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sphincter muscle [keywords]
- The effects of tamsulosin and alfuzosin on iris morphology: an ultrasound biomicroscopic comparison. [JOURNAL ARTICLE]
- Cutan Ocul Toxicol 2014 Apr 14.
Abstract Context: It is well known that Alpha-1 adrenergic receptor antagonists affect the receptors in the prostate and also iris dilator muscle, leading to loss of iris muscle tone. Objective: To compare morphological alterations of iris secondary to tamsulosin and alfuzosin use. Participants: Patients included in the study were grouped as follows: 16 patients treated with tamsulosin (Group 1), 14 patients treated with alfuzosin (Group 2) and 18 untreated controls (Group 3). Materials and methods: All patients underwent ultrasound biomicroscopic and pupillometric examination. Iris thickness was measured at the dilator muscle region (DMR; measured at half of the distance between the scleral spur and the pupillary margin) and sphincter muscle region (SMR; Standardized at 0.75 mm from the pupillary margin). DMR/SMR was also calculated for each patient. Differences among groups were analysed. Main outcome measures were DMR, SMR, DMR/SMR and pupillary diameter. Results: Mean duration of treatments were 2.4 ± 0.96 years (1-4) and 2.3 ± 1.01 years (1-4) in Groups 1 and 2. Pupillary diameters were reduced in Groups 1-2 compared to Group 3 (p < 0.001, p < 0.001). The SMR was similar in Groups 1 and 2 (p: 0.114). These values were not significantly different from that of Group 3 (p: 0.196, p: 0.209). However, thickness in the DMR in Groups 1-2 were significantly lower than that of controls (Group 3) whereas there was no significant difference between Groups 1 and 2 (p: 0.041, p: 0.039 and 0.986, respectively). Mean DMR/SMR ratios were significantly lower in Groups 1-2 than that of Group 3 (p: 0.040 and p: 0.040, respectively). Conclusions: In patients using these medications, the iris seems to be thinner at the dilator muscle region, but preserving the sphincter muscle region.
- Substance P is essential for maintaining gut muscle contractility: a novel role for co-neurotransmission revealed by botulinum toxin. [JOURNAL ARTICLE]
- Am J Physiol Gastrointest Liver Physiol 2014 Apr 3.
Background & Aims: Substance P (SP) is commonly co-expressed with acetylcholine in enteric motor neurons and according to the classical paradigm, both these neurotransmitters excite smooth muscle via parallel pathways. We hypothesized that in addition, SP was responsible for maintaining the muscular responsiveness to acetylcholine (ACh). We tested this hypothesis by using botulinum toxin (BoNT/A), a known blocker of vesicular release of neurotransmitters including acetylcholine and neuropeptides. Methods: BoNT/A was injected into rat pyloric sphincter in different doses; as control we used boiled BoNT/A. At the desired time point, the rats were sacrificed and pyloric contractility was measured ex vivo in an organ bath and by measuring phosphorylation of myosin light chain 20 (MLC20). Results: BoNT/A (10 IU) significantly reduced the response of pyloric muscle to exogenous ACh, an effect that was accompanied by reduced MLC20 phopshorylation in the muscle. Both effects were reversed by exogenous SP. CP-96345, a NK1 receptor antagonist, blocked the ability of exogenous SP to reverse the cholinergic hyporesponsiveness as well as the reduction in MLC20 phosphorylation induced by BoNT/A. Conclusion: We have identified a novel role for SP as a co-neurotransmitter that appears to be important for the maintenance of muscular responsiveness to the principal excitatory neurotransmitter, acetylcholine. These results also provide new insight into the effects of botulinum toxin on the enteric nervous system and gastrointestinal smooth muscle.
- Pantoprazole decreases gastroesophageal muscle tone in newborn rats via rho-kinase inhibition. [JOURNAL ARTICLE]
- Am J Physiol Gastrointest Liver Physiol 2014 Apr 3.
