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Biomedical subjects

A Lösch

Publications and source records attributed to A Lösch.

At least 19 recordsLinked to original sources
PubMed2006

[Diagnostic procedure for uveitis patients: reduction of costs by a targeted assessment of laboratory tests based on clinical findings].

BACKGROUND: Interdisciplinarity is an essential prerequisite for extensive and high-quality diagnostic work-up, therapy, and care of patients with inflammatory rheumatic disease. The ophthalmological status significantly narrows down the possible causes for the primary disease and facilitates an effective diagnostic approach. METHODS: We developed an assessment procedure according to the individual clinical findings to use as an ideal diagnostic strategy for an interdisciplinary center. To permit comparability we first introduced this new diagnostic tool in November 2002 (intervention), replacing the existing cost-intensive standard diagnostic procedure for uveitis patients. RESULTS: The average costs for laboratory tests (calculated according to GOA numbers, scale of fees for physicians) were reduced from 670+/-11 euros per patient before the intervention to 238+/-18 euros per patient after the intervention. Before intervention 16 of 31 (52%) could be assigned to a specified disease compared to 27 of 53 (51%) after the intervention. With our strategy we were able to obtain a 64% reduction of costs in the diagnostics of uveitis patients without a deterioration of our diagnostic quality. CONCLUSION: It is possible to reduce costs and still improve the care of uveitis patients by using a targeted assessment according to the individual clinical findings.

Clinical Laboratory Techniques↗
PubMed2004

Cathepsin D in ovarian cancer: prognostic value and correlation with p53 expression and microvessel density.

OBJECTIVE: Overexpression of ubiquitous lysosomal aspartyl protease cathepsin D (CD) is involved in the progression of cancer. This study investigates the prognostic value and the association of cathepsin D expression with clinicopathological parameters, p53 expression, and angiogenesis in ovarian cancer. METHODS: Cathepsin D was determined immunohistochemically in 43 ovarian tumors of low malignant potential (LMP) and 80 invasive tumors FIGO stage I-IV. Results were correlated with clinicopathological characteristics, p53, and microvessel density (MVD). Survival analysis of cathepsin D expression and MVD was performed in invasive tumors. RESULTS: Epithelial tumor cathepsin D expression was more common in LMP tumors (65.1%) compared to invasive tumors (43.7%; P = 0.02). In LMP tumors, stromal cathepsin D was associated with mucinous tumors (P = 0.01), whereas in invasive tumors, epithelial cathepsin D expression was associated with clear cell tumors (P = 0.003). Invasive tumor cathepsin D had a negative relation to p53 expression. In LMP tumors, stromal cathepsin D correlated with microvessel density (P = 0.03). Stromal cathepsin D expression was an independent prognostic factor for disease-free survival (DFS) in patients with invasive cancer (P = 0.03, Cox regression), while cathepsin D expression missed to be of prognostic value for overall survival (OS) in invasive ovarian cancer. MVD had no influence on survival in invasive ovarian cancer (P > 0.05). CONCLUSION: Our study demonstrates a prognostic value of cathepsin D expression in invasive ovarian cancer, while cathepsin D expression in LMP tumors seems to be linked to angiogenesis. The relation among cathepsin D, p53 expression, and angiogenesis demonstrates biological differences between invasive ovarian cancer and LMP tumors.

Adult↗
PubMed2001

Leiomyosarcoma of the vulva. A case report.

BACKGROUND: Leiomyosarcoma of the vulva is a rare mesenchymal tumor. Biologic features of a low grade tumor were investigated by an immunohistochemical workup. CASE: A 38-year-old woman presented with a slowly growing vulvar mass. Surgical treatment was performed, and a low grade leiomyosarcoma of the vulva was diagnosed. Immunohistochemical reactions were performed with monoclonal antibodies against desmin, vimentin, smooth muscle actin, cytokeratin, S-100 protein, estrogen, progesterone and androgen receptor, p53 protein, Ki-67 antigen, leukocyte common antigen and polyclonal antibodies to factor VIII-related antigen. Expression of estrogen, progesterone and androgen receptor was present in addition to a moderate number of Ki-67-positive cells and absence of p53 protein overexpression and lymphatic cell infiltration besides adequate microvessel density for smooth muscle tumors. Since the immunohistochemical markers indicated a less aggressive tumor, any further adjuvant therapy was rejected. The patient was without recurrence 24 months later. CONCLUSION: The immunohistologic profile proved the low histologic grade of vulvar leiomyosarcoma. The findings helped to estimate prognosis and plan therapy.

