martes, 29 de noviembre de 2011

APRENDIZAJE BASADO EN PROBLEMAS

A 30-year-old man with a long history of intravenous drug abuse and chronic hepatitis B presents with jaundice. Physical examination reveals a malnourished man with ascites, dependent pitting edema, spider angiomata, female secondary sex characteristics, and bilateral gynecomastia. Rectal examination reveals yellow-brown stool and a negative stool gualac. External hemorrhoids are present. The patient has poor concentration, but no asterixis is present
He has the following biochemical profile:
Total protein 8.3 g,d/L (normal, 6.O-7.8 g/dL)
Serum albumin 2.5 g/dL (normal, 3.5.-5.5 g/dL)
Serum globulins 5.8 g/dL (normal, 2.3-3.5 g/dL)
Serum calcium 6.5 mg/dL (normal, 8.4-10.2 mg/dL)
Serum total bilirubin 6.0 mg/dL (normal, 0.1-1.0 mg/dL)
Urinalysis: positive for bilirubin
Serum AST 200 U/L (normal, 8-20 U/L)
Serum ALT 350 U/L (normal, 8-20 U/L)
Serum AP 180 U/L (normal, 20-70 U/L)
Serum GGT 100 U/L (normal, 6-37 U/L)
Serum LDH 300 U/L (normal, 45-90 U/L)
• CBC: macrocytic anemia, hypersegmented neutrophils, mild neutropenia, mild thrombocytopenla
• Coagulation: prothrombin time (PT) is prolonged and does not correct with intramuscular vitamin K.

1. What is the clinical significance of his abnormal liver function tests, hypoalbuminemia, and prolonged prothrombin time that does not correct with intramuscular vitamin K?
2. What is the clinical significance of hypocalcemia in this patient?
3. What is the most likely cause of the macrocytic anemia?

viernes, 25 de noviembre de 2011

Chew Gum, Lose Weight? Hormone That Helps People Feel 'Full' After Eating Can Be Delivered Into Bloodstream Orally

Most people understand that serious weight loss requires changing attitudes toward what they eat and how often they exercise. But, what if the process could be aided by simply chewing a stick of gum after meals? That's the question a team of scientists, led by Syracuse University chemist Robert Doyle, is trying to answer. In a groundbreaking new study, Doyle's team demonstrated, for the first time, that a critical hormone that helps people feel "full" after eating can be delivered into the bloodstream orally.

Doyle's study was published online Nov. 4, 2011 in the American Chemical Society's Journal of Medicinal Chemistry and is forthcoming in print. Doyle is an associate professor in the Department of Chemistry in SU's College of Arts and Sciences. He collaborated on the study with researchers from Murdoch University in Australia.

The hormone, called human PYY, is part of a chemical system that regulates appetite and energy. When people eat or exercise, PYY is released into the bloodstream. The amount of PYY that is released increases with the number of calories that are consumed. Past studies have shown that people who are obese have lower concentrations of PYY in their bloodstream both when fasting and after eating than their non-obese counterparts. Additionally, intravenous infusion of PYY into a volunteer group of obese and non-obese individuals increased the serum levels of the hormone and lowered the number of calories both groups consumed.

"PYY is an appetite-suppressing hormone," Doyle says. "But, when taken orally, the hormone is destroyed in the stomach and that which isn't destroyed has difficulty crossing into the bloodstream through the intestines."

What's needed is a way to disguise the PYY so that it can travel through the digestive system relatively unharmed. Several years ago, Doyle developed a way to use vitamin B12 as a vehicle for the oral delivery of the hormone insulin. B12 is able to pass through the digestive system with relative ease and carry with it insulin, or other substances, into the bloodstream. Similarly, his research team attached the PYY hormone to his patent-pending vitamin B12 system. "Phase one of this study was to show that we could deliver a clinically relevant amount of PYY into the bloodstream," Doyle says. "We did that, and we are very excited by the results."

The next step involves finding ways to insert the B12-PYY system into such things as chewing gum or an oral tablet to create a nutritional supplement to assist individuals in losing weight in much the same way as nicotine-laced gum is used to help people stop smoking. "If we are successful, PYY-laced gum would be a natural way to help people lose weight," he says. "They could eat a balanced meal, then chew a stick of gum. The PYY supplement would begin to kick in about three to four hours later, decreasing their appetite as they approach their next meal."

Syracuse University. "Chew gum, lose weight? Hormone that helps people feel 'full' after eating can be delivered into bloodstream orally."ScienceDaily, 21 Nov. 2011. Web. 25 Nov. 2011


Physical Activity Impacts Overall Quality of Sleep

ScienceDaily (Nov. 22, 2011) — People sleep significantly better and feel more alert during the day if they get at least 150 minutes of exercise a week, a new study concludes

A nationally representative sample of more than 2,600 men and women, ages 18-85, found that 150 minutes of moderate to vigorous activity a week, which is the national guideline, provided a 65 percent improvement in sleep quality. People also said they felt less sleepy during the day, compared to those with less physical activity.

