Annals of Anatomy-Anatomischer Anzeiger最新文献

Background

Dermal white adipose tissue (dWAT) in humans can be characterized as a relaxed dermal skin compartment consisting of functionally interlinked adipocytes. dWAT is typically discerned both in terms of morphology and function from subcutaneous white adipose tissue (sWAT). In particular in human thigh, the dWAT appears as thin extensions from the adipose panniculus to the dermis, and it is primarily associated with pilosebaceous units, hair follicles, sebaceous glands, and erector pili muscles. In this work, human fat tissue samples obtained post-mortem from the gluteo-femoral region were analyzed focusing on the thin extensions of dWAT named dermal cones. This anatomical region was chosen to deepen the dWAT morphological features of this site which is interesting both for clinical applications and genetical studies. The purpose of this exploratory methodological study was to gain deeper insights into the morphological features of human dWAT through a multimodal imaging approach.

Methods

Optical microscopy, Magnetic Resonance Imaging (MRI) and Scanning Electron Microscopy (SEM), have been employed in this study. The cones’ length and their distances were measured on the acquired images for optical microscopy and SEM. The cone’s apparent regular distribution in MRI images was evaluated using a mathematical criterion, the conformity ratio, which is the ratio of the mean nearest-neighbor distance to its standard deviation.

Results

The imaging techniques revealed white adipocytes forming a layer, referred to as sWAT, with cones measuring nearly 2 mm in size measured on SEM and Optical images (2.1 ± 0.4 mm), with the lower part embedded in the sWAT and the upper part extending into the dermis. The distance between the cones results about 1 mm measured on MRI images and they show an overall semiregular distribution.

Conclusions

MRI images demonstrated an orderly arrangement of cones, and their 3D reconstruction allowed to elucidate the dermal cones’ disposition in the tissue sample and a more general comprehensive visualization of the entire fat structure within the dermis.

Introduction

The purpose of this study was to characterize the morphological variations in the quadratus femoris muscle (QF) and to create an anatomical classification that could be used in the planning of surgical procedures in this area, radiological imaging, and rehabilitation.

Materials and methods

Ninety-two lower limbs from 46 cadavers, fixed in 10 % formalin solution, were examined.

Results

The QF muscle was present in all specimens. According to morphology, the QF muscle was classified into three types. The most common type was Type I, characterized by one muscular belly (78.3 %), while the second most common type was Type II, characterized by two bellies, was observed in 17.4 % of cases. The rarest type was Type III. It was characterized by three bellies and was found in 4.3 % of the cases.

Conclusions

The current classification system on quadratus femoris morphological variability is novel. Morphological variants may contribute to clinical issues, such as the ischiofemoral impingement syndrome, that could arise from type I quadratus femoris. Hence, the current study may be applicated to planning surgical procedures, imaging, and rehabilitation.

Embolization of coronary arteries and their terminal arterioles causes ischemia of all tissues distributed within a cardiac wall including the intrinsic cardiac ganglionated nerve plexus (ICGP). The disturbed blood supply to the ICGP causes chronic sympathetic activation with succeeding atrial and ventricular arrhythmias. This study analyses the anatomy of microcirculation of epicardial nerves and ganglia using the hearts of 11 domestic pigs. Our findings demonstrate that thicker epicardial nerves are normally supplied with blood via 12 epineural arterioles penetrating the endoneurium regularly along a nerve, and forming an endoneurial capillary network, which drains the blood into the myocardial blood flow. The mean diameter of intraneural capillaries was 7.2 ± 0.2 µm, while the diameters of arterioles were 25.8 ± 0.7 μm and involved 45 endothelial cells accompanied by circular smooth muscle cells. Usually, two or three arterioles with a mean diameter of 28.9 ± 1.7 μm supplied blood to any epicardial ganglion, in which arterioles proceeded into a network of capillaries with a mean diameter of 6.9 ± 0.3 μm. Both the epicardial nerves and the ganglia distributed near the porta venarum of the heart had tiny arterioles that anastomosed blood vessels from the right and the left coronary arteries. The density of blood vessels in the epicardial nerves was significantly lesser compared with the ganglia. Our electron microscopic observations provided evidence that blood vessels of the pig epicardial nerves and ganglia may be considered as either arterioles or capillaries that have quantitative and qualitative differences comparing to the corresponding blood vessels in humans and, therefore, a pig should not be considered as an animal model of the first choice for further heart functional studies seeking to improve the treatment of cardiac arrhythmias via trans-coronary cardiac neuroablation.

Structured abstract

This study details the anatomy of microcirculation of epicardial nerves and ganglia, from which intracardiac nerves and bundles of nerve fibers extend into all layers of the atrial and ventricular walls in the most popular animal model of experimental cardiology and cardiac surgery - the domestic pig. Our findings provided evidence that blood vessels of the pig epicardial nerves and ganglia may be considered as either arterioles or capillaries that have quantitative and qualitative differences comparing to the corresponding blood vessels in humans and, therefore, a pig should not be considered as an animal model of the first choice for further heart functional studies seeking to improve the treatment of cardiac arrhythmias via trans-coronary cardiac neuroablation.

