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Biomedical subjects

Jitendra Kumar

Publications and source records attributed to Jitendra Kumar.

14 recordsLinked to original sources
PubMed2006

Effects of fortified milk on morbidity in young children in north India: community based, randomised, double masked placebo controlled trial.

OBJECTIVE: To evaluate the efficacy of milk fortified with specific multiple micronutrients on morbidity in children compared with the same milk without fortification. DESIGN: Community based, double masked, individually randomised trial. SETTING: Peri-urban settlement in north India. PARTICIPANTS: Children (n=633) aged 1-3 randomly allocated to receive fortified milk (n=316) or control milk (n=317). INTERVENTION: One year of fortified milk providing additional 7.8 mg zinc, 9.6 mg iron, 4.2 microg selenium, 0.27 mg copper, 156 microg vitamin A, 40.2 mg vitamin C, 7.5 mg vitamin E per day (three feeds). MAIN OUTCOME MEASURES: Days with severe illnesses, incidence and prevalence of diarrhoea, and acute lower respiratory illness. RESULTS: Study groups were comparable at baseline; compliance in the groups was similar. Mean number of episodes of diarrhoea per child was 4.46 (SD 3.8) in the intervention (fortified milk) group and 5.36 (SD 4.1) in the control group. Mean number of episodes of acute lower respiratory illness was 0.62 (SD 1.1) and 0.83 (SD 1.4), respectively. The fortified milk reduced the odds for days with severe illnesses by 15% (95% confidence interval 5% to 24%), the incidence of diarrhoea by 18% (7% to 27%), and the incidence of acute lower respiratory illness by 26% (3% to 43%). Consistently greater beneficial effects were observed in children aged < or =24 months than in older children. CONCLUSION: Milk is well accepted as a means of delivery of micronutrients. Consumption of milk fortified with specific micronutrients can significantly reduce the burden of common morbidities among preschool children, especially in the first two years of life. TRIAL REGISTRATION: NCT00255385 [ClinicalTrials.gov].

Animals↗
PubMed2006

Development of controlled release formulations of carbofuran and evaluation of their efficacy against Meloidogyne incognita.

Controlled release (CR) formulations of the insecti-nematicide carbofuran have been prepared using commercially available rosin, sodium carboxymethylcellulose and sodium carboxymethylcellulose with clay (bentonite, kaolinite, and Fuller's earth). The kinetics of carbofuran release in soil from the different formulations were studied in comparison with that of the commercially available granules (3G). Release from the commercial formulation was faster than with the new CR formulations. Addition of clay in the biodegradable polymer matrix reduced the rate of release. The diffusion exponent (n value) of carbofuran in soil ranged from 0.462 to 0.740 in the tested formulations. The half-release (t1/2) values ranged between 4.79 and 25.11 days, and the period of optimum availability (POA) of carbofuran ranged from 15.10 to 43.97 days. The mean EC50 of the commercial formulation against Meloidogyne incognita was quite high as compared to those of CR formulations. The effective duration (te) of carbofuran from the CR and commercial formulations was predicted by fitting the mean EC50 values of test formulations in the model (M(infinity) - Me)/M(infinity) = Kdte. It was 0.7 day in commercial 3G in comparison with 17.8 days for CMC-bentonite. The bioassay studies revealed that with the rosin-yellow polymer, the dose of carbofuran could be reduced to half of its recommended dose for nematode control. Overall, a comparison of CR formulations with the commercial one showed an earlier degradation of carbofuran in the latter and relatively prolonged activity in the former.

Animals↗
PubMed2006

Mitochondrial iPLA2 activity modulates the release of cytochrome c from mitochondria and influences the permeability transition.

The mitochondrial Ca(2+)-independent phospholipase A(2) is activated during energy-dependent Ca(2+) accumulation under conditions where there is a sustained depression of the membrane potential. This activation is not dependent on induction of the mitochondrial permeability transition. Bromoenol lactone, which inhibits the phospholipase, is effective as an inhibitor of the transition, and this action can be overcome by low levels of exogenous free fatty acids. Apparently, activation of the Ca(2+)-independent phospholipase is a factor in the mechanisms by which depolarization and Ca(2+) accumulation promote opening of the permeability transition pore. Sustained activity of the Ca(2+)-independent phospholipase A(2) promotes rupture of the outer mitochondrial membrane and spontaneous release of cytochrome c on a time scale similar to that of apoptosis occurring in cells. However, more swelling of the matrix space must occur to provoke release of a given cytochrome c fraction when the enzyme is active, compared with when it is inhibited. Through its effects on the permeability transition and release of intermembrane space proteins, the mitochondrial Ca(2+)-independent phospholipase A(2) may be an important factor governing cell death caused by necrosis or apoptosis.

