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Biomedical subjects

A Shafik

Publications and source records attributed to A Shafik.

At least 19 recordsLinked to original sources
PubMed2006

Vaginal and uterine pressure response to semen deposition into the vagina and uterus: human study.

PURPOSE OF INVESTIGATION: The effect of semen deposition in the vagina or uterine cavity on both uterine and vaginal pressure has scarcely been reported in the literature. We investigated the hypothesis that semen deposition in the vagina or uterus effects changes in their pressure. METHODS: The study comprised 27 healthy women volunteers (mean age 36.4 +/- 11.6 years). Both uterine and vaginal pressure were measured under basal conditions and on semen or saline deposition in the vagina and uterus. RESULTS: Upon semen deposition in the vagina, the vaginal pressure showed no significant changes (p > 0.05) while the uterine pressure exhibited a significant intermittent rise (p < 0.05). Semen deposition into the uterine cavity caused no vaginal pressure changes (p > 0.05) while the uterine pressure exhibited an intermittent increase (p < 0.01). Saline injection into the vagina or uterus showed no significant pressure changes (p > 0.05). CONCLUSION: Semen deposition into the vagina or uterine cavity was associated with uterine pressure elevation that might eventually help transport the sperm to the oviduct. Further studies are required to define the substances responsible for this effect.

Adult↗
PubMed2006

A study on the etiology of uterine pressure rise on semen deposition in the vagina or uterus.

PURPOSE OF INVESTIGATION: In a recent study we have demonstrated that semen deposition into the vagina or uterus effects uterine pressure rise which is suggested to assist in "sucking" semen into the uterine cavity. The purpose of this study was to investigate whether the uterine pressure rise is effected by the sperm or the substances contained in the seminal plasma, and to test the response of the vagina and uterus to abnormal semen deposition. METHODS: Semen was obtained from 60 men divided into four groups: A) obstructive azoospermia, B) Sertoli cell-only syndrome, C) oligozoospermia and D), fertile subjects. Before and after semen deposition into the vagina and uterus both vaginal and uterine pressure were recorded. RESULTS: Semen from groups A and B produced no significant vaginal or uterine pressure changes (p > 0.05) when it was deposited into either the vagina or uterus. Group C and D semen when placed in the vagina or uterus separately effected significant intrauterine pressure rise (p < 0.05) but no vaginal pressure changes (p > 0.05). The pressure rise was higher when the semen was deposited in the uterus than in the vagina (p < 0.05) and with the normospermic than oligozoospermic semen (p < 0.05). In groups C and D, the seminal plasma produced no vaginal or uterine pressure changes (p > 0.05), whereas the sperm effected intrauterine pressure rise (p < 0.05) which was more elevated with sperm from normospermic than oligozoospermic semen (p < 0.05). CONCLUSIONS: Aspermic semen did not effect vaginal or uterine pressure rise, while oligozoospermic and normospermic semen produced rise of uterine but not vaginal pressure. Uterine pressure rise was induced by the sperm and not the seminal plasma. Further studies are required to define the sulstances secreted by the sperm which produce this increased uterine pressure.

Adult↗
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

The histomorphologic structure of the levator ani muscle and its functional significance.

The levator ani muscle (LAM), unlike other striated muscles has resting myoelectric activity, the cause of which is not precisely known. In a recent study this activity was suggested to be related to the presence of smooth muscle bundles in the LAM. The present study investigated this point in 25 cadaveric specimens (10 neonates, 15 adults). Histologic examination of the LAM was performed in 12 specimens, three to six slices being taken from the lateral to the medial side of each muscle, processed and stained with H&E and Masson's trichrome stain. The remaining 13 specimens were studied by direct dissection and photographed. Microscopic examination of specimens from adult cadavers showed that the lateral part of the LAM consisted of purely skeletal muscle bundles, mostly of the small-caliber type and few of the large or intermediate type. As we proceeded medially, smooth muscle bundles started to appear. Examination of slices medial to the midportion of the LAM showed that the muscle began to be separated into two layers: a deep (pelvic) one formed of smooth fibers and a superficial (perineal) one of skeletal fibers, separated by a neurovascular plane. Microscopic examination of specimens from neonates showed that the whole LAM consisted of skeletal fibers; no smooth fibers or separation into two layers were identified. By direct dissection of the adult specimens the medial part of the LAM consisted of two layers, superficial and deep, which were separated by fascia containing vessels and nerves. The muscle was thicker at its medial part and tapered laterally, with loss of demarcation, into two layers. Specimens from neonates showed no differentiation of the LAM, into two layers. It is suggested that the deep layer of the LAM, which was formed of smooth fibers, acts involuntarily, supporting the pelvic viscera by its tone and responding to variations in intra-abdominal pressure by adaptation of this tone. The superficial layer of the LAM, made of skeletal fibers, appears to represent the functional mobile part that acts voluntarily during urination or defecation. The presence of the smooth fibers in the adult LAM and not in neonates seems to be adaptational, caused by the action of intra.abdominal pressure and visceral weight. The skeletal fibers pass into various histologic stages before they transform to smooth fibers.

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

Study of the levator ani muscle in the multipara: role of levator dysfunction in defecation disorders.

