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S Taneja

Publications and source records attributed to S Taneja.

36 records · Page 2Linked to original sources
PubMed1996

In vitro modulation of tumor progression-associated properties of hormone refractory prostate carcinoma cell lines by cytokines.

BACKGROUND: Cytokines exert cytostatic and immunomodulatory effects on carcinoma cells. Growth inhibition of human prostate carcinoma by cytokines has been demonstrated both in vitro and in vivo, whereas the cellular and molecular changes in prostate carcinoma properties after cytokine treatment have never been characterized. We have thus investigated whether the intrinsic properties of prostate carcinoma cells that are associated with tumor development and progression can be altered by direct cytokine treatment. METHODS: LNCaP, DU-145, and PC-3 cell lines were treated with tumor necrosis factor-alpha (TNF-alpha) (200 U/mL), interferon-gamma (IFN-gamma) (500 U/mL), human leukocyte interferon (IFN-alpha) (500 U/mL), and interleukin-2 (IL-2) (400 U/mL). The expression of (prostate-specific antigen [PSA] and prostate-specific membrane [PSM]), androgen receptor (AR), growth factors, oncogenes, collagenase, cell adhesion molecules, HLA antigens, cell adhesion to human bone marrow stroma, and cell growth were determined by quantitative polymerase chain reaction (PCR) analysis, fluorescence-activated cell sorter (FACS) analysis, and cell attachment and proliferation assays, and were compared with non-treated cells. RESULTS: PCR analysis indicated that only LNCaP cells expressed PSA, PSM, and AR mRNA. Cytokine treatment did not alter PSM mRNA expression, whereas a 15-fold decrease in PSA and a 5-fold reduction in AR mRNA expression was detected in TNF-alpha-treated cells. The down regulation of PSA production was also demonstrated at the protein level in a dose-dependent fashion. A fivefold decrease in PSA mRNA was also detected in IL-2-treated LNCaP cells but without a reduction in AR. Down regulated epidermal growth factor receptor (EGF-R) and basic fibroblast growth factor (b-FGF) mRNA expressions were detected in TNF-alpha- and IFN-alpha-treated DU-145 and PC-3 cells, whereas, only reduced EGF-R expression was observed in LNCaP cells. IFN-gamma and IL-2 treatment down regulated the expression of collagenase Type IV mRNA in DU-145 and PC-3 cells, whereas tumor transforming growth factor-beta (TGF-beta) and IL-6 mRNA expressions did not exhibit any essential changes after cytokine treatment. A reduction in c-myc mRNA expression was observed in TNF-alpha- and IFN-alpha-treated cells, whereas no change in HER-2 expression was noted in any cytokine treated cells. Up regulated P-cadherin, but not E-cadherin, mRNA expression was detected in TNF-alpha- and IFN-gamma-treated PC-3 cells. FACS analysis revealed that all but IL-2-treated cells had enhanced HLA Class I expression, with the maximum effect seen in TNF-alpha-treated LNCaP cells (threefold increase). Up regulated HLA Class II expression was seen only in IFN-gamma-treated cells. All cytokine-treated DU-145 and PC-3 cells expressed reduced levels of alpha3, but not beta1, integrin. Up regulated of ICAM-1 expression was seen in all cytokine treated DU-145 and PC-3 cells, whereas no change in CD44 occurred. Cytokine treatment reduced the binding affinity of LNCaP and DU-145, but not of PC-3 cells, to human bone marrow stromal cells, and all cytokines but IL-2 showed a mild to moderate growth inhibition to prostate cancer cells, with a marked inhibition only observed in TNF-alpha-treated LNCaP cells. CONCLUSIONS: Cytokine treatment can effectively alter several prostate carcinoma properties that are closely associated with tumor invasion and a metastatic phenotype, suggesting that immunotherapy via the local delivery of cytokines may have a potentially therapeutic role in the treatment of hormone-refractory prostate cancer through both direct and indirect antitumor mechanisms.

Antigens, Neoplasm↗
PubMed1996

MR of the pituitary in patients with Prader-Willi syndrome: size determination and imaging findings.

