Oral mucosal lesions in denture wearers

doi:10.1111/j.1741‐2358.2009.00289.x
Oral mucosal lesions in denture wearers Objective: To determine the prevalence of oral mucosal lesions (OMLs) and denture‐related mucosal lesions (DMLs) in denture wearers and to co‐relate the prevalence with age, gender, type of denture and any systemic conditions. Materials and methods: Dental records of 380 denture wearers were retrospectively reviewed for OMLs and DMLs. Results: We found 45% of the denture wearers had DMLs and 60.8% had OMLs not related to denture wearing. Although the prevalence of DMLs was higher in complete denture wearers than in partial denture wearers (49% vs. 42.2%), this difference was not significant. The most common DMLs were traumatic ulcer (19.5%) and denture‐induced stomatitis (18.1%). When analysed by type, traumatic ulcer, denture hyperplasia, frictional keratosis and candidiasis were more common in complete denture wearers, whereas denture‐induced stomatitis was more common in partial denture wearers. Frictional keratosis was more common in men than in women. The prevalence of OMLs not related to denture wearing was higher in complete denture wearers than in partial denture wearers, and the most common OML was fissured tongue (27.6%). No association between DMLs and systemic conditions or xerostomic drugs was noted. Conclusion: No differences in the prevalence of DMLs in association with denture type were found. The prevalence of OMLs not related to denture wearing was higher in complete denture wearers than in partial denture wearers. This difference was affected by age, and the data were similar to the findings observed in the elderly.     

Oral health and access to dental care: a qualitative investigation among older people in the community

doi:10.1111/j.1741‐2358.2009.00320.x
Oral health and access to dental care: a qualitative investigation among older people in the community Objective: The aim of this study was to explore older persons’ beliefs and attitudes towards oral health and access to and use of dental care services. Background: As the proportion of dentate older people increases, the need and demand for dental services will rise (J Public Health Dent, 60, 2000, 276). Design: Focus groups and semi‐structured interviews were used for data collection. Setting and subjects: The study participants included 63 older people in Perth, WA. Results: Five major themes emerged from the interviews – the need for information and knowledge; accessibility of services; cost and affordability of oral care; fear and anxiety regarding dental visits and relationships with dentists. Attitudes and behaviours were slow to change in this group. Conclusion: This investigation provided important perspectives regarding oral health and dental access for older people residing in the community and demonstrated the importance of understanding this group when considering provision and use of services.     

Evaluation of three indices for biofilm accumulation on complete dentures

doi:10.1111/j.1741‐2358.2009.00285.x
Evaluation of three indices for biofilm accumulation on complete dentures Objectives: The objective of this study was to evaluate the accuracy and reproducibility of three complete denture biofilm indices (Prosthesis Hygiene Index; Jeganathan et al. Index; Budtz‐Jørgensen Index) by means of a computerised comparison method. Background: Clinical studies into denture hygiene have employed a large number of biofilm indices among their outcome variables. However, the knowledge about the validity of these indices is still scarce. Materials and methods: Sixty‐two complete denture wearers were selected. The internal surfaces of the upper complete dentures were stained (5% erythrosine) and photographed. The slides were projected on paper, and the biofilm indices were applied over the photos by means of a scoring method. For the computerised method, the areas (total and biofilm‐covered) were measured by dedicated software (Image Tool). In addition, to compare the results of the computerised method and Prosthetic Hygiene Index, a new scoring scale (including four and five graded) was introduced. For the Jeganathan et al. and Budtz‐Jørgensen indices, the original scales were used. Values for each index were compared with the computerised method by the Friedman test. Their reproducibility was measured by means of weighed κ. Significance for both tests was set at 0.05. Results: The indices tested provided similar mean measures but they tended to overestimate biofilm coverage when compared with the computerised method (p < 0.001). Agreement between the Prosthesis Hygiene Index and the computerised method was not significant, regardless of the scale used. Jeghanathan et al. Index showed weak agreement, and consistent results were found for Budtz‐Jorgensen Index (κ = 0.19 and 0.39 respectively). Conclusion: Assessment of accuracy for the biofilm indices showed instrument bias that was similar among the tested methods. Weak inter‐instrument reproducibility was found for the indices, except for the Budtz‐Jørgensen Index. This should be the method of choice for clinical studies when more sophisticated approaches are not possible.     

Hypoxia-inducible factor-1α mediates oral squamous cell carcinoma invasion via upregulation of α5 integrin and fibronectin

With progressive and rapid growth of malignant tumors, cancer cells in an ischemic condition are expected to develop an increased potential for local invasive growth. To address this hypothesis, we first examined the effect of hypoxia on the invasiveness of oral squamous cell carcinoma (OSCC) cells using the Matrigel invasion assay. We then investigated the effect of hypoxia on the protein and mRNA expression of α5 integrin and fibronectin, which are major factors involved in tumor cell invasion. We showed that (i) hypoxia increased the invasiveness of OSCC cells, (ii) α5 integrin and fibronectin protein and mRNA expression levels were increased in OSCC cells under hypoxic conditions, (iii) hypoxia stimulated autocrine secretion of fibronectin in OSCC cells, (iv) administration of siRNA_HIF-1α caused a significant decrease in α5 integrin and fibronectin protein, confirming that HIF-1α plays a role in their induction, and (v) siRNA_HIF-1α abrogated hypoxia-induced cell invasion. Collectively, these data suggest that hypoxia promotes OSCC cell invasion that is elicited by HIF-1α-dependent α5 integrin and fibronectin induction.     

