The Minimum Alveolar Concentration of Desflurane in Cats

Eight adult cats, 4 male and 4 female, (3.5 ± 0.9 [SD] kg) were used to determine the minimum alveolar concentration (MAC) of desflurane. Desflurane (DES) anesthesia was induced in a 20 L chamber with an oxygen inflow of 10 L/min and the DES vaporizer set at 18%. After 3.5 ± 0.5 min, the cats were removed from the chamber and anesthesia was maintained via mask (14% DES, 3L/min O₂) until successful intubation. Anesthesia was maintained with DES in oxygen at a flow of at least 200 mL/kg/min through a nonrebreathing circuit. The time from the start of induction to completion of intubation was 6.2 ± 1.1 min. Esophageal temperature was maintained between 37.8°C and 38.6°C. Hand-collected end-tidal gas samples were obtained from a catheter positioned inside the lumen of the endotracheal tube. Inspired and end-tidal DES concentrations were measured with a Biochem 8100 anesthetic agent monitor that was calibrated with known gas standards and modified to accept hand-collected samples. A constant alveolar concentration of DES was maintained for at least 15 minutes, then a clamp was applied to the tail and the cat observed for gross purposeful movement. The end-tidal DES was then increased (if a positive response) or decreased (if a negative response) by 20% and the test repeated after 15 minutes of constant conditions. The final iteration was 10%. The MAC of DES in these cats was 9.79 ± 0.70 vol %. The F_A/F_I ratio for desflurane was always greater than 0.97.     

Focal Heat Stimulation for the Determination of the Minimum Alveolar Concentration of Halothane in the Rabbit

Sobair, A.T.H., Cottrell, D.F. and Camburn, M.A., 1997. Focal heat stimulation for the determination of the minimum alveolar concentration of halothane in the rabbit. Veterinary Research Communications, 21 (3), 149-159A focal heat stimulus of 54.37 ± 0.07 (SD)°C was applied for 30 s to the inner aspect of the pinna of the ear for the determination of the minimum alveolar concentration (MAC) of halothane in New Zealand White rabbits. The latency before head movement was measured electromanometrically. The MAC value was 1.05 ± 0.09 (SD)%. Other physiological responses occurred inconsistently and could not be used as reliable end points for the determination of the MAC in the rabbit.     

Butorphanol Does Not Reduce the Minimum Alveolar Concentration of Halothane in Dogs

This study evaluated the effect of butorphanol tartrate, a synthetic opioid agonist-antagonist, on halothane minimum alveolar concentration (MAC) in dogs. Baseline halothane MAC was determined in each of six dogs. Butorphanol was administered and halothane MAC was redeter-mined. Each dog received butorphanol at 0.2, 0.4, and 0.8 mg/kg intravenously at 1 week intervals. Heart rate and arterial blood pressure decreased after butorphanol administration, but returned to baseline by 50 minutes. There was little effect on respiratory parameters. A halothane-sparing effect was not noted with any butorphanol dose.     

9种抗菌药物对大肠埃希菌最小抑菌浓度的测定

畜禽养殖中会用到一些抗菌药物,而药物选用需要进行药物敏感性试验,目前市售的药敏纸片多为人用抗菌药物,为了制备兽用抗菌药物的药敏纸片,需要对药物的最小抑菌浓度(MIC)进行测定。该研究筛选了国家兽用药物名录中规定的、兽医临床上常用6类共9种抗菌药物(头孢噻呋钠、硫酸链霉素、强力霉素、土霉素、氨苄西林、氟苯尼考、替米考星、硫酸新霉素、青霉素),以大肠埃希菌为指标菌,通过微量肉汤稀释法分别测定了9种常用抗菌药物的最小抑菌浓度(MIC)。结果表明,头孢噻呋钠、硫酸链霉素、强力霉素、土霉素、氨苄西林、氟苯尼考、替米考星、硫酸新霉素、青霉素对指标菌的MIC值分别为为2、4、4、16、8、16、64、32、250μg/mL。研究结果为这些药物的临床应用和药敏纸片的研制提供了基础资料。     

