PubMed Health⌕ Search

Biomedical subjects

A Balakrishnan

Publications and source records attributed to A Balakrishnan.

16 recordsLinked to original sources
PubMed1995

Interaction of filarial proteins on growth regulation of normal lung epithelial cells in vitro.

An in vitro model to examine the effects of filarial proteins on lung epithelial cells has been developed. Several of these proteins appear in circulation of infected individuals. A close association between tropical pulmonary eosinophilia (TPE) and filariasis has been reported by several workers. [3H]-thymidine studies do indicate that when optimum concentration of these filarial proteins were added to lung cultures in proliferating and basal/maintenance media a further increase in growth stimulation was observed early in culture. However, on longer exposures and at higher concentrations an inhibitory effect with distinct morphological changes were noted. The dual role of these proteins on lung epithelial cells in vitro may highlight the possibility of a direct interaction of these proteins with lung cells during disease also contributing to tissue damage.

Animals↗
PubMed1994

Palatine tonsillar metastasis from carcinoma of the colon.

Metastatic carcinoma of the palatine tonsil is rare, with only 92 cases reported in the world literature. We report a case of tonsillar metastasis from the colon. This is an unusual case not only because it is the first case report of tonsillar metastasis from this site but also because the tonsillar secondary is the first sign of the primary disease.

Adenocarcinoma↗
PubMed1992

Development of an antibody against a 170-kDa fragment of fibroin isolated from cocoon fibres of Bombyx mori.

A simple method for the isolation of denatured fragments of the fibroin protein from cocoon fibres by alkali solubilization is discussed. This 170-kDa antigen has been purified and used to raise the polyclonal antibody in rabbit. The specificity of this antibody to the purified cocoon protein has suggested strong immunoreactivity up to a titre of 1:5000 dilution of the antibody. Further, dot-blot analysis with the tissue extracts from silk glands of different larval stages (3rd to 5th) reveals that this antibody reacts showing a stage-specific increase in the intensity of the colour, correlating well with the in-vivo expression of the silk protein. This study suggests the availability of a specific polyclonal antibody that detects the native fibroin with no crossreactivity with other tissue proteins.

Animals↗
PubMed1992

Branchial cleft and pouch anomalies.

We present a retrospective study of 106 patients with branchial cleft and pouch anomalies who presented to the Hospital for Sick Children between 1948 and 1990. The relevant embryology of the branchial apparatus is summarized and a theoretical description of individual anomalies given. Second branchial cleft sinuses were the most common anomalies, and the majority were managed simply, with adequate excision and a low recurrence rate. Five cases of first branchial cleft anomalies are presented, emphasizing the delay in diagnosis, the need for complete excision to prevent recurrence, and for a parotidectomy incision to protect the facial nerve from damage. The two third branchial pouch anomalies presented with a cystic neck swelling, one with recurrent infection and discharge, and the other with stridor. In both, the diagnosis was made at operation. The single fourth branchial pouch cyst was an unexpected finding in a patient with stridor.

Branchial Region↗
PubMed1992

Photometrics: a new method of measuring the cross-sectional area of the subglottis.

A new endoscopic method of measuring the cross-sectional area of a subglottic stenosis is presented. The method was tested against existing techniques using a model. By standardizing the distance from the objective of the endoscope to the stenotic area we were able to measure the cross-sectional area using a graduated grid held against the video screen. This technique was then compared with the standard one of estimating the diameter of a stenosis from the external diameter of the bronchoscope which can be passed through the stenosis. The methods were found to be equally accurate in measuring the lumen diameter. However, when measuring the minimum cross-sectional area, three of five observers were significantly better (P less than 0.01) using the photometric method rather than the standard method (Wilcoxon's rank sum test for paired data). The photometric technique of measuring the cross-sectional area of the subglottis is easily performed, non-traumatic, and allows a visual record to be kept.

Bronchoscopes↗
PubMed1991

Plunging ranula following bilateral submandibular duct transposition.

Submandibular duct transposition is now a standard surgical procedure for the treatment of severe drooling. However, this is our first experience of a plunging ranula arising as a complication of the technique. In the surgical management of this complication, the single most important step is excision of the sublingual gland to prevent recurrence.

Child↗
PubMed1991

Lymphangioma of the tongue. A review of pathogenesis, treatment and the use of surface laser photocoagulation.

