Objective To study the effects of intramedullary pressure on the fluid flow behavior in bones.Methods Multi-scale models of macro bone tissue and macro-meso osteon groups were established using the COMSOL Multiphysics software.Considering the interrelationship of different pore scales,such as the bone marrow cavity,Haversia canal,and bone lacunar-canaliculus,the pore pressure and flow rate of hollow bone tissues and bone tissues with intramedullary pressure were compared,and the effects of the amplitude and frequency of intramedullary pressure on the pressure and flow velocity of the liquid in the bone were analyzed.Results When intramedullary pressure was considered,the pore pressure in bone tissues with intramedullary pressure was 6.4 kPa higher than that in hollow bone tissues.The flow pressure increased significantly with an increase in the intramedullary pressure amplitude,but the flow velocity remained unchanged.The frequency of intramedullary pressure had little effect on pore pressure and flow velocity.Conclusions The multi-scale pore model established in this study can accurately analyze bone fluid flow behavior.These results are of great significance for an in-depth understanding of force conduction in the bone.

OBJECTIVES: Over 25% of the global population is affected by metabolic dysfunction-associated fatty liver disease (MAFLD), yet its pathogenesis remains unclear. Endoplasmic reticulum stress (ERS) may be involved in the onset and progression of MAFLD. Adenosine 5'-monophosphate-activated protein kinase α2 (AMPKα2), a key regulator of hepatic energy metabolism, may influence MAFLD development via ERS modulation. This study aims to investigate the role of AMPKα2 in a high-fat diet-induced MAFLD mouse model and its regulatory effect on the inositol-requiring enzyme 1 alpha (IRE1α)-c-Jun N-terminal kinase (JNK) signaling pathway. METHODS: Liver-specific AMPKα2 knockout mice on a C57BL/6 background were generated and subjected to MAFLD induction. Mice were divided into four groups: wild-type control (WT+Chow, basic diet for 12 weeks), wild-type high-fat diet (WT+HFD, high-fat diet for 12 weeks), AMPKα2 knockout control (AMPKα2 KO+Chow), and AMPKα2 knockout high-fat diet (AMPKα2 KO+HFD). Blood glucose, lipid levels, and liver function were assessed post-treatment. Liver histology was analyzed using Oil Red O, hematoxylin-eosin, Masson, and Sirius Red staining. Western blotting was used to evaluate the expression of AMPKα2, ERS markers, autophagy, apoptosis, and ferroptosis-related proteins. RESULTS: Compared with the WT+Chow group, the WT+HFD group showed significantly elevated blood glucose, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels (all P<0.01); histological analyses revealed hepatic steatosis, vacuolization, and fibrosis, with a significantly increased non-alcoholic steatohepatitis activity score (NAS) (P<0.001). Phosphorylated IRE1α and the autophagy marker microtubule-associated protein light chain (LC) 3II/LC3I were markedly upregulated, while apoptotic proteins (Cleaved-Caspase 3, BAX, Bcl-2) and ferroptosis markers (SLC7A11, GPX4) showed no significant change (P>0.05). In the AMPKα2 KO+HFD group, blood glucose, ALT, and AST levels were significantly reduced compared to the WT+HFD group. Histological improvements were observed with reduced vacuolization and lipid accumulation. Expression of p-IRE1α, JNK, and LC3II/LC3I was significantly decreased (P<0.05). CONCLUSIONS Hepatic AMPKα2 knockout alleviates high-fat induced MAFLD, potentially by inhibiting the IRE1α-JNK pathway and reducing autophagy.
Animals ; AMP-Activated Protein Kinases/physiology* ; Protein Serine-Threonine Kinases/metabolism* ; Mice, Knockout ; Diet, High-Fat/adverse effects* ; Mice, Inbred C57BL ; Mice ; Endoplasmic Reticulum Stress ; Endoribonucleases/metabolism* ; Male ; Liver/pathology* ; Non-alcoholic Fatty Liver Disease/metabolism* ; MAP Kinase Signaling System/physiology* ; Fatty Liver/metabolism* ; Signal Transduction

Background: and Purpose Intracranial vertebrobasilar atherosclerotic stenosis (IVBAS) is a major cause of posterior circulation stroke. Some patients suffer from stroke recurrence despite receiving medical treatment. This study aimed to determine the prognostic value of a new score for the posterior communicating artery and the P1 segment of the posterior cerebral artery (PCoA-P1) for predicting stroke recurrence in IVBAS. Methods: We retrospectively enrolled patients with severe IVBAS (70%–99%). According to the number of stroke recurrences, patients were divided into no-recurrence, single-recurrence, and multiple-recurrences groups. We developed a new 5-point grading scale, with the PCoA-P1 score ranging from 0 to 4 based on magnetic resonance angiography, in which primary collaterals were dichotomized into good (2–4 points) and poor (0 or 1 point). Stroke recurrences after the index stroke were recorded. Patients who did not experience stroke recurrence were compared with those who experienced single or multiple stroke recurrences. Results: From January 2012 to December 2019, 176 patients were enrolled, of which 116 (65.9%) had no stroke recurrence, 35 (19.9%) had a single stroke recurrence, and 25 (14.2%) had multiple stroke recurrences. Patients with single stroke recurrence (odds ratio [OR]= 4.134, 95% confidence interval [CI]=1.822–9.380, p=0.001) and multiple stroke recurrences (OR=6.894, 95% CI=2.489–19.092, p<0.001) were more likely to have poor primary collaterals than those with no stroke recurrence. Conclusions The new PCoA-P1 score appears to provide improve predictions of stroke recurrence in patients with IVBAS.

