Expansion Of Plate Research Articles

Precocious chondrocyte differentiation disrupts skeletal growth in Kabuki syndrome mice.

Kabuki syndrome 1 (KS1) is a Mendelian disorder of the epigenetic machinery caused by mutations in the gene encoding KMT2D, which methylates lysine 4 on histone H3 (H3K4). KS1 is characterized by intellectual disability, postnatal growth retardation, and distinct craniofacial dysmorphisms. A mouse model (Kmt2d+/βGeo) exhibits features of the human disorder and has provided insight into other phenotypes; however, the mechanistic basis of skeletal abnormalities and growth retardation remains elusive. Using high-resolution micro-CT, we show that Kmt2d+/βGeo mice have shortened long bones and ventral bowing of skulls. In vivo expansion of growth plates within skulls and long bones suggests disrupted endochondral ossification as a common disease mechanism. Stable chondrocyte cell lines harboring inactivating mutations in Kmt2d exhibit precocious differentiation, further supporting this mechanism. A known inducer of chondrogenesis, SOX9, and its targets show markedly increased expression in Kmt2d-/- chondrocytes. By transcriptome profiling, we identify Shox2 as a putative KMT2D target. We propose that decreased KMT2D-mediated H3K4me3 at Shox2 releases Sox9 inhibition and thereby leads to enhanced chondrogenesis, providing a potentially novel and plausible explanation for precocious chondrocyte differentiation. Our findings provide insight into the pathogenesis of growth retardation in KS1 and suggest therapeutic approaches for this and related disorders.

Experimental and Numerical Study on the Characteristics of the Thermal Design of a Large-Area Hot Plate for Nanoimprint Equipment

A numerical study was conducted on the thermal performance of a large-area hot plate specifically designed as a heating and cooling tool for thermal nanoimprint lithography processes. The hot plate had the dimensions 240 mm × 240 mm × 20 mm, in which a series of cartridge heaters and cooling holes were installed. Stainless steel was selected to endure the high molding pressures. To examine the hot plate’s abnormal thermal behavior, ANSYS Fluent V15.0, which is commercial CFD code, was used to perform computational analysis. A numerical model was employed to predict the thermal behavior of the hot plate in both the heating and cooling phases. To conduct the thermal design of a large-area hot plate for nanoimprint equipment, we selected the model to be studied and proposed a cooling model using both direct and indirect cooling methods with and without heat pipes. In addition, we created a small hot plate and performed experimental and computational analyses to confirm the validity of the proposed model. This study also analyzed problems that may occur in the stage prior to the large-area expansion of the hot plate. In the case of a stainless steel (STS304) hot plate for large-area hot plate expansion, the heat pipes were inserted in the direction of the cartridge heaters to address the problems that may occur when expanding the hot plate into a large area. As a result, the heating rate was 40 °C/min and the temperature uniformity was less than 1% of the maximum working temperature of 200 °C. For cooling, when considering pressure and using air as the coolant for the ends, a cooling rate of 20 °C/min and thermal performance of less than 13.2 °C (less than 7%) based on the maximum temperature were obtained. These results were similar to the experimental results.

An unusual presentation of a periodontal-endodontic lesion

Periodontal-endodontic (perio-endo) lesions involve pulpal and periodontal disease in the same tooth and are seen routinely by dental practitioners. An unusual presentation of a perio-endo lesion in the lower left mandible is demonstrated. It caused significant buccal expansion and perforation of the lingual plate, and was provisionally diagnosed as a malignancy. CPD/Clinical Relevance: This case has highlighted the need for clinicians to be aware of the unusual way that periodontal-endodontic lesions may present both clinically and radiographically.

Water Absorption, Hydrothermal Expansion, and Thermomechanical Properties of a Vinylester Resin for Fiber-Reinforced Polymer Composites Subjected to Water or Alkaline Solution Immersion.

