Stress responses to warming in the mussel Brachidontes rodriguezii (d'Orbigny, 1842) from different environmental scenarios.

The intertidal mussel B. rodriguezii is a representative species from hard bottom substrates where both anthropogenic and natural stressors are present. Pre-exposure to these different stressors can modify the tolerance to additional stressors such as warming. Moreover, this tolerance can vary depending on intraspecific variables such as the organism's sex. The effects of warming and its intraspecific variability in representative coastal species are crucial to understanding the tolerance to future environmental scenarios. The mussels were collected in different environmental scenarios, including low (Control), chemical (Harbour) and natural stressed (Estuary) sites, and then exposed to different water temperatures (10-30 °C) for 14 days. Lethal and sublethal responses were evaluated in different mussel populations. Thus, cumulative death rate, air survival time, heat shock proteins (HSC70/HSP70), total ubiquitin, catalase (CAT), glutathione-s-transferase (GST) and lipid peroxidation (TBARS) were assessed in mussels from different areas and different sexes. The results revealed diminished air survival time and high cumulative mortality rate in mussels collected at the harbour and those exposed to higher temperatures, respectively. The sublethal responses of the field animals showed different patterns according to the different areas investigated. Besides, the results revealed that these differences were also observed between sexes. Regarding the sublethal responses in mussels exposed to warming, the interactive effects of temperature and sites showed a strong influence on all biochemical parameters analyzed (p < 0.001). Therefore, harbour mussels showed a distinct pattern compared to other locations and reflecting the most damaging effects of warming. The influence of sex and its interactions with warming were also crucial in most of the sublethal responses (p < 0.05). Multivariate analysis was performed with all sublethal responses, and the different warming scenarios showed different groups according to the sites. In the predicted warming scenarios, males showed no differences between sites. In contrast to males, females showed differences between sites in the predicted and the worse-case warming scenarios. Our results highlight the importance of compensatory mechanisms in the mussel warming tolerance like HSP70. The influence of sex is also crucial in understanding warming tolerance in mussels chronically exposed to pollutants in their natural environment. Also, lethal endpoints are essential for understanding the non-reversibility signature of the observed biochemical responses.

Effects of 6% Tetrastarch and Lactated Ringer's Solution on Extravascular Lung Water and Markers of Acute Renal Injury in Hemorrhaged, Isoflurane-Anesthetized Healthy Dogs.

BACKGROUND: Tetrastarch can cause acute kidney injury (AKI) in humans with sepsis, but less likely to result in tissue edema than lactated Ringer's solution (LRS). OBJECTIVES: Compare effects of volume replacement (VR) with LRS and 6% tetrastarch solution (TS) on extravascular lung water (EVLW) and markers of AKI in hemorrhaged dogs. ANIMALS: Six healthy English Pointer dogs (19.7-35.3 kg). METHODS: Prospective crossover study. Animals underwent anesthesia without hemorrhage (Control). Two weeks later, dogs hemorrhaged under anesthesia on 2 occasions (8-week washout intervals) and randomly received VR with LRS or TS at 3 : 1 or 1 : 1 of shed blood, respectively. Anesthesia was maintained until 4 hour after VR for EVLW measurements derived from transpulmonary thermodilution cardiac output. Neutrophil gelatinase-associated lipocalin (NGAL) and creatinine concentrations in plasma and urine were measured until 72 hour after VR. RESULTS: The EVLW index (mL/kg) was lower at 1 hour after TS (10.0 ± 1.9) in comparison with controls (11.9 ± 3.4, P = 0.04), and at 4 hour after TS (9.7 ± 1.9) in comparison with LRS (11.8 ± 2.7, P = 0.03). Arterial oxygen partial pressure-to-inspired oxygen fraction ratio did not differ among treatments from 0.5 to 4 hour after VR. Urine NGAL/creatinine ratio did not differ among treatments and remained below threshold for AKI (120,000 pg/mg). CONCLUSIONS AND CLINICAL IMPORTANCE: Although TS causes less EVLW accumulation than LRS, neither fluid produced evidence of lung edema (impaired oxygenation). Both fluids appear not to cause AKI when used for VR after hemorrhage in healthy nonseptic dogs.

