[A simple, low-cost and non-invasive method for screening Y microdeletions in infertile men]. / Evaluation d'une technique simple et rapide de détection de microdélétions du bras long du chromosome Y.

OBJECTIVES: Recent investigations showed a high prevalence of Y chromosome microdeletions in men with severely impaired spermatogenesis. Screening for these men is recommended prior to assisted reproduction techniques. The aim of this study was to set up a simple method to detect Y deletion in infertile men. First, we tested the feasibility of cytobrush to collect oral cells as source of DNA. Second, we compared a classic PCR corresponding to European recommendations to the Promega kit. PATIENTS AND METHODS: Seventeen infertile male patients with previously characterized deletions were included in the present study, after fully informed written consent. Both oral cells and blood were used for DNA extraction. A specific DNA extraction protocol was carried out on the buccal cells. The DNAs were tested for Y deletion screening by two different methods. RESULTS: We retrieved between 4 and 10 microg of DNA per brush from buccal cells, allowing several multiplex PCR. The Promega kit detected all the deletions but one: an AZFa deletion was not detected by the two markers of the kit covering this region. In addition, sY130, sY133 and SY153, included in the kit, are not reliable. DISCUSSION AND CONCLUSIONS: Buccal cells represent a convenient substitute for blood in testing for Y microdeletions. Both false negative and false positive results were obtained with Promega Kit. On the opposite, PCR according to the European recommendations allow the accurate detection of Y microdeletion in our 17 cases, at a lower cost.

A simple, low cost and non-invasive method for screening Y-chromosome microdeletions in infertile men.

BACKGROUND: Recent investigations emphasized a high prevalence of Y-chromosome microdeletions in men having severely impaired spermatogenesis. Screening of these men is recommended prior to assisted reproduction techniques. METHODS: The aim of this study was to define a reliable and efficient method to detect Y-chromosome deletions in infertile men. At first the feasibility of using a cytobrush to collect buccal cells as a source of DNA was tested. Then, a multiplex PCR in accordance with European recommendations (European Andrology Academia: EAA) was compared with a commercial kit. The test population consisted of 18 infertile male patients (with a known Y-deletion). Both buccal and blood cells were used for DNA extraction. A specific DNA extraction protocol was carried out on the buccal cells. RESULTS: Between 4-10 micro g of DNA were retrieved per brush, allowing for several PCR attempts. The commercial kit failed to detect an AZFa deletion. Furthermore, markers sY130, sY133 and sY153, included in the kit, are not reliable. Both false negative and false positive results were generated by the commercial kit. CONCLUSION: A multiplex PCR performed pursuant to EAA recommendations is proposed. When the testing is conducted with DNA extracted from buccal cells, this protocol is simple, accurate and affordable.

[Interest of gene amplification by PCR for the diagnosis of Mycoplasma pneumoniae infections in the child]. / Intérêt de l'amplification génique par PCR pour le diagnostic des infections à Mycoplasma pneumoniae chez l'enfant.

Between december 1996 and february 1998, rhinopharyngeal and tracheal aspirates from 165 children exhibiting symptoms compatible with M. pneumoniae infection were tested by a PCR method using in the same tube primers specific for M. pneumoniae P1 adhesin gene and for a human control gene. The positive cases were controlled using culture and/or serology. PCR was positive in 22 out of 165 samples (13.3%); an evaluation of the clinical and biological data was possible in 20 of these infected children. From 17 PCR positive respiratory samples tested by culture, 13 (76.5%) grew M. pneumoniae. From 14 serum specimens tested by ELISA, 12 exhibited specific IgM (3 of them with low titers); cold agglutinins were detected in all 7 tested sera. Only one case was not confirmed by any of the 3 former markers. The mean age of patients was 8.1 years. The main clinical symptoms included fever > 38 degrees C, cough, clinical and radiological pneumonia in 90, 95, 50 and 85% of cases, respectively. Neurological symptoms were the main clinical manifestation in 3 patients; another child exhibited a pneumonia associated to an hemophagocytic syndrome and a bone marrow failure which needed a graft. These results emphasize the value of PCR for the rapid diagnosis of M. pneumoniae infection in children.

Arbitrarily primed PCR, ribotyping, and plasmid pattern analysis applied to investigation of a nosocomial outbreak due to Enterobacter cloacae in a neonatal intensive care unit.

In December 1992, Enterobacter cloacae was isolated from the oropharynx and respiratory tract of six ventilated neonates hospitalized in the intensive care unit (ICU) of our hospital. To establish the spread of the outbreak, 41 strains of E. cloacae were analyzed for genotypic markers by three methods: plasmid profile analysis, ribotyping with EcoRI or PvuII endonuclease, and arbitrarily primed (AP) PCR. The tested strains included 12 isolates from the 6 epidemic cases, 4 isolates from the respiratory tract of 4 children hospitalized in other wards during the same period, 13 isolates from 12 children hospitalized in pediatric units before or after the outbreak, and 12 epidemiologically unrelated isolates. Ribotyping and AP PCR demonstrated that each of the last 12 strains exhibited distinct genomic patterns, as did each of the strains isolated from neonates hospitalized before or after the epidemic peak. Conversely, two clones of strains were found among the isolates recovered in December, with concordant results being obtained by the three typing methods: the first clone included seven strains from five ventilated children in the ICU and two children from another ward; another clone was shared by one neonate in the ICU and an infant from another ward. These results indicate that ribotyping and AP PCR-the latter applied, to our knowledge, for the first time to the genotypic analysis of E. cloacae--represent very discriminatory tools for the investigation of nosocomial outbreaks caused by this species.

