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M Arnaud

Publications and source records attributed to M Arnaud.

15 recordsLinked to original sources

Adolescent osteoporosis disclosing familial osteopenia.

The observations of familial juvenile osteoporosis, presumably of genetic origin are exceptional. The authors report the observation of a 16-year old adolescent suffering from osteoporosis, confirmed by histomorphometry and decrease in bone density (lumbar vertebrae 0.79 g/cm2 and femoral neck 0.88 g/cm2: LUNAR DPX). We prescribed fluorine and calcium therapy. Lumbar bone density increases by 11% and bone density of the thighbone neck by 7.6%. We cannot rule out growth as a factor in the changes observed, given that the propositus is only 16. A densitometric investigation performed in 4 of his 12 brothers shows a decrease in the lumbar bone mineral content (from 61 to 94% expressed as Z score). A genotypic origin seems to be conceivable, especially since no other cause could be considered (endocrinal, alimentary...). On the other hand, there is no argument in favour of osteogenesis imperfecta disease. The bone densitometry is a useful diagnostic means to detect familial forms of osteoporosis.

Adolescent

Regulation of the sacPA operon of Bacillus subtilis: identification of phosphotransferase system components involved in SacT activity.

The sacT gene which controls the sacPA operon of Bacillus subtilis encodes a polypeptide homologous to the B. subtilis SacY and the Escherichia coli BglG antiterminators. Expression of the sacT gene is shown to be constitutive. The DNA sequence upstream from sacP contains a palindromic sequence which functions as a transcriptional terminator. We have previously proposed that SacT acts as a transcriptional antiterminator, allowing transcription of the sacPA operon. In strains containing mutations inactivating ptsH or ptsI, the expression of sacPA and sacB is constitutive. In this work, we show that this constitutivity is due to a fully active SacY antiterminator. In the wild-type sacT+ strain or in the sacT30 mutant, SacT requires both enzyme I and HPr of the phosphotransferase system (PTS) for antitermination. It appears that the PTS exerts different effects on the sacB gene and the sacPA operon. The general proteins of the PTS are not required for the activity of SacY while they are necessary for SacT activity.

Bacillus subtilis

[The image of intravertebral somatic gaseous dissection. Report of 9 cases one of which has a triple localization and review of the literature].

We report a series of 9 cases of vertebral somatic gaseous dissection studied between 1978 and 1989. We find most of the characteristics established from the literature data: advanced age, possible medullar compression contrary to the vertebral compression by common osteoporosis, predilection for the dorso-lumbar junction, frequency of the osteoporosis, possibility of metabolic disorders, of occurrence after radiotherapy. The context of the occurrence and the paraclinical examinations of the whole have enabled us to eliminate, in this series, a malignant pathology. However, when there exists a doubt on a malignant origin, it is preferable to carry out a vertebral biopsy with a trocar. In fact, the image may not be pathognomonic of a benign vertebral osteoporosis. Finally, we give the first description of a triple localization of vertebral gaseous dissection.

Aged

Bacillus subtilis 168 genetic transformation mediated by outgrowing spores: necessity for cell contact.

Transforming activity released in sequential genetic order during the first synchronous cycle of DNA replication during outgrowth of spores of Bacillus subtilis 168 was investigated. A transformation assay was used consisting of outgrowing spores as DNA donors and multiply marked competent cells as recipients. DNA synthesis inhibitors known to stop DNA release were used during and subsequent to DNA transfer to recipient cells. The released DNA sedimented with the outgrowing cells after low-speed centrifugation, and it was discovered that markers released both early and late were resistant to up to 500 microgram of deoxyribonuclease per ml under conditions in which the transforming capacity of purified DNA was eliminated by 5 microgram of the nuclease per ml. Inaccessibility to deoxyribonuclease was increased and maintained during the transformation event while detergents and proteolytic attack did not expose the released chromosome to nuclease action. The results indicate that tight physical contact between outgrowing spores and competent cells is required for transformation in this system.

Bacillus subtilis

[Prospective study of the analgesic action of clomipramine versus placebo in refractory lumbosciatica (68 cases)].

The authors sought to determine the analgesic activity of clomipramine (CMP) versus placebo, efficacy and side-effects according to the time of administration, long term clinical results and the relationship between plasma levels and analgesic effect. This double-blind randomised trial involved the infusion of 250 ml of glucose solution morning and evening versus placebo. CMP was administered at progressive doses for 8 days (maximum dosage 75 mg), either in the morning at 8 a.m. or in the evening at 6 p.m. Sixty eight patients accepted to be treated, all suffering from low back pain with or without sciatica. Maintenance treatment at the dose of 75 mg/day was then administered. CMP had a statistically significant analgesic action independent (rapidity of action) of its antidepressant activity. CMP was more effective and better tolerated (sedative and tranquilizer effect) in the evening. Long term results were poor (75% of cases). There was no link between plasma levels and clinical response. The authors noted that the analgesic activity of CMP was rapid, but for a duration limited to the short term and that this efficacy compared with the quite good results obtained with the placebo could be explained by a possible methodological bias (patients hospitalised and treated by intravenous infusions). The finding that CMP was better tolerated in the evening, without any loss of efficacy, is a positive feature (chronotherapeutic trial). Poor long term results could be partially explained by side-effects (66%). There was no relationship between analgesic effect and plasma levels.

Adult