Vitamin D prevents articular cartilage erosion by regulating collagen II turnover through TGF-β1 in ovariectomized rats

OBJECTIVE

To explore the effect of vitamin D on turnover of articular cartilage with ovariectomy (OVX) induced OA, and to investigate transforming growth factor-β1 (TGF-β1) as a possible underlying mechanism mediated by 1α,25(OH)2D3.

DESIGN

Sixty-six rats were randomly allocated into seven groups: sham plus control diet (SHAM+CTL), OVX+CTL diet, sham plus vitamin D-deficient (VDD) diet, OVX+VDD diet, and three groups of ovariectomized rats treated with different doses of 1α,25(OH)2D3. The cartilage erosion and the levels of serum 17β-estradiol, 1α,25(OH)2D3 and C-telopeptide of type II collagen (CTX-II) were measured. TGF-β1, type II Collagen (CII), matrix metalloproteinases (MMP)-9,-13 in articular cartilage were assessed by immunohistochemistry. TGF-β1 and CTX-II expression were measured in articular cartilage chondrocytes treated with/without tumor necrosis factor (TNF-α), 1α,25(OH)2D3, and TGF-β receptor inhibitor (SB505124) in vitro.

RESULTS

Cartilage erosion due to OVX was significantly reduced in a dose-dependent manner by 1α,25(OH)2D3 supplementation, and exacerbated by VDD. The expressions of TGF-β1 and CII in articular cartilage were suppressed by OVX and VDD, and rescued by 1α,25(OH)2D3 supplementation. The expression of MMP-9,-13 in articular cartilage increased with OVX and VDD, and decreased with 1α,25(OH)2D3 supplementation. In vitro experiments showed that 1α,25(OH)2D3 increased the TGF-β1 expression of TNF-α stimulated chondrocytes in a dose-dependent manner. 1α,25(OH)2D3 significantly counteracted the increased CTX-II release due to TNF-α stimulation, and this effect was significantly suppressed by SB505124.

CONCLUSION

VDD aggravated cartilage erosion, and 1α,25(OH)2D3 supplementation showed protective effects in OVX-induced OA partly through the TGF-β1 pathway.

Relationship between the dynamic parameters and injury severity of chest subject to impact

Seventeen dogs were subjected to blunt left lateral impact at velocities from 7.14 m/s to 19.05 m/s. The impacts to the thoracic wall were recorded by accelerometers fixed on the ribs at the impacted point and other areas. From this information the dynamic parameters (compression response, instantaneous deformation velocities, and viscous response) were calculated. The thoracic injury scores were recorded according to the Abbreviated Injury Scale (AIS-85). The results showed that the chest was a viscoelastic structure. The dynamic parameters of the chest wall were correlated with the physical parameters in exponential function or logarithmic function. There was a more significant relationship between viscous criterion and injury score among the various parameters. The relationship curve was sigmoid. The results indicated that the viscous response might be a valid parameter for indicating the severity of injury.

Studies on the mechanisms of stress wave propagation in the chest subjected to impact and lung injuries

To gain some quantitative understanding of the nature and properties of stress wave propagation and the pathological characteristics of lung injuries, pressure values at eight sites in the lungs during an impact period were recorded. The lung injury severity scores in the corresponding regions were determined in 11 dogs, which were subjected to blunt, left lateral impact at a velocity of 16.33 m/sec with a 24.5% compressive response. The results showed that the pressure value at the contact point was the greatest and that pressure decreased significantly from left side to right side. However, at the left hilum a second pressure peak developed. The pressure value at the contact point was 0.68 and 0.50 times greater than those at left lung and left hilum, respectively. The speed at which the pressure at the contact point rose was much faster than the speed at other points. The lung injury scores at different sites corresponded well with the pressure values (p < 0.001). The data indicated that the reflection and refraction of the stress waves result in the accumulation of forces at some points, transferring more energy to the tissues at those points. Therefore, the severity of injury at these points in these tissues was more severe.

