Morphological aspects of the euphonic voice

The high quality of a euphonic voice is the result of complex interactions between many organs and systems. Vibrating vocal folds play a crucial role in this process. Their physiological motion is conditioned by the presence of the layered structure of laryngeal mucosa. In this study, we assessed the degree of dysphonia according to the Union of European Phoniatrics (UEP) scale. Videoendoscopy (VLS) and videostroboscopic (VLSS) examination of the larynx was used to visualize the vibration of the vocal folds. Morphological assessment of the inter-membranous part of the vocal fold mucosa was carried out using material collected after surgical treatment (60%) or obtained from autopsy (40%). The samples were examined by light microscopy and transmission electron microscopy. In euphonic voices, 1° of dysphonia (UEP) and the physiological endoscopic (VLS) and stroboscopic (VLSS) findings of vocal folds were registered. No morphological or ultramorphological changes were observed in the cells of the multilayered flat epithelium, basal membrane or in the stroma. Unchanged epithelial cells were situated on the basal membrane with folds. Moreover, numerous pericytes, vessels with multiplication of basal membranes, scanty collagenous fibers, plasmatic cells and lymphocytes were seen. Morphological changes with signs of atrophy and polypoid degeneration of the vocal fold mucosa were found in only 3 (15%) patients.     

Morphological aspects of the hypothalamic-hypophyseal system

Summary Enzyme-histochemical methods were used to study the metabolic activity of specialized ependyma of the ventrolateral walls and floor of the third ventricle in young male and female rats during the critical period of sexual differentiation of the hypothalamus (one week after birth). Histochemical tests were conducted for glutamic dehydrogenase, lactic dehydrogenase, glucose-6-phosphate dehydrogenase, glycerophosphate dehydrogenase and NADH₂-dehydrogenase. Enzyme activity was judged by cytospectrophotometry. All the data were treated statistically.It was found that the specialized ependyma of the ventrolateral wall and floor of the third ventricle (median eminence) in rats differed in their enzyme behaviour in males and females during the critical period of sexual differentiation of the hypothalamus. At the level of the arcuate nucleus ( ²-tanycytes) and the medial part of the median eminence ( ²-tanycytes) the ependyma was characterized by similar indices of metabolic activity in males and females in the decisive terms of the critical period (days 3, 5, and 7). On day 5 metabolic activity of these cells was reduced both in the males and in the females. Prominent sexual differences in the intensity of the enzyme reactions studied were noted in the ependyma of the lateral parts of the median eminence ( ¹-tanycytes) in the critical period. On day 5 metabolic activity of ¹-tanycytes was reduced in males and increased in females. It is suggested that these differences are caused by the receptor nature of ¹-tanycytes and suggest their implication in the mechanisms of sexual differentiation of the hypothalamus.     

Morphological aspects of the hypothalamic-hypophyseal system

Summary The vascularity of the hypothalamus in rats, cats, and dogs was studied with various injection methods. Particular attention was paid to the capillary architecture of the hypothalamus. The density of the capillary bed in the nuclei of the anterior and medial hypothalamus was studied in male albino rats after filling the cerebral vessels with 5 per cent India ink—gelatin mass. The data obtained were compared with the magnitude-S (projection areas of the capillary meshes of the three-dimensional meshwork) distributions and with the calibres of the capillaries. Distinct inverse correlations were demonstrated between these indices. The objective tests used provided evidence that the peculiar features of the capillary architecture in the various nuclei of the anterior and medial hypothalamus are closely connected with the degree of their vascularity. The rich vascularity of the neurosecretory nuclei is discussed in connection with the peculiarities of their metabolism.The author wishes to express his sincere gratitude to Prof. S. M. Blinkov for valuable advice, to Dr. V. I. Prilutsky for the help received from him in biometric treatment and mathematical analysis of the data obtained, and to Natalia Samushkina and Galina Yankova for their helpful technical assistance.     

