Bacteribilia with resistant microorganisms after preoperative biliary drainage--the influence of bacteria on postoperative outcome.

BACKGROUND: In pancreatic surgery, preoperative biliary drainage (PBD) leads to bacteribilia. Whether positive bile duct cultures are associated with a higher postoperative morbidity might be related to the resistance of the species isolated from bile. STUDY: Intraoperative bile duct cultures were collected from all patients who underwent pancreatic surgery. Postoperative morbidity was analyzed according to the species and the resistance found on bile duct cultures. RESULTS: Fifty-five percent (166/301) of patients had PBD, while 45% (135/301) underwent primary operation. PBD was associated with a positive bile duct culture in 87% (144/166) versus 21% (28/135) in patients without PBD (p = 0.001) and polymicrobial infections in 53% (88/166) versus 6% (8/135) (p = 0.001). Postoperative morbidity was 40% (121/301); mortality was 3% (9/301). PBD was not associated with morbidity and mortality, but resistant species on bile duct cultures lead to significantly more postoperative complications, 54% (25/46) versus 38% (96/255) (p = 0.033), with significantly more antibiotic therapies. CONCLUSION: PBD is associated with polymicrobial infections with resistant microorganisms, resulting in more postoperative complications. Since PBD cannot always be avoided, surgeons and gastroenterologists must be aware of their institutional surveillance data to identify patients at risk for postoperative complications.

Reduced pancreatic volume and beta-cell area in patients with chronic pancreatitis.

BACKGROUND & AIMS: Chronic pancreatitis (CP) often leads to the development of diabetes. To understand better this pathogenic mechanism, we investigated whether islet cell area and pancreatic volume are reduced in CP patients, islet cell turnover increases in CP patients, and islet cells are less vulnerable to apoptosis than acinar cells. METHODS: Pancreatic tissues from 43 patients with CP and 27 controls were examined by immunohistochemistry and quantitative morphometry. Pancreas volume was determined using abdominal computed tomography data. RESULTS: The pancreatic volumes were 64.9 +/- 4.3 cm(3) in CP patients and 82.3 +/- 6.7 cm(3) in controls (P = .035). beta-cell areas were 0.69% +/- 0.08% in CP patients and 0.97% +/- 0.08% in controls (P = .017), whereas alpha-cell areas did not differ between the groups (P = .47). There were no differences in the frequencies of replication among groups of alpha-cells, beta-cells, duct cells, or acinar cells nor were there differences in numbers of apoptotic alpha-cells or beta-cells between CP patients and controls. However, CP patients had an approximately 10-fold increase in numbers of apoptotic acinar cells compared with controls (P < .0001). CONCLUSIONS: Pancreatic volume was reduced by 21%, and the area comprising beta-cells was reduced by 29% in patients with CP. The lack of increased beta-cells turnover in CP patients, despite an approximately 10-fold increase in the number of apoptotic acinar cells, suggests that the damage to the pancreas is highly specific for the exocrine compartment and affects the endocrine islets to a lesser extent.

Bacteribilia after preoperative bile duct stenting: a prospective study.

STUDY DESIGN: A prospective analysis of intraoperative bile duct cultures in patients undergoing surgery for both, malignant or benign periampullary diseases at the Department of Surgery, St Josef Hospital, Bochum, Germany, during a period of 18 months, between January 2004 and June 2005. GOALS: The goals of the presented study were to investigate the effects of preoperative bile duct stenting on intraoperative bile duct cultures and postoperative outcome in patients undergoing pancreatic surgery. BACKGROUND: In pancreatic surgery, bile duct stenting is often aimed at improving postoperative outcome. As implantation of xenograft material in the main bile duct facilitates bacterial contamination and cholangitis, a critical evaluation of stenting is mandatory. STUDY: In all patients with a hepaticojejunostomy (n=80), a bile duct culture was collected during the operation. All patients received antibiotic prophylaxis perioperatively and a retrograde flushing of bile ducts with warm saline after bile duct resection. Fifty-one percent (41/80) patients had biliary drainage before surgery, whereas 49% (39/80) were operated without preoperative draining procedures. RESULTS: After bile duct stenting, 98% of patients had a positive bile culture, whereas only 21% of infected bile was seen in patients without drainage (P<0.001). Despite infected bile, only 2% stented patients developed acute cholangitis postoperatively, versus 13% patients in the group without stent (P=0.231). After stenting, major complications occurred in 12%, versus 8% in patients without stent (P=0.817). CONCLUSIONS: Preoperative biliary drainage leads to an almost 100% bacterial contamination of bile ducts. With hospital-adjusted antibiotic prophylaxis and retrograde flushing of bile ducts, the postoperative rate of acute cholangitis and morbidity is not elevated. A critical evaluation of benefits from preoperative biliary drainage for each patient is necessary.

