Nitric oxide (NO) is a short-life free radical that acts as the small biological molecule, and exists in body extensively. Since its discovery over 20 years ago, NO has been found to play an important regulation role in angiogenesis, nerve and immune system. The subsequent studies also showed that NO exerted an important biological action in wound repairing and healing, which involved in the following phases of wound repair, inflammation, cell proliferation, matrix deposition and remodeling. This paper reviews recent findings from in vitro & in vivo studies of NO in wound repair, and the biological function and mechanisms of NO in wound repair.
Animals ; Humans ; Neovascularization, Physiologic ; Nitric Oxide ; metabolism ; physiology ; therapeutic use ; Wound Healing ; drug effects ; physiology

This study sought to detect the pathological changes of anterior cruciate ligament (ACL) and medial collateral ligament (MCL) under injury stretch. Bone-ACL-Bone (B-ACL-B) and B-MCL-B complexes were isolated from 20 male Wister rats, and were immersed in phosphate buffered saline. The complexes were stretched with 10% or 20% strain for 10 min or 30 min. After being stretched, the specimens were fixed in 10% buffered formalin, then mounted in paraffin. Sections were stained with Alcian blue-PAS and HE. The following results were found: In the control group, the matrix in ACL contained much more GAGs, as compared with that in MCL. When stretched with 10%, most of the fibroblasts in ACL were elongated like spindles in shape, and some pyknotic nuclei were found increased with stretching time. With 20% strain, ACL showed disruption in parts of collagen fibrils and lysis. But MCL was often torn at its tibia end. The injury can be detected in pathological slices under microscope, even this injury can not be found with naked eye. This injury first starts with the disturbance of the nucleus in the ligament, but following further stretching, it will extend to the rupture of collagen fibrils, and the serious injury of the fibroblasts is especially bad to the repair of the ligament.
Animals ; Anterior Cruciate Ligament ; pathology ; Anterior Cruciate Ligament Injuries ; Male ; Medial Collateral Ligament, Knee ; injuries ; pathology ; Rats ; Rats, Wistar ; Stress, Mechanical

Studies have recently suggested that the coupling mechanism of bone formation and bone resorption are affected by particulate wear debris inducing aseptic loosening around the bone-prosthesis microenviroment. There may be direct impacts on osteoblasts, resulting in net decrease in bone formation. In addition, the influences of particulate wear debris in different size on the osteogenesis should be various. In order to investigate the hypothesis that particulate wear debris derived from prosthetic biomaterials affects the osteogenesis of osteblasts, we studied the influence of different-sized titanium particles loading on the osteoblastic differentiation by assaying the secretion of alkaline phosphatase (ALP), osteocalcin (OCN), N-terminal type I procollagen (PINP), and on the osteoblastic mineralization with the use of calcified node number, calcified node area and Alizarin Red S (ARS) concentration. Upon in vitro culture in the absence of titanium particles, we observed that cultures of osteoblasts isolated from newborn Japanese rabbits' cranium were excellently capable of differentiation and mineralization. Phi6.9 microm titanium particles did not evidently alter osteoblastic differentiation and mineralization. In comparison, phi2.7 microm and phi0.9 microm titanium particles, especially phi0.9 microm (submicron), significantly suppressed ALP expression, reduced PINP production, decreased OCN secretion and inhibited matrix mineralization. Results of transmission electron microscopy (TEM) of titanium particles-loaded osteoblastic cultures revealed that osteoblasts phagocytized titanium particles and exhibited ultrastructional changes consistent with cellular dysfuction. Combined with our previous studies in vitro findings, these results suggest that particles size play a key role in the process of aseptic loosening, which submicron particles are closely associated with inhibition of bone formation while bigger particles with enhancement of bone resorption. Further understanding the nature of osteoblastic bioreactivity to different-size wear particles should provide additional insights into mechanisms underlying aseptic loosening.
Animals ; Animals, Newborn ; Calcification, Physiologic ; drug effects ; Cell Differentiation ; Cells, Cultured ; Female ; Male ; Osteoblasts ; cytology ; Osteocalcin ; biosynthesis ; Osteogenesis ; drug effects ; Particle Size ; Prostheses and Implants ; Prosthesis Failure ; Rabbits ; Titanium ; pharmacology

