect of cardiovascular disease, cancer, or all-cause mortality. The USPSTF concludes with "moderate certainty" the net benefit of vitamin-E supplementation is zero. And regarding the use of minerals or multimineral combinations, the USPSTF makes similar recommendations. Complex Pharmacology Commenting on the USPSTF statement for heart wire , Dr Gervasio Lamas (Mount Sinai Medical Center, Miami Beach, FL) agreed with the conclusions of the reviewers and said their recommendations were fair, if a little cautious. He said numerous clinical trials with single vitamins, including vitamins A, C, D, and selenium have all been negative, or as is the case with vitamin A, have shown the potential to cause harm. He pointed out, however, that multivitamin pharmacology is complex and it remains a difficult-to-study area of medicine. In contrast with these other vitamin and mineral studies, patients in the Trial to Assess Chelation Therapy (TACT) undergoing chelation were given large doses of oral vitamins and minerals, nearly all of which exceeded the daily recommended values. For example, 1200 mg of vitamin C, 25 000 IU of vitamin A, 400 IU of vitamin E, 200 mg of niacin, and 800 µg of folate were prescribed. "These were vitamins used at levels far beyond what was needed to replete a nutritional deficiency," said Lamas, the lead investigator of TACT. Given the hint of benefit at very large doses in TACT— there was a nonsignificant 11% reduction in the risk of cardiovascular outcomes—Lamas said other high-dose multivitamin and multimineral studies might be worth a second look. He said the pharmacologic properties of aspirin change when used at different doses. At 81 mg, aspirin is used an antiplatelet agent, at 650 mg as a treatment to reduce fever, and when 1 to 2 g per day are prescribed it can be used to treat rheumatoid arthritis. That said, Lamas believes the recommendation to stay away from over-the-counter (OTC) multivitamins and multiminerals to reduce cardiovascular disease is a good one. He points out the multivitamin combination used in Centrum Silver (Pfizer) even failed to reduce the risk of MI, stroke, or cardiovascular mortality in one study, yet the company still advertises it as a heart-healthy supplement. "Overall, this is a good statement from the USPSTF, but they don't have the advertising dollars of the vitamin industry," said Lamas. In the US, spending on dietary supplements is a big business, with Americans spending $28.1 billion in 2010 alone. In fact, the USPSTF notes that surveys conducted by the vitamin industry have found that many physicians and nurses have recommended multivitamins to their patients for health and wellness. Fuente: http://www.medscape.com/viewarticle/820988?nlid=50283_2566&src=wnl_edit_medp_card&spon=2

domingo, 23 de febrero de 2014

Siempre es refrescante recordar lo lindo que es ser médico....

I Can't Always Cure, But I Can Always Care

I started kissing patients in med school. And I haven’t stopped.

During my third-year pediatric rotation, I used to stay up late at night in the hospital, holding sick and dying children. I’d lift them from their cribs, kiss them, and sing to them, rocking them back and forth until they fell asleep. One day the head of the department pulled me aside. He said that I was a doctor when my patients needed a doctor and a mother when they needed a mother.

Twenty years later, I’m still mothering my patients.

I’m a family physician born into a family of physicians. My parents warned me not to pursue medicine. They worried that big government would kill the small-town physician. But I love being a family doctor. And I love my patients. I hug them and kiss them, and I do house calls. And most patients call me Pamela or sweetie, or honey. They all have my home phone number. I’m on call 24/7, but I never feel like I’m working.

I’m not good with boundaries. I’m never sure when work ends and play begins. It all feels the same to me. Many of my patients are friends. I do their physicals and eat over their homes for dinner.

I’m not a fan of professional distance. But I’ve been trained to maintain distance from patients. How can I remain distant when I’m looking deep inside people in places nobody has been before? How can I remain detached when delivering a mother’s first baby, saving a brother’s sister, or helping a child’s grandfather die?

Apparently, maintaining a safe distance from patients will help my objectivity, limit favoritism, maintain clear sexual boundaries, and prevent exploitation. But patients today don’t want professional distance; they want professional closeness with a doctor who has a big heart and a great love for people and service in a clinic where people feel warm, nurtured, loved, and important.

And I want to be that kind of doctor.

The truth is: I can’t always stop patients with heart attacks from eating bacon double cheeseburgers. I can’t always stop smokers from smoking. I can’t always stop little kids from dying.

I can’t always cure, but I can always care—and kiss my patients.

