Increased bone resorption that outpaces increased bone formation: An important pathology of rapidly destructive coxarthrosis

Rapid joint destruction caused by rapidly destructive coxarthrosis (RDC) can increase surgical complexity and intraoperative blood loss. This single-center retrospective study investigates osteoporosis-related biomarkers for early RDC diagnosis and explores new treatment targets. We included 398 hip joints from patients who underwent total hip arthroplasty, examining medical records for preoperative patient demographics, bone mineral density of the hip and lumbar spine from dual-energy X-ray absorptiometry scans, and osteoporosis-related biomarkers including TRACP-5b, total P1NP, intact parathyroid hormone, and homocysteine. We compared RDC and osteoarthritis (OA) patients, and univariate analysis showed that RDC patients were older (p < 0.001) and had lower serum levels of albumin (p < 0.001) and higher serum levels of TRACP-5b, total P1NP (p < 0.001), and homocysteine (p = 0.006). Multivariable analysis showed that the ratio of serum TRACP-5b to total P1NP had a more significant difference in RDC patients than in OA patients (p = 0.04). Serum TRACP-5b levels were negatively correlated with the time between RDC onset and blood collection, and Japanese Orthopedic Association pain score. Receiver operating characteristic curve analysis revealed that the ratio of serum TRACP-5b to total P1NP had the highest area under the curve value. This study is the first to demonstrate that the ratio of serum TRACP-5b to total P1NP-increased bone resorption that outpaces increased bone formation-is significantly elevated in patients with RDC and that TRACP-5b is higher in the early stages of RDC. Inhibiting serum levels of TRACP-5b, activated osteoclasts, during early RDC may suppress disease progression.

Factors determining the resection ability of snares in cold snare polypectomy: Construction of an ex vivo model for accurately evaluating resection ability

OBJECTIVES

Cold snare polypectomy (CSP)-dedicated snares (DSs) may have a higher resection ability than conventional snares. However, a model that can accurately and objectively evaluate and compare the resection ability of each snare has yet to be determined, and characteristics of snare parts that increase resection ability remain unknown. Therefore, we elucidated DSs' resection ability and all characteristics of the parts required for acquiring high resection ability.

METHODS

An ex vivo model for evaluating resection ability was generated using human colons obtained from forensic autopsy specimens. The force required to resect a 15 mm wide human colonic mucosa (FRR) was measured using this model; if the FRR is small, the resection ability is high. Next, after measuring the stiffness of each snare part, the correlation between the stiffness and resection ability was analyzed.

RESULTS

The force required to resect using SnareMaster Plus, Micro-Tech Cold Snare, Captivator Cold, Exacto Cold Snare, or Captivator II was 13.6 ± 1.0, 12.5 ± 1.2, 7.4 ± 1.2, 6.5 ± 1.0, and 28.7 ± 3.7 N, respectively. All DSs had significantly lower FRR than the conventional snare (Captivator II) and had higher resection ability (P < 0.001). A negative correlation was found between FRR and sheath or wire spindle stiffness, with correlation coefficients of 0.72 (P = 0.042) or 0.94 (P < 0.001), respectively. Moreover, 1 × 7 type wire rings had significantly higher friction coefficients than 1 × 3 type wire rings (P < 0.002).

CONCLUSION

Sheath and wire spindle stiffness should be increased to increase resection ability; 1 × 7 type wire rings may be suitable for CSP-snare parts.

Association of osteoporosis and high serum homocysteine levels with intraoperative periprosthetic fracture during total hip arthroplasty: a propensity-score matching analysis

INTRODUCTION

Intraoperative periprosthetic fracture, one of the most frequent complications of total hip arthroplasty, is a very important factor that affects rehabilitation, hospitalization time, and cost of treatment. Osteoporosis is common in total hip arthroplasty patients and likely contributes to the increasing incidence of periprosthetic fracture. Despite this awareness, preoperative and postoperative osteoporosis evaluations remain insufficient. The purpose of this study was to evaluate the relationships between the occurrence of intraoperative periprosthetic fractures and both bone mineral density (BMD) and osteoporosis-related biomarkers.

MATERIALS AND METHODS

This single-center retrospective study included a total of consecutive 487 hip joints of patients with a mean age of 65.5 ± 11.8 years who underwent total hip arthroplasty between July 2017 and December 2020. Patients with low BMD defined as T-score < -1.0 versus those with normal BMD were matched by a 1:1 propensity score to balance for patient baseline characteristics, and outcome was analyzed by a modified Poisson regression model. Our primary outcome was the incidence of intraoperative periprosthetic fracture during surgery. We also investigated the effect modification of osteoporosis-related biomarkers, including tartrate-resistant acid phosphatase 5b (TRACP-5b), total procollagen type 1 amino-terminal propeptide (total P1-NP), intact parathyroid hormone (intact PTH), and homocysteine, on osteoporosis and outcomes.

RESULTS

After matching, 250 patients were analyzed. The risk of fracture was significantly higher in patients with low BMD than in normal BMD patients (Incidence rate ratio 5.00 [95% CI 1.11-22.43], p = 0.036). We also observed significant effect of high serum homocysteine on the occurrence of intraoperative fractures (Incidence rate ratio 8.38 × 106 [95% C; 3.44 × 106-2.01 × 107], p < 0.01).

CONCLUSION

Preoperative osteoporosis and high serum homocysteine levels were risk factors for intraoperative periprosthetic fractures.

LEVEL OF EVIDENCE

III, A single-center retrospective study.

A resonant sextuplet of sub-Neptunes transiting the bright star HD 110067

Planets with radii between that of the Earth and Neptune (hereafter referred to as 'sub-Neptunes') are found in close-in orbits around more than half of all Sun-like stars1,2. However, their composition, formation and evolution remain poorly understood3. The study of multiplanetary systems offers an opportunity to investigate the outcomes of planet formation and evolution while controlling for initial conditions and environment. Those in resonance (with their orbital periods related by a ratio of small integers) are particularly valuable because they imply a system architecture practically unchanged since its birth. Here we present the observations of six transiting planets around the bright nearby star HD 110067. We find that the planets follow a chain of resonant orbits. A dynamical study of the innermost planet triplet allowed the prediction and later confirmation of the orbits of the rest of the planets in the system. The six planets are found to be sub-Neptunes with radii ranging from 1.94R⊕ to 2.85R⊕. Three of the planets have measured masses, yielding low bulk densities that suggest the presence of large hydrogen-dominated atmospheres.

Stabilization and compensation strategy of the hip angle during gait in hip-osteoarthritis patients from the perspective of whole-body movement synergy

BACKGROUND

The implementation of a strategy to control the hip angle during gait is important to avoid disease progression in patients with hip osteoarthritis (OA).

RESEARCH QUESTION

Do patients with hip OA tend to stabilize their hip angles by a combination of whole-body movements during gait in terms of variability?

METHODS

A public gait dataset comprising 80 asymptomatic participants and 106 patients with hip OA was used. Uncontrolled manifold analysis was performed using the joint angles as elemental variables and the hip joint angles as performance variables. The synergy index ΔV, variances of elemental variables that did not affect the performance variable (VUCM) and of those that affected the performance variable (VORT), and index of covariation strategy (COV) were calculated in sagittal and frontal plane. A one-sample t-test for statistical parametric mapping (SPM) analysis was used for ΔV and COV. Two-sample t-tests of SPM analyses were used for ΔV, VUCM, and VORT to compare the two groups.

RESULTS

In both planes, the ΔV and COV were significantly larger than zero in both groups (p < 0.001). In the sagittal plane, the VORT was higher in the hip OA group than in the control group after 77 % of stance phase. In the frontal plane, the hip OA group had larger ΔV and VUCM after last half and last quartile of stance phase compared to the control group, respectively. The VORT was smaller in the hip OA group than in the control group.

SIGNIFICANCE

The hip angle was stabilized in the hip OA group in the frontal plane but insufficiently stabilized in the sagittal plane; however, the patients changed their hip angle during the early phase of stance. The combination of whole-body movements contributed to the stabilization of hip angle.

Discovery of E2730, a novel selective uncompetitive GAT1 inhibitor, as a candidate for anti-seizure medication

OBJECTIVE

As of 2022, 36 anti-seizure medications (ASMs) have been licensed for the treatment of epilepsy, however, adverse effects (AEs) are commonly reported. Therefore, ASMs with a wide margin between therapeutic effects and AEs are preferred over ASMs that are associated with a narrow margin between efficacy and risk of AEs. E2730 was discovered using in vivo phenotypic screening and characterized as an uncompetitive, yet selective, inhibitor of γ-aminobutyric acid (GABA) transporter 1 (GAT1). Here, we describe the preclinical characteristics of E2730.

METHODS

Anti-seizure effects of E2730 were evaluated in several animal models of epilepsy: corneal kindling, 6 Hz-44 mA psychomotor seizure, amygdala kindling, Fragile X syndrome, and Dravet syndrome models. Effects of E2730 on motor coordination were assessed in accelerating rotarod tests. The mechanism of action of E2730 was explored by [3 H]E2730 binding assay. The GAT1-selectivity over other GABA transporters was examined by GABA uptake assay of GAT1, GAT2, GAT3, or betaine/GABA transporter 1 (BGT-1) stably expressing HEK293 cells. To further investigate the mechanism for E2730-mediated inhibition of GAT1, in vivo microdialysis and in vitro GABA uptake assays were conducted under conditions of different GABA concentrations.

RESULTS

E2730 showed anti-seizure effects in the assessed animal models with an approximately >20-‍fold margin between efficacy and motor incoordination. [3 H]E2730 binding on brain synaptosomal membrane was abolished in GAT1-deficient mice, and E2730 selectively inhibited GAT1-mediated GABA uptake over other GABA transporters. In addition, results of GABA uptake assays showed that E2730-mediated inhibition of GAT1 positively correlated to the level of ambient GABA in vitro. E2730 also increased extracellular GABA concentration in hyperactivated conditions but not under basal levels in vivo.