In the present paper, a vinyl ester (VE) resin, potentially used as a resin matrix for fiber-reinforced polymer (FRP) composite sucker rods in oil drilling, FRP bridge cables, or FRP marine structures, was investigated on its resistance to water and alkaline solution immersion in terms of water uptake, hydrothermal expansion, and mechanical properties. A two-stage diffusion model was applied to simulate the water uptake processes. Alkaline solution immersion led to a slightly higher mass loss (approx. 0.4%) compared to water immersion (approx. 0.23%) due to the hydrolysis and leaching of uncured small molecules (e.g., styrene). Water immersion caused the expansion of VE plates monitored with Fiber Bragg Grating (FBG). With the same water uptake, the expansion increased with immersion temperatures, which is attributed to the increased relaxation extent of the resin molecular networks. Although an obvious decrease of the glass transition temperatures (Tg) of VE due to water immersion (5.4 to 6.1 °C/1% water uptake), Tg can be recovered almost completely after drying. Tensile test results indicate that a short-term immersion (less than 6 months) enhances both the strength and elongation at break, while the extension of the immersion time degrades both the strength and elongation. The modulus of VE shows insensitive to the immersion even at elevated temperatures.

Generation of the squamous epithelial roof of the 4th ventricle.

We use the transparency of zebrafish embryos to reveal the de novo generation of a simple squamous epithelium and identify the cellular architecture in the epithelial transition zone that ties this squamous epithelium to the columnar neuroepithelium within the embryo's brain. The simple squamous epithelium of the rhombencephalic roof plate is pioneered by distinct mesenchymal cells at the dorsal midline of the neural tube. Subsequently, a progenitor zone is established at the interface between columnar epithelium of the rhombic lip and the expanding squamous epithelium of the roof plate. Surprisingly, this interface consists of a single progenitor cell type that we have named the veil cell. Veil cells express gdf6a and constitute a lineage restricted stem zone that generates the squamous roof plate by direct transformation and asymmetrically fated divisions. Experimental restriction of roof plate expansion leads to extrusion of veil cell daughters and squamous cells, suggesting veil cell fate is regulated by the space available for roof plate growth.

Odontogenic myxoma- A rare case report

Odontogenic myxoma is benign, slow-growing, locally aggressive tumour arising from the ectomesenchyme of a developing tooth. It is the third most common odontogenic tumour. It occurs mainly in the 2nd and 3rd decades with slight predilection in females, and the mandible is more commonly involved than the maxilla. The lesion often grows without symptoms and presents as a painless swelling. Radiographic features are variable with a unilocular or multilocular radiolucency showing honeycomb, soap bubble or tennis racket pattern with cortical plate expansion. Histologically odontogenic myxoma shows loosely arranged stellate to spindle shaped cells interspersed in myxoid matrix. A case of odontogenic myxoma in 46- year-old female patient involving the right maxilla resulting in gross facial deformity within a span of 6 months is reported.

OSTEOSARCOMA: A REPORT OF 2 CASES WITH SIMILAR RADIOGRAPHIC FEATURES

Background Osteosarcoma is the most common primary malignant bone tumor of the jaws but is relatively rare.1-4 Osteosarcoma can be osteodestructive, osteogenic, or, more frequently, a combination of the 2.1,4 Osteosarcoma commonly occurs in the posterior mandible, but we report on 2 cases involving the anterior mandible, 1 occurring in a 20-year-old male patient (patient A) and 1 occurring in a 76-year-old male patient (patient B). Objective To describe the clinical and radiologic findings of 2 patients presenting with osteosarcoma in the anterior mandible. Clinical and Radiologic Findings Patient A presented with an intraoral swelling of 1.5 month duration and measuring 2 × 2 cm in size. There was loosening of teeth, but no pain or paresthesia was reported. The lesion extended from teeth #23 to #27. Periodontal ligament (PDL) widening was present on all teeth, being most notable on #26 and #27. Tooth #26 was displaced mesially. A patchy sclerotic bone pattern was present, with irregular thinning, expansion, and interruption of the facial plate. Adjacent to the alveolar bone, there was an irregular and unorganized density, similar to bone, at the level of #26 and #27. Patient B presented with a fixed, asymptomatic 2 × 2 cm intraoral swelling. Radiographically, a similar pattern of tooth displacement, PDL widening, and patchy sclerotic bone pattern was present. An unorganized density, similar to bone, was present adjacent to the facial plate. Differential or Definitive Interpretation Patient A and patient B: osteosarcoma versus chondrosarcoma. Discussion Widening of the PDL space is an important finding associated with malignant disease and may occur with sarcomas and non-Hodgkin lymphoma. 2,5 Widening of the PDL space was identified in nearly half the osteosarcoma cases reported by Fernandes et al.2 The combination of PDL widening, sclerotic bone pattern with bone formation, and higher incidence of osteosarcoma compared with chondrosarcoma can be used to identify osteosarcoma cases radiographically.

