Pharmacokinetics/pharmacodynamics cut-off determination for fosfomycin using Monte Carlo simulation in healthy horses.

Fosfomycin (FOM) is an approved veterinary medicinal product for large animals in Japan, but Clinical breakpoint (CBP) for antimicrobial susceptibility test (AST) is not defined for animals. This study aimed at conducting a pharmacokinetics/pharmacodynamics (PK/PD) analysis to determine the PK/PD cutoff for the CBP in horses. Drug concentrations following single intravenous administration (IV) of 20 mg/kg body weight (BW) FOM in nine horses were measured using liquid chromatography/mass spectrometry. The data were modelled using a nonlinear mixed-effects model, followed by Monte Carlo simulations. A 90% probability of target attainment for a PK/PD target of the ratio of Area Under the free plasma concentration-time curve divided by the minimal inhibitory concentration (MIC) >24 hr was set as PK/PD cut-off. The PK/PD cutoff for FOM 20 mg/kg BW q12 hr IV was estimated with the MIC value of ≤16.0 mg/L, and this regimen was considered effective against E. coli (MIC90; 16.0 mg/L) in healthy horses based on the MIC90 values of the wild population. Owing to the relevance of FOM to human health, veterinarians should use q 12 hr FOM 20 mg /kg against E. coli infections with an MIC <16 µg/mL, as suggested by our PK/PD cutoff after AST.

Incidence of surgical site infection after internal fixation of the first phalangeal bone and the third metacarpal/metatarsal bone fractures in Thoroughbred racehorses.

Surgical site infection (SSI) is one of the major complications of equine fracture surgery. The purpose of this study was to investigate the incidence of and risk factors for SSI after internal fixation of the first phalangeal bone (P1) and the third metacarpal/metatarsal bone (MC3/MT3) fractures in Thoroughbred racehorses. Between 2011 and 2020, 451 cases underwent surgery with screws or a locking compression plate (LCP) for sagittal fractures of P1 or condylar fractures of MC3/MT3. Overall, 2.9% (13/451) of the cases developed an SSI. The incidence was significantly higher in plate fixation (21.4%) than in screw fixation (2.3%). There was no significant association with other variables, such as sex, age, number of screws, experience of surgeon, or prophylactic antimicrobials. The median duration of hospitalization for screw fixation was 14 days without an SSI and 20 days with an SSI, and those for plate fixation were 26 and 25-88 days, respectively, indicating that the development of SSI prolongs the duration of hospitalization. On the other hand, there were no significant differences in discharge and race resumption rates between cases with and without an SSI. These data indicate that the incidence of SSI in this study was low and that it was higher following plate fixation than screw fixation.

Effects of resveratrol and its analogues on the cell cycle of equine mesenchymal stem/stromal cells.

Resveratrol (RSV; trans-3,5,4'-trihydroxystilbene) strongly activates sirtuin 1, and it and its analogue V29 enhance the proliferation of mesenchymal stem/stromal cells (MSCs).Although culture medium containing 5-azacytydine and RSV inhibits senescence of adipose tissue-derived MSCs isolated from horses with metabolic syndrome, few studies have reported the effects of RSV on equine bone marrow-derived MSCs (eBMMSCs) isolated from horses without metabolic syndrome. The aim of this study was to investigate the effects of RSV and V29 on the cell cycle of eBMMSCs. Following treatment with 5 µM RSV or 10 µM V29, the cell proliferation capacity of eBMMSCs derived from seven horses was evaluated by EdU (5-ethynyl-2'-deoxyuridine) and Ki-67 antibody assays. Brightfield images of cells and immunofluorescent images of EdU, Ki-67, and DAPI staining were recorded by fluorescence microscopy, and the number of cells positive for each was quantified and compared by Friedman's test at P<0.05. The growth fraction of eBMMSCs was significantly increased by RSV and V29 as measured by the EdU assay (control 28.1% ± 13.8%, V29 31.8% ± 14.6%, RSV 32.0% ± 10.8%; mean ± SD; P<0.05) but not as measured by the Ki-67 antibody assay (control 27.0% ± 11.2%, V29 27.4% ± 10.8%, RSV 27.7% ± 6.8%). RSV and V29 promoted progression of the cell cycle of eBMMSCs into the S phase and may be useful for eBMMSC expansion.

