Effect of Local Delivery of Vancomycin and Tobramycin on Bone Regeneration.

OBJECTIVE: A bone defect rat model was established to investigate the osteogenic effect of local delivery two antibiotics (vancomycin and tobramycin powder) on bone regeneration. METHODS: Twenty-four Sprague-Dawley (SD) male rats (6 to 8 weeks, 200 to 250 g) were used in this study. All these rats were randomly divided into four groups. Based on dose conversion between rat and human via body surface area, the rat dose of two antibiotics was 88µg/g and 176 µg/g for vancomycin and tobramycin, respectively. Con group (no antibiotic), Van group (vancomycin, 88 µg/g), Tob group (tobramycin 176 µg/g), and Van+Tob group (vancomycin 88µg/g combined with tobramycin 176 µg/g). A 5.0-mm full-thickness standardized mandibular bone defect was performed with a drill in each rat and different antibiotic powders were placed over the bone defect space, respectively. All these animals were sacrificed after 12 weeks post-operation. The mandible bones were harvested for further radiographic and histologic analysis. The bone volume/total volume (BV/TV) ratio, bone volume (BV), and bone fractional area (BFA) in the defect area via micro-computed tomography (µCT scanning) were further analyzed. Then, we performed a histological assessment via hematoxylin and eosin (H&E) and Masson's trichrome staining to analyze bone regeneration and also analyze the number of osteoblasts per filed. RESULTS: There were no postoperative deaths, signs of vancomycin-related or tobramycin-related toxicity, or signs of systemic illness in any of the four groups. All wounds healed well, and no complications or surgical site infection were observed in all rats. From the µCT scans analyses, there was less bone regeneration in the Van group than in the Con group (BV/TV: F = 64.29, R2  = 0.9602; P = 0.0052; BFA: F = 76.17, R2  = 0.9662, P = 0.0007; BV: F = 194.4, R2  = 0.9865, P = 0.0022). However, when the tobramycin and vancomycin were combined, an increase in bone defect re-ossification was found in the Van+Tob group than in the Van group (BV/TV: F = 64.29, R2  = 0.9602, P = 0.0033; BFA: F = 76.17, R2  = 0.9662, P = 0.0006; BV: F = 194.4, R2  = 0.9865, P = 0.0033). Routine H&E and Masson staining supported the finding of µCT scanning. Quantitative indices confirmed that both the bone regeneration and the number of osteoblasts per filed in the defect area was higher in the Van+Tob group than in the Van group (percentage of bone tissue: F = 145.7, R2  = 0.9562, P = 0.0008; number of osteoblasts per file; F = 67.3, R2  = 0.9098, P < 0.0001). There was no significant difference between the Con group and the Van+Tob group on the number of osteoblasts each field (F = 145.7, R2  = 0.9562, P > 0.9999). CONCLUSION: For bone defect, local application of vancomycin combined with tobramycin was recommended over vancomycin alone. This animal study presents data suggesting that the use of local delivery of vancomycin and tobramycin should be investigated further in clinical studies.

Spine system changes in soldiers after load carriage training in a plateau environment: a prediction model research.

BACKGROUND: Low back pain is the most common spinal disorder among soldiers, and load carriage training (LCT) is considered the main cause. We aimed to investigate changes in the spine system of soldiers after LCT at high altitudes and the change trend of the lumbar spine and surrounding soft tissues under different load conditions. METHODS: Magnetic resonance imaging scans of the lumbar spines of nine soldiers from plateau troops were collected and processed. We used ImageJ and Surgimap software to analyze changes in the lumbar paraspinal muscles, intervertebral discs (IVDs), intervertebral foramina, and curvature. Furthermore, the multiple linear regression equation for spine injury owing to LCT at high altitudes was established as the mathematical prediction model using SPSS Statistics version 23.0 software. RESULTS: In the paraspinal muscles, the cross-sectional area (CSA) increased significantly from 9126.4 ± 691.6 mm2 to 9862.7 ± 456.4 mm2, and the functional CSA (FCSA) increased significantly from 8089.6 ± 707.7 mm2 to 8747.9 ± 426.2 mm2 after LCT (P < 0.05); however, the FCSA/CSA was not significantly different. Regarding IVD, the total lumbar spine showed a decreasing trend after LCT with a significant difference (P < 0.05). Regarding the lumbar intervertebral foramen, the percentage of the effective intervertebral foraminal area of L3/4 significantly decreased from 91.6 ± 2.0 to 88.1% ± 2.9% (P < 0.05). For curvature, the lumbosacral angle after LCT (32.4° ± 6.8°) was significantly higher (P < 0.05) than that before LCT (26.6° ± 5.3°), while the lumbar lordosis angle increased significantly from 24.0° ± 7.1° to 30.6° ± 7.4° (P < 0.05). The linear regression equation of the change rate, △FCSA% = - 0.718 + 23.085 × load weight, was successfully established as a prediction model of spinal injury after LCT at high altitudes. CONCLUSION: The spinal system encountered increased muscle volume, muscle congestion, tissue edema, IVD compression, decreased effective intervertebral foramen area, and increased lumbar curvature after LCT, which revealed important pathophysiological mechanisms of lumbar spinal disorders in soldiers following short-term and high-load weight training. The injury prediction model of the spinal system confirmed that a load weight < 60% of soldiers' weight cannot cause acute pathological injury after short-term LCT, providing a reference supporting the formulation of the load weight standard for LCT.

