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K Thon

Publications and source records attributed to K Thon.

At least 19 recordsLinked to original sources
PubMed2000

Telomere length in different tissues of elderly patients.

Telomeres are supposed to play a role in cellular aging and might contribute to the genetic background of human aging and longevity. During the past few years telomere length has been measured in various human tissues. However, very little is known about the individual telomere loss in different tissues from the same donor. Therefore we have measured telomere restriction fragment (TRF) length in three unrelated tissues (leukocytes, skin and synovial tissue) of nine elderly patients (age range 73-95 years old). Dependent on the tissue specific proliferation rate we have found significantly shorter telomeres (6546+/-519 bp, mean +/- S.D.) in leukocytes compared to skin (7792+/-596 bp, P<0.01) and synovial tissue (7910+/-420 bp, P<0.001). In general, we have observed an inverse relationship between donor age and TRF length which becomes significant in leukocytes (P=0.04, R(2)=0.49) and skin specimens (P=0.006, R(2)=0.81). Interestingly, linear correlations (P values between 0.017 and 0.038, R(2) values between 0.54 and 0.79) were also obtained on comparison of telomere length in each pair of two different tissues from the same donor without taking donor age into account. This suggests that genetic determination of the regulation of telomere length is tissue-independent. Furthermore, our results indicate that TRF measurement in easily accessible tissues such as blood could serve as a surrogate parameter for the relative telomere length in other tissues.

Aged↗
PubMed2000

Perforated appendicitis: is laparoscopic operation advisable?

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.

Adolescent↗
PubMed1992

Peptic ulcer bleeding: medical and surgical point of view. Results of a prospective interdisciplinary multicenter observational study. DUSUK Study Group.

Various treatment policies and clinical disciplines compete for the treatment of bleeding peptic ulcer. In a prospective multicenter and interdisciplinary study performed during a 1-year period at ten hospitals in Düsseldorf, all patients admitted for peptic ulcer bleeding were recorded. The characteristics of patients admitted to surgical and to medical departments, the distribution of endoscopic treatment, indications for surgery, type of surgical procedures, and outcome were investigated. In the study period 387 bleeding peptic ulcers were recorded. Of these patients 82% were primarily admitted to medical and 18% to surgical departments. No differences in terms of severity of ulcer disease or bleeding activity were noted between the groups of medical and surgical patients. However, accompanying or underlying diseases were detected more often in patients admitted to medical departments. Endoscopy treatment was performed in the majority of patients with arterial spurting bleeding (88%) or a visible vessel (80%). Injection therapy with epinephrine or polidocanol was mainly used (78%). In 16% of cases the patients underwent operation; 44% of the patients primarily admitted to a surgical department were operated (medical departments, 10%). About half of the operated patients underwent emergency surgery; in the majority of cases resections were performed (gastric ulcer, 76%; duodenal ulcer, 56%). Overall mortality was 11%, with no difference between surgical and medical patients. A high mortality was observed in the subgroup of patients with late recurrent bleeding (27%). It is concluded that for optimal treatment of peptic ulcer bleeding intensive cooperation between physicians and surgeons is necessary, and that agreed and evaluated treatment policies are needed.

Aged↗
PubMed1992

Incidence and pattern of peptic ulcer bleeding in a defined geographical area. DUSUK Study Group.

Despite the introduction of effective medical treatment for peptic ulcer disease, no decrease in the incidence of bleeding has been observed. Unfortunately, most incidence studies rely on a questionable case ascertainment and poor data. We therefore conducted a prospective study, to achieve an unbiased estimate of incidence and pattern of peptic ulcer bleeding in Düsseldorf (Germany). In a 1-year period all patients with endoscopically verified peptic ulcer bleeding who were admitted to the departments of internal medicine or surgery in nine hospitals or seen by nine general practitioners offering endoscopic service were included in the study. Incidence rates were calculated in accordance with sociodemographic variables and expressed per 100,000 person-years of observation. The overall incidence of peptic ulcer bleeding was 51.4, with almost even rates for gastric (26.5) and duodenal (24.9) ulcer. Age was associated with an increased likelihood of bleeding in gastric ulcer patients of 19 per decade from about 40 years onwards (duodenal ulcer, 15). The incidence was about twice as high in men as in women (relative risk = 1.9). The pattern of peptic ulcer bleeding was similar in gastric and duodenal ulcers with regard to ulcer size, multiple lesions, and bleeding activity at endoscopy. However, patients with gastric ulcer bleeding had significantly more often accompanying or underlying diseases. No significant differences were observed between gastric and duodenal ulcer bleeding with regard to nonsteroidal antiinflammatory drug intake and ulcer history. The incidence rates in our study are in the upper range of the literature and comparable to rates from the USA and UK both before and after the introduction of H2 blockers. We hypothesize that the persistently high incidence rate is a superposition of two trends: higher incidences due to a more elderly and diseased population and more NSAID intake, and lower incidences due to effective medical treatment.

