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Biomedical subjects

A Barnes

Publications and source records attributed to A Barnes.

At least 91 records · Page 5Linked to original sources
PubMed1990

The prevalence of naturally acquired multiple infections of Wuchereria bancrofti and human malarias in anophelines.

Malaria and filaria infection rates were determined for anopheline mosquitoes collected whilst biting and resting in village houses in Papua New Guinea. The number of anophelines infected with both parasites was greater than expected from the infection rates of each parasite and this difference was significant in resting collections. The excess of multiply infected mosquitoes is probably a result of a vector population composed of individuals with differing numbers of opportunities to become infected. Malaria-positive Anopheles punctulatus from resting catches had a significantly greater number of Stage 3 Wuchereria bancrofti larvae than malaria-negative mosquitoes. However, multiply infected mosquitoes appear to suffer greater mortality than non-infected or singly infected mosquitoes when the filarial worm reaches the third stage. Any potential increase in transmission resulting from multiple infections is thereby offset by a greater mortality rate in these mosquitoes.

Animals↗
PubMed1990

Predictive value of cyclosporin A level for efficacy or renal dysfunction in psoriasis.

Cyclosporin A (CyA) trough (pre-dose) levels were measured in whole blood with a radioimmunoassay (RIA) using specific monoclonal antibody in 193 patients receiving CyA for the treatment of psoriasis. These patients received either CyA 2.5 mg/kg/day (n = 134) or 5 mg/kg/day (n = 59). In addition, a subgroup of 94 patients also had CyA trough levels measured using a non-specific polyclonal RIA. Within each CyA dose group, no difference was detected between mean CyA trough levels in relation to success or failure nor to the presence or absence of renal dysfunction with the use of either the specific or non-specific RIA. Based on the experience in transplantation, CyA thresholds of 100 and 200 ng/ml (specific) were selected for the assessment of efficacy and renal dysfunction. The success rate was higher by 10-15% when the CyA level was above, rather than below, 100 ng/ml in both the CyA 2.5 mg and 5 mg/kg/day groups. A slightly increased incidence of renal dysfunction was only found in the 5 mg/kg/day group when the CyA level was above 200 ng/ml. Because of its low predictive value, measurement of the level of CyA was not particularly useful for monitoring patients with psoriasis treated with low-dose CyA.

Adult↗
PubMed1990

Variations in malaria transmission rates are not related to anopheline survivorship per feeding cycle.

Anopheline survivorship, vectorial capacity, and mosquito infection probability estimates from mosquito infection rates were determined 4 times in 1 year in a Papua New Guinea village. Estimates of survivorship over the length of the extrinsic incubation period differed significantly during the year. However, survivorship per feeding cycle, individual mosquito vectorial capacity, and mosquito infection probability did not vary significantly. Estimates of these parameters were then compared to estimates of survivorship, individual vectorial capacity, and mosquito infection probability in mosquito populations in other villages in the study area. Since survivorship per feeding cycle did not vary significantly among the mosquito populations in these villages, changes in malaria transmission potential can be better gauged from estimates of survivorship over the length of the extrinsic incubation period. However, as measurements of relative inoculation rates are easier to perform and have been related to parasite prevalences in children in this area, estimates of inoculation rates are a preferred option for estimating malaria transmission in the Madang area of Papua New Guinea.

Animals↗
PubMed1989

Transfusion practice in the private hospital.

Recognition that human immunodeficiency virus could be transmitted by blood transfusion has brought the practice of transfusion medicine into the public consciousness with great force. Patients are informed about the dangers of receiving a blood transfusion and are expressing their preferences about the source of the blood they may receive and the conditions under which they may receive it. Government, blood bank organizations, and physicians are responding to the public demand for a safe blood supply. As a result, profound changes are underway in hospital blood donor services, transfusion service inventory controls, and patient transfusion practices. A much more bureaucratic and complex system has emerged. Providing help to patients and physicians as they struggle to cope with the vicissitudes of this confusing new transfusion medicine is the role of the medical director of the hospital blood bank.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Factors influencing silhouette trap captures of the blackfly Austrosimulium bancrofti in Queensland, Australia.

Three silhouette traps of novel design were used to investigate the trap finding ability of female Austrosimulium bancrofti (Taylor) (Diptera: Simuliidae) in southeast Queensland. The traps were 'upright', 'elongate' or 'square' in shape. Five highly significant factors: hour after sunrise, temperature, relative humidity, trap shape and distance between traps, were included in a model which generated fitted estimates of flies captured under defined conditions. The rate of increase and the level of maximum capture rate indicated that the elongate trap captured the highest numbers of blackflies. An interaction between hour after sunrise and temperature suggests a strong endogenous modification of trap finding activity. Numbers captured increased with increasing distance between traps and decreasing relative humidity. The importance of these results in understanding behaviour of A. bancrofti is discussed.

Animals↗
PubMed1987

Sudden infant deaths and clear weather in a subtropical environment.

Particulate pollution levels were found to decrease, on average, over the 10-day period preceding SIDS incidence in a study of 369 cases over 15 years in Brisbane, Australia. This unexpected association could not be explained by correlations between daily pollution levels and daily precipitation, wind velocity, air temperature or cloud. Of the meterological variables studied, which might have given rise to the particulate-SIDS associations, only visibility showed associations with SIDS incidence. Average visibility increased prior to SIDS in both summer and winter cases. It is hypothesised that these findings may be due to either direct effects of light, or due to increased outdoor exposure of infants and/or to changes in parental behaviour during clear weather.

Australia↗
PubMed1987

A latex agglutination assay for D dimer: evaluation and application to the diagnosis of thrombotic disease.

Although latex agglutination assays have been used for some years to diagnose thrombotic disorders, only recently has it been possible to measure specifically the products of fibrin breakdown in the presence of fibrinogen degradation products, by using monoclonal antibodies. We have evaluated a preparation of latex particles coupled to the monoclonal antibody DD-3B6/22, which is specific for cross-linked fibrin degradation products (XDP) and allows accurate discrimination between normal and pathological conditions. Of samples from 515 apparently healthy volunteers, 97.7% failed to agglutinate the latex; the normal reference interval for XDP determined by enzyme immunoassay was less than 78-320 micrograms/L. The use of different anticoagulants with or without the addition of a protease inhibitor had no significant effects on the results of the latex assay. The latex preparation provides a useful, rapid diagnostic tool for assaying small numbers of samples or as an emergency test.

Antibodies, Monoclonal↗
PubMed1986

Weekly variations in body weight and plasma testosterone concentrations in the captive male possum, Trichosurus vulpecula.

The possum is a seasonally breeding marsupial which gives birth in Queensland from March through to September. To ascertain whether this seasonality in breeding is manifest in the male reproductive system, body weight and plasma testosterone concentrations were examined in five possums. Plasma testosterone concentrations fluctuated throughout the year and a seasonal cycle was observed, with a peak in testosterone concentration in March and a nadir in September. Body weights fluctuated in a similar manner. Statistical analysis suggested that the annual plasma testosterone profile correlated well with the rate of change of daylength.

Animals↗