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Biomedical subjects

R Harris

Publications and source records attributed to R Harris.

At least 307 records · Page 17Linked to original sources
PubMed1987

Clinic experience of prenatal diagnosis of cystic fibrosis by use of linked DNA probes.

96 families at risk of having a child with cystic fibrosis have been counselled about prenatal diagnosis by the use of linked DNA probes. Of the first 30 pregnancies 9 children have been born and confirmed to be free from CF, as predicted; 8 pregnancies were terminated (1 of these was found to be miscarrying at time of termination); 12 pregnancies, in which the fetuses are predicted to be unaffected, are in progress; and 1 has miscarried. No couple with a prenatal prediction of CF decided to continue with the pregnancy. 1 pregnancy was terminated because of a 50:50 chance of an affected fetus. In 1 twin pregnancy the affected fetus was selectively aborted, and the other baby was confirmed after birth to be unaffected, as predicted. In the other twin pregnancy the two chorionic plates could not be samples separately; the pregnancy was continued on the basis of normal findings for the lower plate, and both twins have turned out to be normal. Many couples at risk see early prenatal diagnosis as a way to help them have an unaffected child.

Abortion, Induced↗
PubMed1987

Endogenous opioids and ventilatory adaptation to prolonged hypoxia in goats.

To investigate whether endogenous opioid peptides mediate time-dependent changes in ventilatory control during prolonged hypoxia, we studied four adult goats at rest during 14 days at simulated high altitude in a hypobaric chamber (PB approximately 450 Torr). Arterial PCO2 fell during the first several hours of hypoxia, remained stable over the next 7 days, and then rose slightly (but without statistical significance) by day 14. Ventilatory responsiveness to CO2 increased during the first week of hypoxia. By day 14, while still greater than control, the ventilatory response to CO2 was less than that observed on day 7. Immunoactive beta-endorphin levels in plasma and CSF did not change during the 14-day period. Administration of naloxone on day 14 did not restore the ventilatory response to CO2 to the level observed during the first week of acclimatization. We conclude that in adult goats, time-dependent changes in ventilatory response to CO2 during acclimatization to prolonged hypoxia are not primarily attributable to alterations in endogenous opioid peptide activity.

Adaptation, Physiological↗
PubMed1987

Restriction fragment length polymorphism at the HLA-C locus.

We have used the HLA-C-specific DNA probe pC250 to investigate restriction fragment length polymorphism (RFLP) at the HLA-C locus. Genomic Southern blot hybridization included DNA prepared from a panel of homozygous typing cells representing serological specificities Cw1 to Cw8 and also from samples representing Cw blanks. Although many restriction nucleases failed to reveal any polymorphism, RFLPs were evident with Taq I, Pvu II, Bst XI, Nde I, and Nci I in addition to the previously reported Eco RI. In the case of Bst XI, a unique RFLP defined a subset of serologically defined Cw blanks. Comparison of RFLP sizes with restriction fragment lengths obtained from the known HLA-Cw3 gene sequence permitted the localization of intragenic C locus RFLPs and the identification of a variable Taq I site in the second intron, a variable Nci I site near the end of the fourth exon, and a variable Pvu II site in the fifth intron.

Chromosome Mapping↗
PubMed1987

Medical therapy in the elderly.

Recommendations concerning nutrition and physical activity are an important part of health care in the elderly. There is increasing evidence that diet and exercise influence the development and progression of cardiovascular disease in the elderly as well as the young. Decreases in coronary risk factors can be achieved in the elderly by attention to proper diet and exercise.

Aged↗
PubMed1987

The prevalence and correlates of Rose Questionnaire angina among women and men in the Lipid Research Clinics Program Prevalence Study population.

The prevalence and correlates of Rose Questionnaire angina were investigated in a sample of 4,661 white woman and men aged 30 years and above who participated in the Lipid Research Clinics Program Prevalence Study 1972-1976. Among men, the prevalence of Rose angina increased with age from about 1% to 12%, while the prevalence among women ranged from about 3% to 6%. Young women compared with men also had a relatively high prevalence of dyspnea, which was strongly correlated with Rose angina in both sexes. For women and men younger than 50 years, the dyspnea-Rose angina odds ratio was about 6 (p less than 0.001), while older women and men had somewhat lower sand higher odds ratios, respectively. Major and minor resting electrocardiographic abnormalities and self-reported history of a heart attack were not significantly associated with Rose angina among young participants of either sex, but they did show positive associations among older participants with the exception of minor electrocardiographic abnormalities in men. A logistic regression analysis revealed a strong inverse association between high density lipoprotein cholesterol and Rose angina in both sexes. Because mortality studies consistently show an excess of coronary heart disease death among young men compared with women, the female excess of Rose angina at young ages suggests that the grouping of angina and myocardial infarction into a single endpoint in cardiovascular disease studies may be more appropriate for young men than for young women.

Adult↗
PubMed1987

Posttransplant antidonor lymphocytotoxic antibody production in relation to graft outcome.

