This study explores the use of mesenchymal stem cells (MSCs) for intervertebral disc regeneration. We used an in vivo model to investigate the feasibility of exogenous cell delivery, retention, and survival in the pressurized disc space. MSC injection into rat coccygeal discs was performed using 15% hyaluronan gel as a carrier. Injections of gel with or without MSCs were performed. Immediately after injection, fluorescently labeled stem cells were visible on sections of cell-injected discs. Seven and 14 days after injection, stem cells were still present within the disc, but their numbers were significantly decreased. At 28 days, a return to the initial number of injected cells was observed, and viability was 100%. A trend of increased disc height compared to blank gel suggests an increase in matrix synthesis. The results indicate that MSCs can maintain viability and proliferate within the rat intervertebral disc.

The most 5' mouse Hoxa and Hoxd genes, which occupy positions 9-13 and which are related to the Drosophila AbdB gene, are all active in patterning developing limbs. Inactivation of individual genes produces alterations in skeletal elements of both forelimb and hindlimb; inactivation of some of these genes also alters hindlimb innervation. Simultaneous inactivation of paralogous or nonparalogous Hoxa and Hoxd genes produces more widespread alterations, suggesting that combinatorial interactions between these genes are required for proper limb patterning. We have examined the effects of simultaneous inactivation of Hoxa10 and Hoxd10 on mouse hindlimb skeletal and nervous system development. These paralogous genes are expressed at lumbar and sacral levels of the developing neural tube and surrounding axial mesoderm as well as in developing forelimb and hindlimb buds. Double-mutant animals demonstrated impaired locomotor behavior and altered development of posterior vertebrae and hindlimb skeletal elements. Alterations in hindlimb innervation were also observed, including truncations and deletions of the tibial and peroneal nerves. Animals carrying fewer mutant alleles show similar, but less extreme phenotypes. These observations suggest that Hoxa10 and Hoxd10 coordinately regulate skeletal development and innervation of the hindlimb.

Crosslinks, when added to short-segment posterior fixation, improve stiffness and decrease motion in axial rotation, but do not restore baseline stability in this corpectomy model. Short-segment posterior fixation is also inadequate in restoring stability in flexion with injuries of this severity. Short-segment posterior instrumentation alone can achieve baseline stability in lateral bending, and crosslinks provide even greater stiffness.

Background: Jackhammer esophagus (JE) is a newly described esophageal motility disorder. However, there are limited data on JE and this entity remains misunderstood. Methods: We performed a systematic review of clinical series on JE through MEDLINE, EMBASE, and Web of Science. Data from included studies were then extracted, and random-effects meta-analyses were performed. Results: Thirty-eight studies met inclusion criteria. The pooled prevalence of JE was 1.97% [95% CI: 1.39%-2.78%] among patients referred for high-resolution manometry (HRM). The mean age at diagnosis was 60.8 years [95% CI: 57.1-64.4] and 65% [95% CI: 58%-72%] of patients were female. JE was significantly more prevalent in postlung transplant patients and morbidly obese patients undergoing HRM (23.99% [95% CI: 9.00%-38.97%] and 5.18% [95% CI: 1.76%-14.3%] respectively). Dysphagia was the most common presentation of JE (64% [95% CI: 52%-77%]) followed by gastroesophageal reflux disease (46% [95% CI: 26%-67%]). The pooled mean distal contractile integral (DCI) of all standard HRM swallows was 9249 mm Hg•s•cm [95% CI: 7834-10 663], and the pooled mean integrated relaxation pressure (IRP) was 13.9 mm Hg [95% CI: 8.2-19.7]. Overall, 73.6% [95% CI: 64.0%-83.1%] of JE patients who underwent treatment achieved clinical symptom improvement (79% [95% CI: 74%-85%] for endoscopic treatment and 63% [95% CI: 47%-79%] for medical treatment). The pooled clinical success rate of peroral endoscopic myotomy (POEM) specifically was 82% [95% CI: 75%-90%]. Conclusions: JE is a new motility disorder most commonly presenting with dysphagia. High clinical suspicion is important because the diagnosis can only be made through HRM.

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The proof of MeCP2 expression in enteric neurons suggests that the GI dysmotility in Rett may arise from enteric network dysfunction secondary to MeCP2 mutation.

It is concluded that in patients with bidirectional CTI block, pacing from the CS may be associated with TC mimicking a conduction leak through the isthmus. Pacing just outside the CS os helps distinguish pseudo from true isthmus block.