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Biomedical subjects

U Jonas

Publications and source records attributed to U Jonas.

At least 19 recordsLinked to original sources
PubMed2006

Transurethral microwave thermotherapy for the treatment of BPH: still a challenger?

Minimally invasive therapies for treatment of benign prostatic hyperplasia (BPH) compete with the gold standard transurethral resection of the prostate (TURP). Comparisons of efficacy and safety have broadened the knowledge of different treatment modalities. Concerns of quality of life such as unaltered sexual function as well as cost considerations drive the market to develop techniques of lower level invasiveness. Among the competitors the office based transurethral microwave thermotherapy (TUMT) provides the broadest scale of scientific data. Numerous manufacturers sell various modifications of this technology. According to different clinical studies TUMT proved to be an effective, safe, and durable therapy for the treatment of lower urinary tract symptoms (LUTS) secondary to BPH. However, TURP still holds the steadier long-term results and is more effective to reduce obstruction as well as other LUTS.

Humans↗
PubMed2006

[Regenerative medicine in andrology: tissue engineering and gene therapy as potential treatment options for penile deformations and erectile dysfunction].

Tissue engineering and gene therapy are currently investigated in animal studies for reconstructing penile tissue or treating erectile dysfunction. This review aims to ecamine these experimental efforts from the last years and tries to give a brief introduction to the basic methodology of these new techniques from the field of regenerative medicine.

Animals↗
PubMed2006

[In vitro effects of cAMP- and cGMP-stimulating drugs on the relaxation of the prostate smooth muscle tissue contraction induced by endothelin-1].

Results from experimental studies suggested a significance of the nitric oxide (NO)-cGMP- and cAMP-pathways in the control of the function of the smooth musculature of the human prostate. In addition, it has also been assumed that the vasoconstrictory peptide endothelin-1(ET-1) may play a role in the dynamic component of benign prostatic hyperplasia (BPH) and the so-called lower urinary tract symptomatology (LUTS). Nevertheless, up till now, little is known as to potential interactions between the contraction of prostatic smooth muscle mediated by ET-1 and the relaxation induced by NO and cGMP. Thus, it was the aim of the study to elucidate the effects of drugs interfering with the cGMP-pathway on the tension induced by ET-1 of isolated human prostate tissue, as well as contractile responses of isolated strip preparations to ET-1 and angiotensin-II (AT-II). Macroscopically normal human prostate tissue from the transition zone was obtained from male patients who had undergone surgery for localized cancer of the prostate or urinary bladder. Using the organ bath technique, the ability of ET-1 and AT-II to contract isolated prostate strips was evaluated. In another set-up, the effects of the NO-donor S-nitrosogluthatione (GSNO) and C-type natriuretic peptide(CNP), known as an endogenous ligand of the membrane bound guanylyl cyclase, (1 nM-1/10 microM) on the tension induced by 0.1 microM ET-1 of human prostate strips were investigated. The adenylyl cyclase stimulating agents forskolin and NO-donor natrium nitroprusside (NNP) were used as reference compounds. While AT-II failed to contract the prostate tissue, ET-1 induced stable and reproducible contractions of the tissue strips. The tension induced by 0.1 microM ET-1 was dose-dependently reversed by the drugs. The rank order of efficacy was forskolin >NNP>CNP(1 microM)>GSNO. R(max) values ranged from 55% (forskolin) to 35% (GSNO). Forskolin was the only compound which reached an EC50 value. Our results demonstrate that drugs in terfering with the cGMP- and cAMP-pathways can reverse the tension induced by ET-1. These findings are in support of the hypothesis that both cGMP and cAMP contribute to the control of the prostate smooth muscle tension and may provide new strategies for the future pharmacotherapy of LUTS und BPH.

Adenylyl Cyclases↗
PubMed2006

[Spontaneous ruptures of the urinary bladder in the routine forensic examination].

