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L Ghosh

Publications and source records attributed to L Ghosh.

At least 19 recordsLinked to original sources
PubMed2005

Structural changes of beta-lactoglobulin during thermal unfolding and refolding--an FT-IR and circular dichroism study.

We have quantitatively characterized by FT-IR spectroscopy the contents of secondary structure of beta-lactoglobulin during thermal unfolding and subsequent refolding. Our data clearly indicate that considerable amount of secondary structure, particularly beta-sheet, still remained intact even at 90 degrees C. Noticeable changes in secondary structure of beta-lactoglobulin were observed only above 70 degrees C. The refolded protein regained, within limits of experimental error, all of the secondary structure lost during thermal unfolding. The data also indicate that the refolding mechanism operating at pH 7.0 and 2.0 are the same. Identical secondary structure of native and refolded beta-lactoglobulin was also indicated by far-UV circular dichroic spectra of the two forms of protein. Near UV circular dichroic spectra of the same two forms showed considerable differences indicating less tertiary structure of refolded beta-lactoglobulin. The combined CD and FT-IR data indicated that refolded form of beta-lactoglobulin could be characterized as a molten globule state as it had native-like secondary structure and compromised tertiary structure.

Circular Dichroism↗
PubMed2001

Oxidative DNA damage in prostate cancer patients consuming tomato sauce-based entrees as a whole-food intervention.

BACKGROUND: Human prostate tissues are vulnerable to oxidative DNA damage. The risk of prostate cancer is lower in men reporting higher consumption of tomato products, which contain high levels of the antioxidant lycopene. We examined the effects of consumption of tomato sauce-based pasta dishes on lycopene uptake, oxidative DNA damage, and prostate-specific antigen (PSA) levels in patients already diagnosed with prostate cancer. METHODS: Thirty-two patients with localized prostate adenocarcinoma consumed tomato sauce-based pasta dishes for the 3 weeks (30 mg of lycopene per day) preceding their scheduled radical prostatectomy. Serum and prostate lycopene concentrations, serum PSA levels, and leukocyte DNA oxidative damage (ratio of 8-hydroxy-2'-deoxyguanosine [8-OHdG] to 2'-deoxyguanosine [dG]) were assessed before and after the dietary intervention. DNA oxidative damage was assessed in resected prostate tissue from study participants and from seven randomly selected prostate cancer patients. All statistical tests were two-sided. RESULTS: After the dietary intervention, serum and prostate lycopene concentrations were statistically significantly increased, from 638 nM (95% confidence interval [CI] = 512 to 764 nM) to 1258 nM (95% CI = 1061 to 1455 nM) (P<.001) and from 0.28 nmol/g (95% CI = 0.18 to 0.37 nmol/g) to 0.82 nmol/g (95% CI = 0.57 to 1.11 nmol/g) (P <.001), respectively. Compared with preintervention levels, leukocyte oxidative DNA damage was statistically significantly reduced after the intervention, from 0.61 8-OHdG/10(5) dG (95% CI = 0.45 to 0.77 8-OHdG/10(5) dG) to 0.48 8-OHdG/ 10(5) dG (95% CI = 0.41 to 0.56 8-OHdG/10(5) dG) (P =.005). Furthermore, prostate tissue oxidative DNA damage was also statistically significantly lower in men who had the intervention (0.76 8-OHdG/10(5) dG [95% CI = 0.55 to 0.96 8-OHdG/10(5) dG]) than in the randomly selected patients (1.06 8-OHdG/10(5) dG [95% CI = 0.62 to 1.51 8-OHdG/10(5) dG]; P =.03). Serum PSA levels decreased after the intervention, from 10.9 ng/mL (95% CI = 8.7 to 13.2 ng/mL) to 8.7 ng/mL (95% CI = 6.8 to 10.6 ng/mL) (P<.001). CONCLUSION: These data indicate a possible role for a tomato sauce constituent, possibly lycopene, in the treatment of prostate cancer and warrant further testing with a larger sample of patients, including a control group.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2001

Dysphagia caused by a fetus-in-fetu in a 27-year-old man.

