Local Thickenings Research Articles

Ultrasound Imaging of Ankle Retinacula: A Comprehensive Review.

The retinacula of the ankle are specialized anatomical structures characterized by localized thickenings of the crural fascia that envelop the deep components of the lower leg, ankle and foot. The ankle retinacula include the extensor retinacula, the peroneal retinacula and flexor retinaculum. Despite their potential to explain persistent and unexplained pain following an injury, these structures are often overlooked or incorrectly diagnosed. Hence, this comprehensive review was performed aiming to investigate the use and the methodology of US imaging to assess ankle retinacula. The search was performed on PubMed and Web of Science databases from inception to May 2024. The MeSH keywords used were as follows: "Ankle Retinacula", "Foot Retinacula", "Superior extensor retinaculum", "Inferior extensor retinaculum", "peroneal retinaculum", "superior peroneal retinaculum", "inferior peroneal retinaculum", "flexor retinaculum", "Ultrasound Imaging", "Ultrasound", "Ultrasonography" and "Ultrasound examination". In total, 257 records underwent screening, resulting in 22 studies meeting the criteria for inclusion after the process of revision. Data heterogeneity prevents synthesis and consistent conclusions. The results showed that advanced US imaging holds promise as a crucial tool to perform an US examination of ankle retinacula, offering static and dynamic insights into ankle retinacula pathology. Understanding normal anatomy and US imaging is essential for accurately identifying injuries. Future research should focus on clinical trials to validate parameters and ensure their reliability in clinical practice.

Alterations in the Anatomy and Ultrastructure of Leaf Blade in Norway Maple (Acer platanoides L.) Growing on Mining Sludge: Prospects of Using This Tree Species for Phytoremediation.

Alterations in leaf architecture can be used as an indicator of the substrate toxicity level as well as the potential of a given plant species in the phytoremediation of polluted areas, e.g., mining sludge. In this work, we demonstrated, for the first time, the nature and scale of alterations in leaf architecture at the tissue and cellular levels occurring in Norway maple growing on mining sludge originating from a copper mine in Lubin (Poland). The substrate differs from other mine wastes, e.g., calamine or serpentine soils, due to an extremely high level of arsenic (As). Alterations in leaf anatomy predominantly included the following: (1) a significant increase in upper epidermis thickness; (2) a significant decrease in palisade parenchyma width; (3) more compact leaf tissue organization; (4) the occurrence of two to three cell layers in palisade parenchyma in contrast to one in the control; (5) a significantly smaller size of cells building palisade parenchyma. At the cellular level, the alterations included mainly the occurrence of local cell wall thickenings-predominantly in the upper and lower epidermis-and the symptoms of accelerated leaf senescence. Nevertheless, many chloroplasts showed almost intact chloroplast ultrastructure. Modifications in leaf anatomy could be a symptom of alterations in morphogenesis but may also be related to plant adaptation to water deficit stress. The occurrence of local cell wall thickenings can be considered as a symptom of a defence strategy involved in the enlargement of apoplast volume for toxic elements (TE) sequestration and the alleviation of oxidative stress. Importantly, the ultrastructure of leaf cells was not markedly disturbed. The results suggested that Norway maple may have good phytoremediation potential. However, the general shape of the plant, the significantly smaller size of leaves, and accelerated senescence indicated the high toxicity of the mining sludge used in this experiment. Hence, the phytoremediation of such a substrate, specifically including use of Norway maple, should be preceded by some amendments-which are highly recommended.

