The effect of mentoplate application on the condyle.

BACKGROUND: The aim of the study was to investigate the changes occurring in the mandibular condyle by using mentoplate together with rapid maxillary expansion (MP-RME) treatment in the correction of skeletal class III relationship, using fractal analysis (FA). METHODS: The sample consisted of 30 individuals (8-11 years) diagnosed with skeletal Class III malocclusion who underwent MP-RME treatment. Archival records provided cone-beam computed tomography (CBCT) images taken at two intervals: before MP-RME treatment (T0) and after treatment (T1). The CBCT images were obtained using standardized settings to ensure consistency in image quality and resolution. The trabecular structures in the bilateral condyles at both T0 and T1 were analyzed using FA. The FA was performed on these condylar images using the Image J software. The region of interest (ROI) was carefully selected in the condyle to avoid overlapping with cortical bone, and the box-counting method was employed to calculate the fractal dimension (FD). Statistical analysis was conducted to compare the FD values between T0 and T1 and to evaluate gender differences. The statistical significance was determined using paired t-tests for intra-group comparisons and independent t-tests for inter-group comparisons, with a significance level set at p < 0.05. RESULTS: The analysis revealed no statistically significant differences in the trabecular structures of the condyles between T0 and T1 (p > 0.05). However, a significant gender difference was observed in FA values, with males exhibiting higher FA values in the left condyle compared to females at both T0 and T1 (p < 0.05). Specifically, the FA values in the left condyle increased from a mean of 1.09 ± 0.09 at T0 to 1.13 ± 0.08 at T1 in males, whereas in females, the FA values remained relatively stable with a mean of 1 ± 0.09 at T0 and 1.03 ± 0.11 at T1. CONCLUSION: The findings indicate that MP-RME therapy does not induce significant alterations in the trabecular structure of the mandibular condyle. These results suggest the treatment's safety concerning the structural integrity of the condyle, although the observed gender differences in FA values warrant further investigation.

Role of p38 MAPK, Akt and NFκB in renoprotective effects of nebivolol on renal ischemia-reperfusion injury in rats.

Renal ischemia-reperfusion (I-R) injury is a complex pathophysiologic condition characterized by oxidative stress, inflammation and apoptosis. We investigated the potential renoprotective effect of nebivolol, a ß1 adrenergic receptor blocker, against renal I-R injury. We focused on the role of nebivolol in activating p38 mitogen-activated protein kinase (MAPK) signaling, Akt (protein kinase B) and nuclear factor-κB (NFκB) transcription factors, which contribute to oxidative stress, inflammation and apoptosis during renal I-R. We divided 20 adult male Wistar albino rats into three experimental groups. Group 1 was a sham control in which only laparotomy was performed. Group 2 was the I-R group in which both kidneys were made ischemic for 45 min, then reperfused for 24 h. Group 3 was the I-R + nebivolol group in which 10 mg/kg nebivolol was administrated by gavage for 7 days before I-R. We measured Inflammation, oxidative stress and active caspase-3 as well as activation of p38 MAPK, Akt (protein kinase B) and NFκB transcription factor. Nebivolol significantly reduced oxidative stress and increased superoxide dismutase levels during renal I-R. We found that nebivolol significantly decreased interstitial inflammation, and TNF-α and interleukin-1ß mRNA expression. Nebivolol significantly reduced active caspase-3 and kidney injury molecule-1 (KIM-1) expressions. Nebivolol also significantly decreased activation of p38 MAPK signaling and NFκB, and induced Akt activation during renal I-R. Our findings suggest that nebivolol may be useful for management of renal I-R injury.

Protective effects of alpha-lipoic acid on bleomycin-induced skin fibrosis through the repression of NADPH Oxidase 4 and TGF-ß1/Smad3 signaling pathways.

The aim of this study was to determine the protective effects of alpha-lipoic acid (ALA), which is known as a powerful antioxidant, and the possible related molecular mechanisms that mediate its favorable action on skin fibrosis in the bleomycin (BLM)-induced scleroderma (SSc) model in mice. The experimental design was established with four groups of eight mice: Control, ALA (100 mg/kg), BLM (5 µg/kg), and BLM + ALA group. BLM was administered via subcutaneous (sc) once a day while ALA was injected intraperitoneally (ip) twice a week for 21 days. Histopathological and biochemical analyses showed that ALA significantly reduced BLM-induced dermal thickness, inflammation score, and mRNA expression of tumor necrosis factor-alpha (TNF-α) in the skin. Besides, the mRNA expressions of the subunits of NADPH oxidase, which are Nox4 and p22phox, were found to be significantly induced in the BLM group. However, ALA significantly reduced their mRNA expression, which were in parallel to its decreasing effect on serum total oxidant status (TOS) level. Moreover, it was found that ALA downregulated the mRNA expressions of alpha-smooth muscle actin (α-SMA), collagen type I and fibronectin in the skin tissue of the BLM group. Additionally, it was shown that ALA reduced significantly the TGF-ß1 and p-Smad3 protein expressions in the BLM + ALA group. On the other hand, ALA did not exhibit any significant effect on the p38 mitogen-activated kinase (MAPK) activation induced by BLM. All these findings point out that ALA may be a promising treatment for the attenuation of skin fibrosis in SSc patients.