Proton pump inhibitors reduce gastric acid secretion and are commonly utilized in the management of gastroesophageal reflux disease (GERD) across all ages. Yet a decrease in lower esophageal sphincter tone has been reported in vitro in rats through an unknown mechanism, however their effect on the gastroesophageal muscle tone early in life was never studied. Hypothesizing that proton pump inhibitors also reduce gastroesophageal muscle contraction in newborn and juvenile rats, we evaluated the in vitro effect of pantoprazole on gastric and lower esophageal sphincter muscle tissue. Electrical field stimulation (EFS) and carbachol-induced force were significantly (P<0.01) reduced in the presence of pantoprazole, whereas the drug had no effect on the neuromuscular-dependent relaxation. When administered in vivo, pantoprazole (9 mg/kg) significantly (P<0.01) reduced gastric emptying time at both ages. In order to ascertain the signal transduction pathway responsible for the reduction in muscle contraction, we evaluated the tissue rho-associated kinase 2 (ROCK-2) and CPI-17 activity. Pantoprazole reduced myosin light chain phosphatase MYPT-1, but not CPI-17 phosphorylation of gastric and lower esophageal sphincter tissue strongly suggesting that it is a ROCK-2 inhibitor. To the extent that these findings can be extrapolated to human neonates, the use of pantoprazole may impair gastric and lower sphincter muscle tone and thus paradoxically exacerbate esophageal reflux. Further studies addressing the effect of proton pump inhibitors on gastroesophageal muscle contraction are warranted to justify its therapeutic use in GERD.
- Nerves and fasciae in and around the paracolpium or paravaginal tissue: an immunohistochemical study using elderly donated cadavers. [Journal Article]
- Anat Cell Biol 2014 Mar; 47(1):44-54.
The paracolpium or paravaginal tissue is surrounded by the vaginal wall, the pubocervical fascia and the rectovaginal septum (Denonvilliers' fascia). To clarify the configuration of nerves and fasciae in and around the paracolpium, we examined histological sections of 10 elderly cadavers. The paracolpium contained the distal part of the pelvic autonomic nerve plexus and its branches: the cavernous nerve, the nerves to the urethra and the nerves to the internal anal sphincter (NIAS). The NIAS ran postero-inferiorly along the superior fascia of the levator ani muscle to reach the longitudinal muscle layer of the rectum. In two nulliparous and one multiparous women, the pubocervical fascia and the rectovaginal septum were distinct and connected with the superior fascia of the levator at the tendinous arch of the pelvic fasciae. In these three cadavers, the pelvic plexus and its distal branches were distributed almost evenly in the paracolpium and sandwiched by the pubocervical and Denonvilliers' fasciae. By contrast, in five multiparous women, these nerves were divided into the anterosuperior group (bladder detrusor nerves) and the postero-inferior group (NIAS, cavernous and urethral nerves) by the well-developed venous plexus in combination with the fragmented or unclear fasciae. Although the small number of specimens was a major limitation of this study, we hypothesized that, in combination with destruction of the basic fascial architecture due to vaginal delivery and aging, the pelvic plexus is likely to change from a sheet-like configuration to several bundles.
- Nerves supplying the internal anal sphincter: an immunohistochemical study using donated elderly cadavers. [JOURNAL ARTICLE]
- Surg Radiol Anat 2014 Apr 2.
Nerves serving the internal anal sphincter (NIAS) have been described as the lower rectal branches of the pelvic autonomic nerve plexus. However, their topographical anatomy and fiber components have remained unclear.Using histological sections from ten elderly donated cadavers, we investigated the topographical anatomy and composite fibers of the NIAS using immunohistochemistry for S100 protein, neuronal nitric oxide synthase (nNOS), vasoactive intestinal polypeptide (VIP) and tyrosine hydroxylase (TH).At the 2-3 o'clock position in the lower rectum, the NIAS originated from nerves at the posterolateral corner of the prostate in males or in the lower paracolpium in females. The nerves ran inferiorly along the internal aspect of the levator ani muscle, and joined branches of the myenteric plexus at a level slightly above the epithelial junction. The NIAS contained both nNOS-positive parasympathetic nerve fibers and TH-positive sympathetic fibers, but VIP-positive fibers were few in number.The origin of the NIAS at the posterolateral corner of the prostate as well as in the lower paracolpium might be sacrificed or damaged during radical prostatectomy or tension-free vaginal tape insertion. Low anterior resection of rectal cancer will most likely render damage to the NIAS because of its intersphincteric course. Although the nerve composition of the NIAS is characterized by a higher proportion of sympathetic nerve fibers than the myenteric plexus in the large intestine, their role is unclear. However, evaluation of sphincteric function after surgery would appear to be difficult because of the complex control mechanism independent of nerve supply.
