Effects of pico-tesla electromagnetic field treatment on wound healing in rats

OBJECTIVE: To evaluate the effects of a pico-tesla electromagnetic field (PTEF) on healing of sutured and open skin wounds and clinicopathologic variables in rats. ANIMALS: 64 male Fischer-344 rats. PROCEDURE: An incision made in the dorsal aspect of the neck was sutured (n = 32) or left open to heal (32). In each group, 16 rats were not PTEF-treated (controls). Wound treatment consisted of exposure to a PTEF once daily. Rats in each group were euthanatized at days 2, 4, 7, and 14. Wounds were evaluated via tensiometry (sutured wounds), digital planimetry (open wounds), laser Doppler perfusion imaging, bacteriologic culture, and histologic examination. Blood samples were collected from all rats for analysis. RESULTS: At day 14, sutured wounds in PTEF-treated rats were stronger (ultimate stress) and tougher (strain energy) than were sutured wounds in control rats. Open wounds in PTEF-treated rats contracted more quickly at days 2 and 4 than did those in control rats. Compared with control wounds, histologic changes (indicative of improved healing) in sutured and open wounds in PTEF-treated rats were detected as early as day 4. Laser Doppler perfusion measurements, results of CBCs, serum biochemical analyses, and bacteriologic cultures were not different between groups. CONCLUSIONS AND CLINICAL RELEVANCE: Exposure to the PTEF caused no adverse effects on clinicopathologic, histologic, or bacteriologic variables tested in this study. It appears that PTEF is a safe form of adjuvant treatment for wounds and improves strength of sutured wounds and speeds contraction of open wounds.     

Sedative and analgesic effects of intravenous xylazine and tramadol on horses

This study was performed to evaluate the sedative and analgesic effects of xylazine (X) and tramadol (T) intravenously (IV) administered to horses. Six thoroughbred saddle horses each received X (1.0 mg/kg), T (2.0 mg/kg), and a combination of XT (1.0 and 2.0 mg/kg, respectively) IV. Heart rate (HR), respiratory rate (RR), rectal temperature (RT), indirect arterial pressure (IAP), capillary refill time (CRT), sedation, and analgesia (using electrical stimulation and pinprick) were measured before and after drug administration. HR and RR significantly decreased from basal values with X and XT treatments, and significantly increased with T treatment (p < 0.05). RT and IAP also significantly increased with T treatment (p < 0.05). CRT did not change significantly with any treatments. The onset of sedation and analgesia were approximately 5 min after both X and XT treatments; however, the XT combination produced a longer duration of sedation and analgesia than X alone. Two horses in the XT treatment group displayed excited transient behavior within 5 min of drug administration. The results suggest that the XT combination is useful for sedation and analgesia in horses. However, careful monitoring for excited behavior shortly after administration is recommended.     

Pharmacokinetics and analgesic efficacy of intranasal administration of tramadol in dogs after ovariohysterectomy

ObjectiveTo assess analgesic efficacy and the pharmacokinetics of intranasal (IN) tramadol in dogs following ovariohysterectomy.Study designRandomized, blinded clinical study.AnimalsA total of 30 bitches undergoing elective ovariohysterectomy.MethodsDogs were randomly assigned to one of three experimental groups (10 dogs per group): IN tramadol 4 mg kg^–1 (group T-IN), intravenous (IV) tramadol 4 mg kg^–1 (group T-IV) and IV methadone 0.2 mg kg^–1 (group M). Drugs were administered at extubation. At established time points (before surgery and up to 8 hours after drug administration) analgesia was assessed using the Italian version of the Glasgow Composite Measure Pain Scale Short Form and physiological variables were recorded. To determine the pharmacokinetics of IN tramadol, blood samples were collected at predetermined time points. Shapiro–Wilk test was used to assess whether data were normally distributed and consequently parametric or non parametric tests were applied. A p value < 0.05 was considered significant.ResultsNo significant intergroup differences were observed in the dogs that were administered rescue analgesia and time of its administration. Excluding dogs that were administered rescue analgesia, no significant intergroup differences emerged in pain scores and physiological variables, except for a lower rectal temperature in group M compared with the tramadol groups. After IN administration, tramadol was rapidly absorbed into the systemic circulation, reaching its maximum concentration (range 74.74–200.29 ng mL^–1) within 30–60 minutes, it then decreased rapidly and was detectable in plasma for up to 2 hours after treatment in all dogs.Conclusions and clinical relevanceIN tramadol administration appears to be as effective as IV tramadol and methadone treatments in pain management of dogs after elective ovariohysterectomy. Given its low concentrations and short detection time in plasma after the IN route, systemic tramadol action appears unlikely.     