Study on characteristics of blast-fragment combined injury in dogs

It is known that blast wave and fragments are the primary causes of casualties from explosive weapons. To study the characteristics of blast-fragment combined injuries, functional and morphological changes were investigated in three groups of anesthetized dogs with blast injury, high velocity fragment extremity injury, and combined injuries of both types. The same parameters were also examined in a control group. Several of the functions investigated were systemic pressure, mean pulmonary arterial pressure (PAP), oxygenic partial pressure of arterial blood (Po2), thromboxane B2(TXB2), and 6-keto-prostaglandin F1 alpha (6-keto-PGF alpha). The morphologic study included gross, light microscopic, and transmission electronic microscopic observations. In the blast injury group, Po2 decreased and PAP, levels of blood plasma 6-keto-PGF alpha and level of TXB2 increased after injury, whereas PAP and level of 6-keto-PGF alpha decreased 24 hours after injury. The levels of 6-keto-PGF alpha and TXB2, in lung tissues, lung/body weight index were higher than those of the control group 24 hours after injury. The TXB2/6-keto-PGF alpha level in blood plasma increased slightly after injury, but showed no difference in lung tissue 24 hours after injury compared with the control group. The morphological changes showed that most of the animals sustained moderate lung injury. In the fragment injury group, Po2 decreased slightly and PAP increased slightly after injury; the levels of 6-keto-PGF alpha, TXB2 and TXB2/6-keto-PGF alpha in blood plasma increased after injury and were higher in lung tissue than in the control group 24 hours after injury. The lung/body weight index was nearly equal to that of control group. The morphological changes showed that only a few animals suffered from mild lung injury. In the combined injury group, Po2 and PAP changed in a manner similar to those of the other two injury groups but were more significantly. The level of blood plasma 6-keto-PGF alpha decreased gradually, whereas that of TXB2 increased permanently; thus, the levels of TXB2/6-keto-PGF alpha obviously increased after injury and were much higher than those in the other injury groups. The level of TXB2 in lung tissue was higher than that of the control group 24 hours after injury, but that of 6-keto-PGF alpha showed no change compared with that of the control group, and the level of TXB2/6-keto-PGF alpha was higher than in the other three groups. The morphological changes showed that most of animals sustained severe lung injury. It is concluded that extremity injury from high velocity fragment will aggravate lung blast injury. Changes in the levels of PGI2 and TXA2, can be used to determine the extent of injury in the three kinds of wounds. This may be useful for early diagnoses and rational treatment of the victims of explosion.

Penetration depth study of the type-I superconductor PdTe2

Superconductivity in the topological non-trivial Dirac semimetal PdTe₂ was recently shown to be type-I. We hereby report measurements of the relative magnetic penetration depth, [Formula: see text], on several single crystals using a high precision tunnel diode oscillator technique. The temperature variation [Formula: see text] follows an exponential function for [Formula: see text], consistent with a fully-gapped superconducting state and weak or moderately coupling superconductivity. By fitting the data we extract a [Formula: see text]-value of  ∼500 nm. The normalized superfluid density is in good agreement with the computed curve for a type-I superconductor with nonlocal electrodynamics. Small steps are observed in [Formula: see text], which possibly relates to a locally lower [Formula: see text] due to defects in the single crystalline sample.

Pathologic study of thoracic impact injury involving a relatively static impact pattern

Fifty-five rabbits were subjected to left thoracic wall lateral blunt impact involving a relatively static impact pattern. The impact velocities ranged from 7.92 m/s to 16.33 m/s and the compression response ranged from 14.08% to 45.84% of the thoracic width. The surviving animals were sacrificed 6 hours after trauma and autopsies were performed. The lung was divided into bronchial and alveolar regions. Injury scores were assigned according to the hemorrhage area and the injury type (e.g., rupture or rib fracture). The results showed that the severity of bronchial injury was greater than alveolar injury when the impact velocity was low. However, alveolar injury was much more severe than bronchial injury at all levels of impact displacement when the impact velocity was high. The ratio of left/right lung injury decreased when the product of impact velocity and compression criterion increased. The latter was also well correlated with the severity of lung and heart injuries. In addition, the severity of rib injury was mainly related to compression response.

