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sphincter muscle [keywords]
- Identification of motor neurons and a mechanosensitive sensory neuron in the defecation circuitry of Drosophila larvae. [JOURNAL ARTICLE]
- Elife 2014 Oct 30.
Defecation allows the body to eliminate waste, an essential step in food processing for animal survival.In contrast to the extensive studies of feeding, its obligate counterpart, defecation, has received much less attention until recently. Here we report our characterizations of the defecation behavior of Drosophila larvae and its neural basis. Drosophila larvae display defecation cycles of stereotypic frequency, involving sequential contraction of hindgut and anal sphincter. The defecation behavior requires two groups of motor neurons that innervate hindgut and anal sphincter, respectively, and can excite gut muscles directly. These two groups of motor neurons fire sequentially with the same periodicity as the defecation behavior, as revealed by in vivo Ca(2+) imaging. Moreover, we identified a single mechanosensitive sensory neuron that innervates the anal slit and senses the opening of the intestine terminus. This anus sensory neuron relies on the TRP channel NOMPC but not INACTIVE, NANCHUNG, or PIEZO for mechanotransduction.
- Retraction of the Soft Palate During a Modified Hynes Pharyngoplasty: A Technical Note. [JOURNAL ARTICLE]
- Cleft Palate Craniofac J 2014 Oct 28.
Surgical management of velopharyngeal insufficiency by construction of sphincter pharyngoplasty is well described in the medical literature. Hynes advocated splitting an intact soft palate when it would be helpful for better exposure of the posterior pharyngeal wall for flap inset. We describe a modification used in modified Hynes pharyngoplasty whereby the soft palate is retracted upward, giving the operator unrestricted surgical access to the salpingopharyngeus muscles and their overlying mucosa. This allows the surgeon to raise and inset the flaps, as described by Hynes, without the need to divide the soft palate. The retraction catheters avoid the need for splitting a soft palate, whose function has been optimized by either a Furlow or soft palate re-repair in the past, avoiding unnecessary compromise of the integrity and architecture of the soft palate.
- Anal sphincter complex: 2D and 3D endoanal and translabial ultrasound measurement variation in normal postpartum measurements. [JOURNAL ARTICLE]
- Int Urogynecol J 2014 Oct 25.
Women may experience anal sphincter anatomy changes after vaginal birth (VB) or Cesarean delivery (CD). Therefore, accurate and acceptable imaging options to evaluate the anal sphincter complex (ASC) are needed. ASC measurements may differ between translabial (TLUS) and endoanal (EAUS) ultrasound imaging and between 2D and 3D US. The objective of this analysis was to describe measurement variation between these modalities.Primiparous women underwent 2D and 3D TLUS imaging of the ASC 6 months after VB or CD. A subset of women also underwent EAUS measurements. Measurements included internal anal sphincter (IAS) thickness at proximal, mid, and distal levels and the external anal sphincter (EAS) at 3, 6, 9, and 12 o'clock positions, as well as bilateral thickness of the pubovisceralis muscle (PVM).There were 433 women presenting for US: 423 had TLUS and 64 had both TLUS and EAUS of the ASC. All IAS measurements were significantly thicker on TLUS than EAUS (all p < 0.01), while EAS measurements were significantly thicker on EAUS (p < 0.01). PVM measurements with 3D or 2D imaging were similar (p > 0.20). On both TLUS and EAUS, there were multiple sites where significant asymmetry existed in left versus right measurements.US modality used to image the ASC introduces small but significant changes in measurements, and the direction of the bias depends on the muscle and location being imaged.
- Topography of the extrinsic internal anal sphincter nerve supply during laparoscopic-assisted TAMIS TME: five key zones of risk from the surgeons' view. [JOURNAL ARTICLE]
- Int J Colorectal Dis 2014 Oct 15.