Metabolism and Microstructure of the Small Intestine Wall in Patients With Colorectal Cancer

RELEVANCE In patients with colorectal cancer (CRC), the normal small intestine, located outside the pathological focus, undergoes changes that may be the cause of digestive dysfunction after radical surgery to remove the tumor.The assessment of metabolic and microstructural changes in the ileum mucosa in patients with colorectal cancer is necessary to correct the algorithms of postoperative therapy and enteral nutrition. Modern means of optical bioimaging are potentially capable of solving this complex diagnostic problem.AIM OF STUDY To study the features of metabolism and morphological structure of the wall of a conditionally normal small intestine in the mucosa in patients with stage 1–3 CRC using macro- FLIM and optical coherence tomography (OCT).MATERIAL AND METHODS The object of the study was the wall of the ileum (66 samples) from the mucosal side of patients with histologically confirmed CRC stages 1–3 with tumor location in the right sections of the colon. Eight samples were obtained from patients with stage 1 CRC, 38 samples were obtained from patients with stage 2 and 20 samples were obtained from patients with stage 3 tumor. The volume of surgical intervention is right-sided hemicolectomy with total mesocolonectomy, CME (D2 lymph node dissection). Fresh tissue samples were examined using fluorescent lifetime macroimaging (macro-FLIM ) and OCT, followed by histological analysis of the material.RESULTS According to a histological study in the small intestine of patients with stage 1 CRC, the mucosa is covered with a normal single-layer prismatic border epithelium. In the intestine samples of patients with stage 2 CRC, mucus hypersecretion with areas of fibrosis and vascular congestion was observed. At the 3rd stage of CRC, the mucous membrane of the small intestine was loose, with local thickenings, areas of fibrosis with severe leukostasis, and foci of atrophy. None of the samples showed histological signs of a malignant tumor.According to OCT data, in the mucous membrane of the small intestine in patients with the 1st and 2nd stages of CRC, the contours of the villi and, partially, the crypts were well visualized. The structure of the villi was smooth, not coarse, and the shape was regular. In patients with stage 3 CRC, the contours of the crypts and villi were indistinct. There were no differences in the OCT picture between histologic preparations in the 1st and 2nd stages of CRC: the structure of the villi of the small intestine was clear, the shape was unchanged. According to FLIM data, statistically significant differences were revealed in the mean fluorescence lifetime values of reduced nicotinamide dinucleotide (phosphate) NAD(P)H (τm) between 2nd and 3rd (p=0.031), 1st and 3rd (p=0.018) by CRC stages. At the 1st stage of CRC τm was 1.61 [1.30; 2.02] ns, at the 2nd stage 1.50 [1.36; 1.73] ns, at the 3rd stage 1.37 [1.22; 1.51] ns. The FLIM results suggest an increase in the role of glycolysis in enterocyte energy metabolism along with progression of the CRC stage.CONCLUSION In patients with cancer of the right colon, lesions of the microstructure of the mucous membrane were revealed in the ileum not affected by the malignancy. At the same time, the severity of microstructural disorders in the wall of the small intestine is associated with the stage of tumor development in the colon. Bioimaging technologies, namely, methods of optical coherence tomography and fluorescence lifetime macroimaging, made it possible to objectively display microstructural and metabolic disorders in the ileum wall. The data of optical colorectal tomography demonstrated differences in the structural picture of the intestinal villi in patients with stages 1–2 and 3 of colorectal cancer. Results of fluorescence lifetime macroimaging of the metabolic cofactor nicotinamide dinucleotide (phosphate) confirmed an increase in the role of glycolysis in the energy metabolism of enterocytes along with an increase in the stage of colorectal cancer. The identified disorders in the state of the small intestine develop in patients with colorectal cancer before surgery and are highly likely to be an important pathogenetic link of malabsorption in the postoperative period. If the hypothesis is confirmed, the developed algorithm for the complex diagnosis of microstructural and metabolic disorders in tissues will expand the possibilities for the rehabilitation of patients with cancer of the right colon.

Transcriptomic landscape of early hair follicle and epidermal development

Morphogenesis of ectodermal organs, such as hair, tooth, and mammary gland, starts with the formation of local epithelial thickenings, or placodes, but it remains to be determined how distinct cell types and differentiation programs are established during ontogeny. Here, we use bulk and single-cell transcriptomics andpseudotime modeling to address these questions in developing hair follicles and epidermis and produce a comprehensive transcriptomic profile of cellular populations in the hair placode and interplacodal epithelium. We report previously unknown cell populations and marker genes, including early suprabasal and genuine interfollicular basal markers, and propose the identity of suprabasal progenitors. By uncovering four different hair placode cell populations organized in three spatially distinct areas, with fine gene expression gradients between them, we posit early biases in cell fate establishment. This work is accompanied by a readily accessible online tool to stimulate further research on skin appendages and their progenitors.

