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Biomedical subjects

J Menon

Publications and source records attributed to J Menon.

At least 19 recordsLinked to original sources

Microbial growth in vials of Botulinum toxin following use in clinic.

PURPOSE: Botulinum toxin has various applications in ophthalmology and is used in the outpatient department, where it is often exposed to room temperatures for 3-4 h. The manufacturer's recommendations are that the reconstituted toxin be stored in a refrigerator when not in use and discarded 4 h after reconstitution. The aim of our study was to examine such used bottles of Botulinum toxin for microbial growth after 4 h at room temperature. METHODS AND RESULTS: Eleven consecutive bottles of Botulinum toxin used with aseptic precautions in the Ophthalmology outpatient clinics were exposed to room temperatures for 4 h. These were subsequently analysed for microbial growth. No growth was directly obtained from any of the Botulinum toxin bottles during our study. CONCLUSIONS: This pilot study suggests that if aseptic precautions are followed during the use of Botulinum toxin, the contents of the bottle remain sterile despite being exposed to room temperatures for up to 4 h. This has implications on the use of the reconstituted toxin after the recommended 4 h.

Asepsis↗

Fasciolopsiasis: a first case report from Malaysia.

Fasciolopsiasis is a disease caused by the largest intestinal fluke, Fasciolopsis buski. The disease is endemic in the Far East and Southeast Asia. Human acquires the infection after eating raw freshwater plants contaminated with the infective metacercariae. There has been no report of fasciolopsiasis either in man or in animal in Malaysia. We are reporting the first case of fasciolopsiasis in Malaysia in a 39-year-old female farmer, a native of Sabah (East Malaysia). This patient complained of cough and fever for a duration of two weeks, associated with loss of appetite and loss of weight. She had no history of traveling overseas. Physical examination showed pallor, multiple cervical and inguinal lymph nodes and hepatosplenomegaly. Laboratory investigations showed that she had iron deficiency anemia. There was leukocytosis and a raised ESR. Lymph node biopsy revealed a caseating granuloma. Stool examination was positive for the eggs of Fasciolopsis buski. The eggs measure 140 x 72.5 microm and are operculated. In this case, the patient did not present with symptoms suggestive of any intestinal parasitic infections. Detection of Fasciolopsis buski eggs in the stool was an incidental finding. She was diagnosed as a case of disseminated tuberculosis with fasciolopsiasis and was treated with antituberculosis drugs and praziquantel, respectively.

Adult↗

Ultrastructural observations on effects of different concentrations of calcium and thyroxine in vitro on larval epidermal cells of Rana catesbeiana tadpoles.

During anuran metamorphosis dramatic changes in morphogenesis and differentiation of epidermis occur under the influence of thyroid hormones. Modification of ionic calcium concentration also markedly alters the pattern of proliferation and differentiation in amphibian epidermal cells in vitro. The present study was designed to determine the direct effect of low (0.05 mM) and high (0.5 mM) calcium (Ca2+) in the absence or presence of thyroxine (10(-7) M) on epidermal cells of the body and tail tissue in vitro. When tail fin and body skin explants were maintained in low (0.05 mM) calcium for 48 h, normal ultrastructural morphology and integrity of the cells was observed in both the tissue types. When tissues were exposed to high levels of calcium (0.5 mM) in culture medium, tail epidermis showed stratification, and skein cells exhibited apoptosis, both in the presence or absence of thyroid hormones. Under high calcium conditions, the body epidermis showed keratinization of apical cells, apoptosis of skein cells, and increased desmosome formation. These results suggest that (1) optimal Ca2+ concentration for larval epidermal cells is quite low (0.05 mM), (2) high Ca2+ leads to keratinization only in body epidermis, and (3) apoptosis occurred in skein cells of both the tissues at high Ca2+ concentrations (0.5 mM). The present study therefore suggests that the extracellular calcium concentration regulates the process of cell death and differentiation in Rana catesbeiana larval epidermis, and this effect may be similar to the effect of calcium on mammalian epidermal cells.

