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Oral Diseases Nov 2023Amelogenesis imperfecta (AI) is defined as inherited enamel malformations. LAMA3 (laminin alpha-3) encodes a critical protein component of the basement membrane...
OBJECTIVE
Amelogenesis imperfecta (AI) is defined as inherited enamel malformations. LAMA3 (laminin alpha-3) encodes a critical protein component of the basement membrane (laminin-332). Individuals carrying heterozygous LAMA3 mutations have previously been shown to have localized enamel defects. This study aimed to define clinical phenotypes and to discern the genetic etiology for four AI kindreds.
MATERIALS AND METHODS
Whole-exome analyses were conducted to search for sequence variants associated with the disorder, and micro-computed tomography (μCT) to characterize the enamel defects.
RESULTS
The predominant enamel phenotype was generalized thin enamel with defective pits and grooves. Horizonal bands of hypoplastic enamel with chalky-white discoloration and enamel hypomineralization were also observed and demonstrated by μCT analyses of affected teeth. Four disease-causing LAMA3 mutations (NM_198129.4:c.3712dup; c.5891dup; c.7367del; c.9400G > C) were identified. Compound heterozygous MMP20 mutations (NM_004771.4:c.539A > G; c.692C > T) were also found in one proband with more severe enamel defects, suggesting a mutational synergism on disease phenotypes. Further analyses of the AI-causing mutations suggested that both α3A (short) and α3B (long) isoforms of LAMA3 are essential for enamel formation.
CONCLUSIONS
Heterozygous LAMA3 mutations can cause generalized enamel defects (AI1A) with variable expressivity. Laminin-332 is critical not only for appositional growth but also enamel maturation.
Topics: Humans; Amelogenesis Imperfecta; Laminin; X-Ray Microtomography; Dental Enamel; Extracellular Matrix Proteins; Mutation; Phenotype; Biological Variation, Population; Pedigree
PubMed: 36326426
DOI: 10.1111/odi.14425 -
Biomedical Materials (Bristol, England) Nov 2022Three-dimensional cell constructs comprising only tissue-specific cells and extracellular matrix secreted by them would be ideal transplants, but their fabrication in a...
Three-dimensional cell constructs comprising only tissue-specific cells and extracellular matrix secreted by them would be ideal transplants, but their fabrication in a cell aggregation manner without cell scaffolds relies on random cell self-aggregation, making the control of their size and shape difficult. In this study, we propose a method to fabricate band-shaped tissues by inducing the self-aggregation of cell sheets using the developed cell self-aggregation technique (CAT). Acting as cell aggregation stoppers, silicone semicircular pillars were attached to two positions equidistant from both short ends of the rounded rectangular culture groove and coated with a specifically charged biomimetic polymer as a CAT-inducing surface. Mesenchymal stem cells, chondrocytes, and skeletal myoblast cells seeded on the surface of the culture grooves formed band-shaped aggregates between the two aggregation stoppers following spontaneous detachment with aggregation of the cell sheet from the outer edge of the grooves during day one of culture. The aggregated chondrocyte band matured into a cartilage-like plate with an abundant cartilage matrix while retaining its band shape after two weeks of chondrogenic cultivation. Additionally, the aggregates of mesenchymal stem cells and myoblast cell bands could patch the induced collagen membrane derived from rat subcutaneous tissue like a bandage immediately after their formation and successfully mature into fat and muscle tissues, respectively. These results indicate that, depending on the cell type, scaffold-free band-shaped cell aggregates produced by CAT have the potential to achieve tissue regeneration that follows the shape of the defect viamaturation culture ororganization.
Topics: Rats; Animals; Chondrogenesis; Cartilage; Chondrocytes; Mesenchymal Stem Cells; Mesoderm
PubMed: 36270422
DOI: 10.1088/1748-605X/ac9c7f -
Cureus Jan 2022This study aimed to investigate the operator's ease, satisfaction, and comfort of using a circumferential matrix system and sectional matrix system on the proximal...
OBJECTIVES
This study aimed to investigate the operator's ease, satisfaction, and comfort of using a circumferential matrix system and sectional matrix system on the proximal contact points and contours when restoring class II cavities in posterior teeth.
MATERIALS AND METHODS
This cross-sectional study was performed at the clinics in the Department of Conservative Dental Sciences, College of Dentistry, Qassim University. A total of 105 dental students randomly participated in this study to restore a class II cavity with direct composite resin restoration. Operators' comfort and satisfaction were evaluated according to their assessment of the contact points they reproduced and the emergence profiles of restorations, using a circumferential matrix system and sectional matrix system.