Adult↗
PubMed1991

Histamine and the stomach: chemical histamine assays.

Histamine assays in gastroduodenal tissues and body fluids are not an absolute objective of scientific interest but are related to the role of histamine in health and disease. Hence, the reliability of histamine assays has to be assessed in relation to this aim. Sensitivity and specificity of the chemical histamine assays are similar in tissues and body fluids. The modern developments in a fluorometric-fluoroenzymatic assay guarantee the highest sensitivity and specificity, especially by tests that monitor specificity in each single run of histamine determinations. Precision and accuracy of histamine measurement were especially investigated for the fluorometric assay. They included tests on the coefficient of variation over the whole concentration range, long-term precision with double-sample standard control charts, comparison of several methods for histamine assay including bioassay, and long-term accuracy with the use of Cusum charts. Finally, appropriate sample preparation, sample-taking, relevant body fluids and tissues, and the right time for sample-taking were evaluated in extended methodologic studies. Histamine assays are not just methods for a normal routine laboratory. Extended knowledge about histamine release and metabolism will be necessary to analyse data in this particular field with reasonable validity.

Animals↗
PubMed1991

Diagnostic emergency endoscopy in upper gastrointestinal bleeding--do we have any decision aids for patient selection?

The benefit of emergency endoscopy and therapeutic policies based on certain stigmata of bleeding has recently been demonstrated in patients with peptic ulcer hemorrhage. Applying a simple method of computer-aided diagnosis to a set of prospective data (n = 571) we investigated the question as to whether information on the history (28 variables) and clinical examination (8 variables) could be used to predict ulcer bleeding or certain stigmata of bleeding, with a view to deciding when to perform an emergency endoscopy in patients with upper gastrointestinal bleeding. The patients were assigned to either a high-risk group (probability greater than 0.50 for ulcer bleeding, arterial bleeding, etc.) or a low-risk group (p less than 0.50), and the prediction was compared with the actual findings at endoscopy. The results were disappointing, with an overall accuracy of 71% for the prediction of bleeding peptic ulcer and 71% for the prediction of a bleeding or non-bleeding visible vessel. Despite a relative risk of 2.8 for "bleeding ulcer" and 2.5 for "visible vessel" in the high-risk group, only 72% of all "bleeding ulcer" patients, and 69% of the "visible vessel" patients could be identified by the model. These results indicate that neither a bleeding ulcer nor stigmata of bleeding can be reliably predicted by the patient's history and clinical examination. Emergency endoscopy should therefore be performed in all patients with gastrointestinal bleeding.

Diagnosis, Computer-Assisted↗
PubMed1990

[Status of gastrectomy in the multi-modality therapy concept of primary non-Hodgkin's lymphoma of the stomach].

Retrospectively analyzed data of 41 patients with gastric non-Hodgkin lymphoma are presented with special regard to the required extent of gastric resection in multimodality treatment. Thirty lymphomas of low, 2 of intermediate and 9 of high grade malignancy were distributed on stage Ie in 44%, stage IIe in 15%, stage IIIe in 12% and stage IV in 29%. The cumulative 5 years survival rate was 85% for stage Ie and 55% for the stages IIe and IIIe. Stage IV showed a 3 years survival of 10%. The proximal part of the stomach was involved in 73%, polycentric lesions were found in 15%. The majority (71%) of the tumours showed an infiltrating growth, an invasion of the oesophagus and/or the duodenum was seen in 20%. Five patients (12%) had synchronous adenocarcinoma as second gastric tumour. Regarding our morphological and topographical data curative surgery for primary gastric lymphoma required total gastric resection.

Adult↗
PubMed1990

Prognostic scores in oesophageal or gastric variceal bleeding.

Numerous scoring systems have been developed for the prediction of outcome of variceal bleeding; however, only a few have been evaluated adequately. The object of this study was to improve the classical Child-Pugh score (CPS) and to test other scores from the literature. Patients (n = 82) with endoscopically confirmed variceal bleeding and long-term sclerotherapy were included in the study. Linear logistic regression (LR) was applied to different sets of prognostic variables with regard to 30-day mortality. In addition, scores from the literature were evaluated on the data set. Performance was measured by the accuracy and receiver-operating characteristic curves. The application of LR to all five CPS variables (accuracy, 80%) was superior to the classical CPS (70%). LR with selection from the CPS variables or from other sets of variables resulted in no improvement. Compared with CPS only three scores from the literature, mainly based on subsets of the CPS variables, showed an improved accuracy. It is concluded that CPS is still a good scoring system; however, it can be improved by statistical analysis using the same variables.

