Development of the interatrial wall during the ontogenesis of foetuses and children up to one year of age

Background: The foramen ovale, present in foetal interatrial septum, plays an important role during foetal life. During delivery, foramen ovale closes and becomes fossa ovalis, starting the pulmonary circulation. The aim of our study was to describe the growth of the interatrial wall and changes in location of the foramen ovale, and fossa ovalis during the ontogenesis in the human hearts.Materials and methods: The study was performed on post-mortem material obtained from 92 human hearts from 22nd week of foetal life up to 1 year of age, fixed in a 4% formalin solution.Results: The interatrial wall size in the studied development period was greater in the horizontal than in the vertical dimension. During ontogenesis up to 1 year old, the anterior and inferior parts of the interatrial wall increased their shares considerably by 8% and 6%, respectively. The percentage participation of foramen ovale in the interatrial wall construction in the foetal period formed more than 50% of its size and fairly decreased reaching in infants about 39%.Conclusions: Our study demonstrated that during ontogenesis, from the foetal period to infancy, the parts of the interatrial wall increase their dimensions unevenly. The foramen ovale growth is smaller, compared to the rest of the interatrial wall development. On the basis of our data we can assume that the foramen ovale centre tends to be found in the postero-inferior quadrant of the interatrial wall (foetuses) and in postero-superior quadrant of the interatrial wall — in infants

The initial zones of the atrioventricular node: really neglected anatomical features of potential clinical significance?

The constant evolution of medical knowledge and accompanying development of diagnostic and treatment possibilities for arrhythmias and conduction disturbances has reawakened interest in the structure and function of the conduction system of the human heart, especially in the region of the atrioventricular (AV) junction and within the junction itself. Of the large number of studies dealing with the AV junction few focus on the initial zones of the AV node. These were described for the first time by Tawara in 1906. Similarly, Anderson et al. distinguished two origins of the AV node, the left one running towards the basis of the mitral valve and the right one leading towards the tricuspid valve. The differences in length and scale could be the result of the adoption of different reference points. The study was carried out on the material of 50 human hearts, of both sexes and ranging in age from 22 to 93, which were fixed in 10% formalin and 98% ethanol solution. The tissue obtained was fixed in the 10% formalin solution and, after being sunk in the paraffin, was cut into layers of about 10 μm thick. According to the age of the hearts, every 10th or 6th section was stained by the Masson-Goldner method. The preparations were examined under a LEICA 2000 and BIOLAR 2 microscope at magnifications of 2× to 400×. Each of the 50 examined hearts contained the atrioventricular node and its initial parts. We observed that the initial zone of the AV node is created by an assembly of cells typical for a conduction system that can create three groups that are initially independent of each other and are always arranged around the AV nodal artery. In all the hearts examined we found at least two initial parts of the node: the superior and inferior. These two groups were present in 45 hearts (90%). In the last 5 cases (10%) there was also a middle group. No cases were found either with a single initial group or without any initial groups. In the sections examined the superior group appeared to be first in 27 hearts (54%), while in 23 cases (46%) the inferior group was first. The length of each group was measured from its first appearance to its first direct contact with the second part. The length of the superior part varied from 0.15 to 2.91 mm (mean 0.90 ± 0.6 mm), the inferior from 0.11 to 2.41 mm (mean 0.88 ± 0.6 mm) and the middle from 0.67 to 2.21 mm (mean 1.04 ± 0.7 mm). As mentioned above, in all 50 hearts there was a direct connection between the atrial muscle and the upper origin of AV node. Furthermore, in all sections (100%) the same part of the interatrial septal muscle was connected to the compact part of the node. Additionally, in 3 cases (6%) we were able to observe direct connections between the muscle fibres running from the fasciculus limbicus inferior to the initial zone of the AV node: in 2 cases (4%) with the superior group and in 1 case (2%) with the inferior group. In 8% of the material the atrial muscle of the supra-orificial zone made direct contact with the superior initial group and the compact zone of the node and in 10% there was contact between the suborificial muscle and the inferior group and the compact part of the node. This configuration was not observed in relation to the middle and inferior groups

