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Biomedical subjects

S Goyal

Publications and source records attributed to S Goyal.

At least 37 records · Page 2Linked to original sources
PubMed1996

Prolonged survival follows resection of oesophageal SCC downstaged by prior chemoradiotherapy.

BACKGROUND: The poor survival rate of surgically treated patients with oesophageal cancer has not improved substantially over the last 25 years, but combined modality therapy has shown early promising results. METHODS: A prospective study was undertaken to determine the effect of pre-operative synchronous chemoradiotherapy followed by oesophagectomy in 53 patients with squamous cell carcinoma (SCC) of the oesophagus. The patient group was unselected, other than by fitness for surgery. RESULTS: In 25% of patients, complete pathological regression of the tumour was achieved. All but one of the patients in this subgroup had T2 tumours on pre-operative clinical staging and two had evidence of lymph node involvement, but postoperative pathological examination revealed that pre-operative chemoradiotherapy had downstaged their disease to T0N0. There was no hospital mortality in this subgroup and the actuarial 7 year survival was 69%. CONCLUSIONS: For squamous oesophageal tumours deep to the submucosa this is an extremely good survival. For the present, this form of therapy for SCC of the oesophagus appears capable of achieving results comparable to, or better than, those reported for 3-field lymphadenectomy.

Adult↗
PubMed1995

Lasers.

Explore the source record for details and available documents.

Humans↗
PubMed1994

Effect of cysteine substitutions on the mitogenic activity and stability of recombinant human keratinocyte growth factor.

Human Keratinocyte growth factor (hKGF), a member of the FGF family of growth factors, contains five cysteines at amino acid positions 1, 15, 40, 102, and 106. We expressed five cysteine mutants of hKGF in which the cysteines were cumulatively replaced with alanine or serine, starting with cysteine-1. Recombinant hKGF has an inherently higher mitogenic activity and stability to heat and acid than reported for glycosylated hKGF. Mitogenic activity is increased an additional 2.6 fold by substitution of cysteine-1 with alanine. Mutants with the conserved cysteine substituted at position 40 were more susceptible to heat inactivation than rhKGF, but showed no significant difference in acid inactivation. Cysteine-free rhKGF is mitogenic, demonstrating that neither cysteines nor disulfide bonds are required for mitogenic activity. However, cysteine-free rhKGF does not bind Heparin-Sepharose and is unstable to heat and acid compared to rhKGF, suggesting that the cysteines have a role in maintaining KGF's structure. This information will useful in the development of a more stable and more potent wound healing agent from hKGF.

Animals↗
PubMed1994

Structural and functional role of lipids in yeast and mycelial forms of Candida albicans.

The levels of total lipids, sterols and phospholipids were found to be significantly higher in the mycelial form (log phase) of Candida albicans than in the yeast form. Increased phospholipid levels in the mycelial form were due to higher levels of phosphatidylcholine, phosphatidylserine and phosphatidylinositol. Analyses of fatty acid composition also revealed higher levels of myristic acid (40%) in the yeast form, resulting in higher levels of saturated lipids than in the mycelial form. The changes in the lipid composition were also manifested in altered thermotropic phase behavior as gel-to-liquid crystalline phase transitions were observed at 36 and 27 degrees C for the lipids of the yeast and mycelial forms, respectively. These changes coincided with higher uptake rate, i.e., Km and Vmax values, for the transport of L-proline and with a higher sensitivity of the mycelial form against antifungal drugs.

Antifungal Agents↗
PubMed1992

Phospholipid composition and subcellular distribution in yeast and mycelial forms of Candida albicans.

Lipids were found to constitute 3.9% and 4.7% of the dry weight of yeast and mycelial forms of Candida albicans, respectively. Phospholipids were localized mainly in the microsomal fraction of both growth forms and phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and cardiolipin were the major phospholipids. Myristic acid and palmitic acid were the predominant fatty acids in the yeast form while the mycelial form contained palmitic, palmitoleic and oleic acid as major fatty acids. Yeast forms showed significantly higher specific activities of intracellular phospholipase A and lysophospholipase when compared with mycelial forms. No significant difference in the specific activity of extracellular phospholipase A was seen in either morphogenic form while the activity of extracellular lysophospholipase was higher in the yeast form. These results are discussed in the context of the virulence of this fungus.

Candida albicans↗
PubMed1991

Agalactosyl IgG: an aid to differential diagnosis in early synovitis.

Sixty consecutive patients presenting with early-onset synovitis were studied by measuring rheumatoid factor (RF) titers and the percentage of oligosaccharide chains attached to the C gamma 2 domain of IgG that lack galactose (GAL[0]). After 2 years of followup, 39 patients (65%) had developed rheumatoid arthritis (RA), and 21 had developed a variety of other inflammatory joint diseases. A combination of RF positivity and GAL(0) levels above the age-corrected mean gave a positive predictive value for a diagnosis of RA in 94% of these patients. These observations may well have clinical utility.

Adult↗
PubMed1991

Elevated plasma histamine in chronic uremia. Effects of ketotifen on pruritus.

