Sangeeta Dey - Academia.edu (original) (raw)

Papers by Sangeeta Dey

Journal of Evolution of medical and Dental Sciences, 2014

INTRODUCTION: Diarrhoea is defined as passage of loose, liquid or watery stools. In the developin... more INTRODUCTION: Diarrhoea is defined as passage of loose, liquid or watery stools. In the developing countries, diarrhoea remains a wet season disease with bacteria playing a greater role. The agents responsible for infantile diarrhoea may be bacteria, viruses, parasites, malnutrition and drugs. Infectious agents that cause diarrhoeal disease are usually spread by the fecal-oral route. Escherichia coli (E. coli) is a gram-negative bacillus that may be found in the normal intestinal flora of humans and animals, but can also be an important cause of enteric illness. Our present study is an attempt to fulfil this vacuum and investigate the most common pathogens causing these diseases amongst patients in and around a tertiary care hospital of eastern Bihar, with special reference to the serotypes of Escherichia coli. MATERIAL AND METHODS: Samples were collected from both male and female patients below five years of age, admitted to the Pediatrics Department, with complains of diarrhoea an...

Journal of Membrane Science and Research, 2018

Zirconia ultrafiltration membranes are widely developed and used for past several years. But the ... more Zirconia ultrafiltration membranes are widely developed and used for past several years. But the conventional sol-gel methods of zirconia membrane preparation involve many steps. In the present study an attempt was made to develop defect free zirconia ultrafiltration (UF) membrane in single step coating of zirconia nanopowder suspension by slip casting method over multichannel ceramic support. The porous support was made from a novel composition of clay and α-alumina having 19-channels circular configuration. Zirconia UF membrane was developed at the inner surface of the support up to 0.2 m length. Membrane had a mean pore diameter of 40 nm. Clean water permeability of 48 lm-2h-1bar-1 was obtained for the membrane under cross-flow filtration mode. Membrane was utilized for treatment of industrial and domestic wastewater. Membrane treated water was characterized to evaluate the reduction of organic and inorganic contaminants. About 82% and 92% removal of COD were obtained for tannery...

Indian Journal of Medical Microbiology, 2021

BACKGROUND Conjunctivitis is one of the most common nontraumatic eye complaints and is one of the... more BACKGROUND Conjunctivitis is one of the most common nontraumatic eye complaints and is one of the most frequently reported diseases in the outpatient and emergency departments. Bacterial conjunctivitis has been reported as one of the most common type of infectious conjunctivitis after viral infections. It is also considered as the primary cause of acute conjunctivitis in children. This study was conducted to isolate and identify organisms causing bacterial conjunctivitis and to determine their in vitro susceptibility or resistance. METHODS This descriptive study was conducted in the Departments of Ophthalmology and Microbiology at Katihar Medical College from December 2018 to May 2020. Sociodemographic and clinical data were collected from 175 patients using structured questionnaire. External ocular specimens were collected using sterile swabs and inoculated on blood agar, MacConkey’s agar and chocolate agar. Presumptive isolates were further identified by a series of biochemical tests. All isolated organisms were tested for their in vitro antimicrobial susceptibility against various antibiotics using the Kirby-Baur disk diffusion method. RESULTS A total of 175 samples were collected, out of which, 62.8 % (110 / 175) showed growth of bacteria. Maximum cases of bacterial conjunctivitis were seen in the age group 11 - 20 years. The male to female ratio was 2.7:1. Maximum frequency of bacterial conjunctivitis was observed from May to September. Staphylococcus aureus was the most common bacteria isolate 65.5 % (72 / 110) followed by Staphylococcus epidermidis 19.1 % (21 / 110). Most of the Staphylococcus aureus isolates were found to be sensitive to moxifloxacin 98.6 % (71 / 72) and gentamicin 95.8 % (69 / 72). 25 % (18 / 72) of Staphylococcus aureus strains were found to be resistant to cefoxitin and were considered as methicillin-resistant Staphylococcus aureus (MRSA) strains. Maximum numbers of gram-negative strains were sensitive to moxifloxacin 100.0 % (9 / 9) followed by tobramycin 88.9 % (8 / 9). Pseudomonas aeruginosa strains showed maximum sensitivity to moxifloxacin 100.0 (8 / 8) followed by ofloxacin and ciprofloxacin 62.5 % (5 / 8). CONCLUSIONS This study provides an insight into the organisms isolated from cases of bacterial conjunctivitis in Katihar District of Bihar. Determining the susceptibility pattern of these pathogens to available antibiotics is crucial for effective management of bacterial conjunctivitis especially when treatment has to be given empirically. KEY WORDS Bacterial Conjunctivitis, Antibiogram

