44 research outputs found
Towards a sterile insect technique field release of <it>Anopheles arabiensis </it>mosquitoes in Sudan: Irradiation, transportation, and field cage experimentation
No full textAbstract Background The work described in this article forms part of a study to suppress a population of the malaria vector Anopheles arabiensis in Northern State, Sudan, with the Sterile Insect Technique. No data have previously been collected on the irradiation and transportation of anopheline mosquitoes in Africa, and the first series of attempts to do this in Sudan are reported here. In addition, experiments in a large field cage under near-natural conditions are described. Methods Mosquitoes were irradiated in Khartoum and transported as adults by air to the field site earmarked for future releases (400 km from the laboratory). The field cage was prepared for experiments by creating resting sites with favourable conditions. The mating and survival of (irradiated) laboratory males and field-collected males was studied in the field cage, and two small-scale competition experiments were performed. Results Minor problems were experienced with the irradiation of insects, mostly associated with the absence of a rearing facility in close proximity to the irradiation source. The small-scale transportation of adult mosquitoes to the release site resulted in minimal mortality ( Conclusion It is concluded that although conditions are challenging, there are no major obstacles associated with the small-scale irradiation and transportation of insects in the current setting. The field cage is suitable for experiments and studies to test the competitiveness of irradiated males can be pursued. The scaling up of procedures to accommodate much larger numbers of insects needed for a release is the next challenge and recommendations to further implementation of this genetic control strategy are presented.</p
Design and synthesis of novel thiophenecarbohydrazide, thienopyrazole and thienopyrimidine derivatives as antioxidant and antitumor agents
No full textEtilni ester 2-amino-5-acetil-4-metil-tiofen-3-karboksilne kiseline (1) i 5-acetil-2-amino-4-metiltiofen-3-karbohidrazid (2) sintetizirani su i upotrebljeni kao reaktanti u sintezi novih spojeva 1-(5-amino-4-(3,5-dimetil-1H-pirazol-1-karbonil)-3-metiltiofen-2-il) etanona (3a), 1-(5-amino-4-(4-klor-3,5-dimetil-1H-pirazol-1-karbonil)-3-metiltiofen-2-il) etanona (3b), 1-(4-metil-2-amino-5-acetiltiofen-3-karbonil) pirazolidin-3,5-diona (4), (Z)-N'-(4-metil-2-amino-5-acetiltiofen-3-karbonil) formohidrazonske kiseline (5a), (Z)-etil-N'-(4-metil-2-amino-5-acetiltiofen-3-karbonilformo hidrazonata (5b), 6-acetil-3-amino-2,5-dimetiltieno2,3-dpirimidin-4(3H)-one (8), 5-metil-3-amino-2-merkapto-6-acetiltieno2,3-dpirimidin-4(3H)-ona (10) i 5-metil-6-acetil-2-tiokso-2,3-dihidrotieno2,3-dpirimidin-4(1H)-ona (12) kao potencijalnih antioksidansa i citostatika. Farmakološka ispitivanja ukazuju na to da spojevi 6a, 6b, 8, 10 i 12 imaju značajno antitumorsko i antioksidativno djelovanje.2-Amino-5-acetyl-4-methyl-thiophene-3-carboxylic acid ethyl ester (1) and 5-acetyl-2-amino-4-methylthiophene-3-carbohydrazide (2) were synthesized and used as starting materials for the synthesis of new series of 1-(5-amino-4-(3,5-dimethyl-1H-pyrazole-1-carbonyl)-3-methylthiophen-2-yl) ethanone (3a), 1-(5-amino-4-(4-chloro-3,5-dimethyl-1H-pyrazole-1-carbonyl)-3-methylthiophen-2-yl) ethanone (3b), 1-(4-methyl-2-amino-5-acetylthiophene-3-carbonyl) pyrazolidine-3,5-dione (4), (Z)-N'-(4-methyl-2-amino-5-acetylthiophene-3-carbonyl) formohydrazonic acid (5a), (Z)-ethyl-N'-(4-methyl-2-amino-5-acetylthiophene-3-carbonylformo hydrazonate (5b), 6-acetyl-3-amino-2,5-dimethylthieno2,3-dpyrimidin-4(3H)-one (8), 5-methyl-3-amino-2-mercapto-6-acetylthieno2,3-dpyrimidin-4(3H)-one (10) and 5-methyl-6-acetyl-2-thioxo-2,3-dihydrothieno2,3-dpyrimidin-4(1H)-one (12) as potential antioxidant and antitumor agents. Pharmacological results showed that compounds 6a, 6b, 8, 10 and 12 exhibited promising antitumor and antioxidant activity
Rational deployment of antimalarial drugs in Africa: should first-line combination drugs be reserved for paediatric malaria cases?
