Search PubMed⌕ Search

Biomedical subjects

P Ghosh

Publications and source records attributed to P Ghosh.

At least 343 records · Page 19Linked to original sources
PubMed1983

Effect of postoperative immobilisation on the regrowth of the knee joint semilunar cartilage: an experimental study.

Bilateral total medial meniscectomy was undertaken in the knee joints of 12 adult greyhounds. One-half of the animals had one meniscectomised joint immobilised by an external fixation system for 5 weeks following meniscectomy. All animals were sacrificed 6 months after surgery. The menisci (regrown and normal) were examined for collagen content and analysed histochemically to assess collagen assembly and glycosaminoglycan (GAG) distribution. Although the collagen content of regrown tissues were not statistically different from normal medial or lateral menisci, the fibre development and GAGs were abnormal. It is concluded that movement following meniscectomy is likely beneficial to the matrix formation in the regenerating tissue, but this together with weight bearing may have a detrimental effect on articular cartilage of the medial joint compartment.

Animals↗
PubMed1983

The interaction of pentosan polysulphate (SP54) with human neutrophil elastase and connective tissue matrix components.

The binding of pentosan polysulphate (SP54) to human polymorphonuclear leucocyte elastase (PMNE) and some of its natural and synthetic substrates has been investigated. Using an ion exchange (DE52) assay system the binding of SP54 to PMNE was found to be 100 times stronger than to collagen or proteoglycan (PG). While the order for in vitro binding of the drug to purified substrates was found to be PG greater than gelatin greater than type I collagen, in vivo experiments indicated that SP54 was localized in tissues rich in collagen. Using gel-exclusion chromatography it was shown that these tissues also contained proteinaceous components other than PG and collagen which interacted with SP54. These results indicate that the potent inhibitor activity of SP54 against PMNE (50% inhibition at 1.7 X 10(-7)M) probably occurs by a specific interaction with the enzyme rather than by substrate binding inhibition, although the latter interaction may be important for localising the drug in these tissues.

Cartilage, Articular↗
PubMed1983

The effects of postoperative joint immobilization on articular cartilage degeneration following meniscectomy.

Bilateral medial meniscectomy was performed in 12 mature greyhounds. One knee joint of half the group was immobilized by a Kirschner splint for a period of 5 weeks immediately following meniscectomy, after which the device was removed and the animals were allowed free movement for a further 21 weeks before sacrifice. Three greyhounds served as controls. While the collagen levels of articular cartilage from the femoral condyles and tibial plateaus of meniscectomized animals were the same as that of controls, differences were found for proteoglycan (PG) content and extractability using nondissociative conditions (0.5 M guanidinium hydrochloride (GuHCl) but not dissociative conditions (4.0 M GuHCl). With nondissociative conditions, twice as much PG was extracted from medial femoral condyle of meniscectomized animals encouraged to bear weight on joints immediately after surgery compared to that from controls or animals in whom joints were immobilized after surgery. Proteoglycans from medial tibial plateau cartilage of the free contralateral joints of the immobilized group were more readily extracted using 0.5 M GuHCl and also showed a statistically significant depression of uronic acid levels relative to both controls and tissues of other surfaces. The data suggest that postoperative management of meniscectomy in the human may be more important than has hitherto been recognized.

Animals↗
PubMed1983

Statico-dynamic palatopharyngoplasty with transmitted dynamism--a new technique.

A new operation, 'Statico-dynamic palatopharyngoplasty with transmitted dynamism', is described for correction of rhinolalia aperta and nasal regurgitation in palato-pharyngeal incompetence. This is a simple one-stage operation and, besides offering good speech correction, prevents nasal regurgitation. The principle involves imparting dynamism to the conventional static posterior pharyngeal flap, based superiorly, by a muscle sling created by transplanting the palatopharyngeus/salpingopharyngeus complex. This mechanism brings about dynamic competence in the palato-pharyngeal mechanism.

Humans↗
PubMed1982

Effects of 4-nitro- and 4-sulpho-7-substituted benzofurazans on nucleic acid and protein synthesis of a malignant fibrosarcoma cell line in combination with mild hyperthermia.

The inhibitory effects of substituted nitro- and sulphobenzofurazans on DNA, RNA and protein synthesis were compared in a new malignant fibrosarcoma cell line at 37 degrees C and 41 degrees C. The effects of these drugs with and without mild hyperthermia were evaluated by determining the % inhibition of incorporation of 3H-precursors into DNA, RNA and protein. None of the sulphobenzofurazan derivatives (Sbf) were effective inhibitors of nucleic acid and protein synthesis at 37 degrees C nor did they enhance the inhibitory effect of hyperthermia alone. The nitrobenzofurazan derivatives (Nbf) at concentrations 10% that used for the Sbf derivatives strongly inhibited biopolymer synthesis in a dose related manner; 4-chloro-7-nitrobenzofurazan (Nbf-Cl) being the most potent inhibitor. Hyperthermia amplified the effect of all the Nbf compounds tested on RNA and protein synthesis but did not further affect DNA synthesis. This selective synergistic effect was most pronounced when the lowest concentrations of Nbf compounds were studied. The synergism however, did not follow a uniform pattern. 6-Mercaptopurine and 6-(1-methyl-4-nitro-5-imidazoyl)thiopurine (Azathioprine) (100 microM) had marginal effects on nucleic acid and protein synthesis when the cells were exposed to these two thiopurines for 1 h at both 37 degrees C and 41 degrees C and they had only a moderate inhibitory effect after exposure for 15 h.

Animals↗
PubMed1982

[Extra-nasopharyngeal extensions of angiofibroma].

Four cases of NPA with extra-nasopharyngeal extensions have been presented, two of which had an intracranial extension. On of the cases with intracranial extension underwent a transtemporal craniotomy removal and four temporal fossa. The other three cases were managed by the sublabial and transantral routes. Methods of pre-operative diagnosis of such extensions have been discussed and the importance of pre-operative recognition of extension in every NPA has been emphasized. Various approaches to the lateral and intracranial extensions have been reviewed. We feel that, for lateral extensions, sublabial and/or transantral or transzygomatic approaches are adequate, while the radical approach of Karnik is to be preferred only in large lateral extensions and in cases of intracranial extensions without symptoms of a space-occupying intracranial lesion. However, for patients with intracranial symptoms, a staged procedure is indicated and is safe for the patient.

Adolescent↗
PubMed1982

Liposomes as carrier for production of sugar specific antibodies: preparation of antigalactosyl antiserum.

Negatively charged multilamellar liposomes, covalently coupled with p-aminophenylated derivative of D-galactose, have been used to raise galactose specific antibodies in rabbits. The specificity of the antiserum has been characterized by immunodiffusion, quantitative precipitation and hapten inhibition studies. In addition to its specificity against the sugar moiety the antibody population also recognizes the aromatic aglycone portion of the introduced hapten. This offers a new method of raising sugar specific antibodies using liposomes as immunological carriers.

Animals↗