Association between capillaroscopy, haemorheological variables and plasma proteins in patients bearing Raynaud's phenomenon.

Raynaud's phenomenon is a paroxysmal and reversible vasospasm affecting generally the acral circulatory regions. The relevance of the haemorheological alterations in these patients, as a source of ischemic events has been neglected. The objective of the present work was to evaluate and correlate the rheological blood properties, some biochemical parameters, e.g., plasma fibrinogen and immunoglobulin levels, and periungual capillaroscopy. The explicative variables considered were: blood viscosity, plasma viscosity, erythrocyte rigidity index, plasma fibrinogen, erythrocyte sedimentation rate, erythrocyte aggregate size, erythrocyte aggregation rate and serum immunoglobulin (IgG and IgM). The response variable was the nailfold capillary pattern categorised as either normal or pathological. Fibrinogen, erythrocyte aggregation rate and IgM are significantly higher in patients with a pathological pattern in comparison with patients bearing a normal one. The statistical analysis enabled us the modelling of the pathological pattern occurrence probability in function of plasma fibrinogen. Consequently, 100 mg/dl plasma fibrinogen increase, increases twice the probability of presenting a pathological pattern. Therefore, we can conclude that high levels of fibrinogen in Raynaud's phenomenon patients are associated with impaired skin microcirculation assessed by periungual capillaroscopy.

[Correlation between ABH glycolipids in sperm and functional test]. / Correlación entre glicolipidos ABH en espermatozoides y test funcionales.

OBJECTIVE: To determine the association, if any, between the human spermatic membrane integrity test and normal or altered membrane ABH glycosphingolipids expression. METHODS: Semen samples from 50 patients who consulted at the infertility services of the Provincial del Centenario and Eva Peron de Granadero Belgorria teaching hospitals in Rosario (Argentina) were collected and analyzed in accordance with WHO guidelines. The percentage of dead sperm was analyzed by the eosin test while the percentage of swollen sperm was analyzed by the hypoosmotic test. They were classified according to their ABH expression, either diminished or absent (group 1) or normal (group 2), by applying the hemagglutination inhibition and specific antibody consumption technique. For the statistical analysis the two groups were compared with both spermatic viability tests using the non parametric Mann-Whitney technique for independent samples, since the assumptions for the application of the parametric test (test t) were not fulfilled. RESULTS: A significant difference was found in the percentage of dead sperm (eosin test) of both groups (p < 0.001). However, there was no significant difference in the percentage of swollen sperm (hypoosmotic test) of the two groups. CONCLUSIONS: Our results and the data published in the literature indicate a relationship between a reduced ABH expression and spermatozoid membrane integrity, especially at the level of the head, which leads us to consider that ABH glycosphingolipids are mainly located in this segment of the human spermatozoon involved in the spermatozoon-ovum interactions.

Glicoesfingolípidos de membrana y test de viabilidad espermática / Glicosfingolipides ABH and sperm viability test

Los espermatozoides presentan estructuras glicoesfingolipídicas asociadas a la membrana que son propias de los antígenos ABH. Los glúcidos que conforman estas moléculas participan en la adhesión, reconocimiento e inhibición del contacto celular. Por esta razón los antígenos de grupo sanguíneo podrían tener relevancia en los mecanismos moleculares del proceso reproductivo. El objetivo de este trabajo fue evaluar si exite asociación entre los tests de integridad de la membrana espermática y la alteración en la expresión de los glicoesfingolípidos ABH. Se seleccionaron 50 pacientes infértiles cuyas muestras de semen fueron procesadas según normas OMS. La expresión ABH en los espermatozoides se estudió por técnicas inmunohematológicas y se clasificó según estuviera disminuida o ausente (grupo 1), o normal (grupo 2). La integridad de la membrana se evaluó con Test de Burgos y De Paola y Test Hiposmótico. Se efectuó la comparación de los dos grupos respecto de ambos test de viabilidad espermática. El análisis estadistico demostró que: 1) Existe diferencia significativa en la variable porcentaje de muertos (Burgos De Paola) para los dos grupos (p<0.001). 2) No existe diferencia significativa en la variable porcentaje de hinchados (Test Hiposmótico) para los dos grupos. Sobre la base de los resultados obtenidos podemos concluir que existe asociación entre expresión ABH disminuida e integridad de la menbrana del espermatozoide, principalmente a nivel de la cabeza. Lo que nos lleva a pensar que los glicoesfingolípidos ABH, se localizan preferentemente en esta zona del espermatozoide, involucrada fundamentalmente en la interacción con el ovocito. Nos proponemos ampliar la población en estudio e investigar el gen responsable de la estructura final de los antígenos del ABO tratando de profundizar en las alteraciones del plasmalema a nivel molecular

[Influence of temperature and pH on the in vitro adherence of Candida albicans.]. / Efecto de la temperatura y el pH en la adherencia de Candida albicans in vitro.

Yeast adherence to epithelial cells is a very important step in colonization and infection caused by these opportunistic pathogens. This phenomenon may be modified in vitro by many factors. The aim of this work was to find out how variations in pH and temperature modify the in vitro adherence of Candida albicans to epithelial cells. We worked with epithelial buccal cells and a yeast strain according to Gibbons and Van Houte technique with slight modifications. In the first assay, adherence at 28 degrees C and 37 degrees C, and three pH values, 6, 7.2 and 8.4 were simultaneously studied. We did not find significant variations in adherente capacity, but a slight increase was detected at pH 7.2 and 37 degrees C. In the second assay, temperature was fixed at 37 degrees C and four pH values were studied: 3, 4, 5, and 7.2. We find a highly significant difference (p < 0.001) between adherente at pH = 7.2 with respect to the other pH values. According to these results C. albicans adherence to epithelial buccal cells, in vitro, is produced at 37 degrees C and pH 7.2 in optimal conditions.

Actividad celulolitica de cepas de aspergillus niger y a. flavus aisladas de suelos con cultivo de trigo y tratamiento herbicida / Cellulolytic activity of aspergillus niger and a. flavus strains isolated from soils with wheat cultivation and herbicide treatment

Se estudia la actividad celulolítica de cepas de aspergillus niger y a. flavus aisladas de suelo del sur de la provincia de Santa Fe, sembrado con trigo y tratado con metsulfurón-metil+dicamba. Dichas cepas fueron las más frecuentes en un muestreo que abarcó distintas etapas del cultivo de trigo en 1994 y mostraron a su vez, variaciones en su frecuencia a lo largo del mismo. Nuestro objetivo fue conocer si dichas variaciones de frecuencia se correlacionaron con cambios en la actividad celulolítica de las mismas. Se trabajó con tres cepas de a. niger y dos de a. flavus. En los filtrados de los cultivos, se determinó: peso seco, proteínas solubles, producción de exoglucanasas frente a la celulosa cristalina, endoglucanasas frente a carboximetilcelulosa y celobiasis extracelulares. En a. niger, no hubo una correlación clara entre frecuencia y actividad enzimática, sólo se obserbó que las cepas de a. niger de mayor frecuencia (superior al 50 porciento) tuvieron también mayor actividad. En a. flavus, en cambio, se observó una correlación diversa.