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F M Debruyne

Publications and source records attributed to F M Debruyne.

At least 217 records · Page 12Linked to original sources
PubMed1994

Analysis of ultrasonographic prostate images for the detection of prostatic carcinoma: the automated urologic diagnostic expert system.

This paper describes a study on the automated analysis of ultrasonographic prostate images. With image processing, tissue characterization in the prostate was performed to assess the probability of malignancy. During prostate examinations, images were recorded at the positions where biopsies were taken. The used samples were divided into three groups. Two of them were used for the construction of a classification tree, and the third was used for the evaluation of this classification. A sensitivity of 80.6% and specificity of 77.1% were reached retrospectively. In a prospective way, these results were 80.0% and 88.2%, respectively. The prospective predictive value for cancer detection was 85.7%. The presented prospective value for image analysis was almost twice as high as the values normally found for prostate examination.

Aged↗
PubMed1994

A practical clinical method for contour determination in ultrasonographic prostate images.

This paper describes a practical method for automated determination of the contour of the prostate in ultrasonographic images. In this method, we use specific edge detection techniques, based on nonlinear Laplace filtering. Possible edges are located at zero-crossings of the second derivative of the image. The strength of the edge is reflected by the value of the gradient of the image at that location. Combining the information about location and strength, an edge intensity image is constructed from the initial ultrasonographic image. In our method, edge enhancement techniques are performed on the edge intensity image. Edges that actually represent a boundary are selected and linked: interpolation techniques are used to fill the gaps between detected boundary edges. The method for contour determination in ultrasonographic images is used for accurate volume measurements in an everyday clinical environment. Its computer implementation is fast, accurate (mean difference within 6% of exact volume) and easy to use.

Humans↗
PubMed1994

The reliability of computer analysis of ultrasonographic prostate images: the influence of inconsistent histopathology.

This article describes a method to investigate the influence of inconsistent histopathology during the development of tissue discrimination algorithms. Review of the pathology is performed on the biopsies used as training set of a computer system for cancer detection in ultrasonographic prostate images. The influence of the discrepancies found between independent pathologists on the discriminating power of the system is investigated. A high diagnostic consistency in histopathology concerning only the categories malignant and nonmalignant is found. Therefore, review of the pathology does not significantly influence the results of tissue discrimination algorithms for cancer detection. However a high interobserver variability is obtained in the differentiation between more histology classes.

Biopsy↗
PubMed1994

Prognosis and treatment of T1G3 bladder tumours. A prognostic factor analysis of 121 patients. Dutch South Eastern Bladder Cancer Study Group.

Patients with T1G3 bladder cancer have a considerable risk for recurrence and/or progressive disease. Until now no consensus has been achieved on the optimal treatment. Within the Dutch South Eastern Bladder Cancer Study Group, 155 patients with a T1G3 bladder tumour were seen between 1983 and 1988. After review of histology, 121 could be evaluated and recurrence-free interval was studied with regard to prognostic factors. Prognostic factors such as sex, age, blood group, abnormalities on intravenous urography, pretreatment tumour configuration, number of tumours, number of locations involved in the bladder, voided urine cytology, results of random biopsies and mitotic index were evaluated, using a multivariate analysis with the Cox proportional hazard model. During the follow-up period, 70 (58%) patients had recurrent bladder cancer, and of these 30 (43%) had progression into invasive disease. Of the possible prognostic factors analysed, only multiplicity (P = 0.03) and the number of locations of the tumours (P = 0.03) were independent prognostic factors in relation to the risk of recurrence. The recurrence-free interval was influenced by the therapy. For T1G3 tumours, additional intravesical immunotherapy/chemotherapy or radiotherapy after transurethral resection (TUR) increased the recurrence-free interval significantly. Because most other parameters did not show additional prognostic value, the T1G3 tumours can be considered as homogeneous with regard to prognosis. Only multiplicity and the number of locations involved added to the prognostic significance of patients with these bladder tumours. In addition, it is advisable to give patients with T1G3 tumours additional treatment after the initial TUR.

