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Biomedical subjects

M Verma

Publications and source records attributed to M Verma.

At least 19 recordsLinked to original sources
PubMed2006

Bacillus thuringiensis fermentation of hydrolyzed sludge--rheology and formulation studies.

Rheology of Bacillus thuringiensis fermentation of hydrolyzed sludge was investigated in bench scale fermenter. Stable liquid formulations were developed and optimized for two-year based studies comprising various physical/chemical (viscosity, particle size, corrosion and suspendibility) and biological (microbial contamination, viable spores and entomotoxicity) parameters at different pHs and temperatures. The hydrolyzed sludge depicted non-Newtonian and pseudoplastic behaviour during fermentation with 90% to 96% confidence of fits into Casson, Power and IPC paste models. Higher values of consistency and flow index during exponential growth and stationary phase, respectively, affected downstream processing. The power law was also followed by stable formulations. Sorbitol, sodium monophosphate and sodium metabisulfite (2.2:1:1) as suspending agents produced suspendibility ranging from 69% to 94%. The stable formulation (FH-4) comprising sorbitol, sodium monophosphate and sodium metabisulfite deteriorated at pHs 6, 6.5 and temperatures, 40 and 50 degrees C, with no signs of corrosion and microbial contamination. The viscosity of FH-4 formulations decreased with shear rate which could improve handling and consequent spraying.

Bacillus thuringiensis↗
PubMed2006

Starch industry wastewater as a substrate for antagonist, Trichoderma viride production.

Starch industry wastewater was investigated to assess and improve its potential as a raw material for the conidia production of biocontrol fungi, Trichoderma viride. The wastewater was tested with and without supplements of glucose, soluble starch, meat peptone and probable conidiation inducer chemicals in shake flask culture. Addition of complex carbon source (soluble starch, 1% and 2% w/v) produced maximum conidia ( approximately 3.02 and 4.2 x 10(10)CFU/mL, respectively). On the other hand, glucose addition as a simpler carbon source was either ineffective or, reduced conidia production (from 1.6 x 10(8) in control to 3.0 x 10(7)CFU/mL in 5% w/v glucose supplement). Supplement of nitrogen source showed a small increase of conidia concentration. Propionic, maleic and humic acids, EDTA, pyridine, glycerol and CaCO(3) were examined as probable conidiation inducers and showed effect only on initial rate of conidiation with no increase in final conidia concentration. Intra and extracellular ATP correlation with spore production showed dependence on growth media used and conidia concentration at the end of fermentation. Addition of carbon and nitrogen sources showed an increase in protease activity (from 0.4985 to 2.43 IU/mL) and entomotoxicity (from 10448 to 12335 spruce budworm unit (SBU)/microL). Entomotoxicity was improved by 11% in fermenter over shake flask when starch industry wastewater was supplemented with meat peptone.

Animals↗
PubMed2006

Dissolved oxygen as principal parameter for conidia production of biocontrol fungi Trichoderma viride in non-Newtonian wastewater.

Dissolved oxygen (DO) concentration was selected as a principal parameter for translating results of shake flask fermentation of Trichoderma viride (biocontrol fungi) to a fermenter scale. All fermentations were carried out in a 7.5 l automated fermenter with a working volume of 4 l. Fermentation performance parameters such as volumetric oxygen transfer coefficient (k (L) a), oxygen uptake rate (OUR), rheology, conidia concentration, glucose consumption, soluble chemical oxygen demand, entomotoxicity and inhibition index were measured. The conidia concentration, entomotoxicity and inhibition index were either stable or improved at lower DO concentration (30%). Variation of OUR aided in assessing the oxygen supply capacity of the fermenter and biomass growth. Meanwhile, rheological profiles demonstrated the variability of wastewater during fermentation due to mycelial growth and conidiation. In order to estimate power consumption, the agitation and the aeration requirements were quantified in terms of area under the curves, agitation vs. time (rpm h), and aeration vs. time (lpm h). This simple and novel strategy of fermenter operation proved to be highly successful which can be adopted to other biocontrol fungi.

Animals↗
PubMed2006

Efficient centrifugal recovery of Bacillus thuringiensis biopesticides from fermented wastewater and wastewater sludge.