Longitudinal course and outcome of social jetlag in adolescents: A 1-year follow-up study of the adolescent sleep health epidemiological cohorts.

The discrepancy in sleep timing between weekdays and weekends - social jetlag (SJL) - is known to negatively affect student quality of life (QOL). However, the association between social jetlag and physical/mental QOL among adolescents and the precise effect of social jetlag on depressive symptoms and daytime sleepiness remains unknown. This study investigated the longitudinal course, risk factors, and effects of social jetlag, a circadian misalignment, in a school-based cohort. The participants were 427 students (13.3 ± 0.6 years, 45.2% girls) from five junior high schools. We performed a baseline survey in 2019 and a 1-year follow-up survey in 2020. Depressive symptoms, QOL, and daytime sleepiness were assessed using the Birleson Depression Self-Rating Scale for Children, Paediatric Quality of Life Inventory, and Paediatric Daytime Sleepiness Scale. In the baseline survey, 49.6% of the students reported SJL ≥1 h, and 17.1% reported SJL ≥2 h. Among them, 37.2% and 6.8% reported persistent SJL at follow-up, respectively. New incidences of SJL ≥1 h were associated with older age, non-attainment of menarche or voice changes, and longer duration of smartphone use, whereas its persistence was associated with a later chronotype. Persistence of SJL ≥1 h and ≥2 h predicted depressive symptoms and daytime sleepiness at follow-up, whereas new incidences of SJL ≥2 h predicted lower QOL. In conclusion, social jetlag has a persistent course, and daytime functioning can deteriorate as social jetlag becomes chronic. Our findings suggest the need for intensive interventions for social jetlag among adolescents.

Social jetlag as a predictor of depressive symptoms among Japanese adolescents: Evidence from the Adolescent Sleep Health Epidemiological Cohort.

OBJECTIVES: Social jetlag, a circadian misalignment, has been associated with depressive symptoms in the general and working populations. However, evidence for this association in adolescents is inconsistent. This cross-sectional study aimed to investigate the association between social jetlag and depressive symptoms among Japanese adolescents and to evaluate differences by sex. METHODS: The participants were 1493 students (13.6 ± 0.9years, 52.4% girls) from five junior high schools. Questionnaires, including demographic information and the Munich ChronoType Questionnaire, were distributed. Social jetlag was defined as the difference between midsleep on weekdays and weekends, and was categorized as <0 hour (negative), 0 to <1 hour, 1 to <2 hours, or ≥2 hours. Depressive symptoms were assessed using the Birleson Depression Self-Rating Scale for Children. Multivariate logistic regression was used to estimate the odds ratio with adjustments for potential confounders, such as puberty- and lifestyle-related factors. RESULTS: The distribution of students with <0 hour, 0 to <1 hour, 1 to <2 hours, and ≥2 hours of social jetlag was 9.4%, 37.0%, 33.3%, and 20.4%, respectively. The multivariate-adjusted model revealed that social jetlag ≥2 hours and <0 hour were associated with an elevated risk of depressive symptoms among girls and boys, respectively. These associations were nonlinear for both sexes in restricted cubic spline analyses. CONCLUSIONS: Social jetlag is associated with depressive symptoms among adolescents. Specifically, the risk of depressive symptoms increased with positive social jetlag scores for girls and negative social jetlag scores for boys.

Characteristic Inflammatory Biomarkers in an Equine Model of Persistent Synovitis Induced By the Intra-Articular Administration of Monoiodoacetic Acid.