SIGNIFICANCE

E2730 is a novel, selective, uncompetitive GAT1 inhibitor, which acts selectively under the condition of increasing synaptic activity, contributing to a wide margin between therapeutic effect and motor incoordination.

Evaluation of Environmental Stability and Disinfectant Effectiveness for Human Coronavirus OC43 on Human Skin Surface

The environmental stability of human coronavirus OC43 (HCoV-OC43) on the surface of human skin and the effectiveness of disinfectant against HCoV-OC43, which are important to prevent contact transmission, have not been clarified in previous studies. Using previously generated models, we evaluated HCoV-OC43 stability and disinfection effectiveness. Then we compared the results with those for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The median survival time of HCoV-OC43 on the surface of human skin was 24.6 h (95% confidence interval, 19.7 to 29.6 h), which was higher than that of SARS-CoV-2 (10.8 h). Although the in vitro disinfectant effectiveness evaluation showed that HCoV-OC43 has a higher ethanol resistance than SARS-CoV-2, HCoV-OC43 on the skin surface was completely inactivated by a minimum of 50% ethanol within 5 s (the log reduction values were >4.0). Moreover, 1.0% chlorhexidine gluconate and 0.2% benzalkonium chloride showed relatively high disinfectant effectiveness, and the log reduction values when these disinfectants were applied for 15 s were >3.0. HCoV-OC43 is highly stable on the skin surface, which may increase the risk of contact transmission. Although HCoV-OC43 has relatively high ethanol resistance, appropriate hand hygiene practices with current alcohol-based disinfectants sufficiently reduce the risk of contact transmission. IMPORTANCE This study revealed the environmental stability of HCoV-OC43 and disinfectant effectiveness against HCoV-OC43, which had not been demonstrated in previous studies. HCoV-OC43 is highly stable on the surface of human skin, with a survival time of approximately 25 h. High stability of HCoV-OC43 may increase the risk of contact transmission. Furthermore, the in vitro disinfectant effectiveness evaluation showed that HCoV-OC43, which is classified as an envelope virus, has a relatively high ethanol resistance. This finding suggests that disinfectant effectiveness may vary greatly depending on the virus and that each virus targeted for infection control should be evaluated individually. HCoV-OC43 on the skin surface was rapidly inactivated by 50% ethanol, which suggests that appropriate hand hygiene practices with current alcohol-based disinfectants can sufficiently reduce the risk of HCoV-OC43 contact transmission.

Wear rate and osteolysis in two types of second-generation annealed highly cross-linked polyethylene in total hip arthroplasty: A retrospective comparative study with a minimum of five years

BACKGROUND

As no previous study has directly compared the linear wear rate in two types of second-generation annealed highly cross-linked polyethylene, we performed a retrospective study with a minimum of 5-year follow-up to assess primary arthroplasties in the (1) wear rates and (2) incidence of osteolysis of the two types of HXLPE.

HYPOTHESIS

There was no significant difference in the linear wear rate and the incidence of osteolysis between the two types of second-generation annealed highly cross-linked polyethylene.

PATIENTS AND METHODS

In this single-center study, we reviewed 257 cases of primary cementless total hip arthroplasties between 2011 and 2015, which were performed with 32mm delta ceramic on second-generation annealed highly cross-linked polyethylene (X3 and E1 were used in 105 and 103 cases, respectively.). The mean wear rate was evaluated using a computer-assisted method, and the incidence of osteolysis was evaluated based on the appearance of a localized area with loss of trabecular bone or cortical erosion adjacent to the implants during the latest follow-up.

RESULTS

In total, we evaluated 208 cases, followed postoperatively for over 5 years (mean, 6.1 years, range: 5.0-8.0). There were no significant differences between the two groups with respect to age (list in order of Group X, Group E, p value) (61.2±12.3, 62.7±12.1, p=0.36), sex (ratio of male: 17.1%, 14.6%, p=0.61), body mass index (22.9±3.7, 22.8±4.0, p=0.91), pre- (49.9±14.8, 48.5±13.8, p=0.49) and post-operative (91.3±9.1, 92.7±7.0, p=0.23) Japanese Orthopaedic Association Hip Score, cup size (50.8±3.0, 50.9±2.2, p=0.70), cup inclination (38.7±4.8, 37.6±4.8, p=0.10), and cup anteversion (18.7±6.9, 18.5±7.6, p=0.80). The mean linear wear rates of the X3 and E1 groups were 0.057±0.039 (range: 0-0.16) and 0.054±0.037mm/year (range: 0-0.15), respectively (p=0.61). No osteolysis was found on the final plain radiographs in both groups.

DISCUSSION

This study revealed that both types of highly cross-linked polyethylene have excellent linear wear rates and were equally safe to use. However, the difference between the two materials in terms of the long-term wear rate should be further validated.

LEVEL OF EVIDENCE

III; retrospective case control study.

The prevalence and treatment of osteoporosis in patients undergoing total hip arthroplasty and the levels of biochemical markers of bone turnover

AIMS

Osteoporosis is common in total hip arthroplasty (THA) patients. It plays a substantial factor in the surgery's outcome, and previous studies have revealed that pharmacological treatment for osteoporosis influences implant survival rate. The purpose of this study was to examine the prevalence of and treatment rates for osteoporosis prior to THA, and to explore differences in osteoporosis-related biomarkers between patients treated and untreated for osteoporosis.

METHODS

This single-centre retrospective study included 398 hip joints of patients who underwent THA. Using medical records, we examined preoperative bone mineral density measures of the hip and lumbar spine using dual energy X-ray absorptiometry (DXA) scans and the medications used to treat osteoporosis at the time of admission. We also assessed the following osteoporosis-related biomarkers: tartrate-resistant acid phosphatase 5b (TRACP-5b); total procollagen type 1 amino-terminal propeptide (total P1NP); intact parathyroid hormone; and homocysteine.

RESULTS

The prevalence of DXA-proven hip osteoporosis (T-score ≤ -2.5) among THA patients was 8.8% (35 of 398). The spinal osteoporosis prevalence rate was 4.5% (18 of 398), and 244 patients (61.3%; 244 of 398) had osteopenia (-2.5 < T-score ≤ -1) or osteoporosis of either the hip or spine. The rate of pharmacological osteoporosis treatment was 22.1% (88 of 398). TRACP-5b was significantly lower in the osteoporosis-treated group than in the untreated group (p < 0.001).

CONCLUSION

Osteoporosis is common in patients undergoing THA, but the diagnosis and treatment for osteoporosis were insufficient. The lower TRACP-5b levels in the osteoporosis-treated group - that is, osteoclast suppression - may contribute to the reduction of the postoperative revision rate after THA.Cite this article: Bone Joint Res 2022;11(12):873-880.

Relationship among airborne pollen, sensitization, and pollen food allergy syndrome in Asian allergic children

Background

Causes of pediatric pollen food allergy syndrome (PFAS) differ depending on airborne pollen levels in a particular region. We aimed to analyze airborne pollen counts, IgE sensitization rates, and PFAS incidence among children with allergies in South Korea and Japan.

Methods

This cross-sectional study included children aged 5-17 years with allergies in 2017. Airborne pollen samples were collected from Busan in South Korea, and Fukuoka and Tochigi in Japan. Questionnaires were used to assess bronchial asthma, seasonal allergic rhinitis, atopic dermatitis, food allergy, and PFAS. The serum IgE specific to Dermatophagoides pteronyssinus, pollen, tomato, and peach were investigated.

Results

In total, 57, 56, and 20 patients from Busan, Fukuoka, and Tochigi, respectively, were enrolled. Airborne Japanese cedar and cypress pollen were predominant in Fukuoka and Tochigi, whereas pine and alder pollen were predominant in Busan. Children with allergies in Fukuoka and Tochigi had a significantly higher sensitization rate to Japanese cedar, cypress, juniper, orchard grass, ragweed, Japanese hop, and tomato compared with children in Busan. In Fukuoka and Tochigi, where Japanese cedar and cypress pollen were frequently scattered, high sensitizations among allergic children were observed. The sensitization rate was not affected by the pollen count in alder, grass, ragweed, and Japanese hop. In multivariable analysis, only alder sensitization was found to be associated with PFAS (odds ratio: 6.62, 95% confidence interval: 1.63-26.87, p = 0.008). In patients with PFAS in Busan and Tochigi, peach associated with birch allergen Bet v 1 was a causative food item for PFAS. Moreover, PFAS was associated with ragweed and Japanese hop pollen sensitization in Fukuoka.

Conclusion

Regardless of pollen counts, alder pollen sensitization was associated with PFAS in children. Ragweed and Japanese hop pollen sensitization were associated with PFAS, particularly among children in southern Japan.

Short stature and short distance between the anterior acetabular rim to the femoral nerve are risk factors for femoral nerve palsy following primary total hip arthroplasty using the modified Watson-Jones approach

BACKGROUND

Nerve palsy following total hip arthroplasty (THA) critically impacts patient clinical function. However, few studies have focused on femoral nerve palsy (FNP) following THA via the modified Watson-Jones approach. Previous reports have suggested that THA, regardless of the approach, is associated with several FNP risk factors, including female gender, hip dysplasia, revision surgery, and short stature. Magnetic resonance imaging (MRI) has suggested that a shorter distance between the femoral nerve and the anterior acetabular edge (dFN) is related to FNP after THA. The purposes of this study were: 1) to determine the presumed risk factors through a retrospective investigation of FNP clinical courses, and 2) to identify the relationships between FNP occurrence and the short dFN following primary THA via the modified Watson-Jones approach.