TP26. TP026 DIAGNOSIS, ASSESSMENT, AND PROGNOSIS OF FIBROTIC ILD, 2021

Journal of Radioanalytical and Nuclear Chemistry, 2020

In order to develop radiation resistant membranes for the treatment of high level waste (HLW), ce... more In order to develop radiation resistant membranes for the treatment of high level waste (HLW), ceramic tubular membranes were prepared by incorporating varying amounts of ammonium molybdophosphate (AMP), known for efficient Cs(I) uptake from acidic feeds, for the recovery of radio-caesium. The sorption of Cs(I) onto the membrane increased linearly with increasing the AMP content (10%-40%). Radiation stability of the membranes was evaluated by exposing them to gamma radiation obtained from a 60 Co source. The composite ceramic material showed excellent radiation stability without any morphological change up to 1100 kGy, indicating its potential application in radioactive waste treatment. For 10% AMP loaded ceramic membrane, the Cs(I) sorption decreased linearly with radiation dose. However, Cs sorption was not altered up to 1100 kGy dose for 20% and 40% loaded AMP.

Transactions of the Indian Ceramic Society, 2019

ABSTRACT Dispersion of zirconia powder in aqueous suspension using suitable dispersant for coatin... more ABSTRACT Dispersion of zirconia powder in aqueous suspension using suitable dispersant for coating application was studied. Zeta potential experiments were conducted in search of stable suspensions. Sedimentation tests were carried out in both acidic and basic pH range, i.e. from 2 to 11. Zirconia slurry as coating material was used for coating on clay-alumina tubular ceramic support. The slurry was composed of zirconia nano powder, water, dispersant and organic binder. Z irconia nano powders were characterized by XRD, surface area by multipoint BET and TEM. The effect of dispersant concentration on zeta potential of zirconia suspension and effect of pH, sedimentation rate and rheology (viscosity) of zirconia suspension were studied. The coated tubes were air dried and sintered in furnace at 700°C for 2 h. The prepared UF membrane was subjected to characterization in terms of permeability, FESEM, molecular weight cut off, etc. The UF membrane was used for separation of two types of water – effluent A (kitchen sink wastewater) and effluent B (surface water of a lake). The membrane was effective to remove the pathogenic organisms, organic load in terms of BOD, COD, etc. The treated water may be reused in agriculture or industrial purposes. GRAPHICAL ABSTRACT

Journal of Evolution of Medical and Dental Sciences, 2017

BACKGROUND Injuries secondary to severe burns rank among the most serious forms of trauma resulti... more BACKGROUND Injuries secondary to severe burns rank among the most serious forms of trauma resulting in anatomic, physiologic, endocrinologic and immunologic stress, especially when burns involve more than 20% of Total Body Surface Area (TBSA). In patients surviving the initial burn and resuscitative phase, infections are a leading cause of mortality. The burnt surface is sterile immediately following thermal injury but after 48 hours the wound is colonised with skin pathogens that typically reside in sweat glands and hair follicles before the burn. After 5 to 7 days, wounds become colonised with yeast and/or Gram-positive and Gram-negative organisms from the host's intestinal and upper respiratory tracts, or from the hospital environment and health care workers' hands. MATERIALS AND METHODS Surface swabs were collected from 200 patients with burn wound infection of both sexes and all age groups. The microorganisms were identified as per standard protocol based on colony morphology; Gram's staining findings and biochemical tests. ESBL (Extended Spectrum Beta-lactamases) detection was done using PCDDT (Phenotypic Confirmatory Disc Diffusion Test). RESULTS A total of 268 organisms were isolated from 200 samples. Out of the 268 isolates, 213 (79.48%) were Gram-negative bacilli, 42 (15.67%) were Gram-positive cocci and 13 (4.85%) were fungi. Among the Gram-negative bacilli, Pseudomonas aeruginosa was the most common bacteria isolated at 45.15% (121/268). The isolates exhibited maximum resistance to 3 rd generation cephalosporins with good response to piperacillin/tazobactam and carbapenems. Among all the Gram-negative bacilli, 30.99% (66/147) were ESBL producers. CONCLUSION The study showed that burn wound infection was more common in females than males. Majority of cases had a burn sustained from an open flame, mostly in winters. Gram-negative bacilli were the predominant isolates (80%) from patients with burn wound infection. Fungi were isolated in about 5% of cases. Pseudomonas aeruginosa was the commonest isolate (45%). Amongst the Gram-positive cocci, staphylococci and enterococci were isolated consistently from patients.

