Biomedical subjects

P J Moore

Publications and source records attributed to P J Moore.

10 recordsLinked to original sources

PubMed1979

Regional geochemical mapping and interpretation in Britain.

Regional geochemical atlases of Britain and the British North Sea prepared by the Institute of Geological Sciences are discussed with special reference to their environmental significance. Factors affecting the selection of sample types are considered, and sample preparation, analytical procedure and monitoring error discussed. Stream sediment is shown to be the optimum sample type for regional geochemistry in areas of upland Britain underlain by crystalline bedrock, although soils may provide the optimum sample medium in areas of intensive agriculture. Geochemical mapping of the continental shelf is based on superficial seabed material obtained by grab or cone dredge. Examples of geochemical maps of northern Scotland for several elements of environmental significance including Cu, Mo, Pb, and U are considered in relation to geology, topography, vegetation, land use and the chemistry of surface waters. Geochemical maps are shown to provide the best available source of information on chemical variations in bedrock, although there are many difficulties in relating geochemical or biological activity to the total trace element values. In any attempt to correlate trace element levels with disease, careful consideration must be given to factors affecting the availability and flux of the trace elements if meaningful associations are to be obtained. Geochemical maps of the North Sea indicate that the contents of Cu, Pb, Zn, Cd and Hg are uniformly low over most of the offshore area although higher concentrations occur in coastal samples. The highest concentrations of Cu, Pb and Zn occur off the Tyne estuary while the highest values for Cd and Hg occur further south.

Geography↗

PubMed1979

The effect of an intrauterine device on mast cell numbers and distribution in the hamster uterus.

The effect of an IUD on mast cell numbers and distribution in the uterus was studied in castrated, castrated hormone-treated and cycling hamsters. The device had a stimulatory effect on total mast cell numbers in those animals that received no treatment, peanut oil, or estrogen therapy and in all cycling animals. The device also apparently causes mast cells to be redistributed in the different areas of the uterus. The results indicate that the IUD alters the uterine mast cell response to exogenous hormones and cycle times.

Animals↗

PubMed1979

The effect of an intrauterine device on myometrial glycogen in the hamster.

The myometrical glycogen content of the uterine horns of cycling, castrated and castrated hormone-treated hamsters was basically unaffected by the presence of an intrauterine device (IUD). The study also indicates that visual evaluation of histochemical localization of glycogen is not adequate to determine minor differences in staining intensity. The "estrogen-like" effect or stimulatory effect of the IUD on uterine glycogen in the rat is not duplicated in the hamster.

Animals↗

PubMed1979

Some effects of an intrauterine device on glucosaminoglycans of the hamster uterus.

The effect of an intrauterine device (IUD) on non-heparin sulfomucopolysaccharide (SMP) was studied in castrated, hormone-treated, and cycling hamsters by photographic densitometry of tissue sections stained specifically for SMP with Alcian blue. Non-heparin SMP increased slightly in the myometrium of IUD-containing uteri of all castrated groups, with the increase being significant in only the peanut oil-treated group. The endometrium also showed slight increases in sulfomucin in IUD-containing uteri of peanut oil, progesterone, and estrogen plus progesterone-treated animals. These increases, however, were not statistically significant. In cycling hamsters the IUD had little effect on uterine non-heparin SMP in most cycle stages.

Animals↗

PubMed1976

The use of a molluscicide in conjunction with chemotherapy to control Schistosoma haematobium at the Barombi Lake foci in Cameroon. II. Urinary examination methods, the use of niridazole to attack the parasite in man, and the effect on transmission from man to snail.

The use of niridazole, in conjunction with snail control, in an attempt to control the transmission of Schistosoma haematobium at 2 Cameroon crater-lake villages is described. Quantitative examinations of urines for S. haematobium eggs were made on the whole population before control began, at intervals during the maintenance of control, and again after control ceased. The methods and difficulties are described, and their accuracy is discussed. After each examination all accessible egg-passers were treated or re-treated with niridazole. The drug was well tolerated and effective. Most treated patients ceased to pass live eggs, and most of those who later became positive again were thought to represent reinfections rather than relapses. During the maintenance of snail control, niridazole treatment of the 'whole' community reduced the total load of S. haematobium eggs passed to less than 1 per cent of the pre-control figure; and repeated subsequent treatments maintained a level of the same order. Despite this, there remained at different times 0.6-50.9 per cent of persons passing small quantities of live eggs, and these were an important source of continuing transmission. The possibility that more than one strain of S. haematobium was involved is discussed. An index of transmission from man to snail is proposed and discussed in relation to determining the level of the "break-point" in transmission. Although combined niridazole/molluscicide control reduced transmission from man to snail by about 3 log cycles, the "break-point", which is thought to lie 4 or more log-cycles lower, was not reached. When control was stopped, transmission built up again, with the prevalence rate in man rising more rapidly than the intensity of infections.

Adolescent↗

PubMed1976

The use of a molluscicide in conjunction with chemotherapy to control Schistosoma haematobium at the Barombi Lake foci in Cameroon. III. Conclusions and costs.

