Hiperinsulinemia y resistencia insulínica en niños de dos escuelas públicas de Oaxaca, México / Hyperinsulinemia and insulin resistance in children

Background: Obesity during childhood is a risk factor for developing cardiovascular diseases during adulthood. Aim: To measure insulin and glucose levels and parameters of insulin resistance in obese, overweight and normal weight Mexican children. Material and Methods: Comparative study of 21 obese children with a body mass index (BMI) over percentile 95, aged 10 ± 1 years (10 males), 14 children aged 10 ± 2 (7 males) with a BMI between percentiles 85 and 94 and 16 children aged 9 ± 2 years (3 males) with a body mass index between percentiles 10 and 84. Body weight, blood pressure and waist circumference were measured and a blood sample was obtained to measure fasting glucose and insulin levels. Homeostasis model of insulin resistance (HOMA) and quantitative insulin sensitivity check index (QUICKI) were calculated. Results: Among obese, overweight and normal weight children, insulin levels were 14.9 (95% CI 10.90-18.99), 7.20 (CI 5.12-9.28) and 4.73 (CI 95% 1.92-7.53) uU/ml, respectively. The figures for HOMA were 3.16 (95% CI 2.20-4.12), 1.49 (95% CI 1.03-1.94) and 0.97 (95% CI 0.35-1.60), respectively. The figures for QUICKI were 0.331 (95% CI 0.319-0.343), 0.371 (95% CI 0.349-0.393) and 0.419 (95% CI 0.391-0.446), respectively. Compared to their normal weight counterparts, the risk of obese children and those with a waist circumference over percentile 90 of having a HOMA over 3.16 was 17 and 10 times higher, respectively. BMI correlated better than waist circumference with insulin levels. Conclusions: Obese children have higher levels of insulin resistance than their normal weight counterparts.

A study on inorganic elements in psammomas from ovarian & thyroid cancer.

Background & objectives: Concentric lamellar calcifications known as psammoma bodies (PB) are found in benign and malignant tumours. Whether or not the inorganic element concentrations in psammomas are similar to serous adenocarcinoma of the ovary and thyroid papillary cancer tissues has not yet been ascertained. We undertook this retrospective study to establish if there is any difference in the concentrations of inorganic ions found in psammomas in serous adenocarcinoma of the ovary, and those found in thyroid papillary cancer tissue. Methods: PB samples from patients with adenocarcinoma of the ovary (n = 10) and with thyroid papillary cancer (n = 10) were analyzed through inductively-coupled plasma spectroscopy (ICP). Results: There were no significant differences in the concentrations of inorganic elements in PB from thyroid papillary cancer than in those PB from ovarian cancer. Interpretation & conclusions: Differences in the concentrations of inorganic elements may be due to the variation in environmental pollution. Our study had limitation of small sample size. Our results suggest that some inorganic elements can participate in the origin of psammoma bodies.

Alteraciones plaquetarias en la diabetes mellitus tipo 2 / Platelet abnormalities in type 2 diabetes mellitus

Diabetes mellitus is a problem of health worldwide being vascular complications the main causes of morbidity and mortality in this population. Diabetics have a fast atherothrombotic evolution which is worse than that observed for other clinical entities; however, hyperglycemia itself may not totally explain the ischemic complications observed in these patients. Most ischemic arterial events are precipitated by plaque rupture, platelet activation, and thrombosis. Several abnormalities in the blood coagulation system have been described associated to diabetes mellitus, all of them predisposing to thrombosis: endothelial cell dysfunction, platelet hyperreactivity, thrombin generation and hypofibrinolysis. Platelets play a key role in diabetic atherothrombosis due to platelet hypersensitivity to physiological agonists, low response to therapeutical antiplatelet agents, platelet hyperreactivity in sites of endothelial cell damage, hyperaggregability, resistance to the inhibitory effects of the insulin, and low endothelial production of prostacyclin and nitric oxide. All these phenomena have been associated to either a toxic microenvironment due to hyperglycemia or to intrinsic platelet abnormalities. Based on all these facts, it is proposed that platelets may be another target for the negative effects of insulin-resistance state. Because platelets are crucial in the atherosclerotic process and in the genesis of the vascular complications of diabetes mellitus, this review analyses the platelet abnormalities observed in this metabolic disease.

Role of concanavalin A lectin in recognition of pterygium remnant after surgical excision: preliminary results of a prospective study.

BACKGROUND: Pterygium is one of the most common conjunctival diseases among ophthalmic pathologies. The frequency of recurrences is high, either after surgical treatment or after treatment combined with mitomycin C or beta-radiation therapy. AIMS: The purpose of this study was to determine whether concanavalin A (ConA) lectin bound to the pterygial surface can be used to detect recurrence or remnants of pterygium after surgical excision. MATERIALS AND METHODS: This was a prospective study on 20 patients with pterygium, divided in five stages, pre-surgery, early post-surgery (24h), late post-surgery (seven days), very late post-surgery (four weeks) and two months after the procedure. A drop of fluorescein-marked Con A (35 microg/mL) was instilled in the lower conjunctival eyelid sac and the eye was exposed to the light of a Wood's lamp for an average of five seconds. RESULTS: Out of the 20 patients, eight patients were found to have fluorescent stretch marks over the scar corresponding to residual pterygial tissue at four weeks; two months after the procedure of re-surgery we observed no fluorescent remnants. All residual pterygia were confirmed through histochemistry studies. CONCLUSION: It was possible to detect remnants of pterygium in postoperative patients and recurrences in early pre-clinical stages through the visualization of fluorescent ConA bound to the pterygial surface.

