There is a theory that people who are in loving relationships may experience neuro-hormonal changes that have positive effects on the body, including the cardiovascular system," Damp said, explaining that there are certain hormone levels in the body that vary depending on the level of an individual's stress and anxiety.
BLOG DE TEMAS, ARTICULOS, CASOS CLINICOS Y NOTICIAS MEDICAS CON UN ENFOQUE AL LABORATORIO CLINICO
viernes, 30 de marzo de 2012
Love, Chocolate Good for the Heart, Says Cardiologist
There is a theory that people who are in loving relationships may experience neuro-hormonal changes that have positive effects on the body, including the cardiovascular system," Damp said, explaining that there are certain hormone levels in the body that vary depending on the level of an individual's stress and anxiety.
APRENDIZAJE BASADO EN PROBLEMAS
ABG: pH 7.31 pCO2 33 mmHg
HCO3 16 pO2 93 mmHg
miércoles, 28 de marzo de 2012
Sientan las bases para prevenir la enfermedad cardíaca mediante antiinflamatorios no esteroideos
Los resultados apoyan la hipótesis de la inflamación en enfermedades del corazón y fomentan la exploración de la modulación de las vías de IL6R como un medio para prevenir las enfermedades cardíacas.
Ahora, el primer artículo del metanálisis muestra de que una variación genética responsable de amortiguar la inflamación reduce el riesgo de sufrir enfermedades del corazón. En particular, los investigadores analizaron la información genética y los biomarcadores de más de 200.000 personas, de 82 estudios, para evaluar si una variante genética funcional (Asp358Ala) en el gen IL6R, conocida por controlar la señalización de IL6R, podría afectar a la susceptibilidad de padecer una enfermedad coronaria. Como resultado, el alelo 358Ala se asoció con un claro efecto anti-inflamatorio, que se muestra por las reducciones en los niveles de proteína C-reactiva y fibrinógeno en la sangre, así como una reducción de un 3,4% del riesgo de EC, por cada copia heredada de 358Ala.
Bloqueo del receptor IL6
jueves, 22 de marzo de 2012
Los nuevos fármacos para tratar la hepatitis C permitirán la curación de tres de cada cuatro pacientes
La próxima utilización de las nuevas moléculas de los inhibidores de la proteasa, junto con los fármacos que ya se utilizan, propiciará la curación de un 25% de pacientes respecto a las tasas actuales.
"Con la inminente llegada a los servicios sanitarios de la nueva familia de fármacos basados en los inhibidores de la proteasa, se espera que la cifra de curación de las personas afectadas con el virus de la hepatitis C suba a tres de cada cuatro pacientes”. Así lo ha anunciado el doctor Juan Arenas Ruiz-Tapiador, adjunto de Hepatología del Servicio de Aparato Digestivo del Hospital Donostia, que esta tarde a partir de las 19 horas impartirá la conferencia 'Hepatitis C: el reto de afrontar una nueva epidemia', en el Paraninfo de la Universidad del País Vasco.
El médico ha adelantado que “actualmente, con el tratamiento estándar basado en el uso del interferón y la ribavirina, se están curando entre el 50 y el 60% de todas las hepatitis C. La llegada de los inhibidores de la proteasa va a suponer un salto cualitativo, ya que se espera la curación del 75% de los casos". Estos inhibidores se dirigen especialmente al genotipo 1 del virus, “que es el más difícil de curar y el causante del 50 o 60% de los casos”.
"Alredeor del 2% de la población de nuestro entorno ha entrado en contacto con el virus de la hepatitis C, lo que da unas cifras aproximadas de unas 800.000 personas en España”, ha señalado este especialista.
