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U T Hopt

Publications and source records attributed to U T Hopt.

At least 55 records · Page 3Linked to original sources
PubMed2003

[Hepatocellular carcinoma. Pathogenesis and multicentricity].

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in some areas of the world, with an extremely poor prognosis. The clinical and molecular pathogenesis of HCC is very complex and involves alterations in the structure or expression of several tumor suppressor genes, oncogenes and, possibly, mechanisms leading to genetic instability due to mismatch repair deficiency or chromosomal instability and aneuploidy due to defective chromosomal segregation. Central to the molecular pathogenesis of HCC are mutations of various genes and a genetic instability which, in most cases, result from chronic liver disease and the associated enhanced liver cell regeneration and mitotic activity. The prognosis is generally very poor. Most studies report a 5-year survival rate of less than 5% in symptomatic HCC patients. Therapeutic strategies include resection, liver transplantation, and nonsurgical interventions such as percutaneous ethanol injection, radiofrequency thermal ablation, transarterial embolization, and chemoembolization. HCC has been shown to be quite resistant to radio- and chemotherapy.

Antineoplastic Agents↗
PubMed2003

[Pancreas transplantation: a survey on indications, surgical techniques, immunosuppression, complications and outcome].

Since its introduction in 1966, pancreas transplantation has undergone considerable progress. Refinements in surgical technique, better organ preservation solutions, and more potent immunosuppressive therapies have improved patient and graft-survival rates dramatically. Survival rates for patient and pancreas at 1 year approach 95 and 83 %, resp., for simultaneous pancreas and kidney transplantation, and 97 and 78 %, resp., for pancreas alone. US pancreas graft and patient survival rates do not significantly differ from the results of the European centers. However, there is still a hesitant acceptance of combined pancreas-kidney transplantation in Germany. Combined pancreas-kidney transplantation is nowadays the treatment of choice in carefully selected patients with type 1 insulin-dependent diabetes mellitus and end-stage renal failure. Many US centers even advocate combined transplantation in diabetic patients at a pre-uremic stage. Pancreas transplantation significantly improves quality of life and provides excellent long-term glycemic control which halts or even ameliorates secondary diabetic complications such as microangiopathy and neuropathy. In addition, there is increasing evidence that successful pancreas transplantation significantly prolongs patient survival mainly by a reduction of cardiovascular-related mortality. Current 10-year patient survival rate after SPK exceeds 70 %. For diabetics with end-stage renal disease there is no alternative treatment available with comparable live expectancy. However, morbidity and mortality after SPK is still higher than for kidney transplantation alone in the first year. Outcome of isolated pancreas transplantation is also improving but this technique is still restricted to non-uremic patients with severe diabetic complications or with brittle diabetes and severe impairment of quality of life.

Contraindications↗
PubMed2002

Do complications related to laparoscopic cholecystectomy influence the prognosis of gallbladder cancer?

BACKGROUND: Laparoscopy is thought to worsen the prognosis of gallbladder cancer (GBC) discovered unexpectedly at laparoscopic cholecystectomy (LC). However, laproscopy has never been shown to have an influence on patient survival in clinical series. METHODS: We Performed a two-center retrospective analysis of 28 patients with GBC (11 previously known, 17 unexpectedly discovered by LC) to determine whether laparoscopy and complications related to LC had any influence on the prognosis of GBC. Resectability for cure after LC, survival, and recurrence related to both the procedure itself and complications associated with LC were analyzed. RESULTS: Of the 17 patients with unexpected GBC, 16 were considered resectable for cure at the time of LC. Advanced disease was detected in eight patients by re staging (n = 5) or exploration (n = 3). Seven patients (43.8%) underwent reoperation for cure. Mean survival of patients with unexpected GBC was 26.5 months. Mean survival was shorter when complications (bile spillage, injury of common bile duct, or tumor violation) occurred during LC (10.2 vs 33 months, p = 0.016). If bile spillage was the only complication at LC, there was also a trend to shorter survival (12 vs 33 months, p = 0.061). CONCLUSION: Complications during LC significantly worsen the prognosis of GBC. Therefore, bile spillage and excessive manipulation of the gallbladder should be avoided.

Aged↗
PubMed2002

Effect of nitric oxide in ischemia/reperfusion of the pancreas.

BACKGROUND: Ischemia/reperfusion injury, and thus graft pancreatitis, remains a major problem in pancreas transplantation. Contradictory results about the role of nitric oxide (NO) in pancreatic ischemia/reperfusion have been reported; however, in none of the reports has a detailed comparison between inhibition of NO synthase and NO supplementation been carried out. METHODS: Vascular isolation of the pancreatic tail was performed in landrace pigs. After splenectomy catheters placed in the distal part of the splenic vessels allowed collection of the venous effluent and perfusion of the pancreatic tail. Three hours of complete warm ischemia was followed by 6 h of reperfusion. The effect of the NO donor sodium nitroprusside (SNP) and L-arginine was compared to a control group and NO synthase inhibition with L-NAME. RESULTS: Lipase in the venous effluent of the pancreas was significantly decreased in the SNP and the L-arginine groups. Vascular resistance was markedly elevated in the L-NAME group and reduced in the NO donor groups. Tissue pO2 after reperfusion was only significantly elevated in the SNP group. Granulocyte infiltration and also overall histological tissue injury were most severe in the control group followed by the L-NAME group, the SNP group, and the L-ARG group. CONCLUSION: The data show that supplementation of nitric oxide is clearly protective in pancreatic ischemia/reperfusion. However, inhibition of NO synthesis does not lead to an equally clear aggravation of tissue injury.

