No expression of angiotensin II receptors and angiotensin-converting enzyme in myxomatous canine mitral valve leaflets. An autoradiographic study

The renin-angiotensin system, including angiotensin (Ang) II and angiotensin-converting enzyme (ACE), plays an important role in cardiac fibrous tissue formation. Since changes in valvular collagen are a central part of myxomatous mitral valve disease in the dog, we speculated that Ang II and ACE might play a role in the pathogenesis of this disease. In 10 mitral valves, five with and five without clear myxomatous changes, the presence and distribution of Ang II receptors and ACE was examined autoradiographically, using 125I-Ang II and 125I-lisinopril, respectively. At postmortem examination, diseased valves were taken from old dogs, control valves from young adult dogs. No significant level of Ang II and lisinopril binding was found in normal as well as diseased valve leaflets. Equally low, insignificant levels of 125I-Ang II binding were found in the myocardium of dogs with and without valvular disease. No significant level of myocardial 125I-lisinopril binding was found. The lack of autoradiographic evidence of Ang II receptors and ACE in normal and diseased canine mitral valve leaflets suggests that the renin-angiotensin system does not play a major role in the pathogenesis of the valvular changes.     

Structural remodelling of the heart valves extracellular matrix during embryo development

Alterations in heart valve development represent more than 20% of congenital cardiovascular malformations. Most of the functional properties of heart valves depend on extracellular matrix. Despite its relevance, little is known about fibrillar components on developing stages. Our objective is to define histological changes on valves fibrillar components in late embryonic development of Mus musculus. We found type III collagen as the predominant fibre type in the ECM in prenatal stages followed by a switch to a type I predominance for postnatal ages. The change in fibrillar components is necessary to support the normal mechanical function of adult heart valves.     

A new and unusual species of Parachiton (Mollusca: Polyplacophora) from South Africa

A new species of the genus Parachiton, P. hodgsoni n.sp., which inhabits shallow water off the South African coast, is described. The radula is unusual for the genus Parachiton. It consists of about 160 transverse rows of very small mature teeth of which the major lateral teeth have very narrow tridentate cusps. The intermediate valves are granulose with the granules arranged in widely spaced, longitudinal rows on the central area of the valves. There are 20–31 longitudinal rows on the central areas of the intermediate valves. Variability in the morphology of the tail valve is shown.     

Temperature and salinity tolerance of adult hermit crabs,Diogenes brevirostris,Stimpson (Crustacea: Decapoda: Anomura)

Diogenes brevirostris was found to be tolerant to low salinities (0,5 - 4,0 %) at a wide range of temperatures (12 to 27°C). Tolerance to temperature and salinity were inversely related. At low salinities (0,5 and 1,0 %) the rate of mortality increased with temperature throughout the range, whereas at higher salinities (1,5 and 4,0 0/00) temperature had no effect on mortality. These results are discussed in relation to the distribution of D. brevirostris in estuaries. It appears that temperature and salinity tolerance are not solely responsible for limiting distribution of these crabs to estuary mouths.     

Doppler-derived velocity of blood flow across the cardiac valves in the normal dog.

Doppler echocardiography is a relatively new procedure used to assess certain cardiovascular disorders in the dog. The objectives of this study were to determine the range of values for the maximal peak velocity of blood flow across each of the four cardiac valves in a sample population of normal adult dogs, using duplex continuous wave Doppler echocardiography, and to determine the optimal tomographic planes to use for an adequate continuous wave Doppler evaluation of the canine heart. Twenty normal dogs were examined to obtain values for peak transvalvular velocity for each of the four cardiac valves. The mean values +/- 1 SD, in cm/s were: 98.1 +/- 9.4 for the pulmonary valve imaged from the left side of the chest, 95.5 +/- 10.3 for the pulmonary valve imaged from the right side of the chest (n = 19), 118.1 +/- 10.8 for the aortic valve, 86.2 +/- 9.5 for the mitral valve and 68.9 +/- 8.4 for the tricuspid valve. Regurgitation was detected across the pulmonic valve in 14 of the 20 dogs, and across the tricuspid valve in ten dogs. The analysis of the tomographic images confirmed that for a complete assessment of a given intracardiac valve, the valve must be examined from all possible directions to obtain maximum values for peak velocity.     

