The Anatomical and Biomechanical Superiority of Novel Posterior En Bloc Elevation Cervical Laminoplasty.

Objectives. In this study, we performed a novel type of posterior en bloc elevation cervical laminoplasty (PEEL) to keep the integrity of the posterior structure, aiming to reduce axial symptoms complicated by a conventional cervical laminoplasty procedure. Methods. Twelve human cervical cadaveric spines (C2-T1) were sequentially tested in the following order: intact condition, open-door laminoplasty (ODL) through bilateral intermuscular approach (mini-invasive ODL), PEEL, and laminectomy (LN). After bilateral transecting at the junction of lamina and lateral mass through the tubular retraction system, the PEEL procedure symmetrically elevated all the posterior structure which was further stabilized with bone grafts and titanium plates. Computed tomography (CT) scan and biomechanical testing were performed after each condition. Results. Both mini-invasive ODL and PEEL procedures were accomplished with 2 small incisions on each side. Two types of laminoplasties could enlarge the spinal canal significantly both in cross-sectional area and anteroposterior diameter comparing with intact condition. The PEEL procedure demonstrated a significantly higher enlargement rate on a canal area and a symmetrical expansion pattern. Compared with intact condition, mini-invasive ODL performed from C3-C7 demonstrated significantly decreased motion in all testing directions except the flexion range of motion (ROM); the PEEL procedure showed mild and insignificant decrease on ROM in all directions. Laminectomy resulted in a statistically significant increase in all directions except the lateral bending ROM. Conclusions. Posterior en bloc elevation cervical laminoplasty can enlarge the canal more effectively and preserve better ROM after operation than the ODL procedure. Although technically challenging, the PEEL procedure probably would decrease the common complications associated with ODL laminoplasty.

A method of percutaneous vertebroplasty under the guidance of two C-arm fluoroscopes.

OBJECTIVE: To compare the clinical application in the percutaneous vertebroplasty under the guidance of one or two C-arm fluoroscopes. METHODS: One hundred forty three elderly patients with Osteoporotic vertebral compression fractures (OVCFs) underwent percutaneous vertebroplasty under the guidance of one or two C-arm fluoroscopes. The number of pulsed imagings, the time of operation and the incidence of cement leakage were recorded. RESULTS: The average number of pulsed imagings was 16.00±1.58 vs 13.07±2.00 per patient under the guidance of one vs two C-arm fluoroscopes. The average time of operation was 48.42±5.00 minutes vs 39.70±7.42 minutes per patient under the guidance of one vs two C-arm fluoroscopes. The incidence of cement leakage was 20% vs 15.7% of the patients under the guidance of one vs two C-arm fluoroscopes. The differences in the number of pulsed imagings and the time of operation were statistically significant. The difference in incidence of cement leakage was not statistically significant. CONCLUSION: The two-fluoroscopic technique reduce the labor cost, the radiation, the time of operation and the operation risk.

[The biological functions of lysine methyltransferase PR-SET7].

PR-SET7 (also named SET8 or KMT5a) is a sole lysine methyltransferase that catalyzes monomethylation of histone H4 lysine 20 (H4K20me1) in higher eukaryotes. The abundance of PR-SET7 is dynamically mediated by the distinct E3 ubiquitin ligases in different cell cycle phases. PR-SET7 is closely related to the regulation of cell proliferation, and the H4K20me1 catalyzed by PR-SET7 has been implicated in regulating the diverse biological processes, including DNA replication, chromosome condensation and the activation of DNA replication checkpoints. Loss of PR-SET7 results in mas-sive DNA damage, cell cycle arrest and induction of apoptosis. In addition, PR-SET7 involves in regulating the transcrip-tion of several genes, such as ERa, Wnt and p53. PR-SET7 is also essential for individual development and participates in the formation of genomic imprinting. Moreover, PR-SET7 has been reported to promote tumorigenesis and metastasis, sug-gesting that PR-SET7 may be a potential target for cancer treatment. In this review, we focus on analyzing the structure of PR-SET7 and factors influencing histone modification on regulation of PR-SET7, and discuss the mechanisms by which PR-SET7 modulates cell-cycle progression, gene transcription, individual development and tumorigenesis.

Probing the chemical functionalization of single-walled carbon nanotubes with multiple carbon ad-dimer defects.

