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Biomedical subjects

F Steinbach

Publications and source records attributed to F Steinbach.

At least 19 recordsLinked to original sources
PubMed2005

[Scrotal diverticulum of the urinary bladder -- rare cause of an inguinal hernia].

INTRODUCTION: Massive herniation of the bladder through the inguinal canal is a rare entity. We report on a patient with a large inguinoscrotal herniation of the urinary bladder commonly referred as "scrotal cystocele". Diagnostic means and therapeutic strategies are discussed. CASE REPORT: After laparoscopic repair of a bilateral inguinal hernia, a 60-year-old man described a persistent right groin mass that varied in size with the degree of bladder distension. Diagnostic evaluation revealed a large bladder diverticulum extending into the right scrotum. Treatment consisted of inguinal resection of the bladder diverticulum, the peritoneal sack and closure of the hernia. CONCLUSION: Inguinal herniation of a large bladder diverticulum has to be considered in the differential diagnosis of inguinal hernias, especially in patients with obstructive symptoms of the bladder outlet.

Diverticulum↗
PubMed2005

[Intravesical adjuvant chemotherapy for superficial bladder cancer -- results of a survey in Saxony].

For patients with superficial bladder cancer, adjuvant intravesical chemotherapy or immunotherapy with Bacillus Calmette-Guerin (BCG) is recommended in national and international guidelines. We analyzed whether the recommended therapeutic regimens are used in daily urological practice. Questionnaires concerning the adjuvant intravesical therapy were sent to 152 urologists in the German Federal State of Saxony. Of the surveyed physicians, 134 practiced in an outpatient medical facility and 18 in a hospital. Of the questionnaires, 73 (48.02 %) were returned and evaluated. An adjuvant intravesical therapy after transurethral bladder tumor resection was performed in every second patient (median value 50.07 %). The majority of the urologists (79.4 %) treated the bladder tumors with intravesical chemotherapy or BCG depending on tumor stage and grade of malignancy. Chemotherapeutic agents or BCG was exclusively used in 13.6 % and 4.1 % of treated patients, respectively. Chemotherapeutic agents were predominantly applied up to the primary tumor stage T1 and malignancy grade G2. In cases with recurrent T1 bladder tumors of G2 or higher grade of malignancy, BCG was the main agent for intravesical treatment. In patients with recurrent T1G3 tumors, the majority of urologist (57.1 %) preferred another therapeutic regimen than intravesical instillation. Only 23.2 % of the urologists believed that intravesical BCG is superior to chemotherapeutic agents. These data demonstrate that adjuvant intravesical instillation with chemotherapeutic agents and BCG is well established in urological practice. In contrast to the recommendations of national and international guidelines, chemotherapeutic agents are more frequently used in cases with a high risk of progression.

Administration, Intravesical↗
PubMed2003

[Spontaneous rupture of a lumbar artery. A rare etiology of retroperitoneal hematoma].

A ruptured lumbar artery is an uncommon lesion for a retroperitoneal hematoma. This report describes a 77-year-old man with bladder carcinoma who developed a spontaneous retroperitoneal hemorrhage during anticoagulation therapy for an artificial cardiac valve. The diagnosis was suggested by computed tomography scan and confirmed with angiography. Successful treatment consisted of occluding bleeding arteries by transcatheter embolization.

Aged↗
PubMed2000

Statistics of resonances and of delay times in quasiperiodic Schrodinger equations

We study the distributions of the resonance widths P(gamma) and of delay times P(tau) in one-dimensional quasiperiodic tight-binding systems at critical conditions with one open channel. Both quantities are found to decay algebraically as gamma(-alpha) and tau(-gamma) on small and large scales, respectively. The exponents alpha and gamma are related to the fractal dimension D(E)(0) of the spectrum of the closed system as alpha = 1+D(E)(0) and gamma = 2-D(E)(0). Our results are verified for the Harper model at the metal-insulator transition and for Fibonacci lattices.

Journal Article↗
PubMed2000

New class of eigenstates in generic hamiltonian systems

In mixed systems, besides regular and chaotic states, there are states supported by the chaotic region mainly living in the vicinity of the hierarchy of regular islands. We show that the fraction of these hierarchical states scales as Planck's over 2pi(alpha) and we relate the exponent alpha = 1-1/gamma to the decay of the classical staying probability P(t) approximately t(-gamma). This is numerically confirmed for the kicked rotor by studying the influence of hierarchical states on eigenfunction and level statistics.