Sparing the extrinsic autonomic innervation of the internal anal sphincter during total mesorectal excision is important for the preservation of anal sphincter function. This study electrophysiologically confirmed the topography of the internal anal sphincter nerve supply during laparoscopic-assisted transanal minimally invasive surgery for total mesorectal excision.This prospective study was conducted at two large multispecialty referral centers. Six patients (five males and one female) aged between 45 and 65 years with low rectal cancer (≤5 cm from the anal verge) were enrolled. Surgery was performed under electric stimulation of the pelvic autonomic nerves with observation of the electromyographic signals of the internal anal sphincter.The minimally invasive transanal surgical approach enabled advantageous visualization of the pelvic autonomic nerves in all patients. In particular, extrinsic innervation to the internal anal sphincter near the levator muscle was consciously spared under electrophysiological confirmation. The evoked absolute electromyographic amplitudes of the internal anal sphincter during transanal minimally invasive surgery were significantly lower than the initial results of the laparoscopic approach [3.7 μV (interquartile range 2.4; 5.7) vs. 4.3 μV (interquartile range 3.1; 8.6); p = 0.002]. Five key zones of risk for pelvic autonomic nerve damage were identified. No complications occurred.The electromyographic results of this preliminary study indicate advantages for sparing the internal anal sphincter innervation during transanal minimally invasive mesorectal dissection considering the specific in situ neuroanatomical topography.
- Zenker's diverticulum: a case report and literature review. [Journal Article]
- Pan Afr Med J 2014.:267.
The pharyngeal pouch (Zenker's diverticulum) is a diverticulum of the mucosa of the pharynx, just above the cricopharyngeal muscle (i.e. above the upper sphincter of the oesophagus). It occurs commonly in elderly patients (over 70 year) and the typical symptoms include dysphagia, regurgitation, chronic cough, aspiration and weight loss. We are reporting a case of an oropharyngeal dysphagia due to a Zenker's diverticulum in 75 years old Sudanese man with a chronic history of dysphagia for solids. The pathophysiology of Zenker's diverticulum, clinical presentation, and management are reviewed.
- Nitrergic neuromuscular transmission in the mouse internal anal sphincter is accomplished by multiple pathways and post-junctional effector cells. [JOURNAL ARTICLE]
- Am J Physiol Gastrointest Liver Physiol 2014 Oct 9.
The effector cells and second messengers participating in nitrergic neuromuscular transmission (NMT) were investigated in the mouse internal anal sphincter (IAS). Protein expression of guanylate cyclase (GCα, GCβ) and cyclic GMP dependent protein kinase I (cGKI) were examined in cryostat sections with dual labeling immunohistochemical techniques in PDGFRα(+) cells, interstitial cells of Cajal (ICC) and smooth muscle cells (SMC). Gene expression levels were determined with qPCR of dispersed cells from Pdgfrα(egfp/+), Kit(copGFP/+) and smMHC(Cre-egfp) mice sorted with FACS. The relative gene and protein expression levels of GCα and GCβ were: PDGFRα(+) cells>ICC>SMC. In contrast, cGKI gene expression sequence was SMC=ICC>PDGFRα(+) cells while cGKI protein expression sequence was neurons>SMC>ICC=PDGFRα(+) cells. The functional role of cGKI was investigated in cGKI(-/-) mice. Relaxation with 8-Br-cGMP was greatly reduced in cGKI(-/-) mice while responses to sodium nitroprusside (SNP) were partially reduced and forskolin responses were unchanged. A nitrergic relaxation occurred with nerve stimulation (NS, 5Hz, 60s) in cGKI(+/+) and cGKI(-/-) mice although there was a small reduction in the cGKI(-/-) mouse. L-NNA abolished responses during the first 20-30s of NS in both animals. The GC inhibitor ODQ greatly reduced or abolished SNP and nitrergic NS responses in both animals. These data confirm an essential role for GC in NO-induced relaxation in the IAS. However, the expression of GC and cGKI by all three cell types suggests that each may participate in coordinating muscular responses to NO. The persistence of nitrergic NMT in the cGKI(-/-) mouse suggests the presence of a significant GC-dependent, cGKI-independent pathway.
- Endoscopic myotomy for achalasia. [Journal Article, Review]
- Adv Surg 2014.:27-41.
POEM is an effective treatment of functional manometric esophageal outflow obstructive disorders with excellent relief of dysphagia. Reflux rates seem to be similar to that seen with traditional Heller myotomy with fundoplication. The POEM technique provides a true surgical esophageal myotomy without incisional pain. As such, POEM represents the first truly practical application of natural orifice surgery.
- Length tension function of puborectalis muscle: implications for the treatment of fecal incontinence and pelvic floor disorders. [Journal Article]
- J Neurogastroenterol Motil 2014 Oct 30; 20(4):539-46.