Acute Disease↗
PubMed2002

[Primary aortoduodenal fistula as a late complication of para-aortic radiation therapy. A case report].

Primary aortoenteric fistulae (AEFs) are rare vascular entities. More than 75% of primary AEFs involve the duodenum, with the overwhelming majority located in the third or fourth portion. Atherosclerosis, leading to formation of an aortic aneurysm, remains the most common etiology, accounting for more than 3/4 of the cases reported. Primary aortoenteric fistulae following radiotherapy are rare. The case of a 49-year-old man with aortoduodenal fistula 22 years after para-aortic radiation is presented. In November 1997, the patient suddenly developed hematemesis and melena. Endoscopy suggested the presence of an ulcus but no definitive bleeding source could be seen. Bleeding stopped spontaneously. Six hours later he developed massive hematemesis and was transferred to our department. An emergency operation was performed. We found an aorto-duodenal fistula in the third portion of the duodenum without an aortic aneurysm. We directly sutured the aortic wall laceration and resected the third and fourth part of the duodenum. Histology revealed typical signs of radiation damage. The patient is alive and well 2 years after surgery. To our knowledge, this is the sixth case of a primary aorto-duodenal fistula following radiotherapy ever to be reported in world literature.

Aorta↗
PubMed2002

[Pancreatic leakage after pancreas resection. An analysis of 345 operated patients].

INTRODUCTION: Complications after pancreatic resections remain frequent despite a decreasing mortality. Pancreatic leakages represent a relevant part of those complications but data on risk factors for their occurrence are rare. We analyzed our experience with incidence, clinical course, and risk factors of pancreatic leakage in a large patient group. METHODS: We analyzed the prospectively documented perioperative data of 345 patients with pancreatic resections carried out between 1994 and 2001. Main indications for surgery were chronic pancreatitis (57%) and malignant tumors (37%). The following operations were performed: Whipple's operation 15%, pylorus-preserving pancreaticoduodenectomy 53%, duodenum-preserving pancreatic head resection 19%, and distal pancreatic resection 13%. Risk factors were analyzed using uni- and multivariate methods. RESULTS: Postoperative mortality and complication rate were 2.9% and 41%, respectively. A pancreatic leakage occurred in 9.9%. In the majority of patients, pancreatic leakage was asymptomatic and controlled by prolonged drainage. However, one fourth of the patients with pancreatic leakage required reoperation. The mortality of pancreatic leakage was 12%. No patient with chronic pancreatitis died as a consequence of pancreatic leakage. Impaired preoperative renal function was the only risk factor for the occurrence of postoperative pancreatic leakage. CONCLUSIONS: Although easily managed in the majority of cases, pancreatic leakage still represents a relevant postoperative complication after pancreatic resection, especially in patients with malignant disease. Because of an increased risk of developing pancreatic leakage, an impaired renal function should be considered specifically in the perioperative management of the patients.

Adolescent↗
PubMed2002

[Successful catheter-guided local thrombolysis in acute pulmonary embolism in the early postoperative period after pancreatic head resection].

Pulmonary embolism in the early postoperative period is characterized by high morbidity and mortality. Systemic application of thrombolytic agents during this time is contraindicated; operative thrombectomy also has a high mortality rate. We report a case of successful local lysis in combination with catheter fragmentation of a massive two-sided pulmonary embolism diagnosed on the 4th postoperative day after pylorus-preserving duodenopancreatectomy for distal carcinoma of the common bile duct. Thrombolysis was performed in three sessions by a combination of catheter-supported interventional fragmentation of the thrombus with local rt-PA lysis. There were no bleeding complications or disturbances of anastomotic healing. The patient was discharged from the hospital on the 23rd postoperative day after changing anticoagulation to a vitamin K antagonist. The case presented demonstrates the possibility of local lysis in combination with interventional methods as a therapeutic option for pulmonary embolism in the early postoperative period as an alternative to surgical strategies.

Adenocarcinoma↗
PubMed2002

MTS colorimetric assay in combination with a live-dead assay for testing encapsulated L929 fibroblasts in alginate poly-L-lysine microcapsules in vitro.