Perfil de los afectados por la hepatitis C
De hecho, existen dos perfiles de afectados claramente diferenciados. Por un lado "están las personas, en su mayoría mayores, que han tenido contacto con el virus de la hepatitis C a través de transfusiones o hemodiálisis, con anterioridad a que se instauraran los actuales mecanismos de control. Por otro lado, tenemos a pacientes de mediana edad que, en su juventud, hace 20 o 30 años, tuvieron algún tipo de contacto con drogas de administración parenteral y quedaron infectados. Para ambos grupos puede ser muy positivo".
miércoles, 21 de marzo de 2012
viernes, 16 de marzo de 2012
Scientists Discover Effects of PD-1 Blockade On ART Therapy in SIV-Infected Monkeys
In earlier research, the scientists showed that PD-1 blockade could restore T and B cell function against SIV. Now they have new findings about the effects of PD-1 blockade along with antiretroviral therapy (ART).
Vijayakumar Velu, PhD, a scientist at Yerkes National Primate Research Center and the Emory Vaccine Center presented the information at the 19th Conference on Retroviruses and Opportunistic Infections in Seattle, Wash. Rama Rao Amara, PhD, associate professor of microbiology and immunology at Yerkes and the Emory Vaccine Center, led the project.
The researchers treated SIV-infected rhesus macaque monkeys with ART from 16 to 21 weeks post infection then interrupted the therapy. The SIV viral load rapidly increased, along with the frequency of SIV-specific CD8 T cells. Four weeks later, the researchers treated some of the macaques with anti-PD-1 antibody and monitored both the treated and control animals.
Half the animals treated with PD-1 blockade, but only those with measurable CD8 T cells at the time of ART interruption, had a rapid decline in plasma viral load. PD-1 blockade did not enhance the frequency of SIV-specific CD8 T cells, but rather enhanced their function.
"Our results show PD-1 blockade after ART interruption can significantly enhance viral control, but the effect seems to depend on maintaining measurable SIV-specific CD8 T cell response following therapy," says Velu.
Rafi Ahmed, director of the Emory Vaccine Center and a key member of this research team, first identified the PD-1 molecule as a target for therapy designed to reactivate exhausted immune cells in chronic diseases. Other members of the research team are Gordon J. Freeman of Harvard Medical School and Kehmia Titanji, Ravi Dyavar Shetty and Hyun Woo Lee from Yerkes and the Emory Vaccine Center. The team plans to continue studying the interactive effects of PD-1 blockade combined with ART.
Emory University. "Scientists discover effects of PD-1 blockade on ART therapy in SIV-infected monkeys." ScienceDaily, 8 Mar. 2012. Web. 16 Mar. 2012.
Common medicines may cut cancer drug potency: study
Many patients taking a widely prescribed class of oral cancer drugs are also using a variety of medications that could reduce the effectiveness of the cancer treatment or increase its toxic side effects, according to research by Medco Health Solutions Inc.
For example, 43 percent of patients taking the highly effective leukemia drug Gleevec were also on another medicine that could diminish its efficacy, while 68 percent were taking something that could potentially raise the toxicity level, the study found.
Not surprisingly, the study found that the vast majority of the cancer drugs were prescribed by an oncologist, while the other medicines were typically prescribed by a primary care physician.
"More communication needs to take place across all doctors that are prescribing for the patient," said Medco's Steve Bowlin, who is presenting the study findings on Friday at the American Society for Clinical Pharmacology and Therapeutics meeting in Washington.
The Medco drug interaction study looked at pharmacy claims of about 11,600 patients who had been prescribed any of nine oral drugs known as kinase inhibitors, used to treat a variety of cancers. They include Gleevec and Tasigna from Novartis; Pfizer Inc's Sutent; Nexavar from Onyx Pharmaceuticals Inc and Bayer AG; Tarceva, sold by Roche Holding and Japan's Astellas Pharma Inc; Sprycel from Bristol-Myers Squibb Co; and GlaxoSmithKline Plc's Tykerb.
The medications that could potentially cause such adverse "drug-drug interactions" (DDI) include commonly used heartburn drugs known as proton pump inhibitors (PPIs), such as Nexium and Prevacid; steroids; a class of blood pressure and heart medications known as calcium channel blockers; and some antibiotics and antifungal treatments.