- Effect of vaginal delivery on the external anal sphincter muscle innervation pattern evaluated by multichannel surface EMG: results of the multicentre study TASI-2. [JOURNAL ARTICLE]
- Int Urogynecol J 2014 Apr 1.
A correlation exists between external anal sphincter (EAS) damage during birth and the subsequent development of fecal incontinence. This study evaluated the effect of delivery-related trauma on EAS innervation by means of intra-anal EMG performed with a rectal probe with 16 silver electrodes equally spaced along the circumference, before and after delivery.Pre-partum EMG measurements were performed on 511 women, by nine clinical partners from five European countries at the 28th to 34th gestational weeks and the 6th to 8th post-delivery weeks; 331 women returned, after delivery, for the second test. The innervation zones (IZ) of EAS single motor units were identified by means of an EMG decomposition algorithm.The subjects were divided into four groups according to the delivery mode (Caesarean, vaginal with no evident damage, spontaneous lacerations and episiotomies). The number of IZs before and after delivery was compared. In the 82 women who underwent right mediolateral episiotomy, a statistically significant reduction of IZs was observed, after delivery, in the right ventral quadrant of the EAS (side of the episiotomy). Women who had Caesarean section, spontaneous lacerations or lack of evident damage did not present any significant change in the innervation pattern.Right episiotomy reduces the number of IZs on the right-ventral side of the EAS. The fast and reliable test proposed indicates the sphincter innervation pattern before delivery and helps obstetricians to evaluate the risks and to choose the preferred side of the episiotomy, if deemed necessary at the time of delivery.
- [Clinical application of magnetic resonance imaging in congenital anorectal malformation]. [English Abstract, Journal Article]
- Zhonghua Er Ke Za Zhi 2014 Jan; 52(1):41-5.
To investigate the clinical value of MRI examination in congenital anorectal malformation (CARM).Forty-four cases with operatively proved anorectal malformation from May 2008 to May 2012 in the authors' hospital were reviewed. Of the 44 cases, 25 were males and 19 females, their age ranged from 1 day to 2 years. MRI was performed in all patients.Of all 44 cases, 15 cases had high imperforate anus (34%), rectum blind end were above PC line, the distance of rectum blind end and anus nest was (29.12 ± 2.35) mm; 8 cases had median imperforate anus (18%), rectum blind ends were near PC line, the distance of rectum blind end and anus nest was (18.98 ± 2.21) mm; 21 cases had low imperforate anus (48%), rectum blind ends were below PC line, the distance of rectum blind end and anus nest was (7.54 ± 1.08) mm. Twenty-five cases with fistula in 44 cases were confirmed by rectal angiography and surgery, accounting for 57%. In 13 cases with fistula, the lesion could be clearly demonstrated on MRI, in the remaining 12 cases with fistula, the lesion could not be visualized clearly or no image development occurred on MRI. Of all 44 cases, 1 case had tethered cord with filum terminale lipoma, 1 case had tethered cord, 2 cases had syringomyelia, 1 case had right kidney agenesis, 1 case had hydrocele. In 44 cases of multi-planar MRI imaging could clearly show the perianal muscles developmental situation, 36 cases had perianal muscles dysplasia, amd showed levator ani muscle, puborectalis and anal sphincter asymmetry, muscle belly slim.MRI examination has a high clinical value in CARM diagnosis, can help accurately judge the anal atresia type, display the presence and running of most of the fistula, and diagnose perianal muscle development and other systems malformations, finally provide a reliable diagnostic basis for surgical program and prognostic assessment.
