In the present study, we investigated the effects of type 2 diabetes-induced hyperglycemia on the integrity of the blood–brain barrier and tight junction markers in the rat hippocampus. ...Forty-week-old diabetic (Zucker diabetic fatty, ZDF) rats and littermate control (Zucker lean control, ZLC) rats were used in this study. We evaluated the integrity of the blood–brain barrier by measuring sodium fluorescein extravasation and blood vessel ultrastructure. In addition, tight junction markers, such as zona occludens-1, occludin and claudin-5, were quantified by western blot analysis. ZDF rats showed significantly increased sodium fluorescein leakage in the hippocampus. Tight junction markers, such as occludin and claudin-5, were significantly decreased in the hippocampi of ZDF rats compared to those of ZLC rats. In addition, ZDF rats showed ultrastructural changes with phagocytic findings in the blood vessels. These results suggest that chronic untreated diabetes impairs the permeability of the hippocampal blood–brain barrier by down-regulating occludin and claudin-5, indicating that chronic untreated diabetes may cause hippocampus-dependent dysfunction.
The effect of different build angles on the tissue surface adaptation of complete denture bases manufactured by digital light processing (DLP) is unclear.
The purpose of this in vitro study was to ...evaluate the effect of build angle on the tissue surface adaptation of DLP-printed complete denture bases.
Both maxillary and mandibular denture bases were virtually designed based on reference casts and fabricated by the DLP technique. For each arch, a total of 40 denture bases were fabricated with 4 different build angle conditions (90, 100, 135, and 150 degrees) and divided into 4 groups (90D, 100D, 135D, and 150D; 10 denture bases per group). The scanned intaglio surface of each DLP denture base was superimposed on the scanned edentulous area of the reference cast to compare the degree of tissue surface adaptation. Root-mean-square estimate, positive average deviation, and negative average deviation values were measured and displayed with a color deviation map. The Mann-Whitney test and Kruskal-Wallis analysis of variance were used for statistical analyses (α=.05).
No statistically significant differences were found for root-mean-square estimate values among any build angle groups in either the maxillary or mandibular arch. With the increase of build angles, the area of positive deviation in the maxillary arch moved from the palatal region to the posterior palatal seal area, and negative deviation became pronounced at the posterior tuberosity. In the maxillary arch, the 135D group showed favorable color distribution of surface deviation. In the mandibular arch, a positive deviation was detected at the labial slope to the crest of the ridge, whereas a negative deviation was observed at the buccal shelf and the retromolar pad. The 100D group showed favorable distribution of surface deviation in the mandible.
In both arches, the difference of overall tissue surface adaptation was not statistically significant in the 4 different build angles. However, the color deviation map revealed that the 135-degree build angle may be appropriate in the maxillary DLP-printed denture base and the 100-degree angle, in the mandibular denture base.
High‐translucency restorative materials are commonly used in the restoration of anterior teeth where aesthetics is a critical factor. In this in vitro study, the impact of mouthwash on the colour ...stability and surface characteristics of high‐translucency computer‐aided design and computer‐aided manufacturing (CAD‐CAM) dental restorative materials was evaluated. Two‐hundred specimens were fabricated from five high‐translucency CAD‐CAM materials: a resin nano ceramic; a polymer‐infiltrated ceramic network; a feldspathic ceramic; a lithium disilicate glass ceramic; and high‐translucency zirconia. Each group of ceramic specimens was then divided into four subgroups: conventional mouthwash (LISTERINE); whitening mouthwash (LISTERINE Healthy White); chlorhexidine gluconate; and distilled water. Oral rinsing was simulated at 100 rpm for 180 h, representing 15 yr of clinical simulation. The specimens were then evaluated for colour, translucency, gloss, roughness, and surface morphology. Two‐way ANOVA and linear mixed models were used for intergroup comparisons (α = 0.05). The polymer‐infiltrated ceramic network and feldspathic ceramic became brighter, more opaque, less glossy, and rougher after rinsing with the whitening mouthwash. The long‐term use of specific mouthwashes can cause deterioration of the optical and surface properties of high‐translucency CAD‐CAM dental restorations.
This in vitro study investigated the impact of various dentifrices on the shade, translucency, gloss, and surface characteristics of polishing- or glazing-finished monolithic zirconia surfaces after ...simulated toothbrushing. Eighty square-shaped monolithic zirconia specimens were divided into two major groups based on the finishing methods-polished (P) and glazed (G). Next, specimens from the two major groups were categorized into four subgroups: stored in distilled water (DW, control); brushed with a fluoride-free conventional dentifrice (C); brushed with a fluoride dentifrice (F); and brushed with a whitening dentifrice (W). Overall, eight groups were created-PDW, PC, PF, PW, GDW, GC, GF, and GW (
= 10 each). Shade, translucency, surface gloss, surface roughness, crystalline phase, and superficial topography data were obtained. Repeated-measures ANOVA and two-way ANOVA were used for intergroup comparison (all
= 0.05). The color differences (Δ
) between pre- and posttreatment were 0.3158 (PDW), 0.7164 (PC), 0.7498 (PF), 0.8106 (PW), 0.1953 (GDW), 0.301 (GC), 0.3051 (GF), and 0.4846 (GW). A statistically significant difference was observed among the Δ
, surface gloss, and surface roughness of monolithic zirconia. Thus, brushing with several dentifrices markedly affects the optical properties and surface characteristics of monolithic zirconia finished with polishing or glazing methods.