Esophageal and Gastric Varices↗
PubMed1989

[The value of computerized tomography for preoperative staging of stomach cancer].

The validity of computed tomography (CT) for the preoperative staging (TNM) of gastric carcinoma was studied in 74 patients, first in a prospective study, then under routine clinical conditions. Comparing CT-staging to intraoperative findings in the study patients showed correct assessment of the T-category in 70%, the N-category in 36%, and of both T and N in 26%. Validity was also low with 27% for both T- and N-staging when the CT was set against pathological-anatomical findings. The results in clinical routine were even more disappointing. The examination is of little value for deciding on operative indication and planning. Computed tomography therefore should not be part of a preoperative routine diagnostic assessment in gastric carcinoma.

Adult↗
PubMed1989

[Computer-assisted documentation in upper gastrointestinal endoscopy: experiences with routine use at 3 clinics].

The introduction of powerful and inexpensive personal computers (PC) enabled us to develop a documentation system for upper gastrointestinal endoscopy. The system was programmed using the database management system dBASE III. It works on-line, and no computer knowledge or additional staff is needed to run the system. It is now routinely used in the endoscopic units of three different hospitals. Features of performance are a menu-driven data input, automatic report generation and record retrieval, listing according to different criteria as well as other dBASE III facilities. This paper deals with the quality, time effort and user acceptance of the PC-aided system in clinical routine. The analysis showed a good data quality with respect to completeness and adequate use of terminology. Reliability and validity of the documentation were satisfactory considering the methodological problems encountered at their determination. The system was generally judged useful, but time effort was increased compared to conventional documentation.

Documentation↗
PubMed1988

[Choice of surgical procedure in esophageal cancer].

In a retrospective study results of surgical treatment of esophageal cancer by transthoracic and abdominal transhiatal approach are compared with each other. 70% of the patients (n = 21) had tumor stage III. The overall 30-day-lethality is 9.5%, being identical for the transthoracic (n = 10) and the transhiatal (n = 11) group with 10% and 9%, respectively. The frequency of postoperative, mainly pulmonary complications is equally distributed. The cumulative 3-years-survival-rate is 19%. However, a considerable difference among both approaches is obvious being 30% for group I and only 9% for group II.

Adenocarcinoma↗
PubMed1988

[Diagnostic strategies of the esophagus].

The oesophagus has a limited repertoire of symptoms but most of them are highly specific. Thus oesophageal disorders may often be diagnosed quite accurately on the sole basis of the patients clinical history. Nevertheless this preliminary diagnosis has to be verified or rejected by scientific methods. Particularly patients with the symptom "dysphagia" require a careful clinical workup to confirm or exclude malignancy. An exact knowledge of the reliability of all diagnostic methods leads to a rational diagnostic strategy, including preoperative investigations if surgery is required.

Deglutition Disorders↗
PubMed1987

Reliability and practicability of the fluorometric-fluoroenzymatic histamine determination in pathogenetic studies on peptic ulcer: detection limits and problems with specificity.

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

Biopsy↗
PubMed1987

[Principles of risk research in surgery: definition, calculation and clinical use in the problem of upper gastrointestinal hemorrhage].

In surgery, risk research is of great importance at the present time but is controversely discussed with contradictory definitions, calculations and applications. In this paper standardized and quantitative definitions of risk and risk factors using probabilities are given. A calculation of risk, risk factors and risk rates is performed using data from studies on bleeding duodenal ulcers. Possible applications of risk and risk factor research (risk analysis) in suitable treatment policies are demonstrated using data from patients with bleeding duodenal ulcers. The utility of this type of approach, using decision tree analysis, clearly manifests itself in the reduction of lethality. Objective and quantitative surgical risk research and its application as risk analysis using probabilities can improve patient care in standard surgical situations.

Duodenal Ulcer↗
PubMed1986

[Principles of surgical indications: aids in decision making].

Several types of clinical studies provide important decision aids for surgical indications. They include quantitative data on outcomes and utility analysis, graphic illustration of the various possibilities for decisions by decision trees, controlled clinical trials with data used in decision trees and--if these trials fail for several reasons--carefully conducted and documented prospective and retrospective trials. Items for defining the term "surgical indication" were illustrated by constructing a decision tree for treatment of chronic duodenal ulcer.

Diagnosis↗