At the high end of the range, 74 percent of patients who were taking Glaxo's kidney cancer drug Votrient were also taking a drug that could increase toxicity, researchers said.
Fifty-seven percent of Tarceva patients were also taking a drug that could weaken effectiveness, more than for any of the other cancer treatments.
Sutent had the lowest incidence of potentially troubling drug interactions, with 23 percent of patients taking a medicine that could decrease its effectiveness and 24 percent on a drug that could increase Sutent's toxicity.
"The fact that one-quarter to 75 percent of patients on these oral drugs may not be getting the full benefit of their treatment or may in fact be putting their health at further risk because of another medication they are taking is concerning," Dr. Milayna Subar of Medco's Oncology Therapeutic Resource Center said in a statement.
The PPI drugs for heartburn and acid reflux were the most likely to alter the effectiveness and toxicity of Gleevec, researchers said. For the lung cancer drug Tarceva, steroids and PPIs were most likely to decrease efficacy, while certain antibiotics were most likely to increase toxicity.
Even though the Tarceva label cautions against using the antibiotic ciprofloxacin when taking that cancer drug, the analysis found that the two were co-prescribed for a significant number of patients.
"There are other therapeutic alternatives that could be prescribed that would not have the same potential for interaction," said study co-author Eric Stanek, who called for increased surveillance of patient prescribing.
The analysis also found that the overlap for patients taking one of the oral cancer drugs and a medicine that could cause problems was rarely for just a day or two.
"In many instances, 30 or 40 percent of the time people were on a cancer drug they were also on a DDI drug," Bowlin said. "On average, it was substantial amount of time."
Medco, a pharmacy benefit manager that is in the process of being acquired by rival Express Scripts Inc, offers a Drug Utilization Review program under which its oncology pharmacists can alert doctors about potentially troubling medication interactions.
Tomado de Reuters.com: Reporting By Bill Berkrot; Editing by Gerald E. McCormick
viernes, 9 de marzo de 2012
Evalúan pruebas sin ayuno de detección para la disglicemia
Las pruebas de detección incluyeron una prueba de glucosa al azar, la fructosamina, la hemoglobina glicosilada (HbA1c), después de una prueba formal de tolerancia a la glucosa (POTG) realizada en una consulta previa.
Los científicos de la Universidad de Michigan (Ann Arbor, MI, EUA) realizaron un estudio transversal de 254 niños con sobrepeso u obesos de 10-17 años. Los individuos provenían de dos visitas a una unidad de investigación clínica. Llegaron en ayunas, a la primera visita y se realizó una prueba de tolerancia a la glucosa, de HbA1c y fructosamina. Para la segunda consulta, llegaron sin ayuno y les hicieron una glucosa plasmática al azar, una prueba de tolerancia de glucosa, una hora después de ingerir 50 gramos de glucosa (1-h GCT) y una prueba en orina con tira reactiva. El punto final primario fue disglucemia, o sea, una glucemia en ayunas de más de 99 mg/dL o una post-glucosa a las dos horas mayor de 139 mg/dL. Aproximadamente el 50% de los niños eran niñas, 59% eran blancos, y el 30% negros.
Los resultados del estudio mostraron que hubo 99 (39%) casos de prediabetes y 3 (1,2%) casos de diabetes. La tira reactiva de orina, la HbA1c y la fructosamina mostraron mala discriminación para identificar a los niños con disglucemia. Tanto la glucosa al azar como la 1-h GCT tenían mejores niveles de discriminación que la HbA1c o la fructosamina.
La glucosa, la fructosamina y la HbAlc fueron medidas utilizando el Analizador de Química, Cobas Mira Plus (Roche, Basilea, Suiza). La prueba de tira reactiva de orina se realizó usando las tiras Chemstrip 10, también fabricadas por Roche.
