Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0024312 (lymphopenia)
 4,859 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the present study we evaluated the possibility that patients with severe combined immunodeficiency (SCID) might be deficient in lymphoid progenitor cells in bone marrow. Bone marrow from six patients with SCID was studied for the presence of cells expressing antigens associated with the earliest known stages of lymphopoiesis--terminal transferase (Tdt), the common acute lymphocytic leukemia antigen (CALLA), and p24. Four of six patients had detectable Tdt+, CALLA+, and p24+ cells, although they were quantitatively reduced compared to results from normal infant marrow. In two of six patients no bone marrow mononuclear cells expressing any of these markers were detected. These two patients were more lymphopenic than the other four SCID patients. The absence or deficiency of Tdt+, CALLA+, and p24+ bone marrow cells in some patients with SCID (two of six in the present study) is consistent with the lymphopenia seen in these patients and suggests that the underlying defects which result in SCID affect the production of immature as well as more differentiated lymphocytes.
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PMID:Lymphoid progenitor cells in severe combined immunodeficiency. 387 11

The amounts of cell-surface glycosphingolipids and plasma membrane enzymes produced on the peripheral blood mononuclear cells (PBMNCs) isolated from 101 intravenous drug users (IDUs), of whom 91 were HIV-1 seropositive, were examined. Seronegative IDUs and age-matched healthy donors served as controls. The numbers of circulating CD3+, CD4+, and CD8+ T lymphocytes decreased during the advanced stages of the infection. There were also fewer CD4+ T-helper cells in HIV-1--seronegative IDU drug addicts. PBMNCs from HIV-1--seropositive subjects had abnormal surface enzyme kinetics. The phospholipase C had two pH optima, whereas the enzyme on normal cells has only one. The specific activity in cells from AIDS subjects was 4 times lower than that in normal PBMNCs. 5'-Nucleotidase showed a similar trend, whereas neutral endopeptidase activity did not correlate with the amounts of surface common acute lymphoblastic leukemia antigen (CALLA). These enzyme activities were decreased in HIV-seronegative IDUs. The subcellular distribution of enzymes and the profile of surface glycosphingolipids were also markedly changed, indicating the profound alterations in the membranes of PBMNCs from HIV-1--seropositive IDUs. These data suggest that intravenous drug use compromises the biochemical and structural integrity of the membrane surface of PBMNCs even before the onset of HIV.
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PMID:Changes in membrane enzymes and glycosphingolipids in lymphocytes from HIV-1--infected and noninfected intravenous drug users. 855 2