The CCK-2/gastrin splice variant receptor retaining intron 4 transactivates the COX-2 promoter in vitro.

The expression of the human cholecystokinin-2/gastrin receptor (CCK-2R) has been widely reported in human colorectal cancers. Recently, a splice variant of the CCK-2R retaining intron 4 (CCK-2i4svR) has been cloned from human colorectal cancers and postulated to exhibit constitutive activity. But its role in mediating carcinogenic effects of mature-amidated gastrin in colorectal cancers has not been fully explored. The purpose of the present study was to determine whether the activation of CCK-2i4svR by gastrin transactivates the COX-2 promoter in human colon cancer cells and in COS-7 cells. In this study, Colo320 cells and COS-7 cells were transfected with the human CCK-2R wild type (CCK-2wtR) (COS-7WT, Colo320WT) and the human CCK-2i4svR (COS-7SV, Colo320SV) cDNA. After stimulation with gastrin-17 (G-17), transactivation of the COX-2 promoter was determined by luciferase reporter gene assay. 5'deletions of the COX-2 promoter were transfected into Colo320 cells to narrow down the minimally required regulatory element. Induction of COX-2 expression was further explored at the mRNA level using real time RT-PCR. The effects of CCK-2i4svR activation on phosphorylation of ERK1/2, p38(MAPK) and JNK were examined by using immunoblotting. Prostaglandin E(2) (PGE(2)) secretion was measured by ELISA. Our results showed that gastrin transactivates the COX-2 promoter in both Colo320 cells and COS-7 cells expressing the CCK-2i4svR cDNA. Inhibition of p38(MAPK) pathway using specific inhibitor significantly blocked the gastrin-induced COX-2 transactivation. Gastrin time-dependently increased COX-2 mRNA expression, the peak mRNA levels appeared at 10 h after stimulation. PGE(2) secretion from gastrin-treated cells increased significantly 8 h after stimulation. Treatment with gastrin also stimulated PGE(2) secretion in the Colo320 cells expressing CCK-2i4svR. In conclusion, the CCK-2i4svR mediates transactivation of the COX-2 promoter and MAPK pathway is involved in this process.

Orlistat reduces gallbladder emptying by inhibition of CCK release in response to a test meal.

BACKGROUND AND AIMS: Orlistat is a covalent inhibitor of digestive lipase derived from lipstatin, the natural product of Streptomyces toxytricini. By blocking the active site of intestinal lipase, orlistat inhibits hydrolysis of dietary triglycerides and thus reduces the intestinal lipid absorption. It is uncertain whether intestinal inhibition of lipase by orlistat also interferes with nutrient-induced CCK release from intestinal I-cells. The aim of the present study was therefore to assess whether oral administration of orlistat inhibits CCK release in response to a test meal and thus causes impaired gallbladder emptying. METHODS: 22 healthy volunteers were given a test meal consisting of 200 ml dairy cream and two teaspoons of chocolate powder (552 kcal=2328 kJ; 56.0 g fat; 5.2 g proteins, 6.6 g carbohydrates), with and without oral application of 120 mg orlistat. Gallbladder volume was determined by ultrasound before and 5, 10, 20, 30 and 40 min after meal ingestion. In parallel, a venous blood sample was collected for the measurement of bioactive CCK. CCK activity was assessed using a bioassay with isolated rat pancreatic acini cells. RESULTS: Oral administration of orlistat significantly impairs gallbladder emptying. After ingestion of the test meal the gallbladder contracted by 78.5% in the control group, whereas the test group with orlistat only showed a contraction of 45.7% (p<0.01). Maximal contraction was reached after 35 to 40 min, the maximal gallbladder emptying was delayed up to 10 min by orlistat. Orlistat induced a significant reduction of bioactive CCK levels in response to a test meal (CCK(max) with orlistat=4.1 pmol/l; CCK(max) without orlistat=7.8 pmol/l). CCK levels were reduced by 47% and the onset of maximal CCK secretion was delayed up to 10 min. CONCLUSION: The inhibition of intestinal lipolytic activity by orlistat results in reduced gallbladder emptying through inhibition of meal-mediated CCK release. We therefore hypothesize that impaired gallbladder motility may represent a risk factor in chronic treatment of severe obesity using orlistat.