RESULTS
Out of 105 operators, 57 were satisfied with using circumferential matrix bands for most of their cases while 78 of the operators were satisfied with sectional matrix bands. There were no significant differences between operator satisfaction and the use of circumferential matrix band system (P > 0.05) and sectional matrix band system (P = 0.134) but there was a significant difference between difficulty levels in the use of both matrix band systems (P < 0.05; P = 0.000).
CONCLUSION
Circumferential and sectional matrix band systems showed no significant differences with operators' satisfaction during restoring class II cavities in posterior teeth but using a sectional matrix band system was considered easier than using a circumferential matrix band system.
PubMed: 35004091
DOI: 10.7759/cureus.20957 -
NeuroImage. Clinical 2022Post-stroke aphasia is a consequence of localized stroke-related damage as well as global disturbances in a highly interactive and bilaterally-distributed language...
Post-stroke aphasia is a consequence of localized stroke-related damage as well as global disturbances in a highly interactive and bilaterally-distributed language network. Aphasia is increasingly accepted as a network disorder and it should be treated as such when examining the reorganization and recovery mechanisms after stroke. In the current study, we sought to investigate reorganized patterns of electrophysiological connectivity, derived from resting-state magnetoencephalography (rsMEG), in post-stroke chronic (>6 months after onset) aphasia. We implemented amplitude envelope correlations (AEC), a metric of connectivity commonly used to describe slower aspects of interregional communication in resting-state electrophysiological data. The main focus was on identifying the oscillatory frequency bands and frequency-specific spatial topology of connections associated with preserved language abilities after stroke. RsMEG was recorded for 5 min in 21 chronic stroke survivors with aphasia and in 20 matched healthy controls. Source-level MEG activity was reconstructed and summarized within 72 atlas-defined brain regions (or nodes). A 72 × 72 leakage-corrected connectivity (of AEC) matrix was obtained for frequencies from theta to low-gamma (4-50 Hz). Connectivity was compared between groups, and, the correlations between connectivity and subscale scores from the Western Aphasia Battery (WAB) were evaluated in the stroke group, using partial least squares analyses. Posthoc multiple regression analyses were also conducted on a graph theory measure of node strengths, derived from significant connectivity results, to control for node-wise properties (local spectral power and lesion sizes) and demographic and stroke-related variables. Connectivity among the left hemisphere regions, i.e. those ipsilateral to the stroke lesion, was greatly reduced in stroke survivors with aphasia compared to matched healthy controls in the alpha (8-13 Hz; p = 0.011) and beta (15-30 Hz; p = 0.001) bands. The spatial topology of hypoconnectivity in the alpha vs. beta bands was distinct, revealing a greater involvement of ventral frontal, temporal and parietal areas in alpha, and dorsal frontal and parietal areas in beta. The node strengths from alpha and beta group differences remained significant after controlling for nodal spectral power. AEC correlations with WAB subscales of object naming and fluency were significant. Greater alpha connectivity was associated with better naming performance (p = 0.045), and greater connectivity in both the alpha (p = 0.033) and beta (p = 0.007) bands was associated with better speech fluency performance. The spatial topology was distinct between these frequency bands. The node strengths remained significant after controlling for age, time post stroke onset, nodal spectral power and nodal lesion sizes. Our findings provide important insights into the electrophysiological connectivity profiles (frequency and spatial topology) potentially underpinning preserved language abilities in stroke survivors with aphasia.
Topics: Aphasia; Brain; Brain Mapping; Humans; Language; Magnetic Resonance Imaging; Magnetoencephalography; Stroke
PubMed: 35561556
DOI: 10.1016/j.nicl.2022.103036 -
Molecules (Basel, Switzerland) Oct 2021Analytical ultracentrifugation is a versatile approach for analysing the molecular mass, molecular integrity (degradation/aggregation), oligomeric state and... (Comparative Study)
Comparative Study Review
Analytical ultracentrifugation is a versatile approach for analysing the molecular mass, molecular integrity (degradation/aggregation), oligomeric state and association/dissociation constants for self-association, and assay of ligand binding of kinase related membrane proteins and glycans. It has the great property of being matrix free-providing separation and analysis of macromolecular species without the need of a separation matrix or membrane or immobilisation onto a surface. This short review-designed for the non-hydrodynamic expert-examines the potential of modern sedimentation velocity and sedimentation equilibrium and the challenges posed for these molecules particularly those which have significant cytoplasmic or extracellular domains in addition to the transmembrane region. These different regions can generate different optimal requirements in terms of choice of the appropriate solvent (aqueous/detergent). We compare how analytical ultracentrifugation has contributed to our understanding of two kinase related cellular or bacterial protein/glycan systems (i) the membrane erythrocyte band 3 protein system-studied in aqueous and detergent based solvent systems-and (ii) what it has contributed so far to our understanding of the enterococcal VanS, the glycan ligand vancomycin and interactions of vancomycin with mucins from the gastrointestinal tract.
