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Biomedical subjects

V David

Publications and source records attributed to V David.

At least 145 records · Page 8Linked to original sources

HLA-A, B and DR antigen frequencies in patients with AIDS-related persistent generalized lymphadenopathy (PGL) and thrombocytopenia.

HLA-A, B, DR phenotype frequencies were studied in 69 homosexual patients with persistent generalized lymphadenopathy (PGL), in 8 patients with LAV/HTLV III related thrombocytopenic purpura and in 21 homosexual controls. Antigen DR5 was significantly increased in PGL patient groups as compared to controls. Our findings suggest that genetic factors associated with HLA-DR5 antigen may predispose individuals infected by the LAV/HTLV III virus to the occurrence of PGL and/or thrombocytopenia.

AIDS-Related Complex↗

A study of 609 HLA haplotypes marking for the hemochromatosis gene: (1) mapping of the gene near the HLA-A locus and characters required to define a heterozygous population and (2) hypothesis concerning the underlying cause of hemochromatosis-HLA association.

We compared 609 haplotypes carrying the idiopathic hemochromatosis allele with 475 control haplotypes. Four haplotypes were more frequent in hemochromatosis: A3, B7 (actually A3, CW., B7, Bfs, DR2); A3, B14 (actually A3, CW., B14, BfF, DRW6); A11, B35; and A11, B5. The linkage disequilibrium for A3, B7 and A3, B14 (and probably also for A11, B5) was undeniably stronger in hemochromatosis than in controls. Two haplotypes--A3, B12 and A3, B15--were more frequent in hemochromatosis, without linkage disequilibrium. Four haplotypes in linkage disequilibrium in hemochromatosis--i.e., A2, B12; A1, B8; A9, B7; and A29, B12--were also found to have the same frequency and strength of linkage in controls. The dual observation (1) that haplotypes carrying A3 without either B7 or B14 were highly significantly more frequent in hemochromatosis than in controls and (2) that haplotypes carrying B7 or B14 but not A3 had the same frequency in hemochromatosis and controls led to the formal conclusion that only A3 is an independent marker for the hemochromatosis allele, B7 and B14 being involved only owing to the haplotypic mode of marking; the hemochromatosis allele can thus be mapped closer to locus A than to locus B. Our findings fit well with the hypothesis that the hemochromatosis mutation was a rare if not unique event that produced an ancestral HLA marking that was subsequently modified by recombinations and geographical scattering due to migrations.

Alleles↗

DNA polymorphism related to the idiopathic hemochromatosis gene: evidence in a recombinant family.

The metabolic error involved in idiopathic hemochromatosis, as well as the underlying genetic defect remain unknown. It has, however, been recently shown that this genetic lesion occurs at a locus linked to the major histocompatibility complex, probably close to the HLA-A locus, and that the disease is recessively transmitted. Therefore, in a family where one subject has idiopathic hemochromatosis his HLA-identical siblings should also be affected. We present here the restriction polymorphism with two MHC class I probes and one DR beta probe in an exceptional family with three HLA-identical siblings: one (the proband) has a major form of idiopathic hemochromatosis, while the other two are free of any clinical or biochemical signs of the disease. The restriction patterns observed after DNA digestion by enzymes EcoRI, EcoRV, BglII, BamHI, PvuII, TaqI, HincII, and HindIII led to the conclusion that one of the proband's chromosome 6 had undergone two alterations: one, a deletion in the DR region, was revealed by missing fragments all correlated with DR5; the other was an unbalanced cross-over or a genetic conversion in the MHC class I region. This latter alteration was revealed by modifications in the patterns of high molecular weight HindIII bands which hybridize with probe pHLA2 and also by the absence of a HindIII fragment of 7.4 kb hybridized by another class I probe. This latter alteration most likely involved the hemochromatosis gene and could be the first step toward a molecular approach to this gene.

Adult↗

[HLA typing in patients with chronic adenopathies in a population at risk for AIDS].