Glucagon-like peptide 2 inhibits ghrelin secretion in humans.

INTRODUCTION: The growth hormone secretagogue receptor ligand ghrelin is known to play a pivotal role in the central nervous control of energy homeostasis. Circulating ghrelin levels are high under fasting conditions and decline after meal ingestion, but the mechanisms underlying the postprandial drop in ghrelin levels are poorly understood. In the present study we addressed, whether (1) exogenous GLP-2 administration decreases ghrelin levels and (2) what other endogenous factors are related to ghrelin secretion under fasting conditions. PATIENTS AND METHODS: Fifteen healthy male volunteers were studied with the intravenous infusion of GLP-2 (2 pmol l(-1) min(-1)) or placebo over 120 min in the fasting state. Plasma concentrations of glucose, insulin, C-peptide, glucagon, intact GLP-2 and ghrelin were determined. RESULTS: During the infusion of GLP-2, plasma concentrations of intact GLP-2 increased from 10.0+/-1.5 pmol/l to steady-state levels of 207.7+/-8.3 pmol/l (p < 0.0001). Administration of GLP-2 led to an approximately 10% reduction in ghrelin concentrations, whereas placebo administration was without an effect (p < 0.001). After cessation of the GLP-2 infusion, ghrelin levels returned to baseline values, and were no longer different from those in the placebo experiments. There was a strong inverse linear relationship between the fasting concentrations of ghrelin and the respective levels of glucose, insulin and C-peptide (r = 0.49, p < 0.01; r = 0.55, p < 0.01 and r = 0.59, p < 0.001, respectively). In contrast, there was no detectable association between fasting ghrelin levels and the ambient concentrations of glucagon or intact GLP-2. CONCLUSIONS: GLP-2 inhibits ghrelin secretion in humans at plasma levels of approximately 200 pmol/l. However, the physiological importance of this effect appears to be minor compared to the actions of insulin and glucose.

Increased abundance of cyclooxygenase-2 correlates with vascular endothelial growth factor-A abundance and tumor angiogenesis in gastric cancer.

To understand the role of cyclooxygenase-2 (COX-2) in gastric cancer, we examined the abundance of COX-2, vascular endothelial growth factor-A (VEGF-A), and CD34 in 45 surgically resected human gastric cancers and paired normal gastric mucosa by immunohistochemical analysis. In addition, the message RNA (mRNA) expression of COX-2 and VEGF-A was evaluated in ten fresh surgically resected human gastric cancers and paired normal gastric mucosas using semi-quantitative reverse transcriptional polymerase chain reaction analysis. Our results confirmed an increased abundance of COX-2 and VEGF-A, and the microvessel density, which was assessed by CD34 abundance, in gastric cancer tissues compared with normal paired mucosa. Abundance of COX-2 and VEGF-A was significantly associated with tumor-node-metastasis (TNM) stage (P<0.05) and lymph node metastasis (P<0.001). In addition, abundance of VEGF-A associates with distance metastasis. A significant correlation was found between COX-2 and VEGF-A abundances (P<0.001). Both abundance of COX-2 and VEGF-A were significantly correlated with microvessel density (P<0.001, respectively). In six of ten cancerous tissues and in one of ten paired normal mucosas, the mRNA expression of COX-2 and VEGF-A was detected in the same specimen. In one other cancerous tissue, only COX-2 mRNA was detected. This study indicates that COX-2 is related to tumor angiogenesis in gastric cancer. VEGF-A might play a main role in the COX-2 angiogenic pathway.

Rapid tyrosine phosphorylation of focal adhesion kinase, paxillin, and p130Cas by gastrin in human colon cancer cells.

