Impairment of larval development and a sex-ratio distortion in <i>Litomosoides sigmodontis</i> caused by <i>Wolbachia</i>-depleted microfilariae and localization of a filarial nematode phosphate permease up-regulated during <i>Wolbachia</i> depletion

The thesis investigates the endosymbiosis between Wolbachia bacteria and their host filarial nematodes. The rodent filaria Litomosoides sigmodontis harbour Wolbachia endosymbionts and the pattern of infection and migration of these parasites mimics that of human filarial parasites such as Wuchereria bancrofti and Onchocerca volvulus. The first aim of the thesis was to study the effect of tetracycline, which depletes Wolbachia, on the development of microfilariae (L1 larvae, MF) to L3 larvae in the intermediate mite host Ornithonyssus bacoti, and to observe the development of Wolbachia-depleted L3 larvae in Mongolian gerbils (Meriones unguiculatus). Microfilaremic gerbils were treated with tetracycline for 6 weeks in drinking water (1º Tet) or left untreated (1º Con). Six weeks post-treatment, there was no difference in microfilaremia between 1º Tet and 1º Con, but there was significantly lower levels of Wolbachia in MF from 1º Tet in comparison to those in 1º Con. Naive mites were then fed on the 1º Tet and 1º Con gerbils and were used to infect uninfected gerbils (2º Tet, 2º Con). The number of MF that developed into L3 larvae in naive mites after feeding on the Wolbachia-depleted MF in 1º Tet gerbils was significantly lower than controls. Fewer female worms developed in 2º Tet gerbils but there was no significant difference in the number of male worms that developed in 2º Tet and 2º Con gerbils, resulting in a male biased sex-ratio. This suggests that Wolbachia have more influence on the development of female than male worms which is supported by the fact that male worms with significantly fewer Wolbachia could be selected by tetracycline treatment but female worms cannot. Since the worms analyzed were only exposed to tetracycline as MF, the experimental set-up rules out direct effects of tetracycline during larval development in the mites or 2º infected gerbils, suggesting that the initial loss of Wolbachia in MF was the cause of impaired larval development, not an antifilarial effect of tetracycline. The second aim of the thesis was to study the molecular basis governing endosymbiosis between Wolbachia and their filarial host - L. sigmodontis. Previously in our research group, Heider et al., 2006 studied the gene expression of L. sigmodontis during Wolbachia depletion using differential display which revealed an up-regulation of a phosphate permease gene (Ls-ppe-1). We hypothesized that Ls-ppe-1 had an important role in nucleotide metabolism as depletion of Wolbachia induced expression of Ls-ppe-1, perhaps to compensate for lack of nucleotides in the absence of their endobacteria. To test this hypothesis, firstly, the regulation of phosphate permease during Wolbachia depletion was studied at the protein level in L. sigmodontis and O. volvulus, and secondly, the localization of phosphate permease and Wolbachia in L. sigmodontis and O. volvulus were investigated in untreated and antibiotic treated filarial worms. Results of the studies show the up-regulation of L. sigmodontis phosphate permease (Ls-PPE) both at the mRNA and protein levels and immunohistology results demonstrate that Ls-PPE is localized to areas of the worms that contain Wolbachia. Results also demonstrated the up-regulation of O. volvulus phosphate permease (Ov-PPE) at the protein level during Wolbachia depletion by doxycycline treatment of onchocerciasis. Ls-PPE and Ov-PPE are localized to areas in worms where Wolbachia are found and are up-regulated in response to Wolbachia depletion, supporting a role of phosphate permease in nematode-Wolbachia endosymbiosis. Further ultrastructural analysis using electron microscopy promises to bring insight into the molecular interaction between phosphate permeases and Wolbachia and RNAi mediated knockdown of Ls-ppe-1 in L. sigmodontis will elucidate the exact function of PPE in the Wolbachia-nematode symbiosis

Vaccination with recombinant Brugia malayi cystatin proteins alters worm migration, homing and final niche selection following a subcutaneous challenge of Mongolian gerbils (Meriones unguiculatus) with B. malayi infective larvae.