The study, out in the December issue of the journal Mental Health and Physical Activity, lends more evidence to mounting research showing the importance of exercise to a number of health factors. Among adults in the United States, about 35 to 40 percent of the population has problems with falling asleep or with daytime sleepiness.

"We were using the physical activity guidelines set forth for cardiovascular health, but it appears that those guidelines might have a spillover effect to other areas of health," said Brad Cardinal, a professor of exercise science at Oregon State University and one of the study's authors.

"Increasingly, the scientific evidence is encouraging as regular physical activity may serve as a non-pharmaceutical alternative to improve sleep."

After controlling for age, BMI (Body Mass Index), health status, smoking status, and depression, the relative risk of often feeling overly sleepy during the day compared to never feeling overly sleepy during the day decreased by 65 percent for participants meeting physical activity guidelines.

Similar results were also found for having leg cramps while sleeping (68 percent less likely) and having difficulty concentrating when tired (45 percent decrease).

Paul Loprinzi, an assistant professor at Bellarmine University is lead author of the study, which was conducted while he was a doctoral student in Cardinal's lab at OSU. He said it is the first study to examine the relationship between accelerometer-measured physical activity and sleep while utilizing a nationally representative sample of adults of all ages.

'Our findings demonstrate a link between regular physical activity and perceptions of sleepiness during the day, which suggests that participation in physical activity on a regular basis may positively influence an individual's productivity at work, or in the case of a student, influence their ability to pay attention in class," he said.

Cardinal said past studies linking physical activity and sleep used only self-reports of exercise. The danger with this is that many people tend to overestimate the amount of activity they do, he said.

He added that the take-away for consumers is to remember that exercise has a number of health benefits, and that can include helping feel alert and awake.

"Physical activity may not just be good for the waistline and heart, but it also can help you sleep," Cardinal said. "There are trade-offs. It may be easier when you are tired to skip the workout and go to sleep, but it may be beneficial for your long-term health to make the hard decision and get your exercise."


Oregon State University. "Physical activity impacts overall quality of sleep." ScienceDaily, 22 Nov. 2011. Web. 25 Nov. 2011

jueves, 17 de noviembre de 2011

Childhood Adiposity and Cardiovascular Risk

Childhood obesity has reached epidemic proportions, and has moved beyond public health discourse and onto the public stage. No doubt, efforts to prevent and treat childhood obesity are critical. But in the face of highly visible social campaigns -from school lunch reform to the elimination of “food deserts,” it can be tough to tell where medical knowledge ends, and common sense begins.

Here’s what we do know: First, childhood obesity is a big problem-in the US, 16.9% of children and adolescents age 2 to 19 years of age are estimated to be obese. We also know that obese children are likely to go on to become obese adults. We know that risk factors for cardiovascular disease such as hypertension, dyslipidemia, and insulin resistance, are already present in obese children. And finally, we know that childhood obesity is associated with an increased risk of an adult cardiovascular event.

But what we didn’t know, at least not until today, is whether childhood obesity confers a lifetime of increased cardiovascular risk, or whether this risk can be attenuated if obese kids become normal-sized adults. No one is about to object to efforts to combat childhood obesity, but knowing whether childhood obesity predicts adult cardiovascular risk, independent of adult BMI, is critical to shaping our efforts moving forward. Now some clarity may be coming our way.

In today’s issue of the NEJM, Juonala et al. publish their results from 6328 subjects, who averaged 11.4 years of age at baseline, and were prospectively followed for a mean 23 years. The good news? Obese children, who become nonobese by adulthood, have the same cardiovascular risk profile as adults who were never obese.

The study authors looked at four cohorts of children from the US, Australia, and Finland. The primary outcomes assessed were the presence of diabetes, hypertension, dyslipidemia, and high-risk carotid intima-media thickness. There were 274 obese children who went on to become nonobese adults.

As would be predicted from previous studies, childhood overweight or obesity was associated with overall increased cardiovascular risk, with some variation in the individual parameters within each cohort. However, in the group of obese children who went on to become nonobese adults, the cardiovascular risk profile was similar to that in the group of nonobese children who went on to become nonobese adults.

The unfortunate corollary is that being a nonobese child does not protect you if you go on to become an obese adult. For example, obese adults, regardless of childhood adiposity status, have a risk of type 2 diabetes that is four times that of nonobese adults.