The Inferior Alveolar Nerve of the Horse: Course and Anatomical Relationship with Mandibular Cheek Teeth

The precise location of neurovascular structures within the relatively long mandibular canal of the horse is of paramount importance in surgical procedures of the area. The inferior alveolar nerve (IAN) enters the mandibular canal on the medial (lingual) surface of the mandible and innervates all the mandibular teeth. During its course, the nerve moves laterally, crossing the roots of the inferior cheek teeth. However, the exact anatomical relationships occurring between the IAN and the roots of the equine mandibular cheek teeth have not been described in detail. In this study, the mandibles of 40 horses were examined with CT scans and then used for bilateral detailed anatomical dissection, to assess the path of the IAN and its relationship to the roots of the lower cheek teeth. The data obtained show that the equine IAN is located ventral to the apices of the molar teeth (311/411, 310/410, 309/409 according to the Triadan numerical system). At the level of PM₄ (308/408), the IAN is located on the lingual side of the roots and coronally to its apices. At the level of PM₃ (307/407), the IAN is then found on the lingual side of the roots but in proximity to the apices. In 2 of 40 horses (=5%), the IAN moves towards the lingual side between the mesial and the distal root of PM₄. Our observations are valuable for planning a surgical approach to the ventral side of the mandible in the horse and to avoid potential post‐operative complications.     

福建白羽肉鸡鸡毒支原体的分离鉴定及最小抑菌浓度测定

为了解福建白羽肉鸡中鸡毒支原体（MG）对临床常用药物的敏感性,本研究从2个商品代白羽肉鸡养殖场采集了疑似患慢性呼吸道病（CRD）的鸡喉拭子40份,接种于适宜的支原体培养基上进行纯化。通过对菌株生物学特性分析、细菌形态学观察、PCR测序及动物回归试验进行鉴定,并利用最低抑菌浓度（MIC）测定了分离株对临床常用抗菌药的敏感性。结果显示,本试验成功获得2株MG,命名为MX和HY。将分离株接种于含有酚红的支原体液体培养基中能分解葡萄糖产酸使培养基颜色由红变黄;固体培养基于低倍镜下观察到典型的"荷包蛋"状菌落;分离株经过Dienes染色后的菌落中心呈致密深蓝色,边缘淡蓝,且30 min后不褪色,并具有较强吸附红细胞的能力,呈现典型MG培养特征;动物回归试验和分离株pvpA基因测序结果显示,2株MG分离株均具有较强致病性,证实其与R株的亲缘关系最近;药敏试验结果显示,MX和HY对泰妙菌素、氟苯尼考和泰乐霉素表现出了高度敏感性,其次是盐酸恩诺沙星、盐酸大观霉素,而对具有与泰乐霉素类似分子结构和抗菌谱的畜禽专用抗生素替米考星敏感性较差,此差异可能与临床上长期应用该药有关。研究结果表明,福建地区商品代白羽肉鸡中存在致病性MG流行,泰妙菌素可以作为临床防治MG的首选药物。     

微生物浊度法测定3种兽用抗生素效价的研究

分别以金黄色葡萄球菌和大肠杆菌为试验菌,抗生素检定培养基Ⅲ号为试验用培养基,制成菌悬液。将硫酸安普霉素、泰乐菌素、硫酸黏菌素稀释成不同的浓度加入菌悬液中,37℃培养3～4h,确立浓度的对数值与相对应的吸光度呈直线相关的线性范围,并对所建立的浊度法进行准确度、精密度、浊度法与管碟法比较及专属性等验证。结果表明硫酸安普霉素、泰乐菌素、硫酸黏菌素的线性浓度范围分别为2．9—7．2、0．6～2．0、44．9～93．2u／mL,相关系数r分别为0．9974、0．9984、0。9978。硫酸安普霉素、泰乐菌素、硫酸黏菌素所建立的浊度法平均回收率及平均可信限率分别为99．82％,2．48％、99．66％,2．80％、99．61％,7．62％。管碟法与浊度法所测结果无显著差异。硫酸安普霉素和泰乐菌素浊度法具有可信限率低、灵敏度高、精密度高、快速等优点;硫酸黏菌素建立的浊度法可信限率与管碟法接近。     