A role for histamine in the pathogenesis of uremic pruritus was investigated in maintenance hemodialysis patients. Venous plasma histamine levels, as determined by radioenzymatic assay, were significantly higher (p less than 0.05) in hemodialysis patients with pruritus (368 +/- 103 pg/ml [mean +/- SEM], n = 6) than in those without pruritus (146 +/- 22 pg/ml, n = 5) and in normal controls (142 +/- 16, n = 5). Arteriovenous fistula histamine levels (202 +/- 52 pg/ml, n = 6) were significantly lower (p less than 0.05) than simultaneously drawn venous samples. Markedly elevated histamine-degrading enzyme (histaminase) activities were found in both hemodialysis patients with (2.95 +/- 0.18 pg histamine degraded/minute) and without (2.44 +/- 0.28) pruritus, but was undetectable in normal controls. Histaminase activities did not significantly differ in simultaneously drawn venous and fistula samples. With hemodialysis, histaminase activities fell significantly (p less than 0.01), whereas plasma histamine did not change. We further examined the effects of ketotifen, a putative mast cell stabilizer, on severe uremic pruritus. Five of five patients had significant (p less than 0.01) reductions in pruritus, as judged on a six-point pruritus index, after 8 weeks of drug (x = 2.3), as compared to conventional therapy (x = 5.9). Despite these improvements, no significant differences were noted in pre- versus post-drug plasma histamine levels, histaminase activities, or the histamine content per gram of skin biopsy specimen. These data support prior hypotheses that mast cell activation contributes to the pruritus of uremia.

Chronic Disease↗
PubMed1990

N-nitrosodimethylamine blood levels in patients with chronic renal failure: modulation of levels by ethanol and ascorbic acid.

We measured levels of N-nitrosodimethylamine (NDMA) in peripheral blood from 13 fasting male patients, 30-74 years old, who had chronic renal failure, and in five healthy control subjects (four males and one female) 31-50 years old. In the patients, we found significant (P less than .01) levels of NDMA (mean +/- SD; 201 +/- 111 ng/kg of blood), which is known to be carcinogenic in animals. Five minutes after oral administration of ethanol (0.4 g/kg of body weight), all patients exhibited a significant (P less than .01) rise in blood NDMA levels (338 +/- 125 ng/kg), suggesting continuous endogenous formation of NDMA that was unmasked by ethanol's ability to inhibit first-pass hepatic metabolism of NDMA. In five of six patients, pretreatment with oral ascorbic acid resulted in a blunting, but not statistically significant, effect on maximum blood NDMA levels after consumption of ethanol. Mean levels were 340 +/- 100 ng/kg before treatment with ascorbic acid and 237 +/- 127 ng/kg during treatment. Ethanol administration unmasks increased gastrointestinal formation of NDMA in patients with chronic renal failure. Further studies are required to confirm a possible link between endogenous NDMA formation and the increased incidence of cancer in these patients.

Adult↗
PubMed1986

Serum glycolytic enzymes in breast carcinoma.

Serum levels of lactate dehydrogenase and its isoenzymes, phosphohexos isomerase, aldolase and hexokinase were determined in 152 cases of breast carcinoma, in search of proper diagnostic and prognostic parameters. The enzyme levels showed a relation to the clinical stage of the tumor and were, on an average, higher in advanced stages of disease. Phosphohexose isomerase and lactate dehydrogenase-isoenzyme levels were of best diagnostic significance even at an early stage of the disease. The enzyme levels correlated well with the prognosis of the disease. In group three, the prognosis was very poor and the patients responded only slightly to the treatment, and only up to the third month; after that enzyme levels again increased.

Breast Neoplasms↗
PubMed1984

An in-vitro study of the kinematics of the normal, injured and stabilized cervical spine.

The relative motion between various vertebrae of multi-level cervical ligamentous spinal segments (C2-T2), using Bryant angles, is described. A three-dimensional sonic digitizer was utilized to study the motion in flexion, extension, right lateral bending and right axial rotation. Effects of a number of injuries and stabilization (interspinous wiring and acrylic cement, PMMA) on the motion behavior of C5-C6 (injured) and C4-C5 (superior to injured) levels were investigated. The data were normalized with respect to intact specimens. The injury to capsular ligaments at C5-C6 produced a significant increase in the relative motion at C4-C5. Although the interspinous wiring reduced the motion at C5-C6 the C4-C5 motion was still higher. The application of PMMA made the motion at C4-C5 comparable to the intact specimen.

Adult↗
PubMed1984

Round robin investigation of methods for the recovery of poliovirus from drinking water.

Six laboratories actively involved in water virology research participated in a methods evaluation study, conducted under the auspices of the American Society for Testing and Materials Committee on Viruses in the Aquatic Environment, Task Force on Drinking Water. Each participant was asked to examine the Viradel (virus adsorption-elution) method with cartridge-type Filterite filters for virus adsorption and organic flocculation and aluminum hydroxide-hydroextraction for reconcentration. Virus was adsorbed to filter media at pH 3.5 and eluted with either glycine buffer (pH 10.5) or beef extract-glycine (pHG 9.0). Considerable variation was noted in the quantity of virus recovered from four 100-liter samples of dechlorinated tapwater seeded with low (350 to 860 PFU) and high (1,837 to 4,689 PFU) doses of poliovirus type 1. To have a more uniform standard of comparison, all the test samples were reassayed in one laboratory, where titers were also determined for the virus seed. Test results of the Viradel-organic flocculation method indicated that the average percentage of virus recovery for low-input experiments was 66%, with a range of 8 to 20% in two laboratories, 49 to 63% in three laboratories, and 198% in one laboratory. For the high-input experiments, two laboratories reported recoveries of 6 to 12%, and four laboratories reported recoveries of 26 to 46%. For the Viradel aluminum hydroxide-hydroextraction procedure, two laboratories recovered 9 to 11%, whereas four obtained 17 to 34% for low-input experiments. For the high-input tests, two laboratories reported a recovery of 3 to 5%, and four recovered 11 to 18% of the seeded virus.(ABSTRACT TRUNCATED AT 250 WORDS)

Aluminum Hydroxide↗