Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0406810 (NAME)
 13,345 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Three studies about relation between pregnancy and malaria have been conducted in CAR. The comparative study between plasmodic indexes (PI) et placental appositions (PAP) had shown that PAP offers biggest sensibility in the diagnosis of malaria infection (37.1% for PAP versus 17.1% for PI). The comparison of the PAP with placental anatomopathological study (PAN) revealed the same sensibility of both technics but the PAP's realization is very easy, at the opposite PAN's realization is long and requires sophisticated equipment. Moreover, PAP allows the differentiation between recent and post-malaria infection. The simultaneous realization of the PAP and chloroquinaemia had allowed to develop a surveillance of chloroquine resistance level of Plasmodium falciparum to amino-4-quinolines.
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PMID:[Interest in placental apposition as an epidemiological marker for malaria]. 181 96

Freeze-thawing of blood infected with malaria parasites is a technique which brings about the destruction of all stages except the merozoites and makes possible investigations on the behaviour of these merozoites and the schizogonic rhythm of each species. Merozoites of Plasmodium y. yoelii remain in the blood during the 24 hrs. following inoculation; it is concluded that their penetration in the erythrocytes occurs gradually during this time. Synchronism is poor. Merozoites of P. vinckei petteri penetrate rapidly inside the erythrocytes independently of the time of inoculation. Infection is therefore synchronous and does not follow the circadian rhythm of the host. Penetration of merozoites of P. c. chabaudi is predominant at midnight when rodents are maintained with a normal circadian rhythm (light from 8 am to 8 pm) and predominant at noon when the rhythm of the host is inverted (light from 8 pm to 8 am). Infection is therefore synchronous and follows the host rhythm. The three species of plasmodia coexisting in Thamnomys rutilans from CAR show the same periodicity of 24 hrs. but, because of differences in the biology of the merozoites, they occupy three distinct niches. These notions have great practical implications in chronotherapy, as many data lead to the idea that merozoites are drug resistant.
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PMID:[Timing niches of 3 species of Plasmodium coexisting in a rodent in Central Africa]. 210 60

Nitric oxide (NO) is widely known to inhibit platelet and leukocyte adhesion to endothelium through its regulatory effect on adhesion molecule expression. The objective of the present study was to investigate if NO affects the cytoadherence of Plasmodium falciparum-infected erythrocytes (IRBCs) to human microvascular endothelium (HDMECs) under flow conditions in vitro. The effect of endogenous NO was studied using the NO synthase inhibitor L-N(G)-nitro-arginine-methyl-ester (L-NAME). Treatment of HDMECs with 3 mmol/L of L-NAME for 4 hours significantly enhanced IRBC adhesion and the effect could be reversed by an anti-P-selectin but not an anti-VCAM-1 antibody. The effect of exogenous NO on cytoadherence was studied by using the NO donor 3-(2-hydroxy-2-nitroso-1-propylhydrazino)-1-propanamine (PPN). PPN (300 micro mol/L) treatment reduced the number of adherent IRBCs on resting HDMECs by down-regulating basal ICAM-1 expression, and on tumor necrosis factor-alpha-stimulated HDMECs by inhibition of VCAM-1 induction and down-regulation of ICAM-1 expression. The inhibitory effect of PPN on tumor necrosis factor-alpha-induced VCAM-1 expression at 24 hours was evident when the NO donor was added for as short as 2 hours. These findings suggest that NO may be protective against P. falciparum infection by inhibiting cytoadherence, and underscore the therapeutic potential of NO in the treatment of severe falciparum malaria.
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PMID:Anti-adhesive effect of nitric oxide on Plasmodium falciparum cytoadherence under flow. 1270 49

Malaria, a major endemic tropical disease, is caused by the infection of blood cells by Plasmodium protozoa. Most patients control their parasitemia by a not fully understood spleen-dependent mechanism. SDF-1alpha is a chemokine produced by stromal cells such as reticular spleen cells. Nitric oxide (NO) has several immune functions, including killing of intracellular pathogens and its function in malaria is debated. We have previously shown that SDF-1alpha production peaks during the ascending parasitemia in Plasmodium chabaudi infection and its supplementation in lethal models could reduce the parasitemia. In the present study, we analyzed SDF-1 production by spleen cells as related to NO metabolism in the P. chabaudi rodent malaria model using IFN-gamma; TNFR and iNOS-knockout mice or iNOS-blocked, L-NAME- or aminoguanidine-treated mice. Parasitemia and production of SDF-1alpha and SDF-1beta were determined by RT-PCR. In vitro NO production by spleen adherent cells was also tested. The data showed that parasitemia was less intense in both iNOS(-/-) or NO-inhibited mice than in controls, with increased and long-lasting production of SDF-1alpha mRNA. In the absence of cytokines involved in the final regulation of NO production by effector cells, as is the case for TNFR(-/-) and GKO mice, the infection progressed in an uncontrolled manner regardless of SDF-1alpha production, suggesting that these cytokines must be involved in the control of parasitemia after the SDF-1alpha dependent process. The SDF-1beta isoform was constitutive in all experiments, with elevated levels only clearly seen in TNFR(-/-) mice. We conclude that SDF-1 is involved in the promotion of parasitemia control in malaria, and excessive NO could affect its production.
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PMID:Stromal cell-derived factor-1 production by spleen cells is affected by nitric oxide in protective immunity against blood-stage Plasmodium chabaudi CR in C57BL/6j mice. 1455 70

