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Study Design: In vitro biomechanical study using human spine specimens. Objective: To find the biomechanical consequences of prophylactic vertebroplasty post fatigue loading. Summary Of Background Data: Percutaneous vertebroplasty man be an effective treatment for osteoporotic vertebral compression fracture. One frequently observed complication post surgery is the adjacent vertebral failure (AVF). The prophylactic vertebroplasty was proposed to prevent the AVF. The vertebroplasty is, nevertheless, an invasive intervention. More scientific proves are needed for the application of this surgery on a still intact vertebra. Methods: Fourteen 5-level fresh human cadaveric thoracic motion segments were divided into standard and prophylactic group. Both ends of the specimen were mounted, leaving the center 3 vertebrae free. The lower level of free vertebrae was artificially injured and cement augmented. The center level vertebra of standard group remained intact and nonaugmented. The center level vertebra of prophylactic group also remained intact, but augmented with bone cement. The specimen was applied with a 2-hour, 5-Hz, 630-N (mean) compressive fatigue loading. Impulse test and CT scanning were conducted both before and after fatigue loading to find the variance of strain compliance of cortical shell and height of vertebral body. Results: The strain compliance of cortical shell is generally not statistically significantly affected by the fatigue loading, cement augmentation and vertebral level (All P > 0.05). The only exception is that the cortical strain compliance of augmented vertebrae tentatively decreased post fatigue loading (P = 0.012 for tensile strain compliance, and P = 0.049 for compressive strain compliance). The height loss of intact vertebra adjacent to a 2-level augmented (or intact-augmented) vertebra is significantly lower than the one adjacent to a 1-level augmented (or injury-augmented) vertebra (P = 0.014). For an osteoporotic vertebra, neither cortical strain compliance nor vertebral height loss is connected with bone mineral density (all P > 0.05). Conclusion: The strain compliance of cortical shell is generally not a sensitive indicator to predict risk of fatigue injury if the fatigue loading is mild. The prophylactic augmentation strengthens the osteoporotic vertebrae, decreases the progression of vertebral height loss, reduces the anterior body shift, and hence protects the adjacent intact vertebra from elevated flexion bending. It can be cautiously suggested that if the vertebra is osteoporotic and adjacent level is located at pivot or lordotic level of spinal column, the prophylactic augmentation may be an option to prevent the AVF. [ABSTRACT FROM AUTHOR]

Vocal process granulomas are benign lesions involved in the healing of posterior glottis injuries. Here, we report the results of our conservative treatment of vocal process granulomas. Fifty-three patients with 54 occurrences of granulomas between 1998 and 2007 were enrolled. All patients were observed without surgical excision or specific medications and regularly monitored with telescopic examinations until the granulomas disappeared. Data on age, sex, clinical presentation, prior history of intubation or gastroesophageal reflux, telescopic findings, management and clinical course were reviewed. There were 41 males and 12 females. The mean ages of granuloma occurrence were 48.1 years in men and 41.6 years in women (p=0.16). Symptoms included hoarseness in 42 patients, cough in 13 patients, lumping sensation in the throat in 15 patients and sore throat in 14 patients. Ten occurrences were stable during the follow-up period, and the other 44 (81%) achieved complete remission (mean period of 30.6 weeks). The remission patterns included progression and remission in 6 occurrences, slow remission in 22 and rapid remission in 16. The remission rate of granulomas was not significantly related to age (p=0.71), sex (p=0.43), prior intubation (p=0.71), acid reflux (p=0.47), unilateral/bilateral lesions (p=1.00) or granuloma size (p=0.46). The remission time was significantly shorter in patients with prior intubation (p=0.04), but not significantly associated with age (p=0.89), sex (p=0.87), acid reflux (p=0.91), unilateral/bilateral lesions (p=0.26) or granuloma size (p=0.96). Long-term observation has demonstrated that vocal process granulomas can be cured at high remission rates without implementing specific treatments. [ABSTRACT FROM AUTHOR]