Although the expression of CCK(2) receptors is widely reported in human colorectal cancers, little is known on its role in mediating the proliferative effects of mature amidated gastrin (G17 amide) on colorectal cancers. The purpose of the present study was to determine the effects of G17 amide on tyrosine phosphorylation of focal adhesion kinase (FAK), paxillin, and p130 Crk-associated substrate (p130(Cas)) in Colo 320 cells, a human colorectal cancer cell line which expresses CCK(2) receptors. By immunoprecipitation and immunoblotting, an increase in tyrosine phosphorylation of FAK (tyrosine-397), paxillin (tyrosine-31), and p130(Cas) was detected in a time- and dose-dependent manner. Overexpression of CCK(2) receptors in Colo 320 cells (Colo 320 WT) by stable transfection with the human CCK(2) receptor cDNA resulted in an increased tyrosine phosphorylation of FAK, paxillin, and p130(Cas). After incubation with 1 microM L-365,260, a specific CCK(2) receptor antagonist, this increase was completely inhibited. Our results demonstrate that in human colon cancer cells, gastrin caused a rapid tyrosine phosphorylation of FAK, paxillin, and p130(Cas) by activation of CCK(2) receptor. The phosphorylation of these proteins might be important in mediating gastrin effects on proliferation, apoptosis, and metastasis.

Inhibition of cytosolic phospholipase A2 mRNA expression: a novel mechanism for acetylsalicylic acid-mediated growth inhibition and apoptosis in colon cancer cells.

Acetylsalicylic acid (ASA) has been confirmed to inhibit proliferation and to induce apoptosis in human colorectal cancer cells in vitro. However, the mechanism by which ASA exhibits antiproliferative and proapoptotic effects in cyclooxygenase 2 (COX-2)-negative cells remains to be further elucidated. In the present study, SW480, a COX-2-negative colon cancer cell line, was treated with various concentrations of ASA (0, 2.5, 5, and 10 mM). The antiproliferative and proapoptotic effects of ASA were confirmed by MTT assay, flow cytometry of propidium iodide (PI)-stained cells, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay. After treatment with ASA, intracellular cyclic AMP (cAMP) levels were increased and the production of prostaglandin E2 (PGE2) was decreased. RT-PCR analysis revealed that treatment of ASA induced a concentration-dependent downregulation of cytosolic phospholipase A2 (cPLA2) mRNA expression in SW480 cells and also in two other colorectal cancer cell lines, Colo320 and HT-29 cells. Intracellular calcium levels were unaffected by ASA treatment. Our results indicate that the ASA-induced downregulation of cytosolic phospholipase A2 mRNA expression might be a novel mechanism for ASA-mediated growth inhibition and apoptosis in colon cancer cells.

Expression, purification and characterization of recombinant sucrose synthase 1 from Solanum tuberosum L. for carbohydrate engineering.

The gene sus1 from Solanum tuberosum L. encoding for sucrose synthase 1 was cloned into the plasmid pDR195 under the control of the PMA1 promotor. After transformation of Saccharomyces cerevisiae strain 22574d sus1 was constitutively expressed giving a specific activity of 0.3Umg(-1) protein in the crude extract. A one-step purification by Q-Sepharose resulted in an 14-fold purified enzyme preparation in 74% yield. SuSy1 was subsequently purified by immobilized metal ion affinity chromatography and characterized for its utilization in synthesizing different nucleotide sugars and sucrose analogues. The kinetic constants for the cleavage and synthesis reaction were determined: K(m) (UDP) 4microM; K(iS) (UDP) 0.11mM; K(m) (sucrose) 91.6mM; K(m) (UDP-Glc) 0.5mM; K(iS) (UDP-Glc) 2.3mM; K(m) (D-fructose) 2.1mM; K(iS) (D-fructose) 35.9mM. Different nucleoside diphosphates as well as different donor substrate were accepted as follows: UDP>dTDP>ADP>CDP>GDP in the cleavage reaction and UDP-Glc>dTDP-Glc>ADP-Glc>CDP-Glc in the synthesis reaction. SuSy1 shows also a broad acceptance of D- and L-ketoses and D- and L-aldoses. The acceptance of aldoses was deduced from the binding of the inhibitor 5-deoxy-D-fructose (K(i) 0.3mM), an analogue of the natural substrate D-fructopyranoside. The broad substrate spectrum renders SuSy1 from potato a versatile biocatalyst for carbohydrate engineering.

Gastrin stimulates the VEGF-A promotor in a human colon cancer cell line.

