Advances in echocardiography

Before the development of echocardiography, cardiac disease in the horse was diagnosed if a loud heart murmur (grade III-IV/VI or louder) and clinical signs of congestive heart failure (coughing, edema, venous distention, jugular pulsations) were detected on physical examination. Arrhythmias that persisted during and after exercise also indicated cardiac disease, which could be characterized electrocardiographically. Electrocardiography, thoracic radiography, angiography, cardiac catheterization, and oximetry could add only small pieces of information about the heart. M-mode echocardiography provided the first "window" with which to evaluate the heart and its intracardiac structures, albeit an ice-pick one-dimensional view. With M-mode echocardiography, the diameter of the aorta at the valves, the left ventricle, right ventricle, and left atrial appendage, as well as the thickness of the interventricular septum and left ventricular free wall, could be measured. Motion and thickness of the tricuspid, mitral, and aortic valves could be assessed, but only in a one-dimensional plane. Two-dimensional echocardiography provided an added dimension, resulting in visualization of all the intracardiac structures, aorta, and pulmonary artery. Two-dimensional echocardiography became the diagnostic technique of choice for the evaluation and characterization of congenital cardiac disease in critically ill neonates, as well as in adult horses. Two-dimensional echocardiography also improved the ability to diagnose valvular regurgitations, characterize valvular lesions (bacterial endocarditis, ruptured chorda tendineae), myocardial function (segmental wall motion abnormalities), atrial size, mass lesions (endocarditis, neoplasia, and thrombi), and pericardial effusion. Information about blood flow was obtained using contrast echocardiography but was limited to certain cardiac abnormalities (congenital cardiac defects and tricuspid regurgitation). This information about blood flow was limited to the detection of positive or negative contrast jets. Comprehensive information about blood flow was lacking until the application of Doppler echocardiography to equine cardiology. Pulsed-wave and color flow Doppler echocardiography resulted in precise localization of the abnormal blood flow and semiquantitation of the shunt flow or regurgitant jet. Color flow Doppler echocardiography sped up the localization and semiquantitation of the jet in many instances and provided some information about blood flow velocity in the enhanced and variance modes. The peak velocity of jets can be determined using continuous-wave Doppler echocardiography. This value then can be used to estimate pressure difference between cardiac chambers or to calculate cardiac output noninvasively if angles parallel to flow can be obtained. Thus, information about cardiac size, function, and blood flow can be combined to diagnose cardiac disease in horses and to formulate a prognosis for life and performance.     

Advances in equine ultrasonography.

The digital storage and transfer of images coupled with the development of the Internet have revolutionized diagnostic imaging. With the press of a button, practitioners can exploit the diagnostic skills of specialists anywhere in the world and enlist their help with challenging cases. This easy transfer of images and digital data should stimulate a greater number of multicenter studies so that the sensitivity and specificity of ultrasonographic techniques can be established in larger and more meaningful cohorts of patients. There is now no doubt that we can identify a plethora of conditions of the horse with ultrasonography; however, there is a continuing need to look critically at how we use such information to improve patient management and outcome.     

Advances in respiratory imaging.

Although conventional radiography is still the first diagnostic imaging approach to respiratory disease, CT is proving to be invaluable as an adjunctive procedure in characterizing nasal and thoracic pathologic findings. CT eliminates superimposition of overlying structures and offers superior contrast resolution as compared with conventional radiography. These advantages allow for more precise characterization and localization of lesions and are invaluable for guiding rhinoscopic, bronchoscopic, and surgical procedures.     

Advances in respiratory therapy.

Effective respiratory therapy depends on obtaining a definitive diagnosis and following established recommendations for treatment. Unfortunately, many respiratory conditions are idiopathic in origin or are attributable to nonspecific inflammation. In some situations, disorders are controlled rather than cured. Recent advances in pulmonary therapeutics include the use of new agents to treat common diseases and application of local delivery of drugs to enhance drug effect and minimize side effects.     

