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Biomedical subjects

I A McGregor

Publications and source records attributed to I A McGregor.

At least 19 recordsLinked to original sources
PubMed2000

Maternal grandmothers improve nutritional status and survival of children in rural Gambia.

Hypotheses for the evolution of human female life-history characteristics have often focused on the social nature of human societies, which allows women to share the burden of childcare and provisioning amongst other members of their kin group. We test the hypothesis that child health and survival probabilities will be improved by the presence of kin using a longitudinal database from rural Gambia. We find that the only kin to improve the nutritional status of children significantly (apart from mothers) are maternal grandmothers, and that this is reflected in higher survival probabilities for children with living maternal grandmothers. There is also evidence that the reproductive status of the maternal grandmother influences child nutrition, with young children being taller in the presence of non-reproductive grandmothers than grandmothers who are still reproductively active. Paternal grandmothers and male kin, including fathers, have negligible impacts on the nutritional status and survival of children.

Child, Preschool↗
PubMed1999

Prenatal or early postnatal events predict infectious deaths in young adulthood in rural Africa.

BACKGROUND: Research over the past decade has suggested that prenatal and early postnatal nutrition influence the risk of developing chronic degenerative diseases up to 60 years later. We now present evidence that risk of death from infectious diseases in young adulthood is similarly programmed by early life events. METHODS: In three rural Gambian villages, affected by a marked annual seasonality in diet and disease, we have kept detailed demographic, anthropometric and health records since 1949. Fate was known with certainty for 3,162 individuals (2,059 alive/1,103 dead, most dying in childhood). For this case-control analysis of antecedent predictors of premature mortality, all adult deaths (n = 61) were paired with two randomly selected controls matched for sex and year of birth. RESULTS: Mean age at death was 25 (SD: 8) years. Adult death was associated with a profound bias in month of birth with 49 cases born in the nutritionally-debilitating hungry season (Jul-Dec) versus 12 in the harvest season (Jan-Jun). Relative to harvest season the hazard ratio for early death in hungry-season births rose from 3.7 (for deaths >14.5 years, P = 0.000013) to 10.3 (for deaths >25 years, P = 0.00002). Anthropometric and haematological status at 18 months of age was identical in cases and controls, indicating an earlier origin to the defect. Most deaths for which cause was known had a definite or possible infectious aetiology; none were from degenerative diseases of affluence. CONCLUSIONS: Early life exposures, correlated with season of birth, strongly influence susceptibility to fatal infections in young adulthood. The evidence suggests that nutritionally-mediated intrauterine growth retardation may permanently impair the development of immune function.

Adolescent↗
PubMed1998

Possible routes of spread of carcinoma of the maxillary sinus to the oral cavity.

Carcinomas arising in the maxillary sinus, occasionally present clinically in the oral cavity along the occlusal ridge of the upper alveolus. The mechanism of this spread has not been investigated but it may resemble invasion of the mandible by oral carcinomas, which tend to invade the soft tissues rather than eroding through bone. In Britain, such patients are usually edentulous. This project examines deficiencies in the bony walls of the maxillary sinus to determine possible routes of spread. Maxillae were obtained from one side of 17 dissecting room cadavers, aged 71-95 years; 15 were edentulous. The roof of the maxillary sinus was removed in all specimens. Five maxillae were each cut into six slices, 0.5 cm thick, in a vertical bucco-lingual plane. In all, soft tissues were removed by treatment in dilute bleach. Histological sections, cut in the horizontal plane, were prepared of a further three maxillae. Several possible routes were identified by which tumors could spread from the sinus to the oral cavity: 1) directly through foramina in its floor; 2) through numerous foramina in its floor to the marrow cavity of the alveolar process, which mostly contained fat amongst narrow bony trabeculae. (The marrow cavity, in turn, had numerous communications with the occlusal surface); 3) through foramina which carried branches of the superior alveolar nerves and vessels; 4) through deficiencies in the bony walls of the sinus at the neurovascular grooves and elsewhere.

Aged↗
PubMed1993

Towards a vaccine against malaria.