Journal of Evolution of Medical and Dental Sciences, 2017

BACKGROUND Staphylococcus aureus is notorious for its ability to become resistant to antibiotics.... more BACKGROUND Staphylococcus aureus is notorious for its ability to become resistant to antibiotics. MRSA emerged as nosocomial pathogen in the early 1960s. Methicillin Resistant Staphylococcus aureus (MRSA) are implicated in serious infections and nosocomial infection outbreaks. These strains show resistance to a wide range of antibiotics, thus limiting the treating options to very few agent s such as vancomycin and teicoplanin. Vancomycin has been regarded as the first-line drug for treatment of MRSA. At the same time, there has been an increase in the use of this antibiotic for other infections as well. This has further lead to an increase in the number of both Vancomycin Intermediate Staphylococcus aureus (VISA) and Vancomycin Resistant Staphylococcus aureus (VRSA). Aims-To determine the presence of MRSA and VRSA among staphylococcal isolates in Eastern Bihar. MATERIALS AND METHODS A total of 10806 samples from patients attending inpatient and outpatient departments from January 2011 to April 2013 were included in the study. Samples were processed as per standard protocol and antibiotic susceptibility testing was done by modified Kirby-Bauer method. Isolates were tested by disc diffusion using oxacillin disc 1 µg, cefoxitin disc 30 µg and by agar dilution for MRSA. VRSA isolates were tested using 30 µg vancomycin disc. MIC of vancomycin to Staphylococcus aureus was determined by agar dilution method. RESULTS Out of a total of 633 Staphylococcus aureus isolates, 22.4% were found to be methicillin resistant, 9.95% were VISA and 3.79% were VRSA. Results of oxacillin agar dilution method were in concordance with the cefoxitin disc diffusion method in detecting MRSA strains. All VISA strains were sensitive to linezolid and all VRSA were sensitive to imipenem. 88.7% and 87.3% of all MRSA isolates were sensitive to imipenem and linezolid respectively. CONCLUSION The present shows that antibiotic resistance is steadily on the rise. It is also quite clear that MRSA is acquiring resistance to drugs like rifampicin, teicoplanin, amikacin, netilmicin and imipenem which were at one time used as an alternative to vancomycin. It is therefore imperative for the medical community to work together to fight against this man-made phenomenon called antibiotic resistance.

Respiratory Research, 2016

Small airway fibrosis is the main contributor to physiological airway dysfunction in COPD. One po... more Small airway fibrosis is the main contributor to physiological airway dysfunction in COPD. One potential mechanism contributing to small airway fibrosis is epithelial mesenchymal transition (EMT). When associated with angiogenesis (so called EMT-Type-3) it may well also be the link with the development of airway epithelial cancer, which is closely associated with COPD and predominantly in large airways. In a recent study published in Respiratory Research, Reimann and colleagues, showed increased expression of S100A4 in vasculature of human COPD and murine lungs. It is quite possible that the process of endothelial to mesenchymal transition (EndMT) is active in COPD lungs which we wish to comment on.

Science Advances, 2015

Enzymes lead to the discovery of new, shape-tunable ligands for controlling catalytic chemistry.

Natural Product Research, 2009

Thin layer chromatography bioautography (using DPPH spray reagent) guided fractionation of Glycyr... more Thin layer chromatography bioautography (using DPPH spray reagent) guided fractionation of Glycyrrhiza glabra led to the isolation of two caffeic acid derivative esters, viz. eicosanyl caffeate (1) and docosyl caffeate (2). The two compounds exhibited potent elastase inhibitory activity, with IC(50) values of 0.99 microg mL(-1) and 1.4 microg mL(-1) for 1 and 2, respectively. The compounds also showed moderate antioxidant activity in DPPH and ABTS scavenging assays. The results indicate a possible role of caffeic acid derivatives, in addition to flavonoids in the anti-ulcer properties of G. glabra.

Journal of the American Chemical Society, 2005

Combinatorial methods have made an important impact on catalyst discovery in recent years. 1 Nota... more Combinatorial methods have made an important impact on catalyst discovery in recent years. 1 Notable examples include the discovery of catalysts for asymmetric acylation 2a and Stetter-type chemistry, 2b,c Pd(0)-2d and Cu(I)-mediated 2e allylic alkylations, Agbased carbene insertion, 2f FeCl 2-mediated epoxidation, 2g and early transition-metal-based additions to imines. 2h,i These successes have spurred interest in catalyst screening. 3 Screens for active lead catalysts, based upon IR thermography, 4a,b fluorescence, 4c-f and dye formation 4g /bleaching 4h have been reported. Particularly valuable

Journal of Pharmaceutical Sciences, 2001

The purpose of this study is to assess the permeability of acyclovir (ACV) prodrugs through the r... more The purpose of this study is to assess the permeability of acyclovir (ACV) prodrugs through the rabbit corneal cell line (SIRC) as well as the cornea, and characterize the SIRC cell line for transport and metabolism studies of ester prodrugs. Prodrug derivatization of an acycloguanosine antiviral agent, acyclovir, was employed to improve its permeability across the cornea. New Zealand albino rabbits were used as an animal model for corneal studies. The SIRC cell line grown on polyester membranes was used for transport of these prodrugs. SIRC cells grown on the membrane support for 10 days developed four to six layers of epithelial cells, and this is comparable to the normal rabbit corneal epithelial layer. Transport experiments were conducted across the rabbit cornea and con¯uent SIRC cells using side-by-side diffusion-cell apparatus. Enzymatic hydrolysis of these compounds was evaluated in SIRC cell lysates. Appropriate reversed phase HPLC method(s) were employed for quantitation of both the prodrug and ACV simultaneously. Corneal permeabilities of some of these prodrugs (Malonyl ACV and Acetyl ACV) were higher relative to ACV. The SIRC cell line permeability values of all the prodrugs were higher compared to that of the intact cornea. The total amount of ACV-prodrugs transported, i.e., unhydrolyzed prodrugs and regenerated ACV, across the SIRC cell line was more relative to ACV. Hydrolytic studies in the SIRC cell line homogenate demonstrated the bioreversion potential of the prodrugs and the presence of enzymes, particularly the cholinesterase in the SIRC cell line. It may be concluded that the SIRC cell line is leakier compared to the cornea. Keeping in mind the limitations, the SIRC cell line after further characterization may be used for transport and metabolism studies of ester prodrugs.