Advances in information technology.

Advances in digital technology have vastly increased the speed and content of information transfer. Equine practitioners of the future should be in contact with their office and other information resources at all times through an array of digital networks. Patients and practitioners alike should benefit from better information access.     

Advances in flea control.

With an increase in our knowledge of flea life cycle and biology, flea control has improved tremendously over the past 10 years. Treatment programs should be tailored to each case. The goal of effective flea control is to eliminate adults and to prevent reinfestation and the development of new generations of fleas. New products are of great benefit to flea-infested and flea-allergic animals and allow a safe and effective way to control fleas. Even if the consistent use of a topical adulticide alone is tempting, rotation and a combination of products should still be used to delay resistance. In addition, environmental flea control is a wise approach, especially in cases of severe infestation or in situations where there is a flea-allergic animal. Finally, in order to avoid failures and resistance, it is important to treat all pets in the household.     

Stress echocardiography and its role in performance assessment.

Stress echocardiography in the horse is in its infancy, and investigations need to continue to determine the significance and mechanism of postexercise echocardiographic abnormalities detected in horses. This work should be coupled with investigations on the exercise-induced changes in cardiac isoenzymes, cTnI, arterial oxygen content, and cardiac rhythm that may occur concurrently. With continued investigations into the cardiovascular problems that occur in the exercising horse, the sport horse veterinarian should be better able to accurately diagnose and treat problems causing poor performance in the horse.     

Advances in equine practice management.

As equine practices move forward in the 21st century, we feel increasing pressure to manage our businesses like business people. This requires outside expertise, in-house business-trained managers, and continuing education on various aspects of practice life. Aside from the AAEP, several other organizations are providing continuing education in management, including the Association of Veterinary Practice Managers, the Veterinary Management Institute offered at Purdue University Krannert Graduate School of Management, the American Animal Hospital Association through (The Virginia-Maryland Regional College of Veterinary Medicine's) on-line practice management course, and the University of Illinois Equine Practice Management modules.     

Doppler echocardiography

Echocardiography offers an invaluable noninvasive technique for examining structures within the heart, for measuring the size of cardiac chambers and for assessing myocardial function. Doppler provides a further objective measure of blood flow within the heart and great vessels that reflects the haemodynamic function of the heart. Furthermore, it demonstrates valvular disorders very accurately, especially with the aid of colour-flow mapping.     

胡枝子属植物研究进展

胡枝子属(Lespedeza)的部分种属于自花授粉植物,部分属于异花授粉植物。该属植物种子硬实性比较高,在播种时需要处理,破除其硬实性,才能保证其播种时有较好的出苗率。抗逆性研究比较少,主要集中在种子萌发期及幼苗的抗逆性,对后期生长研究比较少;种研究的也比较少,主要集中在少数几个种上。胡枝子属植物具有较大的药用价值,在西部干旱山区和水土流失地区栽植,既能防止水土流失,也能为当地群众提供一定的经济收入。我国进行胡枝子属植物研究的单位比较少,未能系统的对其进行深入研究,所涉及的种比较少,研究的技术手段比较落后。因此,需要扩大研究单位以及加强科研单位之间的合作,争取国家更多的经费投入,对胡枝子属植物进行全面而深入的研究,使其在生态环境建设、退化草地改造以及促进农村经济发展等方面发挥更大的作用。     

Use of echocardiography in the diagnosis of dilated cardiomyopathy in Irish wolfhounds.

