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Biomedical subjects

E Wenzl

Publications and source records attributed to E Wenzl.

At least 73 records · Page 4Linked to original sources

[Repair of the duodenal mucosa following acid damage. A protective mechanism as an approach to new therapeutic principles?].

Epithelial repair after luminal acid exposure was studied in the rabbit duodenum in vivo, HCl (200 mM for 30 min) caused uniform damage of the mucosa confined to the villi, 50% of the total villus height was affected by the acid-induced lesion in the proximal, and 70% in the distal duodenum. After demarcation and detachment of the necrotic tissue the defect was bridged by the remaining viable epithelial cells underneath a layer of mucus and necrotic debris (= necrotic layer). Mucosal repair resulted in a reduction of villus height by 62% in the proximal, and 77% in the distal duodenum. This process of mucosal repair progressed continuously, so that 9 hours after acid damage only 33% of villi in the proximal, and 41% in the distal duodenum were not yet fully restored, irrespective of luminal pH(pHL = 7 or pHL = 3). The difference between proximal and distal duodenum is due to the higher acid susceptibility of the distal duodenum. Rapid epithelial repair of the duodenal mucosa in vivo provides an important protective mechanism against the aggression from luminal acid.

Animals↗

Results of a rigorous follow-up system in colorectal cancer.

Results of a computer-aided follow-up programme for patients with colorectal cancer are analyzed. Between 1978 and 1987 1293 patients underwent this programme, the drop-out rate was 17%. 299 recurrences in 168 patients were discovered (40% local recurrence, 29% liver metastases and 31% others). Fifty-one per cent of patients with local recurrence and 47% with liver metastases were symptom free. Radical surgery could be performed in 50% of local recurrences and in 26% of liver metastases. The three year survival rate after radical surgery for recurrence was 35% for local recurrences and 33% for liver metastases, the five-year-survival rate 23% and 15%, respectively.

Cohort Studies↗

Rectal cancer: factors influencing the development of local recurrence after radical anterior resection.

The study was designed to select criteria which influence the incidence of local recurrence after radical anterior resection for rectal cancer. Local recurrence developed in 18 patients (20%) out of 90. All patients entered a prospective clinical study for the detection of local recurrence (mean observation time: 50 months). The following criteria were evaluated retrospectively: age, sex, staging, grading, gross appearance of the tumour, lymphatic reaction, invasion of lymph- and blood vessels, perineural invasion, mucus production of the tumour and width of the distal margin of clearance (measurement in cm in the specimen immediately after resection). The incidence of local recurrence (%) depended on Dukes stage (A: 7%, B: 17%, C: 40%; p less than or equal to 0.03), grading (well differentiated: 5%, average: 20%, poorly differentiated: 55%; p less than or equal to 0.02), gross appearance (protuberant: 15%, infiltrating: 47%; p less than or equal to 0.006), lymphatic stroma reaction (yes: 10%, no: 45%; p less than or equal to 0.006), invasion of veins (yes: 75%, no: 20%; p less than or equal to 0.0002), perineural invasion (yes: 52%, no: 17%; p less than or equal to 0.001) and the margin of clearance (less than 1 cm: 52%; 1-3 cm: 10%, greater than 3 cm: 15%; p less than or equal to 0.02 Mantel, p less than or equal to 0.05 Breslow between less than 1 cm vs 1-3 cm and greater than 3 cm, respectively). Local recurrence was not related to age, sex and mucus production of the tumour. Unfavourable morphological criteria may help to define groups with a higher risk of developing local recurrence.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗

Vein bypass surgery for femoro-popliteal arteriosclerosis: influence of different risk factors on patient survival and the importance of anticoagulant treatment.

For femoro-popliteal arteriosclerosis the autologous saphenous vein graft implanted in reverse has evolved as the standard procedure, but the impact of postoperative anticoagulant treatment upon patient survival in particular remains uncertain. Patients undergoing elective surgery during the years 1970-86 (n = 668) were analysed using Kaplan-Meier estimates. This demonstrated that the preoperative status of the patient exerted a significant influence on the probability of survival (P less than 0.0001 Mantel). Anticoagulants started postoperatively significantly prolonged the life of the patients (P less than 0.0001). Of the various risk factors the patient's age had the most important influence (P less than 0.0001), whereas the presence or absence of diabetes mellitus (P less than 0.064) and the duration of the operation (P less than 0.407), were not significant. Using the proportional hazards regression model to test the validity of a prognostic factor, while other variables were checked, we found preoperative clinical status (P less than 0.0001), the patient's age (P less than 0.0001) and anticoagulant treatment (P less than 0.0001) to be of statistical importance.

