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Biomedical subjects

S Chauhan

Publications and source records attributed to S Chauhan.

At least 37 records · Page 2Linked to original sources
PubMed2001

Microbial ecology of muffins baked from cassava and other nonwheat flours.

Cassava flour was evaluated as a partial substitute for wheat flour in gluten-free muffins. Four replicate test bakes were carried out to evaluate the microbial ecology of two muffin mixes, made with different combinations of cassava, soya, sorghum, sago, and potato flour. The muffins were baked at 180 degrees C for 25 min, stored at 30 degrees C and analysed microbiologically for up to 10 days post-baking. Raw materials were similarly analysed microbiologically on the day of baking. Characterization of predominant bacterial and mould isolates from the raw materials and the muffins was carried out. The rope-free and minimum mould-free shelf life of both muffin types were approximately 1 day and approximately 3 days, respectively. The predominant bacterial isolates from the raw materials and muffins were Bacillus species (83 and 99%, respectively). The moulds predominating in the raw materials were Gloeosporium (42%), Penicillium (13%) and Mucorales (13%), and from muffins Penicillium (37%) and Aspergillus (37%).

Bacillus↗
PubMed2001

Aerosol delivery systems in childhood asthma.

Asthma in younger children appears to be increasing in prevalence, whilst at the same time it is recognized that inhaled corticosteroids and bronchodilators are the mainstay of treatment for this condition. Presently the devices available for aerosol treatment of young children are mostly developed for use in older children and adults. However, an awareness of the need for delivery systems dedicated to use by young children is increasing. The devices available at present for aerosol treatment of young children comprises the nebulizer, metered-dose inhaler with spacer, and dry powder inhaler. The inhaler strategy found most useful at present can be summarized as follows: children younger than 2 years can use MDI+spacer+mask or nebulization, while children above 2 years can use MDI+spacer (without mask). Older children (3-4 years) can be easily taught the use of a Rotahaler.

Aerosols↗
PubMed2001

Effect of herbo-mineral formulation EHb in experimental anaemia in rodents.

EHb-a herbo-mineral formulations of iron (ferrous form) produced a significantly higher and dose dependent increase in the haemoglobin level, as compared to Fefol (a non-complex-chelated iron preparation). Also, EHb did not produce any overt toxicity or gastric irritation at these dose levels. The results suggest that EHb can be of a better choice in the treatment of anaemia than any other commercially available chelated iron preparations.

Anemia↗
PubMed2000

Does the site of intestinal delivery of oleic acid alter the ileal brake response?

Previous work has demonstrated that high doses of oleic acid can activate the ileal brake but the importance of site of delivery has yet to be investigated. The objective of this study was to use modified release capsules to release oleic acid in different regions of the intestine. When tested by in vitro dissolution in pH 6.8 phosphate buffer, one batch released the contents almost immediately, another after around 30 min and the last batch after around 60-70 min. The effect of oleic acid release site on the ileal brake was assessed by the measurement of transit time of radiolabelled non disintegrating tablets by gamma scintigraphy. The results demonstrated that the transit of tablets could be slowed down by oleic acid and therefore it appears the ileal brake can be activated along the entirety of the small intestine.

Capsules↗
PubMed2000

Spectral light quality affects protein profile of Synechococcus sp. PCC 7942: a comparative 2-dimensional gel electrophoresis (2-DGE) analysis.

We report here a comparative analysis of the effect of blue (450 nm), red (660 nm), and white light (400-700 nm) on the protein profile of cyanobacteria Synechococcus sp. PCC 7942. In vivo labeling of cells with [(35)S] methionine and their subsequent analysis by two-dimensional gel electrophoresis (2-DGE) showed that eight polypeptides were unique to dark adapted cells, ten were blue light specific, and four were specifically induced in red light. The results show that Synechococcus sp. respond to various light treatments rapidly and synthesize new polypeptides in dark and blue/red light.

Bacterial Proteins↗
PubMed2000

Efficacy of aprotinin, epsilon aminocaproic acid, or combination in cyanotic heart disease.

