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Biomedical subjects

P Shenoy

Publications and source records attributed to P Shenoy.

12 recordsLinked to original sources
PubMed1999

Differences in phosphatase modulation of alpha4beta1 and alpha5beta1 integrin-mediated adhesion and migration of B16F1 cells.

It is well established that a biphasic relationship exists between the adhesive strength of beta1 integrins and their ability to mediate cell movement. Thus, cell movement increases progressively with adhesive strength, but beyond a certain point of optimal interaction, cell movement is reduced with further increases in adhesive function. The interplay between the various kinase and phosphatase activities provides the balance in beta1 integrin-mediated cell adhesion and migration. In the present study, the significance of protein tyrosine phosphatases (PTP) and ser/thr protein phosphatases (PP) in alpha4beta1 and alpha5beta1 integrin-mediated mouse melanoma B16F1 cell anchorage and migration on fibronectin was characterized using phosphatase inhibitors. At low fibronectin concentration, alpha5beta1 functioned as the predominant receptor for cell movement; a role for alpha4beta1 in B16F1 cell migration increased progressively with fibronectin concentration. Treatment of B16F1 cells with PTP inhibitors, sodium orthovanadate (Na3VO4) and phenylarsine oxide (PAO), or PP-1/2A inhibitor, okadaic acid (OA), abolished cell movement. Inhibition of cell movement by PAO and OA was associated by a reduction in the adhesive strength of alpha4beta1 and alpha5beta1. In contrast, treatment of B16F1 cells with Na3VO4 resulted in selective stimulation of the adhesive function of alpha5beta1, but not alpha4beta1. Therefore, our results demonstrate that (i) both PTP and PP-1/2A have roles in cell movement, (ii) modulation of cell movement by PTP and PP-1/2A may involve either a stimulation or reduction of beta1 integrin adhesive strength, and (iii) distinct phosphatase-mediated signaling pathways for differential regulation of the various beta1 integrins exist.

Animals↗
PubMed1994

First cleft branchial fistula in a child--a modified surgical technique.

Congenital first branchial cleft fistulae, their embryology, anomalies, varied relationships to the facial nerve and surgical techniques for their excision have been well described in the literature. We report a case of a type II first cleft fistula in a three-year-old child which required a modification of the standard surgical approach to achieve safe and complete excision with identification and preservation of the facial nerve.

Branchioma↗
PubMed1993

A case of quinsy in a fifteen-month old child.

A case of peritonsillar abscess in an infant is described, which is a rare lesion in infants and young children. To our knowledge this is the youngest child described in the English literature. The clinical presentation and treatment of peritonsillar abscess in infants and young children are discussed. Serious complications can occur early in the course of the disease because of physiological and anatomical factors and thus early aggressive treatment is required.

Anti-Bacterial Agents↗
PubMed1989

Mycotic infection of the ear (otomycosis): a prospective study.

Otomycosis (fungal infection of the ear) is not uncommon clinical problem encountered in our ENT practice. It makes up to 6 per cent of all patients with symptoms of ear disease seen in the Outpatient Clinic. Of the 193 patients with a clinical diagnosis of otomycosis, 171 cases produced positive fungal isolates. In this study Aspergillus species (niger and fumigatus) have been the most common fungal pathogens. Various aetiopathological factors have been examined in detail, and the available literature reviewed. The results of the treatment by nine antifungal agents currently available in Bahrain have been analysed.

Adolescent↗
PubMed1989

Maxillary antral lavage--infiltration and surface anaesthesia compared.

A prospective study on 210 patients was conducted to determine the relative efficacy of infiltration anaesthesia as against surface anaesthesia for antral lavage. The patients were categorized into three groups and comparisons were made on patient response and our observations. This study confirms that infiltration technique is superior to surface anaesthesia and is, also, less time consuming.

Administration, Topical↗
PubMed1989

Osteoma of the ear canal presenting with headache.

Osteoma of external auditory canal is a rare benign tumour. Usually it is found incidentally and often symptomless. Here we have a case of osteoma arising from the anterior wall of the bony external auditory canal, causing ipsilateral temporal headache which was relieved by removal of tumour.

Adult↗
PubMed1988

Haemangiopericytoma of the nasal septum.

Haemangiopericytoma is a rare vascular tumour originating from pericytes which are cells surrounding the capillaries. Only 23 cases of haemangiopericytoma arising from the nose and sinuses have been reported in the literature, of which three are from the nasal septum. We are pleased to report one more case.

Adult↗
PubMed1988

Odontogenic keratocyst involving the maxillary antrum.

An unusual case of odontogenic keratocyst arising from the maxilla, involving the maxillary antrum has been reported. Presence of an ectopic canine tooth under the orbital floor was a noticeable feature of this case. The clinical presentation, radiological, and histological aspects and treatment have been reviewed.

Adult↗