Journal of the American Oil Chemists' Society, 2014

An indigenously developed low‐cost clay‐alumina‐based ceramic microfiltration membrane of 19‐chan... more An indigenously developed low‐cost clay‐alumina‐based ceramic microfiltration membrane of 19‐channel configuration has been evaluated for degumming, dewaxing and deacidification of rice bran oil (RBO) miscella having different oil contents at pilot scale. Rice bran wax and soap particles in miscella will aggregate with changes in temperature. This suggests a technique for their effective separation. Low‐temperature cross‐flow membrane filtration was used for single‐stage degumming‐dewaxing and showed 70 % and 80 % removal of acetone insoluble residue from two RBO miscella samples, respectively. Color reduction was 50 %, and oryzanol retention was 70 %. NaOH was used for deacidification in a 10 % excess of that required based on the free fatty acid content in oil. This reduced free fatty acids to 0.2 %. Operating for 10 h with a 0.7 bar trans‐membrane pressure, permeate fluxes of 15 and 8 L/m2 hr were obtained for the degumming‐dewaxing and deacidification operations, respectively. T...

Investigative Opthalmology & Visual Science, 2003

PURPOSE. A dipeptide prodrug of the antiviral nucleoside acyclovir (ACV), val-val-ACV (VVACV), wa... more PURPOSE. A dipeptide prodrug of the antiviral nucleoside acyclovir (ACV), val-val-ACV (VVACV), was evaluated in vivo as a potential drug candidate for improving antiviral efficacy against herpetic epithelial and stromal keratitis. METHODS. The effect of 1% VVACV on epithelial keratitis induced by inoculation of HSV-1 strain McKrae (25 L of 10 5 plaque-forming units [PFU]) in the scarified rabbit cornea and stromal keratitis induced by intrastromal injection of HSV-1 strain RE (10 L of 10 5 PFU) was compared with that of 1% trifluorothymidine (TFT) and balanced salt solution as the vehicle control. Both eyes of 10 rabbits were used in each treatment group. Lesions were evaluated by slit lamp examinations over a 2-week period after infection. Aqueous humor samples and corneas were analyzed for drug concentrations at the end of each experiment. Cytotoxicity of VVACV in comparison with val-acyclovir (VACV), ACV, and TFT was evaluated in cellular proliferation assays. RESULTS. The dipeptide prodrug VVACV demonstrated excellent activity against HSV-1 in the rabbit epithelial and stromal keratitis models: 1% VVACV was as effective as 1% TFT. The prodrug was also less cytotoxic than TFT, which is the only effective drug currently licensed and routinely used for topical treatment of ocular herpes infections in the United States. CONCLUSIONS. The less cytotoxic and highly water-soluble prodrug VVACV, which showed excellent in vivo activity against HSV-1 in rabbit epithelial and stromal keratitis, is a promising drug candidate for treatment of ocular HSV infections. (Invest

Expert Opinion on Biological Therapy, 2003

Membrane transporters/receptors are involved in drug transport processes and play a key role in i... more Membrane transporters/receptors are involved in drug transport processes and play a key role in intestinal absorption, tissue distribution and elimination. Drug targeting to specific transporters and receptors using carrier-mediated absorption has immense clinical significance. Ocular drug delivery is a challenging task since it involves drug transport across various barriers in the eye. Specialised transport processes exist at these barriers, which control the entry of drugs and xenobiotics. Ocular drug therapy involving topical or systemic administration of drugs has various limitations. Transport processes in the eye have been targeted in an effort to increase ocular bioavailability of drugs following topical instillation. This review discusses various transport processes in the eye and drug delivery strategies utilising these transporters/receptors.

Clinical Research and Regulatory Affairs, 2011

A rapid, simple, and sensitive liquid chromatography tandem mass spectrometric (LC-MS/MS) method ... more A rapid, simple, and sensitive liquid chromatography tandem mass spectrometric (LC-MS/MS) method for the determination of clopidogrel in human plasma was developed and validated using clopidogrel-d4 as the internal standard (IS). The analyte and the IS were ...

Angewandte Chemie International Edition, 2007

All reactions were conducted under nitrogen atmosphere using flame or ovendried glassware, unless... more All reactions were conducted under nitrogen atmosphere using flame or ovendried glassware, unless otherwise indicated. Methylene chloride was distilled from CaH 2. Toluene, THF and Et 2 O were distilled from sodium benzophenone ketyl.