The levator ani muscle (LAM) shares in the mechanism of defecation and urination as well as in visceral support. Levator dysfunction occurs in conditions of chronic straining or increased intra-abdominal pressure. Studies have shown that the gravid uterus, by virtue of its weight and associated increased intraabdominal pressure, might disturb the levator function. It is postulated that this effect is augmented with repeated pregnancies. The current study investigated the functional activity of the LAM in 50 multipara, 30 primipara and 20 nullipara (controls). The 50 multipara (age 46.4 years, 4-7 deliveries) were divided into group A (28 women with normal deliveries) and group B (22 women with a prolonged 2nd stage of labour). Of the 30 primipara (age 44.2 years) 18 had normal delivery (group A) and 12 prolonged 2nd stage of labour (group B). The mean age of the nullipara was 45.3+/-7.6. The LAM activity at rest and on contraction was recorded. The rectal and anal canal pressure response to LAM stimulation was also registered. In group A of the multipara, the LAM EMG activity at rest was similar to (P>0.05), and on contraction lower (P<0.05) than the LAM EMG of the controls (nullipara). Group B exhibited a lower activity at rest and on contraction (P<0.01, both). Primipara group A had a resting and contractile EMG activity similar to the controls, while group B showed diminished activity in both conditions (P<0.05, both) which was significantly higher (P<0.05, P<0.01, respectively) than that of group B multipara. The rectal pressure in the multipara and primipara did not differ from the nullipara (P>0.05, both). In groups A and B of multiparous women, the anal canal pressure at rest was significantly lower and on LAM contraction significantly higher than that of nullipara. Group A of the primipara showed no significant difference against the controls, while group B exhibited a decline at rest (P<0.05) and no difference on LAM contraction (P>0.05). In conclusion, levator dysfunction might occur in the parous women. It was more common in the multipara than the primipara and in particular those with a history of a prolonged 2nd stage of labour. Levator dysfunction may lead to constipation and faecal or urinary incontinence as a result of pudendal neuropathy and the development of pudendal canal syndrome.

Adult↗
PubMed2002

Sacral magnetic stimulation in puborectalis paradoxical syndrome.

BACKGROUND AND PURPOSE: Our earlier studies have demonstrated that sacral magnetic stimulation (MS) in the canine model, in healthy volunteers and in constipated subjects effected rectal pressure rise, decline of the rectal neck (anal canal) pressure as well as rectal evacuation. Based on these results, we studied the effect of sacral MS on defecation in patients with puborectalis paradoxical syndrome (PPS). METHODS: Eleven subjects (8 women, 3 men; age 36-53 years) with PPS were enrolled in the study. The magnetic coil was placed on the back with its center located between L4 and L5. Stimulation parameters were set at 70% of maximum intensity, 40 Hz frequency and 2-second burst length with 2 seconds off. During MS, the rectal neck and gastric (intra-abdominal) pressures were measured. The procedure was performed in the empty and in the full rectum using the balloon expulsion test in the latter. RESULTS: MS of the empty and balloon-filled rectum effected rise of the rectal pressure (p < 0.001), decline of the rectal neck pressure (p > 0.001) and no significant change of the intragastric pressure (p > 0.05). The balloon was expelled to the exterior in all the patients. CONCLUSIONS: Sacral MS succeeded in dispelling to the exterior the water-filled rectal balloon. The method is simple, easy, non-invasive, non-radiologic and can be performed on an outpatient basis for the treatment of PPS.

Adult↗
PubMed2001

Role of the sigmoid colon in the defecation mechanism with evidence of sigmoido-anal inhibitory and ano-sigmoid excitatory reflex.

In spite of voluminous literature that has been written on defecation, the exact mechanism has not yet been fully cleared up. The current study investigated the effect of sigmoid colon (SC) distension on anal motile activity and of anal distension on SC motility. Sixteen healthy volunteers (age 36.2 +/- 11.6 SD years, 10 men) were studied. The SC was distended by a balloon in 10 ml increments of CO2, and the anal, rectal and SC pressure response was recorded before and after their individual anesthetization. The anal, rectal and SC pressure response to anal distension in increments of 2 ml of CO2 was also registered. SC distension with big volumes (mean 86.2 +/- 1.9 ml) effected a SC pressure increase (p<0.05) and no rectal pressure response (p>0.05); the balloon was expelled to the exterior. Distension of the anesthetized SC caused no SC, rectal or anal pressure response (p>0.05, p>0.05, p>0.05, respectively); the response returned after the anesthetic effect had waned. SC distension while the rectum had been anesthetized, affected a significant SC pressure rise as well as an anal pressure decrease and balloon expulsion to the exterior. Anal balloon distension produced a significant pressure rise of the SC (p<0.001) and rectum (p<0.01). Distension of the anesthetized rectal neck (anal canal) caused no SC or rectal pressure response (p>0.05, p>0.05, respectively); response returned after the anesthetic effect had disappeared. SC distension appears to effect anal dilatation while anal distension causes SC contraction. This reciprocal action is suggested to be reflex and mediated through the "sigmoido-anal inhibitory reflex" and the "ano-sigmoid excitatory reflex". These 2 reflexes are believed to keep the SC contracting and the rectal neck dilated until complete SC evacuation occurs. The study seemingly negates the role of rectal distension as a prerequisite for balloon expulsion.

Adult↗