Morphological aspects of the hypothalamic-hypophyseal system

Summary The reaction of neural structures of the medial basal hypothalamus (MBH) to its complete deafferentation was studied in male rats by means of enzyme-histochemical and histoautoradiographic methods. Particular attention was paid to nerve cells of the arcuate nucleus and to the tanycytes. The metabolic activity of these cells increased upon the whole.According to the indices of metabolic activity in normal conditions and following deafferentation, the authors distinguish among the ependymal cells of the recessus infundibularis in rats, -tanycytes, which correspond to the ependymal lining at the level of the arcuate nucleus, and -tanycytes, which correspond to the ependyma of the median eminence. In normal conditions both were marked by a sufficiently high level of metabolism, which did not exclude the possibility of protein synthesis. Following deafferentation, -tanycytes seemed most reactive. The most active elements among the -tanycytes were the ependymal cells of the lateral part of the median eminence (¹-tanycytes).The metabolic peculiarities of the nerve cells of the arcuate nuclei and the tanycytes, revealed in normal conditions and after deafferentation, are discussed in connection with the modern concepts of the role of these cells in hypothalamic-hypophyseal transmission.     

Effect of hydrazine deproteination on bone mineral phase: a critical view

Over the last 30 years several techniques have been developed to separate bone matrix and bone mineral, in order to allow for a study of each component independently of the other. Preservation of original characteristics of the phase studied after isolation has always been a great challenge for all such techniques. The hydrazine deproteination procedure, first proposed by Termine, has been one of the processes most widely used for studying bone mineral. It is found to be one of the most effective, notwithstanding controversy over its efficiency in bone deproteination and criticism regarding possible changes it could make to the characteristics of bone mineral. In this work, we have studied the possible chemical and physical alterations caused by the hydrazine deproteination process to bone mineral from rats and to other materials of biological interest. Materials were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray diffractometry (XRD), inductive coupled plasma-optical emission spectroscopy (ICP-OES), C-H-N analysis and infrared spectroscopy (FTIR), before and after hydrazine deproteination. Finally, here we present a comprehensive discussion on the criticism of hydrazine deproteination. The experimental results obtained in this work, even when compared to the results in the literature, show that most widespread criticism to the hydrazine deproteination process is not completely justified.     

Morphological and functional aspects of the temporal bone articular tubercle morphology inHomo erectus andHomo sapiens

The morphological variability of the temporal articular tubercle was studied inHomo erectus andHomo sapiens. Five configurations have been defined. There is a high heterogeneity amongHomo erectus. The Neandertal lineage and that leading toHomo sapiens sapiens are more homogenous, each of them exhibits a high frequency of one configuration. This study has also focused on the functional implications of this variation. A theoretical approach to two different configurations of the articular tubercle is considered in the same bony, muscular and ligamentary context. This suggests that the configuration which consists of a transverse concavity is, for the mandible depression, concomitant with a slight functional disadvantage in comparison with the cylindrical configuration. It appears that a midfacial projection allows for a compensation of this disadvantage. It is concluded that this model can be proposed for Neandertals which present a very concave articular tubercle and a typical midfacial projection.     

Morphological aspects of the science of human ecology

Human ecology is the science on interaction of the man with the environment including the social surrounding. In the human ecological morphology biogenic and sociogenic peculiarities are distinguished; they are formed in the phylo- or ontogenesis. Peculiarities of the body integument, proportions, development of the fat component of the body mass etc. are related with the biogenic signs of the phylogenic origin, since they are connected with life in certain climato-natural conditions. These signs have certain analogues among Mammalia. The sociogenic signs of the phylogenic origin include complexes of bepedality, labour and informative-speech activity. They are characteristic for the human being only. The sociogenic peculiarities of the ontogenic origin include certain changes of the organism connected with professional and sporting activities. According to the human organism state, observed in dynamics, it is possible to judge on biogenic and sociogenic consequences of the environmental influences. For this purpose the data of anthropometric observations in newborn are considered to be important. The role of the biogenic changes is followed in the example of shifts of the body dimensions in time, connected with the solar activity cycles; the sociogenic changes are considered in an example of growth processes under conditions of different gas-pollution of the atmosphere with industrial waste.     

