Biomedical subjects

U Mansmann

Publications and source records attributed to U Mansmann.

At least 37 records · Page 2Linked to original sources

PubMed2001

[Criteria for evaluating prognostic factors].

In oncology prognostic factors are defined as variables (covariates) with independent influence on outcome. Toxicity and complications of treatment are not considered. The significance and independence of a putative prognostic factor has to be proven by multivariate analysis. The results of prognostic factor analysis differ depending on tumor entity and residual tumor status. Sometimes differences are observed for various endpoints and certain patient subgroups. For identification of prognostic factors a systematic step-wise procedure is recommended. A checklist of important methodological aspects is suggested. The acceptance of new prognostic factors requires a standardized way to determine the factors, adequate evidence of significance and independence and the demonstration of additional prognostic information and its clinical relevance. By integration of multiple prognostic factors the present tumor classification will be extended to prognostic systems.

Humans↗

PubMed2001

The prognostic inhomogeneity in pT3 rectal carcinomas.

To obtain data on locoregional recurrence and survival rates in prognostically inhomogeneous pT3 rectal carcinomas we analyzed the data on 853 patients of the Erlangen Registry for Colo-Rectal Carcinomas (ERCRC) and 600 patients of the Study Group for Colo-Rectal Carcinoma (SGCRC), stage I-III, treated by radical surgery alone. The category pT3 was subdivided according to the histological measurement of the maximal tumor invasion beyond the outer border of the muscularis propria: pT3a (up to 5 mm) and pT3b (more than 5 mm). In the ERCRC locoregional recurrence rates were 10.4% (95% confidence interval 6.0-14.6) for pT3a and 26.3% (20.6-31.6) for pT3b (P<0.0001). The cancer-related 5-year survival rates were 85.4% (80.6-90.5) for pT3a and 54.1% (48.5-60.5) for pT3b (P<0.0001). Lymph node negative pT3a and pT2 patients showed very similar 5-year survival rates (91.2% vs. 93.6%, respectively) as well as lymph node positive pT3a and pT2 patients (77.8% vs. 82.8%, respectively). In the SGCRC patients similar but statistically marginal differences between pT3a and pT3b tumors were observed. An extended pT classification (pT1, pT2, pT3a, pT3b, pT4) thus allows an improved prediction of outcome in rectal carcinoma patients. The subdivision of pT3 enables the identification of stage II patients (pT3a pNO) who might not benefit from adjuvant treatment.

Adult↗

PubMed2001

Concepts and data model for a co-operative neurovascular database.

BACKGROUND: Problems of clinical management of neurovascular diseases are very complex. This is caused by the chronic character of the diseases, a long history of symptoms and diverse treatments. If patients are to benefit from treatment, then treatment decisions have to rely on reliable and accurate knowledge of the natural history of the disease and the various treatments. METHODS: Recent developments in statistical methodology and experience from electronic patient records are used to establish an information infrastructure based on a centralized register. RESULTS: A protocol to collect data on neurovascular diseases with technical as well as logistical aspects of implementing a database for neurovascular diseases are described. The database is designed as a co-operative tool of audit and research available to co-operating centres. CONCLUSION: When a database is linked to a systematic patient follow-up, it can be used to study prognosis. Careful analysis of patient outcome is valuable for decision-making.

Adult↗

PubMed2001

Determination of glutaraldehyde residues on flexible endoscopes after chemothermal treatment in an endoscope washer-disinfector.

BACKGROUND AND STUDY AIMS: Although there are several cases of glutaraldehyde-induced colitis following colonoscopy there is only one study on residues after disinfecting. Our report describes the determination of water-soluble glutaraldehyde residues after processing endoscopes with a glutaraldehyde-containing disinfectant. MATERIALS AND METHODS: A gastroscope and a colonoscope were processed in a washer-disinfector and then immersed in 201 of NaCl solution. Glutaraldehyde was determined by high performance liquid chromatography in 84 samples. Samples were taken after immersing the endoscopes for 5 h and 24 h with and without rinsing the channels. RESULTS: After 5 h and with the channels having been rinsed, the median for colonoscopes was only 0.409 mg/l. The highest level of glutaraldehyde was 0.846 mg/l. CONCLUSIONS: After endoscopes have been processed in the washer-disinfector there is no risk of a glutaraldehyde-induced colitis, proctitis or diarrhoea.