Decompression as an Initial Procedure in Unicystic Ameloblastoma

Unicystic ameloblastoma (UCA) is a variant of ameloblastoma that presents as a single cystic cavity. Usually, slightly more than 50% of the cases occur in the second decade of life. They are characterized by slow growth and relatively local aggressiveness, with the posterior portion of the mandible as the main site of origin. This case report describes a UCA occurring in the left mandible of an 18-year-old boy. He presented with progressive asymptomatic swelling with expansion of the buccal cortical plates of the left mandible. Panoramic imaging showed a well-defined unilocular asymmetric radiolucency with root resorption of some teeth in the affected area. An incisional biopsy revealed a single cavity lesion; thus, a plastic device was placed for decompression. The histopathological diagnosis was UCA. A follow-up after 3 months showed significant bone formation and decrease of the lesion. The patient is under follow-up.

Cellular rearrangement of the prechordal plate contributes to eye degeneration in the cavefish

Astyanax mexicanus consists of two different populations: a sighted surface-dwelling form (surface fish) and a blind cave-dwelling form (cavefish). In the cavefish, embryonic expression of sonic hedgehog a (shha) in the prechordal plate is expanded towards the anterior midline, which has been shown to contribute to cavefish specific traits such as eye degeneration, enhanced feeding apparatus, and specialized brain anatomy. However, it is not clear how this expanded expression is achieved and which signaling pathways are involved.Nodal signaling has a crucial role for expression of shh and formation of the prechordal plate. In this study, we report increased expression of prechordal plate marker genes, nodal-related 2 (ndr2) and goosecoid (gsc) in cavefish embryos at the tailbud stage. To investigate whether Nodal signaling is responsible for the anterior expansion of the prechordal plate, we used an inhibitor of Nodal signaling and showed a decreased anterior expansion of the prechordal plate and increased pax6 expression in the anterior midline in treated cavefish embryos. Later in development, the lens and optic cup of treated embryos were significantly larger than untreated embryos. Conversely, increasing Nodal signaling in the surface fish embryo resulted in the expansion of anterior prechordal plate and reduction of pax6 expression in the anterior neural plate together with the formation of small lenses and optic cups later in development. These results confirmed that Nodal signaling has a crucial role for the anterior expansion of the prechordal plate and plays a significant role in cavefish eye development. We showed that the anterior expansion of the prechordal plate was not due to increased total cell number, suggesting the expansion is achieved by changes in cellular distribution in the prechordal plate. In addition, the distribution of presumptive prechordal plate cells in Spemann's organiser was also altered in the cavefish. These results suggested that changes in the cellular arrangement of Spemann's organiser in early gastrulae could have an essential role in the anterior expansion of the prechordal plate contributing to eye degeneration in the cavefish.

Ameloblastoma uniquístico intramural, reconstrucción tardía y rehabilitación con implantes dentales. Reporte de caso

Introducción: el ameloblastoma uniquístico es considerado una variante del ameloblastoma, con características clínico-radiográficas e histológicas particulares, mostrando un mejor pronóstico que la forma sólida. Objetivo describir el manejo y procederes de un paciente con ameloblastoma uniquístico intramural (AUIM) en línea media mandibular con énfasis en la reconstrucción tardía y su rehabilitación. Materiales y métodos: se presenta un varón de 18 años con una lesión indolora en la zona anterior de la mandíbula, relacionada con un diente retenido. Radiográficamente, mostraba imagen unilocular, corticalizada, que causaba expansión de las corticales óseas. Se realizó la resección segmental y ajuste de placa de reconstrucción; en un segundo tiempo quirúrgico se colocó injerto óseo autólogo y, posteriormente, se procedió a la rehabilitación con implantes. Discusión: en el artículo se discute la elección del tratamiento basado en el comportamiento biológico del AUIM, así como la necesidad de restablecer la estética y la función después de una cirugía radical.

