Biomedical subjects

D Schilling

Publications and source records attributed to D Schilling.

At least 73 records · Page 4Linked to original sources

PubMed1998

Loop III region of platelet-derived growth factor (PDGF) B-chain mediates binding to PDGF receptors and heparin.

Site-directed mutagenesis of the platelet-derived growth factor (PDGF) B-chain was conducted to determine the importance of cationic amino acid residues (Arg160-Lys161-Lys162; RKK) located within the loop III region in mediating the biological and cell-association properties of the molecule. Binding to both PDGF alpha-and beta-receptors was inhibited by the conversion of all three cationic residues into anionic glutamates (RKK-->EEE), whereas an RKK-->SSS mutant also exhibited a modest loss in affinity for beta-receptors. Replacements with serine at either Arg160 (RKK-->SKK) or at all three positions (RKK-->SSS) had little effect on binding to alpha-receptors. Replacements with either glutamic or serine residues at any of the three positions also resulted in significant inhibition of heparin-binding activity. Furthermore, the RKK-->EEE mutant exhibited decreased association with the cell surface and accumulated in the culture medium as 29-32 kDa forms. Stable transfection of U87 astrocytoma cells with RKK-->EEE mutants of either the A-chain or the B-chain inhibited malignant growth in athymic nude mice. Despite altered receptor-binding activities, each of the loop III mutants retained full mitogenic activity when applied to cultured Swiss 3T3 cells. CD spectrophotometric analysis of the RKK-->EEE mutant revealed a secondary structure indistinguishable from the wild type, with a high degree of beta-sheet structure and random coil content (50% and 43% respectively). These findings indicate an important role of the Arg160-Lys161-Lys162 sequence in mediating the biological and cell-associative activities of the PDGF-BB homodimer, and reveal that the mitogenic activity of PDGF-BB is insufficient to mediate its full oncogenic properties.

Animals↗

PubMed1998

Helicobacter pylori infection: prevalence and clinical relevance in a large company.

Although gastrointestinal (GI) illnesses account for considerable sick absenteeism, there have been few workplace studies of GI disorders. We determined the prevalence of Helicobacter pylori infection by serology and assessed its relation to upper GI tract complaints, personal ulcer history, and family history of stomach cancer in 6,143 employees (mean age, 40.4 years) at BASF's main chemical production facilities in Ludwigshafen, Germany. Employees were recruited during occupational health clinic visits (n = 4,488) and through broad communications efforts (n = 1,655). Participation among clinic attendees was 66%, and this recruitment method was particularly effective in reaching shift employees. Positive immunoglobulin G (IgG) serology (38.2%), ulcers (4.9%), nonulcer dyspepsia (20.4%), and a family history of stomach cancer (6.1%) were common occurrences in this work setting. Further diagnostic evaluation and eradication therapy was recommended for 795 employees (12.9%), based on a combination of positive serology and either upper GI tract complaints or family stomach cancer history, and has been completed for 541 employees. A weak but consistent association was seen between positive serology and cigarette smoking, and shift work was found to be associated with positive serology, but not with ulcer or nonulcer dyspepsia occurrence.

Adolescent↗

PubMed1998

A prospective evaluation of magnetic resonance cholangiopancreatography in patients with suspected bile duct obstruction.

BACKGROUND: The value of magnetic resonance cholangiopancreatography (MRCP) is under debate. AIMS: To assess the diagnostic accuracy of MRCP and endoscopic retrograde cholangiopancreatography (ERCP) and to determine whether MRCP may help to prevent unnecessary interventional procedures. METHODS: Eighty six patients with suspected common bile duct obstruction who presented between January and December 1996 were enrolled. Twenty six were excluded due to anatomical reasons or because MRCP or ERCP could not be performed successfully. Results of MRCP were interpreted by two radiologists and a gastroenterologist unaware of clinical diagnosis. Final diagnosis was determined by ERCP and histopathological findings or a follow up of at least 12 months. RESULTS: MRCP images of diagnostic quality were obtained in all 60 patients. Thirteen patients had a clear bile duct. Sensitivity and specificity for the detection of any abnormality (n=47) were 89% and 92%, and for the detection of malignancy (n=27) 81% and 100%, respectively. These results were equivalent to the respective figures of ERCP (91% and 92% for any abnormality, and 93% and 94% for malignant diseases). CONCLUSIONS: MRCP is as sensitive as ERCP in the evaluation of bilary tract diseases. As the specificity of this non-invasive technique is close to 100%, MRCP may prevent inappropriate invasive explorations of the common bile duct and pancreatic duct.

Adolescent↗

PubMed1998

[Possibilities and limits of invasive endoscopy in treatment of endoscopic surgical complications after operations of the biliary tract].

