Ismail A. Shafik
Cairo University
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Featured researches published by Ismail A. Shafik.
Archives of Andrology | 2005
Ali A. Shafik; Ismail A. Shafik; Olfat El-Sibai
The prostate exhibits electric activity in the form of slow waves (SWs) and action potentials (APs). As the interstitial cells of Cajal (ICCs) are considered the pacemaker cells which generate the electric waves, we investigated the hypothesis that the prostate contains ICC. Prostatic biopsies were obtained from 15 healthy volunteers (mean age 36 ± 3.8 SD years). They were subjected to c-kit immunohistochemistry. Controls for the specificity of the antisera consisted of tissue incubated with normal rabbit serum substituted for the primary antiserum. C-kit-positive cells were identified as fusiform with dendritic processes. The cytoplasm was granular and the nucleus large and oval. Mast cells, also c-kit-positive, were round and lacked the dendritic processes. Immunoreactivity was absent in the negative controls. There were cells in the prostate with morphological and immunological phenotypes similar to ICCs of the gut. We predict an abnormal distribution of these cells in prostatic diseases. The study of the integrity of these cells may prove to be a useful investigative tool in the diagnosis of prostatic diseases and in the planning of an appropriate treatment.
Diseases of The Colon & Rectum | 2007
Ahmed Shafik; Olfat El Sibai; Ali A. Shafik; Ismail A. Shafik
PurposePerineal body is considered by investigators as a fibromuscular structure that is the site of insertion of perineal muscles. We investigated the hypothesis that perineal body is the site across which perineal muscles pass uninterrupted from one side to the other.MethodsPerineal body was studied in 56 cadaveric specimens (46 adults, 10 neonatal deaths) by direct dissection with the help of magnifying loupe, fine surgical instruments, and bright light.ResultsPerineal body consisted of three layers: 1) superficial layer, which consisted of fleshy fibers of the external anal sphincter extending across perineal body to become the bulbospongiosus muscle; 2) tendinous extension of superficial transverse perineal muscle crossing perineal body to contralateral superficial transverse perineal muscle, with which it formed a criss-cross pattern; and 3) tendinous fibers of the deep transverse perineal muscle; the fibers crossing perineal body decussated in criss-cross pattern with the contralateral deep transverse perineal muscle. A relation of levator ani or puborectalis muscles to perineal body could not be identified.ConclusionsPerineal body (central perineal tendon) is not the site of insertion of perineal muscles but the site along which muscle fibers of these muscles and the external anal sphincter pass uninterrupted from one side to the other. Such a free passage from one muscle to the other seems to denote a “digastric pattern” for the perineal muscles. Perineal body is subjected to injury or continuous intra-abdominal pressure variations, which may eventually result in perineocele, enterocele, or sigmoidocele.
Archives of Andrology | 2006
Ali A. Shafik; A. A. Shafik; O. El Sibai; Ismail A. Shafik
Several techniques have been developed to measure the amount of sperm DNA damage in an effort to identify more objective parameters for evaluation of infertile men. The integrity of sperm DNA influences a couples fertility and helps predict the chances of pregnancy and its successful outcome. The available tests of sperm DNA damage require additional large-scale clinical trails before their integration into routine clinical practice. The physiological/molecular integrity of sperm DNA is a novel parameter of semen quality and a potential fertility predictor. Although DNA integrity assessment appears to be a logical biomarker of sperm quality, it is not being assessed as a routine part of semen analysis by clinical andrologists [26]. Extensive investigation has been conducted for the comparative evolution of these techniques. However, some of these techniques require expensive instrumentation for optimal and unbiased analysis, are labor intensive, or require the use of enzymes whose activity and accessibility to DNA breaks may be irregular. Thus, these techniques are recommended for basic research rather than for routine andrology laboratories. Sperm chromatin structure evaluation is applied to detect male factors that may affect the chance of success with IVF as well as natural fertility. Further research is needed to define the optimal test of sperm chromatin structure. The clinical application of this test will evolve as well.
