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Biomedical subjects

J Steffens

Publications and source records attributed to J Steffens.

At least 19 recordsLinked to original sources

Prepubic urethrectomy with urethral stripping.

PURPOSE: Prepubic urethrectomy is a simple, safe alternative to perineal urethrectomy. The lithotomy position can be avoided and, thus, operative time and risk of deep venous thrombosis are decreased. We developed a simple modification because of difficulty in dissecting the bulbous urethra. MATERIALS AND METHODS: From 1996 through 1998 prepubic urethrectomy was performed using a modified procedure in 21 patients with invasive bladder carcinoma undergoing radical cystectomy and supravesical diversion. After periurethral mobilization the urethra was cannulated with an 18F catheter, sutured distal and stripped free. RESULTS: Operative time decreased to 20 to 30 minutes with no significant postoperative complications. CONCLUSIONS: Our modification of prepubic urethrectomy is safe, fast and easy.

Humans

Critical evaluation of the specificity of MRI and TVUS for differentiation of malignant from benign adnexal lesions.

The aim of our work was to study the specificity of MRI in comparison with transvaginal US for differentiation of malignant from benign adnexal lesions. A total of 67 patients with clinically suspicious adnexal lesions were evaluated by MRI. Transaxial and coronal images were acquired using T1-weighted sequences before and following IV contrast and T2-weighted sequences. In all patients transvaginal ultrasound examinations (TVUS) were performed. For both imaging modalities each lesion was classified separately as either benign or malignant according to previously published criteria. Pathologic findings were available in 65 cases. Both MRI and TVUS correctly classified the 12 malignant lesions (sensitivity 100 %). Specificity (MRI: 78.2 %, TVUS: 65.5 %) and accuracy (MRI: 82 %, TVUS: 71.6 %) were higher with MRI than with TVUS, but differences were statistically not significant (p = 0.18 and p = 0.20, chi-square test). There was agreement/disagreement between findings of MRI and US in 52/15 lesions. The macroscopic criteria for malignancy are unspecific and result in a limitation of the specificity of both MRI and TVUS. The MRI technique is a valuable adjunct to TVUS by enabling further clarification of adnexal tumors with equivocal complex or solid vaginal sonographic findings.

Adnexal Diseases

Oral L-ornithine-L-aspartate therapy of chronic hepatic encephalopathy: results of a placebo-controlled double-blind study.

BACKGROUND/AIMS: In the current state of knowledge of the pathophysiology of hepatic encephalopathy, a reduction in hyperammonemia is the most important evidence of effective treatment. Therefore, the therapeutic efficacy of oral L-ornithine-L-aspartate, which improves impaired ammonia detoxification, was investigated in patients with cirrhosis, hyperammonemia and stable, overt, chronic hepatic encephalopathy, and in subclinical hepatic encephalopathy in a randomized, double-blind, placebo-controlled clinical trial. METHODS: Oral L-ornithine-L-aspartate was administered three times daily at fixed times for 14 consecutive days in a total dose of 18 g per day. The design was chosen to prevent an increase in ammonia induced by a protein meal of 0.25 g/kg body weight, given at the start of the daily treatment period. Efficacy variables were: fasting and postprandial ammonia concentration, Number-Connection-Test time, mental state grades, and a Portosystemic Encephalopathy Index. Analyses were based on the total study sample of 32 placebo- and 34 L-ornithine-L-aspartate-treated patients as well as on the subgroup samples in the overt (20 placebo- and 23 L-ornithine-L-aspartate-treated) and subclinical hepatic encephalopathy (12 placebo- and 11 L-ornithine-L-aspartate-treated) patients. RESULTS: Number Connection Test performance times (p<0.01) as well as fasting (p<0.01) and postprandial (p<0.05) venous blood ammonia concentrations in the L-ornithine-L-aspartate-treated group showed improvement in comparison to placebo. Also, the mental state grade (p<0.05) and the Portosystemic Encephalopathy Index (p<0.01), improved to a much greater degree in the L-ornithine-L-aspartate group than in the placebo group. Adverse events were observed in neither the placebo nor the L-ornithine-L-aspartate-treated patients. CONCLUSION: Oral L-ornithine-L-aspartate is a safe, well-tolerated treatment with a good compliance rate and a beneficial therapeutic effect in patients with cirrhosis and stable, overt, chronic hepatic encephalopathy.