The valves of the cardiac outflow tract of the starry ray,Raja asterias (Chondrichthyes; Rajiformes): Anatomical,histological and evolutionary aspects

The cardiac outflow tract of chondrichthyans is composed of the myocardial conus arteriosus, equipped with valves at its luminal side, and the bulbus arteriosus devoid of myocardium. Knowledge of the histomorphology of the conal valves is scarce despite their importance in preventing blood backflow to the heart. Current information on the subject refers to a single shark species. The present report is the first to describe the structure of the conal valves of a batoid species, namely, Raja asterias. Hearts from seven starry rays were examined using scanning electron microscopy and histochemical techniques for light microscopy. In all hearts, the conus showed four transverse rows of three pocket‐like valves each. Each valve was composed of a leaflet and its supporting sinus. The leaflet had a stout central body, rich in glycosaminoglycans, which contained fibroblasts, collagen and elastin. The central body was surrounded by two thin fibrous layers, outer and inner, formed mainly by collagen. The valves of the anterior row, which were the largest of the valvular system, were attached proximally to the conus arteriosus and distally to the bulbus arteriosus, and not to the ventral aorta as previously reported for chondrichthyans. The arrangement of the anterior valves in the starry ray is an anatomical pattern that apparently has been preserved throughout the evolution of vertebrates.     

Effects of formalin, chloramine-T, and low salinity dip on the behavior and hemolymph biochemistry of the American lobster.

The purpose of this research was to investigate the salinity and formalin sensitivity of a ciliate parasite (Anophryoides haemophila) of the American lobster (Homarus americanus), and to examine the target-animal (lobster) safety of chemical-bath treatments involving low salinity, formalin, or chloramine-T that could be used to control this parasite in lobster pounds. "Bumper car" disease, caused by An. haemophila, is an important concern to lobster pound operators in eastern North America, because of the implicated lobster mortality rate and the general lack of preventive and therapeutic intervention regimes. We determined, using an in vitro method, that formalin at 50 mg/L, or low salinity at 8.0 parts per thousand (ppt) for 1 hour killed 100% of the parasites. When healthy lobsters were exposed to formalin at 200 mg/L, there were no negative behavioral responses and no significant differences in a panel of hemolymph biochemical indices. Similar results occurred when lobsters were exposed to chloramine-T, a common finfish therapeutic agent for topical bacteria and protozoa, at 10 mg/L for 1 hour. The low salinity treatment (8.0 ppt) resulted in significant adverse changes in lobster behavior and biochemical indices; however, these changes did not persist for more than 1 week after treatment ended. Although these treatments are unlikely to kill parasites that have already invaded the lobster carapace, they should be effective in reducing parasite loads on the gill and carapace surface of the lobster and in the environment of the impoundment housing.     

Influence of the thermocline on the vertical migration of medusae during a 48 h sampling period

The vertical distribution and migratory movements of epiplanktonlc medusae were studied at an oceanic station off northern Namibia (18°00’S /10°30’E). Samples were collected from five separate depth strata (200–100 m, 100–60 m, 60–40 m, 40–20 m, and 20–0 m) using a multiple opening and closing RMT 1 x 6 net over a 48–h period. The area was characterized by mixing of the Angola Current surface waters with the northernmost subsurface waters of the Benguela Current. During the sampling period there was a continuous flow of water from Angola, giving rise to a strong thermocline between 20 and 40 m depth. A total of 17 species of medusae were captured, of which Aglaura hemistoma, Liriope tetraphylla, and Solmundella bitentaculata were the most abundant. Both the number of species and the number of individuals were higher on the second than on the first day of sampling, chiefly in the 20–0 stratum. Differences in abundance appeared to be related to the patch size of each species. The depth diistributlon of the medusae population was characterized by the existence of two assemblages, one associated with each current, and by the presence of the thermocline, which acted as a boundary between the two water masses and did not facilitate migratory movements of the most abundant species. The non-migratory distribution pattern of most of the species was attributable to the high concentration of potential prey items and to the absence of predators in the layer above the thermocline throughout the sampling period.     