Measurement of the trabecular bone structure of the TMJ region in patients with transverse maxillary deficiency: a CBCT fractal analysis study.

OBJECTIVE: This study aimed to evaluate the effect of transverse maxillary deficiency on condylar morphology via visual examination and fractal analysis of cone beam computed tomography (CBCT) scans. STUDY DESIGN: In total, 97 patients with posterior crossbite or maxillary narrowness and 36 control patients were included. The presence of degenerative changes in the bilateral condyles was evaluated with CBCT. Fractal dimension (FD) was calculated on the condylar images using ImageJ. RESULTS: Degenerative bone changes were discovered in 38 of the 133 scans (28.6%). There was no significant difference between the groups in terms of the incidence of degenerative changes for either the right or left sides (P ≥ .670). In coronal sections and in mean measurements, FD was significantly lower in the control group compared with the other groups in the right condyle (P ≤ .031). No significant differences were found between the mean FD values of the condyles with degenerative bone changes or the mean FD values of the normal condyles (P ≥ .256). CONCLUSIONS: In the presence of maxillary transverse deficiencies, degenerative bone changes in the mandibular condyle were not significantly different, but the FD of the right condyle was found to be higher compared with the control group.

Alpha-lipoic acid alleviates colistin nephrotoxicity in rats.

Colistin methanesulfonate (CMS), a clinical form of colistin, is widely used as a last-line treatment for multidrug-resistant (MDR) gram-negative bacterial infections in critically ill patients presenting a considerably high mortality rate. However, nephrotoxicity is considered to be a critical adverse effect that limits CMS's clinical use. Alpha-lipoic acid (ALA) is a strong antioxidant that is effective in preventing nephrotoxicity in many models. The aim of this study was to investigate ALA's ability to protect against nephrotoxicity induced by colistin in rats. Male Wistar albino rats were randomly divided into four groups. Group 1 was the control group (Control; n = 6), in which isotonic saline was administered to the rats. Group 2 was the ALA group (ALA; n = 6) in which rats received 100 mg/kg ALA. Groups 3 was the CMS (CMS; n = 7) in which 450.000 IU/kg/day of CMS was administered to the rats. Groups 4 was the CMS + ALA group (n = 6), in which rats were injected with 100 mg/kg of ALA 30 min before administration of CMS. All injections were performed intraperitoneally at 1, 4, 7, and 10 days. Urine was collected by using a metabolic cage for 24 h after each administration. The rats were euthanized under ether anesthesia after 24 h of the last administration. Blood and kidney samples then were collected for histological and biochemical analysis. ALA pretreatment could reverse the effects of colistin-induced nephrotoxicity, partly through its suppressing effect on Nox4 and caspase-3, which in turn results in its antioxidant and antiapoptotic effect. Therefore, ALA may be an effective strategy for the management of colistin nephrotoxicity.

Alpha lipoic acid attenuates iron induced oxidative acute kidney injury in rats.

Iron has been implicated in oxidative tissue injury owing to its ability to generate reactive oxygen species (ROS). We investigated the reno-protective effects of alpha lipoic acid (ALA) by investigating its effects on the kidney isoform of NADPH oxidase (Nox4) and the specific signaling pathways, p38 MAPK and PI3K/Akt, which participate in apoptosis and survival, respectively. We established four groups of seven rats: control, 100 mg/kg ALA, 80 mg/kg iron sucrose (IS) and IS + ALA. IS and ALA were injected intravenously and rats were sacrificied after 6 h. The mRNA expression of the subunits of NADPH oxidase, Nox4 and p22phox; tumor necrosis factor-alpha (TNF-α); and kidney injury molecule-1 (KIM-1) were measured using quantitative real time polymerase chain reaction (qRT-PCR). Active caspase-3 protein expression was evaluated by immunostaining. Also, p38 MAPK and PI3K/Akt signaling pathways were analyzed using western blot. ALA suppressed the mRNA expression of Nox4, p22phox, TNF-α and KIM-1. Active caspase-3 protein expression induced by IS was decreased by ALA. ALA also suppressed p38 MAPK and activated the PI3K/Akt signaling pathway following IS administration. We found that ALA may be an effective strategy for preventing oxidative acute kidney injury caused by IS.

