Mutaciones del gen supresor de tumor p53 en adenocarcinoma gástrico / Mutations of p53 suppressor gene in gastric adenocarcinoma

Background: We have shown numeric alterations such as hyperploidy and hypoploidy with loss of chromosome 17 in primary gastric cancer. This chromosome maps p53 suppressor gene that induces the transcription of genes related to cellular cycle control, DNA synthesis and repair, cellular differentiation and apoptosis. Aim: To analyze, at a molecular level, the possible alterations of p53 suppressor gene in samples of gastric cancer and non tumoral mucosa. Material and methods: Tissue samples of gastric carcinoma and non tumoral gastric mucosa coming from 26 patients subjected to a total gastrectomy were analyzed. The mutation of p53 suppressor gene exons 7 to 9 were determined using a conformational polymorphism analysis in single strands of the gene and indirect sequencing in some cases. Results: Alterations in p53 gene were found in 77 percent of tumoral and 19 percent of non tumoral samples. T insertions in codons 260, 317 and 321, G insertion in codon 328 and G-T transvertion in codon 302 were found. Aminoacid sequence analysis of p53 protein obtained with sequencing data showed that T insertion in codon 260 could translate three erroneous aminoacids after the mutation and produce a truncated protein due to the creation of a stop codon. No associations between alterations of p53 gene and clinical or pathological variables such as age, sex, tumor localization, histological type and presence of Iymph node metastases were observed

Hemorragias mucocutáneas: evaluación clínica, secuencia de estudio y frecuencia relativa de enfermedades hereditarias de la hemostasia en población chilena / Mucocutaneous hemorrhages: clinical evaluation, study sequency and related frequency of hemostatic hereditary disases in Chilean population

Patients and methods: Five hundred eighty nine patients whose main symptom was the presence of mucocutaneous hemorrhages were studied. Bleeding time, platelet count, coagulant activity of factor VIII (FVIII:C), FvW: Ag and FvW:CoRis and ABO blood group were measured in all patients in a first stage. According to the results of these tests, further studies were decided. Results: In patients younger than 13 years old, males predominated and, in older patients, females consulted with higher frequency. There was a higher proportion of individuals with O blood type than in the normal population. Bleeding time was abnormal in 330 patients (56 percent). One hundred ten patients (19 percent) had von Willebrand disease and, among them, one third had a normal bleeding time. Isolated reduction of factor VIII activity was found in 66 patients (11 percent, 51 males) and 32 of these had normal bleeding time. Eighty one patients (14 percent) were considered to have an hereditary platelet function defect. A precise diagnosis was not achieved in 332 patients (56 percent). Conclusions: Among patients consulting for mucocutaneous hemorrhages, 19 percent had von Willebrand disease, 11 had an isolated reduction of factor VIII activity, 14 percent had platelet function defects and in 56 percent, a precise diagnosis was not reached

Activación plaquetaria en el síndrome hipertensivo inducido por el embarazo / Platelet activation in hypertensive syndrome due to pregnancy

Para evaluar la activación y agregación plaquetaria en tres grupos de 18 pacientes (mujeres sanas no embarazadas, embarazadas normales y embarazadas con síndrome hipertensivo del embarazo), se determinaron los valores de factor plaquetario-4 en plasma y serotonina intraplaquetaria. Los estudios de variancia y comparaciones múltiples no revelaron diferencias significativas entre los distintos grupos. La alteración de la función plaquetaria no sería un hecho relevante al inicio de la enfermedad hipertensiva del embarazo o, sí ésta existe, no sería reflejada a nivel sistémico. Se discute así la falta de fundamentos para el uso de antiagregantes plaquetarios para la prevención o control de esta enfermedad

Actividad electrica amigdalino-piriforme registrada con tecnica estereotaxica. / Amygdala-pyriform electric activity registered with stereotaxic technic

Se presenta una serie de registros en area piriforme y nucleo amigdalino realizados en 26 pacientes sometidos a operacion estereotaxica por diferentes causas. El modo particular de actividad electrica espontanea detectada en esas regiones se supone relacionado con una funcion convergente de potenciales aferentes, sin connotacion patologica