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Biomedical subjects

T K Chattopadhyay

Publications and source records attributed to T K Chattopadhyay.

At least 19 recordsLinked to original sources
PubMed2005

Gallbladder cancer in India: a dismal picture.

BACKGROUND: Gallbladder cancer (GBC) is one of the most common gastrointestinal malignancies. The data regarding GBC are, however, limited. METHODS: Records of 634 patients with GBC over a 10-year period were examined with regard to the clinical presentation, investigative findings, treatment, operative findings and outcome. RESULTS: The mean age of patients was 51 +/- 11 years and men : women ratio was 0.36:1.00. Pain, jaundice and hepatomegaly were seen in 81.0%, 76.0% and 61.5% patients, respectively. On imaging, a mass replacing the gallbladder was seen in 73% patients. Gallstones were present in 54% patients. Surgery was carried out in 291 (46%) patients and endoscopic treatment in 72 (19%) patients but no intervention was carried out in the remaining patients because of disseminated disease. Among the patients who were operated on, 2.0% had stage I GBC, 3.4% stage II, 17.5% stage III, 47.0% stage IVa and 29.8% stage IVb. Radical resection was possible in 133 (46%) patients. The 30-day mortality was 10% with most (90%) deaths in patients with stage IV disease. The median survival after simple cholecystectomy and radical surgery was 33.5 and 12.0 months, respectively. However, among those who underwent debulking, palliative bypass or exploratory laparotomy alone, the survival ranged between 1 and 3 months. Logistic regression analysis showed that only radical resection improved the long-term survival (P < 0.05). CONCLUSIONS: The majority of patients with GBC in India have advanced unresectable disease. Detection of GBC at an early stage is incidental and rare but is associated with long-term survival. Radical surgery, when feasible, is the only option for achieving long-term survival.

Adult↗
PubMed2004

Thoracic duct injury during esophagectomy: 20 years experience at a tertiary care center in a developing country.

Thoracic duct injury is an uncommon complication of esophagectomy. Experience in managing these cases is limited to large centers performing esophagectomies in good numbers. We analyzed the prospectively maintained esophageal diseases database of patients presenting to a surgical unit between 1982 and 2002. Among 552 esophagectomies during this period we had encountered 14 cases of chylothorax (2.54%). We analyzed the type and site of lesion and the impact of neoadjuvant therapy on the incidence of thoracic duct injury. Among 459 patients of transhiatal esophagectomy, 11 developed postoperative chylothorax (2.40%). In 93 transthoracic resections, there were three cases of chylothorax (3.23%; (P = 0.9185)). The incidence following preoperative radiotherapy was 2.17%. None of the 31 patients, who had undergone esophagectomy for benign diseases had developed chylothorax. In the carcinoma group the incidence in middle third lesions was 5.85% and in lower third lesions was 0.80% (P = 0.0018). Seven patients were managed conservatively. Two of these patients, for whom surgery had been planned, died before they could be taken up for surgery. In the remaining seven patients transthoracic ligation of the thoracic duct was performed. Two patients in this group died. The average hospital stay was 20 days in the conservative group and 12 days in the surgery group. Among the factors studied, patients with middle third lesions were at increased risk of developing postoperative chylothorax, when compared to upper or lower third lesions.

Adenocarcinoma↗
PubMed2001

Esophageal squamous cell carcinomas with DNA replication errors (RER+) are associated with p16/pRb loss and wild-type p53.

PURPOSE: Microsatellite instability (MSI) as a determinant of propensity to esophageal squamous cell carcinoma (ESCC) at seven microsatellite markers at 2p (2p15-16), 3p (3p13, 3p14.1-3, 3p25, and 3p26) and 16q (16q12.1-3) was investigated to analyze their putative role as indicators of predisposition to esophageal malignancies. METHODS: Seven microsatellite loci were amplified by polymerase chain reaction, from surgically resected tumor tissues from 30 ESCC patients from Indian population, to assess the loss of heterozygosity (LOH) and replication error repeats (RER) and to correlate these alterations with aberrations in major cell cycle regulatory proteins and histopathological parameters. RESULTS: LOH and RER analyses at these loci demonstrated moderate microsatellite alterations, suggesting the involvement of MSI in esophageal tumorigenesis in a subset of the Indian population. MSI, defined as RER in at least two or more of the loci studied, was observed in ten of 30 (33%) patients. Twenty-two of 30 patients (73%) showed LOH at one or more loci, while 17 of the 30 patients (60%) showed RER in at least one of the loci studied. RER-positive patients showed a trend towards better prognosis when compared to RER-negative patients. MSI demonstrated a significant association with concomitant loss of p16 and pRb (p16-/pRb- phenotype) (P=0.046). Interestingly, we observed an inverse correlation between MSI and p53 mutations (P=0.03) suggesting that MSI may provide a p53-independent pathway for esophageal tumorigenesis in RER+ patients. MSI showed a trend towards longer survival and absence of distant organ metastasis (P=0.06). CONCLUSIONS: The present study demonstrates the probable role of MSI in esophageal squamous cell carcinoma in the Indian population. Instability associated with the repetitive sequences--the revealing marks of loss of DNA replication fidelity may serve as an indicator of predisposition to esophageal cancer.