Prevalencia de esteatohepatitis no alcohólica en adultos con síndrome metabólico en Oaxaca / Prevalence of non-alcoholic esteatohepatitis in adults with metabolic syndrome in Oaxaca

La esteatohepatitis no alcohólica (EHNA) es una enfermedad crónica del hígado que ocurre en pacientes que no consumen o tienen ingesta mínima de alcohol, caracterizada por esteatosis macrovesicular, necrosis hepatocelular, infiltrado inflamatorio mixto, grados diversos de fibrosis y cuerpos hialinos de Mallory en algunos pacientes. Su prevalencia se desconoce; estudios recientes indican que en la población general es de 3%, si bien las tasas se incrementan en ciertas subpoblaciones, como en la obesidad y diabetes mellitus. El objetivo del trabajo fue determinar la prevalencia de la esteatohepatitis no alcohólica en una muestra de pacientes con síndrome metabólico del Hospital Regional "Presidente Juárez". Fue un estudio observacional, descriptivo y transversal en el cual, mediante muestreo aleatorio simple, seleccionamos una muestra de 110 pacientes con diabetes mellitus tipo 2, hipertensión arterial sistémica, obesidad y dislipidemia, solas o en combinación. Se llevó a cabo evaluación clínica y de laboratorio, seleccionando a los pacientes con hipertransaminasemia persistente, a quienes se les realizaron estudios para descartar otras causas de la anormalidad enzimática. Una vez excluidas, a cinco pacientes se les realizó una biopsia hepática diagnosticando esteatohepatitis no alcohólica. La prevalencia de EHNA fue de 4.54%. Sus características clínicas y de laboratorio se presentan en el cuerpo del artículo.

Nonalcoholic steatohepatitis (NASH) is a chronic liver disease that occurs in patients with no significant alcohol consumption, characterized for macrovesicular steatosis, hepatocellular necrosis, mixed inflammatory infiltrate and various grades of fibrosis and, in some cases, Mallory bodies. The prevalence of this disease is unknown; recent studies indicate that in the general population, incidence is about 3%, although the rates are higher in some subpopulations as are obesity and diabetes mellitus. The goal of this work was to determine the prevalence of nonalcoholic steatohepatitis in one sample of patients with the metabolic syndrome, patients at "Presidente Juárez" Regional Hospital. It was a cross-sectional and descriptive study in which, by means of random selection a sample of 110 patients with type 2 diabetes mellitus, arterial hypertension, obesity and dyslipidemia, alone or in combination was chosen. We carried out a clinical and laboratory evaluation, selecting those patients with persistent elevation of aminotransferases for whom additional studies were made, in order to exclude other causes of enzyme abnormality. Five patients were selected for percutaneous liver biopsy, all they had NASH. The prevalence of NASH was 4.54%. The clinical and laboratory characteristics of these patients will be discussed in the article.

Causalidad en medicina / Causality in Medicine

El concepto de causalidad es parte de la vida común, pues el hombre desde siempre ha buscado el porqué de las cosas, como una forma de entender y adaptarse al mundo. En medicina, uno de los objetivos centrales de estudio es la identificación de los factores o agentes que causan las enfermedades, con el propósito de establecer tratamientos y sobretodo, para aplicar mediadas preventivas. En este trabajo, realizamos una breve revisión de las posiciones filosóficas sobre la causalidad, los modelos biológicos de la misma, así como las herramientas utilizadas en epidemiología clínica para evaluar las asociaciones causales.

The concept of causality is apart of every day life because man has always searched for the why of things as a way of dealing with and adapting to the world. In medicine, one of the central aims of study is identification of the factors or agents that cause disease with the intention of establishing treatments and especially, to apply preventive strategies. In this work, we conducted a brief review of the philosophical positions on causality, its biological models, as well as the tools used in clinical epidemiology to evaluate causal associations.

Efecto de la concanavalina A en el cultivo del fitopatógeno: ustilago maydis / Effect of concanavalin A in the culture of the phytopatogen: ustilago maydis

El efecto de la adición de la lectina Concanavalina A al cultivo del hongo Ustilago maydis es examinado para contribuir al entendimiento de los mecanismos de reconocimiento e infección entre hongos y plantas. La cinética de crecimiento del hongo en cultivo mostró que la adición de Con A tiene un discreto efecto activador sobre las basidiosporas a partir de la 9h de incubación. Por otra parte, la unión de Con A a las basidiosporas causó diversos cambios morfológicos, agregación, múltiples ramificaciones y una incremantada capacidad de gemación. La unión de Con A a las basidiosporas fue evidencia utilizando un conjugado fluorescente de la lectina (Alexa-flúor), observándose mayor intensidad de fluorescencia en las puntas y zonas de gemación de las basidiosporas, lo que sugiere la distribución heterógena de estructuras sacarídicas (receptores) sobre la superficie de la pared celular del hongo durante el crecimiento. Los efectos de la adición de Con A en el cultivo del hongo se inhiben al incubar previamente la lectina con &-manopiranosa.