Jing Yang

Further proof that the spinal cord, and not the brain, mediates the immobility produced by inhaled anesthetics.

Background:Previous investigations indicate that the spinal cord, perhaps with a minor cerebral contribution, mediates the capacity of inhaled anesthetics to produce immobility in the face of noxious stimulation. The implications of these investigations may be limited by the trauma associated with their experimental methods (e.g., cardiopulmonary bypass or transection of the spinal cord). The present study avoided such trauma. Methods:Thirty goats received emulsified isoflurane via either the initial section of the aorta (arterial group; preferential isoflurane delivery to the spinal cord) or an ear vein (venous group; equal delivery of isoflurane to the cord and brain). The authors determined the minimum partial pressure of isoflurane (the isoflurane partial pressure in the blood required to produce immobility in 50% of the goats exposed to a noxious stimulus). Results:For the venous group, the minimum partial pressure in carotid versus femoral arterial blood (9.56 ± 1.86 mmHg vs. 9.68 ± 1.90 mmHg) did not differ. For the arterial group, the minimum partial pressure in carotid arterial blood was half that in femoral arterial blood (5.35 ± 1.45 mmHg vs. 10.97 ± 3.04 mmHg, P < 0.05). As these data show, the minimum partial pressure in femoral arterial blood did not differ for the arterial group versus the venous group. Conclusions:In this novel and minimally traumatic model, the anesthetic partial pressure delivered to the spinal cord governed the suppression of movement in response to noxious stimulation. The results indicate that the spinal cord is the primary mediator of immobility and that the brain plays little or no role.

Polymerized Placenta Hemoglobin Improves Cardiac Functional Recovery and Reduces Infarction Size of Isolated Rat Heart

Objective: To investigate the cardioprotective effect of polymerized human placenta hemoglobin (PolyPHb) to rat heart subjected to 8-hour hypothermic storage and 2-hour normothermic reperfusion. Methods and Results: Isolated rat hearts were perfused with Langendorff model; after 30 minutes of baseline, the hearts were arrested and stored by St. Thomas’ solution (STS) without (STS group) or with 0.5 gHb/dL PolyPHb (PolyPHb group) at 4°C for 8 hours, then reperfused for 2 hours. Compared with STS group, PolyPHb in STS greatly improved the recovery of left ventricular developed pressure (LVDP), maximum LVDP increase and decrease rate (±dp/dt), coronary flow rate (CF). Also, both the cardiac enzyme release, including creatine kinase (CK) and lactate dehydrogenase (LDH), and myocardial infarction size were significantly reduced in PolyPHb group. Conclusion: Our study demonstrated that the PolyPHb was beneficial to improving cardiac functional recovery and reducing myocardial infarction of 8-hour hypothermic stored rat heart.

Targeting the kynurenine pathway as a potential strategy to prevent and treat Alzheimer’s disease

Alzheimers disease (AD) is a progressive neurodegenerative disorder of the elderly accounting for the vast majority of dementia. Recently, many studies have implicated the role of inflammatory response, especially neuroinflammatory response in the development and progression of AD. However, the underlying mechanism of how inflammatory response induces AD is unknown. Kynurenine pathway is a major route of the amino acid tryptophan catabolism, resulting in the production of nicotine adenine dinucleotide and other neuroactive intermediates: quinolinic acid (QA) and kynurenic acid (KA). QA exerts different toxic effects, including over-activation of N-methyl-d-aspartate (NMDA) receptor and excitotoxicity, synaptic dysfunction and neuronal death. On the other hand, KA is identified as the only endogenous NMDA receptor antagonist and could modulate neurotoxic effects of QA. We hypothesize that an activated kynurenine pathway induced by inflammatory cytokines would generate more neurotoxic metabolites, which could be closely related to the pathogenesis of AD in elderly patients. Moreover, some measures, which facilitate KA synthesis and reduce the formation of QA, may emerge as a new therapeutic strategy against AD.

Reversible conduction block in isolated toad sciatic nerve by emulsified isoflurane.

BACKGROUND:Studies have shown that the local use of volatile anesthetics can produce local anesthetic effects. We designed this study to evaluate the characteristics of nerve conduction block of emulsified isoflurane (EI) and compare its nerve blockade with 1%lidocaine, by measuring compound nerve action potential (CNAP) parameters in isolated toad sciatic nerve. METHODS:One hundred isolated toad sciatic nerves were selected and randomly assigned to 10 groups of 10 each, administered 2% to 8% EI (v/v) (EI8 group, etc.), 1% lidocaine, 30% Intralipid® (Huarui Pharmacy, Wuxi, Jiangsu, China), and Ringer solution (RS) for 10 minutes, respectively. All nerves were then washed and soaked with RS for 10 minutes and 30 minutes. The nerve conduction block effect was represented by CNAP parameters that were recorded by an extracellular recording technique per minute. RESULTS:The results showed that the negative amplitudes of CNAP were decreased by EI and lidocaine (P < 0.05), and the conduction velocities of CNAP were also decreased at some time points (D7–W3) (P < 0.05). After RS washing, the 2 parameters recovered gradually. The changes in the 2 parameters induced by EI had slower onset rates and faster recoveries than those produced by lidocaine (7 minutes vs 1 minute and 9 minutes vs 30 minutes). The nerve blockade induced by EI was dose dependent (P < 0.05), and the half maximal inhibition concentration of EI was 5.46%. CONCLUSIONS:EI produced completely reversible and dose-dependent nerve conduction inhibition, which had slower onset and faster recovery compared with those produced by lidocaine.

