Detection of Leishmania donovani and L. tropica in Ethiopian wild rodents

Human visceral (VL, also known as Kala-azar) and cutaneous (CL) leishmaniasis are important infectious diseases affecting countries in East Africa that remain endemic in several regions of Ethiopia. The transmission and epidemiology of the disease is complicated due to the complex life cycle of the parasites and the involvement of various Leishmania spp., sand fly vectors, and reservoir animals besides human hosts. Particularly in East Africa, the role of animals as reservoirs for human VL remains unclear. Isolation of Leishmania donovani parasites from naturally infected rodents has been reported in several endemic countries; however, the status of rodents as reservoirs in Ethiopia remains unclear. Here, we demonstrated natural Leishmania infections in rodents. Animals were trapped in 41 localities of endemic and non-endemic areas in eight geographical regions of Ethiopia and DNA was isolated from spleens of 586 rodents belonging to 21 genera and 38 species. Leishmania infection was evaluated by real-time PCR of kinetoplast (k)DNA and confirmed by sequencing of the PCR products. Subsequently, parasite species identification was confirmed by PCR and DNA sequencing of the 18S ribosomal RNA internal transcribed spacer one (ITS1) gene. Out of fifty (8.2%) rodent specimens positive for Leishmania kDNA-PCR and sequencing, 10 were subsequently identified by sequencing of the ITS1 showing that five belonged to the L. donovani complex and five to L. tropica. Forty nine kDNA-positive rodents were found in the endemic localities of southern and eastern Ethiopia while only one was identified from northwestern Ethiopia. Moreover, all the ten ITS1-positive rodents were captured in areas where human leishmaniasis cases have been reported and potential sand fly vectors occur. Our findings suggest the eco-epidemiological importance of rodents in these foci of leishmaniasis and indicate that rodents are likely to play a role in the transmission of leishmaniasis in Ethiopia, possibly as reservoir hosts.     

Assessing the Performance of CareStart Malaria Pf/Pv Combo Test Against Thick Blood Film in the Diagnosis of Malaria in Northwest Ethiopia

Bivalent rapid diagnostic tests are promising diagnostic tools for Plasmodium falciparum and P. vivax. Their diagnostic performance was evaluated against thick blood smear to assist national malaria control programs. A cross-sectional study was conducted to evaluate the performance of CareStart against thick blood smears among 398 acute febrile patients visiting the Felegeselam Health Center in December of 2011. Thick blood smears were examined under 100× objectives to diagnose Plasmodium species. Similarly, CareStart Malaria Pf/Pv Combo Test was performed as per the manufacturer''s instruction. The ability of CareStart Malaria Pf/Pv Combo Test to diagnose Plasmodium malaria was very good, with 99.8% (95% confidence interval = 97.7–100%) sensitivity and 97.7% (95% confidence interval = 94.6–99.1%) specificity. The sensitivity and specificity of the CareStart Test is comparable with the thick blood smear in diagnosing malaria. Hence, it is preferable to use the CareStart Malaria Pf/Pv Combo Test instead of microscopy in areas where microscopic diagnosis is limited.     

莫沙必利对阿司匹林致大鼠急性胃黏膜损伤的保护作用

研究显示促胃肠动力药物莫沙必利对胃黏膜损伤具有一定的保护作用。目的：研究不同剂量莫沙必利对阿司匹林致大鼠急性胃黏膜损伤的保护作用及其机制。方法：将50只大鼠随机分为阴性对照组、单纯损伤组以及不同剂量莫沙必利干预组（0．25mg／kg、0．50mg／kg、0．75mg／kg）。干预组大鼠以不同剂量莫沙必利灌胃行预处理,以150mg／kg阿司匹林灌胃制备急性胃黏膜损伤模型。实验第4d,处死大鼠。评估大鼠胃黏膜损伤指数和组织学变化,以免疫组化法检测Occludin蛋白分布,蛋白质印迹法检测Occludin、ZO．1以及磷酸化ERK（p-ERK）、磷酸化JNK（p-JNK）和磷酸化p38（p-p38）蛋白表达。结果：与单纯损伤组相比,各莫沙必利干预组胃黏膜损伤指数均明显降低（P〈0．05）;胃黏膜组织学明显改善;胃黏膜Occludin、ZO-1蛋白表达呈剂量依赖性升高（P〈0．05）;胃黏膜p-ERK、p-p38蛋白表达呈剂量依赖性降低（P〈0．05）;而胃黏膜p-JNK蛋白表达无明显差异。结论：莫沙必利对阿司匹林致大鼠急性胃黏膜损伤具有明显保护作用,其机制可能为降低MAPKs信号通路中ERK和p38蛋白磷酸化程度,并上调胃黏膜紧密连接蛋白Occludin和ZO-1表达,从而改善胃黏膜屏障的功能。     