Cytogenetic experience in prenatal fra(X) detection on amniotic fluid cultures.

Since 1987, we have had experience with 13 prenatal diagnoses of 11 women at risk for the fragile X syndrome by cytogenetic studies on amniotic fluid cultures. The induction method included TC 199 medium and methotrexate. Results were obtained in all cases. Ten were males and three were prenatally diagnosed as being affected. Three were females and none of them was fra(X)-positive. Results were confirmed in 10/13 cases. In these cases, we had neither false-positive nor false-negative results.

[t(Y; 15) translocation in a fertile male, detected at the time of amniocentesis]. / Translocation t(Y; 15) chez un homme fertile, dépistée à l'occasion d'une amniocentèse.

Cytogenetic studies on a phenotypically normal fertile male revealed an unbalanced Y; 15 translocation. His wife referred for a prenatal diagnosis because of maternal age. The foetus was male and carried the same translocation.

Collagen biosynthesis in a case of infantile myofibromatosis.

Cells from a skin nodule from a patient with a recurrent form of familial myofibromatosis were cultivated in vitro. A metabolic study showed that these cells behaved like fibroblasts with collagen synthesis, a normal percentage of type III collagen, hydroxylation rate and the ability to contract a collagen gel. The main disturbances were the decreased synthesis and increased cell multiplication rate after a lag phase. This behavior was compared with that of a fibroblast culture from normal skin.

[Systematic neonatal detection of Duchenne's muscular dystrophy. Results after 10 years' of experience in Lyons (France)]. / Dépistage néonatal systématique de la dystrophie musculaire de Duchenne. Bilan après dix ans d'expérience dans la région de Lyon (France).

Neonatal screening of Duchenne Muscular Dystrophy using serum CK level measurement has been performed for 10 years in a part of the Rhône-Alpes area (40,000 newborns per year). This test avoids consecutive cases in an affected family by mean of an early genetic counselling. So, 10 potential DMD boys have been avoided (i.e. one out of five of the D.M.D., as a whole which would be born during this same ten year study). Details on familial structures and efficiency of genetic counselling are given, and this efficiency will be increased by the DNA study of the concerned families.

Six cases of partial duplication-deficiency 21 syndrome: 21(dupq22delp23) due to maternal pericentric inversion: inv(21)(p12;q22). A family study.

Six probands, apparently not related, with a minimal phenotype of Down's syndrome were investigated between 1970 and 1984 in our laboratory. We found in all of them an identical chromosomal abnormality 46,XX or XY,-21,+ der21(dupq22delp23). The der 21 was due to aneusomie de recombinaison, each mother having an abnormal chromosome 21: inv(21)(p12;q22). The fathers' caryotypes were normal. All parents were young and healthy. Pedigrees were established in order to find a relationship between these families. Four of our probands could be related. Familial investigations are still in progress for the last two cases; the ancestors being born in the same small geographical area (within 50 km2) we think that we shall be able to establish a relationship with the others families.

[Coxsackie B5 infection in a newborn infant. Meningoencephalitis and myocarditis]. / Infection à coxsackie B5 chez un nouveau-né. Méningo-encéphalite et myocardite.

A coxsackie virus B5 was isolated from a neonate with aseptic meningitis and myocardial dysfunction. This infection is probably acquired in utero: a high level of specific antibodies was found in the mother and the titer increase later on. At 34 months the baby is totally free of sequelae.

[Pyridoxine-dependent convulsions : familial case]. / Convulsions pyridoxino-dépendantes: observation familiale.

A 32 hours old boy was diagnosed as vitamin B6 dependent convulsions. This boy was the third from family, the first two died in status epilepticus at 34 hours and 15 months.

[Sirenomelia and multicystic renal dysplasia. Apropos of 2 cases]. / Sirénomélie et dysplasie rénale multikystique. A propos de deux observations.

Two cases of sirenomelia with multicystic renal dysplasia (Potter's type II A) are reported. One case was discovered on fetal ultrasonography. Multicystic renal dysplasia in sirenomelia is an additional plea for a primitive mesoblastic defect in the caudal regression syndrome.

Unusual morphodysplasia as a result of early amnion rupture: umbilico-cephalic adherence.

We present a fetus with an umbilico-cephalic adherence, probably secondary to an early amnion rupture. The fetal ectoderm and the collagenous layers of the chorion can attach as large amounts of fibronectin are present in the amniotic fluid. Until now, no case of this particular type of "amnion rupture sequence" syndrome has been reported.