The effect of short-duration, high-intensity electromagnetic pulses on fresh ulnar fractures in rats

Pulsed electromagnetic fields (PEMFs) have been found to be beneficial to a wide variety of biological phenomena. In particular, PEMFs have been shown to be useful in the promotion of healing of ununited fractures. Conflicting information exists regarding the benefit of using PEMFs to accelerate the healing of fresh fractures. This paper reports on the evaluation of the effect of a new PEMF generator (PAP IMI) on the healing of fresh ulnar fractures in rats. This device is unique by virtue of the extremely high power output of each of the pulses it generates. Ulnar fractures were created in rats by using a bone cutter, thus producing a 2-3 mm bone defect. Rats were then randomly divided into treatment and control groups. The treatment group underwent periodic treatments with the PAP IMI, and the control group received no treatment. Radiographs of rats from both groups were taken at 1-week intervals. Histological evaluation was performed at the end of the study. Radiographic and histopathological evaluations were scored, and scores were used to assess both rate and quality of healing. The radiographic results demonstrated gradual bridging callus formation in both control and treatment groups, however, the healing process was faster in rats that were not treated by PEMF. Histological evaluation demonstrated that the fibrous content of the callus in rats belonging to the treatment group was significantly higher than that in rats belonging to the control group. The results of this study do not support the claim that PEMF generated by the PAP-IMI stimulate osteogenesis and bone healing after the creation of fresh ulnar fractures in rats.     

曲马多对大鼠不同脑区AMPK表达量的影响

为研究曲马多(tramadol,INN)作用下大鼠不同脑区AMPK(腺苷单磷酸活化蛋白激酶)表达量的变化,探讨INN的中枢镇痛机制,将30只SD纯种大鼠随机分为对照组和INN组(Q组),Q组又分为4个亚组:Q1组(注射INN后10min)、Q2组(注射INN后20min)、Q3组(注射INN后40min)和Q4组(注射INN后60min),各组大鼠到达预定的时间点后分别采取脑组织,应用RT-PCR法检测脑内AMPKα1、α2mRNA转录量,应用Western blot方法检测p-AMPK蛋白的相对表达量。结果显示:腹腔注射INN后引起大鼠各脑区AMPKα1、α2mRNA高效表达,各时期AMPKα1、α2mRNA表达与对照组比较差异显著(P<0.01或P<0.05);在小脑区p-AMPK蛋白的相对表达量在10min时间点与对照组比较差异极显著(P<0.01),在大脑皮层、丘脑和脑干区其相对表达量在40,60 min时间点与对照组比较差异显著(P<0.01或P<0.05),海马区则只在40min时间点差异极显著(P<0.01)。结果提示,大鼠各脑区的AMPK参与了INN的镇痛过程,而INN的镇痛机制可能与AMPK的高效表达有关。     

A preliminary investigation of the effect of selected electromagnetic field devices on healing of cannon bone osteotomies in horses

The effect of electrical stimulation by means of selected electromagnetic field devices on healing of cannon bone osteotomies in horses was examined. The defects were created as 3 cm x 1 mm longitudinal osteotomies through the dorsal cortices of the mid-metacarpi/metatarsi of adult horses. This type of defect would asses bone healing in a situation similar to an acute, stable fracture of the cortex. Three electromagnetic devices of different design were tested in three different groups of horses. Healing was evaluated radiographically and histologically. Results showed that osteotomies treated with the electromagnetic devices healed similarly to untreated controls. Our conclusion is that the electromagnetic devices studied did not have a local effect on the repair process of an acute, stable, osseous defect.     

Suppressive effect of hyaluronan on chondrocyte apoptosis in experimentally induced acute osteoarthritis in dogs

Dogs receiving anterior cruciate ligament transection (ACLT) were treated with either intravenous (IV) or intraarticular (IA) administration of hyaluronan (HA), and differences in appearance of chondrocyte apoptosis of the stifle joint were investigated. Chondrocyte apoptosis was detected using flow cytometry as well as by staining with TdT-mediated dUTP nick end labeling (TUNEL). The percentage of apoptotic chondrocytes in dogs with ACLT was significantly higher than that in intact (non-ACLT) dogs. Dogs treated with IA or IV injection of HA after ACLT had fewer apoptotic chondrocytes than non-treated dogs after ACLT. It was suggested that ACLT-induced apoptosis of chondrocytes was suppressed by HA administration of either IA or IV.     