Displacement of the mitotic apparatuses by centrifugation reveals cortical actin organization during cytokinesis in cultured tobacco BY-2 cells

In plant cytokinesis, actin is thought to be crucial in cell plate guidance to the cortical division zone (CDZ), but its organization and function are not fully understood. To elucidate actin organization during cytokinesis, we employed an experimental system, in which the mitotic apparatus is displaced and separated from the CDZ by centrifugation and observed using a global-local live imaging microscope that enabled us to record behavior of actin filaments in the CDZ and the whole cell division process in parallel. In this system, returning movement of the cytokinetic apparatus in cultured-tobacco BY-2 cells occurs, and there is an advantage to observe actin organization clearly during the cytokinetic phase because more space was available between the CDZ and the distantly formed phragmoplast. Actin cables were clearly observed between the CDZ and the phragmoplast in BY-2 cells expressing GFP-fimbrin after centrifugation. Both the CDZ and the edge of the expanding phragmoplast had actin bulges. Using live-cell imaging including the global-local live imaging microscopy, we found actin filaments started to accumulate at the actin-depleted zone when cell plate expansion started even in the cell whose cell plate failed to reach the CDZ. These results suggest that specific accumulation of actin filaments at the CDZ and the appearance of actin cables between the CDZ and the phragmoplast during cell plate formation play important roles in the guidance of cell plate edges to the CDZ.

A Three-Stage Split-Crest Technique: Case Series of Horizontal Ridge Augmentation in the Atrophic Posterior Mandible

This paper introduces a three-stage split-crest (TSSC) technique for horizontal ridge augmentation in the atrophic posterior mandible. The first stage consists of splitting the ridge. Following a 3- to 4-week healing interval, the second stage consists of expansion of the cortical plate (without elevating the periosteum) and placement of a bone replacement graft material. After 3 to 4 months of healing, the implants are placed. The advantages of this three-stage technique are increased vascularization to the surgical area, a decrease in procedure complications, and improved implant survival rates. An extended treatment time is the main disadvantage. The purpose of this retrospective case series is to review and discuss a new step-by-step surgical procedure of a TSSC technique using a delayed implant placement protocol. The results, advantages, and limitations were also presented.

Experimental research of steel-concrete load bearing components of bridge column piers

A new constructive design of a bridge column pier, which is a load-bearing component of bridges and overpasses as well as of complex multilevel interchanges underlying a transport infrastructure, is proposed. The design is based on a steel mesh casing that is made from a solid-web plate by means of cutting meshes and further expansion of the solid-web plate using non-waste technology. Experimental research data on the bearing capacity and deformability of the cylindrical steel-concrete load bearing components of bridge column piers are provided. They are compared with research data on load bearing components having a solid casing. To make the experimental picture complete, analogous research data on cylindrical concrete load bearing components are provided. This experiment includes static and low-cycle loadings of samples under axial compression mentioned above. On the basis of the information obtained, the effort and travel fields are formed, the critical forces of structure buckling are determined. The analysis of the rationality of the cylindrical steel-concrete load bearing component of bridge column piers is carried out, using the experimental research data. To verify the research data, which are obtained in the course of the study of the critical forces of cylindrical steel-concrete load bearing component buckling, the experimental results are compared with theoretical ones.

Large Periapical or Cystic Lesions in Association with Roots Having Open Apices Managed Nonsurgically Using 1-step Apexification Based on Platelet-rich Fibrin Matrix and Biodentine Apical Barrier: A Case Series

