Progress of genome wide association study in domestic animals

ABSTRACT: Domestic animals are invaluable resources for study of the molecular architecture of complex traits. Although the mapping of quantitative trait loci (QTL) responsible for economically important traits in domestic animals has achieved remarkable results in recent decades, not all of the genetic variation in the complex traits has been captured because of the low density of markers used in QTL mapping studies. The genome wide association study (GWAS), which utilizes high-density single-nucleotide polymorphism (SNP), provides a new way to tackle this issue. Encouraging achievements in dissection of the genetic mechanisms of complex diseases in humans have resulted from the use of GWAS. At present, GWAS has been applied to the field of domestic animal breeding and genetics, and some advances have been made. Many genes or markers that affect economic traits of interest in domestic animals have been identified. In this review, advances in the use of GWAS in domestic animals are described.     

成都市区犬猫狂犬病病毒和弓形虫感染的调查

为了解四川省成都市区家养犬、猫狂犬病病毒及弓形虫的感染情况,采用商品化狂犬病病毒和弓形虫抗原快速检测试纸卡,对2010年8～10月间来自成都市区的103份家养犬以及75份家猫的唾液和血液样品进行检测;同时采用文献报道的PCR方法对家养犬血液样品中的弓形虫核酸进行检测。结果显示,103份家养犬唾液样品狂犬病病毒抗原均为阴性,而75份家猫唾液样品中,检出阳性样品5份(阳性率6.7%),可疑样品7份;103份家养犬血液样品弓形虫抗原阳性样品33份(32.0%),可疑样品22份,75份家猫血液样品中,检出阳性样品2份(阳性率2.7%),可疑样品3份。弓形虫核酸PCR检测结果显示,96份家养犬血液样品弓形虫核酸阳性样品57份(阳性率59.4%),与弓形虫抗原阳性和可疑样品总和所占比例基本一致(53.4%)。提示应重视源于家猫的狂犬病病毒和家养犬弓形虫对人的威胁。     

《家畜环境卫生学》教学模式的探索

 《家畜环境卫生学》是动物科学和动物医学专业的专业基础课,是一门理论和实践应用紧密结合的课程。结合对动物科学、动物医学专业教学改革实际,论文从教学方法和手段、实验课程教学以及教学实习基地建设等方面进行论述,探索家畜环境卫生学理论与实践教学模式,提升教学效果。     

EFFICACY AND TOXICITY OF AN ACCELERATED HYPOFRACTIONATED RADIATION THERAPY PROTOCOL IN CATS WITH ORAL SQUAMOUS CELL CARCINOMA

Squamous cell carcinoma (SCC) is the most common feline oral tumor. Standard radiation protocols have been reported to achieve tumor control durations of 1.5–5.5 months (45–165 days). The purpose of this study was to describe the efficacy and toxicity of an accelerated hypofractionated radiation therapy protocol in cats with oral SCC. Twenty‐one cats with histologically confirmed oral SCC and T1‐3N0M0 were treated with 10 once‐daily fractions (Monday–Friday) of 4.8 Gy. Seventeen cats had macroscopic disease and four were microscopic after incomplete excision. Acute toxicity consisted of grade 2 mucositis in all cats and this was effectively managed using esophageal or gastric tube feeding, pain medication, and antibiotics. Late toxicity effects for cats with available follow‐up data included alopecia (4 cats), leukotricia (6), tongue ulceration (1), and oronasal fistula (1). Response could be assessed in 17 cats (seven complete response and five partial response). Four cats (19%) developed metastatic disease without evidence of local progression. The median progression‐free survival (PFS) was 105 days (1 year PFS of 23%), median local progression‐free survival (LPFS) was 219 days (1 year LPFS of 41%), and median overall survival (OS) was 174 days (1 year OS of 29%). Only tumor stage was prognostic, with T1 having a median PFS of 590 days. Findings indicated that this accelerated hypofractionated radiation therapy protocol was well tolerated in cats with oral SCC, with manageable adverse events. Tumor response was observed in most cats and long tumor control durations were achieved in some cats.     

