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Biomedical subjects

M Stöckle

Publications and source records attributed to M Stöckle.

At least 37 records · Page 2Linked to original sources
PubMed2002

[Cerebrospinal fluid shunting: anesthetic particularities].

The symptomatic treatment of hydrocephalus remains cerebrospinal fluid (CSF) drainage to an external reservoir (external CSF drainage) or to an internal cavity mainly the peritoneum or the right atrium via a unidirectional valve (internal CSF drainage) and finally by endoscopic ventriculocisternostomy. Local anaesthesia is adequate for external CSF drainage in adults and children above 10 years while general anaesthesia is required in all other cases. The main problems encountered in these patients are difficult intubation and full stomach associated with increased intracranial pressure. The anaesthetic approach should favour homeostasis. With the exception of ketamine and enflurane, the majority of anaesthetic drugs can be used. Anti-epileptic drug are mandatory. Antibioprophylaxis mainly against staphylococcus is systematic in internal CSF drainage. Rapid emergence from anaesthesia and extubation should be encouraged. Complications (infectious, mechanical and bleeding kinds) are frequent and are often the cause of reinterventions or revisions of the device, exposing the patients to iterative anaesthesia. Furthermore, patients with shunts are at risk of malfunction of the device when exposed to situations like pregnancy, magnetic resonance imaging, or laparoscopy. Under these circumstances, it is recommended to associate the neurosurgical team in the management of these patients and to verify that the shunt is working well before and after the procedure or event.

Anesthesia↗
PubMed2001

Cyclic homooligomers from sugar amino acids: synthesis, conformational analysis, and significance.

Sugar amino acids (SAAs) were designed as new building blocks carrying an amino group and a carboxyl group on a carbohydrate scaffold. By exploiting standard solid- and solution-phase coupling procedures, linear and cyclic homooligomers containing glucosyluronic acid methylamine (Gum) were synthesized. We achieved a high yield and a very short coupling time for the oligomerization and cyclization of sequences encompassing two, three, four, and six Gum units. The synthesis of cyclic oligomers containing only SAAs as repetitive units has not been reported before. The conformational preferences in aqueous solution of the cyclic derivatives and their applications as potential host molecules are described herein. Benzoic acid and p-nitrophenol were chosen as model guest molecules to study the formation of cyclodextrin-like inclusion complexes. The complexation behavior of the cyclic hexamer was proved from three different points of view: chemical shifts, longitudinal relaxations (T(1)), and diffusion coefficients. All of them showed different values for host and guest molecules measured independently and in the presence of each other.

Amino Acids↗
PubMed2001

Comparison of the malignant phenotype and genotype of the human androgen-independent cell line DU 145 and a subline derived from metastasis after orthotopic implantation in nude mice.

To investigate the potential genetic changes underlying the progression of human hormone-resistant prostate cancer, we related chromosomal alterations of the DU 145 cell line and a subline isolated form a metastasis in an orthotopic model to tumorigenicity, metastasis and chemoresistance. In 15 mice 1 x 10(5) DU 145 cells were injected into the dorsal prostate. From a resulting paraaortic lymphnode metastasis, we isolated a subline (DU 145 MN1), which was injected into 15 nude mice. The sulforhodamine B (SRB) assay was used to analyze cell doubling time and the IC(50) of cisplatin and 5-fluorouracil for both cell lines. Cytogenetic characterization was performed with conventional karyotype analysis and fluorescence in situ hybridization (FISH). After orthotopic implantation of DU 145 cells tumorigenicity was 100% whereas only 2 mice revealed lymphnode metastases. In contrast, the take rate after implantation of DU 145 MN1 was 100%, with lymphnode metastases in 7 mice. The SRB assay revealed a 8-fold increased IC(50) for cisplatin and a 2.5-fold increase for 5-FU in DU 145 MN1 as compared to DU 145 cells. There was gain of a chromosome 8 and only two copies of chromosome 17 in the DU 145 MN1 cells as compared to the parental cell line. The emergence of an i(9)(q10) in addition to two normal chromosome 9 homologues in the DU 145 MN1 cell line was confirmed by FISH using a chromosome 9-specific painting probe. In summary, clonal evolution of the chromosomal changes following repeated orthotopic implantation, may assist in locating the genes involved in the progression and chemoresistance of human hormone-resistant prostate cancer.