Lymphangiomas of the tongue are rare tumours. Several reports of this interesting condition have appeared in the literature with varying modalities of treatment being employed to control tongue size. We present here our experience with seven children who have lymphangiomas of the head and neck with tongue involvement seen over the past eight years. If the tongue is large with protrusion outside the lip margins, we advocate early tongue reduction so as to promote proper speech and deglutition, reduce orthodontic problems and achieve good cosmesis. However, the natural history of these tumours is one of recurrent tongue enlargement secondary to infection and trauma, irrespective of surgical reduction. We describe our technique of surface CO2 laser photocoagulation which has been successfully employed in controlling tongue size and removing superficial lymphangioma in all our patients. We propose therefore that this should be the mainstay of follow-up therapy in lingual lymphangiomas.

Child↗
PubMed1991

The cricoid split: an alternative to paediatric tracheostomy.

Advances in neonatal intensive care has increased the salvage rate of preterm infants. Many of these require ventilatory support for Respiratory Distress Syndrome or other cardiopulmonary problems. This has lead to an apparent increase in the incidence of acquired subglottic stenosis with difficulties in extubation. In the past, after several attempts at extubation, a tracheostomy is performed with definitive therapy instituted later. Since the first report of the Anterior Cricoid Split (ACS) in 1980, the extubation success rate of all centres average about 77%. The ACS is thus an alternative to tracheostomy, provided it is done for the correct indications and strict selection criteria are applied. How it works is still unclear, but certainly it achieves laryngotracheal decompression with relief of tension and oedema of the cricoid ring. The original indication was for cases of non-fibrous subglottis stenosis; these have now been expanded in recent years to include children with glottic pathology and with a tracheostomy in situ. The availability of excellent intensive care facilities is a prerequisite to doing an ACS; otherwise a tracheostomy is a safer option.

Cricoid Cartilage↗
PubMed1990

Controlled clinical trial of two multidrug regimens with and without rifampin in highly bacilliferous BL/LL south Indian patients: a five-year report.

A controlled clinical trial of two multidrug regimens in multibacillary lepromatous and near-lepromatous patients with a bacterial index (BI) of 2.5 or more was conducted. Patients were randomly allocated to either a two-drug regimen of dapsone plus clofazimine for 60 months or a four-drug regimen of rifampin, isoniazid, dapsone, and clofazimine for the first 3 months and clofazimine plus dapsone for the next 57 months. There was no difference between the rifampin and nonrifampin regimens with respect to the clinical improvement or bacteriological status of the patients at 60 months. Reactive states and neuritis were observed to be equal in the two patient groups.

Adolescent↗
PubMed1989

Differential proliferative response to linoleate in cultures of epithelial cells from normal human breast and fibroadenomas.

Human breast epithelial cells isolated from normal breast tissues of premenopausal women demonstrated direct evidence of a proliferative effect by linoleate (18:2 omega 6) or prostaglandin E2 (PGE2) in the presence of insulin and epidermal growth factor in serum-free cultures within a collagen gel matrix. Neither epidermal growth factor nor 18:2 omega 6 by itself was capable of stimulating growth but together they stimulated proliferation synergistically. Epithelial cells isolated from fibroadenomas on the other hand failed to exhibit any growth stimulation due to 18:2 omega 6 or PGE2. The linoleate-stimulated growth in normal breast epithelial cells was inhibited by indomethacin, a cyclooxygenase inhibitor, which however could be reversed by PGE2. The proliferative response of normal breast epithelial cells to 18:2 omega 6 was accompanied by a greater conversion of [14C]18:2 omega 6 to arachidonic acid and [14C]20:4 omega 6 to prostaglandins than that seen in epithelial cells from fibroadenomas. The turnover of [14C]18:2 omega 6 in the phospholipids of normal cells was higher than in fibroadenomas indicating a possible role of phospholipids in mediating the 18:2 omega 6 effect in normal cells. Both normal and fibroadenoma cells can proliferate in response to cholera toxin and glucocorticoids when supplemented to the insulin- and epidermal growth factor-containing medium. From the results it appears that, unlike normal cells, fibroadenoma cells may have a specific defect in the PGE2-responsive cyclic AMP-generating mechanism whereas cholera toxin-induced mechanism is operative in both types of cells.

Adenofibroma↗
PubMed1988

The lack of effect of phenol red or estradiol on the growth response of human, rat, and mouse mammary cells in primary culture.