Although Frescon successfully controlled snails on the margins of the Barombi lakes, and although the continuation of niridazole and Frescon control reduced transmission of S. haematobium very considerably, practical difficulties, which are discussed, rendered the twin goals of snail- and parasite-eradication impossible to achieve. The "break-point" in transmission of S. haematobium appears to lie so low as to be practically synonymous with total eradication. Control operations would thus have had to be maintained indefinitely in order to avoid a rapid return to the pre-control situation. The cost of the control element in this combined chemotherapeutic and molluscicidal research project, at 2 lacustrine foci of S. haematobium transmission in the United Republic of Cameroon, was 9 to 10 U.S. dollars per year per head of population protected. This sum is about three times the country's total estimated expenditure per head of population on all health and social services for the year 1974-1975. The high cost of such operations is only likely to be acceptable where schistosomiasis causes much ill-health and reduced economic productivity, and where tangible benefits may be expected from a reduction in the intensity of infections, short of eradication.

Bulinus↗

PubMed1976

Microfilariae in the cerebrospinal fluid, and neurological complications, during treatment of onchocerciasis with diethylcarbamazine.

Microfilariae of Onchocerca volvulus were found in the cerebrospinal fluid (CSF) of 5/8 heavily infected onchocerciasis patients. During treatment with diethylcarbamazine citrate 10/11 patients showed increased numbers of 0. volvulus microfilariae in the CSF. Patients with concentrations of 8-31 mf/ml CSF developed severe vertigo, and some other neurological manifestations, during treatment. A hypothesis is put forward to account for this clinical piciture, and its importance in relation to the treatment of onchocerciasis is discussed.

Arachnoid↗

PubMed1976

The populatin dynamics of Onchocerca volvulus microfilariae during treatment with suramin and diethylcarbamazine.

During treatment with suramin the numbers of O. volvulus microfilariae in the blood, urine, sputum, and anterior chambers of the eye fell before those in the skin. When diethylcarbamazine (DEC) was given after suramin, increased numbers of microfilariae appeared in the blood, urine, cerebrospinal fluid (CSF) and sputum, but the increase in the blood was less marked, and of shorter duration, than in similar patients receiving DEC without previous suramin. Microfilariae are thought to enter the urine, sputum and CSF directly from the blood by penetrating the capillary walls in the glomeruli, pulmonary alveoli, and choroid plexuses. Those in the aqueous humour do not appear to come directly from the bloodstream. The total numbers of microfilariae in the skin of some heavily infected onchocerciasis patients are estimated, as are the total numbers moving into the blood-stream under the influence of DEC and the proportion which escape into the urine, sputum and CSF. It is concluded that the majority of the microfilariae which appear in the blood during DEC therapy must be destroyed in the body, probably in the liver.

Anterior Chamber↗

PubMed1976

The use of a molluscicide, in conjunction with chemotherapy, to control Schistosoma haematobium at the Barombi Lake foci in Cameroon. I. The attack on the snail hosts, using N-tritylmorpholine, and the effect on transmission from snail to man.

The background and strategy of a campaign to control the transmission of Schistosoma haematobium at the isolated crater-lake villages of Barombi Mbo and Barombi Kotto are outlined. A two-pronged attack was envisaged, using N-tritylmorpholine (Frescon) to control the snail host, and niridazole (Ambilhar) to control the parasite in man. The lake villages and their environs are described. Observations, relevant to control, are recorded on the biology of Bulinus rohlfsi and B. camerunensis. Snail populations were sampled by hand picking, and by the use of basket traps baited with dead leaves. Some experiments on the susceptibility of both snails to S. haematobium are described, together with observations on the strains of schistosome developing in monkeys exposed to cercariae from naturally-infected snails from the lakes. Frescon was applied through a tube to the bottom layers at the edge of the lakes, where the snails lived. Concentrations of 2 ppm down to 0.5 ppm N-tritylmorpholine proved necessary for adequate kills. Intervals of 6 weeks between treatments sufficed to control B. rohlfsi, but applications every 2 weeks were needed for B. camerunensis. The numbers of egg-masses, of snails, and of infective snails of both species were recorded before, during and after Frescon/Ambilhar control; and snail transmission rates and indices have been calculated. Control operations reduced transmission by R. rohlfsi to 2.4% of the pre-control level, or to below the detectable threshold. They were most effective at Mbo, where B. rohlfsi was the only intermediate host. At Kotto, despite excellent B. rohlfsi control, transmission of the residual infections in the human population by B. camerunensis persisted during control operations, until the intervals between Frescon applications were cut to 2 weeks.

Animals↗

PubMed1975

Loa loa: experimental infection in two species of African primates.

Four species of primates, baboon (Papio anubis), patas monkeys (Erythrocebus patas), green monkey (Cercopithecus aethiops) and chimpanzee (Pan troglodytes) were inoculated with third-stage larvae of a human strain of Loa loa from Cameroon, West African. The baboon and patas monkeys developed patent infections after 135 to 148 days; the green monkeys and chimpanzee did not. In each animal which became patent, microfilaremia rose rapidly to high levels. In the baboon, but not in the patas monkeys, there was a suppression of microfilaremia during the 4th month of patency. After splenectomy, microfilariae reappeared in the peripheral blood in large numbers. In both baboon and patas monkeys, the microfilariae of Loa loa maintain the diurnal periodicity so characteristic of their behavior in man.

Animals↗