Dysgeusia: A review in the context of COVID-19

BackgroundTaste disorders in general, and dysgeusia in particular, are relatively common disorders that may be a sign of a more complex acute or chronic medical condition. During the COVID-19 pandemic, taste disorders have found their way into the realm of general as well as specialty dentistry, with significance in screening for patients who potentially may have the virus.Types of Studies ReviewedThe authors searched electronic databases (PubMed, Embase, Web of Science, Google Scholar) for studies focused on dysgeusia, ageusia, and other taste disorders and their relationship to local and systemic causes.ResultsThe authors found pertinent literature explaining the normal physiology of taste sensation, proposals for suggested new tastes, presence of gustatory receptors in remote tissues of the body, and etiology and pathophysiology of taste disorders, in addition to the valuable knowledge gained about gustatory disorders in the context of COVID-19. Along with olfactory disorders, taste disorders are one of the earliest suggestive symptoms of COVID-19 infection.ConclusionsGustatory disorders are the result of local or systemic etiology or both. Newer taste sensations, such as calcium and fat tastes, have been discovered, as well as taste receptors that are remote from the oropharyngeal area. Literature published during the COVID-19 pandemic to date reinforces the significance of early detection of potential patients with COVID-19 by means of screening for recent-onset taste disorders.Practical ImplicationsTimely screening and identification of potential gustatory disorders are paramount for the dental care practitioner to aid in the early diagnosis of COVID-19 and other serious systemic disorders.     

Electrochemical behaviour of 2-(4′-hydroxybenzeneazo)benzoic-acid at pyrolytic graphite electrodes

The electrochemical reduction of 2-(4′-hydroxybenzeneazo)benzoic acid (I) has been studied at pyrolytic graphite electrodes in the pH range 2.0–10.4. The cyclic voltammetric behaviour clearly indicated an ECE mechanism in acidic medium in which the two-electron two-proton reduction of I gives the hydrazo derivative. The acid catalysed disproportionation of the hydrazo intermediate was also studied in the pH range 2.0–6.0 and the value of k′/[H⁺] was found to be 1.4 × 10^?2 1 mol^?1 s^?1 The products of the reduction have been isolated and characterized using IR, melting point, mass and related techniques.     

HSV-TK/GCV联合IL-2对人舌癌移植瘤的抑制作用

目的观察HSV-TK联合IL-2对人舌癌细胞生长的抑制作用,并初步探讨其作用机理。方法建立舌癌Tca8113移植瘤动物模型,采用HSV-TK基因联合IL-2基因对人舌癌移植瘤进行裸鼠体内实验。实验分A、B、C、D四个实验组,每组5只裸鼠。A组为对照组,每瘤注射生理盐水;B组为空病毒组,每瘤注射空病毒5×108PFU;C组为单纯TK治疗组,每瘤注射TK5×108PFU;D组为TK联合IL-2治疗组,每瘤注射TK(5×108PFU) IL-2(5×108PFU)。48小时以后,对B、C、D组裸鼠每日腹腔注射GCV,100mg/kg/日,2次/日,连续10天。最后一次给药后第二天处死裸鼠,测量肿瘤重量并计算抑瘤率;光镜观察移植瘤组织学变化,透射电镜观察细胞的超微结构。结果A、B、C、D组裸鼠瘤重量均数分别为:1.52±0.49g,1.44±0.42g,0.91±0.24g,0.36±0.24g。C组的抑瘤率为40%;D组抑瘤率为76%。经统计学检验发现TK组和TK联合IL-2组的肿瘤生长均受到抑制,A组和C组、A组和D组之间有显著性差异(P<0.01)。与单用TK组比较,TK联合IL-2组抗瘤作用明显增强。光镜观察发现,TK组肿瘤组织呈灶状凋亡,可见核固缩的细胞。TK联合IL-2组凋亡细胞增加,肿瘤细胞减少。电镜观察发现,TK组和TK联合IL-2组出现大量的细胞凋亡:凋亡细胞皱缩,胞核体积缩小,染色质浓缩,电子密度增加,呈新月状边集于核膜下。结论TK联合IL-2治疗可显著抑制Tca8113移植瘤的生长,其治疗效果优于TK单独应用。     