INTRODUCTION: Hypergastrinemia has been observed in patients suffering from colorectal cancer. Vascular endothelial growth factor (VEGF) is known to play a pivotal role in tumour growth. Therefore, we addressed whether gastrin-17-gly and gastrin-17-amide regulate VEGF-A-gene and protein expression. MATERIALS AND METHODS: Colo-320-cells were stably transfected with a VEGF-Luciferase-reporter gene. Luciferase activity was assessed after stimulation with various gastrin concentrations. Relevant promotor elements were identified by deletion analyses. VEGF protein levels in culture supernatants were quantified by ELISA. RESULTS: VEGF-A stimulation with gastrin induced a dose- and time-dependent stimulation of luciferase activity. The greatest activities were found 6h after stimulation at concentrations of 10(-)(6)mmol/l. VEGF-promotor expression resulted in significantly (p<0.05) increased VEGF-A protein secretion. These effects were restricted to gastrin-17-amide. CONCLUSION: Gastrin-17-amide enhances VEGF-A gene and protein expression in Colo320 cells stably transfected with a wild-type CCK-B/gastrin receptor. The induction of VEGF-A transcription and translation may contribute to the carcinogenic effects of gastrin observed in clinical studies. Therefore, CCK-B receptor antagonists may represent a treatment strategy in patients with colorectal cancer.

Selective amino acid deficiency in patients with impaired glucose tolerance and type 2 diabetes.

INTRODUCTION: Amino acids are important modulators of glucose metabolism, insulin secretion and insulin sensitivity. However, little is known about the changes in amino acid metabolism in patients with diabetes. PATIENTS AND METHODS: The circulating amino acid levels were determined in 17 patients with type 2 diabetes, 17 individuals with impaired glucose tolerance (IGT), and 14 control subjects. RESULTS: Total amino acid concentrations were 2850+/-57micromol/l in patients with type 2 diabetes, 2980+/-77micromol/l in individuals with IGT, and 2886+/-74micromol/l in control subjects (p=0.38). Patients with type 2 diabetes exhibited significant reductions in the concentrations of gamma-aminobutyric acid (GABA), arginine, glutamine and phosphoethanolamine (p<0.05), whereas valine levels were higher than in controls (p=0.008). In IGT subjects, GABA levels were reduced, while tyrosine concentrations were increased (p<0.05). The plasma levels of essential amino acids were positively related to fasting and post-challenge glucose levels, fasting C-peptide, HOMA insulin resistance and fasting glucagon levels (p<0.05). CONCLUSIONS: Total amino acid levels are similar in patients with diabetes, IGT subjects and controls, but the individual levels of several amino acids differ significantly between these groups. These alterations may contribute to the disturbances in insulin secretion and action in diabetic patients and may provide a rationale for offering specific amino acid supplementations to diabetic patients.

Amino acid malnutrition in patients with chronic pancreatitis and pancreatic carcinoma.

OBJECTIVES: Chronic pancreatitis (CP) and pancreatic cancer (CA) have been associated with intestinal malabsorption and inflammation. However, little is known about the changes in amino acid metabolism in such patients. METHODS: The circulating amino acid levels were determined in 12 patients with CP, 12 CA patients, and 12 controls. RESULTS: Total amino acid concentrations were 2850 +/- 71 micromol/L in controls, 2640 +/- 96 micromol/L in CP patients, and 2210 +/- 123 micromol/L in CA patients (P < 0.001). In CP patients, significant reductions in the concentrations of citrulline, gamma-aminobutyric acid, taurine, and aspartic acid were found (P < 0.05), whereas in CA patients, the levels of phosphoethanolamine, gamma-aminobutyric acid, aspartic acid, taurine, arginine, threonine, alanine, citrulline, and tryptophan were reduced. There was a significant inverse relationship between the total amino acid levels and the white blood cell counts (r = -0.44, P = 0.008). CONCLUSIONS: Both patients with CP and with CA exhibit alterations in amino acid levels. The mechanisms underlying these defects may involve intestinal malabsorption as well as systemic inflammation. Providing selective amino acid supplementation to such patients may minimize the excess morbidity and mortality associated with protein malnutrition.

Impaired glucose-induced glucagon suppression after partial pancreatectomy.