BACKGROUND: Aprotinin and epsilon aminocaproic acid are antifibrinolytic agents used to reduce postoperative blood loss after cardiopulmonary bypass. We compared low dose aprotinin with epsilon aminocaproic acid and a combination of the two agents to reduce postoperative blood loss in infants with congenital cyanotic heart disease undergoing corrective surgical procedures. METHODS: This prospective study was conducted randomly on 300 children. Group I (n = 80) acted as the control and did not receive either of the study drugs. Group II (n = 100) received low dose aprotinin, group III (n = 60) received epsilon aminocaproic acid, and group IV (n = 60) received a combination of the two antifibrinolytic agents. RESULTS: The control group had the longest time for sternal closure, maximum blood loss at 24 hours, and greatest requirements for packed red blood cells and platelets. Fibrinogen levels were significantly lower, and levels of fibrin breakdown products were significantly higher compared with the groups given either or both of the antifibrinolytics. CONCLUSIONS: Epsilon aminocaproic acid is as efficacious as low dose aprotinin in reducing postoperative blood loss and packed red blood cell and platelet requirements in children with congenital cyanotic heart disease. The combination of the two was slightly more effective.

Adolescent↗
PubMed2000

Adenosine for cardioplegic induction: a comparison with St Thomas solution.

OBJECTIVE: To determine if quicker cardiac standstill obtained by adding adenosine to potassium crystalloid cardioplegia translated into better myocardial preservation and cardiac function in the early postoperative period compared with the same cardioplegia without adenosine. DESIGN: A prospective study. SETTING: Cardiac center of a teaching institute. PARTICIPANTS: Sixty consecutive patients with left main vessel or triple-vessel disease undergoing coronary artery bypass surgery under moderate hypothermia. INTERVENTIONS: The study comprised two groups of patients. Group N (n = 15) was the control group, given St Thomas cardioplegic solution after aortic cross-clamping, without adenosine; whereas group A (n = 45) received 250 microg/kg of adenosine into the aortic root after aortic cross-clamping, followed by the same St Thomas cardioplegia as in group N. The two groups were otherwise similar in all aspects of perfusion management. MEASUREMENTS AND MAIN RESULTS: Time taken to achieve cardiac standstill after aortic cross-clamping was significantly greater, 18.7+/-3.1 seconds, in the control group compared with the adenosine group, 3.4+/-0.9 seconds (p<0.001). The quicker arrest of the adenosine group led to better postoperative function, in the form of higher cardiac index (p<0.01), lower filling pressures (pulmonary artery wedge pressure) (p<0.05), and lower mean pulmonary artery pressure (p<0.05) at 6 hours. In the adenosine group, only 3 of 45 (6.6%) patients had elevated creatine phosphokinase (CPK) (MB) values greater than 50 U/L over preoperative CPK values compared with 3 of 15 (20%) in the control group (p<0.01). CONCLUSIONS: Injection of 250 microg/kg of adenosine into the aortic root before administration of cold crystalloid St Thomas cardioplegia solution after cross-clamping, in patients with severe coronary artery disease, produces significantly faster cardiac standstill, better myocardial preservation, and better cardiac function in the early postoperative period.

Adenosine↗
PubMed2000

Characterization of MPP+ secretion across human intestinal Caco-2 cell monolayers: role of P-glycoprotein and a novel Na(+)-dependent organic cation transport mechanism.

1. In the kidney, a number of transport proteins involved in the secretion of permanently charged organic cations have recently been cloned. To evaluate the possible similarities between intestine and kidney in the handling of organic cations we investigated the transport of 1-methyl-4-phenylpyridinium (MPP+) across monolayers of intestinal Caco-2 cells. MPP+ is a prototypic substrate of the cloned organic cation transporters hOCT1 and hOCT2. 2. In Caco-2 cell monolayers, the basolateral to apical flux of MPP+ was significantly greater than the apical to basolateral flux, consistent with net secretion of MPP+. 3. Net secretion of MPP+ was abolished by addition of either 10 microM cyclosporin A or 100 microM verapamil to the apical membrane. In contrast, secretion of MPP+ was unaffected by addition of either TEA (2 mM) or decynium-22 (2 microM) to either apical or basolateral membranes. These results suggest that MPP+ secretion is mediated primarily by P-glycoprotein located at the apical membrane. We found no evidence of a role for hOCT1 or hOCT2 in the secretion of MPP+. 4. In addition to net secretion of MPP+, we found evidence of a Na(+)-dependent MPP+ uptake mechanism at the apical membrane of Caco-2 cells. 5. Na(+)-dependent MPP+ uptake was sensitive to inhibition by the organic cations; decynium-22 (2 microM), TEA (2 mM) and cimetidine (5 mM) but not by carnitine, guanidine or proline. 6. These results suggest that net secretion of MPP+ across the apical membrane of Caco-2 cells is a function of the relative contributions of MPP+ secretion mediated by P-glycoprotein and MPP+ absorption mediated by a novel Na(+)-dependent transport mechanism.