Teeth having open apices in the absence of a natural apical constriction pose several challenges during conventional endodontic treatment, especially when establishing an apical seal. Treatment is further challenging when these teeth are associated with large periapical or cystic lesions having resulted in expansion and/or thinning of adjacent cortical plates. Although surgical intervention is commonly adopted in the management of such cases, a conservative treatment option offering equally good prognosis is always desirable. This case series describes 3 cases: a 39-year-old woman, a 45-year-old woman, and a 15-year-old boy having teeth with concomitant open apices and large periapical/cystic lesions managed conservatively by (1) following a strict intracanal disinfection protocol, (2) intracanal aspiration with digital decompression of associated swelling, and (3) 1-step apexification for closure of the root apex by placing a preliminary barrier of platelet-rich fibrin (PRF) and a secondary barrier of Biodentine (Septodont, Saint-Maur-des-Fossés, France). In all 3 cases, the treatment outcomes, both clinical and radiographic, were highly satisfactory. PRF and Biodentine collectively rendered an apical plug that proved to be a suitable alternative to commonly used mineral trioxide aggregate in 1-step apexification. Biodentine provides good interfacial adhesion and sealing with dentin attributed to its property of hydroxyapatite crystal deposition at the material-dentin interface. Also, because of its bioactivity, it likely promotes the conversion of adjacent PRF into a calcific barrier, thus reinforcing the apical seal. Additionally, host-modulating responses of PRF contribute in expediting the healing process. Reasonable osseous healing in the periapex could be appreciated as early as 3 months in all patients. The rapidity with which healing occurred may have been an incidental finding but definitely draws attention.

Finite element analysis of residual stress in cold expanded plate with different thickness and expansion ratio

Cold expansion of fastener/rivet holes is a common way to generate beneficial compressive residual stress around the fastener hole. In this study, cold expansion process was simulated by finite-element method in order to determine the residual stress field around two cold expanded holes by varying the plate thickness and expansion ratio of the hole. The model was developed in ANSYS and assigned to aluminium alloy 7475-T61 material model. The results showed that the residual stress become more compressive as the plate thickness is increased up to t/d = 2.6 and decreased for further level of thickness. In addition, the residual stress at the edge of the hole become more compressive as the expansion ratio is increased up to 4.5% and decreased for further level of expansion. This study also found that the residual stresses near the entrance and the exit face of the plate are less compressive than the residual stresses on the mid-thickness of the plate.

Katanin Effects on Dynamics of Cortical Microtubules and Mitotic Arrays in Arabidopsis thaliana Revealed by Advanced Live-Cell Imaging.

Katanin is the only microtubule severing protein identified in plants so far. Previous studies have documented its role in regulating cortical microtubule organization during cell growth and morphogenesis. Although, some cell division defects are reported in KATANIN mutants, it is not clear whether or how katanin activity may affect microtubule dynamics in interphase cells, as well as the progression of mitosis and cytokinesis and the orientation of cell division plane (CDP). For this reason, we characterized microtubule organization and dynamics in growing and dividing cotyledon cells of Arabidopsis ktn1-2 mutant devoid of KATANIN 1 activity. In interphase epidermal cells of ktn1-2 cortical microtubules exhibited aberrant and largely isotropic organization, reduced bundling and showed excessive branched microtubule formation. End-wise microtubule dynamics were not much affected, although a significantly slower rate of microtubule growth was measured in the ktn1-2 mutant where microtubule severing was completely abolished. KATANIN 1 depletion also brought about significant changes in preprophase microtubule band (PPB) organization and dynamics. In this case, many PPBs exhibited unisided organization and splayed appearance while in most cases they were broader than those of wild type cells. By recording PPB maturation, it was observed that PPBs in the mutant narrowed at a much slower pace compared to those in Col-0. The form of the mitotic spindle and the phragmoplast was not much affected in ktn1-2, however, the dynamics of both processes showed significant differences compared to wild type. In general, both mitosis and cytokinesis were considerably delayed in the mutant. Additionally, the mitotic spindle and the phragmoplast exhibited extensive rotational motions with the equatorial plane of the spindle being essentially uncoupled from the division plane set by the PPB. However, at the onset of its formation the phragmoplast undergoes rotational motion rectifying the expansion of the cell plate to match the original cell division plane. Conclusively, KATANIN 1 contributes to microtubule dynamics during interphase, regulates PPB formation and maturation and is involved in the positioning of the mitotic spindle and the phragmoplast.

Vesicle Dynamics during Plant Cell Cytokinesis Reveals Distinct Developmental Phases.

