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Biomedical subjects

A A Shafik

Publications and source records attributed to A A Shafik.

At least 19 recordsLinked to original sources
PubMed2005

Tunica albuginea overlapping: a novel technique for the treatment of erectile dysfunction.

Tunica albuginea (TA) in venogenic erectile dysfunction (VED) was found subluxated and flabby because of degeneration and atrophy of its collagen fibres. This had apparently led to derangement of TA veno-occlusive mechanism. We investigated the hypothesis that overlapping of the subluxated and flabby TA would achieve a competent veno-occlusive mechanism during erection. Tunical overlapping was performed in nine VED patients (age 35.6 +/- 1.6 years). Intracorporal pressure (ICP) was measured pre- and postoperatively. After penile degloving, TA on lateral penile aspect was divided along whole length of corpus cavernosum (CC) and tunical double-breasting for 1-1 1/2 cm was performed. A biopsy was taken from TA and stained with haematoxylin and eosin and Masson's trichrome. Clinical efficiency of the operation was evaluated after 6 months. ICP increased (P < 0.01) postoperatively in the nine patients. The increase was maintained during follow-up period in eight patients and decreased to preoperative level in one. Six months after operation, the eight patients had significantly (P < 0.01) improved scores for the erectile function domain over the preoperative scores. Microscopic examination of TA biopsies showed atrophy of the collagen fibres. Tunical overlapping aims at correction of TA flabbiness, corporal tissue support and improving of veno-occlusive mechanism.

Adult↗
PubMed2004

The corporo-glans ligament: description and functional significance of a ligament connecting the corpora cavernosa to the glans penis.

The two corpora cavernosa (CC) end blindly under cover of the glans penis (GP). The method of attachment of the CC to the GP could not be traced in the literature. The current communication investigated the hypothesis of a ligamentous attachment existing between the two corporal ends and the GP. In all, 18 male cadaveric specimens were studied by direct dissection and histologically. Six were neonates and 12 adults (mean age 32.3+/-10.6 s.d. y). After examining and photographing the connection between the CC and GP, sagittal, parasagittal, and coronal sections of the connection were stained and studied microscopically. A triangular fibrous tissue band connected the distal blind ends of the two CC with the GP. The base of this band was attached to the tunica albuginea of the two CC, while the apex was continuous with the fibrous septa between the sinusoids of the cavernous tissue of the GP. Microscopically, the ligament consisted of collagen and elastic fibers; in some sections, the collagen fibers of the tunica albuginea were continuous with those of the band. A band of collagen and elastic fibers could be identified connecting the two CC to the GP; we term it the 'corporo-glans ligament'. This ligament presumably affords the connection with rigidity, flexibility, and tissue strength. We suggest that it firmly connects the GP to the CC during penile thrusting. Further studies are required to assess the possible role of this ligament in erectile dysfunction.

Adolescent↗
PubMed2004

Overactive corpus cavernosum: a novel cause of erectile dysfunction.

Our recording of the electromyographic (EMG) activity of the corpus cavernosum (CC) in 59 patients with erectile dysfunction (ED) revealed 18 patients who had elevated electric activity, which presumably points to heightened tone of the CC smooth muscles. We investigated the hypothesis that this elevated EMG activity and muscular tone of the CC could be the cause of ED. The study comprised the said 18 subjects with the hypertonic CC muscles as study group (42.6 +/- 5.3 SD years), 15 healthy volunteers (41.8 +/- 5.1 SD years) and 15 patients (41.6 +/- 5.5 SD years) with ED who had not recorded elevated tone of the CC muscles as control group. The EMG activity was registered in the flaccid, erectile and detumescent phases by two electrodes inserted into the CC. Electrocavernosography (ECG) of healthy volunteers recorded in the flaccid phase showed regular slow waves (SW) and random action potentials (APs). The wave variables declined significantly in the erection phase (P < 0.01). In the study group, the SW variables in the flaccid phase increased significantly (P < 0.05) compared with the healthy volunteers and the rhythm was irregular. Erection did not occur with sildenafil but with intracavernosal injection of papaverine, which led to decline of the SW variables (P < 0.05). The control ED group exhibited in the flaccid phase diminished SW variables (P < 0.05) compared with the healthy volunteers. On erection with sildenafil administration, the SW variables showed significant reduction (P < 0.05). CC hypertonicity or 'overactive CC' was identified as a possible cause of ED. An elevated EMG activity of the CC muscle fibres in the flaccid phase presumably denotes hypertonicity of these fibres and their failure to relax to effect erection. The cause of elevated CCEMG activity and presumed muscle hypertonicity is unknown and could be functional or organic. Erection was produced by intracavernosus injection of papaverine and not by sildenafil. This condition of 'overactive CC' should be considered in the diagnosis of ED. However, further studies in the pathogenesis of the condition are warranted.