Mechanical obstruction of the distal esophagus by a fetus-in-fetu is an extremely rare condition that has not been previously reported. We present the case of a 27-year-old man who presented with dysphagia caused by fetus-in-fetu contained within a retroperitoneal cystic cavity. The tumor, noticed since childhood, did not cause any symptoms until a year before presentation when symptoms of dysphagia developed. We propose including this entity in the differential diagnosis of a retroperitoneal mass.

Adult↗
PubMed2001

Study on the diuretic activity of Strychnos potatorum Linn. seed extract in albino rats.

Methanol extract of Strychnos potatorum Linn. seeds (SPSE) was evaluated for its diuretic activity in Wistar albino rats. The SPSE was administered at the graded doses of 200, 400, and 600 mg/kg body weight. The parameters which were taken into account during the experimental on each rat were: total urine volume (corrected for water intake during the test period), body weight before and after the experiment, and the concentration of sodium, potassium, and chloride ions in urine. The total urine volumes of the SPSE (600 mg/kg)-treated rats were evaluated nearly two and half fold then compared with the control (saline treated) group. Excretion of cations (sodium and potassium ions) and anions (chloride ions) also increased significantly with respect to the control group. The diuretic effect was comparable with that of the standard drug Furosemide. The increase of cations in the urine on treatment with Strychnospotatorum seed extract (SPSE) was dose-dependent. This effect supports the use of the Strychnos potatorum seeds as a diuretic in folk remedies.

Animals↗
PubMed2000

Evaluation of antidiarrhoeal profile of Jussiaea suffruticosa linn. extract in rats.

The antidiarrhoeal potential of a methanol extract of the aerial parts of Jussiaea suffruticosa Linn. (MEJS) was studied with several experimental models of diarrhoea in rats. MEJS treated rats showed significant inhibitory activity against castor oil induced diarrhoea and PGE(2) induced enteropooling. It also showed a significant reduction in gastrointestinal motility following a charcoal meal in rats. The extract exhibited significant antidiarrhoeal potential at doses of 100,200 and 300 mg/kg in all the animal models and thus established the efficacy of MEJS as a potent antidiarrhoeal agent.

Animals↗
PubMed2000

Evaluation of antitussive potential of Jussiaea suffruticosa linn. extract in albino mice.

The antitussive activity of a methanol extract of Jussiaea suffruticosa Linn. (MEJS) (family Onagraceae) leaves has been evaluated for its potential on a cough induced by sulphur dioxide (SO(2)) gas model in mice. The extract (MEJS) showed significant antitussive activity in a dose dependent manner. The antitussive potential of MEJS was comparable to that of codeine phosphate (10 mg/kg), a standard drug. The extract (MEJS) at a dose level of 200 and 400 mg/kg, p.o. showed appreciable inhibition on the cough reflex by 48.52% and 59.8% respectively during 120 min of the experiment.

Animals↗
PubMed1999

Effect of unilateral testicular torsion on blood flow and histology of contralateral testes.

BACKGROUND/PURPOSE: Infertility occurs in 25% of patients after unilateral testicular torsion; hence, the authors examined hemodynamic and histological changes in both testes after acute testicular torsion in neonatal piglets. METHODS: The animals were anesthetized, intubated, ventilated, catheterized, and assigned randomly to a sham group or one of three experimental groups undergoing 720 degrees torsion of the left testis for 8 hours after which it was untwisted in group I and removed in group II. In group III, both testes were removed. Data were collected at baseline (T = 0), 4 hours (T = 4), and 8 hours of torsion (T = 8) and at the ninth hour of the experiment (T = 9). Testicular blood flow was determined by using radiolabeled microspheres. The testes also were examined blindly with routine and electron microscopy. RESULTS: In group I, testicular blood flow decreased in the affected testis during torsion and increased significantly after detorsion, whereas blood flow to the contralateral testis increased significantly after detorsion. Sham-operated animals showed no histological abnormality in either testis. In all torsion groups, the affected testis showed extensive changes caused by hemorrhagic necrosis. The contralateral testis only showed changes in group I. CONCLUSION: Unilateral testicular torsion resulted in ipsilateral damage caused by a decrease and subsequent increase in blood flow while in the contralateral testis; damage was the result of a significant increase in blood flow after detorsion.

