Submyeloablative cord blood transplantation corrects clinical defects seen in IPEX syndrome.
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Biomedical subjects
Publications and source records attributed to D Ungar.
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Most of the completely sequenced prokaryotic genomes contain genes of potassium channel homologues, but there is still not much known about the role of these proteins in prokaryotes. Here we describe the large-scale overproduction and purification of a prokaryotic voltage-gated potassium channel homologue, Kch, from Escherichia coli. After successful overproduction of the protein, a specific increase in the potassium permeability of the cells was found. Kch could be purified in large amounts using classical purification methods to prevent aggregation of the protein. The physiological state of the protein was revealed to be a homotetramer and the protein was shown to be localized to the cytoplasmic membrane of the cells. In the course of the localization studies, we found a specific increase in the density of the cytoplasmic membrane on Kch production. This was linked to the observed increase in the protein to lipid ratio in the membranes. Another observed change in the membrane composition was an increase in the cardiolipin to phosphatidylglycerol ratio, which may indicate a specific cardiolipin requirement of Kch. On the basis of some of our results, we discuss a function for Kch in the maintenance of the membrane potential in E. coli.
The natural history of chronic hepatitis C (HCV) infections in long-term leukemia survivors has not been well characterized. We studied the prevalence of HCV infections, measured HCV RNA levels, and evaluated the severity of liver disease in patients with leukemia who achieved long-term remissions after intensive chemotherapy or bone marrow transplantation (BMT). HCV antibody tests were performed by the enzyme-linked immunosorbent assay (ELISA) and positive tests confirmed by the recombinant immunoblot assay (RIBA). HCV RNA levels were measured by the branched DNA (bDNA) assay. Seventy-five leukemia survivors with 25 or more blood donor exposures were identified. Nine (12%) were anti-HCV positive. All were infected before 1992 when second generation HCV screening tests were implemented. Mean HCV RNA levels were 10.3 x10(6) eq/mL versus 3.2 x 10(6) eq/mL (P =.056) in a control group of 20 anti-HCV positive immunocompetent individuals of comparable age who were infected twice as long (17.8 +/- 6.5 years v 9.0 +/- 4.4 years in leukemia survivors, P =.001). Liver biopsies were performed on six of the nine anti-HCV positive leukemia survivors. All showed at least moderate portal inflammation and half had evidence of bridging fibrosis. We conclude that viral loads in anti-HCV positive leukemia survivors are markedly higher than in immunocompetent controls. Our results suggest that long-term leukemia survivors with chronic HCV may have more rapidly progressive liver disease than has been previously recognized.
Autophonia, the hyperperception of one's own voice and breathing, is one of the consequences of rapid weight loss and is explained within the syndrome of the patulous eustachian tube. We report on a female adolescent, who presented to an otologist for autophonia and was finally diagnosed with anorexia nervosa. The occurrence and relevance of this symptom in eating-disorder patients is discussed.
For neuromuscular patients with progressive respiratory muscle weakness a new training apparatus was developed, which allows a home training of strength as well as endurance of the inspiratory muscles, especially the diaphragma. A significant positive training result could be proved in a comparative study between 2 groups of 15 Duchenne muscular dystrophy (DMD) patients each (8). By the end of the training the satisfaction of patients with the new training equipment was evaluated by means of a questionnaire. The degree of satisfaction was determined at a 10-point scale. Critical ideas were used for improvement of the newly developed training apparatus.
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We have developed a data base of lymphoid proteins detectable by two-dimensional polyacrylamide gel electrophoresis. The data base contains two-dimensional patterns and derived information pertaining to polypeptide constituents of unstimulated and stimulated mature T cells and immature thymocytes, single-cell-derived T- and B-cell clones, leukemia cells, and lymphoid cell lines. Using this data base, we have compared the protein constituents of mature T cells and immature thymocytes before and after mitotic stimulation. A subset of polypeptides that are induced in mature T cells following mitotic stimulation were found to be constitutively expressed in immature thymocytes. Other polypeptides exhibited differences in their expression between mature and immature thymocytes in a manner unrelated to proliferation. The identity of several constitutively expressed or mitotically induced proteins in lymphoid cells was established by microsequencing. These initial findings point to significant differences in the molecular pathways leading to proliferation between mature and immature T cells. The construction of this database should facilitate further studies of lymphoid differentiation and function.
Recent evidence suggests that the human interferon-inducible double-stranded RNA-dependent protein kinase may function as a tumor suppressor. Here we describe the mapping of the gene for this kinase to chromosome region 2p21-22 by fluorescence in situ hybridization. A combined analysis of cytogenetic data from a series of 341 patients with hematologic disorders that exhibited cytogenetic abnormalities and from published reports indicates that abnormalities involving 2p21-22 occur nonrandomly and are observed among patients with acute myelogenous leukemia, raising the possibility of a role for this protein kinase in leukemogenesis.