A preliminary study of possible fibrotic role of meprin metalloproteases in scleroderma patients.

Objectives: This study aims to investigate the possible fibrotic role of meprin metalloproteases and possible fibrotic effects of activator protein-1 (AP-1) in scleroderma patients. Patients and methods: Between April 2018 and April 2019, a total of 85 scleroderma patients (9 males, 76 females; mean age: 54.9 years; range, 22 to 80 years) who met the 2013 American College of Rheumatology/European League Against Rheumatism criteria and 80 healthy control individuals (10 males, 70 females; mean age 42.9 years; range, 19 to 65 years) were included. Patients' data and blood samples were collected. Messenger ribonucleic acid expressions of interleukin (IL)-6, AP-1 subunits, and tumor necrosis factor-alpha (TNF-α) were analyzed by quantitative real-time polymerase chain reaction. Serum meprin alpha and beta protein levels were analyzed using the enzyme-linked immunosorbent assay. Results: Meprin alpha and meprin beta protein levels increased in scleroderma patients. The AP-1 subunits (c-Fos, c-Jun), IL-6, and TNF-α increased in scleroderma patients, compared to controls. Conclusion: Our results provide evidence showing that increased meprins levels may be related to AP-1 levels and increased meprins levels may responsible for increased inflammatory TNF-α and IL-6 levels. All these data suggest meprins as promising therapeutic targets to restore the balance between inflammation and extracellular matrix deposition in scleroderma.

Relationship of Wnt pathway activity and organ involvement in scleroderma types.

OBJECTIVE: Scleroderma (SSc) is a chronic inflammatory autoimmune disease characterized by fibrosis in the skin and internal organs. In SSc, the heart, lung, kidney, gastrointestinal (GIS) system, muscle, and peri-articular structures are damaged. There is no study of the relationship between SSc type, stage, pathogenesis, organ involvement, and Wnt signaling. In this study, we aimed to show the relationship of the Wnt gene family and antagonists in SSc subtypes and different organ involvement. METHODS: Eighty-five SSc patients and 77 controls were included in this study. The gene expressions and protein levels of the Wnt family and antagonists were analyzed from blood samples. The relationship between these parameters and disease stage, type, and organ involvement were evaluated. RESULTS: Wnt-1, Wnt-10b, Wnt-2, and Wnt-6 gene expressions are increased and Axin-2, DKK-1, and Kremen protein expressions are decreased in SSc. Wnt-3a and Wnt-10a gene expressions are increased in generalized SSc compared to limited SSc. Wnt-1, Wnt-2 gene expressions are increased significantly in pulmonary arterial hypertension (PAH)(+) SSc compared to PAH(-) SSc. There was a positive correlation between the modified Rodnan skin score and Wnt-2 in SSc. There was a significant positive correlation between GIS involvement score and Wnt-1, Wnt-2, Wnt-4, Wnt-8a, Wnt-9b in SSc. CONCLUSION: Wnt-1 and Wnt-2 were found higher in scleroderma and organ involvement. They may play a role in the pathogenesis of the disease.

Renoprotective Effects of Alpha Lipoic Acid on Iron Overload-Induced Kidney Injury in Rats by Suppressing NADPH Oxidase 4 and p38 MAPK Signaling.

We aimed to investigate the protective effect of alpha lipoic acid (ALA), a powerful antioxidant, against oxidative kidney damage induced by iron overload in rats. Male Wistar albino rats were separated into groups: control (n = 7), ALA (100 mg/kg (n = 7), iron sucrose (IS) (40 mg/kg) (n = 7), and IS + ALA (40 mg/kg IS administration followed by 100 mg/kg ALA) (n = 7). IS and ALA were injected weekly for 4 weeks via the tail vein. Blood and kidneys were collected at sacrification on day 29. Serum creatinine and iron levels were analyzed. Tubular injury and iron deposits were evaluated histopathologically. Additionally, iron, malondialdehyde (MDA), superoxide dismutase (SOD), catalase, and glutathione (GSH) levels and mRNA expressions of the subunits of NADPH oxidase, known as NOX4 and p22phox, tumor necrosis factor (TNF)-α, kidney injury molecule-1 (KIM-1), and also p38 MAPK signaling in the kidneys, were evaluated biochemically. In the IS group, serum creatinine and iron level, tubular dilation, and loss of brush border in the kidneys were significantly higher than those of the control. Although those changes were reduced by ALA, the differences were not statistically significant. However, ALA reduced significantly MDA level and increased SOD activity in the kidney during IS administration. ALA also significantly reduced mRNA expressions of NOX4 and p22phox induced by IS, which was parallel to significant decreases of TNF-α and KIM-1 mRNA expressions. Moreover, ALA could suppress the activation of p38 MAPK during IS administration. In conclusion, ALA may be an effective strategy to attenuate in IS-induced oxidative kidney injury.