Transmembrane protein 92 performs a tumor-promoting function in breast carcinoma by contributing to the cell growth, invasion, migration and epithelial-mesenchymal transition.

OBJECTIVE: We try to examine the role of transmembrane protein 92 (TMEM92) in the progression of breast carcinoma (BC) and assess its prognostic value. Moreover, the effects of TMEM92 on BC cell phenotypes was explored. METHODS: The levels of TMEM92 in BC tissues were evaluated using bioinformatics analysis according to the Oncomine and The Cancer Genome Atlas databases. mRNA levels of TMEM92 in BC cells were measured by qRT-PCR. Kaplan-Meier methods together with log-rank tests were used to conduct survival analysis, and chi-square tests were employed to assess the relationship between TMEM92 levels and clinicopathological parameters. Cox regression analysis was carried out to identify the independent prognosticators. Small interference RNA targeted to TMEM92 and plasmid vectors pcDNA3.1-TMEM92 were respectively used to silence and over-express TMEM92. Protein levels of molecules in this study were tested by western blot. Cell viability, invasiveness and motility of BC cells were determined by cell counting kit 8, clone formation assay and Transwell assay, appropriately. RESULTS: The data showed that TMEM92 was upregulated in BC tissues or cells in comparison with control. High expression of TMEM92 was notably correlated with stage and metastasis, and led to a poor overall survival. Moreover, cox multivariate analysis model demonstrated that TMEM92 can be seen as an independent prognostic factor. Functional experiments demonstrated that downregulation of TMEM92 showed a significantly inhibitory effect on MDA-MB-231 cell viability, invasiveness and motility, whereas overexpression of TMEM92 could promote the changes of these phenotypes. Furthermore, western blot analysis revealed that depletion of TMEM92 inactivated the epithelial-mesenchymal transition (EMT) process with raised E-cadherin protein levels, while declined N-cadherin, Vimentin and Snail levels. However, enhancement of TMEM92 showed the opposite outcomes on these EMT-related markers. CONCLUSION: TMEM92 had an independent prognostic value for BC patients, and might act as an oncogene to facilitate tumor cells growth, invasiveness and motility by modulating the EMT relative proteins.

Background data on embryo-fetal development toxicity studies in SD rats / 中国药理学与毒理学杂志

