Anti-inflammatory and gastromucosal protective effects of Calotropis procera (Asclepiadaceae) stem bark

This study was aimed at evaluating the anti-inflammatory and gastromucosal protective effect of chloroform extract (CH) and hydroalcoholic extract (HE) of the stem bark of Calotropis procera obtained successively by cold maceration. The anti-inflammatory effect of the CH and HE extracts of the stem bark of Calotropis procera against carrageenan-induced paw oedema and also its gastromucosal protective effect has been studied by using two acute models: aspirin (100 mg/kg, p.o.) and ethanol (96%) in albino rats. CH and HE extracts showed significant anti-inflammatory activity at 200 and 400 mg/kg, while CH extract at 400 mg/kg was also found to have a significant gastromucosal protective effect. As part of investigations to obtain compounds with anti-inflammatory and gastromucosal protective effects in this work, a bioassay was carried out with fractions obtained from the CH extract with n-hexane (NF1), 1-butanol (BF1), ethyl acetate (EF1) and chloroform (CF1). The HE extract of the stem bark was fractionated with n-hexane (NF2), 1-butanol (BF2), ethyl acetate (EF2), chloroform (CF2) and water (WF2). The fractions were evaluated for their anti-inflammatory and gastromucosal protective effects. Fractions NF1, CF1, BF2 and EF2 (20 mg/kg) showed significant anti-inflammatory activity, while NF1 and BF2 (20 mg/kg) also showed gastromucosal protective effects. The results obtained for gastromucosal protective effects were also well supported by histopathological examination of the open excised rat stomach.     

Risque résiduel de transmission du VIH et du VHB par transfusion sanguine entre 2003 et 2005 au Centre national de transfusion sanguine de Dakar (Sénégal)

Background and aimUsing of safety blood products did not stop improving these last years. The use of effective methods as well immunologicals as virologicals ones really reduces risk associated to blood transfusion. However, it persists residual risk (RR) of transfusion transmitted viral diseases. The aim of our study was to detect cases of seroconversion for HIV,and HBV among donors in the Senegalese national blood bank. And then, we estimated the RR of these virus.MethodsWe led a transverse retrospective study from 2003 (January 1st) to 2005 (December 31st). Had been included donors with at least two donations of blood during the period of study. They had to be seronegative for HIV and HBV after the first donation. All donors with only one donation had been excluded. RR was estimated by multiplying incidence rates by the durations of the window periods.ResultsDuring 3 years, we collected 425,503 donations; 388 were positive for HIV and 4240 for HBV. But we noted only two cases of seroconversion for HIV and 23 for HBV. So, RR estimated was 3,5 in 100,000 donation for HIV and 102,45 in 100,000 donations for VHB.ConclusionIt emerges from this study that the risk of blood transmitted virus is always high. Introduction of more sensitive tests (as nucleic acid testing) would allow us to deliver more safety products.     

Is vector body size the key to reduced malaria transmission in the irrigated region of Niono, Mali?

Malaria vectors can reach very high densities in villages near irrigated rice fields in Africa, leading to the expectation that malaria should be especially prevalent there. Surprisingly, this is not always the case. In Niono, Mali, villages from nonirrigated areas have higher malaria prevalence than those within the irrigated regions, which suffer from higher mosquito numbers. One hypothesis explaining this observation is that mosquitoes from irrigated fields with high densities are inefficient vectors. This could occur if higher larval densities lead to smaller mosquitoes that suffer elevated mortality. Three predictions of the hypothesis were studied. First, the effect of larval density on larval body size was measured for both Anopheles gambiae Giles and Anopheles funestus Giles. Second, the relationship between larval and adult body size was tested. Third, evidence of an effect of adult size on survivorship in both irrigated and nonirrigated villages during the wet and dry seasons was sought. There was a modest positive relationship between densities of immatures and larval size, and a strong relationship between larval and adult size. Furthermore, adult survivorship was higher in nonirrigated areas. However, there was no effect of size on survivorship between comparable samples from both the irrigated and nonirrigated zones. Although density may have a causal relationship with reduced transmission in the irrigated areas of Niono, it is unlikely to be because higher density leads to smaller body size and lower survivorship.     