Topics: Bacteria; Bacterial Proteins; Ligands; Membrane Proteins; Molecular Weight; Polysaccharides; Protein Kinases; Ultracentrifugation
PubMed: 34641622
DOI: 10.3390/molecules26196080 -
Sensors (Basel, Switzerland) Jun 2023The combination of ultra-wide band (UWB) and inertial measurement unit (IMU) positioning is subject to random errors and non-line-of-sight errors, and in this paper, an...
The combination of ultra-wide band (UWB) and inertial measurement unit (IMU) positioning is subject to random errors and non-line-of-sight errors, and in this paper, an improved positioning strategy is proposed to address this problem. The Kalman filter (KF) is used to pre-process the original UWB measurements, suppressing the effect of range mutation values of UWB on combined positioning, and the extended Kalman filter (EKF) is used to fuse the UWB measurements with the IMU measurements, with the difference between the two measurements used as the measurement information. The non-line-of-sight (NLOS) measurement information is also used. The optimal estimate is obtained by adjusting the system measurement noise covariance matrix in real time, according to the judgment result, and suppressing the interference of non-line-of-sight factors. The optimal estimate of the current state is fed back to the UWB range value in the next state, and the range value is dynamically adjusted after one-dimensional filtering pre-processing. Compared with conventional tightly coupled positioning, the positioning accuracy of the method in this paper is improved by 46.15% in the field experimental positioning results.
Topics: Algorithms; Judgment; Mutation
PubMed: 37447768
DOI: 10.3390/s23135918 -
Journal of Ayub Medical College,... 2023The reconstruction of proximal defects with tight contacts has always been a challenge for dental clinicians, especially with composite material. Recent literature shows...
BACKGROUND
The reconstruction of proximal defects with tight contacts has always been a challenge for dental clinicians, especially with composite material. Recent literature shows that the most frequently used matrix systems for the restoration of proximal cavities are circumferential or sectional matrix band systems. The objective of this study was to compare the contact tightness that is achieved with these two matrix band systems when using composite material.
METHODS
A total of 30 patients, i.e., 60 cavities were selected in this quasi-experimental study. Patients with two cavities in the posterior teeth were selected. Both the cavities were restored with the circumferential system, i.e., Tofflemire and sectional matrix band system, i.e., Palodent plus on the same appointment. Hence both systems were used in every patient and then contact tightness assess was ed based on an evaluation criterion, i.e., Fédération Dentaire Internationale clinical criteria for evaluation of contact in direct and indirect restorations. To make a comparison between the two systems Chi square test was used and p<0.05.
RESULTS
The mean age of the patients in the study was 31 years (SD, 7.59 years) with a range from 18 to 45 years. Most of the contact tightness in the Palodent matrix system was score 1 (n=33, 55%) and score 2 (n=17, 28.3%) while in Tofflemire was score 4 (n=28, 46.7%) and score 5 (n=19, 31.7%). Statistical analysis showed significance (p=.037) between Palodent matrix system contact tightness and Tofflemire.
CONCLUSION
The sectional matrix band system was statistically superior to the circumferential matrix band system in achieving a tighter contact for class II composite restorations.
Topics: Humans; Adolescent; Young Adult; Adult; Middle Aged; Composite Resins; Matrix Bands; Chi-Square Distribution; Margins of Excision
PubMed: 37422816
DOI: 10.55519/JAMC-02-11541 -
Frontiers in Dentistry 2023Hardness is relevant to the degree of conversion (DC) and depth of cure (DoC). The aim of this study was to determine the micro-hardness and DoC of conventional and...
Hardness is relevant to the degree of conversion (DC) and depth of cure (DoC). The aim of this study was to determine the micro-hardness and DoC of conventional and bulk-fill composite resins in class II restorations using metal and clear matrix bands. Twelve specimens of each of the two composite resins, , Filtek Z350 XT bulk-fill and Gradia posterior conventional composite, were prepared in the form of a class II cavity in a tooth mold, using a clear or metal matrix band. All specimens were cured and stored at 37°C for 24 hours. Vickers hardness was measured as a function of DoC at 2mm intervals. Data were analyzed by two-way ANOVA (alpha=0.05). The bulk-fill composite exhibited significantly higher hardness levels than the conventional composite in all tested surfaces (P<0.001). However, while the metal matrix band had a significant impact on the bottom surface (P=0.059) and also on the furthest surface from the matrix and light source (P=0.04), it did not have a consistent effect across all tested surfaces. The simultaneous interaction of the composites and matrix band types in all surfaces, did not show significant differences in hardness values. The highest bottom-to-top surface hardness ratio (73%) was observed in the conventional composite near the metal matrix band. In deep class II cavities, the bottom-to-top surface hardness ratio did not reach the maximum of 80%, neither for bulk-fill nor conventional posterior composites. Therefore, in such cavities extended light-curing and more incremental composite placement is needed.