Colonoscopes↗

PubMed2001

Right-sided shift found in metachronous colorectal adenomas.

BACKGROUND AND STUDY AIMS: Patients who have had a colorectal adenoma are likely to develop a metachronous adenoma, and therefore need to be kept under surveillance. The question is whether metachronous adenomas will be found at the same anatomical site as the preceding adenomas, thus prompting us to focus surveillance examinations on this region, using flexible sigmoidoscopy or total colonoscopy. PATIENTS AND METHODS: Between 1978 and 1996 a long-term follow up of 1091 patients was prospectively documented at the Erlangen Registry of Colorectal Polyps. The anatomical sites--distal (rectosigmoid) and proximal colon--of two subsequent generations of metachronous adenomas were analysed using logistic regression analysis. RESULTS: In 556 (51%) patients metachronous adenomas were found during follow up. In 211 (37.9%) of these patients a right-sided shift in the first generation of metachronous adenomas in comparison with initial lesions (P<0.0001) was found. Some 305 patients underwent further follow up, and 51 (27.1%) out of 188 patients with metachronous lesions demonstrated a right-sided shift in their second generation (vs. first generation) of metachronous adenomas. Proximally located first generation metachronous adenomas would be missed by flexible sigmoidoscopy in 50.8% of patients with only distal adenomas at baseline colonoscopy, and in 58.7% of patients with second-generation lesions. Multivariate analysis revealed that multiplicity (odds ratio 2.64, 95% CI 1.49-4.66) and size of initial adenomas (>5 mm) (odds ratio 3.60, 95% CI 1.96-6.66) were significantly associated with a right-sided shift in metachronous adenomas, while female gender was associated with a significantly lower tendency to manifest a right-sided shift (odds ratio of 0.64. 95% CI 0.43-0.94). CONCLUSIONS: Metachronous adenomas are found significantly more often in the right colon than would be expected assuming clustering at the same anatomical site as the preceding lesions. Total colonoscopy is thus needed for surveillance, regardless of the initial adenoma site.

Adenoma↗

PubMed2001

Neuroendocrine differentiation is a relevant prognostic factor in stage III-IV colorectal cancer.

OBJECTIVE: To determine the prognostic relevance of neuroendocrine differentiation in colorectal cancer. METHODS: The survival of 116 patients with colorectal cancer of stages III (n = 59) and IV (n = 57) was correlated with the extent of neuroendocrine differentiation. Chromogranin A and synaptophysin were used as neuroendocrine markers. Based on the degree of immunoreactivity for these markers, tumours were classified as 0 (no expression of neuroendocrine markers), 1 (< 2% cells staining positive for neuroendocrine markers) and 2 (> 2% cells staining positive for neuroendocrine markers). Patients were followed up for more than 5 years or until death. RESULTS: Seven of 59 (11.8%) stage III cancers and 13/57 (22.8%) stage IV cancers belonged to group 2. The 96 patients of groups 0 and 1 lived for 48.9 months, whereas the 20 patients of group 2 survived for only 18.6 months (Kaplan-Meier survival curves, P < 0.001). The difference was most striking in stage III disease with 79.4 months' survival for combined groups 0 and 1, and 38.9 months' survival for group 2 (P < 0.01). Using the multivariate Cox regression model, the presence of more than 2% of cells with neuroendocrine differentiation was found to be an independent prognostic parameter for stage III and IV disease. No correlation was observed between neuroendocrine differentiation and tumour location, grade, depth of invasion or stage. CONCLUSION: Neuroendocrine differentiation is often seen in colorectal cancer. It is an independent prognostic factor in stage III-IV colorectal cancer.

Adenocarcinoma↗

PubMed2001

Mycophenolate mofetil is ineffective in the treatment of mucocutaneous Adamantiades-Behçet's disease.

