Browsing by Author "MOHANTY, M"

Now showing 1 - 14 of 14
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    CASEIN AS A CARRIER MATRIX FOR 5-FLUOROURACIL - DRUG-RELEASE FROM MICROSPHERES, DRUG-PROTEIN CONJUGATES AND IN-VIVO DEGRADATION OF MICROSPHERES IN RAT MUSCLE
    (JOURNAL OF PHARMACY AND PHARMACOLOGY, 1994)
    Glutaraldehyde cross-linked casein microspheres were loaded with 5-fluorouracil (5-FU) from concentrated aqueous solutions of the drug after the microspheres were synthesized and cleaned. In-vitro release of the drug was examined in phosphate buffer in the absence and in the presence of protease at 37 degrees C. Drug release data showed that only about 20% of the drug is released in the absence of protease even after 5 days, while digestion of the matrix with protease released the entrapped drug completely in about 24 h. A protein-drug conjugate was synthesized via carbamoyl linkage using 6-(5-FU-1-yl)hexyl isocyanate and the drug release was examined in phosphate buffer at 37 degrees C. Release from the protein-5-FU conjugate was slower compared with the release from microspheres in the presence of protease. Implantation of placebo microspheres of different cross-linking densities in the gluteal muscle of rats showed no adverse tissue reactions over a one-year period. Histopathological examination of the tissues containing injected microspheres suggested that the biological life of casein microspheres in muscle is about 6 months, which is three times that of cross-linked albumin microspheres.
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    CHRONIC ARTERIAL-OCCLUSION IN A CANINE MODEL - A NOVEL TECHNIQUE
    (AMERICAN JOURNAL OF ROENTGENOLOGY, 1990) RAVIMANDALAM, K; RAO, VRK; KUMAR, S; JOSEPH, S; LAL, AV; MOHANTY, M
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    ENDOVASCULAR EMBOLIZATION USING HYDROGEL MICROSPHERES
    (JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE, 1994) JAYAKRISHNAN, A; MOHANTY, M; MANDALAM, R; RAO, VRK; GUPTA, AK; JOSEPH, S
    Controlled alkaline hydrolysis of crosslinked poly(methyl methacrylate) (PMMA) microspheres produced highly hydrophilic, smooth, compressible, nearly perfect microspheres having a range of water content 40-95%. These particles were found to possess many desirable properties as a material for therapeutic embolization. After successful toxicological and animal evaluation, these particles were used to treat various ailments such as arteriovenous malformations (AVM) of the brain, spinal cord, limbs, face and trunks, preoperative devascularization of tumours and in the management of severe life-threatening haemoptysis and haematemesis in clinical trials involving over 90 patients at this Institute. The results of these studies appeared to be very encouraging. The material is found to be an ideal embolic agent in all these clinical situations.
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    EVALUATION OF SOFT-TISSUE RESPONSE TO A POLY(URETHANE UREA)
    (BIOMATERIALS, 1992) MOHANTY, M; HUNT, JA; DOHERTY, PJ; ANNIS, D; WILLIAMS, DF
    Variations in the performance of vascular prostheses constructed of polyurethanes, and some evidence which suggested that these variations could be due not to the properties of the polymer itself, but to differences in the cellular response to the various microstructures of porous polyurethanes require investigation. Experiments were performed to evaluate quantitatively the extent of the cell behaviour adjacent to a series of polyurethane samples. It was shown that, with Biomer(R), a polyurethane urea, the profile of cell behaviour as a function of distance from the implant surface and of time following implantation, the response of cells in general and macrophages in particular, varied considerably with different internal microstructure. This supports the suggestion that the cellular response to different structures and susceptibility to degradation are related.
