Ectopic origin of coronary arteries from the aorta in Syrian hamsters (Mesocricetus auratus)

An ectopic origin of the coronary artery from the aorta beyond the sinotubular junction, a condition commonly referred to as 'coronary artery high take-off', has been described in man and C57BL/6 mice. The present paper reports this congenital coronary artery anomaly in the Syrian hamster (Mesocricetus auratus). Hearts from 14 individuals, aged 53-350 days, were examined by means of a corrosion-cast technique, scanning electron microscopy or histological and immunohistochemical techniques. In 11 hamsters, the right coronary artery was the ectopic vessel. In the other three animals there was a solitary coronary ostium in the aorta. In all cases, the ectopic coronary artery originated at an acute angle and a valve-like ridge was in front of the coronary artery ostium. The ectopic arteries examined microscopically showed an intramural trajectory within the aortic wall. In the hearts with a solitary ostium in the aorta, the left main coronary artery coursed between the aorta and the pulmonary artery. In man, all of these anomalous conditions place the individual at risk of myocardial ischaemia and sudden death. However, none of the affected hamsters had clinical signs of disease. Intimal thickenings of increasing size with age were present in the intramural coronary artery segment of eight hamsters aged 106 days or older, examined histologically. The present findings fit with the notion that coronary arteries with acute angle take-off and an intramural course are subjected to unusual wear and tear, leading to tissue changes in the vessel wall.     

Factors other than genotype account largely for the phenotypic variation of the pulmonary valve in Syrian hamsters

Understanding of the aetiology of congenitally anomalous pulmonary valves remains incomplete. The aim of our study, therefore, was to elucidate the degree to which the phenotypic variation known to exist for the pulmonary valve relies on genotypic variation. Initially, we tested the hypothesis that genetically alike individuals would display similar valvar phenotypes if the phenotypic arrangement depended entirely, or almost entirely, on the genotype. Thus, we examined pulmonary valves from 982 Syrian hamsters belonging to two families subject to systematic inbreeding by crossing siblings. Their coefficient of inbreeding was 0.999 or higher, so they could be considered genetically alike. External environmental factors were standardized as much as possible. A further 97 Syrian hamsters from an outbred colony were used for comparative purposes. In both the inbred and outbred hamsters, we found valves with a purely trifoliate, or tricuspid, design, trifoliate valves with a more or less extensive fusion of the right and left leaflets, bifoliate, or bicuspid, valves with fused right and left leaflets, with or without a raphe located in the conjoined arterial sinus, and quadrifoliate, or quadricuspid, valves. The incidence of the different valvar morphological variants was similar in the outbred and inbred colonies, except for the bifoliate pulmonary valves, which were significantly more frequent in the hamsters from one of the two inbred families. Results of crosses between genetically alike hamsters revealed no significant association between the pulmonary valvar phenotypes as seen in the parents and their offspring. The incidence of bifoliate pulmonary valves, nonetheless, was higher than statistically expected in the offspring of crosses where at least one of the parents possessed a pulmonary valve with two leaflets. Our observations are consistent with the notion that the basic design of the pulmonary valve, in terms of whether it possesses three or two leaflets, relies on genotypic determinants. They also denote that the bifoliate condition of the valve is the consequence of complex inheritance, with reduced penetrance and variable expressivity. Moreover, in showing that the incidence of the bifoliate pulmonary valve significantly differs in two different isogenetic backgrounds, our data suggest that genetic modifiers might be implicated in directing the manifestation of such specific pulmonary valvar malformations. Finally, our findings indicate that factors other than the genotype, operating during embryonic life and creating developmental noise, or random variation, play a crucial role in the overall phenotypic variation involving the pulmonary valve.     

Coincidence of a right retroaortic circumflex coronary artery and a right-sided aortic arch with a retroesophageal course of the left subclavian artery (arteria lusoria)

An anomalous branch of the right coronary artery was found in a 71-year-old male cadaver with a right-sided aortic arch. The anomalous artery arose from the proximal portion of the right coronary artery and ran in a retroaortic course, before reaching the posterior wall of the heart. It was recognized as the right-sided variation of the circumflex coronary artery. The aortic arch had as branches the left common carotid, right common carotid, right subclavian, and left subclavian arteries, in that order, and the descending aorta was located in the right thorax. The left subclavian artery arose from a Kommerell's diverticulum and ran behind the esophagus, and the left-sided ligamentum arteriosum was also connected at the diverticulum. Therefore, the right aortic arch was classified as type N according to Adachi-Williams-Nakagawa and type III-B1 in accordance with Stewart-Edwards. The Kommerell's diverticulum in this case seemed to press on the posterior wall of the esophagus.     

