Coffee and Cigarettes May Protect Against Liver Disease

Coffee and cigarette smoking may protect against the rare liver disease Primary Sclerosing Cholangitis (PSC), study shows.

In a new study from Norway published inClinical Gastroenterology and Hepatology, both coffee consumption and cigarette smoking are shown to potentially protect against primary sclerosing cholangitis (PSC). This is a chronic liver disease caused by chronic inflammation of the bile ducts.

The findings are of great interest against a backdrop of increasing knowledge on coffee as a possible protective agent in other liver diseases.

The cross-sectional study was conducted by researchers at the Norwegian PSC Research Center based at Oslo University Hospital and the University of Oslo.

The study was conducted using a questionnaire about environmental exposures, and included 240 PSC patients and 245 controls.

Coffee

The study shows showed that the PSC patients had lower coffee consumption both currently and in the early adulthood, suggesting that coffee consumption could protect against the development of the disease. PSC patients who drank coffee, however, had lower levels of liver enzymes in the blood, thus suggesting a beneficial effect in the liver.

Cigarettes

Regarding cigarette smoking, only 20% of the patients reported ever daily cigarette smoking, compared with 43% of the healthy controls. In addition, cigarette smokers acquired the disease on average 10 years later than non-smokers. Taken together, these observations confirm and strengthen previous observations of smoking as a possible protective factor in PSC.

About PSC

While PSC is not a common disease, it is a severe condition affecting mostly young adults (30-40 years), and with a high risk of associated cancer of the bile ducts.

Few treatment options are available and PSC is one of the most important reasons for liver transplantation. While the possible protective effect of smoking against PSC seems rather unique to this particular liver disease, coffee consumption has been shown to protect against multiple other liver conditions including liver cirrhosis and liver cancer -- and now for the first time also against PSC.

Tomado de:Oslo University Hospital. "Coffee and cigarettes may protect against liver disease." ScienceDaily, 14 Dec. 2013. Web. 21 Dec. 2013.

An Apple a Day Keeps the Doctor Away

 Prescribing an apple a day to all adults aged 50 and over would prevent or delay around 8,500 vascular deaths such as heart attacks and strokes every year in the UK -- similar to giving statins to everyone over 50 years who is not already taking them -- according to a study in the Christmas edition of The BMJ.

The researchers conclude that the 150 year old public health message: "An apple a day keeps the doctor away" is able to match more widespread use of modern medicine, and is likely to have fewer side effects. The research takes into account people who are already appropriately taking statins to reduce their risk of vascular disease and therefore the authors stress that no-one currently taking statins should stop, although by all means eat more apples.

In the United Kingdom, lifestyle changes are the recommended first step to prevent heart disease. However, trial data suggest that statins can reduce the risk of vascular events, irrespective of a person's underlying risk of cardiovascular disease. As such, calls are being made for greater use of statins at a population level, particularly for people aged 50 years and over.

Using mathematical models a team of researchers at the University of Oxford set out to test how a 150 year old proverb might compare with the more widespread use of statins in the UK population. They analysed the effect on the most common causes of vascular mortality of prescribing either a statin a day to those not already taking one or an apple a day to everyone aged over 50 years in the UK.

The researchers assumed a 70% compliance rate and that overall calorie intake remained constant.

They estimate that 5.2 million people are currently eligible for statin treatment in the UK and that 17.6 million people who are not currently taking statins would be offered them if they became recommended as a primary prevention measure for everyone over 50.

They calculate that offering a daily statin to 17.6 million more adults would reduce the annual number of vascular deaths by 9,400, while offering a daily apple to 70% of the total UK population aged over 50 years (22 million people) would avert 8,500 vascular deaths.

However, side-effects from statins mean that prescribing statins to everyone over the age of 50 is predicted to lead to over a thousand extra cases of muscle disease (myopathy) and over ten thousand extra diagnoses of diabetes.

Additional modelling showed a further 3% reduction in the annual number of vascular deaths when either apples or statins were prescribed to everybody aged over 30. However the number of adverse events is predicted to double.

"This study shows that small dietary changes as well as increased use of statins at a population level may significantly reduce vascular mortality in the UK," say the authors.

"This research adds weight to calls for the increased use of drugs for primary prevention of cardiovascular disease, as well as for persevering with policies aimed at improving the nutritional quality of UK diets," they conclude.

Dr Adam Briggs of the BHF Health Promotion Research Group at Oxford University said: "The Victorians had it about right when they came up with their brilliantly clear and simple public health advice: "An apple a day keeps the doctor away." It just shows how effective small changes in diet can be, and that both drugs and healthier living can make a real difference in preventing heart disease and stroke.

While no-one currently prescribed statins should replace them for apples, we could all benefit from simply eating more fruit."

Tomado de BMJ-British Medical Journal. "An apple a day keeps the doctor away." ScienceDaily, 17 Dec. 2013. Web. 21 Dec. 2013

Daily iron supplementation improved cognitive, physical performance in children with anemia

Children with anemia who received daily iron supplementation demonstrated improved cognitive performance and physical outcomes with few adverse effects, according to results of a systemic review and meta-analysis

Daily iron supplementation also improved hematologic outcomes, reducing the risk for anemia by 50% and the risk for iron deficiency by 79%.

Researchers used electronic databases, including MEDLINE and Embase, to search for randomized and quasi-randomized trials that evaluated the effects of daily iron supplementation in children aged 5 to 12 years.

