Search Results (91)

Background: Lower phylogenetic species are known to rebuild cut-off caudal parts with regeneration of the central nervous system (CNS). In contrast, CNS regeneration in higher vertebrates is often attributed to immaturity, although this has never been conclusively demonstrated. The emergence of stem cells and their effective medical applications has intensified research into spinal cord regeneration. However, despite these advances, the impact of clinical trials involving spinal cord-injured (SCI) patients remains disappointingly low. Long-distance regeneration has yet to be proven. Methods: Our study involved a microsurgical dorsal myelotomy in fetal rats. The development of pioneering long primary afferent axons during early gestation was examined long after birth. Results: A single cut triggered the intrinsic ability of the dorsal root ganglion (DRG) neurons to reprogram. Susceptibility to hypoxia caused the axons to stop developing. However, the residual axonal outgrowth sheds light on the intriguing temporal and spatial events that reveal long-distance CNS regeneration. The altered phenotypes displayed axons of varying lengths and different features, which remained visible throughout life. The previously designed developmental blueprint was crucial for interpreting these enigmatic features. Conclusions: This research into immaturity enabled the exploration of the previously impenetrable domain of early life and the identification of a potential missing link in CNS regeneration research. Central axon regeneration appeared to occur much faster than is generally believed. The paradigm provides a challenging approach for exhaustive intrauterine reprogramming. When the results demonstrate pre-clinical effectiveness in CNS regeneration research, the transformational impact may ultimately lead to improved outcomes for patients with spinal cord injuries. Full article

Objective: The aim of this study was to determine whether preoperative MRI has an impact on surgical planning in breast cancer patients. Tumor extent and molecular breast cancer subtypes were evaluated. Methods: This was a single-center study including 137 female patients with a first diagnosis of invasive breast cancer. Each patient had a standard clinical preoperative workup and an additional breast MRI. The interdisciplinary tumor board made written recommendations regarding the surgical therapy of each patient with and without the knowledge of the MRI findings. Results: The addition of MRI led to changes in surgical recommendations in 32 (23%) of the 137 patients. The highest rate of change in surgical therapy recommendations was observed in patients with multifocal tumors (53%). Molecular subtype had no influence on the changes in surgical therapy recommendations (p = 0.8). Conclusions: Patients with multifocal breast tumors were more likely to have a change in surgical therapy following MRI. Full article

Background/Objectives: This study explores the ocular anatomy and glandular components of domestic dogs compared to their ancestor, the wolf, with the aim of identifying evolutionary changes due to domestication and their implications for ocular pathologies. Methods: Utilizing histological and histochemical techniques, including hematoxylin–eosin, Periodic Acid–Schiff, Alcian Blue, and lectins, this research conducts a detailed analysis of the canine and wolf ocular systems, focusing on the eyelids, tarsal glands, and conjunctival tissues. Results: There are marked histological differences between the two species, particularly in the thickness and secretion levels of the conjunctival epithelia and the structure of the tarsal glands. Dogs exhibit a thicker epithelium with greater Periodic Acid–Schiff and Alcian Blue positive secretion, suggesting enhanced ocular protection and lubrication adapted to domestic environments. Conversely, wolves display more concentrated glandular secretions and a predominance of acidic mucopolysaccharides, aligning with their adaptation to natural habitats. Conclusions: Although this study is constrained by the limited number of samples, the use of mixed dog breeds, and the focus on the Iberian wolf, it nonetheless suggests histological and evolutionary differences between domestic dogs and wolves, particularly in structures related to ocular surface protection and lubrication. These differences likely reflect adaptive responses to domestication in dogs and environmental demands in wolves. Importantly, the findings emphasize the clinical and translational potential of using dogs as comparative models for human ocular surface disorders, given their anatomical proximity to humans. Full article