Ventricular septal defects (VSD) with outflow tract (OFT) malalignment are a common group of congenital heart diseases with varying severity. The developmental process of these defects is challenging to understand due to the complex nature of cardiac morphogenesis and the difficulties in visualizing the temporal and spatial changes that occur during pathogenesis. However, recent advancements in imaging techniques, such as high-resolution episcopic microscopy, have provided valuable insights into the normal septation of ventricular chambers and OFT alignment. Building upon this knowledge, we have utilized lightsheet microscopy, another innovative imaging method, to further investigate the developmental processes that lead to abnormal formation of the ventricular septum and the malalignment of arterial roots with the ventricular chambers. Our study highlights endocardial cushion hypoplasia and insufficient rotation of the outflow tract as two interrelated central factors contributing to the pathogenesis of these defects. This finding has the potential to enhance our understanding of the etiology of congenital heart diseases and may contribute to the development of improved diagnostic and therapeutic strategies in the future.

Background

The regenerative capacity of organisms declines throughout evolution, and mammals lack the ability to regenerate limbs after injury. Past approaches to achieving successful restoration through pharmacological intervention, tissue engineering, and cell therapies have faced significant challenges.

Objectives

This review aims to provide an overview of the current understanding of the mechanisms behind animal limb regeneration and the successful translation of these mechanisms for human tissue regeneration.

Results

Particular attention was paid to the Mexican axolotl (Ambystoma mexicanum), the only adult tetrapod capable of limb regeneration. We will explore fundamental questions surrounding limb regeneration, such as how amputation initiates regeneration, how the limb knows when to stop and which parts to regenerate, and how these findings can apply to mammalian systems.

Conclusions

Given the urgent need for regenerative therapies to treat conditions like diabetic foot ulcers and trauma survivors, this review provides valuable insights and ideas for researchers, clinicians, and biomedical engineers seeking to facilitate the regeneration process or elicit full regeneration from partial regeneration events.

Purpose

In vivo comparison of the regenerative potential of two calcium phosphate-biopolymer osteoplastic composites: а) based on alginate (Alg) and hydroxyapatite (HA) – Alg/HA/CS/Zn/D2, b) based on chitosan (CS) and brushite (DCPD) – CS/DCPD/D2.

Materials and methods

36 white male laboratory rats aged six months were used. A defect to the bone marrow canal in the middle of the femur diaphysis was made with a dental bur of 2 mm. The bone defect healed under the blood clot (control) in the different animal groups and was filled with Alg/HA/CS/Zn/D2 and CS/DCPD/D2. The regeneration of the bone defect was studied on the 30th, 90th, and 140th days by computer tomography (CT).

Results

On the 30th day, all groups' implantation site optical density (OD) was significantly lower than that of the adjacent maternal bone (MB). Intensity of bone formation for Alg/HA/CS/Zn/D2 exceeds CS/DCPD/D2. On the 90th day, the bone trauma site OD with Alg/HA/CS/Zn/D2 (1725.4 ± 86 HU) and CS/DCPD/D2 (1484.9 ± 69 HU) exceeded the OD of the control (942.5 ± 55 HU). On the 140th day, the OD of Alg/HA/CS/Zn/D2 and CS/DCPD/D2 implantation sites was higher than Control and MB OD. Visually, the area of the past injury with the Alg/HA/CS/Zn/D2 could be detected only by the presence of an endosteal bone callus and in the case of CS/DCPD/D2 - by the shadow of the remaining biomaterial in the bone marrow canal.

Conclusions

According to CT data, Alg/HA/CS/Zn/D2 and CS/DCPD/D2 contribute to the complete healing of the femoral diaphysis defect in 140 days, but the regenerative potential of Alg/HA/CS/Zn/D2 from 30 days to 140 days is higher than CS/DCPD/D2 biomaterial.

Background

What textbooks usually call the sublingual gland in humans is in reality a tissue mass of two types of salivary glands, the anteriorly located consisting of a cluster of minor sublingual glands and the posteriorly located major sublingual gland with its outlet via Bartholin’s duct. Only recently, the adrenergic and cholinergic innervations of the major sublingual gland was reported, while information regarding the neuropeptidergic and nitrergic innervations is still lacking.

Methods

Bioptic and autoptic specimens of the human major sublingual gland were examined by means of immunohistochemistry for the presence of vasoactive intestinal peptide (VIP)-, neuropeptide Y (NPY)-, substance P (SP)-, calcitonin gene related-peptide (CGRP)-, and neuronal nitric oxide synthase (nNOS)-labeled neuronal structures.

