Chk2 deficiency alleviates irradiation-induced taste dysfunction by inhibiting p53-dependent apoptosis

Abstract

Objective

Taste dysfunction is one of the most common complications following radiotherapy, which leads to decreased appetite and life quality of patients suffering from head and neck cancer. The aim of this study was to investigate the role of Checkpoint kinase2 (Chk2) deficiency in irradiation-induced taste dysfunction.

Materials and methods

Alterations in oxidative stress, DNA damage and potential signaling pathway were compared between Chk2-deficient (Chk2^-/-) mice and their wild-type (WT) littermates pre-irradiation, and 7 and 30 days post-irradiation by biochemistry and immunohistochemistry.

Results

Chk2^-/- mice showed less loss of type II and type III taste cells, lower expression of p53, Caspase-3 and cleaved Caspase-3, and lower apoptosis levels. However, no significant differences in H₂O₂ and MDA concentrations, T-SOD and GSH-Px activities, and expression of SOD1, SOD2 and 8-OHdG were detected in the taste buds of Chk2^-/- mice as compared to that of WT mice.

Conclusion

Chk2 deficiency down-regulated the expression of p53 and inhibited cellular apoptosis, partly contributing to the radio-protective effect on taste cells, but did not alter oxidative stress levels, antioxidant ability and oxidative DNA damage in taste buds.

This article is protected by copyright. All rights reserved.

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Smartphone apps for skin cancer diagnosis: Implications for patients and practitioners

Abstract

A research team at Stanford recently reported that their deep convolutional neural network had learned to classify skin cancer with a level of competence equivalent to that of board-certified dermatologists. It is possible that in time, and using larger datasets, such software may surpass the average doctor in diagnostic ability, and that highly accurate technology may be available to both clinicians and patients via smartphones. This technology is poised to change the landscape of skin cancer diagnosis for both physicians and patients, but whether such changes are beneficial will depend on how they are regulated and implemented.

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Giant tumour on the foot

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Comparison of skin cancers in liver and renal transplant recipients: Results of a prospective study in an Australian tertiary referral centre

Abstract

Background/Objectives

Organ transplant recipients (OTR) have an increased risk of skin cancers compared with the general population.

Methods

A prospective study of renal (RTR) and liver transplant recipients (LTR) was conducted in a single New South Wales tertiary referral centre over 60 months. Initial and subsequent visit data were recorded in our transplant database. Only patients with a minimum of 11 months follow up were included.

Results

Altogether 142 RTR and 88 LTR were included in the analysis. Compared with RTR, the median age of liver transplant recipients was higher (64 vs 57 years), more men were patients (73 vs 60%) and there were higher rates of high-risk skin types (54 vs 33%) and heavy sun exposure (43 vs 30%). RTR developed 304 non-melanoma skin cancers (NMSC) with a squamous cell carcinoma:basal cell carcinoma ratio of 1.7:1. LTR developed 205 NMSC with a squamous cell carcinoma:basal cell carcinoma ratio of 1.6:1. The odds ratio of developing NMSC in LTR:RTR was 1.8:1 (95% CI: 1.02–3.11, P = 0.044) on univariate analysis but there was no difference on multivariate analysis. A previous history of NMSC, age, time from transplant from first visit, skin phenotype and previous sun exposure were significant risk factors for developing NMSC.

Conclusions

Liver transplant recipients are not at a lower risk of NMSC than RTR. Our study supports routine and regular post-transplant skin surveillance of all LTR, like other OTR.

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Proximal carious lesions infiltration—a 3-year follow-up study of a randomized controlled clinical trial

Abstract

Introduction

Infiltration of carious lesion has been claimed as a promising approach for the management of non-cavitated proximal lesions (NCPL). Clinical studies have suggested that this approach may reduce NCPL progression in individuals whose caries risk was not change over the studied period.

Objective

This study aimed to assess the additional benefit of infiltration of NCPL over a 3-year period in a group of individuals who received treatment and control of carious activity.