Drying-tube-shaped single-walled carbon nanotubes (SWCNTs) with multiple carbon ad-dimer (CD) defects are obtained from armchair (n,n,m) SWCNTs (n=4, 5, 6, 7, 8; m=7, 13). According to the isolated-pentagon rule (IPR) the drying-tube-shaped SWCNTs are unstable non-IPR species, and their hydrogenated, fluorinated, and chlorinated derivatives are investigated. Interestingly, chemisorptions of hydrogen, fluorine, and chlorine atoms on the drying tube-shaped SWCNTs are exothermic processes. Compared to the reaction energies for binding of H, F, and Cl atoms to perfect and Stone-Wales-defective armchair (5,5) nanotubes, binding of F with the multiply CD defective SWCNTs is stronger than with perfect and Stone-Wales-defective nanotubes. The reaction energy for per F(2) addition is between 85 and 88 kcal mol(-1) more negative than that per H(2) addition. Electronic structure analysis of their energy gaps shows that the CD defects have a tendency to decrease the energy gap from 1.98-2.52 to 0.80-1.17 eV. After hydrogenation, fluorination, and chlorination, the energy gaps of the drying-tube-shaped SWCNTs with multiple CD defects are substantially increased to 1.65-3.85 eV. Furthermore, analyses of thermodynamic stability and nucleus-independent chemical shifts (NICS) are performed to analyze the stability of these molecules.

Endohedral metallofullerene Sc3NC@C84: a theoretical prediction.

Very recently, two novel Sc(3)NC-based cluster fullerenes Sc(3)NC@C(80) (Wang et. al. J. Am. Chem. Soc. 2010, 132, 16362) and Sc(3)NC@C(78) (Wu et. al. J. Phys. Chem. C 2011, 115, 23755) were prepared and characterized, respectively. Inspired by these findings, the possibility of encapsulating Sc(3)NC cluster in the C(84) fullerene is performed using density functional theory (DFT). Firstly, the isolated pentagon rule (IPR) D(2d) (23) C(84) fullerene is employed to encase the Sc(3)NC cluster: four possible endohedral metallofullerene isomers a-d are designed. The large binding energies (ranging from 163.7 to 210.0 kcal mol(-1)) indicate that the planar quinary cluster Sc(3)NC can be stably encapsulated in the C(84) (isomer 23) cage. Further, we consider the incorporation of Sc(3)NC into the non-IPR C(s) (51365) C(84) cage leading to isomer e and show the high stability of isomer e, which has a larger binding energy, larger HOMO-LUMO gap, higher adiabatic (vertical) ionization potential, and lower adiabatic (vertical) electron affinity than the former four Sc(3)NC@C(84) (isomer 23). Significantly, the predicted binding energy (294.2 kcal mol(-1)) of isomer e is even larger than that (289.2 and 277.7 kcal mol(-1), respectively) of the synthesized Sc(3)NC@C(80) and Sc(3)NC@C(78,) suggesting a considerable possibility for experimental realization. The (13)C NMR chemical shifts and Raman spectra of this a new endofullerene have been explored to assist future experimental characterization.

Bipolar hemiarthroplasty compared with internal fixation for unstable intertrochanteric fractures in elderly patients.

BACKGROUND: The optimal treatment for unstable intertrochanteric fractures in elderly patients remains controversial. We aimed to compare internal fixation and bipolar hemiarthroplasty for the treatment of unstable intertrochanteric fractures in elderly patients. METHODS: 124 patients aged over 70 years were enrolled into this study (64 internal fixations, 60 bipolar hemiarthroplasties). Patients were followed for two years, and had a clinical, radiological, and functional review at three, six, and twelve months as well as two years. RESULTS: In the internal fixation group, the fracture reduction and internal fixation were regarded as satisfactory in 44 cases and unsatisfactory in 20 cases. Five patients in the internal fixation group (two with satisfactory results and three with unsatisfactory results) and three patients in the arthroplasty group died before the final two-year follow-up. Five patients in the internal fixation group who had unsatisfactory results suffered complications. At 24 months post-operation, patients who were treated satisfactorily with internal fixation had higher Harris scores, less pain, and better walking ability than those treated with hemiarthroplasty and unsatisfactory internal fixation. CONCLUSIONS: Internal fixation with good reduction and fixation quality should be the preferred therapeutic method for elderly unstable intertrochanteric fractures, even when severe osteoporosis is present.

Independent risk factor for surgical site infection after orthopedic surgery.

No significant progress has been made in the study of orthopedic surgical site infection (SSI) after different orthopedic surgery, and the analysis and prevention of risk factors for orthopedic SSI urgently need to be solved. A total of 154 patients underwent orthopedic surgery from April 2018 to December 2020. General information such as gender, age, marriage, diagnosis, surgical site, and anesthesia method was recorded. Statistical methods included Pearson chi-square test, univariate and multivariate logistic regression analyses, and receiver operating characteristic (ROC) curves. Based on Pearson's chi-square test, sex (P = .005), age (P = .027), marriage (P = .000), diagnosis (P = .034), and surgical site (P = .000) were significantly associated with SSI after orthopedic surgery. However, in the multiple linear regression analysis, only the surgical site (P = .035) was significantly associated with SSI after orthopedic surgery. In terms of multivariate logistic regression level, surgical site (odds ratio [OR] = 1.568, P = .039) was significantly associated with SSI. ROC curves were constructed to determine the effect of the surgical site on SSI after different orthopedic surgery (area under the curve [AUC] = 0.577, 95% CI = 0.487-0.0.666). In summary, the surgical site is an independent risk factor for SSI after orthopedic surgery, and "trauma" is more likely to develop SSI than spine, arthrosis, and others.