Normal and neoplastic mammary cells from both human and rodent sources grow in culture in response to a number of hormones and growth factors. However, with the exception of a few human tumor lines, a consistent growth-promoting effect of estrogens on mammary cells has not been observed. Mammary cells can be shown to respond to other hormones and factors, such as PRL, hydrocortisone, and epidermal growth factor. Recent observations suggest that the pH indicator dye phenol red, found in most media, may be masking any exogenous estrogenic effects by acting as a weak estrogen. To test this possibility, we reexamined the effects of estradiol (E2) and the antiestrogen keoxifene on the growth of normal human, mouse, and rat mammary cells in the absence of phenol red. Primary cultures of these mammary cells were grown within a rat tail collagen gel matrix in a serum-free medium made up of Ham's F-12 and Dulbecco's Modified Eagles' medium (1:1) with and without phenol red. The medium was supplemented with various hormones and growth factors. These supplements were selected for each cell type to produce a variety of conditions from nongrowing to rapidly growing. The effects of E2 (10(-10)-10(-8) M, keoxifene (10(-9)-10(-6) M), and phenol red on growth under these various conditions were examined. Phenol red had no effect on growth, and its absence did not restore a response to E2. Keoxifene, in the presence or absence of E2, also had no effect on growth. Although E2 had no effect on growth, it was able to induce a 150% increase in the progesterone receptor levels in normal mouse mammary cells in culture, indicating that the cells retain their capacity to respond to E2. This work supports the idea that the effect of estrogens on growth in vivo may be mediated through some other factor(s).

Animals↗
PubMed1987

Human breast epithelial cells in serum-free collagen gel primary culture: growth, morphological, and immunocytochemical analysis.

Human breast epithelial cells derived from various sources (fibroadenoma, reduction mammoplasty, and mastectomy tissues from premenopausal patients) have been cultured in collagen gel matrix using serum-free medium. Response to various additives has been analyzed for growth-promoting effect when added to a basal medium containing insulin, cholera toxin, and BSA. A consistent observation has been the effect of EGF and cortisol in growth stimulation of human breast epithelial cells, while separately, each additive elicited only a small response. Under this condition, employing EGF and cortisol combinations, these cells gave rise to organized colonies consisting of clusters of cells, usually spherical, without any duct-like extensions. Ultrastructural and immunocytochemical studies, using a panel of monoclonal and polyclonal antibodies, have shown that cell types and features that can be identified in the original breast tissue can also be delineated in the progeny populations. The topographical feature, consisting of lumina surrounded by a single inner layer of epithelial cells and an outer layer of basal/myoepithelial cells, can be re-created in the collagen gel system starting from small clumps of cells.

Adenofibroma↗
PubMed1987

Estrogen receptor in dissociated and cultured human breast fibroadenoma epithelial cells.

Estrogen binding was measured by a whole cell receptor assay in epithelial cells isolated from 20 premenopausal patients with breast fibroadenomas. A high affinity specific binding for estrogens was detected in the epithelial cells isolated from all 20 fibroadenomas. A relationship between estrogen binding and the phase in the menstrual cycle of the patient has been observed. Cell culture experiments using serum-free medium have also shown that estrogen binding can be augmented by cortisol.

Adenofibroma↗
PubMed1986

Different mitogenic and phenotypic responses of human breast epithelial cells grown in two versus three dimensions.

Human breast epithelial cells, derived from fibroadenomas, were cultured under conditions promoting growth in two-dimensions (2D) as monolayers using the collagen-coated dishes and in three-dimensions (3D) inside the collagen gel matrix. Both epidermal growth factor (EGF) and cortisol (F) were required for maximal stimulation in 3D growth, but only cortisol was required for 2D growth. The growth stimulation of exogenously added type IV collagen was no greater than that of type I as a substrate in both the 2D and 3D growth. Immunocytochemical staining, using a polyclonal actin antibody, showed homogeneous staining in all cells in 2D monolayers, whereas more restricted distribution was observed in 3D outgrowths in the collagen gel matrix. The same cells, when cultured in 2D vs 3D, elicit different responses and the original phenotypes may be better maintained in 3D.

Adenofibroma↗
PubMed1981

Technical note--tilting stubbies.

Bilateral amputees who are fitted with standard full length prostheses find it difficult to walk fast or climb up and down stairs. Usually stubbies, or short prostheses with non-articulated rocker bottoms, are also provided, especially for geriatric amputees. An interchangeable system has been evolved which enables the same prosthesis to be used either as a full length prosthesis or as a stubby. An above-knee prosthesis is converted into a stubby by removing the shin and foot piece from the socket/knee unit and replacing it with an articulated hollow rocker. The tilting of the socket/knee unit which is made possible by the articulation at the junction of the rocker and socket enables the amputee to lower his body to use Indian type toilets with the help of a low level folding portable commode, in addition, tilting helps the amputee to work outdoors in gardens and fields. The interchangeable system is particularly suitable for bilateral amputees in developing countries.

Amputation, Surgical↗