Direct measurements of nitric oxide release in relation to expression of endothelial nitric oxide synthase in isolated porcine mitral valves

The aim of this study was to measure the direct release of nitric oxide (NO) from the porcine mitral valve using a NO microelectrode. Furthermore, the expression and localization of endothelial nitric oxide synthase (eNOS) in the mitral valve was studied using immunohistochemistry, Western blotting and RT-PCR. Results show that bradykinin increases NO release from mitral valves (DeltaBradykinin: 33.71 +/- 10.41 nm NO, P < 0.001, n = 10), whereas N-nitro-l-arginine methyl esther (l-NAME) decreases NO release when compared with basal level (Deltal-NAME: 82.69 +/- 15.66 nm NO, P < 0.005, n = 4). Both protein and mRNA expression of eNOS in mitral valves and in isolated valvular endothelial cells suggest that the NO release is mainly associated with the mitral valve endothelium. It is concluded that direct NO release from porcine mitral valves coincides with eNOS expression. This study documents useful techniques for investigations into the role of local NO release in mitral valve diseases.     

The effect of temperature and salinity on oxygen consumption in the brachyuran crab Cyclograpsus punctatus (Crustacea: Decapoda: Grapsidae)

The aquatic oxygen consumption of the estuarine brachyuran crab, Cyclograpsus punctatus, was investigated after a 24-hour acclimation period at different temperature (12.5, 20, 30°C) and salinity (9, 17.5, 35, and 44°) combinations . Salinity had no significant effect on oxygen consumption at 12.5 and 20°C in both large and small crabs. At 30°C and 44°, however, the rate of oxygen consumption declined in large crabs (from 0.233 to 0.176 mg O₂ g wwt/h) and increased in small crabs (0.300 to 0.469 mg O₂ g wwt/h). There was also a significant increase in the oxygen consumption (0.300 to 0.536 mg O₂ g wwt/h) of small crabs at the high temperature/low salinity combination. Temperature had a significant effect on the rate of oxygen consumption at all salinities, with Q₁₀ values ranging from 1.16 to 2.85. In all cases the mass-specific oxygen consumption rate of small crabs was higher than that of large crabs. The results suggest that the confinement of this species to the lower reaches of estuaries may, in part, be due to physiological constraints on juveniles and small individuals.     

温度与盐碱胁迫交互作用对羊草种子萌发与幼苗生长的影响

羊草(Leymus chinensis)是我国东北松嫩盐碱化草地上的建群植物。为明确羊草在种子萌发与幼苗生长阶段对盐、碱胁迫及与温度交互作用的响应,采用3个温度处理(20/10℃,30/20℃和35/25℃),并混合2种中性盐(NaCl:Na₂SO₄=9:1)与2种碱性盐(Na₂CO₃:NaHCO₃=9:1)分别模拟土壤盐、碱胁迫条件进行研究。结果表明:随着盐碱胁迫浓度的增加,羊草种子的发芽率、发芽速率、叶片长度与根系长度均呈下降趋势,且在碱胁迫下其降幅更大;另外这2种胁迫均对羊草幼苗根生长的抑制作用更强。温盐、温碱交互作用显著影响羊草种子的萌发与幼苗生长,其中30/20℃处理下羊草生长最好;在盐胁迫下,当盐浓度<200mmol·L^-1时,低温是影响种子萌发的主要因素,随着盐度继续增加,高温则加剧了盐胁迫对种子萌发的抑制作用;在碱胁迫下,即使碱浓度较低,高温与其交互作用也极大地加剧了对种子发芽的抑制。因此,盐、碱胁迫及温盐、温碱交互作用对羊草种子萌发与幼苗生长的抑制作用明显不同,碱胁迫及其与温度交互作用对羊草的伤害更大。     