Adult↗
PubMed1994

Dysplasia in normal-looking urothelium increases the risk of tumour progression in primary superficial bladder cancer.

Random urothelium biopsies were taken at initial endoscopic surgery from 1001 patients with primary superficial bladder cancer. The clinical course of all the patients was assessed prospectively. Actuarial risks of recurrence and disease progression were determined for prognostic characteristics and comparisons were made using log-rank tests. The independent prognostic significance of concomitant intra-aurothelial dysplastic changes was examined with Cox's regression analyses. The 3-year risk of recurrence in patients with dysplasia and carcinoma in situ (CIS) in macroscopically normal-looking urothelium was only slightly higher than the risk in patients without dysplastic changes (56, 58 and 51%, respectively; P = 0.25). Concomitant dysplasia or CIS significantly increased the 3-year risk of disease progression (17 and 31%, respectively, versus 7%; P < 0.001). After adjustment for the effects of age, tumour stage, grade, size and multicentricity, the result of random biopsies had no prognostic significance regarding the risk of recurrence, but the detection of dysplasia or CIS increased the risk of progression by approximately 80%. This result suggests that random urothelium biopsies may be useful as an additional guide in defining therapy in primary superficial bladder cancer.

Adolescent↗
PubMed1994

Predictors of success with neuromodulation in lower urinary tract dysfunction: results of trial stimulation in 100 patients.

Chronic lower urinary tract dysfunction can be treated by sacral neuro-stimulation. Clinical parameters for selection of patients for this expensive and invasive treatment modality are not well defined to date. Therefore, before implantation of a permanent stimulator, the effect is tested by temporary implantation of a wire electrode connected to an external stimulator. According to the literature, many patients do not respond during temporary implantation and a mean of 25% of the patients with a permanent stimulator implanted fail to respond as well. To improve patient selection, we attempted to define clinical parameters to predict the outcome of sacral neuro-stimulation in 100 consecutive patients who were tested with temporary sacral stimulation. A total of 34 patients achieved a complete cure on trial stimulation. It appeared that detrusor overactivity and urethral instability responded best but they were not predictors of success. We conclude that neither gender, patient age, history nor diagnosis are predictors of success in sacral neuro-stimulation of lower urinary tract dysfunction.

Adolescent↗
PubMed1994

High energy shock waves induced increase in the local concentration of systemically given TNF-alpha.

The influence of high energy shock waves (HESW) on the local concentration of systemically given TNF-alpha was studied in a syngeneic rat bladder tumor model. 125I-TNF-alpha was injected intravenously and within 1 minute was followed by HESW tumor exposure. High energy shock waves were generated using an experimental shock wave emitter based on the Siemens Lithostar Plus. Administration of HESW to RBT323 tumors resulted in a 3-fold increase in uptake of 125I-TNF-alpha in the tumor compared with nontreated tumors, whereas the tissue distribution and pharmacokinetics of nontumor tissue were similar irrespective of HESW exposure. These results demonstrate that HESW administration leads to an increase in the local concentration of a systemically given drug. The capacity of HESW to increase local drug concentrations will be of importance in designing more effective combined treatment strategies.

Animals↗
PubMed1994

Use of sacral reflex latency measurements in the evaluation of neural function of spinal cord injury patients: a comparison of neuro-urophysiological testing and urodynamic investigations.