Journal Article↗
PubMed2000

Differential inhibition of renal cancer cell invasion mediated by fibronectin, collagen IV and laminin.

Invasion of tumor cells into the extracellular matrix is an essential step in the formation of metastases in renal cancer. Cell adhesion molecules such as beta(1)-integrins, which bind to the RGD sequence (arginine-glycine-asparagine) and CD44 are involved in this process. We examined the invasion of a renal carcinoma cell line (CCF-RC1) into the extracellular matrix compounds fibronectin, collagen IV and laminin and the effect of TGFbeta and IFNgamma on this process. The inhibitory effect of an antibody against the beta(1)-subunit of integrins (CD29), as well as a pentapeptide including the RGD sequence, was also evaluated. A micro-chemotaxis chamber, including a polycarbonate membrane with a pore diameter of 8 microm, was used for quantification of cell migration. The addition of the extracellular matrix compounds fibronectin, laminin and collagen IV resulted in a 5-10-fold increase in invasion. This increased invasion depends strongly on the presence of beta(1)-integrins, shown by the use of an antibody against CD29 or a RGD including peptide which inhibit the cell migration by approximately 88%. CD44 is less involved in collagen IV dependent migration and almost no influence of CD44 was observed on a fibronectin and laminin dependent migration. TNFalpha and IFNgamma did not significantly influence the expression of CD29 or CD44, and no alteration in tumor cell migration was observed. These results show that the invasion of renal cancer cells is differentially regulated by compounds of the extracellular matrix, whereby fibronectin seems to be the most critical factor. The molecular interactions in this process are strongly dependent on beta(1)-integrins and the corresponding amino acid sequence RGD.

Carcinoma, Renal Cell↗
PubMed2000

[Surgery of metastases in renal cell carcinoma].

Renal cell carcinomas (RCC) are endowed with impressive metastatic potential. Patients with RCC who present with apparently solitary metastatic lesions represent a small cohort. Due to the different long-term results achieved with surgical resection of metastatic RCC lesions, a generally accepted judgement about this treatment modality is not possible. Several studies suggest that aggressive surgical management can provide an effective treatment, especially in patients with solitary pulmonary metastases. Most noteworthy is the fact that because of the organ distribution of RCC metastases, surgical therapy is dominated by general and thoracic surgeons, neurosurgeons, and orthopaedic surgeons. Therefore, an interdisciplinary approach is one of the most important key points for a successful outcome in these patients.

Carcinoma, Renal Cell↗
PubMed2000

Monocytes from systemic lupus erythematous patients are severely altered in phenotype and lineage flexibility.

OBJECTIVE: Cells of the myeloid lineage comprise a very heterogeneous population with many phenotypes and functional activities including macrophages and dendritic cells. To investigate the status, differentiative potential and lineage commitment of monocytic cells in systemic lupus erythematosus (SLE) patients, this study isolated and cultured peripheral blood monocytes from patients and healthy donors. METHODS: Monocytes were isolated by gradient centrifugation and adherence to plastic dishes. The cells were then cultured for three days, partially supplemented with GM-CSF and interleukin 4 (IL4) to obtain dendritic cells. The differentiation status was monitored by the expression of surface markers using flow cytometry and cytokine secretion. RESULTS: Monocytes from SLE patients expressed significantly lower numbers of the monocytic marker CD14 and HLA-DR while secreting significantly more tumour necrosis factor alpha (TNFalpha) than monocytes from healthy donors. The addition of GM-CSF and IL4 resulted in an inhibition of TNFalpha secretion, but was not sufficient to generate monocytederived dendritic cells. CONCLUSION: Monocytes from SLE patients are severely altered in phenotype and function and have a limited differentiation flexibility towards the accessory type of monocytic cells.

Adult↗
PubMed1999

Enhanced expression of ELAM-1 on endothelium of renal cell carcinoma compared to the corresponding normal renal tissue.

