Uncoupling protein 1 (UCP1) is responsible for non-shivering thermogenesis in brown/beige adipocytes in humans and rodents. Previously, we showed unexpected expression of UCP1 in bovine skeletal muscles. Here we evaluated Ucp1 mRNA levels in the muscle tissue of Japanese Black steers. Expression of Ucp1 was higher in 30-month-old cattle than in 26-month-old cattle. Levels of myosin heavy chain (Myh)1, an MYH predominantly expressed in fast-twitch muscles, were also significantly higher in cattle aged 30 months. A similar tendency was observed in the expression of other Myhs that are highly expressed in fast-twitch muscles, Myh2 and Myh4. Ucp1 expression was positively correlated with expression of Myh1, Myh2, and Myh4. Our results indicate the possibility of Ucp1 expression in fast-twitch muscle fibers.

Immunotherapy is a breakthrough in human cancer therapy and has become a major concern in veterinary oncology. However, in cats, many unclear points of the tumor microenvironment exist, including immune checkpoint molecules. A reason is that very few monoclonal antibodies have been proven to react with feline molecules. Therefore, this study investigated whether anti-human programmed cell death ligand 1 (PD-L1) monoclonal antibody, clone 28-8, which is currently commercially available, can also recognize feline PD-L1 by flow cytometry, immunoprecipitation, and immunohistochemical (IHC) staining. We confirmed that the antibody’s specificity by flow cytometry and immunoprecipitation using NIH3T3 cells transfected with feline PD-L1. Additionally, we revealed that PD-L1 was expressed on the surface of some feline cell lines by flow cytometry and clone 28-8 antibody unbound to the cells where feline PD-L1 was knocked out. Furthermore, IHC analysis revealed that PD-L1 was expressed in macrophages in the spleen and lymph nodes from healthy cats and mast cell tumor cells. Therefore, we indicated that the clone 28-8 antibody is a valuable tool in detecting feline PD-L1, and further analysis of tumor tissues is expected in the future.

Urine neutrophil gelatinase-associated lipocalin (NGAL) is a marker of acute kidney injury and indicates tubular damage. Lupus nephritis-associated renal injury is characterized by damage to the glomeruli and tubular portions of the kidneys. Therefore, NGAL concentrations are expected to vary according to the severity of systemic lupus erythematosus (SLE). In this study, samples from (NZB × NZW) F1 mice at an advanced stage of SLE were used to determine whether serum and urine NGAL concentrations or the urine NGAL:creatinine (uNGAL/C) ratio can be used to reflect diet, disease state, and treatment efficacy. Additionally, the relationship between the levels of NGAL and various cytokines in the serum in SLE was evaluated. Mice were divided into the following four groups (n=15): CN, chow diet and no treatment (saline; intraperitonially injected [i.p.]; 200 μL/day); CP, chow diet and methylprednisolone (i.p.; 5 mg/kg/day); HN, high-fat diet and no treatment (saline [i.p.]; 200 μL/day); and HP, high-fat diet and methylprednisolone treatment (i.p.; 5 mg/kg/day) every day from 6 to 42 weeks of age. The serum and urine NGAL levels and uNGAL/C values were significantly lower in the CP group than those in the CN group. Further, serum NGAL concentration demonstrated a strong positive correlation with urine NGAL levels, uNGAL/C, urine protein concentrations, urine protein:creatinine ratio, and the expression of several cytokines associated with SLE pathogenesis (interleukin [IL]-6, tumor necrosis factor [TNF]-α, and interferon-induced protein [IP]-10). These results suggest that NGAL has a strong positive correlation with the clinicopathological parameters and several key cytokines in SLE.

A 9-year-old female meerkat (Suricata suricatta) succumbed to progressive abdominal distension, anorexia, and depression. Necropsy revealed an extensively distended abdomen with ascites and markedly enlarged liver. The liver had multiple yellowish masses and displaced the thoracic cavity and abdominal organs. There was no evidence of metastatic lesions based on the gross and microscopic findings. Histologically, the liver mass was composed of locally invasive well-differentiated neoplastic adipocytes with Oil Red O-positive lipid vacuoles. Immunohistochemistry revealed positive immunoreactivity to vimentin, S-100 and negative to pancytokeratin, desmin, smooth muscle actin (SMA), ionized calcium-binding adapter molecule 1 (IBA-1). Thus, the primary well differentiated hepatic liposarcoma was diagnosed based on gross, histological and immunohistochemistry results.