This article analyses three cases of death following a spontaneous rupture of the urinary bladder. One case is based on an extensive tamponade of the bladder eight days after a transurethral resection of the prostate gland. Two other cases of death by spontaneous rupture resulted from increased alcohol consumption. The paper presents an overview of pathomorphological findings such as the typical intraperitoneal rupture localisation at the posterior wall of the urinary bladder or bladder dome and the subsequent diagnosed causes of death. In addition predisposing (anamnestic) influencing factors such as chronic alcoholism are highlighted and their relevance for the clinical urologist and the forensic pathologist are discussed.

Adult↗
PubMed2005

The spectrum of vibration modes in soft opals.

Numerous vibrational modes of spherical submicrometer particles in fabricated soft opals are experimentally detected by Brillouin light scattering and theoretically identified by their spherical harmonics by means of single-phonon scattering-cross-section calculations. The particle size polydispersity is reflected in the line shape of the low-frequency modes, whereas lattice vibrations are probably responsible for the observed overdamped transverse mode.

Journal Article↗
PubMed2005

The therapeutic value of adrenalectomy in case of solitary metastatic spread originating from primary renal cell cancer.

INTRODUCTION: Solitary adrenal metastases occur in about 1.2-10% of renal cell cancer patients. Since the vast majority of intraadrenal lesions can be detected preoperatively, we and others have recently recommended to renounce a routine adrenalectomy during surgery of renal cell cancer. However, the impact of adrenalectomy on the patients' clinical prognosis in case of a solitary metastatic lesion within the adrenal gland remains an issue of controversial discussion. Whereas some authors suggest adrenalectomy as a potentially curative treatment option in these cases, others compare its clinical value with that of a mere lymphadenectomy. PATIENTS AND METHOD: Between 1981 and 2000, 648 patients (440 males and 208 females) underwent nephrectomy in combination with adrenalectomy in our clinic for the diagnosis of renal cell cancer. The median age at first diagnosis was 59 (range 33-84) and 60 (range 20-85) years for male and female patients, respectively. The median postoperative follow - up was 2.4 years (0.2-18 years). According to the TNM - classification system (2003) tumor stages were classified as follows: T1, 228 pat. (37%); T2, 70 pat. (11%); T3, 287 pat. (46%); T4, 37 pat. (6%). In total, 339 patients revealed regional lymph node or distant metastases at the time of the surgical treatment. Although metastases of the adrenal gland were diagnosed in 48 patients, solitary intraadrenal metastases without further systemic spread were observed in only 13 cases. Several patients' and tumor characteristics (age, tumor stage and size, the presence of regional lymph node metastases, the presence of metastatic lesions at different organ sites as well as the detection of solitary intraadrenal metastases) were correlated with the patients' overall survival by univariate and multivariate statistical analysis (logistic Cox regression analysis). RESULTS: The median long - term survival was 4.8 years for the entire cohort of patients investigated. The median long - term survival was 13.8 years and 11.7 years for patients with no evidence of metastatic spread as well as for patients with a solitary intraadrenal metastatic lesion, respectively. Accordingly, the long - term survival rates at 5 and 10 years after surgery were 66%/50% and 51%/51% for patients with no evidence of metastatic spread or isolated intraadrenal metastases. This difference was not statistically significant. In contrast, for patients revealing lymph node or distant metastases at other organ sites, the median long - term survival was significantly decreased (lymph node metastases: 0.7 years; distant metastases: 1.2 years). DISCUSSION: For patients with a solitary intraadrenal metastatic lesion, adrenalectomy is a potentially curative treatment option. The observation that the long - term survival of the latter patients is comparable to that of patients with organ - confined disease might suggest the establishment of a separate TNM - category for patients revealing a solitary metastasis within the adrenal gland and no hint at further systemic metastatic spread.

Adrenal Gland Neoplasms↗
PubMed2005

[Medical therapy of urinary incontinence].