Persistent synovitis damages the articular cartilage in horses. To evaluate the effectiveness of treatment for synovitis using a model induced by intra-articular administration of monoiodoacetic acid (MIA), it is necessary to identify inflammatory biomarkers characteristic of the MIA model. Synovitis was induced by administering MIA into the unilateral antebrachiocarpal joints of five horses, and saline was injected into the contralateral joints as a control on day 0. Clinical and ultrasonographic examinations and synovial fluid collection were performed on days 0, 1, 2, 7, 14, 21, 28, and 35. Leukocyte, lactate dehydrogenase (LDH), tumor necrosis factor-α (TNF-α), interleukin-1 receptor antagonist (IL-1Ra), interleukin-6 (IL-6), and transforming growth factor-ß1 (TGF-ß1) concentrations in the synovial fluid were measured. Synovium was obtained after euthanasia on day 42 and histologically examined before quantification of the gene expression of inflammatory biomarkers by real-time PCR. Acute inflammatory symptoms persisted for approximately 2 weeks before returning to control levels. However, some indicators of chronic inflammation remained elevated until day 35. On day 42, synovitis continued histologically, with osteoclasts. The expressions of matrix metalloproteinase 13 (MMP13), a disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS4), receptor activator of nuclear factor kappa-Β ligand (RANKL), and collagen type I α2 chain (Col1a2) were significantly higher in the MIA model than in the control. In the MIA model, representative inflammatory biomarkers in the chronic inflammatory stage were persistently expressed in both synovial fluid and tissue, suggesting that they may be useful for the assessment of the anti-inflammatory effect of drugs.

Rational determination of cefazolin dosage regimen in horses based on pharmacokinetics/pharmacodynamics principles and Monte Carlo simulations.

A pharmacokinetics/pharmacodynamics (PK/PD) approach was used to determine the best empirical dosage regimen of cefazolin (CEZ) after intramuscular (IM) administration of CEZ in horses. Seven horses received a single IM or intravenous (IV) administration of CEZ of 5 mg/kg bodyweight (BW) according to a crossover design. CEZ plasma concentrations were measured using LC-MS/MS. The plasma concentrations in these seven horses and those of six other horses obtained in a previous study with an IV CEZ dose of 10 mg/kg were modelled simultaneously using NonLinear Mixed-Effect modelling followed by Monte Carlo simulations to establish a rational dosage regimen. A 90% Probability of Target Attainment (PTA) for a PK/PD target of a free plasma concentration exceeding MIC90 (fT > MIC ) for 40% of the dosing interval was set for selecting an effective dosing regimen. The typical half-life of absorption and bioavailability after IM administration were 1.25 h and 96.8%, respectively. A CEZ dosage regimen of 5 mg/kg BW q12h IM administration achieved therapeutic concentrations to control both Streptococcus zooepidemicus and Staphylococcus aureus. For the same dose, the fT > MIC after IM administration was significantly longer than after IV administration, and the IM route should be favoured by clinicians for its efficiency and convenience.

Pharmacokinetic/pharmacodynamic analysis of cephalothin after intramuscular administration in Thoroughbred horses.

A pharmacokinetic/pharmacodynamic (PK/PD) approach was used to determine a dosage regimen of cephalothin (CET) after intramuscular (IM) administration in horses. CET plasma concentrations were measured in eight horses after a single IM administration of 11 mg/kg bwt of CET. The data were modeled using a nonlinear mixed-effect model, and the probability of target attainment (PTA) of the PK/PD target was calculated for 5,000 horses generated by Monte Carlo simulations. IM administrations of CET at 11 mg/kg bwt q 8 hr and q 6 hr achieved a PTA of 90% against the MIC90 of S. zooepidemicus and S. aureus, respectively, and were considered to be effective dosage regimens. The total dose for the IM administration recommended in this study was lower than that for intravenous (IV) administration in previous studies.

Concentration of cephalothin in body fluids and tissue samples of Thoroughbred horses.

Cephalothin (CET) concentrations in body fluids (plasma, synovial fluid, pleural fluid, peritoneal fluid, and aqueous humor) and tissue samples (bone, lung, jejunum, hoof, and subcutaneous tissue) were investigated to consider the treatment of infectious diseases in horses. CET 22 mg/kg body weight was intravenously administered to 12 horses. Samples were collected from four different horses at 1, 3, and 5 hr after administration. The CET concentration in body fluids other than aqueous humor was maintained above the MIC90 values of Streptococcus zooepidemicus and Staphylococcus aureus until 5 hr, but it was not maintained above that of S. aureus in bone. CET (22 mg/kg twice a day) is effective for septic arthritis, pleuritis, and peritonitis caused by gram-positive bacteria but ineffective for osteomyelitis.

Study on ultrasonic wave propagation in equine leg bone for screening bucked shin.