Double Puzzle: Morphogenesis of the Bi-Layered Leaf Adaxial Epidermis of Magnolia grandiflora.

Anticlinal ordinary epidermal cell wall waviness is a widespread feature found in the leaves of a variety of land plant species. However, it has not yet been encountered in leaves with multiple epidermides. Surprisingly, in Magnolia grandiflora leaves, ordinary epidermal cells in both layers of the bi-layered adaxial epidermis exhibit wavy anticlinal contour. During the development of the above cells, cortical microtubules are organized in anticlinally oriented bundles under the anticlinal walls, and radial arrays extending from the bundles at the edges of anticlinal and external periclinal walls, under the external periclinal walls. This microtubule pattern is followed by cell wall reinforcement with local thickenings, the cellulose microfibrils of which are parallel to the underlying microtubules. This specialized microtubule organization and concomitant cell wall reinforcement is initiated in the external epidermal layer, while hypodermis follows. The waviness pattern of each epidermal layer is unrelated to that of the other. The above findings are discussed in terms of morphogenetic mechanism induction and any implications in the functional significance of ordinary epidermal cell waviness.

Doppler and clinical characteristic of cephalgia in patients with arterial hypertension during intermittent fasting

There were examined 142 patients with recurrent headache (cephalgia) and arterial hypertension, a mean – 49.26±1.33 years, of whom 69 men, 73 women who used intermittent fasting (patients spent 24 hours without food, 1 time per week, four repetitions). The control group consisted of 32 people of comparable age without hypertension (n=32; mean age 51.0±1.99 years). The purpose of the study was to increase the effectiveness of diagnostic and therapeutic methods in patients with hypertension and headache by establishing the meaning and peculiarities of the influence of intermittent fasting on headaches, neck carotid and intracranial circulation. There were 51 (35.9%±4.03) patients aged 25-44 years’; 45-59 years – 42 (29.58%±3.83) patients; 60-75 years – 49 (34.51%±3.99) patients. It was found that the structural pathology of the main arteries of the head consisted mainly in the thickening of the intima-media from 0,8 to 1,4 mm in 62.7% at the age of 25-44 years; in 71,4% at the age of 45-59; in 51% at the age of 60-75 years. Local thickenings in the bifurcation zone from 1.5 mm without hemodynamically significant stenosis were found in 9.8% at the age of 24-44 years, in 28.6% at the age of 45-59 years and in 49% at the age of 60-75 years. Statistical differences in linear circulatory velocity between the control group and the group of patients were significant already at the age of 25-44 years, for peak systolic velocity in the internal carotid artery (78.03±4.67 vs. 61.0±2.54 in control, p<0.05). At the age of 45-59 years, linear circulatory velocity affected all carotid and vertebral arteries, as in the group aged 60-75. The effect of intermittent fasting on aged hemodynamics consists mainly in changes of velocity of flow in arteries with better results in younger patients. Changes in the elastic-tonic characteristics of the main arteries of the head according to the index of resistance (index was 0.72±0.01 for common carotid artery and 0.63±0.01 after intermittent fasting in patients at the age of 25-44 years; 0.78±0.01 before and 0.67±0.01 after at the age of 60-75 years were revealed). The use of the intermittent fasting method caused mainly an increase in diastolic flow rates in the main arteries (with age dependences) and a decrease in systolic velocity in the age group 25-44 years. The pathophysiological interpretation of such changes is in the reducing the resistance, values of the main arteries of the head.