Fuente: http://www.consultantlive.com/articles/i-cant-always-cure-i-can-always-care?GUID=24510CEB-E6AD-4B62-B3CC-131041EACD56&rememberme=1&ts=20122013

Brain and Islet: Key Partners in Glucose Homeostasis

The idea that the brain plays an important role in glucose homeostasis is not exactly new, though it has been overlooked for quite some time. In the 19th century, Claude Bernard induced diabetes in rabbits by injuring the floor of the fourth cerebral ventricle.1 The discovery of insulin in 1921, however, drew attention away from the brain-centered view of diabetes. Since then, the islet-centered view has dominated. Recently, an international group of researchers has proposed to revive the brain-centered theory. In a review article published in the journal Nature, scientists from the US and Germany describe a brain-centered glucoregulatory system (BCGS) that helps maintain glucose homeostasis via insulin-dependent and insulin-independent mechanisms.2 - See more at: http://www.consultantlive.com/diabetes-type-2/brain-and-islet-key-partners-glucose-homeostasis#sthash.aTzCXnaI.dpuf

Fuente: http://www.consultantlive.com/diabetes-type-2/brain-and-islet-key-partners-glucose-homeostasis

Aspirin in Primary Prevention: Evidence Review


Low-dose aspirin has been shown to be effective in preventing about one-fifth of atherothrombotic vascular complications (non-fatal myocardial infarction, non-fatal stroke, or vascular death) in a meta-analysis of 16 secondary prevention trials in patients with previous myocardial infarction, stroke, or transient cerebral ischaemia. This corresponds to an absolute reduction of about 10–20 per 1000 patients in the yearly incidence of non-fatal events, and to a smaller, but still definite, reduction in vascular death. Against this benefit, the absolute increase in major extracranial bleeding complications [mostly, gastrointestinal (GI)] is 20- to 50-fold smaller, depending on age and sex. Hence, for secondary prevention, the benefits of antiplatelet therapy substantially exceed the risks. For primary prevention, the balance between vascular events avoided and major bleeds caused by aspirin is substantially uncertain because the risks without aspirin, and hence the absolute benefits of antiplatelet prophylaxis, are at least an order of magnitude lower than in secondary prevention. The aim of this article is to review the updated evidence for the efficacy and safety of low-dose aspirin in primary prevention and to discuss additional health benefits resulting from prolonged antiplatelet therapy in apparently healthy people at low average risk of vascular events.

Completo en: http://www.medscape.com/viewarticle/815074?nlid=45004_763&src=wnl_edit_medp_imed&spon=18

Evidencia reciente sobre la IMPORTANCIA de dormir suficiente

Lack of sleep: All about genes and yawns

21. January 2014 
Anybody who frequently sleeps fewer than seven hours per night is weakening his or her immune system. Scientists in Helsinki have for the first time been able to show which biological mechanisms associated with sleep deprivation have an affect on the immune system.  
Sleep deprivation has a direct impact on the human immune system. This is something well known. In a recent study published in the journal PLOS ONE, scientists at the University of Helsinki have now discovered important biological relationships between sleep reduction and the defence mechanisms of the body.

Sleep deprivation and inflammatory responses

Epidemiological studies in which the subjects involved gave information about their sleep patterns led researchers already some time ago to assume that too little sleep raises the risk of cardiovascular disease and type 2 diabetes. Whoever constantly sleeps less than seven hours a night also has an increased mortality risk – according to the available data. Many of the diseases that are associated with lack of sleep are associated with inflammatory responses in the body. Scientists in Helsinki have for the first time been able to show which biological mechanisms associated with sleep deprivation have an affect on the immune system. They were able to make genes identifiable which are also involved in the regulation of the immune system and whose transcription behaviour changes with sleep deprivation.

Only four hours of sleep per night for five days

In order to simulate a working week, nine healthy young men at the laboratories of the Finnish Institute for Occupational Safety were for five days permitted to sleep for only four hours a night. Before and after the sleep deprivation test, blood was taken from the subjects. The scientists isolated white blood cells from them and examined the gene expression in their study participants using microarrays. The results were compared by the researchers with data from four healthy men of similar age who were allowed eight hours of sleep a night during the same period. “We compared the gene expression before and after sleep deprivation and took a close look at the genes whose transcription frequency most varied”, explains Vilma Aho, a participating scientist.

Sleep deprivation altered gene expression

Sleep deprivation altered the frequency of transcription activity for a total of 117 genes. Eight of the 25 most up-regulated gene transcripts were directly linked to the immune system. In the metabolic pathways affected, the researchers met with a similar result: 15 of the 25 most accelerated metabolic pathways were associated with immunological functions. These included, for example, B-cell activation, interleukin8 production and the NF-κB signal pathway. “Under a state of sleep deprivation, for example, the activity of B-cells – also involved in allergic reactions and asthma – increased. This could explain the link between lack of sleep and increased asthmatic reactions”, says Aho. In addition to specific interleukins or signalling molecules that are involved in inflammation, the number of receptors, such as toll-like receptors, increased significantly when the subjects slept too little. At the genetic level this made itself more noticeable, in that the TLR4 gene was transcribed much more often during sleep deprivation periods than during normal sleep patterns. The concentrations of C-reactive protein (CRP) were also increased, indicating inflammation.