For simple, safe, portable, and inexpensive evaluation suitable for leg bone diseases of racehorses in the field, an ultrasonic measurement technique was applied to evaluate wave velocities. A digital model of the third metacarpal bone with the bucked shin was fabricated using high-resolution peripheral quantitative computerized tomography data of a racehorse. This model was anisotropic and heterogeneous, and was constructed using the measured ultrasonic wave velocities in the bone. With this model, ultrasonic wave propagation along the bone axis was simulated using the elastic finite-difference time-domain method. We found two main waves with different propagation velocities. The fast-waves showed a wave velocity close to the longitudinal wave in the axial direction. However, the apparent velocities changed dramatically owing to bone surface irregularities (changes of the shape) in the area of bucked shin. The slow-waves showed a wave velocity close to the shear wave, which was unaffected by the bone surface irregularities. The simple comparison of different wave behaviors may be a suitable parameter for the initial in vivo screening of bucked shin in the legs of racehorses, which can be performed in the field.

Detection of Indiscriminate Genetic Manipulation in Thoroughbred Racehorses by Targeted Resequencing for Gene-Doping Control.

The creation of genetically modified horses is prohibited in horse racing as it falls under the banner of gene doping. In this study, we developed a test to detect gene editing based on amplicon sequencing using next-generation sequencing (NGS). We designed 1012 amplicons to target 52 genes (481 exons) and 147 single-nucleotide variants (SNVs). NGS analyses showed that 97.7% of the targeted exons were sequenced to sufficient coverage (depth > 50) for calling variants. The targets of artificial editing were defined as homozygous alternative (HomoALT) and compound heterozygous alternative (ALT1/ALT2) insertion/deletion (INDEL) mutations in this study. Four models of gene editing (three homoALT with 1-bp insertions, one REF/ALT with 77-bp deletion) were constructed by editing the myostatin gene in horse fibroblasts using CRISPR/Cas9. The edited cells and 101 samples from thoroughbred horses were screened using the developed test, which was capable of identifying the three homoALT cells containing 1-bp insertions. Furthermore, 147 SNVs were investigated for their utility in confirming biological parentage. Of these, 120 SNVs were amenable to consistent and accurate genotyping. Surrogate (nonbiological) dams were excluded by 9.8 SNVs on average, indicating that the 120 SNV could be used to detect foals that have been produced by somatic cloning or embryo transfer, two practices that are prohibited in thoroughbred racing and breeding. These results indicate that gene-editing tests that include variant calling and SNV genotyping are useful to identify genetically modified racehorses.

Incidence of carpal fractures and risk factors for recurrent fractures after arthroscopic removal of carpal chip fracture fragments in Thoroughbred racehorses.

BACKGROUND: We aimed to investigate the recent incidence of carpal fractures and the risk factors for recurrent ipsilateral fractures after arthroscopic removal of clinically active unilateral carpal chip fracture fragments in Thoroughbred racehorses. METHODS: The findings for horses managed under the Japan Racing Association that developed carpal bone fractures between 2014 and 2018 were retrospectively reviewed. The proportion of cases that developed a recurrent carpal fracture in the originally affected joint was calculated, and the risk factors for recurrent fractures were analysed. RESULTS: In total, 2858 carpal fractures were recorded in the study period (incidence, 0.8%). Of the 554 horses that resumed racing after the treatment of the unilateral major carpal chip fracture, 144 had a recurrent fracture (26.0%). Chip fractures of the third carpal bone (odds ratio [OR]: 3.7) or a combination of the distal end of the radius and intermediate carpal bone (OR: 3.0) were associated with a significantly higher risk of recurrent fractures than the distal aspect of the radial carpal bone. CONCLUSIONS: The incidence of carpal fractures remained similar to that reported in Japan in the 1990s. The rate of recurrent ipsilateral fractures differed among lesion sites.

Platelet Lysate Enhances Equine Skeletal Muscle Regeneration in A Bupivacaine-Induced Muscle Injury Model☆.

