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Biomedical subjects

V Mishra

Publications and source records attributed to V Mishra.

At least 19 recordsLinked to original sources

Influence of core suture material and peripheral repair technique on the strength of Kessler flexor tendon repair.

The purpose of our study was to determine the most favourable combination of core suture material and peripheral repair technique for Kessler tendon repair. Thirty freshly thawed pig flexor tendons were repaired by a Kessler technique, either with braided polyester or monofilament nylon suture. A peripheral augmentation was done using one of the three techniques-running, cross-stitch and Halsted. All repairs were tested by cyclic loading, followed by load-to-failure. During cyclic loading six of the 15 tendons with a nylon core failed, but none with a braided polyester core. Irrespective of peripheral technique, the monofilament nylon core suture allowed early central cyclic gapping, resulting in failure of the repair. During load-to-failure testing, the running stitch proved weakest and the cross-stitch repair toughest.

Analysis of Variance↗

Uric acid reduces exercise-induced oxidative stress in healthy adults.

Uric acid (UA) possesses free-radical-scavenging properties, and systemic administration is known to increase serum antioxidant capacity. However, it is not known whether this protects against oxidative stress. The effects of raising UA concentration were studied during acute aerobic physical exercise in healthy subjects, as a model of oxidative stress characterized by increased circulating 8-iso-prostaglandin F2alpha (8-iso-PGF2alpha) concentrations. Twenty healthy subjects were recruited to a randomized double-blind placebo-controlled crossover study, and underwent systemic administration of 0.5 g of UA in 250 ml of 0.1% lithium carbonate/4% dextrose vehicle or vehicle alone as control. Subjects performed high-intensity aerobic exercise for 20 min to induce oxidative stress. Plasma 8-iso-PGF2alpha concentrations were determined at baseline, after exercise and after recovery for 20 min. A single bout of high-intensity exercise caused a significant increase in plasma 8-iso-PGF2alpha concentrations from 35.0 +/- 4.7 pg/ml to 45.6 +/- 6.7 pg/ml (P<0.01). UA administration raised serum urate concentration from 293 +/- 16 to 487 +/- 16 micromol/l (P<0.001), accompanied by increased serum antioxidant capacity from 1786+/-39 to 1899 +/- 45 micromol/l (P<0.01). UA administration abolished the exercise-induced elevation of plasma 8-iso-PGF2alpha concentrations. High UA concentrations are associated with increased serum antioxidant capacity and reduced oxidative stress during acute physical exercise in healthy subjects. These findings indicate that the antioxidant properties of UA are of biological importance in vivo.

Adult↗

Cost analysis of autologous peripheral blood stem cell transplantation for multiple myeloma.

High-dose chemotherapy (HDC) with autologous peripheral blood stem cell (PBSC) support is a common but expensive treatment for various hematological malignancies. A prospective cost analysis of evaluation/mobilization and the HDC + PBSC phase for patients with multiple myeloma was performed. Eleven consecutive patients at the National University Hospital Oslo, taking part in a Nordic treatment protocol, were included in the analysis during the period from May 1999 to December 2000. Clinical and resource use data were obtained prospectively on a daily basis registration and from patient records. The total cost for the evaluation/mobilization and the HDC + PBSC phase varied from 22,999 US dollars to 61,722 US dollars (mean 38,186 US dollars; median 30,569 US dollars). The mean length of hospital stay for the evaluation/mobilization phase was 8 days (range 4-17 days) and for the HDC + PBSC phase 19 days (range 14-29 days). A statistically significant correlation was found between the length of hospital stay and hospital costs for both phases (P < 0.003 and P < 0.010, respectively). A large part of the actual cost in the harvest phase was attributed to stem cell mobilization, including growth factors, harvesting and cryopreservation. In the HDC + PBSC phase, the most important part of the cost was paying nursing care personnel.

Antineoplastic Combined Chemotherapy Protocols↗

Orthopaedic surgery in severe bleeding disorders: a low-volume, high-cost procedure.