HYPOTHESIS

Short stature is a risk factor for femoral nerve palsy following THA. i.e. a significant difference in dFN exists between patients with and without FNP.

PATIENTS AND METHODS

This retrospective case-control study was performed at a single university hospital. From January 2016 to December 2020, 676 THAs were performed via the modified Watson-Jones approach at our institution. These included 495 THAs performed in the supine position and 181 in the lateral position. In this study, FNP was defined as weakness of the quadriceps femoris (manual muscle test<grade 3) with or without sensory disturbance over the anteromedial aspect of the thigh. The incidence of FNP was calculated. Patient background factors (age, sex, preoperative diagnosis, surgical position, height, weight, body mass index, surgeon experience, type of components, the method of anesthesia, leg lengthening during the surgery, and operation time) were compared between the FNP group and a non-FNP control group. The dFN was measured in T1-weighted MRI axial images at the level of the hip center. The distance between the femoral nerve and the anterior acetabular edges, where retractors are commonly placed during surgery, was also measured and compared between the FNP group and the non-FNP control group. The FNP group and non-FNP control group were extracted by 1:4 matching of patient height and weight. All data were statistically evaluated using the Mann-Whitney U test, and p values less than 0.05 were considered statistically significant.

RESULTS

FNP occurred in 6 out of 676 joints (0.88%) following primary THA via the modified Watson-Jones approach. In all 6 cases, the motor deficit recovered completely within a year. Patient height was significantly shorter in the FNP group than in the non-FNP control group (148.4±3.3cm vs. 155.4±8.1cm [p=0.01]). The dFN was significantly shorter in the FNP group (16.3±4.1mm vs. 21.5±4.0mm [p=0.034]).

CONCLUSION

Short stature and short dFN are risk factors for FNP after THA using the modified Watson-Jones approach.

LEVEL OF EVIDENCE

III, case-control study.

Normal and Range Value Evaluations Using Heart Risk View-Function Based on the Japanese Societyof Nuclear Medicine Working Group Database

Background: Gated myocardial perfusion single-photon emission computed tomography (SPECT) has been used to non-invasively evaluate the left ventricular (LV) volume and function. This study aimed to measure the normal and range values for heart risk view-function (HRV-F) software using the Japanese Society of Nuclear Medicine Working Group (JSNM-WG) normal database and clarify the characteristics of the normal database. Methods:We used 206 myocardial perfusion short-axis images from the normal database. Ejection fraction (EF), end-systolic volume (ESV), end-diastolic volume (EDV), peak filling rate (PFR), 1/3 mean filling rate (MFR), time to PFR (TTPF), and TTPF divided by RR interval (TPFR/RR) were calculated. Phase parameters of 95% histogram bandwidth and standard deviation were also computed using the phase analysis. The relationships among phase parameters, LV volumes, and body surface area (BSA) were evaluated in the age group of ≤65 years. Results: Higher EF was observed in females than in males (p<0.0001). EDV and ESV were significantly higher in males than in females (p<0.0001). Additionally, PFR and 1/3 MFR significantly differed between sexes (p≤0.075). Phase parameters were higher in males than in females, and higher at stress than at rest. All diastolic parameters showed no significant differences between sexes in any age group, whereas differences have remained in phase values. Phase parameters were weakly correlated with EDV (r=0.31), ESV (r=0.43), and BSA (r=0.27), respectively. Conclusions: Mean normal and range values of the normal database were determined using the HRV-F software. The normal and range values can help diagnose gated SPECT data in patients with cardiac diseases.

Vision Feedback Control for the Automation of the Pick-and-Place of a Capillary Force Gripper

In this paper, we describe a newly developed vision feedback method for improving the placement accuracy and success rate of a single nozzle capillary force gripper. The capillary force gripper was developed for the pick-and-place of mm-sized objects. The gripper picks up an object by contacting the top surface of the object with a droplet formed on its nozzle and places the object by contacting the bottom surface of the object with a droplet previously applied to the place surface. To improve the placement accuracy, we developed a vision feedback system combined with two cameras. First, a side camera was installed to capture images of the object and nozzle from the side. Second, from the captured images, the contour of the pre-applied droplet for placement and the contour of the object picked up by the nozzle were detected. Lastly, from the detected contours, the distance between the top surface of the droplet for object release and the bottom surface of the object was measured to determine the appropriate amount of nozzle descent. Through the experiments, we verified that the size matching effect worked reasonably well; the average placement error minimizes when the size of the cross-section of the objects is closer to that of the nozzle. We attributed this result to the self-alignment effect. We also confirmed that we could control the attitude of the object when we matched the shape of the nozzle to that of the sample. These results support the feasibility of the developed vision feedback system, which uses the capillary force gripper for heterogeneous and complex-shaped micro-objects in flexible electronics, micro-electro-mechanical systems (MEMS), soft robotics, soft matter, and biomedical fields.

Neuroprotective activity of a virus-safe nanofiltered human platelet lysate depleted of extracellular vesicles in Parkinson's disease and traumatic brain injury models

Brain administration of human platelet lysates (HPL) is a potential emerging biotherapy of neurodegenerative and traumatic diseases of the central nervous system. HPLs being prepared from pooled platelet concentrates, thereby increasing viral risks, manufacturing processes should incorporate robust virus-reduction treatments. We evaluated a 19 ± 2-nm virus removal nanofiltration process using hydrophilic regenerated cellulose hollow fibers on the properties of a neuroprotective heat-treated HPL (HPPL). Spiking experiments demonstrated >5.30 log removal of 20-22-nm non-enveloped minute virus of mice-mock particles using an immuno-quantitative polymerase chain reaction assay. The nanofiltered HPPL (NHPPL) contained a range of neurotrophic factors like HPPL. There was >2 log removal of extracellular vesicles (EVs), associated with decreased expression of pro-thrombogenic phosphatidylserine and procoagulant activity. LC-MS/MS proteomics showed that ca. 80% of HPPL proteins, including neurotrophins, cytokines, and antioxidants, were still found in NHPPL, whereas proteins associated with some infections and cancer-associated pathways, pro-coagulation and EVs, were removed. NHPPL maintained intact neuroprotective activity in Lund human mesencephalic dopaminergic neuron model of Parkinson's disease (PD), stimulated the differentiation of SH-SY5Y neuronal cells and showed preserved anti-inflammatory function upon intranasal administration in a mouse model of traumatic brain injury (TBI). Therefore, nanofiltration of HPL is feasible, lowers the viral, prothrombotic and procoagulant risks, and preserves the neuroprotective and anti-inflammatory properties in neuronal pre-clinical models of PD and TBI.

Differences in environmental stability among SARS-CoV-2 variants of concern: Both Omicron BA.1 and BA.2 have higher stability

Objectives

The increased infectivity and transmissibility of SARS-CoV-2 variants of concern (VOCs) could cause significant human and economic damage. Hence, understanding their characteristics is crucial to control infection. We evaluated the environmental stability of the Wuhan strain and all VOCs (Alpha, Beta, Gamma, Delta, Omicron BA.1, and Omicron BA.2 variants) on plastic and human skin surfaces and their disinfection efficacy.

Methods

To evaluate environmental stability, residual virus titres on plastic and human skin surfaces were measured over time. Their survival time and half-life were calculated using regression analysis. The effectiveness of ethanol-based disinfectants at different concentrations was determined by in vitro and ex vivo evaluations.

Results

On plastic and skin surfaces, the Alpha, Beta, Delta, and Omicron variants exhibited approximately two-fold longer survival times than the Wuhan strain; the Omicron variants had the longest survival time. The median survival times of the Wuhan strain and the Alpha, Beta, Gamma, Delta, and Omicron (BA.1 and BA.2) variants on human skin surface were 8.6, 19.6, 19.1, 11.0, 16.8, 21.1, and 22.5 h, respectively. The in vitro evaluation showed that the Wuhan strain and the Alpha, Beta, Gamma, Delta, and Omicron (BA.1 and BA.2) variants were completely inactivated within 15 s by 32.5%, 35%, 35%, 32.5%, 35%, 40%, and 40% ethanol, respectively. However, all viruses on human skin were completely inactivated by exposure to 35% ethanol for 15 s.

Conclusions

SARS-CoV-2 VOCs, especially the Omicron variants, have higher environmental stability than the Wuhan strain, increasing their transmission risk and contributing to their spread.

Design, Synthesis, and Optoelectronic Properties of the High-Purity Phase in Layered AETMN2 (AE = Sr, Ba; TM = Ti, Zr, Hf) Semiconductors

We report the synthesis and optoelectronic properties of high phase-purity (>94 mol %) bulk polycrystals of KCoO₂-type layered nitrides AETMN₂ (AE = Sr, Ba; and TM = Ti, Zr, Hf), which are expected to exhibit unique electron transport properties originating from their natural two-dimensional (2D) electronic structure, but high-purity intrinsic samples have yet been reported. The bulks were synthesized using a solid-state reaction between AENH and TMN precursors with NaN₃ to achieve high N chemical potential during the reaction. The AETMN₂ bulks are n-type semiconductors with optical band gaps of 1.63 eV for SrTiN₂, 1.97 eV for BaZrN₂, and 2.17 eV for BaHfN₂. SrTiN₂ and BaZrN₂ bulks show degenerated electron conduction due to the natural high-density electron doping and paramagnetic behavior in all of the temperature ranges examined, while such unintentional carrier generation is largely suppressed in BaHfN₂, which exhibits nondegenerated electron conduction. The BaHfN₂ sample also exhibits weak ferromagnetic behavior at temperatures lower than 35 K. Density functional theory calculations suggest that the high-density electron carriers in SrTiN₂ come from oxygen impurity substitution at the N site (O_N) acting as a shallow donor even if the high-N chemical potential synthesis conditions are employed. On the other hand, the formation energy of O_N becomes larger in BaHfN₂ because of the stronger TM-N chemical bonds. Present results demonstrate that the easiness of impurity incorporation is designed by density functional calculations to produce a more intrinsic semiconductor in wider chemical conditions, opening a way to cultivating novel functional materials that are sensitive to atmospheric impurities and defects.

