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Biomedical subjects

M Barthelemy

Publications and source records attributed to M Barthelemy.

At least 19 recordsLinked to original sources
PubMed1996

Implication of Ile-69 and Thr-182 residues in kinetic characteristics of IRT-3 (TEM-32) beta-lactamase.

The substitution of a methionine for an isoleucine at position 69 (Met69Ile), which causes inhibitor resistance to TEM-type beta-lactamases (IRT-3 and IRT-I69), altered the positions of the Asn-170 and Glu-166 side chains as well as the position of the catalytic water molecule. A novel hydrogen bond between the hydroxyl of Thr-182 and the carbonyl of Glu-64 was expected to be responsible for the increase in the catalytic activity of the IST-T182 and IRT-3 enzymes compared with those of TEM-1 and IRT-169, respectively.

Catalysis↗
PubMed1996

The distribution of Ag-NORs proteins and ribosomal RNA genes in human spermatogonia: an original procedure associating silver-staining, fish and confocal microscopy.

It is generally accepted that Ag-NORs proteins are associated with nucleolar components engaged in rRNA synthesis. Since conflicting results have been reported concerning the intranucleolar sites of active ribosomal genes, the relationships between the silver-stained areas and the distribution of rDNA were analyzed in human spermatogonia using confocal microscopy of fluorescent in situ hybridized preparations previously stained with silver. The fluorescent signal strictly corresponded to the silver-stained area, identified at the ultrastructural level as the fibrillar center and the surrounding dense fibrillar component. A quantitative evaluation of nucleolar activity solely based on silver-staining may be misleading, taking into account that only Ag-positive proteins located in the dense fibrillar component can be associated with transcriptional activity, while those stored in the fibrillar center are associated with non-transcribed rRNA genes.

DNA, Ribosomal↗
PubMed1996

Cancer in Gabon, 1984-1993: a pathology registry based relative frequency study.

A pathology based cancer registry was established in 1977 in the pathology department of the faculty of health sciences of the University of Omar Bongo in Librevile, Gabon, which is the only pathology service catering to the needs of the population of approximately 1 million of Gabon. Analysis of the histologically diagnosed cancers during 1984 through 1993 revealed 1,367 male and 1,235 female cases. The leading sites in males were: skin (11.0%), liver (8.9%), non-Hodgkin's lymphoma (8.7%), prostate (7.8%), lung (6.9%), mouth (4.9%) and tongue (4.7%). The predominant sites in females were: uterine cervix (26.3%), breast (13.9%), non-Hodgkin's lymphoma (7.1%), skin (5.1%), liver (3.9%) and ovary (3.3%). Considering the little information available on cancer patterns in Africa, even relative frequency data for different periods from different sources are of considerable interest. We propose to establish population based cancer registration in Libreville (pop 400,000) where 40% of the national population lives, in the near future, which should provide reliable information on the cancer burden and patterns in Gabon.

Adolescent↗
PubMed1994

Petroclival meningioma mimicking the presentation of a transient ischemic attack.

A case of petroclival meningioma with pseudo-vascular clinical feature, documented by magnetic resonance imaging, is described. The location of the tumor and the persistent normality of the clinical examination excluded any surgical attempt. Such transient neurological symptoms in case of posterior fossa meningiomas have been seldom reported. Attempts for a physiological explanation are considered.

Aged↗
PubMed1994

[Properties of a cephalosporinase produced by Proteus penneri inhibited by clavulanic acid].

P. penneri produces an inducible cephalosporinase, as many Enterobacteriaceae. Nevertheless this betalactamase is susceptible to clavulanic acid which is an exception also encountered for P. vulgaris. The authors studied the enzyme produced by P. penneri 14HBC resistant to cefotaxime (MIC 16 mg/l) isolated in Spain in 1992. This betalactamase of isoelectric point 6.65 hydrolyzes first generation cephalosporins, amoxycillin and poorly ticarcillin as it occurs for all cephalosporinases. However, this enzyme hydrolyzes strongly oxyimino-cephalosporins: cefuroxime, cefotaxime, cefepime, cefpirome as it occurs with extended-spectrum betalactamases. Cephamycins and imipenem are not substrates. Clavulanic acid has a very good affinity for this betalactamase which is inactivated progressively. These properties are similar to those of the enzyme of P. vulgaris Ro104 of isoelectric point 8.3 which, contrarily to other cephalosporinases, belongs to the structural Ambler's class A.

Anti-Bacterial Agents↗
PubMed1987

Torsade de pointes during loading with amiodarone.

Torsade de pointes represents a potential complication of chronic amiodarone therapy. Several reports have emphasized the need for a loading dose in order to achieve therapeutic blood levels rapidly. We report a case of torsade de pointes following a single oral dose of amiodarone (1400 mg or 30 mg kg-1) administered after short intravenous loading for prevention of paroxysmal atrial flutter. Torsades de pointes were preceded and associated with marked QT prolongation and bradycardia. This report suggests that careful monitoring of patients undergoing oral amiodarone loading is necessary.

Administration, Oral↗
PubMed1986

Classification of beta-lactamases from Branhamella catarrhalis in relation to penicillinases produced by other bacterial species.

Branhamella catarrhalis strains resistant to commonly used penicillins, and presently isolated, produce a beta-lactamase. Most of these enzymes are chromosomally mediated, but a plasmid-mediated beta-lactamase has been described (enzyme BRO-1). With reference to isoelectric points, 7 different enzymes have been identified: 6 chromosomally mediated and 1 plasmid-mediated. Nevertheless, they have many common properties, such as being biosynthesised constitutively but with a low level of production. They have a penicillinase-type profile, and are strongly inhibited by clavulanic acid.

Bacteria↗
PubMed1985

[Cochleo-vestibular attacks of viral origin].

The viral etiology of some cochlear or vestibular lesions is well documented. Concerning the cochlear congenital lesions, the cytomegalovirus is becoming the main etiologic factor, while the rubella vaccination has shown its efficiency in the United States. The acquired hearing or vestibular diseases were briefly reviewed as well as the pathology and their therapeutic considerations.

Cochlea↗