Before we all jump on the no-cookie-bandwagon, a few caveats. First, these data are observational, and give us no information about cause and effect, nor on how weight loss was achieved. The outcomes assessed are risk factors, rather than hard endpoints like cardiovascular events. The number of obese children who went on to become nonobese adults was quite small compared to those who either stayed obese, or equally concerning, became obese. Finally, most of the subjects enrolled were white, and it is not clear how well these findings would apply to children of other ethnic groups, many of whom are affected by this obesity epidemic.

All that said, given the magnitude of this epidemic and its potential consequences, these results are at least somewhat encouraging. Now, how to help more obese children become nonobese adults? Let’s move indeed.

Posted by Lisa Rosenbaum • November 16th, 2011

Tomado de: blogs.nejm.org


miércoles, 16 de noviembre de 2011

HEMOSTASIA PRIMARIA: FISIOLOGIA Y LABORATORIO

Clase presentada en la rotación de patología clínica Noviembre 2011 por
Dr. Tania Tonantzin Vargas y el Dr. Felipe Piña
Gracias por el material y felicidades

Serum s100 b levels after meningioma surgery

sábado, 12 de noviembre de 2011

Desarrollan un 'lifting celular' para retrasar la aparición de trastornos vinculados a la vejez

Se trata de eliminar aquellas células que alcanzan el estado de senescencia, una especie de 'limbo' en el que ni mueren ni continúan multiplicándose.

Investigadores de la Clínica Mayo en Rochester (Estados Unidos) han demostrado que al eliminar las células que se van acumulando con la edad se evitaría o retrasaría la aparición de trastornos y discapacidades vinculadas al envejecimiento, según los resultados de un estudio que publica la revista Nature.
Dicho estudio, realizado en ratones modificados genéticamente, ofrece las primeras pruebas de que hay células "ociosas" que pueden contribuir al envejecimiento, lo que ofrece un medio para ayudar a las personas a mantenerse sanas según se hacen mayores.
"Al destruir estas células y lo que , algún día se podrá romper la conexión entre los mecanismos del envejecimiento y la predisposición a enfermedades cardíacas, accidentes cerebrovasculares, cáncer y demencia", según asegura el director del Centro Robert y Arlene Kogod de Mayo para el Envejecimiento, James Kirkland.
Hace cinco décadas, los científicos descubrieron que las células atravesaban una cantidad limitada de divisiones antes de dejar de dividirse. Cuando llegan a ese punto, alcanzan un estado de limbo, conocido como senescencia celular, en el cual ni mueren ni continúan multiplicándose. Aunque el sistema inmune elimina regularmente estas células disfuncionales, con el tiempo se vuelve menos eficaz para realizar esta especie de 'aseo'.
Según explica el biólogo molecular Jan van Deursen, autor del estudio, con este hallazgo "la acumulación de estas células ocasiona trastornos y molestias". El doctor Van Deursen y su equipo diseñaron genéticamente un grupo de ratones para que sus células senescentes alojaran una molécula llamada 'caspasa 8' que sólo se activa ante la presencia de un fármaco que no ejerce ningún efecto sobre las células normales.
Cuando se exponía a los ratones transgénicos a este fármaco, la 'caspasa 8' se activaba en las células senescentes, perforando la membrana celular para eliminarlas.
Los científicos observaron que la eliminación permanente de células senescentes retrasó la aparición de trastornos vinculados a la vejez, como cataratas y pérdida o debilidad muscular.
Nature (2011); doi:10.1038/nature10600
JANO.es · 09 Noviembre 2011

jueves, 10 de noviembre de 2011

APREDIZAJE BASADO EN PROBLEMAS (CASO CLINICO)

A 39 year old female CLS complained to the laboratory director of a persistently sore and swelling leg. After a brief discussion he referred her to her HMO primary care ER. She was subsequently admitted to the hospital and found to have a DVT with further documentation of PE.
On oral contraceptives at the time of the event. The affected leg had a history of superficial phlebitis Previous history of a positive ANA and a false positive VDRL.
Parents living, siblings living, 2 children—all healthy; one parent with history of rheumatoid arthritis, no thrombosis.
Immediate environment: includes small farm and association with horses and other small livestock.
Normal CBC for past 10 years.
No neurological complaints
Normal pregnancies with uneventful deliveries and post-partum experiences.