Materials and methods

Twenty-two caries-active subjects that possessed at least a pair of NCPL in posterior teeth were selected for this study totalizing 36 pairs of lesion. In a split-mouth design, lesions were randomly allocated to test (infiltration) or placebo treatments. At follow-up, lesions were radiographically analyzed, progression was determined by radiographic pair-wise comparison and differences in number of progressing lesions between test, and placebo-treated surfaces were compared.

Results

Seventeen subjects (27 pairs of lesions) were followed up. Only four subjects were caries-active at the follow-up. In the test group, 2/27 (7.4%) lesions and in the placebo group 5/27 (18.5%) lesions had progressed. No statistical difference was observed between the studied groups (p = 0.453).

Conclusion

Subjects under treatment focusing on controlling caries activity presented low progression rates in both infiltrated and non-infiltrated NCPL. As only very few lesions progressed in both groups, no significant additional effect could be found. Further studies with larger sample sizes are necessary.

Clinical relevance

Infiltration of NCPL may have limited additional effect if other treatments focused on controlling caries activity are successful.

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Assessment of periodontal bone level revisited: a controlled study on the diagnostic accuracy of clinical evaluation methods and intra-oral radiography

Abstract

Objectives

The accuracy of analogue and especially digital intra-oral radiography in assessing interdental bone level needs further documentation. The aim of this study was to compare clinical and radiographic bone level assessment to intra-surgical bone level registration (1) and to identify the clinical variables rendering interdental bone level assessment inaccurate (2).

Materials and methods

The study sample included 49 interdental sites in 17 periodontitis patients. Evaluation methods included vertical relative probing attachment level (RAL-V), analogue and digital intra-oral radiography and bone sounding without and with flap elevation. The latter was considered the true bone level. Five examiners evaluated all radiographs.

Results

Significant underestimation of the true bone level was observed for all evaluation methods pointing to 2.7 mm on average for analogue radiography, 2.5 mm for digital radiography, 1.8 mm for RAL-V and 0.6 mm for bone sounding without flap elevation (p < 0.001). Radiographic underestimation of the true bone level was higher in the (pre)molar region (p ≤ 0.047) and increased with defect depth (p < 0.001). Variation between clinicians was huge (range analogue radiography 2.2–3.2 mm; range digital radiography 2.1–3.0 mm).

Conclusion

All evaluation methods significantly underestimated the true bone level. Bone sounding was most accurate, whereas intra-oral radiographs were least accurate. Deep periodontal defects in the (pre)molar region were most underrated by intra-oral radiography.

Clinical relevance

Bone sounding had the highest accuracy in assessing interdental bone level.

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Role of HIF-1α and CASPASE-3 in cystogenesis of odontogenic cysts and tumors

Abstract

Objectives

Odontogenic cysts and tumors are the most relevant lesions that affect the gnathic bones. These lesions have in common the formation of cystic areas and this common feature may suggest involvement of similar mechanisms. The hypoxia inducible factor 1 alpha (HIF-1α), a responsive protein to hypoxia and caspase-3, an irreversible apoptosis marker, may contribute to cyst formation. Thus, this study aimed to investigate the immunoexpression of these proteins in odontogenic cysts and tumors.

Material and methods

Twenty cases of ameloblastoma, keratocystic odontogenic tumor (KOT) (n = 20), radicular cyst (RC) (n = 18), dentigerous cyst (DC) (n = 11), calcifying cystic odontogenic tumor (n = 8), and dental follicle (DF) (n = 10) were used to investigate HIF-1α and caspase-3 expression in sequential serial cuts by immunohistochemistry.

Results

HIF-1α was overexpressed in RC, DC, and ameloblastoma when compared with DF. The basal and sometimes the lower suprabasal layer showed no or very low expression in DC, KOT, and ameloblastoma, the last also showing strong expression in solid epithelial areas and initial cystic formation regions. Caspase-3 was found to be overexpressed in all lesions, with the highest expression in odontogenic cysts compared to tumors. HIF-1α and caspase-3 were localized in similar areas of the same lesions, especially in the epithelium surrounding cystic formations.

