Showing papers on "Malaria published in 1970"

Chemotherapy and drug resistance in malaria

Abstract: Chemotherapy and drug resistance in malaria , Chemotherapy and drug resistance in malaria , کتابخانه مرکزی دانشگاه علوم پزشکی تهران

Agranulocytosis due to dapsone.

Abstract: Agranulocytosis developed in 16 U. S. soldiers in Vietnam who were receiving daily dapsone prophylaxis for falciparum malaria. There were eight deaths in the group. All patients had been o...

Suppression of autoimmune disease in NZB and (NZB x NZW) F1 hybrid mice by infection with malaria.

Abstract: VARIOUS immunological changes have been observed in many apparently healthy subjects living in tropical regions that are probably related to multiple parasitic infections from childhood1. Consideration of this in conjunction with the rarity of autoimmune disease in tropical Africa, for example Western Nigeria2, led to the suggestion that the immunological effects of repeated parasitic infection might have some protective action against the development of autoimmune disease2. To investigate this hypothesis we have studied the effects of infection with malaria on the spontaneous autoimmune disease of NZB mice and the (NZB × NZW)F1 hybrid mice (B/W mice). Twenty-one NZB mice and thirteen female B/W mice from the Taplow colony were infected, when one month old, with the rodent malaria parasite Plasmodium berghei yoelii3 by the intraperitoneal injection of 1 × 106 parasites derived from a heavily infected mouse of the same strain. The malaria strain was not contaminated with Eperythrozoon coccoides. Parasitaemia was monitored by the examination of Giemsa stained blood films made from the tails of the mice every second day during the acute phase of the infection and at longer intervals thereafter. To determine whether low parasitaemia was persisting, heparinized blood samples were collected from each mouse 4 months after infection and pooled samples injected into young BALB/c mice.

Exogenous Interferon protects Mice against Plasmodium berghei Malaria

Abstract: WE have shown previously that several inducers of interferon protect mice against Plasmodium berghei malaria and that this protection is far greater against sporozoite-induced infections than against blood form-induced infection1–3. Others have reported that prolonged incubation of parasitized red blood cells (RBC) with serum containing interferon in vitro decreased or abolished the capacity of these cells to initiate lethal malarial infection in mice4. Another group found, however, that interferon had no effect on the development of malaria parasites in RBC in vitro (personal communication from T. Merigan). We show here that exogenous mouse serum interferon protects mice against sporozoite-induced Plasmodium berghei malaria.

Can parasitic infection suppress autoimmune disease

Abstract: These findings implicate both the thymusand bursa-dependent lymphoid systems in MD, and are consistent with the hypothesis that both systems respond directly to the presence of MD virus. Pathologically MD is much more suggestive of an aberrant immunological response with failure of the cellular proliferation to be cut off than it is of a neoplasm arising as a result of virus-induced malignant transformation of a line of lymphoid cells. The majority of lymphoid cells in the tumours in fact appear to be free of virus infection as judged by their lack of infectivity in tissue culture (Churchill & Biggs 1967) and lack of morphological evidence of virus under the electron microscope (Ahmed & Schidlovsky 1968). It may be that the immune deficiencies in MD arise from antigenic competition between MDV and other antigens. If this is so, it would appear that the antigenic challenge presented by MDV infection is of an unusual nature in view of the progressive cellular response leading to tumour formation. The abnormality could be in the nature of the antigen, its amount or the failure of some feedback mechanism responsible for control of cellular proliferation.

Cycles of jungle malaria in West Malaysia.

Abstract: The ecology of primate malaria was investigated in an area of West Malaysia where a person had been naturally infected with Plasmodium knowlesi. Anopheles balabacensis introlatus and Anopheles leucosphyrus (both proved vectors of simian malaria) were trapped in the jungle with man as bait at ground level and monkey as bait in the forest canopy. Neither mosquito was found to invade a nearby village. Anopheles maculatus was found in both village and jungle traps but in such small numbers as to make it an unlikely liaison between human and simian malarias. Sporozoite-infected salivary glands were recorded from both A. b. introlatus and A. leucosphyrus, but no infections resulted when these sporozoites were inoculated into malaria-free rhesus monkeys. Malaria infections, which were believed to be nonprimate in origin, were recorded from Anopheles umbrosus-group mosquitoes. Malaria parasites were observed in 2.5% of 1,117 persons examined from villages, mostly adjacent to the forest study area. However, 14% of this group had fluorescent-antibody titers of 1:20 or higher, indicating recent experience with malaria. Whole, heparinized blood from the same 1,117 persons produced no infections when inoculated into malaria-free rhesus monkeys. Plasmodium knowlesi and Plasmodium inui were identified from indigenous populations of Macaca irus. Leaf monkeys (Presbytis sp.) and gibbons (Hylobates sp.) were also present in the study area but were not examined. It is concluded that man can become naturally infected with simian malaria in this environment only when he becomes involved in the normal mosquito-monkey cycles in the jungle.