Superconductivity under pressure in the Dirac semimetal PdTe2

The Dirac semimetal PdTe₂ was recently reported to be a type-I superconductor (T _c   =  1.64 K, [Formula: see text] mT) with unusual superconductivity of the surface sheath. We here report a high-pressure study, [Formula: see text] GPa, of the superconducting phase diagram extracted from ac-susceptibility and transport measurements on single crystalline samples. T _c (p ) shows a pronounced non-monotonous variation with a maximum T _c   =  1.91 K around 0.91 GPa, followed by a gradual decrease to 1.27 K at 2.5 GPa. Surface superconductivity is robust under pressure as demonstrated by the large superconducting screening signal that persists for applied dc-fields [Formula: see text]. Surprisingly, for [Formula: see text] GPa the superconducting transition temperature at the surface [Formula: see text] is larger than T _c of the bulk. Therefore surface superconductivity may possibly have a non-trivial topological nature. We compare the measured pressure variation of T _c with recent results from band structure calculations and discuss the importance of a Van Hove singularity.

[Reported of 2 cases relapsing polychondritis]

Clinical data of two cases of relapsing polychondritis were reported and the relative literatures were reviewed. The two patients diagnosed relapsing polychondritis after clinical and laboratory examinations.The first case was mild , no larynx and trachea involvement, and her condition improved and controlled after glucocorticoid treatment;The second case which involved larynx and trachea caused breathing difficulty. Two years later he died of lung infection and respiratory failure despite a variety of treatment methods. Relapsing polychondritis is very easily misdiagnosed, early diagnosis and treatment can slow the progression of the disease, for patients with violations of the larynx and trachea should pay close attention to disease progression, tracheotomy or place endotracheal memory alloy stent when necessary.

Screening and bioinformatics analysis of senile osteoporosis genes based on GEO database

OBJECTIVE

Despite improvements in research on osteoporosis in the elderly, the specific mechanism remains unknown. In order to develop better treatment regimens with better efficacy and fewer adverse reactions (ARs), it is vital to unravel the pathogenesis of osteoporosis in the elderly. The GEO chip was used to screen differential genes in senile osteoporosis and analyze their interaction mechanisms in order to obtain potential therapeutic pathways and targets.

MATERIALS AND METHODS

GSE35956 was downloaded from GEO database and used as the research object for KEGG pathway enrichment analysis, GO enrichment analysis and protein-protein interaction (PPI) network analysis, respectively, to explore the related mechanisms of the occurrence and development of osteoporosis in the elderly.

RESULTS

There were 156 differentially expressed genes in the elderly (72 years old) and middle-aged (42 years old) diagnosed with osteoporosis, of which 6 were up-regulated and 150 were down-regulated. An analysis of gene enrichment using GO (gene body) revealed that differentially expressed genes (DEG) were mainly distributed in extracellular matrix (ECM) and other cell structures. Its functions include ossification, parathyroid hormone metabolism, multicellular biological signaling pathway, vitamin catabolism, interleukisn-5 metabolism, transmembrane transporter activity, receptor signaling pathway, calcium metabolism and other molecular functions. According to the Kyoto Encyclopedia of Genes and Genomes (KEGG), an online resource, signaling pathways associated with age-related osteoporosis (OP) are significantly enriched. The DEG enrichment pathways include Wnt, ECM-receptor interaction, cGMP-PKG, GAG degradation, and calcium signaling. A protein and protein interaction (PPI) network was constructed for 14 key genes, including CD44, GRIA1, KNG1 and IL7R.

CONCLUSIONS

The findings of this study indicate that CD44, GRIA1, KNG1, IL7R, and other differential genes affect the Wnt signaling pathway in the elderly, which can provide new targets for the follow-up basic research and treatment of osteoporosis in the elderly.