1-Methyl-4-phenylpyridinium↗
PubMed2000

Na+/myo-inositol symporters and Na+/H+-antiport in Mesembryanthemum crystallinum.

Mitr1 and Mitr2 from Mesembryanthemum crystallinum (common ice plant) are members of a family of genes homologous to H+[or Na+]/myo-inositol symporters (ITRs), not previously studied in plants. MITR1 complemented an Itr1-deficient yeast strain. Mitr1 is strongly expressed in roots, moderately in stems, and weakly in leaves. Its transcripts increased in all organs, most dramatically in roots, under salinity stress. Mitr2 constitutes a rare transcript, slightly upregulated by salt stress in leaves only. Mitr1 transcripts are present in all cells in the root tip, but become restricted to phloem-associated cells in mature roots. Peptide antibodies against the two proteins indicated the presence of MITR1 in all organs and of MITR2 in leaves. Both are located in the tonoplast. MITR1 acts in removing sodium from root vacuoles, correlated with findings of low root sodium, while leaf vacuoles accumulate sodium in the ice plant. Up-regulation in leaves and stems is also found for Na+/H+-antiporter (Nhx-type) transcripts. Under comparable stress conditions, Nhx-and Itr-like transcripts in Arabidopsis were regulated differently. In the ice plant, co-ordinate induction of Na+/H+-antiporters and Na+/myo-inositol symporters transfers sodium from vacuoles in root cells into the leaf mesophyll as a halophytic strategy that lowers the osmotic potential. The tissue-specific differential expression of Itr- and Nhx-type transcripts suggests that the vacuolar sodium/inositol symporters function to reduce sodium amounts in cells of the root and vascular tissue, while sodium/proton antiporters in leaf tissues function to partition sodium into vacuoles for storage.

Amino Acid Sequence↗
PubMed2000

The amniotic fluid index, single deepest pocket, and two-diameter pocket in normal human pregnancy.

OBJECTIVE: This study was undertaken to determine normative values for amniotic fluid index, single deepest pocket, and 2-diameter pocket across gestation. STUDY DESIGN: Fifty patients with normal pregnancies at each gestational age between 14 and 41 weeks' gestation were recruited prospectively and scanned once. Data were transformed into logarithmic (base 10) values for analysis. Polynomial regression equations were used to predict the normal values for amniotic fluid index, single deepest pocket, and 2-diameter pocket across gestational age and to predict the weekly percentage changes. RESULTS: The mean amniotic fluid index, single deepest pocket, and 2-diameter pocket values were significantly lower among patients at <37 weeks' gestation (n = 1150) than among those at > or =37 weeks' gestation (n = 250; P <.001 for all comparisons). The calculated prevalences of oligohydramnios (amniotic fluid index < or =5 cm, single deepest pocket <2 cm, or 2-diameter pocket <15 cm(2)) were significantly different (P <.0001) for the three techniques (8%, 1%, and 30%, respectively). Hydramnios (amniotic fluid index >24 cm, single deepest pocket >8 cm, or 2-diameter pocket >50 cm(2)) was also diagnosed with significantly different (P <.0001) frequencies (0%, 0.7%, and 3%, respectively). CONCLUSIONS: This is the largest prospective study to date to provide normative data for each of three ultrasonographic techniques used to assess amniotic fluid volume. The single deepest pocket appears to be the preferable method, because its use is least likely to lead to the false-positive diagnosis of either oligohydramnios or hydramnios.

Adult↗
PubMed2000

Rhizosphere competitiveness of trichloroethylene-degrading, poplar-colonizing recombinant bacteria.

Indigenous bacteria from poplar tree (Populus canadensis var. eugenei 'Imperial Carolina') and southern California shrub rhizospheres, as well as two tree-colonizing Rhizobium strains (ATCC 10320 and ATCC 35645), were engineered to express constitutively and stably toluene o-monooxygenase (TOM) from Burkholderia cepacia G4 by integrating the tom locus into the chromosome. The poplar and Rhizobium recombinant bacteria degraded trichloroethylene at a rate of 0.8 to 2.1 nmol/min/mg of protein and were competitive against the unengineered hosts in wheat and barley rhizospheres for 1 month (colonization occurred at a level of 1.0 x 10(5) to 23 x 10(5) CFU/cm of root). In addition, six of these recombinants colonized poplar roots stably and competitively with populations as large as 79% +/- 12% of all rhizosphere bacteria after 28 days (0.2 x 10(5) to 31 x 10(5) CFU/cm of root). Furthermore, five of the most competitive poplar recombinants (e.g., Pb3-1 and Pb5-1, which were identified as Pseudomonas sp. strain PsK recombinants) retained the ability to express TOM for 29 days as 100% +/- 0% of the recombinants detected in the poplar rhizosphere expressed TOM constitutively.