OBJECTIVE: To establish the background data on SD rat embryo-fetal development toxicity studies by Shanghai Institute of Planned Parenthood Research (National Evaluation Center for Toxicology of Fertility Regulating Drugs), and provide reference for reproductive toxicology research. METHODS: From the embryonic-fetal developmental toxicity tests of SD rats between 2010 and 2018, the index data on embryo development and fetal growth and development of pregnant rats was selected, including pregnancy body mass and pregnancy outcomes (average of corpora lutea, implantation, live fetuses, absorptions and dead fetuses), the growth and development of fetuses (fetal body mass, body length and tail length) and fetal appearance, viscera, and skeleton. The data was statistically analyzed, and the mean, standard deviation and coefficient of variation were calculated. RESULTS: Totally 217 pregnant rats and 2506 fetuses were included. The body mass of pregnant rats on gestation day 0 (GD0) was (222±22) g, while the food consumption of GD0-1was (18.9±3.8) g·d-1. The body mass of GD20 was (353±30) g and the food consumption of GD19-20was (26.2±4.0) g·d-1. GD20euthanasia cesarean section examination showed that the pregnancy rate was 95.2%, and that the average of corpora lutea, implantation and live fetuses was 12.8±2.1, 11.8±2.8 and 11.5±2.8, respectively. The rate of live fetuses and absorption rate was 97.9% and 2.1%, respectively. Among the fetal development indexes, the body mass and placental mass were 3.6±0.3 and (0.5±0.1) g, respectively. The body length was (35.7±1.5) mm, the tail length was (12.9±0.4) mm, and the sexual ratio (male/female) was 1.0 (1227/1279). The external, visceral and skeletal variations were 0.2%, 0.5% and 7.4%, respectively. CONCLUSION: The background data on embryo-fetal toxicity studies of SD rats has been established, which can provide reference for reproductive toxicity research.

Effects of TRPA1 activation and inhibition on TRPA1 and CGRP expression in dorsal root ganglion neurons.

Transient receptor potential ankyrin 1 (TRPA1) is a key player in pain and neurogenic inflammation, and is localized in nociceptive primary sensory dorsal root ganglion (DRG) neurons. TRPA1 plays a major role in the transmission of nociceptive sensory signals. The generation of neurogenic inflammation appears to involve TRPA1-evoked release of calcitonin gene-related peptide (CGRP). However, it remains unknown whether TRPA1 or CGRP expression is affected by TRPA1 activation. Thus, in this study, we examined TRPA1 and CGRP expression in DRG neurons in vitro after treatment with the TRPA1 activator formaldehyde or the TRPA1 blocker menthol. In addition, we examined the role of extracellular signal-regulated protein kinase 1/2 (ERK1/2) in this process. DRG neurons in culture were exposed to formaldehyde, menthol, the ERK1/2 inhibitor PD98059 + formaldehyde, or PD98059 + menthol. After treatment, real-time polymerase chain reaction, western blot assay and double immunofluorescence labeling were performed to evaluate TRPA1 and CGRP expression in DRG neurons. Formaldehyde elevated mRNA and protein levels of TRPA1 and CGRP, as well as the proportion of TRPA1- and CGRP-positive neurons. In contrast, menthol reduced TRPA1 and CGRP expression. Furthermore, the effects of formaldehyde, but not menthol, on CGRP expression were blocked by pretreatment with PD98059. PD98059 pretreatment did not affect TRPA1 expression in the presence of formaldehyde or menthol.

Transforaminal thoracic interbody fusion : Treatment of thoracic myelopathy caused by anterior compression.

BACKGROUND: The aim of this study was to evaluate the early clinical safety and efficacy of transforaminal thoracic interbody fusion (TTIF) with interbody cage application for thoracic myelopathy caused by anterior compression (TMAC). METHODS: A total of 10 patients who underwent TTIF for TMAC from July 2009 to July 2014 were retrospectively reviewed. Thoracic spinal lesions included thoracic disc herniation, thoracic ossification of posterior longitudinal ligament, thoracic vertebral compression fracture, and thoracic spine fracture dislocation. Demographic data, radiological findings as well as operative information were collected. Postoperative functional outcomes evaluated by the modified Japanese Orthopedic Association (mJOA) score and complications were analyzed. RESULTS: The mean operation time was 186.5 min (range 110-315 min), the mean operative blood loss was 845.0 ml (range 400-2000 ml), and the mean recumbent period was 2.7 days (range 1-8 days). During the follow-up period all patients exhibited significant improvements in neurological deficits. The mJOA score improved from a mean of 6.1 ± 1.7 preoperatively to 7.4 ± 1.6 postoperatively and to 9.3 ± 1.6 at final follow-up (P <0.01), with an overall recovery rate of 69.0 ± 26.1%. Solid fusion was observed in all cases. A wound infection was found in one case, in which the patient recovered with no residual neurological deficits after surgical debridement and administration of intravenous antibiotics. No cage-related complications were found in this study. CONCLUSION: The use of TTIF with cage application can be an effective treatment method of thoracic myelopathy caused by anterior compression, with favorable efficacy and safety.