ULTRASONOGRAPHIC CHARACTERISTICS OF THE CISTERNA CHYLI IN EIGHT DOGS AND FOUR CATS

Ultrasonography of the cisterna chyli has been used in humans to diagnose increased lymphatic flow or lymph flow obstruction and to guide percutaneous embolization of the thoracic duct via the cisterna chyli. The aim of this study was to describe the ultrasonographic characteristics of the dorsal portion of cisterna chyli in dogs and cats with chylous ascites or chylothorax and in a group of healthy dogs and cats. The aorta and the cranial mesenteric artery were used as anatomic landmarks. Ultrasonography was performed before and 2 h after a fatty meal in healthy dogs and cats. The visualized structure was confirmed to be a dilated cisterna chyli at necropsy in a dog with chylous ascites. The confirmed or presumed cisterna chyli was consistently detected using ultrasonography in nonfasted healthy animals and clinically affected animals and appeared as an anechoic tubular structure, without detectable flow, at the right dorsolateral aspect of the aorta. It had a similar ultrasonographic appearance in patients with chyloabdomen and in nonfasted healthy dogs and cats. There was considerable overlap in diameters of the cisterna chyli for affected and healthy animals. The shape and size of the cisterna chyli in an individual animal were variable during the same ultrasound examination and between different examinations. This study demonstrated the appearance of the presumed dorsal portion of the cisterna chyli by ultrasonography and might provide useful preliminary data for further studies into the feasibility of ultrasound‐guided injections or aspirations of the cisterna chyli in dogs and cats.     

Validation of the TonoVet® rebound tonometer in normal and glaucomatous cats

Objective  To validate intraocular pressure (IOP) readings obtained in cats with the TonoVet^® tonometer. Animals studied  IOP readings obtained with the TonoVet^® were compared to IOP readings determined by manometry and by the Tono‐Pen XL^? in 1 normal cat and two glaucomatous cats. TonoVet^® and Tono‐Pen XL^? readings were also compared in a further six normal and nine glaucomatous cats. Procedures  The anterior chambers of both eyes of three anesthetized cats were cannulated and IOP was varied manometrically, first increasing from 5 to 70 mmHg in 5 mmHg increments, then decreasing from 70 to 10 mmHg in 10 mmHg decrements. At each point, two observers obtained three readings each from both eyes, with both the TonoVet^® and Tono‐Pen XL^?. IOP was measured weekly for 8 weeks with both tonometers in six normal and nine glaucomatous unsedated cats. Data were analyzed by linear regression. Comparisons between tonometers and observers were made by paired student t‐test. Results  The TonoVet^® was significantly more accurate than the Tono‐Pen XL^? (P = 0.001), correlating much more strongly with manometric IOP. In the clinical setting, the Tono‐Pen XL^? underestimated IOP when compared with the TonoVet^®. Conclusions  Both the TonoVet^® and Tono‐Pen XL^? provide reproducible IOP measurements in cats; however, the TonoVet^® provides readings much closer to the true IOP than the Tono‐Pen XL^?. The TonoVet^® is superior in accuracy to the Tono‐Pen XL^? for the detection of ocular hypertension and/or glaucoma in cats in a clinical setting.     

Pharmacokinetic and pharmacodynamic modelling of intravenous,intramuscular and subcutaneous buprenorphine in conscious cats

ObjectiveTo describe simultaneous pharmacokinetics (PK) and thermal antinociception after intravenous (IV), intramuscular (IM) and subcutaneous (SC) buprenorphine in cats.Study designRandomized, prospective, blinded, three period crossover experiment.AnimalsSix healthy adult cats weighing 4.1 ± 0.5 kg.MethodsBuprenorphine (0.02 mg kg^?1) was administered IV, IM or SC. Thermal threshold (TT) testing and blood collection were conducted simultaneously at baseline and at predetermined time points up to 24 hours after administration. Buprenorphine plasma concentrations were determined by liquid chromatography tandem mass spectrometry. TT was analyzed using anova (p < 0.05). A pharmacokinetic-pharmacodynamic (PK-PD) model of the IV data was described using a model combining biophase equilibration and receptor association-dissociation kinetics.ResultsTT increased above baseline from 15 to 480 minutes and at 30 and 60 minutes after IV and IM administration, respectively (p < 0.05). Maximum increase in TT (mean ± SD) was 9.3 ± 4.9 °C at 60 minutes (IV), 4.6 ± 2.8 °C at 45 minutes (IM) and 1.9 ± 1.9 °C at 60 minutes (SC). TT was significantly higher at 15, 60, 120 and 180 minutes, and at 15, 30, 45, 60 and 120 minutes after IV administration compared to IM and SC, respectively. IV and IM buprenorphine concentration-time data decreased curvilinearly. SC PK could not be modeled due to erratic absorption and disposition. IV buprenorphine disposition was similar to published data. The PK-PD model showed an onset delay mainly attributable to slow biophase equilibration (t_1/2k_e0 = 47.4 minutes) and receptor binding (k_on = 0.011 mL ng^?1 minute^?1). Persistence of thermal antinociception was due to slow receptor dissociation (t_1/2k_off = 18.2 minutes).Conclusions and clinical relevanceIV and IM data followed classical disposition and elimination in most cats. Plasma concentrations after IV administration were associated with antinociceptive effect in a PK-PD model including negative hysteresis. At the doses administered, the IV route should be preferred over the IM and SC routes when buprenorphine is administered to cats.