Journal of Evolution of medical and Dental Sciences, 2014

INTRODUCTION: Diarrhoea is defined as passage of loose, liquid or watery stools. In the developin... more INTRODUCTION: Diarrhoea is defined as passage of loose, liquid or watery stools. In the developing countries, diarrhoea remains a wet season disease with bacteria playing a greater role. The agents responsible for infantile diarrhoea may be bacteria, viruses, parasites, malnutrition and drugs. Infectious agents that cause diarrhoeal disease are usually spread by the fecal-oral route. Escherichia coli (E. coli) is a gram-negative bacillus that may be found in the normal intestinal flora of humans and animals, but can also be an important cause of enteric illness. Our present study is an attempt to fulfil this vacuum and investigate the most common pathogens causing these diseases amongst patients in and around a tertiary care hospital of eastern Bihar, with special reference to the serotypes of Escherichia coli. MATERIAL AND METHODS: Samples were collected from both male and female patients below five years of age, admitted to the Pediatrics Department, with complains of diarrhoea an...

Journal of Membrane Science and Research, 2018

Zirconia ultrafiltration membranes are widely developed and used for past several years. But the ... more Zirconia ultrafiltration membranes are widely developed and used for past several years. But the conventional sol-gel methods of zirconia membrane preparation involve many steps. In the present study an attempt was made to develop defect free zirconia ultrafiltration (UF) membrane in single step coating of zirconia nanopowder suspension by slip casting method over multichannel ceramic support. The porous support was made from a novel composition of clay and α-alumina having 19-channels circular configuration. Zirconia UF membrane was developed at the inner surface of the support up to 0.2 m length. Membrane had a mean pore diameter of 40 nm. Clean water permeability of 48 lm-2h-1bar-1 was obtained for the membrane under cross-flow filtration mode. Membrane was utilized for treatment of industrial and domestic wastewater. Membrane treated water was characterized to evaluate the reduction of organic and inorganic contaminants. About 82% and 92% removal of COD were obtained for tannery...

Indian Journal of Medical Microbiology, 2021

BACKGROUND Conjunctivitis is one of the most common nontraumatic eye complaints and is one of the... more BACKGROUND Conjunctivitis is one of the most common nontraumatic eye complaints and is one of the most frequently reported diseases in the outpatient and emergency departments. Bacterial conjunctivitis has been reported as one of the most common type of infectious conjunctivitis after viral infections. It is also considered as the primary cause of acute conjunctivitis in children. This study was conducted to isolate and identify organisms causing bacterial conjunctivitis and to determine their in vitro susceptibility or resistance. METHODS This descriptive study was conducted in the Departments of Ophthalmology and Microbiology at Katihar Medical College from December 2018 to May 2020. Sociodemographic and clinical data were collected from 175 patients using structured questionnaire. External ocular specimens were collected using sterile swabs and inoculated on blood agar, MacConkey’s agar and chocolate agar. Presumptive isolates were further identified by a series of biochemical tests. All isolated organisms were tested for their in vitro antimicrobial susceptibility against various antibiotics using the Kirby-Baur disk diffusion method. RESULTS A total of 175 samples were collected, out of which, 62.8 % (110 / 175) showed growth of bacteria. Maximum cases of bacterial conjunctivitis were seen in the age group 11 - 20 years. The male to female ratio was 2.7:1. Maximum frequency of bacterial conjunctivitis was observed from May to September. Staphylococcus aureus was the most common bacteria isolate 65.5 % (72 / 110) followed by Staphylococcus epidermidis 19.1 % (21 / 110). Most of the Staphylococcus aureus isolates were found to be sensitive to moxifloxacin 98.6 % (71 / 72) and gentamicin 95.8 % (69 / 72). 25 % (18 / 72) of Staphylococcus aureus strains were found to be resistant to cefoxitin and were considered as methicillin-resistant Staphylococcus aureus (MRSA) strains. Maximum numbers of gram-negative strains were sensitive to moxifloxacin 100.0 % (9 / 9) followed by tobramycin 88.9 % (8 / 9). Pseudomonas aeruginosa strains showed maximum sensitivity to moxifloxacin 100.0 (8 / 8) followed by ofloxacin and ciprofloxacin 62.5 % (5 / 8). CONCLUSIONS This study provides an insight into the organisms isolated from cases of bacterial conjunctivitis in Katihar District of Bihar. Determining the susceptibility pattern of these pathogens to available antibiotics is crucial for effective management of bacterial conjunctivitis especially when treatment has to be given empirically. KEY WORDS Bacterial Conjunctivitis, Antibiogram

TP26. TP026 DIAGNOSIS, ASSESSMENT, AND PROGNOSIS OF FIBROTIC ILD, 2021

Journal of Radioanalytical and Nuclear Chemistry, 2020

In order to develop radiation resistant membranes for the treatment of high level waste (HLW), ce... more In order to develop radiation resistant membranes for the treatment of high level waste (HLW), ceramic tubular membranes were prepared by incorporating varying amounts of ammonium molybdophosphate (AMP), known for efficient Cs(I) uptake from acidic feeds, for the recovery of radio-caesium. The sorption of Cs(I) onto the membrane increased linearly with increasing the AMP content (10%-40%). Radiation stability of the membranes was evaluated by exposing them to gamma radiation obtained from a 60 Co source. The composite ceramic material showed excellent radiation stability without any morphological change up to 1100 kGy, indicating its potential application in radioactive waste treatment. For 10% AMP loaded ceramic membrane, the Cs(I) sorption decreased linearly with radiation dose. However, Cs sorption was not altered up to 1100 kGy dose for 20% and 40% loaded AMP.