Long-term clinical evaluation of mitral valve replacement with porcine bioprosthetic valves in dogs

This study evaluated the long-term clinical performance of newly developed porcine bioprosthetic valves cross-linked with glutaraldehyde and polyepoxy compound for mitral valve replacement (MVR) in dogs. Five beagle dogs underwent MVR using the porcine bioprosthetic valves during cardiopulmonary bypass. Antithrombotic drugs were administered only for one month after MVR. Six months after MVR, transvalvular regurgitation was not observed in all dogs, paravalvular leakage was seen only in one dog. Twelve months after MVR, mild transvalvular regurgitations were observed in two dogs. Although diastolic atrioventricular pressure gradient was increased gradually, no significant differences were observed. Pressure half-time and valve area were within normal ranges as the bioprosthetic value. There was no clinical symptom of the thrombosis and the thrombogenesis was not observed in the porcine bioprosthetic valve and the annulus in all dogs for twelve months after MVR. The clinical findings suggest that antithrombogenicity of the valves were maintained, though the duability might not be enough in the long-term period.     

荒漠半灌木白滨藜种子的萌发特性及其生态意义

白滨藜是具有抗旱、抗盐碱和耐贫瘠能力的半灌木,为新疆地区的良等牧草。通过研究温度、贮藏时间、苞片及盐分对白滨藜种子萌发的影响,结果表明：白滨藜种子萌发的最适温度为20／30℃和25／35℃。室温干藏2～8个月显著提高种子的萌发速率,干藏10个月后,种子萌发速率与萌发率显著降低。苞片延缓种子吸胀,对种子的最终萌发率有显著影响;去除苞片可以明显促进种子的萌发。浓度低于0．8 mol／L 的 NaCl 溶液对种子萌发的影响不大;但从0．8 mol／L 起萌发率随着浓度增高而降低,直至为零;将在0．05～4．00 mol／L 盐溶液中处理的种子转移至蒸馏水后,仍有一定的萌发恢复率,表明 NaCl 处理后的部分种子有保持活力的能力,部分种子丧失活力。对白滨藜种子萌发特性的研究,为揭示其萌发行为进化和生态适应机制提供科学依据,也为新疆荒漠盐碱地区饲用半灌木引种改良,良种繁育提供基础资料。     

Pathologic and clinical features of infectious endocarditis

Infectious endocarditis is a systemic disease associated with high morbidity and mortality. Clinical recognition and effective management is challenging, but insights can be gleaned from relevant pathologic features. Risk factors include subaortic stenosis, possibly certain other congenital anomalies, and bacteremia. Auscultation can provide clues regarding valvular involvment, particularly when a diastolic left basilar murmur of aortic valve regurgitation is present. Aortic valve vegetations and insufficiency may also alter femoral arterial pulse characteristics. Echocardiography may facilitate diagnosis, particularly with aortic valve lesions, but may not be able to distinguish between small mitral valve vegetations and early chronic degenerative valve disease. Vegetative lesions develop along edges of valve closure on the ventricular aspect of the aortic valve and the atrial surface of atrioventricular valves. They may extend across valve leaflet, from valves to adjacent left atrial endocardium, interventricular or interatrial septum, or chordae tendineae. Vegetations can be friable and frequently embolize to spleen, kidney, and left ventricle — often before clinical recognition of the disease. Valvular insufficiency develops as a consequence of valvular vegetations, necrosis, perforation, or rupture of the chordae tendineae. Histopathologic appearance varies with respect to duration of disease and antimicrobial therapy. These factors influence the amount of necrotic material, blood clot, fibrin, and inflammatory cells which make up the vegetations. Bacteria are not always identified in valvular lesions, especially following antibacterial therapy, but may be detected in other organs. Common sequellae include congestive heart failure, sepsis, arrhythmias, and systemic organ infarction.     

