Fanconi's anemia: chromosome anormalies. / Anémie de Fanconi: anomalies chromosomiques

Two types of chromosome abnormalitie are observed in the bone marrow and the blood of a patient with Fanconi's anemia. There abnormalities involved in two stages: firstly the presence of a clone with 47 chromosomes + 21, which was not found during later examinations. One and a half years later, following a decline in the hematological condition, there appeared duplication of certain chromosome segments of the long arm of the 3 chromosome and of the intermediate segment of the long arm of the 12 chromosome. This latter type of abnormality affected differently the bone marrow and the blood in the bone marrow, we found 2 clones, one bore 2 markers obtained from 3 and 12, the other and marker obtained from the 12 chromosome. In the blood, there was simply a minority clone with only the marker originating in the 3 chromosome. This observation should be compared with the descriptions made by other authors. In all cases abnormal clones present an apparently unbalanced karyotype, characterised by excess material.

Tissue effects of methotrexate injected into the uterine horn of pregnant female rats.

Methotrexate has been proposed as a treatment for unruptured extra-uterine pregnancy, but its effects on the tubal wall remain unknown. In order to analyse these effects, an experimental study was carried out on two groups of pregnant female rats, one receiving methotrexate (n = 8) and the other sodium chloride (n = 6). In both groups, a single intra-embryonic injection was performed in the uterine horn. The genital tract was prepared for histological examination. In all rats which received a single dose of methotrexate (5 mg per 100 g body weight) six days after mating and were killed nine days later, the labyrinthine part and the junctional zone of the placenta were necrotic at the site of the injection, with no embryonic development. The other parts of the genital tract were not visibly altered. In rats receiving sodium chloride and killed under the same conditions, necrosis of the placenta was observed at the site of injection in three animals. In the other three rats, a focal necrosis of the placenta was found, which was probably of mechanical origin. From this study, we conclude that methotrexate is efficient in killing normally implanted embryos and is, at least under light microscopy, non-toxic to the adjacent portions of the genital tract.

[Case of a rare maxillary tumor: osteocementofibroma]. / Un cas de tumeur rare du maxillaire: l'ostéocémentofibrome.

A 17-year-old young girl presented with a rare maxillary tumor, an osteocementoblastoma, which from the ectopic type of position of the wisdom tooth had apparently been present for many years pathologic findings are reported. Post-operative course was normal but regular follow-up is necessary because of the tendency for recurrence of the few cases reported in the literature of this benign tumor.

Expression of rat hepatocyte plasma membrane antigens in hybrid clones: assignment of genes coding for two antigens of the basolateral domain to chromosomes 11 and 13.

Expression of three rat hepatocyte plasma membrane antigens defined by monoclonal antibodies (mAbs) was examined by immunofluorescence in mouse hepatoma x rat hepatocyte hybrid clones segregating rat chromosomes. The antigen defined by mAb B1, a marker of the lateral domain of the hepatocyte plasma membrane in vivo, was expressed in hybrids retaining the rat chromosome 11. The antigen defined by mAb A39, mainly located on the sinusoidal (basal) domain of the plasma membrane in vivo, was expressed when chromosome 13 was present. The genes coding for these two antigens were thus assigned to chromosomes 11 and 13, respectively. The antigen defined by mAb B10, exclusively located on the canalicular (apical) domain of the plasma membrane in vivo, was not expressed in most hybrid clones, and the chromosome location of the gene could not be determined.