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Biomedical subjects

J Tanzer

Publications and source records attributed to J Tanzer.

At least 37 records · Page 2Linked to original sources

Chromosomal analysis of purified B-chronic lymphocytic leukemia lymphocyte cultures: comparison with whole blood cultures and in situ hybridization.

Chromosomal analysis of stimulated whole blood cells and purified B lymphocytes was performed in 13 stage A(0) and 1 stage C(IV) chronic lymphocytic leukemia (B-CLL) patients. Abnormal clones were found in 6 cases in purified B lymphocytes cultures and in a single one in whole blood cultures. In situ hybridization with a chromosome 12 probe was in accordance with the chromosomal analysis of purified B-CLL lymphocytes and not with the results obtained using whole blood culture. Cytogenetic analysis of isolated B cells is simple and sensitive. It enhances the detection of abnormal clones in B-CLL and applied to larger series of patients, it should allow a precise evaluation of the incidence of chromosomal abnormalities in CLL and of their clinical (prognostic) significance.

Aged↗

Molecular mechanisms of hematologic malignancies.

This article reviews both the role of signal transduction in human cancer and the recently uncovered molecular mechanisms involved in a large number of human hematologic malignancies. Chronic myelogenous leukemia, follicular lymphoma, and colorectal carcinoma are used as models to illustrate the different, as well as partly convergent, molecular pathways involved in the multistep process of human neoplasias. Examples are also provided as to how unique molecular markers can be used as fast, sensitive, and precise tools for cancer prevention, early diagnosis, and the management of residual disease.

Base Sequence↗

Improvement of cytogenetic results in B-cell chronic lymphocytic leukemia using immuno-purified leukemic cells.

Cytogenetics of purified B lymphocytes and whole blood cultures were studied in 14 patients with B-CLL and fluorescence in situ hybridization (FISH) was performed on interphase cells in 12 of these cases in order to detect trisomy 12. Only one minor abnormal clone was found on whole blood cell cultures, clonal anomalies were found in a large proportion of mitoses of 6/14 cultures of purified B cells. FISH detected a trisomy 12 in a case, not found in whole blood cultures but found in 78% metaphases of cultures of purified B lymphocyte. This method may be as sensitive as FISH for the detection of trisomy 12 and improves the detection of clonal abnormalities in CLL.

Adult↗

Quantitative determination of the hybrid Bcr-Abl RNA in patients with chronic myelogenous leukaemia under interferon therapy.

In vitro amplification of the Bcr-Abl cDNA has been widely used to assess for the presence of minimal residual disease in patients with chronic myelogenous leukaemia (CML) presenting with complete clinical and cytogenetic remission. However, the level of sensitivity achieved in different laboratories remains largely unknown. Moreover, the results are usually expressed as positive or negative, making a precise follow-up of the patients difficult. In an attempt to overcome these limitations, we devised a quantitative method to measure the amount of Bcr-Abl mRNA in clinical samples. This methodology involves a single reverse transcription step, followed by separate amplifications of Bcr-Abl and total Abl mRNA. These two amplifications are performed in the presence of different dilutions of a same internal standard. This standard consists of Bcr-Abl sequences with an eight bases deletion in exon 2 of Abl. One of the primers used in each separate reaction is labelled with fluorescein. Following amplification, PCR products derived from cellular RNA and those from the internal standard are separated and their relative fluorescence is determined using a laser fluorescent DNA sequencer (ALF, Pharmacia). The number of Bcr-Abl and total Abl mRNA molecules initially present in each sample is then calculated. The accuracy and reproducibility of this method was assessed by studying serial dilutions of K562 RNA into normal RNA. Blood samples from 10 patients in cytogenetic remission under interferon therapy were studied. Only one sample was found negative while the others contained between 0.05 and 17 hybrid Bcr-Abl mRNA molecules per 1000 molecules of Abl mRNA. These results suggest that a variable number of malignant cells are present in the majority of CML patients in cytogenetic remission following interferon therapy.

Adult↗

[Prognosis of chronic myeloid leukemia].

