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Biomedical subjects

D R Hall

Publications and source records attributed to D R Hall.

17 recordsLinked to original sources
PubMed1991

Attraction of Glossina longipalpis (Diptera: Glossinidae) in Guinea-Bissau to odor-baited biconical traps.

The catches of tsetse flies, Stomoxys, and tabanids in biconial traps baited with different synthetic odors were compared in the Jopá-Cobiana Forest, northwestern Guinea-Bissau. Thirty-six traps, the baits of which were randomly interchanged each of 10 sampling days, were baited either with (a) 1-octen-3-ol (octenol) + phenols [4-methylphenol + 3-propylphenol] + acetone + N'dama cow urine ("urine"), (b) octenol + phenols + acetone, (c) octenol + phenols, (d) acetone, (e) acetone + urine, or (f) urine. Six of the traps were not baited (controls). A total of 3,172 tsetse flies (96% Glossina longipalpis Widemann, 3% G. morsitans submorsitans Newstead, and 1% G. palpalis gambiensis Vanderplank), 286 Stomoxys, and 571 Tabanidae was captured. G. longipalpis was caught in statistically greater numbers in traps baited with octenol + phenols + acetone. Traps baited with octenol + phenols, with or without acetone, caught the greatest numbers of tabanids. N'dama urine did not increase the catch of G. longipalpis. Stomoxys was not significantly attracted to any of the odors.

Animals↗
PubMed1986

Uridine monophosphate kinase and susceptibility to invasive Haemophilus influenzae type B disease.

A polymorphic genetic variant of the pyrimidine pathway enzyme, uridine monophosphate kinase-3 (UMPK-3), was positively associated with invasive Hib disease. All UMPK 3-3 homozygotes in this study were Hib cases, and we found that in cases and controls, there was no difference between UMPK phenotype and serum levels of total Hib antibody as measured by radioimmunoassay. This suggests that UMPK-3 may play a role in mediating the non-humoral immunity to Hib. However, unlike other enzyme variants in the nucleoside synthesis pathways which result in syndromes of severe immunodeficiency, this gene appears to confer a more subtle disease susceptibility. Thus, the UMPK-3 allele, although rare in Caucasians, is associated with an increased risk of invasive Hib infection in Alaskan Eskimos.

Alaska↗
PubMed1979

Effect of posture on lung volume: airway closure and gas exchange in hemidiaphragmatic paralysis.

The effects of posture on lung volume, airway closure, and gas exchange were studied in eight patients with hemidiaphragmatic paralysis. The mean vital capacity in the sitting position was 81% of predicted normal, and in the supine posture fell by a further 19% in right-sided but only 10% in left-sided paralysis. The mean arterial oxygen tension was less than predicted in the sitting posture and fell significantly on lying. Single breath gas transfer factor was normal in all cases whereas the diffusion coefficient was greater than predicted in the sitting posture and rose even further on lying. Closing volume showed no positional change but closing volume as a percentage of vital capacity was higher in the supine position. Regional airways closure was expressed as the relationship expiratory reserve volume minus closing volume. Negative values were found in only two of the subjects in the sitting position but seven had negative values supine, indicating significant airway closure during tidal breathing in this position.

Adult↗
PubMed1976

Abnormalities of lung function in hay fever.

Twenty subjects with symptoms of hay fever were studied to see whether abnormalities could be detected in the function of small airways. The investigations included dynamic compliance at varying respiratory frequencies, closing capacity, residual volume, transfer factor, and maximal expiratory flow-volume curves. The tests were repeated in the winter when symptoms had resolved. Frequency dependence of compliance was found in eight subjects with symptoms (40%), closing capacities being abnormal in only two instances. Conventional pulmonary function tests, including expiratory flow rates at mid vital capacity, were within the predicted range of all subjects. When tests were repeated in the winter, frequency dependence of compliance was no longer present in subjects whose symptoms had resolved. The study suggests that reversible small airway abnormalities are present in a significant proportion of subjects with symptoms of hay fever and that such abnormalities are best detected by the measurement of dynamic compliance at varying respiratory frequencies.

Adolescent↗
PubMedDate not supplied

Small airways disease in coal miners. A longitudinal study.

Seventeen of an original cohort of 25 non-smoking working coal miners and 6 age-matched controls studied in 1969 were re-examined in 1973. Measurements included lung volumes, maximal expiratory flow-volume curves, and closing volumes. Miners, when compared with controls, showed a marked decline in maximal expiratory flow at mid-vital capacity (V 50%) over the 4-year period which took place without significant change in the 1-second forced expiratory volume (FEV1). Frequency dependence of dynamic compliance (Cdyn) in association with an increased upstream airways resistance (Rus), and also loss of lung elastic recoil (PL(St)) which were present at the time of the original study led to similar declines in V 50%. An abnormally elevated closing capacity expressed as a percentage of total lung capacity (CC/TLC)% was found in 9 miners (53%) and none of the controls. Closing volume as a percentage of vital capacity (CV/VC)% was abnormal in 4 miners (23.5)% and no controls. Measurement of closing volume did not relate well to the variety of mechanical abnormality present on the original study; namely, loss of recoil or small airways obstruction. The presence of an elevated (CC/TLC)% and (CV/VC)% correlated mainly with the presence of hyperinflation as indicated by an elevated residual volume.

Follow-Up Studies↗