Renal cell carcinoma (RCC) has been shown to respond to an immunological therapy with tumor infiltrating lymphocytes (TIL), which accumulate in RCC at a higher density than in normal renal tissue, suggesting that there is selective tumor invasion. Since invasion of TIL into the malignant tissue is mediated by adhesion molecules, we examined the different expression of the adhesion molecule endothelial-leukocyte-adhesion-molecule-1 (ELAM-1) on endothelial cells of RCC versus normal renal tissue. For a specific quantification, the level of ELAM-1 mRNA was investigated by both semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Northern blot analysis and referred to the content of endothelial cells in the tissue, determined by endothelium specific staining. Quantification of mRNA was evaluated by computer-aided integration. We observed a significantly lower amount of endothelial cells in RCC compared to normal renal tissue. The specific transcription rate of ELAM-1 in RCC, determined by RT-PCR was about 5.2 times that of normal tissue, while Northern blot analysis indicated an approximately 11.8 times increase. Our investigations show a significantly increased expression of ELAM-1 in tumor tissue compared to normal renal tissue, presumably caused by a higher amount of cytokines in the tumor tissue. This enhanced expression may be responsible for the high concentration of TIL in renal tumors.

Blotting, Northern↗
PubMed1999

Results of immunochemotherapy with interleukin-2, interferon-alpha2 and 5-fluorouracil in the treatment of metastatic renal cell cancer.

OBJECTIVE: In patients with advanced metastatic renal cell carcinoma (RCC) seen at a single institution, the toxicity and long-term clinical effects of a combination therapy with recombinant interleukin-2 (rIL-2), recombinant interferon-alpha2 (rIFN-alpha2) and 5-fluorouracil (5-FU) were evaluated. METHOD: From August 1992 through August 1997, 47 consecutive patients (38 men) with metastatic RCC were treated using rIL-2 and rIFN-alpha2 subcutaneously in combination with intravenous 5-FU. An average of 2. 4 cycles/patient (range 1-9) was administered. RESULTS: Toxicity grades II and III (World Health Organization) were observed in 24 and 17 patients, respectively. We achieved 9 major responses (7 complete responses (CR) and 2 partial responses (PR)) for an objective response rate of 19.1% (95% confidence interval 9.1-33.3%). A further 13 patients (27.7%) had a stabilization of disease. After a mean follow-up of 17.9 (2-53) months, 4 patients are alive with no evidence of disease. The 1- and 3-year survival probability was 70 and 37%, respectively. In an univariate analysis, two prognostic factors were correlated with disease outcome: Karnofsky performance index (p = 0.01) and the presence of bone metastases (p = 0.023). CONCLUSION: This triple-drug combination therapy was effective in the treatment of progressive RCC in almost every fifth patient.

Antineoplastic Agents↗
PubMed1998

In situ study on the pathogenesis and immune reaction of equine herpesvirus type 1 (EHV-1) infections in mice.

The mouse model was used to study the pathogenesis of equine herpesvirus type 1 (EHV-1) after primary and secondary intranasal infections. Within a few hours after infection, EHV-1 was found in nasal and olfactorial epithelium and sub-epithelial cells of the respiratory mucosa, but antigen-specific immune cells were never detected. Next to the lung, EHV-1 was transmitted early and directly to the brain, both via the olfactory route and the trigeminal nerve, but traces of degenerative or inflammatory processes were not detected there. In the lung, the immune cells residing or invading the parenchyma did not contain viral DNA or proteins. The primary immune response in the lungs was an alveolar and interstitial inflammation, dominated by the sequential appearance of neutrophils and macrophages, while the number of T and B lymphocytes remained unaltered. Within 24 hr after re-infection, lymphocytes accumulated around the blood vessels, outnumbering monocytes more than twofold, without neutrophils appearing. The lymphocytes comprised of little more B than T cells and the T cells were predominantly CD8+ cells. Those and B cells infiltrated the parenchyma. These results show the route of virus distribution and demonstrate the lack of antigen-specific immune cells in the lungs of mice after primary intranasal infection with EHV-1.

Animals↗
PubMed1998

Dendritic cells presenting equine herpesvirus-1 antigens induce protective anti-viral immunity.