Altered neural activation in ornithine transcarbamylase deficiency during executive cognition: An fMRI study

Background: Ornithine transcarbamylase deficiency (OTCD) is an X‐linked urea cycle disorder characterized by hyperammonemia resulting in white matter injury and impairments in working memory and executive cognition. Objective: To test for differences in BOLD signal activation between subjects with OTCD and healthy controls during a working memory task. Design, setting and patients: Nineteen subjects with OTCD and 21 healthy controls participated in a case‐control, IRB‐approved study at Georgetown University Medical Center. Intervention: An N‐back working memory task was performed in a block design using 3T functional magnetic resonance imaging. Results: In subjects with OTCD we observed increased BOLD signal in the right dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC) relative to healthy age matched controls. Conclusions: Increased neuronal activation in OTCD subjects despite equivalent task performance points to sub‐optimal activation of the working memory network in these subjects, most likely reflecting damage caused by hyperammonemic events. These increases directly relate to our previous finding of reduced frontal white matter integrity in the superior extents of the corpus callosum; key hemispheric connections for these areas. Future studies using higher cognitive load are required to further characterize these effects. Hum Brain Mapp, 2013. © 2011 Wiley Periodicals, Inc.     

Finite Element Modeling and Performance Evaluation of Piezoelectric Energy Harvesters with Various Piezoelectric Unit Distributions

The piezoelectric energy harvester (PEH) is a device for recycling wasted mechanical energy from pavements. To evaluate energy collecting efficiency of PEHs with various piezoelectric unit distributions, finite element (FE) models of the PEHs were developed in this study. The PEH was a square of 30 cm × 30 cm with 7 cm in thickness, which was designed according to the contact area between tire and pavement. Within the PEHs, piezoelectric ceramics (PZT-5H) were used as the core piezoelectric units in the PEHs. A total of three distributions of the piezoelectric units were considered, which were 3 × 3, 3 × 4, and 4 × 4, respectively. For each distribution, two diameters of the piezoelectric units were considered to investigate the influence of the cross section area. The electrical potential, total electrical energy and maximum von Mises stress were compared based on the computational results. Due to the non-uniformity of the stress distribution in PEHs, more electrical energy can be generated by more distributions and smaller diameters of the piezoelectric units; meanwhile, more piezoelectric unit distributions cause a higher electrical potential difference between the edge and center positions. For the same distribution, the piezoelectric units with smaller diameter produce higher electrical potential and energy, but also induce higher stress concentration in the piezoelectric units near the edge.     

The performance of direct agglutination tests (DAT) in the diagnosis of visceral leishmaniasis among Ethiopian patients with HIV co-infection

The incidence of visceral leishmaniasis (VL) in Ethiopia has dramatically increased over the last 10 years, coinciding with the advent of the HIV epidemic. HIV co-infection in VL patients results in atypical, clinical and serological presentations, and may hamper serological diagnosis of VL. The performance of direct agglutination tests (DAT) in the diagnosis of VL in 103 Ethiopian patients with or without HIV infection was therefore investigated. The DAT results indicated that 96 of the patients had leishmanial infections, although amastigotes were only detected in samples from 91. Data on HIV status showed that 50.7% of all patients but 56.0% of the parasitologically confirmed cases of VL patients were HIV-positive. Based on the 95 patients who were each examined both by DAT and parasitological methods, the overall sensitivity of the DAT was 97.7%. Among the parasitologically confirmed cases of VL, a false-negative DAT result was obtained for two (3.9%) of the 51 cases who had HIV co-infection and for none of the 40 HIV-negative cases. In contrast to the observations made in Europe, DAT in Ethiopia therefore remain reasonably sensitive in the diagnosis of VL during HIV co-infection. The results are discussed in view of the possibility of distinctive antibody responses induced by Leishmania donovani donovani and L. d. infantum in HIV-infected patients.     

