Leishmania promastigote membrane antigen-based enzyme-linked immunosorbent assay and immunoblotting for differential diagnosis of Indian post-kala-azar dermal leishmaniasis

Diagnosis of post-kala-azar dermal leishmaniasis (PKDL), caused by Leishmania donovani, is difficult, as the dermal lesions are of several types and resemble those caused by other skin diseases, especially leprosy. Since the disease generally appears very late after the clinical cure of kala-azar in India, it is also difficult to correlate PKDL with a previous exposure to L. donovani. Very few attempts have been made so far to diagnose PKDL serologically, and the diagnostic methods vary in their sensitivities and specificities. Diagnosis of PKDL through sophisticated PCR methods, although highly sensitive, has limited practical use. We have developed a serodiagnostic method using an enzyme-linked immunosorbent assay to detect specific immunoglobulin (Ig) isotypes and IgG subclass antibodies in the sera of Indian PKDL patients. Our assay, which uses L. donovani promastigote membrane antigens, was 100% sensitive for the detection of IgG and 96.7% specific for the detection of IgG and IgG1. Optical density values for individual patients, however, demonstrated wide variations. Western blot analysis based on IgG reactivity could differentiate patients with PKDL from control subjects, which included patients with leprosy, patients from areas where kala-azar is endemic, and healthy subjects, by the detection of polypeptides of 67, 72, and 120 kDa. The recognition patterns of the majority of serum samples from patients with PKDL were also distinct from those of the serum samples from patients with visceral leishmaniasis (VL), at least for a 31-kDa polypeptide. To further differentiate patients with PKDL from those with active and cured VL, we analyzed the specific titers of the Ig isotypes and IgG subclasses. High levels of IgG, IgG1, IgG2, and IgG3 antibodies significantly differentiated patients with PKDL from patients cured of VL. The absence of antileishmanial IgE and IgG4 in patients with PKDL differentiated these patients from those with active VL. These results imply intrinsic differences in the antibodies generated in the sera from patients with PKDL and VL.     

Determination of gene organization in the human IGHV region on single chromosomes

Organization of the IGHV genes (n=108) on single human chromosomes has been determined by detecting these sequences in single sperm using multiplex PCR amplification followed by microarray detection. A total of 374 single sperm samples from five Caucasian males were studied. Three deletion/insertion polymorphisms (Del I-Del III) with deletion allele frequencies ranging from 0.1 to 0.3 were identified. Del I is a previously reported polymorphism affecting three IGHV genes (IGHV1-8, IGHV3-9, and IGHV2-10). Del II affects a region 2-18 kb containing two pseudogenes IGHV(II)-28.1 and IGHV3-29, and Del III spans approximately 21-53 kb involving genes IGHV4-39, IGHV7-40, IGHV(II)-40-1, and IGHV3-41. Deletion alleles of both Dels II and III were found in a heterozygous state, and therefore, could not be easily detected if haploid samples were not used in the study. Results of the present study indicate that deletions/insertions together with other possible chromosomal rearrangements may play an important role in forming the genetic structure of the IGHV region, and may significantly contribute to antibody diversity. Since these three polymorphisms are located within or next to the 3' half of the IGHV region, they may have an important role in the expressed IGHV gene repertoire during immune response.     

A phase I trial of the dual farnesyltransferase and geranylgeranyltransferase inhibitor L-778,123 and radiotherapy for locally advanced pancreatic cancer.

PURPOSE: Preclinical and clinical studies have demonstrated that inhibition of prenylation can radiosensitize cell lines with activation of Ras and produce clinical response in patients with cancer. The aim of this study was to determine the maximally tolerated dose of the dual farnesyltransferase and geranylgeranyltransferase I inhibitor L-778,123 in combination with radiotherapy for patients with locally advanced pancreatic cancer. EXPERIMENTAL DESIGN: L-778,123 was given by continuous intravenous infusion with concomitant radiotherapy to 59.4 Gy in standard fractions. Two L-778,123 dose levels were tested: 280 mg/m2/day over weeks 1, 2, 4, and 5 for dose level 1; and 560 mg/m2/day over weeks 1, 2, 4, 5, and 7 for dose level 2. RESULTS: There were no dose-limiting toxicities observed in the eight patients treated on dose level 1. Two of the four patients on dose level 2 experienced dose-limiting toxicities consisting of grade 3 diarrhea in one case and grade 3 gastrointestinal hemorrhage associated with grade 3 thrombocytopenia and neutropenia in the other case. Other common toxicities were mild neutropenia, dehydration, hyperglycemia, and nausea/vomiting. One patient on dose level 1 showed a partial response of 6 months in duration. Both reversible inhibition of HDJ2 farnesylation and radiosensitization of a study patient-derived cell line were demonstrated in the presence of L-778,123. K-RAS mutations were found in three of the four patients evaluated. CONCLUSIONS: The combination of L-778,123 and radiotherapy at dose level 1 showed acceptable toxicity in patients with locally advanced pancreatic cancer. Radiosensitization of a patient-derived pancreatic cancer cell line was observed.     