This study aimed to investigate the effects of sandblasting on the physical properties and bond strength of two types of translucent zirconia: niobium-oxide-containing yttria-stabilized tetragonal ...zirconia polycrystals ((Y, Nb)-TZP) and 5 mol% yttria-partially stabilized zirconia (5Y-PSZ). Fully sintered disc specimens were either sandblasted with 125 µm alumina particles or left as-sintered. Surface roughness, crystal phase compositions, and surface morphology were explored. Biaxial flexural strength (n=10) and shear bond strength (SBS) (n=12) were evaluated, including thermocycling conditions. Results indicated a decrease in flexural strength of 5Y-PSZ from 601 to 303 MPa upon sandblasting, while (Y, Nb)-TZP improved from 458 to 544 MPa. Both materials significantly increased SBS after sandblasting (p<0.001). After thermocycling, (Y, Nb)-TZP maintained superior SBS (14.3 MPa) compared to 5Y-PSZ (11.3 MPa) (p<0.001). The study concludes that (Y, Nb)-TZP is preferable for sandblasting applications, particularly for achieving durable bonding without compromising flexural strength.
Purpurin has various effects, including anti-inflammatory effects, and can efficiently cross the blood–brain barrier. In the present study, we investigated the effects of purpurin on oxidative stress ...in HT22 cells and mild brain damage in the gerbil hippocampal CA1 region induced by transient forebrain ischemia. Oxidative stress induced by H
2
O
2
was significantly ameliorated by treatment with purpurin, based on changes in cell death, DNA fragmentation, formation of reactive oxygen species, and pro-apoptotic (Bax)/anti-apoptotic (Bcl-2) protein levels. In addition, treatment with purpurin significantly reduced the phosphorylation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase 1/2 (ERK), and p38 signaling in HT22 cells. Transient forebrain ischemia in gerbils led to a significant increase in locomotor activity 1 day after ischemia and significant decrease in number of surviving cells in the CA1 region 4 days after ischemia. Administration of purpurin reduced the travel distance 1 day after ischemia and abrogates the neuronal death in the hippocampal CA1 region 4 days after ischemia based on immunohistochemical and histochemical staining for NeuN and Fluoro-Jade C, respectively. Purpurin treatment significantly decreased the activation of microglia and astrocytes as well as the increases of nuclear factor kappa-light-chain-enhancer of activated B cells p65 in the hippocampal CA1 region 4 days after ischemia and ameliorated the ischemia-induced transient increases of interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α in the hippocampus 6 h after ischemia. In addition, purpurin significantly alleviated the ischemia-induced phosphorylation of JNK, ERK, and p38 in the hippocampus 1 day after ischemia. Furthermore, purpurin treatment significantly mitigated the increases of Bax in the hippocampus 1 day after ischemia and the lipid peroxidation based on malondialdehyde and hydroperoxides levels 2 days after ischemia. These results suggest that purpurin can be one of the potential candidates to reduce neuronal damage and inflammatory responses after oxidative stress in HT22 cells or ischemic damage in gerbils.
Determining the peri-implant marginal bone level on radiographs is challenging because the boundaries of the bones around implants are often unclear or the heights of the buccal and lingual bone ...levels are different. Therefore, a deep convolutional neural network (CNN) was evaluated for detecting the marginal bone level, top, and apex of implants on dental periapical radiographs. An automated assistant system was proposed for calculating the bone loss percentage and classifying the bone resorption severity. A modified region-based CNN (R-CNN) was trained using transfer learning based on Microsoft Common Objects in Context dataset. Overall, 708 periapical radiographic images were divided into training (
= 508), validation (
= 100), and test (
= 100) datasets. The training dataset was randomly enriched by data augmentation. For evaluation, average precision, average recall, and mean object keypoint similarity (OKS) were calculated, and the mean OKS values of the model and a dental clinician were compared. Using detected keypoints, radiographic bone loss was measured and classified. No statistically significant difference was found between the modified R-CNN model and dental clinician for detecting landmarks around dental implants. The modified R-CNN model can be utilized to measure the radiographic peri-implant bone loss ratio to assess the severity of peri-implantitis.
