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Biomedical subjects

C Clarke

Publications and source records attributed to C Clarke.

At least 163 records · Page 9Linked to original sources
PubMed1976

Mountain sickness, retinal haemorrhages, and acclimatisation on Mount Everest in 1975.

During the 1975 British Everest Expedition, which made the first ascent of the south-west face, observations were made in relation to mountain sickness and the appearance of retinal changes. Two Sherpas with cerebral oedema and one Briton with pulmonary oedema were treated. Retinal haemorrhages occurred in four out of six Britons who were newcomers to altitudes over 6000 m (19 685 ft) but in only two out of 14 Britons who had previously visited these altitudes. Intraocular pressures during ascent to 6000 m were within normal limits. The relevance of the ocular findings to acclimatisation in previous years was examined, the results supporting the hypothesis of a "carry-over" effect from previous visits to high altitude.

Acclimatization↗
PubMed1976

Alpha fetoprotein in liver disease in Papua New Guinea.

A radioimmunoassay method was used for the detection of alpha fetoprotein (AFP) in the sera of 112 Papua New Guinean patients who had undergone liver biopsy. Sera from 69 normal subjects and 20 hospital patients were also tested. Alpha fetoprotein was found to be elevated above normal levels in many of these subjects, but particularly in those suffering from viral hepatitis, cirrhosis and primary liver cell carcinoma (PLC). The highest values were found in patients with PLC. It is concluded that because of the elevation of AFP values in all these different types of liver disease the RIA test is not of great value in Papua New Guinea, except in the follow-up of some patients with cirrhosis who are at risk of developing PLC and in those who have undergone treatment for PLC.

Carcinoma, Hepatocellular↗
PubMed1976

Ocular bobbing with survival.

A case is described of prolonged ocular bobbing with survival after subarachnoid haemorrhage from a pontine arteriovenous malformation. Hitherto, this sign has usually been associated with a rapidly fatal outcome.

Adult↗
PubMed1975

Spina bifida and anencephaly: miscarriage as possible cause.

In two retrospective Liverpool surveys the domestic, family, dietary, and medical environments of the mothers of children affected by anencephaly or spina bifida, or both (ASB) were examined. None seemed to be of more than minor importance and the findings of others were therefore examined to see if they suggested a major factor. The most promising lead came from the hypothesis that ASB is usually due to an interaction between twin fetuses or between a fetus and residual trophoblastic material from the previous normal pregnancy, particularly when this is of the opposite sex to the propositus. The sex finding was not confirmed. It was noted that hydatidiform moles, like children with ASB, were usually female and that moles and choriocarcinomas on the one hand and children with ASB on the other occurred in mothers of similar ages, but were to some extent reciprocal in geographical incidence. This suggested that trophoblastic disease might be a factor common to all three and if so then one would expect the frequency of miscarriages to be higher immediately before than immediately after the birth of an ASB child, since mole and choriocarcinoma seldom follow a normal pregnancy. An analysis of published data confirmed that this was almost certainly so. Hence residual pathological trophoblastic material from either a previous miscarriage or a co-twin may interact unfavourably with another fetus to produce ASB and this may be the primary cause of the condition. The hypothesis is consistent with the observed lack of concordance in twins, the high incidence in females, the maternal age effect, and the greater prevalence in social classes IV and V.

Abortion, Spontaneous↗
PubMed1975

The genetics of the mimetic butterfly Hypolimnas bolina (L.).

Hypolimnas bolina is a Nymphalid butterfly having a west to east distribution from Madagascar to Easter Island, and a north to south one from Japan to Australasia. It is highly migratory in some areas. In much of the western part of its range the female is both monomorphic and a mimic of Euploea. Further east it is frequently polymorphic with the majority of the forms being non-mimetic. The polymorphism is sex-limited to the female and controlled by two unlinked loci, one with two allelomorphs, E and e, determining the extent of the dark pigmentation, the other with three allelomorphs, P, Pn and p, determining the presence and distribution of orange-brown. Only butterflies of the genotypes EEpp and to a lesser extent Eepp are satisfactory Batesian mimics of their Euploea models. The details of the mimetic pattern are under multifactorial control, following those of their local model, as is much of the variation within the non-mimetic forms, particularly with regard to the distribution of white and blue scaling.

Adaptation, Biological↗