Objective To investigate the conduction behavior of fluid flow induced by physiological loads at different scales of bone. Method sThe multiscale bone models were established by using the COMSOL Multiphysics software, and the fluid behaviors were investigated at macro-, meso- and micro-scale. Results At macro-meso scale，the distribution of pore pressure and fluid velocity of osteon near the periosteum and endoosteum were different from that in other parts. Due to the different structure and material parameters at different layers, the loading and fluid pressure caused different biomechanical responses in the process of transferring from macro-scale to micro-scale. Conclusions The multi-scale layered modeling of bone structure-osteon-lacunae-bone canaliculi was established, which provided the theoretical reference for deeper understanding of fluid stimulation and mechanotransduction.

Objective To evaluate the sensitivity and specificity of different HbA1C cutoff points for diabetes diagnosis in high risk outpatients in Harbin.Methods A total of 2 122 high risk outpatients(male 1 032 and female 1 090)for diabetes screening in the Fourth affiliated Hospital of Harbin Medical University from April 2013 to February 2015 were included in this study, with the average age of(49.26±13.00)year. Oral glucose tolerance tests(OGTT)were conducted and HbA1C levels were examined in these patients. The sensitivity and specificity of different HbA1C cutoff points were calculated and a receiver operator characteristic(ROC)curve was then built.Results The average level of HbA1C in these subjects was(6.45±1.72)%. The prevalence of diabetes was 41.85%. The area under ROC curve(AUC)was 0.89 with the optimal cutoff point of HbA1C 6.0% and 0.68 for the highest Yonden index. The sensitivity and specificity of HbA1C 6.0% were 84.01% and 83.67% respectively. The sensitivity and specificity of HbA1C 6.5% were 62.84% and 95.92%, respectively. The AUC of HbA1C≥6.5% was 0.732. Conclusion HbA1C works well as the diagnostic standard for diabetes in high risk outpatients of Harbin city. The cutoff point of HbA1C 6.0% is suitable for screening diabetes in high risk population, and HbA1C 6.5% is appropriate for diabetes diagnosis, with high sensitivity and specificity.

BACKGROUND:The previous researches indicate that, shock waves can enhance the proliferation of T-cells and the expression of interleukin (IL)-2 through a mechanism that involves p38 mitogen activated protein kinase (MAPK)activation.OBJECTIVE: To investigate if adenosine triphosphate (ATP) release is an underlying mechanism through which low-density shock waves (LDSWs) augment T-cell function.DESIGN: Controlled repetitive measurement by groups, taking cells as subject.SETTING: Department of Orthopedics, the First Hospital of Jilin University.MATERIALS: KDE-2001 Extracorporeal Shockwave Lithotripter (Beijing Zhongke Jian An Meditechs Co., Beijing, China).p38 MAPK inhibitor SB203580 1 mg (BioSource Inc., Camarillo, CA); p38 MAPK kit for detecting phosphorylation (Cell Signaling Technology, Inc. U.S.A.); P2 receptor inhibitor suramin 50 mg (BIOMOL Research Laboratories Inc., PA) was prepared into 0.02 mol/L solution by 1.749 2 mL IMDM. ATP enzyme: apyrase 200 U (Sigma, U.S.A.); P2X7 receptor antagonist KN-62 (BioSource Inc., Camarillo, CA); ATP Bioluminescence Assay Kit CLS Ⅱ (Roche Diagnostics GmbH,Mannheim, Germany).METHODS: The experiment was carried out in the Orthopedic Laboratory of the First Clinical Hospital in Jilin University from January 2005 to December 2006. ①An Extracorporeal Shockwave Lithotripter (at 7 kV generator voltage, 0.3 μF capacitance, 23 MPa positive pressure, 0.18 mJ/mm2 energy flux density) was applied for LDSWs treatment ranging from 50 to 400 impulses. ②ATP release into the culture supernatant from Jurkat T-cells or human peripheral blood mononuclear cells (PBMCs) was determined with a specific ATP Bioluminescence Assay Kit. ③Negative control group excluded antagonist or inhibitor. Human PBMCs were used to determine the effect of LDSWs on activated T-lymphocyte proliferation. Human Jurkat cells were used to study the effects of LDSWs on IL-2 expression. Expression and phosphorylation of p38 MAPK in Jurkat T-cell were measured by Western Immunoblotting with anti-p38 MAPK antibodies and anti-p38 MAPK phospho-specific antibodies that recognized the phosphorylation (on Thr180/Tyr182).MAIN OUTCOME MEASURES: extra-cellular ATP release, IL-2 expression in cell suspension, cellular proliferation and the phosphorylation of p38 MAPK.RESULTS: ①ATP release under the condition without LDSWs was obviously lower than that with LDSWs of 100, 150,200, 250, 300, 360 and 400 impulses (P ＜ 0.01), and ATP release increased with the LDSWs impulse.②Compared with negative control group, the additions of apyrase, KN-62 or suramin attenuated the 3H-TdR incorporation of the phytohemagglutinin-stimulated PBMCs or CD3/CD28-stimulated Jurkat T-cells, which were effected with LDSWs of 100,150, 200, 250, 300, 330 impulses at 0.18 mJ/mm2 (P＜ 0.01). IL-2 expression in the cellular supernatant was also significant increased (P ＜ 0.01). ATPase, KN-62 or suramin all decreased the effect of LDSWs on p38 MAPK of Jurkat T-cells.CONCLUSION: ①LDSWs deform cellular membranes but have no effect on organelle, which results in ATP release from Jurkat cells. Exogenous ATP release activates P2X7 receptor and p38 MAPK, and increases IL-2 expression. LDSWs enhance T-cell proliferation and IL-2 expression through a mechanism that involves ATP release, P2X7 receptor and phosphorylized p38 MAPK activation. ②The release of ATP plays a key role in the mechanism through which LDSWs regulate the function of T cells.