Diagnosis of endometrial pathologies in West Africa: contribution of saline infusion sonography. Experience of Yopougon's teaching hospital (Abidjan, Ivory Coast)

OBJECTIVE: The aim of this survey was to value the contribution of saline infusion sonography (SIS) to endometrial pathologies diagnosis in a context of work where hysterography is the reference exam rather than hysteroscopy. PATIENTS AND METHODS: A prospective comparative cohort survey led at Yopougon's teaching hospital, from July 1st to April 30th 2003. This study concerned 65 patients. The sensitivity, the specificity, and the Kappa test have been calculated from the morbid results. RESULTS: The SIS has been successfully carried out among 63 patients (96,8%). The polyps (23,8%), and the mucous myomas (14%) dominate the endometrial pathologies. The analysis of the results indicated sensitivity and a global specificity respectively of 100% and 76,5%. The dissonant diagnoses have been decided in 82% of the cases in favour of SIS. Besides, SIS permits to save 31.67 Euros/patient. DISCUSSION AND CONCLUSION: SIS could therefore constitute a tool of choice for the exploration of the uterine cavity in the developing countries.     

Reproduction-longevity trade-off in Anopheles gambiae (Diptera: Culicidae)

Reduced survival and future reproduction due to of current reproduction is a trade-off known as the cost of reproduction. Surprisingly, only a few studies have assessed the cost of reproduction in arthropod disease vectors, despite its effect on longevity, and thus on vectorial capacity. We evaluated the cost of reproduction on survival of Anopheles gambiae Giles by comparing mosquitoes that were denied exposure to the other sex, hereafter named virgins, and those that were allowed exposure to the other sex and mating, hereafter named mated. Merely 6 d of exposure to females with mating activity reduced male survival from a median of 17 d in virgins to 15 d in mated, indicating that male mating cost is substantial. The increase in mortality of mated males began several days after the exposure to females ended, indicating that mating is not associated with immediate mortality risk. Notably, body size was negatively correlated with male mortality in mated males, but not in virgins. The rate of insemination declined after 4 d of exposure to females, indicating that male mating capacity is limited and further supporting the hypothesis that mating is costly for males. Consistent with previous studies, female survival on sugar alone (median=16 d) was shorter than on blood and sugar (median=19 d), regardless if she was mated or virgin. Overall, survival of mated females was lower than that of virgins on a diet of blood and sugar, but no difference was found on a diet of sugar only. However, the cost of reproduction in females remains ambiguous because the difference in survival between virgin and mated females was driven by the difference between virgin (median=19 d) and uninseminated females exposed to males (median=17 d), rather than between virgin and inseminated females (median=19 d). Accordingly, sperm and seminal fluid, egg development, and oviposition have negligible cost in terms of female survival. Only exposure to males without insemination decreased female survival. Nonetheless, if exposure to males under natural conditions is also associated with reduced survival, it might explain why females remain monogamous.     

Effect of Graphene Nanoribbons(TexasPEG) on locomotor function recovery in a rat model of lumbar spinal cord transection

A sharply transected spinal cord has been shown to be fused under the accelerating influence of membrane fusogens such as polyethylene glycol(PEG)(GEMINI protocol). Previous work provided evidence that this is in fact possible. Other fusogens might improve current results. In this study, we aimed to assess the effects of PEGylated graphene nanoribons(PEG-GNR, and called "Texas PEG" when prepared as 1 wt% dispersion in PEG600) versus placebo(saline) on locomotor function recovery and cellular level in a rat model of spinal cord transection at lumbar segment 1(L_1) level. In vivo and in vitro experiments(n = 10 per experiment) were designed. In the in vivo experiment, all rats were submitted to full spinal cord transection at L_1 level. Five weeks later, behavioral assessment was performed using the Basso Beattie Bresnahan(BBB) locomotor rating scale. Immunohistochemical staining with neuron marker neurofilament 200(NF200) antibody and astrocytic scar marker glial fibrillary acidic protein(GFAP) was also performed in the injured spinal cord. In the in vitro experiment, the effects of Texas PEG application for 72 hours on the neurite outgrowth of SH-SY5 Y cells were observed under the inverted microscope. Results of both in vivo and in vitro experiments suggest that Texas PEG reduces the formation of glial scars, promotes the regeneration of neurites, and thereby contributes to the recovery of locomotor function of a rat model of spinal cord transfection.     

