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Biomedical subjects

G Bartsch

Publications and source records attributed to G Bartsch.

At least 199 records · Page 11Linked to original sources
PubMed1996

Inhibitory effects of the nucleoside analogue gemcitabine on prostatic carcinoma cells.

Gemcitabine (2',2'difluoro-2'deoxycytidine, dFdC) is a synthetic antimetabolite of the cellular pyrimidine nucleotide metabolism. In a first series of in vitro experiments, the drug showed a strong effect on the proliferation and colony formation of the human androgen-sensitive tumor cell line LNCaP and the androgen-insensitive cell lines PC-3 and DU-145. Maximal inhibition occurred at a dFdC concentration as low as 30 nM. In contrast to the cell lines which were derived from metastatic lesions of prostate cancer patients, no inhibitory effects were found in normal primary prostatic epithelial cells at concentrations up to 100 nM. The effect of gemcitabine was reversed by co-administration of 10-100 microM of its natural analogue deoxycytidine. In view of a future clinical application of this anti-tumor drug in advanced prostatic carcinoma, we have compared the effect of gemcitabine on prostatic tumor cells with that on bone marrow granulopoietic-macrophage progenitor cells, because neutropenia is a common side effect of gemcitabine treatment. The time course of action on the two kinds of cells was markedly different. Colony formation of tumor cells was inhibited by two thirds at a gemcitabine concentration of about 3.5 nM. The same effect on granulopoietic-macrophagic progenitor cells required a concentration of 9 nM. Co-administration of deoxycytidine to gemcitabine-treated tumor cell cultures completely antagonized the effect of gemcitabine whereas addition of deoxycytidine after 48 hr of gemcitabine treatment could not prevent gemcitabine action on the tumor cells. In contrast, more than half of the granulopoietic-macrophagic progenitor cells could still be rescued by deoxycytidine administration after 48 hr. These findings and the marked difference in the susceptibility of neoplastic and normal prostatic cells suggest that gemcitabine is a promising substance which should be further evaluated as to its efficacy in the treatment of advanced prostatic carcinoma.

Antimetabolites, Antineoplastic↗
PubMed1996

Transurethral prostatectomy: mortality and morbidity.

In 1989 two large-scale multicenter studies on the mortality and morbidity of transurethral resection of the prostate were published [Mebust et al.: J Urol 141:243-247, 1989; Roos et al.: N Engl J Med 320:1120-1124, 1989]. These studies caused us to perform a retrospective study on a total of 1,211 consecutive patients who underwent transurethral resection of the prostate at our department between January 1988 and July 1991. The mortality rate in the 1,211 patients subjected to transurethral resection of the prostate was 0.00%; none of the patients died of intraoperative or postoperative complications. Intraoperative complications were observed in 8.9% of the patients, while the rate of early postoperative complications was 15.8%. Of the 1,211 patients operated on, 775 were followed for at least 1 year postoperatively. Late complications were noted in 11.2% of the patients. Repeat resection had to be performed in 0.9% of patients within 1 year, and in 2.5% within 3 years after surgery. A comparison of the studies by Mebust et al. and Roos et al. yielded similar rates of intraoperative and postoperative complications, whereas our mortality rate and repeat transurethral resection rate were significantly lower.

Adult↗
PubMed1996

Regulation of prostatic growth and function by peptide growth factors.