Conclusions

This study showed distinct immunoexpression of HIF-1α and caspase-3 in odontogenic cyst and tumors, with higher expression observed in odontogenic cysts.

Clinical relevance

These findings suggest a possible correlation between hypoxia, apoptosis, and cystogenesis, leading to understand the mechanisms responsible to cystic formation in odontogenic lesions.

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Evaluation of metal artefact reduction in cone-beam computed tomography images of different dental materials

Abstract

Objective

The aim of this study is to evaluate the efficacy of metal artefact reduction (MAR) in different dental materials with Picasso Trio cone-beam computed tomography (CBCT) scanner.

Materials and methods

Three imaging phantoms were custom-made of acrylic resin. Each phantom presented three cylinders of the same material: dental amalgam alloy, gutta-percha or aluminium-copper alloy. CBCT scans were performed on Picasso Trio unit with and without MAR, and artefact expression (standard deviation of grey values) was obtained and compared by Kruskal-Wallis and Student-Newman-Keuls (post hoc) (α = 0.05).

Results

Significant reduction of artefact expression (p < 0.05) was observed with MAR on areas around dental alloys. No significant difference (p > 0.05) was observed with or without MAR when gutta-percha was scanned.

Conclusion

MAR was effective in reducing artefacts arising from dental alloys on CBCT images.

Clinical relevance

Dental materials of high atomic number and density are widely used in dentistry and can produce artefact that compromise CBCT image. The present study demonstrated that metal artefact reduction algorithm is an effective tool to improve image quality.

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pH influences the biocompatibility of methylene blue solutions

Abstract

Objective

The aim of this study was to investigate the biocompatibility of methylene blue at different pH levels through the method of implantation in subcutaneous tissue.

Materials and methods

Eighty-four sterilized polyethylene tubes were allocated in the subcutaneous tissue of 28 rats, each one receiving four tubes, set into four groups: group tube (G-T)—empty tube, fibrin group (G-F)—tube filled with fibrin sponge, group methylene blue pH 7 (G-MB/pH 7)—tube filled with fibrin sponge soaked by methylene blue (100 μg/ml) at pH 7.0, and group methylene blue pH 1 (G-MB/pH 1)—tube filled with fibrin sponge and soaked by methylene blue (100 μg/ml) at pH 1.0. After 7, 15, and 30 days, seven animals from each group were euthanized, and the tubes involved by the surrounding tissue were removed and fixed with 4% buffered formaldehyde solution. The collected pieces were processed and histological sections (4 μm) were stained with hematoxylin and eosin and analyzed by light microscopy. Scores were assigned to analysis of histopathologic parameters. The results were statistically analyzed by the Kruskal–Wallis test (p ≤ 0.05).

Results

At 7 and 30 days, the G-MB/pH 1 group showed no significant difference in the G-T control group, while G-MB/pH 7 had a significant increase on tissue reaction, also when compared to G-T. At 15 days, there was no statistical difference between the groups.

Conclusion

Within the limits of this study, it is concluded that methylene blue at pH 1.0 provides better biocompatibility than at pH 7.0.

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Three-year survival of ART high-viscosity glass-ionomer and resin composite restorations in people with disability

Abstract

Objectives

To assess the 3-year cumulative survival rate of atraumatic restorative treatment (ART) and conventional resin composite restorations (CRT) placed in persons with disability.

Materials and methods

Patients referred for restorative care to the Haemophilia Foundation special care service were treated by one of two specialists. Patients and/or caregivers were provided with written and verbal information regarding treatment options and selected the alternative they preferred. Treatment was provided as selected unless this option proved clinically unfeasible when an alternative technique was proposed. The treatment protocols were ART (hand instruments/high-viscosity glass-ionomer) in the clinic or CRT (rotary instrumentation/resin composite) in the clinic or under general anaesthesia (GA). After 6, 12, 24 and 36 months, two independent, trained and calibrated examiners evaluated restoration survival using established ART codes. The proportional hazard model with frailty corrections gave survival estimates over 3 years.