Local Thickenings and Thinnings of Hot Rolled Strips

The cross-section profile of the rolled strip is characterized by geometrical parameters such as wedge, convex, difference of thickness, edge wedge and others. Techniques for calculating the values of these parameters are known and generally accepted. However, there are features of the cross-section profile of rolled strips, such as local thickenings/thinnings, the methods of calculating values of which are not common: practically every scientific school of specialists of rolling production use their own techniques, which often produce different results for the same cross-section profiles. The problem of identifying and calculating the local thickenings/thinnings parameters of the rolled strips cross-section profile is to define a so-called “zero level”, the excess/understatement of which is a sign of local thickenings/thinnings. The paper analyzes the accuracy and adequacy of the calculation of the cross-section profile parameters of rolled strips for local thickenings/thinnings. A new method based on statistical methods is proposed. The target function that the thickness distribution across the width of the rolled strip must correspond to is a symmetrical quadratic parabola. However, the actual distribution is always different from the target one for a number of reasons, such as ring wear of the work rolls. In the first step, in the proposed technique, the Walter-Shewhart procedure (control cards) eliminates as emissions of strip thickness values that are dramatically different from the target distribution. But since without excluding the nonlinear (parabolic) component of the measured cross-section profile this procedure cannot be applied, it applies to the first derivative of the cross-section profile thickness distribution function. The result of the developed method is a “zero level” according to which the local thickening/thinning parameters are calculated.

On Adequacy of Parameters of Strip Cross-Section Profile. Part 2. Local Thickenings and Thinnings

On Adequacy of Parameters of Strip Cross-Section Profile. Part 2. Local Thickenings and Thinnings

Fine structure of Drosophila larval salivary gland ducts as revealed by laser confocal microscopy and SEM

The functions of the larval salivary glands (SGs) of Drosophila are traditionally associated with the production of a massive secretion during puparium formation; it is exocytosed into a centrally located lumen and subsequently expectorated via ducts, the pharynx and mouth. This so-called proteinaceous glue serves as an adhesive to attach the puparial case to a solid substrate. Great attention has been paid to the secretory cells of SGs, which are famous for their giant polytene chromosomes. However, substantially less attention has been devoted to individual or common ducts that form the most proximal portion of the SG organ via which the glue is released into the pharynx. In the present paper, we describe the organization and fine structure of the taenidia, highly specialized circumferential ring-like extracellular (cuticular) components on the internal side of these tubes. Two chitin-specific probes that have previously been used to recognize taenidia in Drosophila tracheae, Calcofluor White M2R (also known as Fluorescent Brightener 28) and the novel vital fluorescent dye SiR-COOH, show positively stained ductal taenidia in late larval SGs. As seen using scanning electron microscopy (SEM), the interior of the ductal tube contains regular and densely-arranged ridge-like circumferential rings which represent local thickenings of the cuticle in various geometries. The microtubular arrays that optically colocalize with taenidia in both the trachea and SG ducts are specifically and strongly recognized by fluorescently-conjugated colchicine as well as anti-tubulin antibody. In contrast to taenidia in the tracheae, the analogous structures in SG ducts cannot be detected by fluorescently-labeled phalloidin or even actin-GFP fusion protein, suggesting that the ducts lack a cortical network made of filamentous actin. We speculate that these taenidia may serve to reinforce the duct during the secretory processes that SGs undergo during late larval and late prepupal stages.

On adequacy of parameters of strip cross-section profile. Part 2. Local thickenings and thinnings

