Radiology quiz case 4. Osteosarcoma of the maxilla.
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Biomedical subjects
Publications and source records attributed to N Saravanan.
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Eight selective nitrogen-sulfur donor ligands have been synthesized from the condensation of S-methyldithiocarbazate (SMDTC) with aldehydes and ketones with a view to evaluating their antimicrobial and cytotoxic activities, and also to correlate the biological properties with the structure of the ligands. The compounds were all characterized by elemental analyses and other physicochemical techniques. SMDTC and the Schiff bases were screened for antimicrobial and cytotoxic activities. SMDTC showed very large inhibition zones (24-44 mm) against bacteria and fungi with a minimum inhibitory concentration (MIC) of 390-25,000 and 1562-6250 microg ml(-1), against different bacteria and fungi, respectively. Streptomycin and nystatin were used as the internal standards against bacteria and fungi, respectively. SMDTC along with its Schiff bases with pyridine-2-carboxaldehyde, acetylacetone and 2,3-butanedione were strongly antifungal and the MIC values were comparable to nystatin. Most of the Schiff bases were strongly cytotoxic. In particular, those with pyridine-2-carboxaldehyde and 2,3-butanedione have CD(50) values of 5.5, 1.9-2.0 microg ml(-1), respectively, against leukemic cells, while against colon cancer cells, the values were 3.7 and 2.0 microg ml(-1), respectively. The glyoxal Schiff base was strongly active only against leukemic cell with CD(50) value of 4.0 microg ml(-1). The present findings have been compared with standard drugs.
Calcium oxalate crystal growth and aggregation leads to the formation of renal calculi. It is known to be inhibited by several compounds both in vitro and in vivo conditions. The present study highlights the inhibitory potential of sodium pentosan polysulphate (SPP), a semi-synthetic glycosaminoglycan (GAG) on calcium oxalate crystal growth in vitro. Its efficacy was compared with those of known inhibitors like pyrophosphate, heparin and chondroitin-4-sulphate. Of the above compounds pyrophosphate was found to be the most potent inhibitor. Among the GAGs, SPP exhibited 80% inhibitory activity as compared to heparin. A lesser degree of inhibition was observed with chondroitin-4-sulphate.
OBJECTIVE: To study the effect of L-cysteine on urinary risk factors in hyperoxaluric urolithiasis in rats. MATERIALS AND METHODS: Twenty-four rats were divided into four groups of six rats each; those in Group I served as controls, those in Group II had hyperoxaluria induced using sodium glycollate, those in Group III were given cysteine alone and those in Group IV were given sodium glycollate and cysteine. Samples of 24 h urine were collected and analysed to determine the content of calcium, oxalate, phosphorus and magnesium, and the organic acids, glycollic, glyoxylic and citric acid. RESULTS: Hyperoxaluric rats treated with cysteine had significantly lower excretion rates of calcium, oxalate, phosphorus, glycollic and glyoxylic acid than the glycollate fed rats. When cysteine was given, the excretion of urinary citric acid and magnesium were also increased. CONCLUSION: Cysteine may be a useful agent in preventing oxalate urolithiasis.
Evolutionary algorithms, including evolutionary programming and evolution strategies, have often been applied to real-valued function optimization problems. These algorithms generally operate directly on the real values to be optimized, in contrast with genetic algorithms which usually operate on a separately coded transformation of the objective variables. Evolutionary algorithms often rely on a second-level optimization of strategy parameters, tunable variables that in part determine how each parent will generate offspring. Two alternative methods for performing this second-level optimization have been proposed and are compared across a series of function optimization tasks. The results appear to favor the approach offered originally in evolution strategies, although the applicability of the findings may be limited to the case where each parameter of a parent solution is perturbed independently of all others.
Oxalate, the major stone-forming constituent induces lipid peroxidation during lithogenesis. In experimental condition oxalate formation was induced by the administration of its precursor glycollate. Glycollate-fed rats showed increased susceptibility to lipid peroxidation in the presence of promoters. In addition, antioxidant enzymes-catalase, superoxide dismutase and glutathione peroxidase also showed decreased activity. Reduced glutathione, total thiols and ascorbic acid were also significantly decreased. On the other hand, an increased xanthine oxidase and decreased glucose-6-phosphate dehydrogenase activity was also observed upon glycollate administration. Cysteine, a sulphydryl compound, is known to inhibit free radical toxicity in various pathologies. Cysteine administration to glycollate-fed rats brought about a significant decrease in the peroxidative level, with an increase in the antioxidant status.
Glyoxylic lithiasis by acute intoxication with sodium glyoxylate, significantly raised the levels of renal tissue calcium and oxalate which has been reflected simultaneously in their urinary levels. Administration of DL alpha-lipoic acid lowered the oxalate levels in the kidney and urine. Sodium glyoxylate administration resulted in enhanced liver glycollate oxidase activity, the major enzyme in endogenous oxalate synthesis. DL alpha-lipoic acid decreased glycollate oxidase activity but did not have any effect on lactate dehydrogenase. The possibility of regulating oxalate metabolism in glyoxylic lithiasis with the use of DL alpha-lipoic acid, by way of inhibiting liver glycollate oxidase, looks attractive.
BACKGROUND: Computed tomographic colonography (CTC) is a new technique for detecting colonic neoplasms. Data on the utility of this method in the Indian population are limited. METHODS: Forty-two patients with symptoms of colonic disease underwent CTC and conventional colonoscopy (CC) within one week of each other and the findings at these two investigations were compared. RESULTS: The entire colon could be evaluated in 38 patients on CTC and in 23 patients on CC. Of the 19 patients who had incomplete CC, 14 had occlusive colonic lesions. Of the 86 lesions detected on CC, 76 (88.4%) were correctly identified on CTC with regard to location and size. CTC was false negative for 10 lesions and false positive for 5 lesions in 3 patients. The sensitivity and specificity of CTC were 65% and 77%, respectively, for lesions 1-5 mm; 97% and 83% for 6-9 mm-sized lesions; and 100% and 100% for lesions 10 mm or larger. Extracolonic findings were seen in 24 of 42 patients (57%). CONCLUSIONS: CTC is reliable for detecting lesions 6 mm or larger in size. It permits evaluation of the region proximal to an occlusive growth, which is often not possible with CC.