Effects of long-term sleep deprivation

Since the laboratory conditions resemble those of only few people in the real world, the scientists were also interested in investigating the effects of poor sleep on the immune system under real conditions. For this follow-up study, they referred to samples held by the national FINRISKI Health Survey. The 472 participants in this cohort study had already undergone blood tests and answered questions about their state of health and their sleep behaviour. The scientists compared the data derived from good sleepers with that of bad sleepers. Some changes in the transcription of certain genes were also confirmed by the scientists in this study population. The striking match between laboratory test and cohort study related to gene transcripts from genes with the names TBX21 and TGFBR3, both mediators of the immune system. LGR6 and STX16, which have been repeatedly associated with cancers, were also altered by lack of sleep in their transcription frequency. These four genes could play an important role in how lack of sleep affects the immune system, scientists suspect.
Aho summarises: “These results confirm the assumption that sleep apparently does not just affect our brain functions, but is also associated with our immune system and our metabolism. Sleep deprivation causes changes in the system which our immune system regulates. Some of these changes seem to have long-term consequences and may contribute to the development of diseases which have already been thus linked in epidemiological studies done on sleep deprivation”.

Fuente: http://news.doccheck.com/en/newsletter/593/4186/?utm_source=DC-Newsletter&utm_medium=E-Mail&utm_campaign=Newsletter-EN-DocCheck+News-2014-01-17&user=1479eb13b686c9c528b8911e6b9e012b&n=593&d=28&chk=015dc07b411f7f154ae6ec707419cd05

ADN de neandertal persiste en humanos

Muchos de los genes que contribuyen a configurar la piel y el cabello de la mayoría de los seres humanos tienen bastante de los neandertales, según dos nuevos estudios que examinaron los vestigios de ADN en el genoma de los humanos modernos.
Hace unos 50 mil años, los seres humanos modernos emigraron del norte del África a Europa y el este de Asia, y se encontraron con los neandertales pilosos que habían estado en climas más fríos durante más de cien mil años. Algunos individuos de las dos especies copularon.
Después los neandertales se extinguieron como especie, pero no sin dejar una herencia genética.
Los científicos aislaron las partes del código genético de los humanos modernos no africanos que todavía contienen vestigios de los neandertales.
En general apenas supera el 1%, dicen los dos estudios publicados en las revistas Nature y Science.

Fuente: http://www.prensalibre.com/internacional/ADN-neandertal-persiste-humanos_0_1078092199.html

A Soda a Day Ups CVD Risk by 30%: NHANES Study


Nuestras palabras chapinas con raíces indígenas y no hispánicas

Que lindo conocer que tantas palabras tan FRECUENTES en nuestro hablar realmente son de nuestras raíces indígenas y NO hispánicas...

Unos ejemplos: Guacal, chirmol, aguacate, atole, machote, tanate, petate, milpa...


miércoles, 12 de febrero de 2014

Is Intensive Blood Pressure Lowering Beneficial in Acute Intracerebral Hemorrhage ?

Seemant Chaturvedi, MD reviewing Anderson CS et al. N Engl J Med 2013 May 29. Equivocal outcomes from the INTERACT 2 trial The INTERACT 1 trial (JW Neurol Aug 14 2012) gave preliminary evidence that early, intensive blood pressure lowering might improve intracerebral hemorrhage (ICH) outcomes. Now, researchers report the findings of INTERACT 2. They enrolled patients with acute, spontaneous ICH whose blood pressure could be treated within 6 hours of symptom onset and lacked an overt structural cause, who were not in deep coma and not scheduled for immediate surgery. Patients were randomized to an intensive systolic blood pressure (SBP) target of <140 mm Hg within 1 hour of randomization, maintained for 7 days, or a conventional, guideline-determined SBP target of <180 mm Hg. The primary outcome was death or major disability at 90 days. A secondary analysis assessed improvement across the range of functional outcomes on the modified Rankin scale (ordinal analysis). Among 2794 patients with 90-day outcome data (mean age, 63.5; 63% male; average blood pressure at enrollment, 179/101 mm Hg; 83.5% with deep ICH; 28.4% with intraventricular extension), the mean SBP at 6 hours after randomization was 139 mm Hg with intensive therapy versus 153 mm Hg with conventional treatment. The primary outcome was not significantly different between treatments (52.0% with intensive therapy, 55.6% with conventional therapy; odds ratio, 0.87; P=0.06). In the ordinal analysis, the odds of disability were a significant 13% lower with intensive than with conventional treatment. Death or major disability at 7 days and 28 days did not differ between groups. In a subgroup of patients with repeat imaging at 24 hours, hematoma growth did not differ between the two treatments. Comment In this large-scale trial, the primary outcome missed statistical significance, but there was a trend for improved outcomes, and functional outcomes showed a benefit with intensive blood pressure lowering. The authors achieved their blood pressure target of a 13 mm Hg reduction in systolic blood pressure, but the absolute difference in death and major disability was only 3.6%, not 7.0% as hypothesized, raising questions about whether the patients had too many preexisiting comorbidities or whether the earlier, pilot data were overly optimistic. The greater rate of care withdrawal with intensive versus conventional therapy (5.4% vs. 3.3%) and unreported differences in posthospitalization rehabilitation may have slightly diminished a potential treatment effect. For now, intensive lowering of blood pressure in acute intracerebral hemorrhage appears to be unharmful and may lead to a clinical benefit. Editor Disclosures at Time of Publication Citation(s): Anderson CS et al. Rapid blood-pressure lowering in patients with acute intracerebral hemorrhage. N Engl J Med 2013 May 29; [e-pub ahead of print]. (http://dx.doi.org/10.1056/NEJMoa1214609)