Minimal invasive methods compete with surgical treatment in the therapy of complications after cholecystectomy. We demonstrate our results of endoscopic therapy. 52 patients with postoperative complications (39 stenoses, 5 leakages, 6 stenoses and leakages, 2 complete obliterations of bile duct) were treated by transpapillary or transhepatic biliary drainage over a time period of 12 months. In 73% of patients who completed the therapy protocol successful treatment was possible. In 4 cases a restenosis occurred. 4 patients underwent surgical treatment. We think endoscopic management is the therapy of first choice for postoperative biliary complications. Biliary stricture should be dilatated for 12 months by biliary endoprosthesis, leakage can be drained for shorter time periods.

Adult↗

PubMed1997

Cure with omeprazole plus amoxicillin versus long-term ranitidine therapy in Helicobacter pylori-associated peptic ulcer bleeding.

BACKGROUND: Long-term prophylaxis with ranitidine reduces the risk of recurrent bleeding in patients with a history of bleeding peptic ulcers. To date, no randomized study has been performed to compare cure of Helicobacter pylori infection versus H2 blocker prophylaxis in patients with bleeding peptic ulcer. METHODS: In a prospective randomized study, 95 consecutive patients with H. pylori-associated peptic ulcer bleeding were randomized to either ranitidine prophylaxis (150 mg at night) for 2 years or to H. pylori-eradication with omeprazole 60 mg twice daily plus amoxicillin 750 mg three times daily for 10 days. RESULTS: (Intention-to-treat analysis). Forty-eight patients were enrolled in the ranitidine group; 47 in the omeprazole-plus-amoxicillin group. Mean follow-up was 576 days (77 to 730). Ulcer recurrence rate was 31.3% in the ranitidine group (group 1) versus 6.37% in the eradication group (group 2; p = 0.0018). More patients had recurrent bleeding in group 1 (8.3%) than in group 2 (4.2%) but we were not able to show a statistically significant difference with respect to recurrent bleeding between groups (p = 0.29). Definite cure of H. pylori infection was achieved in 89.3%. CONCLUSIONS: Cure of H. pylori infection reduces recurrence of peptic ulcer and therefore rebleeding more effectively than does long-term maintenance therapy with an H2 blocker.

Adult↗

PubMed1997

Value of magnetic-resonance cholangio-pancreatography (MRCP) after unsuccessful endoscopic-retrograde cholangio-pancreatography (ERCP).

BACKGROUND AND STUDY AIMS: The present study tries to evaluate the success rate of MRCP when two attempts by experts to perform ERCP in a center failed. PATIENTS AND METHODS: From March 1996 to December 1996 thirteen patients fulfilled the inclusion criteria. The MR cholangiopancreatograms were acquired using commercially available software in a clinical MR scanner (Magnetom Expert 1 T-Scanner, Siemens, Erlangen, Germany). MRCP utilized heavily T2-weighted turbo-spin echo sequences with fat supression (HASTE). Maximum intensity projection (MIP) of the pancreatic duct and biliary tree was then carried out. Additionally, T1-weighted sequences were obtained using the breath-hold technique. RESULTS: The MRCP images were of diagnostic quality in all 13 patients. In five cases the diagnoses detected by MRCP were followed by an interventional procedure. One patient showed a pancreatic pseudocyst, that was percutaneously drained using ultrasound guidance. In three cases we found benign bile duct obstruction, all of which were successfully treated by percutaneous transhepatic drainage. In one patient choledocholithiasis was diagnosed, the stone was successfully managed by percutaneous transhepatic extraction. CONCLUSION: MRCP is the method of choice in cases where ERCP is incomplete or where duct cannulation is not possible. A further advantage of MR imaging is the fact that it may provide complementary information about the whole region of interest, thus detecting the cause of duct pathology in many cases.

Aged↗

PubMed1997

Arthralgia as an early extraintestinal symptom of Whipple's disease. Report of five cases.

Five patients with Whipple's disease all suffered from arthralgia for a long time (15 years in one case) before developing gastrointestinal or other symptoms. In all patients, arthralgia was seronegative, and there was no evidence of joint destruction. Arthralgias were symmetric and migrating. Whipple's disease is part of the differential diagnosis of enteropathic arthralgia. Thereby, the polymerase chain reaction can be a helpful tool to prove Whipple's disease in difficult differential diagnosis.

Arthralgia↗

PubMed1997

[Long-term results of endoscopic balloon dilatation of ulcer-induced pyloric stenoses--follow-up of 25 patients].