Laboratory Results
CBC Normal
PT :12.8 seconds (11 – 13 seconds)
APTT: 32.9 seconds (25 – 33 seconds)
DRVVT:43 seconds (35 - 45 seconds)
Fibrinogen: 236 mg/dL (170 – 410 mg/dL)
Anti-Cardiolipin IgG IgM IgA: Negative
Staclot® LA Positive - 12 seconds (Negative < 8 seconds)

Considerations
Is 39 considered young for this event?
Does lifestyle play a role?
Role of oral contraception in hypercoagulation?
Is the false positive VDRL an important clue?
Should a laboratory workup for thrombosis be ordered?

viernes, 4 de noviembre de 2011

Evaluation of Renal Function Guidelines

Evaluation of Renal Function Guidelines
The CARI Guidelines – Caring for Australians with Renal Impairment
(July 2005)

miércoles, 2 de noviembre de 2011

BENEFICIOS DE LOS PROBIOTICOS

Se confirman los beneficios de los probióticos frente a las diarreas infantiles, el síndrome del intestino irritable y las infecciones respiratorias

Un grupo de expertos presenta en el simposio 'Microbiota & Probiotics: A life long relationship' los resultados de las últimas investigaciones sobre el papel que los probióticos desempeñan en la prevención de patologías intestinales.

En el marco del XI Congreso de la Federación Europea de Sociedades de Nutrición se ha llevado a cabo el simposio 'Microbiota & Probiotics: A life long relationship' (Microbiota & probióticos: una relación de larga vida), en el que un grupo de expertos internacionales han presentado los resultados de las últimas investigaciones científicas sobre el papel que los probióticos desempeñan en la prevención y tratamiento de dolencias como las enfermedades diarreicas, las infecciones de las vías respiratorias superiores, la gripe, los trastornos digestivos o las enfermedades funcionales crónicas (estreñimiento, síndrome del intestino irritable, dispepsia, hinchazón).
Durante su intervención, el doctor Francisco Guarner-Aguilar, del Servicio de Patología Digestiva del Hospital Vall d’Hebron, de Barcelona, habló de la composición y las funciones de la microbiota en el intestino humano, y analizó los resultados del proyecto europeo MetaHit, en el cual se ha secuenciado el genoma completo de los microorganismos presentes en la microbiota del intestino humano, identificándose grupos de bacterias presentes en el organismo que pueden responder de manera específica al consumo de alimentos y fármacos. “Las herramientas utilizadas en el proyecto MetaHit para el análisis de la microbiota intestinal se están aplicando actualmente en la investigación del papel que juegan los microorganismos en otras dos patologías: la obesidad y las enfermedades inflamatorias intestinales”.

El profesor Yvan Vandenplas, del Departamento de Pediatría del Hospital Universitario de Bruselas, abordó el tema de la diarrea aguda y otros trastornos funcionales gastrointestinales infantiles, y analizó los resultados de un metanálisis que tomó como base un total de 63 estudios que demostraron el papel beneficioso de los probióticos tanto en la reducción de la duración de las diarreas agudas en niños sanos como en la prevención de la diarrea asociada al consumo de antibióticos en menores. “También hay indicios de que estos microorganismos mejoran los dolores abdominales relacionados con la función gastrointestinal en niños. Sin embargo, sigue habiendo controversias respecto al papel que juegan los probióticos en la prevención de las alergias infantiles”. Así mismo, el doctor Vandenplas se refirió a los resultados positivos obtenidos con la combinación de probióticos.

Por su parte, el doctor Philipe Marteau, del Departamento de Patología Digestiva del Hospital Lariboisière, de París, centró su intervención en el papel de los probióticos en los trastornos funcionales intestinales y el síndrome del intestino irritable en adultos. El doctor Marteau se refirió a los resultados obtenidos en varios estudios randomizados doble ciego que demostraron que varios tipos de probióticos (concretamente Bifidobacteriun animalis DN 173 010, Bifidobacteriun infantis 35624, VSL#3 y Lactobacillus plantarum 299v) alivian los síntomas gastrointestinales y digestivos asociados al síndrome del intestino irritable.

La relación entre los probióticos y el aumento de las defensas frente a las infecciones de las vías respiratorias más frecuentes en los ancianos fue el tema abordado por el doctor Eric Guillemard, del Grupo de Beneficios Inmunitarios de Danone Research. “Los resultados de tres estudios multicéntricos doble ciego randomizados llevados a cabo con personas mayores de 70 años y centrados en los efectos que el consumo de leche fermentada que contenía el probiótico Lactobacillus casei CNCM I-1518/DN-114 001 tenían sobre la respuesta inmunitaria que seguía a la vacuna contra la gripe demostraron que los anticuerpos específicos de la gripe estaban más elevados en aquellos participantes que habían consumido este tipo de leche que en los del grupo de control. De ello se puede deducir que el consumo habitual de leche fermentada rica en este probiótico mejora la resistencia frente a las enfermedades infecciosas más frecuentes, especialmente las respiratorias, y potencia la respuesta inmune frente a la vacuna de la gripe entre la población anciana”.
Tomado de Jano.es Nov 2011