This study aimed to verify the effects of platelet lysate (PL) administration on the repair of injured horse tissue. Skeletal muscle injuries were induced in 26 Thoroughbreds by bupivacaine administration. PL or saline was administered 1 day (1D) after injury. Muscle samples from 22 horses injected with PL or saline were obtained by needle biopsy at 2, 3, 4, or 7 days (2D, 3D, 4D, or 7D, respectively) after injury, and growth-factor concentrations and muscle regeneration-associated gene expression levels were determined. Intact samples were similarly collected before injury, and samples of injured muscle not treated with PL or saline (sham samples) were also obtained at 1D, 2D, 3D, 4D, and 7D as references for comparison. Samples from the remaining 4 horses were obtained by surgical incision following euthanasia at 5 days (5D) and 7D after injury, followed by histological analysis. Although increased growth factor levels caused by PL administration were observed for up to 1-day post-administration (2D), gene expressions were enhanced for up to 6 days post-administration (7D). Moreover, the number of embryonic myosin heavy chain (MHC-e)-positive myofibrils at 5D was higher in the PL-treated group than in the saline-treated group, whereas no significant between-group difference in the number of myofibrils was recorded at 7D. Thus, PL administration in muscle injury upregulated the expression of various genes associated with muscle regeneration and promoted morphological regeneration within 6 days of treatment, although growth factor levels from PL decreased at the injected site by approximately 2 days post-administration.

Antibody Responses to a Reverse Genetics-Derived Bivalent Inactivated Equine Influenza Vaccine in Thoroughbred Horses.

Updating vaccine strains is important to control equine influenza (EI). Previously, we reported that a monovalent inactivated EI vaccine derived from a virus generated by reverse genetics (RG) elicited immunogenicity in horses. In the present study, we compared antibody responses to a bivalent inactivated EI vaccine generated by RG and a commercially available bivalent inactivated EI (CO) vaccine derived from wild-type equine influenza viruses in Thoroughbred horses. The CO vaccine contained A/equine/Ibaraki/1/2007 (Florida sub-lineage clade 1) and A/equine/Yokohama/aq13/2010 (Florida sub-lineage clade 2) as vaccine strains. We generated two RG viruses possessing the hemagglutinin and neuraminidase genes from A/equine/Ibaraki/1/2007 or A/equine/Yokohama/aq13/2010. These viruses were inactivated by formalin, and the hemagglutinin titer of the RG vaccine was adjusted to be the same as that of the CO vaccine. Sixteen unvaccinated yearlings (7 for the RG vaccine group and 9 for the CO vaccine group) received two doses of a primary vaccination course four weeks apart. Thirty-two vaccinated adult horses (18 in the RG-vaccinated group and 14 in the CO vaccine group) received a single dose of a booster vaccination. The patterns of hemagglutination inhibition antibody response to the primary and booster vaccinations were similar for the RG and CO groups in unvaccinated yearlings and vaccinated adult horses. These results suggest that a bivalent vaccine derived from RG viruses elicits equivalent immunogenicity to that elicited by a CO vaccine derived from wild-type viruses. RG viruses can, therefore, be used in multivalent as well as monovalent vaccines for horses.

Growth properties and immunogenicity of a virus generated by reverse genetics for an inactivated equine influenza vaccine.

BACKGROUND: Keeping vaccine strains up to date is the key to controlling equine influenza (EI). Viruses generated by reverse genetics (RG) are likely to be effective for quickly updating a vaccine strain. OBJECTIVES: To evaluate the growth properties of an RG virus in embryonated chicken eggs, and to evaluate antibody responses to a formalin-inactivated vaccine derived from the RG virus in Thoroughbred horses. STUDY DESIGN: In vitro and in vivo experiments. METHODS: Wild-type (WT) viruses (A/equine/Ibaraki/1/2007) or RG viruses (consisting of haemagglutinin [HA] and neuraminidase genes derived from A/equine/Ibaraki/1/2007 and the six other genes derived from high-growth A/Puerto Rico/8/34) were inoculated into embryonated chicken eggs, and the allantoic fluids were harvested at every 24 hours after inoculation. WT and RG viruses were inactivated by formalin for vaccine use. Ten unvaccinated yearlings (five each for WT or RG vaccine) received the first two doses of a primary vaccination course 4 weeks apart followed by their third dose 12 weeks later. Twenty vaccinated adult horses (10 each for WT or RG vaccine) received a single dose of a booster vaccination. RESULTS: The RG virus had high growth properties in embryonated chicken eggs. Unvaccinated yearlings responded poorly to the first vaccination, especially those that received the RG vaccine, but mounted better responses to the second and the third vaccinations, and maintained relatively high haemagglutination inhibition (HI) titres up to 28 weeks after the first vaccination. Vaccinated adult horses did not respond remarkably to the booster vaccination, but no horses showed titres below their pre-booster values even at 12 weeks after vaccination. The RG virus elicited immunogenicity in horses adequate for vaccine use. MAIN LIMITATIONS: No virus challenge study was performed. CONCLUSIONS: The RG viruses are useful as an EI vaccine strain, and quick updates of an EI vaccine strain can be achieved by using RG techniques.