External anal sphincter (EAS) and puborectalis muscle (PRM) play important role in anal continence function. Based on length-tension measurement, we recently reported that the human EAS muscle operates at short sarcomere length under phys-iological conditions. Goal of our study was to determine if PRM also operates at the short sarcomere length.Length-tension relationship of the PRM muscle was studied in vivo in 10 healthy nullipara women. Length was altered by vagi-nal distension using custom-designed probes of 5, 10, 15, 20, 25 and 30 mm diameters as well as by distending a poly-ethylene bag with different volumes of water. Probes were equipped with a reverse perfuse sleeve sensor to measure vaginal pressure (surrogate of PRM tension). PRM electromyogram (EMG) was recorded using wire electrodes. Three-dimensional ultra-sound images were obtained to determine effect of vaginal distension on PRM length.Ultrasound images demonstrate distension volume dependent increase in PRM length. Rest and squeeze pressures of vaginal bag increased with the increase in bag volume. Similarly, the change in vaginal pressure, which represents the PRM contraction increased with the increase in the probe size. Increase in probe size was not associated with an increase in EMG activity (a marker of neural drive) of the PRM.Probe size dependent increase in PRM contraction pressure, in the presence of constant EMG (neural input) proves that the hu-man PRM operates at short sarcomere length. Surgically adjusting the PRM length may represent a novel strategy to improve treat anal continence and possibly other pelvic floor disorders.(J Neurogastroenterol Motil 2014;20:539-546).
- Urethroplasty for high-risk, long segment urethral strictures with ventral buccal mucosa graft and gracilis muscle flap. [JOURNAL ARTICLE]
- J Urol 2014 Sep 24.
Long-segment urethral strictures with a compromised graft bed and poor vascular supply are unfit for standard repair, and are at high-risk for stricture recurrence. Our objective was to assess the success of urethral reconstruction in these patients with a ventral buccal mucosa graft (BMG) and gracilis muscle flap (GMF).A retrospective review of 1039 patients who underwent urethroplasty at Lahey Hospital and Medical Center between 1999 and 2014 was performed. We identified 20 patients who underwent urethroplasty with a ventral BMG and GMF graft bed. Stricture recurrence was defined as the inability to pass a 16 Fr cystoscope.Mean stricture length was 8.2 cm (3.5-15). Strictures were located in the posterior urethra with or without involvement of the bulbar urethra in 50%, bulbomembranous urethra (35%), bulbar urethra (10%), and proximal pendulous urethra (5%). Stricture etiology was radiation therapy in 45% followed by idiopathic (20%), trauma (15%), prostatectomy (10%), hypospadias failure (5%), and transurethral surgery (5%). 9 patients (45%) had previous urethroplasty and 3 (15%) had previous UroLume® stents. Urethral reconstruction was successful in 16 patients (80%), with a mean follow-up of 40 months. Of the failures, one patient had an ileal loop, two a suprapubic tube, and one urethral dilation. Mean time to recurrence was 10 months (2-17). 5 patients (25%) had postoperative incontinence requiring an artificial urinary sphincter.Urethroplasty for high-risk, long segment urethral strictures can be successfully performed with a ventral BMG and GMF avoiding urinary diversion in the majority of patients.
- Botulinum toxin type-A injection to treat patients with intractable anismus unresponsive to simple biofeedback training. [Journal Article]
- World J Gastroenterol 2014 Sep 21; 20(35):12602-7.
To evaluate the efficacy of botulinum toxin type A injection to the puborectalis and external sphincter muscle in the treatment of patients with anismus unresponsive to simple biofeedback training.This retrospective study included 31 patients suffering from anismus who were unresponsive to simple biofeedback training. Diagnosis was made by anorectal manometry, balloon expulsion test, surface electromyography of the pelvic floor muscle, and defecography. Patients were given botulinum toxin type A (BTX-A) injection and pelvic floor biofeedback training. Follow-up was conducted before the paper was written. Improvement was evaluated using the chronic constipation scoring system.BTX-A injection combined with pelvic floor biofeedback training achieved success in 24 patients, with 23 maintaining persistent satisfaction during a mean period of 8.4 mo.BTX-A injection combined with pelvic floor biofeedback training seems to be successful for intractable anismus.