Animals↗
PubMed1998

Fibro-osseous, osseous, and cartilaginous lesions of the orbit and paraorbital region. Correlative clinicopathologic and radiographic features, including the diagnostic role of CT and MR imaging.

Fibro-osseous and cartilaginous lesions of the orbit and facial region share overlapping clinical, radiologic, and pathologic features that may lead to diagnostic confusion and possible misdiagnosis. The value of imaging studies in the histopathologic diagnosis of these lesions cannot be overemphasized. The histopathologic diagnosis of such lesions should not be rendered in the absence of radiographic correlation.

Cartilage Diseases↗
PubMed1998

Immunohistochemical localization of nephrocalcin, a kidney-specific glycoprotein, to renal cell carcinoma.

OBJECTIVES: Nephrocalcin (NC), an acidic glycoprotein produced by renal proximal tubule cells and functioning as an inhibitor of calcium oxalate monohydrate crystalization, has been previously shown to have increased urinary excretion in patients with renal cell carcinoma (RCC). The current study uses immunohistochemical techniques to localize NC to cells of primary RCC. METHODS: We studied 29 kidneys removed because of RCC. Slides were deparaffinized and stained after incubating with anti-NC antibody by using the avidin-biotin-peroxidase complex techniques. Uptake of stain by tumor cells and adjacent normal renal cells was compared. RESULTS: Twenty-seven kidneys (93%) showed positive staining for RCC tumor cells; 2 kidneys staining positive for normal proximal tubule cells failed to stain adjacent RCC tumor cells (7%). CONCLUSIONS: The data suggest that enhanced production of urinary NC in patients with RCC derives from cells of the primary tumor.

Adolescent↗
PubMed1997

Thrombocytopenia in an established solitary pancreas graft recipient.

Isolated, life-threatening thrombocytopenia from a previously well tolerated pancreas allograft has not been reported in the literature. Herein we report such a case where a 31-year-old, Caucasian, Type I diabetic male developed severe thrombocytopenia 6 months following isolated pancreas transplantation and 2 wk after enteric conversion of the graft. Despite extensive diagnostic work-up, the cause remained unclear and his thrombocytopenia did not remit with standard treatment, but did resolve upon explantation. Pathologic examination of the pancreatic graft showed evidence of chronic rejection along with CMV pancreatitis. We conclude that unremitting isolated thrombocytopenia in solitary pancreas grafts may reflect a localized DIC phenomenon that requires graft explantation.

Adult↗
PubMed1995

Up-regulation of E-selectin and intercellular adhesion molecule-1 differs between Crohn's disease and ulcerative colitis.

In present study, we investigated if inflammatory mediators secreted by the inflamed colonic mucosa from patients with Crohn's disease and ulcerative colitis had the ability to up-regulate the expression of two adhesion molecules, E-selectin and intercellular adhesion molecule-1. Organ culture techniques and enzyme-linked immunoassays were used to quantify these up-regulations in human umbilical vein endothelial cells. Our results show that, in Crohn's disease patients, the expression of E-selectin was up-regulated 5.5-fold over control values and intercellular adhesion molecule-1 expression was increased 2.4-fold. In ulcerative colitis patients, E-selectin expression was up-regulated twofold over controls with only a 1.5-fold increase in intercellular adhesion molecule-1 expression. Histologically, there was no difference in the degree of inflammation between the two disease groups. Sulfasalazine, in a dose-dependent manner, inhibited E-selectin expression up to 58% and intercellular adhesion molecule-1 up to 62% when stimulated by lipopolysaccharide. The up-regulation of E-selectin and intercellular adhesion molecule-1 may play an important role in mediating the inflammatory process in inflammatory bowel disease. The observed difference between Crohn's disease and ulcerative colitis may reflect differences in inflammatory cell infiltrates or the histopathological differences between the two diseases.

Adult↗
PubMed1994

Endothelial proliferation in experimental granulomatous colitis. Autoradiography and immunohistochemistry studies.

