Search PubMed⌕ Search

Biomedical subjects

M Barat

Publications and source records attributed to M Barat.

103 records · Page 6Linked to original sources
PubMed1967

Transformation and transduction in recombination-defective mutants of Bacillus subtilis.

The effects on transformation and transduction of an ultraviolet sensitivity (uvr(-)) and two ultraviolet sensitivity-recombination deficiency (rec-1(-) and rec-2(-)) mutations in isogenic strains of Bacillus subtilis were investigated. Transformation frequency in the rec-1(-) and rec-2(-) strains was reduced to approximately 5 and 25%, respectively, of the parental strains. Normal kinetics of deoxyribonucleic acid dose response in transformation were found for the rec-1(+) and rec-2(-) strains. Biphasic curves were obtained with the rec-1(-) strains. Transduction frequency with bacteriophage SP-10 decreased parallel to transformation frequency in the rec-1(-) and rec-2(-) strains. This result suggests that transformation and SP-10 transduction share a common mechanism for genetic recombination. It also indicates that the reduction in transformation frequency of these strains was not due to altered competence. Transduction frequency with bacteriophage PBS-1 or 3NT, on the contrary, was not diminished in rec-1(-) strains. This frequency was reduced in rec-2(-) strains but not as severely as that of transformation or SP-10 transduction. Several hypotheses to interpret these differences are presented. Recombination frequency between linked markers was reduced more than 50% in transformation by the presence of the rec-1(-) mutation. Linkage was unaffected in the rec-2(-) strains. Neither the rec-1(-) nor the rec-2(-) mutation had an effect on linkage in PBS-1 or 3NT transduction. The uvr(-) strains were transformed at a frequency equal to or greater than that of the parental strains. These strains were transduced by all bacteriophage systems at frequencies about twofold higher than those of parental strains.

Bacillus subtilis↗
PubMedDate not supplied

Tracheal bronchus.

Tracheal bronchus is an aberrant bronchus that arises most often from the right tracheal wall above the carina and is the result of an additional tracheal outgrowth early in embryonic life. Its incidence ranges between 0.1 and 5%. This anomaly usually is diagnosed incidentally during bronchoscopy or bronchography performed for various respiratory problems. Occasionally, it represents the underlying etiology for chronic pulmonary disease such as emphysema, atelectasis, and persistent or recurrent pneumonia, especially if it involves the right upper lobe and reflects an abnormal pulmonary clearing mechanism. Tracheal bronchus may be associated with other bronchopulmonary anomalies, tracheal stenosis, or Down's syndrome. In the absence of clinical symptoms, a diagnosis of tracheal bronchus does not require any treatment. In patients with recurrent right upper lobe disease and a tracheal bronchus, therapy should include resection of the aberrant bronchus as well as the lobe it supplies.

Bronchi↗
PubMedDate not supplied

Chronic inflammatory demyelinating polyneuropathy: immunopathological and ultrastructural study of peripheral nerve biopsy in 42 cases.

The authors recently reexamined the peripheral nerve biopsies from 42 patients with chronic inflammatory demyelinating polyneuropathy (CIDP). There were 27 males and 15 females, aged from 9 to 84 years, and 13 had relapses. No patient had vasculitis, monoclonal gammopathy, tumor, diabetes mellitus, Lyme disease, familial neuropathy, HIV, or any other immune deficiency. In the endoneurium, perivascular inflammatory cell infiltrates were present in only one case, but scattered histiocytes marked by KP1 on paraffin-embedded fragments were present in every case and there were no T-lymphocytes. At ultrastructural examination macrophage-associated demyelination was observed in 17 cases, of which 6 had relapses separated by intervals of several months or years. Axonal lesions without associated primary demyelination were observed in 4 cases and 3 of these had relapses. Thirty-two patients had mixed lesions of demyelination and axonal involvement. This study confirms other recent data indicating that in all cases of CIDP, macrophages are present in the endoneurium. Macrophage-associated demyelination is the characteristic feature of demyelinating forms. On the other hand, isolated primary axonal forms, which have been known since 1989, are relatively frequent and prone to relapses.

Adolescent↗
PubMedDate not supplied

Ocular vicarious menstruation.

Vicarious menstruation represents cyclical bleeding in extragenital organs during a normal menstrual cycle. We present an unusual case of ocular vicarious menstruation (bloody tears) in a 17-year-old girl. The indications and treatment of this rare disorder are discussed.

Adolescent↗
PubMedDate not supplied

Early changes in isokinetic lower limb muscle strength in recovering geriatric subjects on the basis of nutritional status.

BACKGROUND: In older people, the decrease in muscle mass and strength has a bad effect on functional status. Malnutrition and lack of physical activity exacerbate this phenomenon. OBJECTIVE: The main purpose of this study was to estimate isokinetic lower limb muscle strength in recovering older subjects on the basis of nutritional status. DESIGN: Twenty-eight elderly subjects hospitalized for an acute event (85.8 +/- 6 years), including 16 malnourished, were enrolled in this study when clinically stable (T0). Re-assessment at one-month was performed in nine after oral supplementation and conventional physiotherapy (T1). The Maximal Peak Torque (MPT) of the ankle plantar flexors was estimated in concentric mode at 30 and 60 degrees /s. The MPT of the knee flexors and extensors was evaluated in the same mode at 30 degrees /s, 60 degrees /s and 120 degrees /s. All patients underwent a nutritional examination with anthropometric measures, dietary intake survey, biochemical indexes and determination of the medial gastrocnemius volume by magnetic resonance imaging. RESULTS: At T0, whatever the muscle group tested (except at 120 degrees /s for the knee), the MPT appeared significantly lower in the malnourished group. At T1, the increase in MPT (plantar flexors) in malnourished patients was greater at 60 degrees /s (+23.8 %) than at 30 degrees /s (+14.8 %). Correlations between MPT and nutritional parameters were observed in the malnourished group only at T1 and in the normal-nourished group. CONCLUSION: Isokinetic assessment seems to be a pertinent method to estimate lower limb muscle strength in older and frail subjects. Early modifications in strength were observed in malnourished patients who received oral supplementation and physiotherapy.

Aged, 80 and over↗
PubMedDate not supplied

[Unusual ischemic cord compression by discal hernia (author's transl)].

The discal hernia are unfrequent in dorsal localization and neurological appearances are deceptive. We report a case with amyotrophic and fasciculations developing a progressive spinal cord amyotrophy aspect. The complementary investigations (gaz myelography and spinal angiography) show the discal hernia in T11-T12 which was operated successfully. The vascular factor role is discussed about semiologic and pathogenic view.

Humans↗
PubMedDate not supplied

[Anatomical and clinical study of a case of uveitis and multiple sclerosis (author's transl)].

Lesions of the uveal tract can be an ocular manifestation of multiple sclerosis. The authors report on a clinical and anatomical study of a severe case of uveitis in a patient with multiple sclerosis confirmed by an anatomical examination of the nervous system. They review the observations published in the literature which were concerned mainly with clinical findings.

Brain↗