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Biomedical subjects

A J Karayiannakis

Publications and source records attributed to A J Karayiannakis.

At least 19 recordsLinked to original sources
PubMed2005

Risk factors for conversion of laparoscopic cholecystectomy to open cholecystectomy.

BACKGROUND: Conversion to open cholecystectomy is still required in some patients. The aim of this study was to evaluate preoperative factors associated with conversion to open cholecystectomy in elective cholecystectomy and acute cholecystitis. METHODS: The records of 1,804 patients who underwent cholecystectomy from May 1992 to January 2004 were reviewed retrospectively. The demographics and preoperative data of patients who required conversion to laparotomy were compared to those with successful laparoscopic cholecystectomy. RESULTS: Conversion to open cholecystectomy was needed in 94 patients (5.2%),of which 44 (2.8%) had no inflammation and 50 (18.4%) had acute inflammation of the gallbladder. Male gender, age older than 60 years, previous upper abdominal surgery, diabetes, and severity of inflammation were all significantly correlated with an increased conversion rate to laparotomy. Also, the conversion from laparoscopic to open cholecystectomy in acute cholecystitis patients was associated with greater white blood cell count, fever, elevated total bilirubin, aspartate transaminase, and alanine transaminase levels, and the various types of inflammation. CONCLUSIONS: None of these risk factors were contraindications to laparoscopic cholecystectomy. This may help predict the difficulty of the procedure and permit the surgeon to better inform patients about the risk of conversion from laparoscopic to open cholecystectomy.

Acute Disease↗
PubMed2004

Extramedullary plasmacytoma: report of two cases with uncommon presentation.

Lymph node infiltration by monoclonal plasma cells can occur either in aggressive forms of myeloma or may represent regional extension of extramedullary plasmacytomas, whereas lymph node plasmacytoma presenting as a solitary extramedullary plasmacytoma is very unusual. We report two cases of lymph node plasmacytomas without systemic disease diagnosed after surgical excision. Clinical remission was achieved after local radiotherapy although one patient relapsed with multifocal extramedullary plasmacytomas 20 months after radiotherapy.

Abdominal Neoplasms↗
PubMed2003

Laparoscopic cholecystectomy in patients with previous upper or lower abdominal surgery.

BACKGROUND: Previous abdominal surgery has been reported as a relative contraindication to laparoscopic cholecystectomy. This study specifically examined the effect of previous intraabdominal surgery on the feasibility and safety of laparoscopic cholecystectomy. METHODS: Data from 1,638 consecutive patients who underwent laparoscopic cholecystectomy were reviewed and analyzed for open conversion rates, operative times, intra- and postoperative complications, and hospital stay. RESULTS: Of the 1,638 study patients 473 (28.9%) had undergone previous abdominal surgery: 58 upper and 415 lower abdominal operations. The 262 patients who had undergone only a previous appendectomy were excluded from further analysis. Adhesions were found in 70.7%, 58.8% and 2.1% of patients respectively, who had previous upper, lower or no previous abdominal surgery with adhesiolysis required, respectively, in 78%, 30% and 0% of these cases. There were no complications directly attributable to adhesiolysis. Patients with previous upper abdominal surgery had a longer operating time (66.4 +/- 34.2 min), a higher open conversion rate (19%), a higher incidence of postoperative wound infection (5.2%), and a longer postoperative stay (3.4 +/- 2.1 days) than those who had undergone previous lower abdominal surgery (50.8 +/- 24 min, 3.3%, 0.7%, and 2.6 +/- 1.4 days, respectively) and those without prior abdominal surgery (47.4 +/- 25.6 min, 5.4%, 1.2%, and 2.8 +/- 1.9 days, respectively). CONCLUSIONS: Previous abdominal operations, even in the upper abdomen, are not a contraindication to safe laparoscopic cholecystectomy. However, previous upper abdominal surgery is associated with an increased need for adhesiolysis, a higher open conversion rate, a prolonged operating time, an increased incidence of postoperative wound infection, and a longer postoperative stay.

Abdomen↗
PubMed2002

Laparoscopic cholecystectomy in a patient with previous open cholecystostomy.