Morphologic aspects and morphogenesis of blood cysts on canine cardiac valves

We investigated retrospectively the morphologic aspects of blood cysts of the atrioventricular valve in eight Beagle dogs and clarified the morphogenesis of the lesions. Study of serial sections revealed that the cysts communicate with the blood vessels; however, they showed no connection with the valve surface. Immunohistochemically, the thin endothelium of the lesions showed positive staining for factor VIII-related antigen. Histologic studies of a variety of sizes of blood cysts revealed four basic stages of blood cyst formation: 1) initially, the involved blood vessel undergoes only a slight enlargement that is not grossly detectable; 2) next, the vessel becomes moderately or markedly dilated and contains a large number of erythrocytes. The changes of this stage are macroscopically detectable; and 3) then, blood flow is arrested partly in the cystic lesion, followed by degeneration and necrosis of the cyst. At this third stage, fibrous tissue or dense collagenous connective tissue is usually seen surrounding the cyst; 4) and finally, metaplastic bone is formed within the lesion. Colloidal carbon infusion into the valves of normal canine hearts revealed the presence of an extensive, dense arrangement of blood vessels in the septal leaflet of the tricuspid valve, which usually is the recognized site to develop blood cysts.     

荒漠半灌木白滨藜种子的萌发特性及其生态意义

白滨藜是具有抗旱、抗盐碱和耐贫瘠能力的半灌木,为新疆地区的良等牧草。通过研究温度、贮藏时间、苞片及盐分对白滨藜种子萌发的影响,结果表明:白滨藜种子萌发的最适温度为20/30℃和25/35℃。室温干藏2~8个月显著提高种子的萌发速率,干藏10个月后,种子萌发速率与萌发率显著降低。苞片延缓种子吸胀,对种子的最终萌发率有显著影响;去除苞片可以明显促进种子的萌发。浓度低于0.8 mol/L的NaCl溶液对种子萌发的影响不大;但从0.8 mol/L起萌发率随着浓度增高而降低,直至为零;将在0.05~4.00 mol/L盐溶液中处理的种子转移至蒸馏水后,仍有一定的萌发恢复率,表明NaCl处理后的部分种子有保持活力的能力,部分种子丧失活力。对白滨藜种子萌发特性的研究,为揭示其萌发行为进化和生态适应机制提供科学依据,也为新疆荒漠盐碱地区饲用半灌木引种改良,良种繁育提供基础资料。     

Relationships between postnatal plasma oxytocin concentrations and social behaviors in cattle

We examined the associations between natural individual variations in basal oxytocin (OXT) in postnatal cattle and social behavioral traits. At 1, 2 and 6 weeks of age, the basal OXT exhibited individual variability in 20 Holstein heifer calves. Cluster analysis of mean OXT for these time periods obtained two subgroups: high OXT (HOXT; n = 9) and low OXT (LOXT; n = 11). Social behaviors were observed for 2 days at week 6 after introduction into a four‐peer group, and at 10–14 months of age (10 months) immediately and 1 week, 1 month and 5 months after introduction into 11–15 heifers. At week 6, the main effect of the OXT groups was not significant for all social behaviors. At 10 months, there tended to be interactions between the OXT groups and time periods with respect to the frequency of escape behaviors. LOXT heifers exhibited more escape behaviors than HOXT heifers on the first day of the second sociality tests. At 10 months, HOXT heifers exhibited both attacking and affiliative behavior for peers more than LOXT heifers during 5 months after the second social introduction. This suggests that postnatal OXT concentrations may have long‐lasting effects on individual differences among social behavioral traits in cattle.     

Effect of Incubation Temperature and Salinity on Expression of the Outer Membrane Protein Profile of Edwardsiella tarda

