Definition and clinical evaluation of a recruiting airway pressure based on the specific lung elastance in anesthetized dogs

ObjectiveTo determine the specific lung elastance (SE_L) in anesthetized dogs and to evaluate the efficacy of a SE_L-based recruiting airway pressure (RP_aw) at improving global and regional lung aeration.Study designRetrospective and prospective clinical study.AnimalsA total of 28 adult dogs were included in the retrospective study and six adult dogs in the prospective study.MethodsRetrospective study: SE_L and SE_L-based RP_aw were determined using previously published data. In mechanically ventilated dogs undergoing thoracic computed tomography (CT), SE_L was calculated as ΔP_L/(V_T/EELV), where ΔP_L is the driving transpulmonary pressure, V_T is the tidal volume and EELV is the end-expiratory lung volume. The ratio of lung to respiratory system elastance (E_L/E_rs) was determined. SE_L and E_L/E_rs were used to calculate the SE_L-based RP_aw. Prospective study: dogs underwent thoracic CT at end-expiration and at end-inspiration using the SE_L-based RP_aw, and global and regional aeration was determined. For analysis of regional aeration, lungs were divided into cranial, intermediate and caudal regions. Regional compliance was also calculated. A p value <0.05 was considered significant.ResultsThe SE_L and E_L/E_rs were 12.7 ± 3.1 cmH₂O and 0.54 ± 0.07, respectively. The SE_L-based RP_aw was 29.1 ± 7.6 cmH₂O. In the prospective study, the RP_aw was 28.2 ± 1.3 cmH₂O. During RP_aw, hyperinflation increased (p = 0.0003) whereas poorly aerated (p < 0.0001) and nonaerated (p = 0.01) tissue decreased. Normally aerated tissue did not change (p = 0.265). Regional compliance was higher in the intermediate (p = 0.0003) and caudal (p = 0.034) regions compared with the cranial region. Aeration did not differ between regions (p > 0.05).Conclusions and clinical relevanceAn SE_L-based RP_aw reduces poorly and nonaerated lung tissue in anesthetized dogs. In nonsurgical anesthetized dogs, an RP_aw near 30 cmH₂O is effective at improving lung aeration.     

The effect of remifentanil infusion on sevoflurane minimum alveolar concentration–no movement (MACNM) and bispectral index in dogs

ObjectiveTo determine the effect of remifentanil infusion on the minimum alveolar concentration of sevoflurane preventing movement (SEVOMAC_NM) and bispectral index (BIS) in dogs.Study designProspective, unmasked study.AnimalsA total of 10 adult Beagle dogs weighing 9.0 ± 1.1 kg.MethodsDogs were anesthetized with sevoflurane and baseline SEVOMAC_NM was determined. Remifentanil was infused at 5, 10 and 20 μg kg^–1 hour^–1, in sequence, with 20 minutes washout between infusions. Variables monitored throughout anesthesia included heart rate (HR), oscillometric blood pressure, end-tidal partial pressure of carbon dioxide, end-tidal sevoflurane concentration (Fe′Sevo) and BIS. SEVOMAC_NM after remifentanil infusion (SEVOMAC_NM-REMI) determination started 20 minutes after the start of each infusion. Venous blood samples were collected for plasma remifentanil concentration determination at baseline, SEVOMAC_NM-REMI determination time points, and 20 minutes after each infusion was stopped. A mixed model analysis was used to determine the effect of remifentanil infusion on response variables. The relationships between BIS and Fe′Sevo, plasma remifentanil concentrations and the percentage decrease in baseline SEVOMAC_NM were evaluated (p < 0.05).ResultsThe overall SEVOMAC_NM at baseline was 2.47 ± 0.11%. Addition of remifentanil at all infusion rates significantly decreased SEVOMAC_NM, but the medium and high doses resulted in significantly greater decreases in SEVOMAC_NM than the lower dose. There was no difference in SEVOMAC_NM percentage change between infusions 10 and 20 μg kg^–1 hour^–1. Plasma remifentanil concentrations were significantly different in all infusion rates. Baseline BIS value was 70 ± 1 and was lower than the BIS values recorded during all remifentanil infusions. BIS values were not significantly different among infusion rates. HR was lower and mean arterial pressure was higher during remifentanil infusions than at baseline.Conclusions and clinical relevanceAll remifentanil infusions decreased SEVOMAC_NM in dogs. Remifentanil infusion at any rate studied did not reduce BIS values.     

uclear factor κB in LPS stimulated rat alveolar macrophages promotes TNF-α secretion