Age Factors↗

Acid stimulated alkaline secretion in the rabbit duodenum is passive and correlates with mucosal damage.

Low luminal acid concentrations stimulate alkaline secretion (AS) by the duodenal mucosa. We investigated acid stimulated alkaline secretion by proximal rabbit duodenal mucosa in an Ussing-chamber under different luminal acid concentrations and its relation to mucosal damage. Luminal alkalinisation and potential difference (PD) were measured and mucosal damage was investigated histologically. Luminal acid caused an increase of alkaline secretion over baseline (0.95 +/- 0.19 mu Eq/cm2/10 min; n = 55): 0.1 mmol: 7%, 1 mmol/l: 17%, 5 mmol/l: 22%, 10 mmol/l: 33%, 20 mmol/l: 34%, 50 mmol: 39%, 100 mmol/l: 27%. At acid concentrations of 10 mmol/l and above the PD fell from 2.0 +/- 1.0 mV to zero. Histology showed [H+]-dependent mucosal damage ranging from villus tip lesions to deep mucosal injury. Stimulation of alkaline secretion was not specific for acid. Ethanol (14%) stimulated alkaline secretion by 26%, and 28% ethanol by 40% over baseline. Ouabain and/or anoxia sensitive (active) alkaline secretion constituted 80% and 100% respectively of basal alkaline secretion. After exposure to various luminal acid concentrations passive diffusion (sensitive only to removal of nutrient HCO3-) was solely responsible for the rise in alkaline secretion. Only after 14% ethanol a small rise in ouabain and/or anoxia sensitive HCO3- transport was observed. Under the conditions of this study stimulation of duodenal alkaline secretion is not specific for luminal acid, but occurs also with luminal ethanol; both agents stimulate alkaline secretion depending on their concentration. In this model passive diffusion of HCO3- associated with increasing mucosal damage is the major component of the rise in alkaline secretion.

Animals↗

[Hemodynamic and metabolic changes during orthotopic liver transplantation].

Hemodynamic and metabolic profiles were obtained on 48 adult patients (mean age 46 years) undergoing orthotopic liver transplantation without using a bypass technique during the anhepatic period. Baseline measurements after induction of anesthesia (A) revealed a high-output circulatory state. During hepatic dissection (B, preclamping control), mean arterial pressure (MAP), mean pulmonary artery pressure (MPAP), pulmonary capillary wedge pressure (PCWP), right atrial pressure (RAP), and elevated cardiac index (CI) were well maintained. Preoperative plasma exchange with fresh frozen plasma in the presence of severe coagulation defects and liberal use of platelet concentrates limited the need for massive blood transfusion, and thus contributed to stable hemodynamics during this stage. Significant cardiovascular changes occurred immediately after clamping of the inferior vena cava and the portal vein (C): there was a marked fall in MAP (-30%), MPAP (-45%), PCWP (-48%), RAP (-40%), and CI (-60%) reflecting the hemodynamic adaptation to the impeded venous return. At the end of the anhepatic period (D), MAP (-21%), MPAP (-38%), PCWP (-39%), RAP (-24%), and CI (-56%) were persistently lowered because no attempts were made to attenuate the clamping response by vigorous volume expansion or infusion of inotropic drugs. The reduction in oxygen availability index (O2AVI) was compensated by enhanced oxygen extraction. Oxygen consumption index (VO2I) fell secondary to the removal of the liver and the decrease in body temperature (BT). Potassium levels and acid-base balance were well controlled; no hypoglycemic episode was observed during the anhepatic period.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid-Base Equilibrium↗

[Secondary achalasia caused by diffuse infiltrating cardial cancer].

Malignant tumors, especially gastric adenocarcinomas infiltrating into the submucosa of the esophagus, can result in a clinical syndrome termed secondary or pseudo-achalasia that mimicks idiopathic primary achalasia. History, symptoms, radiology, esophago-gastroscopy with biopsy, and esophageal manometry do not discriminate secondary from primary achalasia at initial evaluation. The difficulty in establishing the diagnosis is demonstrated on the case of a 57-year old man presenting with dysphagia, vomiting, and weight loss. Fluoroscopically, the esophagus was moderately dilated and bird-beaked. The patient underwent two gastroesophagoscopies, in the second of which the endoscope could not be passed through the esophagogastric junction. Esophageal manometry revealed an only partial relaxation of the lower esophageal sphincter upon swallowing and nonpropulsive, repetitive contractions in the esophageal body, compatible with the diagnosis "vigorous achalasia". After two mechanic dilatations, a myotomy of the sphincter seemed indicated. At operation, a cardiac carcinoma infiltrating submucosally into the esophagus was found. The recognition of secondary achalasia is difficult, and signs such as older age, brief duration of symptoms, marked weight loss and the presence of vigorous achalasia, relatively rare in primary achalasia, are unspecific. Hence, in all instances in which secondary achalasia cannot be ruled out, it seems advisable to perform an explorative laparotomy with eventual sphinctermyotomy as primary therapeutic intervention instead of a mechanic dilatation, which potentially further obscures the underlying disease. To enable the recognition of undetected secondary achalasia, all patients with achalasia should be followed up thoroughly.