As more and more nations are scrutinizing their health care costs, attention has been focused on high-cost low-density disease. Assessment of actual total cost of care for haemophilia and its positive outcome becomes essential to justify support for these patients. In this study, we assessed hospital cost and diagnosis-related group (DRG) reimbursement for patients undergoing elective orthopaedic surgical procedures from May 1999 to December 1999. Hospital cost was assessed by a prospective microcost-analysis method. To identify real hospital costs, we performed registration of preoperative phase, operative phase and 1-year follow-up costs. Hospital cost included personnel costs and costs for clinical and laboratory procedures, blood products, prosthetic implants, coagulation factor concentrates and drugs. These data were compared with hospital DRG reimbursement. We included nine consecutive patients, with a mean age 38 years (19-54 years) who had had 10 major orthopaedic surgical procedures performed during the study period. Six patients had haemophilia A, two had haemophilia B and one had factor VII deficiency. Data analysis showed a mean cost of US$ 54,201 (range US$ 25,795-105,479; 1US$ = 8.5 NOK). The average actual hospital revenue (50% DRG reimbursement + income related to length of stay) was $4,730 (range $ 1,308-13,601). Our study confirms that orthopaedic surgery in patients with severe bleeding disorders puts the hospital to a considerable expense. Activity-based financing, as used in Norway, does not provide a proper reimbursement for this part of the haemophilia care.

Adult↗

Ureteric obstruction caused by pelvic actinomycosis.

Ureteric obstruction is a well-known complication of actinomycosis, however its management in previous case reports has been very variable and sometimes mutilating. We report a rare case presenting with ischiorectal abscess that was successfully treated by JJ stenting and penicillin.

Actinomycosis↗

A comparison of actual registered costs and costs derived from diagnosis-related groups (DRGs) for patients undergoing heart transplantation, lung transplantation, and thoracotomy for other lung diseases.

The Norwegian health care system, like other health care systems in the world, is in the midst of a changing financial environment for hospital reimbursement for patient care. Since 1997 the Norwegian government has introduced a new financing model of block grant and activity-based financing. In this model, diagnosis-related groups (DRGs) play an important role in hospital financing. The initial motive for developing the DRGs was to improve hospital productivity and efficiency and to develop a tool to control increasing hospital costs better. We raised the question as to whether the DRG system in fact covers actual costs in patient groups undergoing heart transplantation (n = 12), lung transplantation (n = 4), and thoracotomy for other diseases (n = 10). A new prospective cost model was developed to measure actual costs related to individual patients. The patients were closely observed and the related data collected during the hospital stay. Each patient's hospital stay was divided into four different categories of resource requirements, defined as heavy intensive care, light intensive care, intermediate care, and ordinary care. In addition, the number of staff involved and the duration of surgery and procedures were recorded, as were medicine costs and material costs. Based on these data, the actual costs for each patient were calculated. These were then compared with the respective DRG reimbursement (100 % coverage) for the corresponding group. We found that the median cost for heart transplantation was US$ 50,590 (1 US$ = 7.5 NOK based on the exchange rate at the time of the study), while the respective DRG reimbursement was US$ 65,662. For lung transplantation, the respective figures were US$ 46,668 vs US$ 65,662, and for thoracotomy, US$ 24,307 vs. US$ 11,004. We found that our method was applicable to a hospital setting. DRG coverage for heart and lung transplantation seems to overestimate the actual costs. For the thoracotomy procedure, the DRG coverage did not cover the actual costs.

Adult↗

A prospective cost evaluation related to allogeneic haemopoietic stem cell transplantation including pretransplant procedures, transplantation and 1 year follow-up procedures.