AIM: To investigate the activation of nuclear factor κB (NF-κB) induced by lipopolysaccharides (LPS) in rat alveolar macrophages (AMs) and its regulatory role in tumor necrosis factor (TNF-α) secretion. METHODS: The dynamic activity changes of NF-κB induced by LPS were determined with electrophoretic mobility shift assay (EMSA). Antisense oligonucleotides of NF-κB subunit (p65) were transfected into AMs prior to LPS stimulation. The effect of antisense oligonucleotide transfection on expressions of p65 and TNF-α in supernatant were measured with Western blotting and enzyme linked immunosorbent assay (ELISA), respectively.RESULTS: NF-κB activity increased markedly and reached its peak level at 4 h after LPS stimulation. After transfected with antisense oligonucleotides of NF-κB subunit (p65), expression of p65 and TNF-α in supernatant decreased markedly.CONCLUSION: NF-κB activity has a positive effect on regulating secretion of TNF-α in AMs induced by LPS.     

猪繁殖与呼吸综合征病毒感染对猪肺泡巨噬细胞外源性抗原加工递呈相关分子和共刺激分子的影响

采用定量竞争PCR技术对猪繁殖与呼吸综合征病毒（PRRSV）感染后不同时相猪肺泡巨噬细胞（PAM）中外源性抗原加工递呈相关分子SLA-DR、Ii链和SLA-DM分子及共刺激分子CD40、CD80、CD86的mRNA转录动态进行了定量检测。结果表明,PRRSV感染后PAM的SLA-DR mRNA转录水平在3、7和14 d下调,低于对照组;感染后3 d,Ii链、SLA-DM和CD40的mRNA转录水平极显著下调（P〈0.01）;CD80和CD86mRNA转录水平也在感染后3 d明显下调（P〈0.05）。用流式细胞术检测PAM表面的SLA-DR抗原的结果表明,在感染后3 d短暂上升,7 d之后一直低于对照组。由此说明,PRRSV感染早期对猪肺泡巨噬细胞的外源性抗原加工和递呈功能产生显著影响,导致其外源性抗原递呈功能下降,进而影响机体的体液免疫应答。     

Wnt5a介导Wnt/Ca2+通路对BCG诱导牛原代肺泡上皮细胞自噬的调控作用

旨在探讨体外分离培养牛肺泡上皮细胞（bovine alveolar epithelial cells,BAECs）的方法及Wnt5a对牛结核分枝杆菌卡介苗（bacille Calmette-Guérin,BCG）感染BAECs细胞自噬的调控机制。试验选用酶联合消化法和机械刮刷法分离细胞,差速贴壁法纯化BAECs,免疫荧光染色检测上皮细胞标志物角蛋白14（cytokeratin 14,CK14）和角蛋白5（cytokeratin 5,CK5）的表达;BCG感染BAECs,并用Box-5抑制Wnt5a的表达,Western blot和免疫荧光染色检测自噬相关蛋白及非经典Wnt信号通路相关蛋白的表达。结果表明,采用酶联合消化法和机械刮刷法能够成功分离纯度较高的BAECs,细胞经CK14和CK5鉴定为阳性;BCG感染BAECs促进Wnt5a表达,增加细胞自噬,Box-5预处理下调BCG诱导的细胞自噬相关蛋白LC3II、P62、Atg7及Atg5的表达,且抑制非经典Wnt/Ca²⁺信号通路相关蛋白Wnt5a、CaMKII及NFAT的表达。综上,试验成功建立BAECs分离培养方法,BCG感染增加BAECs内Wnt5a表达和细胞自噬,抑制Wnt5a下调BCG诱导的BAECs细胞自噬,且Wnt5a是通过非经典Wnt/Ca²⁺信号通路调控BCG诱导的BAECs细胞自噬。     

A systematic review of sevoflurane and isoflurane minimum alveolar concentration in domestic cats

ObjectiveThe purpose of this systematic review is to summarize the results of studies which have determined the minimum alveolar concentration (MAC) of isoflurane and sevoflurane in domestic cats.Study DesignSystematic review.AnimalsCats.Methods usedA comprehensive search of research literature was performed without language restriction. The search utilized the Pubmed, Google Scholar, and CAB Abstracts electronic databases using a combination of free text terms ‘Minimum alveolar concentration’, ‘sevoflurane’, ‘isoflurane’, ‘anesthetic’, ‘cat’, ‘cats’ or ‘feline’. The search was conducted from November 2010 to June 2012.ResultsThe MAC for isoflurane ranged from 1.20 ± 0.13% to 2.22 ± 0.35% and the MAC for sevoflurane ranged from 2.5 ± 0.2% to 3.95 ± 0.33%. The average MAC for isoflurane was 1.71 ± 0.07% and for sevoflurane was 3.08 ± 0.4%.Conclusions &; Clinical RelevanceThe average MAC for isoflurane was 1.71 ± 0.07% and for sevoflurane was 3.08 ± 0.4%. Methodology differed among studies, and particular attention should be paid in the future to appropriate reporting of methods to allow sound conclusions to be made from the results.     