We report the case of a successful elective interval laparoscopic cholecystectomy in a patient with a previous tube cholecystostomy that had been performed surgically 8 weeks earlier for an attack of acute calculous cholecystitis. At surgery, the major omentum was adherent to the right lateral abdominal wall, completely covering the liver edge, the gallbladder, and the inserted tube. The gallbladder and the tube within it were dissected free from the abdominal wall and the greater omentum, the cholecystostomy tube was removed, and the operation was completed successfully without any further difficulties.

Aged↗
PubMed2002

An unusual cause of delayed presentation of laparoscopic common bile duct injury.

We describe an unusual case of a laparoscopic common bile duct (CBD) injury that presented with cholangitis 2 years after an apparently uneventful laparoscopic cholecystectomy. Preoperative ultrasound and endoscopic retrograde cholangiography suggested choledocholithiasis, showing proximal and intrahepatic duct dilatation with an inability to relieve the obstruction. At surgery, a lateral injury of the CBD wall with partial wall loss was found, adherent to an amorphous pigmented mass with the appearance of a knitted fabric causing CBD obstruction. The CBD was successfully reconstructed with a Roux-en-Y end-to-side hepaticojejunostomy, where the end of the Roux loop was anastomosed to the lateral CBD defect.

Aged↗
PubMed2002

Serum E-cadherin concentrations and their response during laparoscopic and open cholecystectomy.

BACKGROUND: Elevated serum levels of the cell adhesion molecule E-cadherin have been associated with the presence of tissue injury and inflammation. We compared soluble E-cadherin response during laparoscopic and open cholecystectomy. METHODS: The E-cadherin response to surgery was studied in 16 patients undergoing laparoscopic cholecystectomy and 12 patients undergoing open cholecystectomy. Serum E-cadherin levels were measured by an enzyme immunoassay (ELISA) preoperatively, 10 and 30 min after the commencement of surgery, and at 6 and 24 h following the operation. RESULTS: Serum E-cadherin levels decreased progressively during laparoscopic cholecystectomy; their concentrations at 24 h after surgery were significantly lower when compared with preoperative values. In the open cholecystectomy group, serum E-cadherin levels did not differ from preoperative values at any time point. Serum E-cadherin concentrations at 24 h after surgery and the cumulative E-cadherin response were significantly higher in the open cholecystectomy group than in the laparoscopic group. CONCLUSION: Compared with open cholecystectomy, the cumulative E-cadherin response is significantly reduced following laparoscopic cholecystectomy.

Cadherins↗
PubMed2002

Abnormal alpha-catenin expression in invasive breast cancer correlates with poor patient survival.

AIMS: alpha-Catenin is a member of the E-cadherin-catenin family of adhesion molecules whose role is essential for the function of the E-cadherin complex. In this study, we have evaluated the expression of alpha-catenin but also of the other catenins (beta-, gamma- and p120-catenin) and E-cadherin in invasive breast cancer and statistically analysed these expressions with known clinicopathological parameters, c-erbB-2 oncoprotein expression and patient survival. METHODS AND RESULTS: Abnormal E-cadherin and beta-catenin expression, especially loss of expression, was associated with lobular histological type of breast carcinomas (P=0.03 and P=0.01, respectively). Abnormal E-cadherin and alpha-catenin expression was associated with high histological grade ductal carcinomas (P=0.01 and P=0.03, respectively). Abnormal E-cadherin and beta-catenin expression was correlated with lymph node metastases (P=0.02 and P=0.05, respectively), while abnormal alpha- and beta-catenin were correlated with the advanced stage of the disease (P=0.04 and P=0.05, respectively). Abnormal p120-catenin expression was associated with loss of PR (P=0.008). Survival analysis demonstrated a statistically significant association between abnormal alpha-catenin expression and poor patient survival (P=0.02). When survival analysis was performed according to the different patterns of abnormal expression, statistically significant associations were seen between cytoplasmic alpha- and beta-catenin expression and poor survival (P=0.006 and P=0.04, respectively). CONCLUSIONS: alpha-Catenin, especially its cytoplasmic expression, seems to be a more sensitive prognostic marker than the other members of the E-cadherin complex in invasive breast cancer.

Adult↗
PubMed2001

Serum levels of E-selectin, ICAM-1 and VCAM-1 in colorectal cancer patients: correlations with clinicopathological features, patient survival and tumour surgery.