Medication control of flunixin in racing horses: Possible detection times using Monte Carlo simulations.

BACKGROUND: For medication control in several jurisdictions, withdrawal time is the period of refrain from racing after drug administration. It is set by adding a safety period to an experimental detection time. However, there are no reports of statistical analyses of detection time for the determination of withdrawal time in flunixin meglumine-treated horses. OBJECTIVE: To analyse the population pharmacokinetics of flunixin in horses through the generation of a dataset for detection time statistical analysis and predictions via Monte Carlo simulation. STUDY DESIGN: Experimental study. METHODS: Drug plasma and urine concentrations following single intravenous administration of flunixin 1.1 mg/kg bodyweight (BW) in 10 horses and multiple administration of q 24 hours for 5 days in 10 horses were measured using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Data were modelled using a nonlinear mixed effect model followed by Monte Carlo simulation. Irrelevant plasma concentration (IPC) and irrelevant urine concentration (IUC) were calculated using the Toutain approach. Detection times were obtained considering the time after the last administration for selected quantiles of 5000 hypothetical horses under the international screening limit (ISL) proposed by the International Federation of Horseracing Authorities (plasma: 1 ng/mL, urine; 100 ng/mL). RESULTS: For a regimen of 1.1 mg/kg BW q 24 hours, the IPC and IUC values were 2.0 and 73.0 ng/mL respectively. Detection times in plasma above the ISL for 90% of simulated horses were estimated as 74 hours after a single 1.1 mg/kg dose administration, 149 and 199 hours after multiple doses over 5 days at either 24- or 12-hour intervals respectively. Corresponding detection times in urine were 46, 68 and 104 hours respectively. MAIN LIMITATION: Only female horses were investigated. CONCLUSIONS: Statistical detection times for different flunixin meglumine regimens indicated a delay of detection time in plasma after multiple administrations under ISL.

Social jetlag among Japanese adolescents: Association with irritable mood, daytime sleepiness, fatigue, and poor academic performance.

Social jetlag, a form of circadian misalignment, has been suggested to induce several clinical symptoms such as mental/physical health problems. However, evidence on the association of social jetlag with general daytime functioning (e.g., school life) is limited. This cross-sectional study aimed to 1) estimate the distribution of social jetlag exceeding one hour and 2) comprehensively explore the associations between social jetlag and irritable mood, daytime sleepiness, and poor academic performance among Japanese adolescents. The study included 4,782 students aged 12-15 years, from 13 junior high schools, who completed a self-administered questionnaire. Social jetlag was calculated as the difference in the midpoint of sleep between weekdays and weekends and was categorized as follow: negative, <1 h, 1-2 h, or ≥2 h. Outcomes were irritable mood, daytime sleepiness, and academic performance, which were analyzed with generalized linear mixed models to examine the relations with social jetlag, with adjustments for potential confounders like sleep quality. The distribution of social jetlag of ≥1 h was 51.1%, including 1-2 h (35.8%) and ≥2 h (15.3%). Its most frequently observed duration was 0 to <1 h (41.0%), followed by negative social jetlag (7.9%). The full adjusted model revealed that social jetlag of ≥1 h was associated with elevated risk of irritable mood, daytime sleepiness, and poor academic performance, while negative social jetlag was associated only with poor academic performance. Social jetlag was highly prevalent among Japanese adolescents and could be a major risk factor for irritable mood, daytime sleepiness, and poor academic performance.Abbreviations: BMI, Body mass index; DLMO, Dim light melatonin onset; CIs, Confidence intervals; MSF, The midpoints of sleep on free days; MSFsc, Sleep-corrected MSF; MSW, The midpoints of sleep on weekdays; PDSS, The Pediatric Daytime Sleepiness Scale.

