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Biomedical subjects

L Ghosh

Publications and source records attributed to L Ghosh.

At least 37 records · Page 2Linked to original sources
PubMed1992

Neoplastic expression in murine cells induced by halogenated hydrocarbons.

The neoplastic expression in mouse embryo fibroblasts exposed to 1,2-dibromoethane and its chloroanalogue, 1,2-dichloroethane in vitro, was examined. Both substances are widely used as fumigants for carpet and upholstery, as gasoline additives, and as organic solvents. Both are known to be highly toxic, mutagenic, and carcinogenic agents. C3H10T1/2 cells treated with these haloalkanes exhibited altered morphology and were selected further by cloning in soft agar. Soft agar clones were found to induce a 100% multitumor occurrence in the nude mouse model. These results suggest that this pair of mutagens have altered the normal phenotype of mouse embryo cells, and these cells have become neoplastic. These neoplastic cell lines will be useful as an in vitro model to study the role of genetic changes in the transformation processes induced by halogenated hydrocarbons.

Animals↗
PubMed1992

Effect of bioamines on uptake of promastigotes of Leishmania donovani by hamster peritoneal macrophages.

Epinephrine and norepinephrine inhibit attachment of Leishmania donovani promastigotes to cultured hamster peritoneal macrophages. The inhibition was significant at catecholamine concentrations of 10(-4) and 10(-5) M and occurred when they were added to the cell mixtures, or after pre-treatment of either macrophages or parasites. Inhibition of attachment after pre-treatment was less marked than when the catecholamines were added to parasite-cell mixtures. Similar results were obtained with dibutyryl cyclic AMP, cholera toxin, theophylline, and cadaverine which raise intracellular cyclic AMP (cAMP). Pretreatment of parasites or macrophages with the bioamines elevated the intracellular cAMP concentration. It is suggested that the inhibitory effect on the host-parasite interaction is mediated through cAMP.

Animals↗
PubMed1992

Down-regulation of ras and myc expression associated with mdr-1 overexpression in adriamycin-resistant tumor cells.

The murine melanoma tumor cells, B16-BL6, are a recognized model for experimental and spontaneous metastasis. B16-BL6 cells express a lower metastatic phenotype upon acquisition of resistance to adriamycin. Using this novel system, the role of ras, c-myc, and multidrug-resistant gene (mdr1) expression in the metastatic and drug-resistant phenotype was examined. The metastatic cells expressed a high level of c-Ki-ras and c-myc, whereas down-regulation of both proto-oncogenes was observed in the adriamycin-resistant cells. The mdr1 gene, which encodes P-glycoprotein of the drug-resistant superfamily gene, was overexpressed in drug-resistant melanoma cells. These results suggest that altered expression of genes that regulate cellular proliferation and growth may be a determinant of metastasis and drug sensitivity of tumor cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1990

Effects of sodium hyaluronate on peridural fibrosis after lumbar laminotomy and discectomy.

Sodium hyaluronate, 1.9% solution, was evaluated for its ability to retard peridural fibrosis after unilateral lumbar hemilaminotomy, anular fenestration, and nuclectomy in dogs. Three materials: fat grafts, gelfoam, and sodium hyaluronate, were compared with empty controls for their ability to inhibit peridural fibrosis. Each dog served as his own internal control and the formation of fibrosis was evaluated at 2, 4, 12, and 26 weeks. Sodium hyaluronate was found to inhibit fibrosis more than the other materials on both a macroscopic and microscopic level. The area of fibrosis and tenacity of the adhesions on dissection were notably less in the sodium hyaluronate group. Microscopically, the thickness of collagen and number of fibroblasts were decreased with the use of 1.9% sodium hyaluronate. The peridural fibrosis occurred equally both anteriorly and posteriorly to the nerve roots and correlated with the area of surgical dissection. Fat grafts were not effective in preventing fibrosis anteriorly, especially in the region of the exiting nerve roots. Gelfoam did not inhibit but actually appeared to increase fibrosis formation. Interposition materials currently used in humans to prevent scar formation such as gelfoam and fat grafts have only addressed the posterior scar formation, which do little to alter the fibrosis anteriorly. The adhesions between the nerve root and the anulus fibrosus bind the nerve root down anteriorly, making it more vulnerable to recurrent disc herniation. Sodium hyaluronate, 1.9% solution, with its viscous semifluid properties, coats the nerve roots and dura anteriorly and posteriorly.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1989