Extremely high origin of the right coronary artery from the ascending aorta.

Coronary artery anomalies, especially variations in the level of origin, are frequent. In most cases, the origin lies just a few millimeters superior to the supravalvular ridge; ectopic origins of more than one centimeter above this border are rare. We report a case in which the right coronary artery arises from the ascending aorta 38 mm above the supravalvular ridge.     

Solitary coronary ostium in the aorta in Syrian hamsters. A morphological study of 130 cases

BACKGROUND: Solitary coronary ostium in the aorta (SCOA) is a rare anomaly, the pathogenesis of which remains uncertain. The lack of an animal model is one of the reasons why little understanding of this question has been gained. The aim was to examine the coronary distribution patterns associated with SCOA in laboratory inbred Syrian hamsters. METHODS: The study concerns 130 cases detected in a database consisting of 1,202 internal casts of the heart, great arterial trunks, and coronary arteries. RESULTS: In 21 (16.2%) cases, the solitary ostium was located in the left aortic sinus. In a further 58 (44.6%) cases, it was in the right aortic sinus. In the remaining 51 (39.2%) cases, the ostium was in the right side of the ventral aortic sinus of a bicuspid aortic valve. The distribution patterns were classified according to the location of the solitary ostium and the presence, or absence, and course of the main coronary arterial vessels. Overall, 14 categories were established, 10 of which had their counterpart in man. CONCLUSIONS: The findings reported substantiate the use of the present inbred Syrian hamsters for further studying the morphogenesis of the SCOA. The results of a statistical analysis indicate that when a sole coronary ostium becomes established in the aortic root, the development of the resultant anomalous coronary arterial tree tends to happen through preferential pathways. In addition, they indicate that the branching mode of the coronary tree and the condition of the aortic valve are independent traits.     

Superdominant right coronary artery with absent left circumflex artery

Noninvasive imaging of coronary artery disease is rapidly replacing angiography as the first line of investigation. Multislice CT is the non-invasive modality of choice for imaging coronary artery disease and provides high speed with good spatial resolution. CT coronary angiography in addition to detecting and characterising atherosclerotic coronary artery disease is also a good imaging tool for evaluating anomalies of coronary arteries. Superdominant right coronary artery with absent left circumflex artery is one such rare coronary artery anomaly which is well evaluated with multislice CT angiography. The authors report one such case of superdominant right coronary artery with absent left circumflex artery imaged with 64-slice MDCT.     

Anomalous origin of additional coronary artery arising from the pulmonary artery in complex congenital heart disease

Anomalous origin of coronary arteries is a rare congenital defect and usually presents as an isolated defect. In only 5% of cases, it may be associated with other cardiac anomalies. In this article, we present a case of a newborn with a very complex congenital cardiac disease accompanied with an anomalous origin of an additional coronary artery.     

Anomalous origin of the left circumflex coronary artery from the right aortic sinus of valsalva and sudden death

Anomalous origin of the left circumflex coronary artery from the right aortic sinus is generally considered a benign condition. We report a 53-year-old man with clinical and pathologic evidence of myocardial infarction and sudden death in the setting of this anomaly, with no evidence of obstructive coronary atherosclerosis.     

Total anomalous origin of the coronary circulation from the right pulmonary artery

Origin of both coronary arteries from a branch of the pulmonary artery is rare and has not been reported as a cause of sudden unexpected death. We report autopsy findings of a 14-day male infant in previously good health who died suddenly. From the proximal right pulmonary artery arose a single coronary artery, which branched into the right and left main coronary arteries. The right proximal coronary artery coursed between the aorta and pulmonary trunk, and the left main traveled along the anterior proximal aorta. The distal course of the coronary circulation was normal. There was concentric subendocardial healing myocardial infarction. No other congenital anomalies were identified. Total anomalous origin of the coronary arteries from the pulmonary trunk or artery should be considered in cases of sudden unexpected death in infants.     

