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Biomedical subjects

K Dellagi

Publications and source records attributed to K Dellagi.

At least 91 records · Page 5Linked to original sources

Molecular cloning of a novel human hsp70 from a B cell line and its assignment to chromosome 5.

A 2391-bp cDNA encoding a novel human hsp70, named hsp70 RY, is described. It was cloned from a cDNA library constructed using mRNA derived from an established EBV-transformed B cell line from a patient with leukocyte adhesion molecule deficiency. hsp70 RY is 701 amino acids long, has the characteristic N-terminal ATP-binding domain and the C-terminal peptide binding domain, and contains four potential N-glycosylation sites. Northern blotting revealed a single mRNA species of 3.0 kb in total RNA prepared from the patient's EBV cell line. In situ hybridization localized the single copy hsp70 RY gene to the long arm of chromosome 5 at 5 q31.1-5 q31.2.

Amino Acid Sequence↗

Large-scale DNA fingerprinting of Mycobacterium tuberculosis strains as a tool for epidemiological studies of tuberculosis.

We conducted a large-scale DNA fingerprinting analysis of Mycobacterium tuberculosis strains in a country in which tuberculosis is endemic (Tunisia) in order to evaluate the importance of microepidemics in the maintenance of the disease within the population. The genetic polymorphisms of 201 strains of M. tuberculosis isolated from 196 unrelated patients living in four districts of northern Tunisia during a 3-year period were studied by restriction fragment length polymorphism (RFLP) analysis by using the insertion sequence IS6110 as a probe. Seventy-three strains isolated from 68 patients living in the districts of Tunis, Nabeul, and Jendouba generated 67 different RFLPs, indicating a high degree of polymorphism of the M. tuberculosis strains within these areas. In contrast, the 128 strains isolated from individuals in the district of Menzel Bourguiba appeared much less heterogeneous since they often generated identical or very similar fingerprints. Seventeen of 29 cases (58%) of active tuberculosis in the city of Menzel Bourguiba could be traced to as few as four M. tuberculosis strains. These results indicate the persistence of underestimated microepidemics in this region. The RFLP typing of a large number of randomly collected strains provides a general picture of the strains involved in tuberculosis. The systematic study of limited areas where tuberculosis is endemic can provide evidence for the existence of persisting epidemics. This stresses the different problems which remain to be solved in order to improve the control of tuberculosis.

DNA Fingerprinting↗

Childhood peripheral neuropathy with autoantibodies to myelin glycoprotein P0.

The serum of a 4-year-old child with severe hypertrophic peripheral neuropathy contained high-titer polyclonal antibodies, mainly of IgG class, reacting with the 30-kd P0 glycoprotein of peripheral nerve. This was demonstrated by indirect immunofluorescence, immunoblot analysis of myelin proteins, and enzyme-linked immunosorbent assay with purified P0 glycoprotein. The antibodies did not react with myelin-associated glycoprotein, sulfated glycuronic acid-containing paragloboside (SGPG and SGLPG), or other peripheral nerve glycolipids or gangliosides. To our knowledge this is the first report of strong antibody activity specifically directed against P0. This antibody may play a causative role in the pathogenesis of the peripheral neuropathy in this patient.

Autoantibodies↗

Alpha heavy chain disease alpha mRNA contain nucleotide sequences of unknown origins.

Human alpha heavy chain disease is characterized by the production of abnormally short alpha IgH chains. In previously published cases it has been found that the malignant cells produce abnormal alpha mRNA, lacking VH and CH1 sequences and composed of a leader sequence peptide, sequences of variable length (69 to 84 bp) and of unknown origin, followed by normal CH2 and CH3 sequences. In this study we established the nucleotide sequence of alpha mRNA for six cases of alpha heavy chain disease. We observed that all six alpha mRNA lack the VH and CH1 sequences as do those previously described. They also contain in-frame inserts of unknown origin between the leader peptide and the normal CH2 and CH3 coding sequences. These inserts are of variable length (42 to 105 bp) and they are unrelated. These results suggest the existence of a common mechanism defect leading to deletions/insertions in alpha heavy chain disease rather than a specific interaction between alpha 1 IgH gene with a unique defined molecular species.

Amino Acid Sequence↗

A human monoclonal IgG reactive with a private idiotope of a monoclonal IgM with autoantibody activity against myelin-associated glycoprotein.

One hundred and thirteen sera from patients with monoclonal IgG were tested for reactivity against a panel of 13 human monoclonal IgM having various autoantibody activities: 6 to myelin-associated glycoprotein (MAG), 2 to vimentin intermediate filament protein and 5 to red blood cell antigens [cold agglutinins with specificity directed to I antigen (3 cases), i antigen (1 case) or Pr antigen (1 case)]. One IgG was found to react with a monoclonal IgM with anti-MAG activity. This reactivity was characterized as idiotypic and directed against a private idiotope of the monoclonal IgM. This work provides further evidence for the existence of anti-idiotypic antibody activity of monoclonal Ig occurring in human B cell neoplasias.

Antibodies, Anti-Idiotypic↗

Purification and characterization of a fibrinogenase from Vipera lebetina (desert adder) venom.

