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Biomedical subjects

A Thiede

Publications and source records attributed to A Thiede.

341 records · Page 19Linked to original sources

Combination of endoscopic argon plasma coagulation and antireflux surgery for treatment of Barrett's esophagus.

Columnar-lined epithelium with specialized intestinal metaplasia of the esophagus (i.e., Barrett's esophagus) is a premalignant condition caused by chronic gastroesophageal reflux disease. Progression of intestinal metaplasia may be avoided by antireflux surgery, whereas regeneration of esophageal mucosa could be achieved by endoscopic argon plasma coagulation (EAPC). The aim of this prospective study was to show the early results of a combination of EAPC and antireflux surgery. Thirty patients with Barrett's esophagus were treated between August 1996 and December 1999. Regeneration of esophageal mucosa was achieved with several sessions of EAPC under general anesthesia. All patients were receiving a double dose of proton pump inhibitors. Endoscopic follow-up was performed 6 to 8 weeks after the last session. Antireflux surgery (Nissen [n = 26] or Toupet [n = 4] fundoplication) followed complete regeneration of the squamous epithelium in the esophagus. One year after laparoscopic fundoplication and EAPC follow-up with endoscopy and quadrant biopsies of the esophagus, 24-hour pH monitoring and esophageal manometry were performed. All 30 patients showed complete regeneration of the squamous epithelium after a median of two sessions (range 1 to 7) of EAPC. Twenty-two patients underwent 1-year follow-up studies. All showed endoscopically an intact fundic wrap. Recurrence of a 1 cm segment of Barrett's epithelium without dysplasia was present in two patients, both of whom had recurrent acid reflux due to failure of their antireflux procedure. Our results indicate that the combination of EAPC and antireflux surgery is an effective treatment option in patients with Barrett's esophagus with gastroesophageal reflux disease. Long-term follow-up of this therapy is necessary to evaluate its effect on cancer risk in Barrett's esophagus.

Adult↗

Quality of life following laparoscopic gastric banding in patients with morbid obesity.

In a prospective study of 188 patients with morbid obesity, the time-dependent changes in the quality of life of individual patients were analyzed following laparoscopic gastric banding (LGB). These 188 patients (148 females and 40 males; age 19 to 59 years; body mass index 33 to 72 kg/m(2)) underwent evaluation of the LGB according to a strict protocol that included psychological testing using standardized instruments, detailed medical evaluation, upper gastrointestinal function studies, and evaluation of quality of life using the Gastrointestinal Quality of Life Index (GIQLI). Following this evaluation, 73 patients (57 females and 16 males; age 37 years [range 19 to 59 years]; body mass index 48 kg/m(2) [range 37 to 72 kg/m(2)]) underwent LGB and were followed up for 2 years focusing on weight loss, postoperative morbidity, weight-related comorbidity, and quality of life. The results demonstrate that LGB is well able to allow for a significant loss of excess weight and a significant improvement in patients' quality of life, both after a rather short period of time after surgery and at a continuous rate throughout the follow-up. The price for this success that was found in approximately 90% of patients is a complication rate of 38%; 85% of these patients, almost one third of all patients, must undergo some type of revision surgery. However, once the complications are resolved, these patients achieve the same level of weight loss and improvement in quality of life as patients with an uncomplicated postoperative course.

Adult↗

Variability in the composition of physiologic duodenogastric reflux.

Duodenogastric reflux has long been associated with various diseases of the foregut. Even though bile is often used as a marker, duodenogastric reflux consists of other components such as pancreatic juice and duodenal secretions. The aim of this study was to investigate the occurrence of duodenogastric reflux, its components, and the variability of its composition in normal subjects. Twenty healthy volunteers (7 men and 13 women) whose median age was 24 years underwent combined 24-hour bilirubin and gastric pH monitoring and intraluminal gastric aspiration. All probes were placed at 5 cm below the lower border of the lower esophageal sphincter. Aspiration was performed hourly and at any time when bilirubin and/or pH monitoring showed signs of duodenogastric reflux. Elastase and amylase were measured in the aspirate. All volunteers had episodes of physiologic duodenogastric reflux. A total of 70 episodes of duodenogastric reflux were registered with a median of three episodes (range 1 to 8) per subject. Most bile reflux occurred separately from pancreatic enzyme reflux. Pancreatic enzyme aspirate was significantly more often associated with a rise in pH in comparison to bile reflux (P <0.01). Duodenogastric reflux is a physiologic event with varying composition. Both bile and pancreatic enzyme reflux frequently occur separately. These findings could explain the disagreement regarding assessment and interpretation of duodenogastric reflux in the past. Thus monitoring of duodenogastric reflux requires more than the detection of just one component.

Adult↗

Adjuvant therapy for gastric adenocarcinoma with the apoptosis-inducing human monoclonal antibody SC-1: first clinical and histopathological results.

In a first clinical trial with the apoptosis-inducing human antibody SC-1 eight patients with poorly differentiated stomach adenocarcinoma of diffuse-type received 20 or 30 mg of purified SC-1 antibody intravenously, followed 24 or 48 h later by gastrectomy and lymphadenectomy. In seven cases a significant induction of apoptotic activity was measured in primary tumors as compared with earlier biopsy material and in five patients a significant regression of tumor mass could be determined histopathologically. No toxic crossreactivity was observed with normal tissue or organs of patients.

Adenocarcinoma↗

Progress in experimental intestinal transplantation in small animal models.