BACKGROUND: Cyclosporine A and azathioprine are effective on mucocutaneous lesions in Adamantiades-Behçet's disease. Mycophenolate mofetil (MMF) is a drug resembling their activity but with comparably negligible adverse reactions. OBJECTIVE: A prospective clinical proof-of-principle study was conducted to investigate the effectiveness and toxicity of MMF in mucocutaneous Adamantiades-Behçet's disease. METHODS: Thirty patients were to be treated with MMF 2 g/day p.o. for 6 months, in combination with prednisolone 30 mg/day p.o. during the first month of treatment. Inefficacy was followed by an increase in MMF dose to 3 g/day. The primary efficacy variable was the decrease in the disease activity index (DAI) according to a modified variant of the Iran Behçet's Disease Dynamic Activity Measure system. RESULTS: The study was interrupted due to inefficacy of the compound after the intermediate evaluation of the first 6 patients (aged 37.0 +/- 7.7 years with disease duration of 10.0 +/- 8.9 years) as required by the ethical committee. Although an improvement of the DAI from 5.2 +/- 3.5 to 1.3 +/- 0.5 was found after the first month of combination treatment, withdrawal of prednisolone led to quick relapses with a new index increase (3.0 +/- 3.5). The treatment was discontinued in 3 patients after 3 months, in 2 patients after 4 months and in another one after 5 months due to deterioration of the disease. Introduction of interferon alpha(2a) (3 x 9 million IU 3x/week s.c.) in 3 patients decreased the activity index from 4.0 +/- 1.0 to 0.0 +/- 0.0. No adverse effects were detected under MMF treatment. CONCLUSION: MMF (2-3 g/day) is unable to control the signs of mucocutaneous Adamantiades-Behçet's disease.

Adolescent↗

PubMed2000

Expression of SIALYL-Le(x) antigen defined by MAb AM-3 is an independent prognostic marker in colorectal carcinoma patients.

Expression of mucin-bound sialyl-Le(x) antigen during the progression of colorectal carcinoma and its potential prognostic value were analysed in sections of tumours from 182 patients with a documented follow-up by immunohistochemistry using the monoclonal antibody (MAb) AM-3. Two groups of colonic carcinomas with weak (n = 79) and strong (n = 103) sialyl-Le(x) expression were discerned. The percentage of strongly expressing tumours increased with the progression of the disease (UICC stage I = 10%, stage II = 46%, stage III = 63%, stage IV = 68%, p < 0.0001). Seventy-four percent of patients with carcinomas exhibiting a strong sialyl-Le(x) expression but only 34% of patients with weak sialyl-Le(x) expression died of the disease (p = 0.0026). In multivariate analysis, strong sialyl-Le(x) expression increased the relative risk of cancer-related death 3.8-fold (95% CI = 1.8-7.9, p = 0.00034). The separate analyses of patients in UICC stage II (n = 56), III (n =5 9) and IV (n = 57) revealed that strong sialyl-Le(x) expression was associated with a reduction of the 5-year overall survival rate in UICC stage II (84% vs. 54%, p = 0.0013) and in stage III patients (86% vs. 35%, p = 0.0008) after curative resection but was not relevant in patients with distant metastases. In conclusion, the strong expression of sialyl-Le(x) antigen defined by the MAb AM-3 in colorectal carcinomas is an independent unfavourable prognostic factor after curative resection in stage II and III patients. The predictive power of the sialyl-Le(x) expression may be helpful to define subgroups of patients at high risk for whom preventive adjuvant therapy can be selectively applied before the occurrence of detectable metastases.

Adult↗

PubMed2000

Histogram-based characterization of healthy and ischemic brain tissues using multiparametric MR imaging including apparent diffusion coefficient maps and relaxometry.

Decreased, renormalized, or increased values of the calculated apparent diffusion coefficient (ADC) are observed in stroke models. A quantitative description of corresponding tissue states using ADC values may be extended to include true relaxation times. A histogram-based segmentation is well suited for characterizing tissues according to specific parameter combinations irrespective of the heterogeneity found for human healthy and ischemic brain tissues. In a new approach, navigated diffusion-weighted images and ADC maps were incorporated into voxel-based parameter sets of relaxation times (T1, T2), and T1- or T2-weighted images, followed by a supervised histogram-based analysis. Healthy tissues were segmented by incorporating T1 relaxation into the data set, ischemic regions by combining T2- or diffusion-weighted images with ADC maps. Mean values of healthy and pathologic tissues were determined, spatial distributions of the parameter vectors were visualized using color-encoded overlays. One to six days after stroke, ischemic regions exhibited reduced relative mean ADC values.

