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Biomedical subjects

C Laurent

Publications and source records attributed to C Laurent.

At least 217 records · Page 12Linked to original sources

[Chronology of the replication of sex chromosome bands in lymphocytes of normal subjects and patients].

The replication sequence of the bands carried by chromosomes X and Y has been studied in normal individuals and in patients with structural abnormalities of the X. By comparing the segment with that of the autosomal bands (which had been previously studied), it was shown that the normal early X replicates in early X-phase for its R-bands and in late S-phase for its Q bands. The late X replicates entirely in late S-phase, and the sequence of band replication is not as stringent as for the early X and the autosomes. The study of fourteen cases of anomalies of chromosome X in females showed the following: in balanced reciprocal X-autosome translocations the rearranged X most often replicates early and the normal X late. Both show a normal replication sequence of their bands. In non-balanced X-autosome translocations, inactivation of the autosome fragment attached to the AUTOSOME FRAGMENT ATTACHED TO THE X may take place. In Xq- or in ter rea (X;X) (pter;pter), band p22 has a delayed replication. In iso-Xor Xp-, the long-arm-band sequence of replication shows a variation comparable to that of the late X in fibroblasts. These replication modifications are likely to induce partial inactivations or changes in activity which correspond to the so-called position effect in Drosophila.

DNA Replication↗

Mosaic 45,x/47,xy,+18.

A poorly developed female infant with buphthalmia, Turner phenotype, and mental retardation is described. Blood culture revealed a 45,X/47,XY,+18 chromosomal mosaicism; fibroblast culture showed only 45,X cells. The baby was dead at 11 months. Post mortem examination exhibited an ovarian agenesis and a calcified aortic stenosis.

Abnormalities, Multiple↗

[Possible localization of the glutathione reductase (EC 1.6.4.2) on the 8p21 band].

Glutathione reductase (EC 1.6.4.2.) (GSR) activity was measured in the red cells of patients with different rearrangements of chromosome 8. Of three patients with mosaic trisomy 8, two had a high GSR activity. The lack of correlation between GSR levels and the degree of mosaicism in lymphocytes is discussed. In six patients with trisomy 8qter the mean value of GSR activities was normal. In one patient with trisomy pter leads to q22.1 and in two with trisomy p11 leads to p22, a significant increase (+60%) of GSR activity was observed. In two patients with monosomy p22 leads to pter and p21 leads to pter, respectively, the GSR levels were normal. It is concluded that the gene locus of GSR can be assigned to the 8p11 leads to p22 segment. A comparison of these results with one other case from the literature suggests a more precise assignment of the GSR locus to band p21.

Chromosome Mapping↗

Multidisciplinary curative treatment for disseminated carcinoma of the breast.

Eighty-four patients with disseminated breast carcinoma were treated with the combination of hormonal therapy and combination chemotherapy from the time of diagnosis. Hormonal treatment included castration for women still menstruating, estrogens for women menopausal for greater than 5 years, and androgens or progesterone for women menopausal for less than 5 years. Combination chemotherapy consisted of monthly 5-day courses of 5-fluorouracil (500 mg/day, Days 1-5), cyclophosphamide (300 mg/day, Days 1 and 4), vincristine (1 mg/day, Days 2 and 5), and methotrexate (100 mg, Day 1) followed by citrovorum factor (12 mg/day, Days 2 and 3). The overall response rate was 83.3%: 43 CRs (51%) and 27 PRs. The median survival time was 17 months: 6 months for the failures, 12 months for the 27 PRs, and 27 months for the 43 CRs. Fifteen patients with CR are still alive: one after 16 months, one after 17 months, two after 19 months, and one each after 23, 24, 25, 31, 35, 37, 38, 43, 48, 68 and 70 months.

Androgens↗

[Chemotherapy in primary and metastatic intrathoracic cancer].

Chemotherapy has procured results which are still modest surely valid in the treatment of inoperable primary bronchial cancer: - prolongation of the mean survival time from 3 1/2 months for the nontreated cases to 8 1/2 months for those patients treated with complex combinations; - more than 15% of very good results with return to normal professional activity for 6 to 18 months; - approximately 30% of considerable subjective improvement with a definite sense of "well being"; - considerable reduction in the use of pain-killers. These results amply justify the pursuit of research. 2) The results for the combination hormone-chemotherapy, in the case of thoracic metastases of breast cancer, are definitely better. After leukemia in children, and Hodgking and non-Hodgkin lymphoma, metastases from breast cancer constitute a third group of chemosensitive tumors: - for 64 cases, the percentage of complete or partial remission is 84.3%; - there were 34 complete remissions: mean survival 27 months, at present 11 patients still remain alive: 1 to 16, 1 to 17, 2 to 19, 1 to 23, 31, 35, 38, 43, 68 and 70 months; - 20 partial remissions, mean survival 10 1/2 months, one patient still alive; - 10 failures, mean survival 6 months; - mean duration of complete remission 18 months; - mean duration of partial remission 6 months.