MYBPC2 and MYL1 as Significant Gene Markers for Rhabdomyosarcoma.

BACKGROUND: Rhabdomyosarcoma is the most common soft tissue tumor in children. Rhabdomyosarcoma commonly results in pain and bleeding caused by tumor compression and is prone to early metastasis and recurrence, which can seriously affect the therapeutic outcomes and long-term prognosis. Up to 37.7% of rhabdomyosarcomas may metastasize. Therefore, the molecular mechanisms underlying rhabdomyosarcoma must be explored to identify an effective target for its early diagnosis and specific treatment. METHODS: A dataset of 18 rhabdomyosarcoma tissue samples and 6 healthy skeletal muscle samples was downloaded. Differentially expressed genes between rhabdomyosarcoma and healthy tissue samples were identified by GEO2R. Kyoto Encyclopedia of Genes and Genomes and gene ontology pathway enrichment analyses were performed. A protein-protein interaction network was constructed, and hub genes were identified. Expression and survival analyses of hub genes were performed. Additionally, 30 patients with rhabdomyosarcoma were recruited, and overall survival information and samples were collected. Reverse transcription quantitative real-time polymerase chain reaction assays were performed to verify the expression of MYBPC2 and MYL1 in rhabdomyosarcoma tumor tissues. The Kaplan-Meier method was used to explore overall survival based on our clinical data. RESULTS: In total, 164 genes were up-regulated and 394 were down-regulated in rhabdomyosarcoma tumor tissues. Gene ontology analysis revealed that variations were predominantly enriched in the cell cycle, muscle contraction, muscle system processes, cytoskeleton, nucleotide binding, and cytoskeletal protein binding. The protein-protein interaction network revealed 3274 edges, and 441 nodes were constructed. Ten hub genes were identified; of these, MYBPC2 and MYL1 were significantly up-regulated in rhabdomyosarcoma. Compared with the healthy group, patients with rhabdomyosarcoma exhibiting high expression of MYBPC2 and MYL1 exhibited significantly worse overall survival. CONCLUSIONS: We found differentially expressed genes between rhabdomyosarcoma and healthy tissue samples. MYBPC2 and MYL1 may be involved in the pathogenesis of rhabdomyosarcoma and therefore deserve further exploration.

[Mechanism of regulating deacetylase SIRT1 expression and activity.].

SIRT1 is an NAD+-dependent deacetylase in mammalian cells and plays important roles in senescence, cell death and tumorigenesis. To clarify the regulation of SIRT1 expression and activity is crucial for scientists to understand the biological function of SIRT1. This review mainly focuses on the mechanisms by which SIRT1 expression and activity are regulated.

The transcutaneous electromyography recording method for intraoperative neuromonitoring of recurrent laryngeal nerve during minimally invasive parathyroidectomy.

Intraoperative neuromonitoring (IONM) facilitates recurrent laryngeal nerve (RLN) protection in thyroid and parathyroid surgeries. This study aimed to investigate a novel transcutaneous electromyography (EMG) recording method for IONM of the RLN during minimally invasive parathyroidectomy (MIP). Twenty patients with primary hyperparathyroidism undergoing MIP were enrolled. Two paired needle electrodes were percutaneously inserted into the bilateral laminas of thyroid cartilage for monitoring the vagus nerve and RLN. A standardized IONM procedure (V1-R1-R2-V2 signals) was strictly followed, and the RLN was routinely located and mapped. Pre- and postoperative laryngofiberoscopy was performed to confirm vocal cord function. The proposed technique was successfully used in all patients, and typical EMG signals were effectively detected. No significant change in EMG signals before and after tumor resection was noted, and a normal vocal cord movement was ensured in all patients with postoperative laryngofiberoscopy. IONM helped localize the position of the RLN and facilitated the safe resection of the parathyroid tumor during MIP. The novel transcutaneous EMG recording method proposed in this study was feasible, convenient, reliable, and inexpensive.

Modified arytenoid muscle electrode recording method for neuromonitoring during thyroidectomy.