Adult↗

PubMed2000

MRA versus digital subtraction angiography in acute subarachnoid haemorrhage: a blinded multireader study of prospectively recruited patients.

We performed a blinded multireader study comparing MR angiography (MRA) with digital subtraction angiography (DSA) in 34 prospectively recruited patients who presented with acute subarachnoid haemorrhage (SAH). Two observers independently reviewed the MRA and DSA studies some months after clinical presentation. Presence of an aneurysm was rated on a 4-point confidence scale. Cases in which the initial interpretation of the observers varied were jointly reviewed to reach a consensus opinion. DSA was deliberately chosen not to represent the reference standard and the clinical course and surgical findings were used to explain significant differences between the consensus readings of MRA and DSA. Diagnostic confidence and interobserver agreement were, overall, higher on DSA than on MRA studies (kappa DSA = 0.64 versus kappa MRA = 0.52 with 95% CI for delta = kappa DSA-kappa MRA [-0.06, 0.31]). With both methods, discrepancies between observers were due to aneurysms overlooked rather than false-positive readings by one observer. Diagnostic accuracy therefore improved when the readings of the two observers were combined, particularly for MRA. Intermethod agreement was only fair and similar for both readers (kappa reader 1 = 0.37 versus kappa reader 2 = 0.32 with 95% CI for delta = kappa reader 1-kappa reader 2 [-0.02, 0.11]). Both interobserver and intermethod agreements improved when the data were analysed on a per-study (positive or negative study) rather than on a per-aneurysm basis. Differences in the consensus reading were due to five aneurysms (four single and one multiple) detected only with MRA and five (two single and three multiple) detected only with DSA. MRA and DSA should be regarded as complementary in the investigation of patients with acute SAH. DSA can no longer be regarded as the reference standard.

Adult↗

PubMed2000

Inflammatory response after laparoscopic and conventional colorectal resections - results of a prospective randomized trial.

BACKGROUND: Short-term benefits of laparoscopic relative to conventional colorectal resections have been demonstrated in randomized controlled trials. It has been suggested that a diminished cytokine and acute-phase response may be responsible for these advantages. METHODS: In a randomized controlled trial, patients underwent laparoscopic (n=30) or conventional (n=30) resection of colorectal tumors. Plasma levels of interleukin-1 receptor antagonist (IL-1RA), interleukin-6 (IL-6), interleukin-10 (IL-10), and C-reactive protein (CRP) were analyzed repeatedly. Postoperative peak levels and area under the curve values were calculated and compared between groups using the Mann-Whitney U-test. RESULTS: Patient characteristics, preoperative cytokine, and CRP plasma levels were not different between each group. Postoperative peak concentrations of IL-6 (P=0.05) and CRP (P<0.001) and the overall postoperative plasma concentrations of IL-6 (P=0.03) and CRP (P=0.002) were lower in the laparoscopic than in the conventional group. Peak and overall IL-1RA (P=0.2; P=0.2) and IL-10 (P=0.4; P=0. 6) plasma concentrations, respectively, were not different between groups. CONCLUSIONS: IL-6 and CRP plasma levels were lower after laparoscopic than conventional colorectal resections. The less intense inflammatory response may be an indicator of the milder surgical trauma inflicted by laparoscopic than conventional colorectal resection.

Acute-Phase Reaction↗

PubMed2000

Factors associated with intracranial hemorrhage in cases of cerebral arteriovenous malformation.

OBJECTIVE: The standard categorization of arteriovenous malformations (AVMs) involves the Spetzler-Martin grading system, which uses a simple analysis of size, location (superficial or deep), and the presence of deep or superficial drainage. Hemodynamic risk factors are also thought to play important roles in the pathogenesis of these lesions and to be associated with the intracranial hemorrhage (ICH) rate. The actual hemodynamic factors for AVMs cannot be easily measured, but angioarchitectural features can be assessed and used as surrogate parameters. METHODS: The AVM angioarchitectural features for 662 patients were analyzed, and their associations with ICH as a presenting sign were studied. A cross-sectional analysis was used to qualify the strength of associations among clinical features, angioarchitectural characteristics, and ICH before treatment. RESULTS: The multivariate analysis indicated that arterial stenosis and arterial ectasia were associated with lower ICH rates, whereas venous stenosis increased the rate of ICH. The presence of angiogenesis modified the effects of arterial and venous stenosis. Furthermore, the effect of venous stenosis depended on the location of the nidus. The presented data do not support a direct positive association between associated aneurysms and ICH. CONCLUSION: Certain angiographic features seem to have prognostic potential with respect to the occurrence of ICH among patients with AVMs. A discriminatory prognostic index is proposed; its relevance must be proven in a future prospective study.

