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Biomedical subjects

M Pandey

Publications and source records attributed to M Pandey.

At least 73 records · Page 4Linked to original sources
PubMed1999

Primary malignant melanoma of the upper aero-digestive tract.

Malignant mucosal melanoma represents 0.3 to 10% of all melanomas. The majority of these lesions arise in the oral cavity or paranasal sinuses. Very few authors report reliable treatment results, however all suggest a uniformly poor outcome. A retrospective analysis of all cases of upper aero-digestive tract melanoma (UADT) treated since 1982 at our centre are presented. During the 15-year period, nine cases of UADT melanoma were identified. Three patients had a lesion in the palate, two in the maxillary alveolus, two in the oropharynx, while one each had a lesion in paranasal sinus and lower alveolus. Mean age was 43.25 years (28-62 years), with a male to female ratio of 1.6:1. Cervical lymphadenopathy was the commonest presenting symptom in seven patients. Radical surgery was carried out in three patients, wide excision in three and radical neck dissection in six, while no surgical intervention was undertaken in two patients. Median follow-up time was eleven months. In four patients, local recurrence occurred, while three developed pulmonary metastasis. One patient was lost to follow-up. We suggest that data from various centres be pooled together in order to carry out a meta-analysis to address the question of optimal treatment for malignant melanoma of the upper aero-digestive tract.

Adult↗
PubMed1999

Survival analysis: caveats and pitfalls.

BACKGROUND: Survival analysis in clinical studies is important to assess the effectiveness of a given treatment and to understand the effect of various disease characteristics. A number of methods exist to estimate the survival rate and its standard error. However, one cannot be certain that these methods have been handled appropriately. The widespread use of computers has made it possible to carry out survival analysis without expert guidance, but using inappropriate methods can give rise to erroneous conclusions. The majority of the biomedical journals now recommend that a statistical review of each manuscript should be carried out by an experienced bio-statistician, in addition to obtaining expert referees' comments on the article. The problem is compounded in papers from third-world countries where bio-statisticians may not be available in all institutions to guide clinicians as to the selection of proper techniques. METHODS: The present paper deals with the various techniques of survival analysis and their interpretation, using a modal data set of malignant upper-aerodigestive tract melanoma patients treated in the Regional Cancer Centre, Trivandrum since 1982. RESULTS: The Kaplan-Meier method was found to be the most suitable for survival analysis. The median survival time is a better method of summarizing data than the mean. Rothman's method of estimation of the confidence limit is better than Peto's method as the confidence limit for survival probability tends to go beyond the range of 0-1.0 when calculated by Peto's method, especially when the sample size is small. CONCLUSION: The results from the present study suggest that survival analysis should be carried out by the Kaplan-Meier method. The median survival time should be provided wherever possible, rather than relying on mean survival. Confidence limits should be calculated as a measure of variability. A suitable rank test should be used to compare two or more survival curves, rather than a Z-test. Stratified analysis and Cox's model, when stratified analysis fails, can be used to define the impact of prognostic factors on survival.

Digestive System Neoplasms↗
PubMed1999

Hepatic duct stones masquerading as Klatskin tumour.

We report woman who presented with painless progressive jaundice following cholecystectomy. Radiological investigations indicated proximal bile duct obstruction suggestive of hilar malignancy. Exploratory laparatomy revealed bilateral hepatic duct stone causing obstruction.

Bile Duct Neoplasms↗
PubMed1998

Tissue factor gene expression in the adipose tissues of obese mice.

Altered expression of proteins of the fibrinolytic and coagulation cascades in obesity may contribute to the cardiovascular risk associated with this condition. We previously reported that plasminogen activator inhibitor 1 (PAI-1) is dramatically up-regulated in the plasma and adipose tissues of genetically obese mice. This change may disturb normal hemostatic balance and create a severe hypofibrinolytic state. Here we show that tissue factor (TF) gene expression also is significantly elevated in the epididymal and subcutaneous fat pads from ob/ob mice compared with their lean counterparts, and that its level of expression in obese mice increases with age and the degree of obesity. Cell fractionation and in situ hybridization analysis of adipose tissues indicate that TF mRNA is increased in adipocytes and in unidentified stromal vascular cells. Transforming growth factor beta (TGF-beta) is known to be elevated in the adipose tissue of obese mice, and administration of TGF-beta increased TF mRNA expression in adipocytes in vivo and in vitro. These observations raise the possibility that TF and TGF-beta may contribute to the increased cardiovascular disease that accompanies obesity and related non-insulin-dependent diabetes mellitus, and that the adipocyte plays a key role in this process. The recent demonstration that TF also influences angiogenesis, cell adhesion, and signaling suggests that its exact role in adipose tissue physiology/pathology, may be complex.

