Showing papers on "Malaria published in 1981"
TL;DR: It is reported here that addition of hypoxanthine to the culture medium permits the production of mature, infectious P. falciparum gametocytes on a regular basis.
Abstract: The form of malaria caused by Plasmodium falciparum is probably the most important infectious disease of man. In tropical Africa alone, where malaria affects almost the entire population, it has been estimated that every year the disease causes the death of 1 million children under 14 yr old1. The mosquito vector of malaria is infected when it ingests mature gametocytes in blood taken from a human carrier of the disease. Development of the parasite continues in the mosquito and culminates with the sporozoite stage, which initiates a new infection when injected by the mosquito into a further human host. Research on P. falciparum sporozoites has been severely limited by a general lack of availability of suitable patients with gametocytes. It was hoped that the recently developed continuous cultivation of P. falciparum2 would solve this, as gametocytes are often produced during cultivation. However, we and others soon found that these gametocytes failed to mature in culture3,4, or at best did so only rarely and unpredictably5–7. We report here that addition of hypoxanthine to the culture medium permits the production of mature, infectious P. falciparum gametocytes on a regular basis.
311 citations
Journal Article•
TL;DR: The Chemotherapy of Malaria (COM) as mentioned in this paper is a widely used cancer treatment for the treatment of malaria in the Middle East, Africa and the Middle-east..
Abstract: Chemotherapy of malaria , Chemotherapy of malaria , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی
283 citations
TL;DR: It is reported that Plasmodium chabaudi adami (556KA) infection in B-cell-deficient mice results in an activation of a T- cell-dependent immune mechanism which terminates acute malaria in a similar way to that seen in immunologically intact mice.
Abstract: Immunity to malaria has a multicomponent basis which requires the participation of both T- and B-lymphocyte systems1. Previous studies have suggested that the T-lymphocyte system has an essential role in ‘re-infection immunity’ to malaria, but that B cells and/or their products are necessary for the host to survive acute infection and to clear the blood of parasites during chronic malaria2–4. Thus, B-cell-deficient mice and chickens died of fulminant malaria when infected with Plasmodium yoelii and Plasmodium gallinaceum, respectively2,3,5, but when their acute infections were controlled with subcurative chemotherapy, B-cell-deficient hosts developed chronic low-grade infections and resisted challenge with homologous parasites2,4. In contrast, athymic nude mice failed to control their endogenous P. yoelii infection after the termination of drug therapy unless they had been thymus grafted before initiation of acute infection3. We now report that Plasmodium chabaudi adami (556KA) infection in B-cell-deficient mice results in an activation of a T-cell-dependent immune mechanism which terminates acute malaria in a similar way to that seen in immunologically intact mice. Furthermore, these immunized B-cell-deficient mice were resistant to homologous challenge infection as well as infections initiated with Plasmodium vinckei, but not with P. yoelii and Plasmodium berghei.
174 citations
Book•
30 Apr 1981
154 citations
TL;DR: Monoclonal antibodies against single antigenic determinant(s) of Plasmodium falciparum are raised and it is reported that some of them inhibit the growth of erythrocytic forms of P. falcIParum in vitro.
Abstract: Malaria is increasing in incidence and prevalence in most tropical areas and is a major problem for both individuals and communities Current malaria research is aimed at developing vaccines and, for this, it may be useful to define Plasmodium antigen(s) related to the development of a protective immune response in the host Monoclonal antibodies have recently been shown to interfere with rodent malaria infection (Plasmodium berghei) at the sporozoite or merozoite stage We have now raised monoclonal antibodies against single antigenic determinant(s) of Plasmodium falciparum and report that some of them inhibit the growth of erythrocytic forms of P falciparum in vitro
135 citations
Journal Article•
TL;DR: The pathophysiology of malaria infection is presented from animal studies and the various manifestations occurring in human cases and the concept of a chain reaction of physiological processes that leads to the disease following malarial infection is proposed.
Abstract: The pathophysiology of malaria infection is presented from animal studies and the various manifestations occurring in human cases. Maegraith (1974) proposed the concept of a chain reaction of physiological processes that leads to the disease following malarial infection. It may be seen that the malaria parasites first damage the infected red blood cells directly and then initiate a chain reaction of nonspecific inflammatory processes and later on immunological responses aggravating further the inflammatory reactions. Because of ther interdependence in nature of these changes as suggested by Maegraith in 1977 it is usually difficult to clearly identify these three mechanisms.
116 citations
TL;DR: The results of this study suggest that fansidar resistance is prevalent at this camp and should prompt more exhaustive studies of the epidemiology of fansidars resistance in the area.
