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Biomedical subjects

A K Gupta

Publications and source records attributed to A K Gupta.

At least 55 records · Page 3Linked to original sources

Interventions for rosacea.

BACKGROUND: Rosacea is a common chronic skin condition affecting the face, characterised by flushing, redness, pimples, pustules, and dilated blood vessels. The eyes are often involved. Frequently it can be controlled, but it is not clear which treatments are most effective. OBJECTIVES: To assess the evidence for the efficacy and safety of treatments for rosacea. SEARCH STRATEGY: We searched the Skin Group Specialised Register (February 2005), Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 1, 2005), MEDLINE (1966 to February 2005), EMBASE (1980 to February 2005), BIOSIS (1970 to March 2002) and the Science Citation Index (1988 to February 2005). Reference lists of trials and key review articles were searched. Relevant manufacturers and experts were contacted. SELECTION CRITERIA: Randomised controlled trials in people with moderate to severe rosacea were included. Studies judged by the authors to have seriously flawed methodology were excluded. DATA COLLECTION AND ANALYSIS: Study selection, assessment of methodological quality, data extraction and analysis were carried out by two independent authors. Disagreements were resolved by discussion and consensus. MAIN RESULTS: The evidence provided by twenty-nine included studies was generally weak because of poor methodology and reporting. One of our primary outcome measures, 'quality of life', was not assessed in any of the studies. Only two studies of ocular rosacea were included. Pooled data from two trials involving 174 participants indicated that according to the participants, topical metronidazole is more effective than placebo (odds ratio (OR) 5.96, 95% confidence interval (CI) 2.95 to 12.06). Data pooled from three between-patient trials showed a clear improvement in the azelaic acid group; the rates of treatment success were approximately 70 to 80% versus 50% to 55% (OR 2.45, 95% CI 1.82 to 3.28). A within-patient trial of azelaic cream versus placebo could not be pooled with the other three studies, but also showed good evidence of efficacy. Data pooled from three studies of oral tetracycline versus placebo involving 152 participants showed that, according to physicians, tetracycline was effective (OR 6.06, 95% CI 2.96 to 12.42). Some evidence of efficacy of oral metronidazole was provided by one small study. AUTHORS' CONCLUSIONS: The quality of studies evaluating rosacea treatments was generally poor. There is evidence that topical metronidazole and azelaic acid are effective. There is some evidence that oral metronidazole and tetracycline are effective. There is insufficient evidence concerning the effectiveness of other treatments. Good RCTs looking at these treatments are urgently needed.

Dermatologic Agents↗

QSAR analysis of thiazole benzenesulfonamide substituted 3-pyridylethanolamines as beta3-adrenergic receptor agonist.

A quantitative structure-activity relationship study on a series of substituted benzene sulfonamide-3-pyridylethanolamines with beta3-adrenergic receptor agonist activity was made using a combination of various physiochemical descriptors. Several significant equations with good co-efficients of correlation (0.930) were obtained; the two models were selected using predictive ability of equations for test set. Both models highlight some common important structural features, that is, high electrostatic potential energy and the lipophilic nature of the molecule, favorable for beta3-adrenergic receptor agonist activity.

Adrenergic beta-3 Receptor Agonists↗

On-matrix derivatisation-extraction of precursors of nitrogen- and sulfur-mustards for verification of chemical weapons convention.

Development and refinement of sample preparation protocols for retrospective detection and identification of chemical warfare agents (CWAs) and their markers is of paramount importance from verification point of view of chemical weapons convention (CWC). Precursors of nitrogen- and sulfur-mustards (NMPs and SMPs) are polar adsorptive markers of vesicant class of CWAs. Their detection in a given environmental sample may imply past contamination with mustards. For the efficient extraction of NMPs and SMPs from soil, on-matrix derivatisation-extraction (OMDEX) method was developed and optimized. The method involved trifluoroacetylation of analytes on soil itself, followed by extraction with suitable solvent. The extracted samples were analyzed by gas chromatography-mass spectrometry (GC-MS). This virtually single-step sample preparation offered better recoveries of NMPs and SMPs in comparison to conventionally used extraction, evaporation and derivatisation. The best recoveries of analytes were obtained with acetonitrile by OMDEX method. Dynamic linearity range of trifluoroacetylated (TFA) derivatives of NMPs and SMPs was 1-12 microg/L in GC-MS analysis in SIM mode. Repeatability and reproducibility of this technique containing 5 and 10 microg analytes/gm soil was <3.3% and <4.6%, respectively. OMDEX technique was finally applied for the detection of TFA derivatives of NMPs in the soil sample supplied in 16th official proficiency test conducted by OPCW in October 2004.