INTRODUCTION: The glucose-induced decline in glucagon levels is often lost in patients with type 2 diabetes. It is unclear whether this is due to an independent defect in alpha-cell function or secondary to the impairment in insulin secretion. We examined whether a partial pancreatectomy in humans would also impair postchallenge glucagon concentrations and, if so, whether this could be attributed to the reduction in insulin levels. PATIENTS AND METHODS: Thirty-six patients with pancreatic tumours or chronic pancreatitis were studied before and after approximately 50% pancreatectomy with a 240-min oral glucose challenge, and the plasma concentrations of glucose, insulin, C-peptide, and glucagon were determined. RESULTS: Fasting and postchallenge insulin and C-peptide levels were significantly lower after partial pancreatectomy (P < 0.0001). Likewise, fasting glucagon concentrations tended to be lower after the intervention (P = 0.11). Oral glucose ingestion elicited a decline in glucagon concentrations before surgery (P < 0.0001), but this was lost after partial pancreatectomy (P < 0.01 vs. preoperative values). The loss of glucose-induced glucagon suppression was found after both pancreatic head (P < 0.001) and tail (P < 0.05) resection. The glucose-induced changes in glucagon levels were closely correlated to the respective increments in insulin and C-peptide concentrations (P < 0.01). CONCLUSIONS: The glucose-induced suppression in glucagon levels is lost after a 50% partial pancreatectomy in humans. This suggests that impaired alpha-cell function in patients with type 2 diabetes may also be secondary to reduced beta-cell mass. Alterations in glucagon regulation should be considered as a potential side effect of partial pancreatectomies.

Functional assessment of pancreatic beta-cell area in humans.

OBJECTIVE: beta-Cell mass declines progressively during the course of diabetes, and various antidiabetic treatment regimens have been suggested to modulate beta-cell mass. However, imaging methods allowing the monitoring of changes in beta-cell mass in vivo have not yet become available. We address whether pancreatic beta-cell area can be assessed by functional test of insulin secretion in humans. RESEARCH DESIGN AND METHODS: A total of 33 patients with chronic pancreatitis (n = 17), benign pancreatic adenomas (n = 13), and tumors of the ampulla of Vater (n = 3) at various stages of glucose tolerance were examined with an oral glucose load before undergoing pancreatic surgery. Indexes of insulin secretion were calculated and compared with the fractional beta-cell area of the pancreas. RESULTS: beta-Cell area was related to fasting glucose concentrations in an inverse linear fashion (r = -0.53, P = 0.0014) and to 120-min postchallenge glycemia in an inverse exponential fashion (r = -0.89). beta-Cell area was best predicted by a C-peptide-to-glucose ratio determined 15 min after the glucose drink (r = 0.72, P < 0.0001). However, a fasting C-peptide-to-glucose ratio already yielded a reasonably close correlation (r = 0.63, P < 0.0001). Homeostasis model assessment (HOMA) beta-cell function was unrelated to beta-cell area. CONCLUSIONS: Glucose control is closely related to pancreatic beta-cell area in humans. A C-peptide-to-glucose ratio after oral glucose ingestion appears to better predict beta-cell area than fasting measures, such as the HOMA index.

Prevalence of and risk factors for hepatitis G (HGV) infection in haemodialysis patients: a multicentre study.

BACKGROUND: Hepatitis G virus (HGV) or GB-virus type C (GBV-C) is, like hepatitis C, a blood-borne virus and a member of the family of flaviviridae. HGV is distributed globally and is present in the volunteer blood donor population. Thus, for epidemiological reasons, HGV is of interest in haemodialysis patients, who are at risk of parenterally transmitted infections. The aim of the present investigation was to assess the prevalence of HGV by antibody testing and HGV-RNA determination by PCR. METHODS: The study was performed in haemodialysis units of the Patienten-Heim-Versorgung, an organization of haemodialysis units throughout Germany. A total of 2796 out of 3042 patients (92%) from 43 haemodialysis units were enrolled prospectively in the trial. Liver function tests were performed and epidemiologic data were obtained to evaluate risk factors for HGV in haemodialysis patients. RESULTS: Antibodies against HGV were detected in 485 patients (17.5%). Viraemia was seen in 380 out of 1935 patients tested (19.6%). Fifty-eight patients (3.0%) were positive for both antibodies and HGV-RNA. Using a standard questionnaire in 1717 out of the 2786 patients, it was found that more than five blood transfusions increased the risk of HGV infection significantly (P<0.05). There was no association found between HGV infection and the length of time on haemodialysis. CONCLUSION: HGV is common in German haemodialysis patients but, in contrast to other parenterally transmitted viruses, there is no further risk for new infections during haemodialysis, except for patients who have received several blood transfusions.