The unique immune response after small bowel transplantation (SBT) has been the subject of extensive research using small animal models in rats and mice. These animals are inexpensive, for most societies ethically acceptable and the existence of inbred strains allows for reproducibility and defined immunobiological conditions. The basic immunological reactions, such as graft-versus-host-reactions (GVHR), host-versus-graft-reactions (HVGR), a combination of both reactions, chronic rejection and tolerance have been described. Almost all immunosuppressive agents of proven or potential clinical relevance have been tested for their efficacy in small bowel transplantation. All techniques which are applied to intestinal transplantation in humans including multiorgan transplantation, can also be performed in rats. Intestinal transplantation in mice is methodically restricted to heterotopic transplantation. The mouse however, offers several advantages compared to the rat model. A large number of congenic and knockout strains is available as well as many analytical tools. In the future, intriguing new insights into the unique immunological mechanisms of allograft rejection will be discovered using murine models.

Animals↗

Improved sensitivity of fuzzy logic based tumor marker profiles for diagnosis of pancreatic carcinoma versus benign pancreatic disease.

BACKGROUND: The definite diagnosis of pancreatic tumors of unknown origin remains a clinical challenge. Imaging techniques may fail to differentiate malignant tumors from inflammation, especially in chronic pancreatitis. In a considerable number of cases, the definitive diagnosis needs laparotomy. Single tumor markers as CA 19-9 or CEA are of limited value in these cases because of their limited sensitivity and specificity. This study was performed to find out, whether a classification method based on fuzzy logic analysis of tumor marker profiles is feasible in patients with pancreatic carcinoma and benign pancreatic disease. PATIENTS AND METHODS: Tumor markers and other clinical and laboratory parameters of 74 consecutive patients, either with histologically proved pancreatic carcinoma (n = 43) or presumed benign pancreatic disease (n = 31) assessed by ultrasound, endoscopic retrograde pancreatography, or computed tomography were analysed in order to detect their diagnostic value in the multi-dimensional approach of fuzzy logic analysis. RESULTS: Given a specificity of 95%, sensitivity was considerably increased by the fuzzy logic method (83%) compared with the best single tumor marker CA 19-9 (65%). CA 19-9, CYFRA 21-1 and CA 15-3 gave the most considerable contributions to the classification system, whereas CEA, CA 125, CA 72-4, AFP, liver enzymes, lipase, amylase, bilirubin, and ferritin were of no or little value. CONCLUSIONS: Tumor marker profiles analysed with the fuzzy logic method may have an improved sensitivity compared with single standard tumor markers. The diagnostic efficacy should be proved in patients with pancreatic tumors of unknown origin.

Adult↗

[Partially common antigenicity of macrophages, epitheloid cells and foreign body giant cells. Experimental studies on rats].

QUESTION: By means of antimacrophage sera it is possible to demonstrate partially common antigenicity of monocytes with peritoneal macrophages, reticulum cells capable of phagocytosis, mast cells and Kupper's cells. The authors continued these studies important for the explantation of cytogenetical interrelations using a special method on epitheloid and giant cells of rats. The experiments aimed for the detection of possible partially common antigenicity with the above mentioned monocytes/macrophages system.

Animals↗

Monocytogenic endothelialization in dacron grafts. Experimental studies on rats.

The cytogenetic relationship between cells of the hematopoetic system and prosthesis lining cells is still not known. The purpose of this experimental study was to determine to what degree blood monocytes may be transformed into those cells which line the inner surface of vascular grafts. Immunological identical rats (donors = 25) were pretreated with a total dose of 150 micrograms C 3H-thymidine. In 25 recipient rats of the same strain the infrarenal aorta had been replaced by a vascular graft of dacron (1.8 mm theta) by using microsurgical techniques. Arteriovenous cross-transfusion was installed in pairs of the donor and recipient animals allowing for mixing the total blood volumes of both many times. Following sacrifice of the recipients the grafts and the area of anastomosis were studied autoradiographically. In all animals labelled monocytes were found in the graft wall with a marking index (MI) running between 1.5% to 5.5%. The marking index of the prosthesis lining cells was 1.9% to 3.4%. In 6 animals the anastomotic area was labelled and the MI run from 1% to 7.5%. With this new experimental model we ascertained that blood monocytes have capability of transformation: our results would indicate the hematogenic origin of new endothelial cells on prosthetic vascular surface by transformation of blood monocytes. This appears to apply to the prosthetic wall as well as the inner surface lining cells and the neighbourhood of the anastomotic area.

Animals↗

Pseudo-endothelial cell growth on auto-alloplastic vascular prostheses. Experimental studies on rats.

Pseudo-endothelial cell growth on Sparks' auto-alloplastic vascular prostheses which had been grafted in the arterial circulatory system are examined by light- and electron microscopy at different intervals after application. The obtained data clarify that in future we should speak of prosthetic endothelium or lining cells when referring to those cells which line the inner surface of prostheses; the present study reveals that these cells lack some important criteria, e.g. complete basement membrane and intercellular bridges, by which real endothelial cells are distinguished. The rapid and complete growth of lining cells, expected to accompany use of Sparks' prostheses, could not be confirmed by the present experiments. Using a new microsurgical experimental model in the rat, we were able to show that even in a small animal species prosthetic arterial replacement is possible. Hereby, an important contribution has been made to microsurgical work in the field of experimental vascular surgery with a technique hitherto unknown in the literature.

Animals↗