Calibration↗

Cerebral microdialysis methodology--evaluation of 20 kDa and 100 kDa catheters.

Microdialysis monitoring of cerebral metabolism is now performed in several neuro-intensive care units. Conventional microdialysis utilizes CMA70 catheters with 20 kDa molecular weight cut-off membranes enabling the measurement of small molecules such as glucose, lactate, pyruvate and glutamate. The CMA71 100 kDa molecular weight cut-off microdialysis catheter has recently been introduced to allow detection of larger molecules such as cytokines. The objective of this study was to perform in vitro and in vivo testing of the CMA71 microdialysis catheter, comparing its performance with the CMA70. In vitro comparison studies of three of each catheter using reference analyte solutions, demonstrated equivalent recovery for glucose, lactate, pyruvate and glutamate (range 94-97% for CMA70 and 88-103% for CMA71). In vivo comparison involved intracranial placement of paired CMA70 and CMA71 catheters (through the same cranial access device) in six patients with severe traumatic brain injury. Both catheters were perfused with CNS Perfusion Fluid without dextran at 0.3 microl min-1 with hourly sampling and bedside analysis on a CMA600 microdialysis analyser. The two catheters yielded equivalent results for glucose, lactate, pyruvate, glutamate and lactate/pyruvate ratio. CMA71 microdialysis catheters can, therefore, be used for routine clinical monitoring of extracellular substances, as well as for their intended research role of larger molecular weight protein sampling.

Adolescent↗

Sample preparation of organic liquid for off-site analysis of chemical weapons convention related compounds.

Off-site analysis of chemical warfare agents (CWAs) and related compounds plays a key role in the verification program of the Chemical Weapons Convention (CWC). The analysis results, aiming toward unambiguous identication of compounds, depend on the type of sample preparation method. Development of milder sample preparation methods, which offer good recoveries and do not alter the structure of analytes, is highly desirable. Organic liquid with high hydrocarbon background is a frequently encountered challenge in off-site analysis and in official proficiency tests conducted by OPCW. Sample cleanup procedures, namely, solvent exchange followed by cooling and liquid-liquid extraction were studied to eliminate the hydrocarbons from organic liquid. Acetonitrile, a polar aprotic solvent, was effectively used to remove the background in both methods, and recoveries of spiked CWAs by the two techniques were between 69 and 99%.

Chemical Warfare Agents↗

Application of single drop microextraction for analysis of chemical warfare agents and related compounds in water by gas chromatography/mass spectrometry.

Retrospective detection and identification of chemical warfare agents (CWAs) is important from the verification point of view of the Chemical Weapons Convention. In the present work, a novel method for determination of CWAs and their markers in water has been described. It is based on a single drop micro extraction (SDME) of analytes and gas chromatography/mass spectrometric identification. Extraction conditions, such as solvent selection, agitation, extraction time, and salt content, were found to have significant influence on SDME. The conditions optimized for extraction of CWAs were 1 microL CH2Cl2/CCl4 (3:1 v/v), 30-min extraction time, 300-rpm stirring rate, and with or without NaCl addition. Under optimized conditions, comparison of SDME, solid-phase microextraction, and liquid-liquid extraction was also made. The limit of detection by SDME ranged from 75 to 10 microg L(-1) at a signal-to-noise ratio of 10:1.

Analytic Sample Preparation Methods↗

Extracellular amino acid changes in patients during reversible cerebral ischaemia.

This study investigated the changes in extracellular chemistry during reversible human cerebral ischaemia. Delayed analysis was performed on samples taken from a subgroup of patients during aneurysm surgery previously reported. Frozen microdialysis samples from 14 patients who had all undergone temporary clipping of the ipsilateral internal carotid artery (ICA) were analysed for another 15 amino acids with HPLC and for glycerol with CMA-600. Changes were characterised according to whether cerebral tissue oxygen pressure (PBO2) decreases were brief or prolonged. Brief ICA clipping (maximum duration of 16 minutes) in 11 patients was not associated with changes in amino acids or glycerol. Cerebral ischaemia, defined by a PBO2 decrease below 1.1 kPa for at least 30 minutes during ICA occlusion, occurred in 3 patients. None of whom developed an infarct in the monitored region. This prolonged reversible ischaemia was associated with transient delayed increases in gamma-amino butyric acid (GABA) as well as glutamate and glycerol, each by two-to-three folds. This study demonstrates detectable transient increases in human extracellular glutamate, GABA and glycerol during identified periods of reversible cerebral ischaemia, maximal 30-60 minutes after onset of ischaemia, but not in other amino acids detected by HPLC.