Higher Viral Stability and Ethanol Resistance of Avian Influenza A(H5N1) Virus on Human Skin

Evaluating the stability of highly pathogenic avian influenza viruses on human skin and measuring the effectiveness of disinfectants are crucial for preventing contact disease transmission. We constructed an evaluation model using autopsy skin samples and evaluated factors that affect the stability and disinfectant effectiveness for various subtypes. The survival time of the avian influenza A(H5N1) virus on plastic surfaces was ≈26 hours and on skin surfaces ≈4.5 hours, >2.5-fold longer than other subtypes. The effectiveness of a relatively low ethanol concentration (32%–36% wt/wt) against the H5N1 subtype was substantially reduced compared with other subtypes. Moreover, recombinant viruses with the neuraminidase gene of H5N1 survived longer on plastic and skin surfaces than other recombinant viruses and were resistant to ethanol. Our results imply that the H5N1 subtype poses a higher contact transmission risk because of its higher stability and ethanol resistance, which might depend on the neuraminidase protein.

Evaluation of the Residual Disinfection Effects of Commonly Used Skin Disinfectants against Viruses: An Innovative Contact Transmission Control Method

Lasting disinfection effects, that is, the residual disinfection effects (RDEs), of skin-coated disinfectants have rarely been considered for infection control owing to the challenges involved in the accurate evaluation of RDEs. In this study, we constructed a new skin evaluation model and determined the RDEs of existing disinfectants against viruses. Our results showed that ethanol and isopropanol had no RDE, whereas povidone-iodine, chlorhexidine gluconate, and benzalkonium chloride (BAC) exhibited RDEs, with 10% povidone-iodine and 0.2% BAC showing particularly strong RDEs. The RDE of 0.2% BAC was strong enough to reduce the median survival times of severe acute respiratory syndrome coronavirus-2, human coronavirus-OC43, and influenza virus from 670 to 5.2, 1300 to 12, and 120 to 4.2 min, respectively. Additionally, this strong RDE was maintained even 4 h after coating the skin. Clinical data also showed that the strong RDE of 0.2% BAC was maintained for more than 2 h. Thus, applying disinfectants with strong RDEs on the skin correlates with a reduction in virus survival time and appears to create a skin surface environment that is not conducive to virus survival. A prolonged reduction in virus survival decreases the contact transmission risk, thereby enabling stronger infection control.

The effectiveness of strict low-density lipoprotein cholesterol management in secondary prevention of Japanese patients

Background

In Japanese guidelines, target value of low-density lipoprotein cholesterol (LDL-C) &lt;100mg/dL is recommended as standard management for secondary prevention of coronary artery disease. On the other hand, the guidelines also state that LDL-C targeting &lt;70mg/dL should be considered in high-risk patients. However, the effectiveness of strict LDL-C management in the prevention of long-term coronary event recurrence in Japanese patients remains unclear.

Purpose

The purpose of the present study was to evaluate whether the strict management of LDL-C targeting &lt;70 mg/dL was effective to prevent recurrence of acute coronary syndrome (ACS) than standard management in patients with previous percutaneous coronary intervention (PCI).

Methods

From January 2007 to August 2020, we performed coronary angiography in 359 patients with previous PCI who were suspected of having signs of recurrent cardiac ischemia. Patients were stratified into three groups according to achieved LDL-C value; &lt;70mg/dL (n=57), 70 to &lt;100mg/dL (n=135) and ≥100mg/dL (n=167). In addition, patients who had previous ACS and/or diabetes mellitus were defined as high-risk group, and sub-analysis by their achieved LDL-C values was performed in high-risk group and non-high-risk group. Endpoint was recurrence of ACS. Moreover, risk factors associated with recurrent-ACS were examined in patients with LDL-C &lt;100 mg/dL.

Results

After follow-up (median 6.1 years), 99 patients (28%) had recurrent-ACS. Recurrent-ACS was significantly lower in patients with LDL-C &lt;70mg/dL than LDL-C 70 to &lt;100mg/dL and LDL-C ≥100mg/dL (p&lt;0.01 and p&lt;0.001, respectively). In sub-analysis, high-risk group with LDL-C &lt;70 mg/dL had lower incidence of recurrent-ACS than LDL-C 70 to &lt;100 mg/dL (p=0.03). Similar tendency was found in non-high-risk group (p=0.08). There was no difference of recurrent-ACS between high-risk group and non-high-risk group in patients with LDL-C &lt;70mg/dL (p=0.41). Moreover, in patients with achieved LDL-C &lt;100mg/dL (n=192), multivariate analysis identified that LDL-C (HR: 1.032, p&lt;0.01) and HbA1c (HR: 1.330, p&lt;0.01) were independent predictors of recurrent-ACS. In these patients, whether or not they were in the high-risk group was not a significant predictor (p=0.61).

Conclusions

Strict management of LDL-C targeting &lt;70 mg/dL should be considered for a wider range of Japanese patients as well as for Westerners to prevent recurrence of ACS in secondary prevention.

Funding Acknowledgement

Type of funding sources: None. Probability of freedom from ACS

Comparison of sodium alginate-based and sodium hyaluronate-based submucosal injection materials based on rheological analysis

As a viscous high-performance submucosal injection material (SIM) used in endoscopic submucosal dissection (ESD), sodium alginate-based SIM (SA-SIM) was recently introduced as high-performance SIM equivalent to sodium hyaluronate-based SIM (HA-SIM) in Japan. However, a comprehensive, detailed comparison of SA and HA is yet to be performed. In this study, we precisely measured the viscoelastic properties, submucosal elevation height (SEH), and injection pressure (IP). Furthermore, we compared the outcomes of ESD using an ex vivo ESD model. There was no significant difference in SEHs between HA-SIM and SA-SIM at all post-injection times, and the IP of the SA-SIM injection was significantly higher than that of the HA-SIM injection in all conditions (P < 0.0001). The viscosity at high shear rates of SA-SIM was higher than that of HA-SIM; this result was consistent with SEH/IP measurement results. No significant difference was observed in ESD procedure time and total volume of injected SIM between HA-SIM and SA-SIM (18.1 ± 6.7 and 17.8 ± 6.0 min, P = 0.8987; 13.3 ± 5.3 and 11.6 ± 5.9 ml, P = 0.4658, respectively). Although SA-SIM was slightly more difficult to inject than HA-SIM, there was no significant difference in performance between the materials. Thus, this basic study demonstrated that SA-SIM can be used for endoscopic treatment as well as HA-SIM, and supported previous clinical research data.

Removal of minute virus of mice-mock virus particles by nanofiltration of culture growth medium supplemented with 10% human platelet lysate

BACKGROUND AIMS

Platelet concentrates (PCs) are pooled to prepare human platelet lysate (HPL) supplements of growth media to expand primary human cells for transplantation; this increases the risk of contamination by known, emerging, and unknown viruses. This possibility should be of concern because viral contamination of cell cultures is difficult to detect and may have detrimental consequences for recipients of cell therapies. Viral reduction treatments of chemically defined growth media have been proposed, but they are not applicable when media contain protein supplements currently needed to expand primary cell cultures. Recently, we successfully developed a Planova 35NPlanova 20N nanofiltration sequence of growth media supplemented with two types of HPL. The nanofiltered medium was found to be suitable for mesenchymal Stromal cell (MSC) expansion.

METHODS

Herein, we report viral clearance achieved by this nanofiltration process used for assessing a new experimental model using non-infectious minute virus of mice-mock virus particle (MVM-MVP) and its quantification by an immunoqPCR. Then, high doses of MVM-MVP (1012 MVPs/mL) were spiked to obtain a final concentration of 1010 MVPs/mL in Planova 35N-nanofiltered growth medium supplemented with both types of HPLs [serum converted platelet lysate SCPL) and intercept human platelet lysate (I-HPL)] at 10% (v/v) and then filtering through Planova 20N.

RESULTS

No substantial interference of growth medium matrices by the immune-qPCR assay was first verified. Log reduction values (LRVs) were ≥ 5.43 and ≥ 5.36 respectively, SCPL and I-HPL media. MVM-MVPs were also undetectable by dynamic light scattering and transmission electron microscopy.

CONCLUSIONS

The nanofiltration of growth media supplemented with 10% HPL provides robust removal of small nonenveloped viruses, and is an option to improve the safety of therapeutic cells expanded using HPL supplements.

Disinfectant effectiveness against SARS-CoV-2 and influenza viruses present on human skin: model-based evaluation

OBJECTIVES

Disinfection effectiveness against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on human skin remains unclear because of the hazards of viral exposure. An evaluation model, which has been previously generated using human skin obtained from forensic autopsy samples, accurately mimics in vivo skin conditions for evaluating the effectiveness of disinfection against the virus. Using this model, we evaluated disinfection effectiveness against viruses on human skin.

METHODS

Ethanol (EA), isopropanol (IPA), chlorhexidine gluconate (CHG) and benzalkonium chloride (BAC) were used as target disinfectants. First, disinfectant effectiveness against SARS-CoV-2 and influenza A virus (IAV) was evaluated in vitro. Disinfectant effectiveness against SARS-CoV-2 and IAV on human skin was then evaluated by titrating viruses present on the skin after applying each disinfectant on the skin for 5-60 seconds.