Biodegradation, Environmental↗
PubMed2000

Epsilon aminocaproic acid in paediatric cardiac surgery to reduce postoperative blood loss.

We have studied the efficacy of epsilon aminocaproic acid in reducing postoperative blood loss in infants and children with congenital cyanotic cardiac anomalies undergoing corrective operative procedures. This prospective study was carried out on 170 infants and children randomly divided into two equal groups. Group A acted as the control group and received normal saline as placebo while group B patients received epsilon aminocaproic acid (100 mg/kg body wt) intravenously slowly soon after anaesthetic induction followed by 100 mg/kg in the cardiopulmonary bypass pump at the time of starting of cardiopulmonary bypass and 100 mg/kg after weaning from bypass over a period of 3 h. In group A the time for sternal closure after separation from bypass and administration of protamine was 75.18 +/- 5.5 min and in group B 50.7 +/- 5.2, (P < 0.001). Blood loss at 24 h in group A was 42.6 +/- 6.9 ml/kg/24 h and in group B 23.7 +/- 5.8 ml/kg/24 h, (P < 0.001). The need for packed red cells in group A was 21.8 +/- 7.1 ml/kg/24 h and in group B 10.7 +/- 7.8 ml/kg/24 h, (P < 0.001). The need for platelet concentrate in group A was 22.0 +/- 6.7 ml/kg/24 h and group B 6.2 +/- 3.2 ml/kg/24 h, (P < 0.001). Fibrin degradation products (split) in group A was 8.2 +/- 0.8 micrograms/ml, and group B 3.8 +/- 1.3 micrograms/ml, (P < 0.001). Reexploration rate was also considerably reduced in group B, 5 of 85 (6%) compared to group A, 13 of 85 (15%), (P < 0.001). It was found that epsilon aminocaproic acid is effective in reducing postoperative blood loss, packed red cells and plasma product requirements in paediatric patients undergoing corrective surgical procedures for congenital cyanotic heart diseases.

Aminocaproic Acid↗
PubMed2000

Femoral artery pressures are more reliable than radial artery pressures on initiation of cardiopulmonary bypass.

OBJECTIVE: To compare radial and femoral artery perfusion pressure during initiation and various stages of cardiopulmonary bypass (CPB). DESIGN: Prospective study. SETTING: The cardiac center of a tertiary referral teaching institute. PARTICIPANTS: Sixty consecutive patients of all ages undergoing a variety of cardiac operations. INTERVENTIONS: Radial and femoral arterial pressures were measured in all patients on the same transducer, from the beginning to end of CPB. MEASUREMENTS AND MAIN RESULTS: Mean perfusion pressures on CPB measured at the femoral artery at 1, 5, 10, and 15 minutes of CPB were 38.4+/-3.6, 46.2+/-3.1, 49.7+/-3.9, and 52.8+/-4.1 mmHg and were significantly greater than the corresponding radial artery pressures (29.9+/-4.1, 35.3+/-6.1, 40.9+/-4.8, and 41.8+/-5.3 mmHg) (p < 0.001). At 30 minutes and 60 minutes of CPB, femoral artery pressures are higher (60.3+/-8.8 mmHg and 66.4+/-8.2 mmHg) compared with radial artery pressures (54.7+/-6.9 mmHg and 59.6+/-6.1 mmHg), but the difference is less significant (p < 0.05). On conclusion of CPB, mean femoral artery pressures (70.9+/-6.7 mmHg) are greater than mean radial artery pressures (67.6+/-8.1 mmHg) (NS). CONCLUSIONS: Although radial artery pressures are more commonly monitored during cardiac surgery, femoral artery perfusion pressures are more reliable during the initial part of CPB, and routine monitoring of femoral artery pressures may prevent vasoconstrictor use on initiation of CPB.

Adolescent↗
PubMed1999

Degradation of 2,4,5-trichlorophenol and 2,3,5,6-tetrachlorophenol by combining pulse electric discharge with bioremediation.