Adolescent↗

PubMed2000

Cerebral arteriovenous malformations and associated aneurysms: analysis of 305 cases from a series of 662 patients.

OBJECTIVE: Spontaneous intracranial hemorrhage is the primary danger for patients with cerebral arteriovenous malformations (AVMs). Associated aneurysms are considered weak points that increase the risk of intracranial hemorrhage. Aneurysms are classified as proximal aneurysms (PROXs) or intranidal aneurysms (INs). METHODS: The present study was based on a series of 662 patients who presented with AVMs between 1985 and 1995. Its purpose was to evaluate prestated hypotheses using prospectively collected data. In 305 of these 662 patients, 372 INs and 313 PROXs were observed and analyzed with respect to their shapes, locations, and sizes. Partial targeted endovascular treatment with n-butylcyanoacrylate was performed for 450 of the 662 patients (68%) in this series, using a standard protocol. Of 450 treated patients, 181 (40%) had at least one IN and 138 (30.7%) had at least one PROX. Analysis of changes in the sizes of PROXs was based on the follow-up data for 83 treated patients, with a total of 149 PROXs. Changes in the sizes of PROXs in treated patients were analyzed with respect to PROX shapes, PROX locations, and treated AVM occlusion rates. Univariate and multivariate event data analyses were used to study factors influencing aneurysm shrinkage. False aneurysms were excluded from the series. RESULTS: Presentation with intracranial hemorrhage was not correlated with any type of aneurysm. However, INs demonstrated a higher rebleeding rate (P < 0.002) before treatment. Among 181 patients, 92.2% of INs were occluded, together with the related portions of the AVM nidi. In cases of PROXs, embolization of the cerebral AVM compartment fed by the artery with the aneurysm was a priority. During follow-up monitoring of 83 treated patients with 149 PROXs, 100% shrinkage was observed for 12 PROXs and more than 50% shrinkage was observed for 33 PROXs. The median time required for more than 50% shrinkage was 3.5 years. The shrinkage of PROXs was influenced by the degree of AVM occlusion (P = 0.027) and occurred faster for PROXs on midline structures, such as the anterior cerebral artery and the circle of Willis, compared with arteries distal to the circle of Willis (P = 0.004). No rupture of untreated PROXs was observed after partial targeted treatment of AVMs. CONCLUSION: PROXs are not primary treatment targets, compared with AVMs themselves. INs should be primary targets of endovascular therapy, because of their increased risk of rebleeding.

Adolescent↗

PubMed2000

Demographic, morphological, and clinical characteristics of 1289 patients with brain arteriovenous malformation.

BACKGROUND AND PURPOSE: The purpose of this study was to assess demographic, clinical, and morphological characteristics of patients with brain arteriovenous malformations (AVMs). METHODS: Prospectively collected data of 1289 consecutive AVM patients from 3 independent databases (1 multicenter [Berlin/Paris/Middle and Far East, n=662] and 2 single centers [New York, n=337, and Toronto, n=290]) were analyzed. The variables assessed were age at diagnosis, sex, AVM size, AVM drainage pattern, AVM location in functionally important brain areas ("eloquence"), and type of presentation (hemorrhage, seizure, chronic headache, or focal neurologic deficit). Comparisons were made by ANOVA, contingency tables, and log-linear models. RESULTS: Overall, mean age at diagnosis was 31.2 years (95% CI 30.2 to 32.2 years), and 45% of the patients were female (95% CI 42% to 47%). AVM maximum diameter was <3 cm in 38% (95% CI 35% to 41%). Deep venous drainage was present in 55% (95% CI 52% to 59%). An eloquent AVM location was described in 71% (95% CI 69% to 74%). AVM hemorrhage occurred in 53% (95% CI 51% to 56%). Generalized or focal seizures were described in 30% (95% CI 27% to 33%) and 10% (95% CI 8% to 12%), respectively. Chronic headache was recorded in 14% (95% CI 12% to 16%). Persistent neurological deficits were found in 7% (95% CI 6% to 9%), and progressive neurological deficits in 5% (95% CI 4% to 6%). Significant differences between centers were found for age (P<0.001), sex (P=0.04), eloquence (P=0.04), size (P<0.001), hemorrhage (P=0.006), persistent neurological deficit (P<0.001), and reversible neurological deficit (P=0.013). The intercenter difference found for hemorrhage frequency did not remain after adjustment for AVM size. CONCLUSIONS: Baseline characteristics differed considerably between centers. The differences found in patient age and AVM size may be explained by center-specific referral patterns and the influence of access to treatment resources, whereas those found for other characteristics may be attributable to center-specific definitions. Analysis of natural history data from tertiary referral center databases may be improved by consistent definitions applicable to the entire population of AVM patients.

