Retrospective study of degenerative mitral valve disease in small-breed dogs: survival and prognostic variables

Small-breed dogs (n = 168; weight < 15 kg) diagnosed with myxomatous mitral valve degeneration based on a routine clinical examination, radiology, electrocardiography, and echocardiography at the Seoul National University Veterinary Medical Teaching Hospital were included in this study. Survival periods were determined, and there were significant differences in survival rates among the three International Small Animal Cardiac Health Council classes. The mean follow-up period was 14.3 ± 12.1 months. Univariate analysis revealed that dyspnea, pulmonary edema, and vertebral heart score were significantly associated with survival time (p < 0.05). Additionally, age, left atrial-to-aortic root ratio, ejection fraction, and left ventricular end diastolic volume were associated with an increased risk of death (p < 0.1), while body weight, body condition score, systolic blood pressure, arrhythmia, syncope, fractional shortening, and end systolic volume were not associated with an increased risk of death. These results suggest that among the assessed variables dyspnea, pulmonary edema, and vertebral heart score could be useful prognostic factors for providing patient information to owners.

Canine adipose tissue-derived mesenchymal stem cells ameliorate severe acute pancreatitis by regulating T cells in rats

Severe acute pancreatitis (SAP) is associated with systemic complications and high mortality rate in dogs. Mesenchymal stem cells (MSCs) have been investigated for their therapeutic potential in several inflammation models. In the present study, the effects of canine adipose tissue-derived (cAT)-MSCs in a rat model of SAP induced by retrograde injection of 3% sodium taurocholate solution into the pancreatic duct were investigated. cAT-MSCs labeled with dioctadecyl-3,3,3′-tetramethylindo-carbocyanine perchlorate (1 × 10⁷ cells/kg) were systemically administered to rats and pancreatic tissue was collected three days later for histopathological, quantitative real-time polymerase chain reaction, and immunocytochemical analyses. Greater numbers of infused cAT-MSCs were detected in the pancreas of SAP relative to sham-operated rats. cAT-MSC infusion reduced pancreatic edema, inflammatory cell infiltration, and acinar cell necrosis, and decreased pancreatic expression of the pro-inflammatory cytokines tumor necrosis factor-α, interleukin (IL)-1β, -6, -12, -17, and -23 and interferon-γ, while stimulating expression of the anti-inflammatory cytokines IL-4 and IL-10 in SAP rats. Moreover, cAT-MSCs decreased the number of clusters of differentiation 3-positive T cells and increased that of forkhead box P3-positive T cells in the injured pancreas. These results indicate that cAT-MSCs can be effective as a cell-based therapeutic strategy for treatment of SAP in dogs.

Hyperammonemic hepatic encephalopathy management through L-ornithin-L-aspartate administration in dogs

Seventeen dogs were treated with L-ornithin-L-aspartate (LOLA; experimental group). Three dogs were treated with lactulose recognized therapy (control group). Following LOLA administration, 15 dogs experienced a significant decrease in ammonia level (p 0.05). These results suggest that LOLA is an effective drug to treat hyperammonemia in veterinary medicine.

Enhanced proliferation and differentiation of Oct4- and Sox2-overexpressing human adipose tissue mesenchymal stem cells

Mesenchymal stem cells (MSCs) are attractive candidates for clinical repair or regeneration of damaged tissues. Oct4 and Sox2, which are essential transcription factors for pluripotency and self-renewal, are naturally expressed in MSCs at low levels in early passages, and their levels gradually decrease as the passage number increases. Therefore, to improve MSC proliferation and stemness, we introduced human Oct4 and Sox2 for conferring higher expansion and differentiation capabilities. The Oct4-IRES-Sox2 vector was transfected into human adipose tissue MSCs (ATMSCs) by liposomal transfection and used directly. Oct4 and Sox2 were successfully transfected into ATMSCs, and we confirmed maintenance of MSC surface markers without alterations in both red fluorescent protein (RFP) (control) and Oct4/Sox2-ATMSCs. Enhanced proliferative activity of Oct4/Sox2-ATMSCs was shown by WST-1 assay, and this result was further confirmed by cell counting using trypan blue exclusion for a long period. In addition, FACs cell cycle analysis showed that there was a reduction in the fraction of Oct4/Sox2-ATMSCs in G1 with a concomitant increase in the fraction of cells in S, compared with RFP-ATMSCs. Increased levels of cyclin D1 were also seen in Oct4/Sox2-ATMSCs, indicating acceleration in the transition of cells from G1 to S phase. Furthermore, Oct4/Sox2-overexpressing ATMSCs showed higher differentiation abilities for adipocytes or osteoblasts than controls. The markers of adipogenic or osteogenic differentiation were also upregulated by Oct4/Sox2 overexpression. The improvement in cell proliferation and differentiation using Oct4/Sox2 expression in ATMSCs may be a useful method for expanding the population and increasing the stemness of ATMSCs.