Complete suprasacral spinal cord injury is followed by great changes in the neural control and function of the lower urinary tract. In the literature there is some controversy about the relationship between detrusor function and results of neurophysiological tests of sacral root conduction after the spinal shock phase. Therefore, we studied this relationship in a group of 73 patients with clinical as well as neurophysiological documented complete suprasacral spinal cord injury, and compared sacral reflex latency measurements (bulbocavernosus and urethro-anal reflexes) with detrusor function, documented by urodynamic investigation. A high incidence of sacral reflex latency abnormalities was found. Comparison of sacral reflex latencies with detrusor reflex activity showed a statistical significant correlation. No such relationship could be found between urodynamic characteristics of the detrusor in patients with detrusor hyperreflexia and sacral reflex latency measurements. We conclude that sacral reflex latency measurements can give an indication about the existence of reflex detrusor activity. On the other hand, these neurophysiological measurements do not provide a reliable indication of the detrusor function after complete spinal cord injury.

Adolescent↗
PubMed1994

Antitumoral effects of liarozole in androgen-dependent and independent R3327-Dunning prostate adenocarcinomas.

We examined the in vivo antitumoral effects of liarozole against androgen-dependent and independent Dunning rat prostatic tumors. Liarozole, applied as a dietary admixture, at a dose of 120 mg./100 gm. food, equivalent to 100 mg./kg. per day, inhibited the growth of the slow growing, well-differentiated, androgen-dependent Dunning-H tumor (median tumor volume decrease of 60%). At the same dose it also significantly reduced the growth of the androgen-independent, moderately differentiated PIF-1 (-60%) and androgen-independent, anaplastic AT-6 tumors (-73%). The growth of AT-6 sq tumor showing squamous metaplasia was unaffected by liarozole. When administered by oral gavage, liarozole at 40 (-82%) mg./kg. twice a day was as effective as castration (-92%) in reducing the androgen-dependent, poorly differentiated Dunning R3327-G tumor. Liarozole, administered by gavage, twice a day, also significantly reduced median tumor volume in the androgen-independent, AT-6 sq (-90% at 60 mg./kg., twice a day). This difference between liarozole administration by gavage and food admixture will have to be taken into account in further experimental studies. Inhibition of the growth of several androgen-dependent and, chiefly, androgen-independent Dunning prostate carcinoma sublines that differ widely in their histological degree of differentiation and growth rate suggests that liarozole may be a suitable agent for evaluation in second line treatment of hormone refractory prostate carcinoma in patients who relapse after androgen ablation.

Adenocarcinoma↗
PubMed1994

Erectile dysfunction in diabetic men: the neurological factor revisited.

In the literature the importance of the neurological factor in the etiology of erectile dysfunction in patients with diabetes mellitus is subject to debate. We report on the findings of neurophysiological investigations in 27 impotent and 30 potent diabetic patients, as well as 102 impotent nondiabetic patients. Additionally, hormonal and vascular evaluations were done. The neurophysiological evaluations consisted of assessment of somatic as well as autonomic sensory nerves, by measuring the latencies of somatosensory evoked potentials of the posterior tibial and pudendal nerves, and of the bulbocavernosus and urethro-anal reflexes. The results show a higher incidence of more severe peripheral and autonomic sensory neuropathy in impotent diabetic men. Also, a preponderance of abnormal intracavernous pharmacological tests, suggesting vasculogenic impotence, was found in impotent diabetic patients. No important endocrinological differences were found among the 3 groups under investigation. Significant differences occurred for plasma glucose and glycosylated hemoglobin. We conclude that diabetic urogenital sensory neuropathy has a crucial role in the etiology of diabetic impotence. Angiopathy seems to be of secondary importance. The results show that poor diabetes regulation is associated with diabetic impotence.

Adult↗
PubMed1994

Bladder compliance after posterior sacral root rhizotomies and anterior sacral root stimulation.

To evaluate the effects of central detrusor denervation on bladder compliance, we studied 27 patients with complete suprasacral spinal cord injury in whom intradural posterior sacral root rhizotomies from S2 to S5 in combination with implantation of an intradural Finetech-Brindley bladder stimulator were performed. All patients initially presented with detrusor hyperreflexia. A majority of these patients had a decreased bladder compliance 5 days postoperatively followed by a rapid increase in bladder compliance thereafter. All patients showed persistent detrusor areflexia after long-term followup. In 2 patients incomplete posterior sacral rhizotomies appeared to be performed. These patients had low bladder compliance, so that secondary posterior sacral root rhizotomies at the level of the conus medullaris were done. Intradural rhizotomies of all posterior sacral root components from S2 to S5 in combination with implantation of an anterior sacral root stimulator is a safe and effective procedure in spinal cord injury patients.

