Biomedical subjects

M Hassouna

Publications and source records attributed to M Hassouna.

At least 19 recordsLinked to original sources

PubMed1998

Sacral root neuromodulation in idiopathic nonobstructive chronic urinary retention.

PURPOSE: Sacral root neuromodulation is becoming a superior alternative to the standard treatment of idiopathic nonobstructive urinary retention. We report results in 20 successive patients who underwent sacral foramen implantation to restore bladder function. MATERIALS AND METHODS: After an initial, thorough baseline assessment 20 patients 19.43 to 55.66 years old with idiopathic nonobstructive urinary retention underwent percutaneous nerve evaluation. Response was assessed by a detailed voiding diary. Responders underwent implantation with an S3 foramen implant, and were followed 1, 3 and 6 months postoperatively, and every 6 months thereafter. RESULTS: Sacral root neuromodulation restored voiding capability in these patients. Bladders were emptied with minimal post-void residual urine, which decreased from 78.3 to 5.5 to 10.2% of the total voided volume from baseline to postoperative followup. These results were reflected in uroflowmetry and pressure-flow studies, which were almost normal after implantation. Furthermore, the urinary tract infection rate decreased significantly and associated pelvic pain improved substantially. The Beck depression inventory and SF-36 quality of life questionnaire indicated some improvement but reached significance in only 1 item. In addition, cystometrography showed no significant difference after 6 months of implantation compared with baseline values. Complications were minimal and within expectations. CONCLUSIONS: Sacral root neuromodulation is an appealing, successful modality for nonobstructive urinary retention. Only patients who have a good response to percutaneous nerve evaluation are candidates for implantation. The high efficacy in patients who undergo implantation, relative simplicity of the procedure and low complication rate make this a treatment breakthrough in this difficult group.

Adult↗

PubMed1998

Sacral nerve root neuromodulation: an effective treatment for refractory urge incontinence.

PURPOSE: Sacral foramina implants have been recognized recently as a method for treatment of refractory urinary urge incontinence. We study the outcome of the procedure with in-depth analysis of the results of 18 implanted cases. MATERIALS AND METHODS: Patients with urinary urge incontinence were subjected to percutaneous nerve evaluation of the S3 roots as a temporary screening test to determine response to neuromodulation. Satisfactory responders were implanted with permanent sacral root neuroprosthesis. The study design included comprehensive voiding diaries for 4 consecutive days twice as a baseline, 1 with percutaneous nerve evaluation screening, 1 after the percutaneous nerve evaluation, 1 at the 1, 3 and 6 post-implantation visits, and every 6 months thereafter. Uroflowmetry and quality of life questionnaires were performed at the same intervals. Urodynamic study was done as a baseline and 6 months after implantation of the neuroprosthesis. RESULTS: All 18 patients (16 women and 2 men) with refractory urge incontinence received a sacral foramina neuroprosthesis after demonstrating a good response to the percutaneous nerve evaluation. Average patient age at presentation was 42.3+/-3.3 years (range 22 to 67) and duration of urinary symptoms was 6.6+/-1.3 years (range 1.2 to 18.8). Average followup was 18.8 months (range 3 to 83). Neuromodulation in these patients showed a marked reduction in leakage episodes from 6.49 to 1.98 times per 24 hours and in the leakage severity score. Eight patients became completely dry and 4 had average leakage episodes of 1 or less daily. Patients showed as well a decrease in urinary frequency with an increase in functional bladder capacity. Associated pelvic pain improved substantially. Cystometrograms demonstrated increased volume at first sensation by 50% and increased cystometric capacity by 15% with the disappearance of uninhibited contractions in 1 of the 4 patients who presented with it preoperatively. There was also noticeable improvement in the quality of life. Complication rate was low and none was life threatening. CONCLUSIONS: Sacral root neuromodulation is an appealing modality for treatment of urge incontinence refractory to conventional pharmacotherapy. The relative simplicity of the technique, promising results and low complication rate make this therapy a likely alternative.

Adult↗

PubMed1997

Alternatives for the pharmacologic management of urge and stress urinary incontinence in the elderly.

Urinary incontinence in the elderly is a common but typically remediable condition that is frequently managed by pharmacotherapy. However, because of age-related changes, the response to a specific dosage of a certain drug administered to an elderly person may be quite different than the response experienced by a younger individual. This article will review general principles of pharmacotherapy in the elderly patient and pharmacologic alternatives for the management of urge and stress urinary incontinence.

Adrenergic alpha-Agonists↗

PubMed1995

Long-term effect of sphincteric fatigue during bladder neurostimulation.