Particulate wear debris within the bone-prosthesis microenvironment generated by normal wear and corrosion of orthopaedic implants is considered to be one of the main factors responsible for chronic aseptic inflammation and development of osteolysis in the long-term instability and failure of total joint arthroplasty. While the decrease in bone volume caused by wear debris-induced osteolysis could have been compensated by enough new bone matrix secreted by osteoblasts. Actually, the normal osteoblastic population depend on the regular differentiation and proliferation of their progenitor cells--bone marrow mesenchymal stem cells (MSCs). This study aims to investigate the potential mechanism for the rat MSCs cytotoxicity upon exposure to Titanium (Ti) particles. Rat mesenchymal stem cells (rMSCs) isolated from 3-month-old male Sprague-Dawley rats by Percoll intensity gradient method were cultured in DMEM medium (low glucose) supplemented with 10% fetal bovine serum, 100 U/ml penicillin, and 100 micrograms/ml streptomycin in a humidified incubator with 5% CO2 at 37 degrees C. In order to gain the homogenous cell population, rMSCs were passaged to 3-4th subpassage which were used in all the experiment groups. Then rMSCs were seeded in the 6 well culture plates and exposed to three different circle diameters (mean size, TD1: 0.9 micron, TD2: 2.7 microns, TD3: 6.9 microns) with three different concentrations (0.1 wt%, 0.05 wt%, 0.01 wt%, W/V) at different durations (8 h, 16 h, 24 h,), respectively. Unexposed rMSCs were used as control. In the given periods of Ti loading, fluid shear stress (FSS) was applied to each group cells. The expression of F-actin and DNA of the rMSCs at the indicated time were determined with laser confocal scanning microscopy and image analysis software. The results showed that there was up-regulation expression of F-actin in the rMSCs without Ti particles loading but in the presence of FSS. Ti particles loading can suppress the expression of F-action and DNA of rMSCs, but this down-regulation response varied with the three circle diameter, concentrations and durations of Ti particles. Among three kinds of diametrically different Ti particles, submicron Ti particles (0.9 micron) had the greatest suppressive response on rMSCs, together with some apoptosis bodies. Under the same diameter condition, the inhibition induced by Ti particles loading was in a manner dependent on the particles concentration and exposure duration. The reductive effects produced from 0.1 wt% Ti was the greatest and earliest among the responses from Ti particles at three different concentrations; and the lower the concentration, the weaker the repressive influence. Furthermore, with the elongation of exposure to Ti particles, the expression of F-actin and DNA decreased gradually, the lowest level was at 32 h. These findings demonstrated that Ti particles loading can attenuate rMSCs' viability in a manner dependent on the circle diameter, particles concentration, treatment period, suggesting that a reduction in the number of viable MSCs together with a compromise of the their differentiation into functional osteoblast may exacerbate aseptic loosening of total joint implant. Further investigation into particles-mediated suppression of MCSs viability may reveal novel mechanism of implant loosening and aid in development and application of osteolytic drug therapy and the optimization of design and selection of future orthopaedic biomaterials, thereby improving long-term compatibility and stability for arthroplasty patients.
Actins ; metabolism ; Animals ; Cells, Cultured ; DNA ; metabolism ; Male ; Mesenchymal Stromal Cells ; cytology ; drug effects ; metabolism ; Particle Size ; Rats ; Rats, Sprague-Dawley ; Stress, Mechanical ; Time Factors ; Titanium ; administration & dosage ; toxicity