Action Potentials↗
PubMed2003

Videodefecography: a study of the rectal motile pattern.

The mechanism of rectal motility has remained largely obscure. Recently, by recording rectal electromechanical activity, we identified the rectal motility pattern as occurring in a "mass squeeze" manner. In the current communication, rectal motility was studied by means of videodefecography. The study comprised 28 healthy volunteers (18 men, 10 women; mean age 37.6+/-11.8 years). Evacuation dynamics were studied and registered using a videocassette tape with a high-resolution recorder. The rectum showed no peristaltic or segmentation activity at rest. When the subject was asked to evacuate, a contraction wave started at the rectosigmoid junction (RSJ) and spread aborally. The upper rectum appeared to contract producing anal canal opening and the closure of the RSJ; after rectal evacuation, the anal canal closed and the RSJ opened. The rectal contraction wave was repeated as long as the rectum still contained barium paste. The subjects strained prior to the start of each contraction wave. Some waves did not effect rectal evacuation. These "incomplete" waves started at the mid- or lower rectum and were followed by "complete" waves that produced evacuation. In five of 28 subjects, rectal intussusception occurred during rectal contraction. A small anterior rectocele occurred in another two subjects during rectal contraction. Videodefecography revealed that upon rectal distension with barium paste, a contraction wave, initiated at the RSJ, effected reflex RSJ closure and anal canal opening. The wave spread aborally, "squeezing" the rectal contents towards the opened anal canal. Two types of contraction waves were observed: "complete" which produced rectal evacuation, and "incomplete" which failed to effect evacuation. Physiologic intussusception or rectocele were seen in a few subjects.

Adult↗
PubMed2003

Study of the functional activity of the cecocolonic junction with identification of a "physiologic sphincter", "cecocolonic inhibitory reflex" and "colocecal excitatory reflex".

Radiologic, endoscopic and histomorphologic studies have suggested the presence of a sphincter at the cecocolonic junction (CCJ), while some investigators have denied its existence. To investigate the physiologic activity at the CCJ, the right colon was exposed during right hemicolectomy for early colonic cancer in 11 patients (mean age 43.6+/-12.3 years; 8 men). Three manometric catheters were introduced through colotomy to be separately located in the cecum, CCJ and ascending colon. We determined the CCJ pressure response to cecal and colonic distension by means of a balloon filled with saline in increments of 10 ml. The test was repeated after individual anesthetization of cecum, CCJ and ascending colon. The CCJ measured 1.6+/-0.6 cm in length and had a higher pressure ( p<0.05) than the cecum or colon. Large-volume cecal distension effected a significant CCJ pressure reduction which was augmented as the distension increased. Latency decreased upon increase of the distending volume. In contrast, the CCJ responded to large-volume colonic distension by pressure elevation which increased upon increase of the distending volume. Latency diminished with increased distension. Small-volume cecal or colonic distension effected no CCJ pressure response. The anesthetized CCJ did not respond to distension of the cecum or colon. Likewise, the CCJ did not exhibit a pressure response to distension of the anesthetized cecum or colon. The CCJ is a high-pressure zone which reacts to cecal or colonic distension by dilatation or narrowing, respectively. These data presumably denote the existence of a physiologic sphincter at the CCJ. We suggest that the CCJ pressure response to cecal or colonic distension is reflex and mediated through the cecocolonic inhibitory and colocecal excitatory reflexes, respectively. The role of the CCJ and related reflexes in colonic motility disorders needs to be studied.

