Mortality and Operational Attributes Relative to Feral Horse and Burro Capture Techniques Based on Publicly Available Data From 2010-2019

Management of excessive feral horse (Equus ferus caballus) and burro (Equus asinus) populations in the United States and globally has been a controversial subject for decades. I reviewed all available US federal feral horse and burro daily gather reports from 2010 to 2019 to extract equine species, technique (bait trapping or helicopter gathering), reason (emergency or other), number gathered, number of mortalities, and mortality attributes (acute or chronic/pre-existing condition, specific cause). I found 70 reports (bait trapping burros n = 10, bait trapping horses n = 24, helicopter gathering horses n = 21) from 9 states (AZ, CA, CO, ID, MT, NV, OR, UT, WY) representing 28,821 horses and 2,005 burros. For bait trapping, 100 animals died (4 burros, 96 horses) with 16 acute causes (1 burro, 15 horses) and 84 chronic/pre-existing causes (3 burros, 81 horses). For helicopter gathering, 268 horses died with 62 acute causes and 206 chronic/pre-existing causes. Mortality ratios did not differ by capture technique (P > .05) for broken necks, emaciation, acute causes, or chronic/pre-existing causes. The most common mortality-causing problems were structural deformations, club foot, blindness, and emaciation. The more horses gathered per day resulted in a greater proportion of chronic/pre-existing mortalities for both trapping techniques, but only an increase of acute mortalities for helicopter gathering. The slope suggests 1 acute mortality for every 300 horses gathered. The capture mortality rate across all gathers [1.1% (368 mortalities out of 30,826 horses and burros captured)] is below a general threshold of 2% suggested for wildlife studies.     

Tissue Doppler and Strain Imaging in Dogs with Myxomatous Mitral Valve Disease in Different Stages of Congestive Heart Failure

Background: Tissue Doppler imaging (TDI) including strain and strain rate (SR) assess systolic and diastolic myocardial function.
Hypothesis: TDI, strain, and SR variables of the left ventricle (LV) and the interventricular septum (IVS) differ significantly between dogs with myxomatous mitral valve disease (MMVD) with and without congestive heart failure (CHF).
Animals: Sixty-one dogs with MMVD with and without CHF. Ten healthy control dogs.
Methods: Prospective observational study.
Results: Radial motion : None of the systolic variables were altered and 3 of the diastolic velocities were significantly increased in dogs with CHF compared with dogs without CHF and control dogs. Longitudinal motion : 2 systolic velocities and 3 diastolic velocities were significantly increased in dogs with CHF compared with dogs without CHF and control dogs. Difference in systolic velocity time-to-peak between LV and IVS was significantly increased in dogs with MMVD with and without CHF compared with control dogs. In total, 11 (23%) of 48 TDI and strain variables differed significantly between groups. Left atrial to aortic ratio was positively correlated to early diastolic velocities, percentage increase in left ventricular internal diameter in systole was positively correlated to systolic and diastolic velocities, and mitral E wave to peak early diastolic velocity in the LV basal segment (E/Em) was positively correlated to radial strain and SR.
Conclusions and Clinical Importance: Few TDI and strain variables were changed in dogs with MMVD with and without CHF. Intraventricular dyssynchrony may be an early sign of MMVD or may be an age-related finding.     

Mechanisms underlying protection of mouse myocardium against LPS-induced injury by Siduqing

AIM: To investigate the protective effect of Siduqing, a Chinese medicine, on LPS-induced myocardium injury in mice and its mechanisms. METHODS: Mice were divided into 4 group: control, LPS, Siduqing treatment and Siduqing group, and administered intragastrically with Siduqing decoction or distilled water (0.2 mL/10 g) twice a day for 3 days, two hours after Chinese herbal medicine treatment on day 3, LPS (30 mg/kg) or normal saline was injected intraperitoneally. The serum creatine kinase (CK) and myocardial superoxide dismutase (SOD) activities were determined, and myocardial tumor necrosis factor α (TNFα) and malondialdehyde (MDA) contents were also detected. In addition, the histological changes and ultrastructure of heart were examined. RESULTS: Histological examination showed edema in myocardium and architectural disarray at 12, 24 h after LPS injection, mitochondrial swelling, condensation and margination of chromatin, irregular nuclear envelope and loss of contractile filaments at 24 h post LPS administration, while Siduqing treatment attenuated the above pathological changes of myocardium. CK activity in serum and myocardial TNFα content were higher in LPS group than control and Siduqing treatment group. Myocardial SOD activity in siduqing treatment group was higher than that in LPS group, but there was no difference in myocardial MDA content between control, LPS and Siduqing treatment group. CONCLUSION: These data suggest that Siduqing protects myocardium against LPS- induced injury via inhibiting myocardial TNFα production.     

