Leishmania donovani triose phosphate isomerase: a potential vaccine target against visceral leishmaniasis

Visceral leishmaniasis (VL) is one of the most important parasitic diseases with approximately 350 million people at risk. Due to the non availability of an ideal drug, development of a safe, effective, and affordable vaccine could be a solution for control and prevention of this disease. In this study, a potential Th1 stimulatory protein- Triose phosphate isomerase (TPI), a glycolytic enzyme, identified through proteomics from a fraction of Leishmania donovani soluble antigen ranging from 89.9–97.1 kDa, was assessed for its potential as a suitable vaccine candidate. The protein- L. donovani TPI (LdTPI) was cloned, expressed and purified which exhibited the homology of 99% with L. infantum TPI. The rLdTPI was further evaluated for its immunogenicity by lymphoproliferative response (LTT), nitric oxide (NO) production and estimation of cytokines in cured Leishmania patients/hamster. It elicited strong LTT response in cured patients as well as NO production in cured hamsters and stimulated remarkable Th1-type cellular responses including IFN-ã and IL-12 with extremely lower level of IL-10 in Leishmania-infected cured/exposed patients PBMCs in vitro. Vaccination with LdTPI-DNA construct protected naive golden hamsters from virulent L. donovani challenge unambiguously (∼90%). The vaccinated hamsters demonstrated a surge in IFN-ã, TNF-á and IL-12 levels but extreme down-regulation of IL-10 and IL-4 along with profound delayed type hypersensitivity and increased levels of Leishmania-specific IgG2 antibody. Thus, the results are suggestive of the protein having the potential of a strong candidate vaccine

Evaluation of Leishmania donovani Protein Disulfide Isomerase as a Potential Immunogenic Protein/Vaccine Candidate against Visceral Leishmaniasis

In Leishmania species, Protein disulfide isomerase (PDI) - a redox chaperone, is reported to be involved in its virulence and survival. This protein has also been identified, through proteomics, as a Th1 stimulatory protein in the soluble lysate of a clinical isolate of Leishmania donovani (LdPDI). In the present study, the molecular characterization of LdPDI was carried out and the immunogenicity of recombinant LdPDI (rLdPDI) was assessed by lymphocyte proliferation assay (LTT), nitric oxide (NO) production, estimation of Th1 cytokines (IFN-γ and IL-12) as well as IL-10 in PBMCs of cured/endemic/infected Leishmania patients and cured L. donovani infected hamsters. A significantly higher proliferative response against rLdPDI as well as elevated levels of IFN-γ and IL-12 were observed. The level of IL-10 was found to be highly down regulated in response to rLdPDI. A significant increase in the level of NO production in stimulated hamster macrophages as well as IgG2 antibody and a low level of IgG1 in cured patient's serum was observed. Higher level of IgG2 antibody indicated its Th1 stimulatory potential. The efficacy of pcDNA-LdPDI construct was further evaluated for its prophylactic potential. Vaccination with this construct conferred remarkably good prophylactic efficacy (∼90%) and generated a robust cellular immune response with significant increases in the levels of iNOS transcript as well as TNF-α, IFN-γ and IL-12 cytokines. This was further supported by the high level of IgG2 antibody in vaccinated animals. The in vitro as well as in vivo results thus indicate that LdPDI may be exploited as a potential vaccine candidate against visceral Leishmaniasis (VL)

Vaginal leiomyoma

Leiomyomas are common benign tumors in the uterus. However, vaginal leiomyomas remain an uncommon entity with only about 300 reported cases. Here, we report a case of a 38-year-old multigravida who presented with lower abdominal pain and vaginal bleeding. A physical examination and ultrasonography were performed, and a diagnosis of cervical fibroid was made. Pervaginal removal of the tumor was performed and subsequent histopathology revealed a vaginal leiomyoma. Although a rare tumor, vaginal leiomyomas may present with a variety of clinical features and may be mistaken preoperatively for cervical fibroid. Removal of tumor by vaginal route, wherever possible, with subsequent histopathological examination appears to be the optimum management plan