Eletroacupuntura para tratamento de hipotensão induzida por isofluorano em cavalos / Electroacupuncture treatment for isoflurane induced hypotension in horses

Objetivou-se avaliar a eficiência do tratamento da hipotensão arterial com eletroacupuntura comparativamente à dobutamina em equinos. Foram avaliados seis cavalos adultos, saudáveis, mantidos em anestesia inalatória, com isofluorano, em ventilação mecânica. Após a estabilização da anestesia, foi induzida hipotensão arterial, através do incremento da concentração do isofluorano, iniciando-se um dos tratamentos: DOB: dobutamina (1,5µg kg-1 min-1, infusão contínua intravenosa); EA: estímulo elétrico no acuponto pericárdio 6 (PC6), bilateralmente; SHAM: estímulo elétrico em ponto falso de acupuntura. Foram mensurados: frequência cardíaca (FC), pressão arterial média (PAM), temperatura retal (T), concentração final expirada de isofluorano (ETiso), variáveis hemogasométricas, concentração sérica de aspartato aminotransferase (AST) e creatina fosfoquinase (CK), tempo e qualidade da recuperação pós-anestésica. Houve incremento na PAM de 50%, 36,6% e 7,5% nos tratamentos DOB, EA e SHAM, respectivamente. Não houve diferença entre os grupos nas variáveis hemogasométricas, FC, T, ETiso, CK, AST, tempo e qualidade de recuperação pós-anestésica. Conclui-se que o tratamento com dobutamina foi mais efetivo para o tratamento da hipotensão em cavalos sob anestesia inalatória quando comparado ao estímulo elétrico do acuponto PC6 ou ponto falso de acupuntura...

This study aimed to evaluate the efficacy of electroacupuncture compared to the dobutamine treatment of hypotension in equines. Six adult horses were maintained in isoflurane anesthesia with mechanical ventilation. After anesthesia was established, the isoflurane concentration was raised until hypotension was achieved. After that the animals were treated with a constant rate of 1.5mg kg -1min-1 intravenous dobutamine (DOB), electroacupunture to pericardium 6 (PC-6) acupoint (EA) and false point treatment (SHAM). Heart rate (HH), median arterial blood pressure (MAP), rectal temperature (T), isoflurane end-tidal concentration, arterial blood gases, creatine kinase (CK), aspartate transaminase (AST), recovery time and quality of recovery were investigated. The MAP increased 50%, 36.5% and 7.5%% in DOB, EA and SHAM treatments, respectively. HH, T, arterial blood gases, CK, AST, recovery time and quality of recovery did not differ among treatments. It was concluded that the dobutamine treatment was more effective than EA and SHAM treatments for the reversion of isoflurane induced hypotension in horses...

Eletroacupuntura para tratamento de hipotensão induzida por isofluorano em cavalos / Electroacupuncture treatment for isoflurane induced hypotension in horses

Objetivou-se avaliar a eficiência do tratamento da hipotensão arterial com eletroacupuntura comparativamente à dobutamina em equinos. Foram avaliados seis cavalos adultos, saudáveis, mantidos em anestesia inalatória, com isofluorano, em ventilação mecânica. Após a estabilização da anestesia, foi induzida hipotensão arterial, através do incremento da concentração do isofluorano, iniciando-se um dos tratamentos: DOB: dobutamina (1,5µg kg-1 min-1, infusão contínua intravenosa); EA: estímulo elétrico no acuponto pericárdio 6 (PC6), bilateralmente; SHAM: estímulo elétrico em ponto falso de acupuntura. Foram mensurados: frequência cardíaca (FC), pressão arterial média (PAM), temperatura retal (T), concentração final expirada de isofluorano (ETiso), variáveis hemogasométricas, concentração sérica de aspartato aminotransferase (AST) e creatina fosfoquinase (CK), tempo e qualidade da recuperação pós-anestésica. Houve incremento na PAM de 50%, 36,6% e 7,5% nos tratamentos DOB, EA e SHAM, respectivamente. Não houve diferença entre os grupos nas variáveis hemogasométricas, FC, T, ETiso, CK, AST, tempo e qualidade de recuperação pós-anestésica. Conclui-se que o tratamento com dobutamina foi mais efetivo para o tratamento da hipotensão em cavalos sob anestesia inalatória quando comparado ao estímulo elétrico do acuponto PC6 ou ponto falso de acupuntura.(AU)

This study aimed to evaluate the efficacy of electroacupuncture compared to the dobutamine treatment of hypotension in equines. Six adult horses were maintained in isoflurane anesthesia with mechanical ventilation. After anesthesia was established, the isoflurane concentration was raised until hypotension was achieved. After that the animals were treated with a constant rate of 1.5mg kg -1min-1 intravenous dobutamine (DOB), electroacupunture to pericardium 6 (PC-6) acupoint (EA) and false point treatment (SHAM). Heart rate (HH), median arterial blood pressure (MAP), rectal temperature (T), isoflurane end-tidal concentration, arterial blood gases, creatine kinase (CK), aspartate transaminase (AST), recovery time and quality of recovery were investigated. The MAP increased 50%, 36.5% and 7.5%% in DOB, EA and SHAM treatments, respectively. HH, T, arterial blood gases, CK, AST, recovery time and quality of recovery did not differ among treatments. It was concluded that the dobutamine treatment was more effective than EA and SHAM treatments for the reversion of isoflurane induced hypotension in horses.(AU)