Androgens↗
PubMed2001

[Bilateral kidney tumor. Therapy management and histopathological results with long-term follow-up of 66 patients].

Bilateral renal cell carcinoma is detected at an incidence rate of 1.6-6% of all renal tumors. The management, histopathological results and the long-term follow-up of 66 patients with bilateral renal cell carcinoma (29 synchronous, 37 asynchronous tumors) are presented in this issue. The incidence rate of bilateral renal cell carcinoma (RCC) at our hospital was 3.5%. Nephron-sparing surgery should be used first for the smaller and favourably located tumor when radical nephrectomy of the contralateral tumor is necessary. Thus, the patients can be spared dialysis. The histopathological results showed a significantly higher incidence rate of chromophil RCCs in cases of synchronous bilateral renal tumors (36%). The 5-year survival rate was 82%. Patients with asynchronous renal cell carcinomas were significantly younger than those with synchronous RCCs (median age: 60.2 years). The histopathological results were similar to unilateral renal cell carcinomas. Clear cell carcinoma was detected in 70% of cases. The 5-year survival rate was 61% and lower than that of synchronous tumors (82%). There was no significant difference because of the small number of cases. Current standardised techniques of nephron-sparing surgery achieve good survival rates, therefore making bilateral nephrectomy only necessary in very poor cases. In cases of chromophil renal cell carcinomas, the contralateral kidney should always be carefully examined, because these tumors were significantly more often detected to be bilateral. The risk of also developing a tumor in the contralateral kidney increases with decreasing age at first manifestation (< 55 years, 6%). Especially in those younger than 55 years, partial nephrectomy seems to be recommended for unilateral renal tumors in patients with a normal contralateral kidney (tumor size < 4 cm in diameter).

Adenocarcinoma, Clear Cell↗
PubMed2001

[After-care of bladder carcinoma].

The present article offers an introduction to the aftercare of patients with carcinoma of the urinary bladder. These recommendations are based on the guidelines of the German Association of Urology and the European Association of Urology. Aftercare always depends on the risk of recurrence and progression of the primary tumor and the extent of the therapy applied. Thus, after transurethral resection of a superficial carcinoma of the urinary bladder, aftercare focuses on follow-up cystoscopy. Radical cystectomy of the muscle-invading and locally advanced carcinoma should be followed by extensive examinations, including computed tomography of the pelvis and the abdomen. In addition, the various forms of urinary diversion after cystectomy with its specific late complications should be included in the aftercare. Moreover, the psychological significance of the follow-up examinations should not be neglected.

Aftercare↗
PubMed2001

The role of adjuvant chemotherapy for locally advanced bladder cancer.

The incidence of locally advanced bladder cancer is estimated at 5 new cases per 100,000 of the population annually in North America and most European countries. Radical cystectomy for muscle-invasive organ-confined tumors and locally advanced disease, which is defined as extravesical tumor growth or involvement of regional lymph nodes, is the preferred treatment in Japan, the United States, and in some countries of Europe. The clinical outcome of radical cystectomy has improved remarkably over the past 20 years as a result of advances in operative technique and perioperative care. Nevertheless, at least 50% of patients with invasive bladder cancer are expected to develop progressive disease within the first 2 years when treated with radical cystectomy alone. In order to improve the fate of muscle-invasive and locally advanced disease, the administration of additional therapy to definite treatment has been studied in various forms, such as neoadjuvant and adjuvant systemic chemotherapy as well as combined radio-chemotherapy. Prolonged progression-free survival for patients suffering from locally advanced bladder cancer by administration of adjuvant systemic chemotherapy has been suggested by three randomized studies, published by Skinner, Freiha and Stöckle since 1991. These studies demonstrated a disease-free survival benefit of 17-50% within the first 3-5 years when applying adjuvant systemic chemotherapy after radical cystectomy. Patients who most likely benefit from adjuvant chemotherapy are those with limited node-positive disease, extravesical tumor, and direct invasion into adjacent viscera, such as prostate, uterus, or vagina. This review will summarize past, current, and future aspects of systemic adjuvant chemotherapy for transitional cell carcinoma of the bladder.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2001

Prostate-specific antigen in female urine: a prospective study involving 217 women.