The progress of research on the the anterior cruciate ligament (ACL) wound healing demonstrates that the synovial tissue in the knee joint plays a very important role in the healing process of injured ACL. Therefore, the molecular response mechanisms of lysyl oxidase (LOX) and matrix metalloproteina (MMP) in normal/injured ACL fibroblast cells could be considered to perform the major analysis function of injured ACL healing mechanism. The mRNA expressions of LOXs and MMPs and the activity expressions of MMP-2 in ACL fibroblasts co-cultured with synovial cells were analyzed by quantitative real-time PCR and zymography. The results showed that co-culture could regulate the mRNA expressions of LOXs and MMPs in the ACL fibroblasts cells. These results suggest that the differential expressions of LOXs and MMP-1, 2, 3 in co-cultured ACL indicate that interaction crosstalk do exist between ACL cells and synovial cells and provide a theoretical basis for subsequent exploration of the mechanisms and treatment of ACL injury and repair.
Anterior Cruciate Ligament ; cytology ; Anterior Cruciate Ligament Injuries ; Coculture Techniques ; Fibroblasts ; cytology ; metabolism ; Humans ; Knee Injuries ; physiopathology ; Knee Joint ; cytology ; Matrix Metalloproteinases ; genetics ; metabolism ; Protein-Lysine 6-Oxidase ; genetics ; metabolism ; Synovial Membrane ; cytology ; Wound Healing ; physiology

INTRODUCTION: Psychiatric comorbidity is common in patients with functional dyspepsia (FD) but a good screening tool for psychiatric disorders in gastrointestinal clinical practice is lacking. Aims: 1) Evaluate the performance and optimal cut-off of 12-item General Health Questionnaire (GHQ-12) as a screening tool for psychiatric disorders in FD patients; 2) Compare health-related quality of life (HRQoL) in FD patients with and without psychiatric comorbidities. METHODS: Consecutive patients fulfilling Rome III criteria for FD without medical co-morbidities and gastroesophageal reflux disease were recruited in a gastroenterology clinic. The followings were conducted at 4 weeks after index oesophagogastroduodenoscopy: self-administrated questionnaires on socio-demographics, dyspeptic symptom severity (4-point Likert scale), GHQ-12, and 36-item short-form health survey (SF-36). Psychiatric disorders were diagnosed with Structured Clinical Interview for DSM-IV Axis I Disorders (SCID) by a trained psychiatrist, which served as reference standard. RESULTS: 55 patients underwent psychiatrist-conducted interview and questionnaire assessment. 27 (49.1%) had current psychiatric disorders as determined by SCID (anxiety disorders: 38.2%, depressive disorders: 16.4%). Receiver operating characteristic curve analysis of GHQ-12 revealed an area under curve of 0.825 (95%CI: 0.698-0.914). Cut-off of GHQ-12 at > or =3 gave a sensitivity of 63.0% (95%CI = 42.4-80.6%) and specificity of 92.9% (95%CI = 76.5%-98.9%). Subjects with co-existing psychiatric disorders scored significantly lower in multiple domains of SF-36 (mental component summary, general health, vitality and mental health). By multivariate linear regression analysis, current psychiatric morbidities (Beta = -0.396, p = 0.002) and family history of psychiatric illness (Beta = -0.299, p = 0.015) were independent risk factors for poorer mental component summary in SF-36, while dyspepsia severity was the only independent risk factor for poorer physical component summary (Beta = -0.332, p = 0.027). CONCLUSIONS: Concomitant psychiatric disorders adversely affect HRQoL in FD patients. The use of GHQ-12 as a reliable screening tool for psychiatric disorders allows early intervention and may improve clinical outcomes of these patients.
Area Under Curve ; Axis, Cervical Vertebra ; Comorbidity ; Diagnostic and Statistical Manual of Mental Disorders ; Dyspepsia ; Early Intervention (Education) ; Gastroenterology ; Gastroesophageal Reflux ; Health Surveys ; Humans ; Linear Models ; Mass Screening ; Mental Disorders ; Psychiatry ; Quality of Life ; Surveys and Questionnaires ; Risk Factors ; ROC Curve ; Rome ; Sensitivity and Specificity