Protective Effect of RNase on Unilateral Nephrectomy-Induced Postoperative Cognitive Dysfunction in Aged Mice

Postoperative cognitive dysfunction (POCD) is a common complication after surgery, especially for elderly patients. Administration of RNase has been reported to exhibit neuroprotective effects in acute stroke. However, the potential role of RNase on POCD is unknown. Therefore, we sought to investigate whether RNase treatment could mitigate unilateral nephrectomy induced-cognitive deficit in aged mice. In the present study, twelve-month-old mice were administered RNase or an equal amount of normal saline perioperatively. All mice underwent Morris Water Maze (MWM) training 3 times per day for 7 days to acclimatize them to the water maze before surgical operation, and testing on days 1, 3 and 7 after surgery. We found that perioperative administration of RNase: 1) attenuated unilateral nephrectomy-induced cognitive impairment at day 3 after surgery; 2) reduced the hippocampal cytokines mRNA production and serum cytokines protein production at day 1 and day 7 (for MCP-1) after surgery, and; 3) inhibited hippocampal apoptosis as indicated by cleaved caspase-3 western blot and TUNEL staining at day 1 after surgery. In addition, a trend decrease of total serum RNA levels was detected in the RNase treated group after surgery compared with the untreated group. Further, our protocol of RNase administration had no impact on the arterial blood gas analysis right after surgery, kidney function and mortality rate at the observed days postoperatively. In conclusion, perioperative RNase treatment attenuated unilateral nephrectomy-induced cognitive impairment in aged mice.

A model of intravenous regional anesthesia in rats.

BACKGROUND:We developed an IV regional anesthesia (IVRA) model using the tails of rats to allow preclinical evaluation of the safety and efficacy of drugs used in IVRA and analgesia. METHODS:Three sequential experiments were designed to determine local anesthetic and analgesic effects of drugs injected IV in the tail. The anesthesia was assessed by monitoring the response of the tail-clamp (RTC) test on the tail, whereas the analgesia was assessed by recording the latency in the tail-flick test on the tail. In the first 2 experiments, we studied the effects of different environmental temperatures (15°C, 25°C, and 37°C) and length of tourniquet time on the tail-flick and tail-clamp tests, respectively. Based on the outcomes of these 2 experiments, the pharmacological effects of 1% lidocaine (L group) and 0.5% bupivacaine (B group) were compared with normal saline (NS group) to evaluate this model in experiment 3. RESULTS:In experiment 1, compared with its baseline, tail-flick latency increased rapidly in the 15°C group (P < 0.0001), whereas there were no changes in tail-flick latency in the 25°C group (P = 0.3640) and the 37°C group (P = 0.0641) after the first 20 minutes of tail submersion in a water bath. RTCs in all rats were positive during the entire observation period. In experiment 2, tail-flick latency did not change compared with baseline tail-flick latency after the first 20 minutes of tourniquet application (P = 0.0902), but significantly increased at the 30-, 40-, 50-, and 60-minute intervals (P = 0.0001). RTCs in all rats were positive during the experiment. In experiment 3, local anesthesia was generated in the tail (distal to the tourniquet) in the L and B groups with a similar onset time of anesthesia (approximately 1 minute), but with a longer recovery time of anesthesia and analgesia in the B group (56.0 ± 22.0 minutes) than the L group (31.0 ± 19.0 minutes), whereas no anesthetic and analgesic effects were observed in the NS group. CONCLUSIONS:A reliable model for studying IVRA and analgesia has been developed in rats.