Prader-Willi syndrome (PWS) is an unusual genetic disorder characterized by short stature, obesity, hypogonadism, hypotonia, cognitive impairment, and dysmorphic facies. There is an interstitial deletion of the proximal long arm of chromosome 15 in about 70 % of patients. Some of these clinical features suggest a central hypothalamic/pituitary dysfunction, and recent investigations have demonstrated a marked impairment in spontaneous growth hormone (GH) secretion. We studied 15 GH-deficient PWS patients by magnetic resonance imaging (MRI) to determine whether there was a diminution in the gross morphological size of the anterior pituitary gland, the site of GH synthesis. We also set out to catalog the pertinent imaging findings in this patient population. Our results indicate that this is the first report documenting pituitary size by MRI in PWS patients. No statistically significant difference was found in the height of the anterior pituitary gland in PWS patients compared with either normal children or children with isolated GH deficiency. An interesting imaging finding is that three of 15 patients (20 %) demonstrated complete absence of the posterior pituitary bright spot (PPBS), and a fourth patient demonstrated a small PPBS. These observations reflect an objective physiologic disturbance in the hypothalamus. The clinical and radiologic implications of these findings are discussed.

Adolescent↗
PubMed1996

Spontaneous extrusion of extraocular cysticercus cysts.

PURPOSE: We treated two patients who had spontaneous extrusion of cysticercus cysts and subconjunctival swelling. Additionally, one patient had severe myositis and restriction of ocular movements. METHODS: The patients were prescribed oral albendazole, 15 mg/kg of body mass per day. Systemic corticosteroids were also given to the patient who had severe myositis. RESULTS: Spontaneous extrusion of the cysts occurred in both patients within three to five days of starting albendazole therapy. The conjunctival defects healed without any surgical intervention. The ocular motility in the patient with myositis returned to normal. CONCLUSION: As extrusion happened soon after the start of albendazole therapy, it is uncertain whether this therapy played any role. Additionally, it is not clear if systemic therapy must be continued in the absence of systemic and neurologic manifestations.

Adult↗
PubMed1995

Prostate tissue specificity of the prostate-specific antigen promoter isolated from a patient with prostate cancer.

We have cloned and characterized a 620-bp fragment of DNA that flanks 5' of the prostate-specific antigen (PSA) gene from a prostate cancer patient. Using DNA transfection, the efficacy of this putative promoter in regulating gene expression was quantitated in several prostate and nonprostate tissue cell lines. Our results demonstrated that the 620-dp DNA fragment actively drives gene expression in LNCaP, a PSA-producing prostate tumor cell line. No promoter activity was detected in the non-PSA-producing prostate tumor lines, DU145 and PC-3, nor in a renal (R11) or breast (MCF-7) cancer cell line. Furthermore, the promoter activity could be regulated in vitro by androgen stimulation. Dihydrotestosterone (DHT) concentrations between 3 and 30 nM induced the highest promoter activity in the transfected LNCaP cells, which parallels the expression profile of the androgen receptor in LNCaP cells. In addition, our PSA promoter exhibited competitive inhibition of the endogenous genomic PSA promoter in transfected LNCaP cells, suggesting that prostate cell-specific DNA-binding proteins are required to activate the PSA promoter. increased its potency four- to five-fold while retaining tissue specificity. Our data suggest that a strong tissue-specific negative regulatory element capable of overriding the nonspecific CMV promoter is present in the PSA promoter and confers its tissue specificity. The use of a highly specific promoter-driven gene vector will allow selective expression of therapeutic genes within PSA-producing prostate cancer cells, providing a unique strategy for prostate cancer gene therapy.

Antigens, Neoplasm↗
PubMed1994

Increased thermal stability of proteins in the presence of amino acids.

This study is a systematic attempt to understand the roles of osmolytes in protecting proteins against denaturing stress. Thermal denaturation of cytochrome c has been studied in the presence of various concentrations of all L-amino acids that are more hydrophobic than glycine and have a solubility of 0.1 M or higher in water at 25 degrees C. The basic observations are as follows. (1) Arginine and histidine destabilize the native protein; both Tm (the midpoint of thermal transition) and delta GDH2O (25 degrees C) (the Gibbs energy of stabilization) decrease with increasing amino acid concentration. (2) Isoleucine, leucine and phenylalanine have no effect on Tm and deltaGDH2O (25 degrees C). (3) Valine and less hydrophobic amino acids stabilize the protein in terms of Tm but deltaGDH2O (25 degrees C) is unchanged. This observation was confirmed by the study of isothermal denaturation of cytochrome c by guanidinium chloride which suggested that delta GDH2O is independent of osmolyte concentration, but Cm (the midpoint of transition) is increased in their presence. (4) In the case of stabilizers, change in Tm/mol of amino acid decreases with increasing hydrophobicity of these osmolytes.

