Hong-Bin Wang

Antagonistic effect of atipamezole, flumazenil and naloxone following anaesthesia with xylazine, tramadol and tiletamine/zolazepam combinations in pigs

OBJECTIVE To evaluate the antagonistic effects of atipamezole (ATI), flumazenil (FLU) and naloxone (NAL) alone and in various combinations following administration of tiletamine-zolazepam-xylazine-tramadol. STUDY DESIGN Prospective, experimental, randomized cross-over study. ANIMALS Eight Chinese miniature pigs (three females and five males) mean age 8 (range 7-10) months and bodyweight 57.5 (52.4-62.1) kg. METHODS All animals were anaesthetized with tiletamine/zolazepam (3.0 mg kg(-1)), xylazine (1.2 mg kg(-1)) and tramadol (1.6 mg kg(-1)) given intramuscularly (IM). Thirty minutes later, one of eight treatments was administered IM: saline control, ATI (0.12 mg kg(-1)), FLU (0.1 mg kg(-1)), NAL (0.03 mg kg(-1)), ATI-FLU, FLU-NAL, ATI-NAL or ATI-FLU-NAL. After injection of antagonists the following times were recorded: to recovery of the palpebral, pedal and tail clamp reflexes, to head movement, sternal recumbency, standing and walking. Posture, sedation, analgesia, jaw relaxation and auditory response were scored at set times until 120 minutes after injection of antagonists. Heart rates, respiratory rates and rectal temperature were measured at those times. Data were analyzed by anova for repeated measures, followed by the Tukeys test to compare differences between means, or by Kruskal-Wallis test as appropriate. RESULTS FLU, NAL alone, or FLU-NAL did not effectively antagonize anaesthesia induced by tiletamine/zolazepam-xylazine-tramadol. ATI, ATI-FLU, ATI-NAL and ATI-FLU-NAL produced an immediate and effective recovery from anaesthesia. The combination of ATI-FLU-NAL was the most effective combination in antagonizing the anaesthetic effect. Adverse effects such as tachycardia, tachypnoea, excitement and muscle tremors were not observed during this study. CONCLUSION AND CLINICAL RELEVANCE ATI-FLU-NAL is the most effective combination for antagonizing tiletamine/zolazepam-xylazine-tramadol anaesthesia in pigs. However, ATI alone or in various combinations also provides effective antagonism.

Serum antioxidant capacity of dairy cows with subclinical ketosis

KETOSIS is a common metabolic disorder that is frequently observed in dairy cows during the early lactation period. Evaluation of oxidative stress has increasingly contributed to the understanding of the fundamental mechanisms involved in metabolic disorders ([Turk and others 2008][1]). However,

Laparoscopic left hepatectomy in swine: a safe and feasible technique.

A purely laparoscopic four-port approach was created for left hepatectomy in pigs. A polyethylene loop was placed on the left two hepatic lobes for traction and lift. Next, penetrating ligation of the lobes using of a double row of silk sutures was performed to control bleeding. A direct hepatic transection was completed using a monopolar hook electrode without meticulous dissection of the left hepatic vein. The raw surface of the liver was coagulated and sealed with fibrin glue. Lobes were retrieved through an enlarged portal. Laparoscopic hepatic lobectomy was completed in all pigs without the use of specialized instruments and with a mean operative time of 179 ± 9 min. No significant perioperative complications were observed. The average weight of each resected lobe was 180 ± 51 g. Complete blood count as well as serum organics and enzyme levels normalized after about 2 weeks. During necropsy, adhesion of the hepatic raw surface to the gastric wall and omentum were observed. No other abnormalities were identified. This minimally invasive left hepatectomy technique in swine could serve as a useful model for investigating liver diseases and regeneration, and offer preclinical information to improve hepatobiliary surgical procedures.

Renal function of dairy cows with subclinical ketosis

KETOSIS is a common disease of dairy cows resulting from a metabolic disorder that leads to hypoglycaemia and the formation of ketones (Zhang and others 2011). The evaluation of renal function has contributed to understanding of the fundamental mechanisms involved in metabolic disorders. However, there have been few studies of the renal function of dairy cows with subclinical ketosis. Impaired renal function is a common clinical diagnosis in animals and human beings (Raskin and Unger 1978, Brown and others 2007); serum creatinine and blood urea nitrogen (BUN) are markers routinely used to evaluate kidney function in animals and human beings (Keegan and Webb 2010). The objective of this study was to examine the differences in β-hydroxybutyrate (BHB), glucose, non-esterified fatty acids (NEFA), total protein (TP), BUN and creatinine concentrations in healthy dairy cows and cows affected by subclinical ketosis during the early lactation period. Venous blood was sampled from 55 healthy cows and 55 subclinically affected cows within the first two months of lactation. Animals included in the study were Holstein dairy cows, three to six years of age, all …

Xylazine Activates Adenosine Monophosphate-Activated Protein Kinase Pathway in the Central Nervous System of Rats

