Bilateral high upper limb replantation in a child

Bilateral high amputation of upper limbs in a child is a very unusual injury. In the present case, although the amputation was high and significant avulsion was present, the age of the child (6 years) made the case both challenging and encouraging--challenging because of the anticipated systemic effects of reperfusion, and encouraging because the long-term prognosis is always more encouraging in a child.     

An enzyme immunoassay for detection of Japanese encephalitis virus-induced chemotactic cytokine

Japanese encephalitis virus (JEV) induces human peripheral blood monocytes to secrete a chemotactic cytokine [human macrophage-derived factor (hMDF)] which causes chemotaxis of neutrophils. The only known assay for hMDF cannot quantify its level in samples, so an enzyme immunoassay has been standardized for detection of hMDF and hMDF-specific antibodies in test samples. The reported enzyme linked immunosorbent assay (ELISA) was found to be sensitive (89%), specific (91%), accurate (92 2%) and reproducible and was able to detect a minimum concentration of 23 ng hMDF/ml in test samples. The chemotactic factor could be detected in JEV inoculated mouse sera and JEV infected culture fluids. Significant finding of the test was the detection of hMDF in sera of human cases of JE.     

Interactions with pocket proteins contribute to the role of human papillomavirus type 16 E7 in the papillomavirus life cycle

Human papillomaviruses (HPVs), most commonly the HPV16 genotype, are the principle etiological determinant for cervical cancer, a common cancer worldwide resulting in over 200,000 deaths annually. The oncogenic properties of HPVs are attributable in part to the virally encoded protein E7, best known for its ability to bind to and induce the degradation of the retinoblastoma tumor suppressor, pRb, and related "pocket proteins" p107 and p130. Previously, we defined a role for E7 in the productive stage of the HPV16 life cycle, which takes place in stratified squamous epithelia. HPV perturbs the normal processes of cell growth and differentiation of stratified squamous epithelia. HPVs reprogram cells to support continued DNA synthesis and inhibit their differentiation in the suprabasal compartment of the epithelia, where cells normally have withdrawn from the cell cycle and initiated a well-defined pattern of terminal differentiation. These virus-induced perturbations, which contribute to the production of progeny HPVs, are dependent on E7. In this study, we define the mechanism of action by which E7 contributes to the productive stage of the HPV16 life cycle. We found that the ability of HPV16 to reprogram suprabasal cells to support DNA synthesis correlates with E7's ability to bind pocket proteins but not its ability to induce their degradation. In contrast, the ability of HPV16 to perturb differentiation correlated with both E7's binding to and degradation of pocket proteins. These data indicate that different hallmarks of the productive stage of the HPV16 life cycle rely upon different sets of requirements for E7.     

The probable significance of tracheal tufts in the 8th abdominal segment of Heliothis virescens (F.) on the development of its parasitoid, Toxoneuron nigriceps (Viereck)

The 8th abdominal segment of Heliothis virescens (Fabricius) larvae contains aerating trachea and tracheole tufts that end in the hemocoel of the 8th segment, unlike the tracheae that invade tissues in other segments. These tracheal tufts from the 8th abdominal segment extend to the tokus region, which along with the telson cavity is known to act as a “lung” for hemocytes in Calpodes ethlius and a few other lepidopteran larvae. The goal of this research was to study the effects of these tracheal tufts in the 8th abdominal segment on parasitoid development inside the host larvae, H. virescens. The first objective was to determine if the eggs of the parasitoid, Toxoneuron nigriceps, are predominantly located among the tracheal tufts of the 8th abdominal segment compared to other body cavity regions irrespective of their oviposition site or the position of the host larvae. The results showed that several hours after oviposition most of the eggs are found in the 8th abdominal segment irrespective of the oviposition site or the position of the host larvae. The second objective was to study the effect of varying oxygen concentrations in vitro on various developmental stages of the egg. The results showed that decreasing oxygen concentrations adversely affects the parasitoid egg development in vitro. A third objective was to determine the oxygen concentration in 8th abdominal segment of the host larvae and compare it to other regions of the body using an oxygen sensor placed in vivo. The results suggested relatively high concentration of oxygen in the 8th abdominal segment compared to other regions of the host, thus supporting our hypothesis that the increased oxygen level in the 8th abdominal segment is important to the development of the parasitoid eggs.     