The serum concentrations of the cell adhesion molecules E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were investigated in 63 patients with colorectal cancer and in 51 controls by an enzyme-linked immunosorbent assay (ELISA). Their relationship to clinicopathological variables and patient survival and changes in their levels after surgery were examined. Colorectal cancer patients showed significantly higher serum levels of E-selectin, ICAM-1 and VCAM-1 compared with healthy controls. There was a significant association between the serum levels of these molecules, disease stage and the presence of both lymph node and distant metastases. Both ICAM-1 and VCAM-1 levels correlated with serum E-selectin and carcinoembryonic antigen (CEA) levels. Serum levels of all three molecules decreased significantly after radical resection of the tumour. Elevated pre-operative E-selectin, ICAM-1 and VCAM-1 levels were significant prognostic factors, although not independent of stage, for patient survival. These findings suggest that serum concentrations of E-selectin, ICAM-1 and VCAM-1 may reflect tumour progression and metastasis. Since these markers are linked to CEA levels, it is uncertain whether their measurement will prove cost-effective in colorectal cancer management.

Aged↗
PubMed2001

Expression patterns of beta-catenin in in situ and invasive breast cancer.

BACKGROUND: beta-Catenin plays a central role in the E-cadherin/catenin cell-cell adhesion complex and is possibly involved in cellular signalling pathways. In this study, we evaluated the expression patterns of this molecule in in situ and invasive breast cancer. METHODS: The expression of beta-catenin was evaluated in 121 breast cancer specimens by immunohistochemistry. Its relationship to clinicopathological features was also investigated. RESULTS: Altered beta-catenin expression was found in 68% of tumours. Lobular carcinomas showed abnormal beta-catenin expression more frequently (77%) than ductal carcinomas (64%) with 46% of lobular cases showing complete absence of beta-catenin immunoreactivity. Cytoplasmic beta-catenin localization was seen only in ductal carcinomas. Aberrant beta-catenin expression was observed in 54% of ductal carcinomas in situ with highly concordant beta-catenin expression patterns in the nearby in situ and invasive components. CONCLUSIONS: Quantitative and qualitative changes in beta-catenin expression occur in a considerable proportion of in situ and invasive ductal carcinomas and are more prominent in invasive lobular carcinomas.

Adult↗
PubMed1999

Mutated epithelial cadherin is associated with increased tumorigenicity and loss of adhesion and of responsiveness to the motogenic trefoil factor 2 in colon carcinoma cells.

Epithelial (E)-cadherin and its associated cytoplasmic proteins (alpha-, beta-, and gamma-catenins) are important mediators of epithelial cell-cell adhesion and intracellular signaling. Much evidence exists suggesting a tumor/invasion suppressor role for E-cadherin, and loss of expression, as well as mutations, has been described in a number of epithelial cancers. To investigate whether E-cadherin gene (CDH1) mutations occur in colorectal cancer, we screened 49 human colon carcinoma cell lines from 43 patients by single-strand conformation polymorphism (SSCP) analysis and direct sequencing. In addition to silent changes, polymorphisms, and intronic variants in a number of the cell lines, we detected frameshift single-base deletions in repeat regions of exon 3 (codons 120 and 126) causing premature truncations at codon 216 in four replication-error-positive (RER+) cell lines (LS174T, HCT116, GP2d, and GP5d) derived from 3 patients. In LS174T such a mutation inevitably contributes to its lack of E-cadherin protein expression and function. Transfection of full-length E-cadherin cDNA into LS174T cells enhanced intercellular adhesion, induced differentiation, retarded proliferation, inhibited tumorigenicity, and restored responsiveness to the migratory effects induced by the motogenic trefoil factor 2 (human spasmolytic polypeptide). These results indicate that, although inactivating E-cadherin mutations occur relatively infrequently in colorectal cancer cell lines overall (3/43 = 7%), they are more common in cells with an RER+ phenotype (3/10 = 30%) and may contribute to the dysfunction of the E-cadherin-catenin-mediated adhesion/signaling system commonly seen in these tumors. These results also indicate that normal E-cadherin-mediated cell adhesion can restore the ability of colonic tumor cells to respond to trefoil factor 2.

Animals↗
PubMed1999

Abnormal expression of the E-cadherin-catenin complex in dysplastic Barrett's oesophagus.

