Integrative genomic analysis of matched primary and metastatic pediatric osteosarcoma

Despite being the most common childhood bone tumor, the genomic characterization of osteosarcoma remains incomplete. In particular, very few osteosarcoma metastases have been sequenced to date, critical to better understand mechanisms of progression and evolution in this tumor. We performed an integrated whole genome and exome sequencing analysis of paired primary and metastatic pediatric osteosarcoma specimens to identify recurrent genomic alterations. Sequencing of 13 osteosarcoma patients including 13 primary, 10 metastatic, and 3 locally recurring tumors revealed a highly heterogeneous mutational landscape, including cases of hypermutation and microsatellite instability positivity, but with virtually no recurrent alterations except for mutations involving the tumor suppressor genes RB1 and TP53. At the germline level, we detected alterations in multiple cancer related genes in the majority of the cohort, including those potentially disrupting DNA damage response pathways. Metastases retained only a minimal number of short variants from their corresponding primary tumors, while copy number alterations showed higher conservation. One recurrently amplified gene, KDR, was highly expressed in advanced cases and associated with poor prognosis. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Epstein-Barr virus BMRF-2 and BDLF-3 expression in hairy leukoplakia

Hairy leukoplakia (HL) is a lesion found on the side of the tongue of immunocompromised individuals, including those with human immunodeficiency virus (HIV) infection. The lesion has unique histopathologic features and is characterised by high-level Epstein-Barr virus (EBV) replication, multiple EBV strains, and extensive inter-and intra-strain recombination. Expression of EBV genes spanning the entire viral life cycle from latency-associated genes to late, replicative genes has been detected in the lesion. HL thus provides a unique opportunity to study EBV expression in oral epithelium, and to study expression of novel EBV genes. We therefore constructed a cDNA library from an HL biopsy and detected expression of two genes not previously described in vivo: BMRF-2 and BDLF-3. Sequence analysis of the cDNAs revealed few amino acid changes from the B95-8 sequence. Expression of both genes was localized to the lower prickle cell layer of the tongue epithelium. BMRF-2 protein expression was primarily detected in the cell nuclei of the upper prickle cell layer. BDLF-3 protein expression was observed in the perinuclear space and Golgi compartment. The function of these proteins is currently under investigation.     

Aetiological factors for oral manifestations of HIV

OBJECTIVES: Describe the oral diseases in HIV-infected individuals in London, UK and identify social and medical factors related to the presence of specific oral diseases.
DESIGN: Cross-sectional analytic study.
SETTING: Dental clinics.
SUBJECTS: Consecutive sample of 456 patients with HIV infection.
METHODS: Social and medical history and clinical examinations. Univariate and logistic regression analysis.
OUTCOMES: Presence of HIV-associated oral disease.
RESULTS: 80% of patients with AIDS and 50% of patients with HIV had a specific oral disease. The most common diseases were hairy leukoplakia (30%), erythematous candidiasis (24%), pseudomembranous candidiasis (14%), angular chielitis (6%), necrotising periodontal disease (8%) and non-recurrent ulceration (6%).
CONCLUSIONS: The presence of erythematous candidiasis was not related to advanced HIV disease. Pseudomembranous candidiasis, hairy leukoplakia and mucosal ulceration were significantly associated with advanced HIV disease. Smoking was also identified as a strong aetiological factor in oral diseases. Longitudinal studies are required to further explore the prognostic significance of oral diseases in HIV infection.     

Clinical evaluation of brushing time and plaque removal potential of two manual toothbrushes

Abstract: Aim: To compare plaque removal efficacy of Oral‐B CrossAction (CA) used for 1 min with an American Dental Association (ADA) manual toothbrush used for 2 or 5 min in an examiner‐blind, three‐treatment, six‐period crossover study. Materials and methods: After refraining from all oral hygiene procedures for 23–25 h, subjects were randomly assigned to one of nine possible six‐period (visit) treatment sequences. Plaque was assessed at baseline (Rustogi Modified Navy Plaque Index). Post‐brushing scores were recorded after brushing with a marketed dentifrice and the assigned toothbrush for the specified duration. The same procedure was followed at each of six subsequent visits. Clinical measurements were carried out by the same examiner. Results: Forty subjects completed the study. All three treatments effectively removed plaque from the whole mouth, along the gingival margin and from approximal surfaces. Whole mouth and gingival margin plaque removal scores with CA for 1 min did not differ significantly from scores with the ADA toothbrush used for 2 min. The ADA brush used for 5 min showed significantly greater whole mouth (P < 0.001) and gingival margin (P < 0.001) plaque reduction than the two other treatments. Approximal plaque removal scores did not differ between the three treatments. Conclusions: Efficient plaque removal can be achieved after 1 min of brushing with CA. The amount of plaque removed did not differ significantly from that achieved with the ADA brush after 2 min of brushing. Greater whole mouth and gingival margin plaque removal scores were seen with the ADA brush after 5 min.     