Anatomy education has long served as a cornerstone of medical training, equipping healthcare professionals with the foundational knowledge necessary for clinical practice. However, the discipline has undergone significant transformations in response to evolving curricula, ethical considerations, and technological advancements. This paper explores the historical development, current state, and future trajectory of anatomy education, focusing on challenges such as ethical concerns regarding cadaveric dissection, and the need for cost-effective alternatives. The study examines innovative teaching methods, including virtual reality, augmented reality and artificial intelligence, which enhance anatomical learning by providing interactive, scalable educational experiences. Additionally, it discusses the integration of anatomy with clinical practice through imaging technologies, competency-based education, and evidence-based approaches. While modern innovations offer valuable learning tools, they cannot entirely replace the hands-on experience and professional identity formation fostered by cadaveric dissection. A balanced approach that combines traditional methodologies with digital advancements is essential for optimizing anatomy education. By leveraging both physical and virtual resources, educators can enhance anatomical comprehension, improve clinical preparedness, and ensure that future healthcare professionals develop both technical expertise and ethical awareness. This paper underscores the need for continued adaptation in anatomy education to align with the demands of modern medicine while preserving its core educational values. Full article

Peripheral nerve injuries (PNIs) commonly result from trauma, compression, or iatrogenic causes, leading to functional deficits. Despite the peripheral nervous system’s regenerative capacity, current treatments yield inconsistent outcomes. Basic science and translational research supporting nerve repair remain underdeveloped, partly due to the absence of standardized protocols, limiting reproducibility. Animal models are essential for studying injury mechanisms, repair strategies, and therapeutic development. This review examines commonly used animal models in PNI research, from non-mammalian species to rodents and large mammals. We discuss the relevance of injury types, experimental variables (i.e., age, sex, nerve type), and study design elements (i.e., nerve gap size, injury induction methods). Assessing these models’ strengths and limitations, this review aims to guide researchers in selecting appropriate models that enhance preclinical relevance. It also addresses the need for standardized protocols and future directions for improving PNI research and patient outcomes. Various PNI treatments—including microsurgery, nerve grafts, scaffolds, stem cells, immunomodulators, nerve augmentation strategies, and polyethylene glycol-mediated fusion—have been developed using animal models. These models are essential for driving innovation and translating emerging therapies to improve outcomes across a broad range of peripheral nerve injuries. Full article

Background: The brachial plexus is a network of nerves responsible for the motor and sensory innervation of the upper limb. Variations in the formation and course of the brachial plexus are well documented, though combinations of multiple unilateral abnormalities are rare. The complex pathology of this structure nerve may result in clinical consequences. We present a unique set of brachial plexus abnormalities involving the C4–C6 nerve roots, superior and middle trunks, additional communicating branches, and delayed median nerve union. Case Presentation: During the routine dissection of a 70-year-old female cadaver, several unique variations in the brachial plexus anatomy were identified. The C4 root contributed to C5 before the superior trunk formed, resulting in a superior trunk composed of C4–C6. The C5 root was located anterior to the anterior scalene muscle, whereas C6 maintained its usual posterior position. Additionally, an anterior communicating branch from the middle trunk to the posterior cord was observed. A communicating branch between the lateral and medial cords split into two terminal branches: one merged with the ulnar nerve, and the other joined the medial contribution of the median nerve. The median nerve contributions from the lateral and medial cords merged approximately two inches above the elbow. Conclusions: This rare combination of brachial plexus anomalies has not been previously described in the literature and is of significant clinical relevance. The additional anterior communicating branch from the middle trunk may suggest potential flexor muscle innervation by the posterior cord, which typically innervates extensor muscles. Additionally, the delayed convergence of the median nerve may provide a protective mechanism in cases of midshaft humeral fracture. Awareness of these peripheral nerve abnormalities is important for diagnostic imaging, surgery, or peripheral nerve blocks. Knowledge of such variations is critical for clinicians managing upper limb pathologies. Full article