Administration, Oral

[Organ preserving surgery of testicular epidermoid cyst in the newborn infant].

Epidermoid cysts are rare, benign tumors of the testis or, less frequently, the inguinal cord. Generally, they affect males between 10 and 39 years. In newborns they are rare. We report on a newborn with an epidermoid cyst of the right testis that had been diagnosed in utero and was removed with preservation of the testicle.

Epidermal Cyst

[Increased incidence of mumps orchitis in adolescence and adulthood--sequelae of low vaccination rate?].

In recent years, mumps orchitis has become a rarely reported disease. However, since October 1994 a clear increase in the incidence of this disease has been observed. At four hospitals in the Saarland, Germany, 45 cases of mumps orchitis in adolescents and adults were diagnosed in this period. In addition to the case history and clinical findings, the diagnosis was confirmed by an increased IgM titer. None of the patients had been previously vaccinated. The main reason for this was a lack of parental knowledge of the necessity for this vaccination, one which has almost no side effects. The goal of this study is to describe the disease, present our own results, and indicate the need for vaccination. In addition to providing information, a further aim of the study is to increase the motivation of adolescents and adults for vaccination. Although many treatments for mumps have been published in recent years, the most successful therapy is still prophylactic vaccination.

Adolescent

Neonatal adrenal abscesses.

Unilateral or bilateral suprarenal abscesses are rare in the neonate. We describe 2 cases, an 8-week-old Syrian female with a right, and a 6-week-old white female infant with a left adrenal abscess, both following adrenal hemorrhage. The etiology and treatment are discussed.

Abdominal Abscess

[Retroperitoneal cystic lymphangioma in a child].

Cystic lymphangiomas are rare, benign tumors, which are mainly located in the neck or axilla. The fourteenth reported case in the literature of a pediatric retroperitoneal cystic lymphangioma is described. Symptoms, diagnostic procedure and therapy are reported and discussed.

Child

[Leydig cell tumors of the testis--clinical and morphologic aspects].

Leydig cell tumors are the most common tumors of the gonadal stroma. They account for 3% of all testicular tumors. Whereas in 10% of adult cases malignancy occurs, the clinical course in children is benign. During childhood the tumor presents with precocious pseudopuberty, in adults with testicular swelling and gynecomastia. We report on 17 cases of Leydig cell tumor, paying special attention to clinical and morphological aspects.

Adult

Evaluation of mitral stenosis with velocity-encoded cine-magnetic resonance imaging.

Velocity-encoded cine-magnetic resonance imaging (VEC-MRI) is a new method for quantitation of blood flow with the potential to measure high-velocity jets across stenotic valves. The objective of this study was to evaluate the ability of VEC-MRI to measure transmitral velocity in patients with mitral stenosis. Sixteen patients with known mitral stenosis were studied. A 1.5 Tesla superconducting magnet was used to obtain velocity-encoded images in the left ventricular short-axis plane. Images were obtained throughout the cardiac cycle at 3 consecutive slices beginning proximal to the mitral coaptation point. To determine the optimal slice thickness for MRI imaging, both 10 mm and 5 mm thicknesses were used. Echocardiography including continuous-wave Doppler was performed on every patient within 2 hours of MRI imaging. Peak velocity was determined for both VEC-MRI and Doppler-echo images. Two observers independently measured the VEC-MRI mitral inflow velocities. Of the 16 patients, imaged data were incomplete in only 1 study, and all images were adequate for analysis. Strong correlations were found for measurements of mitral valve gradient for both 10 mm (peak r = 0.89, mean r = 0.84) and 5 mm (peak r = 0.82, mean r = 0.95) slice thicknesses. Measurements of peak velocity with VEC-MRI (10 mm) agreed well with Doppler: mean 1.46 m/s, mean of differences (Doppler MRI) 0.38 m/s, standard deviation of differences 0.2 m/s. These findings suggest that VEC-MRI can noninvasively determine the severity of mitral stenosis.