At present, the cross-section profile of the rolled strip is characterized by geometrical parameters such as wedge, convex, difference of thickness, displacement of convex, and edge wedge. Some of these parameters are redundant. Techniques for calculating the values of these parameters are known and generally accepted. However, there are features of the cross-section profile of rolled strips, such as local thickenings/thinnings, the methods of calculating values of which are not common: practically every scientific school of rolling scientists or specialists of rolling production use their own techniques, which often produce different results for the same cross-section profiles. The problem of identifying and calculating the local thickenings/ thinnings parameters of the rolled strips cross-section profile is to define a so-called “zero level”, the excess/understatement of which is a sign of local thickenings/thinnings. The paper continues to analyze the accuracy and adequacy of the calculation of the cross-section profile parameters of rolled strips for local thickenings/thinnings. A new method based on statistical methods is proposed. The target function that the thickness distribution across the width of the rolled strip must correspond to is a symmetrical quadratic parabola. However, the actual distribution is always different from the target one for a number of reasons, such as ring wear of the work rolls. In the first step, in the proposed technique, the Walter-Shuhart procedure (control cards) eliminates as emissions of strip thickness values that are dramatically different from the target distribution. But since without excluding the nonlinear (parabolic) component of the measured cross-section profile this procedure cannot be applied, it applies to the first derivative of the cross- section profile thickness distribution function. To determine the “zero level,” after calculating the upper and lower limits of the allowed values of the first derivative, all thicknesses associated with these emissions were eliminated. The result of the repetitive process is a “zero level” according to which the local thickening/thinning parameters are calculated.

On adequacy of parameters of strip cross-section profile. Part 1. Predictive interval

Increasing the level of automation of metallurgical units and the development of industrial information systems increases the number of p ters of production and technological processes available for analysis. The consequence is an increase in the complexity and duration of preliminary data preparation for subsequent mathematical and statistical analysis. It is therefore important to develop new and improve existing techniques for the automated process of primary data production. When developing methods of primary data preparation, it should be taken into account that accuracy and adequacy of results of subsequent mathematical analysis are determined by accuracy and adequacy of used initial data. The cross-sectional profile parameters of hot-rolled strips, such as wedge, convexity, thickness variation, displacement, wedge in near-rim zones, local thickenings and thinning of the strip are calculated parameters, i.e. secondary to actual strip thickness measurements over the length and width of hot-rolled strips. As technology is improved in cold rolling shops, the number of grade groups is increasing, for which technological modes of units and processing routes are selected. They are based on actual values of parameters of cross-section profile in order to further reduce the probability of formation of inappropriate products and increased metal consumption. The presented article provides an overview of conventional calculation methods for parameters of cross-section profile of hot-rolled strip and gives an assessment of accuracy and adequacy of application of the parameters averaged along strip length to the whole strip.

Callose and homogalacturonan epitope distribution in stomatal complexes of Zea mays and Vigna sinensis.

This article deals with the distribution of callose and of the homogalacturonan (HG) epitopes recognized by LM20, JIM5, and 2F4 antibodies in cell walls of differentiating and functioning stomatal complexes of the monocotyledon Zea mays and the dicotyledon Vigna sinensis. The findings revealed that, during stomatal development, in these plant species, callose appears in an accurately spatially and timely controlled manner in cell walls of the guard cells (GCs). In functioning stomata of both plants, callose constitutes a dominant cell wall matrix material of the polar ventral cell wall ends and of the local GC cell wall thickenings. In Zea mays, the LM20, JIM5, or 2F4 antibody-recognized HG epitopes were mainly located in the expanding cell wall regions of the stomatal complexes, while in Vigna sinensis, they were deposited in the local cell wall thickenings of the GCs as well as at the ledges of the stomatal pore. Consideration of the presented data favors the view that in the stomatal complexes of the monocotyledon Z. mays and the dicotyledon V. sinensis, the esterified HGs contribute to the cell wall expansion taking place during GC morphogenesis and the opening of the stomatal pore. Besides, callose and the highly de-esterified HGs allow to GC cell wall regions to withstand the mechanical stresses exerted during stomatal function.