Eighteen plants originating from Ivory Coast were selected by ethnobotanical survey as plants commonly used by traditional healers for the treatment of malaria. Extracts of these plants were tested on two strains of Plasmodium falciparum: FcM29-Cameroon (chloroquine-resistant strain) and a Nigerian chloroquine-sensitive strain. The powdered plants were used to prepare three kinds of extracts: by decoction in water, in ethanol (95%) and in pentane. A radioactive micromethod allowed the evaluation of the antiplasmodial in vitro activity of the extracts on P. falciparum. Concentrations inhibiting 50% of the parasite growth (IC50) ranged from 18 microg/ml to more than 500 microg/ml for aqueous and ethanol extracts and from 4.3 microg/ml to more than 500 microg/ml for pentane extracts. Cytotoxicity was estimated on A375 melanoma cells and a cytotoxicity/antiplasmodial index (CAR) was calculated for each extract, ranging from 1 to 10. The pentane extracts of Cola caricaefolia and Uvaria afzelii, which revealed the strongest antiplasmodial activity had CAR values of about 10.
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PMID:Antiplasmodial activity and cytotoxicity of plants used in West African traditional medicine for the treatment of malaria. 1636 5

Chloroquine (CQ) remains the household drug for the treatment of malaria especially among pregnant women. However, there are reports that CQ inhibits the contractile process in non-pregnant rat's uterus. The aim of this study is to compare responses to CQ between non-pregnant and pregnant mice and identify some mechanisms involved. Experiments were carried out in non-pregnant and pregnant mice pretreated 24 hours before with 1.5 mg/kg-body weight stilboesterol given orally. Strips of uterine smooth muscle, approximately 5 mm in diameter, were mounted in a 20 ml organ bath containing De Jalon solution bubbled with a 95% O2-5% CO2 gas mixture. Responses of the strips to graded concentration of acetylcholine (ACh) (10(-9) to 10(-5) mol/L), oxytocin (OXY) (10(-5) to 10(-2) IU/ml) and CQ (10(-6) to 4 x 10(-4) mol/L) were investigated. The strips were then incubated in 4 x 10(-4) mol/L CQ for 15 mins and the cumulative dose responses for OXY were repeated. To investigate mechanism of action, the strips were incubated for 15 mins in N(w)-nitro L-arginine methyl ester (L-NAME) and the cumulative responses to CQ repeated. Each investigation was carried out in fresh tissue mounted on Grass Model FT03 force transducer coupled unto a 4-channel Grass Model 7D Polygraph. CQ (low to moderate level), ACh and OXY led to increases in contractile responses in the uteri. There were greater contractile responses in non-pregnant than pregnant mice to CQ and ACh. At high doses, CQ had an inhibitory effect on the uterine contraction. Incubating in CQ led to abolition of contractile responses to OXY and ACh. In the presence of L-NAME, inhibitory effect of CQ at high doses was attenuated in pregnant mice only. The results suggest that CQ at high doses inhibits contractile responses in non-pregnant and pregnant mice. Enhanced nitric oxide bioactivity attenuated this inhibitory effect.
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PMID:Effect of chloroquine on strips of non-pregnant and pregnant mice uteri in-vitro. 1768 66

Accelerated suicidal death or eryptosis of infected erythrocytes may delay development of parasitemia in malaria. Eryptosis is inhibited by nitric oxide (NO). The present study has been performed to explore, whether inhibition of NO synthase by L-NAME modifies the course of malaria. We show here that L-NAME (>or=10 microM) increased phosphatidylserine exposure of Plasmodium falciparum infected human erythrocytes, an effect significantly more marked than in noninfected human erythrocytes. We further show that parasitemia in Plasmodium berghei infected mice was significantly decreased (from 50% to 18% of circulating erythrocytes 20 days after infection) by addition of 1 mg/ml L-NAME to the drinking water. According to CFSE labelling L-NAME treatment accelerated the clearance of both, noninfected and infected, erythrocytes from circulating blood, but did not significantly extend the life span of infected animals. In conclusion, treatment with L-NAME shortens the life span of circulating erythrocytes and thus delays development of parasitemia during malaria.
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PMID:Influence of NO synthase inhibitor L-NAME on parasitemia and survival of Plasmodium berghei infected mice. 1845 56

