Rehab Centers: Neural Pathways Involved in Sacral Neuromodulation of Reflex Bladder Activity in Cats.

Neural Pathways Involved in Sacral Neuromodulation of Reflex Bladder Activity in Cats.

Filed under: Rehab Centers

Am J Physiol Renal Physiol. 2013 Jan 2;
Zhang F, Zhao S, Shen B, Wang J, Nelson DE, Roppolo JR, de Groat WC, Tai C

This study examined the mechanisms underlying the effects of sacral neuromodulation on reflex bladder activity in chloralose anesthetized cats. Bladder activity was recorded during cystometrograms (CMGs) or under isovolumetric conditions. S1-S3 dorsal (DRT) or ventral root (VRT) were electrically stimulated at a range of frequencies (1-30 Hz) and at intensities relative to threshold (0.25T-2T) for evoking anal/toe twitches. Stimulation of DRTs but not VRTs at 1T intensity and frequencies of 1-30 Hz inhibited isovolumetric rhythmic bladder contractions; 5 Hz DRT stimulation during CMGs was optimal for increasing (P<0.05) bladder capacity (BC). Stimulation at 15 Hz was ineffective and 30 Hz elicited a weaker response to S1 DRT stimulation and no response to S2 DRT stimulation. Stimulation of the S1 DRT was more effective (increase BC to 143% and 163% of control at 1T and 2T, respectively) than S2 DRT stimulation (increase BC to 126% and 146% of control). Bilateral transection of the hypogastric or pudendal nerves did not change the inhibitory effect induced by S1 DRT stimulation. Repeated stimulation of S1 and S2 DRTs during multiple CMGs elicited a significant (P<0.05) increase in BC (to 155±13% of control) that persisted after termination of the stimulation. These results in cats suggest that the inhibition of reflex bladder activity by sacral neuromodulation occurs primarily in the central nervous system by inhibiting the ascending or descending pathways of the spinobulbospinal micturition reflex. HubMed – rehab


Tibial Tubercle Osteotomy or Quadriceps Snip in Two-stage Revision for Prosthetic Knee Infection? A Randomized Prospective Study.

Filed under: Rehab Centers

Clin Orthop Relat Res. 2013 Jan 3;
Bruni D, Iacono F, Sharma B, Zaffagnini S, Marcacci M

BACKGROUND: Although 7% to 38% of revision total knee arthroplasties (RTKAs) are attributable to prosthetic knee infections, controversy exists regarding the best surgical approach while reducing the risk of extensor mechanism complications and the reinfection rate. QUESTIONS/PURPOSES: We compared The Knee Society Score(©) (KSS), incidences of complications, maximum knee flexion, residual extension lag, and reinfection rate in patients with prosthetic knee infections treated with two-stage RTKAs using either the tibial tubercle osteotomy (TTO) or the quadriceps snip (QS) for exposure at the time of reimplantation. METHODS: We prospectively followed 81 patients with chronic prosthetic knee infections treated between 1997 and 2004. Patients were randomized to receive a TTO or QS for exposure at the time of reimplantation. All patients had the same rehabilitation protocol. The minimum followup was 8 years (mean, 12 years; range, 8-15 years). RESULTS: Patients in the TTO group had a higher mean KSS than the QS group (88 versus 70, respectively). Mean maximum knee flexion was greater in the TTO group (113° versus 94°); with a lower incidence of extension lag (45% versus 13%). We observed no differences in reinfection rate between groups. CONCLUSIONS: We found the TTO combined with an early rehabilitation protocol associated with superior KSS did not impair extensor mechanism function or increase the reinfection rate. We believe a two-stage RTKA with TTO is a reasonable approach for treating prosthetic knee infections. LEVEL OF EVIDENCE: Level I, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
HubMed – rehab


Skeletal growth and the changing genetic landscape during childhood and adulthood.

Filed under: Rehab Centers

Am J Phys Anthropol. 2013 Jan; 150(1): 48-57
Duren DL, Seselj M, Froehle AW, Nahhas RW, Sherwood RJ

Growth, development, and decline of the human skeleton are of central importance to physical anthropology. All processes of skeletal growth (longitudinal growth as well as gains and losses of bone mass) are subjected to environmental and genetic influences. These influences, and their relative contributions to the phenotype, can be asserted at any stage of life. We present here the gross phenotypic and genetic landscapes of four skeletal traits, and show how they vary across the life span. Phenotypic sex differences are found in bone diameter and cortical index (a ratio of cortical thickness over bone diameter) at a very early age and continue throughout most of life. Sexual dimorphism in summed cortical thickness and bone length, however, is not evident until shortly after the pubertal growth spurt. Genetic contributions (heritability) to these skeletal phenotypes are generally moderate to high. Bone length and bone diameter (which both scale with body size) tend to have the highest heritability, with heritability of bone length fairly stable across ages (with a notable dip in early childhood) and that of bone diameter peaking in early childhood. The bone traits summed cortical thickness and cortical index that may better reflect bone mass, a more plastic phenomenon, have slightly lower genetic influences, on average. Results from our phenotypic and genetic landscapes serve three key purposes: 1) demonstration of the integrated nature of the genetic and environmental underpinnings of skeletal form, 2) identification of periods of bone’s relative sensitivity to genetic and environmental influences, 3) and stimulation of hypotheses predicting the effects of exposure to environmental variables on the skeleton, given variation in the underlying genetic architecture. Am J Phys Anthropol, 2013. © 2012 Wiley Periodicals, Inc.
HubMed – rehab


More Rehab Centers Information…