Commercially available stimulators lack several features, including multiple channel capability and flexible stimulation parameters. These factors limit clinical application. A new computerized electrical stimulator system was developed by our team and evaluated for its efficacy in bladder evacuation in an animal model after spinal cord transection. The system can generate a wide range of stimulation characteristics and has the feature of being a programmable multichannel pacemaker. It has enabled us to induce a reversible fatigue to the external sphincter that results in proper bladder emptying on stimulation. Using this new bladder pacemaker, 8 dogs were studied. We applied the concept of fatiguing of the external sphincter via the pudendal nerve to avoid rhizotomy. We determined the optimal stimulation parameters that can reliably empty the dog's bladder for the duration of the experiment, which lasted for 8 months. The new computerized electrical stimulation system achieved the objective of reducing bladder outlet resistance without the need for sacral rhizotomy.

Animals↗

PubMed1995

Increased reactive oxygen species formation in semen of patients with spinal cord injury.

OBJECTIVES: To evaluate reactive oxygen species production of semen samples and Percoll-washed spermatozoa from men with spinal cord injuries and to determine if there is a relationship between this reactive oxygen species production and sperm motility. PARTICIPANTS: Semen samples from healthy volunteers and infertile patients were collected by masturbation. INTERVENTIONS: Semen samples from men with a spinal cord injury were obtained by electroejaculation or by masturbation after treatment with physostigmine. MAIN OUTCOME MEASUREMENTS: Motility was measured using the CellSoft computer-assisted analysis system (Cryo Resources Ltd., Montgomery, NY). Luminol-amplified chemiluminescence was used to measure reactive oxygen species production. RESULTS: Semen samples and Percoll-washed spermatozoa from men with a spinal cord injury produced reactive oxygen species at much higher frequency and levels than equivalent preparations from infertile men or healthy volunteers. There was an inverse relationship between the percentage of motility and reactive oxygen species production in Percoll-washed spermatozoa from men with a spinal cord injury. CONCLUSION: Semen samples and Percoll-washed spermatozoa from men with spinal cord injury produce high levels of reactive oxygen species that may be related to the low sperm motility and infertility observed in these men.

Adult↗

PubMed1994

Dog as an animal model for neurostimulation.

The dog provides an important model to study the effect of neural stimulation of different parts of the central and peripheral nervous systems. A multitude of experiments on neurostimulation and neuromodulation to ensure bladder evacuation have been conducted on dogs. The present article reviews the most prominent contributions in the English literature related to neurostimulation using the dog as an experimental model. The various modes of stimulation using dogs as a model and the rationale for their use as well as their shortcomings will be examined. The prominent anatomic features in the neural control of the bladder and the technical aspects involved in neurostimulation of the canine bladder will be reviewed.

Animals↗

PubMed1993

A transcutaneous implantable bladder controller.

We describe a computerized experimental system to investigate the effect of early electrical stimulation of the bladder during the spinal shock phase in paraplegic dogs. This system is composed of two main devices; an external part (or controller) based on a portable microcomputer, and a versatile implant (internal) based on a multichannel CMOS microstimulator. Using a new operative technique, this system enabled us to obtain many favorable results.

Animals↗

PubMed1993

Effect of balloon dilation of ureter on upper tract dynamics and ureteral wall morphology.

Sixteen male Yucatan minipigs underwent balloon dilation of the right ureterovesical junction (UVJ) and lower ureter to twice its normal caliber. With the bladder open, bilateral upper tract dynamics measurements under different perfusion rates (0.5, 2, and 4 ml/min) were recorded predilation, immediately after dilation, and 1, 2, 3, 4, and 6 weeks after dilation. Immediate and late antegrade nephrostograms, suprapubic cystograms, and right antegrade nephrostograms (oblique view) were taken. In the chronic experiment, no difference in renal pelvic pressure (Ppvs) was detectable between the control and dilated sides immediately after dilation. Only at 4 ml/min was there a statistically significant increase in the Ppvs of the dilated ureter 1 week after dilation when compared with the controls. At 2 weeks, this obstructive change had disappeared. At 3, 4, and 6 weeks, Ppvs of the dilated ureter declined progressively in comparison with the control side, but the difference was not statistically significant. At 6 weeks, Ppvs of the dilated ureter decreased significantly compared with predilation readings only at 4 ml/min. Immediate antegrade radiologic evaluation revealed that 69% of the experimental animals had no extravasation, while 31% showed variable degrees of extravasation, which disappeared completely on late antegrade nephrostograms (6 weeks). Grade 2 reflux occurred in 33% of the experimental animals at 1 week and had disappeared at 6 weeks. Histologic examinations at 1, 2, and 3 weeks revealed a nonhomogeneous pattern of ureteral damage, ranging from total rupture to much less dramatic injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

Effect of early bladder stimulation on spinal shock: experimental approach.