Their analysis included 32 relevant studies, 31 of which were conducted in low- or middle-income settings. The most common study site was India (n=7), followed by Thailand (n=4), Indonesia (n=2) and Kenya (n=2).

The studies included a combined 7,089 children. Of them, 3,837 received oral iron supplementation at least 5 days per week. The other 3,252 children served as controls.

Nine of the studies assessed global cognitive performance.

Results showed children who received iron supplementation demonstrated higher global cognitive scores at the end of the intervention period compared with controls (standardized mean difference [SMD]=0.50; 95% CI, 0.11-0.90). Researchers also observed improvement among children who were anemic at baseline (SMD=0.29; 95% CI, 0.07-0.51).

IQ scores also improved in children with anemia who received iron supplementation (mean difference [MD]=4.55; 95% CI, 0.16-8.94).

All children who received iron supplementation demonstrated improvements in age-adjusted height, and those with anemia who received daily supplementation demonstrated improvements in age-adjusted weight.

Seven studies that included 1,763 children showed daily iron supplementation reduced risk for anemia (RR=0.50; 95% CI, 0.39-0.64). Four studies that included 1,020 children showed daily supplementation reduced risk for iron deficiency (RR=0.21; 95% CI, 0.07-0.63).

Researchers found that children who received iron were not at increased risk for malaria or gastrointestinal adverse effects compared with children who did not receive supplementation.

“Anemia and iron deficiency were prevalent in the included studies (69% and 59%, respectively, in the control groups. Thus, routine daily iron supplementation is likely to benefit cognitive performance in primary school-aged children in developing settings where anemia is prevalent and testing hemoglobin before iron supplementation may not be feasible,” the researchers wrote. “Daily iron supplementation could benefit educational attainment and economic potential at the individual level and, in settings where anemia is prevalent, population level.”

Low M. Can Med Assoc J. 2013;doi:10.1503/cmaj.130628.

Tomado de Healio.com

Venous Thromboembolism and Travel

The association between venous thromboembolism (VTE) and travel was recognized as early as the 1950s, when John Homans, MD, best remembered in connection with Homans’ sign—pain in the calf on active or passive dorsiflexion of the foot that may signal deep venous thrombosis (DVT)—advised that “physicians should be alert to recognize the significance of lameness after airplane flights, automobile trips and other occasions of a prolonged seated position.”¹This article will review the risk of developing VTE associated with travel.

The notion that prolonged travel in a sedentary position increases the risk of VTE seems easy to accept, and clinicians are accustomed to asking about recent travel when they suspect VTE. However, symptomatic VTE after air travel is rare, as demonstrated in a cohort study of 8755 employees of large international companies and organizations.² A total of 22 symptomatic, objectively confirmed VTE events occurred within 8 weeks after 102,429 long-haul flights, defined as 4 hours or longer. This corresponded to an absolute risk of 1 VTE event per 4656 long-haul flights.

A systematic review by Philbrick and colleagues also found a low rate of symptomatic VTE after air travel, with an incidence of 0.5 pulmonary embolisms per 1 million travelers presenting on the day of arrival in the airport, and 27 VTEs (pulmonary embolism and DVT) per 1 million travelers presenting within 2 weeks of arrival.³ When ultrasounds are performed routinely in travelers, the rate of diagnosed DVT may be as high as 1.2%, but the majority of cases are asymptomatic. The risk of an asymptomatic DVT progressing to clinically significant disease is currently unknown.

While some large studies have documented a positive relationship between travel and VTE, others have not. Chandra and colleagues conducted a meta-analysis of observational studies to clarify the conflicting evidence.⁴ In the 14 included studies, the pooled relative risk for VTE associated with travel was 2.0 (95% CI, 1.5-2.7). However, there was significant heterogeneity, with 7 studies reporting an association between travel and VTE, and the other 7 reporting no association. The authors conducted a sub-analysis to exclude 8 case-control studies that had a certain bias in selecting the control participants. In the remaining 6 studies, the relative risk for VTE associated with travel was 2.8 (95% CI, 2.2-3.7). These results appear to resolve the conflicting data and point to an elevated risk of VTE with travel.

The Chandra meta-analysis also reported a significant travel dose-response relationship. The risk for VTE rose by 18% for each 2-hour increase in travel by any mode, and by 26% for each 2-hour increase in travel by air.⁴ The Philbrick systematic review also documented a dose-response relationship, with greatest risk for DVT occurring with flights longer than 8 hours.³

The data on VTE associated with car or train trips is less clear. In the Chandra meta-analysis, the risk of VTE with air travel was slightly higher than for ground travel, but the difference was not statistically significant.⁴ In the Philbrick systematic review, only air travel was associated with VTE, although not all studies assessed other modes of travel.³

Other than flight duration, baseline clinical factors may also influence the risk of VTE. A prospective cohort study monitored travelers with surveillance ultrasound within 24 hours after long flights (average duration, 12.4 hours).⁵ Eleven of the 389 high-risk travelers (previous history of DVT, known coagulation disorder, severe obesity, limited mobility, cancer, large varicose veins) were found to have DVT. In contrast, DVT was not found in any of the 355 low-risk travelers.

In conclusion, symptomatic VTE after travel is not a common event. But considering the popularity of air travel, it is important to recognize the elevated risk of VTE associated with long air flights, especially among patients with other risk factors for VTE. Patients at high risk for DVT induced by prolonged travel should be identified and counseled before they start their journeys.