Background/Objectives: The hypoglossal nerve plays a crucial role in cervical surgery, requiring precise anatomical knowledge to prevent iatrogenic injury. This study examined its position relative to key structures using cadaveric dissections and assessed ChatGPT-4’s reliability in providing anatomical insights. Methods: Ten cadavers were dissected to identify the hypoglossal nerve’s course in relation to the internal jugular vein, carotid arteries, thyro-linguo-facial trunk, hyoid bone, and digastric muscle. Measurements were taken, and ChatGPT was queried for anatomical guidance and surgical recommendations. Results: The hypoglossal nerve was consistently medial to the internal jugular vein and lateral to the carotid arteries. The measured distances to the surrounding structures showed notable variability, particularly with the thyro-linguo-facial trunk. ChatGPT accurately described major landmarks but overlooked lesser-known anatomical triangles and provided no additional dissection guidance. It primarily suggested intraoperative monitoring and preoperative imaging. Conclusions: The carotid and submandibular triangles serve as reliable landmarks for identifying the hypoglossal nerve. This study highlights an unreported variability in its relationship with the thyro-linguo-facial trunk. ChatGPT, while informative, lacked detailed surgical applicability for dissection. Full article

Background: The alignment of a person’s body segments depends on their innate anatomy and neuromuscular status. Sagittal posture assessments provide valuable information on correctable deficits, which can be used to prevent possible health issues or injuries. Methods: This article provides practical guidance on how to perform a basic photometric sagittal posture analysis in a reproducible manner, which reference points should be used, and which errors should be avoided. For this purpose, based on the current literature, four important evidence-based parameters for evaluation are defined, and literature-based reference values are given for the assessment of posture. Conclusions: When done correctly, the sagittal posture analysis is a valuable tool in the fields of medicine and sports. Full article

Background: The dorsal scapular nerve (DSN) and the long thoracic nerve (LTN) exhibit variable anatomical pathways, which may contribute to upper back pain and impaired scapular movement in affected patients. This study investigates these variations to enhance clinicians’ diagnostic and surgical approaches. Methods: The bilateral cervical regions of 32 formalin-embalmed donors (64 sides) were dissected to document the origin of the DSN, the relationship with the scalene muscles of the DSN, and anatomical connections between the DSN and LTN. Measurements of the distance between the mastoid process and the piercing point of the DSN to the scalene muscle were obtained with digital calipers. Additional measurements were obtained from the medial border of the scapula at two specific locations: the scapular spine (zone 1) and the midpoint between the scapular spine and the inferior angle of the scapula (zone 2). Results: The DSN demonstrated four distinct cervical spinal nerve root origins and five unique scalene muscle piercing patterns. The average distance between the DSNs’ scalene muscle piercing point and the mastoid process was 94.87 ± 10.09 mm, with significantly greater distances observed in male donors compared to female donors (p < 0.001). Connections between the DSN and LTN were identified in 65.2% of the examined cervical regions. The mean distance of the DSN from the medial border of the scapula at zone 2 was significantly greater than at zone 1 (p < 0.001). Conclusions: The anatomical variation findings and classification of the DSN provide valuable insights, offering guidance for conducting clinical procedures of the scalene and rhomboid musculature in a way that minimizes the risk of iatrogenic injury. The documented variations may also assist in the diagnosis and management of DSN-related pathologies such as DSN neuropathy. Full article

Background: Clinical-surgical procedures in the thoracic outlet can be challenging due to the proximity of neurovascular structures to the subclavian vein. Methods: During a routine anatomical dissection in an undergraduate medical study at Paracelsus Medical University, Nuremberg, a novel anatomical finding was observed in an ethanol–glycerin embalmed, 79-year-old female body. In addition to the standard measurements, hematoxylin eosin staining of relevant vessels was performed Results: A nerve branch separating from the brachial plexus at the C6 spinal nerve traversed inferiorly and passed through a fenestration of the subclavian vein in the lateral section, rejoining the lateral cord of the brachial plexus. In addition, hypoplasia of the right-sided internal carotid artery (ICA) and a left-sided internal jugular vein (IJV) hypoplasia were detected. At the left venous angle of the left IJV, a venous saccular aneurysm was found. The ectopic origin of the left ascending pharyngeal artery originated from the initial segment of the left ICA. Also, Langer’s axillary arches were observed bilaterally in the same subject. Conclusions: The anatomical findings in the specimen do not provide a direct symptomatic correlation or functional relevance comparable to clinical observations. Nevertheless, it is important to highlight this discovery as a potential clinical reference for future studies. Full article