Adult↗
PubMed2000

Preperitoneal lipoleiomyoma of the abdominal wall in a postmenopausal woman.

OBJECTIVE: Extrauterine leiomyomas are rare events. These tumors may be easily misdiagnosed as ovarian tumors at the clinical investigation. We present the first case of an otherwise healthy postmenopausal woman, hysterectomized 20 years ago, who developed a preperitoneal lipoleimoyoma in the 30-year-old scar of a Pfannenstiel incision. The patient received continuous hormone replacement therapy (HRT) for 5 years with 1.25 mg conjugated estrogen and 5 mg medrogeston per day. METHODS: In sections of the tumor, immunohistochemical reactions with antibodies against actin, desmin, vimentin, estrogen and progesterone receptors and factor VIII related antigen was performed. RESULTS: Histologic findings revealed cellular fascicles of spindle-shaped smooth muscle cells in a whorled arrangement. Mitotic figures were absent. Central degenerative changes and focal edema were observed. Between muscle fascicles, a significant amount of fat cells (20% of tumor volume) was visible. Leiomyocytes showed immunohistochemicaly positive reactions with actin, desmin, vimentin, and steroid hormone receptors. Based on these findings, the tumor was diagnosed as lipoleiomyoma. CONCLUSIONS: Origin of the tumor of smooth muscle cells of vessels located in the abdominal wall and development under influence of oral steroids seems most probable. HRT appears to promote the development of extrauterine leiomyomas in postmenopausal women.

Abdomen↗
PubMed2000

Trends in vulvar neoplasia. Increasing incidence of vulvar intraepithelial neoplasia and squamous cell carcinoma of the vulva in young women.

OBJECTIVE: To determine trends in the epidemiology of vulvar intraepithelial neoplasia (VIN) and squamous cell carcinoma (SCC) of the vulva in a Central European sample during the last decade. STUDY DESIGN: A total of 366 women with VIN 2 and 3 (n = 128) or vulvar SCC (n = 238) presented within two four-year periods separated by one decade (1985-1988 and 1994-1997). We performed a retrospective analysis of the clinicopathologic records of the cohorts. RESULTS: The number of women with high grade VIN (n = 29 vs. 99) tripled during the last decade, while the incidence of vulvar SCC remained stable. In women < or = 50 years old, the incidence of high grade VIN increased by 392% (n = 12 vs. 59) and of invasive vulvar cancer by 157% (n = 7 vs. 18). In the earlier cohort there were 7/126 (5%) women with invasive vulvar SCC under the age of 50 and, in the latter cohort, 18/112 (16%, P < .01). CONCLUSION: Over the past decade a striking increase occurred in the incidence of VIN and an increase in invasive vulvar SCC in young women.

Adult↗
PubMed1999

Prognostic significance of tumor angiogenesis in epithelial ovarian cancer.

Since angiogenesis is considered essential for tumor growth and the development of metastasis, we assessed the correlation of microvessel density (MVD) with overall survival in patients with epithelial ovarian cancer. Histologic slides were immunostained for CD34-antigen. MVD was determined within each tumor by enumeration under a light microscope at 200x magnification and an examination area of 0.25 mm2. The Cox proportional-hazards model was used for multivariate analysis. In 63 patients with epithelial ovarian cancer the 5-year survival rate (OS-%) was as follows: 55.0% (+/-12.5) in 18 patients whose tumors had an MVD < 10/field, and 23.6% (+/-6.7) in 45 patients whose tumors had an MVD(10/field (log-rank P = 0.038). MVD showed a significant influence on survival in univariate analysis, but failed to attain a significant value after adjustment for established prognostic parameters such as patients' age at diagnosis, stage of disease, and histologic grading. High MVD was significantly associated with advanced patients' age at diagnosis. This and a considerable heterogenity in the vascular architecture of ovarian carcinoma tissue might be the reasons why MVD did not reveal prognostic significance in multivariate analysis. In contrast to a variety of solid neoplasms, MVD does not seem to be a useful predictor of survival in patients with epithelial ovarian cancer.