Roles of TGF-β1 and singal protein SMADs in rat myocardial hypertrophy

AIM: To investigate the role of SMADs singal pathway in rat myocardial hypertrophy. METHODS: The rat model of myocardial hypertrophy was produced by constriction of the abdominal aorta. The wet left vertricular/body weight ratio (LVMI) was measured. The expression of TGF-beta l and Smad 2, 3, 7 mRNA were assessed by RT-PCR. RESULTS: The LVMI and the expression of TGF-beta l and Smad 2, 3, 7 mRNA in cardiomyothy were increased in 3 day after the operation and continued at last 4 weeks. The peak expression of TGF-beta l and Smad 2, 3, 7 mRNA was in 2 weeks after operation. The expression of Smad 7 was increased in 3 days after operation, but the peak was in 1 week after operation, then decreased. CONCLUSION: The signal protein Smad 2, 3, 7 are involved in the progress of rat myocardial hypertrophy produced by constriction of abdominal aorta.     

Effect of hypoxia on persistent sodium current in ventricular myocytes from 3-week infarcted rat heart

AIM: To investigate the effect of hypoxia on persistent sodium current (INap) in single ventricular myocyte isolated from acute myocardial infarction (AMI) heart of rats and to study the mechanisms of cardiac arrhythmias that occur after AMI. METHODS: AMI model was induced by ligating the left anterior descending coronary artery in rats. The whole-cell patch clamp technique was used to record the current in epicardial myocytes in infarcted region from rats at 3 week after AMI. RESULTS: In normoxic conditions, the current density of INap in cardiomyocytes of fake operation (FO) and AMI hearts was 0.144±0.022 pA/pF (n=9), 0.121±0.013 pA/pF (n=9，P<0.01)， respectively, which was blocked by tetrodotoxin (TTX). The amplitude of INap was gradually increased with the prolongation of hypoxia time, but the increase in extent of INap in FO cells was significant bigger than that in AMI cells. The INap was blocked by 1 mmol/L glutathione. CONCLUSIONS: After AMI, the amplitude of INaP in infarcted and noninfarcted myocardium showed differences both in normoxic and hypoxic conditions, which increased dispersion of repolarization. This may be one of the reasons of reentrant ventricular arrhythmias that occur after AMI.     

Impacts of connexin 43 degradation on conduction velocity during acute myocardial ischemia

AIM:To study the impacts of the myocardial connexin 43 degradation on conduction velocity during acute myocardial ischemia.METHODS: Studies were carried out in 16 dogs which were randomly divided into control group(n=4) and ischemia group(n=12). The acute myocardial ischemia was induced by ligation of the left anterior descending coronary artery. The conduction velocity of ischemic myocardium was determined. The content of Cx43 of the ischemic myocardium was examined by laser confocal microscopy with a double-label immunohistochemistry technique. RESULTS:(1)The Cx43 degraded rapidly during acute myocardial ischemia, and the conduction velocity of ischemic myocardium declined greatly; (2)The conduction velocity correlated positively with the Cx43 pixel density in each small region of ischemic myocardium; (3) The Cx43 pixel density decreased over 50% in the region which occuring permanent conduction block.CONCLUSION: These data suggest the degradation of Cx43 decreases the conduction velocity greatly during acute short time myocardial ischemia, and severe degradation of Cx43 would lead to permanent conduction block.     

Nitric oxide opens the second window of protection in ischemic preconditioning via induction of heat shock protein 72

AIM:To examine the inhibition of nitric oxide (NO) synthesis during ischemic preconditioning (IP) on the induction of heat shock protein 72 (HSP72) and infarct size-limiting effect of the second window of protection. METHODS:Rabbits were subjected to 4 cycles of 5 min of coronary artery occlusion separated by 10 min reperfusion, or received a sham operation. During this procedure, N^G-nitro-L-arginine methyl ester (L-NAME, an inhibitor of NO synthase) was injected intravenously 5 min before IP followed by its continuous infusion. Twenty-four hours later, the hearts were rapidly excised for assaying HSP72 expression or were subjected to 30 min coronary artery occlusion followed by 120 min reperfusion and then measured infarct size (IS). RESULTS:Twenty-four hours later, immunoblotting revealed an increase in HSP72 protein levels in the IP group, and this was blocked by L-NAME. IS of the IP rabbits was reduced as compared with the control (29.8%±3.7% vs 50.8%±4.3%, P＜0.01). IS in the IP rabbits was elevtated as a result of L-NAME treatment (46.0%±5.1%). Administration of L-arginine reversed the effects of L-NAME on the induction of HSP72 and IS (33.5%±4.0%). The intravenous administration of S-nitroso-N-acetylpenicillamine (SNAP, a NO donor) increased the induction of HSP72 and reduced IS (31.3%±5.7%, P＜0.01vs control) 24 h later. CONCLUSION:These findings suggest that NO may be involved in the induction of HSP72 and the opening of the second window of protection of IP.     