109 citations
92 citations
TL;DR: Thrombocytopenia induced by malaria is due to shortened life span in the peripheral blood and some interaction is present between platelets and malaria plasmodia or parasitized red cells.
Abstract: Platelet counts were investigated in 26 patients withP. falciparum malaria and 39 patients withP. vivax malaria before and after treatment. Before schizontocidal treatment 22 of 26 (85%) patients withP. falciparum malaria and 30 of 39 (72%) patients withP. vivax malaria had depressed platelet counts below 150,000/Μl blood. There was a correlation between low platelet counts and high counts of malarial plasmodia (parasitized red blood cells) inP. falciparum andP. vivax infections (p < 0.001). Platelet survival, studied by malonaldehyde formation in three patients during the period of decreasing parasitaemia, revealed a shortened life span to 2–3 days in comparison to 7–10 days in normal controls. In all patients platelet counts rose to threefold the initial values within 5 days after clearance of parasites.
86 citations
TL;DR: Observations suggest that the intensity of the immune response and of the associated complement activation may be important factors in the pathogenesis of cerebral malaria.
Abstract: A total of 32 patients with Plasmodium falciparum malaria were studied. Of these, 23 had benign infections, and 9 had typical cerebral malaria. Cryoglobulins, circulating immune complexes detected by a C1q-binding assay, and hypocomplementemia were found in eight of nine patients with cerebral malaria. Raised levels of complement component 3 breakdown products (C3d) were found in the seven patients tested. Peak levels of circulating immune complexes and C3d were associated with thrombocytopenia. In contrast, in patients with benign Plasmodium falciparum malaria, cryoglobulins and circulating immune complexes were found only in 3 of 23 patients. Similarly, hypocomplementemia was detected only in 5 of 23 patients. These observations suggest that the intensity of the immune response and of the associated complement activation may be important factors in the pathogenesis of cerebral malaria.
83 citations
TL;DR: Quinidine is an effective antimalarial drug for Plasmodium falciparum infections and may be more potent than quinine, and in-vitro cultures showed that the minimum inhibitory concentration was consistently lower for quinidine than forQuinine.
TL;DR: A trial of drug regimens for treating Plasmodium falciparum malaria was conducted in a refugee camp in eastern Thailand where extensive 'Fansidar' (pyrimethamine-sulfadoxine) resistance had been demonstrated, suggesting that tetracycline should be considered in treating patients with falcine malaria contracted in the area of the Thai-Kampuchean border.
TL;DR: This is the first reported infection with Plasmodium falciparum acquired from continuous cultures of these parasites, and the strain involved, FCR3, was originally isolated from The Gambia, West Africa, and was initially sensitive to chloroquine in vitro and in vivo.
Abstract: This is the first reported infection with Plasmodium falciparum acquired from continuous cultures of these parasites. The strain involved, FCR3, was originally isolated from The Gambia, West Africa, and was initially sensitive to chloroquine in vitro. After nearly 4 years of continuous culture without chloroquine pressure, it became resistant to chloroquine in vitro and in vivo, as demonstrated by the failure of both prophylactic and therapeutic regimens to control an accidental inoculation of parasite-infected erythrocytes.
TL;DR: The results suggest that Hb AS as well as the female genotype GdA-/GdB offer selective advantage against the disease.
Abstract: In 702 Nigerian children under 6 years of age the incidence and the severity of malarial infection was studied with respect to haemoglobin types and red cell glucose-6-phosphate dehydrogenase variants. The results suggest that Hb AS as well as the female genotype GdA-/GdB offer selective advantage against the disease. Parasite densities in carriers of these genotypes were significantly lower than in other subjects. Whereas protection by Hb AS was found mainly in children between 2 and 4 years of age, the advantage afforded by GdA-/GdB was similar in all age groups. Possible mechanisms are discussed.
TL;DR: In vivo tests in all cases and in vitro results in 2 cases confirm that malaria due to chloroquine-resistent P. falciparum is being transmitted in some parts of Africa.
Abstract: Three cases of infection with chloroquine-resistant, Plasmodium falciparum malaria are described. In two cases the infection was acquired in Madagascar; the third infection was acquired in Kenya, all in spite of regular prophylaxis.The WHO extended field tests for the sensitivity of falciparum malaria to chloroquine (1973) were followed by recrudescences of the RI pattern in all three cases. The chloroquine concentrations in serum were measured, both during treatment and at the time of re-appearance of parasites, and were found to be adequate for sensitive strains. In vitro tests were performed and showed resistance in one of the cases from Madagascar and probable resistance in the other, but failed in the case from Kenya.It is concluded that Madagascar is yet another area of Africa where strains of P. falciparum with RI resistance have appeared.