Equine herpesvirus-1 (EHV-1) causes rhinopneumonitis, abortion and CNS disorders in horses. Using intranasal inoculation, the mouse model of this disease mimics the major pathogenic and clinical features of the equine disease. The aim of this study was to investigate whether murine dendritic cells (DC) can be infected with EHV-1 and whether they can be used as cellular vaccines for the induction of prophylactic anti-EHV-1 immunity. It was found that the DC lines FSDC, D2SC1, 18 (all H-2d) and 80/1 (H-2k), when incubated with the Ab4 strain of EHV-1, do not change their morphology and phenotype but sustain virus replication and induce proliferation of naive, syngeneic T cells. An even stronger proliferation of T cells was seen when DC were used that had been pre-exposed to heat-inactivated virus. DC lines were therefore pulsed with inactivated virus and were then administered intranasally to either BALB/c or C3H mice on days -25, -15 and -5. Control groups received either medium, unpulsed DC or inactivated virus only. Animals were challenged with EHV-1. Whereas mice of control panels showed clinical signs of EHV-1 disease and 27% died, animals immunized with the pulsed DC lines showed only subtle clinical symptoms, lost significantly less weight, exhibited a reduced virus load in their lungs and CNS and did not succumb to the disease during the observation period. These results show that murine DC can present EHV-1 and initiate a protective anti-viral immunity in vivo.

Administration, Intranasal↗
PubMed1997

Molecular regulation of intercellular adhesion molecule 1 (ICAM-1) expression in renal cell carcinoma.

Intercellular adhesion molecule-1 (ICAM-1) mediates two important functional aspects of tumor biology, namely enhancement of tumor metastasis and mediation of host defense mechanisms such as lymphocyte-mediated tumor cytotoxicity. Since ICAM-1 is expressed by most renal cell carcinomas (RCC), the regulation of ICAM-1 expression is important in understanding the biological behavior of RCC. We report an investigation on ICAM-1 expression and molecular regulation by cytokines and protein kinase C activator on RCC cell lines. Of the various cytokines, tumor necrosis factor alpha (TNF alpha), interferon-gamma (IFN gamma), and phorbol myristate acetate (PMA) strongly upregulated ICAM-1 protein expression on RCC. The kinetics of ICAM-1 message induction was studied by Northern analysis of total RNA extracted from RCC and normal kidney proximal tubular (NKPT) cells. Time course studies showed that ICAM-1 mRNA was upregulated by INF gamma, TNF alpha, and PMA, plateaued after 2 h, and remained increased for up to 24 h. Although ICAM-1 mRNA in NKPT cells was upregulated by these cytokines, their messages returned to basal levels after 24 h. ICAM-1 mRNA stability assays showed that both unstimulated and stimulated RCC cells had very stable ICAM-1 mRNA up to 24 h. In order to investigate whether increased gene transcription contributes to ICAM-1 upregulation, RCC cells were treated with TNF alpha, IFN gamma, or PMA with or without simultaneous addition of actinomycin D. ICAM-1 message induction-blocking studies suggested that primary upregulation of ICAM-1 mRNA may be caused by transcriptional upregulation. These results suggest that long-lasting ICAM-1 message upregulation in response to cytokines or PMA may be due to transcriptional upregulation in the early phase and stabilization of ICAM-1 message in the later phase (after 4 h). These observations suggest that RCC may lack the normal downregulatory mechanisms which control ICAM-1 expression and may explain the high frequency of ICAM-1 expression observed on primary human RCC.

Carcinoma, Renal Cell↗
PubMed1997

Retroviral transduction of intercellular adhesion molecule-1 enhances endothelial attachment of bladder cancer.

An intercellular adhesion molecule-1 (ICAM-1)-negative RT4 transitional cell carcinoma (TCC) cell line was transduced with full-length ICAM-1 cDNA via a retroviral vector. Flow cytometry showed that a sense-oriented clone (S20) highly expressed ICAM-1 while an anti-sense clone (AS6) did not. Both S20 and AS6 bound with equal frequency (30 +/- 8.7% vs 30 +/- 9.4%) to unstimulated human umbilical vein endothelial cells (HUVECs) in cell attachment assays. However, when phorbol myristate acetate (PMA)-activated T lymphocytes, which express lymphocyte function-associated antigen-1 (LFA-1), were cocultured with tumor cells, attachment of S20 increased twofold (60 +/- 11.9%) but AS6 showed no change (32 +/- 11%). Blocking studies with anti-LFA-1 and anti-ICAM-1 monoclonal antibodies caused an inhibition of the attachment to baseline levels, demonstrating that the enhancement of S20 attachment was dependent upon the LFA-1/ICAM-1 interaction. Enhanced attachment of S20 was not inhibited by the addition of isotypic immunoglobulin G. These results suggest that LFA-1-expressing leukocytes may act as a bridge between the endothelium and tumor cells which express ICAM-1 and, thereby, enhance the potential for hematogenous metastasis.

Carcinoma, Transitional Cell↗