miR-153 promotes LPS-induced myocardial H9C2 cell injury by targeting SORBS2

AIM: To study the effects of microRNA-153 (miR-153) on inflammatory factors, cell viability and apoptosis of embryonic rat H9C2 cardiomyocytes induced by lipopolysaccharide (LPS), and to explore its mechanism. METHODS: The injury model of H9C2 cells was established by LPS stimulation. The H9C2 cells were divided into anti-miR-Con group (transfected with anti-miR-Con), anti-miR-153 group (transfected with anti-miR-153), pcDNA group (transfected with pcDNA), pcDNA-SORBS2 group (transfected with pcDNA-SORBS2), anti-miR-153+si-Con group (co-transfected with anti-miR-153 and si-Con) and anti-miR-153+si-SORBS2 group (co-transfected with anti-miR-153 and si-SORBS2), and treated with LPS after transfection. The expression of miR-153 and SORBS2 mRNA in the cells was detected by RT-qPCR. The viability of H9C2 cells was measured by MTT assay. The protein expression of SORBS2 in the H9C2 cells was determined by Western blot. The contents of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were detected by ELISA. The apoptosis of the H9C2 cells was analyzed by flow cytometry. The targeting relationship between miR-153 and SORBS2 was verified by dual-luciferase reporter assay. RESULTS: The LPS-induced H9C2 cell injury model was successfully constructed. Compared with PBS group, the expression of miR-153 was significantly increased and the expression of SORBS2 was significantly decreased in the H9C2 cells treated with LPS. The inhibition of miR-153 and over-expression of SORBS2 decreased the contents of TNF-α and IL-6 and the level of apoptosis, but increased the cell viability. miR-153 inhibited the luciferase activity of the H9C2 cells containing wild-type SORBS2. Inhibition of SORBS2 reversibly inhi-bited the anti-inflammatory effects of miR-153 on LPS-induced H9C2 cells and increased the viability of the cells. CONCLUSION: miR-153 promotes the secretion of inflammatory factors, induces apoptosis, and inhibits the viability of H9C2 cells induced by LPS, thus enhancing the damage. Its mechanism may be related to targeting SORBS2, which will provide new targets for the treatment of myocardial injury.     

Mangiferin attenuates hypoxia/reoxygenation-induced injury of human myocardial cells

AIM To investigate the effect of mangiferin on hypoxia/reoxygenation (H/R)-induced injury of human myocardial cells and its mechanism. METHODS Human myocardial AC16 cells were divided into normal group, H/R group and H/R + mangiferin (50, 100 and 200 μmol/L) treatment groups. The mRNA and protein expression levels of Kelch-like epichlorohydrin-associated protein-1 (Keap-1), Bax, Bcl-2, caspase-3, caspase-9 and superoxide dismutase 2 (SOD2) were detected by RT-qPCR and Western blot, respectively. The protein expression of nuclear factor E2-related factor 2 (Nrf-2) in nucleus was determined by Western blot. The expression of microRNA-432-3p (miR-432-3p) was detected by RT-qPCR. The generation of reactive oxygen speciess (ROS) in the cells was measured by DCFH-DA probing. The cell viability was measured by CCK-8 assay. Apoptosis was analyzed by flow cytometry. RESULTS No significant difference in the expression of miR-432-3p and Keap-1 between normal group and H/R group was observed. Compared with normal group, the nuclear translocation of Nrf-2, the ROS level, and the mRNA and protein expression of Bax, caspase-3 and caspase-9 were significantly increased in H/R group （P<0.05）. The mRNA and protein expression of SOD2 and Bcl-2, and the cell viability significantly decreased in H/R group compared with normal group, while the apoptosis was increased significantly （P<0.05）. Treatment with mangiferin resulted in an increase in the miR-432-3p expression and a decrease in the ROS level, and the expression of Keap-1, Bax, caspase-3 and caspase-9 was also inhibited as compared with H/R group （P<0.05）. The Nrf-2 nuclear translocation, and the protein levels of SOD2 and Bcl-2 in mangiferin treatment groups were significantly increased as compared with H/R group （P<0.05）. The cell viability was increased significantly, and the apoptosis was decreased significantly in mangiferin treatment groups as compared with H/R group （P<0.05）. The effects of mangiferin in middle- and high-dose groups were better than those in low-dose group, and no significant difference between middle- and high-dose groups was found. CONCLUSION Mangiferin inhibits the decrease in myocardial cell viability and the apoptosis induced by H/R injury. The mechanism may be related to the up-regulation of Nrf-2 antioxidant stress effect via enhancing the expression of miR-432-3p.