Adult↗
PubMed2002

Study of the effect of straining on the bulbocavernosus muscle with evidence of a straining-bulbocavernosus reflex and its clinical significance.

The bulbocavernosus muscle (BCM) surrounds the vaginal introitus and covers the vestibular bulb. Its role in erection is known. However, as it surrounds the vaginal introitus, it may also have a role in intravaginal pressure regulation and in the pathogenesis of uterovaginal prolapse. We investigated the effect of increased intra-abdominal pressure (IAP) on the BCM, aiming to assess its possible function in supporting the uterus, vagina and anorectum. The intrarectal (representative of the IAP) and intravaginal pressures were measured by manometric catheters in 19 healthy women volunteers (mean age 46.2 +/- 10.4 years). The EMG activity of the BCM and its response to straining at different pressures were recorded by a concentric needle electrode. Two types of straining were tested: sudden momentary and slow sustained. The procedure was repeated in 11 of the women after individual anesthetization of the BCM, rectum and vagina. Sudden straining (coughing) produced a significant increase in intrarectal ( P<0.0001) and intravaginal ( P<0.0001) pressure as well as BCM EMG activity. Slow straining effected a similar but lower response: the BCM responded gradually with pressure elevation, whereas the latency exhibited a gradual decrease. The BCM did not react to straining after individual anesthetization of the BCM, vagina and rectum, but did respond to saline administration. The results were reproducible. BCM contraction on straining postulates a reflex relationship, which we call the 'straining-bulbocavernosus reflex'. We hypothesized that this reflex is evoked by straining and results in BCM contraction and closure of the vaginal introitus. The vagina is believed to become a closed cavity, counteracting the increased intra-abdominal pressure and the uterine tendency to prolapse. The high pressure in the closed vaginal cavity presumably supports the rectovaginal septum against the high intrarectal pressure, and is suggested to share in the prevention of rectocele. The role of BCM in the pathogenesis of uterovaginal prolapse and rectocele needs further study.

Adult↗
PubMed2002

Cauterization-plication operation in the treatment of complete rectal prolapse.

The current communication presents a simple technique for treatment of complete rectal prolapse (CRP). The study included 28 patients presenting with CRP (mean age, 36.4 years; 4 children 2-12 years; 17 female and 11 males). Fourteen patients had fecal incontinence. With the patient under general anesthesia in lithotomy position, the prolapsed rectum was pulled outside the anal canal, the mucosa was cauterized in vertical lines and the exposed muscle layer was plicated by 2/0 coated Vicryl sutures. Posterior levatorplasty was done in 14 adult patients in whom the length of prolapsed segment was more than 10 cm and who were incontinent due to a wide levator hiatus. The postoperative follow up was 31.6+/-14.8 months (mean+/-SD). Five had postoperative mucosal prolapse and one had recurrence 3 months of operation. Mucosal plication was performed for the five patients and the operation was redone for the recurrent patient. Fecal impaction, stricture and fistula formation were not encountered. The technique is simple, easy and with minimal complications.

Adolescent↗
PubMed2001

Electric activity of the rectosigmoid canal and its relation to rectal and sigmoid electric activity: an evidence of a sphincteric function of the rectosigmoid canal.

