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Biomedical subjects

A Kumar

Publications and source records attributed to A Kumar.

At least 289 records · Page 16Linked to original sources
PubMed2001

Localized two-dimensional shift correlated MR spectroscopy of human brain.

A two-dimensional (2D) chemical shift correlated MR spectroscopic (COSY) sequence integrated into a new volume localization technique (90 degrees -180 degrees -90 degrees ) is proposed for whole-body MR spectroscopy (MRS). Using the product operator formalism, a theoretical calculation of the volume localization as well as the coherence transfer efficiencies in 2D MRS is presented. Phantom model solutions were used to test and optimize the efficiency of the proposed sequence. A combination of different MRI transmit/receive RF coils was used: a head MRI coil and a 3" surface coil receive combined with a body coil transmit. The J cross-peaks due to N-acetyl aspartate (NAA), glutamate/glutamine (Glx), myo-inositol (mI), creatine (Cr), choline (Ch), aspartate (Asp), gamma-aminobutyrate (GABA), taurine (Tau), glutathione (GSH), threonine (Thr), and macromolecules (MM) were identified. The cross-peak intensities excited by the proposed 2D sequence were asymmetric with respect to the diagonal peaks. Localized COSY (L-COSY) spectra of cerebral prefrontal and occipital gray/white matter regions in 15 healthy controls are presented. Magn Reson Med 46:58-67, 2001.

Adult↗
PubMed2001

Implementing logic gates and the Deutsch-Jozsa quantum algorithm by two-dimensional NMR using spin- and transition-selective pulses.

Quantum logical operations using two-dimensional NMR have recently been described using the scalar coupling evolution technique [J. Chem. Phys. 109, 10603 (1998)]. In the present paper, we describe the implementation of quantum logical operations using two-dimensional NMR, with the help of spin- and transition-selective pulses. A number of logic gates are implemented using two and three qubits with one extra observer spin. Some many-in-one gates (or Portmanteau gates) are also implemented. Toffoli gate (or AND/NAND gate) and OR/NOR gates are implemented on three qubits. The Deutsch-Jozsa quantum algorithm for one and two qubits, using one extra work qubit, has also been implemented using spin- and transition-selective pulses after creating a coherent superposition state in the two-dimensional methodology.

Journal Article↗
PubMed2001

Polyester and polycarbonate synthesis by in vitro enzyme catalysis.

Enzyme technology has significantly expanded in scope and impact over the past 10 years to include organic transformations in non-traditional environments. This is in part due to an increased understanding and capability of using enzyme catalysis in a wide variety of organic solvents, at interfaces, and at high temperatures and pressures. This review focuses on a relatively new but rapidly expanding research activity where in vitro enzyme catalysis is used for the synthesis of non-natural polyesters and polycarbonates. The inclination to use of enzymes for polymer synthesis has been fueled by a desire to carry out these reactions in the absence of heavy metals, at lower temperatures, and with increased selectivity. Aspects of this work that include enzyme-catalyzed step-growth condensation reactions, chain-growth ring-opening polymerizations, and corresponding transesterification of macromolecular substrates are discussed.

Acylation↗
PubMed2001

Long-term outcome of undifferentiated spondylarthropathy.

Undifferentiated spondylarthropathy is one of the common disease subsets in the group of so-called seronegative spondarthritides. It is not exactly known how often it differentiates into ankylosing spondylitis or other well-defined disease subsets over time. The present study was designed to find out the long-term outcome in this subset. Thirty-five patients diagnosed with undifferentiated spondylarthropathy between January 1987 and December 1988 were recruited. Twenty-two (63%) of them were available for detailed assessment 11 years after the original diagnosis. Their baseline characteristics did not differ from those of the original cohort of 35 patients and were as follows: male:female ratio 19:3, median age of onset 17 years (range 8-39), and median duration of disease 8 months (range 4-24). Clinical features were enthesitis (45%) and inflammatory pain in the back (100%), buttock (77%), hip (64%), shoulder (18%), knee (82%), ankle (77%), and hand and wrists (50%). There was no restriction in spinal movement. Family history was positive in two cases. Radiologically, the only finding was grade I sacroiliitis in 17 patients (77%). Human leukocyte antigen (HLA)-B27 was positive in all. Functionally, all were in class I. During follow-up, one patient developed psoriatic skin lesions after 9 years. Uveitis developed in four patients (18%). After a median follow-up of 11 years, 15 (68%) had ankylosing spondylitis, one developed psoriatic arthritis, four remained undifferentiated, and two had natural remission. Functionally, 19 patients (86%) were in class I and three (14%) were in class III. No patient had bamboo spine, but three underwent total hip replacement. Thus, a majority of patients (68%) with undifferentiated spondylarthropathy gradually developed ankylosing spondylitis of mild severity.

