Investigations of incidence of pretreatment, drug sensitivity in vitro, and plasma levels of pyrimethamine in patients with multidrug resistant falciparum malaria following the three combination regimens of artemether/pyrimethamine

The study was carried out to investigate the status of in vitro susceptibility of Plasmodium falciparum to pyrimethamine (PYR) in multidrug resistant area of the Thai-Myanmar border, the incidence of unregulated use of the combination of PYR with sulfadoxine (Fansidar) in this area and the relevance of pharmacodynamic and pharmacokinetic factors in determining the treatment outcome from the three combination regimens of ART/PYR (1-, 2- and 3-day regimens), in patients with acute uncomplicated falciparum malaria. The majority of patients had baseline PYR concentrations in the range of 1-100 (50.6%) or 100-500 (34.8%) ng/ml, while concentrations of more than 500 ng/ml were found in only 1.1%. All of the isolates exhibited high grade resistance to PYR with the minimum inhibition concentration (MIC) of as high as 10(-5) M. No association was observed between treatment outcome and the presence of baseline plasma PYR concentrations. In addition, lack of association between plasma concentrations during the acute phase (day-1 and -2) and treatment outcome was found.     

Components of pathogenic Leptospira spp. with potentials for diagnosis of human leptospirosis

Existing serological methods for diagnosis of leptospirosis are still unsatisfactorily due mainly to their low accuracy. In this study, serum samples of 18 clinically diagnosed-, IgM dipstick positive-, MAT positive-leptospirosis patients (group 1) were analyzed by IgG Western blotting against SDS-PAGE separated-whole cell homogenates of pathogenic and non-pathogenic Leptospira spp. belonging to 20 serovars of 15 serogroups. The samples of group 1 were collected from the patients at days 3 to 10 after the fever onset (fist samples). Second and third samples could be obtained from 4 patients. Sera of the 22 patients with other febrile illnesses (group 2) and 22 healthy counterparts (group 3) were used as patient- and normal- controls, respectively. Irrespective of the serovar or serogroup of the pathogenic Leptospira spp. used as antigen in the Western blotting, all of the 18 sera of patients with leptospirosis (group 1) gave characteristic diffuse antigen-antibody reactive bands located at approximately 35-38 and 22-26 kDa; and thus 100% diagnostic sensitivity of the Western blot assay. Some serum samples of the leptospirosis patients also reacted to components located at 80-100, approximately 70, 60, 54, and 48 kDa. More bands or the early recognized bands with increased intensity were observed when tested the second and third samples. The characteristic bands were not seen when homogenates of L. biflexa, serogroup Semaranga, serovar Patoc (saprophytic) and L. biflexa, serogroup Andamana, serovar Andamana (non-pathogenic but can infect host) were used in the assay. Sera of groups 2 and 3 did not react to the components at the seven locations implying 100% diagnostic specificity of the IgG Western blot assay. While awaiting validation with more patients' samples, the IgG Western Blot analysis aiming at the detection of the characteristic antigen-antibody reactive bands described in this study has high potential for early, rapid, simple and accurate diagnosis of human leptospirosis.     

Intraspecific hybridization of Anopheles minimus (Diptera: Culicidae) species A and C in Thailand

Hybridization tests of laboratory-raised, isolines of Anopheles minimus, species A and C were conducted by induced copulation. The three isolines were established based on three morphological variants of wild-caught, fully engorged females and two distinct types of metaphase chromosomes. They were An. minimus species A: V form (X1,Y1), M form (X2,Y1); species C: P form (X3,Y2). The results of reciprocal and back crosses indicated that the two morphologically variant forms of species A were genetically compatible, providing viable progeny and completely synaptic salivary gland polytene chromosomes, whereas they were genetically incompatible with species C and/or the P form. Hybrid progeny was only obtained from both forms of species A females x species C males, but asynaptic salivary gland polytene chromosomes on 3L and partial development of ovarian follicles in females were seen. Back crosses of F1 hybrid males with parental species A females provided viable progeny, while back crosses of F1 hybrid females with parental species C males provided progeny of low viability and adult males with abnormal spermatozoa, suggesting the partial reproductive isolation of An. minimus species A and C.     