Adenocarcinoma↗

[Significance of alkali secretion in acid tolerance of the rabbit duodenum].

Different rates of alkaline secretion and their effect on acid tolerance were investigated in segments of proximal duodenum of anaesthetized New Zealand white rabbits in situ. Metabolic alkalosis and glucagon led to a significant increase in alkaline secretion, while metabolic acidosis, vasopressin and furosemide significantly reduced alkaline secretion. Mucosal blood flow was significantly increased by glucagon and decreased by vasopressin. Alkaline secretion after an acid challenge was significantly higher than preacid secretion in animals with metabolic alkalosis, glucagon and NaCl, whereas vasopressin reduced alkaline secretion significantly. No significant change was observed during treatment with furosemide or metabolic acidosis. After perfusion with acid, 51.8% of the villi showed superficial damage (stage 1) under control conditions. Damage was significantly reduced after administration of bicarbonate or glucagon, while NH4Cl, vasopressin or furosemide increased damage both quantitatively and qualitatively. There was a direct linear correlation between the degree of damage and alkaline secretion. The proximal duodenum showed considerably less damage than the distal segment. We conclude that a decrease in alkaline secretion is associated with a reduced tolerance of duodenal mucosa to luminal acid, whereas stimulation of alkaline secretion improves mucosal protection. These results support the hypothesis that alkaline secretion is an important factor in the protection of the duodenum against luminal acid.

Acid-Base Equilibrium↗

[Role of postoperative anticoagulant treatment following femoro-popliteal venous bypass. Interim evaluation of a controlled clinical study].

Eighty-eight patients underwent a classical reversed saphenous vein graft for femoro-popliteal occlusive disease and were enrolled in a controlled clinical trial. During the second postoperative week the patients were allocated randomly into one of two groups: group I consisted of 42 patients who received dicumarol and group II (46 patients) served as a control group without any anticoagulant treatment. The mean follow-up time was 24 months. After 12 months the cumulative patency rate was 82%, after 18 months 76% and after 24 months 76%; for patients receiving dicumarol treatment the respective figures were 92%, 86% and 86% and for those with no treatment 70%, 67% and 67%, the difference being significant. When the bypass operation was performed for limb salvage (clinical stages III and IV) the overall results were worse (12 months: 72%, 18 months: 68%, 24 months: 68%) than in stages II, II-III (12 months: 90%, 18 months: 85%, 24 months: 85%). In limb salvage surgery the positive effects of anticoagulant treatment were significant (with treatment: 12 months 87%, 18 months 86%, 24 months 86%; without treatment: 12 months 58%, 18 months 54%, 24 months 54%).

Aged↗

[Results of the surgical therapy of stomach cancer].

1589 patients treated between 1965 and 1985 at the First Surgical Department of Vienna University were investigated to answer the following questions: 1. Development of postoperative mortality. 2. Is a palliative gastrectomy indicated? 3. Does gastrectomy en principe improve survival? 4. Quality of life after total gastrectomy. Postoperative mortality after distal resection was decreased from 8% to 1.2%. After total gastrectomy mortality was reduced from 20% to 4.3%. A significant factor in this improvement was the use of Y-Roux reconstruction as the only method during recent years. After palliative resections the mortality was not higher than in curative operations. Comparison of comparable tumour stages of the mid stomach revealed no benefit of gastrectomy over distal resection in terms of survival. This was found to apply to both cases of negative and positive lymph node involvement as well. Gastrectomy en principe does not seem to improve survival rates. The quality of life after total gastrectomy (Y-Roux) is satisfactory in most patients. Dumping and reflux were rare, diarrhoea occurred in 22%, anaemia in 30% of patients.

Adult↗

[Value of consistent after care in stomach cancer].