Polypeptide growth factors are positive and negative regulators of prostatic growth and function. Expression and biological effects of epidermal growth factor (EGF), transforming growth factors (TGFs) alpha and beta, fibroblast growth factors (FGFs), and insulin-like growth factors (IGFs) in the prostate have been extensively studied. EGF and TGF alpha, which share the same receptor, are strong mitogens for prostatic epithelial and stromal cells. Their paracrine mode of action in normal tissue and early-stage tumors is apparently altered towards an autocrine stimulation in hormone-independent tumors, which gain the ability to produce TGF alpha by themselves. TGF beta has a dual role in the regulation of prostatic growth. It inhibits growth of prostatic epithelial cells in culture and mediates programmed cell death after androgen withdrawal. However, advanced prostatic carcinomas become insensitive to the inhibitory effect of TGF beta. Several members of the FGF family have been identified in the prostate. They are mainly or exclusively expressed in the stromal cells, and stimulate the epithelial cells. In the rat Dunning tumor model, progression is accompanied by distinct changes in the expression of FGFs and their receptors. In the hyperplastic tissue, basic FGF (bFGF) is accumulated. This growth factor is also a potent angiogenic inducer, expression of which may determine the metastatic capability of a tumor. IGFs are paracrine growth stimulators in the normal and hyperplastic prostate. It is still under consideration whether prostatic cancer cells gain the ability to produce IGF-I by themselves and thus shift to an autocrine mode of IGF-I stimulation. Growth factors also interact with the androgen-signaling pathway. IGF-I in particular, other growth factors as well, can activate the androgen receptor.

Animals↗
PubMed1996

Blood pressure changes after extracorporeal shock wave nephrolithotripsy: prediction by intrarenal resistive index.

In order to identify a high-risk group for the development of arterial hypertension after extracorporeal shock wave nephrolithotripsy (ESWL), we correlated the increase in renovascular resistance induced by ESWL in 79 normotensive patients with changes in arterial blood pressure occurring 20 (+/- 3) months after therapy. Renal vascular resistance was measured as resistive index (RI) by duplex Doppler sonography in both kidneys. Mean RI before treatment was 0.620 +/- 0.035 (SD). After treatment, we observed a significant and age-dependent increase in the RI in the treated kidney to 0.673 +/- 0.06. Of the patients with a post-ESWL RI > 0.690, 39% developed hypertension. Posttherapy RI values surpassing 0.690 showed a 0.8 sensitivity and a 0.7 specificity in predicting arterial hypertension. Intrarenal Doppler ultrasound (US) is useful to find the high-risk group for arterial hypertension after ESWL.

Adolescent↗
PubMed1996

Incidence of urethral tumor involvement in 910 men with bladder cancer.

Urethral tumor involvement was examined in 910 patients treated for bladder cancer at a single institution over a period of 25 years. The overall incidence in 2,052 primary and recurrent bladder-tumor events was 6.1%. Risk factors for urethral tumor occurrence are tumors at the bladder neck and recurrent multifocal tumors. Carcinoma in situ (CIS) of the bladder not involving the bladder neck and muscle-invasive tumors with or without lymph-node involvement are not significantly correlated with urethral cancer. Patients at risk for urethral tumors as outlined should be worked up very carefully (multiple urethral biopsies and/or urethral brushings, frozen section of the membranous urethra) before they are considered for an orthotopic neobladder. Altogether, 17 of 89 patients had 1-6 urethral tumor recurrences. The majority of urethral tumors were treated with a single conservative treatment session and did not recur thereafter. A conservative approach toward superficial urethral tumor recurrences in patients with an orthotopic neobladder to the urethra may therefore be feasible.

Adult↗
PubMed1996

The use of orthotopic neobladders in women undergoing cystectomy for pelvic malignancy.

Since June 1990, 21 women aged from 31 to 78 years (mean, 62 years) have undergone lower urinary tract reconstruction by means of an orthotopic Kock ileal reservoir following cystectomy. The indication for cystectomy included 15 patients with transitional-cell carcinoma of the bladder, 2 patients with urachal adenocarcinoma, 1 patient with cervical carcinoma, 1 patient with a mesenchymal tumor of endometrial origin, 1 patient with interstitial cystitis, and 1 patient with a fibrotic irradiated bladder. A total of four complications (two early and two late) have occurred in this group of patients. Excellent continence has been achieved during the day and night in 95% and 89% of the patients, respectively. In all, 16 of 20 patients void volitionally per urethra without a residual urine volume, whereas 4 patients require intermittent catheterization to empty the neobladder. All patients are completely satisfied. One patient died of metastatic transitional-cell carcinoma without a pelvic recurrence. Of the remaining 20 patients, 18 are currently alive without evidence of recurrent disease. Tumor recurrence has occurred in two patients: one patient with an extensive mesenchymal tumor developed a sigmoid recurrence necessitating conversion to a continent cutaneous diversion, and one patient developed a right iliac recurrence. This initial experience with lower urinary tract reconstruction in women has yielded extraordinary results, and we feel that the option of orthotopic reconstruction following cystectomy can safely be offered to selected female patients.