Immunohistochemical and fluorescent microscopic study of histogenesis of salivary mucoepidermoid carcinoma.

The purpose of the present investigation was to study the histogenesis of the mucoepidermoid carcinoma of the salivary glands. Eleven cases of mucoepidermoid carcinoma of the minor salivary glands and five of the major glands were extensively studied employing immunohistochemical and fluorescent microscopic techniques. Both the intermediate cells and the duct cells showed a rather similar pattern of reactivity for vimentin, actin and EMA. Also, the intermediate cells and the myoepithelial cells showed a similar reaction pattern for keratin and UGA-1. The intermediate, myoepithelial and duct cells shared a similar reaction pattern for desmin, myosin, CEA, and S-100 protein. However, the rest of the tumor markers studied (AFP, PNA and WGA) were found to be non contributary. We also found that the intermediate and to some extent the epidermoid tumor cells showed a positive reaction with Azophloxine GA, which is a selective stain for myoepithelial cells in the normal glands. Based on these findings, the duct cells, the myoepithelial cell in the normal glands and the intermediate cells of the mucoepidermoid carcinoma share certain similar characteristics. The intermediate cells may actually be a mixed population, some having characteristics of the myopithelial cells and others of duct cells. These findings are relevant to the possible role of the intermediate cell in the histogenesis of the mucoepidermoid carcinoma.

Actins↗
PubMed1988

Interstitial cystitis is associated with intraurothelial Tamm-Horsfall protein.

A defective barrier between the urine and urothelium has been suggested as an etiology for interstitial cystitis. With immunohistochemical techniques we assayed the bladder biopsies of 14 interstitial cystitis patients and 10 normal controls for intraurothelial Tamm-Horsfall protein to assess indirectly the in vivo permeability of the urothelium. Eight pathological controls, including bladder biopsies from 3 patients with inflammation owing to infection or catheterization and biopsies of 5 transitional cell carcinomas of the bladder, also were assayed. Superficial intraurothelial Tamm-Horsfall protein was identified in the biopsies from 10 of 14 interstitial cystitis patients (71 per cent) but only 1 of 10 controls (10 per cent) (p less than 0.01). Tamm-Horsfall protein was not identified in biopsies from the pathological controls. In 6 of 7 cases when more than 1 biopsy was available for analysis the findings were identical in each specimen. There was a direct correlation between the density of detrusor mast cells and the demonstration of intraurothelial Tamm-Horsfall protein. Seven of the 9 evaluable interstitial cystitis patients with intraurothelial Tamm-Horsfall protein but only 1 of 4 without intraurothelial Tamm-Horsfall protein experienced a favorable response to intravesicle oxychlorosene sodium (p greater than 0.05). These data suggest that abnormal permeability of the urothelium is associated with and a possible cause of interstitial cystitis and that the demonstration of intraurothelial Tamm-Horsfall protein in bladder biopsy specimens may prove to be useful as a diagnostic test for interstitial cystitis.

Administration, Intravesical↗
PubMed1988

Epidermal growth factor in the normal and neoplastic kidney and bladder.