Alterations of root architecture and cell wall modifications in Tilia cordata Miller (Linden) growing on mining sludge

Trees are considered good candidates for phytoremediation of soils contaminated with trace elements (TE), e.g. mine tailings. Using two year-old Tilia cordata plants, we demonstrated the nature and the scale of root architecture, especially root apices, as an indicator of mining sludge toxicity and plant capability to cope with these stress conditions. The novelty of our research is the analysis of the root response to substrate with extremely high concentrations of numerous toxic TE, and the 3D illustration of the disorders in root apex architecture using a clarity technique for confocal microscopy.The analysis demonstrates (1) a marked reduction in the size of the root apex zones (2) the occurrence of vascular tissues abnormally close to the root apex (3) collapse of the internal tissues in many root apices. Simultaneously, at the cellular level we observed some signs of a defensive response - such as a common increase of cell wall (CW) thickness and the formation of local CW thickenings - that enlarge the CW capacity for TE sequestration. However, we also detected harmful effects. Among others, a massive deposition of TE in the middle lamella which caused major damage - probably one of the reasons why the inner tissues of the root apex often collapsed – and the formation of incomplete CWs resulting in the occurrence of extremely large cells. Moreover, many cells of the root apex exhibited degenerated protoplasts.All these alterations indicate the harsh conditions for lime growth and survival and simultaneously, the manifestation of a defensive response.The obtained results allowed us to conclude that analysis of the nature and scale of structural alterations in roots can be useful indicators of plant ability to cope with stress conditions, e.g. in prospect of using the examined plants for reclamation of soils contaminated with TE.

Xanthogranulomatous cholecystitis misdiagnosed as gallbladder carcinoma: an analysis of 42 patients

Objective To study the clinical features of xanthogranulomatous cholecystitis (XGC), and to analyze the difficulties in the differential diagnosis of XGC with gallbladder carcinoma. Methods The clinical data of 42 patients who were diagnosed preoperatively as gallbladder cancer in our hospital from 2008 to 2016 were retrospectively analyzed. Results Of the 42 patients, upper abdominal CT scans were carried out in 38 patients, and MRI examination in 4 patients. Imaging findings showed unclear boundaries between the liver and the gallbladder in 37 patients, and unclear boundaries between the gallbladder and the adjacent tissues in 16 patients. In 11 patients, the regional lymph nodes were enlarged. 22 patients had gallstones. All the 42 patients had gallbladder wall thickness of ≥3 mm. In 27 patients there were diffuse thickenings of the gallbladder wall, while in 15 patients there were only local thickenings. In 35 patients, inhomogeneous enhancement of the gallbladder wall was shown on CT enhancement scanning, and in 11 patients, there were low attenuation nodules in the gallbladder wall. All the 42 patients underwent surgical treatment. During surgery, dissection of the gallbladder triangle was difficult because of dense adhesion of the gallbladder with the surrounding tissues. In 32 patients, the gallbladder was adherent to the omentum, in 16 patients to the duodenum, in 12 patients to the colon, and in 8 patients to the stomach. In 30 patients, intraoperative frozen sections were carried out. Two patients were diagnosed to have early gallbladder cancer (T1a GBC). In 12 patients who did not receive frozen section during operation, 6 patients were subsequently diagnosed to have XGC and 6 patients to have gallbladder cancer. The types of surgical treatment given to these patients were according to the intraoperative diagnosis or frozen sections results. After surgery, one patient each developed surgical site infection in the total cholecystectomy group as well as in the partial cholecystectomy group. In addition, one patient had bile duct injury and another patient had duodenal injury in the total cholecystectomy group. There was one patient who had residual biliary stone in the partial cholecystectomy group. The difference in the postoperative complication rates between the two groups was not significant (P>0.05). Conclusions It is difficult to differentiate XGC from gallbladder cancer based on clinical and imaging findings. The final diagnosis still depends on histopathological examination. Key words: Xanthogranulomatous cholecystitis; Gallbladder carcinoma; Intraoperative frozen-section; Pathology

Sedimentary depocenters on Snowball Earth: Case studies from the Sturtian Chuos Formation in northern Namibia