The purpose of this study was to compare the echocardiographic features of Irish wolfhounds with clinically inapparent dilated cardiomyopathy (DCM) (n = 33) to dogs with advanced DCM (n = 33) and to normal dogs (n = 262). Significant differences were detected between the three groups. In dogs with DCM, the most sensitive diagnostic measurements were: end-systolic volume index (ESVI), E-point to septal separation (EPSS), fractional shortening (FS), and left ventricular internal dimensions (LVIDd and LVIDs). Left atrial diameter was increased markedly in dogs with DCM and 83.3% of affected Irish wolfhounds had concurrent atrial fibrillation. Compared with early DCM, in advanced DCM there was a significant increase in end-diastolic right ventricular diameter, often combined with extensive pleural effusion, the leading sign of congestive heart failure in Irish wolfhounds.     

Measurement of cardiac dimensions with two-dimensional echocardiography in the living horse.

Two-dimensional echocardiography (2DE) was performed on 22 unsedated Thoroughbred and part Thoroughbred horses weighing between 411 and 650 kg to establish normal reference values for 2DE measurements. Animals stood during examinations performed with a 3.5 MHz mechanical sector transducer using various transducer positions and tomographic planes. Right ventricular diameter (RVD), ventricular septal thickness (VSTh), aortic diameter (AoD), area of the chordal lumen of the left ventricle (CTA), left ventricular diameter (LVD) and left atrial diameter (LAD) were determined at ventricular end-diastole (Ed) and/or end-systole (Es). Fractional shortening (FS) of the left ventricle and end-systolic left atrial to aortic ratio (LAD-Es:AoD-Es) also were calculated. Echocardiographic data were related to body weight by linear regression analysis. Intra-observer variability was checked in five horses by measuring each parameter during each of 10 consecutive cardiac cycles. The 2DE data were compared with M-mode values in published reports. In the 18 horses whose weight did not exceed 551 kg, repeatable recordings of good quality were obtained, and 2DE measurements could be made using intra-cardiac reference points. Increasing body weight proved to impose substantial limitations on measurements taken with the available machine and transducer. This problem might be overcome by using probes of lower frequency or equipment with higher quality image display at greater depth. The following parameters correlated significantly to body weight: VSTh-Es (r = 0.69; P less than 0.01). AoD-Es (r = 0.64; P less than 0.01) and CTA-Es (r = 0.84; P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

菠萝蜜研究进展

菠萝蜜（Artocarpus heterophyllus lam.）是集水果、木本粮食和珍贵用材于一体的热带经济作物。本文纵观国内外的菠萝蜜研究进展及动态,就其生长习性、种质资源、繁育技术、品种选育、栽培管理、病虫害、植物化学成分、药理作用、利用价值和问题与展望几个方面进行概述,旨在为我国菠萝蜜产业的开发利用提供参考。     

Advances in BHV1 (IBR) research.

Bovine Herpesvirus Type 1 (BHV1) is the aetiological agent of a number of diseases and not only of IBR, namely infectious pustular vulvovaginitis (IPV), infectious balanoposthitis (IBP), conjunctivitis, encephalomyelitis, mastitis, abortion, enteritis, and lesions in the interdigital space. The serological identical strains differ, however, in some aspects. Typical genital strains usually cause a mild illness, sometimes not even detected clinically, but serologically. They hamper eradication programmes and do not cause IBR when inoculated intranasally. The other--modern--strains are, however, always able to induce a severe disease in the genital tracts. But infection of field or vaccine virus leads to the development of humoral and cell-mediated immunity. The latter is, however, not transmitted to neonates via colostrum. BHV1 antibodies can be found in bovines in all continents, and in many wild species. Prevalences vary greatly depending on herd size and management. Because seronegative cattle play a role in international trade a number of European countries have eradicated BHV1, with very high costs involved. Marker and conventional vaccines can prevent disease but not infection followed by the state of latency. The genomes of several strains, including the marker strains can remain latent in the same animal and be reactivated after stress or injection of corticosteroids. For the detection of humoral antibodies the ELISA is widely used. It is useful for testing bulk milk samples for antibodies derived from field virus and conventional vaccines but not from gE-deleted marker vaccines. Importing countries should consider only vaccinated animals for import. They should require that the animals are seronegative prior to vaccination.