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T Schulz

Publications and source records attributed to T Schulz.

At least 19 recordsLinked to original sources
PubMed2006

Exercise associated genes in rat colon mucosa: upregulation of ornithin decarboxylase-1.

Epidemiology has revealed that physical activity is an important lifestyle factor that reduces the risk of colon cancer. However, the underlying mechanisms of this protective effect have so far not been defined. The aim of this study was to identify molecular targets of physical activity in rat colon mucosa by employing our voluntary exercise model. Twenty male rats underwent a 12-week exercise program, with 9 additional rats serving as a control group. Running distances, body weights and heart weights as measures of physical adaptations were recorded, and changes in mRNA steady-state levels of marker genes involved in vascularization (VEGF, HIF-1 alpha, ODC-1), apoptosis (Bcl-2, PPAR gamma) and prostaglandin synthesis (COX-2) were determined by qRT-PCR. The four housekeeping genes GAPDH, beta-actin, 18S and ALDA served as reference genes. Recorded running distances showed great inter-individual differences resulting in three different groups of low (L-EX, < 2629 m/night; n=5), moderate (M-EX, 3003 - 7458 m/night; n=10) and high (H-EX, > 8314 m/night; n=5) physical activity. The M-EX and H-EX group revealed significant (p<0.05) adaptive changes with an increase in heart mass per kg body weight and a decrease in mean body weight. Amongst the marker genes studied by mRNA expression analysis only ODC-1 appears to be differentially expressed. Its 1.8-fold increased steady-state mRNA level in the H-EX group suggests that synthesis of polyamines may be increased by physical activity. This new finding could provide a link between extensive physical activity and its protective effects on colon cancer development.

Animals↗
PubMed2006

Open versus laparoscopic appendicectomy: a critical review.

BACKGROUND: The benefit of laparoscopic appendicectomy remains unclear. We have analysed available randomised studies comparing laparoscopic and open appendicectomy regarding their clinical pitfalls and statistical relevance. METHODS: Thirty eight studies were analysed in terms of the following aspects: A. clinical problems (e.g., expertise of the surgeons, pre- and postoperative antibiotic treatment, definition of complications, blinding of outcomes) and B. statistical problems (e.g., definition of primary and secondary outcomes, power and sample size, statistical methods, confidence intervals, comparability of groups and studies). RESULTS: Most of the studies have clinical and statistical pitfalls. The most important pitfalls are the uncertain expertise of the operating surgeons, blinding, and the exploratory nature of the studies. Our analysis aims at giving useful information for the appraisal of existing studies and the conduct of further studies. It also gives some preliminary results. CONCLUSIONS: More than twenty years after Semm performed the first laparoscopic appendicectomy, it is necessary to clarify the superiority of laparoscopic or open appendectomy with well-defined, carefully designed randomised studies.

Appendectomy↗
PubMed2006

[Three-dimensional visualization of CT of the neck for surgical planning].

BACKGROUND: Surgical planning in ENT profits from computer assisted preoperative visualization and planning. The informative capability is to be improved by three-dimensional illustrating of the preoperative available data. The possibility of a 3-D-visualization of lymph nodes stands in the center of the interest. METHODS: 16 CT data sets with a tumor-classification of T1N1 or higher were included. Altogether 720 pseudo-3-D-illustrations were provided with an average of 9.3 objects. Current algorithms were used for the segmentation and visualization and the results were divided in three classes. RESULTS: The average time requirement for visualization and segmenting amounted to 122 minutes, the minimum value is at 61 minutes per data set. Automatic segmenting succeeded only with structures with clear grey tone differences to the environment. In all other cases an additional manual interaction had to take place. CONCLUSIONS: 3-D-Visualising of CT of the neck represents a new quality in preoperative planning. A clear trend at increasing detail loyalty and information efficiency showed up in the groups of B and C. It is possible to make from these pictures a quantitative statement on surgery relevant infiltration. Likewise conceivable are the postoperative quality control or planning and process control of a postoperative radio-chemotherapy. The automatic algorithms can be estimated as reliable. Application is still far from a clinically efficient use. With the rising efficiency of the computing systems, the improved software and the imaging systems the problems mentioned are, however, solvable.

Algorithms↗
PubMed2006

[Toxicogenetics and toxicogenomics. Relevance and application in occupational health].

Xenobiotic metabolising enzymes modify most organic compounds into water soluble compounds. Sequence variations of these enzymes can lead to significant interindividual differences in the metabolism of xenobiotics. This review covers important sequence variations of phase I (cytochrome P450) and phase II (glutathion S-transferases, N-acetyltransferases, sulfotransferases, UDP-glucuronosyl transferases) enzymes and elucidates the significance for occupational health. At the present time, the determination of various sequence variations is not suitable for an individual risk assessment in occupational health.