Arterial hypertension and remodeling of the right ventricle

Background: In case of long-term and physiological loads (e.g. during pregnancy or regular athletics training), reversible morphological changes occur in the heart - cardiomyocytes undergo hypertrophy, however, this is not accompanied by impairment of left ventricular function or myocyte metabolism. However, in the course of various pathological processes, as time goes by, gradually permanent morphological changes occur. These changes are referred to as remodeling of the heart muscle, which, regardless of the primary cause, can lead to the development of chronic heart failure. Materials and methods: The study was performed on post-mortem material of 35 human hearts obtained from forensic sections and anatomopathological sections of people who died of non-cardiac causes (mainly traffic accidents, suicide attempts, strokes, acute infections); material was fixed in a 4% formalin solution. The hearts were subjected to macro- and microscopic assessment. During microscopic assessment the features of remodeling were evaluated. Results and conclusions: In vivo and echocardiographic tests, as well as macroscopic evaluation of post-mortem material, suggest the presence of some kind of right ventricular muscle remodeling, however classic microscopic observations, presented in this study do not provide such unambiguous evidence. Thus, the question arises: why and how the right ventricular function is disturbed, sometimes at early stages of arterial hypertension

β1 Integrin-Mediated Adhesion Signalling Is Essential for Epidermal Progenitor Cell Expansion

Background: There is a major discrepancy between the in vitro and in vivo results regarding the role of b1 integrins in the maintenance of epidermal stem/progenitor cells. Studies of mice with skin-specific ablation of b1 integrins suggested that epidermis can form and be maintained in their absence, while in vitro data have shown a fundamental role for these adhesion receptors in stem/progenitor cell expansion and differentiation. Methodology/Principal Findings: To elucidate this discrepancy we generated hypomorphic mice expressing reduced b1 integrin levels on keratinocytes that developed similar, but less severe defects than mice with b1-deficient keratinocytes. Surprisingly we found that upon aging these abnormalities attenuated due to a rapid expansion of cells, which escaped or compensated for the down-regulation of b1 integrin expression. A similar phenomenon was observed in aged mice with a complete, skin-specific ablation of the b1 integrin gene, where cells that escaped Cre-mediated recombination repopulated the mutant skin in a very short time period. The expansion of b1 integrin expressing keratinocytes was even further accelerated in situations of increased keratinocyte proliferation such as wound healing. Conclusions/Significance: These data demonstrate that expression of b1 integrins is critically important for the expansion of epidermal progenitor cells to maintain epidermal homeostasis

Managing hyperemesis gravidarum: a multimodal challenge

Up to 90% of pregnant women experience nausea and vomiting. When prolonged or severe, this is known as hyperemesis gravidarum (HG), which can, in individual cases, be life threatening. In this article the aetiology, diagnosis and treatment strategies will be presented based on a selective literature review. Treatment strategies range from outpatient dietary advice and antiemetic drugs to hospitalization and intravenous (IV) fluid replacement in persistent or severe cases. Alternative methods, such as acupuncture, are not yet evidence based but sometimes have a therapeutic effect

Metric analysis of the lumbar region of human vertebral column

Detailed measurement of lumbar spine, despite the many years of study, still provides new information, especially due to low back pain, which is increasing and unresolved worldwide health problem. This review includes historical background and evolution of measurement methods. The paper also focused on searching optimal animal model of lumbar spine and summarizes current knowledge and essential tips. In addition, practical application of lumbar metric analysis was presented. This summary is a starting point for further consideration

Myocardial bridges in domestic pig - morphological aspects

The morphology of myocardial bridges (MB) in the heart of the domestic pig remain an open issue. Despite numerous analyses of the subject, many controversies still exist. Opinions also differ when the influence of the MB on haemodynamic processes in the coronal vessel system is concerned. In the examined group of 150 domestic pig's hearts, the length of the detected MB varied from 1.8 to 39.7 mm while their thickness amounted to 0.8 - 4.7 mm. Both the longest and the thickest bridges were connected with the posterior interventricular branch. It was noticed that the MB muscle bands cross the long axis of the vessels located in the grooves mostly at almost a right angle. Three forms of perivascular space were educed using the criterion of the distance of the vessel from the surrounding muscularis externa