Adolescent↗
PubMed1994

Bladder pressure sensors in an animal model.

Urinary incontinence due to detrusor hyperreflexia might be inhibited on demand if changes in bladder pressure could be detected by sensors and transferred into pudendal nerve electrostimulation. The aim of this study is to investigate how the bladder wall reacts on different sensor implants. Sensors were implanted in twelve goats. In group 1 (n = 8) real sensors were placed on the peritoneal surface of the bladder dome, between the peritoneum and the muscular layer, and between the cervix and bladder. In group 2 (n = 4), dummy sensors were placed between the mucosal and muscular layers. During follow-up as long as 25 months, urodynamic studies, radiographic control and urine cultures were done. In group 1, sensors placed between the peritoneum and muscular layer gave the best results. In group 2, 11 of the 12 sensors eroded. The authors conclude that implantation of sensors in the bladder wall is feasible.

Animals↗
PubMed1994

Selective sacral root stimulation for bladder control: acute experiments in an animal model.

High bladder pressure is a potential side effect of poststimulus voiding, used to date for stimulation-induced bladder emptying in spinal cord injured patients. To prevent this side effect, selective activation of the bladder without activation of the urethral sphincter by selective stimulation of sacral roots was studied in a canine animal model. On-line registration of bladder, urethral and rectal pressure was performed, and EMG of tail muscles and urethral sphincter was recorded. After laminectomy, intradural left and right sacral root S2 were stimulated with a tripolar cuff electrode. A self-made stimulator generating adjustable pulse shapes was used. Using 200 microsec. rectangular pulses, contraction of bladder and urethral sphincter could be elicited. Selective activation of the bladder occurred with pulses of 600 to 800 microsec. due to anodal blocking of the large nerve fibers in the sacral roots. During acute animal experiments we were able to achieve selective activation of the detrusor without simultaneous activation of the external urethral sphincter, and complete, low-pressure voiding occurred.

Animals↗
PubMed1994

Transurethral microwave thermotherapy (TUMT) in benign prostatic hyperplasia: placebo versus TUMT.

OBJECTIVES: A prospective, randomized placebo-controlled study was designed to exclude a placebo response in transurethral microwave thermotherapy (TUMT). METHODS: During a sham procedure, the microwave applicator was installed in the urethra as in the real TUMT treatment and a complete procedure was simulated by the microwave delivery system (Prostatron). Any patient who entered this study had the option to request a second real TUMT treatment if, 3 months after the initial procedure, his condition had not improved. RESULTS: A total of 48 patients were available for evaluation at 3 months and 28 at 6 months. The TUMT group had an average decrease of 7.3 points (from 13.2 to 5.9) in the Madsen symptom score, an average increase in flowrate of 3.4 mL/s (9.6 to 13.0), and an increase in voiding percentage of 9.6% (81.7 to 91.3). All improvements were statistically significant. In the sham group, the average Madsen score decreased from 12.1 to 8.2 points, the average flowrate decreased from 9.7 to 9.5 mL/s, and the voiding percentage increased from 80.8% to 84.3%. Only the change in symptom score was significant. In both groups, observations at the 3-month follow-up were similar to those after 6 and 12 months. Patients who had TUMT after sham treatment showed similar significant changes in symptom score and peak flow as observed in the original TUMT group. Patients who did not respond favorably to a first TUMT did not experience improvement after a second TUMT. CONCLUSIONS: A placebo effect, although minimal, exists. This placebo response, however, accounts for little of the observed benefit of TUMT.