We have previously demonstrated that the rectosigmoid junction is more than a junction: it is a segment with a mean length of 2.8 cm which we termed the 'rectosigmoid canal' (RSC). Our data support the existence of a physiologic and anatomic sphincter at the RSC which regulates the passage of stools from the sigmoid colon (SC) to the rectum (R). In view of its sphincteric action we investigated the hypothesis that the RSC has a higher electric activity than that of the SC and R. The tests were performed during repair of huge incisional hernia in 11 subjects (age 46.7(12.5 years; 8 women). The electric activity was recorded by means of 2 monopolar electrodes applied to each of the SC, RSC and R. The RSC was then anesthetized with xylocaine and the electric activity of SC, RSC and R was recorded after 10 minutes and one hour. The test was repeated using saline instead of xylocaine. The SC, RSC and R exhibited electric activity in the form of pacesetter potentials (PPs) and action potentials (APs). The PPs were monophasic in the SC and triphasic in the RSC and R. The frequency, amplitude and conduction velocity of the waves recorded from the RSC and R had higher readings (p<0.05) than those from the SC. The RSC and R showed a similar frequency and conduction velocity, but the RSC had a higher amplitude (p<0.05). Ten minutes after RSC anesthetization, electric waves were recorded from the SC but not from the RSC or R; electric activity returned one hour after anesthetization. Saline injection of the RSC did not affect the electric activity of the RSC, SC or R. The electric wave pattern and parameters of the RSC and R differed from those of the SC, suggesting that they are evoked by 2 different pacemakers. The similarity in pattern, frequency and conduction velocity of electric waves of RSC and R supposedly denotes that the rectal waves are a continuation of those of the RSC and that both are evoked by a single pacemaker located in the RSC. The higher amplitude of the RSC waves may be due to the thicker RSC musculosa in comparison to that of the SC and R and may by itself be an evidence of the sphincteric function of the RSC.

Adult↗
PubMed2001

Transverse folds of rectum: anatomic study and clinical implications.

There are controversies with respect to the location, number, and function of the transverse folds of the rectum (TFR), probably because their physioanatomic aspects have not been fully investigated. The purpose of this communication was to study the anatomic and histologic structure of the TFR aiming at elucidation of their function in the light of their structure. The TFR were studied morphologically and histologically in 18 cadavers (10 male, 8 female) with a mean age of 36.6 +/- 10.4 (SD) years. Barium enema studies were also performed in 36 volunteers (20 male, 16 female; mean age 38.6 +/- 15.2 [SD] years). The number of TFR varied, the commonest findings being two and three. In a few cases, TFR were absent or exceeded three in number. Most folds extended beyond the middle of the rectal lumen; a few were narrow. They were thick at the base and tapered gradually. Microscopically, the TFR contained circular and longitudinal smooth muscle fibers; they were rarely purely mucosal. TFR varied in location dividing the rectum into compartments; an alternating side-to-side arrangement allows for a wavy movement of the stool in the rectum. The wavy movement, compartmental division, and the shelving action of the TFR are suggested to retard stool movement in the rectum so as to allow time for fecal sampling (stool or gas) and for impulses to reach the conscious level to decide whether or not to defecate. Further studies are needed to investigate the role of the TFR in clinical practice.

Adolescent↗
PubMed2001

Experimental use of the obturator internus muscle as a functioning pelvic floor muscle in dogs.

OBJECTIVE: To investigate the possibility of using the obturator internus muscle instead of the levator ani as a pelvic floor muscle. DESIGN: Experimental study. SETTING: Teaching hospital, Egypt. ANIMALS: 7 male and 3 female mongrel dogs. INTERVENTIONS: Through a para-anal incision both muscles were exposed; the levator ani was excised and the lower border of the obturator internus was mobilised and sutured to the anorectal junction, the vesical neck, and the vaginal fornix. MAIN OUTCOME MEASURES: Rectal and anal pressures and electromyographic (EMG) activity recorded before and during transposition, and 1, 3, and 6 months later. Histological examination of biopsy specimens taken from the levator ani before, and from the obturator internus before, and 3, 6, and 12 months after, transposition. RESULTS: Stimulation of the levator ani caused anal pressure to decline significantly (p < 0.05). Stimulation of the obturator internus did not change anal pressure before transposition but caused a decline after it. There was EMG activity in the levator ani at rest, but not in the obturator internus before transposition though it was evident by 6 months afterwards. Levator ani consisted of skeletal muscle fibres with smooth muscle fibres in places, whereas the obturator internus consisted of skeletal fibres alone. Six months after operation examination of the obturator internus showed the presence of some smooth muscle fibres. CONCLUSION: These results suggest that the obturator internus might be suitable both anatomically and physiologically to replace the levator ani. However, before it can be suggested as a treatment for levator dysfunction syndrome further experimental studies are necessary.

