A ventricular septal defect with a giant appendiform aneurysm of the membranous septum

We report a case of a 39-year-old female with a ventricular septal defect (VSD) and a giant appendiform aneurysm of the membranous septum, illustrated by echocardiography and magnetic resonance imaging. From the literature a short review of the prevalence of spontaneous closure of VSDs together with the possible complications of persisting VSDs is presented. Since patients stay at risk in later years, follow-up at regular intervals is advised.     

Contribution of the aortopulmonary septum to the muscular outlet septum in the human heart

The development of the outlet septum has been studied microscopically in 14 human embryos, ranging from 9 to 28 mm crown-rump length. Three tissue components are involved in the septation process: condensed mesenchyme of extracardiac origin, myocardium and endocardial cushion tissue. At the stage of 9 1/2 mm the condensed mesenchyme, which is embedded in the endocardial cushion tissue, is in contact with the myocardium at two sites. Graphic reconstructions of a 16 mm embryo show that at these sites of contact the myocardium is "drawn inwards" to form two bulges interconnected by the condensed mesenchyme. With further development the two myocardial bulges become the main mass of what then can be called the outlet septum. Thus the sites of contact between condensed mesenchyme and myocardium can be considered to represent the sites of attachment of the muscular outlet septum. This has important implications for the elucidation of the development of outlet malformations.     

FtsK is an essential cell division protein that is localized to the septum and induced as part of the SOS response

The role of ftsK in the growth of Escherichia coli was examined by turning off its expression. This resulted in smooth filaments without constrictions, indicating that FtsK was required at an early step in septation. Consistent with this, FtsK was found to localize to the septum in 70% of the cells, indicating that it was recruited relatively early in this process. FtsK localization required the function of FtsZ and FtsA but not FtsI and FtsQ. Consistent with this, Z rings were present in FtsK-depleted filaments. Subcellular localization of FtsK confirmed that it was a membrane protein. Only the first 202 amino acids of FtsK were essential for its role in membrane localization, cell division and viability. The expression of ftsK increased as part of the SOS response, and increased expression of ftsK conferred increased resistance to DNA damage.     

The anatomy of the interventricular septum of the heart and the anatomical nomenclature

With the aim to study interrelations of the interventricular septum (IVS) and systematization of their definitions, 151 preparations of hearts of persons died from causes having no connections with cardio-vascular diseases have been studied. The IVS consists of inflow and outflow septa. The inflow septum includes the sinusal (posterior) and trabecular septa, the outflow one--the anterior and conoid septa. The distal part of the anterior and conoid septa form the infundibular septum. From the side of the right ventricle the conoid septum and bulboventricular fold form a supraventricular crest--muscular torus, separating its inflow and outflow parts. From the side of the left ventricle the supraventricular crest is seen as a muscular bar, forming the basal medial wall.     

The development of the septum primum relative to atrial septation in the mouse heart

The septum primum in the mouse originates as a thickened primordium with a straight rather than a sickle-shaped ventral border. It is covered on its ventral border by anterior cushion material which is continuous over the roof of the atrium with the principal anterior cushion mass. A process of cavitation thins the septum primum and precedes actual fenestration. This process shifts the membranous septum to the left thereby providing room for the septum secundum to overlap on the right side. The septum primum cannot contact the posterior cushion until closure of the sinus venosus gutter which is described. The closure of the interatrial foramen, later the foramen primum, is accomplished by cell growth of the anterior cushion material. The ventral thick border of the septum primum contributes to the ventral limbus and the caudal thickened boundary of the fossa ovalis with some contribution from the left venous valve. These boundaries as well as the membranous portion of the interatrial septum are derived from the same primordium, namely the septum primum.     

Light- and electron-microscopic study of electrophysiologically characterized neurons in the mediolateral part of the lateral septum of the guinea-pig

In slices of guinea-pig brains, 36 neurons located in the mediolateral part of the lateral septum were stained intracellularly with horseradish peroxidase (n=28) or biocytin (n=8) after electrophysiological characterization. These neurons belonged to class A neurons (n=23), which generated pronounced Ca⁺⁺-dependent high-threshold spikes in control medium, or to class C neurons (n=9), which were recognized by the occurrence of small-amplitude sodic spikes followed by slower larger calcic spikes. The present results demonstrate that, despite the variety of individual cell types, the major morphological population (30/36 cells) was composed of a homogeneous class of large-sized neurons that displayed thick primary dendrites and abundant dendritic appendages. The remaining 6 cells were small-sized, poorly-spiny neurons. Somatic spines were observed on 5 out of the 30 large cells and on one out of the six smaller cells. Labeled axons were mainly oriented to the anterior commissure. The axons of nine cells richly collateralized near the perikaryon. Ultrastructural examination of 3 horseradish peroxidase-injected cells showed indented nuclei, classic organelles and somatic spines. Terminal boutons established symmetric synapses with the injected cells. These results describe the morphological features of electrophysiologically identified neurons and indicate that class A and class C neurons are distributed among morphological populations differing in perikaryal size. This suggests that the different electrical properties of class A and class C neurons reflect recordings from different parts of the neuron rather than from neurons of different types. Furthermore, the present findings demonstrate that, in the guinea-pig, electrical and morphological characteristics of somatospiny neurons are comparable with those of non-somatospiny neurons. Somatospiny neurons have a recognized integrative role in the hippocampo-septo-hypothalamic complex.     

X-ray and computed tomographic diagnosis of aneurysm of the thoracic aorta

The paper is concerned with the results of x-ray and CT investigations conducted in 62 patients with suspected aneurysm of the thoracic aorta. The diagnosis was confirmed in 56. Of them 38 patients were operated on, 2 died without surgical intervention. X-ray investigations permitted differential diagnosis of mediastinal formations in 91.5% of cases. However in 2 cases when the combined method of intravenous administration of a contrast medium by means of a syringe was not used, aneurysmal aortic dilatation was not detected by CT. This method was found to be effective for diagnosis of complications of aneurysms of the thoracic aorta (calcinosis, aortic wall stratification and thrombosis of aneurysmal cavity).