RESULTS

Both, SARS-CoV-2 and IAV on human skin were completely inactivated within 5 seconds by 40%-80% EA and 70% IPA (log reduction values (LRVs) were >4). However, SARS-CoV-2 and IAV were barely inactivated by 20% EA (LRVs were <1). In vitro evaluation showed that, compared with EA and IPA, CHG and BAC were significantly inferior in terms of disinfection effectiveness. Conversely, the disinfection effectiveness of CHG and BAC against SARS-CoV-2 was higher on human skin than in vitro, and increased with increases in their concentration and reaction time (LRVs of 0.2% CHG/0.05% BAC were >2, and LRVs of 1.0% CHG/0.2% BAC were >2.5).

CONCLUSIONS

Proper hand hygiene practices using alcohol-based disinfectants such as EA/IPA effectively inactivate SARS-CoV-2 and IAV on human skin.

Difference in tapered wedge stem alignment between supine and lateral position in cementless total hip arthroplasty via modified Watson-Jones anterolateral approach

BACKGROUND

Whether different body positions during surgery affect postoperative stem alignment in total hip arthroplasty (THA) remains unclear. The purpose of this study was to clarify differences in tapered wedge stem alignment between supine and lateral positions in THA under the modified Watson-Jones anterolateral approach.

METHODS

We reviewed 242 consecutive, primary cementless THAs performed with ceramic-on-cross-linked polyethylene via the modified Watson-Jones approach in either supine or lateral positions between 2009 and 2015 (supine group: 113 cases; lateral group: 129 cases). No specific reasons to select supine or lateral positions for the surgery were given during the study period. Computed tomography was performed pre- and postoperatively to measure preoperative femoral anteversion and postoperative stem anteversion, respectively. Stem alignment in coronal and sagittal planes was also evaluated.

RESULTS

Mean difference in stem anteversion and femoral anteversion was 8.6 ± 9.4 in the supine position and 13.0 ± 11.4 in the lateral position (p = 0.0013). Although no significant difference was seen between groups for stem alignment in the coronal plane, flexed implantation was more likely in the supine group (46/113, 40.7%) than in the lateral group (20/129, 15.5%). A significant correlation was found between femoral anteversion and stem anteversion in both the supine and lateral groups (r = 0.68, p < 0.0001 and r = 0.52, p < 0.0001, respectively).

CONCLUSION

Although stem anteversion was more strongly correlated with femoral anteversion in the supine position than in the lateral position, neutral position in the sagittal plane was more likely to be found with the lateral position than with the supine position. Surgeons can achieve ideal stem positioning by considering these results in the modified Watson-Jones approach in both the supine and lateral positions.

The β-Secretase BACE1 in Alzheimer's Disease

BACE1 (beta-site amyloid precursor protein cleaving enzyme 1) was initially cloned and characterized in 1999. It is required for the generation of all monomeric forms of amyloid-β (Aβ), including Aβ₄₂, which aggregates into bioactive conformational species and likely initiates toxicity in Alzheimer's disease (AD). BACE1 concentrations and rates of activity are increased in AD brains and body fluids, thereby supporting the hypothesis that BACE1 plays a critical role in AD pathophysiology. Therefore, BACE1 is a prime drug target for slowing down Aβ production in early AD. Besides the amyloidogenic pathway, BACE1 has other substrates that may be important for synaptic plasticity and synaptic homeostasis. Indeed, germline and adult conditional BACE1 knockout mice display complex neurological phenotypes. Despite BACE1 inhibitor clinical trials conducted so far being discontinued for futility or safety reasons, BACE1 remains a well-validated therapeutic target for AD. A safe and efficacious compound with high substrate selectivity as well as a more accurate dose regimen, patient population, and disease stage may yet be found. Further research should focus on the role of Aβ and BACE1 in physiological processes and key pathophysiological mechanisms of AD. The functions of BACE1 and the homologue BACE2, as well as the biology of Aβ in neurons and glia, deserve further investigation. Cellular and molecular studies of BACE1 and BACE2 knockout mice coupled with biomarker-based human research will help elucidate the biological functions of these important enzymes and identify their substrates and downstream effects. Such studies will have critical implications for BACE1 inhibition as a therapeutic approach for AD.

[A CASE OF BIRD-RELATED HYPERSENSITIVITY PNEUMONITIS THAT DEVELOPED IN SUBACUTE COURSE AND PRESENTED WITH ACUTE FINDINGS]

A 52-year-old woman presented to a clinic in late August with exacerbated fatigue and dyspnea on exertion for several months. Then, she was referred and admitted to our hospital in late September. Her chest CT showed bilateral diffuse centrilobular micronodules. In her detailed clinical history, she had kept budgerigars indoors for 15 years. These findings suggested she had a bird-related hypersensitivity pneumonitis (BRHP). By a site environmental investigation, 40 budgerigars were kept in a single breeding room and there were large amounts of droppings on the floor. Serum specific antibody for bird antigens and an environmental provocation test were positive. Bronchoalveolar lavage fluid showed lymphocytosis and a low CD4/CD8 ratio. Trans-bronchial lung biopsy showed lymphocytic infiltration of the alveolar wall and interlobular septa. After antigen avoidance as hospitalization, her symptoms and abnormal shadow improved. From these results, the patient was diagnosed as an acute BRHP.BRHP often presents a chronic onset. This case was diagnosed as an acute type despite the 15-years of budgerigars breeding. Increased exposure of antigens due to lack of cleaning after several days' antigen avoidance was suspected with one of the causes of acute onset.

Differences between two sodium hyaluronate-based submucosal injection materials currently used in Japan based on viscosity analysis

In Japan, two 0.4% sodium hyaluronate (HA)-based submucosal injection materials (SIMs) are currently used in endoscopic submucosal dissection (ESD): MucoUp (HA-Mc) and Ksmart (HA-Ks). HA-Mc and HA-Ks have the same concentration and are, thus, construed by most endoscopists to have no difference. Nevertheless, visual observation conveys the impression that HA-Ks have a higher viscosity than HA-Mc, suggesting that HA-Ks performs better than HA-Mc. This study aimed to examine the differences between HA-Mc and HA-Ks. HA-Ks exhibited higher viscosity due to greater weight-average molecular weight compared with HA-Mc. HA-Ks had significantly greater submucosal elevation height (SEH) than HA-Mc; the SEH of HA-Ks-80% (80% dilution of HA-Ks) was the same as that of HA-Mc. The ESD procedure time was significantly shorter with HA-Ks than with HA-Mc (15.2 ± 4.1 vs. 19.5 ± 5.9; P = 0.049). The total injection volume for HA-Ks was significantly lower than that for HA-Mc (10.8 ± 3.6 vs. 14.4 ± 4.6; P = 0.045). However, no significant difference in these items was observed between HA-Mc and HA-Ks-80%. HA-Mc and HA-Ks were considered to be almost the same. Nonetheless, HA-Ks exhibited higher viscosity and SIM performance than HA-Mc. HA-Ks-80% had almost the same performance as HA-Mc. Thus, understanding SIM performance and characteristics requires a focus on the viscosity of SIMs.

Synovial mesenchymal stem cells promote the meniscus repair in a novel pig meniscus injury model

Stem cell therapy has potential for the treatment of degenerative meniscus injuries; however, an optimal animal model has not been established. Basic and clinical research show that synovial mesenchymal stem cells (MSCs) promote meniscus repair. The purposes of this study were to create a novel meniscus injury model in microminipigs and to investigate the effectiveness of synovial MSCs on meniscus healing in this model. The posterior portion of the medial meniscus in microminipigs was punctuated 200 times with a 23G needle. Allogenic synovial MSC suspension was placed on the injury site for 10 min for transplantation. The meniscus was evaluated histologically and via sagittal magnetic resonance imaging (MRI), radial MRI reconstructed in three dimensional, and T2 mapping at 1 and 8 weeks. Proteoglycan content stained with safranin-o disappeared 1 week after treatment in both the MSC and control groups but increased at 8 weeks only in the MSC group. Histological scores at 8 weeks were significantly higher in the MSC group than in the control group (n = 6). At 8 weeks, the T2 values of the MSC group were significantly closer to those of a normal meniscus than were those of the control group. High signal intensity areas of the MRIs and positive areas stained with picrosirius red coincided with meniscal lesions. In conclusion, we created a novel meniscus injury model in microminipigs. Evaluation via histology, MRIs, and polarized microscopy showed that transplantation of synovial MSCs improved meniscus healing.

Long-year follow-up of acute myocardial infarction with preserved initial LVEF: prognostic impact of progressively reduced LVEF

Background

Severely reduced left ventricular ejection fraction (LVEF ≤35%) is commonly seen in approximately 5% of the myocardial infarction (MI) survivors in its acute-phase, which is recognized as a risk factor of post-MI cardiac death. However, clinical incidence and risk factor of the progressively reduced LVEF in the chronic-phase after MI has not been clarified.

Purpose

To evaluate clinical incidence and risk factor of the progressively reduced LVEF in the chronic-phase after MI by serial echocardiography.

Method

We evaluated 1144 consecutive patients with acute MI with preserved LVEF (≥50%) in acute-phase. Primary outcome was severely reduced LVEF (&lt;35%) in the chronic-pahse. We analyzed the predictive factor using multivariate analysis.

Result

During follow-up (median:1097 days), severely reduced LVEF newly developed in 8.6% of AMI survivors. Kaplan-meier curve is shown in the Figure. Multivariate analysis showed that men, eGFR &lt;30, AMI of LAD and absence of renin-angiotensin system blocking drugs was an independent predictor of severely reduced LVEF.

Conclusions

Progressively reduced LVEF during chronic-phase occurred 8.6% in acute MI survivors with preserved initial LVEF. Especially patients with these risk factors, careful long-term follow-up after MI should be needed to identify possible candidate for the implantable cardioverter-defibrillator.