Tomado de: medpagetoday.com

Epigenetics: A Key to Controlling Acute and Chronic Pain

 Epigenetics, the study of changes in gene expression through mechanisms outside of the DNA structure, has been found to control a key pain receptor related to surgical incision pain, according to a study in the November issue of Anesthesiology. This study reveals new information about pain regulation in the spinal cord.

"Postoperative pain is an incompletely understood and only partially controllable condition that can result in suffering, medical complications, unplanned hospital admissions and disappointing surgery outcomes," said David J. Clark, M.D., Ph.D., Professor of Anesthesia at Stanford University and Director of Pain Management at the VA Palo Alto Health Care System. "We know that histone acetylation and deacetylation modifies many cellular processes and produces distinct outcomes. In this study we found that histones can epigenetically activate or silence gene expression to either increase or decrease incision pain."

Human DNA is wrapped around proteins called histones, much like thread is wrapped around a spool. When a histone undergoes deacetylation, the DNA wraps more tightly around the spool, effectively silencing genes. Conversely, when it undergoes acetylation, the DNA is loosened, allowing for transcription or modifications of genes to occur.

In this study, groups of mice had small surgical incisions made in their hind paws after being anesthetized. These mice were then regularly injected with suberoylanilide hydroxamic acid (SAHA), which prevents deacetylation (thus promoting gene transcription), or anacardic acid, which prevents acetylation (thus reducing gene transcription). The authors tested the animals daily for the degree of pain sensitivity in their hind paws.

The study found that regulation of histone acetylation can control pain sensitization after an incision. Specifically, maintaining histone in a relatively deacetylated state reduced hypersensitivity after incision. This is due, in part, to the epigenetic regulation of a specific gene known as CXCR2 and one of its chemokine ligands (KC). The authors also found that these epigenetic changes far outlasted the recovery of animals from their incisions, a property that might help explain why some patients suffer from chronic postoperative pain. Study authors suggest that looking into the roles of these epigenetic mechanisms may help scientists find new ways to treat or prevent acute and chronic postoperative pain in the future.

"Epigenetics is a relatively underappreciated area of science, but the discoveries yet to be made in this field will be many," said Dr. Clark. "While fascinating information has been found by studying specific genes, we need to bridge the gap in science and focus on groups or systems of many genes simultaneously, which could be give us clues to greater breakthroughs in pain control and other areas of medicine."

Tomado de: American Society of Anesthesiologists (ASA). "Epigenetics: A key to controlling acute and chronic pain." ScienceDaily, 25 Oct. 2013. Web. 22 Nov. 2013.

Sigmoidoscopy may not be enough for older patients

Colon cancer screening with sigmoidoscopy alone could miss up to 50% of colon polyps in older patients.

As people age, polyps seem to develop more and more proximally, Dr. Victor Tsirline said at the annual clinical congress of the American College of Surgeons. His review of more than 120,000 colonoscopies found that a flexible sigmoidoscopy alone could miss 44% of polyps in patients aged 60-69 years and 50% in those aged 70-79 years.

"We found that proximal colon polyps are more frequent with advanced age than previously considered," said Dr. Tsirline of Carolinas Medical Center, Charlotte, N.C. "So if this is true, what happens if we use sigmoidoscopy instead of colonoscopy? If we had, we would have missed 22,800 polyps, and 16,800 of those would have been adenomatous. In [patients 59 and younger] 32%-36% would be missed and in the older patients, 45%-50%."

Dr. Tsirline obtained his data from the Provation MD endoscopy transcription system. He obtained information on 120,365 colonoscopies that were performed from 2003 to 2011.

He cross-referenced this with CoPathPlus, a pathology reporting system. This allowed him to cross-reference polyp pathology (adenoma vs. hyperplasia) by computer algorithm. There was complete information available on 43,833 polyps.

Because of the large sample size, he set his level of statistical significance at P = less than 0.01.

The patients in the study were aged 20-90 years. Of the entire group of procedures, 53,492 colonoscopies (44%) identified polyps. Most studies (64%) found a single polyp; 25% found two, and 11% found three or more. A subset of the colonoscopies was only for average risk screening (44,806). Of these, 46% identified polyps.

Overall, 48% of polyps were adenomatous; 37% were hyperplastic. Pathology was not available for the remainder.

The polyps were fairly evenly distributed throughout the colon: rectum, 18%; sigmoid, 26%; descending, 14%; transverse, 16%; ascending, 15%; cecum, 11%.

However, when broken down by patient age, the distribution changed significantly. With every advancing decade of life, patients were:

• 22% less likely to have polyps in the rectum or sigmoid.

• 7% more likely to have polyps in the descending colon.

• 19% more likely to have polyps in the transverse colon.

• 30% more likely to have polyps in the ascending colon.

• 22% more likely to have polyps in the cecum.

All of these risks were statistically significant, and they held for both adenomatous and hyperplastic polyps.

The findings led Dr. Tsirline to conclude that flexible sigmoidoscopy should not be relied upon as an effective colon cancer screening method in patients older than 60 years. The U.S. Preventive Services Task Force states that sigmoidoscopy every 5 years combined with high-sensitivity fecal occult blood testing every 3 years is an adequate screening alternative.