Acetyltransferases↗
PubMed2006

[Accuracy and precision in the evaluation of computer assisted surgical systems. A definition].

Accuracy represents the outstanding criterion for navigation systems. Surgeons have noticed a great discrepancy between the values from the literature and system specifications on one hand, and intraoperative accuracy on the other. A unitary understanding for the term accuracy does not exist in clinical practice. Furthermore, an incorrect equality for the terms precision and accuracy can be found in the literature. On top of this, clinical accuracy differs from mechanical (technical) accuracy. From a clinical point of view, we had to deal with remarkably many different terms all describing accuracy. This study has the goals of: 1. Defining "accuracy" and related terms, 2. Differentiating between "precision" and "accuracy", 3. Deriving the term "surgical accuracy", 4. Recommending use of the the term "surgical accuracy" for a navigation system. To a great extent, definitions were applied from the International Standardisation Organisation-ISO and the norm from the Deutsches Institut für Normung e.V.-DIN (the German Institute for Standardization). For defining surgical accuracy, the terms reference value, expectation, accuracy and precision are of major interest. Surgical accuracy should indicate the maximum values for the deviation between test results and the reference value (true value) A(max), and additionally indicate precision P(surg). As a basis for measurements, a standardized technical model was used. Coordinates of the model were acquired by CT. To determine statistically and reality relevant results for head surgery, 50 measurements with an accuracy of 50, 75, 100 and 150 mm from the centre of the registration geometry are adequate. In the future, we recommend labeling the system's overall performance with the following specifications: maximum accuracy deviation A(max), precision P and information on the measurement method. This could be displayed on a seal of quality.

Equipment Failure Analysis↗
PubMed2006

[Nasal dermoid and sinus cysts in patients with cleft malformations].

BACKGROUND: Nasal dermoid sinus cysts are uncommon congenital lesions. They are usually isolated occurrences and are not associated with syndromes or additional malformations. The coincidence of both, cleft malformations and nasal dermoid sinus cysts, has seldom been reported. CASE REPORTS: Within the last 2 years two patients with reconstructed cleft lip and palate and additional nasal dermoid sinus cysts underwent surgical removal. One patient with bilateral complete cleft lip exhibited a fistula from the medial third of the nasal dorsum up to the glabella. Another patient with unilateral cleft lip and Peters' plus syndrome had undergone removal of a nasal dermoid sinus cyst 12 years ago and was referred for management of recurrent disease. DISCUSSION: Concerning the common cleft-dependent nose malformations with no midline nasal masses, there are reasons for the assumption that a coincidence of both anomalies might be accidental. Especially in Peters' plus syndrome no frequent occurrence of nasal dermoids has thus far been documented. However, the proximity and temporal closeness of an embryological pathway of the frontonasal region and lip development could also argue for a unique formation of both lesions. Complete surgical removal and plastic reconstruction simultaneously or in a second step are recommended.

Adolescent↗
PubMed2006

[Radiation exposure with 3D rotational angiography of the skull].

PURPOSE: Determination and comparison of radiation exposure for examinations of the skull with unsubtracted 3D Rotational Angiography (3D RA) and 2D Digital Subtraction Angiography (2D DSA). MATERIALS AND METHODS: Measurements were carried out with a skull of an Alderson phantom for 3D RA and for 2D DSA in p. a. and lateral projections using an Innova 4100 angiography system with a digital flat panel detector from GE Healthcare. 45 thermoluminescent dosimeters TLD 100H from Harshaw were placed inside the phantom to measure organ doses. In addition the dose area product was recorded and the effective dose was calculated using the Monte Carlo program PCXMC. RESULTS: For a biplanar DSA run (lateral and p. a. projection), the organ doses were 4 to 5 times higher and the effective dose was 4 times higher than for a 3D RA even though the number of images for the two DSA runs was only half of that for 3D RA. CONCLUSION: The radiation exposure for unsubtracted 3D RA using a flat panel detector is significantly lower than for biplanar DSA. Using 3D RA in place of 2D DSA can reduce the radiation exposure of patients in neuroradiology procedures.

Angiography, Digital Subtraction↗
PubMed2005

Comparative investigation of alloplastic materials for hernia repair with improved methodology.

