miércoles, 18 de diciembre de 2013

Le injertan mano amputada en su tobillo

Fuente: http://elperiodico.com.gt/es/20131217/salud/239783/


Al fin sacan los gringos el esperado documento. Está gratuito aquí: http://jama.jamanetwork.com/article.aspx?articleid=1791497

 Special Communication | December 18, 2013 2014 Evidence-Based Guideline for the Management of High Blood Pressure in Adults: Report From the Panel Members Appointed to the Eighth Joint National Committee (JNC 8)
FREE ONLINE FIRST Paul A. James, MD1; Suzanne Oparil, MD2; Barry L. Carter, PharmD1; William C. Cushman, MD3; Cheryl Dennison-Himmelfarb, RN, ANP, PhD4; Joel Handler, MD5; Daniel T. Lackland, DrPH6; Michael L. LeFevre, MD, MSPH7; Thomas D. MacKenzie, MD, MSPH8; Olugbenga Ogedegbe, MD, MPH, MS9; Sidney C. Smith Jr, MD10; Laura P. Svetkey, MD, MHS11; Sandra J. Taler, MD12; Raymond R. Townsend, MD13; Jackson T. Wright Jr, MD, PhD14; Andrew S. Narva, MD15; Eduardo Ortiz, MD, MPH16,17 [+-]
Author Affiliations 1University of Iowa, Iowa City 2University of Alabama at Birmingham School of Medicine 3Memphis Veterans Affairs Medical Center and the University of Tennessee, Memphis 4Johns Hopkins University School of Nursing, Baltimore, Maryland 5Kaiser Permanente, Anaheim, California 6Medical University of South Carolina, Charleston 7University of Missouri, Columbia 8Denver Health and Hospital Authority and the University of Colorado School of Medicine, Denver 9New York University School of Medicine, New York, New York 10University of North Carolina at Chapel Hill 11Duke University, Durham, North Carolina 12Mayo Clinic College of Medicine, Rochester, Minnesota 13University of Pennsylvania, Philadelphia 14Case Western Reserve University, Cleveland, Ohio 15National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 16at the time of the project,National Heart, Lung, and Blood Institute, Bethesda, Maryland 17currently with ProVation Medical, Wolters Kluwer Health, Minneapolis, Minnesota JAMA. Published online December 18, 2013. doi:10.1001/jama.2013.284427

Otro link de interés: http://www.medpagetoday.com/Cardiology/Hypertension/43489?isalert=1&uun=g419731d448R5519153u&utm_source=breaking-news&utm_medium=email&utm_campaign=breaking-news&xid=NL_breakingnews_2013-12-18

martes, 17 de diciembre de 2013

TACT: No CVD Benefit With High-Dose Multivitamins

MIAMI BEACH, FL — A high-dose regimen that includes 28 vitamins and minerals given to stable patients with a history of MI does not reduce their future risk of cardiovascular events, according to the results of a new analysis[1].
The results, from the second arm of the 2x2 factorial Trial to Assess Chelation Therapy (TACT), funded by the National Heart, Lung, and Blood Institute (NHLBI) and National Center for Complementary and Alternative Medicine (NCCAM), were first presented at the American College of Cardiology 2013 Scientific Sessions and are now published online December 16, 2013 in the Annals of Internal Medicine.
The trial showed no benefit of multivitamin therapy in 1708 patients who received the supplements.
Stop wasting money on vitamin and mineral supplements.
"I'm a completely conventional cardiologist," Dr Gervasio Lamas (Mount Sinai Medical Center, Miami Beach, FL), the lead investigator of TACT, told heartwire . "I don't prescribe vitamins, and I tell my patients not to waste their money on them. But when I think of vitamin, I think of a microgram or a milligram, a nutritional supplement, which is used to replete a nutritional deficiency. But when you get these vitamins and minerals and you bring these up to very high dosages, and then you mix them, I think you do have unpredictable effects that can't be judged based on first principles."
For Dr Eliseo Guallar (Johns Hopkins Bloomberg School of Public Health, Baltimore, MD), Dr Saverio Stranges (University of Warwick, Coventry, UK), Dr Cynthia Mulrow (Annals of Internal Medicine, Philadelphia, PA), and Drs Lawrence Appel and Edgar Miller (Johns Hopkins School of Medicine, Baltimore, MD), the addition of the TACT data to the literature provides yet more evidence that the time has come to "stop wasting money on vitamin and mineral supplements."
"Although available evidence does not rule out small benefits or harms or large benefits or harms in a small subgroup of the population, we believe that the case is closed—supplementing the diet of well-nourished adults with (most) mineral or vitamin supplements has no clear benefit and might even be harmful," state the editorialists. "These vitamins should not be used for chronic disease prevention. Enough is enough."
Studying Mega Doses of Vitamins Used With Chelation
As reported by heartwire , the other, more controversial arm of the TACT trial found investigators and other experts at a bit of a loss when the study showed chelation therapy, an alternative-medicine mainstay, modestly improved clinical outcomes in patients after an acute MI. The difference in the primary end point—a composite of all-cause mortality, MI, stroke, coronary revascularization, and hospitalization for angina—reached the trial's specified threshold for statistical significance.
In this study, the TACT investigators randomized patients 50 years of age or older who had an MI at least six weeks prior to treatment with high-dose multivitamins and multiminerals, including vitamins A, C, and E, as well as selenium and magnesium, or to placebo.
Lamas explained that the multivitamins and multiminerals used in their analysis were standard doses used by centers practicing chelation therapy. Patients undergoing the controversial treatment were given large doses of oral vitamins and minerals, nearly all of which exceed 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, and these amounts all exceed the daily recommended dosages.
Adherence rates were low in the trial, however, with 46% of patients discontinuing the treatment during the study. In total, 76% of participants completed one year of treatment and only 47% of participants in the active-treatment arm completed three years. Dropout rates were also high, with 17% of patients withdrawing from the study.
The primary end point occurred in 27% of patients in the multivitamin arm and 30% of patients in the placebo group. In terms of risk reduction, there was a nonsignificant 11% reduction in the primary end point (TACT was powered for a 25% reduction in risk). Based on the data, Lamas said patients should not be taking vitamin or mineral supplements for cardiovascular-disease prevention