Results

As to the neuropeptidergic innervation of secretory cells (here in the form of mucous tubular and seromucous cells), the findings showed many VIP-containing nerves, few NPY- and SP-containing nerves and a lack of CGRP-labeled nerves. As to the neuropeptidergic innervation of vessels, the number of VIP-containing nerves was modest, while, of the other neuropeptide-containing nerves under study, only few (SP and CGRP) to very few (NPY) nerves were observed. As to the nitrergic innervation, nNOS-containing nerves were very few close to secretory cells and even absent around vessels.

Conclusion

The various innervation patterns may suggest potential transmission mechanisms involved in secretory and vascular responses of the major sublingual gland.

Objectives

The molecular mechanisms behind orthodontic tooth movements (OTM) were investigated by clarifying the role of chemical messengers released by cells.

Methods

Using the Cochrane library, Google scholar, and PubMed databases, a literature search was conducted, and studies published from 1984 to 2024 were considered.

Results

Both bone growth and remodeling may occur when a tooth is subjected to mechanical stress. These chemicals have a significant effect on the stimulation and regulation of osteoblasts, osteoclasts, and osteocytes during alveolar bone remodeling. This regulation can take place in pathological conditions, such as periodontal diseases, or during OTM alone. This comprehensive review outlines key molecular mechanisms underlying OTM and explores various clinical assumptions associated with specific molecules and their functional domains during this process. Furthermore, clinical applications of certain molecules such as relaxin, prostaglandin E (PGE), and interleukin-1β (IL-1β) in accelerating OTM have been reported. Our findings underscore the existing gap between OTM clinical applications and basic research investigations.

Conclusion

A comprehensive understanding of orthodontic treatment is enriched by insights into biological systems. We reported the activation of osteoblasts, osteoclast precursor cells, osteoclasts, and osteocytes in response to mechanical stress, leading to targeted cellular and molecular interventions and facilitating rapid and regulated alveolar bone remodeling during tooth movement. Despite the shortcomings of clinical studies in accelerating OTM, this review highlights the crucial role of biological agents in this process and advocates for prioritizing high-quality human studies in future research to gain further insights from clinical trials.

Background

Patients undergoing orthodontic treatment (OT) face an increased risk of developing external apical root resorption (EARR). A prognostic risk assessment prior to OT can potentially be conducted through anatomical features in panoramic radiography. This retrospective study aimed to assess the significance of Kjær's morphological characteristics in analyzing the risk of EARR.

Methods

Panoramic radiographs of 1,156 patients (624 females, 532 males) were retrospectively analyzed. Anamnestic and treatment-related data were extracted from patient records. The mean age at the start of OT was 12.8 ± 2.2 years (min. 6.4 years, max. 22.3 years) and at the end of OT 15.9 years (min. 8.5 years, max. 24.1 years). The mean treatment duration was 3.1 ± 1.6 years. Panoramic radiographs with a minimum of two per patient were examined for the presence of Kjær’s characteristics. The degree of EARR was registered defining resorption in four degrees of severity. Bivariate analysis and multivariate Poisson regression were performed to assess the association between Kjær’s characteristics and EARR patient- and tooth- related (α = 0.05).

Results

In total, 72.8% of the patients showed EARR at the end of OT with lateral maxillary incisors most frequently affected. Short roots (p < 0.001) were significantly associated with EARR in patients. Tooth-related microdontia (#12, #22, lower second premolars), narrow crowns (#11, #21, lower incisors), short roots (upper incisors, lower first molars) and ectopia (#11, #21, #13), such as shorter distal roots of the mandibular first molar showed a significant association with EARR depending on severity degree. The type of orthodontic appliance (fixed: p < 0.001, fixed and removeable: p = 0.008), as well as treatment duration (p < 0.001) were also identified as risk factors for EARR.

Conclusions

Although the risk assessment for EARR development through panoramic radiography analysis is limited, predisposition appears to be present in specific dental characteristics and treatment-related factors.

Voice production has been an area of interest in science since ancient times, and although advancing research has improved our understanding of the anatomy and function of the larynx, there is still little general consensus on these two topics. This review aims to outline the main developments in this field and highlight the areas where further research is needed. The most important hypotheses are presented and discussed highlighting the four main lines of research in the anatomy of the human larynx and their most important findings: (1) the arrangement of the muscle fibers of the thyroarytenoid muscle is not parallel to the vocal folds in the internal part (vocalis muscle), leading to altered properties during contraction; (2) the histological structure of the human vocal cords differs from other striated muscles; (3) there is a specialized type of heavy myosin chains in the larynx; and (4) the neuromuscular system of the larynx has specific structures that form the basis of an intrinsic laryngeal nervous system. These approaches are discussed in the context of current physiological models of vocal fold vibration, and new avenues of investigation are proposed.