"From this study, it’s pretty apparent that sigmoidoscopy should not be used for colon cancer screening in older patients," he said.

During a discussion, Dr. Tsirline fielded a question about screening the very elderly – patients in their 80s and 90s. The study group did include a small number of these patients, he said.

"I think the argument for not screening older individuals is based on the question of whether finding a colon cancer would change anything. Most people think the risks of screening and treatment would outweigh the benefits. Yes, you may find anything, but what are you going to do about it?"

Tomado de internalmedicinenews.com

New Tool Predicts Survival in Advanced Prostate Cancer

But a good prognostic tool has been lacking in this setting, particularly since a new chemotherapy called cabazitaxel as been approved by the U.S. Food and Drug Administration as another line of treatment.

Now researchers at the Duke Cancer Institute have developed a tool for doctors to forecast the potential survival of individual patients, enabling faster, more accurate information on whether to try additional rounds of treatment or seek clinical trials.

The findings are published online in the Journal of the National Cancer Institute.

"Our findings provide a prognostic tool that relies on information that is routinely collected in clinical practice and should be readily available," said Susan Halabi, Ph.D., professor of biostatistics and bioinformatics at Duke and lead author of the study. "For patients with metastatic prostate cancer who are appropriate candidates for second-line chemotherapy, this model can be helpful for guiding care. It could also be used during clinical trials to assign patients in risk groups based on measurable criteria."

In their study, Halabi and colleagues developed and validated the new prognostic tool using two different clinical trials of prostate cancer patients whose cancer returned after they had undergone a regimen of docetaxel, the standard first-round chemotherapy that is used after hormone treatments have been ineffective.

The researcher's approach provides an understanding of the complex interactions between the host, the tumor factors and clinical outcomes.

By plugging in 17 variables -- including pain intensity, measurable disease, race, age, body mass index and others -- the researchers determined that certain key factors were relevant to overall survival.

Of the 17 variables, nine were determined to be predictive of survival: how a patient's physical performance is rated on a scale of 0-2; the length of time since the first chemotherapy ended; how extensive the disease is; whether the disease has spread to the liver, lungs or other organs; how much pain the patient is experiencing; the duration of hormone use; and levels of hemoglobin, prostate specific antigen and alkaline phosphatase.

Two of those factors had not previously been used in prognostic models -- the duration of hormone therapy and the amount of time since the first-round docetaxel treatment.

"Several new treatments have been developed in recent years that prolong life for men with metastatic prostate cancer," Halabi said. "As a result, it's increasingly important to provide a clear prognostic picture that can help guide both doctors and patients to the best options."

This tool is available online at  https://www.cancer.duke.edu/Nomogram/secondlinechemotheray.html

Duke Medicine. "New tool predicts survival in advanced prostate cancer." ScienceDaily, 18 Oct. 2013. Web. 15 Nov. 2013.

Sleep keeps brain fit by clearing waste

Disease-causing waste that builds up during the day is cleaned out from our brain as we sleep at night, say researchers.

Their findings, published today in the journal Science, could help explain why people spend a third of their lives asleep, and may help in developing treatments for Alzheimer's disease and other neurological disorders.

"This study shows that the brain has different functional states when asleep and when awake," says study leader Dr Maiken Nedergaard from the University of Rochester Medical Center in New York.

"In fact, the restorative nature of sleep appears to be the result of the active clearance of the by-products of neural activity that accumulate during wakefulness."

In lab experiments on mice - whose brains are remarkably similar to humans - Nedergaard and colleagues observed how cellular waste was flushed out via the brain's blood vessels into the body's circulatory system and eventually the liver.

These waste products included amyloid beta, a protein that, when accumulated, is a driver of Alzheimer's disease.

Plumbing system

The researchers say waste is removed from brain tissue by cerebral spinal fluid (CSF) flushed through a 'plumbing system' called the glymphatic system, which appears to be nearly 10 times more active during sleep than while awake.

In their study Nedergaard and colleagues first injected dye into the CSF of mice and watched it flow through their brains, while simultaneously monitoring electrical brain activity. They found the dye flowed rapidly when the mice were unconscious, either asleep or anesthetised, but when the same mice were awake it barely flowed at all.

"We were surprised by how little flow there was into the brain when the mice were awake," says Nedergaard. "It suggested that the space between brain cells changed greatly between conscious and unconscious states."

To test this idea, the researchers used electrodes inserted into the brain to directly measure the space between brain cells.

They found that during sleep, the brain's cells shrink by about 60 per cent, opening up the brain's interstitial space and allowing the fluid to move faster and more freely through it.

Energy use

Nedergaard and colleagues say the amount of energy consumed by the brain does not decrease dramatically while we sleep.

Because pumping CSF demands a great deal of energy, they speculate that the process of cleaning may not be compatible with the functions the brain must perform when we are awake and actively processing information.

"The brain only has limited energy at its disposal," says Nedergaard. "You can think of it like having a house party. You can either entertain the guests or clean up the house, but you can't really do both at the same time."

During the study the researchers also injected labelled amyloid beta proteins into the brains of the mice and found that during sleep CSF cleared away this dirt outside of the cells twice as quickly.

"These findings have significant implications for treating 'dirty brain' disease like Alzheimer's," says Nedergaard. "Understanding precisely how and when the brain activates the glymphatic system and clears waste is a critical first step in efforts to potentially modulate this system and make it work more efficiently."

