Morphology of placentome in Korean water deer Hydropotes inermis argropus

The placenta of the Korean water deer was anatomically examined to accumulate basic information regarding its reproductive system. The convex placentomes with five to nine well-developed pedicles were observed in the whole uterine horns, and therefore, the placenta was classified as oligocotyledonary. The evidence indicating the migration of binucleate cells (BNCs) from trophectoderm to the uterine epithelium led to the histological classification of the placenta as synepitheliochorial. The number of fetuses was markedly higher than that in other ruminant species. However, the number of placentomes was found to be similar to the other Cervidae species. Therefore, these results suggest that the Korean water deer may possess special mechanisms or structures at the fetus attachment site to maintain this unusally high number of fetuses.     

Double aortic arch in a dog

Vascular ring anomalies are developmental anomalies of the thoracic great vessels resulting in complete or partial encircling of the esophagus and the trachea by a vascular ring formation. Persistent right aortic arch with left ligamentum arteriosum accounts for 95% of vascular ring anomalies in dogs. The dog in this report had a double aortic arch, which is a type 4 vascular ring anomaly. Double aortic arch is a rare congenital heart defect resulting from the improper development of the embryonic arches. The prognosis for dogs that have undergone surgery for correction of double aortic arches is generally regarded as poor. The dog in this report underwent surgery for correction of double aortic arches and recovered without dilation or motility disorders of the esophagus. Results indicate that small animals that undergo early surgical correction of double aortic arches with relief of esophageal constriction can have a good prognosis. To the authors' knowledge, there have been no previous reports of dogs that have survived long enough to be discharged from the hospital after surgical correction of double aortic arches.     

Complete interruption of the aortic arch in a dog

Complete interruption of the aortic arch was diagnosed by angiocardiography in a dog with exercise intolerance, a cardiac murmur, polycythemia, and cardiomegaly. The defect was accompanied by a patent ductus arteriosus, ventricular septal defect, and subaortic stenosis. The dog was euthanatized, and the clinical diagnosis was documented by gross dissection of the heart. The site of aortic interruption was between the left carotid and left subclavian arteries, which is the most common location in human beings. The similarity with the pathologic findings of interrupted aortic arch in human beings suggests a similar mechanism responsible for the abnormal cardiac morphogenesis. The defect may be confused with other cardiac anomalies that can result in exercise intolerance, polycythemia, and cardiac murmur. This defect is amenable to surgical treatment, which emphasizes the importance of a correct anatomic diagnosis in clinical patients.     

Interruption of aortic arch in two foals

Two foals with a history of normalcy at birth developed a lack of exercise tolerance and weakness in the first few days of life. Weakness, inability to rise, and reluctance to suckle were common complaints. Physical examination of both foals revealed a cardiovascular abnormality, with a loud systolic murmur audible over both thoracic walls. Additional diagnostic techniques were blood gas analysis, radiography, cardiovascular catheterization, and necropsy. Necropsy findings were ventricular septal defect, atrial septal defect, patent ductus arteriosus, and congenital absence of the aortic arch. Additionally, 1 foal had anomalous drainage of the cranial vena cava into the left atrium.     

Double aortic arch in a Siamese cat.

A double aortic arch is described in an 8-week-old female Siamese cat. In this case a vascular ring anomaly consistent with a double aortic arch is described in a cat. Stridor and dysphagia were noted in the cat. Radiography showed an esophageal dilation, with constriction at the fifth intercostal space. At necropsy, the esophagus and trachea were constricted at the base of the heart. The cause of the constriction of both the esophagus and trachea was a vascular ring formed by well-developed right and left aortic arches. The ascending aorta divided into two asymmetrical arches. The right aortic arch was larger than the left. The origin of the major arteries from the aortic arches were anomalous.     