Results

Sixty-six patients (13.6 ± 7.8 years) with 16 different disability profiles participated. CRT in the clinic proved feasible for five patients (13%), and 14 patients received CRT under GA (21%). ART was used for 47 patients (71.2%). Altogether, 298 dentine carious lesions were restored in primary and permanent teeth (182 ART; 116 CRT). The 3-year cumulative survival rates and jackknife standard errors for the 182 ART and 116 CRT restorations were 94.8 ± 2.1 and 82.8 ± 5.3%, respectively (p = 0.01).

Conclusions

The 3-year follow-up results confirm that ART is an effective treatment protocol.

Clinical relevance

Patients with disability, many of whom have difficulty coping with CRT, may benefit from the ART approach.

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Reducing dentine hypersensitivity with nano-hydroxyapatite toothpaste: a double-blind randomized controlled trial

Abstract

Objectives

The present randomized double-blind clinical trial aimed to compare the efficacy in reducing dentin hypersensitivity of a dentifrice formulation containing nano-hydroxyapatite with a fluoride dentifrice and a placebo.

Methods and materials

One hundred and five subjects were recruited to participate in the study. A computer-generated random table with blocking to one of the three study treatments was used in order to have 35 subjects per group: (1) nano-hydroxyapatite 2% gel toothpaste fluoride free; (2) fluoride gel toothpaste; (3) placebo. Groups 1, 2, and 3 were instructed to treat their teeth for 10 min twice a day with the provided toothpaste gel. The participant's dentin hypersensitivity was evaluated at baseline and after 2 and 4 weeks using airblast and tactile tests. In addition, a subjective evaluation using a visual analogue scale was used.

Results

Significant lower values of cold air sensitivity and tactile sensitivity (p < 0.05) were found for the test group at 2 weeks and 4 weeks. In addition, statistically significant (p < 0.05) lower values of sensitivity were reported for group 1 compared to those for groups 2 and 3 at 2 and 4 weeks, respectively. The VAS scores were significantly lower (p < 0.05) in the test group at 2 and 4 weeks compared to those at baseline and in the control groups.

Conclusion

The application of nano-hydroxyapatite in gel toothpaste fluoride free is an effective desensitizing agent providing relief from symptoms after 2 and 4 weeks.

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Bacterial colonization in the apical part of extracted human teeth following root-end resection and filling: a confocal laser scanning microscopy study

Abstract

Objectives

The purpose of this study was to evaluate Enterococcus faecalis colonization at the apical part of root canals following root-end resection and filling using confocal laser scanning microscopy (CLSM).

Materials and methods

The apical 3-mm root-ends of 55 extracted single rooted human teeth were resected, and 3-mm retrograde cavities were prepared and filled using either mineral trioxide aggregate (MTA), intermediate restorative material (IRM), or Biodentine (n = 10 each); 25 teeth served as controls. The roots were placed in an experimental model, sterilized, and coronally filled with E. faecalis bacterial suspension for 21 days. Then, the apical 3-mm segments were cut to get two slabs (coronal and apical). The slabs were stained using LIVE/DEAD BacLight Bacterial Viability Kit and evaluated using CLSM.

Results

The fluorescence-stained areas were larger in the bucco-lingual directions compared with the mesio-distal directions (p < 0.05). The mean and maximal depths of bacterial colonization into the dentinal tubules were 755 and 1643 μm, respectively, with no differences between the root-end filling materials (p > 0.05). However, more live bacteria were found in the MTA group in comparison to IRM and Biodentine groups (p < 0.05).

Conclusions

CLSM can be used to histologically demonstrate bacterial root-end colonization following root-end filling. This colonization at the filling-dentine interfaces and deeper into the dentinal tubules may be inhomogeneous, favoring the bucco-lingual aspects of the root.

Clinical relevance

Following root-end resection and filling bacterial colonization may lead to inflammatory reactions at the periapical tissues; the viability of the colonized bacteria may be affected by the type of root-end filling material.

