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J De Leval

Publications and source records attributed to J De Leval.

12 recordsLinked to original sources
PubMed1997

Loss of type IV collagen alpha 5 and alpha 6 chains in human invasive prostate carcinomas.

Type IV collagen, a major component of basement membranes, is organized in a network responsible for the mechanical resistance of the basement membranes. It also plays a key role in epithelial cell adhesion to basement membranes. This study was designed to investigate the distribution of type IV collagen alpha-chains in normal, preneoplastic, and malignant prostate basement membranes. For this purpose, immunohistochemistry using specific antibodies raised against the different alpha-chains of type IV collagen was performed in eight normal samples, six prostatic intraepithelial neoplasia, and 20 malignant lesions of the prostate. Our results demonstrate the presence of the "novel" alpha 5 (IV) and alpha 6 (IV) chains along with the "classical" alpha 1 (IV)/alpha 2 (IV) chains in the basement membrane of the normal prostate gland. The alpha 3 (IV) chain was never detected in any prostate specimen. Prostatic intraepithelial neoplasia showed a similar immunostaining pattern to that found in normal glands. In cancer gland basement membranes, we demonstrate for the first time a specific loss of the alpha 5 (IV) and alpha 6 (IV) chains, whereas the classical alpha 1 (IV) and alpha 2 (IV) chains were consistently exhibited. Additionally, type VII collagen colocalized with alpha 5 (IV) collagen chain, and these two proteins, which were always observed in normal and prostatic intraepithelial neoplasia gland basement membranes, were lost in invasive carcinoma basement membranes. This observation raises questions about the possible association or cooperation between alpha 5 (IV)/alpha 6 (IV) chains and anchoring fibrils in prostate glands basement membrane.

Adenocarcinoma↗
PubMed1991

[Bladder substitution. Role of stoma therapy and equipment in continent stomas].

Have been added to the classical urinary diversion techniques the external continent diversion with stoma and the complete reconstruction of a reservoir with bowel attached to the urethra. The new methods offer serious advantages to the patient, but education of the patient is compulsory and the stoma nurse in this field has a role to play.

Humans↗
PubMed1985

[Striated sphincter of the urethra. 4: Therapeutic possibilities].

Treatment of non-neurologic dyssynergia is aimed at diminishing urethral sensory impulses or the motor component of the dysreflexia. Although formal proof of efficacy is lacking, urethral dilatation or meatoplasty in young girls is still used when an obstacle exists to passage of a balloon catheter. Functional obstruction is treated by Valium for its muscle-relaxant properties, alpha-blocking agents or biofeedback. In recent neurologic dyssynergia good results have been obtained after infiltrations of the para-urethral sphincter by an endo-urethral approach. Sphincterotomy is the treatment of choice when fibrosis has developed, particularly when the upper urinary tract is being affected: it can be performed earlier in cases where the dyssynergia fails to respond to well adapted conservative therapy. The site of section should be at 12 o'clock for anatomophysiologic reasons and to reduce the risk of impotence. The only treatment for rhabdosphincter deficiency is physiotherapy: reeducation and electric stimulation. Correctly instituted reeducation involves several phases: beginning with consciousness and learning of sphincter function it terminates in the automatic activation of the sphincter as for example during certain efforts. Results of several documented series in the urologic literature are encouraging.

Bacterial Infections↗
PubMed1984

[The striated sphincter of the urethra. 2: Specific methods for studying the striated sphincter of the urethra].

