Search PubMed⌕ Search

Biomedical subjects

P Ghosh

Publications and source records attributed to P Ghosh.

At least 361 records · Page 20Linked to original sources
PubMed1981

The contribution of the intervertebral disk to the scoliotic deformity.

We have put forward a number of questions about the role of the intervertebral disk in idiopathic scoliosis which are based on experimental evidence and current connective tissue research. It is regrettable that the last two decades have not seen a single major advance in the treatment of scoliosis based on a scientific understanding of the etiology and mechanisms of curve progression. The efficacy of early detection and surgical techniques cannot be denied but orthopedic surgery is not relieved of the responsibility of pursuing the causation and pathogenesis of scoliotic curvature. Spinal fusion for scoliosis cuts across the fundamental principle of orthopedic surgery--the preservation of musculoskeletal function--a maximum which Trueta enunciated so strongly through his surgical lifetime. Clearly, a sacrifice of spinal mobility is not a final acceptable solution to the malady.

Adolescent↗
PubMed1981

1-(2-Thienyl)-2-phenylethylamines as potential non-stimulant anorectics.

A series of 1-(2-thienyl)-2-phenylethylamines was synthesized and tested for anorectic and motor activity effects in rats. Phenyl ring substituents included Cl, Br, F, CF3, CH3, OCH3, and NO2; amino group substituents included alkyl, benzyl and acetyl groups. About half of the compounds produced significant anorexia; only one of these active anorectics increased motor activity. The three most potent non-stimulant anorectics were: 1-(2-thienyl)-2-(4-chlorophenyl)ethylamine, its N-isopropyl analogue, and N-isopropyl-1-(2-thienyl)-2-(4-fluorophenyl)ethylamine.

Animals↗
PubMed1980

Grafting of different glycosides on the surface of liposomes and its effect on the tissue distribution of 125I-labelled gamma-globulin encapsulated in liposomes.

Different glycosides were grafted on the surface of liposomes containing 125I-labelled gamma-globulin by two ways: (1) by using glycolipid and (2) by covalent coupling of p-aminophenyl-D-glycosides to phosphatidylethanolamine liposomes using glutaraldehyde. The distribution of 125I-labelled gamma-globulin was determined in mouse tissues from 5-60 min after a single injection of these liposomes. The liver uptake of encapsulated 125I-labelled gamma-globulin was highest from liposomes having galactose and mannose on the surface. Competition experiments and cross-inhibition studies indicate that this uptake are mediated by specific recognition of the surface galactose and mannose residues of liposomes by the receptors present on the plasma membrane of liver cells. Stearylamine-containing liposomes were found to be more efficient in mediating the uptake of 125I-labelled gamma-globulin by the lung, whereas in the case of spleen, phosphatidylethanolamine liposomes were more efficient. The extent of uptake of 125I-labelled gamma-globulin from all types of liposome decreases as the amount of given liposomes increases. The uptake of 125I-labelled gamma-globulin from liposomes containing asialogangliosides depends upon the phospholipid/glycolipid ratio. These experiments clearly demonstrate that enhanced liposome uptake by liver cells could be achieved by grafting galactose and mannose on the liposomal surface.

Animals↗
PubMed1980

Stapedius reflexometry. A diagnostic test of myasthenia gravis.

Contraction of the stapedius muscle can be measured by electroacoustic impedance bridge. Muscle weakness and easy fatiguability which are cardinal features of myasthenia gravis (MG) are manifested by increased threshold and early decay of the stapedius reflex. This can be used as an objective test in the diagnosis of myasthenia gravis. Stapedius reflex was measured using Madsen Zo72 electroacoustic impedance bridge in 10 patients with myasthenia gravis and in an equal number of controls. The test was done before and 30 min after intramuscular injection of neostigmin. All patients with myasthenia gravis showed an elevated reflex threshold and 5 patients showed reflex decay. These findings reverted to normal after neostigmin injection. Stapedius reflexometry is a simple objective test for the diagnosis of myasthenia gravis.

Acoustic Impedance Tests↗
PubMed1980

Inclination of eye-tracking tracing. (A localising parameter in electro-oculography).

A new diagnostic parameter in electro-oculography, viz. 'Inclination of eye-tracking tracing' is presented. Electro-oculographically the pendular eye-tracking tracing was recorded before and after calorization, using the technique of serial thermal vestibulometry. In some cases of brain-stem lesion, the tracing inclined in the direction of the slow component of the calorically-induced nystagmus; but this phenomenon was not noted in cases with peripheral lesions, nor in pure frontal, occipital, parietal of cerebellar lesions. A neuro-anatomical model is postulated in explanation of this phenomenon. It appears that the basic lesion responsible for this phenomenon is a small one partially involving the slow-discharging neuronal units in the lower reticular core and in the adjacent suprasegmental inhibitory cortico-reticular tracts, thus bringing about a state of relative hyperactivity (release phenomenon) of the remaining surviving neurones which belong to the slow-discharging neuronal units. The latter has been referred to here as the 'Inclination Neuronal Mechanism' and this phenomenon appears to be the converse of "Central vestibular recruitment', the former being caused by a lesion in the 'slow-discharging units', the latter by a lesion in the 'quick-discharging units' ('nystagmogenic area'), the two units belonging to the same reticular system but having opposite functions.