Nectar robbers deter legitimate pollinators by mutilating flowers

Nectar robbing – harvesting nectar illegitimately – can have a variety of outcomes for plant sexual reproduction and for the pollinator community. Nectar robbers can damage flowers while robbing nectar, which could affect the behavior of subsequent flower visitors and, consequently, plant reproduction. However, only nectar manipulation by nectar robbers has so far received attention. We found a short-tongued bee, Hoplonomia sp. (Halictidae), mutilating the conspicuous lower petal of the zygomorphic flowers of Leucas aspera (Lamiaceae) while robbing nectar. We hypothesized that the mutilation of the conspicuous lower petal deters legitimate pollinators on L. aspera flowers, which, in turn, might affect plant reproduction. We first assessed the proportion of naturally-robbed flowers in plant populations for three years to confirm that it was not a purely local phenomenon due to a few individual bees. We then studied diversity, community and visitation characteristics of pollinators, nectar dynamics and fruit set in unrobbed and robbed open flowers in naturally-robbed populations. The proportion of robbed flowers varied significantly across sites and years. Robbing did not affect nectar dynamics in flowers, but it did alter flower morphology, so much so that it reduced pollinator visitation and altered the pollinator community on robbed flowers. However, the maternal function of plant reproduction was not affected by nectar robbing. This study for the first time shows that a nectar robber can have an ecologically significant impact on floral morphology.     

Higher Prevalence of Human Papillomavirus Infection in Adolescent and Young Adult Girls Belonging to Different Indian Tribes with Varied Socio-Sexual Lifestyle

BackgroundDespite high prevalence of human papillomavirus (HPV) infection and cervical cancer in Indian women, no study has been done in tribal populations whose socio-sexual lifestyle is different. Therefore, HPV screening has been carried out in pre-adolescent, adolescent and young adult tribal girls using self-collected urine samples.Methods20–35 ml self-collected midstream urine samples were obtained from a total of 2278 healthy tribal girls (9–25 years) comprising pre-adolescent, adolescent and young adults from three Indian states: Madhya Pradesh, Jharkhand and Chhattisgarh. β-globin positive 2034 samples were employed for HPV detection and genotyping.ResultsThe overall prevalence of HPV infection in tribal girls was 12.9% (262/2034). More than 65% (172/262) of them were infected with HR-HPV types of which HPV16 was the most predominant type (54%). Young adult girls aged 18–25 years showed a significantly higher prevalence of HPV infection (19.2%; OR = 3.36; 95% CI 2.97–6.34, P<0.001) as compared to that in adolescent (11.4%; OR = 1.82; 95% CI 1.20–2.76, P<0.01) or pre-adolescent girls (6.6%).ConclusionThis is a first study showing significantly a very high prevalence of HPV infection in adolescent and young adult tribal girls possibly due to different socio-sexual behavior, indicating a serious health concern for Indian tribal women.     

Antiaging effect of dietary chitosan supplementation on glutathione-dependent antioxidant system in young and aged rats

Aging has been defined as the changes that occur in living organisms with the passage of time that lead to functional impairment and ultimately to death. Free radical-induced oxidative damage has long been thought to be the most important consequence of the aging process. In the present study, an attempt has been made to study the salubrious effects of dietary supplementation of chitosan on glutathione-dependent antioxidant defense system in young and aged rats. The dietary supplementation of chitosan significantly reduced the age-associated dyslipidemic abnormalities noted in the levels of total cholesterol, HDL-cholesterol, and LDL-cholesterol in plasma and heart tissue. Its administration significantly (P < 0.05) attenuated the oxidative stress in the heart tissue of aged rats through the counteraction of free radical formation by maintaining the enzymatic [glutathione peroxidase (GPx) and glutathione reductase (GR)] and non-enzymatic [reduced glutathione (GSH)] status at levels comparable to that of normal young rats. Our results conclude that dietary intake of chitosan restores the depleted myocardial antioxidant status and suggest that it could be an effective therapeutic agent in treatment of age-associated disorders where hypercholesterolemia and oxidative stress are the major causative factors.     