Studies were conducted on harvesting of Bacillus thuringiensis (Bt)-based biopesticides from fermented broths of starch industry wastewater (SIW), wastewater sludge (raw and hydrolyzed-NH and TH, respectively) and semi-synthetic soyameal to enhance entomotoxicity (Tx) by centrifugation. Pertinent factors influencing Tx, solids concentration, pH, temperature and centrifugal force were investigated. The centrifugate solids concentration beyond 100 g/l did not enhance Tx, instead caused pellet formation. Centrifugation efficiency (Tx recovery) was higher at pH 4, and temperature 20 degrees C for starch wastewater (98%), wastewater sludge (98% and 97.8% for non-hydrolyzed and hydrolyzed, respectively) and soya broth (83%). For maximum Tx recovery (SIW-95%; NH-90%; TH-98% and soya-78%), the centrifugal force and time required was 48,000 g and 30 min, respectively. Losses in recovery efficiency were lower for SIW and wastewater sludge in comparison to soya on adopting commercially recommended centrifugal force of 9000 g. The settling velocity computations for different fermented broths enabled calculation of Sigma factor for continuous commercial centrifuge of a given capacity and hence simulation of power requirements. It was established that power requirements for a given Tx recovery efficiency were highest for conventional medium (soya) in comparison to other waste-based fermented broths.

Bacillus thuringiensis↗
PubMed2006

Screening of different adjuvants for wastewater/wastewater sludge-based Bacillus thuringiensis formulations.

Screening of different adjuvants, namely, suspending agents, phagostimulants, stickers, antimicrobial agents, and UV screens to develop aqueous biopesticidal suspensions of Bacillus thuringiensis (Bt) variety kurstaki HD-1 fermented broths, specifically, nonhydrolyzed sludge, hydrolyzed sludge, starch industry wastewater, and soya (commercial medium), were investigated. The selected suspending agents [20% (wt:vol)] included sorbitol, sodium monophosphate, and sodium metabisulfite with corresponding suspendibility of 74-92, 69-85, and 71-82%, respectively. Molasses [0.2% (wt:vol)] increased adherence by 84-90% for all fermented broths. The optimal phagostimulants [0.5% (wt:vol)], namely, soya and molasses, caused entomotoxicity increase of 3-13 and 7-13%, respectively. Sorbic and propionic acids showed high antimicrobial action [0.5% (wt:vol)], irrespective of fermentation medium. Sodium lignosulfonate, molasses, and Congo red, when used as UV screens [0.2% (wt:vol)], showed percent corresponding entomotoxicity losses of 3-5, 0.5-5 and 2-16, respectively. The Bt formulations, when exposed to UV radiation, showed higher half-lives (with and without UV screens) than the fermented broths or semisynthetic soya medium and commercial Bt formulation. UV screen-amended nonhydrolyzed, hydrolyzed, and starch industry wastewater formulations showed 1.3-1.5-fold higher half-lives than commercial Bt formulation. Thus, the recommended formulation comprises sorbitol, sodium monophosphate, sodium metabisulfite (suspending agents); molasses, soya flour (phagostimulants); molasses and skimmed milk powder (rainfasteners); sorbic and propionic acids (antimicrobial agents) and sodium lignosulfate; and molasses and Congo red (UV screens). These waste-based Bt formulations offer better UV resistance in comparison with commercial formulation.

Adhesives↗
PubMed2005

Sludge based Bacillus thuringiensis biopesticides: viscosity impacts.

Viscosity studies were performed on raw, pre-treated (sterilised and thermal alkaline hydrolysed or both types of treatment) and Bacillus thuringiensis (Bt) fermented sludges at different solids concentration (10-40 g/L) for production of biopesticides. Correlations were established among rheological parameter (viscosity), solids (total and dissolved) concentration and entomotoxicity (Tx) of Bt fermented sludges. Exponential and power laws were preferentially followed by hydrolysed fermented compared to raw fermented sludge. Soluble chemical oxygen demand variation corroborated with increase in dissolved solids concentration on pre-treatments, contributing to changes in viscosity. Moreover, Tx was higher for hydrolysed fermented sludge in comparison to raw fermented sludge owing to increased availability of nutrients and lower viscosity that improved oxygen transfer. The shake flask results were reproducible in fermenter. This study will have major impact on selecting fermentation, harvesting and formulation techniques of Bt fermented sludges for biopesticide production.