Pretreatment with paricalcitol attenuates level and expression of matrix metalloproteinases in a rat model of renal ischemia-reperfusion injury
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BACKGROUND: Ischemia-reperfusion injury (IRI) is a leading cause of acute kidney injury (AKI). The inflammatory response that drives IRI involves upregulation of matrix metalloproteinases (MMPs), which results in proteolytic degradation of renal microvascular matrix. Evidence suggests a potential protective role of active vitamin D on ischemic injury by downregulating MMPs. In the present study, we aimed to determine the expression and level of MMP-2 and MMP-9 in renal IRI model and the potential beneficial effect of paricalcitol on both level and expression of MMPs and tubular injury caused by IRI. MATERIALS AND METHODS: 20 Wistar albino rats were divided into three groups: sham-operated, ischemia-reperfusion, and paricalcitol-pretreated. IRI model was induced by bilateral clamping of renal arteries for 45 minutes followed by 24 hours of reperfusion. The analysis of serum creatinine and levels of MMPs were performed after 24 hours of IRI. The effects of paricalcitol on the quantity and expression of MMP-2 and MMP-9 in renal tubular epithelial cells were investigated by enzyme-linked immunosorbent assay and immunohistochemistry, respectively. The pathological examinations were performed to score tubular damage by light microscopy. RESULTS: Creatinine levels decreased in the paricalcitol group, although this was not proven to be significant. Rats in the paricalcitol group showed significant decrease in both level and expression of MMPs and in tubular injury scores as compared to the IRI group. CONCLUSION: Paricalcitol may attenuate renal tubular injury caused by IRI by decreasing both level and expression of MMPs. Further studies are required to investigate the interplay between activated vitamin D and MMPs in AKI.
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Role of the microRNA-29 family in fibrotic skin diseases.

Fibrotic skin diseases are characterized by the accumulation of collagen. The hallmarks of fibrotic skin diseases are unbalanced fibroblast proliferation and differentiation, extracellular matrix production and transforming growth factor-ß signalling. Numerous studies have investigated the possibility that microRNAs (miRNAs or miRs) are involved in the pathogenesis of certain fibrotic diseases, including skin, heart, lung and liver diseases. miRNAs are a class of small non-coding RNAs, which modify gene expression by binding to target messenger RNA (mRNA) and blocking the translation or inducing the degradation of target mRNA. The biological relevance of miRNAs has been investigated in physiological and pathological conditions, and there is increasing evidence that the miR-29 family is associated with fibrotic diseases. The aim of the present review is to provide an up-to-date summary of current knowledge on the latest developments associated with the miR-29 family and fibrotic skin diseases.

Pretreatment with nebivolol attenuates level and expression of matrix metalloproteinases in a rat model of renal ischaemia-reperfusion injury.

AIM: Matrix metalloproteinases (MMPs) are zinc-containing proteinases that are involved in the degradation of extracellular matrix (ECM) and a number of cell surface proteins in order to maintain tissue homeostasis. They are involved in pathogenesis of several ischaemic organ injuries. In the present study, we aimed to determine the expression and level of MMP-2 and MMP-9 in renal ischaemia-reperfusion injury (IRI) model and the potential beneficial effect of nebivolol, a ß1 -adrenergic receptor blocker, on both MMP-2 and -9 level and expression and tubular injury caused by IRI. METHODS: Twenty Wistar albino rats were divided into three groups: sham-operated , ischaemia-reperfusion, and nebivolol-pretreated. IRI model was induced by bilateral clamping of renal arteries for 45 min followed by 24 h of reperfusion. The analysis of serum creatinine levels, quantity and expression of MMP-2 and MMP-9 were performed after 24 h of IRI. The effects of nebivolol on level and expression of MMP-2 and MMP-9 levels were investigated by enzyme-linked immunosorbent assay and immunohistochemistry, respectively. The pathological examinations were performed to score tubular damage by light microscopy. RESULTS: Creatinine levels increased significantly in the ischaemia-reperfusion group compared to the sham-operated group. Rats in the nebivolol-pretreated group showed significant decrease in expression and quantity of MMP-2 and MMP-9 during IRI. The pathological examinations demonstrated significantly low level of tubular injury score in nebivolol-pretreated group. CONCLUSION: Nebivolol attenuated IRI by decreasing the expression and level of MMP-2 and MMP-9.