Epidermal growth factor (EGF) is a cell-regulating polypeptide that appears important to the maintenance and function of some benign tissues and to the transformation and proliferation of certain malignancies. In humans the highest concentrations of EGF are found in the urine. We investigated possible interactions between EGF and normal and neoplastic tissues of the urinary system with indirect immunohistochemical staining of paraffin-embedded tissue sections. A polyclonal antibody directed against mouse EGF but shown to react with human EGF was used in the assays. Positive staining was granular in nature and confined to the cytoplasm. Staining of the renal parenchyma (N = 5) was observed in the epithelium of the proximal and distal tubules and the collecting ducts. There was staining of clear cell (N = 6) and papillary (N = 3) carcinomas of the kidney. Staining of the normal urothelium (N = 5) was limited to superficial cells. All transitional cell (N = 21) and squamous (N = 2) carcinomas of the bladder stained. Subjectively, the staining intensity of the transitional cell carcinomas correlated inversely with tumor differentiation. In light of evidence that internalized, receptor-bound EGF is rapidly degraded, the striking immunohistochemical demonstration of cytoplasmic EGF suggests active synthesis. EGF synthesized by urothelial and renal carcinomas may be involved in an autocrine mechanism of malignant proliferation.

Adenocarcinoma↗
PubMed1988

Epidermal growth factor and prostatic carcinoma: an immunohistochemical study.

Associations between epidermal growth factor (EGF) and carcinoma of the prostate (CAP) have not been systematically investigated. We used indirect immunohistochemical techniques to demonstrate cytoplasmic EGF in paraffin-embedded sections of the following primary prostatic tissues: benign prostatic hyperplasia (BPH) (N = 10), BPH adjacent to CAP (N = 42), clinically localized CAP (N = 45), untreated metastatic CAP (N = 10), and metastatic CAP after varying periods of androgen deprivation (N = 10). In six of the latter 10 cases biopsies of the primary tumor obtained before androgen deprivation therapy were also available for study. Three of the BPH specimens (6%) and 44 of the CAP specimens (68%) stained. Forty per cent of the localized tumors stained but all untreated and treated metastatic tumors stained (p less than 0.01). There were direct but statistically insignificant correlations between the demonstration of EGF and both the Gleason score of localized and untreated metastatic tumors and the pathologic stage of localized tumors. The proportion of malignant cells stained in EGF positive tumors was similar regardless of Gleason score, pathologic stage or the presence or absence of metastases. However, the proportion of cells stained was greater in five of six specimens obtained during hormonal deprivation compared to specimens of the same tumor obtained before treatment. These data suggest that some prostatic cancers interact with EGF and that the interaction may be influenced by the androgenic milieu.

Adenocarcinoma↗
PubMed1988

Amino acid-restricted diets in the treatment of mammary adenocarcinoma in mice.

The effect of a diet moderately restricted in tryptophan on the tumor and the nutritional status of C3H mice bearing mammary adenocarcinoma was examined. Five groups of female tumor-bearing mice were fed ad libitum a diet containing 1) 15% casein, 2) 15% amino acid mixture, 3) 15% amino acid mixture restricted in tryptophan 4) 15% zein supplemented with lysine and tryptophan or 5) 15% zein supplemented with lysine and restricted in tryptophan. Another group of tumor-free mice of similar age fed 15% casein served as a control for the tumor-bearing group fed the 15% casein diet. Moderate restriction of tryptophan in the diet appeared to have no effect on the tumor status of the animal. Tumor burden usually induced malnutrition in the animal. However, tryptophan restriction did not further aggravate this malnutrition. The source of protein, whether casein, amino acid mixture or zein, appeared to make a difference in nutritional status of tumor-bearing animals though not in tumor status. Casein-fed animals generally tended to have higher values for all the nutritional markers studied than did animals fed the amino acid mixture or zein.

Adenocarcinoma↗
PubMed1988

Herpesviridae in the coronary arteries and aorta of young trauma victims.

