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Biomedical subjects

D Payne

Publications and source records attributed to D Payne.

At least 181 records · Page 10Linked to original sources
PubMed1984

Plasmodium falciparum sensitivity to chloroquine in the Buyo Region, Ivory Coast.

As part of a project, supported by the UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases, for achieving a reduction of mortality due to Plasmodium falciparum by means of a primary health care programme, in vivo and in vitro sensitivity testing of P. falciparum to chloroquine was carried out in the Buyo Region of the Ivory Coast. Blood samples from a total of 595 children aged 2-13 years from 5 villages were screened microscopically and 32 of these children were selected for in vivo testing and 36 for in vitro testing. All 32 in vivo test patients were treated with 25 mg chloroquine base per kg, given in divided doses over 3 days, and all of them completed the 7-day observation period. Daily blood slides were taken and these were negative for asexual parasites on days 3 to 7. The mean parasite clearance time was 1.8 days. The 36 in vitro tests produced satisfactory results in 19 isolates. Complete inhibition was achieved in all 19 at 5.7 pmol chloroquine base per well (1.14 mumol/l of blood); 7 of these isolates showed complete inhibition at 1 pmol, 15 at 2 pmol and 17 at 4 pmol.These results showed that in the population studied there was no evidence of chloroquine resistance in either the in vivo or in vitro tests and they give confirmation of a continued response in West Africa to the standard curative regimen of chloroquine.

Adolescent↗
PubMed1983

In-vivo and in-vitro assessment of chloroquine-resistant Plasmodium falciparum malaria in Zanzibar.

A population-based field study was conducted in Zanzibar Town, Zanzibar, Tanzania, to assess the in-vivo and in-vitro susceptibility to chloroquine of Plasmodium falciparum. Single-dose therapy with chloroquine (10 mg base/kg) failed to clear parasitaemia in 11 of 22 (50%) treated subjects, and a standard therapeutic regimen of chloroquine (25 mg base/kg) failed to clear parasitaemia in 11 of 32 (34%) treated subjects. Concurrent in-vitro testing by the Rieckmann micromethod showed that 8 of 12 (66%) isolates were chloroquine-resistant.

Adolescent↗
PubMed1983

The impact of coronary artery disease on carotid endarterectomy.

In a series of 531 CENDX, preoperative cardiac risk was categorized by clinical criteria. Patients with CAD (history of previous MI, angina, congestive heart failure, and/or electrocardiographic evidence of CAD were selected for more invasive studies based on clinical criteria. The overall incidence of postoperative myocardial infarction was 2.5% and increased slightly to 4% in patients with symptomatic cardiac disease. More importantly, the overall mortality was 0.9% and only 3 of 13 (23%) postoperative myocardial infarctions were fatal. Neurologic complications averaged 1.4% and approximately 70% were related to preceding cardiac events. Twenty-two patients or 4% of the entire series underwent carotid endarterectomy combined with coronary artery bypass graft and this approach was associated with one death and one stroke. Therefore, we conclude that a selective approach to coronary arteriography and subsequent CABG based on clinical criteria is associated with an acceptably low mortality and cardiac morbidity.

Arteriosclerosis↗
PubMed1983

Evaluation of amodiaquine treatment of chloroquine-resistant Plasmodium falciparum malaria on Zanzibar, 1982.

Amodiaquine, a 4-aminoquinoline which has been shown to be effective in treating infections with chloroquine-resistant strains of Plasmodium falciparum, was evaluated against chloroquine-resistant infections in children in Zanzibar, Tanzania, during July 1982. A 25-mg base/kg dosage of amodiaquine produced parasite clearance in 34 of 38 (89%) children in a mean of 2.8 days. When followed for 28 days, 15 of 38 (39%) children were completely cured of their infection as judged by the absence of renewed parasitemia. The parasite clearance rates produced by amodiaquine were significantly higher than those observed in a comparison group of children treated with 25 mg base/kg chloroquine. There was, however, no difference in the cure rates in the chloroquine and amodiaquine groups. Despite the enhanced parasite clearance rate, amodiaquine is not sufficiently more effective against Zanzibari strains of P. falciparum to replace chloroquine. Other alternative drugs must be evaluated to define the optimal malaria therapy regimen on Zanzibar.

Amodiaquine↗
PubMed1982

Incipient resistance of Plasmodium falciparum to chloroquine among a semi-immune population of the United Republic of Tanzania. 1. Results of in vivo and in vitro studies and of an ophthalmological survey.

The sensitivity of Plasmodium falciparum strains to chloroquine was tested in one locality in the north-east of the United Republic of Tanzania, where a chloroquine-medicated salt project has been implemented for chemosuppression for many years, and where large amounts of the drug have been available during the last decade for the treatment of malaria infections.Single doses of chloroquine (5 or 10 mg of base/kg of body weight) failed to clear P. falciparum trophozoites in asymptomatic parasite carriers selected from the school population. In comparison, clearance had been obtained easily ten years previously with 5 mg of base/kg of body weight in several localities in the area.A total dose of 25 mg of base/kg of body weight given over a 3-day period succeeded in clearing asexual parasites from the peripheral blood by day 3 in all instances. Asexual parasites were not found again during the nine days following administration of the drug.All the schoolchildren who had received 5 or 10 mg of base/kg of body weight at the beginning of the trial were treated with a further 20 mg of base/kg of body weight at the end of the 7-day observation period. Asexual parasites reappeared in the blood of some of these children 7-10 days after the second administration of the drug.Using the in vitro microtechnique, incomplete schizont inhibition was observed in 3 out of 21 cases at a chloroquine concentration of 1.14 mumol/litre of blood, which is the discriminating dosage for resistance at RI level.No cases of retinopathy related to the prolonged use of chloroquine were detected among the 221 residents who had spent more than 16 consecutive years in the locality.