Desflurane in the dog; Minimum alveolar concentration (MAC) alone and in combination with nitrous oxide

The Minimum Alveolar Concentration (MAC) of desflurane was measured in five male adult Beagle dogs using a supramaximal electrical stimulus. The value for MAC was found to be 10.32 ± 0.14 SEM % (range 9.83 -10.6%). Addition of 50% nitrous oxide to the carrier gas lowered the value of MAC to 7.99 ±0.57 % (range 6.7 -9.13%).
Anaesthetic induction with desflurane was rapid, and any excitement period seen was brief. Side effects noted were opposition to mechanical ventilation (all dogs); episodes of second degree heart block with multifocal ventricular ectopic depolarisations (2 dogs) and transient muscle rigidity (4 dogs). Maintenance of body temperature was difficult, episodes of both hyperthermia and hypothermia occurring. Recovery from anaesthesia was rapid and smooth, the time from extubation to standing being 6 ± 1.27 minutes (range 3–9 minutes).     

微生物浊度法测定硫酸黏菌素E含量的研究

以大肠杆菌为试验菌,抗生素检定培养基Ⅲ号为试验用培养基,研究比浊法测定硫酸黏菌素及其制剂的含量。硫酸黏菌素的浓度在44.9 u/ml～93.2u/ml之间时,检测菌液接种浓度为0.3%,培养时间为2～3h,其浓度的对数值与相对应的吸光度具有良好的线性关系,相关系数：r＝0.9978。所建立的浊度法重现性较好,具有简便、精确、快速的特点,可用于硫酸黏菌素及其制剂含量的测定。     

Minimal Anesthetic Concentration and Cardiopulmonary Dose-Response of Halothane in Ducks

The minimal anesthetic concentration (MAC) for halothane and cardiopulmonary dose-responses at several concentrations of halothane were determined during spontaneous ventilation in nine young adult Pekin ducks. The MAC for halothane was 1.04 +/- 0.11 (mean +/- SD). There were dose-dependent decreases in ventilation, significant reductions in inspiratory and expiratory times, and prolongation of expiratory pause times. The end-tidal halothane concentration at apnea in five ducks was less than 1.53% and anesthetic index was less than 1.51. Heart rate increased significantly as the concentration of halothane was increased, but arterial blood pressure did not change. Cardiac arrhythmias developed in five ducks at end-tidal halothane concentrations as low as 1.15%, and one duck died of cardiac arrest.     

微生物浊度法测定泰乐菌素及其制剂含量的研究

以金黄色葡萄球菌为试验菌,抗生素检定培养基Ⅲ号为试验用培养基,将泰乐菌素稀释成不同的浓度,寻找浓度的对数值与相对应的吸光度呈直线相关的线性范围,建立测定泰乐菌素及其制剂含量的浊度法。泰乐菌素的浓度在0.6-2.0u/mL之间,其浓度的对数值与相对应的吸光度呈直线相关,相关系数r为0.9992。经t检验,泰乐菌素浓度的对数值与相对应的吸光度回归效果显著。所建立的浊度法平均回收率为99.87%,平均可信限率为2.76%,RSD为0.37%。管碟法与浊度法所测结果无显著差异。浊度法具有简便、精确、快速的特点,可用于泰乐菌素及其制剂含量的测定。     