Adult↗
PubMed1996

The use of neobladders in women undergoing cystectomy for transitional-cell cancer.

Recent studies have provided us with new insights into the natural history of female bladder cancer as well as the behavior of the isolated urethra after cystectomy. Based on more than 16 years of experience with orthotopic lower urinary tract reconstruction to the urethra in men, a similar approach was attempted in women with transitional-cell cancer of the bladder. Refinements in the technique of cystectomy and subsequent intestinourethral anastomosis based on anatomical, histological, and clinical studies are described that should improve postoperative results in women undergoing anterior exenteration and creation of an orthotopic neobladder to the urethra. Our findings in a series of 11 patients are presented and compared with data from other institutions. Improved postoperative continence and micturition without compromise of the oncological outcome may be a result of preservation of the entire lateral vaginal walls, nerve-sparing dissection of the bladder neck and proximal urethra, removal of 1 cm of proximal urethra en bloc with the cystectomy specimen, and a J-omentum flap or an additional attachment of the anastomosed intestinal pouch to surrounding pelvic structures. Taken together, our average of 90% daytime and 73% nighttime continence, 90% spontaneous residual-free micturition, and 100% patient satisfaction without compromise of the surgical oncological outcome seems to justify the creation of an orthotopic neobladder in selected women with bladder cancer.

Carcinoma, Transitional Cell↗
PubMed1996

Retroperitoneal lymphadenectomy for clinical stage I nonseminomatous testicular tumor: laparoscopy versus open surgery and impact of learning curve.

PURPOSE: Laparoscopic retroperitoneal lymphadenectomy for clinical stage I nonseminomatous testicular tumors was compared to open surgery, taking into account the impact of the learning curve. MATERIALS AND METHODS: Between August 1992 and September 1995, 29 consecutive patients underwent laparoscopic retroperitoneal lymphadenectomy. Open surgical retroperitoneal lymphadenectomy was performed on 30 patients between January 1988 and July 1992. RESULTS: A comparison of the 14 initial and 15 subsequent laparoscopies showed a steep learning curve (operative time shorter by 36%, blood loss decreased by 50% and postoperative hospital stay shorter by 27%). When comparing the last 15 laparoscopic procedures to the open operations, the latter were superior only in terms of operative time (shorter by 18%). With regard to all other parameters open surgery was inferior (increased blood loss by 38%, longer postoperative hospital stay by 166%, more serious complications and a greater complication rate). Antegrade ejaculation was preserved after all laparoscopic and after 28 of the 30 open operations. There were no retroperitoneal recurrences in either group (mean followup 16 months after laparoscopy and 54 months after open surgery). CONCLUSIONS: Laparoscopic retroperitoneal lymphadenectomy is a demanding operation that is superior to open surgery once the learning curve has been overcome. However, this is possible only if laparoscopic retroperitoneal lymphadenectomy is performed on a regular basis.

Adult↗
PubMed1996

Usefulness of the ratio free/total prostate-specific antigen in addition to total PSA levels in prostate cancer screening.