Ethanol and glucocorticoids are risk factors associated with osteonecrosis. Previous reports suggest ethanol and glucocorticoids induce adipogenesis, decrease osteogenesis in bone marrow stroma cells, and produce intracellular lipid deposits resulting in death of osteocytes. The Wnt/beta-catenin signal pathway is involved in the regulation of homeostasis of bone and we presume glucocorticoids and ethanol may induce osteonecrosis in humans through a similar mechanism as in rodents. We hypothesized (1) ethanol, like glucocorticoids, decreases osteogenesis and increases adipogenesis through the Wnt/beta-catenin signaling pathway in human bone marrow stromal cells; and (2) ethanol decreases intranuclear translocation of beta-catenin. We found both dexamethasone and ethanol decrease the gene and protein expression of osteogenesis and increase that of adipogenesis through Wnt signaling-related genes by semiquantitative and quantitative polymerase chain reaction and Western blot. Ethanol hampered intranuclear translocation of beta-catenin by immunofluorescence analysis. The data suggest the Wnt/beta-catenin signaling pathway may be associated with ethanol-induced osteonecrosis. [ABSTRACT FROM AUTHOR]

Contents The survival and development of pre-implantation embryos are determinant factors affecting the outcome of animal reproduction. It is essential to transfer the expression of the genetic material from maternal sources, that is the ovum to the zygote before implantation to ensure successful development. Differentiation and transformation of blastomeres initiated during the morula and blastocyst stages is an important step of the embryonic development prior to implantation. We collected morula and early blastocyst samples from pure-bred Landrace pigs in vivo to study the differential gene expression patterns at these two stages. Total RNA was extracted from individual embryos and two rounds of amplification were employed. Two micrograms of antisense RNA, targets, were prepared and hybridized with each of four custom made oligo microarrays representing 24 000 porcine genes. The analyses of replicate hybridizations showed that among the 24 000 genes, 162 genes were expressed fivefold or greater in the morula compared to early blastocysts and 2126 genes were expressed fivefold or greater in early blastocysts compared to the morula. Of these differentially expressed genes, 1429 genes were functionally annotated with related human Gene Ontology terms. In addition to basic metabolic processes, genes related to signal transduction, transportation and cell differentiation were found in both stages and were up-regulated as embryo development proceeded. Real time polymerase chain reaction was utilized to quantify 12 genes differentially expressed in the 2 embryonic stages and validated the reliability of major evidences shown in microarrays. In conclusion, we have obtained a preliminary landscape of genes differentially expressed during the transition from morula to early blastocysts in pigs and showed a generally increased transcriptional activity, perhaps in preparation for implantation. Our results provide an opportunity to study the functions of these genes in relation to the development and survival of pre-implantation porcine embryos. [ABSTRACT FROM AUTHOR]

STUDY DESIGN: In vitro and in vivo studies to assess the effect of direct anular repair on subsequent degeneration of intervertebral discs (IVDs). OBJECTIVE: To assess whether a new suturing method could provide sealing effect on IVD after discectomy, and influence degenerative process of IVD. SUMMARY OF BACKGROUND DATA: Recurrent disc herniation and subsequent disc degeneration are major problems after discectomy. Anular repair can reduce the risk of recurrence, but its effect on disc degeneration needs more investigation. METHODS: A new suturing technique, the modified purse-string suture (MPSS), was designed for direct closure of anular incision. Intact motion segments of porcine lumbar spine were used to validate this technique in resisting disc pressure under mechanical loadings. A transverse slit incision was made in the anterior anulus of porcine cervical discs, with or without sealing of the anular defect by this suturing method. Magnetic resonance imaging grading was recorded before and after surgery. Anular healing was assessed histologically and gene expression of aggrecan, collagen type I, II, and matrix metalloproteinase-13 in nucleus pulposus were investigated. RESULTS: The average failure force of axial compression was 1150.3 ± 121.1 N for a simple suture, and 2917.9 ± 627.6 N for a MPSS. Cyclic loading test showed that the repaired discs succeeded against repeated compression forces. Magnetic resonance imaging and gross appearances showed lesser degenerative changes in repaired discs than in injured discs at each time period. In repaired discs, mRNA expression of aggrecan and type II collagen downregulated slightly with time, whereas it decreased rapidly and persistently in unrepaired discs. Histologic findings showed primary healing of outer anular tract in repaired discs. CONCLUSION: In this pilot study, the MPSS can provide effectively sealing for damaged anulus to withstand stresses. Direct repair of anular incision by this suturing method does significantly slow down degenerative process within discs after discectomy. [ABSTRACT FROM AUTHOR]