Background: Endovascular treatment of venous disease is introducing new therapeutic options in neuroradiology. These procedures are technically challenging and require extensive physician training. Currently, training is mainly conducted on animal models, which presents drawbacks such as ethical concerns and anatomical differences from human vascular architecture. There is no training model that simulates treating intracranial venous disease using original instruments in a real angiography suite. Methods: This work presents the development of a venous system model for endovascular training simulations for integration into the existing Hamburg ANatomical NEurointerventional Simulator (HANNES) for arterial interventions. Results: The manufacturing process established at HANNES and the material used for the arterial vascular models were successfully transferred to the larger 3D-printed vein models. The application test was conducted in a real angiography suite with original instruments by an experienced neurointerventional physician to evaluate the system in terms of geometric mapping, flow, haptics and probing. Conclusion: This newly developed model provides a first approach to simulate an endovascular intervention in the venous system within the HANNES environment. Future expansions might include specific treatment simulations for conditions such as arteriovenous malformations, dural arteriovenous fistulas, sinus vein thrombosis and hydrocephalus. Full article

Background: Peripheral nerve surgeries require extensive practice to address anatomical variability and effectively manage neuropathy symptoms. While these procedures are increasingly performed by other surgical specialists, neurosurgeons bring unparalleled expertise in the central and peripheral nervous systems. Microscopic surgical techniques are essential for minimally invasive procedures, and cadaver-based education provides an invaluable medium for trainees to practice these techniques. However, few papers address these concepts in tandem. This study explores lesser-known peripheral nerve entrapments, highlights minimally invasive microscopic approaches, and advocates for cadaver-based training. Methods: Willed cadavers were embalmed through approved methods by the state anatomical board. For each decompression procedure, a 1–2 cm keyhole incision was made. Further methods are described in each nerve entrapment surgery below. Exploratory sessions with wider incisions were conducted either before or after the minimally invasive procedure to review anatomy or assess procedural success, respectively. Results: Neurosurgical medical education using cadavers allows trainees to practice techniques and enhance their skillset. Cadavers provide a valuable medium for exploring the relevant anatomy and visualizing the correct procedural steps after minimally invasive surgeries. Using microscopes for the procedures further facilitates detailed anatomical observation and technique refinement. Conclusions: Here, we show that cadaver-based medical education offers a realistic and controlled environment for exploring anatomical variability and refining surgical techniques. This method allows for a visual, mental, and tactile understanding, while performing minimally invasive procedures with a microscope on cadavers further enhances trainees’ proficiency, precision, and confidence, equipping them with the skills needed for improved surgical outcomes. Full article

This article explores the continuation of the pathological morphology research program at neuroscience-related institutes from the Kaiser Wilhelm Society after World War II. It covers the research tradition in the brain sciences, which can be described by an emphasis on gross anatomy, the functional implications of morphological substrates, and the analysis of neurohistological research paths of the human brain in comparative contexts. To enable examination of the assimilation processes of the Kaiser Wilhelm Society’s legacy, the decisions and developments of the newly created Max Planck Society in Germany and its early brain science facilities will be assessed for the time period from 1948 to 2002. Pertaining to these overall developments in the Max Planck Society, a persistence of the “morphological paradigm” (microanatomy, pathology, comparative anatomy, etc.) can be identified as lasting until the 1960s. The newer “functional paradigm” (neurophysiology, electroencephalography, cybernetics, and behavioral studies) only became more visible when the first generations of the scientific leaders left their positions in this national research society. It is of note that many directors and scientific members, including Detlev Ploog (1920–2005), Dieter Lux (1924–1995), Georg W. Kreutzberg (1932–2019), Otto Detlev Creutzfeldt (1927–1992), Hans Thönen (1928–2012), Manfred Eigen (1927–2019), Erwin Neher (b. 1944), Hartmut Wekerle (b. 1944), Albert Hertz (1921–2018), Bert Sakmann (b. 1942), and Wolf Singer (b. 1943) were part of the American Neuroscience Research Program as associates, members, conference chairs, or trainees. Likewise, they joined the Society for Neuroscience early on, after it had emerged from the Neuroscience Research Program’s steering committee in 1969. This article seeks to clarify the context of the reorganization of the brain research-related Max Planck Institutes during the postwar period after World War II. Its trajectory includes the location of the institutes, their previous involvement in applied research, and personal continuities in scientific leadership positions, contributing to debates during the first decades of the Max Planck Society. The lens of pathological brain research emerges here as an important viewpoint to aid the understanding of the continued impact and concerns over the dominant morphological approaches in postwar West German neurology and psychiatry. Full article