Degradation of 2,4,5-trichlorophenol (2,4,5-TCP) and 2,3,5,6-tetrachlorophenol (TeCP) was studied using a two-stage approach that utilized efficient pulse electric discharge (PED) followed by biological degradation with a consortium from acclimated return activated sludge. The chlorinated phenols were treated in the PED reactor as an aerosol at a voltage of 55-60 kV, a frequency of 385 Hz, a current of 50-60, and with a 200-ns pulse. As determined by gas chromatography and mass spectrometry (GC/MS), the first stage converted 500 ppm 2,4,5-TCP to 163 ppm 2,4,5-TCP and dimethyldecene, dichloronaphthalenol, octyl acetate, and silyl esters. The total carbon content of 2,4,5-TCP after PED treatment was determined to be 228 +/- 35 ppm. The remaining 2,4,5-TCP and the products formed were then mineralized by the acclimated activated sludge in shake flasks; the initial rate of degradation of 2,4,5-TCP was calculated to be 5 nmol min-1 mg protein-1 at 163 ppm initial concentration (three orders of magnitude higher than the only rate found in the literature). By combining the two techniques, a synergistic effect (2.3-fold increase in the concentration of 2,4,5-TCP degraded and 3.3-fold increase in total carbon degraded) was observed, in that bacteria without any treatment degraded a maximum of 70 ppm, 2,4,5-TCP but after PED treatment 163 ppm 2,4,5-TCP was degraded. TeCP was also mineralized by the acclimated activated sludge after treatment with PED. This two-stage approach was also evaluated using a continuous 1-l fluidized-bed reactor.

Chlorophenols↗
PubMed1999

The effect of oleic acid on the human ileal brake and its implications for small intestinal transit of tablet formulations.

PURPOSE: A human volunteer study was carried out to investigate whether activation of the ileal brake mechanism affects the transit of tablets through the small intestine. METHODS: Oleic acid, which has previously been shown to activate the brake, was delivered to the small intestine in a modified release capsule at doses of 300 mg, 600 mg and 1200 mg. The effect of the oleic acid was determined by measuring the transit of two sets of radiolabelled tablets by gamma scintigraphy. One set of tablets was dosed with the capsule and the other one hour later. RESULTS: The results show that in the majority of the volunteers small intestinal residence time was greater with the oleic acid than control. The effect was most pronounced in the tablets given concomitantly with the capsule and with the higher doses of oleic acid. CONCLUSIONS: The ileal brake, activated by oleic acid, can slow the transit of tablets through the small intestine.

Feedback↗
PubMed1999

Development of a system for expressing heterologous genes in the oral spirochete Treponema denticola and its use in expression of the Treponema pallidum flaA gene.

The present communication describes the construction of a new Escherichia coli-Treponema denticola shuttle vector based on the naturally occurring spirochete plasmid pTS1 and the expression of the heterologous T. pallidum flaA gene from the plasmid in T. denticola. This new shuttle vector system should prove useful in characterizing virulence factors from unculturable pathogenic spirochetes.

Flagellin↗
PubMed1999

A comparison of esmolol & diltiazem for heart rate control during coronary revascularisation on beating heart.

This prospective study was done to compare the control of heart rate and haemodynamics during coronary artery revascularisation without cardiopulmonary bypass using either esmolol or diltiazem. Sixty adult patients with one or two vessel coronary artery disease, were randomly divided into 2 equal groups. Group A received a 500 micrograms/kg loading dose of esmolol followed by a 100 micrograms/kg/h infusion, for control of heart rate during surgical anastomosis of the coronary vessel. While Group B received 0.15 mg/kg diltiazem as a loading dose followed by a 5 mg/h infusion for heart rate control, during the anastomosis. It was seen that heart rate control was better in Group A, 51.4 (+/- 1.3) beats/min, than in Group B, 69.6 (+/- 3.9) beats/min but the decrease in heart rate was significant in both the groups at peak effect compared to respective predrug values. Group A patients had unchanged systemic resistance and pulmonary artery wedge pressure but mean pulmonary artery pressure and pulmonary vascular resistance were significantly raised. Group B patients had decreased systemic resistance, mean pulmonary artery pressure and pulmonary artery wedge pressure, and reduced right ventricular stroke work index. We concluded that although esmolol provided dramatically slower heart rates, during surgery, the resulting elevations in mean pulmonary artery pressure and pulmonary vascular resistance would require caution if used in patients with underlying right ventricular dysfunction from ischaemia or infarction. Diltiazem by virtue of its effects on systemic vascular resistance, cardiac output, and lowering of mean arterial pressure may be a better choice in hypertensive patients.

Adrenergic beta-Antagonists↗