Carcinoma, Squamous Cell↗
PubMed2000

Circulating p53 antibodies, p53 gene mutational profile and product accumulation in esophageal squamous-cell carcinoma in India.

Esophageal cancer (EC) in the Indian population presents in advanced stages with poor prognosis and warrants the identification of a non-invasive marker for early detection and better prognostic assessment. We have previously reported high prevalence of p53 protein accumulation in esophageal squamous-cell carcinomas (ESCCs). The present study was designed to determine (i) if esophageal cancer patients elicit a humoral immune response to intra-tumoral p53 protein accumulation and (ii) their relationship with p53 gene mutations. The goal was to compare the cellular events, p53 protein accumulation and gene mutations with the presence of serum anti-p53 antibodies (p53-Abs) and to assess the utility of serological p53-Ab analysis as a surrogate marker for p53 alterations in esophageal cancer. A high prevalence of circulating p53-Abs was observed in 36 of 60 (60%) ESCC patients. In a subset of 44 ESCCs, exons 5-9 of the p53 gene were examined for mutations by PCR and direct sequencing of PCR products. Mutational data have been correlated with p53-Abs and p53 protein accumulation in ESCCs. Circulating p53-Abs in ESCC patients were significantly associated with intra-tumoral p53 protein accumulation (p=0.0005). A strong correlation observed between humoral immune response against p53 protein, missense gene mutations and protein accumulation warrants the application of serological p53-Abs as a non-invasive surrogate marker in screening high-risk populations for early detection of malignancy.

Adult↗
PubMed1999

Adenocarcinoma of distal esophagus and gastroesophageal junction: long-term results of surgical treatment in a North Indian Center.

This retrospective study reports our experience managing 78 patients with adenocarcinoma of the esophagus and gastroesophageal junction operated between January 1982 and December 1996. Altogether 18 patients presented with stage I and II disease, and 60 patients had stage III and IV disease at presentation; 56 patients (71.8%) were found to have resectable disease. Of these, transhiatal esophagectomy was possible in 51 patients. Transthoracic esophagectomy was done in 3 patients, and a left thoracoabdominal approach was used in 2 patients. The stomach was used as conduit in 50 patients and the colon in 6 patients. Twenty-two patients were found to have unresectable lesions at laparotomy and underwent various palliative procedures. Overall operative mortality was 6.3%. Mortality in the resectable group was only 3.6%. Follow-up ranges from 3 to 128 months, with four patients lost to follow-up at 1, 6, 8, and 10 months. The 5-year survival of the whole group according to Kaplan and Meier survival analysis was 21.27% with a median survival of 13.48 months. Univariate analysis using the log-rank test revealed stage of the disease and resectability to be significant predictors of survival. On multivariate analysis, curative resection appeared to be the most significant predictor of survival in patients undergoing resection.

Adenocarcinoma↗
PubMed1999

Crystallization of Pleurotus ostreatus (oyster mushroom) lectin.

Crystals of Pleurotus ostreatus (oyster mushroom) lectin have been grown by the hanging-drop technique using ammonium sulfate as the precipitant at 293 K. Over a period of between two and three weeks, crystals of hexagonal bipyramidal morphology grew to maximum dimensions of 0.2 x 0.2 x 0.5 mm. The crystals belong to space group P6(1)22 or P6(5)22, with unit-cell parameters a = b = 155.9, c = 149. 8 A, V = 3153078 A(3), Z = 12 (assuming 50% solvent), and diffract to 4.1 A at 293 K.

Ammonium Sulfate↗
PubMed1999

Crystallization of Helix pomatia agglutinin (HPA), a protein from the edible snail.

Crystals of Helix pomatia agglutinin (HPA) have been grown by the hanging-drop technique using polyethylene glycol as the precipitant at 293 K. Over a period of one to two weeks the crystals grew to maximum dimensions of 0.10 x 0.05 x 0.02 mm. The crystals belong to space group P6(3)22, with unit-cell dimensions a = b = 63.3, c = 105. 2 A and Z = 12 identical monomers of M(r) = 13 kDa, aggregating into two 78 kDa hexameric protein molecules per unit cell, each with symmetry 32 (D(3)). The diffraction pattern extends to 3.6 A at 293 K.