Animals↗
PubMed2006

Azadirachtin-A and tetrahydroazadirachtin-A concentrates: preparation, LC-MS characterization and insect antifeedant/IGR activity against Helicoverpa armigera (Hübner).

A 60% azadirachtin-A concentrate has been obtained through repeated precipitation with hexane from a methanolic solution of a 20% concentrate. Azadirachtin-A (90%) has been obtained by medium-pressure liquid chromatography of the 60% concentrate with an RP-18 column and a methanol + water (1 + 1 by volume) solvent system. Catalytic hydrogenation of the 60 and 90% azadirachtin concentrates yielded the corresponding tetrahydroazadirachtin concentrates. Dihydroazadirachtin and tetrahydroazadirachtin formed during the first 5 h of hydrogenation were identified by LC-ESI-MS on the basis of their unique mass fragmentation pattern. The efficacy of tetrahydroazadirachtin concentrates in inhibiting the feeding and growth of Helicoverpa armigera (Hübner) larvae has been compared with that of azadirachtin concentrates. They were in general more active and deterred larvae from feeding at all concentrations. Tetrahydroazadirachtin-A (90%) and azadirachtin-A (90%) with respective IC(50) values of 280 and 390 mg L(-1) were effective as insect growth regulators, while tetrahydroazadirachtin-A (90%) displayed higher antifeedant activity (AI(50) 14 mg L(-1)) against the test insect.

Animals↗
PubMed2006

Development and use of behavior and social interaction software installed on Palm handheld for observation of a child's social interactions with the environment.

In settings in developing countries, children often socialize with multiple socializing agents (peers, siblings, neighbors) apart from their parents, and thus, a measurement of a child's social interactions should be expanded beyond parental interactions. Since the environment plays a role in shaping a child's development, the measurement of child-socializing agents' interactions is important. We developed and used a computerized observational software Behavior and Social Interaction Software (BASIS) with a preloaded coding scheme installed on a handheld Palm device to record complex observations of interactions between children and socializing agents. Using BASIS, social interaction assessments were conducted on 573 preschool children for 1 h in their natural settings. Multiple screens with a set of choices in each screen were designed that included the child's location, broad activity, state, and interactions with child-socializing agents. Data were downloaded onto a computer and systematically analyzed. BASIS, installed on Palm OS (M-125), enabled the recording of the complex interactions of child-socializing agents that could not be recorded with manual forms. Thus, this tool provides an innovative and relatively accurate method for the systematic recording of social interactions in an unrestricted environment.

Activities of Daily Living↗
PubMed2005

Optical microbial biosensor for detection of methyl parathion pesticide using Flavobacterium sp. whole cells adsorbed on glass fiber filters as disposable biocomponent.

An optical microbial biosensor was described for the detection of methyl parathion pesticide. Whole cells of Flavobacterium sp. were immobilized by trapping in glass fiber filter and were used as biocomponent along with optic fiber system. Flavobacterium sp. has the organophosphorus hydrolase enzyme, which hydrolyzes the methyl parathion into detectable product p-nitrophenol. The immobilized microbial biocomponent was disposable, cost-effective and showed high reproducibility and uniformity. The detection of methyl parathion by the use of disposable microbial biocomponent with optical biosensor was simple, single step and direct measurement of very low quantity of the sample. The home made reaction vessel was small and needed only 75 microl of sample. A lower detection limit 0.3 microM methyl parathion was estimated from the linear range (4-80 microM) of calibration plot of organophosphorus hydrolase enzymatic assay. The applicability to synthetic methyl parathion spiked samples was demonstrated.

Aryldialkylphosphatase↗
PubMed2005

In vitro plant regeneration and genetic transformation of Dichanthium annulatum.