Los autores concluyeron que se encontraron pruebas de rendimiento razonables para la 1-h GCT y la prueba de glucosa al azar, después de haber evaluado, de forma sistemática, una serie de pruebas de detección, sin ayuno, utilizadas en la práctica clínica para la identificación de disglucemia en una población de adolescentes con sobrepeso y obesidad. Por el contrario, el desempeño de las pruebas de HbAlc, fructosamina y análisis de orina era malo. Sus resultados tienen una relevancia directa para las futuras recomendaciones para la detección y el diagnóstico de disglucemia entre los niños y adolescentes obesos y con sobrepeso. El estudio fue publicado en la edición de diciembre 2011, de la revista Diabetes Care.
lunes, 5 de marzo de 2012
Novedoso dispositivo de prueba detecta el dengue
La prueba se basa en la captura de anticuerpos específicos para el dengue usando antígeno del serotipo 2, del dengue inmovilizado (DENV) y la detección subsiguiente de la inmunoglobulina capturada usando anti IgA humana de cabra, conjugada al oro coloidal.
Científicos en el Instituto Politécnico Nacional (Ciudad de México, México), compararon el dispositivo de prueba inmunocromatográfica, conocida como la prueba Rápida ASSURE Dengue IgA, con otras pruebas comerciales. Se usaron un total de 225 sueros para la evaluación. 172 sueros fueron recogidos durante los años 2009 y 2010 de pacientes con dengue, en los laboratorios regionales de salud pública, como parte del programa de vigilancia nacional para el diagnóstico del dengue en México, y 47 sueros, fueron recolectados de donantes sanos de sangre.
La Prueba Rápida ASSURE Dengue IgA (MP Diagnostics; Solon, OH, EUA) es un análisis inmunocromatográfico indirecto, en fase sólida, en que los anticuerpos en la muestra (suero, plasma o sangre total) forman complejos antígeno-anticuerpo con el antígeno inmovilizado, de la membrana, a medida que la muestra migra hacia arriba desde el pocillo de muestra. Los complejos unidos antígeno-anticuerpo son detectados por la anti-humano IgA conjugada con oro coloidal La línea de control contiene proteína L que se une con IgA humana y el conjugado anti-IgA humana-oro coloidal, y sirve como una indicación de la adición adecuada de la muestra.
La prueba ASSURE detectó como positivas para IgA, 105/172 (61,0%) de los sueros de dengue analizados, mientras que la Dengue IgM Capture ELISA (PanBio, Sinnamon Park, Queensland, Australia; www.panbiodengue.com) detectó como positivos para IgM, 93/172 (54,1%) de los sueros. La especificidad y la sensibilidad global de la prueba, ASSURE, fueron 85,1% y 61,0%, respectivamente. La tasa de positividad para IgA del 33,3%, para los sueros recogidos el mismo día del inicio de la fiebre, subió a 81,2% para los sueros recogidos cinco días después del inicio de la fiebre. Las infecciones por el virus de serotipo 2 fueron detectados de una manera más eficiente de lo que fueron detectados aquellas con el serotipo 1 del virus, y no estaban disponibles sueros de las infecciones por los serotipos 3 y 4. El kit fue dos veces más eficiente para detectar las infecciones secundarias que para la detección de las infecciones primarias.
Los autores concluyeron que la prueba rápida basada en inmunocromatografía requiere pocas instalaciones para que se pueda realizar y es muy adecuada para ser aplicada en muestras individuales. La puesta en práctica, de las pruebas de inmunocromatografía, en el campo, o en los sitios de punto de atención, puede ser una valiosa alternativa, a las pruebas, para el diagnóstico temprano del dengue. El estudio fue publicado en la edición, de febrero 2012, de la revista Diagnostic Microbiology and Infectious Disease.
FDA Adds Diabetes Warning to Statin Label
The FDA said today that all statins must carry warnings about increased risks of elevated blood sugar and possible transient memory and cognition problems, but at the same time the agency removed a standing recommendation for routine liver function tests for patients taking the cholesterol-lowering drugs.