BACKGROUND: A variety of alloplastic materials are used for hernia repair. We discuss the long-term stability and possible shrinkage of these materials. In the past, measurement of pore sizes was used to study the physical properties of alloplastic meshes. The aim of this study was to evaluate the measurement of pore sizes with regard to its correlation to possible mesh alteration. METHODS: The water absorption of different polypropylene (PP) and polyester (PE) mesh materials under defined conditions was studied. For shrinkage studies, meshes were stored in formaldehyde, distilled water, saline solution, trypsin solution, urea solution, and hydrogen peroxide. The measurement of the relation between material and pore was evaluated to investigate the potential shrinking and enlargement processes. This material-pore index (MPI) before as well as 1, 7, and 14 days after incubation was measured. RESULTS: In comparison to measuring single pore sizes, MPI determination is the more efficient method to evaluate the possible shrinking or enlargement processes of alloplastic materials. With this technique, incorrect determination of pore sizes due to the dynamic textile structure of meshes and to shrinkage or enlargement, is excluded. All tested alloplastic materials showed an insignificant increase in water absorption under the condition of rehydration up to 0.4%. We did not observe variances in the material in shrinking or enlargement. CONCLUSIONS: MPI was found to be more reliable than measuring single pores to investigate possible external influences on polymer materials. Biomaterials such as PP and PE proved to be absolutely inert under various in vitro conditions.

Hernia, Abdominal↗
PubMed2005

Precoating of alloplastic materials with living human fibroblasts--a feasibility study.

BACKGROUND: The use of alloplastic materials such as polypropylene and polyester has reduced the recurrence of abdominal wall hernias. Concomitantly, new problems have arisen such as inflammatory response against the implanted material and the development of enteric fistulas in case of direct contact of the bowel to polypropylene and polyester. A precoating of the PP with collagen and other absorbable materials seems to reduce the incidence of adhesions and fistulas. The aim of this study was to show the technical feasibility of a precoating of polypropylene with living human fibroblasts and to investigate the growth properties of the cells under these conditions in vitro. METHODS: The textile structure of three different alloplastic materials is described (SurgiPro), TycoHealthcare; Parietene3 PP1510, Dallhausen; VIPRO II, Ethicon Endosurgery). Enhanced Green Fluorescence Protein (EGFP) transduced human foreskin fibroblasts (KiF5) were seeded onto these different alloplastic materials. Proliferation was analyzed by FACS analysis of Ki67 expression. The coating process of the whole mesh area was observed over time with UV-light microscopy, immunostaining, and scanning electron microscopy (SEM). The expression of collagen type I and III was investigated by immunostaining. RESULTS: The three alloplastic materials used were knitted fabrics with different textile structures. KiF5 colonized the entire alloplastic material within 4-6 weeks. Cells were proliferating, as detected by Ki67 expression. SEM showed surface ruffles and long cellular extensions, indicating an active cell metabolism. Light microscopy and SEM suggested that the cells modify the apolar surface by deposition of extracellular matrix components before colonization. CONCLUSION: Our study shows the feasibility of precoating of polypropylene meshes with living human fibroblasts and opens the possibility for clinical use in the future.

Cells, Cultured↗
PubMed2005

[Pancreas removal by external teams].

Combined pancreas and kidney transplantation is an established procedure for terminal or preterminal, uremic, type 1 diabetics. The current procurement technique allows simultaneous recovery of liver and pancreas. One problem is the assessment of organ quality. It remains unclear how many pancreas organs must be withdrawn during back-table preparation. Between June 1994 and December 2003, 271 pancreas transplantations were performed at our transplant centre. Two hundred sixty-two (89.7%) pancreas grafts were harvested by teams which were not part of the transplant team. Twenty-one (8.0%) grafts were discharged for transplantation at the time of back-table preparation. Liposis of the graft and critical vessel situations were the main reasons for withdrawal. Two kidney grafts were not usable for transplantation, and 92% of the pancreas grafts were. This demonstrates the high standard of pancreas procurement in the Eurotransplant region.

Adipose Tissue↗
PubMed2005

[Health economic aspects of psoriasis therapy. Is inpatient topical treatment of plaque-type psoriasis in this age of biologics still appropriate from both medical and economic viewpoints?].

BACKGROUND: We tried to clarify whether the treatment of plaque psoriasis as an inpatient with dithranol and narrow band UV-B 311 nm is still appropriate and economical when compared to biologics such as efalizumab. PATIENTS AND METHODS: In a 15 month period, all patients admitted to the hospital after unsuccessful outpatient treatment of psoriasis were evaluated prospectively according to medical and economical criteria. RESULTS: PASI-score was reduced by 89% in 74 patients. The direct cost to improve one in-patient by 75% in PASI score (PASI-75) was 4342.27 EUR; the total costs for employed patients were 7441.81 EUR. Direct costs of treatment with efalizumab would come to 15048.89 EUR per patient with PASI-75 in a 12 weeks period. CONCLUSION: Topical inpatient therapy for plaque psoriasis is well tolerated and a less expensive option than biologics in those who fail ambulatory treatment.

Adult↗
PubMed2005

Malignant oesophago-pleuro-pericardial fistula in a patient with oesophageal carcinoma.