Effects of exposure to electromagnetic field (1.8/0.9 GHz) on testicular function and structure in growing rats

The aim of our study was to evaluate the possible effects of whole-body electromagnetic field (EMF) exposure on reproduction in growing male rats. Male albino Wistar rats (2 days old) were exposed to EMF 1800 and 900 MHz for 2 h continuously per day for 90 days. Sham control was kept under similar conditions except that the field was not applied for the same period. After blood samples were collected, the animals were sacrificed 24 h after the last exposure and the tissues of interest were harvested. The mean plasma total testosterone showed similarity among the two study groups and was significantly higher than the sham control rats. The percentage of epididymal sperm motility was significantly higher in the 1800 MHz group (P<0.05). The morphologically normal spermatozoa rates were higher and the tail abnormality and total percentage abnormalities were lower in the 900 MHz group (P<0.05). Histopathologic parameters in the 1800 MHz group were significantly higher (P<0.05). In conclusion, the present study indicated that exposure to electromagnetic wave caused an increase in testosterone level, epididymal sperm motility (forward), and normal sperm morphology of rats. As a consequences, 1800 and 900 MHz EMF could be considered to be a cause of precocious puberty in growing rats.     

Suppressive effect of nonviable Mycoplasma hyopneumoniae on phytohemagglutinin-induced transformation of swine lymphocytes

The effect of nonviable Mycoplasma hyopneumoniae on transformation of swine peripheral blood lymphocytes by mitogen was investigated. Lymphocyte transformation was evaluated as incorporation of [3H]-thymidine, using a microculture system. Mycoplasma hyopneumoniae was grown in Friis medium, inactivated with sodium azide, and washed with phosphate-buffered saline solution. Four strains of M hyopneumoniae, strain J, strain 11, and 2 low-passage isolates (1361A, 1375C), were found to suppress phytohemagglutinin-induced lymphocyte transformation. Mycoplasma hyopneumoniae strains J, 11, and 1361A reduced lymphocyte transformation by about 50%, whereas strain 1375C reduced lymphocyte transformation by 98.7%. The suppressive effect was abrogated by heating M hyopneumoniae at 60 C or at higher temperatures for 30 minutes. Sonication of the heated M hyopneumoniae cells partially restored the suppressive effect.     

Pharmacokinetics, intraoperative effect and postoperative analgesia of tramadol in cats

Tramadol is a synthetic codeine analogue used as an analgesic in human and veterinary medicine, but not approved for use in cats. Tramadol (2 mg/kg) was administered intravenously (IV) as preoperative analgesic in 12 cats (6 males) undergoing surgical gonadectomy. The pharmacokinetic profile of the drug and its O-desmethyl metabolite were determined in 8 animals (4 males), while intraoperative effects and postoperative analgesia, estimated by subjective pain score (0–24), were evaluated in all. Mean intraoperative isoflurane consumption was reduced, but hypoventilation was not observed. Sex-related differences were not observed, particularly in terms of postoperative analgesia: rescue analgesic was never administered. Concentrations of the active O-desmethyl metabolite were persistently high in all the animals. Considering the results obtained in this study, tramadol, at the dose of 2 mg/kg IV, did not produce any evident intraoperative cardiorespiratory side effects and with additional investigation may prove to be an appropriate intraoperative analgesic in cats undergoing gonadectomy.     

Effects of surgery and analgesic administration on spontaneous behaviour in singly housed rats

The study examined the use of behaviour in assessing post-laparotomy pain in rats given subcutaneous injections of saline (0.2 ml 100 g(-1)) or the analgesics buprenorphine (0.05 mg kg(-1)) or ketoprofen (5 mg kg(-1)). Procedural control influences (handling/movement, anaesthesia, injections) were studied in a second group. Of 150 behaviours examined, discriminant analysis classified the main treatment effects, and class mean frequencies were compared between treatments within each group. With the exception of buprenorphine treatment, control procedures reduced the frequency of active, attentive and grooming behaviour, and increased sleeping during 24 hours following each treatment. Moving animals to the theatre was the main factor responsible for these changes. Surgery also reduced active and attentive behaviour. Animals given pre-operative saline were more frequently inactive than those given ketoprofen. These effects most likely resulted from post-surgery pain, but this was not significantly diminished with the ketoprofen dose used. In all cases, buprenorphine outweighed these effects, causing a sustained increase in active, inactive and attentive behaviour, such that determination of any analgesic effects was impossible. The study underlined a role for pain assessments based on rat behaviour. Drug-related effects emphasised a need for more comprehensive assessments encompassing procedural influences, before behaviour changes that are potentially pain related may be determined accurately.     