Morphological aspects of muscle fiber regeneration

Although striated muscle displays remarkable regenerative potential, the three-dimensional cytoarchitecture of the regenerated myofibers is different from that of myofibers formed during fetal development. It has been demonstrated with spaced, serial ultrathin sections that the regenerating myotubes that occur spontaneously (i.e., without secondary trauma) in dystrophic (dy2J) murine muscle and the regenerating fibers found in free whole-muscle transplants of normal, murine extensor digitorum longus muscles branch and recombine, forming a complex syncytium. Multiple motor end-plate regions are observed on the branched syncytia found in dystrophic muscle. Branched fibers persist in long-term grafts and are found with a frequency that indicates that they should be of physiological significance. Although the number of myofibers found in long-term grafts is approximately 68% of that found in control muscle, comparison of the diameter distributions of the regenerated muscle fibers with age-matched control fibers indicates that many of the regenerating fibers fail to achieve normal size. Type IIb fibers appear to be more growth inhibited than type IIa fibers. The size of the motoneuron pool to grafted muscles is smaller than that to control muscles.     

Morphological aspects of oligomeric protein structures

Features of multimeric proteins are reviewed to shed light on the formation of protein assemblies from a structural perspective. The features comprise biochemical and geometric properties. They are compiled on new low-redundancy sets of crystal structures of homomeric proteins with different symmetry and subunit multiplicity, as well as on a set of heteromeric proteins. Crystal structures of likely monomers provide a control group.     

Morphological aspects of the pharyngeal hypophysis in human embryos

In human embryos the hypophyseal sac (Rathke's pouch) originates at the roof of the mouth until stage 15 as a broad rim. As the mandibular arch and the maxillary swelling enhance the mesodermal masses in forming the early palatal shelves the rim is reduced to a cleft of about 0.2 mm in broadness in stage 17. From stage 18 up to stage 23 there is a prominent papilla in the midline of the mouth's roof which later on may become recanalized. The different SEM-aspects of the pharyngeal hypophysis are demonstrated.     

Morphological and molecular aspects of cancerogenesis in the lung

Morphology and some molecular aspects of hyperplastic (bronchial basal cell hyperplasia and alveolar cell hyperplasia), metaplastic (squamous metaplasia), preneoplastic and early neoplastic (dysplasia in squamous metaplasia, cancer in situ and atypical alveolar cell hyperplasia) changes were studied in 180 lungs resected due to non-small cell lung cancer: 106 cases (58.9%) of squamous cell carcinoma, 42 (23.3%) of adenocarcinoma and 32 (17.8%) of large cell carcinoma. P53 protein and PCNA expressions were detected immunohistochemically (using formalin-fixed, paraffin-embedded sections). DNA extracted from the microdissected P53-positive cells was analysed for point mutations in the P53 gene. No P53 immunostaining was observed in normal mucosa, hyperplasia of basal cells, squamous metaplasia without and with minor and moderate dysplasia of bronchial mucosa as well as alveolar cell hyperplasia. Overexpression of P53 protein occurred in 3 out of 12 (25%) cases of severe bronchial dysplasia, 5 out of 11 (45.5%) cases of intraepithelial carcinoma and 6 out of 45 (13.3%) cases of alveolar cell hyperplasia. Using direct sequencing, mutations in the P53 gene were detected in 11 out of 14 (87%) P53-immunopositive samples, including all severe dysplasias, all carcinomas in situ and 3 of 6 alveolar cell hyperplasias. A significant association was observed between PCNA expression and preinvasive as well as invasive lesions. The data clearly show that lung resected due to primary cancer ought to be treated as "field cancerization" in which one can find early morphologic events of multi-step cancerogenesis. P53 protein alterations and P53 gene mutations can occur before invasion and its frequency depends on the degree of dysplasia.