Long-term results of the "through the scope balloon dilatation" for treatment of benign pyloric stenosis are lacking. Therefore we retrospectively analyzed 25 patients treated by balloon dilatation because of benign pyloric stenosis between 1986 and 1995. The mean age was 63 years (18-88 years), there were twelve men and 13 women. The mean follow-up period was 38 months (twelve to 120 months). 92% (23 patients) underwent successful dilatation. 20% (five patients) presented with recurrent obstruction. They were treated again and none of them has had symptoms up to now. There were no complications due to dilatation. Through the scope balloon dilatation is a successful and cost effective therapy for benign gastric outlet obstruction also in long-term follow-up.

Adolescent↗

PubMed1996

[Severe complications in diagnostic laparoscopy. 9 years experience in 747 examinations].

BACKGROUND: Despite the introduction of non-invasive imaging procedures, diagnostic laparoscopy is still indicated in suspected liver cirrhoses, cancer staging and ascites or fever of unknown origin. Although the use of laparoscopy decreased over the last decade, some centers still have much experience and their complication rates are of special interest. PATIENTS AND METHODS: The complication rate of 747 patients undergoing a diagnostic laparoscopy in our clinic during the last 9 years is listed retrospectively, and the respective therapy is examined. RESULTS: Severe complications were found in 11 cases (1.5%): 6 bleeding complications, 2 bowel perforations and 3 other complications. Five of these 11 patients had to be operated on (45%). One patient with metastatic gastric cancer died of a multiple organic failure following a lararoscopic tumor biopsy (0.13%). CONCLUSION: The diagnostic laparoscopy is of significant value and has still a low complication-rate in centers with special experience.

Abdominal Neoplasms↗

PubMed1996

Idiopathic mesenteric varices causing lower gastrointestinal bleeding.

We report a case of lower gastrointestinal bleeding caused by idiopathic mesenteric varices. A 25-year-old man presented with a history of two episodes of lower gastrointestinal bleeding without transfusion. Colonoscopy revealed varices of the entire colon and terminal ileum. Intravariceal blood flow was demonstrated by dopplersonography. Vascular abnormalities were excluded by selective angiography of the upper and lower mesenteric artery. No therapy was given without a new episode of bleeding and there has been no further bleeding to date (a period of 14 months). Mesenteric varices are a rare cause of lower gastrointestinal bleeding, almost always associated with portal hypertension. The varices are idiopathic in only a few cases. The therapy depends on the intensity of bleeding, but resection is the most frequent treatment.

Adult↗

PubMed1994

[Benign bile duct stenosis--conservative management as long as possible?].

The clinical course of 37 patients (15 female, 22 male) treated endoscopically for benign biliary stenosis was analyzed retrospectively. Patients with chronic pancreatitis (n = 20) were compared to those (n = 17) with biliary stenosis due to other reasons, postoperative strictures in most cases. Each patient received at least one 10- or 11.5-French endoprosthesis. The liver enzyme and serum bilirubin levels returned to normal or slightly elevated levels. The average time until exchange or extraction of the prosthesis was 11.4 (range 2 to 33) months in patients with chronic pancreatitis and 5.1 (0.5 to 21) months in patients with postoperative strictures. The therapy was completed by extraction of prosthesis in six patients with chronic pancreatitis (30%) and in 14 patients with stenosis due other reasons (82.3%). None of the patients died of complications related to endoscopic therapy.

Adult↗

PubMed1994

[The feasibility of ultrasonography for the evaluation of stomach motility disorders].

The value of measuring gastric emptying time by ultrasonography in disorders of gastric motility was first assessed in a control group (26 men, 24 women; mean age 51 [23-83] years. Some were healthy volunteers, others were patients without any gastrointestinal disease, the results serving to standardize the method (planimetry of the antrum; 300 ml water as test substance). The mean gastric emptying time (GET) was 24.9 +/- 4.7 min. After this the method was applied in 48 patients (29 men, 19 women; mean age 57.5 [15-90] years) with diabetes type I (n = 14) or II (n = 34) and 59 patients (18 men and 41 women; mean age 54.8 [26-74] years) with functional dyspepsia. GET was 35.9 +/- 12.7 in the diabetics, significantly longer than normal (P < 0.0001). 24 diabetics (50%) had a prolonged GET (> or = 40 min) independent of type, duration and treatment of the diabetes, but more common if the blood sugar level was poorly controlled and there was late diabetic neuropathy. GET was also significantly prolonged in patients with functional dyspepsia (31.4 +/- 9.7 min; P < 0.055). There was a positive correlation with the clinical dismobility type of the dyspepsia. It is concluded from the findings that ultrasonographic measurement of GET successfully identifies noninvasively abnormal gastric motility in different types of disease.

Adolescent↗

PubMed1991

Carbohydrate-electrolyte solutions during field training: an overview.

