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Biomedical subjects

M S Shoukry

Publications and source records attributed to M S Shoukry.

10 recordsLinked to original sources
PubMed2002

Repeated transurethral resection of recurrent superficial bladder tumors--does it affect the spread and stage of the tumor?

OBJECTIVES: This prospective study was done to demonstrate the effect of repeated resection of superficial bladder tumors (TURT) on deep malignant cell infiltration in bladder wall. MATERIAL AND METHODS: Thirty-six patients underwent radical cystectomy for invasive bladder cancer, 16 patients originally had superficial cancer that became invasive after repeated TURT (group I) and the other 20 patients (group II) presented with invasive bladder cancer from the start. Each cystectomy specimen was subjected to a thorough histopathological study. RESULTS: There was a statistically significant difference in pattern of local spread of malignant cells between the two groups. Isolated clusters of malignant cells in-between normal bladder muscle fibers, isolated subserosal malignant deposits as well as cells reaching the adjacent cervix uteri were found only in group I. Intravesical pressure was measured in another 10 patients during TURT and was found to be high reaching up to 80 cm H2O. CONCLUSIONS: We conclude that some malignant cells penetrate through the denuded urothelium during TURT by the effect of high intravesical pressure. This may be responsible, among other factors, for tumor recurrence with deeper stages.

Adult↗
PubMed1998

Detrusor properties in myelomeningocele patients: in vitro study.

PURPOSE: To characterize detrusor properties of myelomeningocele (MMC) bladders which failed conventional therapy. MATERIALS AND METHODS: Bladder strips from five end-stage MMC patients were compared with those from five patients with vesicoureteric reflux. The active and passive properties of the detrusor muscles and the effect of different blocking agents on the transmural nerve stimulation were studied. RESULTS: A significant decrease in contractility (p = 0.003) and increased rigidity (p = 0.019) was found in MMC group. In the control group, atropine blocked 77.7% of the detrusor contractility and tetrodotoxin demonstrated an equal blocking effect. In MMC group, atropine blocked 58.2% and tetrodotoxin blocked 77.4% of the detrusor contractility. CONCLUSION: MMC bladders showed decreased contractility and increased rigidity. In MMC group, the atropine-resistant component which is blocked by tetrodotoxin signifies the possible existence of non-adrenergic, non-cholinergic neurotransmitters (NANC). Further studies are needed to possibly improve the pharmacological therapy of the myelomeningocele detrusor.

Atropine↗
PubMed1998

Urodynamic predictors of upper tract deterioration in children with myelodysplasia.

The clinical and urodynamic data of 62 children with myelodysplasia without previous urological treatment were tested statistically for the ability to predict upper tract deterioration. This was done by comparing these data among 26 children with dilated upper tracts and 36 children with normal upper tracts. Vesicoureteric reflux had a strong positive correlation with upper tract dilation but the maximum cystometric capacity, detrusor instability, compliance, maximum urethral closure pressure and peak flow rate all had no predictive value. Residual urine is sensitive and negatively predictive and leak pressure is specific and positively predictive; detrusor pressure at peak flow, opening pressure, pressure at least flow and the detrusor-adjusted mean passive urethral resistance relation factor (DAMPF) are sensitive and specific with high positive and negative predictive values.

Adolescent↗
PubMed1997

Human vasal changes after vasectomy: in vitro studies.

UNLABELLED: Failure to impregnate, after successful vasovasostomy, has been attributed to immunologic, testicular, and epididymal factors. OBJECTIVES: To study the effect of vasectomy on human vas innervation and vesicoelastic properties. METHODS: Vas rings were obtained from 8 healthy males during vasectomy as controls and compared to those of 3 vasovasostomy patients. The active and passive properties were determined and the cumulative blocking effects of phenoxybenzamine, propranolol, atropine and tetrodotoxin were studied. RESULTS: There was significantly higher rigidity in the vasovasostomy group as compared to the control group but there were similar active forces between the two groups up to 100-120% of stretch. In the control group, phenoxybenzamine blocked 33.3%, propranolol blocked 15.8%, and atropine blocked 36.5% but tetrodotoxin had no further effect. In the vasovasostomy group, phenoxybenzamine blocked 33.3% (similar to control), propranolol blocked 2%, atropine blocked 11.7% and tetrodotoxin blocked 37.1%. CONCLUSIONS: In vasovasostomy group there was increased rigidity without reduction of the active force. There were also decreased cholinergic and possible existence of nonadrenergic noncholinergic neurotransmitters.

Adrenergic alpha-Antagonists↗
PubMed1997

Urethral needle suspension for male urinary incontinence.

A rectus fascia sling was used to suspend the bulbous urethra in 12 males with total sphincteric incontinence. Incontinence was related to prostatectomy in 3 patients, to spinal trauma in 3, and to myelodysplasia in 6 patients. In 3 patients augmentation ileocystoplasty was added to the procedure because of reduced bladder capacity and compliance. Needle suspension of the sling simplified the procedure and obviated difficult retroprostatic dissection. After an average of 13 months 10 out of 11 patients were totally dry, 2 of these are voiding spontaneously with little residual while the rest are on intermittent catheterization. One patient is still wet because of severe postoperative detrusor instability. Urethral erosion occurred in one patient in whom the sling was removed. No upper tract deterioration was found until the last follow-up. In conclusion, a rectus fascia sling is a readily available alternative to the artificial urinary sphincter with comparable success and less reoperation rates. Needle suspension of the sling simplified its application in male patients.