Lipid profiles of autophagic structures isolated from wild type and Atg2 mutant Drosophila

Autophagy is mediated by membrane-bound organelles and it is an intrinsic catabolic and recycling process of the cell, which is very important for the health of organisms. The biogenesis of autophagic membranes is still incompletely understood. In vitro studies suggest that Atg2 protein transports lipids presumably from the ER to the expanding autophagic structures. Autophagy research has focused heavily on proteins and very little is known about the lipid composition of autophagic membranes. Here we describe a method for immunopurification of autophagic structures from Drosophila melanogaster (an excellent model to study autophagy in a complete organism) for subsequent lipidomic analysis. Western blots of several organelle markers indicate the high purity of the isolated autophagic vesicles, visualized by various microscopy techniques. Mass spectrometry results show that phosphatidylethanolamine (PE) is the dominant lipid class in wild type (control) membranes. We demonstrate that in Atg2 mutants (Atg2^?), phosphatidylinositol (PI), negatively charged phosphatidylserine (PS), and phosphatidic acid (PA) with longer fatty acyl chains accumulate on stalled, negatively charged phagophores. Tandem mass spectrometry analysis of lipid species composing the lipid classes reveal the enrichment of unsaturated PE and phosphatidylcholine (PC) in controls versus PI, PS and PA species in Atg2^?. Significant differences in the lipid profiles of control and Atg2^? flies suggest that the lipid composition of autophagic membranes dynamically changes during their maturation. These lipidomic results also point to the in vivo lipid transport function of the Atg2 protein, pointing to its specific role in the transport of short fatty acyl chain PE species.     

Laboratory evaluation of the rapid diagnostic tests for the detection of Vibrio cholerae O1 using diarrheal samples

BackgroundCholera, an acute diarrheal disease is a major public health problem in many developing countries. Several rapid diagnostic tests (RDT) are available for the detection of cholera, but their efficacies are not compared in an endemic setting. In this study, we have compared the specificity and sensitivity of three RDT kits for the detection of Vibrio cholerae O1 and compared their efficiency with culture and polymerase chain reaction (PCR) methods.MethodsFive hundred six diarrheal stool samples collected from patients from two different hospitals in Kolkata, India were tested using SD Bioline Cholera, SMART-II Cholera O1 and Crystal-VC RDT kits. All the stool samples were screened for the presence of V. cholerae by direct and enrichment culture methods. Stool DNA-based PCR assay was made to target the cholera toxin (ctxAB) and O1 somatic antigen (rfb) encoding genes. Statistical evaluation of the RDTs has been made using STATA software with stool culture and PCR results as the gold standards. The Bayesian latent class model (LCM) was used to evaluate the diagnostic tests in the absence of the gold standard.ResultsInvolving culture technique as gold standard, the sensitivity and specificity of the cholera RDT kits in the direct testing of stools was highest with SAMRT-II (86.1%) and SD-Cholera (94.4%), respectively. The DNA based PCR assays gave very high sensitivity (98.4%) but the specificity was comparatively low (75.3%). After enrichment, the high sensitivity and specificity was detected with SAMRT-II (78.8%) and SD-Cholera (99.1%), respectively. Considering PCR as the gold standard, the sensitivity and specificity of the RDTs remained between 52.3–58.2% and 92.3–96.8%, respectively. In the LCM, the sensitivity of direct and enrichment testing was high in SAMRT-II (88% and 92%, respectively), but the specificity was high in SD cholera for both the methods (97% and 100%, respectively). The sensitivity/specificity of RDTs and direct culture have also been analyzed considering the age, gender and diarrheal disease severity of the patients.ConclusionOverall, the performance of the RDT kits remained almost similar in terms of specificity and sensitivity. Performance of PCR was superior to the antibody-based RDTs. The RTDs are very useful in identifying cholera cases during outbreak/epidemic situations and for making them as a point-of-care (POC) testing tool needs more improvement.