A fibrinogenase from Vipera lebetina venom was isolated by gel filtration in a Superose 12 column prep grade HR 16/50 and by ion-exchange in a Mono Q HR 5/5 column. The purified enzyme, which was obtained with a yield of 8 mg from 60 mg of crude venom, is a glycoprotein having an isoelectric point of 5.9 +/- 0.1 and a mol. wt of 26,000 +/- 1000 as estimated by SDS-PAGE. The biochemical characterization of the enzyme revealed that it hydrolyzes readily the B beta chain of fibrinogen and the A alpha chain as well as fibrin and casein. Over a pH range from 4 to 11 the enzyme was not inactivated by a 20 min treatment at 90 degrees C. The isolated fibrinogenase is inhibited by ethylenediamine tetraacetic acid, dithiothreitol and L-cysteine but not by phenylmethylsulfonyl fluoride. On the other hand, it is activated by Ca2+ and Mg2+. Purified fibrinogenase up to a dose of 100 micrograms/mouse shows no toxicity and has no hemorrhagic activity.

Animals↗

Expression of a public idiotype by human monoclonal IgM directed to myelin-associated glycoprotein and characterization of the variability subgroup of their heavy and light chains.

Most studies using rabbit or mouse antisera failed to detect CRI between human IgM directed to MAG. We show here that 9 of 10 such IgM express a public CRI as defined by a nonhuman primate antiserum. Shared idiotype is likely involved in (or close to) the combining site of those IgM since antiidiotypic serum inhibited the binding of IgM to MAG and reacted with IgM having different variable regions of light and heavy chains. Partial aminoterminal sequence of heavy and light chains showed that anti-MAG IgM use either lambda chains (one IgM) or kappa light chains (six IgM) of different variability subgroups (V kappa IV in three instances, V kappa I in two, and V kappa II in one), whereas heavy chains belong to the VHIII (six IgM) or to the VHII (1 IgM) subgroup. These features distinguish these IgM from other human monoclonal IgM with a defined antibody activity, such as rheumatoid factors or cold agglutinins.

Amino Acid Sequence↗

Factor requirements for activation and proliferation steps of human CD2+CD3-CD4-CD8- early thymocytes.

Human CD2+CD3-CD4-CD8- thymocytes were shown to display high in vitro growth ability although their factor requirements for activation and proliferation are not fully known. We have thus isolated these precursors and assayed their activation and proliferation potentials in response to various factors. Our results indicate that these cells proliferate in response to phytohemagglutinin (PHA), recombinant interleukin 2 (rIL 2) and rIL 4. Simultaneous addition of anti-CD2I + III monoclonal antibodies (mAb) and rIL 2 highly increased cell growth while IL 4-induced proliferation was not enhanced upon addition of anti-CD2. Anti-CD2 and PHA, but not IL 2, induced intracytoplasmic Ca2+ influx phosphatidyl inositol turnover as well as IL 2 receptor expression. Sequential studies indicated that CD2 triggering enable many more CD2+ precursors to respond to rIL 2. Endogenous IL 2 synthesis was necessary for PHA-induced cell growth. Neither of these in vitro treatment were able to induce membrane expression of CD3, CD4 or CD8 on CD2+ cells.

Antigens, CD↗

Effect of passive transfer of human anti-myelin-associated glycoprotein IgM in marmoset.

Adult and one week old marmosets were injected intravenously within a one month period or intraperitoneally within a 6 week period respectively, with monoclonal IgM having an anti-myelin associated glycoprotein antibody activity. No clinical or electrophysiological abnormalities could be detected in experimental animals. However, indirect immunofluorescence studies showed IgM deposition in close contact to myelin sheaths. Minor but distinct alterations of nerves were found in the adult: the enlargement of Schmidt-Lanterman incisures seen in electron microscopy could explain the decrease of the proportion of fibers of small diameter found by morphometry of semi-thin section, and the reduction of the mean internodal length in fibers of a given diameter seen in teased nerve fibers studies.

Animals↗

[Carcinoid of the larynx. Well-differentiated neuroendocrine carcinoma. Apropos of 4 cases].

Four new cases of carcinoid (or well differentiated neuroendocrine carcinoma) of the larynx are reported. This tumor has been recognized since 1969 and may be misdiagnosed as a poorly differentiated carcinoma or adenocarcinoma if the Grimelius stain is not done. Chromogranin A, detected by immunocytochemical methods, is also a good marker of these tumors. The analysis of 41 previously published cases allows a better knowledge of this clinico-pathological entity. The main locations are supraglottic and the prognosis is poor which is very different from the bronchial carcinoid.

Female↗

[Pneumoblastoma. Report of a case. Immunohistochemistry and discussion of histogenesis].

A case of pulmonary blastoma in a 50-year old man is reported. The initial diagnosis was one of pulmonary hydatid cyst, but at surgery a solid tumour of the left upper lobe was discovered. The histological study showed the characteristic features of pulmonary blastoma with its two components: epithelial and mesenchymatous. Immunohistochemistry yielded a double cellular response to keratin and vimentin--a finding which supports the hypothesis of a tumour arisen from a multipotent cell.

Humans↗