Adult↗

Genetic diversity and bottleneck studies in the Marwari horse breed.

Genetic diversity within the Marwari breed of horses was evaluated using 26 different microsatellite pairs with 48 DNA samples from unrelated horses. This molecular characterisation was undertaken to evaluate the problem of genetic bottlenecks also, if any, in this breed. The estimated mean (-/+ s.e.) allelic diversity was 5.9 (-/+ 2.24), with a total of 133 alleles. A high level of genetic variability within this breed was observed in terms of high values of mean (-/+ s.e.) effective number of alleles (3.3 -/+ 1.27), observed heterozygosity (0.5306 -/+ 0.22), expected Levene's heterozygosity (0.6612 -/+ 0.15), expected Nei's heterozygosity (0.6535 -/+ 0.14), and polymorphism information content (0.6120 -/+ 0.03). Low values of Wright's fixation index, F(IS) (0.2433 -/+ 0.05) indicated low levels of inbreeding. This basic study indicated the existence of substantial genetic diversity in the Marwari horse population. No significant genotypic linkage disequilibrium was detected across the population, suggesting no evidence of linkage between loci. A normal 'L' shaped distribution of mode-shift test, non-significant heterozygote excess on the basis of different models, as revealed from Sign, Standardized differences and Wilcoxon sign rank tests as well as non-significant M ratio value suggested that there was no recent bottleneck in the existing Marwari breed population, which is important information for equine breeders. This study also revealed that the Marwari breed can be differentiated from some other exotic breeds of horses on the basis of three microsatellite primers.

Alleles↗

Rhino-orbital-cerebral mucormycosis in type 1 diabetes mellitus.

AIM: To describe the presentation and outcome of rhino-orbital-cerebral mucormycosis (ROCM) in adolescents with type 1 diabetes mellitus (T1DM). METHODS: The medical records of six patients of T1DM with ROCM admitted between October 2001 to January 2004 were analysed. RESULTS: The mean (+/- SD) age and duration of DM of these patients were 16.1+/-3.0 years and 26.3 +/- 24.9 months respectively. Four patients had ROCM at presentation, while two developed it during their hospital stay when recovering from diabetic ketoacidosis. Proptosis (100%) and ptosis (100%) were the most common symptoms, and ophthalmoplegia (85%) and vision loss (85%) were the most common signs. Maxillary sinus (85%) was the commonest paranasal sinus to be involved. All patients received amphotericin B and had appropriate surgery except one. Four patients survived. Patients who had altered sensorium, facial necrosis, palatal perforation and cerebral involvement at presentation had poor outcome. CONCLUSION: High index of suspicion of ROCM in T1DM and combined approach with amphotericin B and appropriate surgery is rewarding.

Adolescent↗

Anorectal malformations and their impact on survival.

OBJECTIVE: To evaluate the incidence, types and the effect on outcome of associated anomalies in neonates with anorectal malformations (ARM). METHODS: This retrospective study was carried out on all neonates with ARM admitted to the neonatal surgical intensive care unit (NSICU) from 1998 through 2003. RESULTS: Of the 754 neonates admitted to the NSICU during the study period of 6 years, there were 124 (16.4%) neonates with anorectal malformations. Of these 110 were included in the study. 73 % were male and 27% female. 86% of these were high ARM (HARM) while only 14% were low ARM (LARM). Associated anomalies were seen in 68% of patients. The incidence was 72% for HARM and 50% for LARM. The major associated anomalies consisted of esophageal (13%), gastrointestinal (GIT) (11%), genitourinary (GUT) (32%), skeletal (26%), cardiac (33%) and miscellaneous 26%. The overall survival rate was 84% (82% for HARM and 94% for LARM). The survival among those with associated esophageal anomalies was 43%, GIT 67%, GUT 80%, cardiac 61%, skeletal 76% and miscellaneous 79% respectively. This difference in survival was significant only for those with esophageal (p=0.004) and cardiac anomalies (p=0.0026). The survival rates among those with one, two or more than two organ systems involved with associated anomalies were 88%, 82% and 58% respectively. This difference was significant only for more than two organ systems involvement (p=0.003). CONCLUSION: Associated anomalies are common in neonates with ARM, the incidence being similar for HARM and LARM. The survival depends upon the number and severity of associated anomalies both in patients with LARM and HARM. Neonates with more number of organ systems involved have a poorer survival specially when associated with esophageal and cardiac anomalies. All neonates with ARM merit a meticulous search for associated anomalies so that the management can be tailored for each baby.