In many countries malaria is rapidly regaining its status as one of mankind's most important diseases, affecting not only indigenous populations but also travellers to endemic areas. This has stimulated much research into the mechanisms by which immunity is acquired to plasmodial infections and into the feasibility of producing effective vaccines against these. Four possible vaccines are under study, each targeted at a different stage of the complete life cycle of the Plasmodium. A vaccine targeted against the sporozoite could totally protect humans against mosquito-borne infection, while a vaccine against asexual erythrocytic forms would limit the morbidity and mortality of malaria rather than totally preventing it. In contrast, vaccines directed against the sexual forms of the parasite would not induce protection against infection, but would produce a transmission-blocking action, preventing the parasite developing in the mosquito vector. The construction of such vaccines and the measurement of the immune responses they induce has demanded the deployment of sophisticated and recently developed techniques, especially in immunology and molecular biology. However, man's capacity to acquire effective immunity to malaria has long been recognised and attempts to induce it artificially by means of vaccines have been made since the beginning of this century.

Animals↗
PubMed1992

Agglutination of Plasmodium falciparum-infected erythrocytes from east and west African isolates by human sera from distant geographic regions.

Plasmodium falciparum-infected erythrocytes (PfE) were collected from acutely infected children in The Gambia and Tanzania and cultured for more than 30 hr until the parasites were mature trophozoites. Sera collected from these countries, other African countries, Asia, and South America were used in the PfE microagglutination test to determine whether PfE from East and West Africa share surface antigens. From the patterns of agglutination reactivity, we identified extensive antigenic diversity in surface antigens, but obtained no evidence for greater differences between isolates from East or West Africa and those within one region. The majority of sera from immune adults from The Gambia, Tanzania, Sudan, Nigeria, or Ghana were pan-agglutinating, and agglutinated all PfE isolates from The Gambia and Tanzania. Some sera from immune adults of Irian Jaya also agglutinated each of the seven African isolates, while others agglutinated many but not all of the isolates, similar to sera from immune adults of Flores, Indonesia. In contrast, sera from nonimmune adults from Colombia agglutinated few of the African isolates. It was remarkable, however, that sera from nonimmune Colombians agglutinated any African isolates. Our results are consistent with the following conclusions: some PfE surface antigen(s) are very diverse; this diversity is a feature of the parasite worldwide; the repertoire of isolate-specific surface antigens, although large, includes antigens that are either identical or antigenically cross-reactive in geographically very distant parasite populations; and African adults have pan-agglutinating antibodies that may contribute to protective immunity. Such pan-agglutinating antibodies could reflect the accumulation of a large repertoire of isolate-specific antibodies. The contribution of antibody against any shared PfE surface antigen to the pan-agglutinating reactivities is unknown and awaits development of the appropriate reagents.

Adolescent↗
PubMed1988

The E-flat hand.

The disability suffered by a professional pianist because of difficulty in carrying out certain of the finger movement sequences involved in playing in the key of E flat appeared to be caused by limitation of independent flexion movements between the index and long fingers of his right hand. The range of independent movement of the fingers was considerably increased, with relief of his disability, by dividing the intertendinous connection between the extensor tendons of the two fingers on the dorsum of the hand.

Fingers↗
PubMed1987

Steroid hormone receptors in human salivary gland tumours.

Major salivary gland tumours were studied for the presence of hormone receptors for oestrogen and progesterone. Of the eight salivary gland tumours exhibiting varied histology, none showed high affinity receptors for oestrogen or progesterone. Salivary tissue from four patients with non-neoplastic salivary gland disease was also studied and found not to contain high affinity receptor sites. The absence of hormone receptors in these glands suggests that such tumours are not dependent on endocrine function.

Adult↗
PubMed1986

Haemodynamics of the radial forearm flap.

An electromagnetic blood flow meter was used to study blood flow to the radial forearm flap intra-operatively in 20 patients. Blood flow correlated more significantly with surface area than with weight. Both antegrade and retrograde flow were measured and showed no significant difference. Temperature affected blood flow significantly (P less than 0.01) as did sympathetic block (P less than 0.01). The venous drainage of the flap was studied in five cases. Both superficial and deep systems were equally capable of draining the flap.

Aged↗
PubMed1986

Prophylaxis with tinidazole of infection in major head and neck surgery for malignant disease.

In a double-blind study, 20 patients undergoing surgery for the removal of an oropharyngeal squamous carcinoma received tinidazole either as a single perioperative prophylactic dose of 2 g or as a treatment course of 8 g given over a 7 day period. The wounds were assessed daily and specimens of fluid from the upper neck drain were submitted for culture. Four patients, two in each group, developed complications that might have been associated with infection (flap necrosis, fistula formation or both). There was no significant difference in the efficacy of these two regimens and single dose prophylaxis with tinidazole is advocated.

Adult↗