Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024530 (malaria)
 44,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Between 1985-1987, researchers recruited 419 5-60 year old persons with moderate falciparum malaria to take part in a series of studies in West Pokot, Rusinga Island, Busia, and Bungoma districts in western Kenya to determine malaria parasite sensitivity to chloroquine and amodiaquine. The subject received 25mg/kg of the antimalarial for 3 days. Chloroquine resistance was highest in Busia in May 1986 (51%) followed by Bungoma (45%), Busia in July 1986 (38%), West Pokot (27%), and Rusinga Island (19%). No RIII resistance (failure to decrease parasitemia by at least 75%) occurred in any of the 4 studies. In July 1986, researchers compared the different sensitivity levels of chloroquine and amodiaquine among 119 school children in Busia. None of the children exhibited RIII resistance. None of the falciparum malaria parasites in the 58 children receiving amodiaquine showed RII resistance (failure to clear parasites) compared to 3.3% of those receiving chloroquine. Yet 15.5% of students receiving amodiaquine harbored parasites with RI resistance (recurrence of parasitemia within 7 days), especially delayed RI resistance. Still this percentage was much lower than RI resistance among the students receiving chloroquine (34.4%). Total resistance was significantly much higher in the chloroquine group than the amodiaquine group (p.01). Moreover in vitro studies revealed that the percentages of parasites with minimum inhibitory concentrations (MICs) for chloroquine 114 nM (indicating resistance) varied from 37% in Busia to 68% in Bungoma. Further 20% had MICs for amodiaquine 80 mM (indicating resistance). In conclusion, chloroquine resistant falciparum malaria parasites have established themselves in western Kenya. Despite growing resistance, amodiaquine should still be used in uncomplicated infections, if the health practitioner is able to follow up on the patients.
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PMID:Sensitivity of falciparum malaria to chloroquine and amodiaquine in four districts of western Kenya (1985-1987). 176 12

Parasitic infections are still the main public health problem in the developing countries. Saudi Arabia is a developing country beside, it is the main center for all muslims for "Haj and Omra". Most of the work done in the field of parasitic infections dealt with Saudis or Yemenis. In this paper, most of the patients are muslims coming for Haj and or Omra. The highest rate if infection was 11.63% for Giardia and the lowest was 0.007% for Fasciola. Urine examination showed S. haematobium (2.99%), T. vaginalis (3.82%) and Enterobius eggs (0.04%). Malaria infection was also encountered. P. vivax showed 2.5% and P. falciparum showed 6.5% among a total of 5233 suspected cases. Still the direct examination of urine and stool being the most reliable method for diagnosis of helminthic infections. The whole results were discussed.
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PMID:Parasitic infections among patients of Al Nour Specialized Hospital. 830 58

There are continuing concerns over the safety of the nation's and the world's blood supply. The allogeneic blood supply is tested for antibodies to HIV1/2, HTLVI/II, hepatitis B, hepatitis C (HCV) and syphilis. Testing is also performed for donor ALT (SGOT) levels, for the presence of hepatitis B surface antigen, human immunodeficiency virus (HIV) p24 antigen and, using nucleic acid amplification testing (NAT), for HIV and HCV nucleic acids. Still, there are concerns regarding other pathogenic agents. Dr. Roger Dodd addresses a series of pathogens that are already known to be transmissible by transfusion. These include malaria, Chagas' disease, babesiosis, bacteria and some viral agents. The need for new donor screening assays to protect the integrity and purity of the blood supply must be balanced against the loss of potential donors and the cost of developing and implementing these new screening assays. This issue will be highlighted. Dr. Edward Snyder reviews the status of research into development of systems for pathogen inactivation (PI) of blood and its components. A proactive technology wherein PI reagents such as psoralen, riboflavin, dimethylmethylene blue or inactine are added to blood collection bags could assure multiple log reduction of a variety of pathogens including viruses, bacteria, protozoa and fungi without the need to initially pre-screen the blood for a specific pathogen. Such a program could also cover new pathogens as they enter the blood supply. As a key issue relates to the toxicology of these agents, Dr. Snyder provides data on a novel carcinogenicity assay that uses a heterozygous p53 knock-out mouse model. The criteria likely to be needed for PI technology to be adopted by the transfusion community are summarized.
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PMID:Reducing the risk of blood transfusion. 1172 97