Amino Acids↗
PubMed1994

A new method for testing the functional dependence of unfolding free energy changes on denaturant concentration.

Denaturations of ribonuclease A, lysozyme, and cytochrome c by guanidine hydrochloride (GdnHCl), urea, and GdnHCl-urea mixture were studied at constant temperature and pH to assess the functional dependence of denaturational free energy change (delta GD) on denaturant concentration over an extended GdnHCl concentration range. Conventional analysis of GdnHCl-induced transition curve exhibits a linear plot of delta GD versus [GdnHCl] in the transition zone. To extend delta GD measurements beyond this narrow concentration range, GdnHCl-induced unfolding was measured in the presence of different concentrations of urea. delta GD values from these measurements were corrected for the effect of urea on the free energy change using the appropriate relation. The corrected delta GD data were mapped onto the delta GD versus [GdnHCl] plot. For each protein, the dependence of free energy change on denaturation was found to be linear over the full GdnHCl concentration.

Animals↗
PubMed1992

Determining stability of proteins from guanidinium chloride transition curves.

The guanidinium chloride (GdmCl) denaturation of RNAase A, lysozyme and metmyoglobin was investigated at several pH values by using absorbance measurements at 287, 300 and 409 nm respectively. From these measurements the free-energy change on denaturation, delta Gapp., was calculated, assuming a two-state mechanism, and values of delta Gapp. at zero concentration of the denaturant were measured. For each protein all delta Gapp. values were adjusted to pH 7.00 by using the appropriate relationship between delta Gapp. and pH. Dependence of the adjusted delta Gapp. value on GdmCl concentration increases for metmyoglobin and decreases for the other two proteins as the denaturant concentration decreases. It has been shown that these are expected results if the presence of the acid-denatured state during the GdmCl denaturation of proteins is considered.

Drug Stability↗
PubMed1988

Communicating oesophageal duplication: a report of two cases.

Alimentary duplications which include a variety of alimentary cysts, diverticula and tubular malformations are rare abnormalities. Most of them, especially in relation to the oesophagus, do not communicate with the lumen. We present two very rare cases of communicating oesophageal duplication. Both are left sided and unassociated with any other congenital abnormality. These features again are uncommon with such duplications.

Esophagus↗
PubMed1975

Effect of m3 gene on the development of phage P22.

Mutation of the gene m3 of phage P22 causes permanent depression of macromolecular synthesis in the infected host and thus inhibits phage development as indicated by burst size and lysozyme production. The permanent depression of macromolecular synthesis is most probably due to blockage of the transport process. The m3 allele is dominant over m+. m3 allows some transcription of phage genes (however, the difference between early and late function is not clear). The inhibitory effect of m3 on DNA synthesis may be indirect.

Alleles↗
PubMedDate not supplied

Pharmacokinetics of ciprofloxacin in patients with liver cirrhosis.

BACKGROUND: Bacterial infections are common in patients with cirrhosis of liver and are frequently treated with ciprofloxacin. Literature on pharmacokinetics of ciprofloxacin in patients with cirrhosis of the liver is scanty. The present study compared the pharmacokinetics of ciprofloxacin in cirrhotic patients with that in healthy volunteers. METHODS: In 20 patients with cirrhosis of liver (all Child-Pugh class B) and 10 healthy volunteers, plasma levels of ciprofloxacin were measured using high-performance liquid chromatography at several time points after a 500-mg oral dose. Various pharmacokinetic parameters were calculated. RESULTS: No significant differences were observed in maximum plasma levels reached (mean [SD] 2.6 [0.6] vs 2.6 [1.3] microg/ml), time taken for maximum plasma levels to be reached (1.3 [0.6] vs 1.5 [0.9] h), t1/2a (0.7 [0.3] vs 0.4 [0.9] h), elimination half-life (3.6 [1.2] vs 3.2 [1.8] h), and area under the curve (19.3 [3.8] vs 21.9 [4.5] microg/mL x h) in healthy volunteers and cirrhotic patients, respectively. CONCLUSIONS: Pharmacokinetics of ciprofloxacin is unaltered in patients with liver cirrhosis. Ciprofloxacin can be safely administered in the usual doses in such patients.

Adult↗