Abnormalities, Multiple↗

Statistical analyses of coastal water quality for a port and harbour region in India.

A long-term study of temperature, pH, turbidity, suspended solid, salinity, dissolved oxygen, biochemical oxygen demand and ammonia nitrogen has been performed in a port and harbour region in India for four years from December 1996 to November 2000. Marine water quality results showed no regular trend. The mean monthly values of temperature, pH, turbidity, suspended solid, salinity, dissolved oxygen, biochemical oxygen demand and ammonia nitrogen were in the range of 22.64 +/- 0.4 to 29.05 +/- 1.37 degrees C; 7.65 +/- 0.04 to 7.81 +/- 0.13; 28.8 +/- 14.7 to 64.2 +/- 32.0 NTU; 283.5 +/- 81.8 to 356.0 +/- 159.7 mg/L; 29.78 +/- 7.18 to 29.78 +/- 1.04 ppt; 4.67 +/- 0.50 to 6.01 +/- 1.02 mg/L; 5.41 +/- 1.92 to 7.56 +/- 2.1 mg/L; and 0.25 +/- 0.07 to 0.63 +/- 0.49 mg/L, respectively. The results of correlation analysis showed that biochemical oxygen demand (BOD) was inversely correlated dissolved oxygen (DO) and poorly correlated with all other parameters. Turbidity and suspended solid were moderately correlated with each other while salinity was moderately correlated with other water quality parameters. In factor analysis, four factors were drawn out of the eight variables, which represented 74% of the variance of the original data. Factor I was related to suspended solid and turbidity. Factor II represented mainly temperature and DO showing inverse relation between these two. Factor III implied the degree of pollution at any monitoring station. Factor IV included pH and salinity. It could be concluded that the factor model represented almost all the variables.

Ammonia↗

Fly-ash-induced oxidative stress and tolerance in Prosopis juliflora L. grown on different amended substrates.

Field experiments were conducted to study the impact of metal accumulation on malondialdehyde (MDA), cysteine and non-protein thiol (NPSH) contents in the plants of Prosopis juliflora grown on the fly ash (FA) amended with soil, blue green algae (BGA) biofertilizer, farm yard manure, press mud and Rhizobium inoculation. The analysis of data revealed that the level of MDA, cysteine and NPSH was higher in the roots of the plant than leaves, which was found positively correlated with metal accumulation. An increase of 361.14, 64.25 and 305.62% in MDA, cysteine and NPSH contents, respectively was observed after 45 days in the roots of the plants grown in 100% FA as compared to 100% garden soil (GS). The level of MDA, cysteine and NPSH was found less in the plants grown on various amendments of FA showing ameliorating effect on the toxicity induced due to the accumulation of metals. The decrease in MDA, cysteine and NPSH contents was higher in Rhizobium-inoculated plants as compared to uninoculated plants grown on 100% FA. The results showed a high tolerance potential of the plant, which is further increased by inoculating the plant with FA-tolerant Rhizobium showing feasibility of using P. julifilora in environmental monitoring of FA landfills.

Carbon↗

Molecular variability in different Indian isolates of equine herpesvirus-1.

Three abortigenic Indian isolates of equine herpesvirus-1 (EHV-1) (Tohana, Hisar and Bikaner), along with two exotic abortigenic isolates (AB4 and V592) and another EHV-1 isolate (Jind) obtained from a case of perinatal foal mortality, were studied for variability. For this purpose, PCR and restriction endonuclease (RE) digestion techniques were used simultaneously as a DNA fingerprinting system. Nine different regions of EHV-1 virus were amplified by PCR using primer pairs specific for the regions and the products obtained from these regions were subsequently subjected to various restriction endonucleases to further assess the variability in the number of RE sites as well as in their positions. No difference was observed in all the four abortigenic isolates in terms of the size of different PCR products amplified by all the nine primer pairs, except for primer pairs 'E' and 'C'. PCR products obtained with primer pair E revealed that Tohana and Bikaner isolates were most similar while Hisar isolate was like V592 isolate. However, the PCR product obtained from Jind isolate had a size between the PCR products of Hisar and Tohan/Bikaner isolates. The primer pair 'C' used to amplify the region between 1151 to 3679 in 'Gene 1,2,3' clearly differentiated the EHV-1 isolate obtained from a case of perinatal foal mortality from isolates obtained from abortion cases. This primer pair needs to be exploited more extensively for use as a potential marker for differentiating the EHV-1 isolates, mainly the abortion cases from perinatal foal mortality ones. Restriction endonuclease studies done with PCR product of all the isolates with various primer pairs did not reveal any changes in the position or number of RE sites present in the products amplified, indicating no variation in different RE sites within the amplified PCR products. However, this study clarified that all the Indian isolates belonged to the IP group of EHV-1.