Factors triggering the oral mucosal lesions by complete dentures.

Oral mucosal lesions may represent acute or chronic reactions to factors related with dentures. The aim of this study was to determine the frequency of the oral lesions related to gender, age, the length of time of denture usage, the balance of denture and cleaning methods and frequency. The 106 patients who have old complete dentures came to the Dental Faculty of Marmara University, Istanbul (Turkey) to have new complete dentures were asked to participate in the investigation. The subjects (51 men and 55 women) were 37-80 years of age with a mean age of 60.28+/-10.52 years. All main factors were estimated in subgroups: cleaning methods and frequency were divided into 3 subgroups respectively as toothbrush and toothpaste/soap, denture cleansing tablets and sodium carbonate, and 3 times a day, everyday, every 3 day and once a week. The data obtained was evaluated by One-way ANOVA, Mann-Whitney U-test, Kruskal-Wallis-test, Student t-test and chi(2)-test. The level of statistical significance was set at p<0.05. The patients displayed statistically significant differences in the topics of the length of time of denture usage and the balance of denture in terms of retention. The complete denture wearers should be educated in the importance of periodic examination due to the changing of supporting tissues for detection early mucosal lesions to maintain their oral and dentures hygiene in optimum level.

Fractographic analyses of zirconia-based fixed partial dentures.

OBJECTIVES: Advances in ceramic processing techniques enable clinicians and ceramists to fabricate all-ceramic fixed partial dentures (FPDs) for posterior regions using high-strength yttria-stabilized tetragonal zirconia polycrystals (Y-TZP). However, failures occur in ceramic FPDs due to their design. The objectives of this study were to determine the site of crack initiation and the causes of fracture in clinically failed zirconia-based ceramic FPDs. METHODS: Five clinically failed four-unit Y-TZP-based FPDs (Cercon ceramics, DeguDent GmbH, Hanau, Germany) were retrieved and analyzed. The fragments containing the fracture origins in the veneers (Cercon Ceram S Veneering Ceramic, DeguDent GmbH, Hanau, Germany) of two samples were missing but the rest of veneer structures were present. The other three samples had their veneers intact. Fracture surfaces were examined using fractographic techniques, utilizing both optical and scanning electron microscopes (SEM). Quantitative fractography and fracture mechanics principles were used to estimate the stresses at failure. RESULTS: Primary fractures initiated from the gingival surfaces of connectors at veneer surfaces in four out of the five samples. However, critical flaw sizes could be measured in three of the five cases since fracture origins were lost in the remaining two due to local fragmentation at the crack initiation site. Delaminations between glass veneer and zirconia core were observed in Y-TZP-based FPDs and a secondary fracture initiated from the zirconia core. Secondary fracture controlled the ultimate failure. Failure stresses of the fixed partial dentures that failed due to zirconia fracture ranged from 379 to 501 MPa. Fractures that had origins on the glass veneer surface had failure stresses between 31 and 38 MPa. SIGNIFICANCE: Primary fractures in clinically failed Y-TZP-based FPDs initiated from the veneer surfaces. Interfacial delamination in glass veneer/zirconia core bilayer dental ceramic structures controlled the secondary fracture initiation sites and failure stresses in Y-TZP-based fixed partial dentures.

Effect of five staining solutions on the colour stability of two acrylics and three composite resins based provisional restorations.

The effect of coffee, tea, coca-cola, orange-juice and red wine on the colour stability of acrylic and composite based provisional materials were evaluated. Two acrylic resins and three composite resins were studied. 48 standardized specimens for each provisional material were prepared. Each group was divided into 6 subgroups. Specimens from each group were immersed in staining solutions at room temperature for 30 days. Red wine and tea caused the most significant colour changes and orange juice showed the least significant colour changes. deltaE of all of the provisional restorations materials was changed after the immersion in all of the staining solutions during the experimental process.

Effect of five staining solutions on the colour stability of two acrylics and three composite resins based provisional restorations.

The effect of coffee, tea, coca-cola, orange-juice and red wine on the colour stability of acrylic and composite based provisional materials were evaluated. Two acrylic resins and three composite resins were studied. 48 standardized specimens for each provisional material were prepared. Each group was divided into 6 subgroups. Specimens from each group were immersed in staining solutions at room temperature for 30 days. Red wine and tea caused the most significant colour changes and orange juice showed the least significant colour changes. deltaE of all of the provisional restorations materials was changed after the immersion in all of the staining solutions during the experimental process.