OBJECTIVES: Histomorphologic studies have provided evidence of prostate-specific antigen (PSA)-producing tissue in the female urethra. Some urine samples from women in a small series were positive for PSA, but no systematic investigation of this subject has been done to date. METHODS: In a prospective study, we analyzed whether PSA occurs in the urine of women and what factors induce detectable PSA levels. The urine samples of 217 women were analyzed (Hybritech-Tandem E-PSA) under standardized conditions. The impact of urine pH and volume was investigated, and the results were correlated with clinical data (age, residual urine, urinary tract infection and prior sexual intercourse within 48 hours). RESULTS: A positive PSA level greater than the detection limit of 0.1 ng/mL was found in 11% of the analyzed samples; their mean value was 0.29 ng/mL. pH correction did not result in a significant difference. The voiding volume had no influence on the PSA level. Among the cases of detectable PSA, women younger than 50 years of age (n = 14) had a mean PSA of 0.34 ng/mL and those older than 50 years (n = 9) a mean of 0.23 ng/mL. One of 9 women with and 22 of 208 women without residual urine volume had a detectable PSA level, as did 0 of 20 with and 23 of 197 women without urinary tract infection, and 3 of 7 with and 20 of 210 women without prior sexual intercourse within the previous 48 hours. None of the differences were significant. CONCLUSIONS: A urine PSA level was detected in 11% of all women studied, with PSA values apparently age dependent. Any urine portion is suitable for analysis. No influence was determined for residual urine volume or urinary tract infection. Sexual intercourse may cause detectable PSA values, but the data of this study did not provide sufficient evidence for this hypothesis.

Adult↗
PubMed2001

Cytokeratin-20 reverse-transcriptase polymerase chain reaction as a new tool for the detection of circulating tumor cells in peripheral blood and bone marrow of bladder cancer patients.

OBJECTIVES: Systemic progression is the prevalent form of bladder tumor recurrence after radical cystectomy. The ability to detect circulating tumor cells in peripheral blood or bone marrow could be of prognostic value for the disease with the consequence of early adjuvant chemotherapy. We established a sensitive and specific method using a double cytokeratin-20 (CK-20) reverse-transcriptase polymerase chain reaction (RT-PCR) to detect circulating bladder cancer cells in venous blood and bone marrow MATERIAL AND METHODS: The sensitivity of the detection method was determined by a serial dilution of bladder cancer cells from the cell line HT1376 in whole blood. Bone marrow from 20 bladder cancer patients was drawn prior to radical cystectomy and CK-20 cDNA was amplified by RT-PCR. Additionally, pre- and postoperative venous blood samples from 11 of these patients with bone marrow aspirates and 9 patients undergoing only transurethral resection of the bladder as well as blood samples of 25 healthy volunteers were investigated by CK-20 RT-PCR. RESULTS: The detection limit of the method was 2 bladder cancer cells/ml whole blood containing one million peripheral blood mononuclear cells. The positive detection rate in bone marrow was 7 of 20 (35%) for bladder cancer patients of all stages. However, investigation of the preoperatively collected venous blood samples from 20 patients revealed onyl 2 positive findings, belonging to advanced tumor stages pT4pN0M0 and pT3pN2M0. In contrast, CK-20 was detected in 3 of 20 postoperatively collected venous blood samples from patients with low tumor stages (pTaNXM0 and pT1NXM0) as well as from 1 patient with pelvic lymph node metastases (pT3apN2M0). All venous blood samples of the control group (n = 25) were negative for CK-20. CONCLUSION: The detection of circulating bladder tumor cells in venous blood and bone marrow by the CK-20 RT-PCR is a promising approach that could improve risk assessment and the identification of bladder cancer patients who would benefit from adjuvant chemotherapy.

