scholarly journals Age-related characteristic of human intervertebral discs from normal anatomy’s point of view

2021 ◽  
Vol 102 (1) ◽  
pp. 30-38
Author(s):  
V V Makarova ◽  
M V Volchihin

Aim. To compare morphological characteristics between anterior and posterior parts of human intervertebral discs, taking into account age. Methods. Fragments of 36 intervertebral discs C5C6, D5D6, L5S1 anterior parts taken from deceased persons aged 34 to 94 years, median age 61.0 (50.5; 71.8) years were examined. The comparison group consists of histopathological material obtained from 12 patients with radicular syndrome during planned L5S1 microdiscectomies aged 3577 years, median age 48.5 (43.0; 58.8) years. There were no statistically significant differences in age between the studied groups (p=0.126023). All materials were divided into subgroups depending on the age of the deceased/operated: 3452 and 6094 years for material obtained from the deceased; 3551 and 5877 years for material obtained after surgery. The differences between the three groups were examined by the KruskalWallis test, and quantitative indicators in the two groups were compared by MannWhitney U-test. Results. In the anterior part of the intervertebral discs, signs of degenerative-dystrophic changes were noted in all studied samples. All samples of nucleus pulposus and annulus fibrosus were fibrocartilage with no inflammation. Statistically significant differences (р=0.0283) were obtained in the number of isogenous groups of chondrocytes in intervertebral discs C5C6 anterior part compared with D5D6, L5S1 in individuals aged 3452. Age subgroups (3452 and 6094 years old) differed significantly (р=0.0219) in the number of single chondrocytes according to results of morphometry of anterior part of intervertebral discs L5S1. Anterior and posterior parts of intervertebral discs L5S1 differed statistically significant in the number of isogenous groups of chondrocytes when comparing the subgroup of operated patients aged 3551 years (р=0.008475) with the subgroup of deceased persons aged 3452 years and the subgroup of operated patients aged 5877 years (р=0.033753) with the subgroup of deceased aged 6094 years. Conclusion. Anterior and posterior part of intervertebral discs L5S1 had similar qualitative histological characteristics; however, the number of isogenous groups of chondrocytes in the posterior part of intervertebral discs L5S1 samples indicated a greater effect of compression loading compared to anterior part of the same spinal motion segment.

Author(s):  
E.K. Tsyrenzhapova ◽  
◽  
O.I. Rozanova ◽  
O.I. Mikova ◽  
A.A. Ivanov ◽  
...  

Purpose. To analyze the topographical features of the relief of anterior and posterior corneal surfaces in patients with myopia in the long-term period after anterior radial keratotomy (ARK). Material and methods. We examined 132 patients with age-related cataracts of varying degrees of density and a history of myopia with previously performed ARK. Mean age of patients was 59.67±6.09 (from 47 to 76). In the control group, 30 patients of the same age group with myopia were examined. A comprehensive examination was performed, including optical biometry, keratotopography on the Pentacam HR device with the determination of the elevation points of the anterior and posterior corneal surfaces. Results. The corneal profile differed from the correct spherical configuration in the control group. The average deviation of the profile of the anterior part of the cornea from the BFS was (–)1.41±5.10 µm, the posterior part was (–)5.12±12.25 µm (p=0.0001). The profile of the posterior corneal surface had a pronounced prolapse in the paracentral area with positive elevation values in the lower-outer segment. Negative values were found in the upper and lower sectors in the peripheral area and positive values were found in the inner and outer sectors. The corneal profile was deformed in patients after ARK. Negative elevation values in the central and paracentral area and positive elevation values in the peripheral segments corresponding to its protrusion were noted. At the same time, the relief of anterior and posterior surfaces of the cornea was not regular. Prolapse from the posterior surface of the cornea in the peripheral area was more pronounced than its anterior surface (p=0.0001). Conclusion. The relief of anterior and posterior corneal surfaces in patients of the control group differs in the degree and topography of elevation. In patients after ARK, obvious topographic deformities of the anterior and posterior corneal profiles were detected. Key words: anterior radial keratotomy, corneal elevation, myopia.