It is now accepted that altered E-cadherin-catenin complex expression in oesophageal cancer correlates with clinical and pathological parameters, while abnormal E-cadherin expression occurs early in Barrett's oesophagus. We evaluated immunohistochemically the expression and cellular localization of alpha-, beta-, and gamma-catenin, and E-cadherin in 5 dysplastic and 26 non-dysplastic cases of Barrett's oesophagus. Usually all three catenins were localized at the cell membrane, as was E-cadherin. A similar staining pattern for E-cadherin and the catenins was observed in all cases of non-dysplastic Barrett's syndrome. However, 60% (3/5) of cases with dysplasia showed loss of membranous beta-catenin staining and diffuse cytoplasmic distribution, with predominantly nuclear localization in two cases. Membranous staining and concomitant cytoplasmic localization of E-cadherin, alpha-catenin and gamma-catenin were seen in one case with abnormal beta-catenin immunoreactivity. Our results indicate that altered subcellular distribution of beta-catenin occurs frequently in dysplastic Barrett's oesophagus and possibly reflects the signalling function of this molecule.

Barrett Esophagus↗
PubMed1998

Expression of catenins and E-cadherin during epithelial restitution in inflammatory bowel disease.

Catenins are cytoplasmic proteins associated with E-cadherin, the prime mediator of cell-cell adhesion. Perturbation in any of these molecules results in altered intercellular adhesion, cell differentiation, and increased migration. In this study, the expression and cellular localization of catenins and E-cadherin in inflammatory bowel disease were examined. The expression of E-cadherin; alpha-, beta-, and gamma-catenin; and p120 was evaluated immunohistochemically in 31 paraffin-embedded colonic specimens from 21 patients with ulcerative colitis and Crohn's disease. Loss of normal membranous E-cadherin and alpha-catenin staining was detected at the mucosal edges around epithelial ulcerations in all cases of active ulcerative colitis and in 50 per cent of cases with active Crohn's disease. Reduced expression of p120 protein was also found at the margins of ulcerated mucosa in all cases of active ulcerative colitis and in 75 per cent of those with active Crohn's disease. There was a statistically significant correlation between the expression of E-cadherin, alpha-catenin and p120 and disease activity. There were no changes in beta- and gamma-catenin expression in either ulcerative colitis on Crohn's disease. These findings indicate that altered expression of E-cadherin, alpha-catenin, and p120 occurs during mucosal ulceration in inflammatory bowel disease. These changes may be involved in promoting cell migration during epithelial restitution of the gastrointestinal mucosa.

Cadherins↗
PubMed1998

E-cadherin/catenin complex in benign and malignant melanocytic lesions.

E-cadherin is a calcium-dependent cell-cell adhesion molecule expressed by melanocytes and responsible for their adhesion to keratinocytes in vitro. In this study, the expression of E-cadherin and its associated cytoplasmic proteins alpha-, beta-, and gamma-catenin was evaluated in melanocytic lesions by immunohistochemistry. E-cadherin expression was evaluated in 70 malignant melanomas and the catenins in 35 of these specimens. Twenty benign melanocytic naevi were also evaluated for E-cadherin and catenin expression. In normal epidermis, E-cadherin/catenin immunostaining was localized at the intercellular borders. In melanomas, a differential loss of E-cadherin expression was observed. Membranous E-cadherin staining was absent in dermal nests of melanomas in their radial growth phase and in Clark level II and III lesions, whereas it was present in a high proportion of melanomas in their vertical growth phase, in Clark level IV and V lesions and in metastasizing melanomas. In contrast, superficial compartments of naevi showed membranous E-cadherin immunoreactivity and junctional naevus cell nests displayed heterogeneous or diffuse cytoplasmic staining. Cytoplasmic alpha- and beta-catenin, but not gamma-catenin staining were detected in all benign and malignant lesions. These findings indicate that qualitative changes in the expression and cellular localization of E-cadherin and of alpha-, beta-, and gamma-catenin occur in melanocytic lesions and may reflect different stages in their progression.

Adult↗
PubMed1998

The effect of vertical banded gastroplasty on glucose-induced beta-endorphin response.