Radiology and electromyography of the lower urinary tract are specific techniques for exploration of the urethral rhabdosphincter. Retrograde and mictional urethrography provide data on the extent of the membranous urethra. In the presence of rhabdosphincter lesions a mictional urethrogram is often sufficient to establish a diagnosis from the direct and indirect signs of obstruction it supplies. A retrograde urethrography examination can be added validly to the previous exploration to improve precise definition of sclerosis: in contrast it is indispensable when miction is impossible. Differential diagnosis between spasm and stenosis of striated and dyssynergy of smooth muscle sphincter is by pharmacologic tests. Radiologic study of sphincter contraction is generally by cineradiography with arrest of miction. Results are limited, however, when compared with those of a radiodynamic study: the latter supplies information on the functioning of the para- and peri-urethral rhabdosphincter, and allows measurement of contraction. The electromyogram, with its different practical technical modalities, provides details of the urethral rhabdosphincter. The contact electromyogram gives quantitative data but fails to diagnose a neurological lesion. It analyzes behavior of the sphincter in its para-urethral part and can localize its diaphragmatic portion; dynamic electric profiles are of little reliability, in contrast to static profiles which quantify electric activity at all points in the urethra during the same contraction. The standard percutaneous needle electromyography examination provides qualitative data on the peri-urethral rhabdosphincter, but lacks precision as to the region explored, while qualitative information on the para-urethral sphincter requires the use of an endo-urethral approach. A difference in potential between para- and peri-urethral musculature has been demonstrated a fact confirmed by anatomical findings in Goslings study. In normal subjects, the rhabdosphincter differs from other skeletal muscles by its constant activity except during miction; potentials in children differ from those in adults by their duration. In lower motor neurone disease signs of denervation appear after several weeks, while in upper motor neurone affections the potentials are normal but nociceptive and bulbocavernous stimuli provoke bursts of hyperactivity which reappear very shortly after the paraplegia. Striated muscle fibrosis provokes peripheral signs with persistence of regions of increased reflexes. Tests of responses to stimuli provide important information enabling the site of the neurogenic lesion to be determined.

Electromyography↗
PubMed1984

[The striated sphincter of the urethra. 3: Urodynamic and physiopathologic study of the striated sphincter].

Dysfunction of the rhabdosphincter results from an increase (dyssynergia) or decrease in activity of either neurological or non-neurological origin. We have defined dyssynergia as the absence of urethral relaxation and/or sphincter contraction during and/or before detrusor muscle contraction. Non-invasive exploratory methods include flowmetry, anal contact EMG and an abdominal pressure or EMG examination. Invasive techniques are of various types: urethro-cystometry with EMG, via the perineum in males and the endo-urethral approach in females, provides quantitative data on extent of altered function and relative involvement of either smooth or striated muscle sphincters. An essential complement to urodynamic exploration is a conventional mictional cystogram. We have proposed an etiologic classification of dyssynergia: tonic dyssynergia is pathognomonic of supra-sacral medullary lesions while clonic dyssynergia reflects the bladder-sphincter conflict, whether it be of neurologic or other origin. Clonic dyssynergia in patients with neurologic affections is seen mainly in those with supra-sacral medullary lesions at whatever level, and with a 50 to 100% frequency. Its serious nature is not related to the bladder-sphincter equilibrium but to the high pressures developed by the system. The neurologic rhabdosphincter presents characteristic persistent reflex activity at the spinal shock phase and a possible course leading to fibrosis. In patients without neurologic disease the terms dyssynergia or pseudodyssynergia are used depending on whether the sphincter contraction during bladder contraction is involuntary or voluntary. To explain this non-neurologic pseudodyssynergia, Lapides suggested as a basis the theory of the evolution of sphincter control, Tanagho that of sphincter spasticity. In reality it involves a vicious circle centered on the bladder-sphincter conflict, entry being possible at various levels: bladder instability, urethral instability, urethral hypersensitivity, rhabdosphincter spasticity. These disturbed functions induce the urethral syndrome, repeated urinary infections, reflux and sometimes even renal stasis. Deficient sphincter activity of neurologic origin presents pathognomonic electromyographic signs; from a functional point of view valid data can be obtained from measurement of variations in maximum urethral pressure during a retention effort. Among the neurologic etiologies, the rhabdosphincter is only rarely affected by poliomyelitis or amyotrophic lateral sclerosis.(ABSTRACT TRUNCATED AT 400 WORDS)

Ataxia↗