Transactions of the Indian Ceramic Society, 2019

ABSTRACT Dispersion of zirconia powder in aqueous suspension using suitable dispersant for coatin... more ABSTRACT Dispersion of zirconia powder in aqueous suspension using suitable dispersant for coating application was studied. Zeta potential experiments were conducted in search of stable suspensions. Sedimentation tests were carried out in both acidic and basic pH range, i.e. from 2 to 11. Zirconia slurry as coating material was used for coating on clay-alumina tubular ceramic support. The slurry was composed of zirconia nano powder, water, dispersant and organic binder. Z irconia nano powders were characterized by XRD, surface area by multipoint BET and TEM. The effect of dispersant concentration on zeta potential of zirconia suspension and effect of pH, sedimentation rate and rheology (viscosity) of zirconia suspension were studied. The coated tubes were air dried and sintered in furnace at 700°C for 2 h. The prepared UF membrane was subjected to characterization in terms of permeability, FESEM, molecular weight cut off, etc. The UF membrane was used for separation of two types of water – effluent A (kitchen sink wastewater) and effluent B (surface water of a lake). The membrane was effective to remove the pathogenic organisms, organic load in terms of BOD, COD, etc. The treated water may be reused in agriculture or industrial purposes. GRAPHICAL ABSTRACT

Journal of Evolution of Medical and Dental Sciences, 2017

BACKGROUND Injuries secondary to severe burns rank among the most serious forms of trauma resulti... more BACKGROUND Injuries secondary to severe burns rank among the most serious forms of trauma resulting in anatomic, physiologic, endocrinologic and immunologic stress, especially when burns involve more than 20% of Total Body Surface Area (TBSA). In patients surviving the initial burn and resuscitative phase, infections are a leading cause of mortality. The burnt surface is sterile immediately following thermal injury but after 48 hours the wound is colonised with skin pathogens that typically reside in sweat glands and hair follicles before the burn. After 5 to 7 days, wounds become colonised with yeast and/or Gram-positive and Gram-negative organisms from the host's intestinal and upper respiratory tracts, or from the hospital environment and health care workers' hands. MATERIALS AND METHODS Surface swabs were collected from 200 patients with burn wound infection of both sexes and all age groups. The microorganisms were identified as per standard protocol based on colony morphology; Gram's staining findings and biochemical tests. ESBL (Extended Spectrum Beta-lactamases) detection was done using PCDDT (Phenotypic Confirmatory Disc Diffusion Test). RESULTS A total of 268 organisms were isolated from 200 samples. Out of the 268 isolates, 213 (79.48%) were Gram-negative bacilli, 42 (15.67%) were Gram-positive cocci and 13 (4.85%) were fungi. Among the Gram-negative bacilli, Pseudomonas aeruginosa was the most common bacteria isolated at 45.15% (121/268). The isolates exhibited maximum resistance to 3 rd generation cephalosporins with good response to piperacillin/tazobactam and carbapenems. Among all the Gram-negative bacilli, 30.99% (66/147) were ESBL producers. CONCLUSION The study showed that burn wound infection was more common in females than males. Majority of cases had a burn sustained from an open flame, mostly in winters. Gram-negative bacilli were the predominant isolates (80%) from patients with burn wound infection. Fungi were isolated in about 5% of cases. Pseudomonas aeruginosa was the commonest isolate (45%). Amongst the Gram-positive cocci, staphylococci and enterococci were isolated consistently from patients.