Plasmodium sporozoites are transmitted through the bite of infected mosquitoes and first invade the liver of the mammalian host, as an obligatory step of the life cycle of the malaria parasite. Within hepatocytes, Plasmodium sporozoites reside in a membrane-bound vacuole, where they differentiate into exoerythrocytic forms and merozoites that subsequently infect erythrocytes and cause the malaria disease. Plasmodium sporozoite targeting to the liver is mediated by the specific binding of major sporozoite surface proteins, the circumsporozoite protein and the thrombospondin-related anonymous protein, to glycosaminoglycans on the hepatocyte surface. Still, the molecular mechanisms underlying sporozoite entry and differentiation within hepatocytes are largely unknown. Here we show that the tetraspanin CD81, a putative receptor for hepatitis C virus, is required on hepatocytes for human Plasmodium falciparum and rodent Plasmodium yoelii sporozoite infectivity. P. yoelii sporozoites fail to infect CD81-deficient mouse hepatocytes, in vivo and in vitro, and antibodies against mouse and human CD81 inhibit in vitro the hepatic development of P. yoelii and P. falciparum, respectively. We further demonstrate that the requirement for CD81 is linked to sporozoite entry into hepatocytes by formation of a parasitophorous vacuole, which is essential for parasite differentiation into exoerythrocytic forms.
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PMID:Hepatocyte CD81 is required for Plasmodium falciparum and Plasmodium yoelii sporozoite infectivity. 1248 5

Serologic parameters of kala-azar were evaluated by Western blot analysis. Sera from kala-azar patients with confirmed diagnoses were screened for immunoglobulin G (IgG) and IgG subclass-specific reactivity against Leishmania donovani membrane antigen (LAg). Heterogeneous LAg-specific IgG reactivity with numerous proteins with molecular masses ranging from 18 to 190 kDa was observed. Though the individual band patterns were varied, seven polypeptides of approximately 31, 34, 51, 63, 72, 91, and 120 kDa were immunoreactive with all the sera tested from kala-azar patients. The band patterns of the immunoblots of sera from patients after treatment and clinical cure with sodium antimony gluconate revealed a decrease in the frequency of the bands. Still, recognition of the 63- and 120-kDa bands was 100%, and the 55- and 91-kDa fractions were recognized in 93% of the sera from cured individuals. Among the IgG subclasses, IgG1 reacted with the greatest number of polypeptides. The 63-kDa protein was again detected by all of the IgG subclasses of all the sera tested. Other fractions recognized by the subclasses of more than 70% of the serum samples included those of 47, 51, 55, and 78 kDa. Following treatment, 63- and 51-kDa bands were the most reactive with the IgG subclasses. LAg-associated cross-reaction with other reference human antisera revealed a mild reactivity of the 63-kDa polypeptide with some of the serum samples from leprosy, malaria, typhoid, tuberculosis, and healthy controls. Western blot analysis of LAg entrapped in liposomes, strong vaccine candidates against experimental visceral leishmaniasis, revealed a more restricted band pattern. The 63-kDa fraction revealed by all pre- and posttreatment sera showed almost negligible levels of cross-reaction with sera from patients with other diseases or from healthy controls. These observations provide insight into induced immunity during kala-azar infection for future application.
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PMID:Characterization of immunoglobulin G and its subclass response to Indian kala-azar infection before and after chemotherapy. 1474 30

A 20-year-old, previously healthy woman, presented with high fever, headache and myalgia 3 days after her return from a holiday in Southeast Asia. Laboratory data on admission demonstrated a pronounced increase in plasma creatinine, marked thrombocytopenia and moderately elevated liver aminotransferases. After having ruled out malaria, dengue fever was primarily suspected and supportive intravenous fluid therapy was initiated. Still, 1 day after admission, platelet counts dropped even further and she became anuric although she did not appear hypovolemic. On day 2 after admission, urine production commenced spontaneously and the patient slowly recovered. All laboratory test results had returned to normal approximately 2 months later. Serological analysis for dengue fever was negative. It turned out that the patient had been trekking in the jungle while in Thailand and we, therefore, analyzed serology for Leptospira spirochetes which was clearly positive. The patient was diagnosed with leptospirosis which is a serious condition associated with a high mortality when complicated by acute renal failure. Differential diagnoses in patients with acute renal failure and tropical infections are reviewed. The importance of early recognition of leptospirosis, and prompt treatment with antibiotics in suspected cases, is emphasized.
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PMID:Acute renal failure after a holiday in the tropics. 1717 21