BACKGROUND: Cysteine protease inhibitors of Brugia malayi have been ascribed to be involved in parasite development as well as to immunomodulate the host\u27s immune response. In Onchocerca volvulus, Onchocystatin has been shown to induce partial protection in the mouse diffusion chamber vaccination model. In the present study we investigated the impact of vaccination with recombinant Bm-CPI-1 and Bm-CPI-2 proteins on protection against a subcutaneous challenge of B. malayi third stage larvae in gerbils. FINDINGS: Vaccination with E. coli derived recombinant B. malayi cysteine protease inhibitors (Bm-CPI-1 or -2) did not confer protection against B. malayi L3 challenge infection in gerbils but altered the homing of a significant number of adult worms from the lymphatics to the heart and lungs. CONCLUSION: Bm-CPI vaccination-induced alteration in worm migration is consistent with our previous observations in gerbils vaccinated with B. pahangi excretory-secretory (ES) proteins, which resulted in delayed migration of the L3s and altered the final location of adult worms. Similar observations have also been made in dogs vaccinated with Ancylostoma caninum proteins; an increased number of worms were recovered in the colon and not the expected small intestine. A change in the final niche was also reported in immune versus non-immune hosts of two other gut dwelling nematodes. Vaccination induced alteration of the parasite\u27s final homing might be a rare or a common phenomenon, which unfortunately is rarely recorded. The reason for the alteration in the final niche selection by adult nematode worms following vaccination is unknown and necessitates further investigation

Vaccination of Gerbils with Bm-103 and Bm-RAL-2 Concurrently or as a Fusion Protein Confers Consistent and Improved Protection against Brugia malayi Infection.

BACKGROUND: The Brugia malayi Bm-103 and Bm-RAL-2 proteins are orthologous to Onchocerca volvulus Ov-103 and Ov-RAL-2, and which were selected as the best candidates for the development of an O. volvulus vaccine. The B. malayi gerbil model was used to confirm the efficacy of these Ov vaccine candidates on adult worms and to determine whether their combination is more efficacious. METHODOLOGY AND PRINCIPLE FINDINGS: Vaccine efficacy of recombinant Bm-103 and Bm-RAL-2 administered individually, concurrently or as a fusion protein were tested in gerbils using alum as adjuvant. Vaccination with Bm-103 resulted in worm reductions of 39%, 34% and 22% on 42, 120 and 150 days post infection (dpi), respectively, and vaccination with Bm-RAL-2 resulted in worm reductions of 42%, 22% and 46% on 42, 120 and 150 dpi, respectively. Vaccination with a fusion protein comprised of Bm-103 and Bm-RAL-2 resulted in improved efficacy with significant reduction of worm burden of 51% and 49% at 90 dpi, as did the concurrent vaccination with Bm-103 and Bm-RAL-2, with worm reduction of 61% and 56% at 90 dpi. Vaccination with Bm-103 and Bm-RAL-2 as a fusion protein or concurrently not only induced a significant worm reduction of 61% and 42%, respectively, at 150 dpi, but also significantly reduced the fecundity of female worms as determined by embryograms. Elevated levels of antigen-specific IgG were observed in all vaccinated gerbils. Serum from gerbils vaccinated with Bm-103 and Bm-RAL-2 individually, concurrently or as a fusion protein killed third stage larvae in vitro when combined with peritoneal exudate cells. CONCLUSION: Although vaccination with Bm-103 and Bm-RAL-2 individually conferred protection against B. malayi infection in gerbils, a more consistent and enhanced protection was induced by vaccination with Bm-103 and Bm-RAL-2 fusion protein and when they were used concurrently. Further characterization and optimization of these filarial vaccines are warranted

Vaccination with a genetically modified Brugia malayi cysteine protease inhibitor-2 reduces adult parasite numbers and affects the fertility of female worms following a subcutaneous challenge of Mongolian gerbils (Meriones unguiculatus) with B. malayi infective larvae.