Isolation of a Campylobacter-like organism from healthy Syrian hamsters (Mesocricetus auratus).

A Campylobacter-like organism was isolated from the ilea of normal hamsters. The organism was isolated from an ileal homogenate which was passed through a filter (0.65-micron pore size) and cultured on blood-agar plates in a microaerophilic atmosphere at 37 degrees C. Pinpoint translucent colonies were first observed after 120 h of incubation. The isolated organism measured 2.0 to 3.5 microns in length (excluding flagella) by 0.17 to 0.25 micron in width and typically had a single terminal sheathed flagellum. The organism was oxidase, catalase, and urease positive, reduced nitrates, and was susceptible to nalidixic acid (30-micrograms disk) and resistant to cephalothin (30-micrograms disk). Unlike Campylobacter pylori subsp. mustelae, this organism did not hydrolyze indoxylacetate. Immunofluorescence studies with a Campylobacter species-specific monoclonal antibody (8322-2E6) revealed the presence of numerous positively stained organisms within the crypt epithelial cells of the hamsters from which this organism was isolated. The role of this organism in the pathogenesis of proliferative ileitis in hamsters is uncertain, as is the taxonomic relationship of this organism to other members of the genus Campylobacter.     

Aberrant penetrating posterior descending artery from proximal right coronary artery

We report a rare variant of the posterior descending artery (PDA) in a 51-year-old African-American male discovered in coronary CT angiography. Arising from the proximal right coronary artery near its ostium, the anomalous PDA penetrated posteriorly toward the atrioventricular junction septum, exited through the inferior pyramidal space into the posterior interventricular groove and continued in the groove as a short PDA. Along its course it gave rise to small branches to the medial wall of the right atrium, the atrioventricular node region, and the inferoseptal wall of the right ventricle.     

X-ray kinematics analysis of vaginal scent marking in female Syrian hamsters (Mesocricetus auratus)

Vaginal marking is a stereotyped scent marking behavior in female Syrian hamsters used to attract male hamsters for mating. Although the modulation of vaginal marking by hormones and odors is well understood, the motor control of this proceptive reproductive behavior remains unknown. Therefore, we used X-ray videography to visualize individual bone movements during vaginal marking. Kinematic analyses revealed several consistent motor patterns of vaginal marking. Despite exhibiting a diversity of trial-to-trial non-marking behaviors (e.g. locomotor stepping), we found that lowering and raising the pelvis consistently corresponded with coordinated flexion and extension cycles of the hip, knee, and tail, suggesting that these movements are fundamental to vaginal marking behavior. Surprisingly, we observed only small changes in the angles of the pelvic and sacral regions, suggesting previous reports of pelvic rotation during vaginal marking may need to be reconsidered. From these kinematic data, we inferred that vaginal marking is primarily due to the actions of hip and knee extensor muscles of the trailing leg working against gravity to support the weight of the animal as it controls the descent of the pelvis to the ground. The cutaneous trunci muscle likely mediates the characteristic flexion of the tail. Interestingly, this tail movement occurred on the same time scale as the joint kinematics suggesting possible synergistic recruitment of these muscle groups. These data therefore provide new targets for future studies examining the peripheral control of female reproductive behaviors.     

Variant of the left coronary artery with an unusual origin and course: Anatomic and postmortem angiographic findings

This study demonstrates anatomic and postmortem angiographic findings characterizing the origin of the left coronary (LC) artery arising in common trunk with the right coronary (RC) artery from the right aortic sinus and its course via the ventricular septum (VS) to the left heart. This anomaly was a single finding observed among 388 angiographies and 60 corrosion castings. The course of the LC was divided in four segments. The first three form a curve that is upward concave. Large branches to the septomarginal trabecula (ST), VS, diagonals (DS), and the small anterior interventricular (anterior descending) artery originated from the outer part of this curve. In the anteroposterior x-ray, the above curve resembles a deep-bottom pot with a handle corresponding to the fourth segment. In the right anterior oblique, the first and second segments form a large erect angle. The third segment occupies the lower part of the absent proximal anterior interventricular artery, and the fourth crosses the outflow tract and the first segment in the middle. The course of these four segments of LC resembles the shape of the number 6. These findings are important for interpreting coronary angiographies in patients with this anomaly. Clin. Anat. 11:367–371, 1998. © 1998 Wiley-Liss, Inc.     