Screening of ten plant species for metaphase chromosome preparation in adult mosquitoes (Diptera: Culicidae) using an inoculation technique

The screening of 10 plant species (Aloe barbadensis Mill., Asparagus officinalis L., As. plumosus Bak., As. racemosus Willd., As. sprengeri Regel, Codyline fruticosa Goppert, Dracaena loureiri Gagnep., Gloriosa superba L., Hemerocallis flava L., and Sansevieria cylindrica Bojer) for colchicine-like substance(s) using a mosquito cytogenetic assay revealed that a 1% solution of dried Gl. superba rhizome extracted in 0.85% sodium chloride solution could be used instead of a 1% colchicine in Hanks' balanced salt solution. The metaphase rates and average number of metaphase chromosomes per positive mosquito of Aedes aegypti (L.) after intrathoracic inoculation with 1% Gl. superba-extracted solution were 100% and 29.80 in females, and 90% and 25.78 in males, whereas the inoculation with 1% colchicine solution yielded 100 and 90% metaphase rates, and 20.90 and 12.22 average number of metaphase chromosomes per positive mosquito in females and males, respectively. The application of Gl. superba-extracted solution for metaphase chromosome preparation in other mosquito genera and species [e.g., Culex quinquefasciatus Say, Toxorhynchites splendens (Wiedemann), and Anopheles vagus (D?enitz)] also has yielded the satisfactory results.     

Characterization of circulating monocytes expressing HLA-DR or CD71 and related soluble factors for 2 weeks after severe, non-thermal injury

BACKGROUND: Severe injury is associated with changes in monocytes that may contribute to poor outcomes. Longitudinal characterization of monocyte response patterns after trauma may provide added insight into these immunological alterations. METHODS: Venous blood obtained seven times during post-injury days 1 through 13 from 61 patients with an injury severity score >20 was assessed by flow cytometry for monocytes (CD14+) expressing HLA-DR or CD71 (transferrin receptor) and for circulating levels of interleukin (IL) 1alpha, IL-1beta, IL-6, soluble CD14 (sCD14), tumor necrosis factor-alpha (TNF-alpha), prostaglandin E(2) (PGE(2)), thromboxane B(2) (TXB(2)), and endotoxin. Urine neopterin was measured by high-pressure liquid chromatography, expressed as a neopterin-creatinine ratio. RESULTS: Trauma patients had leucocytosis days 1 through 13, monocytosis days 5 through 13, reduced proportions of CD14+HLA-DR+ cells days 2 through 5, and elevated proportions of CD14+CD71+ cells days 1 through 13. Neopterin was elevated all days, peaking on day 10. sCD14 was elevated days 2 through 13, and there were sporadic elevations of IL-1alpha, IL-1beta, IL-6, TNF-alpha, PGE(2), TXB(2), and endotoxin. Sepsis syndrome patients (n = 6) had larger and more prolonged reductions in CD14+HLA-DR+ cells and higher neopterin values, in comparison with uneventful patient outcomes. CONCLUSIONS: Altered proportions of monocytes expressing HLA-DR and CD71 and elevated sCD14 and urine neopterin levels, for up to 2 weeks after severe injury, underscores an extended period of profound immunological effects. Additional studies to more fully assess temporal monocyte response patterns after severe injury, including activation, may be warranted.     

Pharmacokinetics of the four combination regimens of dihydroartemisinin/mefloquine in acute uncomplicated falciparum malaria

The pharmacokinetics of oral dihydroartemisinin and mefloquine were investigated in 40 patients (aged 16-30 y, weighing 45-60 kg) with acute uncomplicated falciparum malaria following the four combination regimens of dihydroartemisinin/ mefloquine [regimen-I: 300 mg dihydroartemisinin (h-0) plus 750 mg mefloquine (h-0); regimen-II: 300 mg dihydroartemisinin (h-0) plus 750 mg mefloquine (h-24); regimen-III: 300 mg dihydroartemisinin (h-0) plus 750 and 500 mg mefloquine (h-24 and 30); regimen-IV: 300 mg dihydroartemisinin (h-0) plus 750 and 500 mg mefloquine (h-0, 24)]. The four combination regimens were well tolerated. Patients in all treatment groups had a rapid initial response. However, 9 patients (4, 4, and 1 cases in regimens-I, II, and IV) had reappearance of parasitemia during the follow-up period. Significant changes in the pharmacokinetic parameters of both mefloquine and dihydroartemisinin were observed in patients with malaria compared with healthy subjects reported in a paralleled study. For mefloquine, Cmax (mg per dose), AUC0-day1 (mg per dose), and AUC0-day7 (mg per dose) were significantly higher in patients. Furthermore, tmax, was prolonged while V/F contracted and tl/2,z, MRT shortened in patients with malaria. For dihydroartemisinin, Cmax AUC, tmax and Vz/F were changed in the same direction as mefloquine, whereas t1/2z and MRT were prolonged. CL/F was also significantly reduced in patients with malaria. Absorption/disposition kinetics of oral dihydroartemisinin were similar among the various regimens. On the other hand, AUC0-day1 (mg per dose) of mefloquine after regimen-III was significantly higher than the other three regimens. Combination regimens with two divided doses of mefloquine (regimens-III and IV) resulted in a significantly delayed tmax (especially regimens-IV) compared with those with single dose regimens (regimens-I and II).     