BACKGROUND: beta-Endorphin is an endogenous opioid involved in the regulation of food intake and obesity as well as in insulin metabolism. In this study, we investigated glucose-induced beta-endorphin, insulin, and glucose responsiveness in morbidly obese patients and the effect of surgically induced weight loss. METHODS: Thirty-two healthy, nondiabetic, morbidly obese patients (body mass index over 40 kg/m2) and 32 normal-weight controls were studied. Serum levels of beta-endorphin, insulin, and glucose were measured under basal conditions and during an oral glucose tolerance test (OGTT) before and 12 months following vertical banded gastroplasty. RESULTS: Preoperative basal levels of beta-endorphin, insulin, and glucose and their responses during OGTT in obese patients were significantly higher compared with those of controls. After surgery, basal beta-endorphin, insulin, and glucose levels decreased significantly compared with preoperative values. Postoperative basal insulin and glucose levels were similar to those in controls, while beta-endorphin levels remained significantly higher than those of controls. A significant reduction in total responses of beta-endorphin, insulin, and glucose during OGTT was also observed; however, postoperative beta-endorphin and insulin responses remained significantly higher than in controls. CONCLUSION: Morbidly obese patients have an increased glucose-stimulated response of beta-endorphin, insulin, and glucose which is partially corrected with weight loss following vertical banded gastroplasty.

Adult↗
PubMed1998

Sex hormone changes in morbidly obese patients after vertical banded gastroplasty.

Serum sex hormone levels were measured preoperatively in 57 morbidly obese patients (19 men and 38 premenopausal women) and 12 months after vertical banded gastroplasty. In the male group, there was a significant decrease in estradiol and an increase in follicle-stimulating hormone (FSH), total testosterone and sex-hormone-binding globulin (SHBG). Among female patients, a significant decrease in estradiol, total and free testosterone and an increase in FSH and SHBG was found. Irregular menses present preoperatively in 5 women were corrected after successful weight loss. In conclusion, altered sex hormonal levels and gynecologic abnormalities associated with morbid obesity are corrected with adequate weight loss following vertical banded gastroplasty.

Adult↗
PubMed1998

Serum beta-endorphin levels in morbidly obese patients: the effect of vertical banded gastroplasty.

The associations between serum beta-endorphin levels and clinical and metabolic variables as well as beta-endorphin changes after surgically induced weight loss were investigated in 43 morbidly obese patients. A significant positive correlation between beta-endorphin and body weight, degree of body weight increase and ACTH was found preoperatively. Only body weight was independently associated with beta-endorphin levels. Twelve months following vertical banded gastroplasty, there was an extensive weight loss in all patients and improvement in their metabolic profile. A significant reduction in beta-endorphin levels which was proportional to the extent of weight loss was also observed.

Adrenocorticotropic Hormone↗
PubMed1997

Aberrant E-cadherin and alpha-catenin expression in prostate cancer: correlation with patient survival.

E-cadherin maintains the normal differentiated phenotype in epithelial cells; this function is partly mediated by alpha-catenin, which links E-cadherin to the cell cytoskeleton. Dysfunction of E-cadherin in vitro and in vivo is associated with an invasive phenotype. However, the role of alpha-catenin is largely undetermined. We analyzed the expression of E-cadherin and alpha-catenin in prostate cancer to assess the relationship of abnormal expression to stage, grade and survival. E-cadherin expression was evaluated in 99 prostate cancers. In 79 of those specimens, alpha-catenin was also assessed. In benign prostatic epithelium, both E-cadherin and alpha-catenin were expressed uniformly at the cell membrane. Abnormal E-cadherin expression was found in 56% of cancer specimens, whereas alpha-catenin expression was abnormal in 42%. Abnormal expression of each molecule was significantly correlated with Gleason score (P < 0.0001) and the ratio of resection chippings infiltrated by tumor (P < 0.0001). E-cadherin expression was also associated with the extent of disease on the initial bone scan (P = 0.017). Univariate analysis showed significantly lower survival rate for patients with abnormal E-cadherin (P = 0.0003) or alpha-catenin expression (P = 0.031). Multivariate regression analysis showed that the prognostic value of E-cadherin was independent of tumor grade but not of metastasis. These results suggest that perturbation of cell-cell adhesion is involved in the progression of prostate cancer and that analysis of E-cadherin expression may be clinically useful.

Aged↗