Aims: A retrospective study was used to compare laparoscopic appendectomy for perforated appendicitis to open operation. Methods: Between July 1991 and June 1999 a total of 734 patients, all over 14 years of age, underwent operation for acute appendicitis. Of these patients, 125 (17%) displayed perforated appendicitis and were treated with either a laparoscopic appendectomy (n = 80; total conversion rate 36/80, 45%) or a primary open procedure (n = 45). Results: Due to selection, the 3 treatment groups (laparoscopic, laparoscopy with conversion, open operation) showed differences with respect to gender, duration of symptoms, proportion of obese patients and patients with generalized peritonitis. The median operating time was 75 min for the laparoscopic procedure, 90 min for a converted procedure and 70 min for open operation. Only 1 of 44 (2%) patients who had a laparoscopic operation, but 8 of 36 (22%) who had a converted operation, and 8 of 45 (18%) who had an open operation developed wound infection. A similar frequency of intra-abdominal abscess formation was observed in the 3 treatment groups (2/44, 5%; 3/36, 8%; 2/45, 5%). Fatal outcome occurred only in patients who underwent an open operation and presented with severe peritonitis (5/45, 11%). Conclusions: Despite limitations in comparability of patient groups, laparoscopic appendectomy was associated with a significantly lower rate of septic wound complications (p < 0.05). This was especially true for the subgroup of obese patients (BMI >26). Therefore, for patients with perityphlitic abscess or fresh purulent lower abdominal peritonitis, but not for patients with generalized peritonitis, laparoscopic appendectomy is not only justifiable but even recommended as the procedure of choice.

Background: Development of incisional hernia after open abdominal surgery remains a major cause of post-operative morbidity. The aim of this study was to determine the current practice of surgeons in terms of access to and closure of the abdominal cavity in elective open surgery.

Summary:In computer-aided prognosis theoretical arguments in favour of a sophisticated model often do not result in a markedly better performance. In this study, straightforward extensions of the simple and comprehensive independent Bayes model, taking interactions between variables into consideration, are investigated, using a clinical data set of upper gastrointestinal bleeding, four sets of variables and different measures of performance (discriminatory ability, sharpness, reliability). For all criteria of performance, the differences between the models were small in the sets with few variables. In the sets with many variables there were marked differences between the models; however, no model was superior in all aspects of performance. Incorporation of interactions in models based upon Bayes’ theorem are worthwhile if many variables are used and the discriminatory ability is considered.

Background Local defense mechanisms are important for the integrity of the peritoneum, but few details are known about the expression patterns of antimicrobial proteins such as human defensin in normal and damaged peritoneum. Methods Part A: The expression of different defensins in normal ( n = 12), inflamed ( n = 5), and metastatic peritoneum ( n = 4) and in cultured human peritoneal mesothelial cells was analyzed using mRNA and immunohistochemistry. Part B: Using immunohistochemistry the expression of different defensins was analyzed in different subgroups: healthy controls ( n = 25), patients with chronic appendicitis ( n = 25) or acute appendicitis ( n = 10), and end-stage renal disease patients ( n = 25, with 15 on peritoneal dialysis). Results Part A: Human neutrophil peptides (HNP) 1 and 3 and human β-defensins (HBD) 1 to 3 mRNA were detected in peritoneal specimens. In addition, HNP1,3, HBD1, HBD2, and HBD3 proteins were detected using immunohistochemistry. Part B: HBD1 showed a constitutive expression in mesothelium, while HBD2 and HNP1,3 were associated with inflammation. Decreased expressions of HNP1,3 were observed in end-stage renal disease patients and in patients on peritoneal dialysis. Conclusions For the first time, the expression patterns of defensins in normal and damaged peritoneum have been described. The reduced expression of some defensins in end-stage renal disease is of potential clinical interest against the background of the frequent infective complications seen in peritoneal dialysis.

Histamine, among various "biologic-physiologic" abnormalities, is considered as a pathogenetic factor in chronic duodenal ulcer disease. The 10-30 per cent difference between its concentration in gastric and duodenal mucosa of patients compared to healthy controls, however, has to be demonstrated to be specific for the disease. It has to be shown to be neither a methodological artefact nor a common effect, concomitant factor or consequence. This study, after a series of pathogenetic trials examines systematic errors (biases) in the fluorometric-fluoroenzymatic histamine assay under the conditions of field studies including tests on specificity over a time period of 10 years. It concentrates on sensitivity (detection limits) and specificity of a standard technique described herein. A modified Shore procedure for large scale assays in human biopsies was developed including reference luminescence values for all reagents, cleaning material and glassware, reduction of OPD concentration to 0.05%, purification of n-heptan, omission of centrifugation steps in the extraction procedure and use of 2 ml 1 M HClO4 in the homogenization step to prevent losses of histamine due to adherence to the mechanical homogenizer. This assay was sensitive enough to measure histamine without difficulty in any biopsy taken. The detection limit was 3 ng/biopsy, but the smallest quantities of the amine ever obtained were 10.6 and 18.3 ng/biopsy (depending on both histamine content and biopsy weight). A series of problems had to be solved both in achieving and demonstrating specificity. It had to be defined not only for the assay in general, but also for assessing the difference in histamine content between ulcer patients and healthy controls. Exogenous more than endogenous fluorescing material interfering with the determination had to be excluded. A series of pitfalls were detected which had to be overcome in demonstrating the specificity of the assay by physicochemical and enzymatic tests. The specificity of the identification tests was more often impaired than the histamine assay itself. Fluorescing material interfering with the assay occurred in the homogenization, extraction and condensation steps, was found in water, OPD, the organic solvents, the cleaning material and in all kinds of plastic vessels. Plasticizers were shown by physicochemical characteristics including fluorescence spectra to be most likely responsible for this interfering material. Rules were developed to exclude such hazards in specificity in longterm pathobiochemical studies. Enzymatic identification test were applied to exclude endogenous fluorecing substances interfering with the standard technique. Simil