Journal of Evolution of Medical and Dental Sciences, 2017

BACKGROUND Staphylococcus aureus is notorious for its ability to become resistant to antibiotics.... more BACKGROUND Staphylococcus aureus is notorious for its ability to become resistant to antibiotics. MRSA emerged as nosocomial pathogen in the early 1960s. Methicillin Resistant Staphylococcus aureus (MRSA) are implicated in serious infections and nosocomial infection outbreaks. These strains show resistance to a wide range of antibiotics, thus limiting the treating options to very few agent s such as vancomycin and teicoplanin. Vancomycin has been regarded as the first-line drug for treatment of MRSA. At the same time, there has been an increase in the use of this antibiotic for other infections as well. This has further lead to an increase in the number of both Vancomycin Intermediate Staphylococcus aureus (VISA) and Vancomycin Resistant Staphylococcus aureus (VRSA). Aims-To determine the presence of MRSA and VRSA among staphylococcal isolates in Eastern Bihar. MATERIALS AND METHODS A total of 10806 samples from patients attending inpatient and outpatient departments from January 2011 to April 2013 were included in the study. Samples were processed as per standard protocol and antibiotic susceptibility testing was done by modified Kirby-Bauer method. Isolates were tested by disc diffusion using oxacillin disc 1 µg, cefoxitin disc 30 µg and by agar dilution for MRSA. VRSA isolates were tested using 30 µg vancomycin disc. MIC of vancomycin to Staphylococcus aureus was determined by agar dilution method. RESULTS Out of a total of 633 Staphylococcus aureus isolates, 22.4% were found to be methicillin resistant, 9.95% were VISA and 3.79% were VRSA. Results of oxacillin agar dilution method were in concordance with the cefoxitin disc diffusion method in detecting MRSA strains. All VISA strains were sensitive to linezolid and all VRSA were sensitive to imipenem. 88.7% and 87.3% of all MRSA isolates were sensitive to imipenem and linezolid respectively. CONCLUSION The present shows that antibiotic resistance is steadily on the rise. It is also quite clear that MRSA is acquiring resistance to drugs like rifampicin, teicoplanin, amikacin, netilmicin and imipenem which were at one time used as an alternative to vancomycin. It is therefore imperative for the medical community to work together to fight against this man-made phenomenon called antibiotic resistance.

Respiratory Research, 2016

Small airway fibrosis is the main contributor to physiological airway dysfunction in COPD. One po... more Small airway fibrosis is the main contributor to physiological airway dysfunction in COPD. One potential mechanism contributing to small airway fibrosis is epithelial mesenchymal transition (EMT). When associated with angiogenesis (so called EMT-Type-3) it may well also be the link with the development of airway epithelial cancer, which is closely associated with COPD and predominantly in large airways. In a recent study published in Respiratory Research, Reimann and colleagues, showed increased expression of S100A4 in vasculature of human COPD and murine lungs. It is quite possible that the process of endothelial to mesenchymal transition (EndMT) is active in COPD lungs which we wish to comment on.

Science Advances, 2015

Enzymes lead to the discovery of new, shape-tunable ligands for controlling catalytic chemistry.

Natural Product Research, 2009

Thin layer chromatography bioautography (using DPPH spray reagent) guided fractionation of Glycyr... more Thin layer chromatography bioautography (using DPPH spray reagent) guided fractionation of Glycyrrhiza glabra led to the isolation of two caffeic acid derivative esters, viz. eicosanyl caffeate (1) and docosyl caffeate (2). The two compounds exhibited potent elastase inhibitory activity, with IC(50) values of 0.99 microg mL(-1) and 1.4 microg mL(-1) for 1 and 2, respectively. The compounds also showed moderate antioxidant activity in DPPH and ABTS scavenging assays. The results indicate a possible role of caffeic acid derivatives, in addition to flavonoids in the anti-ulcer properties of G. glabra.

Journal of the American Chemical Society, 2005

Combinatorial methods have made an important impact on catalyst discovery in recent years. 1 Nota... more Combinatorial methods have made an important impact on catalyst discovery in recent years. 1 Notable examples include the discovery of catalysts for asymmetric acylation 2a and Stetter-type chemistry, 2b,c Pd(0)-2d and Cu(I)-mediated 2e allylic alkylations, Agbased carbene insertion, 2f FeCl 2-mediated epoxidation, 2g and early transition-metal-based additions to imines. 2h,i These successes have spurred interest in catalyst screening. 3 Screens for active lead catalysts, based upon IR thermography, 4a,b fluorescence, 4c-f and dye formation 4g /bleaching 4h have been reported. Particularly valuable

Journal of Pharmaceutical Sciences, 2001

The purpose of this study is to assess the permeability of acyclovir (ACV) prodrugs through the r... more The purpose of this study is to assess the permeability of acyclovir (ACV) prodrugs through the rabbit corneal cell line (SIRC) as well as the cornea, and characterize the SIRC cell line for transport and metabolism studies of ester prodrugs. Prodrug derivatization of an acycloguanosine antiviral agent, acyclovir, was employed to improve its permeability across the cornea. New Zealand albino rabbits were used as an animal model for corneal studies. The SIRC cell line grown on polyester membranes was used for transport of these prodrugs. SIRC cells grown on the membrane support for 10 days developed four to six layers of epithelial cells, and this is comparable to the normal rabbit corneal epithelial layer. Transport experiments were conducted across the rabbit cornea and con¯uent SIRC cells using side-by-side diffusion-cell apparatus. Enzymatic hydrolysis of these compounds was evaluated in SIRC cell lysates. Appropriate reversed phase HPLC method(s) were employed for quantitation of both the prodrug and ACV simultaneously. Corneal permeabilities of some of these prodrugs (Malonyl ACV and Acetyl ACV) were higher relative to ACV. The SIRC cell line permeability values of all the prodrugs were higher compared to that of the intact cornea. The total amount of ACV-prodrugs transported, i.e., unhydrolyzed prodrugs and regenerated ACV, across the SIRC cell line was more relative to ACV. Hydrolytic studies in the SIRC cell line homogenate demonstrated the bioreversion potential of the prodrugs and the presence of enzymes, particularly the cholinesterase in the SIRC cell line. It may be concluded that the SIRC cell line is leakier compared to the cornea. Keeping in mind the limitations, the SIRC cell line after further characterization may be used for transport and metabolism studies of ester prodrugs.