Optimization of in vitro plant regeneration and genetic transformation of apomictic species such as Dichanthium annulatum would enable transfer of desirable genes. Seven genotypes of this grass species were screened through mature seed explant for embryogenic callus induction, callus growth and quality (color and texture), and shoot induction. Genotype IG-1999, which produced highly embryogenic, rapidly growing good-quality callus capable of regenerating at a high frequency, was selected for transformation experiments. Using a binary vector (pCAMBIA1305), frequency of GUS expression was compared between two methods of transformation. Bombardment of embryogenic calli with gold particles coated with pCAMBIA1305 at a distance of 11 cm, pressure of 4 bars, and vacuum of 27 Hg passing through 100 muM mesh produced maximum GUS expression (23%). Agrobacterium infection was maximum at an optical density of 2.0 when cocultured under vacuum for 15 min and cocultivated for 3 days at 28 degrees C in constant dark on MS medium of pH 5.8 with 3 mg/l 2,4-D, and 400 muM acetosyringone. Among two binary vectors used for Agrobacterium-mediated transformation, pCAMBIA1301 showed higher frequency of GUS expression while pCAMBIA1305 recorded more of the GUS spots per callus. Supplementation of acetosyringone in the cocultivation medium was found indispensable for Agrobacterium-mediated transformation. Injuring the calli through gold particle bombardment before their cocultivation with Agrobacterium improved the transformation efficiency. Several transgenic plants were developed using the PIG method, while stable GUS-expressing calli were multiplied during selection on MS medium containing 250 mg/l cefotaxime and 50 mg/l hygromycin, incubated in constant dark. A highly significant difference was observed between two methods of transformation for both frequency of GUS expression and GUS spots per callus. PIG-mediated transformation resulted in higher GUS expression compared to the Agrobacterium method. These results demonstrate that Dichanthium annulatum is amenable to Agrobacterium-mediated genetic transformation using a binary vector.

Acetophenones↗
PubMed2004

Cognitive and motor development among small-for-gestational-age infants: impact of zinc supplementation, birth weight, and caregiving practices.

OBJECTIVE: Infants who are born small for gestational age (SGA) are at risk for developmental delays, which may be related to deficiencies in zinc, an essential trace metal, or to deficiencies in their ability to elicit caregiver responsiveness (functional isolation hypothesis). The objective of this study was to evaluate at 6 and 10 months of age the impact of a 9-month supplementation trial of 5 mg of zinc on the development and behavior of infants who were born SGA and to evaluate infants' ability to elicit responsive caregiver behavior. METHODS: A randomized, controlled trial of zinc supplementation was conducted among 200 infants in a low-income, urban community in Delhi, India. Infants were recruited when they were full term (>36 weeks) and SGA (birth weight <10th percentile weight-for-gestational age). Infants were randomized to receive daily supplements of a micronutrient mix (folate, iron, calcium, phosphorus, and riboflavin) with or without 5 mg of zinc sulfate. The supplement was administered by field workers daily from 30 days to 9 months of age. At 6 and 10 months, infant development and behavior were measured in a clinical setting using the Bayley Scales of Infant Development II. Caregiver responsiveness, observed on an Indian version of the Home Observation for Measurement of the Environment scale, was measured during a home visit at 10 months. During both the clinic and home visits, caregivers reported on their infant's temperament. RESULTS: There were no direct effects of zinc supplementation on the infants' development or behavior at either 6 or 10 months. In a subgroup analysis among the zinc-supplemented infants, lower birth weight infants were perceived to be more temperamentally difficult than higher weight infants; in the control group, birth weight was not associated with temperament. Heavier birth weight infants had better scores on all measures of development and behavior at 6 months and on changes in mental and motor development from 6 to 10 months, compared with lighter birth weight infants. Boys had better weight gain and higher scores on mental development and emotional regulation than girls. Infants who were from families of higher socioeconomic status (indexed by parental education, house size, and home ownership) had higher scores on mental development and orientation/engagement (exploratory behavior) than infants who were from families of lower socioeconomic status. In keeping with the functional isolation hypothesis, caregiver responsiveness was associated with infant irritability, controlling for socioeconomic status, gender, birth weight, and weight gain. Responsive mothers were more likely to perceive their infants to be temperamentally easy than less responsive mothers. CONCLUSION: Possible explanations for the lack of effects of zinc supplementation on infant development and behavior include 1) subtle effects of zinc supplementation that may not have been detected by the Bayley Scales, 2) interference with other nutritional deficiencies, or 3) no impact of zinc deficiency on infants' development and behavior. The link between birth weight and irritability among infants in the zinc supplementation group suggests that the response to zinc supplementation may differ by birth weight, with irritability occurring among the most vulnerable infants. Longer term follow-up studies among zinc-supplemented infants are needed to examine whether early supplementation leads to developmental or behavioral changes that have an impact on school-age performance. The relationship between infant irritability and low maternal responsiveness lends support to the functional isolation hypothesis and the importance of asking caregivers about infant temperament.