The prognosis of chronic myelocytic leukemia is a current topic owing to the new treatments that have been proposed for this malignant blood disease which, a few years ago, was lethal within 3 to 4 years due to the inescapable occurrence of the terminal acute transformation. Beside bone marrow allograft, which is known to have cured a non-negligible number of patients, the most recent use of interferons offers a reasonable therapeutic alternative to those patients who cannot be allografted. The identification of prognostic variables at the time of diagnosis has become necessary for a better determination of therapeutic indications. The analysis of large published series has made it possible to construct mathematical models which have proved efficient and have been confirmed by prospective studies. The value of new techniques, such as molecular biology, to refine the mathematical models remains to be demonstrated.

Actuarial Analysis↗

Recurrent ctb(7)(q31.3) and possible laminin involvement in a neonatal cutis laxa with a Marfan phenotype.

A 6-week-old girl presented with cutis laxa, emphysema, heart anomalies and a diaphragmatic hernia. She died at 22 weeks. A recurrent ctb(7)(q31.3) was found and the laminin gene was suspected to be involved in the disease. Anti-human laminin antiserum showed that this protein was absent from the skin. This case, together with 17 other similar cases, could represent a new type of connective tissue disease.

Cells, Cultured↗

Two additional cases of isochromosome 21q or translocation 21q21q in hematological malignancies.

We report on 2 patients with isochromosome 21q [i(21q)] or translocation 21q21q [t(21q21q)] in myeloid disorders. Of 18 available cases of i(21q) or t(21q21q), 15 were found in myeloid malignancies, often secondary to a previous carcinogen exposure. Complex karyotypes were found in most cases. Four cases presented with i(21q) or t(21q21q) as the sole anomaly, and this might represent a specific entity.

Aged↗

Nosocomial legionnaires' disease in a bone marrow transplant unit.

We report the outcome of nosocomial legionnaires' disease in three patients who were isolated in the same sterile unit after allogeneic bone marrow transplantation. In all three cases the disease presented with dramatic pulmonary symptoms, and diagnosis was ascertained by direct immunofluorescence on bronchoalveolar fluids. None of the patients underwent seroconversion. This report draws attention to: (1) the fact that bacteriological filters do not ensure absolute security; (2) the need for frequent monitoring of the two factors governing legionella growth, water temperature and chlorination; and (3) the effectiveness of quinolones as a curative and prophylactic treatment of legionnaires' disease in transplanted patients avoiding pharmacological cyclosporin interaction.

Adult↗

[Early acroparesthesia in females: a sign disclosing heterozygote Fabry disease].

Heterozygous Fabry's disease has an inconstant expression and very few complications. The theory of X-chromosome inactivation which, according to Lyon, occurs hazardly, is illustrated by the fact that the disease is expressed even in hemizygous women. Ophthalmic manifestations, as detected by the slit lamp method, are almost constant, 80 p. 100 of women with the disease having a verticillate cornea. Angiokeratoma is present in 20 p. 100 of the cases. Episodes of paraesthesia of the hands and feet are less common; in most cases they are attributed to the disease retrospectively, during family investigations. In two girls aged 10 and 11 years respectively and without history of Fabry's disease the only symptom suggestive of the diagnosis was paroxysmal acroparaesthesia. In one of the girls acroparaesthesia was associated with acrocyanosis, livedo and acro-osteolysis, but concordance was the only argument in favour of a link with Fabry's disease. Alterations of the extremities have been reported in this disease, including palmar erythema and a bluish discoloration of the palms due to dilatation of the superficial veins. Only two cases of livedo have been published. Acrosteolysis has never been documented in Fabry's disease, and its presence must be confirmed in further cases. The diagnosis of heterozygous Fabry's disease in these 2 girls was confirmed by the finding of ceramide trihexoside in urine and by leucocyte alpha-galactosidase levels that were 25 to 30 p. 100 of values obtained in controls. A study of the family of one of the girls showed that the father was involved; this hemizygous type of the disease with a 10 p. 100 alphagalactosidase level was totally asymptomatic.(ABSTRACT TRUNCATED AT 250 WORDS)

Acrodermatitis↗