Saurian malaria: development of sporozoites in two species of phlebotomine sandflies.

Abstract: Sporolzoites of a lizard malaria parasite, Plasmodium mexicanum. developed in two spcies of sandfly-Lutzomyia vexatrix and Lutzomyia stewarti. Salivary g1ands were infected 11 days after the flies took an infective blood meal. This is the first report of a malaria parasite undergoing sporogonic development In an insect other than a mosquito and the first description of lizard malaria sporogenesis.

Acute malaria in newborn infants.

Abstract: was detected. Further aspirations produced no benefit, but an increased dose of steroids helped. However, two weeks later she developed severe respiratory failure and died. At necropsy the lungs showed prominent arterial radicles, a moderate amount of oedema, and scattered, mainly subpleural, areas suggestive of chronic pneumonitis. Both latter features were worse on the left (weight 985g.) than on the right (weight 720g.) Both pleural spaces contained old fibrous adhesions and bilateral yellow effusions. The heart (weight 360g.) showed right ventricular hypertrophy (10mmn.) and dilatation; the right auricle was normal. There was no thrombosis in the syst-mic vessels. The lungs were sent to Professor Herbert Spencer for examination. rn his opinion they showed: (1) Some pulmonary arterial thickening; occasional arteries also showed recanalization; (2) interstitial fibrosis (Fig.) plus recent intra-alveolar fibrinous oedema; (3) pronounced dilatation of the bronchial veins; (4) enormous distension of the alveolar capillaries in places; and (5) thrombosis of smalland medium-sized veins with evidence of recanalization. These changes add up to thrombosis of the pulmonary venous return with subsequent oedema, collateral channel formation, and pulmonary artery hypertension (with occasional arterial thrombosis and recanalization). The disease was an evolving condition in this patient as is apparent from the varying degrees of oedema and venous occlusion. Despite this activity no aetiological agent was discovered. Perhaps virus culture of the sputum would have been revealing, since Liebow suggests haemagglutination associated with pulmonary viral infections is possibly the cause of the thrombosis. More information could have been forthcoming had the patient been diagnosed in life. The object of this report is to remind clinicians and pathologists of the disease, and to underline the opinion of previous authors that it may not be as rare as the literature suggests.-We are, etc.,

Burkitt's lymphoma and sickle cell trait.

Abstract: Only two areas of the world, tropical Africa and New Guinea, are endemic for Burkitt's lymphoma. These are the principal areas of the world where malaria still occurs in hyperand holo-endemic forms, and within these two areas the geographical distribution of the tumour coincides closely with that of endemic malaria. These observations suggest the possibility of a causal connection between chronic stimulation of lymphoid tissue by malaria and the development of the lymphoma (Dalldorf, Linsell, Barnhart, and Martyn, 1964; Edington, Maclean, and Okubadejo, 1964; Burkitt, 1969). Young children with AS haemoglobin (sickle cell trait) are substantially protected against severe falciparum malaria (Allison, 1963). If they could be shown to have a lower incidence of Burkitt's tumour than children with AA haemoglobin, it would provide additional evidence for a role of falciparum malaria in the aetiology of the disease. Williams (1966) compared the haemoglobin electrophoretic patterns of 100 microscopically proven Burkitt's lymphoma patients from Nigeria with those of control children, and he concluded that children with haemoglobin AA were more susceptible to the tumour than those with AS. This paper describes the preliminary results of a patient-control study in Uganda to test this hypo thesis further.

Malaria in soldiers returning from Vietnam. Epidemiologic, therapeutic, and clinical studies.

Abstract: Malaria occurring in the U. S. A. among Army troops who returned from Vietnam in 1966 and 1967 was investigated epidemiologically and clinically. The incidence of malaria among returnees in the U. S. A. varied from 0.11 to 4.66% per year; rates of hospitalization for malaria for the same troops during their service in Vietnam varied from 2.3 to 4.8% per year. Infections with Plasmodium falciparum were rare in the U. S. A. but frequent in Vietnam. Clinically manifest vivax infections occurred significantly less often in Negro than in white men, which appeared to be due to natural resistance of the Negro. The 8-week CP regimen (300 mg chloroquine base plus 45 mg primaquine base once a week for 8 weeks), when used under field conditions as radical cure treatment of clinically manifest vivax malaria acquired in Vietnam, was associated with a 22.3% relapse rate. The disappointing results were due, at least in part, to failure of patients to complete the regimen. A significantly lower relapse rate (7%) was achieved with the easily supervised regimen of 15 mg primaquine base daily for 14 days. The secondary exoerythrocytic forms of Vietnam strains of Plasmodium vivax appear less susceptible to primaquine than those of Korean strains but more susceptible than those of the Chesson strain.

Studies on the chemotherapy of malaria. I. The treatment of overt falciparum malaria with potentiating combinations of pyrimethamine and sulphormethoxine or dapsone in The Gambia.