Environmental pollution caused by antimicrobial resistance is a global public health concern. To investigate the contribution of nutrias (Myocastor coypus) to the presence of extended-spectrum β-lactamase (ESBL)–producing Enterobacterales in the Ijira River, prevalence of ESBL–producing Enterobacterales in their feces was examined using deoxycholate-hydrogen sulfide-lactose agar containing cefotaxime. Additionally, the composition of the fecal microbiota of nutria was examined using DNA metabarcoding analysis of the 16S ribosomal RNA gene and compared with that of Amami rabbit, deer, fox, and raccoon dog. The absence of ESBL–producing Enterobacterales and substantially lower abundance of Enterobacterales was observed in the feces of nutrias than in those of other wild mammals. Our results suggest the low potential of antimicrobial-resistant Enterobacterales persistence and dissemination by nutria.

Micro-endoscopic discectomy (MED) or microscopic discectomy (MD) have been performed for disc herniation in humans. The purpose of this study was to compare the invasiveness of the hemilaminectomy in dogs between the approach using a cylindrical retractor for the MED/MD and a conventional open surgical approaches in dogs. First, as preliminary studies, we analyzed the suitability of the cylindrical retractor for the vertebral body of small to medium-sized dogs on the X-ray computed tomographic images using the three-dimensional analysis software, and confirmed that it was possible to open a bone window of an approximate length of 1.72 clto the spinal canal with the cylindrical retractor with a diameter 17 mm using two medium-sized canine cadavers. Next, to determine difference in the invasiveness of hemilaminectomy, the magnitude of tissue damage, surgical stress and postoperative pain were compared between the conventional open approach (hemilaminectomy group: HL group, n=6) and the surgical approach using the cylindrical retractor (MD group, n=6) in 12 beagle dogs. The plasma creatine phosphokinase, C-reactive protein and cortisol concentrations, incision length and University of Melbourne Pain Scale scores after the hemilaminectomy were significantly lower in the MD group than in the HL group. There were no significant differences between the durations of surgery and the other evaluated indices. The approach using the MD can provide a less invasive hemilaminectomy than the conventional approach in dogs.

Among bats, rhinolophoids and yangochiropterans, but not pteropodids, exhibit laryngeal echolocation. Although Rousettus has been regarded as the only pteropodid capable of echolocation using tongue clicks, recent evidence suggests that other species of pteropodids are also capable of echolocation using wing clicks. Studies on laryngeal echolocators suggest that delicate ear movements are essential for the echolocation behavior of bats and that the cervicoauricularis muscles play a critical role in such ear movements. In this study, we observed the gross anatomy of cervicoauricularis muscles in three species of pteropodids (Cynopterus sphinx, Eonycteris spelaea, and Rousettus leschenaultii) to examine whether ear muscle anatomy varies among pteropodids with different echolocation types and between pteropodids and laryngeal echolocating bats. We found that M. cervicoauricularis profundus originates from the nuchal crest in tongue-click echolocators (R. leschenaultii) and from the midline in wing-click echolocators (C. sphinx and E. spelaea). In general, tongue-click echolocation using high click rates is considered to be more sophisticated in terms of sonar performance than wing-click echolocation. M. cervicoauricularis profundus originating from the nuchal crest (CPNC) is not common in non-bat laurasiatherian mammals, but can be found in laryngeal echolocating bats. As it pulls the ear pinna caudally in the horizontal plane and increases the access to sound, CPNC found in R. leschenaultii and laryngeal echolocating bats may be a key characteristic of the sophisticated active echolocation behavior of bats.

Several studies have documented the effects of anesthesia on pigeons. However, previous studies using pigeons have not examined a combination of injection and inhalation anesthesia. This study aimed to evaluate the effects of intramuscular (IM) administration of alfaxalone in conjunction with mask induction on the quality of isoflurane anesthesia in healthy domestic pigeons (Columba livia domestica). In a randomized, double-blind, crossover study consisting of two phases, six healthy adult pigeons were anesthetized twice with a washout period of 7 days. In each phase, the pigeons were randomly assigned IM administration of either alfaxalone (4 mg/kg) or an equal volume of normal saline. After 20 min, anesthesia was induced with isoflurane through a face mask. Once voluntary movement of the limbs and eyelids ceased, the face mask was removed, and the trachea was intubated. The quality of anesthesia was assessed by scoring sedation prior to anesthetic induction, induction, and recovery. Heart rate, respiratory rate, cloacal temperature, and noninvasive systolic, diastolic, and mean arterial pressure were recorded before the IM injection (baseline) and during the procedure. The minimum anesthetic concentration of isoflurane was determined using the “bracketing” method. Moderate sedation (sedation scores of 2 and 3) was observed only with alfaxalone administration. In the alfaxalone group, the induction score was significantly higher (better induction quality) than in the control group (P=0.041). The combination of alfaxalone and mask induction was effective for inhalation anesthesia in pigeons.