STRUCTURAL CHARACTERISATION OF AN IMMUNOMODULATING POLYSACCHARIDE ISOLATED FROM AQUEOUS EXTRACT OF PLEUROTUS FLORIDA FRUIT-BODIES

The water-soluble glucan was obtained from Pleurotus florida fruit bodies by hot water extraction, ethanol precipitation, DEAE cellulose dialysis and Sephadex G-75 gel filtration. The structural information of the glucan was achieved by chemical (hydrolysis, methylation, periodate oxidation) and spectroscopic (¹H and ¹³C) analyses, indicated a repeating unit built up of (1→6)-linked D-glucose. The following structure has been determined for the repeating unit: →6)-α-D-Glcp-(1→ This fraction exhibited significant macrophage activity through the release of nitric oxide     

Investigating the Acoustic Response and Contrast Enhancement of Drug-Loadable PLGA Microparticles with Various Shapes and Morphologies

Polymer nanoparticles and microparticles have been used primarily for drug delivery. There is now growing interest in further developing polymer-based solid cavitation agents to also enhance ultrasound imaging. We previously reported on a facile method to produce hollow poly(lactic-co-glycolic acid) (PLGA) microparticles with different diameters and degrees of porosity. Here, we investigate the cavitation response from these PLGA microparticles with both therapeutic and diagnostic ultrasound transducers. Interestingly, all formulations exhibited stable cavitation; larger porous and multicavity particles also provided inertial cavitation at elevated acoustic pressure amplitudes. These larger particles also achieved contrast enhancement comparable to that of commercially available ultrasound contrast agents, with a maximum recorded contrast-to-tissue ratio of 28 dB. Therefore, we found that multicavity PLGA microparticles respond to both therapeutic and diagnostic ultrasound and may be applied as a theranostic agent.     

Monitoring and management of antituberculosis drug induced hepatotoxicity

BACKGROUND: Hepatotoxicity to antituberculosis therapy (ATT) poses a major challenge. This often results in inadequate therapy. The risk of fulminant hepatic failure and mortality is high once icteric hepatitis develops. There is no consensus on monitoring protocols and for the reintroduction of ATT. METHODS: All patients (from the Department of Internal Medicine and Gastroenterology, Jagjivanram Hospital and the Department of Gastroenterology, Bombay Hospital, Mumbai, India) with a diagnosis of tuberculosis, who were to receive ATT during the study period, were included in the present study for prospective periodic laboratory monitoring for the development of hepatotoxicity. Those patients who developed hepatotoxicity formed Group A (n = 21), whereas those who did not develop hepatotoxicity were included in Group C (n = 179). For the purpose of comparison with Group A, all the patients who presented directly with ATT induced hepatotoxicity during the study period were categorized as Group B (n = 24). Group A and B were further studied after normalization of liver functions for sequential reintroduction with therapeutic doses at a weekly interval. RESULTS: In Group A, 66.6% (14 patients) of the patients were diagnosed in the asymptomatic period. Seven patients had symptomatic hepatitis, but none had icteric illness. There were no mortalities in Group A. In contrast, all the patients in Group B had symptomatic hepatitis (75% icteric hepatitis). There was a mortality rate of 16.6% (four patients). Of the 41 patients from Groups A and B who survived, reintroduction was successful in 38/39 (97.4%). In the remaining two patients who were in Group B, reintroduction was not attempted because of decompensated liver disease. CONCLUSIONS: Periodic laboratory monitoring is important in detecting hepatotoxicity at an early stage, thereby preventing mortality. Sequential reintroduction is often successful.     