BACKGROUND AND OBJECTIVES: We aim to explore the additional discriminative accuracy of a deep learning (DL) algorithm using repeated-measures data for identifying people at high risk for cardiovascular disease (CVD), compared to Cox hazard regression. METHODS: Two CVD prediction models were developed from National Health Insurance Service-Health Screening Cohort (NHIS-HEALS): a Cox regression model and a DL model. Performance of each model was assessed in the internal and 2 external validation cohorts in Koreans (National Health Insurance Service-National Sample Cohort; NHIS-NSC) and in Europeans (Rotterdam Study). A total of 412,030 adults in the NHIS-HEALS; 178,875 adults in the NHIS-NSC; and the 4,296 adults in Rotterdam Study were included. RESULTS: Mean ages was 52 years (46% women) and there were 25,777 events (6.3%) in NHIS-HEALS during the follow-up. In internal validation, the DL approach demonstrated a C-statistic of 0.896 (95% confidence interval, 0.886–0.907) in men and 0.921 (0.908–0.934) in women and improved reclassification compared with Cox regression (net reclassification index [NRI], 24.8% in men, 29.0% in women). In external validation with NHIS-NSC, DL demonstrated a C-statistic of 0.868 (0.860–0.876) in men and 0.889 (0.876–0.898) in women, and improved reclassification compared with Cox regression (NRI, 24.9% in men, 26.2% in women). In external validation applied to the Rotterdam Study, DL demonstrated a C-statistic of 0.860 (0.824–0.897) in men and 0.867 (0.830–0.903) in women, and improved reclassification compared with Cox regression (NRI, 36.9% in men, 31.8% in women). CONCLUSIONS A DL algorithm exhibited greater discriminative accuracy than Cox model approaches.TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02931500

BACKGROUND AND OBJECTIVES: We aim to explore the additional discriminative accuracy of a deep learning (DL) algorithm using repeated-measures data for identifying people at high risk for cardiovascular disease (CVD), compared to Cox hazard regression.METHODS: Two CVD prediction models were developed from National Health Insurance Service-Health Screening Cohort (NHIS-HEALS): a Cox regression model and a DL model. Performance of each model was assessed in the internal and 2 external validation cohorts in Koreans (National Health Insurance Service-National Sample Cohort; NHIS-NSC) and in Europeans (Rotterdam Study). A total of 412,030 adults in the NHIS-HEALS; 178,875 adults in the NHIS-NSC; and the 4,296 adults in Rotterdam Study were included.RESULTS: Mean ages was 52 years (46% women) and there were 25,777 events (6.3%) in NHIS-HEALS during the follow-up. In internal validation, the DL approach demonstrated a C-statistic of 0.896 (95% confidence interval, 0.886–0.907) in men and 0.921 (0.908–0.934) in women and improved reclassification compared with Cox regression (net reclassification index [NRI], 24.8% in men, 29.0% in women). In external validation with NHIS-NSC, DL demonstrated a C-statistic of 0.868 (0.860–0.876) in men and 0.889 (0.876–0.898) in women, and improved reclassification compared with Cox regression (NRI, 24.9% in men, 26.2% in women). In external validation applied to the Rotterdam Study, DL demonstrated a C-statistic of 0.860 (0.824–0.897) in men and 0.867 (0.830–0.903) in women, and improved reclassification compared with Cox regression (NRI, 36.9% in men, 31.8% in women).CONCLUSIONS: A DL algorithm exhibited greater discriminative accuracy than Cox model approaches.TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02931500
Adult ; Artificial Intelligence ; Cardiovascular Diseases ; Cohort Studies ; Female ; Follow-Up Studies ; Humans ; Insurance, Health ; Learning ; Male ; Mass Screening ; National Health Programs