Urinary incontinence has a high prevalence in both men and women. Women suffer predominantly from stress urinary incontinence and men from urge incontinence. Other types of incontinence are less frequent. Stress urinary incontinence is caused by an insufficient urethral closure mechanism and urge incontinence by uninhibited detrusor contractions. Medical treatment is beside other conservative options and operations only one part of the treatment strategy in incontinence. Duloxetine, a serotonine-norepinephrine reuptake inhibitor, is used to treat stress urinary incontinence, can increase activity of the external urethral sphincter and is able to reduce incontinence episodes in up to 64%. Antagonists of muscarinic receptors can reduce urgency, frequency and urge incontinence as well as increase bladder capacity significantly. In Germany, trospium chloride, tolterodine, solifenacin, oxybutynin and propiverine are available to treat urge incontinence. Efficacy of these agents are comparable. However, tolerability is different and side effects, especially dry mouth, often limit their use. None of the agents show ideal efficacy or tolerability in all patients and, therefore, new agents and formulations are currently under clinical investigation.

Cholinergic Antagonists↗
PubMed2004

Interleukin-2- and interferon alfa-2a-based immunochemotherapy in advanced renal cell carcinoma: a Prospectively Randomized Trial of the German Cooperative Renal Carcinoma Chemoimmunotherapy Group (DGCIN).

PURPOSE: We conducted a prospectively randomized clinical trial to compare the efficacy of three outpatient therapy regimens in 341 patients with progressive metastatic renal cell carcinoma. PATIENTS AND METHODS: Patients were stratified according to known clinical predictors and were subsequently randomly assigned. Treatment arms were: arm A (n = 132), subcutaneous interferon alfa-2a (sc-IFN-alpha-2a), subcutaneous interleukin-2 (sc-IL-2), and intravenous (IV) fluorouracil; arm B (n = 146): arm A treatment combined with per oral 13-cis-retinoic acid; and arm C (n = 63), sc-IFN-alpha-2a and IV vinblastine. RESULTS: Treatment (according to the standard 8-week Hannover Atzpodien regimen) arms A, B, and C yielded objective response rates of 31%, 26%, and 20%, respectively. Arm B, but not arm A, showed a significantly improved progression-free survival (PFS) compared with arm C (P =.0248). Both arm A (median overall survival, 25 months; P =.0440) and arm B (median overall survival, 27 months; P =.0227) led to significantly improved overall survival (OS) compared with arm C (median OS, 16 months). All three sc-IFN-alpha-2a-based therapies were moderately or well tolerated. CONCLUSION: Our results established the safety and improved long-term therapeutic efficacy of sc-IL-2 plus sc-INF-alpha-2a-based outpatient immunochemotherapies, compared with sc-INF-alpha-2a/IV vinblastine.

Adult↗
PubMed2004

[Endoscopic extraperitoneal radical prostatectomy. Results after 300 procedures].

During the last decade laparoscopy has become the standard technique in the urologist's armamentarium due to constant technological advancements and refinements. Laparoscopic radical prostatectomy (LRPE), although technically demanding and associated with a considerable learning curve, has become the operative procedure of choice for patients with clinically localized prostate cancer in selected and specialized urologic centers around the globe. However, a major drawback of LRPE is the transperitoneal route of access to the extraperitoneal organ of the prostate. The principal disadvantages of LRPE are potential intraperitoneal complications. Endoscopic extraperitoneal radical prostatectomy (EERPE) is a further advancement of minimally invasive surgery as it overcomes the limitations of LRPE by the strictly extraperitoneal route of access. Based on our growing experience with this procedure we introduce several technical modifications, improvements, and refinements including a nerve-sparing, potency-preserving approach (nEERPE) in an effort to further improve this minimally invasive procedure. We report our short-term follow-up results after 300 procedures. The mean operative times were 115 min without and 150 min with lymph node dissection, in total 140 min (range: 60-260 min). There was no conversion and the transfusion rate was 1.3%. There were three early reinterventions (two bleeding and one hematoma) and five late reinterventions (four symptomatic lymphoceles and one colostomy due to a rectal fistula). Pathological stage was pT2a in 54 patients (18%), pT2b in 87 patients (29%), pT3a in 115 patients (38.3%), pT3b in 40 patients (13.3%), and pT4 in 4 patients (1.3%). Positive surgical margins were found in 9.2% (13/141) of patients with pT2 tumor and 30.3% (47/155) of patients with pT3 tumor. The mean catheterization time was 6.9 days. Six and twelve months postoperatively 86.3 and 89.6% of the patients were completely continent; 9.2% of patients needed 1-2 pads per day and 4.5 and 1.2% of patients needed more than 2 pads per day, respectively. Short-term oncological and functional results of EERPE are at least as favorable as in LRPE while operative times are shorter and complication rates are low. EERPE is a technical advancement because it combines the advantages of a totally extraperitoneal access with the advantages of a minimally invasive procedure.

