Tenri University

Activated partial thromboplastin time (APTT) prolongation occurs due to coagulation factor deficiencies/inhibitors, lupus anticoagulant (LA), and anticoagulant-taking, necessitating discrimination through further testing. Clot waveform analysis (CWA) can discriminate causes while measuring APTT, but conventional CWA exhibits moderate accuracy due to visual judgement and limited parameter use. We applied deep learning (DL) techniques to huge numerical data constituting clot waveforms and their first- and second-derivative curves (CWA curves) to leverage hidden features for developing an accurate classification model. We utilized a multi-wavelength detection system embedded in modern coagulometers to obtain multi-wavelength CWA curves. A convolutional neural network-based DL model was trained on 683 samples (135 hemophilic, 95 LA-positive, 99 heparin-treated, 105 warfarin-treated, and 249 direct oral anticoagulant-treated) and evaluated using 10-fold cross-validation. Conventional CWA parameters showed limited discrimination abilities (area under the curve [AUC] 0.532-0.858). DL models using single-wavelength CWA curves achieved higher performance (AUC 0.943-0.988), and multi-wavelength CWA curves further improved it (AUC 0.961-0.993) with high sensitivity (≥ 88.0%), specificity (> 92.0%), and overall accuracy (88.4%), although the performance may depend on reagents and/or analyzers. DL models using multi-wavelength CWA curves show promise as high-performance screening tools for classifying APTT prolongation causes and are best built in each laboratory.

We aimed to screen the entire genome for genetic variants associated with passive muscle stiffness, which has been suggested as a risk factor for muscle strain injury.

This genome-wide association study (GWAS) on passive muscle stiffness included 350 physically active young Japanese individuals. Three hamstring constituents were measured using ultrasound shear wave elastography. Skeletal muscle transcriptomes were compared across the genotypes of GWAS-identified variants in 48 healthy Japanese individuals. Association between GWAS-identified variants and history of muscle strain injury was examined in 1428 Japanese athletes.

Two loci on chromosome 11 demonstrated a genome-wide significant association with passive muscle stiffness of the biceps femoris long head (rs12807854 T/C: P = 5.19 × 10−10, rs78405694 T/C: P = 2.09 × 10−8; linear regression analysis adjusted for sex, age, and stretching exercise habits). Skeletal muscle RNA sequencing revealed significantly elevated expression of extracellular matrix-related genes in muscles carrying stiffness-increasing alleles of these variants. Among athletes, rs12807854 T/C was significantly associated with a history of muscle strain injury (P = 0.0254; logistic regression analysis adjusted for age, sex, competitive level, and main sport). Carriers of the C allele, associated with increased muscle stiffness, exhibited a heightened risk of muscle strain injury (odds ratio = 1.62; 95% confidence interval = 1.06–2.47 per C allele increase). By contrast, rs78405694 did not show a significant association with muscle strain injury in this population.

A novel locus associated with passive muscle stiffness and muscle strain injury was identified. Elucidating the detailed mechanisms linking the identified locus to passive muscle stiffness may lead to the development of new strategies to prevent muscle strain injuries.

Five strains related to the genus Rodentibacter were isolated from five pet hamsters kept in Japan. Isolates were genotypically and phenotypically distinct from previously described species within the genus Rodentibacter (family Pasteurellaceae). The five strains were the most genetically similar to Rodentibacter haemolyticus 1625-19T, exhibiting a 16S rRNA gene sequence similarity of 96.5%, an average nucleotide identity value of 90.8% and a digital DNA–DNA hybridization value of 42.7%. Phenotypic characteristics further distinguish the isolated strains from other Rodentibacter species. Although they share β-haemolysis capacity with R. haemolyticus, the novel strains are differentiated by their positive reactions for α-glucosidase, l-arabinose and trehalose, as well as negative reactions for β-glucuronidase, mannose, inositol and glycerol. Genotypic and phenotypic differences between the novel strains and closely related known strains suggested that we have identified a new Rodentibacter species. We propose the name Rodentibacter abscessus sp. nov. The type strain is THUN1654T with a G+C DNA content of 40.6 mol%, and it is deposited in the DSMZ Germany (DSM 118002T), KCTC Korea (KCTC 8595T) and JCM Japan (JCM 37054T).