BMC Urology | 2007
Ahmed Shafik; Ismail A. Shafik; Olfat El Sibai; Ali A. Shafik
BackgroundEtiology of venogenic erectile dysfunction is not exactly known. Various pathologic processes were accused but none proved entirely satisfactory. These include presence of large venous channels draining corpora cavernosa, Peyronies disease, diabetes and structural alterations in fibroblastic components of trabeculae and cavernous smooth muscles. We investigated hypothesis that tunica albuginea atrophy with a resulting subluxation and redundancy effects venous leakage during erection.Methods18 patients (mean age 33.6 ± 2.8 SD years) with venogenic erectile dysfunction and 17 volunteers for control (mean age 31.7 ± 2.2 SD years) were studied. Intracorporal pressure was recorded in all subjects; tunica albuginea biopsies were taken from 18 patients and 9 controls and stained with hematoxylin and eosin and Massons trichrome stains.ResultsIn flaccid phase intracorporal pressure recorded a mean of 11.8 ± 0.8 cm H2O for control subjects and for patients of 5.2 ± 0.6 cm, while during induced erection recorded 98.4 ± 6.2 and 5.9 ± 0.7 cmH2O, respectively. Microscopically, tunica albuginea of controls consisted of circularly-oriented collagen impregnated with elastic fibers. Tunica albuginea of patients showed degenerative and atrophic changes of collagen fibers; elastic fibers were scarce or absent.ConclusionStudy has shown that during erection intracorporal pressure of patients with venogenic erectile dysfunction was significantly lower than that of controls. Tunica albuginea collagen fibers exhibited degenerative and atrophic changes which presumably lead to tunica albuginea subluxation and floppiness. These tunica albuginea changes seem to explain cause of lowered intracorporal pressure which apparently results from loss of tunica albuginea veno-occlusive mechanism. Causes of tunica albuginea atrophic changes and subluxation need to be studied.
Journal of Sex & Marital Therapy | 2009
Ahmed Shafik; Ismail A. Shafik; Olfat El Sibai; Ali A. Shafik
Opinions vary over whether female ejaculation exists or not. We investigated the hypothesis that female orgasm is not associated with ejaculation. Thirty-eight healthy women were studied. The study comprised of glans clitoris electrovibration with simultaneous recording of vaginal and uterine pressures as well as electromyography of corpus cavernous and ischio- and bulbo-cavernosus muscles. Glans clitoris electrovibration was continued until and throughout orgasm. Upon glans clitoris electrovibration, vaginal and uterine pressures as well as corpus cavernous electromyography diminished until a full erection occurred when the silent cavernosus muscles were activated. At orgasm, the electromyography of ischio-and bulbo-cavernosus muscles increased intermittently. The female orgasm was not associated with the appearance of fluid coming out of the vagina or urethra.
International Journal of Gynecology & Obstetrics | 2004
Ali A. Shafik; Olfat El-Sibai; Ismail A. Shafik
Previous studies have shown that the corpus uteri exhibits electric activity in the form of slow waves and action potentials. The action potentials are coupled with uterine pressure elevation and the electric waves appear to be responsible for uterine motile activity; however no electric waves could be registered in the cervix. Selective identification and localization of interstitial cells of Cajal (ICCs) the pacemaker cells of the gut have been facilitated by the discovery of their expression of the c-kit receptor. Specific antibodies to the c-kit receptor have been used to identify ICCs. In view of the concept that ICCs are the pacemaker cells that trigger slow wave activity and as electric waves could be recorded from the corpus uteri we investigated the hypothesis that ICCs exist in the uterus. Specimens of 0.5_0.5_0.5 cm were excised fromthe corpus uteri and cervix of 21 human cadavers and subjected to c-kit immunohistochemistry studies. (authors)
Journal of Spinal Cord Medicine | 2008
Ahmed Shafik; Ali A. Shafik; Ismail A. Shafik; Olfat El Sibai
Abstract Objectives: Approximately one third to one half of the penis is embedded in the pelvis and can be felt through the scrotum and in the perineum. The main arteries and nerves enter the penis through this perineal part of the penis, which seems to represent a highly sensitive area. We investigated the hypothesis that percutaneous perineal stimulation evokes erection in patients with neurogenic erectile dysfunction. Methods: Percutaneous electrostimulation of the perineum (PESP) with synchronous intracorporeal pressure (ICP) recording was performed in 28 healthy volunteers (age 36.3 ± 7.4 y) and 18 patients (age 36.6 ± 6.8 y) with complete neurogenic erectile dysfunction (NED). Current was delivered in a sine wave summation fashion. Average maximal voltages and number of stimulations delivered per session were 15 to 18 volts and 15 to 25 stimulations, respectively. Results: PESP of healthy volunteers effected an ICP increase (P < 0.0001), which returned to the basal value upon stimulation cessation. The latent period recorded was 2.5 ± 0.2 seconds. Results were reproducible on repeated PESP in the same subject but with an increase of the latent period. Patients with NED recorded an ICP increase that was lower (P < 0.05) and a latent period that was longer (P < 0.0001) than those of healthy volunteers. Conclusion: PESP effected ICP increase in the healthy volunteers and patients with NED. The ICP was significantly higher and latent period shorter in the healthy volunteers than in the NED patients. PESP may be of value in the treatment of patients with NED, provided that further studies are performed to reproduce these results.