Adolescent↗
PubMed2001

Pseudoexstrophy of the bladder: a rare variant.

A 15-day-old female presented with a healed omphalocele and a triangular musculoskeletal defect in the hypogastric area similar to the defect seen in classic bladder exstrophy. The bladder was normal on exploration. The defect was successfully closed using a bilateral anterior pubic ramotomy. Only ten cases of pseudoexstrophy have been reported in the world literature.

Abdominal Muscles↗
PubMed2001

Drotaverine hydrochloride vs. valethamate bromide in acceleration of labor.

OBJECTIVES: To compare the efficacy and safety of drotaverine hydrochloride and valethamate bromide in shortening the duration of labor. METHODS: In a randomized controlled trial of 150 nulliparous women in established labor with cervical dilation of 4 cm, 50 women were given drotaverine (group I), 50 women were given valethamate (group II) and another 50 women were not given any medication (group III). Duration of labor, mode of delivery, side effects, and neonatal outcome were measured in all cases. Appropriate non-parametric tests and chi(2) tests were used for assessment of statistical significance. RESULTS: In the three groups, 100%, 96% and 46% women delivered within 6 h, respectively. The injection-to-delivery interval was significantly reduced in the drotaverine group (193.96 min) in contrast to the valethamate group (220.68 min) and control group (412.84 min). The rate of cervical dilation was highest in the drotaverine group (2.04 cm/h) compared with the valethamate bromide group (1.86 cm/h) and control group (1.01 cm/h). There were no major maternal or fetal adverse effects in any group, but minor side effects were more common in the valethamate group. CONCLUSION: Both intramuscular drotaverine hydrochloride and valethamate bromide are effective in acceleration of labor; however, drotaverine accelerates labor more rapidly and is associated with less side effects.

Cervix Uteri↗
PubMed2001

Techno-economic evaluation of soil-aquifer treatment using primary effluent at Ahmedabad, India.

A pilot study was carried out in Sabarmati River bed at Ahmedabad, India for renovation of primary treated municipal wastewater through soil aquifer treatment (SAT) system. The infrastructure for the pilot SAT system comprised of two primary settling basins, two infiltration basins and two production wells located in the centre of infiltration basins for pumping out renovated wastewater. The performance data indicated that SAT has a very good potential for removal of organic pollutants, nutrients as well as bacteria and viruses. The SAT system was found to be more efficient and economical than the conventional wastewater treatment systems and hence recommended for adoption. A salient feature of the study is the introduction of biomat concept and its contribution in the overall treatment process.

Biomass↗
PubMed2001

Integrated biological and physiochemical treatment process for nitrate and fluoride removal.

The feasibility of an integrated biological and physiochemical water treatment process for nitrate and fluoride removal has been evaluated. It consisted of two sequencing batch reactors (SBRs) in series. Performance of the process in the treatment of 24 synthetic water samples having nitrate concentrations of 40, 80, 120, 160, 200, and 250 mg/l (as N) and fluoride concentrations of 6, 10, 15, and 20 mg/l at different combinations was studied. Denitrification followed by defluoridation proved to be the best sequence of treatment. In all cases nitrate could be reduced to an acceptable level of less than 10 mg/l (as N) at 3, 5, and 7 h hydraulic retention times (HRTs) depending on its initial concentration. Fluoride concentrations up to 15 mg/l associated with nitrate concentrations up to 80 mg/l (as N) could be reduced acceptable 1.5 mg/l by alum-PAC slurry using alum doses up 850 mg/l [as Al2(SO4)3 x 16H2O] along with 100 mg/l of powdered activated carbon (PAC). Additional alkalinity produced during denitrification was used up during defluoridation for maintenance of pH avoiding the need for lime addition. On the other hand, residual organics, turbidity, and sulfide present in the denitrified water are removed by alum and PAC at the defluoridation stage along with fluoride, eliminating the need for an additional post-treatment step. At higher nitrate concentrations (> or = 120 mg/l as N), the alkalinity produced at the denitrification stage was in the range of 715-1175 mg/l as CaCO3. This excessive alkalinity inhibited reduction of fluoride to the level of 1.5 mg/l at the defluoridation stage, using alum doses up to 900 mg/l along with 100 mg/l of PAC. In all cases a fluoride concentration of 20 mg/l in water could not be reduced to the acceptable level of 1.5 mg/l.