The Norwegian Ministry of Health and Social Affairs recently introduced activity-based financing for hospitals partly based on diagnosis-related groups (DRG). We soon observed that there seemed to be a considerable discrepancy between the reimbursement amount and the real cost of allogeneic haemopoietic stem cell transplantation. It was therefore decided to undertake a prospective micro-cost analysis to define a more realistic reimbursement. To identify real costs, we undertook a registration of pre-transplant procedures, transplantation and 1 year follow-up costs, including harvesting, personnel costs, clinical and laboratory procedures, together with blood products and drugs related to patients and donors. These data were compared to hospital DRG reimbursement. This information was registered for 17 consecutive patients, with a mean age 40 years (range 17-58 years). Ten patients had chronic myeloid leukaemia, three had acute lymphatic leukaemia, two had acute myeloid leukaemia and two had myelodysplastic syndrome. The data analysis showed a mean cost of US$ 106825 (NOK 901982), (range US$ 42376-362430). The average actual hospital revenue (50% DRG reimbursement + income related to length of stay + special procedure funding) was US$ 36404 (range US$ 26228-55998). Activity-based financing as applied in Norway, under-compensates hospital costs for allogeneic bone marrow transplantation. The government should make realistic estimates of real costs before introducing financial reforms in the health care system.

Adult↗

Enzymes and operons mediating xenobiotic degradation in bacteria.

Aromatic hydrocarbons constitute a major group of environmental pollutants. Bioremediation appears to be the only viable alternative for large-scale decontamination. A number of bacteria have been identified that can degrade a variety of xenobiotics. Extensive studies of the enzymes and genes involved in degradation of aromatic hydrocarbons have revealed that the degradative enzymes could be broadly grouped into two major categories, peripheral and ring-cleavage enzymes. The peripheral enzymes are the ones that catabolize the pollutants initially to a metabolite that is further degraded. A majority of peripheral enzymes are oxygenases that hydroxylate the aromatic compounds, rendering them susceptible to the enzymes of ring-cleavage pathway. The genes of ring-cleavage enzymes have been shown to be highly conserved between different bacterial species. Presently, a number of constraints limit the use of available strains for efficient bioremediation. This review describes the enzymes and genes involved in xenobiotic degradation and underscores the importance of understanding the expression and regulation of genes encoding peripheral enzymes and their intelligent manipulation using recombinant DNA technology for efficient degradation of aromatic compounds.

Bacteria↗

Ligand directed macrophage targeting of amphotericin B loaded liposomes.

Two types of ligand anchored multilamellar liposomes (MLVs) containing amphotericin B (Amp B) were prepared. The MLVs consisting of soya phosphatidylcholine (PC) and cholesterol (Chol) were coated with O-palmitoyl mannan (OPM). Similarly, the MLVs with the same Amp B content consisting of soya PC, Chol and phosphatidylethanolamine (PE) were prepared and covalently anchored with p-aminophenyl-mannopyranoside (PAM). The surface modified MLVs and their plain counterparts were characterised for size, shape, lamellarity, entrapment efficiency and ligand density. The stability in serum and in vivo bio-distribution in albino rats were also determined. It was observed that extent of accumulation of liposomal Amp B in macrophage rich organs, particularly liver, spleen and lungs was significantly high when compared against the free drug. The rates and extent of accumulation were found to increase further on ligand anchoring. In either of the cases, the macrophagic uptake of ligand anchored liposomes was inhibited significantly on pre-injection of hydrolysed mannan, being suggestive of receptor mediated uptake of ligand anchored liposomes. Comparison of biodistruibution pattern of ligand anchored MLVs revealed that PAM linked liposomes exhibited a higher hepato-splenic accumulation where as drug accumulation in lungs was highest in the case of OPM coated liposomes. It was thus observed that mannopyranoside is a specific ligand for targeting bioactives to the macrophages of liver and spleen while OPM could preferentially negotiate the targeting of bioactives to the alveolar macrophages.

Amphotericin B↗

Controlled and targeted drug delivery strategies towards intraperiodontal pocket diseases.