Fuente: http://www.medscape.com/viewarticle/817857?nlid=42483_2086&src=wnl_edit_medp_card&spon=2

lunes, 16 de diciembre de 2013

FDA Wants Proof of Anti-Bacterial Soap Claims

Published: Dec 16, 2013 | Updated: Dec 16, 2013

WASHINGTON -- Manufacturers of nonprescription anti-bacterial hand soaps and body washes will soon be required to show their products are safe for long-term daily use and are more effective than plain soap in stopping the spread of infections, the FDA announced Monday.Failing to meet such a standard would mean that antiseptic ingredients would have to be removed from over-the-counter products, or that anti-bacterial claims be removed from product labeling. The announcement came in a proposed rule released by the agency and doesn't apply to hand sanitizers and wipes -- which are alcohol-based and aren't used with water -- or to anti-bacterial products used in the healthcare setting.
The agency wants to amend a 1994 monograph that declared nearly all antiseptic active ingredients currently in use as "generally recognized as safe and effective." The FDA has been reviewing anti-bacterial active ingredients for the past several years, and hopes to finalize the rule around the fall of 2016.
Janet Woodcock, MD, director of the FDA's Center for Drug Evaluation and Research (CDER), said there are more than 2,200 anti-bacterial hand soaps and body washes currently available for consumers, but there is no scientific evidence showing these products are any more effective at preventing illness than washing hands with plain soap and water.
"Further, the risk of infection in everyday settings such as home, work, school, and public settings is relatively low," Woodcock said in a statement to CDER staff. "Moreover, some data suggest that long-term exposure to certain active ingredients used in anti-bacterial products could pose health risks such as bacterial resistance or hormonal effects."
Examples of those risks come from such ingredients as triclosan (liquid soaps) and triclocarban (bar soaps). Some animal studies that suggest that daily exposure to these products can effect estrogen, testosterone, and thyroid hormones, noted Sandra Kweder, MD, deputy director of the FDA's Office of New Drugs at CDER. Their effect on human safety has not been established.
"In order for anti-bacterial soaps and body washes to be considered generally recognized as effective, manufacturers would be required to conduct clinical trials demonstrating that their products are more effective than plain soap and water in preventing illness and the spread of certain infections when they're used by consumers," Kweder said in a call with reporters. The same would apply for their safety.
Nicole Bouvier, MD, professor of infectious diseases at the Icahn School of Medicine at Mount Sinai in New York City, said triclosan has been deemed an "endocrine disruptor."
"It is still unclear whether triclosan and similar biocides promote the development of antimicrobial resistance to antibiotics, but we do know that triclosan is a long-lived chemical," Bouvier said. "It has been found in soil, waste water treatment plants, lakes and streams, and even in many people's urine, where it has been associated with elevated body mass index and with environmental and food allergies."
The proposed rule will be published soon in the Federal Register with a 180-day public comment period that will close around June 2014. Kweder said manufacturers can submit data until December of next year. Kweder said FDA officials hope that's enough time for the appropriate studies to be completed and presented to the FDA for review.
"We actually don't know how much information companies already have available," she said. "We think that some companies may have some data that [they] have not previously been required to submit to us, and we do believe that some of these studies may already be in the works."
Until the FDA takes further action, consumers should make an "educated choice" about what products they use, Kweder said. "Washing with plain soap and running water is one of the most important steps consumers can take to avoid getting sick and to prevent spreading germs to others."
Alcohol-based hand sanitizers that contain at least 60% alcohol should be used if soap and water are not available, the FDA said.