HLA-A B and DR typing were performed in 77 patients with AIDS related complex (ARC)--69 lymphadenopathy associated syndrome and 8 thrombocytopenic purpura LAV/HTLV III related--and 21 symptom free homosexual males. A significant increase in the frequency of HLA DR5 antigen was observed in patients with ARC mainly in purpura thrombocytopenic patients. We suggest that increase of HLA DR5 antigen support the view that DR5 antigen could be one of the factors necessary at the spreading out clinical symptoms.

AIDS-Related Complex↗

[Management of diabetes during operative procedures].

The described basic scheme for the peroperative care of patients with diabetes mellitus which was for many years successfully used proved to be very efficient and improves the interdisciplinary care. On the basis of a standardized infusion programme in which the carbohydrates are given in combination as glucose and sorbite in many type II diabetics administrations of insulin and tolbutmide may be avoided. Modern anaesthesia techniques have a sedative effect on the postaggression syndrome. The change to oral fluid and food supply takes place as early as possible with adequate good results and advantages also after abdominal interventions. The diabetic and postoperative metabolism have both a common disturbed utilization of glucose which lead to catabolism with increased gluconeogenesis and lipolysis and additionally evoke complications. The necessary therapeutic measures may also be used in other non-postoperative postaggression syndromes without presence of diabetes mellitus. It is particularly referred to the dangers of a too schematic approach.

Anesthesia, Local↗

Gene clusters governing the production of hemolysin and mannose-resistant hemagglutination are closely linked in Escherichia coli serotype O4 and O6 isolates from urinary tract infections.

The genes encoding alpha-hemolysin and mannose-resistant hemagglutination were shown to be closely linked in cloned DNA from two Escherichia coli urinary tract isolates of serotypes O4 (J96) and O6 (C1212). DNA hybridization experiments demonstrated that the hly and mrh gene clusters of other E. coli O6 serotypes were also linked. Colony hybridizations showed that most normal fecal E. coli do not contain hly and mrh DNA but much of the intervening DNA between these two gene clusters is common among all E. coli. We have further demonstrated that there is a small (about 1 kilobase) region of homology located on both sides of the hly sequence and present elsewhere in the C1212 strain. We suggest that linkage of hly and mrh occurred through a transposition event, and we discuss the potential significance of this linkage in the acquisition of virulence determinants by these bacteria.

Base Sequence↗

Properdin factor B (Bf) polymorphism: subtyping of SS phenotypes.

The authors have studied the genetic polymorphism of the properdin factor B (Bf) by the isoelectrofocusing technique. The SS phenotypes, all similar on agarose gel electrophoresis, were shown to be heterogeneous after isoelectrofocusing; this heterogeneity corresponds to the expression of two new suballeles SA and SB, inherited in a codominant manner. Gene frequencies for 121 individuals with SS phenotype are 0.57 for SA, and 0.43 for SB.

Alleles↗

Serum lysosomal acid hydrolase activities in Graves' disease.

The activities of seven lysosomal enzymes (alpha-D-glucosidase, beta-D-galactosidase, beta-D-glucuronidase, hexosaminidase, alpha-L-fucosidase, alpha-D-mannosidase, acid phosphatases) were studied in the serum of 31 untreated patients with Graves' disease, 30 treated hyperthyroid patients whose clinical abnormalities had disappeared and whose hormones had returned to euthyroid levels, and 34 controls. The hyperthyroid state is characterized by increased serum levels of alpha-D-glucosidase, beta-D-glucuronidase, hexosaminidase and especially of alpha-L-glucosidase and alpha-D-mannosidase. In contrast, neither beta-D-galactosidase nor acid phosphatases serum levels were significantly modified. After antithyroid treatment, the activities of these enzymes returned to normal levels, except for alpha-D-mannosidase. The interpretation of these changes in serum acid hydrolases activities is controversial.

Acid Phosphatase↗