Biomedical subjects
Publications and source records attributed to M Whittaker.
Cerebral embolism due to a traumatic aneurysm of the internal carotid artery, and a duodenal tear occurred in a young woman who was wearing a seat belt at the time of a motor care accident. The aneurysm was treated by proximal carotid ligation.
Biochemical properties of plasma cholinesterase of significance to the anaesthetist are reviewed. The role of the genetic variants of the enzyme in suxamethonium sensitivity and hyperthermia are discussed with emphasis on the pregnant patient. Altered gene frequencies of the enzyme variants in some mental disorders is commented upon.
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The plasma cholinesterase variants of 190 mentally ill individuals having lithium prophylaxis have been examined. A significantly increased frequency of the E1f gene is reported. The effect of lithium nitrate and sodium nitrate on the plasma cholinesterase variants have been shown to be identical in the concentration range 25.0-50.0 mmol/l. The usual enzyme is slightly less sensitive to inhibition by either salt than the dibucaine resistant variant. The evidence suggest that the increased frequency of the E1f gene could be a genetic marker associated with some mental illness and not the result of lithium prophylaxis.
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The plasma cholinesterase variants in 80 patients having Down's syndrome have been examined and compared with a random control sample of individuals domiciled in the same area. Neither a change in frequency of known C5+ variant nor any new variant has been found in the electrophoretic studies. A highly significant increase in frequency of the fluoride resistant gene as well as a significant decrease in frequency of the atypical gene has been found in the Down's syndrome individuals. This altered distribution of the rare phenotype of plasma cholinesterase in mental illness may lead to a useful diagnostic acid in genetic counselling.
The distribution of the plasma cholinesterase variants found in 1,374 mentally ill patients differs from that of a random control sample. The patients are more likely to have a rare phenotype than an individual from the normal population. None of the diagnostic groups have been shown to differ in the distribution of the E1a gene, but there is strong statistical evidence that Group IV (psychosis) patients have a higher frequency of the E1f gene than the other groups. The overall frequency of the electrophoretic variant C5 + did not differ significantly from that observed in a Caucasian population, with the exception of the increase observed in Group IV c2. Twenty-eight unrelated patients with Huntington's chorea were found to have a significantly altered incidence of the C5 + variant and six patients from this group were found to have the rare E1f gene. Our results indicate that the plasma cholinesterase variants may provide some insight into the inheritance of Huntington's chorea.
The results of surgical treatment of 550 cases of carcinoma of the rectum presenting to the Professorial Surgical Unit of the General Infirmary, Leeds, from 1955 to 1968 have been analysed.
Two cases of spontaneous rupture of the spleen as a complication of infectious mononucleosis are reported. The literature is briefly reviewed and emphasis placed on the need for awareness of this rare complication.
Blood samples from 580 African leprosy patients living in Rhodesia have been phenotyped for the plasma cholinesterase variants. The Africans have been grouped according to country of origin and tribal affiliation. We have found no individual with an Ea1 gene and are unable to resolve the contradictory evidence for an association between this gene and leprosy. The frequency of the Ef1 gene is higher than that usually found in Caucasian populations, being 0.046 in lepromatous leprosy patients and similar to the 0.056 found in healthy African controls. In tuberculoid leprosy patients the frequency is, however, significantly lower at 0.019. On the other hand, the frequency of the C5+ variant is essentially the same for the tuberculoid leprosy patients and the healthy controls (4%) while for the lepromatous leprosy patients it is about 7% approaching the 10-15% found in many Caucasian populations.
Blood samples from 1,614 Africans living in Rhodesia have been phenotyped for the cholinesterase variants at the E1 and E2 loci. 24% of the African population were non-Rhodesian by birth. 1,227 Rhodesians aligned themselves to 20 tribes, 191 Malawians to 8 tribes. 162 Mozambique Africans to 9 tribes and 34 Zambians to 8 tribes. A high frequency of 0.036 for the Ef1 gene, which varies from tribe to tribe, has been found in Rhodesian and Malawian Africans. Similar high frequencies for this gene are recorded for Zambian (0.045) and Mozambique Africans (0.034). The frequencies of the Es1 gene in these groups are 0.013 (Rhodesian), 0.009 (Malawian), and 0.016 (Mozambique African). The small Zambian sample showed evidence for neither the Es1 nor the C5+ electrophoretic variant. The absence of the Ea1 gene in the 1,613 Africans provides additional evidence of the rarity of this gene in negroid populations. The frequency of the C5+ variant in Rhodesian, Malawian and Mozambique Africans, although varying from tribe to tribe within the range of 0-8%, averages 3% in each group. These represent low frequencies for this variant when compared to other populations. No rare or 'private' electrophoretic variant has been found.
Plasma cholinesterase variants have been examined in blood samples obtained from 23 patients who, after an intravenous injection of suxamethonium 30 mg before e.c.t., had prolonged apnoea. Attempts have been made to screen the relatives of all patients shown to have an unusual plasma cholinesterase. The present study indicates an increased frequency of the fluoride-resistant variants in those psychiatric patients sensitive to suxamethonium.
A case of sarcoidosis of the penis is reported which initially caused ulceration around the external urethral meatus. After an immediate response to steroid therapy, the disease recurred locally in spite of continuing therapy and involved other parts of the penis. Partial amputation of the penis was performed but further ulceration occurred at the cut ends of the corpora cavernosa in the penile stump. This ulceration healed after radiotherapy.
Blood samples from four Bantu tribes in South-East Mozambique have been phenotyped for the plasma cholinesterase variants of the E1 locus. A control roup of 153 Portuguese residents in Mozambique have also been phenotyped. The frequencies of both the E1a and E1f genes in the Portuguese population is very similar to those in other Caucasian populations. The absence of the E1a gene in the four Bantu tribes provides more evidence of the rarity of this gene in Negroid populations. There is an increased frequency of E1f gene in all tribes as compared with previous surveys. The Ronga and Bitonga tribes have similar E1f frequencies of 0.047 and 0.048, respectively. The Shangana has an E1f frequency of 0.060, and the corresponding figure for the Chopi tribe is 0.089. The latter is the highest recorded frequency for this gene. The results give some support to the doubts concerning the affiliation of the Chopi tribe.
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