Adipocytes↗
PubMed1998

Primary malignant melanoma of the mucous membranes.

AIMS: To investigate malignant mucosal melanoma (MMM), a rare disease and one which has, till lately, remained unrecognized. Incidence of MMM ranges from 2 to 10% in various series. METHODS: We retrospectively reviewed the cases of malignant melanoma treated at the Regional Cancer Centre, Trivandrum, India, over a period of 15 years. RESULTS: A total of 163 cases of melanoma were identified, of which 21 had a lesion in mucosal sites. There were eight cases of upper aero-digestive tract (UADT) melanoma, seven cases of rectal melanoma, five cases with lesions in the vagina and one case with a lesion in the urethra. The mean age of the patients was 52.8 years; mean age of presentation in urogenital and anorectal lesions was similar to overall mean age, while this was lower (47.5 years) for UADT lesions. Almost half of the patients presented with ulcer or nodule with or without pigmentation. Pain was present in three-quarters and vaginal bleeding was present in all cases of vaginal lesions. Almost one-third of the patients failed locally while another third developed distant metastasis during the follow-up period. A 2-year disease-free survival rate of 13.2% (95% CI: 2.2-34.1) was observed, which dropped to 6.6% (95% CI: 0.4-25.7) after 3 years. Survival appeared a little better in UADT melanoma compared to urogenital and anorectal melanoma; however, the difference was not statistically significant. CONCLUSIONS: Malignant mucosal melanoma seems to have an aggressive biological behaviour with a high incidence of local failure and metastasis.

Adult↗
PubMed1998

Erythrocyte membrane stearic to oleic acid ratio in carcinoma of the gallbladder: a preliminary study.

AIMS: The role of erythrocyte membrane stearic to oleic acid ratio (saturation index) as a marker of malignancy is still unclear, though an association has been found in colorectal carcinoma, bronchogenic carcinoma, leukaemia, lymphoma and in hepatic malignancies. This study aims to investigate the role of the saturation index in primary carcinoma of the gallbladder. METHODS: This paper describes the results of the stearic to oleic acid ratio determination in 26 subjects with either cholelithiasis or carcinoma of the gallbladder, also including a group of age- and sex-matched controls, using gas chromatography. This is the first report of the saturation index in carcinoma of the gallbladder. RESULTS: A significantly lower saturation index was observed in patients with carcinoma of the gallbladder than with cholelithiasis (t = 2.19, P = 0.043, T = 47, P < 0.05, Wilcoxon P < 0.001, F = 2192.23, P < 0.001; 95% CI 18.45-30.44) and controls (t = 2.5, P = 0.024, T = 36, P < 0.05, F = 10904.11, P < 0.001, Wilcoxon P < 0.001; 95% CI 52.42-63.39). Among the carcinoma patients a further lowering was noted in stage IV disease compared with stage III (T = 6, P < 0.05). CONCLUSIONS: These changes are probably due to a marked increase in oleic acid content at the expense of stearic acid. This lowering of the saturation index in carcinoma of the gallbladder is similar to that observed previously in the other malignancies.

Carcinoma↗
PubMed1998

Carcinoma of the gallbladder presenting as scalp tumour.

Carcinoma of the gallbladder is characterized by rapid tumour growth associated with lymphatic and local tumour invasion. The peritoneum, GIT and lungs are common sites of seeding. Distant metastasis to bone rarely occurs. Here we document a case of silent gallbladder carcinoma presenting as scalp tumour with improved survival.

Carcinoma↗
PubMed1998

Xanthogranulomatous cholecystitis.