The period of spinal shock which frequently follows spinal cord injury is associated with bladder areflexia and urinary retention. We studied the effect of early bladder electric stimulation on detrusor activity during the spinal shock phase in the dog. The animals had a spinal cord section at T10 vertebra, and their bladder management was assigned to one of the three following groups: intermittent catheterization, indwelling catheterization, and electric bladder stimulation. The parameters for evaluating each treatment included: blood chemistry, and radiographic and urodynamic tests. The most important finding was the early return of detrusor activity in the group of animals treated by early electric stimulation of the bladder.

Animals↗

PubMed1992

Electrical stimulation induced sphincter fatigue during voiding.

The stimulation of the sacral nerves to induce voiding is often associated with simultaneous contraction of the striated sphincter rendering micturition difficult or impossible. Rhizotomy of some sacral nerves was found to be necessary to facilitate voiding with stimulation. An main objective in the present experiment was to evaluate the feasibility of achieving the same result using electrical stimulation to fatigue the sphincter. In order to compare the effect of rhizotomy and fatiguing striated sphincter, the bladder outlet resistance was measured. S2 nerves were stimulated with 3 V, 35 Hz and 100 microseconds duration for 5 to 10 sec. Following S2 nerves stimulation the pudendal nerve was stimulated till we obtained sphincteric fatigue. The optimal parameter to induce sphincter fatigue were 3 V, 100-500 Hz and 100 microseconds. for 15-20 sec. The combined pressure-flow studies showed that fatiguing the sphincter via the pudendal nerve using these parameters was as good as cutting it in achieving bladder emptying with stimulation.

Animals↗

PubMed1992

Role of electric stimulation in bladder evacuation following spinal cord transection.

Neural stimulation is potentially a valuable therapeutic tool in the treatment of neurogenic bladder with detrusor areflexia. We studied 20 dogs in different groups, up to eight months, and compared the effect of electric stimulation with intermittent catheterization, specially during spinal shock phase. We found that early stimulation hastened the return of detrusor activity. When stimulation was delayed, the bladder could still regain its activity, and when the pace-maker was turned off, the detrusor activity was gradually decreased. Neurostimulation can completely empty bladder up to eight months. The lowest A.Ch. content in detrusor muscle was found in intermittent catheterization group and in this group the detrusor strips showed marked supersensitivity to urecholine stimulation than the bladders managed by electric stimulation. Also, we found that electric stimulation reduced the complications caused by intermittent catheterization and protected kidney function.

Animals↗

PubMed1991

Digital subtraction cavernosography: method to detect venous leakage.

Cavernosography has become an important diagnostic test for detecting venous leakage as a cause of vasculogenic impotence. Digital subtraction cavernosography (DSC) was carried out on 21 patients with a history of venous leakage resulting in impotence. The DSC technique was compared to conventional cineradiography. Major venous leaks were easily identified in 16 patients. DSC was able to detect minor leaks missed by cineradiography in 2 patients. DSC seems to be a reliable technique that is easy to perform. It should be done in conjunction with pharmacologically induced erection.

Angiography, Digital Subtraction↗

PubMed1989

Keratinophilic fungi on sheep hairs from the West Bank of Jordan.

The mycoflora of the hair in 285 sheep from the West Bank of Jordan was analysed and the frequency of occurrence and the relative importance value for different fungal species found were calculated. Ninety six species which belong to 36 genera were isolated. Forty one of these species were either well-known agents of animal and human mycoses (Trichophyton verrucosum, T. mentagrophytes, Microsporum nanum, M. canis, and others), or have been isolated from human and animal lesions (Arthroderma cuniculi, A. curreyi, Chrysosporium tropicum, Acremonium kiliense, Aphanoascus fulvuscens, Aspergillus versicolor, Paecilomyces lilacinus, Scopulariopsis brevicaulis, and others). These pathogenic fungi comprised 75.4% of all fungi recovered from the hair of sheep. This animal seems to represent an adequate reservoir for several dermatophytes and several potentially pathogenic fungi.

Animals↗

PubMed1989

Priapism: an avoidable complication of pharmacologically induced erection.

Priapism is an alarming complication during treatment of erectile dysfunction with vasoactive drugs, particularly papaverine alone or in combination with phentolamine mesylate. An investigational protocol was designed to identify patients who are more susceptible to priapism after intracavernous injection of papaverine alone or with phentolamine. The protocol was applied in 331 men with impotence of various etiology. The association of a positive response to visual sexual stimulation and penile brachial index of more than 0.8 represented a higher risk for post-injection priapism. We were able to reduce the incidence of this compliance to 1% in the last 101 patients.