Disuse osteoporosis occurs due to rest and reduced mechanical stimulation. Under these conditions, bone resorption exceeds bone formation, leading to a decrease in bone density. Vector potential (VP) generators have been developed, and their ability to maintain cartilage thickness has been reported. However, their effects on bone tissue remain unstudied. In this study, experiments were conducted to test the effects of VP on bones that had undergone weight reduction due to hindlimb suspension as a model of disuse osteoporosis. Methods: In this study, 7-week-old male Wistar rats (N = 6 each) were classified into control (CO), hindlimb suspension (HS), and VP energization intervention groups. The tail was used to suspend the HS and VP to remove the load applied to the hindlimbs. The VP conditions were as follows: voltage, 67 mV; frequency, 20 kHz, 0.12 mA; experimental intervention, 30 min/day, 5 days/week, for 3 weeks. At the end of the experimental period, the rats were euthanized with carbon dioxide gas, and histological specimens were fixed in 4% paraformaldehyde (PFA) in the femur and analyzed by electron microscopy, bone morphometry, immunohistology, bone fracture testing, and gene expression analysis. Results: HS decreased trabecular bone density and strength. However, VP maintained a significantly higher bone mass than HS, and VP did not differ from CO in bone strength; more osteoclasts were observed on the bone surface in HS, but they were suppressed in VP, and gene expression of CTSK and MMP-9 was decreased. Conclusions: VP suppressed bone resorption by osteoclasts, suggesting that VP is useful in the treatment of disuse osteoporosis. Full article

The rhesus monkey (Macaca mulatta) is a non-human primate with a genome that is 93.5% identical to that of humans. Both species, therefore, have numerous phenotypical similarities in common. Consequently, this non-human primate is regularly studied in biomedical research. Not only does the rhesus monkey play an important role as an animal model for studying human disease, but it is also often featured in zoos, and there are substantial feral populations that live in Asia. Since they are exploited as research subjects, their appropriate housing and husbandry and the validation of obtained research data benefit from the comprehension of the rhesus monkey anatomy. Unexpectedly, the number of anatomical documents on the rhesus monkey are largely outnumbered by publications on the anatomy of domestic animals. In addition, the limited number of available anatomical books and atlases are, unfortunately, outdated, e.g., by presenting black-and-white photographs and using archaic nomenclature, or failing to cover the in-depth anatomy of various anatomical systems. Since state-of-the-art data on the rhesus monkey anatomy are requested by biomedical researchers and veterinarians responsible for the daily care of these captive animals, the present study describes the musculature of the foot of the rhesus monkey. It builds on a recently published manuscript on the topographical anatomy of the pelvic limb of this non-human primate. Full-color anatomical (stereomicroscopic) photographs are taken during layer-by-layer dissections of the feet of three rhesus monkeys. All the muscles, from the superficial to the deepest layer, are described using veterinary anatomical nomenclature and annotated on multipaneled figures. Although the foot musculature of the rhesus monkey largely parallels that of its human counterparts, the small number of dissimilarities should be recognized when extrapolating these research data. In addition, a solid understanding of the rhesus monkey anatomy by veterinarians can be valuable during medical interventions, such as surgery for foot injuries. Full article