Xylazine is a potent analgesic extensively used in veterinary and animal experimentation. Evidence exists that the analgesic effect can be inhibited using adenosine 5’-monophosphate activated protein kinase (AMPK) inhibitors. Considering this idea, the aim of this study was to investigate whether the AMPK signaling pathway is involved in the central analgesic mechanism of xylazine in the rat. Xylazine was administrated via the intraperitoneal route. Sprague-Dawley rats were sacrificed and the cerebral cortex, cerebellum, hippocampus, thalamus and brainstem were collected for determination of liver kinase B1 (LKB1) and AMPKα mRNA expression using quantitative real-time polymerase chain reaction (qPCR), and phosphorylated LKB1 and AMPKα levels using western blot. The results of our study showed that compared with the control group, xylazine induced significant increases in AMPK activity in the cerebral cortex, hippocampus, thalamus and cerebellum after rats received xylazine (P < 0.01). Increased AMPK activities were accompanied with increased phosphorylation levels of LKB1 in corresponding regions of rats. The protein levels of phosphorylated LKB1 and AMPKα in these regions returned or tended to return to control group levels. However, in the brainstem, phosphorylated LKB1 and AMPKα protein levels were decreased by xylazine compared with the control (P < 0.05). In conclusion, our data indicates that xylazine alters the activities of LKB1 and AMPK in the central nervous system of rats, which suggests that xylazine affects the regulatory signaling pathway of the analgesic mechanism in the rat brain.

Effect of hydrogen-rich saline on apoptosis induced by hepatic ischemia reperfusion upon laparoscopic hepatectomy in miniature pigs

Hepatic ischemia reperfusion injury (HIRI) occurs commonly in liver surgery and liver transplantation. Hydrogen, a safe and effective antioxidant, exerts a protective effect against liver injury. In this study, we investigated the role of hydrogen-rich saline (HRS) in apoptosis in a miniature pig model of laparoscopic HIRI upon hepatectomy. Bama miniature pigs were randomly assigned to sham, I/R and HRS groups. The pigs received 10 mL/kg HRS by portal venous injection 10 min before reperfusion and at 1 d, 2 d, and 3 d after surgery. The results showed that HRS treatment significantly decreased serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bilirubin (TBIL) activity and TUNEL-positive cells. Upon HRS treatment, the expression of P53 and Bax mRNA and protein by RT-qPCR and Western blot was markedly decreased, whereas the expression of bcl-2 mRNA and protein was significantly increased. Moreover, Caspase-3 and Caspase-9 activities were significantly decreased upon treatment with HRS. In conclusion, the results indicate that HRS could alleviate liver injury and improve liver function via inhibiting apoptosis after laparoscopic HIRI and hepatectomy injury in miniature pigs.

Partial (two-thirds) nephrectomy in pigs: A comparison of three surgical approaches

Partial (2/3) nephrectomy can be performed via the laparoscopic, retroperitoneal, and transperitoneal approach. Outcomes of the three approaches were compared in this study. 2/3 nephrectomy were performed in 21 healthy Bama miniature pigs (mean bodyweight 20.59±2.78kg). Pigs were divided into three groups: those that underwent 2/3 nephrectomy via laparoscopy (LN group, n=7), the retroperitoneal approach (RN group, n=7), or the transperitoneal approach (TN group, n=7). We monitored pre- and postoperative physiologic parameters, blood cell count, and stress and renal function biomarkers. Differences among groups were analyzed. 2/3 nephrectomy was successfully performed in all pigs without any complications. Mean surgical time in the LN group (60.71±7.34min) and the TN group (58.57±4.72min) was significantly longer than that in the RN group (41.14±5.33min). Warm ischemia in the LN group (38±7.57min) was significantly longer than that in the TN group (28.86±4.53min), which was significantly longer than that in the RN group (17.86±2.34min). The postoperative serum concentration of C-reactive protein in the TN group was significantly higher than that in the LN group (p<0.05). So retroperitoneal approach was best choice in case of bilateral renal lesion resulted in shortest ischemia time, and laparoscopic partial nephrectomy should be the primary choice in majority situations resulted in less body stress, smaller surgical incisions and less blood loss.

Minimally invasive catheterization of portal and mesenteric veins and abdominal aorta for quantitative determination of portal-drained viscera metabolism in pigs

Abstract A laparoscopic catheterization of portal and ileal veins as well as abdominal aorta was performed in eight pigs under general anesthesia for quantitative determination of portal-drained viscera metabolism. Three polyurethane catheters were introduced into the target vessels through an abdominal wall cannula using the guide catheter and wire. Surgery duration, length of incisions, and postoperative outcomes were recorded. On days 7 and 30, portal vein blood flow rates were measured by paraaminohippuric acid method. On day 35, a second laparoscopy was performed to monitor the setup of intraabdominal catheters. The laparoscopic procedures were completed with a mean operative time of 82 ± 9 min, and mean total incision size was 4.5 ± 0.5 cm. No major intraoperative or postoperative complications were encountered. The second laparoscopy showed that position and fixation of catheters remain stable 35 d after the surgical preparation. Portal vein blood flow remained similar (P > 0.05) from 7 to 30 d after the laparoscopic surgical procedure. Retention of catheters in six pigs was more than 60 d, and the other two were 42 and 56 d. We conclude that this novel technique is an attractive alternative to traditional surgical catheterization procedures.