Figure 1

Funding Acknowledgement

Type of funding source: None

Effectiveness of more strict managements after achievement of standard target value of low-density lipoprotein cholesterol in secondary prevention of Japanese patients

Background

In secondary prevention of coronary artery disease, target value of low-density lipoprotein cholesterol (LDL-C) &lt;100 mg/dL is recommended as standard management in Japanese guideline. The guideline also stated that strict management of LDL-C targeting &lt;70 mg/dL is considered in some high risk patients. However, in Japanese patients, effectiveness of more strict management of LDL-C lowering therapy for prevention of long-term cardiovascular events remains unclear.

Purpose

The purpose of the present study was to evaluate whether the strict management of LDL-C targeting &lt;70 mg/dL was effective to prevent recurrence of long-term coronary events than standard management in patients with previous percutaneous coronary intervention (PCI).

Methods

We investigated 344 patients with previous PCI who underwent late coronary angiography to examine recurrence of cardiac ischemia beyond the early phase of restenosis from January 2007 to August 2019. Patients were stratified into three groups according to achieved LDL-C value; LDL-C &lt;70mg/dL (n=53), 70 to &lt;100mg/dL (n=130) and ≥100mg/dL (n=161). Endpoints of this study were recurrence of cardiac ischemia presenting as acute coronary syndrome (recurrence-ACS) and any late coronary revascularization.

Results

During average 7.1 years follow-up, 200 patients (58%) underwent any late coronary revascularization. In 94 of those patients, recurrence-ACS was observed. The incidence of recurrence-ACS was significantly lower in patients with achieved LDL-C &lt;70mg/dL than in those with LDL-C 70 to &lt;100mg/dL and LDL-C ≥100mg/dL (p=0.009 and p=0.001, respectively), however, there was no difference between patients with LDL-C 70 to &lt;100mg/dL and LDL-C ≥100mg/dL (p=0.140). Any late revascularization was significantly lower in patients with achieved LDL-C &lt;70mg/dL and in those with LDL-C 70 to &lt;100mg/dL than in those with LDL-C ≥100mg/dL (p=0.002 and p&lt;0.001, respectively), however, no difference was found between patients with LDL-C &lt;70mg/dL and LDL-C 70 to &lt;100mg/dL (p=0.119). Moreover, in patients with achieved LDL-C &lt;100mg/dL (n=183), multivariate analysis identified that LDL-C (HR 1.035, p=0.007) and HbA1c (HR 1.338, p=0.001) were independent predictors of recurrence-ACS. In contrast, only using statins (HR 0.461, p=0.009) was an independent predictor of recurrence-ACS in patients with achieved LDL-C ≥100mg/dL.

Conclusions

LDL-C was the important residual risk of recurrence-ACS even after recommended standard LDL-C lowering management had been achieved. More strict management of LDL-C targeting to &lt;70mg/dL should be considered to prevent recurrence-ACS for wider range of Japanese patients in secondary prevention.

Incidence of late coronary events

Funding Acknowledgement

Type of funding source: None

Prognostic impact of initial serum albumin for newly developing heart failure after acute myocardial infarction

Background/Introduction

Previous studies have shown that poor nutritional status relate to the clinical outcomes in patients with heart failure (HF). However, relationships between initial serum albumin and newly developing HF after acute myocardial infarction (AMI) remain unclear.

Methods

We evaluated 2289 consecutive patients with AMI in our hospital. Primary outcome was HF hospitalization after AMI. We analyzed the predictive impact of initial serum albumin using multivariate analysis, both in all AMI patients and subgroup of AMI patient without known risk factors of HF (LMT, peak CK &gt;8000, eGFR &lt;30, and LVEF &lt;35%).

Result

In the remote-phase(median follow-up: 754 days), 5.4% of all AMI patients were hospitalized due to HF. Multivariate analysis showed that low albumin (&lt;4.0g/dl) was an independent predictor of HF hospitalization after AMI in all patients, as well as other known risk factors. Interestingly, low albumin still showed the predictive value even in the no-HF risk subgroup. Kaplan-meier curve of no-HF risk group is shown in the Figure.

Conclusions

Low initial albumin level would be an useful predictor of newly developing HF in the remote-phase after AMI.

Figure 1

Funding Acknowledgement

Type of funding source: None

Catheter ablation of atrial fibrillation benefits the patients with heart failure and preserved ejection fraction as well as those with heart failure and reduced ejection fraction

Background

Although catheter ablation of atrial fibrillation (AF) has recently been shown to improve the cardiac function and even mortality in patients with heart failure (HF) and reduced ejection fraction (HFrEF), few studies have examined the outcomes of AF catheter ablation in patients with HF with preserved ejection fraction (HFpEF).

Purpose

To verify the impact of AF catheter ablation on the cardiac function and HF status in patients with HFpEF.

Methods

We studied 306 patients with HF who had a history of an HF hospitalization and/or preprocedural serum BNP levels &gt;100pg/ml (age, 68.9±8.2 years old; male, 66.3%; non-paroxysmal AF, 63.1%, left atrial diameter [LAD], 42.5±6.3 mm; left ventricular ejection fraction [LVEF], 60.6±12.0%) out of 596 consecutive patients who underwent pulmonary vein isolation-based catheter ablation of AF. The patients with an LVEF ≥50% were defined as having HFpEF (n=262; age, 69.0±8.2 years old; male, 64.5%; non-paroxysmal AF, 61.8%, LAD, 42.1±5.9 mm; left LVEF, 64.0±8.2%) and the remaining patients with an LVEF &lt;50% were defined as having HFrEF (n=44, age, 67.9±8.7 years old; male, 77.0%; non-paroxysmal AF, 70.5%, LAD, 44.9±8.2 mm; LVEF, 40.1±10.2%). The patients received periodic follow-ups for 12 months after the catheter ablation. The cardiac function parameters including the echocardiographic findings and HF functional status of the patients were compared between baseline and 12 months, stratified by the HF subgroup.

Results

AF recurred in 60 patients with HFpEF (22.9%) and in 14 with HFrEF (31.8%) during the 12 month follow-up (p=0.27), however, sinus rhythm was maintained at 12 months in most of the patients (253 patients with HFpEF [96.6%] and 42 patients with HFrEF [95.5%]) (p=0.71). Figure 1 compares the changes in the cardiac function parameters and NYHA functional class from baseline to the 12-month follow-up stratified by the HF subgroup. Both the patients with HFpEF and HFrEF had significant improvements in the serum BNP levels, chest thorax ratio, and LVEF determined by echocardiography. LA reverse remodeling as shown by a significant reduction in the LAD was observed in both HF subgroups, however, the E/E', an index of the LV diastolic function, did not significantly change in either of the subgroups. Similar to the patients with HFrEF, an improvement in the NYHA functional class was seen in those with HFpEF.

Conclusions

Catheter ablation of AF may benefit patients with HFpEF as well as those with HFrEF. Sinus rhythm maintenance achieved by AF catheter ablation in patients with HFpEF may lead to LA reverse remodeling and a better LV systolic function, thereby improving the NYHA functional class. It is unclear whether changes in the LV diastolic function may contribute to this favorable process.

Funding Acknowledgement

Type of funding source: None

Survival of SARS-CoV-2 and influenza virus on the human skin: Importance of hand hygiene in COVID-19

Background

The stability of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on human skin remains unknown, considering the hazards of viral exposure to humans. We generated a model that allows the safe reproduction of clinical studies on the application of pathogens to human skin and elucidated the stability of SARS-CoV-2 on human skin.

Methods

We evaluated the stability of SARS-CoV-2 and influenza A virus (IAV), mixed with culture medium or upper respiratory mucus, on human skin surfaces and the dermal disinfection effectiveness of 80% (weight/weight) ethanol against SARS-CoV-2 and IAV.

Results

SARS-CoV-2 and IAV were inactivated more rapidly on skin surfaces than on other surfaces (stainless steel/glass/plastic); the survival time was significantly longer for SARS-CoV-2 than for IAV (9.04 hours [95% confidence interval, 7.96– 10.2 hours] vs 1.82 hours [1.65–2.00 hours]). IAV on other surfaces was inactivated faster in mucus versus medium conditions, while SARS-CoV-2 showed similar stability in the mucus and medium; the survival time was significantly longer for SARS-CoV-2 than for IAV (11.09 hours [10.22–12.00 hours] vs 1.69 hours [1.57–1.81 hours]). Moreover, both SARS-CoV-2 and IAV in the mucus/medium on human skin were completely inactivated within 15 seconds by ethanol treatment.

Conclusions

The 9-hour survival of SARS-CoV-2 on human skin may increase the risk of contact transmission in comparison with IAV, thus accelerating the pandemic. Proper hand hygiene is important to prevent the spread of SARS-CoV-2 infections.

AB0619 PROGNOSTIC FACTORS OF PATIENTS WITH ANTI-MDA5 ANTIBODY-POSITIVE DERMATOMYOSITIS COMPLICATED WITH INTERSTITIAL PNEUMONIA -A JAPANESE SINGLE CENTER STUDY-

Background:

Anti-melanoma differentiation-associated gene 5 antibody (anti-MDA5 Ab)-positive dermatomyositis (DM) is frequently associated with rapidly progressive interstitial pneumonia (RPIP), whose prognosis is assumed to be poor[1]. Although outcome of DM-RPIP has been reported to be improved by early immunosuppressive therapy, we still experience the cases with severe outcome. Only several reports mentioned the prognostic factors and they have not been fully elucidated.

Objectives:

To identify the predictors of prognosis in patients with anti-MDA5 Ab-positive DM associated with interstitial pneumonia (DM-IP).

