Articular chondrocytes experience a transient increase in proliferation and subsequent loss of chondrogenic phenotype in the early stage of osteoarthritis (OA). Pentosan polysulfate sodium (PPS) is a highly sulfated polysaccharide semi-synthetic from glucuronoxylan hemicelluloses, which has been applied for OA management in animals. To investigate the efficacy of different sulfate levels (5, 16%, and 19% as full sulfate level; w/w% of sulfur atoms) of PPS and unsulfured glucuronoxylan (as 0%) on cell cycle regulation and promotion of chondrogenic phenotype in canine articular chondrocytes. Canine chondrocytes were cultured for 24 hr, then incubated with PPS for 72 hr. Chondrocyte viability was measured by a 3-(4,5-di-methylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cytotoxicity of PPS and cell cycle progression of chondrocytes were checked by flow cytometry. The mRNA levels of cell cycle regulators and chondrocyte phenotypic markers was quantitatively evaluated. Activity of PI3K/Akt pathway was detected by Western blotting. All sulfate levels PPS showed no cytotoxic effect in chondrocytes, while fully sulfated PPS suppressed chondrocyte cell cycle transition from the G1 to later phases at a high concentration. Chondrocytes cultured with full sulfate level PPS significantly reduced cyclin dependent kinase 4 (CDK4) and cyclin D1 (CCND1) mRNA levels, and upregulated type II collagen (COL2A1) and SRY-box 9 (SOX9) expression levels. Akt phosphorylation and PI3K catalytic subunit alpha (p110α) protein production were inhibited in “full” group. PPS suppressed the proliferation in canine articular chondrocytes by targeting PI3K/Akt pathway, and promoted chondrocyte specific gene expression. Full sulfate level maybe necessary for PPS to achieve these effects in chondrocytes.

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The open field test is a basic test used to assess exploratory behavior, anxiety, and locomotor activity in rodents. Some quantitative trait loci (QTLs) regarding mouse behavior in open field were identified so far. A QTL associated with grooming duration was identified in chromosome (Chr) 4 using recombinant inbred strain made from DBA/2 (D2) and C57BL/6 (B6) mice. We previously generated D2 congenic line, D2.B6-Sen1, in which most region of Chr 4 was replaced to B6 haplotype. In this paper, to confirm the position of this QTL and to investigate candidate genes, two sub-congenic lines, D2.B6-Sen1.1 and D2.B6-Sen1.2, were generated. From results of open field test with a congenic and two sub-congenic strains, we found that D2.B6-Sen1.2 increased grooming duration compared with D2, but D2.B6-Sen1.1 demonstrated opposite result, suggesting two genes responsible for grooming duration located in Chr 4. We also found that only D2.B6-Sen1 mice decreased the time in thigmotaxis zone, suggesting another gene responsible for this behavior located in B6-derived chromosomal region.

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Chicken is a potent source of human Campylobacter infections. Hence, we investigated the prevalence and antimicrobial resistance of Campylobacter in 440 vacuum-packed chicken breast products during April–December 2021. Campylobacter was isolated from 174 samples (39.5%), in which the mean concentration of Campylobacter was 1.42 ± 0.65 log₁₀ CFU/g, and 19.0% of the positive samples contained > 2.0 log₁₀ CFU/g of Campylobacter. Campylobacter prevalence was significantly (P < 0.01) higher in Western Japan (64.2%) than in Eastern Japan (26.6%). The highest prevalence of Campylobacter in Western and Eastern Japan was observed in August (74.1%) and October (47.8%), respectively. A total of 149 Campylobacter jejuni and 37 C. coli isolates were obtained. C. coli was more frequent among Campylobacter isolated from Western Japan (29.1%) than those obtained from Eastern Japan (6.6%). Among all C. coli isolates, 73.0% and 37.8% were ciprofloxacin- and erythromycin-resistant, respectively. All C. jejuni isolates were susceptible to erythromycin. However, 42.3% of them were ciprofloxacin-resistant. Ciprofloxacin-resistant C. jejuni was significantly (P < 0.01) more frequently in isolates collected from Western Japan than in isolates obtained from Eastern Japan. This study revealed the geographical and seasonal variations in the prevalence of Campylobacter in chicken products. Chicken meat becomes contaminated with Campylobacter while slaughtering Campylobacter-infected broiler flocks in processing plants. Therefore, the development of efficient strategies for decreasing Campylobacter infection in broiler flocks in Western Japan should be prioritized to reduce human Campylobacter infections.

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Bovine respiratory disease (BRD) is an important and complex disease caused by various pathogens and stressors. Although BRD is often caused by viruses, secondary bacterial infections can worsen symptoms and prognosis. Due to this viral-bacterial synergy, the evaluation of bacterial infections in BRD is important for the diagnosis and prognosis of BRD. In this study, we analyzed the serum concentrations of procalcitonin (PCT), a biomarker of bacterial infection, in 41 calves with BRD. We demonstrate that when calves are categorized into PCT-positive and PCT-negative groups based on serum PCT concentrations, the PCT-positive group shows more persistently high BRD scores. These findings suggest that the measurement of serum PCT is potentially useful for the diagnosis and prognosis of calves with BRD.

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