Blood transfusion practice: A survey in Sichuan, China

OBJECTIVEnTo get full knowledge of current conditions and development in the past seven years of clinical transfusion practice in Sichuan, China.nnnSTUDY DESIGN AND METHODSnThis survey was performed by means of a questionnaire which consisted of three parts of questions including basic conditions of blood banks in the hospitals, procedures for clinical blood transfusion and the utilization of different types of blood products. Thirty-five representative hospitals from different geographic locations in Sichuan province participated in this survey.nnnRESULTSnAll of the 35 hospitals returned the questionnaires and 33 hospitals (94.3%) answered the questions completely. The blood bank information system began to be used by more hospitals from 2006 (21.21%, 7/33) to 2012 (48.48%, 16/33). Automated grouping and cross-matching systems have not been used in level 2 hospitals and only 3 level 3 hospitals used automated systems in 2012. Still less common were procedures for evaluation of blood order forms for appropriateness (2/33, 6.06%) and evaluation of appropriateness and effect of blood component transfusion (8/33, 24.2%), and all the hospitals having these procedures are level 3 hospitals. The percentage of whole blood usage in the volume of all types of blood products used decreased a lot from 7.45% in 2006 to 0.16% in 2010. Technological instruments for bedside checking are not used by any of the hospitals.nnnCONCLUSIONSnThe transfusion service degree of the hospitals in Sichuan, China, has developed a lot in the past seven years; however, there are still some problems including whole blood still being used, albeit decreasing; lack of independent blood banks within the hospitals; lack of dedicated personnel for the transfusion services; lack of education; lack of blood bank information systems and automation; lack of screening for appropriateness for blood orders. Thus, the quality control center of clinical blood transfusion (QCCCBT) of Sichuan province should help the transfusion departments to attract more investment in staffing, equipment and information system from the hospitals, enhance the training of transfusion department staffs, and emphasize the supervision of transfusion departments work on directing clinical blood utilization and evaluating clinical transfusion appropriateness.

A model for the preferential delivery of isoflurane to the spinal cord of the goat

To identify the blood supply of the caprine central nervous system, six anaesthetised goats were perfused with coloured suspension into the brachiocephalic artery, the aorta, the iliac artery and the femoral artery. The subsequent distribution indicated that the brain and the main segments of the spinal cord were supplied by the brachiocephalic artery and aorta, respectively. Ten similarly anaesthetised goats then received emulsified isoflurane randomly via either the proximal part of the descending aorta (arterial group) or an ear vein (venous group). In the arterial group, the isoflurane partial pressure (P(iso)) in femoral arterial blood was almost double the P(iso) in jugular venous blood. The model showed that preferential delivery of isoflurane to the goat spinal cord in situ was possible and could be used for further research into the mechanisms of anaesthetic action, particularly factors affecting immobility.

STEP ENZYMATIC HYDROLYSIS OF SODIUM HYDROXIDE-PRETREATED CHINESE LIQUOR DISTILLERS' GRAINS FOR ETHANOL PRODUCTION

Distillers grains are a co-product of ethanol production. In China, only a small portion of distillers grains have been used to feed the livestock because the amount was so huge. Nowadays, it has been reported that the distillers grains have the potential for fuel ethanol production because they are composed of lignocelluloses and residual starch. In order to effectively convert distillers grains to fuel ethanol and other valuable production, sodium hydroxide pretreatment, step-by-step enzymatic hydrolysis, and simultaneous saccharification and fermentation (SSF) were investigated. The residual starch was first recycled from wet distillers grains (WDG) with glucoamylase to obtain glucose-rich liquid. The total sugar concentration was 21.3 g/L, and 111.9% theoretical starch was hydrolyzed. Then the removed-starch dry distillers grains (RDDG) were pretreated with NaOH under optimal conditions and the pretreated dry distillers grains (PDDG) were used for xylanase hydrolysis. The xylose concentration was 19.4 g/L and 68.6% theoretical xylose was hydrolyzed. The cellulose-enriched dry distillers grains (CDDG) obtained from xylanase hydrolysis were used in SSF for ethanol production. The ethanol concentration was 42.1 g/L and the ethanol productivity was 28.7 g/100 g CDDG. After the experiment, approximately 80.6% of the fermentable sugars in WDG was converted to ethanol.

The common anesthetic, sevoflurane, induces apoptosis in A549 lung alveolar epithelial cells

Lung alveolar epithelial cells are the first barrier exposed to volatile anesthetics, such as sevoflurane, prior to reaching the targeted neuronal cells. Previously, the effects of volatile anesthetics on lung surfactant were studied primarily with physicochemical models and there has been little experimental data from cell cultures. Therefore it was investigated whether sevoflurane induces apoptosis of A549 lung epithelial cells. A549 cells were exposed to sevoflurane via a calibrated vaporizer with a 2xa0l/min flow in a gas‑tight chamber at 37˚C. The concentration of sevoflurane in Dulbeccos modified Eagles medium was detected with gas chromatography. Untreated cells and cells treated with 2xa0µM daunorubicin hydrochloride (DRB) were used as negative and positive controls, respectively. Apoptosis factors, including the level of ATP, apoptotic‑bodies by terminal deoxynucleotidyl transferase‑mediated dUTP nick end labeling (TUNEL) assay, DNA damage and the level of caspasexa03/7 were analyzed. Cells treated with sevoflurane showed a significant reduction in ATP compared with untreated cells. Effects in the DRB group were greater than in the sevoflurane group. The difference of TUNEL staining between the sevoflurane and untreated groups was statistically significant. DNA degradation was observed in the sevoflurane and DRB groups, however this was not observed in the untreated group. The sevoflurane and DRB groups induced increased caspasexa03/7 activation compared with untreated cells. These results suggest that sevoflurane induces apoptosis in A549 cells. In conclusion, 5% sevoflurane induced apoptosis of A549 lung alveolar epithelial cells, which resulted in decreased cell viability, increased apoptotic bodies, impaired DNA integrality and increased levels of caspasexa03/7.