Cardiopulmonary effects of desflurane in horses

OBJECTIVE: To determine the cardiopulmonary effects of desflurane (DES) in horses. ANIMALS: Six healthy adult horses, three males and three females, aged 9 +/- 4 (mean +/- SD) years and weighing 370 +/- 36 kg. MATERIALS AND METHODS: Anaesthesia was induced with an O2 (10 L minute(-1)) and DES mixture (vaporizer setting 18%). After oro-tracheal intubation, horses were positioned in right lateral recumbency. Anaesthesia was maintained with DES in O2 (20 mL kg(-1) minute(-1)) delivered through a large animal circle breathing system. The minimum alveolar concentration of DES (MAC(DES)) that prevented purposeful movement in response to 60 seconds of electrical stimulation of the oral mucous membranes was determined for each horse. The delivered concentration of DES was then increased to achieve end-tidal concentrations corresponding to 1.5 x MAC(DES), 1.75 x MAC(DES), and 2.0 x MAC(DES). Heart rate (HR), mean arterial blood pressure (MAP), respiratory rate (fr), tidal volume (VT), minute volume (VM) and core temperature were determined, and blood samples for arterial blood gas analysis taken at each DES concentration. All data were analysed by two-way anova for repeated measures and Fisher's test for multiple comparisons. A probability level of p < 0.05 was applied. RESULTS: Desflurane concentrations of 2.0 x MAC(DES) increased HR whereas lower concentrations did not. Mean arterial pressure was not affected by 1.0 x MAC(DES) 1.5 x MAC(DES) or 1.75 x MAC(DES), whereas it decreased at 2.0 x MAC(DES). All concentrations of DES examined significantly depressed fr, VT and VM. CONCLUSIONS AND CLINICAL RELEVANCE: Desflurane concentrations between 1.0 and 1.75 x MAC(DES) reduces fr and VM but does not affect HR or MAP in horses.     

猪瘟病毒E2蛋白与猪RACK1相互作用的鉴定

为筛选和鉴定与猪瘟病毒(CSFV)E2蛋白相互作用的猪宿主蛋白,我们采用酵母双杂交方法筛选猪肺泡巨噬细胞表达文库得到与CSFV E2蛋白相互作用的宿主细胞RACK1蛋白,经共转化试验和GST pull-down试验进一步证实两者可以特异性结合,并且共聚焦试验表明两者共定位于细胞的细胞浆。本研究显示E2蛋白与宿主细胞RACK1蛋白存在相互作用,RACK1在CSFV感染过程中所发挥的功能有待进一步研究。     

Effect of transdermally administered fentanyl on the minimum alveolar concentration of isoflurane in cats

OBJECTIVE: To determine the effect of two doses of fentanyl, administered transdermally, on the minimum alveolar concentration (MAC) of isoflurane in cats. STUDY DESIGN: Prospective, randomized study. ANIMALS: Five healthy, spayed, female cats. METHODS: Each cat was studied thrice with at least 2 weeks between each study. In study 1, the baseline isoflurane MAC was determined in triplicate for each cat. In studies 2 and 3, isoflurane MAC was determined 24 hours after placement of either a 25 or 50 microg hour(-1) fentanyl patch. In each MAC study, cats were instrumented to allow collection of arterial blood and measurement of arterial blood pressure. Twenty-four hours prior to studies 2 and 3, a catheter was placed and secured in the jugular vein and either a 25 or 50 microg hour(-1) fentanyl patch was placed in random order on the left thorax. Blood samples for plasma fentanyl determination were collected prior to patch placement and at regular intervals up to 144 hours. After determination of MAC in studies 2 and 3, naloxone was administered as a bolus dose (0.1 mg kg(-1)) followed by an infusion (1 mg kg(-1) hour(-1)) and MAC redetermined. RESULTS: The baseline isoflurane MAC was 1.51 +/- 0.21% (mean +/- SD). Fentanyl (25 and 50 micro g hour(-1)) administered transdermally significantly reduced MAC to 1.25 +/- 0.26 and 1.22 +/- 0.16%, respectively. These MAC reductions were not significantly different from each other. Isoflurane MAC determined during administration of fentanyl 25 micro g hour(-1) and naloxone (1.44 +/- 0.16%) and fentanyl 50 micro g hour(-1) and naloxone (1.51 +/- 0.19%) was not significantly different from baseline MAC (1.51 +/- 0.21%). CONCLUSIONS AND CLINICAL RELEVANCE: Fentanyl patches are placed to provide long-lasting analgesia. In order to be effective postoperatively, fentanyl patches must be placed prior to surgery. Plasma fentanyl concentrations achieved intraoperatively decrease the need for potent inhalant anesthetics in cats.