Adult

Regulation of prostatic smooth muscle contractility by intracellular second messengers: implications for the conservative treatment of benign prostatic hyperplasia.

The increased sympathetic neurotransmission in benign prostatic hyperplasia (BPH) results in a alpha 1C-adrenoceptor-mediated increase in prostatic smooth muscle tone which seems to be responsible for the dynamic infravesical obstruction occurring in BPH. The prostatic smooth muscle contractions evoked by norepinephrine can be efficiently blocked by alpha 1-adrenoceptor blockers. Moreover, an impressive number of clinical trials illustrated the beneficial results of alpha 1-adrenoceptor blockers in the treatment of BPH. However, despite knowledge of alpha 1-adrenergic neurotransmission and the clinical application of its blockade by selective alpha 1-adrenoceptor antagonists, very little is known about the intracellular pathways involved in the regulation of prostatic smooth muscle contractility. To study the intracellular mechanism of the alpha 1C-adrenoceptor-induced prostatic smooth muscle contraction, the patch-clamp technique in the whole-cell configuration mode combined with the Fura-II fluorescence technique was used in human, enzymatically isolated smooth muscle cells obtained from patients undergoing transurethral resection of the prostate because of symptomatic BPH. Furthermore changes in prostatic smooth muscle contractility were registered in organ bath experiments. Application of the selective alpha 1-adrenoceptor agonist phenylephrine (PE) increased the L-type Ca(2+)-channel current (ICa) dose dependently from 8 up to 18.5 microA/cm2, simultaneously elevating the free cytoplasmic Ca2+ concentration ([Ca2+]i) up to 1.9 microM. Pretreating the myocytes with pertussis toxin, an exotoxin of Bordetella pertussis which inactivates GTP-binding proteins (G proteins) of the Gi and G(o) family by ADP ribosylation, reduced the PE-induced ICa stimulation by 71.5 +/- 5.6% (n = 21). Dialysis of the cytosol with the second messenger inositol-1,4,5-trisphosphate (IP3), which releases Ca2+ from intracellular non-mitochondrial, IP3-sensitive Ca2+ pools, imitated the PE-evoked responses. Pretreating the myocytes with the Ca(2+)-release blockers ryanodine (10-100 microM, n = 8), thapsigargin (0.1 microM, n = 11) or low-molecular weight heparin (n = 14) largely attenuated the PE-evoked responses. The experimental results suggest a coupling of alpha 1-adrenoceptors to phospholipase C-converting phosphoinositol-4,5-bisphosphate into diacylglycerol, an endogenous activator of the protein kinase C and IP3 which releases Ca2+ from intracellular stores stimulating ICa via Ca(2+)-calmodulin-dependent protein kinase induced phosphorylation of voltage-dependent Ca2+ channels. This knowledge could be of interest for conservative treatment in symptomatic BPH.

Calcium Channel Blockers

Urinary undiversion after implantation of an alloplastic urethral sling for male continence.

A man in whom urinary diversion (colon conduit) was performed after 2 unsuccessful implantations of artificial urethral sphincters for treatment of iatrogenic incontinence became continent again after implantation of an alloplastic sling. Three months later the patient underwent urinary undiversion with augmentation cystoplasty. After 3 years ureteroneocystostomy was necessary due to distal ureteral stenoses. At 7-year followup the patient is continent. He has good bladder capacity, bladder emptying and a normal upper urinary tract.

Follow-Up Studies

A possible ontogenic etiology for idiopathic left varicocele.

A total of 659 consecutive patients underwent venography for the evaluation of idiopathic left varicocele before sclerotherapy. In 484 cases no valves of the left spermatic vein could be demonstrated, while 172 patients demonstrated competent valves or absent insertions of the left spermatic vein at the typical point on the left renal vein plus retrograde flow over persistent intercardinal anastomoses. Stenosis of the renal vein occurred in 103 patients (15.7%). In only 3 patients was stenosis observed in the course of the left iliac vein, suggestive of the so-called distal nutcracker phenomenon. We propose that during embryogenesis disturbances in the development of the secondary venous system may result in the idiopathic left varicocele.

Adolescent