Traditional continuing medical education (CME) depended primarily on periodic courses and conferences. The cost-effectiveness of these courses has not been established, and often the content is not tailored to best meet the needs of the students. Internet training has the potential to accomplish these goals. Over the last 10 years, we have developed a Web site entitled "Orthochina.org," based upon the wiki concept, which uses an interactive, case-based format. We describe the development of online case discussions, and various technical and administrative requirements. As of December 31, 2007, there were 33,984 registered users, 9,759 of which passed the confirmation procedures. In 2007, an average of 211 registrants visited daily. The average number of first page clicks was 4,248 per day, and the average number of posts was 70 per day. All cases submitted for discussion include the patient's complaint, physical examination findings, and relevant images based on specific criteria for case discussion. The case discussions develop well professionally. No spam posting or unauthorized personal advertisement is permitted. In conclusion, online academic discussions proceed well when the orthopaedic surgeons who participate have established their identities. [ABSTRACT FROM AUTHOR]

STUDY DESIGN: A prospective interview study. OBJECTIVE: To determine whether items of the Frenchay Activities Index (FAI) measure Instrumental Activities of Daily Living (IADL), as a unidimensional construct, in patients with spinal cord injury (SCI). To examine whether the response categories of the FAI are useful in discerning the various ability levels of IADL. SUMMARY OF BACKGROUND DATA: No known IADL scale has been designed for SCI patients. The FAI, to our knowledge, has never been validated in patients with SCI. METHODS: A total of 233 persons with SCI participated in this study. The FAI was administered to the patients by interview at locations convenient for the participants. A Rasch analysis was used to examine the unidimensionality and appropriateness of the response categories of the FAI. RESULTS: All but 2 items ('going outside' and 'reading books') of the FAI fitted the model's expectations. The results of Rasch analysis indicated that the response categories for the remaining 13 items of the FAI should be collapsed to create more suitable response categories (4 items, into dichotomies, and the remaining 9 items, into trichotomies). Thus, a revised 13-item FAI was formed by deleting the 2 misfitting items and collapsing the response categories of the items. CONCLUSIONS: This study demonstrated that the revised 13-item FAI assesses a single, unidimensional IADL for SCI patients living in the community. The revised FAI shows potential for assessment of IADL in SCI patients. [ABSTRACT FROM AUTHOR]

• Dual-wavelength lasers are often used as light sources for sum-frequency systems. • Adjusting Q-switching delay is reported in a 1064/1342 nm Nd:YVO 4 Q-switched laser. • The simultaneous output of dual-wavelength laser is realized.. In this paper, an all-solid-state Nd:YVO 4 laser with peak synchronize output of 1064/1342 nm dual-wavelength Q-switched pulse is designed. Double-cavity structure with single Nd:YVO 4 crystal and double RbTiOPO 4 (RTP) electro-optic (EO) Q-switch is built. At repetition frequency of 10 kHz, taking the trigger time of EO Q-switch at 1342 nm as reference, at the delay time of EO Q-switch at 1064 nm as 1.3 μs, the pulse peak synchronize dual-wavelength laser is obtained, and the pulse power is 1.63 W and 1.63 W with the width is 55.64 ns and 105.2 ns respectively. The beam quality is M x 2 =1.61 , M x 2 =1.64 and M x 2 =1.43 , M y 2 = 1.54 , respectively. [ABSTRACT FROM AUTHOR]