2020 ◽  
Vol 9 (3) ◽  
pp. 9-15
Author(s):  
I. V. Gaivoronskii ◽  
M. V. Markeeva ◽  
O. Yu. Aleshkina ◽  
N. V. Tarasova

The aim of the study was to describe morphometric characteristics of the posterior parts of the nasal cavity in different periods of childhood and to specify the age-related norm for improving surgical treatment options of choanal atresia and providing an optimal access to the anterior part of the skull base. Material and methods. The study included 87 children aged 1-21 who were exposed to craniometry of the nasal cavity structures. Results. The age-related variability of the linear dimensions and shape of the choanae, their relationship with the dimensions of the pyriform aperture and the height of the nasal cavity in the posterior part were defined in the study. The increase in the height of the choanae and the height of the nasal cavity at the back starts from 2– 3 years of age, and the width – from 8–12 years of age. The height and width of the pyriform aperture are equal to the age of 8–12; these parameters increase in older children's groups with a predominance of the height over the width. The height of the nasal cavity at the back increases in all age periods. The growth of the studied structures of the nasal cavity is completed by adolescence. In infancy, the height of the choanae is less than the height of the nasal cavity at the back by 45%, and less than the height of the pyriform aperture by 20%; in adolescence, these ratios are 42% and 23%, respectively. In infancy the choanal width is less than the width of the pyriform aperture by 49%, and in adolescence – by 40%. In infancy and early childhood, the choanae are typically small in height and width. Their shape is round in 25% of cases, however, ovoid shape is also found. The height and width of the pyriform-shaped aperture at these age periods are similar and do not exceed 17–18 mm; the height of the nasal cavity at the back is 25–27 mm. Conclusion. The authors have described age-related morphometric features of the posterior structures of the nasal cavity. These features should be taken into account by otorhinolaryngologists and neurosurgeons when planning endoscopic intranasal surgical access in children. The younger the child is, the more difficult it is to perform a surgery due to the significant restriction of the access resulted from the small size of the piriform opening and the nasal cavity, and the obstinacy of the nasal septum. When performing choanotomy for atresia, it is necessary to form the choana comparing it in shape and size with the age-related norm


Author(s):  
Len Wen-Yung ◽  
Mei-Jung Lin

Four cone-shaped rectal papillae locate at the anterior part of the rectum in Dacus dorsalis fly. The circular base of the papilla protrudes into the haemolymph (Fig. 1,2) and the rest cone-shaped tip (Fig. 2) inserts in the rectal lumen. The base is surrounded with the cuticle (Fig. 5). The internal structure of the rectal papilla (Fig. 3) comprises of the cortex with the columnar epithelial cells and a rod-shaped medulla. Between them, there is the infundibular space and many trabeculae connect each other. Several tracheae insert into the papilla through the top of the medulla, then run into the cortical epithelium and locate in the intercellular space. The intercellular sinuses distribute in the posterior part of the rectal papilla.The cortex of the base divides into about thirty segments. Between segments there is a radial cell (Fig. 4). Under the cuticle, the apical cell membrane of the cortical epithelium is folded into a regular border of leaflets (Fig. 5).


Author(s):  
I. R. Khuzina ◽  
V. N. Komarov

The paper considers a point of view, based on the conception of the broad understanding of taxons. According to this point of view, rhyncholites of the subgenus Dentatobeccus and Microbeccus are accepted to be synonymous with the genus Rhynchoteuthis, and subgenus Romanovichella is considered to be synonymous with the genus Palaeoteuthis. The criteria, exercising influence on the different approaches to the classification of rhyncholites, have been analyzed (such as age and individual variability, sexual dimorphism, pathological and teratological features, degree of disintegration of material), underestimation of which can lead to inaccuracy. Divestment of the subgenuses Dentatobeccus, Microbeccus and Romanovichella, possessing very bright morphological characteristics, to have an independent status and denomination to their synonyms, has been noted to be unjustified. An artificial system (any suggested variant) with all its minuses is a single probable system for rhyncholites. The main criteria, minimizing its negative sides and proving the separation of the new taxon, is an available mass-scale material. The narrow understanding of the genus, used in sensible limits, has been underlined to simplify the problem of the passing the view about the genus to the other investigators and recognition of rhyncholites for the practical tasks.


2020 ◽  
Vol 13 (4) ◽  
pp. 283-290 ◽  
Author(s):  
Vamshi Krishna Rapalli ◽  
Srividya Gorantla ◽  
Tejashree Waghule ◽  
Arisha Mahmood ◽  
Prem Prakash Singh ◽  
...  

Age-related Macular Degeneration (AMD) is one of the common diseases affecting the posterior part of the eye, of a large population above 45 years old. Anti-Vascular Endothelial Growth Factor- A (Anti-VEGF-A) agents have been considered and approved as therapeutic agents for the treatment of AMD. Due to the large molecular weight and poor permeability through various eye membranes, VEGF-A inhibitors are given through an intravitreal injection, even though the delivery of small therapeutic molecules by topical application to the posterior part of the eye exhibits challenges in the treatment. To overcome these limitations, nanocarrier based delivery systems have been utilized to a large extent for the delivery of therapeutics. Nanocarriers system offers prodigious benefits for the delivery of therapeutics to the posterior part of the eye in both invasive and non-invasive techniques. The nano size can improve the permeation of therapeutic agent across the biological membranes. They provide protection from enzymes present at the site, targeted delivery or binding with the disease site and extend the release of therapeutic agents with prolonged retention. This leads to improved therapeutic efficacy, patient compliance, and cost effectiveness of therapy with minimum dose associated side-effects. This review has summarized various nanocarriers explored for the treatment of AMD and challenges in translation.