NDRG2 is a candidate tumor-suppressor for oral squamous-cell carcinoma

Oral cancer is one of the most common cancers worldwide, and squamous-cell carcinoma (OSCC) is the most common phenotype of oral cancer. Although patients with OSCC have poor survival rates and a high incidence of metastasis, the molecular mechanisms of OSCC development have not yet been elucidated. This study investigated whether N-myc downstream-regulated gene 2 (NDRG2) contributes to the carcinogenesis of OSCC, as NDRG2 is reported to be a candidate tumor-suppressor gene in a wide variety of cancers. The down-regulation of NDRG2 mRNA, which was dependent on promoter methylation, was seen in the majority of OSCC cases and in several cases of precancerous leukoplakia with dysplasia. Induction of NDRG2 expression in an HSC-3/OSCC cell line significantly inhibited cell proliferation and decreased colony formation ability on soft agar. The majority of OSCC cell lines showed an activation of PI3K/Akt signaling, and enforced expression of NDRG2 in HSC-3 cells decreased the level of phosphorylated Akt at Serine 473 (p-Akt). Immunohistochemical p-Akt staining was detected in 56.5% of the OSCC tumors, and 80.4% of the tumors were negative for NDRG2 staining. Moreover, positive p-Akt staining was inversely correlated with decreased NDRG2 expression in OSCC tumors with moderate to poor differentiation (p < 0.005). Therefore, NDRG2 is a candidate tumor-suppressor gene for OSCC development and probably contributes to the tumorigenesis of OSCC partly via the modulation of Akt signaling.     

Influence of castration-induced testosterone and estradiol deficiency on obesity and glucose metabolism in male Göttingen minipigs

Low testosterone and estradiol concentrations are predictive for the development of the metabolic syndrome in men and women, respectively. The aim of this study was to investigate the influence of sex hormone deficiency on food intake, body weight, body composition and glucose metabolism in male Göttingen minipigs.Five adult male Göttingen minipigs were studied before castration (pre-cast), 10-18 days (post-cast 1) and 10-11 weeks (post-cast 2) after castration. Parameters of interest were food intake, body weight, body fat percentage and sex hormone concentrations. Furthermore glucose tolerance, glucagon suppression, insulin resistance, beta cell function and disposition index were evaluated by oral and intravenous glucose tolerance tests.Castration led to almost complete disappearance of circulating testosterone and estradiol and secondarily to increased food intake, body weight and body fat percentage. Ten-eighteen days sex hormone deficiency (post-cast 1) did not significantly change any of the investigated metabolic parameters compared to pre-cast levels. Ten weeks after castration (post-cast 2) significant insulin resistance, glucose intolerance and hyperglucagonemia was found, and the beta cell function and the disposition index both were decreased.In conclusion, castration-induced sex hormone deficiency in male Göttingen minipigs results in hyperphagia, obesity and disturbed glucose metabolism, which are some of the features typical for the human metabolic syndrome.     

口服补液减轻40%血容量失血大鼠肠组织缺血性损伤

目的：研究口服葡萄糖-电解质液（GES）对大鼠40%血容量失血时肠组织缺血性损伤的影响。方法：雄性SD大鼠,用氯胺酮-速眠新Ⅱ肌注复合麻醉后,行右颈动脉插管。随机分为3组（n=24）：GES对照组（GES）,失血性休克组（HS）和失血性休克＋口服GES液组（HS＋GES）。GES组：不放血,手术后口服GES;HS和HS＋GES组按全身血容量的40%分两次间隔15min放血制作失血性休克模型。HS＋GES组于失血后0.5h、1h和6h分3次给予3倍失血量的GES灌胃。用激光多谱勒血流仪测定失血后2h、4h和24h肠组织血流量（IBF）后,处死动物后取肠组织检测二胺氧化酶（DAO）和Na^＋-K^＋-ATP酶活性,测定肠组织含水率（WG）,并做病理学检查。结果：HS＋GES组IBF和Na-K-ATP酶活性均显著高于HS组（P〈0.05）,但显著低于GES组（P〈0.05）;失血各组肠WG显著高于GES组（P〈0.05）,24h时HS＋GES组WG显著低于HS组（P〈0.05）;HS＋GES组24hDAO活性均显著高于HS组（P〈0.05）,但显著低于GES组（P〈0.05）;失血后24h病理检查HS＋GES组肠组织水肿和充血改变比HS组明显减轻。结论：口服GES液能显著增加大鼠失血性休克早期IBF,提高Na^＋-K^＋-ATP酶和DAO活性,减轻肠组织水肿和缺血性损伤。     

乳酸菌用作口服疫苗传递载体的研究

乳酸菌是食品级安全菌,利用乳酸菌为表达载体制成的口服疫苗安全无毒,能诱导机体产生有效的免疫应答和免疫耐受。乳酸菌口服疫苗通过胃肠粘膜进行抗原呈递,使用方便,而且较传统注射途径的免疫效果和依从性好,是理想的疫苗,有广阔的发展前景。     

Lipid-based colloidal carriers for peptide and protein delivery--liposomes versus lipid nanoparticles

This paper highlights the importance of lipid-based colloidal carriers and their pharmaceutical implications in the delivery of peptides and proteins for oral and parenteral administration. There are several examples of biomacromolecules used nowadays in the therapeutics, which are promising candidates to be delivered by means of liposomes and lipid nanoparticles, such as solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC). Several production procedures can be applied to achieve a high association efficiency between the bioactives and the carrier, depending on the physicochemical properties of both, as well as on the production procedure applied. Generally, this can lead to improved bioavailability, or in case of oral administration a more consistent temporal profile of absorption from the gastrointestinal tract. Advantages and drawbacks of such colloidal carriers are also pointed out. This article describes strategies used for formulation of peptides and proteins, methods used for assessment of association efficiency and practical considerations regarding the toxicological concerns.