Aims: Acute liver failure (ALF) is a fatal syndrome attributed to massive hepatocyte death. Hydrogen sulfide (H 2 S) has been reported to exert cytoprotective or cytotoxic effects. Here, we examined the role of cystathionine clyase (CSE, an enzyme produces H 2 S) in ALF induced by D-Galactosamine (GalN) and lipopolysaccharide (LPS). Results: Wild-type (WT) mice exhibited high mortality rate, prominent liver injury, and increased plasma alanine aminotransferase levels after GalN/LPS challenge. Congenital deficiency or chemical inhibition of CSE by DLpropargylglycine attenuated GalN/LPS-induced liver injury. CSE deficiency markedly improved survival rate and attenuated GalN/LPS-induced upregulation of inflammatory cytokines and activation of caspase 3 and poly (ADP-ribose) polymerase (PARP) in the liver. CSE deficiency protected primary hepatocytes from GalN/tumor necrosis factor-a (TNF-a)-induced cell death without affecting LPS-induced TNF-a production from primary peritoneal macrophages. Beneficial effects of CSE deficiency were associated with markedly elevated homocysteine and thiosulfate levels, upregulation of NF-E2 p45-related factor 2 (Nrf2) and antioxidant proteins, activation of Akt-dependent anti-apoptotic signaling, and inhibition of GalN/LPS-induced JNK phosphorylation in the liver. Finally, administration of sodium thiosulfate (STS) attenuated GalN/LPS-induced liver injury via activation of Aktand Nrf2-dependent signaling and inhibition of GalN/LPS-induced JNK phosphorylation in WT mice. Innovation: These results suggest that inhibition of CSE or administration of STS prevents acute inflammatory liver failure by augmenting thiosulfate levels and upregulating antioxidant and anti-apoptotic defense in the liver. Conclusion: Congenital deficiency or chemical inhibition of CSE increases thiosulfate levels in the liver and prevents ALF at least in part by augmentation of antioxidant and anti-apoptotic mechanisms. Antioxid. Redox Signal. 20,[204][205][206][207][208][209][210][211][212][213][214][215][216]

BackgroundHydrogen sulfide (H2S) exhibits protective effects in various disease models including cerebral ischemia–reperfusion (I/R) injury. Nonetheless, mechanisms and identity of molecules responsible for neuroprotective effects of H2S remain incompletely defined. In the current study, we observed that thiosulfate, an oxidation product of H2S, mediates protective effects of an H2S donor compound sodium sulfide (Na2S) against neuronal I/R injury.Methods and ResultsWe observed that thiosulfate in cell culture medium is not only required but also sufficient to mediate cytoprotective effects of Na2S against oxygen glucose deprivation and reoxygenation of human neuroblastoma cell line (SH‐SY5Y) and murine primary cortical neurons. Systemic administration of sodium thiosulfate (STS) improved survival and neurological function of mice subjected to global cerebral I/R injury. Beneficial effects of STS, as well as Na2S, were associated with marked increase of thiosulfate, but not H2S, in plasma and brain tissues. These results suggest that thiosulfate is a circulating “carrier” molecule of beneficial effects of H2S. Protective effects of thiosulfate were associated with inhibition of caspase‐3 activity by persulfidation at Cys163 in caspase‐3. We discovered that an SLC13 family protein, sodium sulfate cotransporter 2 (SLC13A4, NaS‐2), facilitates transport of thiosulfate, but not sulfide, across the cell membrane, regulating intracellular concentrations and thus mediating cytoprotective effects of Na2S and STS.ConclusionsThe protective effects of H2S are mediated by thiosulfate that is transported across cell membrane by NaS‐2 and exerts antiapoptotic effects via persulfidation of caspase‐3. Given the established safety track record, thiosulfate may be therapeutic against ischemic brain injury.

Pulmonary artery temperature measurement is recommended to estimate brain temperature during deep hypothermic cardiopulmonary bypass, even if it is conducted with the sternum opened; however, caution needs to be exercised in interpreting its measurements during periods of the cardioplegic solution infusion.