WTAP/IGF2BP3 mediated m6A modification of the EGR1/PTEN axis regulates the malignant phenotypes of endometrial cancer stem cells

Endometrial cancer (EC) stem cells (ECSCs) are pivotal in the oncogenesis, metastasis, immune escape, chemoresistance, and recurrence of EC. However, the specific mechanism of stem cell maintenance in EC cells (ECCs) has not been clarified. We found that WTAP and m6A levels decreased in both EC and ECSCs, and that knocking down WTAP promoted ECCs and ECSCs properties, including proliferation, invasion, migration, cisplatin resistance, and self-renewal. The downregulation of WTAP leads to a decrease in the m6A modification of EGR1 mRNA, and it is difficult for IGF2BP3, as an m6A reader, to recognize and bind to EGR1 mRNA that has lost m6A modification, resulting in a decrease in the stability of EGR1 mRNA. A decrease in the EGR1 level led to a decrease of in the expression tumor suppressor gene PTEN, resulting in deregulation and loss of cellular homeostasis and thereby fostering EC stem cell traits. Notably, the enforced overexpression of WTAP, EGR1, and PTEN inhibited the oncogenic effects of ECCs and ECSCs in vivo, and the combined overexpression of WTAP + EGR1 and EGR1 + PTEN further diminished the tumorigenic potential of these cells. Our findings revealed that the WTAP/EGR1/PTEN pathway is important regulator of EC stem cell maintenance, chemotherapeutic resistance, and tumorigenesis, suggesting a novel and promising therapeutic avenue for treating EC.

[Rasmussen syndrome: a clinicopathologic study of four cases]

Objective: To investigate the clinicopathologic features of Rasmussen syndrome (RS) and to raise awareness of this rare disease. Methods: Clinicopathologic data of 4 cases of RS were retrospectively analyzed at Beijing Haidian Hospital from 2008 to 2016. Results: The clinical manifestations included epilepsia partialis continua and progressive neurologic deficits in all patients.MRI demonstrated unihemispheric focal cortical atrophy in all cases. The histopathologic changes included variable degrees of lymphocytic infiltrate within the cortex, subarachnoid space and perivascular cuffing.Microglial nodules and neuronophagia were seen. Mild to severe neuronal loss was noted with variable degrees of reactive gliosis. Spongy edema and cavitation were observed in focal cortex. Inflammation involving hippocampus was seen in one case. Three cases were accompanied by focal cortical dysplasia (FCD) Ⅲd. Immunohistochemical staining showed that the infiltrative lymphocytes were positive for CD3, CD8, granzyme B and TIA1 and the proliferating microglial cells were positive for CD68. NeuN positive neurons decreased significantly and reactive astrocytes were GFAP positive. Conclusions: Pathologic changes of RS are similar to viral encephalitis and the inflammation is progressive and multifocal involving the hemisphere. The diagnosis of RS relies on pathologic features combined with clinical findings and neuroradiological examinations.

Analysis and experimental validation of disulfidptosis related genes solute carrier family 3 member 2 (SLC3A2) in endometrial cancer

Disulfidptosis, a novel cell death paradigm triggered by disulfide stress, remains underexplored, particularly its implications for endometrial cancer (EC). This study focused on the prognostic significance of disulfidptosis-related genes (DRGs) in EC, highlighting the pivotal role of SLC3A2. To predict EC patient outcomes, we developed a model centered on DRGs, employing LASSO-Cox regression for its construction. The model revealed a strong correlation between DRG risk score, gene set enrichment analysis (GSEA), single-sample GSEA (ssGSEA), clinical characteristics, the tumor microenvironment (TME), and the response to immunotherapy. Key genes were pinpointed using random forest maps. To establish SLC3A2's oncogenic effects in EC, we conducted comprehensive studies including apoptosis, cell cycle, TRANSWELL, CCK-8, and tumor xenograft assays. SLC3A2 expression was further confirmed via qRT-PCR. The impact of SLC3A2 on EC's malignant behavior was corroborated through both in vitro and in vivo experiments.