Advances in the understanding of the aetiology, epidemiology, pathogenesis and microbiology of periodontal pocket flora have revolutionized the strategies for the management of intraperiodontal pocket diseases. Intra-pocket, sustained release, drug delivery devices have been shown to be clinically effective in the treatment of periodontal infections. Several degradable and non-degradable devices are under investigation for the delivery of antimicrobial agents into the periodontal pocket including non-biodegradable fibres, films (biodegradable and non-biodegradable), bio-absorbable dental materials, biodegradable gels/ointments, injectables and microcapsules. With the realization that pocket bacteria accumulate as biofilms, studies are now being directed towards eliminating/killing biofilm concentrations rather than their planktonic (fluid phase) counterparts. Intraperiodontal pocket drug delivery has emerged as a novel paradigm for the future research. Similarly, bioadhesive delivery systems are explored that could significantly improve oral therapeutics for periodontal disease and mucosal lesions. A strategy is to target a wide range of molecular mediators of tissue destruction and hence arrest periodontal disease progression. Research into regenerating periodontal structures lost as a result of disease has also shown substantial progress in the last 25 years.

Biofilms↗

Need for bringing in a change in biochemistry curriculum to make it clinically oriented?

OBJECTIVES: This study was conducted to (a) assess the views of medical students and doctors regarding relevance of biochemistry training, (b) explore if they have any suggestion to bring in any improvement in contents of biochemistry curriculum and mode of teaching. METHODS: In 1997-98, a structured questionnaire was filled up by 114 medical students and 118 doctors. RESULTS: As many as 62/114 (55%) medical students and 40/118 (34%) doctors believed that it is not important to remember minute details of biochemical reactions (p value < 0.0001). Among medical students, 108/110 (98.2%) agree that a clinician should be invited to seminars for developing skills of interpretation of laboratory investigations; whilst 110/118 (93.2%) doctors expressed similar view, p value ns. Approximately 92% responders favored that departments biochemistry and physiology should co-ordinate on the topics of common interest in order to save time and effort. What is the most informative and effective way of teaching biochemistry?' in response to this question only 0.9% responders opted lecture as the best option. Seminars with active participation of medical students was preferred by 93.2% responders. About 6.9% responders reckoned that symposium prepared by a more than one teacher. In response to the question whether it is possible to cover pre-clinical subjects in 12 months so as to allow spiral mode of curriculum, 73% of all the responders agreed that it would be good idea, there was no difference of opinion among the doctors and medical students. On the other hand, 27% were strongly opposed to this suggestion. CONCLUSIONS: We suggest that there is a need to modify the contents, methods of teaching, and curriculum organization of training in clinical biochemistry. How best the curriculum can be made problem oriented needs to be debated among medical educationists.

Biochemistry↗

Self-Preservation of the Drop Size Distribution Function and Variation in the Stability Ratio for Rapid Coalescence of a Polydisperse Emulsion in a Simple Shear Field

Coalescence of oil-in-water emulsion droplets in a simple shear flow produced by a Couette device is considered. A phase Doppler anemometer was used to measure the droplet size distribution as a function of time for shear rates ranging from 55 to 213 s-1 and for sodium chloride salt concentrations from 0.095 to 0.6 M. The initial droplet size distribution was log-normal. During the coalescence process, the size distribution was self-preserving in accordance with D. L. Swift and S. K. Friedlander's analysis [J. Colloid Sci. 19, 621 (1964)]. In the limiting case of negligible repulsive force due to the electric double layer, the calculated stability ratios, corrected for droplet polydispersity, agree well with the theoretical analyses of G. R. Zeichner and W. R. Schowalter [AIChE J. 23, 243 (1977)] and D. L. Feke and W. R. Schowalter [J. Fluid Mech. 133, 17 (1983)] for the case of solid particle aggregation. The good agreement between the stability ratios for the case of coalescence of droplets in the present study and those for aggregation of solid particles indicates that resistance to film deformation and thinning present in the case of coalescence is not important compared with the collision process. Copyright 1998 Academic Press. Copyright 1998Academic Press

Journal Article↗

Anticonvulsant activity of thioureido derivatives of acetophenone semicarbazone.