Abortion, Veterinary↗

Effect of reduction in tube current on reader confidence in paediatric computed tomography.

BACKGROUND: Computed tomography (CT) contributes significantly to the total radiation dose derived from medical imaging in children. As the number of CT examinations increases there is renewed interest in possible ways to minimize such radiation. AIM: To study the effect of decremental reduction in tube current settings on structural resolution and on reader confidence in being able to reach a final diagnosis. MATERIALS AND METHODS: The study involved spiral CT of children aged 0-13 years. CT performed at reduced mA settings (60-75, 76-90 and 91-130 mA for thoracic, abdominal and pelvic examinations, and 76-90 and 91-130 mA for cranial examinations) were compared with similar investigations at conventional settings (180-240 mA). Images were scored by two blinded readers for structural resolution and diagnostic confidence. Structural resolution was scored on a binary (adequate or not) scale for six structures each in cranial, thoracic and pelvic examinations and for eight structures in abdominal studies, and reader confidence was scored on a four-point scale as 25-100%. Scores from the two readers were averaged for comparison in subgroup analyses. RESULTS: Reduction of tube current settings to 75-90 mA for thoracic, abdominal and pelvic examinations and to 90-130 mA for cranial examinations was not associated with any significant deterioration in image quality. The number of scans considered satisfactory were comparable even at 60-75 mA, although the total relative scores for structural resolution at this setting were lower. CONCLUSION: Tube current settings can be significantly reduced in all paediatric age groups, in all regions. In younger children the impact of such reduction in tube current is likely to be greater. Cranial scans are more sensitive to such reductions as compared to thoracic or abdominopelvic examinations.

Adolescent↗

Leishmania donovani: effect of therapy on expression of CD2 antigen and secretion of macrophage migration inhibition factor by T-cells in patients with visceral leishmaniasis.

Visceral leishmaniasis (VL) commonly known as Kala-azar in India is one of the several clinically important infections, where Th1 sub-population of CD4+ T-cells, despite a pre-requisite, fails to express macrophage migration inhibition factor (MIF) and interferon-gamma which both activate the macrophage and coordinate the immune response to intra-cellular Leishmania sp. Expression of CD2 receptors before and after antileishmanial therapy on CD4+ T-cells of VL patients and their corresponding effect on MIF were examined. Before treatment the number of T-cells expressing CD2 was low which incorporated insignificant MIF response. The immunological reconstitution was, however, observed after treatment as manifested through upregulation of CD2+ T-cells with pronounced MIF generation response. The study, therefore, identifies a possible role of CD2 antigen in immunity to VL.

Animals↗

A comparative study of the effect of three different syncytiotrophoblast micro-particles preparations on endothelial cells.

Pre-eclampsia is a pregnancy-associated multi-system disorder of unknown etiology, characterized by damage to the maternal endothelium. The latter facet has been suggested to be mediated in part by elevated shedding of inflammatory placental syncytiotrophoblast micro-particles (STBM) into the maternal circulation. In this study, we have examined STBM prepared by three different methods: mechanical dissection, in vitro placental explant culture and perfusion of placental cotyledons. All three preparations yielded morphologically similar STBM, as confirmed by scanning electron microscopy, and all contained syncytiotrophoblast-specific proteins as determined by the presence of placental alkaline phosphatase. The functional properties of the three STBM preparations were examined on human umbilical vein endothelial cells (HUVEC), where the mechanically prepared particles were found to inhibit proliferation to the greatest extent. Furthermore, only mechanically prepared STBM lead to the detachment and apoptosis of HUVEC cells. Our study, therefore, suggests that STBM prepared from placental perfusion or in vitro explant culture are biologically different from mechanically prepared ones, and may provide a better approximation of physiologically produced placental micro-particles.

Adult↗