Meningoencephalitis associated with COVID-19: a systematic review

Journal of NeuroVirology - With the growing number of COVID-19 cases in recent times. significant set of patients with extra pulmonary symptoms has been reported worldwide. Here we venture out to...     

Increased levels of interleukin-10 and IgG3 are hallmarks of Indian post-kala-azar dermal leishmaniasis

BACKGROUND: Post-kala-azar dermal leishmaniasis (PKDL), an established sequela of visceral leishmaniasis (VL), is proposed to facilitate anthroponotic transmission of VL, especially during interepidemic periods. Immunopathological mechanisms responsible for Indian PKDL are still poorly defined. METHODS: Our study attempted to characterize the immune profiles of patients with PKDL or VL relative to that of healthy control subjects by immunophenotyping, intracellular cytokine staining of peripheral blood mononuclear cells, and enzyme-linked immunosorbent assay for serum cytokines and immunoglobulin G (IgG) subclasses. RESULTS: Patients with PKDL had significantly raised percentages of peripheral CD3+CD8+ cells compared with control subjects, a difference that persisted after cure. Patients with PKDL showed an intact response to phytohemagglutinin, with the percentages of lymphocytes expressing interferon (IFN)-gamma, interleukin (IL)-2, IL-4, and IL-10 being comparable to those in control subjects. Patients with VL had decreased IFN-gamma and IL-2 expression, which was restored after cure, and increased IL-10 expression, which persisted after cure. In their response to Leishmania donovani antigen, patients with PKDL showed a 9.6-fold increase in the percentage of IL-10-expressing CD3+CD8+ lymphocytes compared with control subjects, and this percentage decreased with treatment. Patients with PKDL had raised levels of IgG3 and IgG1 (surrogate markers for IL-10), concomitant with increased serum levels of IL-10. CONCLUSIONS: IL-10-producing CD3+CD8+ lymphocytes are important protagonists in the immunopathogenesis of Indian PKDL.     

A Representative Study of Deaths of North Indian Migrants and Its Medical Certification Across the World

Many Indians is moving to other nations of the world in the search of employment, education or other reasons. The process of globalization along with the faster mode of traveling and communication has facilitated this movement in the hope of getting more opportunities and earning of easy money abroad, than in India. Unfortunately, sometimes they meet a tragic end and their families in India get only their dead bodies back from abroad. This study focuses on these kind of unfortunate tragic events faced by Indians in different countries and thereby raise a concern on their safety abroad and necessitate the need of relooking in to the quality of medical certification of death and medico legal investigations to find out the real reasons of deaths to avoid any kind of doubt in mind. Data was collected from medical death certificates and passports of the deceased Indians. There was a total of 711 dead bodies/human remains received in 2012 at IGI airport New Delhi. The Middle East countries together contributed a total of 398 (55.98?%) cases. The distribution as per manner of death shows that in maximum number of cases (269), the manner of death was ambiguous with unspecified aetiology. The study therefore recommends for upgradation of the level of medico legal investigations in form of 2nd autopsy in recipient country and proper medical death certification.     

PTEN is a mechanosensing signal transducer for myosin II localization in Dictyostelium cells

To investigate the role of PTEN in regulation of cortical motile activity, especially in myosin II localization, eGFP–PTEN and mRFP–myosin II were simultaneously expressed in Dictyostelium cells. PTEN and myosin II co-localized at the posterior of migrating cells and furrow region of dividing cells. In suspension culture, PTEN knockout ( pten ⁻) cells became multinucleated, and myosin II significantly decreased in amount at the furrow. During pseudopod retraction and cell aspiration by microcapillary, PTEN accumulated at the tips of pseudopods and aspirated lobes prior to the accumulation of myosin II. In pten ⁻ cells, only a small amount of myosin II accumulated at the retracting pseudopods and aspirated cell lobes. PTEN accumulated at the retracting pseudopods and aspirated lobes even in myosin II null cells and latrunculin B-treated cells though in reduced amounts, indicating that PTEN accumulates partially depending on myosin II and cortical actin. Accumulation of PTEN prior to myosin II suggests that PTEN is an upstream component in signaling pathway to localize myosin II, possibly with mechanosensing signaling loop where actomyosin-driven contraction further augments accumulation of PTEN and myosin II by a positive feedback mechanism.