20 research outputs found
Aeropalynology of Parthenium hysterophorus L. in Relation to Meteorological Parameters from Srinagar Valley of Garhwal Himalaya, Uttarakhand
Parthenium hysterophorus (congress grass) is a harmful weed and its pollen grains are important allergens. Due to its minute size and allergenic activity, this particular type of pollen is selected for the study. The aeropalynological survey was conducted for the year 2019 at Chauras Campus, Hemvati Nandan Bahuguna Garhwal University, Srinagar, Uttarakhand. It is located on the right bank of the Alaknanda river (30°13’35.81”N & 78°48’11.05”E; 560 m amsl). A Rotarod sampler was used for air sampling. The maximum pollen count was observed in July. To evaluate the correlation matrix in R software, correlations (Pearson’s and Spearsman’s) between pollen count and meteorological parameters have been calculated. Back trajectory analysis has also been done using NOAA HYSPLIT MODEL
Severe Esophagitis and Chemical Pneumonitis as a Consequence of Dilute Benzalkonium Chloride Ingestion: A Case Report
Background: Benzalkonium chloride (BAC) has been used as an active ingredient in a wide variety of compounds such as surface disinfectants, floor cleaners, pharmaceutical products and sanitizers. Solutions containing <10% concentration of BACs typically do not cause serious injury. As the available data regarding acute BAC toxicity is limited, we report a case of dilute benzalkonium chloride ingestion resulting in bilateral chemical pneumonitis and significant gastrointestinal injury requiring mechanical ventilatory support.
The Case: A 42-year-old male presented with chief complaints of nausea, vomiting and excessive amount of blood- mixed oral secretions after accidental ingestion of approximately 100ml of BAC solution (<10%). Later he developed respiratory distress with falling oxygen saturation for which he was intubated and mechanical ventilatory support was administered. Computed tomography (CT) chest was suggestive of bilateral chemical pneumonitis and upper gastrointestinal (GI) endoscopy revealed diffuse esophageal ulcerations. The patient was managed with intravenous fluids, corticosteroids, proton pump inhibitor, empiric antibiotics and total parenteral nutrition.
Conclusion: The present case report emphasizes that dilute BAC compounds can cause severe respiratory and gastrointestinal injuries. Immediate and aggressive medical treatment is crucial for improving patient outcomes and reducing the complication rates
Efficacy of a monovalent human-bovine (116E) rotavirus vaccine in Indian children in the second year of life
Rotavirus gastroenteritis is one of the leading causes of diarrhea in Indian children less than 2 years of age. The 116E rotavirus strain was developed as part of the Indo-US Vaccine Action Program and has undergone efficacy trials. This paper reports the efficacy and additional safety data in children up to 2 years of age. In a double-blind placebo controlled multicenter trial, 6799 infants aged 6-7 weeks were randomized to receive three doses of an oral human-bovine natural reassortant vaccine (116E) or placebo at ages 6, 10, and 14 weeks. The primary outcome was severe (≥11 on the Vesikari scale) rotavirus gastroenteritis. Efficacy outcomes and adverse events were ascertained through active surveillance. We randomly assigned 4532 and 2267 subjects to receive vaccine and placebo, respectively, with over 96% subjects receiving all three doses of the vaccine or placebo. The per protocol analyses included 4354 subjects in the vaccine and 2187 subjects in the placebo group. The overall incidence of severe RVGE per 100 person years was 1.3 in the vaccine group and 2.9 in the placebo recipients. Vaccine efficacy against severe rotavirus gastroenteritis in children up to 2 years of age was 55.1% (95% CI 39.9 to 66.4; p<0.0001); vaccine efficacy in the second year of life of 48.9% (95% CI 17.4 to 68.4; p=0.0056) was only marginally less than in the first year of life [56.3% (95% CI 36.7 to 69.9; p<0.0001)]. The number of infants needed to be immunized to prevent one episode of severe RVGE in the first 2 years of life was 40 (95% CI 28.0 to 63.0) and for RVGE of any severity, it was 21 (95% CI 16.0 to 32.0). Serious adverse events were observed at the same rates in the two groups. None of the eight intussusception events occurred within 30 days of a vaccine dose and all were reported only after the third dose. The sustained efficacy of the 116E in the second year of life is reassuring
Dictyostelium discoideum—a promising expression system for the production of eukaryotic proteins
In general, four different expression systems, namely, bacterial, yeast, baculovirus, and mammalian, are widely used for the overproduction of biochemical enzymes and therapeutic proteins. Clearly, bacterial expression systems offer ease of maneuverability with respect to large-scale production of recombinant proteins, while, a baculovirus expression system ensures proper protein modifications, processing, and refolding of complex proteins. Despite these advantages, mammalian cells remain the preferred host for many eukaryotic proteins of pharmaceutical importance, particularly, those requiring post-translational modifications. Recently, the single-celled slime mold, Dictyostelium discoideum (Dd), has emerged as a promising eukaryotic host for the expression of a variety of heterologous recombinant eukaryotic proteins. This organism possesses the complex cellular machinery required for orchestrating post-translational modifications similar to the one observed in higher eukaryotes. This review summarizes the advantages and disadvantages of Dictyostelium as an alternate system compared to other well-established expression systems. The key lessons learned from the expression of human recombinant proteins in this system are reviewed. Also, the strengths, weaknesses, and challenges associated with industrial-scale production of proteins in Dd expression system are discussed