Humans↗

PubMed1989

The effect of early bladder stimulation on spinal shock: a preliminary report.

The period of spinal shock which frequently follows spinal cord injury is associated with bladder areflexia and urinary retention. We studied the effect of early bladder electric stimulation on detrusor activity during the spinal shock phase in the dog. The animals had a spinal cord section at T10 vertebra and their bladder management was assigned to one of the three following groups: intermittent catheterization, indwelling catheterization and electric bladder stimulation. The parameters for evaluating each treatment included: blood chemistry, radiographic and urodynamic tests. The salient feature was the early return of detrusor activity in the group of animals treated by early electric stimulation of the bladder.

Animals↗

PubMed1988

Keratinophilic fungi on the hair of goats from the West Bank of Jordan.

The mycoflora of the hair in 178 goats from the West Bank of Jordan was analysed and the frequency of occurrence and the relative importance value for the different keratinophilic fungi found were calculated. One hundred and seven species which belong to 38 genera were isolated. Thirty six of these species were either well recognised agents of mycoses (Trichophyton mentagrophytes, T. verrucosum, and M. nanum), or have been frequently isolated from human and animal lesions (Arthroderma spp., Acremonium kiliense, Alternaria alternata, Aspergillus flavus, Cladosporium carionii, and several other species). These potentially pathogenic fungal species comprised 66.9% of all keratinophilic fungi found on the hair of goats. The role of this animal as a reservoir for dermatophytes and other potentially pathogenic fungi is discussed.

Animals↗

PubMed1988

Keratinophilic fungi on the hair of cows, donkeys, rabbits, cats, and dogs from the West Bank of Jordan.

The mycoflora of hair of 111 cows, donkeys, rabbits, cats, and dogs were analysed and the frequency of occurrence and the relative importance value of the different fungal species isolated were calculated. Total numbers of species 56, 45, 48, 23, and 11 were recovered from cows, donkeys, rabbits, cats, and dogs respectively. The majority of the keratinophilic fungi isolated were either well-known mycotic agents or have been recovered from various animal and human lesions. These comprised 87.8%, 66.7%, 61.4%, 59.3%, and 55.2% of the hair mycoflora in cats, dogs, rabbits, cows, and donkeys respectively. Seven species of dermatophytes were isolated: Trichophyton mentagrophytes, T. verrucosum, Microsporum gypseum, M. nanum, T. ajelloi, and M. canis. Cats harboured the largest number of dermatophytes (5 species), followed by cows (4 spp), rabbits (3 spp), and donkeys and dogs (1 sp). The role of these animals in the persistence and transmission of pathogenic fungi is discussed.

Animals↗

PubMed1987

Effects of verapamil and sodium nitroprusside on acetylcholine-induced contraction of the rabbit detrusor muscle.

Effects of extracellular and intracellular Ca2+ on acetylcholine-induced contraction of the bladder detrusor muscle were studied in vitro, utilizing two types of Ca2+ antagonists of different mechanisms of action; verapamil and sodium nitroprusside (NP). Acetylcholine (10(-8) to 10(-2) M) caused dose-dependent contractions of the detrusor muscle strips. Pretreatment of the strips with verapamil (10(-7), 10(-6) M) significantly inhibited the acetylcholine-induced contraction in a dose-dependent manner, whereas NP (10(-7) to 10(-5) M) failed so suppress the contraction. The contraction of the strips once elicited by acetylcholine (10(-6) M) could be completely relaxed by verapamil (10(-5) M) addition, but only incompletely by NP (10(-5), 10(-4) M). In Ca2+-free solution containing 0.01 mM EGTA, replenishment of Ca2+ (2.5 mM) to the medium caused contractions of the strips. Addition of acetylcholine (10(-6) M) to the medium enhanced the Ca2+-induced contraction, which was significantly inhibited by pretreatment with verapamil (10(-6) M), but not affected by NP (10(-6) M). In Ca2+-free medium containing 0.1 mM EGTA, acetylcholine caused a slight degree of tension increase of the strips in a dose-dependent fashion, at higher concentrations exceeding 10(-6) M. These results suggest that the detrusor muscle contraction induced by acetylcholine is mostly dependent of extracellular Ca2+ influx both in its initiation and maintenance. It is also supposed, however, that intracellular Ca2+ fractions will partly participate in the acetylcholine-induced contraction and possibly in its maintenance.

Acetylcholine↗