Biomaterials such as applied in microcapsules may have harmful effects on encapsulated cells. Up to now, there are no adequate assays available for testing the function and viability of cells in capsules. Therefore, we investigated whether the combination of MTS proliferation assay and live-dead viability assay is suitable for testing microencapsulated L929 fibroblasts in long-time culture. Proliferation of L929 cells was shown by a significant increase of formazan absorbance within the first 3 weeks (Day 0: 0.132 +/- 0.047; Day 7: 0.404 +/- 0.101; Day 14: 0.728 +/- 0.239; Day 21: 0.877 +/- 0.224) followed by stagnation and decrease thereafter. This was confirmed by an increasing proportion of dead cells measured by the live-dead assay. Thus, proliferation of encapsulated L929 can be reliably investigated by the MTS assay. In combination with life-dead assays, the proliferation can be correlated to the survival rate of the encapsulated cells.

Alginates↗
PubMed2002

Characterization of microcirculatory disturbance in a novel model of pancreatic ischemia-reperfusion using intravital fluorescence-microscopy.

INTRODUCTION: Microcirculatory disturbances caused by ischemia-reperfusion injury (IRI) are the crucial hallmarks of pancreatitis following pancreas transplantation. AIMS: To develop a novel rodent model of normothermic in situ ischemia of a pancreatic tail-segment that simulates the clinical situation of pancreas transplantation by flushing the organ via an inserted microcatheter and thus enables selective treatment of the organ via this access. METHODOLOGY: Four experimental groups were investigated (n = 7 Wistar rats/group): sham animals without ischemia and dissection of the pancreas; control animals with dissection of a pancreatic tail segment pedunculated on the splenic vessels and flushing od this segment with saline via a microcatheter; and two groups of animals treated like controls with a pancreatic ischemia time of 1 hour or 2 hours. With use of intravital epifluorescence microscopy, the microcirculatory damage was characterized by investigation of functional capillary density (FCD) and leukocyte adherence in postcapillary venules (LAV) before ischemia and during a reperfusion time of 2 hours. Dry:wet ratio determinations, light microscopy, and electron microscopic investigations were performed to characterize the histologic organ damage. RESULTS: FCD decreased significantly (p < 0.05) 2 hours after reperfusion in the groups of 1-hour (-29.21%) and 2-hour ischemia (-42.73%), in comparison with baseline values. LAV increased significantly (p < 0.05), 4.3- and 5.8-fold, after 1-hour and 2-hour ischemia during the observation time. The histologic damage was similar to posttransplantation pancreatitis in humans 1 hour after reperfusion. In sham and control animals these alterations were not significant. CONCLUSIONS: The rodent in situ model of pancreatic IRI showed standardized microcirculatory damage dependent on the ischemia time. Offering the possibility of selective treatment by the direct artery access to the ischemic pancreatic area, the model enables investigations of questions related to human pancreas transplantation.

Animals↗
PubMed2002

[Stomach and rectum replacement with pouches--is less more?].

The effects of pouch reconstruction on long term are dependent not only on the capacity of the pouch, but also on its motility and contractibility. Problems with evacuation of the pouches in the upper and lower abdominal tract may become a major problem in a significant part of the patients. Thus the length of the pouches should be limited to 5 cm at the most in patients with complete rectal resection and to 10-15 cm after gastrectomy. The evacuation profile of the pouches is influenced in addition by the outlet characteristics of the pouch. Finally one should take into consideration that the beneficial effects of pouch reconstruction disappear with time due to adaptation of the bowel after straight reconstruction procedures, while on the other hand the evacuation problems persist.

Colonic Pouches↗
PubMed2001

Impairment of microcirculation in the early reperfusion period predicts the degree of graft pancreatitis in clinical pancreas transplantation.

BACKGROUND: Graft pancreatitis is thought to be induced by ischemia/reperfusion. Animal experiments have suggested that an impaired microcirculation is crucial in this process. We have therefore studied the relevance of microcirculation in clinical pancreas transplantation. METHODS: In 17 patients undergoing pancreas transplantation, tissue pO2 was monitored continuously by an electrode implanted into the pancreatic tail. A catheter was inserted in the distal part of the splenic vein of the pancreas graft. After reperfusion blood samples were taken from this catheter and blood flow was measured by the venous outflow method. The degree of graft pancreatitis was assessed by peak-C-reactive protein (CRP) defined as highest CRP within 3 days after transplantation. RESULTS: Tissue pO2 increased within 5 min after reperfusion. Thereafter, in most patients a transient decrease was noted, indicating impairment of nutritive perfusion. During this period there was an increasing negative correlation between peak-CRP and tissue pO2 which was highly significant at 60 min after reperfusion (r=-0.70, P<0.002). Also donor age correlated significantly with peak-CRP (r=0.64, P<0.005) and to a somewhat lesser extend with tissue pO2 60 min after reperfusion (r= -0.55, P<0.03). CONCLUSION: These data show that the degree of organ damage in clinical pancreas transplantation is directly related to an impairment of microcirculation in the early reperfusion period. These data also support the idea that grafts from older donors have a higher probability to develop graft pancreatitis and that this might be due to an increased incidence of microcirculatory disturbances in these organs.

Adult↗