Biosynthesis of entamoeba histolytica proteophosphoglycan in vitro
A complex glycoconjugate proteophosphoglycan (PPG) is present on the surface of the pathogenic protozoan parasite Entamoeba histolytica but not in the non-pathogenic Entamoeba dispar. It is thought to be an important molecule involved in pathogenesis. In order to study its biosynthesis, an in vitro cell-free system was developed. The specificity of the system was demonstrated by various criteria including immunoprecipitation by a specific monoclonal antibody. The in vitro synthesized molecule was found to be susceptible to mild acid hydrolysis, digestion by phosphoinositol-specific phospholipase c and nitrous acid deamination, the salient features for a PPG-like molecule. The in vitro product was not synthesized when heat-treated cellular-extract was used in the assay or when the cell extract was prepared from Entamoeba invadens, a species that lacks these glycoconjugates. Analysis of the glycan side chains of the in vitro synthesized product by thin layer chromatography revealed side chains of variable sizes including a fraction greater than six glycan units. The crude membranes used in the cell-free system were further fractionated by sucrose density gradient centrifugation. The fraction containing the PPG synthesizing activity when used in the assay resulted in a 10-fold increase in specific activity. Development of this cell-free system will facilitate further studies on the nature of intracellular organelles and the pathways that are involved in PPG biosynthesis
Preform Map for Mild Steel Upsetting and Its Experimental Verification.
In upsetting process, an initial block of metal (billet) is compressed between two or more dies to produce a complex part. Geometry of the final product is strongly dependent on the shape of initial work piece as well as on the perform shapes at each of the subsequent forming stages. Design of the optimum preform for near net shape manufacturing is a crucial step in the designing of many upsetted products of mild steel. In this study, the same is realized by using profile map, which is generated using the results of FE simulations of varying geometrical and processing parameters. The map is further verified experimentally using a mild steel specimen. It is shown that preform designed on the basis of profile map results in near net shape manufacturing. Such map offers a powerful tool for near net shape upsetting
Glycosylated inositol phospholipid from Entamoeba histolytica: identification and structural characterization
This article does not have an abstract
Compliance of mothers following recommendations to breastfeed or withhold breast milk during rotavirus vaccination in North India: A randomized clinical trial
Background: Neutralizing antibodies in breast milk may adversely influence the immune response to live oral vaccines. Withholding breastfeeding around the time of vaccine administration has been suggested for improving vaccine performance. However, we do not know whether mothers find withholding breastfeeding around the time of vaccination acceptable and how they perceive this recommendation. Methods: In a clinical study designed to examine predictors of poor immune response to rotavirus vaccine in infants in India, Rotarix® was administered to infants at 6 and 10 weeks with other childhood vaccines. For the study, 400 mother–infant pairs were randomized into two groups in a 1:1 ratio. Mothers were either recommended to withhold breastfeeding or were encouraged to breastfeed half an hour before and after administration of Rotarix®. The mother–infant pairs were observed and the breastfeeding intervals were recorded during this period. Mothers were administered a questionnaire about their perception of the intervention after the infants received the second dose of Rotarix®. Results: Almost 98% (391/400) of the infants received both doses of Rotarix®. Adherence to the recommendations was high in both groups. All mothers in the group who were asked to withhold breastfeeding did so, except one who breastfed her infant before the recommended time after the first dose of Rotarix®. Of the mothers, 4% (7/195) reported that the recommendation to withhold breastfeeding was difficult to follow. All mothers in this group reported that they would withhold breastfeeding at the time of vaccination if they were asked to by a health-care provider. Only one mother responded that withholding breastfeeding would be a reason for not giving rotavirus vaccine to her infant. Conclusions: Withholding breastfeeding half an hour before and after vaccination appears to be acceptable to mothers in this setting. If withholding breastfeeding produces an improvement in the performance of the vaccine, it could be used to increase the public health impact of rotavirus immunization
Synergy between tuberculin skin test and proliferative T cell responses to PPD or cell-membrane antigens of Mycobacterium tuberculosis for detection of latent TB infection in a high disease-burden setting.