Tomado de ABC science at abc.net.au

Gold-plated nano-bits find, destroy cancer cells

Comparable to nano-scale Navy Seals, Cornell scientists have merged tiny gold and iron oxide particles to work as a team, then added antibody guides to steer the team through the bloodstream toward colorectal cancer cells. And in a nanosecond, the alloyed allies then kill the bad guys – cancer cells – with absorbed infrared heat.

This scenario is not science fiction – welcome to a medical reality.

“It’s a simple concept. It’s colloidal chemistry. By themselves, gold and iron-oxide alloys are benign and inert, and the infrared light is low-power heating,” said Carl Batt, Cornell’s Liberty Hyde Bailey Professor of Food Science and the senior author on the paper. “But put these inert alloys together, attach an antibody to guide it to the right target, zap it with infrared light and the cancer cells die. The cells only need to be heated up a few degrees to die.”

Batt and his colleagues – Dickson K. Kirui, Ph.D. ’11, a postdoctoral fellow at Houston Methodist Research Institute and the paper’s first author; Ildar Khalidov, radiology, Weill Cornell Medical College; and Yi Wang, biomedical engineering, Cornell – published their study in Nanomedicine (print edition, July 2013).

For cancer therapy, current hyperthermic techniques – applying heat to the whole body – heat up cancer cells and healthy tissue, alike. Thus, healthy tissue tends to get damaged. This study shows that by using gold nanoparticles, which amplify the low energy heat source efficiently, cancer cells can be targeted better and heat damage to healthy tissues can be mitigated. By adding the magnetic iron oxide particles to the gold, doctors watching MRI and CT scanners can follow along the trail of this nano-sized crew to its target.

When a near-infrared laser is used, the light penetrates deep into the tissue, heating the nanoparticle to about 120 degrees Fahrenheit – an ample temperature to kill many targeted cancer cells. This results in a threefold increase in killing cancer cells and a substantial tumor reduction within 30 days, according to Kirui. “It’s not a complete reduction in the tumor, but doctors can employ other aggressive strategies with success. It also reduces the dosage of highly toxic chemicals and radiation – leading to a better quality of life,” he explained.

Tomado de: news.cornell.edu

Prueba automatizada para detectar la tuberculosis en pacientes pediátricos

Un equipo de investigadores sudafricanos comparó la efectividad de una nueva prueba automatizada, que detecta simultáneamente la tuberculosis (TB) y la resistencia a la rifampicina y la compararon con la microscopía clásica y los métodos de cultivo en pacientes pediátricos.

La Organización Mundial de la Salud (OMS), calculó que, solamente en 2011, aparecieron más de 500.000 casos nuevos de TB, con casi 64.000 muertes entre los menores de 15 años de edad.

Los autores de este estudio recopilaron casi 1.500 muestras pareadas de esputo y nasofaríngeas de 354 niños que se presentaron en una clínica de atención primaria con síntomas de tuberculosis. Las muestras fueron analizadas con la prueba Cepheid (Sunnyvale, CA, EUA) Xpert MTB/RIF, y se comparó la exactitud diagnóstica de los resultados con los patrones de referencia del cultivo y la baciloscopia.

La prueba Xpert MTB/RIF detecta la tuberculosis y la resistencia a la rifampicina, con alta sensibilidad, incluso en muestras negativas por frotis o muestras positivas por cultivo. La prueba produce resultados en dos horas y no requiere instrumentos diferentes al Sistema GeneXpert.

El sistema GeneXpert de Cepheid es una plataforma cerrada, autónoma, totalmente integrada y automatizada que combina la preparación de muestras a bordo con la amplificación de la PCR (reacción en cadena de la polimerasa), en tiempo real, y las funciones de detección para el análisis de ácidos nucleicos totalmente integrado y automatizado. El sistema está diseñado para purificar, concentrar, detectar, e identificar secuencias de ácidos nucleicos específicos, suministrando de este modo respuestas directamente a partir de muestras sin procesar.

Los resultados revelaron que cinco niños (1%) dieron resultados positivos para tuberculosis en la baciloscopia, 26 (7%) dieron un resultado positivo por Xpert MTB/RIF, y 30 (8%) dieron positivo mediante el cultivo. Entre los niños que en realidad no tienen la enfermedad, los resultados de la prueba Xpert, informaron un resultado negativo para TB con un 99% de exactitud. Estos hallazgos sugieren que la prueba Xpert MTB/RIF, en las secreciones respiratorias, es una prueba útil para el diagnóstico rápido de la tuberculosis pulmonar pediátrica en atención primaria.

El Dr. Fred Tenover, director jefe de asuntos científicos de Cepheid, dijo: “Si se va a inocular una prueba Xpert MTB/RIF, al mismo tiempo que usted comienza la preparación de sus frotis acidorresistentes, en el momento en que termina de leer las láminas, el resultado de la prueba Xpert MTB/RIF estaría listo, diciéndole si su coloración ácido-alcohol resistente positiva era tuberculosis y si la cepa era resistente a la rifampicina, que es un excelente marcador sustituto de la TM-MDR (TB resistente a múltiples fármacos). Estoy seguro de que Koch y Pasteur no sólo estarían muy complacidos con el avance tecnológico; probablemente dirían: ‘Ya es hora’”.