Adolescent↗
PubMed1997

A telemetric multichannel computer-based system for monitoring urodynamic parameters in awake rhesus monkeys.

For comprehensive telemetric monitoring of bladder function in monkeys, transducers were implanted in the bladder wall and abdominal cavity. The EMG lead was buried in the external sphincter. All wires terminated in a subcutaneous transmitter. Conventional urodynamics were performed for comparison. Excellent reproducibility with conventional urodynamics was found. Implantation caused detrusor instability, which subsided in 6 to 8 weeks. Real-time computer-based multichannel telemetric studies of voiding are feasible and reliable. Telemetric studies monitor for long periods without stress or anesthesia and provide an excellent model for lower urinary tract studies.

Animals↗
PubMed1996

Conventional, continuous, and telemetric monitoring of urodynamic parameters in non-human primates: a comparative study.

A comparison between three different techniques for monitoring urodynamic parameters in non-human primates was conducted in six adult female rhesus monkeys. This study was divided into two phases. In phase I, the animals were studied by conventional and continuous methods. During the study, uroflow and micturition pattern were obtained while the animals housed in a specially designed metabolic cage. Pressure transducers and EMG electrodes were surgically implanted. Then the animals were trained for 6 weeks to sit in a specially designed chair. Upon completion of the training period, continuous monitoring of the urodynamic parameters could be carried out for periods up to 14 hours. In phase II, the animals were studied with the conventional and telemetric methods. The same type of pressure transducers and EMG electrodes were implanted but they terminated in a radio transmitter powered by a long-life battery and controlled by a radio-operated switch. Conventional studies under ketamine sedation significantly increased bladder capacity, as well as the pressure at capacity (P < 0.05). Continuous monitoring was feasible, physiological, and more sensitive than the conventional techniques. Telemetric studies are superior to continuous monitoring, since the animal is not tethered to wires and provide data over a longer period of time. It is concluded that telemetric monitoring provides significantly different parameters, which could help in diagnosis and management of different voiding dysfunctions. In normal non-human primates, lower bladder capacity, higher maximum voiding pressure, higher bladder compliance, and higher incidence of detrusor instability without urethral relaxation were found. Telemetric urodynamic data on different pathological processes are currently unavailable and further work is needed in this area.

Animals↗
PubMed1996

Effects of anesthesia on urodynamic studies in the primate model.

PURPOSE: To elucidate the effect of anesthesia on bladder function and urodynamic studies by performing controlled comparisons of the effects of 2 anesthetics on urodynamics in a primate model. MATERIALS AND METHODS: Cystometrograms were performed in 4 awake adult female Rhesus monkeys (Macaca mulatta) via implantable transducer for continuous monitoring and compared with cystometrograms obtained under anesthetic agents. A total of 183 cystometric studies was performed (48 in the awake group, 74 under ketamine anesthesia and 61 under flurane anesthesia. RESULTS: Maximum detrusor contraction pressure [Pdet(max)] was significantly lower under flurane than under ketamine anesthesia (33.1 +/- 2.5 versus 49.1 +/- 8.1 cm.H2O). In the awake state Pdet(max) (47.7 +/- 25.2 cm.H2O) was equal to that obtained under ketamine anesthesia. Cystometric bladder capacity was significantly larger under flurane (101.5 +/- 81.8 ml.) than under ketamine (70.3 +/- 56.1 ml.) anesthesia. It was only (32.9 +/- 15.9 ml.) in the awake state. Cystometric bladder capacity under both anesthetics was larger than the mean voided volume (43.3 +/- 6.3 ml.), but was comparable to the largest voided volume (102.3 +/- 31 ml.). Cystometric reflex contractions with bladder filling occurred more frequently with ketamine (96%) than with flurane anesthesia (66%). CONCLUSIONS: These findings show that anesthesia has profound effects on the bladder, and careful interpretation of urodynamic data is suggested. These findings also suggest that ketamine is a suitable anesthetic for urodynamic studies in the subhuman primate.

Anesthesia, General↗
PubMed1992

Effect of time interval and overdistension on repeated urodynamic studies.

Repeated urodynamic testing of the lower urinary tract is often needed both clinically and experimentally. The objective of this study is to find out the time interval needed if repeated urodynamic tests are required even if overdistension occurs initially. Three hundred forty urodynamic studies were performed using five female rhesus monkeys (Macaca mulatta). Two groups of experiments (with or without bladder overdistension) were performed at the following time intervals: immediate, 15, 30 and 45 minutes after the initial urodynamic study. All urodynamic parameters (pressure, capacity, compliance and detrusor strength) were reproducible after a 30-minute waiting period. In case of overdistension, a 45-minute period is required.

Animals↗