Tuberculin skin test (TST) is used most widely for the detection of latent tuberculosis infection (LTBI), even though evidences suggest that it could be underreporting the prevalence of LTBI particularly in high disease-burden settings. We have explored whether in vivo (TST) and in vitro (cell-proliferative) T cell responses to PPD can serve as complementary measures. In addition, we also probed whether in vitro T cell response to cell-membrane antigens (Mem) of Mycobacterium tuberculosis (MTB) can serve as a biomarker for LTBI. Study subjects comprised 43 healthcare workers (HCWs), and 9 smear-positive TB patients served as 'disease control'. To measure proliferative T cell responses, 0.1 ml blood (diluted 1:10) was incubated (5 days) with test or control antigen. Cells were stained with fluorescent antibodies to T cell (CD3+/CD4+/CD8+) surface markers and, after fixation and permeabilization, to nuclear proliferation marker Ki67. Data was acquired on a flow cytometer. HCWs who had an intimate exposure to MTB showed significantly higher TST positivity (85%) than the rest (43%), notwithstanding their BCG vaccination status. The proliferative responses of CD4+ and CD8+ subsets of T cells were comparable. Sixty seven and 100% TST-negative HCWs, respectively, were positive for proliferative T cell response to PPD and MTBMem. Cumulative positivity (TST or in vitro) was 86% with PPD and 100% with MTBMem indicating complementarity of the two responses. As standalone in vitro assay, MTBMem provided a significantly higher positivity (95%) than PPD (67%). T cell responses of TB patients were 'generally' depressed, having implications for the development of immunological assays for 'progressive' LTBI. Altogether, these results demonstrate that in vivo and in vitro T cell responses to PPD are complementary and in vitro response to MTBMem can be developed as a highly sensitive biomarker for LTBI
Immune responses to Mycobacterium tuberculosis membrane-associated antigens including alpha crystallin can potentially discriminate between latent infection and active tuberculosis disease.
Changes in expression of membrane antigens may accompany the transition of Mycobacterium tuberculosis (Mtb) from 'dormant' to 'active' states. We have determined whether antibody and T cell responses to Mtb membrane (MtM)-associated antigens, especially the latency-induced protein alpha crystallin (Acr), can discriminate between latent tuberculosis infection (LTBI) and active TB (ATB) disease. Study subjects comprised a previously described cohort of healthcare workers (HCWs, n = 43) and smear-positive ATB patients (n = 10). HCWs were further categorized as occupational contacts (OC, n = 30), household contacts of TB (HC, n = 8) and cured TB (CTB, n = 5). Levels (ΔOD) of serum antibody isotypes (IgG, IgA and IgM) were determined by ELISA and blood T cell proliferative responses were determined by flow cytometry using Ki67 protein as marker for DNA synthesis. Antibodies to MtM and Acr were predominantly IgG and their levels in HCWs and ATB did not differ significantly. However, HCWs showed a significantly higher level of anti-MtM IgM and a significantly lower level of anti-Acr IgA antibodies than the ATB patients. Also, a larger proportion of HCWs showed a high (>1) ΔODAcr/ΔODMtM ratio for IgG. HCWs also showed a higher, though not significantly different from ATB, avidity of anti-MtM (IgG) antibodies. A higher proportion of HCWs (35% of OC, 62.5% of HC and 20% of CTB), compared with ATB (10%) showed a positive T cell response to Acr along with significant difference (P <0.05) between HC and ATB. A significant correlation (r = 0.60, P <0.0001) was noted between T cell responses of HCWs towards Acr and MtM (reported earlier by us) and both responses tended to decline with rising exposure to the infection. Even so, positive responses to Acr (38.5%) were significantly lower than to MtM (92%). Neither antibody nor T cell responses to either antigen appeared affected by BCG vaccination or reactivity to tuberculin. Results of the study suggest that the levels of IgM antibodies to MtM, IgA antibodies to Acr and proliferative T cell responses to both the antigens can potentially discriminate between LTBI and active TB disease. They also underscore the necessity of SOPs for antibody assays