OBJECTIVES: Two different studies were performed. The aim of the first study was to define whether the measurement of the ratio between free and total prostate-specific antigen (f/t PSA) in serum may enhance the ability of PSA-based screening for early detection of prostate cancer in men with elevated serum PSA levels. A second study was undertaken to investigate the value of f/t PSA ratio in serum to improve the specificity of prostate cancer screening in men with serum PSA levels between 2.5 and 10.0 ng/mL. METHODS: In a retrospective study of 266 men with elevated PSA levels and proven biopsy results, f/t PSA levels were measured using deep frozen serum samples. In a second study we enrolled 158 men with elevated PSA levels according to age reference ranges apparent from our current PSA screening study with additional measurement of the f/t PSA ratio. All study volunteers with a free f/t PSA ratio cutoff point of < or = 22% underwent digital rectal examination, transrectal ultrasonography, and biopsy of the prostate. Free and total PSA levels were measured with the Delfia PSA dual label f/t PSA kit (Wallac Oy Turku, Finland). RESULTS: 106 of 158 men with elevated total PSA values between 2.5 and 10.0 ng/mL (group 1) have been further evaluated and 37 prostate cancers were detected. Mean percentage of free PSA was 10% in men with cancer and 22% in men with benign prostatic hyperplasia. Using a f/t PSA ratio of < or = 22% as a biopsy criterion 30% of the negative biopsies could be eliminated while still detecting 98% carcinomas. CONCLUSIONS: Measurement of f/t PSA reduces the number of unnecessary biopsies in PSA screening without missing many cancers.

Aged↗
PubMed1996

Laparoscopic and retroperitoneoscopic repair of ureteropelvic junction obstruction.

OBJECTIVES: The aim of this study was to evaluate laparoscopic and retroperitoneoscopic pyeloplasty and to compare the efficacy of dismembered and nondismembered techniques. METHODS: Since May 1993, a modified laparoscopic transperitoneal (14 patients) and a retroperitoneoscopic approach (3 patients) have been used for the management of ureteropelvic junction obstruction. In 7 patients aberrant vessels were encountered; 1 patient had a horseshoe kidney. Surgical repair was achieved by dismembered pyeloplasty (8 patients), nondismembered Fenger-plasty (longitudinal incision, transverse closure; 3 patients), transaction and reanastomosis of the renal pelvis (1 patient), ureterolysis and displacement of crossing vessels (4 patients). RESULTS: In 1 patient dismembered pyeloplasty could not be scheduled because of cardiovascular problems. A minimal transient lesion of the sympathetic nerve was observed postoperatively in 1 patient and pulmonary embolism in another. The operative time in dismembered pyeloplasty was between 240 and 360 minutes (mean, 280); the results were good in all patients. Equally good results were obtained with nondismembered Fenger-plasty, and the operating time was shorter (120 to 180 minutes). Ureterolysis was found to have a failure rate of 50%. CONCLUSIONS: Laparoscopic dismembered pyeloplasty yielded good results but it is too complicated to become a standard procedure. Nondismembered Fenger-plasty, which also showed good results, is more suitable for laparoscopy and retroperitoneoscopy. The indications for this technique should be defined more precisely as more experience is being collected. The results of ureterolysis when used as a single measure were poor, and, therefore, this technique should be abandoned.

Adolescent↗
PubMed1996

Prostate zones in three-dimensional transrectal ultrasound.

OBJECTIVES: This study was undertaken to evaluate the efficacy of three-dimensional transrectal ultrasound to identify and measure the prostate zones. METHODS: In an anatomic-sonographic study, eight specimens were investigated by means of three-dimensional transrectal ultrasound. Subsequently, the volumes of the prostate and the transition zone were measured by means of a special planimetric program; the images and results obtained were compared with anatomic sections and water displacement volume measurement. Then two groups of patients were investigated by means of three-dimensional transrectal ultrasound; the first group included 90 patients ranging in age from 55 to 85 years who presented with benign prostatic hyperplasia (BPH), which was verified by means of histologic examination. Three-dimensional transrectal ultrasound was performed prior to ultrasound-guided biopsies of the prostate. The second group comprised 10 patients aged between 17 and 30 years whose prostates were free of disease. RESULTS: Three-dimensional transrectal sonography is the first imaging technique that can simultaneously demonstrate relevant structures in three planes; apart from the sagittal and the horizontal (or axial) plane, the region of interest can be examined in the coronal plane as well. The structural differences of the prostatic zones in BPH and the juvenile gland can be clearly identified with the help of three-dimensional transrectal ultrasound. The coronal plane provides important additional information; the central zone and the enlarged transition zone can be identified best in this third plane. CONCLUSIONS: The prostate zones, their interrelations, and, in particular, the hyperplasia of the transition zone in BPH are clearly demonstrable. Furthermore, the size of the enlarged transition zone can be exactly measured.