PubMed: 37701657
DOI: 10.18502/fid.v20i20.12912 -
Polymers Jan 2023Hydroxyapatite has the closest chemical composition to human bone. Despite this, the use of nano-hydroxyapatite (nHA) to produce biocomposite scaffolds from a mixture of...
Hydroxyapatite has the closest chemical composition to human bone. Despite this, the use of nano-hydroxyapatite (nHA) to produce biocomposite scaffolds from a mixture of polylactic acid (PLA) and polycaprolactone (PCL) using cold isostatic pressing has not been studied intensively. In this study, biocomposites were created employing nHA as an osteoconductive filler and a polymeric blend of PLA and PCL as a polymer matrix for prospective usage in the medical field. Cold isostatic pressing and subsequent sintering were used to create composites with different nHA concentrations that ranged from 0 to 30 weight percent. Using physical and mechanical characterization techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and density, porosity, tensile, and flexural standard tests, it was determined how the nHA concentrations affected the biocomposite's general properties. In this study, the presence of PLA, PCL, and nHA was well identified using FTIR, XRD, and SEM methods. The biocomposites with high nHA content showed intense bands for symmetric stretching and the asymmetric bending vibration of PO. The incorporation of nHA into the polymeric blend matrix resulted in a rather irregular structure and the crystallization became more difficult. The addition of nHA improved the density and tensile and flexural strength of the PLA/PCL matrix (0% nHA). However, with increasing nHA content, the PLA/PCL/nHA biocomposites became more porous. In addition, the density, flexural strength, and tensile strength of the PLA/PCL/nHA biocomposites decreased with increasing nHA concentration. The PLA/PCL/nHA biocomposites with 10% nHA had the highest mechanical properties with a density of 1.39 g/cm, a porosity of 1.93%, a flexural strength of 55.35 MPa, and a tensile strength of 30.68 MPa.
PubMed: 36771860
DOI: 10.3390/polym15030559 -
Scientific Reports Jun 2021Matrix metalloproteinase13 (MMP13) can be released by keratinocytes and fibroblasts and involved in the pathogenesis of skin disorders. Retinoic acid derivative drugs...
Matrix metalloproteinase13 (MMP13) can be released by keratinocytes and fibroblasts and involved in the pathogenesis of skin disorders. Retinoic acid derivative drugs include tazarotene and acitretin. Tazarotene/acitretin and narrow-band ultraviolet B (NB-UVB) irradiation are common treatment options for psoriasis. However, their impact on MMP13 expression in the context of psoriasis has yet to be determined. The expression of MMP13 was analyzed in patients with psoriasis. The effects of tazarotene/acitretin and NB-UVB on MMP13 expression were also investigated in a mouse model of psoriasis. Human HaCaT keratinocytes were exposed to acitretin or NB-UVB and then assayed for cell proliferation and MMP13 expression levels. We showed that patients with psoriasis had increased levels of MMP13 protein in skin lesions and serum samples. Exposure to acitretin and NB-UVB irradiation alone or in combination led to reduction of cell proliferation and MMP13 expression in HaCaT cells. Consistently, tazarotene treatment or NB-UVB irradiation attenuated imiquimod-induced psoriasis-like dermatitis and decreased MMP13 expression in a mouse model. Based on these from HaCaT keratinocytes cells and animal experiments, we suggest that tazarotene/acitretin and NB-UVB irradiation can inhibit the expression of MMP13 in HaCaT keratinocytes and psoriasis mouse models. Blockade of MMP13 activity may have therapeutic potential in improving symptoms of psoriasis.
Topics: Animals; Cell Line; Cell Proliferation; Disease Models, Animal; HaCaT Cells; Humans; Imiquimod; Keratinocytes; Matrix Metalloproteinase 13; Mice; Nicotinic Acids; Psoriasis; Retinoids; Ultraviolet Rays; Ultraviolet Therapy
PubMed: 34172768
DOI: 10.1038/s41598-021-92599-w