Vaccination of Mongolian gerbils with Brugia malayi cysteine protease inhibitor-2 in which the amino acid Asn66 was mutated to Lys66 (Bm-CPI-2M) resulted in reduced parasite numbers of 48.6% and 48.0% at 42 and 90 days p.i. with B. malayi L3s. Fertility of female worms was also affected at 90 days p.i. In vitro killing of L3s observed in the presence of gerbil peritoneal exudate cells and anti-Bm-CPI-2M sera suggests antibody-dependent cell-mediated cytotoxicity as a putative protective mechanism. These observations suggest that Bm-CPI-2M is a promising prophylactic and anti-fecundity vaccine candidate

South Indian Children's Neurodevelopmental Outcomes After Group B Streptococcus Invasive Disease: A Matched-Cohort Study.

BACKGROUND: This study is part of a multicountry matched-cohort study designed to estimate the risk of long-term neurodevelopmental impairment (NDI) of children exposed to invasive group B Streptococcus (iGBS). The specific objective of this paper is to compare NDI across domains of iGBS survivors with a matched non iGBS group in our population. METHODS: Survivors of iGBS in a South Indian hospital were identified and recruited between January 2020 and April 2021. Cases were compared with age- and gender-matched non iGBS children. Participants were assessed using Bayley Scales of Infant and Toddler Development-3rd edition (BSID-III), Wechsler Preschool and Primary Scale of Intelligence-4th edition (WPPSI-IV), Wechsler Intelligence Scale for Children-5th edition (WISC-V), Child Behavior Checklist (CBCL), and Bruininks-Oseretsky Test of Motor Proficiency, 2nd edition (BOT-2), depending on age. RESULTS: Our cohort comprised 35 GBS-exposed and 65 matched non iGBS children, aged 1-14 years. The iGBS-exposed group had 17 (48.6%) children with impairment in ≥1 domain compared to 25 (38%) in the non iGBS group (unadjusted OR, 1.51; 95% CI, .65-3.46), 9 (26%) children with "multi-domain impairment" compared to 10 (15.4%) in the non iGBS group (unadjusted OR, 1.90; 95% CI, .69-5.24), and 1 (2.9%) child with moderate to severe impairment compared to 3 (4.6%) in the non iGBS group (unadjusted OR, .60; 95% CI, .06-6.07). In the iGBS group, more children had motor impairments compared with the non iGBS group (unadjusted OR, 10.7; 95% CI, 1.19-95.69; P = .034). CONCLUSIONS: Children with iGBS seem at higher risk of developing motor impairments compared with a non iGBS group

A pathway proteomic profile of ischemic stroke survivors reveals innate immune dysfunction in association with mild symptoms of depression: a pilot study

Depression after stroke is a common occurrence, raising questions as to whether depression could be a long-term biological and immunological sequela of stroke. Early explanations for post-stroke depression (PSD) focused on the neuropsychological/psychosocial effects of stroke on mobility and quality of life. However, recent investigations have revealed imbalances of inflammatory cytokine levels in association with PSD, though to date, there is only one published proteomic pathway analysis testing this hypothesis. Thus, we examined the serum proteome of stroke patients (n = 44, mean age = 63.62 years) and correlated these with the Montgomery–Åsberg Depression Rating Scale (MADRS) scores at 3 months post-stroke. Overall, the patients presented with mild depression symptoms on the MADRS, M = 6.40 (SD = 7.42). A discovery approach utilizing label-free relative quantification was employed utilizing an LC-ESI–MS/MS coupled to a LTQ-Orbitrap Elite (Thermo-Scientific). Identified peptides were analyzed using the gene set enrichment approach on several different genomic databases that all indicated significant downregulation of the complement and coagulation systems with increasing MADRS scores. Complement and coagulation systems are traditionally thought to play a key role in the innate immune system and are established precursors to the adaptive immune system through pro-inflammatory cytokine signaling. Both systems are known to be globally affected after ischemic or hemorrhagic stroke. Thus, our results suggest that lowered complement expression in the periphery in conjunction with depressive symptoms post-stroke may be a biomarker for incomplete recovery of brain metabolic needs, homeostasis, and inflammation following ischemic stroke damage. Further proteomic investigations are now required to construct the temporal profile, leading from acute lesion damage to manifestation of depressive symptoms. Overall, the findings provide support for the involvement of inflammatory and immune mechanisms in PSD symptoms and further demonstrate the value and feasibility of the proteomic approach in stroke research