Increased expression of RelA/nuclear factor-kappa B protein correlates with colorectal tumorigenesis.

OBJECTIVE: To identify the role of RelA/nuclear factor-kappa B, an important inhibitor of apoptosis in colorectal tumorigenesis, we examined the expression of RelA in normal colorectal mucosa (n = 10), colorectal adenomas (n = 30) and colorectal adenocarcinomas (n = 30). Furthermore, the association of RelA expression with tumor cell apoptosis, proliferation, and expression of Bcl-2/Bcl-x(L )was also studied. METHODS: Paraffin sections were stained with monoclonal antibodies directed against RelA, Bcl-2, Bcl-x(L), and Ki-67 to assess protein expression patterns in normal, adenomatous and colon cancer tissue. Apoptotic cells were detected by terminal deoxynucleotidyl-transferase-mediated dUTP-biotin nick end labeling (TUNEL) using an in situ detection kit. RESULTS: The results of immunohistochemical staining revealed that expression of RelA, Bcl-2, Bcl-x(L), and Ki-67 labeling index (LI) significantly increased in the transition from adenoma with low dysplasia to adenocarcinoma. This transition was associated with a significant decrease in the apoptotic index (AI) and a significant increase in the Ki-67 LI. The expression of RelA correlated inversely with the AI and correlated positively with the expression of Bcl-2, Bcl-x(L), and Ki-67 LI in the transition from low-grade dysplasia to adenocarcinoma. CONCLUSION: Our results suggest that increased expression of RelA/nuclear factor-kappa B plays an important role in the transition from colorectal adenoma with low-grade dysplasia to adenocarcinoma in the pathogenesis of colon cancer in humans.

Deletion of the FHIT gene in human colorectal cancer is independent of high-risk HPV infection.

BACKGROUND AND AIMS: The fragile histidine triad (FHIT) gene, which is frequently lost in many cancers, has been identified as a candidate tumor suppressor gene at chromosome 3p locus 14.2. Human papillomaviruses (HPVs) are the major cause of cervical carcinoma and have been found to be able to integrate its genes into the chromosome 3 fragile site of cultured cells, deleting a piece of DNA which includes the FHIT gene. MATERIALS AND METHODS: We used nested reverse transcriptase PCR and DNA sequencing to evaluate 32 cases of colorectal adenocarcinoma and matched nearby normal tissues for aberrant transcripts of FHIT and infection of high-risk HPVs. RESULTS: Aberrant transcripts of the FHIT gene were observed in 34.4% of colorectal adenocarcinoma and in 6.3% of matched nearby normal tissues. The HPV(16) DNA was detected in 21.9% of colorectal adenocarcinomas and 3.1% of matched nearby normal tissues using PCR. Only two cases of colorectal adenocarcinoma contained both aberrant transcripts of FHIT and HPV(16) infection. No HPV(18) infection was detected in the present study. CONCLUSION: Our results indicate that alteration of the FHIT gene and HPV(16) infection are important genetic events associated with colorectal adenocarcinoma. However, there is no correlation between FHIT abnormalities, clinicopathological features, and HPV(16) infection in colorectal adenocarcinoma.

Increased expression of nuclear factor-kappaB/RelA is correlated with tumor angiogenesis in human colorectal cancer.

BACKGROUND AND AIMS: Recent studies have shown that nuclear factor-kappa B/RelA (NF-kappa B/RelA) is involved in tumor angiogenesis. This study examined whether NF-kappa B/RelA expression is associated with vascular endothelial growth factor (VEGF) expression and microvessel density in human colorectal cancer. MATERIALS AND METHODS: Ten specimens from normal colorectal mucosa and 52 colorectal adenocarcinomas were obtained by surgery or endoscopy. Immunohistochemical expression of NF-kappa B/RelA, VEGF, and CD34 was detected on paraffin-embedded tissue sections. RESULTS: NF-kappa B/RelA and VEGF were significantly overexpressed and associated with microvessel density in colorectal cancer. A significant association was found between NF-kappa B/RelA and VEGF expression. Clinicopathological features were not correlated with NF-kappa B/RelA, VEGF expression, or microvessel density. CONCLUSION: Our results suggest that increased expression of NF-kappa B/RelA contributes to tumor angiogenesis in colorectal cancer. VEGF may play an important role in mediating the NF-kappa B/RelA angiogenic pathway.