Cell division in plant cells requires the deposition of a new cell wall between the two daughter cells. The assembly of this plate requires the coordinated movement of cargo vesicles whose size is below the diffraction-limited resolution of the optical microscope. We combined high spatial and temporal resolution confocal laser scanning microscopy with advanced image-processing tools and fluorescence fluctuation methods and distinguished three distinct phases during cell plate expansion in tobacco (Nicotiana tabacum) 'Bright Yellow-2' cells: massive delivery of preexisting vesicles to a disk-shaped region at the equatorial plane precedes a primary rapid expansion phase followed by a secondary, slow expansion phase during which the extremity of the circular plate seeks contact with the mother wall and brings about the separation of the two portions of cytoplasm. Different effects of pharmacological inhibition emphasize the distinct nature of the assembly and expansion mechanisms characterizing these phases.

Bilateral dentigerous cyst involving mandibular first molars- a case report

Dentigerous cyst is one of the common odontogenic cysts and they are associated with unerupted or impacted teeth. However, multiple dentigerous cysts are rare and they are usually associated with syndromes such as basal cell nevus syndrome, mucopolysaccharidosis (type VI) or cleidocranial dysplasia. Very few cases of multiple dentigerous cysts involving first permanent molars are reported. This report is of a rare case of bilateral dentigerous cyst involving mandibular first molars in a non- syndromic 7 year old male patient. A provisional diagnosis of a dentigerous cyst was given based on clinical finding of missing 36 and 46 with buccal cortical plate expansion and presence of a pericoronal radiolucency attached to the CEJ irt to 36 and 46 on panoramic image. The computed tomographic finding revealed a well defined expansile cystic lesion in right and left mandibular molar regions. Enucleation of the cyst with extraction of 36 and 46 was done and the specimen was sent for histopathological examination which confirmed the diagnosis of dentigerous cyst.

CENTRAL GIANT CELL GRANULOMA- A CASE REPORT

Central giant cell granuloma (CGCG) is a benign intraosseous lesion of the jaw that is found predominantly in children and young adult. It is an uncommon pathological condition occurring in less than 7% of all benign lesions of the jaw and diagnosed during the first two decades of life. It is considerably more common in the mandible than in the maxilla. A case of 30 yr old male with CGCG in mandible is presented. A single, focal, diffuse swelling of size 9cm x 6cm was seen on the lower anterior region of jaw which was hard in consistency, non tender with no local rise in temperature. Intraorally, solitary well circumscribed oval shaped swelling was present on the anterior mandible extending from right second premolar to left second premolar region obliterating the labial vestibule. It was associated with expansion of labial cortical plate.Pulp vitality test was carried out from right mandibular first premolar to left mandibular second premolar which revealed no response suggesting it to be non- vital. Radiographs of the patient included occlusal view to check expansion of cortical plate and panoramic view to check extent of lesion which revealed presence of solitary multilocular lesion extending from mesial aspect of 36 till mesial aspect of 46 with minute loculations giving honey comb appearance. There is profuse expansion of buccal and lingual plate along with resorption of roots in anterior region., incisional biopsy was carried out which showed cellular vascular stroma with large number of multinucleate giant cells proliferating fibroblasts, histiocytes areas of hemorrhage and new bone formation.Treatment was started with Kenacort –A (10mg/ml) and lidocaine solution 2% with epinephrine 1: 200,000 (50% mixture by volume). Post-operative and follow up, panoramic view and Cone Beam Computed Tomography was taken which revealed regression in the size of the lesion along with osteoblastic activity resulting in formation of the lost bone measuring thickness of about 0.5cm at the inferior border of mandible

Nonexpansile Unicystic Ameloblastoma: A Rare Case Report

Ameloblastoma is the most common benign odontogenic tumor that has the potential to grow into a large size. Unicystic ameloblastoma (UA) is a variant of the solid or multicystic ameloblastoma. It is a rare (relative frequency 5–22%) benign, locally invasive odontogenic tumor of young age that mimics clinically and radiographically as an odontogenic cyst. Radiographically it may present as unilocualr or multilocular with cortical plate expansion. Conventional radiograph has less advantage to determine their extension into soft tissue. Hence, conventional tomography, cone-beam computed tomography, and magnetic resonance imaging may be used to determine expansion, root resorption and relation with adjacent structures. It has low recurrence rate after conservative therapy. Here, we present a rare case of nonexpansile UA with an unusual presentation in a young male patient.