Adult↗
PubMed1980

Phonosurgery (combined approach palatopharyngoplasty--CAP).

A new surgical approach (CAP--Combined Approach Palatopharyngoplasty) is described for the correction of speech defects in palatopharyngeal incompetence. In palatopharyngeal incompetence the spatial relationships between the various components of the palatopharyngeal mechanism are disturbed. This combined approach brings about near-normal relationships (viz. intrapalatal and palatopharyngeal), as well as providing a competent palatopharyngeal sphincter, thus offering a remarkable improvement in speech. The operation comprises a two-stage procedure: stage I:--(a) submucosal transplantation of the levator palati muscles posteriorly to the region of the uvula and (b) 'crossed' palatopharyngoplasty; isolation of the palatopharyngeus muscles (posterior pillars) with their bases superiorly placed at their junctions with the soft palate, and transplantation of the lower free ends into the transverse retropharyngeal musculo-fascial pockets on the opposite side, the flaps thus crossing each other in the midline: stage II:--'check-valve' palatopharyngoplasty; elevation of a superiorly based posterior pharyngeal flap with anastomosis to the soft palate. The dynamics which are responsible for the improvement in speech are: (a) elevation of the palate to about the level of the atlas; (b) statico-dynamic constriction of the pharyngeal phonetic passage at the following levels: (i) at the newly placed levator eminence, (ii) at the newly constructed dynamic sphincter situated between the above-mentioned crossing and the free margin of the soft palate, and (iii) at the junction of the check-valve flap with the posterior pharyngeal wall; (c) increase in the effective length of the soft palate. The phonetic stream is prevented from entering the nasal chambers during the utterance of non-nasal pressure sounds by the newly constructed three-tier protective mechanism. This is identical with, but a 'reverse' representation of, the normal three-tier protective mechanism of the larynx, which prevents food from entering the tracheo-broncheal tree during deglutition. The operation has been performed in eight cases and the results are satisfactory, in so far as improvement in the quality of speech is better than that observed following other operations. In conclusion, the principles of phonosurgery may well be diagrammatically represented in Fig. 7.

Humans↗
PubMed1980

A radioassay for proteolytic cleavage of isolated cartilage proteoglycan. 2. Inhibition of human leukocyte elastase and cathepsin G by anti-inflammatory drugs.

20 non-steroidal anti-inflammatory drugs and other agents were evaluated for their effectiveness in directly inhibiting the proteolytic activity of human leukocyte elastase and cathepsin G. The proteolysis of hide powder azure by leukocyte granule extracts was used for initial testing, and selected drugs were then studied further using a radioassay of the proteolysis of isolated proteoglycan by purified leukocyte elastase and cathepsin G. The results indicated that at drug concentrations likely to be attained to vivo, phenylbutazone may significantly inhibit elastase, while gold thiomalate and mucopolysaccharide polysulfonic acid ester (MPSE; Arteparon) could limit the action of cathepsin G. Oleic acid may provide a useful starting point for development of agents specifically designed to inhibit cartilage erosion.

Anti-Inflammatory Agents↗
PubMed1979

Neutral protease inhibitors from human intervertebral disc and femoral head articular cartilage.

Assays of several proteases, incorporating guanidinium chloride extracts of human femoral head cartilage and intervertebral disc, demonstrated that both tissues contain inhibitors of certain serine proteases. Trypsin, chymotrypsin and a granule extract of human polymorphonuclear leukocytes containing elastase and cathepsin G activities, were inhibited by low molecular weight fractions prepared by Sephadex G-75 chromatography. Using a radioassay, it was further shown that these fractions inhibit proteolysis of cartilage proteoglycan. The inhibitor in intervertebral disc is concentrated in the nucleus pulposus, with a decreasing gradient to the periphery of the annulus fibrosus. It is proposed that these inhibitors confer at least partial protection against pathological proteolysis of the proteoglycans in human articular cartilage and nucleus pulposus.

Animals↗
PubMed1979

The pathogenesis of osteoarthrosis.

Recent investigations on protease inhibitors in articular cartilage have provided new insights into the possible initial lesions of osteoarthrosis. A hypothesis has been formulated based upon an impaired ability of chondrocytes to synthesize protease inhibitors, which leads to loss of matrix integrity and vascular invasion from subchondral bone and the joint margins.

Cartilage, Articular↗