No full textArtemisinin-based combination therapy is exerting novel selective pressure upon populations of Plasmodium falciparum across Africa. Levels of resistance to non-artemisinin partner drugs differ among parasite populations, and so the artemisinins are not uniformly protected from developing resistance, already present in South East Asia. Here, we consider strategies for prolonging the period of high level efficacy of combination therapy for two particular endemicities common in Africa. Under high intensity transmission, two alternating first-line combinations, ideally with antagonistic selective effects on the parasite genome, are advocated for paediatric malaria cases. This leaves second-line and other therapies for adult cases, and for intermittent preventive therapy. The drug portfolio would be selected to protect the 'premier' combination regimen from selection for resistance, while maximising impact on severe disease and mortality in children. In endemic areas subject to low, seasonal transmission of Plasmodium falciparum, such a strategy may deliver little benefit, as children represent a minority of cases. Nevertheless, the deployment of other drug-based interventions in low transmission and highly seasonal areas, such as mass drug administration aimed to interrupt malaria transmission, or intermittent preventive therapy, does provide an opportunity to diversify drug pressure. We thus propose an integrated approach to drug deployment, which minimises direct selective pressure on parasite populations from any one drug component. This approach is suitable for qualitatively and quantitatively different burdens of malaria, and should be supported by a programme of routine surveillance for emerging resistanc
Synthesis, Spectral Studies and Therapeutic Activity of some Heterocyclic Compounds
No full textNot availabl
Dynamics of <it>pfcrt </it>alleles CVMNK and CVIET in chloroquine-treated Sudanese patients infected with <it>Plasmodium falciparum</it>
No full textAbstract Background Parasite resistance to the anti-malarial drug chloroquine is common in eastern Sudan. Dynamic within-host changes in the relative abundance of both sensitive and resistant Plasmodium falciparum parasites were examined in a cohort of chloroquine-treated patients presenting with uncomplicated falciparum malaria, using a novel allele-specific quantitative approach. Methods Treatment outcomes were determined for 93 patients of all ages in a per protocol cohort using a modified 14-day WHO protocol. Parasite DNA samples at days 0, 1, 2, 3, 7 and 14 following treatment were analysed using real-time quantitative PCR methods that distinguished resistant and sensitive genotypes at amino acids 72 - 76 of the pfcrt locus. Results Chloroquine treatment was not efficacious, and of 93 assessable patients, only 10 individuals (10.7%; 95% C.I. 4.34 - 17.2%) enjoyed an adequate clinical and parasitological response. Resistant parasites with the haplotype CVIET at codons 72-76 of the pfcrt locus were dominant in the starting population. Chloroquine sensitive parasites with the haplotype CVMNK were detected in 19 individuals prior to treatment (20.43%; 95% C.I. 5.14 - 18.5%). In these patients, CQ treatment rapidly selected CVIET parasites, and this haplotype overwhelmingly dominated the parasite population in each individual by day 2 after treatment. Conclusions Such rapid intra-host selection of particular genotypes after the introduction of drug will cause frequent misidentification of parasite genotypes present in the starting population. This will have a potentially serious confounding effect on clinical trials which employ PCR-corrected estimates of treatment failure, as resistant parasites below the detection threshold in the pre-treatment sample can be erroneously classified as "new" infections during follow-up, over-estimating drug efficacy.</p
Studies on ticks and tick–borne diseases of export Sheep at Alkadaro Slaughter house
No full textThis study was carried to survey ticks and tick-borne diseases
(theileriosis, cowdriosis, anaplasmosis and babesiosis) and species of
ticks that infest of sheep brought to Alkadaro Slaughter House from
Central Sudan during the period from September 2002 to August 2003.