人体微生物组在辅助2型糖尿病诊疗中的潜在应用

人体微生物组是指人体体表及内部的微生物的遗传信息总和,与人类健康与疾病状态存在密切关系。口腔和肠道微生物是最具多样化的微生物群落,两者可以交互影响,在疾病发生发展过程中共同发挥作用,并可以实时反映机体的健康与疾病状态。2型糖尿病是由遗传和环境因素引起的代谢紊乱,最近的研究指出微生物与糖尿病存在关联。本文结合近期的研究进展,就2型糖尿病患者口腔微生物和肠道微生物的特征进行综述,有望为探索基于微生物组特征的2型糖尿病风险预测、诊断和预后预测的疾病模型的建立提供参考依据。     

Matrix metalloproteinase-2 expression induced by two different adhesive systems on human pulp fibroblasts

Introduction

This study evaluated the expression of matrix metalloproteinase-2 (MMP-2) in primary cultures of human pulp fibroblasts (HPFs) when exposed to extracts from dentin-bonding systems.

Methods

Polymerized resin disks of the bonding agent of a 2-step self-etch adhesive (TechBond, Isasan, Rovello Porro, Italy) or of the primer/bonding agent a 2-step etch-and-rinse adhesive (Optibond Solo; Sybron-Kerr, Orange, CA) were immersed in HPF culture medium for 24 or 96 hours. HPFs were incubated in the adhesive-conditioned or control (untreated) culture medium for 24 hours. Western blot and immunofluorescence analyses were performed to assay MMP-2 expression.

Results

MMP-2 expression levels in HPFs cultured for 24 hours in culture medium were similar in both the control and experimental media groups showing a faint band at 67 kDa. Conversely, the HPFs incubated in the medium that contain polymerized resin disks for 96 hours showed increased MMP-2 expression compared with the untreated medium. The self-etch adhesive displayed the most pronounced induction of MMP-2 expression. These findings were confirmed by immunofluorescence analysis.

Conclusions

HPFs display increased MMP-2 expression after 96 hours of conditioning of the HPF culture medium with polymerized disks of dentin bonding systems. This MMP-2 expression/activation may represent a defence mechanism exhibited by HPFs towards monomers eluted from the dentin bonding systems.     

Diversity of supernumerary tooth formation in siblings with cleidocranial dysplasia having identical mutation in RUNX2 : possible involvement of non-genetic or epigenetic regulation

INTRODUCTION: Cleidocranial dysplasia (CCD, MIM #119600) is an autosomal-dominant disorder characterized by hypoplasia or aplasia of clavicles, patent fontanelles and short stature. The responsible gene has been identified as RUNX2. CCD is also accompanied by characteristic dental abnormalities, e.g. supernumerary teeth, delayed eruption and impaction of permanent teeth. Intrafamilial variations of skeletal abnormalities are reported but those of dental abnormalities are obscure. To clarify this point, a precise examination of the dental features of CCD siblings having identical mutation was performed. DESIGN: Gene mutational analysis of three Japanese CCD siblings and their father was performed. Skeletal and dental characteristics were examined by the inquiry and radiographs. RESULTS: Three siblings uniformly showed patent fontanelles and short stature. They and their father had a novel missense mutation in the RUNT-domain (P210S) of RUNX2. The siblings were completely discordant for the dental characteristics with the position and number of supernumerary teeth being completely different. The youngest, a 12-year-old boy, had six supernumerary teeth, which appeared symmetrically around the maxillary canines and mandibular premolars. The second, a 15-year-old girl, had four supernumerary teeth which appeared around the mandibular incisors. The oldest, a 17-year-old boy, had 11 supernumerary teeth, which were symmetrically around the mandibular lateral dentition and asymmetrically around the maxillary incisors and premolars. CONCLUSION: The present study suggests the involvement of non-genetic or epigenetic regulation in supernumerary tooth formation in CCD.     