Adolescent↗
PubMed1981

Autoimmune hemolytic anemia and ovarian dermoid cysts: case report and review of the literature.

A case of autoimmune hemolytic anemia (AIHA) associated with an ovarian dermoid cyst is presented. Early recognition and specific therapy for this entity is stressed for optimal results since conventional forms of therapy of AIHA are ineffectual. Unusual features of the case are discussed. The literature is reviewed and possible mechanisms of the hemolytic process are discussed.

Adult↗
PubMed1980

Pyrimethamine sensitivity in Plasmodium falciparum: determination in vitro by a modified 48-hour test.

Four strains of Plasmodium falciparum recently isolated in culture were assessed in vitro for their response to pyrimethamine. A simple modified 48-hour test was used, which showed two strains to be sensitive to the drug in vitro, while the other two were resistant at a very high level. In the two strains for which relevant clinical information was available the in vivo response to pyrimethamine was corroborated by the in vitro findings. This modified 48-hour test is thus useful for determining patterns of drug sensitivity in laboratory-adapted strains, and would be a valuable asset if found to be equally applicable under field conditions.

Adult↗
PubMed1980

Use of the in vitro microtechnique for the assessment of drug sensitivity of Plasmodium falciparum in Sennar, Sudan.

In 1978, studies on the chloroquine sensitivity of Plasmodium falciparum were carried out in the district of Sennar, Sudan. The results of the in vivo tests showed parasites resistant at the RI level only, but the mean clearance time of trophozoites from the blood was higher than for strains found in many other areas of tropical Africa. The in vitro tests, using the microtechnique, indicated a lower sensitivity to chloroquine in the local P. falciparum isolates than in those of most other African countries. However, similar results have been reported from Ethiopia. The chloroquine sensitivity of P. falciparum from Sennar is close to the critical level of resistance. The in vitro microtechnique was also used to test for the sensitivity to Dabequin, 4-aminobenzo-quinoline, and was generally found to be a suitable and reproducible method, with a greater potential than the standard macro method. At parasite densities of over 100 000 asexual parasites per microlitre of blood the effect of a given concentration of chloroquine was related to the parasite density owing to the selective uptake of the compound by the parasitized cells.

Adolescent↗
PubMed1978

Disulfiram neuropathy.

A 35-year-old man developed a distal sensorimotor polyneuropathy after taking disulfiram, 500 mg daily for five months. His symptoms improved after the drug therapy was discontinued. Clinical, electrophysiological, and pathological observations during the acute stage and during recovery suggest that disulfiram produces a distal axonopathy.

Adult↗
PubMed1978

Evaluation of fenitrothion for the control of malaria.

Fenitrothion was evaluated for residual spraying in antimalaria programmes in a large-scale field trial near Kisumu, Kenya from 1972 to 1976. The insecticide was applied in a hyper/holoendemic malarious area of 200 km(2) inhabited by about 50 000 people. All houses and animal shelters were sprayed at a target dosage rate of 2 g/m(2) at 3-month intervals for a total of 8 consecutive spray rounds in 2 years. The malaria vectors Anopheles gambiae species A and B and A. funestus were reduced to negligible densities indoors and outdoors immediately after initiation of spraying and for 10 months after the last spray round. However, A. gambiae reappeared during the main wet season at densities high enough to reestablish low-level transmission for short periods. Spraying produced a marked and rapid decrease in both the incidence and prevalence of malaria. The daily probability of acquiring malaria infection was reduced from 0.009 before spraying to 0.0003 under spray protection, a reduction of 96%. Data collected on a longitudinal basis indicated that sustained spray protection would reduce malaria prevalence to an asymptotic limit of 6.9% under the assumption that the inoculation and recovery rates remain stable. However, to attain malaria eradication in this type of epidemiological situation, complementary measures such as mass drug administration appear to be necessary.

Evaluation Studies as Topic↗
PubMed1976

Impact of control measures on malaria transmission and general mortality.

This paper is an attempt to relate modifications observed in general and infant mortality rates with the dynamic changes in transmission induced by malaria control measures. The observations indicated relationships between the efficacy of control and a decrease in mortality. The daily parasitological inoculation rate was reduced from 0.00958 infective bites per individual before treatment to 0.00037 after treatment (a decrease of 96%). In two years, general mortality decreased from 23.9 to 13.5 deaths per 1000 population and infant mortality decreased from 157 to 93 per 1000 live births. This indirect benefit of malaria control deserves attention in a wider assessment of measures directed against vector-borne diseases.

Adult↗