Adult↗
PubMed2004

[The prevalence of sexual problems in female medical students].

Female sexual dysfunction and even female sexual function are widely unknown. We therefore evaluated the sexual behaviour of younger and older women using a questionnaire. A total of 998 young women entered the study at Hannover Medical school. They were between 19 and 43 years old (median 24 years), and 64% answered the questionnaire. A total of 97.1% of the female students were heterosexual, 1.6% were lesbians and 1.3% were bisexual. Lack of sexual intercourse in the previous month was recorded by 21.1%, while 21.3% recorded intercourse 1-3 times a month, 46.8% 1-3 times a week and 5.5% daily. Adverse reactions to sexual situations were reported by 25% of the women, 20.5% had a negative perception for special partners or circumstances. Some 55% of the evaluated women were satisfied with their sexual life in the last month, 20% were fairly satisfied and 21% were un-satisfied. This study of a selected population of medical students shows a wide variety of sexual problems with a high prevalence of different disorders.

Adult↗
PubMed2004

[Biological vascularized matrix (BioVaM): a new method for solving the perfusion problems in tissue engineering].

A new technique is presented to harvest an acellular matrix from a porcine small bowel segment preserving the mesenteric arterial and venous pedicles. Reseeding of this biological vascularized matrix (BioVaM) with functional cells, i.e. smooth muscle and urothelial cells isolated from the urinary tract, and resurfacing of its vascular structures with endothelial precursor cells results in a vascularized tissue engineered graft for reconstruction and augmentation of the urinary bladder. First promising short term implantation experiments using a porcine model for the evaluation of early graft perfusion after vascular anastomosis are presented.

Animals↗
PubMed2004

[Positron emission tomography (PET) for diagnosis and monitoring of treatment for urological tumors].

Positron emission tomography (PET) using ((18)F)2-fluoro-D-2-desoxyglucose (FDG) has been shown to be a highly sensitive and specific imaging modality in the diagnosis of primary and recurrent tumors and in the control of therapies in numerous non-urologic cancers. It was the aim of this review to validate the significance of PET as a diagnostic tool in malignant tumors of the urogenital tract. A systematic review of the current literature concerning the role of PET for malignant tumors of the kidney, testicles, prostate, and bladder was carried out. The role of FDG PET for renal cell cancer can be seen in the detection of recurrences after definitive local therapy and metastases. The higher sensitivity of PET in comparison to other therapeutic modalities (CT, ultrasound, MRI) in recurrent and metastatic renal cell cancer suggests a supplemental role of this diagnostic procedure to complement other imaging modalities.The clinical value of PET is established for the identification of vital tumor tissue after chemotherapy of seminomatous germ cell tumors. This diagnostic method has little significance for primary tumor staging and diagnosis of non-seminomatous germ cell tumor because of the high probability of false-negative results in adult teratomas. FDG PET is not sensitive enough in the diagnosis of primary or recurrent tumors in prostate or bladder cancer. Also PET did not prove to be superior to conventional bone scintigram in the detection of mostly osteoblastic metastases in prostate cancer. The recent use of alternative tracers, which are partly not eliminated by urinary secretion (acetate, choline) has increased the sensitivity and specificity of PET also in this tumor entity so that further clinical investigations are needed to validate these technical modifications in their significance for this imaging modality. PET appears to be sufficiently evaluated only for the diagnostic follow-up of patients with seminomatous germ cell tumors after chemotherapy to regard it is the diagnostic tool of first choice. For all other tumors of the urogenital tract this proof is still awaited.

Algorithms↗
PubMed2004

Late relapse after treatment for nonseminomatous testicular germ cell tumors according to a single center-based experience.