Presence of Essential Hypertension or Diabetes Mellitus Is a Predictor of Intracranial Bleeding in Elderly Patients: A Study of 108 Patients with Isolated Thrombocytopenia from a Single Reference Center

INTRODUCTION: Thrombocytopenia poses a significant problem in the elderly. Not only are there varied causes, but it is also associated with significant morbidity and mortality. We carried out a study to learn the causes of isolated thrombocytopenia in elderly patients and to correlate the severity of thrombocytopenia and bleeding manifestations with various etiologic factors and comorbidities. METHODS: A total of 108 patients above 50 years of age presenting with isolated thrombocytopenia (platelet counts of <100x109/L with normal hemoglobin and total leukocyte counts) were enrolled in the study. Detailed history and clinical examinations were carried out for each patient. Complete blood counts were analyzed by automated cell counter. Peripheral smears were examined in all cases. HbsAg, anti-HCV, and anti-HIV testing by enzyme-linked immunosorbent assay was done in all patients. Wherever clinically indicated, bone marrow aspiration biopsy and cytogenetic studies were done. RESULTS: Out of 108 patients, 102 (94.4%) presented with bleeding tendencies. Twenty-nine (26.8%) presented with serious (World Health Organization grade 3/4) bleedings. Major findings were immune thrombocytopenic purpura in 79 (73.1%), myelodysplastic syndrome in 7 (6.5%), drug-induced thrombocytopenia in 7 (6.5%), and connective tissue disorder in 4 (3.7%) cases. Ten patients presented with intracranial bleedings. Upon logistic regression analysis, comorbidities in the form of essential hypertension and diabetes mellitus were significantly associated with occurrence of intracranial bleeding. There was no correlation of serious bleedings with platelet counts. DISCUSSION AND CONCLUSION: Isolated thrombocytopenia in the elderly is associated with significant morbidity. Diligent clinical and laboratory evaluation is required to elucidate the cause of thrombocytopenia in the elderly. Comorbidities in this population are associated with serious bleedings and not low platelet counts as is commonly thought

A novel recombinant Leishmania donovani p45, a partial coding region of methionine aminopeptidase, generates protective immunity by inducing a Th1 stimulatory response against experimental visceral Leishmaniasis

The development of a vaccine against visceral leishmaniasis (VL) conferring long-lasting immunity remains a challenge. Identification and proteomic characterization of parasite proteins led to the detection of p45, a member of the methionine aminopeptidase family. To our knowledge the present study is the first known report that describes the molecular and immunological characterization of p45. Recombinant Leishmania donovani p45 (rLdp45) induced cellular responses in cured hamsters and generated Th1-type cytokines from peripheral blood mononuclear cells of cured/endemic VL patients. Immunization with rLdp45 exerted considerable prophylactic efficacy (∼85%) supported by an increase in mRNA expression of iNOS, IFN-γ, TNF-α and IL-12 and decrease in TGF-β and IL-4, indicating its potential as a vaccine candidate against VL

Antidiabetic and antihyperlipidemic activity of hydroalcoholic extract of Withania coagulans Dunal dried fruit in experimental rat models