Adolescent↗
PubMed1996

Electromotive diffusion (EMD) and photodynamic therapy with delta-aminolaevulinic acid (delta-ALA) for superficial bladder cancer.

Recent reports have shown that topical application of delta-aminolaevulinic acid (delta-ALA) can be used for the photodynamic diagnosis and therapy of superficial bladder tumours. Electromotive diffusion (EMD) increases the cellular uptake of polar substances. In six patients with biopsy-proven recurrent carcinoma in situ of the bladder after Bacillus Calmette-Guérin (BCG) treatment, 100 cm3 of a 0.5% delta-ALA solution at pH approximately 6 was instilled into the bladder. With a special Foley catheter containing a stainless steel electrode, EMD, with a 15 mA, pulsed current, positive polarity at the catheter, was created for 20 min in the sedated patient. Thereafter a laser fibre with a spheric diffuser was inserted into the bladder over a cystoscope. The bladder surface was irradiated at a wavelength of 632 nm with 350 mW s-1 (total dose, 30-50 J cm-2). Follow-up consisted of a cystoscopy and biopsy after 6 weeks and cystoscopy and cytology every 3 months thereafter. The whole procedure was well tolerated. Currently, five patients are tumour free after a follow-up of 10-16 months. One patient has recurred after 10 months with a Ta G3 superficial tumour at the bladder neck which was resected. In a transwell cell culture model, we investigated the effect of delta-ALA treatment with and without application of EMD. In this in vitro system, application of an electric field showed only a small increase in delta-ALA uptake compared with uptake by passive diffusion.

Aged↗
PubMed1996

Pneumothorax complicating laparoscopic ureterolysis.

In a 71-year-old female marked left-sided ureteral stenosis secondary to retroperitoneal fibrosis was diagnosed. Since conservative therapy with cortisone had failed, laparoscopic ureterolysis was performed. Following tracheal intubation the lungs were ventilated with 40 vol% O2 in air and isoflurane 0.5-2%, using a positive end-expiratory pressure of 6 cm H2O. A CO2 pneumoperitoneum was established with a pressure-controlled high-flow insufflator; the intraabdominal pressure during the procedure was 14 mm Hg. Two hours after gas instillation, the peak airway pressure increased from 22 to 40 cm H2O, and the PaCO2 from 45 to 70 mm Hg. Breath sounds over the right lung were no longer heard, and subcutaneous emphysema was noted over the neck and face. An intraoperative chest X-ray confirmed a right pneumothorax. Following peritoneal gas evacuation, the PaCO2 returned to 35 mm Hg, the subcutaneous emphysema diminished, and a repeat chest X-ray showed complete resolution of the pneumothorax. The course of this event led us to the conclusion that the pneumothorax was due to diffusion of CO2 from the peritoneal to the pleural cavity through congenital defects in the diaphragm. Ureterolysis could be continued by laparotomy.

Aged↗
PubMed1996

Laparoscopic surgery in pediatric urology.

OBJECTIVES: In pediatric urology laparoscopy is more and more used for diagnostic and therapeutic indications. METHODS: From January 1992 to August 1995, we performed 86 laparoscopic procedures in pediatric patients. RESULTS: In 23 patients with cryptorchidism laparoscopy was used for diagnostic and/or therapeutic reasons. Laparoscopic repair of varicocele (n = 37) and hydrocele (n = 4) was performed. Vesicoureteral implantation was done in 6 patients and nephroureterectomy/heminephroureterectomy in 3 and 9 patients. In 2 patients vesical diverticulum were excised laparoscopically and in intersex laparoscopy was used in 2 patients. CONCLUSION: Laparoscopy is the most reliable diagnostic tool in children with cryptorchidism and allows, if necessary, therapy in the same procedure, such as orchiectomy or dissection of the testicular vessels in preparation for a Fowler-Stephens procedure. For varicocele repair the laparoscopic approach offers a simple and effective method with a low recurrence rate. More technically demanding and performed only in specialized centers are laparoscopic nephrectomy or heminephroureterectomy. These latter procedures have shown to be superior to the open surgical approach regarding morbidity, complication rate and hospital stay.