Adult↗
PubMed1999

Leiomyoma of the round ligament in a postmenopausal woman.

OBJECTIVE: Leiomyoma of the round ligament of the uterus is a rare condition. We present the first case of a postmenopausal, previously hysterectomised, woman who received combined hormonal replacement therapy and developed a leiomyoma of the right round ligament. METHOD: In sections of the tumor, immunohistochemical reaction with monoclonal antibodies against smooth muscle actin, desmin, vimentin, estrogen receptor and progesterone receptor was performed. RESULTS: The leiomyoma showed bizarre histologic appearance in absence of mitotic figures and degenerative changes. Leiomyocytes presented a positive immunohistochemical reaction with monoclonal antibodies against smooth muscle actin, desmin vimentin and progesterone receptor in absence of estrogen receptor. CONCLUSION: Progestin as part of a combined hormonal replacement therapy may play an important role in promoting the development of leiomyoma in hormonal responsive tissue of the round ligament in postmenopausal women.

Diagnosis, Differential↗
PubMed1998

Prognostic value of cathepsin D expression and association with histomorphological subtypes in breast cancer.

This study investigated the prognostic value of immunohistochemically detected cathepsin D expression in 103 invasive ductal carcinomas of the breast at stages pT1 and 2. We also assessed the association between cathepsin D expression and histomorphological tumour subtypes (invasive ductal carcinoma with extensive intraductal component, multifocal tumour). Cathepsin D expression was examined at two cut-off levels (positive and highly positive) and separately identified within the epithelial and stromal component of all tumours. Positive and highly positive epithelial expression was detected in 32 (31.1%) and 20 (19.4%) patients respectively. Stromal expression was found in 35 (34%) and 19 (18.4%) cases respectively. Epithelial cathepsin D expression was associated with stage and nuclear grade, but not with lymph node or oestrogen receptor status. Positive and highly positive epithelial cathepsin D expression showed significant prognostic value for overall survival (P = 0.003 and 0.01) and recurrence-free interval (P = 0.04 and 0.02). Cathepsin D expression in stromal cells was not associated with either several established prognostic factors or survival. Multivariate analysis revealed that cathepsin D expression failed to be an independent predictor of patients' outcome. Cathepsin D expression shows no significant association with histomorphological subtypes of breast cancer. Our study supports the prognostic impact of immunohistochemically detected cathepsin D expression in the epithelial component of breast cancer.

Adult↗
PubMed1998

Differentiating vulvar intraepithelial neoplasia from nonneoplastic epithelial disorders. The toluidine blue test.

OBJECTIVE: To determine the effectiveness of the toluidine blue test in the differentiation of vulvar intraepithelial neoplasia (VIN) and nonneoplastic epithelial disorders (NNEDs). STUDY DESIGN: This retrospective clinical study included all women with VIN (n = 24) and NNED (n = 72) referred to a vulvar clinic at a university hospital during a two-year period. Vulvoscopy, staining of vulvar epithelium with 1% toluidine blue and punch biopsy were performed. RESULTS: Vulvar epithelium demonstrated toluidine blue staining in 100% of the patients with VIN 3, in 83% of women with VIN 1-2, in 50% of the women with squamous cell hyperplasia and in 10% of the women with lichen sclerosus. The differences in staining between the groups were statistically significant (P < .001). The sensitivity of toluidine blue staining for the detection of VIN was 92%; the negative predictive value 96% in teh investigated cohort. The specificity for strong staining was 88%. CONCLUSION: The toluidine blue test is an inexpensive and reliable method of separating VIN from hyperplastic NNED areas and choosing a biopsy site on the vulva.

Adult↗
PubMed1997

[Massive edema of the ovary].