Global overview of the management of acute cholecystitis during the COVID-19 pandemic (CHOLECOVID study)

Background: This study provides a global overview of the management of patients with acute cholecystitis during the initial phase of the COVID-19 pandemic. Methods: CHOLECOVID is an international, multicentre, observational comparative study of patients admitted to hospital with acute cholecystitis during the COVID-19 pandemic. Data on management were collected for a 2-month study interval coincident with the WHO declaration of the SARS-CoV-2 pandemic and compared with an equivalent pre-pandemic time interval. Mediation analysis examined the influence of SARS-COV-2 infection on 30-day mortality. Results: This study collected data on 9783 patients with acute cholecystitis admitted to 247 hospitals across the world. The pandemic was associated with reduced availability of surgical workforce and operating facilities globally, a significant shift to worse severity of disease, and increased use of conservative management. There was a reduction (both absolute and proportionate) in the number of patients undergoing cholecystectomy from 3095 patients (56.2 per cent) pre-pandemic to 1998 patients (46.2 per cent) during the pandemic but there was no difference in 30-day all-cause mortality after cholecystectomy comparing the pre-pandemic interval with the pandemic (13 patients (0.4 per cent) pre-pandemic to 13 patients (0.6 per cent) pandemic; P = 0.355). In mediation analysis, an admission with acute cholecystitis during the pandemic was associated with a non-significant increased risk of death (OR 1.29, 95 per cent c.i. 0.93 to 1.79, P = 0.121). Conclusion: CHOLECOVID provides a unique overview of the treatment of patients with cholecystitis across the globe during the first months of the SARS-CoV-2 pandemic. The study highlights the need for system resilience in retention of elective surgical activity. Cholecystectomy was associated with a low risk of mortality and deferral of treatment results in an increase in avoidable morbidity that represents the non-COVID cost of this pandemic

Modeling 'hot flow' and 'cold flow' solids deposition from waxy mixtures

Bibliography: p. 144-151This study presents a mathematical model, based on moving boundary formulation, for solids deposition from 'waxy' mixtures. An experimental study was undertaken to measure the wax precipitation temperature (WPT) of several compositions of a multi-component 'waxy' mixture, at controlled cooling rates. The results of this study indicated the WPT of a 'waxy' mixture is not a constant property, as it varied with the cooling rate. The mathematical model was used to describe the static cooling of 'waxy' mixtures in a cylindrical vessel. The predictions for the liquid region, deposit region temperature profile, the deposit layer growth and the location of the liquid-deposit interface were validated with recent experimental results. The model was extended for studying wax deposition from 'waxy' mixtures under turbulent flow, in radial direction in a circular pipe. The effects of various operating parameters on the wax deposit thickness during "hot flow" and "cold flow" scenarios were investigated. The model predictions indicated a higher value of mixture temperature, pipe wall temperature, and heat transfer coefficient yield a thinner deposit at steady state. The mathematical model was further extended for solids deposition from 'waxy' mixtures under turbulent flow in a pipeline. Predictions were obtained for the deposit growth with time, both radially and axially in the pipeline, under 'hot flow' and 'cold flow' conditions. The results of this study suggest that solids deposition, in pipelines carrying 'waxy' mixtures under turbulent flow, could be decreased by maintaining the flow under 'cold flow' conditions. This study provides further confirmation that solids deposition from 'waxy' mixtures or crude oils can be modeled satisfactorily as a thermally-driven process

Rapid assessment on mass mortality of fishes in Ennore estuary of Tamil Nadu, India

1647-1650Mass mortality of fishes and aquatic organisms are reported from Ennore estuary from time to time due to water pollution . Extensive fish mortality was observed in this estuary during 20th August 2014. Dead fishes were found buoyant and spread out for about 3 km distance in the region between Ennore Thermal Power Station to Railway Bridge