Identification of core pathogenic genes and pathways in elderly osteoporosis based on bioinformatics analysis / 中华预防医学杂志

Objective: Using bioinformatics methods to analyze the core pathogenic genes and related pathways in elderly osteoporosis. Methods: From November 2020 and August 2021, eight elderly osteoporosis patients who received treatment and five healthy participants who underwent physical examinations in Beijing Jishuitan Hospital were selected as subjects. The expression level of RNA in the peripheral blood of eight elderly osteoporosis patients and five healthy participants was collected for high-throughput transcriptome sequencing and analysis. The gene ontology (GO) analysis Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis was performed for the differentially expressed genes (DEGs). The protein-protein interaction (PPI) network was constructed using the STRING website and Cytoscape software, and the most significant modules and hub genes were screened out. Results: Among the eight elderly osteoporosis patients, there were seven females and one male, with an average age of 72.4 years (SD=4.2). Among the five healthy participants, there were four females and one male, with an average age of 68.2 years (SD=5.7). A total of 1 635 DEGs (847 up-regulated and 788 down-regulated) were identified. GO analysis revealed that the molecular functions of DEGs were mainly enriched in structural constituents of the ribosome, protein dimerization activity, and cellular components were mainly enriched in the nucleosome, DNA packaging complex, cytosolic part, protein-DNA complex and the cytosolic ribosome. KEGG pathway analysis showed that DEGs were mainly enriched in systemic lupus erythematosus and ribosome. Gene UBA52, UBB, RPS27A, RPS15, RPS12, RPL13A, RPL23A, RPL10A, RPS25 and RPS6 were selected and seven of them could encode ribosome proteins. Conclusion: The pathogenesis of elderly osteoporosis may be associated with ribosome-related genes and pathways.

Preliminary histological and biomechanical study about the timing of surgical repair for acute rotator cuff tears in rabbits / 中华外科杂志

<p><b>OBJECTIVES</b>To establish the animal model of acute rotator cuff tear in rabbits, and study the effect of timing of surgical repair on healing of tendon-bone interface, formation and distribution of collagens in the supraspinatus tendon insertion and biomechanical properties of supraspinatus.</p><p><b>METHODS</b>Supraspinatus tenotomy was performed in the right shoulder of 90 skeletally matured male New Zealand white rabbits to establish the animal model of acute rotator cuff tear. The rabbits were randomly divided into 3 groups : group of early repair, repaired at 1 week after tenotomy; group of late repair, repaired at 4 weeks after tenotomy; and group without repair, used as control. At 2 weeks, 4 weeks and 8 weeks after repair, healing of tendon-bone interface was observed by HE staining. Collagens were observed by Sirius Red F 3B (SR) in saturated carbazotic acid staining. The areas of type I and III collagens were measured by using imaging analysis software and the ratio of type I and III collagens were calculated. Failure loads of supraspinatus on both sides were measured. The percentage of failure loads of the surgical side was calculated and contralateral supraspinatus were uninjured.</p><p><b>RESULTS</b>There was no obvious fatty infiltration and muscle atrophy in supraspinatus in all groups. At 8 weeks, the formation of a new enthesis of supraspinatus in groups of early and late repair were observed. In groups of early and late repair, the ratio of areas of type I and III collagens at 8 weeks (2.02 ± 0.77 and 2.06 ± 0.58) was larger than that at 2 weeks (1.10 ± 0.24 and 1.14 ± 0.50, t = 3.082, 3.655, P < 0.01). At 2, 4 and 8 weeks, the percentages of failure loads of the surgical side and uninjured contralateral supraspinatus in group of early repair(38% ± 11%, 66% ± 7%, 89% ± 4%) and group of late repair (41% ± 16%, 63% ± 7%, 89% ± 9%) were both higher than that in group without repair (14% ± 6%, 32% ± 4%, 56% ± 12%); the differences were all statistically significant (group of early repair: t = 3.311, 8.549, 5.719; group of late repair: t = 3.713, 8.063, 6.044; P < 0.01). The percentage of failure loads of the surgical side and uninjured contralateral supraspinatus at 8 weeks was higher than those at 4 weeks (t = 3.878 - 4.613, P < 0.01) and 2 weeks (t = 7.158 - 10.024, P < 0.01) in all groups.</p><p><b>CONCLUSIONS</b>Surgical repair within 4 weeks of acute rotator cuff tear lead to formation of a new enthesis of supraspinatus, improvement of both ratio of type I collagen in the supraspinatus tendon insertion and biomechanical properties of supraspinatus.</p>

Biomechanical research of antegrade intramedullary fixation for the metacarpal fractures / 中华外科杂志

<p><b>OBJECTIVE</b>To study the biomechanical characteristics of antegrade intramedullary fixation for metacarpal fractures.</p><p><b>METHODS</b>From March to May 2008, both the 4th and 5th metacarpals from 25 formalin embalmed cadaver hands had three-point bending test after transverse osteotomy followed by randomly fixation with one of the following three methods: plate and screw, antegrade intramedullary K-wire, crossed K-wire. While, both the 2nd and 3rd metacarpals had torsional loading test after the same management as the 4th and 5th metacarpal had undergone.</p><p><b>RESULTS</b>In the three-point bending test, both the maximum bending moment (M(max)) and bending rigidity (EI) of the antegrade intramedullary K-wire were comparable with those of the plate and screw, and were significantly larger than those of the crossed K-wire. In the torsional loading test, the antegrade intramedullary K-wire had a statistically smaller maximum torque (T(max)) than the plate and screw, and had a comparable T(max) with the crossed K-wire; while, the torsional rigidity (GJ) of the intramedullary K-wire was statistically weaker than that of both the plate and screw and the crossed wire.</p><p><b>CONCLUSIONS</b>One single antegrade intramedullary K-wire can provide a satisfactory M(max) and EI for metacarpal fixation and shows relatively weak in the torsional loading test. The injured finger should be well protected to avoid torsional deformity in clinical practice.</p>