Anal Canal↗
PubMed2000

Rectal pacing in patients with constipation due to rectal inertia: technique and results.

In a previous study we determined the rectal pacing parameters needed for rectal evacuation in patients with rectal inertia. Here we investigated the effect of rectal pacing on rectal myoelectric activity, motility, and evacuation in ten patients with constipation due to rectal inertia. A pacemaker was implanted in a subcutaneous pocket above the inguinal area, with a lead threaded in the anal submucosa to be hooked at the rectosigmoid junction. The effect of rectal pacing on rectal electric activity was investigated by inserting two recording electrodes to the rectal mucosa. The patients were then trained for home pacing. No waves were recorded from the rectum at rest. On rectal pacing, slow waves or pacesetter potentials (mean frequency 2.3+/-1.1 cpm, amplitude 0.86+/-0.1 mV, velocity 3.4+/-1.6 ms) were registered after a latency period of 5.2+/-1.6 min. Rectal evacuation, on pacing, occurred in seven of the ten patients. The three who showed no significant response exhibited low wave parameters. Three of seven patients were able to evacuate spontaneously without pacing after having performed daily pacing for 5-6 months. The pacemaker was removed in six patients (three failures and three after spontaneous defecation). Thus rectal pacing succeeded in inducing rectal evacuation in 70% of the patients. The procedure failed in three patients. Three had spontaneous defecation after a few months of rectal pacing. No complications were encountered, and the method was tolerated and acceptable. Further studies on a large group of patients are required.

Action Potentials↗
PubMed2000

Magnetic stimulation of the cavernous nerve for the treatment of erectile dysfunction in humans.

A recent study in dogs has demonstrated that magnetic stimulation (MS) of the cavernous nerve produced an increase of the intracorporeal pressure and full penile erection. In view of these results, we tested the possible application of this procedure in humans with erectile dysfunction (ED). The study comprised 32 patients with ED (age 38.3 +/- 9.6 y) and 20 healthy volunteers (age 36.8 +/- 8.8 y). Routine erectile function tests suggested that impotence was neurogenic. A magnetic coil was placed over the dorsal aspect of the penis in the vicinity of the symphysis pubis. MS was performed using a stimulation of 40% intensity, 20 Hz frequency, 50 s on and 50 s off for 10 minutes duration. In the healthy volunteers, the coil was placed as aforementioned but was not activated. The intracorporeal pressure was recorded and penile tumescence and rigidity observed during MS in the patients and without stimulation in the controls. MS led to gradual increase in length and diameter of the penis until full erection was achieved; the penis became firm, rigid and pulsatile. The intracorporeal pressure increased significantly (P < 0.0001) at full erection. Mean latency to full erection was 19.3 +/- 3.4 s. Upon off-stimulation, penile erection and intracorporeal pressure returned to baseline after a mean of 22.7 +/- 3.2 s. Penile and pressure response to MS was resumed after an off-time of 50 s. The response was reproducible infinitely if the off-time was observed. The controls showed no penile tumescence or rigidity or increase of the intracorporeal pressure. In conclusion, MS of the cavernous nerve is effective in inducing penile rigidity. It is a simple, easy and non-invasive method which has no adverse effects. It might prove to be suitable for application in patients with ED.

Adult↗
PubMed2000

Is myoelectric activity transmittable from one muscle to another: an experimental study.