Relationship between the ultrasonographic findings of suspected superficial digital flexor tendon injury and the prevalence of subsequent severe superficial digital flexor tendon injuries in Thoroughbred horses: a retrospective study.

The onset of severe injury to the superficial digital flexor tendon (SDFT) is extremely difficult to predict from slight changes in ultrasonographic findings in cases with no apparent clinical signs. This study investigated the relationship between an increased cross-sectional area (CSA) or edema in the subcutaneous tissue around the tendon and the subsequent onset of severe SDFT injury in Thoroughbred racehorses. Horses were classified into three groups based on ultrasound diagnosis (USD) findings: Group A included cases with enlarged tendons; Group B included cases with tendons of normal size but with prominent edema in the peritendinous tissue; and Group C (control group) included cases with no abnormal USD findings. The incidence of subsequent severe tendon injury was significantly higher in the horses in Groups A (25.7%, 28/101) and B (28.3%, 65/212) than in those in Group C (4.9%, 2/41). There were no significant differences in the median period and the median number of races from the first examination to the subsequent tendon injury between Groups A (140 days, 1 race) and B (120 days, 1 race). The results of this study revealed that horses with increased CSA and peritendinous edema are likely to suffer a subsequent severe tendon injury. Also, these two USD findings, i.e., increased CSA and peritendinous edema, indicate the risk of onset of severe SDFT injury.

ERRγ enhances cardiac maturation with T-tubule formation in human iPSC-derived cardiomyocytes.

One of the earliest maturation steps in cardiomyocytes (CMs) is the sarcomere protein isoform switch between TNNI1 and TNNI3 (fetal and neonatal/adult troponin I). Here, we generate human induced pluripotent stem cells (hiPSCs) carrying a TNNI1EmGFP and TNNI3mCherry double reporter to monitor and isolate mature sub-populations during cardiac differentiation. Extensive drug screening identifies two compounds, an estrogen-related receptor gamma (ERRγ) agonist and an S-phase kinase-associated protein 2 inhibitor, that enhances cardiac maturation and a significant change to TNNI3 expression. Expression, morphological, functional, and molecular analyses indicate that hiPSC-CMs treated with the ERRγ agonist show a larger cell size, longer sarcomere length, the presence of transverse tubules, and enhanced metabolic function and contractile and electrical properties. Here, we show that ERRγ-treated hiPSC-CMs have a mature cellular property consistent with neonatal CMs and are useful for disease modeling and regenerative medicine.

Prevalence and associated factors of circadian rhythm sleep-wake disorders and insomnia among visually impaired Japanese individuals.

BACKGROUND: Although earlier studies have demonstrated that circadian rhythm sleep-wake disorders (CRSWD) are more prevalent in visually impaired individuals, the actual prevalence of CRSWD and insomnia among the visually impaired Japanese population remains unclear. The aim of this cross-sectional, telephone-based study was to estimate the prevalence of CRSWD and insomnia, and explore factors associated with CRSWD and insomnia among visually impaired Japanese individuals. METHODS: A nationwide telephone survey was conducted among visually-impaired individuals through local branches of the Japan Federation of the Blind. In total, 157 visually impaired individuals were eligible for this study. Demographic information and information about visual impairments, lifestyle, and sleep patterns were assessed using questionnaires and subsequent telephone interviews. CRSWD and insomnia were defined according to the International Classification of Sleep Disorders-Third Edition criteria. RESULTS: The prevalence of CRSWD in visually impaired individuals was 33.1%. Among those with CRSWD, a non-24-h/irregular sleep-wake rhythm type was the most frequently observed (26.8%), followed by an advanced sleep-wake phase type and a delayed sleep-wake phase type (3.8 and 2.5%, respectively). Furthermore, 28.7% of the visually impaired individuals were found to have insomnia. In the visually impaired individuals, the absence of light perception, unemployment, living alone, and use of hypnotics were significantly associated with CRSWD, whereas only the use of hypnotics was extracted as a marginally associated factor of insomnia. CONCLUSIONS: CRSWD and insomnia were highly prevalent in visually impaired Japanese individuals. The presence of CRSWD among the visually impaired individuals was associated with a lack of light perception and/or social zeitgebers.