The inability of Streptococcus mutans and Lactobacillus acidophilus to form a biofilm in vitro on dentine pretreated with ozone

Background: The use of ozone therapy in the treatment of dental caries is equivocal. The aim of this study was to use an in vitro model to determine the effects of prior ozone application to dentine on biofilm formation and to measure any associated reduction in bacteria viability. Methods: Twenty dentine discs were bonded to the bases of 5 mL polycarbonate screw top vials. Ten dentine discs were infused with ozone for 40 seconds, 10 samples remained untreated as a control. The vials were filled with nutrient medium, sterilized and placed into the outflow from a continuous chemostat culture of Streptococcus mutans and Lactobacillus acidophilus for four weeks. At the conclusion of the experiment bacterial growth was monitored by taking optical density readings of the growth medium in each vial and the outer surface of the dentine specimens were examined by scanning electron microscopy as shown by SEM analysis. Results: Ozone infusion prevented biofilm formation on all the treated samples while there was substantial biofilm present on the control specimens. While the average optical density of the control specimens was almost twice that of the ozone infused dentine (0.710 for the control with a SD of 0.288 and 0.446 for the ozonated samples with a SD of 0.371), the results were not significant (p > 0.05). Conclusions: This preliminary study has shown that the infusion of ozone into non‐carious dentine prevented biofilm formation in vitro from S. mutans and L. acidophilus over a four‐week period. The possibility exists that ozone treatment may alter the surface wettability of dentine through reaction with organic constituents.     

Placebo effect in burning mouth syndrome: a systematic review

Placebo controls play a critical role in the evaluation of any pharmacotherapy. This review surveys the placebo arm in 12 randomized controlled trials (RCTs) investigating burning mouth syndrome (BMS) and documents a positive placebo response in 6 of them. On average, treatment with placebos produced a response that was 72% as large as the response to active drugs. The lack of homogeneity in the use of placebos adds to the difficulty in comparing results and aggregating data. Future RCTs investigating BMS would benefit from larger sample sizes, adequate follow‐up periods, and use of a standard placebo.     

GABAergic and glutamatergic afferents in the dorsal raphe nucleus mediate morphine-induced increases in serotonin efflux in the rat central nervous system

To characterize the effects of morphine on serotonin (5-HT) in the central nervous system, we used microdialysis in freely behaving rats. Subcutaneous injection of morphine sulfate produced a dose-dependent increase in extracellular 5-HT in the dorsal raphe nucleus (DRN) and a forebrain site, the nucleus accumbens (NAcc). To determine the site of action for this effect, the opioid receptor antagonist naltrexone was infused into either the DRN or NAcc. Naltrexone infusion (300 microM) into the DRN but not the NAcc attenuated the increase in 5-HT elicited by systemic morphine (20 mg/kg). This suggests that morphine acts in the DRN to alter the activity of 5-HT neurons that project to NAcc. Consistent with this conclusion, infusion of the GABA(A) receptor antagonist bicuculline (100 microM) into the DRN but not the NAcc also blocked the effect of systemic morphine. Similarly, the effect of systemic morphine was blocked by infusion into the DRN of the GABA(A) receptor agonist muscimol (30 microM) and attenuated by the GABA(B) receptor agonist (+/-)-baclofen (100 microM). This provides evidence that morphine indirectly influences 5-HT release via opioid receptors on GABAergic neurons in the DRN. A new finding is that ionotropic glutamate receptor antagonists [kynurenate or a mixture of (+/-)-2-amino-5-phosphonopentanoic acid and 6,7-dinitro-quinoxaline-2,3-dione] infused in the DRN also attenuated the effect of systemic morphine. These results suggest that morphine acts on GABAergic and glutamatergic afferents to indirectly influence the activity of 5-HT neurons in the DRN. Understanding the details of this neural circuitry may provide new leads for treatment of opiate addiction.