微生物浊度法测定三种兽用抗生素效价

分别以金黄色葡萄球菌和大肠杆菌为试验菌,抗生素检定培养基Ⅲ号为试验用培养基,制成菌悬液.将硫酸安普霉素、泰乐菌素、硫酸黏菌素稀释成不同的浓度加入菌悬液中,37℃培养3～4 h,确立浓度的对数值与相对应的吸光度呈直线相关的线性范围,并对所建立的浊度法进行准确度、精密度、浊度法与管碟法比较及专属性等验证.结果表明硫酸安普霉素、泰乐菌素、硫酸黏菌素的线性浓度范围分别为2.9 ～7.2 、0.6～2.0、44.9～93.2 u/mL,相关系数r分别为0.997 4、0.998 4、0.997 8.硫酸安普霉素、泰乐菌素、硫酸黏菌素所建立的浊度法平均回收率及平均可信限率分别为99.82%,2.48%、 99.66%,2.80%、99.61%,7.62%.管碟法与浊度法所测结果无显著差异.硫酸安普霉素和泰乐菌素浊度法具有可信限率低、灵敏度高、精密度高、快速等优点;硫酸黏菌素建立的浊度法可信限率与管碟法接近.     

微生物浊度法测定硫酸黏菌素及其制剂含量的研究

以大肠杆菌为试验菌,抗生素检定培养基Ⅲ号为试验用培养基,研究微生物比浊法测定硫酸黏菌素及其制剂的含量.硫酸黏菌素的浓度在44.9 u/mL～93.2 u/mL之间时,检测菌液接种浓度为0.3%,培养时间为2～3 h,其浓度的对数值与相对应的吸光度具有良好的线性关系,相关系数:r＝0.997 8.所建立的微生物浊度法重现性较好,具有简便、精确、快速的特点,可用于硫酸黏菌素及其制剂含量的测定.     

Minimal Anesthetic Concentration and Cardiopulmonary Dose Response of Isoflurane in Ducks

The minimal anesthetic concentration (MAC) for isoflurane was determined during spontaneous ventilation in nine male Peking ducks (7 to 12 weeks of age; 3.0 +/- 0.4 kg). While each bird was awake, arterial blood was collected for analysis of pH, PaCO2, and PaO2. After anesthesia was induced with isoflurane in oxygen, MAC was determined for isoflurane in each bird during spontaneous ventilation in a manner similar to MAC determinations in mammals. Pulmonary dose-response data were collected at 1 MAC and 1.5 MAC. Anesthetic index (Al; an index of anesthetic-induced apnea) was calculated from ducks that became apneic. The MAC for isoflurane was 1.30 +/- 0.23% (mean +/- SD). There was a dose-dependent decrease in ventilation as evidenced by a statistically significant increase in PaCO2. Apnea or unacceptable hypercarbia (PaCO2 greater than 110 mm Hg), or both, were common occurrences at end-tidal isoflurane concentrations greater than 1.5 MAC. Anesthetic index calculated from four ducks was 1.65 +/- 0.13 (mean +/- SEM). There was no significant difference between the means of either heart rate or mean arterial blood pressure in birds at 1.0 and 1.5 MAC.     

影响妊娠伊犁马结合雌激素浓度的因素分析

试验通过分析伊犁母马妊娠时间、年龄和尿量对伊犁马孕马尿中结合雌激素浓度的影响,以期为企业生产动物结合雌激素提供参考。选取相同饲养条件下妊娠期为28～38周伊犁孕马35匹并按年龄分为3组,每周采尿样1次并记录24 h尿量。高效液相色谱（HPLC）法测定结合雌激素的浓度。采用SAS 8.1最小二乘法分析妊娠时间、年龄因素对结合雌激素浓度的影响;相关分析法分析尿量与结合雌激素浓度的相关性。结果显示,妊娠时间对结合雌激素浓度有极显著影响（P＜0.01）。年龄对17α-双氢马烯雌酮硫酸钠浓度影响不显著（P＞0.05）;年龄对雌酮硫酸钠浓度和马烯雌酮硫酸钠浓度影响极显著（P＜0.01）。尿量与17α-双氢马烯雌酮硫酸钠和马烯雌酮硫酸钠浓度呈极显著负相关（P＜0.01）;尿量与雌酮硫酸钠浓度呈不显著负相关（P＞0.05）。结果表明,伊犁孕马妊娠时间是影响结合雌激素浓度的关键因素;采集尿液的伊犁孕马年龄不宜超过13岁;伊犁孕马尿液中结合雌激素浓度与孕马尿量呈极显著负相关。     