延胡索及其不同配伍镇痛作用研究

延胡索系罂粟科紫堇属多年生草本植物延胡索（Corydalia yanhusuo W．T.Wang）的块茎,《本草纲目》曰：“延胡索能行血中气滞，气中血滞,故专治一身上下诸痛,用之中的,妙不可言，盖延胡索活血化气,第一品药也”，现代药理研究证明延胡索具有较好的镇痛作用,其强度为阿片的1／100。临床上延胡索常与其它药物配伍治疗各种疼痛,血瘀气滞所致疼痛配伍川芎,阳明头痛配伍白芷,风湿痹阻配伍当归。笔者采用热板法和扭体法，观察延胡索、延胡索配伍川芎、延胡索配伍白芷、延胡索配伍当归的镇痛作用,为中医的临床用药提供实验依据。     

Evaluation of anti-nociceptive effect of epidural tramadol, tramadol-lidocaine and lidocaine in goats

Objective To compare the anti‐nociceptive effect of tramadol, a combination of tramadol‐lidocaine, and lidocaine alone when administered in the epidural space. Study design Experimental randomized cross‐over study. Animals Seven healthy male goats, aged 9–11 months, weight 17.5–25.5 kg. Methods Treatments were lidocaine, 2.86 mg kg^?1, tramadol‐lidocaine (1 mg kg^?1 and 2.46 mg kg^?1, respectively) and tramadol (1 mg kg^?1) given into the epidural space. The volume of all treatments was 0.143 mL kg^?1. Nociception was tested by pin prick and by pressure from a haemostat clamp. Times to the onset and duration of anti‐nociception in the perineal region were recorded. Recumbency and ataxia were noted. Rectal temperature, heart rate and respiratory rate were recorded before and at 15 minute intervals for 2 hours after the administration of each treatment. Statistical comparison used one‐way anova with a post hoc Duncan’s test as a post hoc. Significance was taken as p < 0.05. Results Times (mean ± SD) to onset of and duration of loss of sensation, respectively in minutes were; lidocaine, 3 ± 1 and 85 ± 11), tramadol‐lidocaine 4 ± 1 and 140 ± 2; tramadol 12 ± 1 and 235 ± 18. Onset and duration times were significantly longer with tramadol than the other two treatments. Duration was significantly longer with tramadol‐lidocaine than with lidocaine alone. With lidocaine treatment all goats were severely ataxic or recumbent, after tramadol‐lidocaine mildly ataxic, and after tramadol not ataxic. Rectal temperature, heart and respiratory rates did not differ significantly from baseline after any treatment. Conclusions and clinical relevance The combination of tramadol‐lidocaine given by epidural injection produced an anti‐nociceptive effect in the perineal region, which was rapid in onset and had a longer duration of action than lidocaine alone. This combination might prove useful clinically to provide analgesia in goats for long‐duration obstetrical and surgical procedures but surgical stimuli were not investigated in this study.     

Preliminary study of quantitative aspects and the effect of pulsed electromagnetic field treatment on the incorporation of equine cancellous bone grafts

The quantitative aspects of equine cancellous bone graft incorporation and the possibility of influencing graft incorporation by daily exposure to a pulsed electromagnetic field (PEMF) was studied in eight yearling ponies. In order to be able to quantify formative aspects of graft remodelling, a double and treble tetracycline intravital labelling technique was used. Intravital radiographs were obtained at regular intervals throughout the trial, but were found to be of little assistance in assessing any differences between stimulated and non-stimulated grafts. The ponies were humanely destroyed at regular intervals between nine and 241 days after installation of the graft. Light microscopy and fluorescent light microscopy were used to evaluate quantitative aspects of graft incorporation and to compare PEMF-stimulated grafts with control grafts. There was a small but statistically significant effect of PEMF-stimulation on cancellous bone graft incorporation. In view of this, these observations can only be considered as indicative of a possible trend, but should encourage further studies using different signal modalities.