2021 ◽  
Vol 11 (14) ◽  
pp. 6300
Author(s):  
Igor Smolyar ◽  
Daniel Smolyar

Patterns found among both living systems, such as fish scales, bones, and tree rings, and non-living systems, such as terrestrial and extraterrestrial dunes, microstructures of alloys, and geological seismic profiles, are comprised of anisotropic layers of different thicknesses and lengths. These layered patterns form a record of internal and external factors that regulate pattern formation in their various systems, making it potentially possible to recognize events in the formation history of these systems. In our previous work, we developed an empirical model (EM) of anisotropic layered patterns using an N-partite graph, denoted as G(N), and a Boolean function to formalize the layer structure. The concept of isotropic and anisotropic layers was presented and described in terms of the G(N) and Boolean function. The central element of the present work is the justification that arbitrary binary patterns are made up of such layers. It has been shown that within the frame of the proposed model, it is the isotropic and anisotropic layers themselves that are the building blocks of binary layered and arbitrary patterns; pixels play no role. This is why the EM can be used to describe the morphological characteristics of such patterns. We present the parameters disorder of layer structure, disorder of layer size, and pattern complexity to describe the degree of deviation of the structure and size of an arbitrary anisotropic pattern being studied from the structure and size of a layered isotropic analog. Experiments with arbitrary patterns, such as regular geometric figures, convex and concave polygons, contour maps, the shape of island coastlines, river meanders, historic texts, and artistic drawings are presented to illustrate the spectrum of problems that it may be possible to solve by applying the EM. The differences and similarities between the proposed and existing morphological characteristics of patterns has been discussed, as well as the pros and cons of the suggested method.


2017 ◽  
Vol 4 (12) ◽  
pp. 171288 ◽  
Author(s):  
Alexander L. Vereshchaka ◽  
Anastasia A. Lunina ◽  
Jørgen Olesen

Species within Gennadas differ from each other largely only in male (petasma) and female (thelycum) copulatory characters, which were restudied in scanning electron microscopy and used as a basis for phylogenetic analyses. Twenty-six petasma characters and 49 thelycum characters were identified. All 16 recognized species of Gennadas and Aristaeomorpha foliacea (outgroup) were included as terminals. Four robust monophyletic clades were retrieved, described and diagnosed as new species groups. The thelycum characters had greater impact on tree topology and supported deeper nodes than did the petasma characters. We hypothesize that features of the thelycum evolved first followed by aspects of the petasma. Relatively more conservative characters include parts of the sternites of the thelycum and of the petasma, while the scuti and protuberances on the thelycum and the shape and subdivisions of the petasma lobes are evolutionarily plastic. We identified two groups of copulatory characters, which are likely coupled functionally and interlinked evolutionarily: (i) the external part of the petasma and the posterior part of the thelycum and (ii) the internal part of the petasma and anterior part of the thelycum. We reconstruct possible mating position during copulation for each of the new species groups presented here. We also present an updated key to genera of Benthesicymidae and key to species of Gennadas .


Development ◽  
1994 ◽  
Vol 120 (5) ◽  
pp. 1137-1150 ◽  
Author(s):  
R. Reuter ◽  
M. Leptin

Two zygotic genes, snail (sna) and twist (twi), are required for mesoderm development, which begins with the formation of the ventral furrow. Both twi and sna are expressed ventrally in the blastoderm, encode transcription factors and promote the invagination of the ventral furrow by activating or repressing appropriate target genes. However, sna and twi alone do not define the position of the ventral furrow, since they are also expressed in ventral cells that do not invaginate. We show that huckebein (hkb) sets the anterior and the posterior borders of the ventral furrow, but acts by different modes of regulation. In the posterior part of the blastoderm, hkb represses the expression of sna in the endodermal primordium (which we suggest to be adjacent to the mesodermal primordium). In the anterior part, hkb antagonizes the activation of target genes by twi and sna. Here, bicoid permits the co-expression of hkb, sna and twi, which are all required for the development of the anterior digestive tract. We suggest that mesodermal fate is determined where sna and twi but not hkb are expressed. Anteriorly hkb together with sna determines endodermal fate, and hkb together with sna and twi are required for foregut development.


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