Massive edema of the ovary is a rare condition found in young women as a result of partial or intermittent torsion of the ovary. Differentiation of this entity from tumors of the ovary is important to prevent overtreatment. Organ-preserving surgical treatment is indicated as the correct approach to management. We present a case of massive edema of the ovary associated with post partum involution of the female genital tract and discuss the clinical features in the light of the known literature.

Adult↗
PubMed1997

A non-invasive technique for 3-dimensional assessment of articular cartilage thickness based on MRI. Part 2: Validation using CT arthrography.

Established methods for the measurement of articular cartilage thickness are invasive and cannot be sequentially applied in living subjects. In the present study, the distribution of cartilage thickness throughout entire joint surfaces was determined from MR images obtained with a fat-suppressed gradient-echo sequence at a resolution of 0.31 x 0.31 x 2.00 mm3, and compared to that derived from CT arthrography. A minimal distance algorithm was employed to produce 3D cartilage thickness maps of seven cadaveric human knee joints. The mean amount of deviation of the cartilage volumes was 5.6% (+/- 4.6), statistical analysis showing that there was high agreement between the two methods (r = 0.995, slope = 1.037, y-intercept = -90.5 mm3). The 3D thickness maps yielded a striking agreement between the two methods, the maximum values generally yielding a deviation of none or one thickness interval of 0.5 mm. This investigation shows that accurate 3D assessment of articular cartilage thickness can be performed with MRI, this technique having the advantage that it is suitable for investigating living subjects.

Adult↗
PubMed1997

A non-invasive technique for 3-dimensional assessment of articular cartilage thickness based on MRI. Part 1: Development of a computational method.

Articular cartilage thickness is of relevance in various fields in diagnostics and biomedical research. In view of recent improvements of MR cartilage imaging a computational method has been developed for three-dimensional determination of cartilage thickness from tomographic datasets. A correction algorithm that compensates for the error implied in the voxel based distance measurements is implemented. Four different thickness definitions have been applied to two numerical test structures in order to judge their usability in the medical realm. The results for each of the thickness measurement methods are shown as color-coded thickness maps wrapped round the test objects. An algorithm determining at each point the minimal distance from the articular surface to the bone-cartilage interface is suggested to give the most suitable demonstration of articular cartilage. This algorithm is successfully applied to a 3-dimensional data set of human knee joint cartilage obtained with a fat-suppressed gradient-echo sequence from a healthy volunteer. A non-invasive method for determining cartilage thickness could become a very valuable tool in diagnostic radiology, orthopaedic practice and biomechanics.

Adult↗
PubMed1997

[Three-dimensional thickness and volume measurements of the knee joint cartilage by MR tomography: reproducibility in volunteers].

OBJECTIVE: To determine the reproducibility of three-dimensional volume and thickness measurements of the knee joint cartilage with MRI in volunteers. METHODS: The knees of 7 healthy individuals (ages 23 to 58 yrs.) were sagittally imaged with a resolution of 2 x 0.31 x 0.31 mm3, using a fat-suppressed FLASH-3 D sequence. The knee was repositioned in between replicate acquisitions, 6 data sets being obtained in each case. After semiautomatic segmentation and three-dimensional reconstruction of the cartilage, the thickness was determined independent of the original section orientation. The coefficient of variation for repeated volume measurements and the deviations of the maximal cartilage thickness values were calculated subsequently. RESULTS: The mean variation of the cartilage volumes of the replicate measurements was 1.4% (+/- 0.8%) in the patella, 1.7% (+/- 1.5%) in the femur, 3.0% (+/- 1.2%) in the medial tibial plateau and 3.5% (+/- 2.0%) in the lateral tibial plateau. The comparison of the distribution patterns of cartilage thickness yielded a high degree of agreement. Only in rare cases deviations of more than 0.5 mm were observed. CONCLUSIONS: The results show that the presented method for determining the quantitative distribution of articular cartilage yields a high degree of precision. It offers new possibilities in screening risk groups, monitoring the course of degenerative joint disease and the investigation of functional adaptation of the cartilage to mechanical loading.