Glutamate and the aggression neural circuit in adolescent anabolic steroid-treated Syrian hamsters (Mesocricetus auratus)

Adolescent exposure to anabolic androgenic steroids (AAS) alters the development and activity of the glutamate neural system in the latero-anterior hypothalamus (LAH) in hamsters (Mesocricetus auratus); that is, an important neural component of the adolescent AAS-induced aggressive response. In this article, we used retrograde tracing to investigate glutamate-specific alterations in the connections between the LAH and several other nuclei implicated in adolescent AAS-induced aggression. Briefly, hamsters were treated with AAS or sesame-oil control during adolescence and then microinjected with retrograde tracer into the medial amygdala (MeA), lateral septum (LS), or bed nucleus of the stria terminalis (BNST). Brains were then processed for vesicular glutamate transporter 2 (VGLUT2) and examined for AAS-induced changes in the number VGLUT2 cells containing retrograde tracer (VGLUT2/tracer) within the LAH. It is interesting to note that while aggressive AAS-treated hamsters injected retrograde tracer into the MeA showed a significant reduction in the number of VGLUT2/tracer cells in the LAH, aggressive AAS-treated hamsters injected tracer into the BNST showed a significant increase in the number of VGLUT2/tracer cells in the LAH when compared with controls. Last, AAS hamsters injected with tracer into the LS had a comparable number of LAH-VGLUT2/tracer cells to controls. The current results indicate that glutamate likely functions as the major aggression output system from the LAH and that adolescent AAS treatment significantly alters the neural circuitry modulating aggression. Moreover, increases in the number of glutamate projections from the LAH to the BNST in AAS hamsters identify the BNST as an area particularly important for the regulation of AAS-induced aggression.     

左前降支长支起自右冠状动脉或右冠状窦的双前降支变异的CT血管成像解剖学特征分析

目的 探讨左前降支（LAD）长支起自右冠状窦（RCS）/右冠状动脉（RCA）的双前降支变异的CT血管成像（CTA）影像解剖学特征及临床意义。方法 横断面研究。纳入2015年1月—2022年1月在济宁医学院附属医院接受冠状动脉CTA（CCTA）检查的79 617例患者中LAD长支起自RCS/RCA的双前降支变异的患者25例,其中男16例、女9例,年龄29~87（59.0±15.2）岁。根据LAD长支走行方式将患者分为肺动脉前型12例（pre-LAD组）和肺动脉下型13例（sub-LAD组）。另纳入30例CCTA检查无冠状动脉变异者作为对照组,其中男17例、女13例,年龄34~76（59.6±11.6）岁。观察指标：（1）测量和比较LAD短支及LAD长支全程长度、起始段管径的差异;比较pre-LAD组、sub-LAD组、对照组患者年龄、性别、LAD长度（全程、前室间沟前段）、管径（起始段、中段、远段）的差异。（2）比较pre-LAD组、sub-LAD组患者的LAD长支起源、对角支、间隔支及右圆锥支的差异。（3）评估pre-LAD组与sub-LAD组患者冠状动脉各分支有无斑块以及管腔有无狭窄,比较2组患者冠状动脉整体斑块发生率的差异,以及pre-LAD长支与sub-LAD长支、LAD长支与LAD短支斑块发生率的差异。结果 LAD长支起自RCS/RCA变异的发生率为0.31‰（25/79 617）,其中0.20‰（16/79 617）起自RCS、0.11‰（9/79 617）起自距RCA开口10 mm范围内的RCA近段。（1）LAD长支、LAD短支的全程长度分别为（137.5±23.4）mm和（47.6±12.3）mm,差异有统计学意义（t=17.01,P<0.001）;二者起始段管径的差异无统计学意义（P>0.05）。对照组、pre-LAD组、sub-LAD组患者的年龄及性别差异均无统计学意义（P值均>0.05）;对照组LAD全程长度[（149.0±17.6）mm]大于sub-LAD组[（129.2±21.2）mm];pre-LAD组长支进入前室间沟前段长度[（90.8±15.7）mm]依次大于sub-LAD组[（48.1±8.4）mm]和对照组[（21.6±5.2）mm];对照组LAD起始段管径依次大于pre-LAD组和sub-LAD组;对照组LAD及pre-LAD组长支中段管径均大于sub-LAD组;对照组LAD及sub-LAD组长支远段管径均大于pre-LAD组：差异均有统计学意义（P值均<0.05）。对照组LAD及pre-LAD组长支由近段至远段管径均逐渐缩小;但sub-LAD组长支远段管径较中段增大,差异有统计学意义（t=-3.14,P=0.004）。（2）pre-LAD组与sub-LAD组患者LAD长支起源位置及对角支的差异均无统计学意义（P值均>0.05）;3条pre-LAD长支（3/12）和11条sub-LAD长支（11/13）可见间隔支发出,差异有统计学意义（P=0.005）;pre-LAD组中右圆锥支均起自LAD长支,sub-LAD组中右圆锥支均起自RCA近段或RCS,差异有统计学意义（P<0.001）。（3）pre-LAD组与sub-LAD组患者的整体冠状动脉斑块发生率为8/12与8/13,2组患者的LAD长支的斑块发生率为2/12与0/13,差异均无统计学意义（P值均>0.05）;2组25条LAD长支中有2条存在斑块（8%,2/25）,25条LAD短支中有12条存在斑块（48%,12/25）,差异有统计学意义（χ²=9.92,P=0.002）。结论 LAD长支起自RCS/RCA的双前降支变异,与正常LAD解剖差异很大。全面评估双前降支变异中LAD长支及LAD短支的起源、走行、分支、重要解剖关系及管腔情况,对于相关心血管症状的解释及手术计划的制定具有重要临床意义。     