The introduction of cisplatin-based systemic chemotherapy into the clinical routine has resulted in a substantial improvement of the recurrence-free and long-term survival of patients with metastatic testicular germ cell tumors. Late relapses after the completion of first-line therapy, comprising systemic chemotherapeutic treatment in combination with a complete resection of residual tumor masses visible in about 25-50% of patients, have been reported to occur in 1-5% of patients later than 2 years following the initial treatment. It has been reported that the risk for the development of late recurrence is correlated to the tumor burden at first diagnosis and/or the presence of teratomatous components within the primary testicular cancer. Second-line chemotherapy in combination with surgery, although not very well standardized, has been recommended as the most effective therapeutic regimen during the treatment of patients suffering from late recurrent germ cell tumors. Herein, we report our single-center experience with 14 patients in different clinical stages who developed late relapse after successful first-line therapy. In the present series, the risk for late relapse was not correlated to the clinical stage at first diagnosis or the presence of teratomatous elements within the primary tumor. It became evident that in selected cases chemotherapy alone can be considered a curative treatment option.

Combined Modality Therapy↗
PubMed2004

Testosterone therapy in the ageing male: what about the prostate?

The concerns about testosterone therapy in ageing men with late-onset hypogonadism mainly address the risk of prostatic disease, i.e. either benign prostatic hyperplasia (BPH) or prostate cancer (PCa). Both conditions are highly dependent on androgen action and recent clinical data on the cancer-preventive effect of the 5alpha-reductase inhibitor finasteride have supported the possible role of androgens in PCa. However, the clinical data especially on the long-term effects of exogenous androgen substitution in regard to prostate safety are nonconclusive in many respects. As sufficient clinical studies on these risks will not be available in the near future, the approach of testosterone therapy towards prostate complications should be kept on a safe but practical basis. This review includes some recommendations in regard to testosterone therapy and prostate monitoring in patients with BPH and bladder outlet obstruction, with previous history of curative treatment for PCa or with prostatic intraepithelial neoplasia.

Humans↗
PubMed2003

Controlled, double-blind, multicentre clinical trial to investigate long-term tolerability and efficacy of trospium chloride in patients with detrusor instability.

Our objectives were to ascertain the tolerability and efficacy of trospium chloride in doses of 20 mg twice daily for long-term therapy (52 weeks) in patients with urge syndrome. The trial comprised a total of 358 patients with urge syndrome or urge incontinence. After randomisation in the ratio of 3:1, participants were treated continuously for 52 weeks with either trospium chloride (20 mg twice daily) or oxybutynin (5 mg twice daily). At intervals of 4-8 weeks, patients were physically examined with measurements of blood pressure and pulse rate, were questioned about any adverse events, checked for compliance and underwent relevant laboratory tests. As an additional safety measure, an ECG was made at 26 and 52 weeks. Urodynamic measurements were performed at the beginning, and at 26 and 52 weeks to determine the maximal cystometric bladder capacity. Among others things, the frequencies of micturition, incontinence and number of urgency events were recorded in patient diary protocols in weeks 0, 2, 26 and 52. The evaluation of vital parameters, laboratory results and ECGs did not show any relevant changes attributable to the action of the anticholinergics. Analysis of the micturition diary clearly indicated a reduction of the micturition frequency, incontinence frequency, and a reduction of the number of urgencies in both treatment groups. Mean maximum cystometric bladder capacity increased during treatment with trospium chloride by 92 ml after 26 weeks and 115 ml after 52 weeks (P=0.001). Further comparison with oxybutynin did not reveal any statistically significant differences in urodynamic variables between the drugs. Adverse events occurred in 64.8% of the patients treated with trospium chloride and 76.7% of those treated with oxybutynin. The main symptom encountered in both treatment group was dryness of the mouth. For patients on trospium chloride, the estimated risk of an unexpected adverse event was 0.027 per patient per week for all adverse events and 0.009 for dryness of the mouth, resulting in a considerably lower risk during treatment given with trospium chloride than with oxybutynin (0.045 and 0.021, respectively). An overall assessment for each of the drugs reveals a comparable efficacy level and a better benefit-risk ratio for trospium chloride than for oxybutynin due to better tolerability.

Adult↗