Adult↗
PubMed1997

Virtual reality in medicine-computer graphics and interaction techniques.

This paper describes several new visualization and interaction techniques that enable the use of virtual environments for routine medical purposes. A new volume-rendering method supports shaded and transparent visualization of medical image sequences in real-time with an interactive threshold definition. Based on these rendering algorithms two complementary segmentation approaches offer an intuitive assistance for a wide range of requirements in diagnosis and therapy planning. In addition, a hierarchical data representation for geometric surface descriptions guarantees an optimal use of available hardware resources and prevents inaccurate visualization. The combination of the presented techniques empowers the improved human-machine interface of virtual reality to support every interactive task in medical three-dimensional (3-D) image processing, from visualization of unsegmented data volumes up to the simulation of surgical procedures.

Algorithms↗
PubMed1997

Hybrid rendering of multidimensional image data.

The most important rendering methods applied in medical imaging are surface and volume rendering techniques. Each approach has its own advantages and limitations: Fast surface-oriented methods are able to support real-time interaction and manipulation. The underlying representation, however, is dependent on intensive image processing to extract the object surfaces. In contrast, volume visualization is not necessarily based on extensive image processing and interpretation. No data reduction to geometric primitives, such as polygons, is required. Therefore, the process of volume rendering is currently not operating in real time. In order to provide the radiological diagnosis with additional information as well as to enable simulation and preoperative treatment planning we developed a new hybrid rendering method which combines the advantages of surface and volume presentation, and minimizes the limitations of these approaches. We developed a common data representation method for both techniques. A preprocessing module enables the construction of a data volume by interpolation as well as the calculation of object surfaces by semiautomatic image interpretation and surface construction. The hybrid rendering system is based on transparency and texture mapping features. It is embedded in a user-friendly open system which enables the support of new application fields such as virtual reality and stereolithography. The efficiency of our new method is described for 3-D subtraction angiography and the visualization of morpho-functional relationships.

Computer Graphics↗
PubMed1996

Glycolipid-independent sorting of a secretory glycoprotein to the apical surface of polarized epithelial cells.

Proteins attached to the membrane by a glycosylphosphatidylinositol (GPI)-anchor cluster together with glycolipids in detergent-insoluble complexes at the site of sorting in the trans-Golgi network. This process has been shown to be critical for the targeting of these proteins to the apical cell surface in polarized epithelial cells. We show in this study that gp80 (clusterin), an apically secreted glycoprotein, is not included in detergent-insoluble complexes in Madin-Darby canine kidney cells. Furthermore in Fisher rat thyroid cells, which target GPI-anchored proteins preferentially to the basolateral cell surface, gp80 is secreted apically. Together these results suggest that this secretory glycoprotein and GPI-linked proteins use different mechanisms to reach the apical membrane.

Animals↗
PubMed1996

Determination of knee joint cartilage thickness using three-dimensional magnetic resonance chondro-crassometry (3D MR-CCM).

The objective of this article was to analyze the accuracy and precision with which the quantitative distribution of articular cartilage can be determined in the knee joint using MRI. A three-dimensional (3D) technique that accounts for the out-of-plane deviation of the interface normal in strongly curved joint surfaces (3D MR-CCM) has been developed for cartilage thickness measurements. Eight cadaveric knee-joint specimens and six volunteers were imaged using a fat-suppressed gradient-echo sequence at a resolution of 2 x 0.31 x 0.31 mm3. Cartilage volumes and topographical thickness maps were obtained and compared with those derived from anatomical sections by image analysis. The deviation of the MR volumes from those of the sections was 1-12%, the coefficient of variation after repositioning ranged from 2.9% (patella) to 8.2% (lateral tibial plateau). Between 60% and 80% of all image points could be attributed to identical thickness intervals, less than 20% deviating by more than 0.5 mm. The intraobserver and interobserver reproducibilities were very high in both the specimens and the volunteers. In the knee joint, 3D reconstructions of the cartilages, and measurements that take into account the out-of-plane deviation of the interface normals (3D MR-CCM), are required.

Adult↗