Serial serum samples from 266 recipients of primary renal allografts were monitored posttransplant for the presence of panel reactive lymphocytotoxic antibodies (PRA). The minimum posttransplant follow-up period was 18 months. Patients were classified according to whether or not they produced PRA before and/or after transplantation. The groups were as follows: PRA negative before and after transplant, -/-, 171; PRA positive before and negative after transplant, +/-, 5; PRA positive before and positive after transplant, +/+, 27; PRA negative before and positive after transplant, -/+, 63. Actuarial graft survival at 1 year for each group was 81.3%, 100%, 70.4%, 47.6%, respectively. Fifty-five of the 63 -/+ recipients were retrospectively crossmatched with posttransplant sera against stored donor lymphocytes. Of these, 50 (91%) were posttransplant cross match positive, and 37 (67%) have lost their grafts. In 23 of the 26 cases where an anti-HLA specificity was defined, the antibody was directed against antigens present in the donor but not in the recipient. These results clearly indicate that the production of PRA in recipients of renal transplants is associated with antidonor reactivity and poor graft outcome. The fact that these PRA were often directed against donor HLA antigens emphasizes one of the hazards of mismatching for HLA at transplantation.

Blood Transfusion↗
PubMed1987

Day-case herniotomy in children. A comparison of ilio-inguinal nerve block and wound infiltration for postoperative analgesia.

Forty-nine boys scheduled for day-case inguinal herniotomy were studied to compare ilio-inguinal nerve block and wound infiltration for postoperative analgesia. Both techniques were simple to perform and produced no complications. In the ilio-inguinal block group, 100% had either no pain or very mild discomfort when assessed 60 minutes after return to the day unit, compared to 95% in the infiltration group. Some children did appear to have pain following discharge but in all cases this responded well to simple analgesics. We conclude that both techniques provide satisfactory analgesia whilst the complications of narcotics are avoided, and suggest that simple infiltration of the wound with local anaesthetic solution should be encouraged in paediatric anaesthesia.

Ambulatory Surgical Procedures↗
PubMed1987

Bridging markers defining the map position of X linked hypophosphataemic rickets.

Hypophosphataemic rickets is commonly an X linked dominant hereditary disorder associated with a renal tubular defect in phosphate transport and bone deformities. The gene causing this disorder has been mapped to Xp22.31----p21.3 by using cloned human X chromosome sequences identifying restriction fragment length polymorphisms (RFLPs) in linkage studies of affected families. The hypophosphataemic rickets gene locus (HPDR) was previously mapped distal to the X linked polymorphic locus DXS41 (99.6) but its position in relation to the distal loci DXS43 (D2) and DXS85 (782) was not established. In order to obtain a precise mapping of the disease locus in relation to these genetic loci, additional affected families informative for these X linked markers have been investigated. The combined results from the two studies have established linkage with the loci DXS41 (99.6) and DXS43 (D2); peak lod score for DXS41 (99.6) = 7.35, theta = 0.09, and peak lod score for DXS43 (D2) = 4.77, theta = 0.16. Multilocus linkage analysis mapped the hypophosphataemic rickets gene distal to the DXS41 (99.6) locus and proximal to the DXS43 (D2) locus, thereby revealing two bridging genetic markers for the disease.

Chromosome Mapping↗
PubMed1987

Familial orofaciodigital syndrome type I presenting as adult polycystic kidney disease.

A three generation family with orofaciodigital syndrome type I is described. Several family members had been thought to suffer from autosomal dominant polycystic kidney disease but examination of the proband led to establishment of the correct diagnosis. The genetic implications for the offspring of the affected women and other family members were significantly altered.

Abnormalities, Multiple↗
PubMed1987

Wolf-Hirschhorn locus is distal to D4S10 on short arm of chromosome 4.

We report a family in which Wolf-Hirschhorn syndrome in two children with partial monosomy of the short arm of chromosome 4 is the result of unbalanced segregation of a reciprocal 4;12 translocation in the mother. Studies with the DNA probe G8 show that the translocation breakpoint in this family is distal to the D4S10 locus. Previously reported cases of Wolf-Hirschhorn syndrome have involved the deletion of D4S10. These observations may prove helpful in the search for better genetic markers for Huntington's chorea, which maps close to D4S10.

Abnormalities, Multiple↗
PubMed1987

Cellular incorporation of poly-beta-hydroxybutyrate into plasma membranes of Escherichia coli and Azotobacter vinelandii alters native membrane structure.

Under growth-limiting conditions or conditions which mediate genetic transformation, Escherichia coli and Azotobacter vinelandii incorporate poly-beta-hydroxybutyrate into their plasma membranes. Genetic transformation competence of both bacteria increased in proportion to the concentration of membrane poly-beta-hydroxybutyrate. The effects of this lipid polymer on membrane structure were investigated by freeze-fracture electron microscopy. Before poly-beta-hydroxybutyrate incorporation, freeze-fracture revealed a typical mosaic of particles and pits on both concave and convex surfaces of the plasma membrane. As the cells incorporated the lipid polymer into the membrane, transformability developed and small semiregular plaques which possessed shallow particles were seen. These plaques grew in size and frequency as the membrane poly-beta-hydroxybutyrate concentrations and transformability increased.

Azotobacter↗