Animals↗

A case for a neonatal, low-dose BCG vaccination trial.

The rational design of a successful vaccination strategy against tuberculosis requires certain kinds of information and must take account of several considerations: (i) the nature of the immune response that protects the large majority of individuals infected by Mycobacterium tuberculosis, designated as healthy contacts, must be defined and distinguished from that in tuberculosis patients, whose immune system must have failed; (ii) the vaccination strategy must incorporate a way of priming the immune system to guarantee in all individuals this protective response, normally generated in healthy contacts, upon natural infection by M. tuberculosis; (iii) the strategy must incorporate a mechanism for ensuring that the effectiveness of this priming is not abrogated by exposure to environmental mycobacteria; and (iv) the strategy must take account of the fact that the vaccinated population is genetically heterogeneous, and that individuals will therefore respond variably to most standard vaccination protocols. We describe a tentative proposal for how these interrelated problems might be solved and discuss predictions of this tentative vaccination strategy. Critical testing of the neonatal, low-dose BCG vaccination strategy can only be achieved by a field trial and we outline the considerations underlying this proposal.

Animals↗

Developmental implications of differential effects of calcium in tail and body skin of Anuran tadpoles.

The effects of external Ca(++) on metamorphosis of Rana catesbeiana tadpoles were assessed. Treatment of tadpoles with Ca(++) (0.05 mM) during early prometamorphic stages induced precocious metamorphic events such as tail regression, shortening of the intestine, forelimb emergence, and keratinization of body epidermis within 23 days of treatment compared to control tadpoles still in mid-prometamorphic stages. These effects of Ca(++) are probably mediated by the thyroid gland, as indicated by histological features of the gland at the light and electron microscopic levels. Calcium levels of tail and body skin were measured at various stages of development by atomic absorption spectrophotometry. In control and experimental groups, body skin had significantly higher Ca(++) concentrations than tail skin. There were no statistically significant effects of developmental stage on Ca(++) levels of tail or body skin. Experimental Ca(++) treatment significantly increased Ca(++) concentration in tail but not body skin. Ultrastructure studies and gel electrophoresis indicated that calcium induced keratinization of body skin, but not tail epidermis. Ca(++)-treated tail epidermis showed various autolysing figures in apoptotic cells. In summary, calcium treatment accelerated metamorphosis and induced the following region-dependent cellular events: keratinization of body skin-a characteristic of adult epidermis-and programmed cell death in the tail. Whatever signal elicited by calcium in this experimentally induced accelerated metamorphosis is probably mediated via the thyroid gland.

Animals↗

Aneurysmal bone cyst of the orbit: a case report and review of literature.

Aneurysmal bone cyst is a benign fibroosseous lesion which rarely occurs in the orbit. We report on a 7-year-old girl with aneurysmal bone cyst of the orbit who presented with painless proptosis and diplopia. Optic nerve compression resulted in field loss and delayed visual evoked potentials. Radiological and histological features are discussed. The lesion was excised via a frontal craniotomy and the orbital roof reconstructed with a prefabricated titanium plate. Post-operatively a rapid resolution of the proptosis and diplopia followed. Previous reported cases of this rare entity in the orbit are also reviewed.

Bone Cysts, Aneurysmal↗

Universal Total Wrist Implant: experience with a carpal component fixed with three screws.