“Ha habido una percepción, entre los trabajadores de la salud, de que el diagnóstico rápido de la tuberculosis en los niños no era posible en la atención primaria, pero este estudio refuta esa opinión, dijo la primera autora, Dra. Heather Zar, profesora de pediatría en la Universidad de Ciudad del Cabo (Sudáfrica). “Teniendo en cuenta nuestros resultados, la adopción generalizada de las pruebas rápidas para la tuberculosis y la resistencia a los medicamentos en los niños puede mejorar sustancialmente la salud pública, sin aumentar considerablemente los costos”.

Los resultados del estudio sudafricano fueron publicados en la edición de agosto de 2013, de la revista Lancet Global Health.

Tomado de Labmedica.es

High dependency predicts BMI increase during smoking cessation

Smokers who are heavily addicted to nicotine are significantly more likely to gain weight when they try to quit, researchers report.

Investigators studying 186 patients who successfully quit smoking after receiving nicotine replacement therapy at an outpatient clinic found that mean body mass index increased significantly from 23.5 kg/m² at an initial consultation to 23.9 kg/m² at 3 months after the start of therapy. A high Fagerstrom Test for Nicotine Dependence (FTND) score, indicating severe dependency, was found on multivariate analysis to be the strongest predictor of increase (using a gender-adjusted standardized coefficient).

Dr. Maki Komiyama of Kyoto (Japan) Medical Center and colleagues reported their findings online Aug. 21 in the open access journal PLoS One (PLoS One 2013 Aug. 21[doi:10.1371/journal.pone.0072010]).

The findings are important because, while smoking cessation is known to reduce cardiovascular and cancer risk and to reduce all-cause mortality, associated weight gain is linked with greater risk of glucose intolerance and a reduction in the beneficial effects that quitting has on pulmonary function. Concerns about weight gain also can lead to a failure to quit smoking, they said.

"Even if one is expected to experience post-cessation weight gain, quitting smoking still leads to a reduced cardiovascular risk. However, there is also a possibility that if one can prevent post-cessation weight gain, then this will further reduce the cardiovascular risk due to having ceased smoking," they wrote

Thus, they continued, the ability to predict which patients are likely to gain weight during smoking cessation therapy – and performing weight control accordingly at the outset – could lead to improved outcomes, and the findings of this study may be useful for discriminating such patient groups.

Study participants were 132 men and 54 women with a mean age of 59.6 years who visited the smoking cessation clinic at the National Hospital Organization Kyoto Medical Center between July 2007 and November 2011 and successfully quit smoking.

Other factors found on univariate analysis to be significantly associated with BMI increase included triglyceride level, high-density lipoprotein cholesterol, and daily cigarette consumption. "To further investigate ... we performed multivariate analysis. The results demonstrated that the triglyceride level and FTND score were factors determining the post-cessation BMI increase, and that the FTND score was the strongest one," the investigators wrote.

An FTND score of 8 or more (on a scale of 1-10) was associated with larger postcessation BMI increase, and the increase was statistically significant when compared with the level of BMI increase in those with a score of 7 or less, they noted.

"The result that a high FTND score was the most important determinant of a BMI increase supports the hypothesis that post-cessation weight gain is one of the nicotine withdrawal symptoms," they said.

As for the association between triglyceride elevation and weight gain, the mechanism is not clearly understood and requires further study, they noted.

With the exception of two patients who did not receive medical treatment, study participants were treated with either oral varenicline (95 patients) or nicotine patch (89 patients). No difference was seen between the varenicline and nicotine patch groups with respect to BMI increase, but the varenicline group had higher nicotine dependency.

They also noted that, in their study, "although a significant increase in BMI was confirmed after smoking-cessation therapy, the BMI increase was only 0.4 kg/m² (1.1 kg), which is much smaller than reported in previous studies for people who quit smoking on their own initiative (2.8-3.8 kg)."

Additional study is needed to determine the appropriate timing for initiating interventions against post–smoking cessation weight gain, they noted.

This study was supported by a grant-in-aid for clinical research from the National Hospital Organization and the Pfizer Health Research Foundation. The authors reported that one study drug (varenicline) is manufactured by Pfizer but confirmed "that this does not alter their adherence to all the PLoS One policies on sharing data and materials."

Tomado de:familypracticenews.com

Yeast infection four times as likely with penicillin use

 Only certain classes of antibiotics increased the risk of yeast infections in a study of 650 women followed for 18 months to see what factors were associated with new-onset vulvovaginal candidiasis.

Penicillins increased the risk the most (adjusted hazard ratio, 4.1), followed by cephalosporins (aHR, 3.3) and metronidazole (aHR, 2.8), compared with women who did not report antibiotic use. Other classes of antibiotics were not associated with yeast infections.

"Many women and physicians believe that if you take an antibiotic, you’re just bound to get yeast. The message is that not all antibiotics are associated with yeast vaginitis; it’s certain classes of antibiotics that carry the highest risk," said senior investigator Sharon L. Hillier, Ph.D., a professor of obstetrics and gynecology and reproductive sciences at the University of Pittsburgh.

"When women are given antibiotics, I think it’s useful to help them understand they have some likelihood of getting a yeast infection with these three, and less so with quinolones or tetracyclines or something else," she said at the annual scientific meeting of the Infectious Diseases Society for Obstetrics and Gynecology.

The 650 subjects – 18-40 years old, not pregnant, and with no signs or symptoms of yeast at baseline – were followed at 2-month intervals during the investigation, and had a total of 4,934 follow-up office visits. Each time, they were asked what antibiotics they had been on, if any, among other questions.