The time sequence and magnitude of endothelial cell proliferation was investigated in an experimental model of granulomatous colitis in rats, induced by intramural inoculations of mycobacterium Bacillus Calmette-Guerin. Colonic tissues were assessed by gross examination, histopathology, autoradiography, and immunohistochemistry. Gross examination of the colonic tissue showed thickening of the colonic wall, erythema, hemorrhage, and scattered ulcers. Histopathological findings were characterized by an acute transmural inflammation, progressing to chronic inflammation accompanied by regenerative changes in the glandular epithelium, goblet cell depletion, mucosal atrophy and fibrosis. Well-developed noncaseating granulomas were first observed at day 5 and were found to be a dominant feature up to day 17. Autoradiographic studies showed increased endothelial cell labeling up to 17% at 48 hr, compared to less than 1% labeling in control animals. Immunostaining for factor VIII-related antibody, an endothelial cell marker, showed increased numbers of microvessels and individual positive cells located in areas of inflammation as early as 24 hr. At day 5 these individual cells along with dilated neocapillaries were found surrounding the granulomas. This model of granulomatous colitis mimics many features of the human disease state. The early increase in endothelial cell proliferation that precedes granuloma formation during the course of the inflammatory response may suggest that the events leading to the expression of granulomatous colitis are dependent on endothelial proliferation.

Animals↗
PubMed1993

Mutation in the nm23 gene is associated with metastasis in colorectal cancer.

The human nm23 gene, a candidate metastatic suppressor gene, consists of two genes, nm23-H1 and nm23-H2. The potential mutation in the nm23-H1 gene was examined in colorectal cancer using a reverse transcription polymerase chain reaction amplification followed by DNA sequencing analysis. Genomic alterations in the nm23 gene were also examined by Southern hybridization. Genetic alterations either as a deletion in the coding sequence of nm23-H1 or as an allelic deletion were detected in four among eight colorectal adenocarcinomas associated with metastases in lymph nodes, lung, or liver. No alteration was observed in 12 additional colorectal cancer specimens without metastasis. These results provide first evidence for novel mutation in the nm23 gene and demonstrate a correlation between the mutation in the nm23 gene and metastasis in colorectal oncogenesis which suggests that the nm23 gene plays a role in the causation of metastasis.

Alleles↗
PubMed1993

Primary alveolar soft part sarcoma of the tongue of an elderly man. A case report and review of the literature.

A 64-year-old black man had a primary alveolar soft part sarcoma of the tongue. It is unusual for this rare tumor to develop in this site in the elderly age group. The patient survived nearly 3 years with disease. When the patient expired, a complete autopsy was performed. The biopsy material of the primary tumor showed characteristic light microscopic appearance, intracellular periodic acid-Schiff positive inclusions after diastase reaction, and electron microscopic presence of crystals. Immunohistochemistry for neuron-specific enolase was positive. The autopsy confirmed widespread visceral and lymphatic metastases. The atypical features of this case, including the site of the primary lesion, age of the patient at diagnosis, immunohistochemistry of the tumor, and natural history of this neoplasm, suggest that alveolar soft part sarcoma may behave differently when arising in an extraskeletal site, and could possibly have a different histogenesis from the typical alveolar soft part sarcoma found in a younger population.

Humans↗
PubMed1992

DNA polymerase beta mutations in human colorectal cancer.

Increasing numbers of alterations have been found in protooncogenes (e.g., ras, myc), as well as tumor suppressor genes (e.g., p53, Rb) in various types of tumors. The multiple mutations cannot be explained by the spontaneous mutation rate. It has been suggested that mutator phenotypes leading to the accumulation of these mutations may be required in the early stages of tumorigenesis. To test this hypothesis, the entire coding region of DNA polymerase beta, a repair enzyme, mRNA from colorectal tumors, and corresponding normal mucosa were amplified by polymerase chain reaction, cloned, and sequenced. Mutations in the catalytic domain of DNA polymerase beta were detected in colorectal tumor specimens compared to the normal colorectal mucosa, placenta, and blood samples. Since these mutations changed the structure of polymerase beta, it is expected that the efficiency of the DNA repair system would be impaired and thus may account for the high mutation rate observed in colorectal carcinomas.

Base Sequence↗