The basic stages of putting into practice of tuberculosis monitoring systems in the Central Asian Region (CAC) (Uzbekistan, Kazakhstan, Kyrghyz, and Tajikistan) with the assistance of the USA Centers for Disease Control and Prevention, Central Asian Region Programs (CDC/CAR), and the USA Agency for International Development in 2000-2006 are considered. These stages comprised: 1) modification of accounting and reporting forms in accordance with the requirements of the uniform statistical tuberculosis registration system; 2) development, adaptation, and introduction of an electronic tuberculosis monitoring and management system (ETMMS) in the regions and countries of Central Asia; 3) epidemiological analysis of information of tuberculosis monitoring systems, by using the elements of evidence-based medicine. At present, policy electronic tuberculosis monitoring systems entirely cover the areas of three countries of the region. The quality of entries and their processing and analysis is assured by a wide training system set up by the CDC/CAR jointly with the leading national tuberculosis facilities of CAR with the support of the Global Fund for AIDS, Tuberculosis, and Malaria Control. The information obtained by ETMMS has permitted a detail comparative analysis of the structure of tuberculosis at the level of individual regions to identify characteristic groups of areas in the demographic and sociooccupational characteristics of new tuberculosis cases.
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PMID:[Detection of tuberculosis in the countries of Central Asia by the electronic monitoring system data]. 1906 65

A universal feature of metazoan sexual development is the generation of oocyte P granules that withhold certain mRNA species from translation to provide coding potential for proteins during early post-fertilization development. Stabilisation of translationally quiescent mRNA pools in female Plasmodium gametocytes depends on the RNA helicase DOZI, but the molecular machinery involved in the silencing of transcripts in these protozoans is unknown. Using affinity purification coupled with mass-spectrometric analysis we identify a messenger ribonucleoprotein (mRNP) from Plasmodium berghei gametocytes defined by DOZI and the Sm-like factor CITH (homolog of worm CAR-I and fly Trailer Hitch). This mRNP includes 16 major factors, including proteins with homologies to components of metazoan P granules and archaeal proteins. Containing translationally silent transcripts, this mRNP integrates eIF4E and poly(A)-binding protein but excludes P body RNA degradation factors and translation-initiation promoting eIF4G. Gene deletion mutants of 2 core components of this mRNP (DOZI and CITH) are fertilization-competent, but zygotes fail to develop into ookinetes in a female gametocyte-mutant fashion. Through RNA-immunoprecipitation and global expression profiling of CITH-KO mutants we highlight CITH as a crucial repressor of maternally supplied mRNAs. Our data define Plasmodium P granules as an ancient mRNP whose protein core has remained evolutionarily conserved from single-cell organisms to germ cells of multi-cellular animals and stores translationally silent mRNAs that are critical for early post-fertilization development during the initial stages of mosquito infection. Therefore, translational repression may offer avenues as a target for the generation of transmission blocking strategies and contribute to limiting the spread of malaria.
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PMID:Universal features of post-transcriptional gene regulation are critical for Plasmodium zygote development. 2016 88

The expression of genes encoding the antimicrobial peptides (AMPs) attacin, cecropin and gambicin, as well as the effects of NO and H(2)O(2) on their expression was investigated in midguts and fat bodies of Anopheles albimanus during the midgut infection with Plasmodium berghei. Midgut infection induced an increase in the expression of the three AMPs in both tissues; while NO and H(2)O(2) were present in haemolymph. Treatment with L-NAME and vitamin C reduced the effect of P. berghei infection on the AMP's expression, and exogenous NO and H(2)O(2) induced their expression in the mosquito fat body. The induction of AMPs in abdominal tissues, while the malaria parasites are in the mosquito midgut, suggests communication between the midgut epithelial cells and the abdominal tissue which has not yet had direct contact with the parasites. Free radical production in mosquito midgut and haemolymph during Plasmodium infection and their inductive effect on AMPs in abdominal tissues indicates the possible participation of these radicals in mediating a systemic immune response in this mosquito.
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PMID:The effect of nitric oxide and hydrogen peroxide in the activation of the systemic immune response of Anopheles albimanus infected with Plasmodium berghei. 2070 28


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