Adolescent↗

PubMed2000

The German experience: the surgeon as a prognostic factor in colon and rectal cancer surgery.

The data of the German prospective multicenter study of the Study Group for Colo-Rectal Carcinoma (SGCRC) were analyzed by uni- and multivariate methods with regard to surgeon-related prognostic factors. The parameters were frequency of intraoperative local tumor spillage, surgical volume, and department and surgical quality group. The results obtained from the data of the SGCRC implicate consequences for analyses and comparisons of therapy results and studies on adjuvant therapy in colon and rectal cancer. All identified prognostic factors must be regarded and respectively considered in study designs. Colon and rectal cancer patients must also be distinguished and separate analyses are necessary for these.

Aged↗

PubMed2000

A loss-effectiveness analysis of risk-adapted surveillance after colorectal polypectomy.

Surveillance of patients after initial polypectomy is considered as an effective means to prevent the development of colorectal carcinoma. Several proposals with varying follow-up schedules are given in the literature. Based on a growing awareness on possibilities to prevent colorectal cancer from developing, the discovery of colorectal adenoma and consequently the need for surveillance by colonoscopy will increase. In this paper, a strategy for a cost-effectiveness analysis of adenoma surveillance will be discussed. Obstacles to reach a conclusive result are pointed out, gaps in information needed are marked, modelling techniques used in a sound sensitivity analysis will be described.

Adenomatous Polyps↗

PubMed2000

Convergence diagnosis for Gibbs sampling output.

Gibbs sampling is a technique to calculate a complex posterior distribution as steady state measure of a Markov chain. The fundamental problem of inference from Markov chain simulation is that there will always be areas of the target distribution that have not been covered by the finite chain. Deciding when to stop the chain in order to have reached enough coverage of the support of the target distribution is an important matter. Techniques based on one long single chain and on multiple chains are discussed in the framework of a linear mixed effects model. The diagnostics used do not provide a consistent view on the convergence. Practical consequences on the estimates are shown.

Arteriosclerosis↗

PubMed1999

Differential gene expression in colon carcinoma cells and tissues detected with a cDNA array.

Expression of selected genes coding for proteins with defined cellular functions was analysed in human cell lines derived from normal colonic mucosa, non-mucinous colonic carcinomas and mucinous colonic carcinomas. Altered expression of 10 genes in colon carcinoma cells was found by using a cDNA array; 6 of these alterations (60%) were confirmed by Northern blotting or semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). Among these 6 genes, 3 transcription factors as well as the topoisomerase II alpha and the mitosis inhibitor WEE1Hu gene were significantly suppressed in the tumour cell lines. In addition, the gene coding for the cell cycle inhibitor p21 was overexpressed only in cell lines derived from mucinous carcinomas. The significant suppression of the kinase WEE1Hu gene in carcinoma cells of both phenotypes and the tendency of the mucinous phenotype to overexpress p21 protein were confirmed in human colon carcinoma tissues. Our data show that the cDNA array method permits a correct identification of changes in gene expression with a relatively high accuracy. The different expression of the p21 gene in the non-mucinous and mucinous carcinoma cells supports the hypothesis that these phenotypes may develop along different genetic pathways. The detection of WEE1Hu gene suppression in colon carcinoma cells and tissues suggests its potential role in tumourigenesis.

Adenocarcinoma, Mucinous↗