BACKGROUND: Intraoperative neuromonitoring (IONM) is an important application for protecting recurrent laryngeal nerve (RLN) during thyroid surgery. The method for recording arytenoid muscle electromyography (EMG) signals is reported to be feasible and reliable. However, the parameters of EMG signals are not provided. This study aimed to analyze the clinical characteristics of EMG signal parameters by modifying the insertion direction of needle electrodes. METHODS: A total of 92 patients who were scheduled to undergo thyroidectomy were recruited. Two paired needle electrodes were inserted in bilateral angle points between rectus cricothyroid muscle and inferior margin of thyroid cartilage (TC) intraoperatively, and then the information from the EMG signals was recorded according to four-step method (V1-R1-R2-V2). Pre-and post-operative laryngo-fiberoscopy was performed to confirm the vocal cord function. RESULTS: A total of 122 RLNs were successfully recorded during thyroidectomy, with the mean EMG amplitude and latency were 1,857±1,718/2,347±2,323 µV and 3.89±1.12/2.26±0.05 ms for V1/R1 signals before resection, and 1,924±1,705/2,450±2,345 µV and 3.87±1.17/2.27±0.08 ms for R2/V2 signals after resection. There were no significant changes before and after resection, and a normal vocal cord movement was observed postoperatively. The amplitude of left nerves was higher than that of the right ones. Furthermore, the latency of the right vagus was shorter than the left ones, but there was no difference in the amplitude and latency between age, sex and pathological types. CONCLUSIONS: Modified arytenoid muscle EMG recording method was considered to be safe, feasible and reliable. The latency of right vagus EMG signals were shorter than the left ones, and the amplitude of EMG signals might be related to different sides.

Theoretical study on monometallic cyanide cluster fullerenes MCN@C74 (M=Y, Tb).

New monometallic cyanide cluster endohedral fullerenes MCN@C74 (M=Y, Tb) have been investigated using density functional theory. Four isomers of MCN@C74 are considered based on four lowest energy C74 (2-) isomers, namely one cage with isolated pentagons and three isomers with a pentagon-pentagon junction. The results show that the variation of the cluster size has slight influence on the structures and relative stabilities of MCN@C74. The MCN@D3h(14246)-C74 derived from the only C74 cage with the isolated pentagons are predicted to possess the lowest energy. More importantly, in MCN@D3h(14246)-C74, the encapsulated YCN or TbCN cluster is triangular, similar to the results reported on YCN@Cs(6)-C82 and TbCN@C2(5)-C82. Furthermore, IR spectra and (13)C NMR spectra have also been explored to assist future experimental characterization.

Histological study of chordoma origin from fetal notochordal cell rests.

STUDY DESIGN: The histological comparative study was performed on chordoma and notochordal cell rests (NCRs). OBJECTIVE: To understand the histological similarity and homology of chordoma and NCRs, further supplying direct evidence of chordoma origin from NCRs. SUMMARY OF BACKGROUND DATA: Although many studies supported the hypothesis that chordoma arise from NCRs, there has been little direct evidence reported to date. Of the base of our previous study, we conducted a comparative histological study among NCRs coexisting in chordoma, fetal NCRs, and chordoma tumor components. METHODS: Thirty fetal nucleus pulposus and 46 chordoma specimens were harvested, and classic chordoma tumor markers and brachyury expression levels were investigated through immunohistochemical method. RESULTS: The fetal NCRs existed in the form of clusters in the center of nucleus pulposus <36 gestational weeks; NCRs coexisting in chordoma specimens consisted of packed cells without extracellular myxoid matrix. Both the above-mentioned NCRs as well as chordoma tumor components showed high sensitivity for classic chordoma tumor makers (epithelial membrane antigen, AE1/AE3, CAM5.2, vimentin, S-100); both kinds of NCRs showed completely negative expression for brachyury, whereas chordoma tumor components demonstrated 100% positivity. CONCLUSION: Our study results supported histological similarity and homology of NCRs coexisting in chordoma and in fetal nucleus pulposus. Brachyury activation probably takes an important role in chordoma tumoregenesis.

Classic chordoma coexisting with benign notochordal cell rest demonstrating different immunohistological expression patterns of brachyury and galectin-3.

Increasing numbers of studies support the hypothesis that chordoma arises from notochordal cell rests, although the mechanism awaits further research. Brachyury is the first specific molecule linking chordoma with the notochord, and galectin-3 has been widely used as a marker of notochordal cells. We conducted a histological study of the expression of these two molecules in 46 classic chordoma specimens and unexpectedly found that classic chordoma tumor cells coexisted with benign notochordal cell rests in six specimens. Brachyury and galectin-3 expression were investigated by immunohistochemistry. All specimens contained atypical chordoma tumor cells set within an abundant myxoid matrix, which strongly expressed brachyury and galectin-3. However, brachyury and galectin-3 were not expressed in the notochordal cells. Benign notochordal cells, present as notochord rests, could undergo malignant transformation to form chordoma; however, the cause and role of brachyury and galectin-3 expression in chordoma tumorigenesis requires further careful study.