Distribution of hypocretin-(orexin) immunoreactivity in the central nervous system of Syrian hamsters (Mesocricetus auratus)

The hypocretins are peptides synthesized in neurons of the hypothalamus. Recent studies have suggested a role for these peptides in the regulation of sleep, feeding, and endocrine regulation. The distribution of hypocretin-immunoreactive cell bodies and fibers has been extensively described in rats, but not in other species. This study was designed to examine the distribution of hypocretin immunoreactivity in Syrian hamsters, as important differences in neuropeptide distribution between rats and hamsters have previously been demonstrated. Immunoreactive cell bodies were found primarily in the lateral hypothalamic area and the perifornical area, although a few hypocretin-positive cells were also located in the dorsomedial hypothalamus and the retrochiasmatic area. Fibers were distributed throughout the brain in a pattern similar to that seen in rats. The densest projections were found in the paraventricular nucleus of the thalamus, locus coeruleus, dorsal raphe, and lateroanterior hypothalamus. The innervation of the anterior hypothalamus may be of particular interest as similar cluster of immunoreactivity does not appear to be present in rats. Moderate levels of immunoreactivity could be seen throughout the hypothalamus, the lateral septum, bed nucleus of the stria terminalis, A5 noradrenergic area, and the midline thalamic nuclei. Hypocretin-immunoreactive fibers are present in all lamina of the spinal cord, with the greatest axon densities in lamina 1 and 10. The widespread distribution of hypocretin suggests its involvement in a wide variety of physiological and behavioral processes. Our results in hamsters indicate that the organization of the hypocretin system is strongly conserved across species, suggesting an important role for the peptide and its projections.     

Autoregulation by the right coronary artery in dogs with open chests; comparison with the left coronary artery

Experiments were conducted to study autoregulatory responses of the right and left coronary arteries in dogs with open chests. The right and left circumflex coronary artery were cannulated and perfused with blood from the femoral artery via a pressurized reservoir. The perfusion pressure was varied in steps over a wide range and coronary blood flow rates were measured. Both the right and left coronary arteries exhibited autoregulation but the pressure at the lower end of the autoregulatory range was lower in the right (39.8±9.1 mm Hg) than in the left circumflex coronary artery (57.6±14.5 mm Hg). The slope of the pressure-flow relationship in the autoregulatory range was less steep in the right than the left circumflex coronary artery. The closed-loop gain when the perfusion pressure was less than 100 mm Hg was greater in the right than in the left circumflex coronary artery. Increases in the right ventricular afterload produced by pulmonary artery constriction decreased the closed-loop gain, shifted the autoregulatory range upward and to the right, and made the slope steeper. These results indicate that more effective autoregulation is carried out by the right than the left circumflex coronary artery.