单中心18726例腹腔镜胆囊切除术并发症分析及预防处理对策探讨

目的 分析腹腔镜胆囊切除术(LC)的并发症及其影响因素，探讨并发症防治策略。方法 采用回顾性分析法，对自1992年3月至2001年7月在我腹腔镜中心行LC的18726例病人，术中、术后并发症及其发生因素进行分析。结果 术中胆总管损害28例(0.15％)，术后胆漏62例(0．33％)，腹腔出血6例(0．03％)，术后腹腔内脓肿及切口疝7例(0．03％)，总计103例，并发症发生率为0．55％。分析其原因与比适应证选择不当及术者对胆道解剖变异等缺乏足够认识等因素有关。结论 胆漏以及胆管损伤是比的主要并发症，精确操作可避免其损伤，术中及时发现和处理，一般预后是良好的。     

Prevalence of onchocercal skin disease and infection among workers of coffee plantation farms in Teppi,southwestern Ethiopia

In June 1996, a study on the economic impacts of onchocercal skin disease was initiated in southwestern Ethiopia. We made parasitological and clinicoepidemiological investigations among 1619 workers of a coffee plantation firm in Teppi, south-western Ethiopia. Sixty percent of the workers were included in the study. The prevalence of onchocercal skin disease (OSD) was 85.3%. Severe OSD (SOSD) was found in 17.3% of the study subjects. This was 1/5 of all OSD cases. The overall nodule carrier rate was 44.2%, which differed significantly by age classes from a rate of 12.3% to 73.0%. This rate varied by sex, 51.7% in males and 22.6% in females. Microfilarial carrier rate (MFCR) was 77.6%. This rate did not vary neither with severity of disease nor with presence or absence of pruritus or onchodermatitis. Mean microfilarial count was determined to be 38.1 per mg of skin snip or 44.4 per mg of infected skin snips. The geometric mean of microfilarial load per infected skin was 23.8. The community microfilarial load (CMFL) was estimated to be 14.0 per mg skin snip. The study showed that SOSD is prevalent in Teppi and affects a substantial number of the working population. An intervention program is called for.     

Distinct immunity in patients with visceral leishmaniasis from that in subclinically infected and drug-cured people: implications for the mechanism underlying drug cure

Significant levels of IgG3 and IgG4 and high levels of IgG1 leishmania-specific antibody differentiated the immune states in 10 patients with visceral leishmaniasis from those of virtually all 20 drug-cured and 18 subclinically infected subjects, whereas the level of IgG2 antibody was nondiscriminating. The most extreme "subclinically infected" outlier subsequently developed disease. Overall, the immune states in subclinically infected and drug-cured persons were mutually indistinguishable but were readily distinguished from those of patients. These findings may have implications for the immunologic mechanism underlying drug cure in visceral leishmaniasis.     

Childhood meningitis in a tertiary hospital in Addis Ababa: clinical and epidemiological features

Hospital based prospective study of 136 children aged 3 months to 12 years admitted as cases of meningitis between June 1996 and May 1997 was undertaken to assess the epidemiological features, evaluate the outcome and measure the duration of clinical improvement after initiation of treatment. Infants accounted for 79 (58%) of cases and 23 (68%) of deaths. Next to fever and vomiting, neurologic signs were the commonest presentation. H. influenzae, S. pneumoniae and N. meningitidis accounted for 90% of culture isolates. Delayed presentation, partial treatment, altered sensorium at admission and pneumococcal meningitis were risk factors for mortality. The morbidity and mortality rates were 25% of total cases each. The mean duration of fever was 3.7 (+/- 2.27) days after treatment. The morbidity and mortality rates are still high in this hospital.