Journal Article•
TL;DR: Malaria profoundly affects pregnancy by influencing the state of health of both the mother and the foetus, and in rare cases congenital malaria occurs.
Abstract: Malaria profoundly affects pregnancy by influencing the state of health of both the mother and the foetus. and in rare cases congenital malaria occurs.
Journal Article•
TL;DR: The measures being applied to control malaria in China are described and the present situation in the country is outlined and much work is needed before the ultimate goal of complete eradication of malaria can be achieved.
Abstract: This report describes the measures being applied to control malaria in China and outlines the present situation in the country. In the 1940s, it was estimated that approximately 350 million people were at risk of infection and that about 30 million cases of malaria occurred annually. In the last 30 years, large-scale antimalaria campaigns have been established and have achieved much success. In 1979, there were just over 2 million reported cases of malaria and approximately 64% of the population now live in areas where the incidence is below 5 per 10 000. However, there are still several major difficulties to be overcome, and much work is needed before the ultimate goal of complete eradication of malaria in China can be achieved.
TL;DR: It is suggested that if Epstein-Barr virus infection and malaria are important in the aetiology of Burkitt's lymphoma, they produce their effects independently and case-control studies and screening programmes involving anti-VCA levels will have to take these two findings into account.
TL;DR: The data are interpreted as supportive of the Duffy-vivax hypothesis with reference to a part of eastern Africa, and it is suggested thatThe Duffy-negative genotype may represent the original, rather than the mutant, condition in tropial Africa.
Abstract: We investigated an hypothesis relating the Duffy-negative blood type with insusceptibility to vivax malaria—and previously associated only with people of West African ancestry—in three population samples of eastern African stock. The samples included Nilotic and Hamitic-Semitic residents of a malarious locale in Ethiopia and Hamito-Semites in Addis Ababa where malaria is not endemic. Fresh red blood cells from 191 subjects were tested with Duffy antisera, anti-Fya and anti-Fyb. Duffy-positive rates in the malarious community were 8% for the Nilotes and 70% for the Hamito-Semites; the Hamito-Semites in Addis Ababa were 98% Duffy-positive. The relative prevalences of Plasmodium vivax in the two study groups at risk to malaria were 2.4% for the Nilotes and 27.3% for the Hamito-Semites, producing a ratio similar to the ratio of Duffy-positives in the two samples. We interpret the data as supportive of the Duffy-vivax hypothesis with reference to a part of eastern Africa, and we suggest that the Duffy-negative genotype may represent the original, rather than the mutant, condition in tropical Africa.
TL;DR: The hypothesis that key features of traditional Sardinian culture had adaptive value against the ecological threat of malaria because they limited exposure of certain social segments to the malaria vector, Anopheles labranchiae is examined.
Abstract: Endemic malaria was a primary ecological variable which historically affected traditional Sardinian culture. While the biogenetic impact of malaria has been examined in detail, this paper examines the hypothesis that key features of traditional Sardinian culture had adaptive value against the ecological threat of malaria because they limited exposure of certain social segments to the malaria vector, Anopheles labranchiae. The concept of cultural adaptation is first developed. Cultural adaptations analyzed include: settlement pattern; pastoral transhumance; social organization of production; restricted mobility for pregnant women; and the folk medical beliefs of Intemperie and Colpo d'Aria. These cultural traits are predicated on a folk etiological theory of malaria in which the disease was caused by “bad air,” but they function to reduce exposure to mosquitoes and thereby limit malaria rates for certain social groups. It is argued that this mode of analysis can aid in understanding the interactio...
TL;DR: It is illustrated that parasites, notably malaria, are important determinants of the serum antibodies of children in the tropics and suggests that mild undernutrition has little effect.
TL;DR: A case of Plasmodium falciparum malaria resistant to Fansidar (sulphadoxine plus pyrimethamine) at a level corresponding to R III and resistant to chloroquine is reported.
Abstract: A case of Plasmodium falciparum malaria resistant to Fansidar (sulphadoxine plus pyrimethamine) at a level corresponding to R III and resistant to chloroquine is reported. The infection was most certainly acquired in Malaysia, but diagnosed and treated in a non-malarious area. Normal resorption and elimination rates of the Fansidar components excludes cure failure due to abnormal drug fate in the host. P. falciparum parasites from the patient have been maintained in in vitro cultures. The patient was permanently cured with mefloquine.