Child↗
PubMed1996

Technique and results of laparoscopic adrenalectomy.

OBJECTIVES: Our technique of laparoscopic adrenalectomy as well as the results of this method are presented. METHODS: Transperitoneal laparoscopic adrenalectomy was performed in 18 consecutive patients (10 right side, 8 left side) for Conn's disease (7 patients), pheochromocytoma (6 patients), Cushing's syndrome (1 patient), and large inactive adenoma (4 patients). The tumor size ranged between 1 and 8 cm (mean 4.2). One of the patients, who presented with Conn's disease and bilateral adenoma, underwent enucleation of the larger adenoma on the right side leaving the uninvolved portion of the adrenal gland intact. RESULTS: The mean operative time was below 3 h; blood loss was minimal in all cases except 2. Hypertensive crisis was not encountered in this series. The only postoperative complication seen was transient diabetes insipidus which occurred in 1 patient. Analgesics were required only on the first 2 postoperative days. Oral intake and ambulation were resumed within 24 h. Mean postoperative hospitalization was 4.6 days. CONCLUSIONS: In our hands, laparoscopic adrenalectomy proved to be associated with a low morbidity and few complications. In addition, it is one of the few procedures where laparoscopy can compete with open surgery in terms of operative time.

Adrenal Gland Neoplasms↗
PubMed1996

Transforming growth factors-beta 1 and beta 2 in serum and urine from patients with bladder carcinoma.

PURPOSE: Transforming growth factors-beta (TGF-beta) are cellular regulators and potent angiogenic factors. We determined serum and urinary levels of TGF-beta 1 and beta 2 in patients with bladder carcinoma to study a correlation with tumor stage, grade and metastatic spread. MATERIALS AND METHODS: Using commercial immunoassays TGF-beta 1 and beta 2 were determined in serum and urine samples from 57 bladder cancer patients and 18 healthy controls. RESULTS: Serum TGF-beta 1 levels were significantly elevated in 21 patients with invasive bladder cancer (61.5 ng./ml.) compared to 18 healthy controls (36.3 ng./ml.), whereas serum TGF-beta 1 levels in 36 patients with superficial bladder tumors were within the normal range (33.4 ng./ml.). Serum TGF-beta 1 was increased in 27 patients with grade 3 tumors (55.7 ng./ml.), compared to 16 with grade 1 and 14 with grade 2 tumors (32.6 and 33.3 ng./ml., respectively). By contrast, serum TGF-beta 2 levels were not different from those of controls. No significant increase in serum TGF-beta 1 and beta 2 could be found in patients with lymph node metastases. In urine specimens there was no significant correlation of TGF-beta 1 and beta 2 with tumor stage. CONCLUSIONS: Our results suggest that elevated serum TGF-beta 1 may be relevant for diagnosis of bladder cancer and further studies are warranted.

Adult↗
PubMed1996

[Laparoscopic spermatic vein ligation].

Between December 1991 and November 1995 a total of 231 patients underwent laparoscopic varix ligation in our department. The laparoscopic varicocelectomy offers a lower rate of morbidity, allows for microscopic dissection with preservation of the spermatic artery and is amenable to bilateral ligation without a second incision. The spermatic arteries were identified by using a laparoscopic vascular Doppler probe. Any laparoscopic procedure carries some risk of injury to intra-abdominal organs when placing the primary trocar. Therefore, a new extraperitoneal approach has been developed to avoid these risks.

Adult↗