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Genome-wide gene expression profiling of tongue squamous cell carcinoma by RNA-seq

Abstract

Objective

Tongue squamous cell carcinoma (TSCC) is significantly more malignant than other type of oral squamous cell carcinoma (OSCC). In this study, we aimed to identify specific global gene expression signatures of TSCC to investigate the more invasive behavior of the deeply infiltrating cancer.

Methods

Using RNA-seq technology, we detected gene expression of 20 TSCCs, 20 matched paratumor tissues, and 10 healthy normal mucosa tissues. Enrichment analysis of gene ontology (GO) and pathway was conducted using online tools DAVID for the dysregulated genes. Additionally, we performed the quantitative real-time RT-PCR (qRT-PCR) to validate the findings of RNA-Seq in 10 samples of TSCC, matched paratumor, and normal mucosa, respectively.

Results

We detected 252 differentially expressed genes (DEGs) between TSCC and matched paratumor tissue, including 117 up-regulated and 135 down-regulated genes. For comparison between TSCC and normal mucosa, 234 DEGS were identified, consisting of 67 up-regulated and 167 down-regulated genes. For both two comparisons, GO categories of muscle contraction (GO: 0006936), epidermis development (GO: 0008544), epithelial cell differentiation (GO: 0030855), and keratinization (GO: 0031424) were commonly enriched. Altered gene expression affected some cancer-related pathways, such as tight junction. The qRT-PCR validation showed that gene expression patterns of FOLR1, NKX3-1, TFF3, PIGR, NEFL, MMP13, and HMGA2 were fully in concordance with RNA-Seq results.

Conclusion

Findings in this study demonstrated the genetic and molecular alterations associated with TSCC, providing new clues for understanding the molecular mechanisms of TSCC pathogenesis.

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Severe macroglossia after posterior fossa and craniofacial surgery in children

Massive swelling of the tongue can occur after posterior fossa and craniofacial surgery. Several hypotheses have been proposed to explain the occurrence of such severe postoperative macroglossia, but this phenomenon is still poorly understood. Severe postoperative macroglossia can be a life-threatening condition due to upper airway obstruction. Three cases of severe postoperative macroglossia that occurred after cervical spine, craniofacial, and posterior fossa surgical procedures are reported here.

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Postoperative nausea and vomiting after oral and maxillofacial surgery: a prospective study

Postoperative nausea and vomiting (PONV) is one of the most unpleasant experiences after surgery. It reduces patient satisfaction and also increases hospital costs due to longer hospitalizations. The aim of this prospective study was to determine whether orthognathic surgery is associated with more PONV than less invasive maxillofacial surgery. Three hundred and eight patients aged 8–87 years who underwent maxillofacial surgery were included. The PONV score, based on the Apfel score, was calculated preoperatively.

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Postoperative nausea and vomiting after oral and maxillofacial surgery: a prospective study

Publication date: Available online 1 January 2018
Source:International Journal of Oral and Maxillofacial Surgery
Author(s): M. Dobbeleir, J. De Coster, W. Coucke, C. Politis
Postoperative nausea and vomiting (PONV) is one of the most unpleasant experiences after surgery. It reduces patient satisfaction and also increases hospital costs due to longer hospitalizations. The aim of this prospective study was to determine whether orthognathic surgery is associated with more PONV than less invasive maxillofacial surgery. Three hundred and eight patients aged 8–87 years who underwent maxillofacial surgery were included. The PONV score, based on the Apfel score, was calculated preoperatively. PONV occurred in 142 (46.1%) patients during the first three postoperative days; these patients were further categorized as having postoperative nausea (PON) and/or postoperative vomiting (POV). PON was most frequent after orthognathic surgery to the mandible (75%), and POV was most frequent after maxillary surgery, including bimaxillary surgery, Le Fort I osteotomy, and surgically assisted rapid palatal expansion (SARPE) (43.1%). There was a small significant relationship between the preoperative PONV score and the incidence of PONV: patients experienced more PONV when the PONV score calculated preoperatively was higher. The incidence of PONV after orthognathic surgery was very high compared with the incidence after dental extractions and other minor surgeries. Further investigation is required to establish a strategy to reduce PONV after orthognathic surgery.



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