[Gene diagnosis and treatment of hereditary hemorrhagic telangiectasia with epistaxis as its main symptom]

Objective:The aim of this study is to investigate the gene diagnosis and the treatment of hereditary hemorrhagic telangiectasia (HHT) with epistaxis as the main symptom, and to analyze the mutation of ACVRL1 gene in the family. Method:Detailed pedigree investigation was carried out on the proband.Sixtynine genes related to coagulation disorder were sequenced and analyzed by high throughput sequencing for the father and son of the proband. Result:Four generations of the family consisted of 30 probands, including 11 patients. A pathogenic mutation ACVRL1_ex9 c.1313T > C (p.M438T) was detected in both patient and his father. Conclusion:Recurrent epistaxis is the main manifestation of hereditary hemorrhagic telangiectasia in this family. The mutation of ACVRL1 gene is the pathogenic gene of this family, which can be treated by surgery and medicine.

Pathologic study of thoracic impact injury involving a movable impact pattern

The left thoracic walls of 28 rabbits were subjected to lateral blunt impact in a movable impact pattern. The impact velocities ranged from 7.95 m/s to 16.13 m/s, and the compression response ranged from 15.69% to 46.14% of the thoracic width. The surviving animals were sacrificed at 6 hours after trauma and were autopsied. Injury scores were assigned according to the hemorrhage area and the injury type (e.g., rupture or rib fracture). When compared with the pathologic characteristics of the thoracic injury involving a relatively static impact pattern, the severity of thoracic injury involving a movable impact pattern was milder. Also there were more significant differences in the severity of injury to lungs and ribs on the left as compared with the right sides. The viscous criterion is still a good parameter reflecting the severity of injury to lungs and heart. The severity of rib injury was mainly related to compression response.

Studies on lung injuries caused by blast underpressure

This study was designed to determine the effects of underpressure on the lungs of rats and rabbits. An underpressure generator was made to simulate reliably the underpressure parameters at various levels. The peak level and duration ranged from -45.5 kPa to -86.5 kPa and from 21.3 milliseconds to 1,900 milliseconds, respectively. The time to peak negative pressure ranged from 3.5 milliseconds to 7.4 milliseconds. The results showed that underpressure at a certain level could inflict injuries on rats and rabbits. The severity of injury ranged from mild to extremely severe, even to death. These injury patterns were similar to those induced by blast overpressure. The lungs were the organs most vulnerable to underpressure. The pulmonary pathological changes included hemorrhage and edema. The typical hemorrhagic stripes on the lung surfaces resulted from the interfacial impacts of the lungs on the chest wall. The severity of lung injury increased with increased peak pressure and duration levels. This relationship can be expressed with linear regressive equations and the physical parameters of the underpressure can be used to indicate the severity of injury to lungs.

[Effect of modified body position on cVEMP in normal young people]

Objective: To observe the effect of modified body position on cervical vestibular evoked myogenic potential(cVEMP) in normal young people. Method: Thirty normal young people were selected as subjects. CVEMP test was performed by supine head position and sitting submandibular lower body position respectively. The cVEMP examination results were observed and compared. Result: The elicitation rate of the two kinds of position of cVEMP were 100%. There was no significant difference in P1 latency, N2 latency, amplitude and asymmetry ratio. Different body position comfort VAS score, submandibular pressure of sitting position was better than supine head up position(P<0.05). Conclusion: Submandibular pressure of sitting position has no effect on the results of cVEMP examination, and the subjects are more comfortable, and can be used for old age and inability to cooperate with supine head up position.

[Horizontal semicircular canals light cupulopathy: 2 cases report]

SummaryAnalyze 2 cases of horizontal semicircular canals light cupulopathy patient history, clinical manifestations, vestibular function and hearing test results, summarize the clinical features of the disease. All of the 2 patients showed a typicaln light cupulopathy nystagmus. That is, the nystagmus of the Roll-Test test is sustained to the ground, and there is no latency and attenuation with null plane. When the patient's nystagmus is characterized by direction changing positional nystagmus and head deflection nystagmus disappearance（null plane）, the possibility of horizontal semicircular canals light cupulopathy is to be thought of. In this paper, 2 cases of horizontal semicircular canals light cupulopathy received in our hospital are reported as follows.