The Universal Wrist Implant was used to treat 31 patients (37 wrists), who had symptoms indicating pancarpal arthritis of the wrist, diagnosed as total wrist arthroplasty. Their mean age was 58.1 years. Follow-up ranged from 48 to 120 months with a mean of 79.4 months (6.7 years). The carpal component of the Universal Total Wrist is fixed to the carpus by titanium screws. Unlike other total wrist prostheses, the primary fixation of the carpal component is in the capitate and not in the third metacarpal. Intercarpal fusion provides a solid bony support for the carpal plate and results in improved longevity. Articular surface of the radial component is inclined 20 degrees, similar to the articular surface of the radius. Components can be inserted with or without cement. In three patients, the prosthesis had to be removed due to infection and persistent dislocation. Of the remaining 34 wrists, 30 (88%) achieved excellent pain relief. Complications occurred in 12 cases (32%). Of these 12 complications 9 (75%) resolved with appropriate treatment. The most common complication with this nonconstrained prosthesis was dislocation. The Universal Total Wrist Implant provides a predictable option to preserve motion and relieve pain when managing wrist joint arthritis.

Arthritis, Rheumatoid↗

Epidemiology of aplastic anaemia in the state of Sabah, Malaysia.

Aplastic anaemia is a rare disease which is more prevalent in the Far East. In Malaysia, it appears to be unusually common in the state of Sabah. A retrospective analysis of all cases of aplastic anaemia diagnosed between January 1993 and March 1996 was undertaken. The criteria of the International Aplastic Anaemia and Agranulocytosis Study (IAAAS) was used. In this 39 month period, 31 cases were confirmed by marrow trephine biopsy to be aplastic anaemia. The male-to-female ratio was 3.4. Median age of diagnosis was 23 years. There were 24 patients (77%) who were from the Kadazan-Dusun ethnic group, which forms 18% of the population of Sabah. The incidence of aplastic anaemia in Sabah appears to be higher than that reported elsewhere in the Far East, at 4.8 per million population per year. Peak incidence is in the elderly group at 8.6 per million followed by a second peak in young people aged 15 to 24 (7.9 per million). The aplastic anaemia to total acute leukaemia ratio is 0.37. The marked male preponderance and apparent susceptibility of the Kadazan-Dusun people are also notable. A further prospective study to address the true incidence of aplastic anaemia and possible aetiologic factors accounting for these observations is necessary.

Adolescent↗

Clinicopathologic studies of thymic carcinoids in multiple endocrine neoplasia type 1.

Thymic carcinoid is part of the multiple endocrine neoplasia type 1 (MEN1) syndrome occurring predominantly in male patients who were heavy smokers, presenting most commonly in middle age. In contrast with metastatic midgut carcinoids, MEN1-related thymic carcinoid is not associated with carcinoid syndrome, nor is it associated with Cushing syndrome, in contrast with sporadic thymic carcinoids. Local invasion and metastasis are common. Prognosis is poor because of late detection, lack of effective treatment, and the aggressive nature of the tumor. All patients with thymic carcinoids should be investigated for MEN1, including thorough clinical evaluation and family studies. Anterior mediastinal lesions in MEN1 male patients should be considered thymic carcinoids until proven otherwise. All male MEN1 patients and asymptomatic gene carriers should be warned of the risk of thymic carcinoids and the possible link to smoking. Computed tomography (CT) of the chest is recommended on first screening for MEN1 in male patients more than 25 years of age, followed by yearly chest X-rays and chest CT every 3 years. Prophylactic thymectomy should be carried out during subtotal or total parathyroidectomy on MEN1 patients.

Adult↗

Arthroscopic management of trapeziometacarpal joint arthritis of the thumb.

Open partial trapeziectomy and interpositional arthroplasty have proven to be effective in ameliorating the symptoms of carpometacarpal joint arthritis of the thumb. Surgical technique of arthroscopic partial resection of the trapezium and interpositional arthroplasty is described. Thirty-three interpositional arthroplasties were carried out arthroscopically. Autogenous tendon graft. Gortex (WL Gore & Associates, Inc. Flagstaff, AZ) and fascia lata allograft were used as interpositional material; 87.8% of patients got relief from pain. Average postoperative pinch strength was 11 lbs. No ligament reconstruction was required because the capsule was left intact. The procedures were done on an outpatient basis and all patients were discharged the same day. There were no complications associated with radial sensory nerve.

Aged↗