Animals↗
PubMed2005

Cell agglomeration in acidogenic, mixed, and methanogenic cultures at different loading and mixing conditions.

Cell agglomeration studies were conducted in anaerobic fluidized bed reactors without any external support. Granulation was studied at different combinations of loading and mixing conditions utilizing synthetic wastewater. Both single-stage and two-stage biomethanation processes were studied. Reactors of volume 0.55, 10, and 16 l were operated with height to diameter ratio of 7-8. It was found that the acidogens were more liable to form granules among mixed culture of anaerobes, while the methanogens were capable of forming cell agglomerates in the form of flocs. In acidogenic granules, rod shaped bacteria were dominating, while in case of methanogens, there were more cocci. It was found that for an upflow liquid linear velocity upto 2.0 m h(-1), acidogens showed very good granulation but at relatively higher values of upflow liquid linear velocities granulation was affected adversely, causing breakage and dissociation of granules. In the case of methanogens and mixed process, it was found that upflow liquid linear velocities up to 4.0 m h(-1) were suitable and biomass flocs were actively growing. The maximum organic loadings applied were 39.0 and 54.4 kg COD m(-3) d(-1) (at 27.3 and 35.36 kg COD m(-3) d(-1) degradation respectively) for single-stage and two-stage biomethanation respectively.

Bacteria, Anaerobic↗
PubMed2005

Starch industry wastewater-based stable Bacillus thuringiensis liquid formulations.

Liquid formulations were developed from Bacillus thuringiensis (Bt)-fermented broths of starch industry wastewater (SIW) and of soya medium. Stability studies were carried out for 1 yr. Storage stability was tested by studying various physical and chemical (e.g., viscosity, particle size, corrosion, and suspendibility) and biological (e.g., microbial contamination, viable spores, and entomotoxicity) parameters at different pH levels and temperatures. Three suspending agents, sorbitol, sodium monophosphate, and sodium metabisulfite, were added to fermented broth in different concentrations. Sorbitol and sodium monophosphate in the ratio 3:1 was the best suspending agent combination for both formulations. Starch industry wastewater fermentation yielded cell and viable spore counts 10- and 4-fold greater than those from soya medium, respectively, and a 1.7-fold increase in entomotoxicity. However, both formulations started deteriorating at pH 6 and 6.5 and 40 and 50 degrees C. There were no signs of corrosion and microbial contamination in both types of formulations.

Animals↗
PubMed2004

Biomarkers for risk assessment in molecular epidemiology of cancer.

One out of four deaths in the USA is due to cancer. Identification of populations at risk of developing cancer is important as it provides opportunities for prevention and treatment of cancer. Biomarkers are measurable indicators of exposure effects and susceptibility or disease state, and are used to understand the mechanisms of cancer progression. In recent molecular epidemiology studies genomic, proteomic, and epigenomic markers have been utilized which exhibit high sensitivity and specificity for different tumor types and can be assayed in biofluids and other specimens collected by non-invasive technologies. The current challenges and future directions in the field are discussed in this article.

Biomarkers, Tumor↗
PubMed2004

Development of sludge based stable aqueous Bacillus thuringiensis formulations.

This study focuses on development of aqueous flowable (suspension) formulations for Bacillus thuringiensis (Bt) based biopesticides from wastewater sludge. Different inerts like sorbitol, sodium monophosphate, sodium metabisulphite, sorbic acid, propionic acid, Tween-80, Triton X-100 and glycerol were tested for formulations. Five different formulations for non-hydrolyzed (NH) secondary sludges were tried and the best combination selected on the basis of various physical parameters like viscosity, particle size, suspendibility, entomotoxicity, and microbiological purity tests. F5 formulations (for secondary sludge) comprising sorbitol, sodium monophosphate and sodium metabisulphite gave better physical and biological characteristics with a small effect on entomotoxicity and spore concentration after 120 days at pH 6, 6.5 and temperatures 40 and 50 degrees C and viscosity change at 40 and 50 degrees C. The formulations were more stable at pH 4.0 to 5.0 and temperatures 4 to 30 degrees C whereas at pH 6.0 and 6.5 and temperatures 40 and 50 degrees C, there was degeneration of the product. Lower proteolytic activity and physical factors like ionic strength and surface group changes at pH 6 and 6.5 were responsible for the instability of the formulation.