Increased Sparc release from subchondral osteoblasts promotes articular chondrocyte degeneration under estrogen withdrawal

OBJECTIVE

The incidence of osteoarthritis (OA) in menopausal women is significantly higher than in same-aged men. Investigating the role of subchondral osteoblasts in estrogen deficiency-induced OA may help elucidate the pathological mechanism, providing new insights for the diagnosis and treatment of menopausal OA.

METHODS

A classical ovariectomy-induced OA (OVX-OA) rat model was utilized to isolate primary articular chondrocytes and subchondral osteoblasts, which were identified and then cocultured in Transwell. The expression of chondrocyte anabolic and catabolic indicators was evaluated. The differentially expressed proteins in the conditioned medium (CM) of osteoblasts were identified by Liquid Chromatograph-Mass Spectrometer (LC-MS/MS). Normal chondrocytes were treated with osteoblast CM, and then RNA sequencing was performed on the treated chondrocytes. KEGG was used to identify significant enrichment of signaling pathways, and Simple Western was used to verify the expression of related proteins in the signaling pathways.

RESULTS

Coculture of OVX-OA subchondral osteoblasts with chondrocytes significantly downregulated the expression of the anabolic indicators and upregulated the expression of the catabolic indicators in chondrocytes. 1,601 proteins were identified in both normal and OVX osteoblast culture supernatants. Protein-protein interaction network analysis revealed that Sparc was one of the hub proteins. The AMPK/Foxo3a signaling pathway of chondrocytes was downregulated by OVX-OA osteoblasts CM. AICAR, the AMPK agonist, partially reversed the catabolic effect of OVX-OA osteoblasts on chondrocytes.

CONCLUSIONS

Sparc secreted by OVX-OA subchondral osteoblasts can downregulate the AMPK/Foxo3a signaling pathway of chondrocytes, thereby promoting chondrocyte degeneration.

Analysis and experimental validation of fatty acid metabolism-related genes prostacyclin synthase (PTGIS) in endometrial cancer

The deregulation of fatty acid metabolism plays a pivotal role in cancer. Our objective is to construct a prognostic model for patients with endometrial carcinoma (EC) based on genes related to fatty acid metabolism-related genes (FAMGs). RNA sequencing and clinical data for EC were obtained from The Cancer Genome Atlas (TCGA). Lasso-Penalized Cox regression was employed to derive the risk formula for the model, the score = esum(corresponding coefficient × each gene's expression). Gene set enrichment analysis (GSEA) was utilized to examine the enrichment of KEGG and GO pathways within this model. Correlation analysis of immune function was conducted using Single-sample GSEA (ssGSEA). The "ESTIMATE" package in R was utilized to evaluate the tumor microenvironment. The support vector machine recursive feature elimination (SVM-RFE) and randomforest maps were employed to identify key genes. The effects of PTGIS on the malignant biological behavior of EC were assessed through CCK-8 assay, transwell invasion assay, cell cycle analysis, apoptosis assay, and tumor xenografts in nude mice. A novel prognostic signature comprising 10 FAMGs (INMT, ACACB, ACOT4, ACOXL, CYP4F3, FAAH, GPX1, HPGDS, PON3, PTGIS) was developed. This risk score serves as an independent prognostic marker validated for EC. According to ssGSEA analysis, the low- and high-risk groups exhibited distinct immune enrichments. The key gene PTGIS was screened by SVM-RFE and randomforest method. Furthermore, we validated the expression of PTGIS through qRT-PCR. In vitro and in vivo experiments also confirmed the effect of PTGIS on the malignant biological behavior of EC.