Past, present and future of HIV vaccine trials in developing countries

A safe, effective and accessible preventive vaccine is our best long-term hope for the control of the HIV/AIDS pandemic. The first phase I trial of an HIV vaccine was conducted in the US in 1987. Since then, >30 candidate vaccines have been tested in over 60 phase I/II clinical trials, involving >8000 healthy human volunteers. The majority of these trials have been conducted in the US and Europe, however, trials have also been conducted in developing countries (Brazil, China, Cuba, Haiti, Kenya, Thailand, and Uganda), including an ongoing phase III efficacy trial of a rgp120 candidate vaccine in Thailand. The effort to develop and evaluate HIV vaccines must increase, especially in Africa.     

Icodextrin-induced peritonitis: study of five cases and comparison with bacterial peritonitis

BACKGROUND: An epidemic of aseptic peritonitis related to the presence of peptidoglycan contaminant in some batches of icodextrin solution (Extraneal, Baxter Healthcare Corporation) occurred in Europe in the first six months of 2002. METHODS: By case-control study we examined the clinical and biologic features of 5 patients with icodextrin-induced peritonitis (group AP) and compared them with 7 patients with bacterial peritonitis (group BP) recruited in our clinical center between January and June 2002. RESULTS: Diagnosis of icodextrin-induced peritonitis was confirmed in all cases by a positive reintroduction test with contaminated batches of icodextrin. No recurrence was observed on re-exposure to icodextrin free of peptidoglycan. Skin tests were positive with contaminated icodextrin in 2 of 5 patients, while they were negative with icodextrin solution free of peptidoglycan (<0.6 ng/mL). During peritonitis, serum level of C-reactive protein (CRP) was lower in group AP (42.4 +/- 34 mg/L) than in group BP (135 +/- 59 mg/L) (P= 0.01). Leukocyte number in peritoneal dialysis effluent was lower in group AP (284 +/- 101/mm3), with a lower neutrophil/monocyte ratio (N/M = 0.67) than in group BP (1410 +/- 973/mm3; N/M = 4) (P < 0.05). A low number of peritoneal fluid eosinophilia (11 +/- 8%) was detected in group AP. CONCLUSION: Icodextrin-induced peritonitis was associated with a burst of intraperitoneal cytokines. The phenotype of peritoneal neutrophils was different between aseptic and bacterial peritonitis, indicating that inflammatory stimuli that activate neutrophils in both types of peritonitis are clearly distinct. Finally, peritoneal injury measured by weight gain, peritoneal permeability, and CA125 concentration seemed to be less severe during icodextrin-induced peritonitis than during bacterial peritonitis.     

Visuospatial skills and computer game experience influence the performance of virtual endoscopy

Advanced medical simulators have been introduced to facilitate surgical and endoscopic training and thereby improve patient safety. Residents trained in the Procedicus Minimally Invasive Surgical Trainer-Virtual Reality (MIST-VR) laparoscopic simulator perform laparoscopic cholecystectomy safer and faster than a control group. Little has been reported regarding whether factors like gender, computer experience, and visuospatial tests can predict the performance with a medical simulator. Our aim was to investigate whether such factors influence the performance of simulated gastroscopy. Seventeen medical students were asked about computer gaming experiences. Before virtual endoscopy, they performed the visuospatial test PicCOr, which discriminates the ability of the tested person to create a three-dimensional image from a two-dimensional presentation. Each student performed one gastroscopy (level 1, case 1) in the GI Mentor II, Simbionix, and several variables related to performance were registered. Percentage of time spent with a clear view in the endoscope correlated well with the performance on the PicSOr test (r = 0.56, P < 0.001). Efficiency of screening also correlated with PicSOr (r = 0.23, P < 0.05). In students with computer gaming experience, the efficiency of screening increased (33.6% +- 3.1% versus 22.6% +- 2.8%, P < 0.05) and the duration of the examination decreased by 1.5 minutes (P < 0.05). A similar trend was seen in men compared with women. The visuospatial test PicSOr predicts the results with the endoscopic simulator GI Mentor II. Two-dimensional image experience, as in computer games, also seems to affect the outcome. Presented at the Forty-Fifth Annual Meeting of The Society for Surgery of The Alimentary Tract, New Orleans, Louisiana, May 15–19, 2004 (oral presentation).