World Journal of Surgery | 2006
Ahmed Shafik; Ismail A. Shafik; Olfat El Sibai; Randa M. Mostafa
The mechanism of prevention of gastric reflux into the esophagus is not exactly known. The lower esophagus has a barrier function provided by the lower esophageal sphincter. We investigated the hypothesis that the crural diaphragm shares in the barrier function not only mechanically but also actively through a crural–esophageal–gastric reflex action. The study was performed during repair of abdominal ventral and incisional hernias in 20 subjects (11 men, 9 women; age 38.6 ± 4.8 years). The electromyographic response of the crural diaphragm to individual balloon distension of esophagus and stomach was recorded by means of a needle electrode inserted into the crural diaphragm and connected to an electromyographic apparatus. The recordings were repeated after separate crural, esophageal, and gastric anesthetization. The crural diaphragm exhibited basal motor unit action potentials, which decreased on esophageal distension (P < 0.001) after a mean latency of 17.3 ± 2.8 SD ms. The crural diaphragm response to esophageal distension did not occur after the crural diaphragm or esophagus was anesthetized. Gastric distension effected an increase of crural diaphragm electromyographic activity with a mean latency of 18.4 ± 4.6 ms; this effect could not be achieved after the crural diaphragm or stomach was anesthetized. The crural diaphragm has a resting tone that relaxes after esophageal distension and contracts after gastric distension. This sphincter-like action of the crural diaphragm appears to be a reflex and is mediated through the esophagocrural inhibitory and gastrocrural excitatory reflexes. The crural diaphragm seems to share actively in the gastroesophageal competence mechanism.
The American Journal of the Medical Sciences | 2007
Ahmed Shafik; Ismail A. Shafik; Ali A. Shafik; Olfat El Sibai
Background:We investigated the hypothesis that urethral stimulation effects vesical contraction. Methods:Vesical pressure response to urethral balloon distension with normal saline in increments of 1 mL was recorded in 26 healthy volunteers (17 men, 9 women; mean age, 36.9 ± 9.7 SD years) before and after individual anesthetization of the urinary bladder and urethra. Urethral distension was effected by a 6F balloon-ended catheter introduced per urethra. Vesical pressure was measured by means of a microtip catheter. Results:Vesical pressure recorded gradual increase on increase of urethral balloon distension. Bladder response was maintained as long as urethral distension was continuous. The response showed no significant difference when we distended different parts of the male or female urethrae. Urethral distension after individual vesical and urethral anesthetization effected no change in the vesical pressure. Conclusions:Urethral distension produced a vesical pressure increase that presumably denotes vesical contraction. Vesical contraction on urethral stimulation by distension is suggested to be mediated through a “urethrovesical stimulating reflex” that seems to facilitate vesical contraction. Provided further studies to be performed in this respect, the reflex may prove to be of diagnostic significance in micturition disorders.
Journal of Investigative Surgery | 2006
Ahmed Shafik; Ali A. Shafik; Olfat El-Sibai; Ismail A. Shafik
Colonic wall contains interstitial cells of Cajal. In view of studies demonstrating that Cajal cells generate electric waves which are presumably responsible for colonic motor activity, and that these waves are absent in total colonic inertia, we investigated the hypothesis that colonic Cajal cells might be disordered in patients with total colonic inertia. The study comprised 28 patients (age 41.6 ± 8.2 SD years, 19 women, 9 men) with total colonic inertia in whom total colectomy was performed. Colonic specimens obtained from normal segments of the excised colon of 24 cancer patients acted as controls. Specimens were subjected to c-kit immunohistochemistry. Controls for antisera specificity consisted of tissue incubated with normal rabbit serum that had been substituted for the primary antiserum. C-kit-positive branched Cajal-like cells were detected in the musculature of the normal colonic segments. They were distinguishable from the C-kit-negative smooth muscle cells and the C-kit-positive but unbranched mast cells. No Cajal cells were detected in colon of total colonic inertia patients. The absence of Cajal cells in patients with total colonic inertia can be assumed to explain the absence of electric waves and motile activity previously reported in these patients. Further studies are needed to investigate the cause of Cajal-cell absence.