Pericardial and cardiac fistulae secondary to oesophageal or gastric tumours are a rare complication. We report about a 50-year-old male patient with a 10-month history of distal oesophageal carcinoma with lung and liver metastases who was referred to our hospital after 6 cycles of palliative chemotherapy at the beginning of March 2004. The patient presented with dysphagia, dyspnea, tachycardia, and hypotension. Purulent pericardial and bilateral pleural effusion was diagnosed, and the patient was treated with antibiotics, repeated pleurocentesis and pericardial drainage with daily polihexanide lavage. Oesophagogastroduodenoscopy, Peritrast swallow and computed tomographic scans of chest revealed a malignant oesophago-pleuro-pericardial fistula. A total of three coated, expandable metal stents were inserted into the oesophagus, which sealed successfully the fistula. Unfortunately, the patient succumbed to his carcinoma three months later.

Esophageal Fistula↗
PubMed2005

[Hemangiopericytoma (extrapleural solitary fibrous tumour). Exemplified and discussed on the basis of two cases].

BACKGROUND: Hemangiopericytoma was first mentioned in 1942. It is a very uncommon potentially malignant vascular tumour which can occur at every site of the body. According to the WHO, most of the tumours formerly diagnosed as hemangiopericytomas are considered to be extrapleural solitary fibrous tumours. The diagnosis of "hemangiopericytoma" is now only determined if a constant histological picture of hemangiopericytoma is present. The tumour can lead to lymphogenous or hematogenous metastasis. The major location of occurrence is the cutis and subcutis. It originates from the pericytes of the vascular wall. This is reflected in its vascular character and therefore the hemangiopericytoma might clinically be mistaken for a hemangioma. CASE REPORTS: Patient 1: 60 years, female; diagnosis: malignant suboccipital hemangiopericytoma; size: 4.9 x 4.5 x 4.2 cm; pT1bNXMX L0 V0 Pn0; stage IA; grading G1; R0.Patient 2: 38 years, male; diagnosis: benign hemangiopericytoma infraorbital left; size 1.5 x 1.5 x 1.5 cm. DISCUSSION: Most often the hemangiopericytoma becomes clinically conspicuous as a slowly growing, painless swelling. The consistency ranges from soft to dense, and the color is greyish-blue. The slow and painless growth carries the danger of a clinically wrong diagnosis and thus delayed therapy. The histological diagnosis of hemangiopericytoma is determined by biopsy. Besides histology, MRI and angiography are methods that can be employed to diagnose hemangiopericytoma. The therapy of choice is the complete tumour-resection with a safety margin of 1 cm. In the case of an aggressive growth pattern, adjuvant postoperative radiotherapy is recommended. Until now there has been no documented specific therapy concept for managing incomplete resection and the occurrence of metastasis. There are reports about chemo- and radiotherapy either on their own or combined which evidence differing degrees of success. Lifelong monitoring is necessary because recrudescences and metastases can occur even decades later.

Adult↗
PubMed2005

Pediatric MR-guided interventions.

MRI guided interventions are a relatively new but steadily growing field within surgery in pediatric age. Besides the advantages of MRI, such as multiplanar capability and excellent soft tissue contrast and spatial resolution, particularly relevant for the pediatric population is the lack of ionizing radiation. There is meanwhile a group of well defined diagnostic or therapeutic indications for applying MR imaging during pediatric interventions. Aim of this review is to give an overview about indications of MR-guided procedures in children as well as the advantages and disadvantages of MR-guided interventions. We also briefly discuss interventional MR-systems and MR-compatible devices. It is our opinion that MR-guidance for pediatric interventions is a promising technique at the beginning of its development.

Child↗
PubMed2005

Computerized CT-based 3D visualization technique in living related liver transplantation.

INTRODUCTION: For living donor liver transplantation (LDLT) accurate diagnostic workup is essential. Multiple imaging approaches are currently used. Problems arise in the assessment of vascular and bile duct anatomy, liver graft volume, and vascular territories involved. A 3D visualization system that improves anatomic assessment, allows interactive surgery planning, and acts as an intraoperative guide with enhanced precision is required. Refinements in computed tomography (CT) technology with the introduction of multidetector-row CT scanners and implementation of mathematical methods on computerized digital data has enabled CT-based 3D visualizations. MATERIALS AND METHODS: Sixteen LDLT candidates and three LDLT recipients were assessed by multislice CT examination. Image processing of the digital raw data for 3D visualization included segmentation and calculation of center lines. A hierarchical mathematical model representing the vascular and biliary tree was created. This allowed calculation of individual vascular territories. RESULTS: 3D CT-based visualization in LDLT facilitates diagnostic workup with high accuracy for analyses of vascular and bile duct variants, volumetry, and assessment of the optimal surgical splitting line of the living donor liver. Resultant areas of either arterial devascularization or venous congestion can be displayed and quantified preoperatively. The diagnostic method is of major impact on patient selection and directly influences intraoperative surgical guidance. The currently practiced "multiple imaging approach" approach, especially with regard to invasive diagnostics, can be avoided in the future.

Family↗