Birth Weight↗
PubMed2004

Learning phacoemulsification. Results of different teaching methods.

We report the learning curves of three eye surgeons converting from sutureless extracapsular cataract extraction to phacoemulsification using different teaching methods. Posterior capsule rupture (PCR) as a per-operative complication and visual outcome of the first 100 operations were analysed. The PCR rate was 4% and 15% in supervised and unsupervised surgery respectively. Likewise, an uncorrected visual acuity of > or = 6/18 on the first postoperative day was seen in 62 (62%) of patients and in 22 (22%) in supervised and unsupervised surgery respectively.

Education, Medical, Continuing↗
PubMed2003

An efficient method for the purification and characterization of nematicidal azadirachtins A, B, and H, using MPLC and ESIMS.

Azadirachtin A enriched concentrate containing 60% active ingredient (a.i.) was prepared from the methanolic extract of the de-fatted neem (Azadirachta indica A. Juss) seed kernels. Azadirachtins A, B, and H, the three major bioactive constituents of neem seed kernel, were purified from this methanolic concentrate by employing reverse phase medium-pressure liquid chromatography (MPLC), using methanol-water solvent system as an eluant. The three pure azadirachtin congeners thus obtained were characterized by their unique mass spectral fragmentation, using electrospray probe in positive ion mode (ESI). All three azadirachtins exhibited nematicidal and antifungal activities. Azadirachtin B was the most effective against the reniform nematode Rotylenchulus reniformis (EC(50) 96.6 ppm), followed by Azadirachtin A (119.1 ppm) and H (141.2 ppm). At 200-ppm concentration, the test compounds caused 50-65% mortality of Caenorhabditis elegans nematode. Azadirachtin H showed the highest activity against the phytophagous fungi Rhizoctonia solani (EC(50) 63.7 ppm) and Sclerotium rolfsii (EC(50) 43.9 ppm), followed by B and A. The isolation of pure azadirachtins A, B, and H directly by MPLC purification from its concentrate and their characterization by ESIMS are unique and less time-consuming.

Antifungal Agents↗
PubMed2003

Histopathological spectrum of childhood nephrotic syndrome in Indian children.

Nephrotic syndrome in children is a clinical manifestation of different histopathological subtypes. There is a paucity of recent large studies dealing with the histopathological spectrum from developing countries. A prospective study was performed from January 1990 to December 2000 at our center, involving 600 children (with age of onset up to 16 years) with idiopathic nephrotic syndrome (INS). The objectives were: (1) to study the histopathological distribution of different subtypes of INS and (2) to compare the clinical and biochemical parameters at the time of diagnosis of minimal change disease (MCD) with non-MCD subtypes. For the purpose of this study we analyzed only those children with INS who underwent biopsies. The study group included 290 children in which adequate biopsy reports were available. There were 213 males and 77 females. Mean age at onset of INS was 7.9+5.1 years. Facial edema was found in 286 (98.6%), microhematuria in 120 (41.3%), gross hematuria in 7 (2.5%), and hypertension in 77(26.8%) patients. All patients of the study group were seronegative for HBsAg and HIV. Focal and segmental glomerulosclerosis (FSGS) was the most common histopathological subtype, occurring in 110 of 290 children (38%). Other subtypes included MCD in 95 children (32%), membranoproliferative glomerulonephritis (MPGN) in 44 children (15%), mesangioproliferative glomerulonephritis in 33 children (11%), membranous glomerulonephritis in 5 children (2%), and diffuse mesangial sclerosis in 3 children (1%). In children under 8 years of age, MCD was the most common entity, whereas FSGS predominated in children with age at onset greater than 8 years. The age at onset of nephrotic syndrome was significantly higher in the non-MCD group than the MCD group. The incidence of hypertension, microhematuria, and gross hematuria was significantly lower in the MCD group. MCD remains the most common histopathological subtype in Indian children with INS and onset under 8 years of age. The incidence of MPGN continues to be high. MCD can be differentiated from non-MCD subtype by younger age at onset, absence of hypertension, and absence of microscopic hematuria.