[Analysis of the content of ten kinds of metal elements in cerebrolysin by atomic absorption spectrophotometry]

The contents of Mg, K, Ca, Cr, Mn, Fe, Co, Ni, Cu and Zn in eight different brand cerbrolysins were determined by flame atomic absorption spectrophotometry. The statistical results as follows: the metal elements have significant difference between in seven kinds of Chinese products and in the cerebrolysin made by Austria. According to the results, we studied the inter relation of metal elements with medicine result, and analyzed the effect of trace elements in cerebrolysin. It provided useful data for medicine on clinical practice.

The effect of BMP2/Smads pathway mediating platelet-rich fibrin on rat bone mesenchymal stem cells

OBJECTIVE

We explored the influences on platelet-rich fibrin (PRF) to rat Bone Mesenchymal Stem Cells (BMSCs), as well as the role of bone morphogenetic protein 2 (BMP2)/maternal signal protein homolog (Smads) pathway.

MATERIALS AND METHODS

The proposed research is approved by the ethics board of the Second Affiliated Hospital of Harbin Medical University. The BMSCs were isolated and purified. The BMSCs were assigned to a control group arbitrarily, PRF group, BMP activator group and BMP inhibitor group (hereinafter referred to as activator group and inhibitor group). Each group of BMSCs in the logarithmic growth phase was detected for the alkaline phosphatase (ALP) activity since 3 days and 14 days of culture; CCK-8 assay was conducted for detection of the proliferation of BMSCs; Real time PCR was conducted for detection of the osteogenic differentiation marker collagen I (COL-I), BMP2, Runt-related transcription factor 2(RUNX2), osteocalcin (OCN) mRNA relative expression levels; Western-Blot detection of BMP2, OCN, P-SMAD1/5/8, relative expression level of RUNX2 protein.

RESULTS

In contrast to the control group, BMSCs' the ALP activity of the PRF group, activator group, as well as inhibitor group increased for 3 days and 14 days, and the activator group>PRF group>inhibitor group (p≤0.05). ALP activity in each group was elevated with the increase in culture time, the ALP activity of the control group, PRF group, activator group and inhibitor group increased (p≤0.05). In comparison to the control group, the relevant expression levels of COL-I, BMP-2, RUNX2 and OCN in the PRF group, activator group, and inhibitor group increased, and the activator group>PRF group>inhibitor group (p≤0.05). The relative expression levels of BMP2, OCN, p-SMAD1/5/8 and RUNX2 protein in each group were statistically different, the activator group>PRF group>control group>inhibitor group (p≤0.05).

CONCLUSIONS

PRF can promote the proliferation and osteogenic differentiation of BMSCs by activating the BMP2/Smads signaling pathway.

Development of serial bio-shock tubes and their application

OBJECTIVE

To design and produce serial shock tubes and further examine their application to experimental studies on blast injury.

METHODS

Bio-medical engineering technique was used for the design and development of the serial shock tubes. One thousand four hundred and fifty nine animals (757 rats, 105 guinea pigs, 335 rabbits, 240 dogs and 22 sheep) were then used to test the wounding effects of the shock tubes.

RESULTS

Three types of bio-shock tubes, that is, large-, medium- and small-scale shock tubes were made in our laboratory. The large-scale shock tube is 39 meters long; the inner diameter of the test section is 1 meter; and the maximum overpressure in the driving section is 10.3 MPa. A negative pressure could be formed by means of the reflected rarefactive wave produced by the end plate. The medium-scale shock tube is 34.5 meters long; the maximum overpressure in the driving section is 22 MPa; the test section is designed to be a knockdown, showing 5 basic types with inner diameter of 77 to 600 millimeters, which could be used for researches on overpressure, explosive decompression, underwater explosion, and so on. The small-scale shock tube is 0.5 meter long with the maximum endured overpressure of 68.6 MPa. Results from animal experiments showed that this set of shock tubes could induce various degrees of systemic or local blast injury in large or small animals.

CONCLUSIONS

This set of bio-shock tubes can approximately simulate typical explosive wave produced by nuclear or charge explosion, and inflict various degrees of blast injury characterized by stability and reproducibility. Therefore, they can meet the needs of blast research on large and small animals.