Alum Compounds↗
PubMed2001

Synthesis and anti-inflammatory activity of 1-acetyl-5-substituted aryl-3-(beta-aminonaphthyl)-2-pyrazolines and beta-(substituted aminoethyl) amidonaphthalenes.

The title compounds were prepared by reaction of beta-acetylamino-naphthalene with different aromatic aldehydes followed by cyclisation with hydrazine hydrate and with different primary or secondary amines (Mannich's reaction), respectively. The structures of new compounds were confirmed by 1H-NMR and IR spectral data. Anti-inflammatory and ulcerogenic activities in vivo were evaluated and compared with the standard drugs, phenylbutazone and indomethacin. Some compounds of the series exhibited promising anti-inflammatory activity with a lower ulcerogenic liability than the standard drugs.

Animals↗
PubMed2001

Day surgery anterior cruciate ligament reconstruction: Sheffield experiences.

A review of the safety, practicality and cost effectiveness of day surgery anterior cruciate ligament reconstruction was studied in the British set-up. We evaluated 20 patients prospectively who underwent ACL reconstruction as a day surgery procedure for pain control, recovery time, post-operative complications and cost effectiveness. All patients on a verbal response score (VRS) for pain expressed themselves as satisfied or very satisfied. All patients regained a range of movement of 0-90 degrees by 1 week and 0-130 degrees by 6 weeks post-operatively. None of the patients required hospitalisation, only two patients had superficial wound infections at the graft-harvesting site. Cost analysis showed that day surgery ACL reconstruction was cost effective. The average saving per patient was in the range of 20-25% when compared to inpatient ACL reconstruction.

Adult↗
PubMed2001

Functional evaluation of the modified Elmslie-Trillat procedure for patello-femoral dysfunction.

A series of 28 knees in 27 patients were evaluated at an average of 36 months following surgical treatment for patella dislocation, patello-femoral pain, or a combination of both. All cases were treated by the modified Elmslie-Trillat procedure, which involves a lateral retinacular release and medialisation of the tibial tubercle on a distal pedicle. The evaluation included subjective, objective (Fulkerson and Kujala functional knee scores) and radiographic assessments. Subjectively, eight knees (28%) had excellent results, nine knees (33%) good results and seven knees (25%) fair results, accounting for an overall improvement of 86% over the preoperative status. All the knees in patients with a primary symptom of patella dislocation had an excellent or good subjective result, whilst only four knees (40%) in those patients with a primary symptom of pain and four knees (44%) in those with both pain and dislocation had a good or excellent result. The mean objective knee score was excellent for patients with dislocation only, and fair for those with only pain or both pain and dislocation. There have been no further episodes of dislocation in all patients. Six knees (21%) required later screw removal. The modified Elmslie-Trillat procedure produces a favourable outcome in patients with patella dislocation.

Adolescent↗
PubMed2001

Inhibition of the HIV-1 rev-RRE complex formation by unfused aromatic cations.

RNA viruses cause a wide range of human diseases. Development of new agents to target such viruses is an active area of research. Towards this goal, a series of diphenylfuran cations as potential inhibitors of the Rev-RRE complex have been designed and synthesized. Analysis of the interaction of the diphenylfurans with RRE and TAR RNA model systems by gel shift assays indicates that they exhibit both sequence and structure-dependent binding modes. Our results show a strong interaction between the diphenylfuran ring system and RRE bases, while the TAR interactions are much weaker with the compounds that are the best inhibitors of Rev-RRE.

Aminoglycosides↗