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    HYDROGEL MICROSPHERES FROM CROSSLINKED POLY(METHYL METHACRYLATE) - SYNTHESIS AND BIOCOMPATIBILITY STUDIES
    (BULLETIN OF MATERIALS SCIENCE, 1989) JAYAKRISHNAN, A; THANOO, BC; RATHINAM, K; MANDALAM, KR; RAO, VRK; LAL, AV; MOHANTY, M
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    INVIVO BIOCOMPATIBILITY OF ALIPHATIC SEGMENTED POLYURETHANE IN RABBIT
    (JOURNAL OF BIOSCIENCES, 1989) JAYABALAN, M; RATHINAM, K; KUMARY, TV; MOHANTY, M
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    LONG-TERM SOFT-TISSUE RESPONSE TO METALS, CERAMICS AND COMPOSITES - A COMPARATIVE HISTOPATHOLOGICAL EVALUATION
    (BULLETIN OF MATERIALS SCIENCE, 1987) MOHANTY, M; RATHINAM, K; KARTHA, CC
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    MODIFICATION AND INVITRO EVALUATION OF STROMA-FREE HEMOGLOBIN
    (CURRENT SCIENCE, 1988) KUMARI, TV; MOHANTY, M; VIJAYAKUMARI; JAYAPRAKASH, PA
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    PREPARATION AND INVITRO CHARACTERIZATION OF CRYSTALLINE STROMA FREE HEMOGLOBIN SOLUTION
    (INDIAN JOURNAL OF MEDICAL RESEARCH, 1987) MOHANTY, M; KUMARI, TV; FREDERICK, L; JAYAPRAKASH, PA
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    PREVENTION OF CALCIFICATION OF TISSUE VALVES
    (ARTIFICIAL ORGANS, 1994)
    In this study an attempt was made to find an optimum method of chemical treatment to prevent the calcification of bioprosthetic heart valves. Bovine pericardium was washed in a 5% sodium chloride solution followed by trypsin (Tr) treatment and was kept in 0.1% glutaraldehyde (GA) with a gradual increase in concentration up to 0.25% GA and finally posttreated with a 4% chitosan (Ch) solution. Fresh, 0.2% GA, 0.625% GA, and sodium chloride-Tr-GA treated pericardial samples were taken for comparative study. Tensile testing showed comparable strength and elongation at the breaking point for all groups. The thermal shrinkage studies indicated merit of the proposed treatment (5% sodium chloride-trypsin-glutaraldehyde treated pericardia with chitosan and without chitosan posttreatment). Collagenase assay showed that all differently treated (GA) materials were equally resistant to collagenase. All samples were implanted subcutaneously in rats for 2, 4, 8, or 12 weeks for calcification study. Morphological and mineral analyses showed complete prevention of calcification in sodium chloridetrypsin-GA-chitosan treated pericardium (Ca was 1.1 +/- 0.27 mg/g, von Kossa 0) at the 12th week of implantation.
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    PULMONARY VASOSPASM IN RABBITS INFUSED WITH STROMA FREE HEMOGLOBIN SOLUTION
    (INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY, 1989) MOHANTY, M; KUMARI, TV; RATHINAM, K; VIJAYAKUMARI
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    STUDIES ON THE EFFECT OF DEGREE OF HYDROPHILICITY ON TISSUE-RESPONSE OF POLYURETHANE INTERPENETRATING POLYMER NETWORKS
    (BIOMATERIALS, 1992)
    Interpenetrating polymer networks of polyurethane and vinyl monomers such as polyacrylamide, polyvinyl pyrrolidone, poly(hydroxyethyl methacrylate) and poly(methyl methacrylate) were implanted intramuscularly in rabbits. Attempts were made to correlate the morphological aspects of the interpenetrating polymer networks to their histological response. A relatively increased hydrophillicity of hydrophobicity of the interpenetrating polymer networks as in the case of polyurethane-polyvinyl pyrrolidone and polyurethane-poly(methyl methacrylate) interpenetrating polymer networks, respectively, could elicit an inert response whilst degradation of materials promoted reactivity.
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    USE OF GLUTARALDEHYDE-GENTAMICIN-TREATED BOVINE PERICARDIUM AS A WOUND DRESSING
    (BIOMATERIALS, 1994) CHANDA, J; RAO, SB; MOHANTY, M; Muraleedharan, CV; ARTHUR, VL; BHUVANESHWAR, GS; VALIATHAN, MS
    Glutaraldehyde (GA)-pretreated gentamicin post-fixed bovine pericardium has been evaluated as a wound dressing in this study. Two excisions approximately 7 x 4cm, each of full thickness skin, from the upper and lower parts down to, but not including, the panniculus carnosus were made from the back of the guinea pig. The skin excised from the upper part was placed on the wound bed of the lower part as an autograft, whereas the upper wound was closed using 5% sodium chloride-trypsin-0.1% GA-0.048% gentamicin-treated bovine percardium and sutured for comparative study. The wounds were inspected every 3-6 d for infection and exudation. Histopathological studies were performed at weekly intervals in the post-operative period. At the fifth week, a very thin linear scar on the epidermal aspect without remarkable contracture was observed and histopathology showed the completion of epithelization across the wounds in all cases. This study demonstrates that GA-pretreated, gentamicin-post-fixed bovine pericardium may be used as an alternative biological dressing in the case of large wounds.