Bacillus thuringiensis↗
PubMed2003

Virtual reality simulator for vitreoretinal surgery.

AIM: To develop computer simulation of steps in vitreoretinal surgery using virtual reality technology. MATERIAL AND METHODS: A workstation with three-dimensional position tracking stylus was attached to a Pentium II desktop PC with a graphic accelerator. Computer algorithms were developed using Open GL and Microsoft Visual C++ languages to control the interaction and update the visual feedback tracking the instruments. Soft tissue computer modelling was carried out to mimic the removal of a vitreous opacity. Lens touch with the instruments was also detected. Mathematical modelling to allow for lens distortion was taken into account. RESULTS: A virtual reality computer model has been developed that can simulate initial steps of vitreoretinal surgery. Soft tissue modelling of the vitreous opacity and its removal by the vitrector was successfully simulated. The movements of the active and passive instruments in the dummy eye corresponded to the movements on the computer screen. On evaluation of the system, there was a minimal but discernable time lag between the stylus movement and the visual feedback. There was no tactile feedback when the lens touch was simulated. No further complex vitreoretinal surgery simulation was possible at this stage.

Algorithms↗
PubMed2001

Prevalence of behavioral problems in school going children.

The study was conducted on 957 school children using Rutter B scale which was to be completed by the class teachers in Ludhiana, India. One hundred and forty-one children (14.6%) scored more than 9 points and were included in the second part of the study. An equal number of sex matched children scoring less than 9 points served as controls. Both these groups were called for an interview with a child psychiatrist along with their parents. Only 117 and 124 children turned up and were included in the analysis. Based on the screening instrument results and parental interview, 45.6% of the children were estimated to have behavioural problems, of which 36.5% had significant problems. It was noticed that neither the screening instrument nor the interview was able to detect all the problems. Scholastic under-achievement was found to be associated with maximum problems. Scholastic under-achievement can be a useful starting point of identifying children with behavioural problems. Close cooperation between school teachers, parents, and health care providers is essential to ensure healthy development of children.

Child↗
PubMed2001

Prevalence and natural history of subclinical hepatic encephalopathy in cirrhosis.

BACKGROUND AND AIMS: The natural history of subclinical hepatic encephalopathy (SHE) is unknown. The present study was conducted to study the prevalence and the natural history of SHE in patients with cirrhosis of the liver. METHODS: One hundred and sixty-five patients with cirrhosis of the liver were studied. A total of nine psychometric tests (trail making and Wechsler adult intelligence scale-performance (WAIS-P) tests) were administered. Subclinical hepatic encephalopathy was present if two or more psychometric tests were abnormal. Seventy-two patients (SHE 40, without SHE 32) also underwent serial psychometric testing on follow-up visits at 6-8 week intervals. RESULTS: Subclinical hepatic encephalopathy was present in 103 (62.4%) patients. The number and figure connection, block design and picture completion tests were the most useful in the detection of SHE. Severity of SHE, as assessed by the number of abnormal tests, was greater in patients with more severe liver disease. During follow up, SHE tended to persist or worsen in patients with poorer liver function. Although other clinical complications were similar in different groups, overt hepatic encephalopathy developed more commonly in those patients who had SHE at entry compared to those who did not (22.6 vs 5.6%, P = 0.044). Among the patients with SHE, the development of overt hepatic encephalopathy was more common in patients with Child's score of > 6 than with Child's score of <or= 6 (40 vs 5%, P = 0.019). CONCLUSIONS: We conclude that SHE is common in cirrhosis. The natural history of SHE is worse in patients with advanced cirrhosis and SHE probably predisposes the cirrhotic patient to overt hepatic encephalopathy.

Adult↗
PubMed2001

Behavioral problems in school-going children: implications for medical teachers in developing countries.

A large number of children suffer from behavioral problems during their development. Many of these problems are transient and may not even be noticed. At times, however, the extent of these problems and their overall effects on a child's development can be serious (Morita et al., 1993). Further, children may exhibit these behaviors in one setting and not in others (e.g. at home or in school, but not both). In developed countries, parents tend to seek advice for even minor problems, such as persistent thumb sucking, while in developing countries, major problems, even childhood schizophrenia, may go unattended. An awareness of the prevalence of these problems is important so that appropriate mental health services can be planned and provided for affected children, to improve their prospects for leading healthy, productive lives. Such awareness can help enhance the teaching of graduate doctors, equipping them to deal with these problems effectively.