Antineoplastic Agents↗

[Translocation t(Y;14) in an azoospermic man].

A study of meiosis in an azoospermic man with a translocation between the Y and 14 chromosomes shows complete arrest of gametogenesis after the second division (spermatocyte II stage). At pachytene, the distal segment of the Y chromosome which is translocated onto the 14, is in contact with the sex vesicle.

Adult↗

[Multidisciplinary treatment of primary cancer of the breast].

The prognosis of surgery for carcinoma of the breast is directly and closely related with the number of homolateral axillary lymph nodes involved. When node involvement is present, recurrences are numerous and early, this tendency being increased in accordance with the number involved. When 4 or more nodes are involved, 35 to 52% of recurrences are seen during the first 18 months, according to the differend statistics available. Such recurrences are distant in 85% of cases. This is due to the fact that carcinoma of the breast, even in its early stages, is most often a generalised disease with disseminated lesions in the form of distant micrometastases. In these cases with a poor prognosis, some form of treatment to complement surgery is necessary. Radiotherapy has proved a failure, useless and often harmful as a result of prolonged reduction in cellular immune defences. Prolonged polychemotherapy, by contrast, has shown its great, not to say astonishing, effectiveness. Continued study is thus essential.

Antineoplastic Agents↗

[Four new cases of X-autosome translocation in man (author's transl)].

Four new cases of translocations involving the X chromosome are reported. The first is a balanced t(1;X) observed in an abnormal girl. In most of the cells, the normal X is inactivated. The second case is a woman with oligomenorrhea, who has had two spontaneous abortions. She carries an umbalanced t(X-autosome). In all cells, the abnormal X, including the autosomal segment, is inactivated. The third and fourth cases are a mother, and her son. The mother has oligomenorrhea, carries a t(X,X), and has a karyotype of 46,X,+der t(X;X) and that of her son is 47,XY,+der t(X;X) and shows behavioral abnormalities. The abnormal X chromosome is inactivated in all the cells analyzed.

Acridines↗

[2 cases of trisomy 11q(q23.2-- qter) with the same abnormality of external genitalia].

Two unrelated individuals are reported with the same clinical picture and trisomic for the same segment of chromosome 11 (q23 leads to qter). That both were seen because of micropenis raises the possibility that genes interfering with the reproductive function are located on chromosome 11 and that the q23 band might be a preferential breakage point of chromosome 11. Certain earlier reports support such a possibility.

Abnormalities, Multiple↗

[Trisomy 11q. Individualization of a new syndrome].

The comparison of nine examples of trisomy for the distal segment of 11q permits definition of a clinical syndrome which includes the following: axial hypotonia with hypertonia of the limbs; an old-looking wrinkled face; a large beaked nose; microretrognathia with malformation of the palate; low-set ears; a prominent anterior helix; a prominent anthelix; a short neck; a narrow chest with nipples set widely apart; micropenis in the boys; congenital heart disease; renal agenesis or malformations of the urinary tract; agenesis of the thoracic girdle; dysplasia of the acetabulum; clubfeet.

Abnormalities, Multiple↗

[Trisomy 10q24--10qter].

The syndrome of trisomy 10q24leads to 10qter is described from three patients studied by the authors and five cases reported from the literature. The characteristic dysmorphy of the syndrome, although different from that of trisomy 21, nevertheless is reminiscent because of euroasiatic facies. The facies is broad, round, because of euroasiatic facies. The facies is broad, round, and flat, with a prominent malar region and a high and convex forehead. Palpebral fissures are narrow with bilateral epicanthal folds, and the nasal bridge is hypoplasitc. Marked joint laxity allows spontaneous and reductible subluxations. Growth retardation is the rule, and mental retardation is severe. No specific dermatoglyphic abnormalities are noted; there is a gap between the first and second toes, with a marked plantar crease separating them. Although trisomy 10q24leads to10qter results from various terminal translocations or pericentric inversion in one case, the location of the breakage point in band 10q24 suggests a particular lability of this zone.

Abnormalities, Multiple↗

[A second example of telomeric fusion 2 X chromosomes].

A translocation which originated by telomeric "fusion" of X short arms, t(X;X), was found in a woman with primary amenorrhea and a phenotype corresponding partially to Turner's syndrome. Staining with acridine orange after BrdU incorporation showed the distal segments of both Xp's to be much more modified by the treatment than equivalent segments of normal late replicating X's. This could mean important inactivation of segments usually active even in late replicating X's. This functional monosomy for X would have a clinical effect similar to a true monosomy.

Amenorrhea↗

Partial 4q trisomy. Apropos of 3 cases.

Three observations of partial trisomy 4q are reported: the first due to a familial translocation the second to a de nove translocation, the third to a "mirror" duplication. The very characteristic phenotype is compared to that of 4 other patients already reported in the literature. The most evocatory symptoms include: absent or poorly indicated nose bridge; pursed lips; shortness of the philtrum; and constant existence of a fold on the antitragus continuing the anthelix reachinghe insertion of the pinna.

Abnormalities, Multiple↗