Adolescent↗
PubMed2003

Peritoneal infection in acute intermittent peritoneal dialysis.

A prospective study was done to evaluate the incidence and microbiological trend of peritoneal infection in patients undergoing acute intermittent peritoneal dialysis (PD). Complete sterile procedure was ensured and at the completion of the procedure PD fluid was sent for bacteriological culture, sensitivity, and total and differential cell count. During the period September 2000 to February 2001 a total of 100 patients were evaluated. Male female ratio was 72:28. Mean age was 43.17 +/- 17.2 years. In 26 patients cyclers were used. Bacterial culture was positive in total of 30 cases (30%). Gram positive, Gram negative and mixed infection was found in 10%, 15%, and 5% respectively. Number of exchanges (31.61 +/- 7.7 vs. 31.3 +/- 6, p = 0.8) were similar and number of repositioning was significantly more in the infected group (23.3% vs. 11.4%, p < 0.01). Total cell count was significantly higher in infected group (274.3 +/- 502 vs. 31.25 +/- 79.34, p < 0.01). Among Gram +ve organisms Staphylococcus was found in 7, Enterococcus faecalis in 4 and Coryne bacterium sps. in 2 cases. Among Gram -ve organisms, E. coli was found in 4, Enterobacter in 3, Klebsiella 1, Pseudomonas 1, Acinetobacter arinatus 5, Acinetobacter baumani 3, and Citrobacter freundii 3. Mixed flora comprised of Enterococcus faecalis 3, Enterobacter 1, Staphlococcus 1, E. coli 3, Citrobacter 1, Acinobacter baumani 1. Although with the cyclers using collapsible bags, staphylococcus was not isolated, the total incidence of infection (11/26 cases) was not decreased with the use of cyclers. We conclude that in acute intermittent peritoneal dialysis the incidence of bacterial infection is 30% with preponderance of Gram -ve over Gram +ve organisms and organism of fecal origin being commoner than those of skin origin. Use of cycler-assisted over manual PD do not improve the incidence of infection. Repositioning of the stiff catheter significantly increases the incidence of infection.

Adult↗
PubMed2003

mSin3A/histone deacetylase 2- and PRMT5-containing Brg1 complex is involved in transcriptional repression of the Myc target gene cad.

The role of hSWI/SNF complexes in transcriptional activation is well characterized; however, little is known about their function in transcriptional repression. We have previously shown that subunits of the mSin3A/histone deacetylase 2 (HDAC2) corepressor complex copurify with hSWI/SNF complexes. Here we show that the type II arginine-specific methyltransferase PRMT5, which is involved in cyclin E repression, can be found in association with Brg1 and hBrm-based hSWI/SNF complexes. We also show that hSWI/SNF-associated PRMT5 can methylate hypoacetylated histones H3 and H4 more efficiently than hyperacetylated histones H3 and H4. Protein-protein interaction studies indicate that PRMT5 and mSin3A interact with the same hSWI/SNF subunits as those targeted by c-Myc. These observations prompted us to examine the expression profile of the c-Myc target genes, carbamoyl-phosphate synthase-aspartate carbamoyltransferase-dihydroorotase (cad) and nucleolin (nuc). We found that cad repression is altered in cells that express inactive Brg1 and in cells treated with the HDAC inhibitor depsipeptide. Using chromatin immunoprecipitation assays, we found that Brg1, mSin3A, HDAC2, and PRMT5 are directly recruited to the cad promoter. These results suggest that hSWI/SNF complexes, through their ability to interact with activator and repressor proteins, control expression of genes involved in cell growth and proliferation.

Aspartate Carbamoyltransferase↗