Symmetrical double aortic arch in a beagle puppy

Double aortic arch denotes the persistence of both fourth aortic arches and has been reported as 'very rare' in the dog. Most reported cases have been seen in German shepherd dogs. An eight-week-old, male, 1.5-kg beagle presented with a three-week history of regurgitation and dyspnoea. A barium oesophagram showed severe oesophageal constriction cranial to the base of the heart, and a provisional diagnosis of a persistent right aortic arch was made. A left-sided fourth intercostal thoracotomy was performed. The ligamentum arteriosum was ligated and divided. The oesophagus was seen lying on the right-hand side of the aorta. Postoperatively, the puppy deteriorated and was euthanized. Postmortem revealed a double aortic arch entrapping both the oesophagus and trachea. The inexperienced surgeon could consider computed tomography or angiography to determine the exact vascular ring, and other possible concurrent vascular anomalies present, before surgery.     

Investigation of the potential heritability of persistent right aortic arch in Greyhounds

In 2 successive matings of the same dam and sire in a Greyhound kennel, 1 of 6 puppies and 2 of 6 puppies were born with persistent right aortic arch (PRAA) in the first and second litters, respectively. Many congenital heart defects in dogs are believed to be heritable; however, proof of this has been difficult to obtain. Genetic predisposition to PRAA has been reported in German Shepherd Dogs and Irish Setters. The occurrence of PRAA in related Greyhounds within a kennel suggested a genetic predisposition to PRAA in a breed with which it has not been associated previously. Although the number of matings available for analysis was insufficient to conclusively prove a genetic basis for these observations, the occurrence of PRAA in puppies arising from successive matings of the same dam and sire strongly suggests that some lines of dogs of various breeds may be genetically predisposed to PRAA.     

Branching pattern characteristics and anti-windbreakage ability of Pinus thunbergii in sandy coast

沙质海岸空间梯度上环境差异较大,黑松(Pinus thunbergii)在长期的适应过程中树冠结构变化也很大.为揭示黑松树冠结构与环境间的适应机制,在山东省胶南市灵山湾国家森林公园距海岸线0-50、200-250和400-450 m梯度内各设置1个样带,记为带Ⅰ、带Ⅱ、带Ⅲ,采用枝构型的理论和方法,对黑松的分枝格局进行了研究,并采用模拟自然风法测定了黑松枝条的抗风折能力.结果表明:1）在海岸梯度上黑松分枝格局差异较大,随着距离海岸越来越远,黑松各级枝的分枝长度、总体分枝率均逐渐增大,而枝径比和逐步分枝率逐渐减小,各级分枝角度表现为带Ⅰ＞带Ⅲ＞带Ⅱ.2）带Ⅰ树冠背风面与迎风面相比,分枝长度、分枝角度、分枝数量、枝条干枯率分别是迎风面的1.62、1.38、2.65和0.59倍,随着距离海岸越来越远,这种不对称性逐渐减弱,至带Ⅲ树冠基本对称.3）海风是影响带1分枝角度偏转、枝条干枯和冠型不对称现象的主要原因.4）带Ⅲ枝条的抗风折能力高于带Ⅰ,且两个样带模拟风速与枝条所承受的拉力之间的关系均符合逻辑斯蒂方程,相关系数R2均达0.97以上.该研究揭示了不同海岸梯度上黑松分枝格局的形成机制及其抗风折能力,可为沿海黑松防护林的合理经营提供科学依据.     

Right aortic arch in a lamb and two pigs

The necropsy findings of right aortic arch in a lamb, a mini-pig foetus and a mini-pig are described, and the pathogenesis of the vascular pattern found in these animals is discussed.     

Persistent right aortic arch in a yearling horse.

A 14-month-old filly with chronic pharyngitis was diagnosed with incomplete esophageal constriction and megaesophagus due to a persistent right aortic arch. This report is unusual because clinical signs of respiratory dysfunction secondary to chronic regurgitation occurred prior to the recognition of dysphagia.     

Branches of the aortic arch in the cynomolgus macaque (Macaca fascicularis).

The aortic arch branching patterns of 49 male macaques (Macaca fascicularis) were described and classified according to the classification systems of DeGaris, and the incidence of each pattern was determined. The most frequent pattern observed was a two-branch type in which a truncus communis of intermediate length (7 to 11 mm) and the left subclavian artery constituted the only aortic arch branches. Five patterns not previously described in the cynomolgus were observed. Comparison of the cynomolgus and the rhesus macaques indicated a significant difference between the two species with the rhesus generally having a shorter truncus communis.