Xanthogranulomatous cholecystitis exists in a small but significant proportion of routine cholecystectomy specimens. A few recent reports have shown a possible association of this disease with carcinoma of the gallbladder. All cholecystectomized specimens were prospectively evaluated over a period of two and half years in a single surgical unit to examine the incidence of xanthogranulomatous cholecystitis and its association, if any, with carcinoma of the gallbladder in an area that is prone to gallbladder diseases. A total of 460 cholecystectomies were performed for various gallbladder diseases. Histological confirmation revealed chronic cholecystitis in 311 (67.6%) cases, carcinoma of the gallbladder in 62 (13.5%), acute cholecystitis in 29 (6.3%), xanthogranulomatous cholecystitis in 41 (8.9%), and xanthogranuloma and carcinoma of the gallbladder in one case (0.2%) only. Almost all cases were suspected to have chronic cholecystitis on clinical and ultrasonographic features. Two specimens on gross examination showed mass lesions, and hence were suspected to be carcinoma of the gallbladder. Subsequent frozen section and histopathology demonstrated xanthogranulomatous cholecystitis. Only one case of xanthogranuloma was found to be associated with carcinoma of the gallbladder but no firm association could be established between xanthogranulomatous cholecystitis and carcinoma of the gallbladder.

Acute Disease↗
PubMed1998

Metallothionein expression in carcinoma of the gallbladder.

AIMS: Metallothioneins (MT) are sulphur-rich, low molecular-weight, intracellular metal-binding proteins with a possible role in carcinogenesis of some human tumours. Metallothionein expression in gallbladder cancer has not been studied previously. METHODS AND RESULTS: Immunohistochemical expression of metallothionein was studied in 42 gallbladders (27 cases of carcinoma of the gallbladder, eight chronic cholecystitis and seven cases of normal gallbladder). Metallothionein expression was significantly higher in cases with carcinoma of the gallbladder (70.37%) as compared to chronic cholecystitis (25%) and normal gallbladders (0%). There was a trend suggestive of increasing MT expression with increasing histological dedifferentiation of carcinoma of the gallbladder. CONCLUSIONS: The increased expression of MT in cases of carcinoma of the gallbladder may represent an increased exposure to heavy metals, which are known carcinogens, and may have a role in gallbladder carcinogenesis. Metallothionein over-expression in carcinoma of the gallbladder may be relevant to the poor prognosis and chemoresistance seen in these cases.

Adult↗
PubMed1998

Cardiff repair of incisional hernia: a university hospital experience.

OBJECTIVE: To analyse our results of the "Cardiff' (far and near) repair in incisional hernias. DESIGN: Prospective study. SETTING: University hospital, Varanasi, India. SUBJECTS: 50 patients who presented with incisional hernias between January 1990 and December 1994. INTERVENTION: Interrupted far-and-near sutures inserted after excision of the sac. The contents were pushed into the abdomen and the peritoneum sutured with non-absorbable polypropylene (prolene). MAIN OUTCOME MEASURES: Early and late morbidity. Six patients developed postoperative complications (wound infection, n=3; flap necrosis, n=2; and wound sinus, n=1). No patient has been lost to follow up and there have been no signs of recurrence after a mean follow up of 52 months. CONCLUSION: The meticulous application of this simple surgical technique has low morbidity and is cost effective. We recommend it for small and medium size defects.

Adolescent↗
PubMed1998

The Splendore-Hoeppli phenomenon in hepatic botryomycosis.

A 68 year old diabetic man developed septicaemia and multiple liver abscesses due to Streptococcus intermedius. Liver biopsy revealed streptococcal botryomycosis which showed the Splendore-Hoeppli phenomenon. Diabetes mellitus is an example of the immunosuppressed states that have been associated with botryomycosis.

Aged↗
PubMed1997

Expression and characterization of Pichia etchellsii beta-glucosidase in Escherichia coli.

The beta-glucosidase enzyme is important as the terminal enzyme involved in hydrolysis of cellobiose and short-chain cellodextrins generated during enzymatic cellulose degradation. Under controlled reaction conditions the enzyme also displays cello-oligosaccharide synthesizing ability (based on either the thermodynamic or kinetic approach). We present here the purification of the enzyme beta-glucosidase (BGL) of Pichia etchellsii from recombinant pBG55 Escherichia coli clone. The kinetic parameters, substrate specificity and oligosaccharide synthesizing ability of the purified enzyme are also reported. The purified 200-kDa protein (tetramer of 50 kDa) was identified as a broad-substrate-specificity enzyme exhibiting increased temperature and glucose tolerance compared to the native yeast enzyme. Temperature directed substrate specificity for aryl beta,1-4 linkage, and beta (1-2), beta(1-4), beta(1-6) and beta(2-1) linkages in various natural disaccharides was observed. Glycosylation of the enzyme was found to be unimportant for enzyme activity. With both cellobiose and glucose, oligosaccharide synthesis was detected. The implications of this information with regard to cellulose hydrolysis and oligosaccharide synthesis are discussed.

