Type and frequency of chromosome aberrations in 781 couples undergoing intracytoplasmic sperm injection.

Cytogenetic investigations were performed in 781 couples prior to intracytoplasmic sperm injection (ICSI) because of severe male infertility or fertilization failures in previous in-vitro fertilization attempts. Out of these 1562 patients, 1012 had a normal karyotype without any aberrations (64.8%), 204 patients had an abnormal karyotypes (13.

Frequent 4-bp deletion in exon 9 of the SMAD4/MADH4 gene in familial juvenile polyposis patients.

Familial juvenile polyposis (FJP) is a hamartomatous polyposis syndrome characterized by the appearance of juvenile polyps in the gastrointestinal tract. Patients with this syndrome are at an increased risk for cancer of the colon, stomach, and pancreas. Recently, germline mutations in the SMAD4/DPC4 gene (official symbol MADH4) have been found in the majority of patients suffering from FJP.

Genetic counseling in a patient with XXY/XXXY/XY mosaic Klinefelter's syndrome: estimate of sex chromosome aberrations in sperm before intracytoplasmic sperm injection.

Objective: To report the sex chromosome aberrations in the sperm of a patient with mosaic Klinefelter's syndrome before ICSI.

Design: Case report.

Setting: Institute of Human Genetics, University Hospital

Patient(s): A patient with an XXY/XXXY/XY mosaic Klinefelter's syndrome and extreme oligozoospermia.

[Experience and problems with biochemical differentiation of Enterobacteriaceae with microtiter plates].

A self-made miniaturized test system for the biochemical identification of enterobacteriaceae in microtitre plates has been examined. Special emphasis was laid on easy and unequivocal interpretation of the reactions. This was achieved among other things by including further sugar fermentations.

[Increased yields of insulin by recycling of non-combined insulin chains].

The yield of insulin by the combination of reduced A and B chains is increased from 15% to 33-34% if the non-insulin-containing fractions of the gel filtration are isolated and used for further combinations (recycling). Crude insulin recovered by gel filtration can be highly purified by preparative high-performance liquid chromatography. Lower yields of insulin were obtained on recombination of chains which had been recycled five times or more.