The presence of herpes simplex virus (HSV) and cytomegalovirus (CMV) nucleic acid and/or antigen was demonstrated in the coronary arteries and thoracic aortas of young trauma victims by the in situ DNA hybridization and ABC immunoperoxidase methods, respectively. Epstein-Barr virus (EBV) nucleic acid and capsid antigen were not detected in the arteries sampled in this study. Of 8 subjects in which virus was detected in the coronary arteries, 6 were positive for HSV and 2 for CMV; of 7 cases positive in the thoracic aorta, 5 were identified as HSV and 2 as CMV. Viral DNA and/or antigen were found in occasional cells in the intact luminal surface and in focal clusters of spindle-shaped or "foamy" cells in the intimal layer. The histologic findings indicate that HSV and CMV are associated with areas showing early or advanced atheromatous changes in the coronary arteries and with lesion-free as well as lesion areas in the thoracic aorta. The virologic findings support the concept that herpes-viruses may potentially play a direct or indirect role in the pathogenesis of human atherosclerosis.

Adolescent↗
PubMed1988

Myelolipoma and endocrine dysfunction.

Myelolipoma is an uncommon benign tumor of which the pathogenesis is unknown. It is rarely associated with endocrine disorders. We present a case of a myelolipoma in conjunction with congenital adrenal hyperplasia secondary to 21-hydroxylase deficiency. Nine previously reported cases of myelolipoma associated with endocrine dysfunction are reviewed with potential correlation of the hormonal imbalance to pathogenesis.

Adrenal Gland Neoplasms↗
PubMed1987

Congenital embryonal rhabdomyosarcoma of the hand and Apert's syndrome.

A unique case of congenital embryonal rhabdomyosarcoma of the hand in a patient with Apert's syndrome is presented. Immediately after birth a 1 cm soft, bluish mass of the right thenar eminence was clinically diagnosed as a hemangioma. Several months later when the lesion started rapidly enlarging the nature of the tumor was identified, and it was treated with a multidisciplinary approach that included surgical resection, chemotherapy, and radiation.

Acrocephalosyndactylia↗
PubMed1986

The demonstration of papilloma virus in cervical dysplasia and/or neoplasia.

Thirty-three random biopsy specimens of uterine cervix were studied by immunoperoxidase technique to evaluate the presence of HPV antigen in dysplastic and neoplastic cells. Four cases of mild dysplasia, nine cases of moderate to severe dysplasia, two cases of carcinoma in situ and one case of invasive carcinoma were associated with condylomatous lesions. Intranuclear dark-brown precipitates were observed in superficial and intermediate zones of the dysplastic epithelium. Positive reaction was seen in condylomatous epithelium associated with neoplasia. No nuclear precipitates were observed in carcinoma cells, but one noncondylomatous lesion with moderate dysplasia showed positive intranuclear staining. These preliminary findings suggest that papilloma viruses may play a role in the development of human cervical neoplasias.

Condylomata Acuminata↗
PubMed1984

Ovarian androblastoma metastatic to tonsil.

Structural pattern of a tonsillar tumor found in a 67-year-old female was similar to a small ovarian androblastoma diagnosed histologically 6 1/2 years earlier. Electron microscopic study of the tonsillar mass revealed crystalloid structures suggestive of the Leydig cell origin of the tumor. After tonsillectomy, there was no local recurrence of the tumor, but the patient died a year later of multiple metastases. There appeared to be no previous reports of ovarian tumors metastatic to tonsil, and malignant androblastomas of the Leydig cell type are extremely rare.

Female↗
PubMed1984

Can carbon fiber implants substitute for collateral ligament?

The biomechanic and histologic changes following replacement of the medial collateral digit of the knee with carbon fiber filament prostheses of varying diameters were studied in young rabbits. Biomechanic testing showed changes with time in the mode of failure and force to failure of the replacements, but the initial differences in the force to failure of the three diameter groups diminished over the 12-week experimental period. Histologic studies with both light and electron microscopy revealed resorption of the carbon fibers and replacement by fibrosed ligaments. There was a correlation between the change in mode of failure and force to failure and increased production, orientation, and organization of new collagen fibrils, as well as simultaneous fragmentation of the carbon fibers.

Animals↗