There were 82 clinical yeast vaginitis diagnoses and 58 self-diagnosed infections with documented antifungal use. The results were largely similar when the team limited analysis to just clinically diagnosed cases.

A total of 312 women used an antibiotic at least once. Macrolides, metronidazole, and penicillins were used most often among the nine classes of reported antibiotics. The most common indications were upper respiratory tract infections, bacterial vaginosis, urinary tract infections, and sexually transmitted infections.

Having two or more male sexual partners was also a strong predictor of yeast vaginitis (aHR, 5.0), "and that was something that was a little bit surprising because it’s not a sexually transmitted infection. It’s useful maybe to tell women that limiting their numbers of sex partners will also decrease their risk," Dr. Hillier said.

Using depot medroxyprogesterone acetate (Depo-Provera), meanwhile, had a protective effect (aHR, 0.3), compared with women not using hormonal contraceptives. "Depo-Provera has a very strong progestin; some women who get the shot actually have estrogen depletion in the vaginal epithelium. The finding suggests that when you remove the estrogen from the [vaginal] epithelium, it can reduce your risk for yeast vaginitis," Dr. Hillier said.

Other forms of hormonal contraception were not associated with yeast vaginitis. Although "many women believe oral contraceptives and other hormonal methods increase the risk, there was no evidence of increased risk in this study," she said.

Tomado de: familypracticenews.com

Lifestyle Influences Metabolism Via DNA Methylation

An unhealthy lifestyle leaves traces in the DNA. These may have specific effects on metabolism, causing organ damage or disease. Scientists of Helmholtz Zentrum München have now identified 28 DNA alterations associated with metabolic traits. This world-first epigenome-wide association study (EWAS) of modified genes and metabolites has been now published in the journal Human Molecular Genetics.

In the course of life, aging processes, environmental influences and lifestyle factors such as smoking or diet induce biochemical alterations to the DNA. Frequently, these lead to DNA methylation, a process in which methyl groups are added to particular DNA segments, without changing the DNA sequence. Such processes can influence gene function and are known as epigenetics. Scientists of the Institute of Genetic Epidemiology (IGE) and the Research Unit Molecular Epidemiology (AME) at Helmholtz Zentrum München are seeking to determine what association exists between these epigenetic processes and the health consequences, in particular for the metabolism.

To this end, the team led by Christian Gieger (IGE) and Melanie Waldenberger (AME), in in collaboration with Karsten Suhre of Weill Cornell Medical College in Qatar analyzed blood samples from more than 1800 participants of the KORA study *. In doing so, they analyzed more than 457,000 loci in the DNA as to biochemical alterations and compared them with the concentrations of 649 different metabolites. The analysis showed that the methylation of 28 DNA segments changed a number of important metabolic processes.

In the relevant DNA regions there were also already known disease-related genes: for example, the TXNIP gene that regulates glucose metabolism and is associated with the development of diabetes mellitus. Appropriately, with the methylated TXNIP there were altered concentrations of metabolites from the lipid and glucose metabolism. Also genes that are known to be biochemically altered due to smoking affect different metabolic activities, and specifically those with corresponding biological functions.

"This study gives us new insights into how lifestyle factors can influence metabolism via the resulting alterations in the DNA," said Gieger, research group leader at the IGE. "We can now use these results to develop new diagnostic and therapeutic approaches for lifestyle-related diseases such as diabetes."

Tomado de: Helmholtz Zentrum Muenchen - German Research Centre for Environmental Health. "Lifestyle Influences Metabolism via DNA Methylation." ScienceDaily, 20 Sep. 2013. Web. 23 Sep. 2013.

Long-term Efficacy Data on CRC Screening Methods

Screening can reduce colorectal cancer mortality, as well as the incidence of the disease, but it is has been unclear which screening method is the best.

Two long-term studies confirm the effectiveness of major screening technologies, but leave the question of superiority up in the air. Both appear in the September 19 issue of the New England of Medicine.

In one study with a 22-year follow-up period, colonoscopy was shown to have advantages over sigmoidoscopy for the prevention of colorectal cancer. In addition, screening colonoscopy reduced the risk for any colorectal-cancer-associated death, whereas sigmoidoscopy lowered the risk of dying only from left-side tumors.

"Our data support the use of colonoscopy as a the preferred screening option for patients if the primary consideration is maximal reduction in risk of colorectal cancer," said study coauthor Andrew Chan, MD, MPH, associate professor of medicine, gastroenterology, at the Massachusetts General Hospital in Boston.

In the second study, which has a 30-year follow-up period, annual and biennial screening with fecal occult blood testing reduced the risk for death from colorectal cancer. The risk for death from colorectal cancer was 32% lower with annual screening, compared with no screening, and 22% lower with biennial screening.

The Best Method?

But how does colonoscopy compare to fecal occult blood screening?

Both of these tests are effective for colorectal cancer screening, and both these studies support current screening guidelines, according to an accompanying editorial by Theodore R. Levin, MD, and Douglas A. Corley, MD, PhD, from Kaiser Permanente Medical Centers in California.

In addition, the screening tests have improved since the trial participants first used them.

The editorialists emphasize that these studies are quite different from one another, which makes it difficult to make direct comparisons of effectiveness.

