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Biomedical subjects

J A Miles

Publications and source records attributed to J A Miles.

At least 37 records · Page 2Linked to original sources
PubMed1978

Lack of effect of helium breathing on catecholamine levels in the adrenal vein blood of the rabbit.

Catecholamine levels were measured in the adrenal vein blood of the chloralose anesthetized rabbit during periods of helium-oxygen breathing (50% He-50% O2) and of air breathing. Blood samples were taken from the T-arm of a venous shunt made by cannulating the renal vein proximally to the orifice of the adrenal vein and connecting the distal end of the cannula to one in the femoral vein. Adrenal vein blood flow varied from 0.09-0.30 g/min in five animals, and catecholamine release from 10-92 ng/min. There were large differences between levels from animal to animal but no significant differences in any one animal between levels measured while breathing helium and levels measured while breathing air. The same held true for respiratory rate, blood pressure, heart rate, and percent change in blood pressure during a simulated valsalva maneuver. Although there were changes seen in catecholamine release during some of these experiments, they could not be related to an effect of gases breathed. It is concluded that if there was an effect of helium breathing on catecholamine release in these anesthetized rabbits it was masked by other conditions with stronger action on the sympatho-adrenal system.

Adrenal Glands↗
PubMed1974

Mosquito-borne infections in Fiji. V. The 1971-73 dengue epidemic.

A dengue epidemic due to type 2 virus involving some 3,400 cases began in Fiji early in 1971, had a peak during May, June and July, and cases have continued to occur with a low incidence during 1972 and 1973. Many of the notified cases showed classical dengue fever symptoms and there were no confirmed cases of haemorrhagic fever. A serological survey indicated that there had been at least 20,000 subclinical infections. It is probable that the virus was introduced to Fiji either through the port of Lautoka or Nadi international airport in February 1971. The normal travel patterns of residents must have spread the virus to all the more accessible localities but, with the exception of Rotuma, it caused infections only in areas where Aedes aegypti was available as a vector. There was no evidence that pre-existing dengue type 1 serum antibody gave any protection during this epidemic.

Adolescent↗
PubMed1974

Papovaviridae.

Explore the source record for details and available documents.

Animals↗
PubMed1973

The ecology of Whataroa virus, an alphavirus, in South Westland, New Zealand.

The findings of a survey on the ecology of an alphavirus over the years 1964-9 are reviewed. Evidence is presented to show that wild birds constitute a vertebrate reservoir of the virus and that mosquitoes, primarily Culiseta tonnoiri and Culex pervigilans, which are both endemic New Zealand species, are responsible for summer transmission.Serological evidence of infection was obtained in all years and evidence is presented to indicate that the virus is enzootic rather than being reintroduced each spring. The number of birds with antibody increased before mosquitoes became active in the spring and possible explanations of this are discussed.The mean temperature in the hottest month in the study area is substantially below that in other areas with enzootic mosquito-borne viruses and experimental studies showed that Whataroa virus was able to replicate more rapidly in mosquitoes at low temperatures than any arboviruses previously studied.The main natural focus of infection appeared to be in a modified habitat and the introduced song thrush (Turdus philomelos) to be the main vertebrate reservoir host.

Aedes↗
PubMed1973

A study of immunity to rubella in villages in the Fiji islands using the haemagglutination inhibition test.

In the villages of Fiji, apart from Viti Levu, rubella is a disease occurring solely in widely spaced epidemics. Some villages may not be infected for over 20 years and will then contain substantial numbers of susceptible women of child-bearing age.Evidence is produced that haemagglutination-inhibiting (H.I.) antibody to rubella is very long lasting in Fijians. The infectivity of the virus is discussed and it is suggested that, on the average, 50% of susceptibles are infected in a Fijian village during a rubella epidemic, but there are large variations.

Adolescent↗
PubMed1971

Mosquito-borne infections in Fiji. II. Arthropod-borne virus infections.

Surveys of arbovirus activity in Fiji were conducted over a 10-year period from December 1959 to December 1969. No arboviruses were isolated from over 200,000 mosquitoes, 9000 ticks, or 575 serum samples. Eight thousand human and 1117 bird, bat and animal sera were tested for haemagglutination-inhibiting arbovirus antibody using a variety of group A, group B and Bunyamwera group antigens. Only a small number of low-titre reactions were found among the non-human sera, but 14% of all human sera were found to contain Group B antibody. The antibody prevalence increased with increasing age, from less than 1% for persons born since 1950, to 70% for persons born before 1900. The age differences in prevalence could be used to estimate the time and size of previous epidemics. Differences were found in antibody prevalence between the sexes, between ethnic groups and between persons from different regions. These differences could be explained in terms of climate, location and custom.Historical and serological evidence both suggest that all the antibody detected was due to past exposure to dengue virus. The very high proportion of the population with no dengue antibody makes Fiji a high-risk area for a further dengue epidemic. Dengue virus is known to be active in the Pacific and South-East Asia.

Adolescent↗