Adult↗
PubMed2000

Long term follow-up of combined radiochemotherapy for locally advanced bladder carcinoma.

BACKGROUND: The 5- and 10-year survival rates and the toxicity of combined radiochemotherapy for 53 consecutive patients with locally advanced bladder carcinoma were studied in a noncomparative trial. METHODS: Between November 1986 and October 1987, 53 consecutive patients (mean age, 68 years) with muscle invasive and/or locally advanced bladder carcinoma were treated by simultaneous chemotherapy and hyperfractionated irradiation. Radiation was administered during the first to fourth week and during the ninth to tenth week as an interrupted treatment protocol. Cisplatin and epirubicin were used as radiosensitizers before radiation. The maximum dose of irradiation was 57.6 grays. RESULTS: Of 53 patients, 45 completed the planned treatment course. Causes for discontinuing therapy in 8 patients were pronounced myelosuppression (n = 2), severe gastrointestinal symptoms (n = 2), nephrotoxicity (n = 1), and severe radioproctitis (n = 1). Two additional patients stopped therapy due to vascular diseases independent of treatment-related toxicity. The overall survival for all 53 patients was 23% after 5 years and 8% after 10 years. Cause specific survival was 36% after 5 years and 29% after 10 years. Four patients are still alive after 10 years without disease progression. One of them received incomplete therapy due to toxicity. All four patients underwent transurethral resections for superficial, local tumor recurrences. CONCLUSIONS: The poor prognosis group of patients with invasive and/or locally advanced bladder carcinoma was found to have a limited disease specific survival after combined radiochemotherapy.

Adult↗
PubMed2000

[Improvement of transrectal ultrasound. Artificial neural network analysis (ANNA) in detection and staging of prostatic carcinoma].

As a result of the enhanced clinical application of prostate specific antigen (PSA), an increasing number of men are becoming candidates for prostate cancer work-up. A high PSA value over 20 ng/ml is a good indicator of the presence of prostate cancer, but within the range of 4-10 ng/ml, it is rather unreliable. Even more alarming is the fact that prostate cancer has been found in 12-37% of patients with a "normal" PSA value of under 4 ng/ml (Hybritech). While PSA is capable of indicating a statistical risk of prostate cancer in a defined patient population, it is not able to localize cancer within the prostate gland or guide a biopsy needle to a suspicious area. This necessitates an additional effective diagnostic technique that is able to localize or rule out a malignant growth within the prostate. The methods available for the detection of these prostate cancers are digital rectal examination (DRE) and Transrectal ultrasound (TRUS). DRE is not suitable for early detection, as about 70% of the palpable malignancies have already spread beyond the prostate. The classic problem of visual interpretation of TRUS images is that hypoechoic areas suspicious for cancer may be either normal or cancerous histologically. Moreover, about 25% of all cancers have been found to be isoechoic and therefore not distinguishable from normal-appearing areas. None of the current biopsy or imaging techniques are able to cope with this dilemma. Artificial neural networks (ANN) are complex nonlinear computational models, designed much like the neuronal organization of a brain. These networks are able to model complicated biologic relationships without making assumptions based on conventional statistical distributions. Applications in Medicine and Urology have been promising. One example of such an application will be discussed in detail: A new method of Artificial Neural Network Analysis (ANNA) was employed in an attempt to obtain existing subvisual information, other than the gray scale, from conventional TRUS and to improve the accuracy of prostate cancer identification.

Adult↗
PubMed2000

Retroperitoneal mature teratoma 15 years after initial treatment of testicular mixed germ cell tumor.