Evaluation of Serum Electrolytes and Blood Lactate Concentration During Repeated Maximal Exercise in Horse

Modifications of some serum electrolyte concentration during two international *** show jumping competition performed in two consecutive weekends were evaluated. Serum sodium (Na), chloride (Cl), magnesium (Mg), potassium (K), phosphorous (P), calcium (Ca), iron (Fe), and blood lactate on 14 well-trained Italian saddle horses were assessed. Blood samples were collected before the beginning of the competition (T0B), within 10 minutes after the end of race (R1, R2, and R3), and on the day after competition (T0R). The same procedure was followed on the second weekend (R4, R5, R6, and T1R). One-way repeated measures analysis of variance was applied on collected data, and a significant effect on sampling time (P < .05) on all parameters studied was found. These results suggest that serum electrolytes and blood lactate concentration are responsive to intense exercise and could be considered an important factor for a correct management training's planning.     

Interrelationships Between Age and Trace Element Concentration in Horse Mane Hair and Whole Blood

The use of hair as a sample matrix to determine the mineral status of an animal has received a lot of interest. The objective of this study was to determine if the trace element content in horse mane hair changed with age when evaluated in a group of horses representing a large age range. As a second objective, whole blood trace element content was evaluated, and its relationship to mane hair trace element content, as well as age, were tested. Therefore, mane hair and whole blood samples were obtained from 59 horses, ranging from 2 months to 26 years in age, housed on the same farm. Mane hair samples were washed, and hair and blood digested and analyzed for 11 trace elements. Weak correlations (P < .05) between age and mane hair trace element content was detected for arsenic (r = 0.29), copper (r = −0.39) and selenium (r = −0.27). While the mane hair color did not affect trace element concentration, greater variability was detected in the black mane hair samples. This resulted in outliers that were removed from the final statistical analysis. However, data is presented to the reader both ways. Correlations were also detected (P < .05) between age and whole blood iron (r = 0.62), selenium (r = 0.76) and zinc (r = 0.47). This is similar to what has been reported in horses using serum or plasma. The trace element concentrations of mane hair and whole blood were not correlated (P > .05) in this study. However, the concentrations of trace elements in mane hair were higher than that of blood. Trace elements, specifically chromium and lead, that were below detection levels in the blood, were detectable in mane hair. This suggests that mane hair may be a potential means to investigate suspected exposure to excessive levels of trace minerals or heavy metals that are difficult to detect in blood.     

Dorsal Laminectomy in the Horse II. Evaluation in the Normal Horse

Subtotal dorsal cervical laminectomy was performed on nine normal horses to evaluate positioning, refine the surgical technique, and assess the immediate and long-term effects of this procedure in the horse. Funkquist type B laminectomies were performed at various levels from C3-C4 to C6-C7. Absorbable gelatin sponge or autogenous nuchal fat was placed over the exposed dura mater. Surgery times varied from 2 to 3 hours, and all horses recovered without complication. Rapid primary intention wound healing occurred, with two horses showing neck pain. All remained neurologically normal. The horses were euthanized 6 weeks, 3 months, or 6 months postoperatively. Myelograms performed just prior to euthanasia demonstrated normal or expanded dye column widths. Necropsy revealed that all surgical sites had healed well. The laminectomy membrane was soft and pliable and could be easily separated from the underlying dura mater when fat was used as interpositional material. When gelatin sponge was used, the laminectomy membrane was firmly bonded to the dura. Spinal cords at the level of laminectomy appeared normal and moved freely within the vertebral canal. Histological evaluation of the laminectomy sites and associated spinal cord revealed no abnormalities attributable to the surgery. It was concluded that dorsal cervical laminectomy can be performed in horses without untoward sequelae. The procedure may be useful for the treatment of equine cervical compressive myelopathies.