viernes, 13 de diciembre de 2013

DPP-4: The Physiology of Incretin Degradation


After the ingestion of a meal, the gut secretes the incretin hormones glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). The results include1:
  • Glucose-dependent insulin secretion by the pancreas
  • Decreased glucagon secretion by the liver
  • Delayed gastric emptying
  • Appetite suppression

As with any hormone, the amount of circulating GLP-1 is governed by its elimination as well as its secretion. The enzyme dipeptidyl peptidase-4 (DPP-4) is the primary agent that metabolizes these incretin hormones.2 This article reviews its physiology.
DPP-4 was originally known as either the lymphocyte cell surface marker CD26 or the adenosine deaminase (ADA)-binding protein. It is a 766-amino acid serine protease that cleaves peptide hormones with a position 2 alanine or proline.3
DPP-4 exists in the body in 2 forms: 1 membrane-bound and another smaller, soluble form.3 So in addition to being widely expressed and enzymatically active on numerous cell types and different vascular beds, DPP-4 enzymatic activity has also been detected in serum, urine, seminal plasma, and amniotic fluid. Although it has been suggested that the soluble form is a result of cleavage of the membrane-bound form, this has not been proven.4

Establishing the importance of DPP-4 in incretin physiology and in the pathophysiology of type 2 diabetes began with the observation that DPP-4 could metabolize both GLP-1 and GIP in vitro.5 Subsequent studies in DPP-4-deficient rats demonstrated reduced ability to metabolize these incretin hormones, providing further evidence.6 Finally, humans with type 2 diabetes experienced rapid degradation of incretin hormones even when they were given intravenous or subcutaneous doses in experimental conditions. Hence, DPP-4 is viewed as the primary determinant of the half-life of the incretin hormones in the circulation.3
Interestingly, the role of DPP-4 in immune function is also being explored. Some of the most compelling findings have been conducted in DPP-4- deficient mice. These mice have significantly lower T-cell counts, as well as decreased amounts of T-cell-mediated tumor lysis activity. It also appears that the ability of these mice to mount an antibody response is impaired—with lower levels of IgG and IgE produced in response to antigen challenge compared with normal mice.3
A role for DPP-4 in the inflammatory response is also suggested by its association with inflammatory arthritis. Evidence in both animal models and humans has shown that the levels of DPP-4 are inversely correlated with the severity of rheumatoid arthritis in affected subjects. Taken together, both lines of evidence suggest that there is clearly some role for DPP-4 in immune function. However, it remains to be seen whether this is due to specific enzymatic activity or other noncatalytic actions.3
At present, DPP-4 is primarily known for its role in incretin degradation and its association with type 2 diabetes. However, as new data are generated, we may come to understand its function within a broader range of disease states. Studies are ongoing.
Published: 05/20/2013
  1. Freeman JS. Role of the incretin pathway in the pathogenesis of type 2 diabetes mellitus. Cleve Clin J Med. 2009;76(suppl 5):S12-S19.
  2. Freeman JS. A physiologic and pharmacological basis for implementation of incretin hormones in the treatment of type 2 diabetes mellitus. Mayo Clin Proc. 2010;85(suppl 12):S5-S14.
  3. Drucker DJ. Dipeptidyl peptidase-4 inhibition and the treatment of type 2 diabetes: preclinical biology and mechanisms of action. Diabetes Care. 2007;30:1335-1343.
  4. Hildebrandt M, Reutter W, Arck P, et al. A guardian angel: the involvement of dipeptidyl peptidase IV in psychoneuroendocrine function, nutrition and immune defence. Clin Sci (Lond). 2000;99:93-104.
  5. Mitani H, Takimoto M, Kimura M. Dipeptidyl peptidase IV inhibitor NVP-DPP728 ameliorates early insulin response and glucose tolerance in aged rats but not in aged Fischer 344 rats lacking its enzyme activity. Jpn J Pharmacol. 2002;88:451-458.
  6. Kieffer TJ, McIntosh CH, Pederson RA. Degradation of glucose-dependent insulinotropic polypeptide and truncated glucagon-like peptide 1 in vitro and in vivo by dipeptidyl peptidase IV. Endocrinology. 1995;136:3585-3596.

Fuente: http://www.medpagetoday.com/resource-center/diabetes/incretin-degradation/a/39265?eun=g419731d0reun=g419731d0r