Harm reduction (HR) interventions began in Central-Eastern Europe and Central Asia in the mid-1980s with the establishment of substitution treatment (ST) in Yugoslavia. In the mid-1990s, the first needle and syringe programmes (NSPs) opened in selected countries following the outbreaks of HIV among injecting drug users (IDUs). The number of NSPs continues to increase via a combination of international and state funding with large expansions made possible via the Global Fund to Fight AIDS, Tuberculosis and Malaria. While ST is still unaccepted in several countries, others have made some progress which is especially visible in South Eastern and Central Europe and the Baltic States. Development of regional networking including Central and Eastern European HR Network and a number of national networks helped to coordinate joint advocacy effort and in some cases sustain HR services. Activism of drug users and people living with HIV (PLWH) increased in the region in the last several years and helped to better link HR with the affected communities. Still a number of challenges remain important for the movement today such as repressive drug policies; stigma and discrimination of IDUs, PLWH, sex workers and inmates, including poor access to prevention and treatment; lack of important components of HR work such as naloxone distribution and hepatitis B vaccination, prevention in prisons; issues of quality control; sustaining services after finishing of major international projects; reaching of adequate coverage and others.
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PMID:Implementation of harm reduction in Central and Eastern Europe and Central Asia. 1768 55

Invasion of hepatocytes by Plasmodium sporozoites is a prerequisite for establishment of a malaria infection, and thus represents an attractive target for anti-malarial interventions. Still, the molecular mechanisms underlying sporozoite invasion are largely unknown. We have previously reported that the tetraspanin CD81, a known receptor for the hepatitis C virus (HCV), is required on hepatocytes for infection by sporozoites of several Plasmodium species. Here we have characterized CD81 molecular determinants required for infection of hepatocytic cells by P. yoelii sporozoites. Using CD9/CD81 chimeras, we have identified in CD81 a 21 amino acid stretch located in a domain structurally conserved in the large extracellular loop of tetraspanins, which is sufficient in an otherwise CD9 background to confer susceptibility to P. yoelii infection. By site-directed mutagenesis, we have demonstrated the key role of a solvent-exposed region around residue D137 within this domain. A mAb that requires this region for optimal binding did not block infection, in contrast to other CD81 mAbs. This study has uncovered a new functionally important region of CD81, independent of HCV E2 envelope protein binding domain, and further suggests that CD81 may not interact directly with a parasite ligand during Plasmodium infection, but instead may regulate the function of a yet unknown partner protein.
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PMID:Hepatocyte permissiveness to Plasmodium infection is conveyed by a short and structurally conserved region of the CD81 large extracellular domain. 1838 82

Insecticide-treated nets (ITNs) are effective in substantially reducing malaria transmission. Still, ITN coverage in sub-Saharan Africa (SSA) remains extremely low. Policy makers are concerned with identifying the most suitable delivery mechanism to achieve rapid yet sustainable increases in ITN coverage. Little is known, however, on the comparative costs of alternative ITN distribution strategies. This paper aimed to fill this gap in knowledge by developing such a comparative cost analysis, looking at the cost per ITN distributed for two alternative interventions: subsidized sales supported by social marketing and free distribution to pregnant women through antenatal care (ANC). The study was conducted in rural Burkina Faso, where the two interventions were carried out alongside one another in 2006/07. Cost information was collected prospectively to derive both a financial analysis adopting a provider's perspective and an economic analysis adopting a societal perspective. The average financial cost per ITN distributed was US$8.08 and US$7.21 for sales supported by social marketing and free distribution through ANC, respectively. The average economic cost per ITN distributed was US$4.81 for both interventions. Contrary to common belief, costs did not differ substantially between the two interventions. Due to the district's ability to rely fully on the use of existing resources, financial costs associated with free ITN distribution through ANC were in fact even lower than those associated with the social marketing campaign. This represents an encouraging finding for SSA governments and points to the possibility to invest in programmes to favour free ITN distribution through existing health facilities. Given restricted budgets, however, free distribution programmes are unlikely to be feasible.
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PMID:Comparative cost analysis of insecticide-treated net delivery strategies: sales supported by social marketing and free distribution through antenatal care. 1975 78

Malaria remains one of the most serious world health problem and the major cause of mortality and morbidity in the endemic regions. Brazil is among the 30 high-burden countries and most of the cases occur in the Legal Amazonian Region. New chemotherapeutical agents are needed for the treatment of malaria. Many plant species are used in traditional medicines of malarious countries and a relatively few number of these have been investigated for evaluation of their antimalarial effect. Still lower is the number of those that have had the active natural compounds isolated and the toxicity determined. This area is, then, of great research interest. discovery project of antimalarial natural products from plants traditionally used to treat malaria must include in vitro and in vivo assays as well as bioguided isolation of active compounds. The final products would be antimalarial chemical entities, potential new drugs or templates for new drugs development, and/or standardized antimalarial extracts which are required for pre-clinical and clinical studies when the aim is the development of effective and safe phythomedicines. This review discusses these two approaches, presents briefly the screening methodologies for evaluation of antimalarial activity and focuses the activity of alkaloids belonging to different structural classes as well as its importance as new antimalarial drugs or leads and chemical markers for phytomedicines.
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PMID:Plant-derived antimalarial agents: new leads and efficient phythomedicines. Part I. Alkaloids. 1989 98


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