The survey covered animals coming from five locations, namely Kosti,
Singa, ElObeid, AlDamazin and AlGadarif. About 20 samples on a
monthly basis (at a rate of 5 samples weekly) were collected during the
year. The type of sheep was Hamari and Watish. The samples collected
included ticks, whole blood for blood smears, serum samples,
haematological and biochemical values.
Ticks identified in this study indicated that sheepwere infested
with 4 tick genera and 11 different species. The genera were
Amblyomma, Boophilus, Hyalomma and Rhipicephaluswhile the species
included A. lepidum, B. decoloratus, H. anatolicum anatolicum, H.
dromedarii, H. impeltatum, H. marginatum rufipes, H. truncatum, R.
evertsi evertsi, R. muhsamae, R. camicasi and R. guilhoni.
Serum samples were tested using ELISA to determine the rate of
prevalence of antibodies against Cowdria ruminantiumthat causes
heartwater in sheep in the area of study. The results revealed that 170
samples were carrying the antibodies for the disease. The total prevalence
rate reached 70.8%. The prevalence rates were in Kosti 75%, Al Gadarif
70% Al Dmazin 80% and the highest prevalence rate was found in Singa
82.9% and lowest was recorded in El Obeid 55.7%. It was observed that
C. ruminantiumantibodies were found in sheep serum throughout the
year.
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The result of examination of blood smears revealed that 15.4% of
the sheep examined contained piroplasms stage for Theileria. spp.
Laboratory results for haematologicaland biochemical values revealed
that there was a relative decrease in Hb and PCV valuesand there was no
change in RBCs count while there was a slight increase in WBCs count.
In the biochemical tests for plasma content there was no blood chemical
change (total protein, albumen) withthe exception of a slight increase in
urea.
These findings imply that the prevalence of tick-borne diseases
was very high during the study period in the export sheep at Alkadaro
Slaughter House. The study also showed that the ELISA test is important
in examination of heartwater diseaseand other tick-borne diseases in the
Sudan. It is strongly recommended to carry out investigations using
advanced techniques
Increased pfmdr1 copy number and sequence polymorphisms in Plasmodium falciparum isolates from Sudanese malaria patients treated with artemether-lumefantrine.
No full textMolecular markers for surveillance of Plasmodium falciparum resistance to current antimalarials are sorely needed. A 28-day efficacy study of artemether-lumefantrine in eastern Sudan identified 5 treatment failures among 100 evaluable patients; 9 further individuals were parasite positive by PCR during follow-up. Polymorphisms in pfatpase6 and pfmdr1 were evaluated by DNA sequencing. One individual carried parasites with a novel pfmdr1 polymorphism (F1044L). pfmdr1 gene amplification in parasites prior to treatment occurred in three individuals who had recurrent infection during follow-up
The increase in humidity in the morning is associated with the flooding of the plant beds
No full text<p><b>Copyright information:</b></p><p>Taken from "Towards a sterile insect technique field release of mosquitoes in Sudan: Irradiation, transportation, and field cage experimentation"</p><p>http://www.malariajournal.com/content/7/1/65</p><p>Malaria Journal 2008;7():65-65.</p><p>Published online 25 Apr 2008</p><p>PMCID:PMC2397438.</p><p></p