Journal of the American Oil Chemists' Society, 2014

An indigenously developed low‐cost clay‐alumina‐based ceramic microfiltration membrane of 19‐chan... more An indigenously developed low‐cost clay‐alumina‐based ceramic microfiltration membrane of 19‐channel configuration has been evaluated for degumming, dewaxing and deacidification of rice bran oil (RBO) miscella having different oil contents at pilot scale. Rice bran wax and soap particles in miscella will aggregate with changes in temperature. This suggests a technique for their effective separation. Low‐temperature cross‐flow membrane filtration was used for single‐stage degumming‐dewaxing and showed 70 % and 80 % removal of acetone insoluble residue from two RBO miscella samples, respectively. Color reduction was 50 %, and oryzanol retention was 70 %. NaOH was used for deacidification in a 10 % excess of that required based on the free fatty acid content in oil. This reduced free fatty acids to 0.2 %. Operating for 10 h with a 0.7 bar trans‐membrane pressure, permeate fluxes of 15 and 8 L/m2 hr were obtained for the degumming‐dewaxing and deacidification operations, respectively. T...

Investigative Opthalmology & Visual Science, 2003

PURPOSE. A dipeptide prodrug of the antiviral nucleoside acyclovir (ACV), val-val-ACV (VVACV), wa... more PURPOSE. A dipeptide prodrug of the antiviral nucleoside acyclovir (ACV), val-val-ACV (VVACV), was evaluated in vivo as a potential drug candidate for improving antiviral efficacy against herpetic epithelial and stromal keratitis. METHODS. The effect of 1% VVACV on epithelial keratitis induced by inoculation of HSV-1 strain McKrae (25 L of 10 5 plaque-forming units [PFU]) in the scarified rabbit cornea and stromal keratitis induced by intrastromal injection of HSV-1 strain RE (10 L of 10 5 PFU) was compared with that of 1% trifluorothymidine (TFT) and balanced salt solution as the vehicle control. Both eyes of 10 rabbits were used in each treatment group. Lesions were evaluated by slit lamp examinations over a 2-week period after infection. Aqueous humor samples and corneas were analyzed for drug concentrations at the end of each experiment. Cytotoxicity of VVACV in comparison with val-acyclovir (VACV), ACV, and TFT was evaluated in cellular proliferation assays. RESULTS. The dipeptide prodrug VVACV demonstrated excellent activity against HSV-1 in the rabbit epithelial and stromal keratitis models: 1% VVACV was as effective as 1% TFT. The prodrug was also less cytotoxic than TFT, which is the only effective drug currently licensed and routinely used for topical treatment of ocular herpes infections in the United States. CONCLUSIONS. The less cytotoxic and highly water-soluble prodrug VVACV, which showed excellent in vivo activity against HSV-1 in rabbit epithelial and stromal keratitis, is a promising drug candidate for treatment of ocular HSV infections. (Invest

Expert Opinion on Biological Therapy, 2003

Membrane transporters/receptors are involved in drug transport processes and play a key role in i... more Membrane transporters/receptors are involved in drug transport processes and play a key role in intestinal absorption, tissue distribution and elimination. Drug targeting to specific transporters and receptors using carrier-mediated absorption has immense clinical significance. Ocular drug delivery is a challenging task since it involves drug transport across various barriers in the eye. Specialised transport processes exist at these barriers, which control the entry of drugs and xenobiotics. Ocular drug therapy involving topical or systemic administration of drugs has various limitations. Transport processes in the eye have been targeted in an effort to increase ocular bioavailability of drugs following topical instillation. This review discusses various transport processes in the eye and drug delivery strategies utilising these transporters/receptors.

Clinical Research and Regulatory Affairs, 2011

A rapid, simple, and sensitive liquid chromatography tandem mass spectrometric (LC-MS/MS) method ... more A rapid, simple, and sensitive liquid chromatography tandem mass spectrometric (LC-MS/MS) method for the determination of clopidogrel in human plasma was developed and validated using clopidogrel-d4 as the internal standard (IS). The analyte and the IS were ...

Angewandte Chemie International Edition, 2007

All reactions were conducted under nitrogen atmosphere using flame or ovendried glassware, unless... more All reactions were conducted under nitrogen atmosphere using flame or ovendried glassware, unless otherwise indicated. Methylene chloride was distilled from CaH 2. Toluene, THF and Et 2 O were distilled from sodium benzophenone ketyl.