No evidence for a role of CRISPLD2 in non-syndromic cleft lip with or without cleft palate in an Italian population

Non-syndromic cleft lip with or without cleft palate (NSCLP) is a malformation with variable phenotypes, resulting from a mixture of genetic and environmental factors. Some studies have supported a role for the 16q24 region and its candidate gene, CRISPLD2, in clefting. A replication study is necessary to confirm these findings. The aim of the present study was to test, by genetic linkage and association analyses, whether the candidate gene, CRISPLD2, represents a risk factor for NSCLP. The analysis of 39 multigenerational families provided formal exclusion of a linkage between NSCLP and the CRISPLD2 locus under different genetic models and non-parametric analyses. The family-based study of 239 unrelated probands and their parents revealed no association between any particular allele or haplotype and NSCLP. Therefore, the present investigation did not support the hypothesis of the involvement of CRISPLD2 in NSCLP malformation, at least with regard to the Italian population.     

Prostaglandin E2 and interleukin-1 levels in smokeless tobacco-induced oral mucosal lesions

Inflammatory mediators released as a result of smokeless tobacco (ST)-induced irritation may play a role in the development of oral mucosal lesions at habitual tobacco placement sites in ST users. The present study examined levels of interleukin-1 (IL-1) and prostaglandin E2 (PGE2) in ST-induced mucosal lesions and compared these to mediator levels in clinically normal mucosa. Soft tissue biopsies were obtained from white mucosal lesions at habitual placement sites and normal alveolar mucosal tissue at non-placement sites in 18 ST users. Fifteen non-tobacco using subjects also provided normal alveolar mucosal biopsies. IL-1 and PGE2 were recovered from the specimens, and mediator levels were determined by enzyme immunoassay. Prostaglandin E2 levels (pg/mg) were lower in both regions in the ST subjects, but values did not vary significantly between the regions with 2.77±0.72 and 2.86±0.99 at placement and non-placement sites, respectively, in ST users and 7.31±3.84 in non-tobacco users. Both IL-1α and IL-lβ (pg/mg) were significantly (p < 0.0I) elevated in ST lesions (IL-lã=25.56±4.00; IL-1β=7.76±1.68) compared to either non-placement sites in ST users (IL-lα=14.64±2.65; IL-lβ=1.63±0.72) or non-tobacco users (IL-lα=12.84±2.60; IL-lβ=2.04±0.75). In view of IL-l's role in keratinocyte proliferation and its inflammatory effects, this cytokine may contribute to mucosal and gingival alterations observed in ST users.     

Herpesviruses in HIV-periodontitis

BACKGROUND/AIMS: Human herpesvirus-associated diseases exhibit elevated morbidity and mortality in patients infected with human immunodeficiency virus (HIV).This study aimed to investigate the occurrence of herpesviruses in HIV-periodontitis. METHOD: Gingival biopsies from periodontitis lesions of 21 HIV-patients and 14 non HIV-patients were studied. Nested-polymerase chain reaction methods were employed to detect human cytomegalovirus, Epstein-Barr virus type 1 and 2 (EBV-1, EBV-2), herpes simplex virus, human herpes virus (HHV)-6, HHV-7 and HHV-8. RESULTS: Gingival biopsies from HIV-periodontitis lesions showed on average 4.0 herpesvirus species and gingival biopsies from HIV periodontitis lesions of non-HIV patients revealed an average of 1.9 herpesvirus species (p<0.001). Occurrence of 4 to 6 different herpesviruses was more common in HIV- than in non HIV-gingival biopsies (71% vs. 7%) (p<0.001). EVB-2 was detected in 12 (57%) biopsies from HIV-periodontitis but was absent in non HIV-periodontitis biopsies (p= 0.002). HHV-6 also occurred in significantly higher frequency in HIV-periodontitis (71%) than in non HIV-periodontitis (21%) (p=0.01). HHV-8 was detected only in biopsies from HIV-periodontitis lesions.. CONCLUSION: HIV-periodontitis seems to be associated with elevated occurrence of EBV-2, HHV-6 and herpesvirus co-infections compared to periodontitis in non-HIV-patients. The periodontopathic significance of herpesviruses in HIV-periodontitis constitutes a research topic of considerable interest.