BACKGROUND: In contrast to other striated muscles in the body, pelvic floor muscles possess resting electric activity. We have demonstrated that this activity was due to smooth muscle fibers detected in the levator ani muscle (LAM) which presumably develop in adaptation to variations in the intraabdominal pressure and visceral weight action. AIMS: The current communication tries to answer the question whether this resting myoelectric activity is transmittable to other muscles which lack such activity. METHODS: The LAM and obturator internus muscle (OIM) were exposed in 14 mongrel dogs through a paraanal incision. The resting EMG activity of both muscles was recorded. The border of the LAM closest to its origin at the white line, was released and sutured to the obturator fascia. The EMG activity of both the LAM and OIM was recorded at rest and on LAM stimulation. The EMG recording was repeated after suturing of the LAM to the OIM whose fascia had been removed. The test was repeated after LAM anesthetization. RESULTS: Resting and stimulated EMG activity was recorded in the LAM, but not in the OIM, before and after suturing the LAM to the obturator fascia. On removing the obturator fascia, both muscles recorded similar EMG activity at rest and on LAM stimulation (p > 0.05, p > 0.05, respectively). Thirty minutes from LAM anesthetization both muscles showed no EMG activity at rest or on LAM stimulation; after 3 hours, the 2 muscles recorded an activity similar to that before anesthetization (p > 0.05). CONCLUSION: The myoelectric activity can be transmitted to defasciated muscles. This finding may be useful in electrostimulation therapy and in developing type 1 fibers in striated muscles.

Animals↗
PubMedDate not supplied

Response of the internal reproductive organs to clitoral stimulation: the clitorouterine reflex.

We investigated hypothesis that uterine erection, elevation and enlargement during sexual response are reflex and result from penis buffeting the glans clitoris (GC). In 23 healthy women, two recording electrodes were applied to the uterine mucosa and one to cervix uteri (CU). GC was stimulated electrically and mechanically by pencil electrode. The uterine and CU pressures were measured. Tests were repeated after anesthetization of the uterus or GC. Uterine electrodes recorded slow waves, followed by random bursts of action potentials (APs). No waves registered from CU. Electrical or mechanical GC stimulation eliminated uterine electric waves, but anesthetized GC did not, nor did GC stimulation while the uterus anesthetized. Uterine pressure declined on electrical or mechanical stimulation. Results suggest presence of reproducible reflex relationship between GC and the uterus, we call 'clitorouterine reflex'. GC buffeting seems to evoke reflex and initiate uterine responses. Reflex may prove of diagnostic significance in sexual disorders.

Adult↗
PubMedDate not supplied

Electrocavernosogram in erectile dysfunction: a diagnostic tool.

Corpora cavernosa (CC) evoke electric waves that appear to be of diagnostic significance in evaluation of erectile dysfunction (ED). We investigated the hypothesis that electrocavernosography (ECG) exhibits different patterns in the various types of ED: neurogenic, vasculogenic, and psychogenic. Electrocavernosography was performed in the flaccid phase in 16 neurogenic, 28 vasculogenic (15 arteriogenic, 13 venogenic), and 24 psychogenic patients with ED, and in 15 healthy volunteers (controls). Two needle electrodes were introduced into the CC and the EMG activity was recorded in each of the 2 CCs of the same subject. Two 20 minute recording sessions were performed for each subject. The controls recorded slow waves (SWs) with regular rhythm and identical frequency, amplitude and conduction velocity from the 2 electrodes of the same subject. Random action potentials (APs) were superimposed on or followed the SWs. The ECG in the neurogenic ED recorded no waves in 14/16 patients and occasional irregular waves in 2. The SWs of the arteriogenic ED had irregular rhythm and variable and low parameters compared to those of the controls. The ECG of the patients with venogenic ED was similar to that of the controls, while the ECG of the psychogenic ED exhibited SWs with irregular rhythm and higher parameters than the controls. The study has revealed various ECG patterns in ED: "silent" in neurogenic. "bradyarrhythmic" in arteriogenic, "normal" in venogenic, and "overactive" in psychogenic ED. We suggest that electrocavernosography has the potential to function as an investigative tool in diagnosing the type of ED provided further studies are performed to verify the described findings.

Action Potentials↗
PubMedDate not supplied

Sperm DNA fragmentation.

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 couple's 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. 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.

Apoptosis↗