The rationale and methods of evaluating two carbohydrate-electrolyte solutions at a field training exercise in hot weather are presented in this overview. The carbohydrate-electrolyte solutions were formulated to produce a multipurpose replacement beverage which could satisfy diverse requirements of troops working in hot climates. Several uses of these beverages include replacement of electrolytes and fluid while in Mission Oriented Protective Posture IV, fluid replacement for mild heat casualties, and oral rehydration therapy for treatment of diarrheal losses.

Adult↗

PubMed1980

[Thoracical circular focus opacities--a problem of differential diagnostics (author's transl)].

Reported on tumourlike circular focus opacities in the thoracic X-ray photogramms of 34 patients, 27 of them were discovered by mass x-ray surveys. They include: 13 organoid tumours, 1 bronchial adenoma, 2 mucodermoid, 1 cystic adenocarcinoma of bronchus, 1 fibroma, 1 reticulo-cytoma, 1 bronchial papilloma, 7 cystic tumours, partially located in the mediastinum, 3 intrapulmonary malformations of blood vessels, 1 mediastinal neurinoma, and 3 cases with suspicion of organoid tumours. 29 patients had to undergo an operation. Finally the authors give a review of literature of indication for surgical treatment, and they represent guidelines for the medical expert assessment fitness for the National Service.

Blood Vessels↗

PubMed1977

Facility location: a review of context-free and EMS models.

EMS location models are those formulated to address specific problems of emergency medical services systems; context-free location models are those developed without reference to particular applications. The literature on these two types of public facility location models is reviewed, and the development of the maximal covering model from several earlier context-free models is described, with emphasis on problem statements and articulation of service objectives. An application of the maximal covering model to fire truck location points up the ability of this model to handle multiple objectives; its ability to compare alternative solutions gives it great utility for planning and evaluating EMS systems of a wide range of complexity. Potential applications of the maximal covering model are discussed regarding EMS problems involving multiple time standards and service objectives, location of special equipment, and siting of fixed facilities.

Delivery of Health Care↗

PubMed1976

[Pancreatic pain: a clinical-experimental study].

In 26 patients endoscopic-radiologic pancreography routinely performed caused severe pain with certain origin from pancreatic glan. Pain could be stopped immediately and with constant effect by lingual application of nitroglycerine. According to these informations we suppose that pancreatic pain is started by vascular reactions and ischemia. The good effect of nitroglycerine is worth a control in patients with common acute pancreatitis.

Endoscopy↗

PubMedDate not supplied

Predictions and associations of cholecystectomy in patients with cholecystolithiasis treated with extracorporeal shock wave lithotripsy.

Extracorporeal shock wave lithotripsy (ESWL) is effective in the treatment of symptomatic cholecystolithiasis in well-selected patients. We analyzed the predictors of cholecystectomy in a large series of gallstone patients after ESWL. This was a retrospective follow-up cohort-study of consecutive patients undergoing ESWL for symptomatic cholecystolithiasis over a 9-year period. It was possible to analyze a total of 297 patients; there were 211 women and 86 men, with a mean age of 52 years (range, 8-81 years). Patients that had been cholecystectomized after ESWL were compared to patients with their gallbladder still in situ and determinants of cholecystemctomy in terms of clinical, stone, and gallbladder parameters and symptoms analyzed. The mean duration of follow-up was 99 months (range, 27-134 months). During follow-up, 106 (36%) patients underwent a cholecystectomy at a mean of 34 months (range, 0-127 months) after ESWL. Histological data showed a normal gallbladder wall in only 4 cases; 101 examinations revealed some kind of (chronic) inflammation, which was not different from histological gallbladder results in patients without prior lithotripsy. Three gallbladder polyps were found, but no carcinoma. Cholecystectomy after ESWL of gallbladder stones was strongly associated with persitent and/or renewed biliary symtoms. Nevertheless, only three of four patients became asymptomatic after CE. Thus, ESWL proved to be a valuable organ-preserving alternative to cholecystectomy in selected patients.

Adolescent↗

PubMedDate not supplied

Inheritance of stereotyped gibbon calls.

Little is known about how vocal patterns develop in non-human primates, mainly because suitable controlled experiments are difficult to carry out on these animals. Results of isolation experiments and observations of interspecific hybrids suggest no greater role for vocal learning than exists in many other vertebrates, and less than has been found in birds. We have now studied vocal patterns of hybrids between white-handed gibbons (Hylobates lar) and pileated gibbons (Hylobates pileatus) in natural mixed-species groups, in a zone of interspecies contact in central Thailand, and in some captive mixed-species groups. We find that in female hybrids, the patterns of the loud and stereotyped 'great-calls' show no evidence of learning from parents, and appear to be under strong genetic control. Daughters maturing in groups with genetically unlike parents develop great-calls unlike those of their mothers, even though these calls develop only while the daughters sing simultaneously with their mothers.

Animals↗