Cryogenian synglacial deposits are regionally thin but locally thick, considering glacial duration, but the reasons for local thickening are poorly known. We studied three local thickenings of the Sturtian Chuos Formation in northern Namibia by measuring closely spaced columnar sections, not only of the synglacial deposits but also of the bounding pre- and post-glacial strata. This enabled incised paleovalleys filled by glacial debris to be distinguished from morainal buildups. In case 1, a U-shaped paleovalley, ∼450 m deep by ∼3.0 km wide, is incised into pre-glacial strata and 10% overfilled by ice-contact and subglacial meltwater deposits. In case 2, a wedge of glacial diamictite, ~220 m thick by 2.0 km wide, overlies a disconformity that is demonstrably not incised into underlying pre-glacial strata. The wedge, draped by a post-glacial cap carbonate and argillaceous strata, is erosionally truncated at its apex by Marinoan glacial deposits and their basal Ediacaran cap dolomite. The wedge was a positive topographic feature, either a terminal moraine or an erosional outlier of formerly more extensive glacial deposits. In case 3, a wedge of conglomerate, glacial diamictite, and subglacial lake deposits thickens to >2000 m where it abuts against granitoid basement rock uplifted along a border fault. Fault movement ceased before the Sturtian cap carbonate was deposited. The locus of maximum deposition shifted over time from proximal to distal with respect to the border fault, similar to Mesozoic half grabens developed above listric detachments imaged seismically on offshore North Atlantic margins.

Invagination of Ectodermal Placodes Is Driven by Cell Intercalation-Mediated Contraction of the Suprabasal Tissue Canopy.

Ectodermal organs such as teeth, hair follicles, and mammary glands begin their development as placodes. These are local epithelial thickenings that invaginate into mesenchymal space. There is currently little mechanistic understanding of the cellular processes driving the early morphogenesis of these organs and of why they lead to invagination rather than simple tissue thickening. Here, we show that placode invagination depends on horizontal contraction of superficial layers of cells that form a shrinking and thickening canopy over underlying epithelial cells. This contraction occurs by cell intercalation and is mechanically coupled to the basal layer by peripheral basal cells that extend apically and centripetally while remaining attached to the basal lamina. This process is topologically analogous to well-studied apical constriction mechanisms, but very different from them both in scale and molecular mechanism. Mechanical cell–cell coupling is propagated through the tissue via E-cadherin junctions, which in turn depend on tissue-wide tension. We further present evidence that this mechanism is conserved among different ectodermal organs and is, therefore, a novel and fundamental morphogenetic motif widespread in embryonic development.

Developing Methods of Analyzing and Evaluating the Accuracy of the Cross Section of a Hot-Rolled Product

A method has been developed and introduced for determining the characteristics of local thickenings in the cross section of rolled products. The method is based on the mathematical methods of band-pass filtering and the analysis of extremes. The method provides an objective, automatic real-time evaluation of the extent to which the cross section satisfies prescribed criteria. It gives hot-rolling mill operators information for taking corrective actions, gives inspection services data for product certification, and gives technical services results that can be used to analyze and improve the technology.

Patterns of scute development in turtle shell: Symmetry and asymmetry

The scute mosaic (pholidosis) in the turtle shell is characterized by two phenomena: phylogenetic stability of the general body plan and wide individual variability. The study of turtle morphogenesis allowed this phenomenon to be explained. It is shown that scute rudiments are formed in embryogeny as local epidermal thickenings, placodes; the positions of placodes is strictly confined to certain parts of the body and their foundation is realized in strict sequence. In particular, in the carapace, placodes are formed exclusively opposite the transverse trunk myosepta, in septal depressions of the embryonic integument; at the same time, marginal placodes are formed in each septal depression (i.e., segment by segment); placodes of pleural and central series are formed in alternate position in the even and odd depressions, respectively. The stability of the scute pattern is connected with the basic mechanisms of morphogenesis, providing the maintenance of bilateral symmetry and determination of scute positions by the primary embryonic segmentation. The main sourse for pholidosis variability is the presence in turtle embryos of vacant septal depressions, in which extraordinary placodes could have developed in the case of minor disturbances of embryogenesis. These aberrations are rather frequent and usually result in asymmetry of the scutation. The breaking of turtle pholidosis symmetry is connected with deviations in ontogenesis, such as asymmetrical formation of epidermal placodes, with a shift to one body side for a segment or more, the formation of additional placodes in the vacant septal depressions, atypical fusion of neighboring epidermal placodes, the absence of regular epidermal placodes in typical body segments.