The FDA said the label changes apply to atorvastatin (Lipitor), fluvastatin (Lescol), lovastatin (Mevacor), lovastatin extended-release (Altoprev), pitavastatin (Livalo), pravastatin (Pravachol), rosuvastatin (Crestor), and simvastatin (Zocor).
Despite the additional warnings, the FDA said it "continues to believe that the cardiovascular benefits of statins outweigh these small increased risks."
Rather than regular monitoring of liver function, the agency said that clinicians should now simply order a liver function test before starting a patient on a statin. Although the drugs do carry a risk of liver damage, the agency has judged the risk to be "rare and unpredictable in individual patients."
The diabetes warning has been rumored as a possibility since the findings from the JUPITER trial of rosuvastatin revealed an unexpected 27% increase in new onset diabetes among patients randomized to the statin.
That finding was especially perplexing because JUPITER was a study of statins in patients who had no history of cardiovascular disease, the so-called healthy patient trial. Moreover, based on the JUPITER results, the FDA approved rosuvastatin for primary prevention.
The FDA said hyperglycemia was also observed among patients treated with 40-mg atorvastatin in a substudy of PROVE-IT TIMI 22, and a meta-analysis of data from 13 statin trials "reported that statin therapy was associated with a 9% increased risk for incident diabetes."
The cognitive data are a bit sketchier and rely mainly on post-marketing adverse event reporting. The FDA said those reports "generally described individuals over the age of 50 years who experienced notable, but ill-defined memory loss or impairment that was reversible upon discontinuation of statin therapy."
In addition to those broad label changes, the FDA added a number of restrictions to the lovastatin (Mevacor) label, including a list of 10 drugs or drug classes that are contraindicated with lovastatin.
Drugs contraindicated with lovastatin include:
- Itraconazole
- Ketoconazole
- Posaconazole
- Erythromycin
- Clarithromycin
- Telithromycin
- HIV protease inhibitors
- Boceprevir
- Telaprevir
- Nefazodone
Additionally, the new lovastatin label states that cyclosporine and gemfibrozil should be "avoided" when taking lovastatin, and lovastatin dosing should be limited to 20 mg for patients taking danazol, diltiazem, or verapamil. Finally, patients taking amiodarone should limit lovastatin to 40 mg daily.
In general, cardiologists contacted by ABC News/MedPage Today, applauded the FDA action -- particularly the decision to remove the requirement for liver function testing. Harlan Krumholz, MD, of Yale University, said, "Good news on liver testing -- provides no benefit and a lot of Americans are being monitored unnecessarily."
But Krumholz and others worried about patients being scared off statins by the diabetes and memory warnings.
"All drugs have side effects and rarely some patients will have an odd reaction to statins -- cognitive effects are among those, which are usually mild and resolve with stopping the medication. The blood sugar and diabetes issue has emerged over the last couple of years -- this appears to be a side effect," Krumholz wrote in an email.
Scott Grundy, MD, of the University of Texas Southwestern Medical Center in Dallas, was dubious about the level of evidence linking diabetes and cognition problems with statins. "I do not believe there is enough hard evidence to justify information and warnings about memory loss and confusion or increase in blood sugar."
And Grundy, too, worried about the impact on patients, writing, "I also think that these warnings will cause some people who need statins to stop taking them. That would be unfortunate."
The Cleveland Clinic's Steven Nissen, MD, often a critic of the FDA, told ABC News/MedPage Today, "these are reasonable and prudent recommendations. I am pleased that FDA did not overstate the diabetes and cognitive function risks. Both problems are uncommon and don't diminish the importance of statins in cardiovascular protection. For the vast majority of patients, the benefits far outweigh the risks."
Moreover, Nissen said, the FDA's decision on liver monitoring could boost statin use because it "will help to allay public apprehension about the liver safety of statins."
This article was developed in collaboration with ABC News.