We present a patient with a retroperitoneal tumor noted 15 years after treatment of a testicular mixed germ cell cancer. The patient initially underwent right-sided orchiectomy and retroperitoneal lymph node dissection for clinical stage I disease. An early relapse indicated by increasing tumor markers shortly after retroperitoneal lymph node dissection was successfully treated with five cycles of combined chemotherapy. However, 187 months after completion of chemotherapy, a symptomatic right-sided iliac mass was diagnosed. Radical surgical excision of the mass was performed and histologic examination revealed differentiated mature teratoma. This represents the longest time interval reported in the literature for a mature teratoma following treatment of a testicular germ cell tumor.

Adult↗
PubMed1999

Direct amifostine effect on renal tubule cells in rats.

Clinical trials indicate that amifostine offers protection against cisplatin-induced nephrotoxicity. It is unclear whether a direct pharmacological t on renal tubular cells is involved. We investigated the effect of amifostine pretreatment on the tubular apparatus and evaluated its nephroprotective potential. A total of 32 rats were treated by i.p. administration of 0.9% saline solution (group 1), 5 mg/kg cisplatin (group 2), 25 mg/kg amifostine (group 3), and 25 mg/kg amifostine followed by 5 mg/kg cisplatin (group 4) after 30 min. We recorded elevation of N-acetyl-beta-D-glucosaminidase (NAG) in 24 h pooled urine as a specific marker for tubular lesions, renal leakage of magnesium as an unspecific nephrotoxicity marker, and survival over a 10-day observation period. A significant (P < 0.002) increase in urinary NAG after treatment was documented only in cisplatin-treated group 2 [day 2 (mean+/-SE), 93+/-2.1 units/gram creatinine; day 4, 70.6+/-16 units/gram creatinine; normalization at day 8]. Treatment with amifostine before cisplatin administration resulted in a slight urinary NAG leakage (day 2, 2.8+/-1.8 units/gram creatinine; day 4, 13.8+/-13 units/gram creatinine; normalization at day 6). No increase in urinary enzyme levels was seen in the other groups, and there were no significant differences in urinary magnesium between all groups. Four of eight rats in the cisplatin-treated group and one of eight rats in the amifostine plus cisplatin-treated group died.

Acetylglucosaminidase↗
PubMed1999

Artificial neural network analysis (ANNA) of prostatic transrectal ultrasound.

BACKGROUND: Our purpose was to determine the diagnostic potential of a new, computerized method of interpreting transrectal ultrasound (TRUS) information by artificial neural network analysis (ANNA). This method was developed to resolve the current dilemma of visual differentiation between benign and malignant tissue on TRUS. To train and objectively evaluate ANNA, a new precise method of computerized virtual correlation of preoperative ultrasound findings and radical prostatectomy histopathology was devised. After training with this pathologically confirmed digitized TRUS information, ANNA was tested in a blinded study. METHODS: Following radical prostatectomy, 289 pathology whole-mount sections of 61 patients were correlated digitally with the corresponding TRUS slices. Specific selection of TRUS areas unequivocally identified on the correlated digitized pathohistology resulted in 553 pathology-confirmed representations (samples). Of these, 53 were used for training and 500 were subjected to blind analysis by ANNA. RESULTS: ANNA classified 378 (99%) of the 381 benign pathology-confirmed samples correctly as benign. The false-positive rate was 1% (n = 3). Of the 119 pathology-confirmed malignant samples, 94 (79%) were classified correctly; 25 (21%) were falsely classified as normal. Out of all 119 cancers, ANNA classified 60 (71%) of the hypoechoic cancers as malignant and 24 (29%) as benign. Surprisingly, 34 (97%) of the isoechoic cancers were correctly classified by ANNA, missing only one sample. CONCLUSIONS: The introduction of ANNA enhanced the accuracy of TRUS prostate cancer identification. Although not all malignant areas were detected, cancer was detected in each patient. The ability to detect isoechoic cancerous lesions appears to be the essential innovation over conventional TRUS interpretation.

Aged↗