Early local differentiation of the cell wall matrix defines the contact sites in lobed mesophyll cells of Zea mays.

The morphogenesis of lobed mesophyll cells (MCs) is highly controlled and coupled with intercellular space formation. Cortical microtubule rings define the number and the position of MC isthmi. This work investigated early events of MC morphogenesis, especially the mechanism defining the position of contacts between MCs. The distributions of plasmodesmata, the hemicelluloses callose and (1 → 3,1 → 4)-β-d-glucans (MLGs) and the pectin epitopes recognized by the 2F4, JIM5, JIM7 and LM6 antibodies were studied in the cell walls of Zea mays MCs. Matrix cell wall polysaccharides were immunolocalized in hand-made sections and in sections of material embedded in LR White resin. Callose was also localized using aniline blue in hand-made sections. Plasmodesmata distribution was examined by transmission electron microscopy. Before reorganization of the dispersed cortical microtubules into microtubule rings, particular bands of the longitudinal MC walls, where the MC contacts will form, locally differentiate by selective (1) deposition of callose and the pectin epitopes recognized by the 2F4, LM6, JIM5 and JIM7 antibodies, (2) degradation of MLGs and (3) formation of secondary plasmodesmata clusterings. This cell wall matrix differentiation persists in cell contacts of mature MCs. Simultaneously, the wall bands between those of future cell contacts differentiate with (1) deposition of local cell wall thickenings including cellulose microfibrils, (2) preferential presence of MLGs, (3) absence of callose and (4) transient presence of the pectins identified by the JIM5 and JIM7 antibodies. The wall areas between cell contacts expand determinately to form the cell isthmi and the cell lobes. The morphogenesis of lobed MCs is characterized by the early patterned differentiation of two distinct cell wall subdomains, defining the sites of the future MC contacts and of the future MC isthmi respectively. This patterned cell wall differentiation precedes cortical microtubule reorganization and may define microtubule ring disposition.

Morphology and Phylogenetic Position of the Freshwater Green Microalgae Chlorochytrium (Chlorophyceae) and Scotinosphaera (Scotinosphaerales, ord. nov., Ulvophyceae).

The green algal family Chlorochytriaceae comprises relatively large coccoid algae with secondarily thickened cell walls. Despite its morphological distinctness, the family remained molecularly uncharacterized. In this study, we investigated the morphology and phylogenetic position of 16 strains determined as members of two Chlorochytriaceae genera, Chlorochytrium and Scotinosphaera. The phylogenetic reconstructions were based on the analyses of two data sets, including a broad, concatenated alignment of small subunit rDNA and rbcL sequences, and a 10-gene alignment of 32 selected taxa. All analyses revealed the distant relation of the two genera, segregated in two different classes: Chlorophyceae and Ulvophyceae. Chlorochytrium strains were inferred in two distinct clades of the Stephanosphaerinia clade within the Chlorophyceae. Whereas clade A morphologically fits the description of Chlorochytrium, the strains of clade B coincide with the circumscription of the genus Neospongiococcum. The Scotinosphaera strains formed a distinct and highly divergent clade within the Ulvophyceae, warranting the recognition of a new order, Scotinosphaerales. Morphologically, the order is characterized by large cells bearing local cell wall thickenings, pyrenoid matrix dissected by numerous anastomosing cytoplasmatic channels, sporogenesis comprising the accumulation of secondary carotenoids in the cell periphery and almost simultaneous cytokinesis. The close relationship of the Scotinosphaerales with other early diverging ulvophycean orders enforces the notion that nonmotile unicellular freshwater organisms have played an important role in the early diversification of the Ulvophyceae.