Abstract
Carboxyl terminus of Hsc70-interacting protein (CHIP) is highly conserved and is linked to the connection between molecular chaperones and proteasomes to degrade chaperone-bound proteins. In ...this study, we synthesized the transactivator of transcription (Tat)-CHIP fusion protein for effective delivery into the brain and examined the effects of CHIP against oxidative stress in HT22 cells induced by hydrogen peroxide (H
2
O
2
) treatment and ischemic damage in gerbils by 5 min of occlusion of both common carotid arteries, to elucidate the possibility of using Tat-CHIP as a therapeutic agent against ischemic damage. Tat-CHIP was effectively delivered to HT22 hippocampal cells in a concentration- and time-dependent manner, and protein degradation was confirmed in HT22 cells. In addition, Tat-CHIP significantly ameliorated the oxidative damage induced by 200 μM H
2
O
2
and decreased DNA fragmentation and reactive oxygen species formation. In addition, Tat-CHIP showed neuroprotective effects against ischemic damage in a dose-dependent manner and significant ameliorative effects against ischemia-induced glial activation, oxidative stress (hydroperoxide and malondialdehyde), pro-inflammatory cytokines (interleukin-1β, interleukin-6, and tumor necrosis factor-α) release, and glutathione and its redox enzymes (glutathione peroxidase and glutathione reductase) in the hippocampus. These results suggest that Tat-CHIP could be a therapeutic agent that can protect neurons from ischemic damage.
Translucent zirconia, manufactured by increasing the yttria content, offers improved translucency, but may have a negative effect on esthetic outcomes under clinical conditions such as discolored ...abutment because of the reflection of the underlying color. The purpose of this in vitro study was to compare the translucency parameter and masking ability of 3 mol % yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP (Katana HT)), 4Y-ZP (Katana STML), and 5Y-ZP (Katana UTML) with those of lithium disilicate (Rosetta SM). Zirconia and lithium disilicate specimens of 10 mm diameters and 0.8 and 1.5 mm thicknesses were fabricated. Their CIE L*a*b* values (L*, brightness; a*, red-green value; b*, yellow-blue value) were measured at the center of the specimens against black and white backgrounds using a spectrophotometer, and translucency parameter (TP) values were determined. The microstructure of the specimens was observed using scanning electron microscopy. Four cylindrical backgrounds of different shades were prepared. The zirconia and lithium disilicate specimens were placed on the backgrounds without any intervening medium. CIE L*a*b* values were obtained, and the color difference value (ΔE) was calculated. Thresholds for acceptability and perceptibility were assumed as ΔE = 5.5 and ΔE = 2.6, respectively, to evaluate masking ability. Data were compared using one-way analysis of variance and post-hoc was performed using Scheffe’s test (α = 0.05). In zirconia specimens, the TP value increased as the yttria content increased from 3 mol %, through 4 mol % to 5 mol %, and all zirconia specimens showed lower TP values than lithium disilicate specimens did. All zirconia specimens showed optimal masking ability against a normal dentin shade (ND3) and acceptable masking ability against titanium at a minimum thickness of 1.5 mm. However, no zirconia specimen could mask severely discolored dentin (ND9), regardless of thickness. The decrease in zirconia thickness from 1.5 to 0.8 mm significantly increased translucency. Monolithic Y-TZP ceramics could mask a normal dentin background but could not mask severely discolored dentin at either 0.8 or 1.5 mm thicknesses.
Cuprizone is commonly used to induce neuronal demyelination in mice. In the present study, we compared the cuprizone-induced demyelination in the corpus callosum and investigated the effects of ...cuprizone on proliferating cells and neuroblasts in the dentate gyrus of young adult and aged mice. 5-week- and 23-month-old mice were fed a normal diet or a 0.2% cuprizone-enriched diet for 5 weeks. Mice fed a cuprizone-supplemented diet showed a significant reduction in myelin basic protein-positive structures in the corpus callosum, with the reduction in myelinated fibers being confirmed by electron microscopic analysis. In addition, we observed a marked increase in Ki67-positive proliferating cells and doublecortin-immunoreactive neuroblasts in young adult mice in response to cuprizone treatment, although not in aged mice, as the basal levels of these cells were significantly lower in these older mice. Furthermore, Ser133-phosphorylated cAMP response element-binding protein (pCREB)-positive nuclei and brain-derived neurotrophic factor (BDNF) protein levels were significantly reduced in young adult mice following cuprizone treatment in young adult, although again not in the aged mice. However, in both young adult and aged mice, there were no significant reductions in hippocampal mature neurons in response to cuprizone treatment. These observations indicate that in the mice of both age groups a cuprizone-supplemented diet contributes to an increase in demyelination in the corpus callosum and neural progenitor cells in the dentate gyrus, although the damage is more pronounced in young adult mice. This demyelination and reduction in neural progenitor cells may be associated with changes in the levels of BDNF and pCREB in the dentate gyrus.
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