Objective: Evaluation of antidiabetic potential of the hydroalcoholic extract of Withania coagulans Dunal dried fruit (WCDF) alone and in combination with glipizide, in streptozotocin-induced diabetes, and evaluation of possible antihyperlipidemic activity of the same extract in high-cholesterol diet-induced hyperlipidemia, in albino rats. Materials and Methods: Experimental diabetes was induced in 30 albino rats with intraperitoneal injection of streptozotocin (55 mg/kg). The rats were divided into five groups receiving the following treatments orally for 4 weeks: Vehicle, glipizide (2.5 mg/kg), WCDF extract (1000 mg/kg), WCDF extract (1000 mg/kg) plus glipizide (1 mg/kg) and WCDF extract (1000 mg/kg) plus0 glipizide (2.5 mg/kg). Fasting and postprandial blood glucose levels were measured every week for 4 weeks. Endocrine pancreas histopathology was done at the end. In a separate set of experiment, five groups of six albino rats each, received orally for 4 weeks, vehicle, cholesterol (25 mg/kg/day), cholesterol (25 mg/kg/day) plus atorvastatin (7.2 mg/kg/day), cholesterol (25 mg/kg/day) plus WCDF extract (1000 mg/kg/day) and no treatment, respectively. Estimation of serum lipid profile and liver histopathology was done at the end of 4 weeks. Statistical Analysis: Between-group and within-group comparisons were respectively done by analysis of variance (ANOVA) and repeated measures ANOVA, followed by post hoc Tukey′s test, with a significance level of P < 0.05. Results and Conclusions: The 4-week treatment with WCDF extract significantly reversed hyperglycemia in streptozotocin-induced diabetes that was comparable to glipizide. When combined with glipizide (2.5 mg/kg), WCDF extract produced a synergistic antihyperglycemic effect as well as improvement in pancreatic histopathology. Moreover, hydroalcoholic extract of WCDF was effective and comparable to atorvastatin in controlling the high-cholesterol diet-induced hyperlipidemia in rats

Efficacy of Leishmania donovani trypanothione reductase, identified as a potent Th1 stimulatory protein, for its immunogenicity and prophylactic potential against experimental visceral leishmaniasis

In visceral leishmaniasis (VL), Th1-type of immune responses play an important role which correlates with recovery from and resistance to disease resulting in lifelong immunity. Based on this rationale, the soluble leishmanial antigens that elicit cellular responses in peripheral blood mononuclear cells (PBMCs) from cured Leishmania patients were characterized through immunoproteomic approach which led to the identification of trypanothione reductase (TPR) (a cytosolic enzyme explored as a drug target), as one of the potent Th1 stimulatory protein. In this study, the immunogenicity of recombinant Leishmania donovani TPR (rLdTPR) was assessed in PBMCs of cured Leishmania-infected patients/hamsters and further evaluated its prophylactic efficacy against L. donovani challenges in hamsters. Substantial proliferative responses to rLdTPR, as compared to soluble L. donovani antigen, were observed in Leishmania-infected cured patients as well as in hamsters. Moreover, rLdTPR reasonably stimulated PBMCs of cured Leishmania patients to produce IFNγ, IL-12, and TNF-α but not IL-4 or IL-10. On the other hand, the protein downregulated LPS-induced IL-10 as well as soluble L. donovani antigen-induced IL-4 production in PBMCs of Leishmania patients. In case of cured hamsters, rLdTPR generates mixed Th1 and Th2 immune response. Vaccination with rLdTPR along with Bacillus Calmette–Guerin (BCG) was able to provide considerably good prophylactic efficacy (~60 %) against L. donovani challenge in hamsters. The efficacy was supported by the increased inducible NO synthase mRNA transcript and Th1-type cytokines IFNγ, IL-12, and TNF-α and downregulation of IL-4, IL-10, and TGF-β. Since rLdTPR protein is an important target, further attempts towards determination of immunodominant regions for designing fusion peptides may be taken up to optimize its prophylactic efficacy

Leishmania donovani: oral therapy with glycosyl 1,4-dihydropyridine analogue showing apoptosis like phenotypes targeting pteridine reductase 1 in intracellular amastigotes

Glycosyl 1,4-dihydropyridine analogue (2,6-dimethyl-4-(3-O-benzyl-1,2-O-isopropylidene-β-l-threo pentofuranos-4-yl)-1-phenyl-1,4-dihydro-pyridine-3,5-dicarboxylic acid diethyl ester) synthesized in our laboratory, inhibited Leishmania donovani infection in vitro and in hamsters (Mesocricetus auratus) when administered orally. This analogue is nontoxic, cell-permeable and orally effective. This glycosyl dihydropyridine analogue functioned through arrest of cells in sub-G0/G1-phase, triggering mitochondrial membrane depolarization-mediated programmed cell death of the intracellular amastigotes