Journal Article↗
PubMed2001

Proteomic approaches within the NCI early detection research network for the discovery and identification of cancer biomarkers.

In the postgenome era, proteomics provides a powerful approach for the analysis of normal and transformed cell functions, for the identification of disease-specific targets, and for uncovering novel endpoints for the evaluation of chemoprevention agents and drug toxicity. Unfortunately, the genomic information that has greatly expounded the genetic basis of cancer does not allow an accurate prediction of what is actually occurring at the protein level within a given cell type at any given time. The gene expression program of a given cell is affected by numerous factors in the in vivo environment resulting from tissue complexity and organ system orchestration, with cells acting in concert with each other and responding to changes in their microenvironment. Repositories of genomic information can be considered master "inventory lists" of genes and their maps, which need to be supplemented with protein-derived information. The National Cancer Institute's Early Detection Research Network is employing proteomics, or "protein walking", in the discovery and evaluation of biomarkers for cancer detection and for the identification of high-risk subjects. Armed with microdissection techniques, including the use of Laser Capture Microdissection (LCM) to procure pure populations of cells directly from human tissue, the Network is facilitating the development of technologies that can overcome the problem of tissue heterogeneity and address the need to identify markers in easily accessible biological fluids. Proteomic approaches complement plasma-based assays of circulating DNA for cancer detection and risk assessment. LCM, coupled with downstream proteomics applications, such as two-dimensional polyacrylamide gel electrophoresis and SELDI (surface enhanced laser desorption ionization) separation followed by mass spectrometry (MS) analysis, may greatly facilitate the characterization and identification of protein expression changes that track normal and disease phenotypes. We highlight recent work from Network investigators to demonstrate the potential of proteomics to identify proteins present in cancer tissues and body fluids that are relevant for cancer screening.

Biomarkers, Tumor↗
PubMed2001

Biomarkers for early detection of colon cancer.

There is an increasing demand for biomarkers in colon cancer for risk assessment, early detection, prognosis, and surrogate end points. A number of biomarkers have been identified for early detection of colon cancer, although the risk factors have not been identified extensively. The major advances in understanding colorectal cancer include the identification and the involvement of APC, p53, and Ki-ras in the development and progression of the disease, the identification of the aberrant crypt foci as an early preinvasive lesion, and its relation to the development of cancer. Detecting malignant neoplasms in the early stages offers clinical advantages; therefore, the National Cancer Institute has established an Early Detection Research NETWORK: The emphasis of the network is on translational research and collaboration among scientists.

Adenoma↗
PubMed2001

Deposition of 7-aminoflunitrazepam and flunitrazepam in hair after a single dose of Rohypnol.

In recent years, there has been a notable increase in the number of reports on drug-facilitated sexual assault. Benzodiazepines are the most common so-called "date-rape" drugs, with flunitrazepam (Rohypnol) being one of the most frequently mentioned. The aim of this study was to determine whether flunitrazepam and its major metabolite 7-aminoflunitrazepam could be detected in hair collected from ten healthy volunteers after receiving a single 2 mg dose of Rohypnol using solid phase extraction and NCI-GC-MS. Such data would be of great importance to law enforcement agencies trying to determine the best time interval for hair collection from a victim of drug-facilitated sexual assault in order to reveal drug use. Ten healthy volunteers (eight women and two men, 21 to 49 years old) participated in the study. The following hair samples were collected from each volunteer: one before flunitrazepam administration, and 1, 3, 5, 14, 21, and 28 days after. In five volunteers, 7-aminoflunitrazepam was detected 24 h after flunitrazepam administration and remained in hair throughout the entire 28-day study period (0.6-8.0 pg/mg). In two cases, 7-aminoflunitrazepam appeared in hair 21 days after drug intake (0.5-2.7 pg/mg), and in two subjects 14 days later (0.5-5.4 pg/mg). In one volunteer, 7-aminoflunitrazepam was detected on day 14 and 21 but concentrations were below the quantitation limit. Flunitrazepam was detected in some samples but all concentrations were below the quantitation limit (0.5-2.3 pg/mg).

Adult↗