Methods:

Anti-MDA5 Ab-positive DM-IP patients admitted to Fujita Health University Hospital between January 2010 and October 2019 were consecutively included and stratified into 2 groups, the survived and the deceased groups. DM was diagnosed according to the criteria proposed by Bohan and Peter[2]. Clinically amyopathic DM was diagnosed according to the criteria proposed by Sontheimer [3]. Diagnosis of IP was based on findings of high resolution CT scan (HRCT). The definition of RPIP was rapid exacerbation of hypoxemia or HRCT findings in a period of days to one month after the onset. Clinical features and prognosis of the patients were collected retrospectively and compared between groups. Candidates of predictors are extracted by the univariable analysis using Fisher’s exact test for dichotic parameters and Wilcoxon signed-rank test for continuous parameters and multivariable analysis using logistic regression analysis. Receiver operating characteristic (ROC) curve analysis was examined to obtain the cut-off level. Survival was examined using Kaplan-Meier method and Log-rank test.

Results:

Twenty-one patients were involved. Eight were deceased and 13 were survived. The deceased group had a higher ratio of male (75% versus 25%, p= 0.018). All deceased cases were with RPIP and 67 % in the survived cases. Levels of serum ferritin (4490 versus 646 ng/mL, p = 0.0026), CRP (2.1 versus 0.9 mg/dL, p = 0.0490), CK (1150 versus 290 U/L, p = 0.017), AST (194 versus 108 U/L, p = 0.025) and LDH (674 versus 368 U/L, p = 0.011) were higher in the deceased group. Interestingly, skin ulcers were tended to be more frequent (12.5% versus 87.5%, p= 0.0587), and anti-SS-A antibody was also more frequently detected (14.3% versus 85.7%, p=0.0072) in the survived group. Using ROC analysis cut-off values were 963 ng/mL for serum ferritin level (sensitivity 100%, specificity 83%), 0.7 mg/dL for CRP (sensitivity 75%, specificity 69%), 308 U/L for CK (sensitivity 88%, specificity 77%), 62 U/L for ALT (sensitivity 100%, specificity 62%), and 454 U/L for LDH (sensitivity 88%, specificity 77%). Patients were divided into two groups based on these cut-offs or based on dichotic parameters and survival was examined between 2 groups. Except CRP and anti-SS-A antibody, survival was significantly worse in parameter-positive or higher groups. Interestingly, anti-SS-A antibody-positive group had better outcome compared with those without.

Conclusion:

In our analysis, novel candidates such as serum CK, AST, and LDH levels were newly extracted and parameters previously reported was also included and those were also associated with the clinical outcome. In addition, anti-SS-A antibody was identified as a novel protective factor associated with a good outcome.

References:

[1]Nakashima R, Hosono Y, Mimori T. Clinical significance and new detection system of autoantibodies in myositis with interstitial lung disease. Lupus 2016;25:925-33.

[2]Bohan A, Peter JB. Polymyositis and dermatomyositis. N Eng J Med 1975;292:344-7.

[3]Sontheimer RD. Dermatomyositis: an overview of recent progress with emphasis on dermatologic aspects. Dermatol Clin 2000;20:387-408.

Disclosure of Interests:

None declared

0634 Volume-Assured Pressure Support is Effective Treatment for Obstructive Sleep Apnea Patients Who Failed CPAP Titration

Introduction

Obstructive sleep apnea (OSA) is a common disease, often treated using continuous positive airway pressure (CPAP). In many cases, patients fail an attended CPAP titration study, often due to inadequate control of AHI, and treatment-emergent central apneas as CPAP is increased. Here, we report our experience using volume-assured pressure support (VAPS) for these patients.

Methods

We retrospectively reviewed records of 45 adults who had OSA diagnosed on polysomnography (PSG) in whom CPAP titration had failed. In these patients, VAPS-AE (adjustable expiratory pressure) titrations were performed. Patients with central sleep apnea on baseline PSG were excluded.

Results

Reasons for CPAP titration failure included: treatment emergent central apneas (25), failure of maximum CPAP pressure to treat OSA (18), and persistent hypoxia (2). Average age was 57.9±13.1, BMI was 40.2±8.7, 26 males, Epworth sleepiness score was 10.7±7.9. The following significant changes from baseline PSG to VAPS titration were observed: AHI: 65.3±29.3 to 22.3 ±16.1 (p&lt;.001) events/hour. Time &lt; 88% saturation: 63.7 (median) to 6.9 (median) min (p&lt;.001). The number of patients with AHI&lt;15 was 0 on PSG and 16 (36%) on VAPS-AE, while the number of patients with AHI&lt;30 was 7 (16%) on PSG and 32 (71%) on VAPS-AE. Improvement in AHI was not related to gender, age, or narcotic use, but was correlated with BMI: ΔAHI = 12.2 - (1.4 * BMI); p=.05. VAPS resulted in improved sleep architecture: slow wave sleep increased (medians: 1.4% to 19.6% total sleep time (TST)) (p&lt;.001), REM sleep increased (medians 6.4% to 13.6% TST) (p&lt;.01).

Conclusion

For OSA patients for whom CPAP titration failed, titration with VAPS-AE was an effective treatment for many patients.

Support

N/A

0633 Volume Assured Pressure Support is an Effective Treatment in Patients with Central Sleep Apnea Syndrome

Introduction

Central sleep apnea syndrome (CSA) is commonly found in patients with congestive heart failure, brainstem disorders, and narcotic use. Various treatment modalities have been used with varied effectiveness in reducing the apnea-hypopnea index (AHI) and improving ventilation in patients with CSA. This study assessed whether Volume Assured Pressure Support (VAPS), a BiLevel mode of ventilation, is effective in treating CSA.

Methods

We performed a retrospective review of polysomnography (PSG) and VAPS titration studies on 11 patients at our institution: 7 patients had CSA with Cheyne-Stokes Respiration, 2 patients had CSA attributed to narcotic use, and 2 patients had primary CSA. CSA was diagnosed if more than 50% of the disordered breathing events were central. Five patients had failed a Continuous Positive Airway Pressure (CPAP) titration and then proceeded to VAPS while in 6 patients, VAPS was the initial treatment modality tried. We examined the effectiveness of VAPS in reducing AHI, improving oxygenation, and improving sleep architecture.

Results

Among the 11 patients, age was 63.0±12.1 yo, BMI was 33.7 ±4.5, 7 were males, Epworth sleepiness score was 9.3±4.9. The following significant changes from baseline PSG to VAPS titration were observed: AHI: 59.1± 8.0 to 27.2 ± 9.9 (p&lt;.01); Time ≤ 88% O2 saturation (min): 48.1±14.5 to 15.4±6.1 (p&lt;.05). Improvement in AHI was not related to gender, body mass index, narcotic use, or age. No significant changes in sleep architecture between the two studies were found. Ten (91%) patients had AHI &gt; 30 on initial PSG. In 6 (55%) patients AHI was reduced to &lt;15 with VAPS use. An additional patient had AHI reduced to 22.2, while 4 (36%) patients did not achieve an AHI &lt; 30 with VAPS.

Conclusion

VAPS is an effective mode of treating CSA in the majority of patients.

Support

NA

Nanofiltration of growth media supplemented with human platelet lysates for pathogen-safe xeno-free expansion of mesenchymal stromal cells

Background aims

Human platelet lysate can replace fetal bovine serum (FBS) for xeno-free ex vivo expansion of mesenchymal stromal cells (MSCs), but pooling of platelet concentrates (PCs) increases risks of pathogen transmission. We evaluated the feasibility of performing nanofiltration of platelet lysates and determined the impact on expansion of bone marrow–derived MSCs.

Methods

Platelet lysates were prepared by freeze-thawing of pathogen-reduced (Intercept) PCs suspended in 65% storage solution (SPP+) and 35% plasma, and by serum-conversion of PCs suspended in 100% plasma. Lysates were added to the MSC growth media at 10% (v/v), filtered and subjected to cascade nanofiltration on 35- and 19-nm Planova filters. Media supplemented with 10% starting platelet lysates or FBS were used as the controls. Impacts of nanofiltration on the growth media composition, removal of platelet extracellular vesicles (PEVs) and MSC expansion were evaluated.

Results

Nanofiltration did not detrimentally affect contents of total protein and growth factors or the biochemical composition. The clearance factor of PEVs was >3 log values. Expansion, proliferation, membrane markers, differentiation potential and immunosuppressive properties of cells in nanofiltered media were consistently better than those expanded in FBS-supplemented media. Compared with FBS, chondrogenesis and osteogenesis genes were expressed more in nanofiltered media, and there were fewer senescent cells over six passages.

Conclusions

Nanofiltration of growth media supplemented with two types of platelet lysates, including one prepared from pathogen-reduced PCs, is technically feasible. These data support the possibility of developing pathogen-reduced xeno-free growth media for clinical-grade propagation of human cells.

P762 Preserved mitral apparatus dynamics predict the improvement of acute ischemic mitral regurgitation: four-dimensional quantitative echocardiographic study

Background

We sought to evaluate the predictive value of acute stage mitral apparatus geometry and dynamics for the reduction of ischemic mitral regurgitation (IMR) in the remote phase after successful primary percutaneous coronary intervention (pPCI) by using real-time 3D-transthoracic echocardiography (3D-TTE).

Methods

We performed 2D and 3D-TTE in consecutive 44 first acute MI patients with more than mild IMR within 3 days after successful pPCI. 3DTTE of left ventricle (LV) volumes and mitral apparatus dynamics through the cardiac cycle were quantified offline. We compared the 3D geometric and dynamic parameters in the acute phase between 1)20 remained MR group and 2)24 improved MR group in 6-to-12 months after MI onset.