Background Therapeutic hypothermia (TH) improves neurological outcomes after cardiac arrest (CA) and cardiopulmonary resuscitation (CPR). Although nitric oxide prevents organ injury induced by ischemia and reperfusion, role of nitric oxide during TH after CPR remains unclear. Here, we examined the impact of endogenous nitric oxide synthesis on the beneficial effects of hypothermia after CA/CPR. We also examined whether or not inhaled nitric oxide during hypothermia further improves outcomes after CA/CPR in mice treated with TH. Methods Wild-type (WT) mice and mice deficient for nitric oxide synthase 3 (NOS3−/−) were subjected to CA at 37°C and then resuscitated with chest compression. Body temperature was maintained at 37°C (normothermia) or reduced to 33°C (TH) for 24 hours after resuscitation. Mice breathed air or air mixed with nitric oxide at 10, 20, 40, 60, or 80 ppm during hypothermia. To evaluate brain injury and cerebral blood flow, magnetic resonance imaging was performed in WT mice after CA/CPR. Results Hypothermia up-regulated the NOS3-dependent signaling in the brain (n=6–7). Deficiency of NOS3 abolished the beneficial effects of hypothermia after CA/CPR (n=5–6). Breathing nitric oxide at 40 ppm improved survival rate in hypothermia-treated NOS3−/− mice (n=6) after CA/CPR compared to NOS3−/− mice that were treated with hypothermia alone (n=6, P<0.05). Breathing nitric oxide at 40 (n=9) or 60 (n=9) ppm markedly improved survival rates in TH-treated WT mice (n=51) (both P<0.05 vs TH-treated WT mice). Inhaled nitric oxide during TH (n=7) prevented brain injury compared to TH alone (n=7) without affecting cerebral blood flow after CA/CPR (n=6). Conclusions NOS3 is required for the beneficial effects of TH. Inhaled nitric oxide during TH remains beneficial and further improves outcomes after CA/CPR. Nitric oxide breathing exerts protective effects after CA/CPR even when TH is ineffective due to impaired endogenous nitric oxide production.

Pupil reactivity can be used to evaluate central nervous system function and can be measured using a quantitative pupillometer. However, whether anesthetic agents affect the accuracy of the technique remains unclear. We examined the effects of anesthetic agents on pupillary reactivity. Thirty-five patients scheduled for breast or thyroid surgery were enrolled in the study. Patients were divided into four groups based on the technique used to maintain anesthesia: a sevoflurane-remifentanil (SEV/REM) group, a sevoflurane (SEV) group, a desflurane-remifentanil (DES/REM) group, and a propofol-remifentanil (PRO/REM) group. We measured maximum resting pupil size (MAX), reduction pupil size ratio (%CH), latency duration (LAT) and neurological pupil index (NPi). A marked reduction in MAX and %CH compared with baseline was observed in all groups, but LAT was unchanged during surgery. NPi reduced within the first hour of surgery in the SEV/REM, SEV, and DES/REM groups, but was not significantly different in the PRO/REM group. Compared with the PRO/REM group, mean %CH and NPi in patients anesthetized with SEV/REM, SEV or DES/REM were markedly lower at 1 h after surgery had commenced. There was no correlation between NPi and bispectral index. Fentanyl given alone decreased pupil size and %CH in light reflex, but did not change the NPi. NPi was decreased by inhalational anesthesia not but intravenous anesthesia. The difference in pupil reactivity between inhalational anesthetic and propofol may indicate differences in the alteration of midbrain reflexs in patients under inhalational or intravenous anesthesia.

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We present a case of an esophageal submucosal hematoma that developed after endovascular treatment for coil embolization for an unruptured cerebral aneurysm. The patient had received antiplatelet therapy before surgery and anticoagulation therapy during surgery. The orogastric tube was removed at case end with sustained negative pressure. After surgery, the patient reported chest and back pain and was diagnosed with an esophageal submucosal hematoma. The hematoma might have been related to the gastric tube insertion or removal. Providers should keep in mind the possibility of this complication when a patient who was given antithrombotic therapy reports chest or back pain after surgery.

BackgroundsRemifentanil has been reported to cause post-anesthetic shivering (PAS). Higher doses of remifentanil reportedly induce more intense PAS. Tramadol, a synthetic opioid that acts at multiple sites, is considered to be an effective treatment for PAS, but the evidence for its therapeutic benefit after remifentanil anesthesia is limited. We investigated the effect of tramadol on the incidence of PAS after remifentanil anesthesia.MethodsSixty-three patients who had undergone upper abdominal surgery under general anesthesia were studied retrospectively. Tramadol was administered at induction of anesthesia. The patients were divided into four groups: HT(+), high dose remifentanil (1–1.5 μg/kg/min) with tramadol; HT(−), high dose remifentanil without tramadol; LT(+), low dose remifentanil (0.15–0.25 μg/kg/min) with tramadol; and LT(−), low dose remifentanil without tramadol. We recorded perioperative changes in nasopharyngeal temperature and episodes of PAS on emergence from anesthesia.ResultsThe incidences of PAS in both tramadol treatment groups were significantly lower than the groups that did not receive tramadol. Nasopharyngeal temperature after surgery fell significantly more from baseline in the tramadol treatment groups compared with the non-treatment groups.ConclusionTramadol administered at induction of anesthesia appears to suppress PAS following remifentanil anesthesia.