Aged↗
PubMed1994

p53 mutations have no additional prognostic value over stage in bladder cancer.

Evidence is accumulating that the tumour-suppressor gene p53 is involved in the development of bladder cancer. Therefore we studied p53 mutations in 47 bladder cancers obtained from 45 patients using polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) analysis. Eight out of 24 invasive tumours appeared to have a p53 mutation, while no p53 mutations were found in the superficial tumours. All the p53 mutations were found in grade 3 tumours. The tumours with altered p53 showed a higher frequency of allelic loss (FAL) than the tumours without a mutation (55.8% vs 21.1%, P < 0.05, chi 2 test). This increase in FAL suggests a correlation between p53 mutations and genetic instability. A significant correlation between mutated p53 and poor survival in the whole group studied was found (P < 0.001, log-rank test). However, within the group of muscle-invasive tumours the occurrence of p53 mutations had no additional prognostic value. Therefore, even though p53 mutations were found in aggressive tumours, the clinical usefulness of its detection seems limited. Nevertheless, these results imply that p53 is involved in the clinical behaviour of bladder cancer; its role in the progression of superficial cancer to invasive disease merits further attention.

Adult↗
PubMed1994

Selective stimulation of sacral nerve roots for bladder control: a study by computer modeling.

The aim of this study was to investigate theoretically the conditions for the activation of the detrusor muscle without activation of the urethral sphincter and afferent fibers, when stimulating the related sacral roots. Therefore, the sensitivity of excitation and blocking thresholds of nerve fibers within a sacral root to geometric and electrical parameters in tripolar stimulation using a cuff electrode, have been stimulated by a computer model. A 3-D rotationally symmetrical model, representing the geometry and electrical conductivity of a nerve root surrounded by cerebrospinal fluid and a cuff was used, in combination with a model representing the electrical properties of a myelinated nerve fiber. The electric behavior of nerve fibers having different diameters and positions in a sacral root was analyzed and the optimal geometric and electrical parameters to be used for sacral root stimulation were determined. The model predicts that an asymmetrical tripolar cuff can generate unidirectional action potentials in small nerve fibers while blocking the large fibers bidirectionally. This result shows that selective activation of the detrusor may be possible without activation of the urethral sphincter and the afferent fibers.

Animals↗
PubMed1994

Should random urothelial biopsies be taken from patients with primary superficial bladder cancer? A decision analysis. Members of the Dutch South-East Co-Operative Urological Group.

OBJECTIVE: To evaluate whether it is worthwhile to implement routine random biopsies from the normal-looking urothelium in the management of patients with primary superficial bladder cancer. PATIENTS AND METHODS: Two hypothetical management policies were compared, one of which incorporated random biopsies as an additional prognostic test. In the 'no-biopsy policy', all patients were treated with transurethral resection (TUR) alone, except for patients with a pT1G3 tumour who were treated with adjuvant prophylactic intravesical therapy. In the 'biopsy policy', the choice of treatment was influenced by the presence or absence of dysplastic urothelium in random biopsy specimens, except in patients with a pT1G3 tumour who received adjuvant treatment, irrespective of the result of random biopsies. Decision analysis was used to compare the outcome of these hypothetical policies with respect to the expected 3-year risks of recurrence and progression. Baseline data used in the analysis originated from a large unselected case series, prospectively documented in the Netherlands. RESULTS: The 'biopsy policy' resulted in a 3 year risk of recurrence and a 3 year risk of progression of 52% and 11%, respectively. These 3 year risks were almost identical to the 'no-biopsy policy': 54% and 11%, respectively. In a sensitivity-analysis, the expected 3 year risks of recurrence as well as the expected 3 year risks of progression were found to remain similar with both policies, even with quite extreme assumptions favouring the 'biopsy policy'. CONCLUSION: In view of the expected small difference in disease outcome between the two management policies, taking random biopsies of normal-looking urothelium at the time of the TUR has no practical value.

Adolescent↗