Results

Ejection fraction (EF) was preserved in the improved MR group compared to the remained MR group (49.0 ± 11.2 vs. 56.5 ± 7.0%, p = 0.013). Mitral valve annulus area, leaflet tenting length and papillary muscles spatial position had no significant difference between the two groups (all p &gt; 0.05) throughout cardiac cycle. In contrast, mitral annulus saddle shape was preserved in the improved MR group than the remained MR group (p = 0.010) and annular area changed dynamically through early- to late-systole in the improved MR group (phasic p = 0.017) despite it was adynamic in remained MR group (phasic p = 0.201). Conclusions: IMR improvement in the remote phase after AMI associated with preserved EF, mitral annulus saddle shape and dynamics during systole in the acute phase of MI. 4D dynamics of the mitral apparatus can be clinically useful predictor of the improvement in acute IMR and may contribute to the clinical decision making including surgical or percutaneous intervention for IMR.

P292 The risk of adverse outcome with ischemic mitral regurgitation at 6-month after myocardial infarction: possible benefit of early intervention by transcatheter mitral-valve repair

Background

The latest study has demonstrated the better outcomes of transcatheter mitral-valve repair in patients with decompensated heart failure (HF) and left ventricular (LV) dysfunction. However, it is unknown whether earlier intervention for mitral regurgitation (MR) can improve the outcome of myocardial infarction (MI).

Purpose

The aim of this study was to investigate the prognostic value of ischemic MR (IMR) at 6-month after MI for the later incidence of HF and death.

Methods

We retrospectively examined 723 MI patients who were admitted to our hospital. 95.5% of the patients were treated by primary coronary intervention. Patients were clinically followed-up at 6-month after the onset of MI, and divided into 3 groups according to the degree of IMR, i.e. No/Trivial IMR group (n = 528), Mild IMR group (n= 154) and ≥Moderate IMR group (n= 41). We compared the later incidence of hospitalization for HF and all-cause death at 3-year for each group.

Results

The studied population had preserved ejection fraction (EF) (56.9 ± 10.7%, average) and mostly asymptomatic at 6-month after MI. All-cause mortality within 3-year was higher in patients with ≥Moderate IMR (p &lt; 0.001), and the incidence of hospitalization for HF was significantly higher depends on the degree of IMR at 6-month (p &lt; 0.001). Multivariate analysis showed EF and the degree of IMR were the independent predictor for the hospitalization for HF.

Conclusions

IMR at 6-month after MI was associated with the later adverse events despite relatively preserved LV contraction without heart failure symptoms at the index examination. Early intervention for IMR potentially benefit for the better outcome.

Abstract P292 Figure. Caplan-Meier estimates on adverse events

P1520 Aortic flow reversal caused by aortic regurgitation deteriorates renal function

Background

Chronic kidney disease is a growing public health problem. Renal dysfunction is known as a strong risk factor for cardiovascular disease and end-stage renal failure. The presence of pan-diastolic flow reversal in the abdominal aorta is a very specific sign of severe aortic regurgitation (AR). A higher aortic reverse/forward flow ratio is associated with lower intrarenal forward flow. However, the influence of AR on renal function has been poorly understood. We hypothesized that the aortic flow reversal reduces the renal artery forward flow and accordingly leads to renal dysfunction in patients with severe AR.

Methods

The study consisted of 21 consecutive patients (mean age 69 ± 11 years) with severe AR who underwent aortic valve replacement (AVR). We compared echocardiographic indices and the glomerular filtration rate (GFR) before and 603 ± 541 days after AVR.

Results

Blood pressure was 122 ± 16/54 ± 8 mmHg before AVR and 123 ± 16/76 ± 11 mmHg after AVR. After AVR, left ventricular (LV) end-diastolic dimension decreased from 57 ± 9 to 44 ± 5 mm and LV ejection fraction increased from 58 ± 12 to 60 ± 11 %. Estimated GFR significantly increased from 62.9 ± 18.9 to 71.8 ± 18.1 mL/min per 1.73 m2 after AVR (p = 0.003).

Conclusions An increase in aortic flow reversal caused by severe AR reduces forward flow into the kidney and thereby deteriorates renal function. This study demonstrated a key mediating role of central hemodynamic factors, particularly an exaggerated aortic flow reversal in renal dysfunction and severe AR.

mDia1/3-dependent actin polymerization spatiotemporally controls LAT phosphorylation by Zap70 at the immune synapse

The mechanism by which the cytosolic protein Zap70 physically interacts with and phosphorylates its substrate, the transmembrane protein LAT, upon T cell receptor (TCR) stimulation remains largely obscure. In this study, we found that the pharmacological inhibition of formins, a major class of actin nucleators, suppressed LAT phosphorylation by Zap70, despite TCR stimulation-dependent phosphorylation of Zap70 remaining intact. High-resolution imaging and three-dimensional image reconstruction revealed that localization of phosphorylated Zap70 to the immune synapse (IS) and subsequent LAT phosphorylation are critically dependent on formin-mediated actin polymerization. Using knockout mice, we identify mDia1 and mDia3, which are highly expressed in T cells and which localize to the IS upon TCR activation, as the critical formins mediating this process. Our findings therefore describe previously unsuspected roles for mDia1 and mDia3 in the spatiotemporal control of Zap70-dependent LAT phosphorylation at the IS through regulation of filamentous actin, and underscore their physiological importance in TCR signaling.

1182 Clinical evidence of the mitral valve leaflet remodeling after st-elevation acute myocardial infarction: longitudinal observation using real-time 3D echocardiography

Background

Mitral valve (MV) leaflet remodeling after acute myocardial infarction (AMI) has been proposed as biological and physiological reaction under the ischemic environment mainly by animal experiments. Clinical evidence of leaflet growth after AMI is lacking.

Purpose

We aimed to assess the clinical evidence of the mitral valve leaflet remodeling after acute myocardial infarction by serial 2D/3D transthoracic echocardiography.

Methods

Sixty-six patients with first-onset ST-elevation MI (33 anterior and 33 inferior) were serially examined by 2D/3D-transthoracic echocardiography. MV complex geometry including leaflet surface area and leaflet thickness was quantitatively analyzed in acute phase and 6-month follow-up.

Results

3D-leaflet surface area was significantly increased in 6-month follow-up (anterior MI; 5.58 [4.93-6.00] versus 5.98 [5.68-6.40] cm²/m²; P &lt; 0.001, inferior MI; 5.48 [4.69-6.07] versus 5.79 [4.74-6.37] cm²/m²; P &lt; 0.001). In anterior MI, both anterior and posterior leaflet lengths significantly increased (anterior leaflet; 12.78 [11.55-13.55] versus 13.63 [12.52-14.15] mm/m²; P = 0.001, posterior leaflet; 9.61 [8.73-10.77] versus 9.84 [8.94-10.96] mm/m²; P = 0.037). In inferior MI, posterior leaflet length significantly increased (9.18 [8.50-10.38] versus 10.00 [8.56-10.85] mm/m²; P = 0.029), while there was no significant change in anterior leaflet length (12.54 [11.61-13.56] versus 12.56 [12.08-14.06] mm/m²; P = 0.214). Leaflet thickness was found to become greater in both groups in 6-month follow-up (anterior MI; 1.08 [0.92-1.21] versus 1.32 [1.25-1.45] mm; P &lt; 0.001, inferior MI; 1.14 [0.98-1.25] versus 1.32 [1.21-1.49] mm; P &lt; 0.001) (Figure).

Conclusions

In six months from the onset of AMI, MV enlarged in area and increased in thickness. Anterior leaflet mainly enlarged in anterior MI, while posterior leaflet enlarged in inferior MI. This is the first clinical evidence of the MV remodeling after AMI, and long-year follow-up should contribute to assess the course of valve growth with relation to ischemic mitral regurgitation.

Abstract 1182 Figure. 3D analysis of the mitral valve

Polymer gel with a flexible and highly ordered three-dimensional network synthesized via bond percolation

Gels are a soft elastic material consisting of a three-dimensional polymer network with nanometer-sized pores and are used in a variety of applications. However, gel networks typically have a substantial level of defects because the network formation reaction proceeds stochastically. In this study, we present a general scheme to fabricate gels with extremely low levels of defects by applying geometric constraints into pregel solution based on the "bond percolation" concept. In the formed gel, stationary laser speckles, which are an indicator of spatial defects, were not observed at all. In addition, we found that the concentration fluctuations of the polymer chains were ergodic across the whole gel network. In such a homogeneous gel, both the spatial and temporal correlations of polymer chains are the same before and after gelation.

Comparison of High-Hydrostatic-Pressure Decellularized Versus Freeze-Thawed Porcine Menisci

The meniscus functions as a load distributor and secondary stabilizer in the knee, and the loss of the meniscus increases the risk of osteoarthritis. Freeze-thawed menisci are used in clinical practice to replace defective menisci; however, the disadvantages of freeze-thawed tissues include disease transmission and immune rejection. In this study, we decellularized menisci using high hydrostatic pressure (HHP) and compared the decellularized menisci with freeze-thawed menisci. Porcine menisci were either pressurized at 1,000 MPa for 10 min and then washed with DNase solution or frozen at -80°C for 2 days and thawed. These menisci then underwent in vitro histological, biochemical, and biomechanical comparisons with native menisci. The HHP-treated and freeze-thawed menisci were also subcutaneously implanted in a pig, and later harvested for histological analysis. The numbers of histologically detected cells were significantly lower and the amount of biochemically detected DNA was approximately 100-fold lower in HHP-treated than in native and freeze-thawed menisci. The compression strength of the HHP-decellularized menisci was decreased after 1 and 50 cycles at 20% strain but was unchanged in the freeze-thawed menisci. After implantation, the numbers of multinucleated giant cells were significantly lower around the HHP-treated menisci than around the freeze-thawed menisci. Recellularization of the HHP-decellularized menisci was confirmed. Thus, although the HHP-decellularized menisci were mechanically inferior to the freeze-thawed meniscus in vitro, they were immunologically superior. Our study is the first to demonstrate the use of HHP for decellularization of the meniscus. © 2019 The Authors. Journal of Orthopaedic Research^® published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 37:2466-2475, 2019.