- Combined Cystometrography and Electromyography of the External Urethral Sphincter Following Complete Primary Repair of Bladder Exstrophy. [JOURNAL ARTICLE]
- J Urol 2014 Mar 25.
Concern in patients with bladder exstrophy after reconstruction regarding potential injury to pelvic neurourological anatomy and a resultant functional deficit prompted combined (simultaneous) cystometrography and electromyography after complete primary repair of bladder exstrophy. We determined whether complete primary repair of bladder exstrophy would adversely affect the innervation controlling bladder and external urethral sphincter function.Complete primary repair of bladder exstrophy was performed via a modified Mitchell technique in newborns without osteotomy. Postoperative evaluation included combined cystometrography and needle electrode electromyography via the perineum, approximating the external urethral sphincter muscle complex. Electromyography was done to evaluate the external urethral sphincter response to sacral reflex stimulation and during voiding.Nine boys and 4 girls underwent combined cystometrography/electromyography after complete primary repair of bladder exstrophy. Age at study and time after complete primary repair of bladder exstrophy was 3 months to 10 years (median 11.5 months). Cystometrography revealed absent detrusor overactivity and the presence of a sustained detrusor voiding contraction in all cases. Electromyography showed universally normal individual motor unit action potentials of biphasic pattern, amplitude and duration. The external urethral sphincter sacral reflex response was intact with a normal caliber with respect to Valsalva, Credé, bulbocavernosus and anocutaneous (bilateral) stimulation. Synergy was documented by abrupt silencing of external urethral sphincter electromyography activity during voiding.After complete primary repair of bladder exstrophy combined cystometrography/electromyography in patients with bladder exstrophy showed normal neurourological findings, including sacral reflex responses, sustained detrusor voiding contraction and synergic voiding, in all patients postoperatively. These findings confirm the safety of complete primary repair of bladder exstrophy. Based on our results we have discontinued routine electromyography in these patients.
- Normal anatomy of urethral sphincter complex in young Chinese males on MRI. [JOURNAL ARTICLE]
- Int Urol Nephrol 2014 Mar 28.
In this research, the normal anatomy of urethral sphincter complex in young Chinese males has been studied.The sagittal, coronal, and axial T2-weighted non-fat suppressed fast spin-echo images of pelvic cavities of 86 Chinese young males were studied.Urethral sphincter complex is a cylindrical structure surrounding the urethra and extending vertically from bladder neck to perineal membrane. Urethral striated sphincter covers the anteriolateral urethra like a hat from bladder neck to verumontanum, while it surrounds the urethra in a ring shape from verumontanum to perineal membrane and backwards ends in central tendon of the perineum. From bladder neck to perineal membrane, the thickness of urethral smooth sphincter decreases gradually, and it extends forward to surround urethra with urethral striated sphincter as a ring. The length of urethral striated sphincter is 12.26-20.94 mm (mean 16.59 mm) at membranous urethra: 27.88-30.69 mm (mean 28.99 mm) from verumontanum to perineal membrane. The thickness of striated sphincter at membranous urethra is 4.29-6.86 mm (mean 5.56 mm) for the muscle of the anterior wall and 2.18-2.34 mm (mean 2.26 mm) for the muscle of the posterior wall.In this paper, we summarized the normal anatomy of urethral sphincter complex in young Chinese males with no urinary control problems.
- [Application of sacral nerve stimulation in patients with fecal incontinence]. [English Abstract, Journal Article]
- Zhonghua Wei Chang Wai Ke Za Zhi 2014 Mar; 17(3):297-300.
Fecal incontinence is one of diseases effecting the quality of life and mental health. Germany surgeon used sacral nerve stimulation(SNS) to treat fecal incontinence at first in 1995. The aim of SNS is to mobilize the ability to control the feces through stimulating the nerves of dominating the sphincter muscles and pelvic floor muscles. Standard SNS includes two stages: evaluation stage of SNS and permanent implantation stage. Preoperative evaluation plays important role in guaranteeing the success of treatment. SNS is the primary treatment of choice for severe fecal incontinence. The complications of SNS include pain, shift of electronic probe, wound dehiscence, bowel dysfunction and infection.