CpG DNA, liposome and refined antigen oral cholera vaccine

An oral cholera vaccine made up of three Vibrio cholerae antigens, i.e. lipopolysaccharide (LPS), recombinant toxin co-regulated pili (rTcpA) and heat-treated cholera toxin (H-CT) has been developed in six different formulations. Eight-week-old Wistar rats were divided into nine groups and immunized as follows: the first group received the oral vaccine 1 consisting of the three antigens (LPS, rTcpA and H-CT) associated with a liposome (L) and bacterial CpG-DNA (ODN#1826). The rats of groups 2 and 3 received oral vaccines 2 and 3 consisting of the liposome-associated three antigens with and without non-bacterial CpG-DNA (ODN#1982), respectively. Rats of groups 4 received oral vaccine 4 consisting of the three antigens mixed with the ODN#1826, similar to vaccine 1, but without liposome. Rats of groups 5 and 6 received oral vaccines 5 and 6 consisting of the three antigens with and without ODN#1982, respectively, similar to vaccines 2 and 3, but without liposome. Rats of groups 7, 8 and 9 received oral placebos, namely liposomes (L), ODN#1826 (CpG), and vaccine diluent, i.e. 5% NaHCO3 solution, respectively. All vaccines were given in three doses at 14-day intervals. It was found that the combination of liposome and ODN#1826 in vaccine 1 evoked the highest immune response to V. cholerae antigen compared to other vaccine formulations and placebos, as measured by the appearance of antigen-specific antibody-producing cells in the intestinal lamina propria. The immunogenicity according to the magnitude of the immune response was: V1>V2=V3>V4>V5=V6>V7=V8=V9. The results of this study indicate that CpG-DNA and liposome are effective mucosal adjuvants for an oral cholera vaccine prepared from refined V. cholerae antigens and their combination seems to be synergistic. The potential role of liposome as a vaccine delivery vehicle has been confirmed.     

Polygamy: the possibly significant behavior of Aedes aegypti and Aedes albopictus in relation to the efficient transmission of dengue virus

The polygamous behavior of male Aedes aegypti (L.) and Ae. albopictus (Skuse) was investigated by co-habiting a newly-emerged male and females in a 30 cm3 cage (1 male: 20 females) for up to 5 consecutive days. As determined by insemination rates, the results indicated that one Ae. aegypti and Ae. albopictus male could successfully mate with 1.10 (0-4), 4.10 (1-8), 5.40 (4-8), 5.10 (2-8), 5.15 (3-9) and 0.20 (0-3), 1.70 (0-3), 2.35 (1-4), 2.30 (0-4), 2.35 (1-4) Ae. aegypti and Ae. albopictus females, respectively on day 1,2,3,4 and 5 consecutively. The possibly significant role of their polygamy in relation to dengue virus transmission is discussed.     

Malocclusion,psycho-social impacts and treatment need: A cross-sectional study of Tanzanian primary school-children

Background  

studies on the relationship between children's malocclusion and its psycho-social impacts are so far largely unexplored in low-income countries. This study aimed to assess the prevalence of malocclusion, reported dental problems and dissatisfaction with dental appearance among primary school children in Tanzania. The relationship of dissatisfaction with socio-demographic characteristics, clinically defined malocclusion and psychosocial impacts of dental anomalies was investigated. Orthodontic treatment need was estimated using an integrated socio-dental approach.