This study analyses the efficacy of a consistent, strict follow-up programme in the management of patients with gastric cancer. Between 1978 and 1986 671 patients were treated, of whom 361 (54%) had a radical operation. The data were fed into an electronic data base and patients were invited to attend the follow-up investigations. The drop-out rate was 21%. Recurrence was detected in 177 cases, 25% in the liver, 25% as carcinosis, 21% in lymph nodes, 15% locally and 14% in other localizations. 78% of the recurrences were seen two years postoperatively and 27% were asymptomatic; 10% underwent radical operation, 27% palliative operation and 63% conservative treatment. Survival rates after 3 and 5 years were 73% and 62% in patients without recurrence and 21% and 8% with recurrence, respectively (p = 0.0 Breslow and Mantel test). The survival rate 2 years after treatment of recurrence was 37% after radical surgery and 0% after palliative operations or conservative treatment (p less than 0.06 Breslow and p less than 0.002 Mantel test). Furthermore, a tight follow-up programme enables control of surgical quality and accurate follow-up during clinical trials, whilst the opportunity to advise patients after operation is an important aspect.

Adult↗

[Non-Hodgkin's lymphoma of the stomach: surgical therapy and prognosis].

This study reports 43 patients (male: n = 17, female: n = 26) with non-Hodgkin's lymphoma of the stomach, who underwent surgery between 1. January 1977 and 31. December 1986. The main clinical symptoms were abdominal pain, weight loss and vomiting. Symptoms preceded diagnosis by 13 weeks. Barium meal and endoscopy were useful diagnostic procedures. The biopsy specimens indicated malignancy in 80% of cases. Operations performed were: total gastrectomy (n = 18), distal resection (B I: n = 4, B II: n = 14), partial duodenopancreatectomy (n = 3), proximal gastric resection (n = 1), local excision (n = 1) and explorative laparotomy (n = 2). Perioperative mortality was 0%. Peritonitis occurred in 1 patient due to leakage of the duodenal stump. According to the Ann-Arbor system we found stage I in 19, stage II in 10 and stage III in 14 cases. The histological type according to the Working Formulation showed low grade of malignancy in 15 and high grade of malignancy in 28 patients. All patients underwent postoperative chemotherapy and/or radiotherapy with respect to tumour staging and morphology. 24 patients are alive without relapse, 16 patients died intercurrently. The data were collected retrospectively and analysed by means of Kaplan-Meier survival functions. For comparisons we used the Breslow and the Mantel test. We investigated the prognostic significance of: sex, clinical symptoms, localisation of the tumour, type and radicality of operation, lymphadenectomy, splenectomy, splenic infiltration, tumour size and depth of infiltration, staging and grading. The 2-year survival rate was 82%, the 5-year rate was 55%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Repair of rabbit duodenal mucosa after acid injury in vivo and in vitro.

Epithelial repair after luminal acid exposure was studied in the rabbit duodenum in vivo and in vitro. Hydrochloric acid (200 mM, 30 min in vivo; 10 mM, 10 min in vitro) caused a uniform damage of the mucosa confined to the villi. After demarcation and detachment of the necrotic tissue the defect was bridged by the remaining viable epithelial cells, resulting in a reduction of villus height. This process of mucosal repair proceeded continuously, so that 9 h after acid damage only 33% of villi in the proximal duodenum and 41% in the distal duodenum remained not fully restored, at both luminal pH 7 and luminal pH 3. The difference is due to the higher acid susceptibility of the distal duodenum. In vitro, most of the mucosal surface was reconstituted 5 h after acid injury, at both luminal pH 7.4 and luminal pH 3. The potential difference declined and reversed after mucosal damage; restitution to original values was only observed at luminal pH 7 in vivo and luminal pH 7.4 in vitro.

Animals↗

The influence of anticoagulant treatment on the probability of function in femoropopliteal vein bypass surgery: analysis of a clinical series (1970 to 1985) and interim evaluation of a controlled clinical trial.

