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Biomedical subjects

J Fraisse

Publications and source records attributed to J Fraisse.

At least 55 records · Page 3Linked to original sources

Determination of betaxolol, a new beta-blocker, by gas chromatography mass spectrometry: application to pharmacokinetic studies.

Betaxolol, a beta selective adrenoceptor antagonist recently approved for the treatment of hypertension, was determined by monitoring in chemical ionization mode with ammonia the [MH]+ ions of the trimethylsilyl derivatives of the drug and of its internal standard [2H5)betaxolol). Its pharmacokinetic profile obtained following administration of a 20 mg oral dose was characterized by a half-life of 22 h and a bioavailability of 85%. The main acid metabolite formed by elimination of the isopropylamino group may also be determined as the methyl TMS derivative but methylation with BF3-methanol should be used with caution since it may induce the opening of the cyclopropyl group. The routine electron capture determination procedure was compared to this mass spectrometric method and an excellent correlation was found (r = 0.9974). Both procedures have the same sensitivity (1 ng ml-1). Finally it was observed that under electron impact mode betaxolol trimethylsilyl side chain rearranged to lose TMS-O-CH=CH2; this elimination was confirmed by deuterium labelling studies.

Adrenergic beta-Antagonists↗

[Chromosome abnormalities in acute granulocytic leukemias or in non-lymphoid acute leukemias].

Chromosome anomalies, structural and/or numerical changes are present in about 50% of acute non lymphoïd leukemia (ANLL). They are non-random: chromosome 8, 7, 5 and 11 being more frequently involved. Correlations between chromosomal anomalies and type of proliferation have been established: translocation t (8;21) and acute myeloblastic leukemia M2; translocation t (15;17) and acute promyelocytic leukemia M3; structural anomalies of chromosome 11 long arm and acute monoblastic leukemia M5. A relationship between prognosis and leukemic karyotype has been found. Median survival is generally longer in patients with normal karyotypes. Future studies may correlate chromosome anomalies and metabolic changes with the help of progress in gene mapping. A better knowledge will provide not only a better therapy but also a better understanding of the leukemic process.

Chromosome Aberrations↗

[Cytogenetic study of acute leukemia].

Chromosome banding techniques have been useful to define abnormal chromosomes in acute leukemia. The comparison between cases reported from different centers has been possible only with the acceptance of a universal system of classification and nomenclature for acute leukemia as well as for chromosomal rearrangements. Chromosomes abnormalities in acute leukemia are found in about 50 per cent of patients. They appear to be non random. Clinical, morphologic and cytogenetic findings have been correlated. Diagnosis and prognosis significance of chromosome abnormalities is of importance. The problem of normal or so called normal cells in 50 per cent of acute leukemia is set.

Acute Disease↗

A simple combined Ag-I/RHG technique for human metaphase chromosomes.

A combination of the Ag-I staining method of the human nucleolus organizer regions (NORs) with an RHG banding method is described. This technique gives a reliable identification of each of the Ag + NOR acrocentric chromosomes. Its probable chemical nature is discussed.

Chromosome Banding↗

[Polymorphism of NOR bands in a normal French population].

The segregation of NORs-Ag positive and negative acrocentric chromosomes was studied with a combined staining technique (Ag-I/RHG), in a normal French population (Saint-Etienne, Loire, France). The observed frequencies of homozygous and heterozygous NOR-Ag individuals, either for each acrocentric pair or for all the pairs of acrocentric chromosomes are not statistically different from the ones expected according to Hardy-Weinberg's law. The genotypic frequencies of homozygous subjects (+/+) for each acrocentric pair are the following: 13: 0,900; 14: 0,895; 15: 0,880; 21: 0,900 and 22: 0,870. The average modal number of NOR-Ag positives for the sample is 8,58 +/- 0,81. The comparison between these results and other data from European Caucasian populations, was possible by using the same criteria of classification. The discriminative value of NOR banding polymorphisms is discussed.

Cells, Cultured↗

[Partial monosomy 20q : a new syndrome. Regional assignment of the ADA locus on 20q132 (author's transl)].

A karyotype 46,XY,20q-(q13 leads to qter) was found in an infant with severe mental deficiency, epilepsy, and the following dysmorphic features : upward slanting palpebral fissures, hypoplastic nasal bridge, bulbous nose, long philtrum, microretrognathia, and aplasia of the middle phalanx of fingers and toes. Adenosine deaminase activity was within the hemizygous range, permitting regional assignment of the ADA locus to 20q13 leads to qter.

Abnormalities, Multiple↗

[Introduction to the cytogenetic study of acute leukemias].

Chromosome banding techniques have been useful to define abnormal chromosomes in acute leukemia. The comparison between cases reported from different centers has been possible only with the acceptance of a universal system of classification and nomenclature for acute leukemia as well as for chromosomal rearrangements. Chromosomes abnormalities in acute leukemia are found in about 50 per cent of patients. They appear to be non random. Clinical, morphologic and cytogenetic findings have been correlated. Diagnosis and prognosis significance of chromosome abnormalities is of importance. The problem of normal or so called normal cells in 50 per cent of acute leukemia is set.

Acute Disease↗

[Chromosome anomalies in acute granular leukemias or acute nonlymphoid leukemias].

Chromosome anomalies, structural and/or numerical changes are present in about 50% of acute non lymphoid leukemia (ANLL). They are non-random: chromosome 8, 7, 5 and 11 being more frequently involved. Correlations between chromosomal anomalies and type of proliferation have been established: translocation t (8;21) and acute myeloblastic leukemia M2; translocation t (15;17) and acute promyelocytic leukemia M3; structural anomalies of chromosome 11 long arm and acute monoblastic leukemia M5. A relationship between prognosis and leukemic karyotype has been found. Median survival is generally longer in patients with normal karyotypes. Future studies may correlate chromosome anomalies and metabolic changes with the help of progress in gene mapping. A better knowledge will provide not only a better therapy but also a better understanding of the leukemic process.

Chromosome Aberrations↗

EBV-positive Burkitt's lymphoma from Algeria, with a three-way rearrangement involving chromosomes 2, 8 and 9.

Burkitt's lymphoma was diagnosed in male Algerian child presenting with abdominal and jaw tumours. Viral studies revealed that this non-endemic case was associated with the Epstein-Barr virus. Cytogenetic examination of tumour cells showed a complex three-way rearrangement involving chromosomes 2, 8 and 9. Our report indicates that, in Burkitt's lymphoma, not only simple but also complex translocation involving chromosome 8 may arise. This finding in a North African case emphasizes the need for more detailed study of the clinical, virological and cytogenetic features of Burkitt's lymphoma throughout the world.

Burkitt Lymphoma↗

Variant translocation in Burkitt's lymphoma: 8;22 translocation in a French patient with an Epstein-Barr virus-associated tumor.

A variant translocation t(8;22)(q23;q11) has been found in tumor cells from a 19-year-old white man with an Epstein-Barr virus-associated Burkitt's lymphoma (BL). The tumor, which appeared 2 years after the patient had infectious mononucleosis, bore histopathological features characteristic of BL, although only the lymph nodes in the cervical region were involved. This case and some other recent cytogenetic observations of nonendemic BL emphasize the importance of chromosome #8 rearrangement in this B-cell-type lymphoma.

Adult↗