This paper is aimed to investigate the effect of titanium (Ti) particles and tumor necrosis factor alpha (TNF-alpha) on the expressions of MMP-1, 2, 3 in human synovial cells, so as to explore the possible mechanism of osteolysis post-operation of metal-on-metal total joint arthroplasty in human synovial cells induced by Ti particles. In vitro cell cultures, human synovial cells were treated by Ti particles and/or TNF-alpha. The total RNA was isolated at 2 hours after the treatment. The gene expression of MMP-1, 2, 3 was analyzed by Semi-quantitative Reverse-transcriptional PCR and quantitative real-time PCR. Cell supernatant was collected at 12, 24, 48 hours after the treatment and Gelatin zymography was performed to detect the activity of MMP-2. Compared to those in the control group (untreated), Ti particles and TNF-alpha increased the gene expression of MMP-1, 2, 3 respectively (P < 0.05), and the effect of combination of the two was even more significant (P < 0.01). The trend of activities of MMP-2 is similar with gene expression. Ti particles and TNF-alpha increased MMP-2 activities by 1.3 times and 1.5 times respectively (P < 0.05), and the combination of the two increased by 1.7 times (P < 0.01). Ti particles and TNF-alpha-induced the stimulation of MMP-1, 2, 3 expressions and MMP-2 activities in human knee joint synovial cells may be involved in aseptic loosening after metal-on-metal arthroplasty through increasing the degradation of bone matrix and declining of osseous support structure mechanics.
Cells, Cultured ; Humans ; Joint Prosthesis ; Knee Joint ; cytology ; Matrix Metalloproteinase 1 ; genetics ; metabolism ; Matrix Metalloproteinase 2 ; genetics ; metabolism ; Matrix Metalloproteinase 3 ; genetics ; metabolism ; Matrix Metalloproteinases ; genetics ; metabolism ; Particle Size ; Prosthesis Failure ; adverse effects ; RNA ; genetics ; metabolism ; Synovial Membrane ; cytology ; enzymology ; Titanium ; pharmacology ; Tumor Necrosis Factor-alpha ; pharmacology

Background: and Purpose Recent studies suggested an increased incidence of cerebral venous thrombosis (CVT) during the coronavirus disease 2019 (COVID-19) pandemic. We evaluated the volume of CVT hospitalization and in-hospital mortality during the 1st year of the COVID-19 pandemic compared to the preceding year. Methods: We conducted a cross-sectional retrospective study of 171 stroke centers from 49 countries. We recorded COVID-19 admission volumes, CVT hospitalization, and CVT in-hospital mortality from January 1, 2019, to May 31, 2021. CVT diagnoses were identified by International Classification of Disease-10 (ICD-10) codes or stroke databases. We additionally sought to compare the same metrics in the first 5 months of 2021 compared to the corresponding months in 2019 and 2020 (ClinicalTrials.gov Identifier: NCT04934020). Results: There were 2,313 CVT admissions across the 1-year pre-pandemic (2019) and pandemic year (2020); no differences in CVT volume or CVT mortality were observed. During the first 5 months of 2021, there was an increase in CVT volumes compared to 2019 (27.5%; 95% confidence interval [CI], 24.2 to 32.0; P<0.0001) and 2020 (41.4%; 95% CI, 37.0 to 46.0; P<0.0001). A COVID-19 diagnosis was present in 7.6% (132/1,738) of CVT hospitalizations. CVT was present in 0.04% (103/292,080) of COVID-19 hospitalizations. During the first pandemic year, CVT mortality was higher in patients who were COVID positive compared to COVID negative patients (8/53 [15.0%] vs. 41/910 [4.5%], P=0.004). There was an increase in CVT mortality during the first 5 months of pandemic years 2020 and 2021 compared to the first 5 months of the pre-pandemic year 2019 (2019 vs. 2020: 2.26% vs. 4.74%, P=0.05; 2019 vs. 2021: 2.26% vs. 4.99%, P=0.03). In the first 5 months of 2021, there were 26 cases of vaccine-induced immune thrombotic thrombocytopenia (VITT), resulting in six deaths. Conclusions During the 1st year of the COVID-19 pandemic, CVT hospitalization volume and CVT in-hospital mortality did not change compared to the prior year. COVID-19 diagnosis was associated with higher CVT in-hospital mortality. During the first 5 months of 2021, there was an increase in CVT hospitalization volume and increase in CVT-related mortality, partially attributable to VITT.