"It would be tempting to use these 2 studies to draw conclusions about which test is more effective," they write.

The reduction in mortality was better with colonoscopy than with annual fecal occult blood testing (68% vs 32%). However, it is a mistake to directly compare these results, the editorialists point out. "The 2 study populations are not comparable: one was a randomized trial, the other an observational study of volunteers, and both tests have undergone improvements since the studies were performed."

To date, no completed studies directly compare fecal occult blood testing with colonoscopy, although randomized trials are ongoing.

Although the performance of colonoscopy has probably improved because of the greater recognition of nonpolypoid colorectal neoplasia, and it "appears to have a performance edge over the old guaiac fecal occult blood test, fecal occult blood testing has largely been replaced by the more effective fecal immunochemical test (FIT)," they note. This newer test has better sensitivity than the guaiac fecal occult blood testing used in that study.

Of importance, recent data show that individuals were more likely to "complete screening if they were offered guaiac fecal occult blood tests, a choice between colonoscopy and guaiac fecal occult blood tests, or FIT alone, as compared with being offered colonoscopy alone," they write.

In the Kaiser Permanente Northern California health system, where both editorialists practice, a combined approach is used, and substantial improvement in rates of colorectal cancer screening has been achieved.

Colonoscopy vs Sigmoidoscopy

In the first study, Dr. Chan and colleagues evaluated the association between the use of lower endoscopy (updated biennially from 1988 to 2008) and colorectal cancer incidence (to June 2010) and mortality (to June 2012). The cohort involved 88,902 individuals who participated in the Nurses' Health Study and the Health Professionals Follow-up Study.

Over a follow-up period of 22 years, there were 1815 documented cases of colorectal cancers and 474 colorectal-cancer-specific deaths.

When endoscopy screening was compared with no screening, multivariate hazard ratios (HRs) for colorectal cancer were 0.57 after polypectomy, 0.60 after negative sigmoidoscopy, and 0.44 after negative colonoscopy.

A negative colonoscopy was associated with a reduced incidence of proximal colon cancer (multivariate HR, 0.73), and the rate of mortality from proximal colon cancer was lower after screening colonoscopy (multivariate HR, 0.47), but not after sigmoidoscopy.

The multivariate HRs for colorectal cancer mortality were 0.59 after screening sigmoidoscopy and 0.32 after screening colonoscopy.

Even though colonoscopy appears to have some advantages over sigmoidoscopy, there are reasons patients might opt for the latter. "A screening sigmoidoscopy generally does not require a full bowel preparation or the administration of sedation, so patients undergoing the procedure can generally expect to miss less work," Dr. Chan told Medscape Medical News.

"In addition, although serious complications from both colonoscopy and sigmoidoscopy are quite rare — generally about 1 to 3 per 1000 patients — they do occur at a higher rate with colonoscopy than with sigmoidoscopy," he noted.

Dr. Chan and colleagues point out that although randomized controlled trials have shown that screening with flexible sigmoidoscopy reduces the incidence of colorectal cancer and associated mortality, comparable data for screening colonoscopy are not yet available.

"I think that, based on the data assembled so far and the widespread availability of colonoscopy, we should continue our current practice of recommending colonoscopy as one of a few screening options, with a full discussion of the risks, benefits, and areas of uncertainty associated with each test," said Dr. Chan.

Reduces Long-term Risk

In the second study, Aasma Shaukat, MD, MPH, from the University of Minnesota in Minneapolis, and colleagues provide an update to the Minnesota Colon Cancer Control Study, which assessed the long-term effect of fecal occult blood test screening on all-cause and colorectal cancer mortality.

The initial cohort involved 46,551 participants 50 to 80 years of age who were randomized to usual care or to annual or biennial screening with fecal occult blood testing. Screening tests were performed from 1976 to 1982 and from 1986 to 1992.

The researchers used the National Death Index to obtain updated information about the participants and to determine cause of death.

A total of 33,020 participants (70.9%) died from any cause during the 30-year follow-up period; 732 of the deaths were attributable to colorectal cancer.

Table. Deaths From Colorectal Cancer in the Study Groups

Deaths	Annual Screening (n = 11,072)	Biennial Screening (n = 11,004)	Usual Care (n = 10,944)
n (%)	200 (1.8%)	237 (2.2%)	295 (2.7%)

Annual screening lowered colorectal cancer mortality (relative risk [RR], 0.68), as did biennial screening (RR, 0.78). There was no reduction in all-cause mortality with annual screening (RR, 1.00) or with biennial screening (RR, 0.99).

Men 60 to 69 years of age got the most benefit from screening. RR for death from colorectal cancer was 0.46 with annual screening, 0.42 with biennial screening, and 0.44 for either screening.

The overall reduction in colorectal cancer death associated with biennial screening was greater for men than women (P = .04 for interaction). This difference was not observed with annual screening (P = .30 for interaction) or with the 2 screening methods combined (P = .06 for interaction).

"The reductions in colorectal cancer mortality in the Minnesota Colon Cancer Control Study are comparable to those reported in randomized clinical trials of screening with flexible sigmoidoscopy, suggesting that fecal occult blood testing remains an effective and acceptable method of screening," the authors write. "Stool-based tests for colorectal cancer screening are an active area of current research, with development and testing of new stool-based tests."

Tomado de: medscape.com
Referencia: N Engl J Med. 2013; 369:1095-1105, 1106-1114, 1164-1166