During the years 1970 to 1985, 463 patients with obliterative atherosclerosis at the femoropopliteal level underwent elective surgery. The operation performed was an autologous saphenous vein bypass using the reversed technique. The vascular surgical treatment was documented in reasonable detail (both baseline and follow-up) in accordance with the documentation system of the Austrian Society of Vascular Surgery. On-line data entry with use of SAS data-base management software was used. The patency curves were estimated in accordance with the Kaplan-Meier method; possible differences were checked by means Breslow's and Mantel's tests. The preoperative clinical status (claudicants, n = 200; limb salvage, n = 263) influenced the postoperative results in a statistically significant manner (Breslow p less than 0.01; Mantel p less than 0.03). All the other risk factors analyzed (site of distal anastomosis above versus below the knee, n = 231, and n = 232, respectively; Breslow p less than 0.58, Mantel p less than 0.58. Presence [n = 122] or nonpresence [n = 341], of diabetes mellitus [Breslow p less than 0.77, Mantel p less than 0.68]; smoking habits [nonsmokers, n = 93, smokers n = 370, Breslow p less than 0.68, Mantel p less than 0.69;]) did not reach statistical significance. Anticoagulant treatment (n = 101) had no effect (Breslow p less than 0.93, Mantel p less than 0.72), even when the therapy was restricted to cases with disease at advanced clinical stages (stages III, IV; n = 50; Breslow p less than 0.55, Mantel p less than 0.95). On the basis of these analyses, a prospective trial was initiated in 1979. Eighty-eight patients were studied; those in group I (n = 42) received dicumarol, and those in group II (n = 46) were controls who did not receive anticoagulant treatment. At present, the median follow-up time is at 30 months. Treatment with dicumarol favorably influenced graft patency (Breslow, p less than 0.03, Mantel p less than 0.07; one-tailed tests). The patients' preoperative clinical status affected the results of surgery (Breslow p less than 0.03, Mantel p less than 0.02; one-tailed tests). In relation to the preoperative clinical status, a therapeutic effect was observed in stages III and IV (n = 45; Breslow p less than 0.03, Mantel p less than 0.07; one-tailed tests), while no effect of therapy was demonstrable in claudicants (n = 43; Breslow p less than 0.3, Mantel p less than 0.4; one-tailed tests).(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗

The effect of acid perfusion on mucosal blood flow and intramural pH of rabbit duodenum.

To evaluate the role of blood flow for acid tolerance of the duodenal mucosa, we perfused the duodenums of anesthetized rabbits with different concentrations of hydrochloric acid (HCl). Acid perfusion stimulated blood flow to the duodenal wall in a concentration-dependent fashion up to 80 mmol/L HCl (0 mmol/L; 0.44 +/- 0.05, 10 mmol/L; 0.84 +/- 0.14, 50 mmol/L; 1.44 +/- 0.11, 80 mmol/L; 2.03 +/- 0.12, 100 mmol/L; 1.82 +/- 0.07 ml/gm/min X +/- SEM). The pH in the lamina propria of the mucosa, which was measured with antimony microelectrodes was not changed in experiments during perfusion with 50 and with 80 mmol/L HCl in normotension. Acidosis in the lamina propria could be demonstrated only when the duodenum was perfused with 100 and with 80 mmol/L HCl combined with hemorrhagic hypotension. Damage to the mucosa, which developed after 30 and 60 minutes of acid perfusion, also showed a H+-dependent pattern. Reduction of blood flow by hemorrhagic hypotension aggravated the morphologic damage. We conclude that luminal acid stimulates blood flow in the duodenum. The decrease in blood flow induced by hypotension results in a greater susceptibility to mucosal damage.

Animals↗

Progress in reconstruction after resection of the head of the pancreas.

Fistulas of the pancreas due to dehiscence of pancreaticojejunostomy after partial pancreaticoduodenectomy caused severe postoperative complications. Whereas various methods with and without anastomosis of the pancreas are recommended to deal with the pancreatic stump, mortality rates of 20 to 75 per cent have been reported. These different results prompted us to start a prospective, nonrandomized study in which three methods of reconstructing the remnant of the pancreas involving anastomosis were compared with pancreaticocutaneous drainage without anastomosis. One hundred and thirty-one patients with partial pancreaticoduodenectomy entered this trial, 54 female and 77 male patients with an average age of 55.9 years. The indications included: 42 instances of chronic pancreatitis, 44 instances of carcinoma of the pancreas and 45, periampullary carcinoma. We performed 33 end to side pancreaticojejunostomy procedures (four fistulas of the pancreas, a mortality rate of 15.0 per cent), 31 end to end anastomoses (three fistulas of the pancreas, a mortality rate of 6.5 per cent) and 48 double loops with anastomoses of the pancreatic and hepatic duct to separate jejunal loops (nine fistulas of the pancreas, a mortality rate of 2 per cent). Nineteen patients were operated upon using external drainage of the pancreatic stump by means of Penrose drains (five fistulas of the pancreas, a mortality rate of zero per cent). To reduce the fatal risks caused by combined fistulas of the pancreas and biliary tract, the use of separate intestinal loops for anastomoses of the pancreas and biliary tract offers the best solution, since no fatal complications of the pancreaticojejunostomy were observed. In contrast, pancreaticocutaneous drainage was performed upon patients with endangered pancreatic anastomoses due to local morphologic conditions, such as tender pancreatic parenchyma or thin pancreatic ducts. The total loss of exocrine function and the high morbidity rate of 37 per cent is justified in spite of the mortality rate of zero per cent. Total pancreaticoduodenectomy, for technical reasons, represents no acceptable alternative in view of higher mortality rates.

Adult↗