A series of thioureido derivatives of acetophenone semicarbazone were synthesized and evaluated for anticonvulsant activity. Some compounds provided significant protection against maximal electroshock (MES) and subcutaneous pentylenetetrazol (scPTZ) induced seizures. The compound (2e) was the most active compound in the series with a dose of 30 mg kg-1 and ED50 23.5 mg kg-1 and equipotent to phenytoin ED50 23.2 mg kg-1. The toxicity of the compounds was assessed by determination of their approximate TD50 and LD50 values in order to have a better assessment of their pharmacological profile and protective index.

Acetophenones↗

Synthesis of aryl semicarbazone of 4-aminoacetophenone and their anti-HIV activity.

The thioureido derivative of 4-aminoacetophenone aryl semicarbazone have been prepared. These derivatives have been characterised on the basis of different physicochemical evidences. The anti-HIV-1 (HTLV-IIIB) and -HIV-2 (ROD) activity and cytotoxicity of the compounds were tested. The compound VII and VIII showed maximum protection among the series.

Acetophenones↗

Anisotropy of an 192iridium high dose rate source measured with a miniature ionization chamber.

The anisotropy of a high dose rate (HDR) 192Ir source was measured in air and in water using a miniature (0.147 cm3) ionization chamber. Measurements were made at a distance of 5 cm from the source center at polar angles from 10 degrees-170 degrees. The anisotropy was found to be less pronounced in water, and the anisotropy is asymmetric about the transverse axis. The results agree with previous ionization chamber and TLD measurements to within +/- 4%. Mean anisotropy factors were determined at each angle from all existing data at 5 cm distance, and compared to published Monte Carlo calculations, and to the values used in the microSelectron HDR brachytherapy planning system (BPS). The Monte Carlo photon transport code appears to systematically underestimate the anisotropy factor by up to 4% in the forward direction and overestimate it by up to 3% in the backward direction. The mean anisotropy factors also indicate that the BPS systematically underestimates the anisotropy factor by up to 3% in the forward direction, and overestimates it by up to 15% in the backward direction. However, the 15% difference occurs at 180 degrees where it is not likely to be clinically significant.

Air↗

Quantitative evaluation of radiochromic film response for two-dimensional dosimetry.

Radiochromic film (RCF) is attractive as a thin, high resolution, 2D planar dosimeter. We have studied the uniformity, linearity, and reproducibility of a commercially supplied RCF system (model MD-55). Forty 12 cm long strips of RCF were exposed to uniform doses of 6 MV x rays. Optical density (OD) distributions were measured by a helium-neon scanning laser (633 nm) 2D densitometer and also with a manual densitometer. All film strips showed 8%-15% variations in OD values independent of densitometry technique which are evidently due to nonuniform dispersal of the sensor medium. A double exposure technique was developed to solve this problem. The film is first exposed to a uniform beam, which defines a pixel-by-pixel nonuniformity correction matrix. The film is then exposed to the unknown dose distribution, rescanned, and the net OD at each pixel corrected for nonuniformity. The double exposure technique reduces OD/unit dose variation to a 2%-5% random fluctuation. RCF response was found to deviate significantly from linearity at low doses (40% change in net OD/Gy from 1 to 30 Gy); a finding not previously reported. To study the tradeoff between statistical noise and spatial resolution, OD was averaged over blocks of adjacent 50 microns pixels (ranging from 1 x 1 to 10 x 10 pixels). Reproducibility, defined as the standard deviation of repeated single-pixel measurements on separate film pieces, was 2% at 30 Gy for a resolution of 0.25 mm. With careful correction for nonlinearity and nonuniformity, RCF is a promising quantitative 2D dosimeter for radiation oncology applications.

Absorptiometry, Photon↗