Abstract: Hospital trials of pyrimethamine, sulphormethoxine and dapsone were carried out in Gambian patients with overt malaria. Small single doses of pyrimethamine were effective in acute attacks of malaria but further treatment with pyrimethamine alone in some cases led to the emergence of resistant asexual falciparum parasites. Treatment with sulphormethoxine or dapsone alone was unsatisfactory but when combined with as little as 0·01 mg./kg. of pyrimethamine, a potent schizontocidal effect was sustained indicating a strong potentiating link in the action of these drugs in combination with pyrimethamine. Treatment with the adult equivalent of pyrimethamine 5 mg. and sulphormethoxine 100 or dapsone 50 mg. was completely effective in terminating acute attacks of falciparum malaria in susceptible children although the period of fever was prolonged after elimination of asexual parasitaemia in patients with high parasitaemias. Field trials with weekly or fortnightly doses with these combinations are advocated for malaria suppression in ‘semi-immunes’.

Plasmodium ovale malaria acquired in Viet-Nam.

Abstract: Four cases of Plasmodium ovale malaria are reported among US servicemen stationed in Viet-Nam between January 1966 and March 1969 Taken together with other cases cited by the authors, these provide strong evidence of the existence (sometimes disputed) of this Plasmodium in continental South-East Asia None of the men had served in any other area of endemic malaria and their travel and medical histories suggest that all 4 infections were acquired by mosquito transmission They constitute only 0066% of the 6036 malaria cases reported among servicemen returning from Viet-Nam during this period and represent only 011% of the blood films from 3686 individuals examined at the US National Malaria Repository during the same period Serological testing for malaria antibodies with the indirect fluorescent technique corroborated the diagnosis of P ovale in 1 case Speciation was not possible in the other 3 cases since titres to P vivax and P ovale antigens were identical Only 1 of the patients reported previous experience with vivax malaria Most of the parasites seen in thin blood films were developing trophozoites and immature schizonts; ring forms and gametocytes were rare; mature schizonts were not found The morphology of the parasites was typical of P ovale, with more than 50% of the infected cells showing fimbriations, an oval shape or both

The Prevalence of Malaria in Tselemti Wereda, North Ethiopia: A Retrospective Study.

Abstract: BACKGROUND: A significant segment of the world’s population is at risk of contracting malaria infection at any one time. In Ethiopia, sustained control efforts have been made in the past decade to fight malaria. Yet, it remains as the major cause of morbidity, mortality and socioeconomic problems in the country. The intensified control of malaria can further be augmented by analyzing health facility based malaria data. Hence, the aim of this study was to determine the magnitude of malaria infection in Northwest Ethiopia. METHODS: A retrospective record review was conducted in Northwest Ethiopia from February-April 2016. All blood film results reported between January 2013 and December 2015 in the seven health centers were extracted and analyzed. RESULTS: A total of 41,773 patients with chief malaria complaint were screened for malaria in the three years period. The overall prevalence of microscopically confirmed malaria was 28.1%. Males (29.5%) were more affected by malaria than females (26.5%). Malaria was also higher in the age group >15 years (32.6%) followed by 5-15 years (29.3%) and under-five children (20.5%). Plasmodium falciparum, Plasmodium vivax and mixed infections accounted for 58.2%, 35.5% and 6.3%, respectively. The highest prevalence of confirmed malaria cases was observed during spring (35.6%) and summer (25.1%). Higher prevalence of slide positive malaria was recorded in Dima (46.1%), Cherecher (45.3%) and Fyel wuha (35.3%) health centers. CONCLUSION: Malaria specific outpatient cases were high in the study area. Both plasmodia species were of public health significance in the area with predominance of Plasmodium falciparum.

Suppression of adjuvant arthritis by infection with a strain of the rodent malaria parasite Plasmodium berghei.

Abstract: Hospital data (Greenwood, 1968) and a population survey (to be published) suggest that rheumatoid arthritis is an uncommon disease in Western Nigeria. Furthermore, Nigerian patients satisfying the American Rheumatism Association criteria for a diagnosis of definite or probable rheumatoid arthritis (Ropes, Bennett, Cobb, Jacox, and Jessar, 1959) have a clinically milder disease than European patients with the condition (Greenwood, 1969) and rarely show any of the immunological changes associated with the disease (Greenwood and Herrick, 1970). The limited literature available suggests that rheumatoid arthritis is uncommon in some other parts of tropical Africa and also in New Guinea. However, rheumatoid arthritis is seen frequently in American Negroes (Engel, Roberts, and Burch, 1966), many of whom are of West African origin. It thus seems probable that environmental factors play some part in determining the infrequent occurrence of clinical cases of rheumatoid arthritis in some parts of tropical Africa. It has been suggested (Greenwood, 1968) that the effects of repeated parasitic infections from childhood might be one of these factors. In order to investigate this hypothesis we have studied the effects of malaria infection on adjuvant arthritis in the rat, a widely used animal model for human rheumatoid arthritis.