Animals↗
PubMed1996

Emptying of the intrathoracic stomach using three different pylorus drainage procedures--results of a comparative study.

Patterns of gastric emptying in the vagotomized intrathoracic stomach (used for esophageal replacement) were studied using radioisotope techniques. Following esophagectomy and gastric mobilization, the patients were randomized into three groups: group 1, pyloroplasty; group 2, pyloromyotomy; and group 3, pylorus stretching. A total of 30 patients surviving the operation and who were still alive at least 3 months afterwards were included in this study. Gastric emptying (GE) was evaluated 6-8 weeks after the operation. The mean GE time for liquids was 3.3 +/- 2.7, 4.1 +/- 3.1, and 5.5 +/- 4.3 min in the three groups, respectively. The corresponding GE time for solids in the three groups was 9.9 +/- 5.1, 10.31 +/- 6.6, and 7.7 +/- 3.4 min. No statistical difference was observed in the GE in the three groups even though liquids tend to empty faster than solids. Clinically there was also no significant difference in their ability to tolerate normal meals. When evaluated for clinical evidence of altered GE (effect of vagotomy) there did not appear to be any significant differences between the three groups. It is therefore concluded that all pylorus drainage procedures behave in much the same way. Patients may develop some problems, but these disappear in due course after proper adjustments have been made in both posture and diet.

Dilatation↗
PubMed1995

Role of gastrografin study in the assessment of anastomotic leaks from cervical oesophagogastric anastomosis.

Gastric pull-up with cervical oesophagogastric anastomosis is a common procedure after oesophageal resection. Contrast studies are used by many surgeons for detection of anastomotic leaks but may be unnecessary. A prospective study was undertaken to compare gastrografin study and test feeding using water for detection of cervical anastomotic leaks. In 25 patients, gastrografin study showed three leaks, two of which were clinically silent and patients did not have any problems. One patient had aspiration of contrast and the study could not be completed. Two of the leaks detected clinically were missed by contrast study (one because of an incomplete study and the other was a satisfactory study). Delayed leaks occurred in two patients. All leaks healed spontaneously. A contrast study may thus be unnecessary for evaluation of a cervical oesophagogastric anastomosis and can be replaced with the simpler and safer technique of 'test feeding' using water.

Adenocarcinoma↗
PubMed1994

Liposarcoma of the mesocolon--case report of a rare lesion.

A middle-aged man with a 2-month history of lower abdominal pain was found to have a large left-sided abdominal lump. Radiological investigations (barium enema, ultrasound, and computed tomography scan) revealed a mass lesion in the area of the descending colon, the sigmoid colon, and the rectum. Flexible sigmoidoscopy showed only mucosal edema and luminal narrowing. At laparotomy, a diffuse thickening of both the descending and sigmoid mesocolon extending into the mesorectum was seen, which suggested an inflammatory pathology. A left hemicolectomy with Hartmann's procedure was performed. After obtaining a histopathological diagnosis of liposarcoma of the mesocolon, an abdominoperineal resection of the rectum was done. The patient was advised to undergo postoperative radiotherapy but he did not comply and was thereafter lost to follow-up.

Humans↗
PubMed1993

Intragastric bile acid and symptoms in patients with an intrathoracic stomach after oesophagectomy.

Bile acid concentration and symptoms were evaluated in 24 patients after total oesophagectomy and gastric pull-up. Patients were randomly allocated to receive pyloroplasty or not. After operation all were followed for a minimum of 6 months. Bile acid concentration in the gastric juice was estimated. The mean(s.d.) bile acid concentration 6 months after surgery was similar in patients with and without pyloroplasty (34.9(30.1) and 25.0(24.2) mg/dl respectively). Postprandial discomfort and bilious eructations were the two most commonly observed symptoms in both groups. Other features noted were vomiting, anaemia and anorexia. These did not however seem to be related to intragastric bile acid concentration of individual patients in either group and occurred irrespective of whether pyloroplasty was performed or not.

Adolescent↗
PubMed1992

Congenital tracheo-oesophageal fistula in a young adult.

Congenital tracheo-oesophageal fistula (TEF) is rare in adults. Patients who present with repeated attacks of chest infection since birth or cough, choking and cyanosis during feeding should be investigated for TEF. It should be possible to detect all cases of tracheo-oesophageal fistulae using bronchoscopy, oesophagoscopy and CT either singly or in combination. These investigations also help in deciding on the route of exploration and the type of surgery. Disconnection of the abnormal fistulous tract brings dramatic relief of symptom and prevents further pulmonary damage.

Adult↗