Abstract.The total nerve cell numbers in the right and in the left human entorhinal areas have been calculated by volume estimations with the Cavalieri principle and by cell density determinations with the optical disector. Thick gallocyanin-stained serial frozen sections through the parahippocampal gyrus of 22 human subjects (10 female, 12 male) ranging from 18 to 86 years were analysed. The laminar composition of gallocyanin (Nissl)-stained sections could easily be compared with Braak's (1972Braak's ( , 1980 pigmentoarchitectonic study, and Braak's nomenclature of the entorhinal laminas was adopted. Cellsparse laminae dissecantes can more clearly be distinguished in Nissl than in aldehydefuchsin preparations. These cell-poor dissecantes, lamina dissecans externa (dis-ext), lamina dissecans 1 (dis-l) and lamina dissecans 2 (dis-2), were excluded from nerve cell number determinations. An exact delineation of the entorhinal area is indispensable for any kind of quantitative investigation. We have defined the entorhinal area by the presence of pre-alpha cell clusters and the deeper layers of lamina principalis externa (pre-beta and gamma) separated from lamina principalis interna (pri) by lamina dissecans 1 (dis-l). The human entorhinal area is quantitatively characterized by a left-sided (asymmetric) higher pre-alpha cell number and an age-related nerve cell loss in pre as well as pri layers. At variance with other CNS cortical and subcortical structures, the neuronal number of the entorhinal area appears to decrease continuously from the earliest stages analysed, although a secular trend has to be considered. The asymmetry in pre-alpha cell number is discussed in the context of higher human mental capabilities, especially language.
Hoof kick injuries account for a significant proportion of equine injuries and occur when riders are dismounted, most frequently when grooming without wearing protective equipment. Head and facial injuries occur most frequently and suggest that mandatory helmet and facial grill use should be considered during all horse-related activities.
The vocal ligaments insert at the anterior and posterior commissures of the larynx. These structures fulfil biomechanical functions, balancing the different elastic moduli of tendon, cartilage or bone and undergo age-related changes that may be responsible for voice changes with increasing age. The aim of this study was to analyse the insertion structures of the vocal ligaments by means of macroscopic, histological, immunohistochemical and electron-microscopic methods and to draw conclusions from age-related structural changes on a functional basis. Investigations were carried out on the larynges of 22 males and 15 females (aged 1-95 y). In adolescence, the insertion zone of the vocal ligament tendon, a dense network of connective tissue rich in sulphated glycosaminoglycans at the thyroid cartilage, is characterised by a layer between tendon and cartilage comparable to fibrocartilage. The insertion zone lacks a perichondrium. Collagen fibrils of the vocal ligament tendon penetrate directly into the thyroid cartilage. In the insertion area, the chondrocytes are surrounded by collagen fibrils, which show positive reactivity to antibodies against type I and type III collagen. Sulphated glycosaminoglycans are integrated between the collagen fibrils. In the area of the posterior glottis, elastic cartilage rests like a cap on the hyaline base of the arytenoid cartilage. There is no distinctive border between the structures. With increasing age, ossification of the laryngeal skeleton occurs, involving hyaline cartilage at the posterior glottis and hyaline and fibrocartilage at the anterior commissure. At the same time, a loss of sulphated glycosaminoglycans is observed inside the vocal ligament tendon. Advanced ossification of the laryngeal skeleton, particularly in the area of the commissures, an increasing loss of glycosaminoglycans in the vocal ligament tendon and changes in the elastic tissue reduce the elastic modulus between tendon, cartilage and bone, thus ' stiffening ' the insertion zones, which could be one factor among others favouring voice changes with advancing age.
The purpose was to analyze magnetic resonance (MR) plaque imaging at 3.0 Tesla and 1.5 Tesla in correlation with histopathology. MR imaging (MRI) of the abdominal aorta and femoral artery was performed on seven corpses using T1-weighted, T2-weighted, and PD-weighted sequences at 3.0 and 1.5 Tesla. Cross-sectional images at the branching of the inferior mesenteric artery and the profunda femoris were rated with respect to image quality. Corresponding cross sections of the imaged vessels were obtained at autopsy. The atherosclerotic plaques in the histological slides and MR images were classified according to the American Heart Association (AHA) and analyzed for differences. MRI at 3.0 Tesla offered superior depiction of arterial wall composition in all contrast weightings, rated best for T2-weighted images. Comparing for field strength, the highest differences were observed in T1-weighted and T2-weighted techniques (both P< or =0.001), with still significant differences in PD-weighted sequence (P< or =0.005). The majority of plaques were histologically classified as calcified plaques. In up to 21% of the cases, MRI at both field strengths detected signal loss characteristic of calcification although calcified plaque was absent in histology. MRI at 3.0 Tesla offers superior plaque imaging quality compared with 1.5 Tesla, but further work is necessary to determine whether this translates in superior diagnostic accuracy.
This study is not able to show an association between wearing a torso protector and protection from torso injuries, probably due to confounding. We did not detect a high effect of safety vest usage in our study population. Whether the development of a new generation of safety vests might be more effective remains unclear. An effective vest should be adapted to the requirements of children and adolescents and should protect the thorax and abdomen, but also the cervical and the lumbar spine.
Splenic artery aneurysms are an uncommon form of vascular disease that have a significant potential for rupture, resulting in life-threatening intraperitoneal hemorrhage. We describe the case of a 33-year-old man who died suddenly and unexpectedly due to the rupture of a splenic artery aneurysm. At medicolegal autopsy, 3000 mL of fluid blood were recovered from the peritoneal cavity. The source of bleeding was a sack-like aneurysm of the splenic artery, measuring 2 cm in diameter. Histologic examination of the splenic artery aneurysm revealed fibromuscular dysplasia. No atherosclerotic lesions or any inflammatory changes were apparent within the wall of the splenic artery. Portal hypertension and pancreatitis, previously described as important factors promoting splenic artery aneurysm formation, were excluded by autopsy and histology. From the forensic pathologist's viewpoint, this rare case underlines the importance of splenic artery aneurysm rupture as a relevant differential diagnosis of intraperitoneal hemorrhage and sudden death, respectively, since such cases may be misinterpreted as a result of blunt-force trauma.
The human entorhinal region consists of a number of areas; however, there is no generally accepted nomenclature for these cytoarchitectonic fields, and the designation of its constituent layers or strata is a matter of controversy. Here, we consider a hitherto neglected adjacent field, the preamygdaloid claustrocortex. Its medial subfield has a small common border with the rostromedial entorhinal region (width maximal 2 mm). Both fields are cytoarchitectonically rather similar. The rostromedial oral entorhinal field lacks ascending terminal islands. Its unusually small pre-alpha cells are arranged in a thin band or small clusters consisting of pyramidal, triangular, or polymorphic cells. The conspicuous chromophilic pre-beta cell clusters are composed of a variety of cell types, including groups of ‘immature’ spindle-shaped or bipolar nerve cells. Furthermore, a rare sulcus within the entorhinal region (central sulcus of the entorhinal region: observed in 4% of the 450 brains examined) is associated with an unusual lamination of the entorhinal layers in its wall and floor. Both the specific shape and arrangement of neurones in the claustrocortical-rostral entorhinal border region and the unusual lamination within the rare central entorhinal sulcus are regarded as reflecting neurodevelopmental disturbances characteristic of schizophrenic brains. In contrast, our observations in a large sample of serially sectioned brains from controls, schizophrenics, and patients suffering from neuropsychiatric diseases other than schizophrenia do not support this assumption.
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