Abstract

Outer membrane proteins (OMP) of 10 isolates of Edwardsiella tarda were compared by sodium dodecyl sulfate-polyacrylamide gradient gel electrophoresis. The OMP profile of the type strain E. tarda ATCC 15947 cultured at 25°C had five major protein bands of 40, 36.5, 34, 28.5, and 25 kDa and a large number of minor proteins ranging in size from approximately 10 to 120 kDa. Differences between the OMP profiles of the isolates of E. tarda included the inconsistent presence of the 34- or 36.5-kDa proteins in five isolates of E. tarda and two major bands of 47 and 44 kDa that were present in only two isolates of E. tarda. There were no differences in the outer membrane protein profiles of 9 out of 10 isolates of E. tarda incubated at a temperature of 25°C compared with those at 35°C. To evaluate the effect of salinity, 10 isolates of E. tarda were cultured in brain heart infusion broth containing 0.5, 1.5, and 3.0% sodium chloride. Reactions of isolates of E. tarda to the different salinity levels were placed into three groups. The first group expressed more or fewer protein bands at 1.5% sodium chloride. The second group lost major bands at 3% salinity, whereas the third group had no change in the OMP profile with salinity. The OMP profile differences and the different reactions to salinity levels suggest that the isolates are heterogeneous.     

卵黄性腹膜炎、鸡白血病对种鸡死亡率、产蛋率影响的初步调查

为了探讨卵黄性腹膜炎和鸡白血病对种鸡死亡率和产蛋率的影响，在2016年1月至2017年4月中旬，对江苏省常州市某种鸡场岭南黄鸡、花鸡（金茅花鸡）、草鸡（金茅草鸡）、黄脚麻鸡4个品种鸡的发病及死亡情况进行临床症状观察及病理剖解；同时记录鸡场每日的鸡死亡数、产蛋数、每日免疫和用药情况，分析不同时期的死亡率和产蛋率，比较不同品种鸡的产蛋率及产蛋高峰期产蛋率与正常蛋鸡产蛋高峰期产蛋率（参考值80%）之间的差异。从死亡鸡的剖解结果来看，腹腔内卵黄凝固黏连在肠道上，输卵管肿大，充满白色或淡黄色干酪样物，初步诊断为卵黄性腹膜炎；肝脏和脾脏肿大，肠系膜或胸壁有肿瘤状物体，初步诊断为鸡白血病。岭南黄鸡产蛋后期的死亡率极显著高于产蛋上升期和高峰期（P<0.01），黄脚麻鸡产蛋后期的死亡率极显著低于产蛋高峰期（P<0.01）；花鸡、草鸡、黄脚麻鸡产蛋高峰期产蛋率平均值均低于60%，与参考值（80%）差异极显著（P<0.01）。综合试验结果，卵黄性腹膜炎和鸡白血病对鸡场影响严重，导致鸡死亡率上升，产蛋率下降；抗应激药和营养药可以起到缓解预防的作用，但无法根治，尚无有效的治疗方法。     

A retrospective study of clinical signs and epidemiology of chronic valve disease in a group of 207 Dachshunds in Poland

Background

Chronic mitral valve disease is frequently seen in the Dachshund. Dachshunds (n=207) made up 11.73% of the dogs admitted to the Cardiology Service at the Small Animal Clinic, Warsaw University of Life Sciences, Poland (first visits only).

Results

Of these, 35 dogs had no clinically detectable heart disease while 172 had chronic valve disease with the mitral valve affected most often (130 dogs), both mitral and tricuspid valves infrequently (39 dogs) and rarely the tricuspid valve (3 dogs). Males were affected more frequently than females and the average age of dogs with chronic valve disease was 11.9 years for females and 11.3 years for males. A majority of the diseased Dachshunds were classified as ISACHC 2 (79), followed by ISACHC 1 (60). Most frequent clinical signs noted by owners included coughing, exercise intolerance, dyspnea and tachypnea. Heart murmurs were generally louder with increased disease severity; however there were 20 dogs in the ISACHC 1 group with no audible heart murmurs. The most frequent electrocardiographic abnormalities included an increased P wave and QRS complex duration, increased R wave amplitude and tachycardia. With increased disease severity, echocardiography revealed an increase in heart size. A higher ISACHC class was related to increased heart size (based on echocardiography) and increased percentage of patients exhibiting enlargement of both left atrium and left ventricle (based on radiography).

Conclusions

The Dachshund is often affected by chronic mitral valvular disease with a late onset of associated clinical signs and few cardiac complications.