The first report of the ante-mortem diagnosis of Ollulanus tricuspis infection in two dogs

Ollulanus tricuspis is a small nematode parasite of the stomach, and its infection has been reported worldwide in cats but only one report in dogs as post-mortem diagnosis. Two dogs, kept in the Tokyo area, were presented for chronic vomiting. Chronic gastritis was diagnosed histologically, and many nematodes were detected in endoscopically-biopsied gastric samples and in the mucus of vomitus in both dogs. The parasites were small (<1 mm), and their morphological characteristics were consistent with those previously reported for O. tricuspis. The symptoms in one dog completely disappeared after anthelmintic therapy. To our knowledge, this is the first report describing ante-mortem diagnosis of spontaneous gastric O. tricuspis infection in dogs in which infectivity and pathogenicity of the nematode are suggested.     

Enhancement of interleukin-2 production by bovine peripheral blood mononuclear cells treated with the combination of anti-programmed death-ligand 1 and cytotoxic T lymphocyte antigen 4 chimeric monoclonal antibodies

Our previous studies demonstrate the therapeutic efficacy against bovine diseases of an anti-bovine programmed death-ligand 1 (PD-L1) chimeric antibody. In humans, PD-1 and PD-L1 antibodies are more effective when combined with an antibody targeting cytotoxic T lymphocyte antigen 4 (CTLA-4) and these combination therapies are therefore clinically used. Here we generated an anti-bovine CTLA-4 chimeric antibody (chAb) to enhance the therapeutic efficacy of the PD-L1 antibody. We further analyzed the effects of dual blockade of CTLA-4 and PD-1 pathways on T-cell responses. The established anti-bovine CTLA-4 chAb showed comparable blocking activity on the binding of bovine CTLA-4 to CD80 and CD86 as the anti-bovine CTLA-4 mouse monoclonal antibody. Anti-bovine CTLA-4 chAb also significantly increased IL-2 production from bovine peripheral blood mononuclear cells (PBMCs). Further, the combination of anti-CTLA-4 chAb with anti-PD-L1 chAb significantly upregulated IL-2 production by PBMCs. These results suggest that the combination of antibodies have higher potential to enhance immune responses against pathogens compared with single administration.     

Elucidation of the neurological effects of clothianidin exposure at the no-observed-adverse-effect level (NOAEL) using two-photon microscopy in vivo imaging

Neonicotinoid pesticides (NNs) cause behavioral abnormalities in mammals, raising concerns about their effects on neural circuit activity. We herein examined the neurological effects of the NN clothianidin (CLO) by in vivo Ca²⁺ imaging using two-photon microscopy. Mice were fed the no-observed-adverse-effect-level (NOAEL) dose of CLO for 2 weeks and their neuronal activity in the primary somatosensory cortex (S1) was observed weekly for 2 weeks. CLO exposure caused a sustained influx of Ca²⁺ in neurons in the S1 2/3 layers, indicating hyperactivation of neurons. In addition, microarray gene expression analysis suggested the induction of neuroinflammation and changes in synaptic activity. These results demonstrate that exposure to the NOAEL dose of CLO can overactivate neurons and disrupt neuronal homeostasis.     

Maximum volume of nasal administration using a mucosal atomization device without aspiration in Japanese White rabbits

Recently, a mucosal atomization device (MAD) has been applied in veterinary medicine. In the present study, the maximum volume of nasal atomization without aspiration using MAD was examined in eight healthy female Japanese White (JW) rabbits. Each rabbit had their head and neck examined by computed tomography before and after nasal atomization with four different doses (0.15, 0.3, 0.45, and 0.6 ml per nostril) of diluted contrast medium (1:2 mixture of iohexol and saline). This was done under general anesthesia by an intramuscular administration of alfaxalone 2.5 mg/kg, medetomidine 40 μg/kg, and butorphanol 0.4 mg/kg, with a 7-day washout period between each treatment. The diluted contrast medium was distributed in the nasal cavity, external nares, and/or oral cavity in all rabbits receiving each treatment. The intranasal distribution volumes of the contrast medium were 287 (250–333) mm³ [median (interquartile range)] for 0.15 ml, 433 (243–555) mm³ for 0.3 ml, 552 (356–797) mm³ for 0.45 ml, and 529 (356–722) mm³ for 0.6 ml of treatment. The intranasal distribution volume for 0.15 ml treatment tended to be lower than that for 0.6 ml treatment (P=0.083). The contrast medium was deposited in the trachea in one rabbit (12.5%) and four rabbits (50%) receiving treatments of 0.45 and 0.6 ml per nostril, respectively. The maximum volume of nasal atomization without aspiration into the trachea was 0.3 ml per nostril for the JW rabbits.     

Glutathione supplementation to semen extender improves the quality of frozen-thawed canine spermatozoa for transcervical insemination

The present study was conducted to evaluate whether supplementation of semen extender with glutathione (GSH) can maintain the quality of frozen-thawed canine spermatozoa. Eighteen ejaculates were obtained from 5 dogs and placed in extender (20% egg yolk, Tris, citric acid, lactose, raffinose, antibiotics and 6.5% glycerol) containing 0 (control), 2.5, 5, 7.5 or 10 mM GSH. The samples were cooled to 4 C and then frozen in liquid nitrogen vapor. Motility parameters of the sperm were evaluated at 0, 1, 2, 3, 4, 12 and 24 h after thawing. Sperm motility was higher in the 5 mM GSH group than in the control or 2.5 and 10 mM GSH groups; this effect was observed at 1 to 24 h after thawing (P < 0.05). The 5 mM GSH group had a higher sperm viability index at 12 and 24 h after thawing compared with the other groups (P < 0.05). Acrosome integrity, evaluated at 4 h after thawing, was greater in two of the GSH-treated groups (5 and 10 mM) compared with the control. Lipid peroxidation (LP) levels immediately after thawing were lower in the 5 and 10 mM GSH groups compared with the control, while those at 12 h after thawing did not differ significantly. Frozen-thawed semen in the 5 mM GSH group was used for transcervical insemination of 4 bitches, resulting in delivery of 5 puppies from 2 bitches. These results indicate that supplementation of semen extender with 5 mM GSH was effective in improving motility, longevity and acrosomal integrity and inhibiting LP levels in post-thaw canine spermatozoa, without any adverse impacts on full-term development after transcervical insemination.