Blotting, Southern↗
PubMed1997

Haemangiopericytoma: current status, diagnosis and management.

Haemangiopericytoma (HPC) is a rare tumour, characterized by unidentifiable light microscopic features. Despite first being described over 50 years ago, nothing much was known about this tumour until the early 1980s, when ultrastructural studies and tumour markers made it possible to differentiate it from other mesenchymal tumours. Advancements in radiology and the emergence of MRI technology helped surgeons in better planning. Pre-operative vascular embolization helped to reduce the menace of operative haemorrhage. Improvements in localization and delivery of radiotherapy, coupled with early diagnosis, has tremendously improved the treatment outcome of haemangiopericytoma.

Hemangiopericytoma↗
PubMed1997

Primary hydatid cyst of sacral spinal canal: case report.

OBJECTIVE AND IMPORTANCE: Primary hydatid cysts of the spinal canal are very rare. The patient in the present case presented with lower cauda equina compression caused by a primary solitary hydatid cyst of the sacral spinal canal, which is a remote possibility. To the best of our knowledge, such a case has not been reported previously. CLINICAL PRESENTATION: A 15-year-old male patient presented with lower motor neurone type of bladder and bowel involvement, with saddle-shaped anesthesia involving S2-S5 dermatomes. Plain x-rays and magnetic resonance imaging (MRI) scans revealed a widened sacral canal with pressure changes. MRI scans confirmed the cystic nature of the lesion, which had no specific characteristics and demonstrated intensities that were similar to those of cerebrospinal fluid. TECHNIQUE: Surgical exploration of the sacral canal with enucleation of the cyst in toto was performed. A midline posterior approach was used by decompressing thinned posterior elements. Adjuvant therapy with mebendazole or albendazole was not administered, although recently, some authors claim good results with integrated surgical and medical treatment. CONCLUSION: The patient experienced dramatic improvement and became continent. At a follow-up examination after 1 year, he had only minimal urinary stress incontinence. If spinal hydatid cyst is surgically removed unruptured and other common primary sites are excluded, medical treatment can be deferred, provided the patient undergoes strict follow-up. MRI, although not specific for hydatid disease, should be the investigation of choice in suspected cases of spinal hydatid cyst.

Adolescent↗
PubMed1997

Elevated expression of transforming growth factor-beta in adipose tissue from obese mice.

BACKGROUND: Tumor necrosis factor-alpha (TNF-alpha) is chronically elevated in the adipose tissue from obese humans and mice. This increase in TNF-alpha contributes to the insulin resistance, elevated plasminogen activator inhibitor-1 (PAI-1) levels, and cardiovascular complications associated with obesity and noninsulin-dependent diabetes (NIDDM). PAI-1 gene expression in adipose tissue is also stimulated by transforming growth factor-beta (TGF-beta). Experiments were performed to determine whether TGF-beta is regulated by TNF-alpha and elevated in obesity. MATERIALS AND METHODS: The concentration of TGF-beta and PAI-1 mRNA in murine adipose tissue and cultured 3T3-L1 adipocytes was determined by quantitative reverse transcription polymerase chain reaction (RT-PCR), and the cellular localization of these molecules was evaluated using in situ hybridization and cell fractionation. Total TGF-beta protein was determined by employing an ELISA assay. RESULTS: TGF-beta mRNA and protein were increased in the adipose tissue from two different strains of genetically obese mice (i.e., ob/ob and db/db), compared with their lean counterparts. This increase in TGF-beta may result from TNF-alpha since TNF-alpha increased TGF-beta mRNA expression in the adipose tissue of lean mice and stimulated TGF-beta production by cultured adipocytes. Administration of TGF-beta increased PAI-1 antigen in the plasma and PAI-1 mRNA in the adipocytes of lean mice, and enhanced the rate of PAI-1 synthesis by adipocytes in vitro. CONCLUSIONS: TNF-alpha contributes to the elevated TGF-beta expression demonstrated in the adipose tissue of obese mice. A potential role for TGF-beta in the increased PAI-1 and vascular pathologies associated with obesity/NIDDM is suggested.

3T3 Cells↗