Temporal Stability of the Salivary Microbiota in Oral Health

Objectives

Saliva is a biological fluid suitable for biomarker analysis, and differences in the salivary microbiota in oral health and disease have been reported. For such comparative analyses, time of sampling is critical since the bacterial composition may vary throughout the day, i.e., diurnal variation. The purpose of this study is to compare the salivary microbiome over time to determine the optimal time for sampling.

Design

Stimulated saliva samples were collected from 5 orally healthy individuals in 4 h intervals for 24 h, and collection was repeated 7 days later (number of samples per person, n = 12, total number of samples, n = 60). Salivary microbiota was analyzed using the Human Oral Microbe Identification using Next Generation Sequencing (HOMINGS), and statistical analysis was performed using the Kruskal-Wallis test with Benjamini-Hochberg’s correction for multiple comparisons, cluster analysis, principal component analysis and correspondence analysis.

Results

From a total of 60 saliva samples, 477 probe targets were collectively identified with a mean number of probes per sample of 207 (range: 153–307). Little or no variation in microbial profiles within subjects was observed over time.

Conclusions

Although there was considerable variation between subjects, microbial profiles within subjects were stable throughout a 24 hour period and after 1 week. Since there is little or no evidence of diurnal variation of the salivary microbiome, time of sampling of saliva is not critical for perturbation or other microbial studies.     

Salivary Microbiota and Metabolome Associated with Celiac Disease

This study aimed to investigate the salivary microbiota and metabolome of 13 children with celiac disease (CD) under a gluten-free diet (treated celiac disease [T-CD]). The same number of healthy children (HC) was used as controls. The salivary microbiota was analyzed by an integrated approach using culture-dependent and -independent methods. Metabolome analysis was carried out by gas chromatography-mass spectrometry–solid-phase microextraction. Compared to HC, the number of some cultivable bacterial groups (e.g., total anaerobes) significantly (P < 0.05) differed in the saliva samples of the T-CD children. As shown by community-level catabolic profiles, the highest Shannon''s diversity and substrate richness were found in HC. Pyrosequencing data showed the highest richness estimator and diversity index values for HC. Levels of Lachnospiraceae, Gemellaceae, and Streptococcus sanguinis were highest for the T-CD children. Streptococcus thermophilus levels were markedly decreased in T-CD children. The saliva of T-CD children showed the largest amount of Bacteroidetes (e.g., Porphyromonas sp., Porphyromonas endodontalis, and Prevotella nanceiensis), together with the smallest amount of Actinobacteria. T-CD children were also characterized by decreased levels of some Actinomyces species, Atopobium species, and Corynebacterium durum. Rothia mucilaginosa was the only Actinobacteria species found at the highest level in T-CD children. As shown by multivariate statistical analyses, the levels of organic volatile compounds markedly differentiated T-CD children. Some compounds (e.g., ethyl-acetate, nonanal, and 2-hexanone) were found to be associated with T-CD children. Correlations (false discovery rate [FDR], <0.05) were found between the relative abundances of bacteria and some volatile organic compounds (VOCs). The findings of this study indicated that CD is associated with oral dysbiosis that could affect the oral metabolome.     

Oral Defenses and Disease: Salivary Gland Function 1

Recent studies on parotid gland flow rate and composition in healthy subjects do not support the conventional wisdom that there is a gradual deterioration in salivary gland function with aging. With gustatory stimulation a diminution in flow rate was observed only in post-menopausal women taking medications. Studies of whole saliva and preliminary studies of submandibular saliva flow rate, however, suggest that these glands may exhibit functional changes not seen in the parotid. This would be consistent with histological findings. Reports to date on age effects on composition suggest modest selective changes in electrolytes (e.g. sodium) and only subtle changes in proteins (e.g. amylase isoenzymes). Clinical concerns (rampant caries, stomatitis, periodontal disease) arise largely because of the high number of elderly on medications or therapeutic interventions that affect salivary flow and the increase in incidence of diseases of the salivary gland (e.g. sialadeneitis, Sjogren's, sarcoidosis). Reduction in flow rate and alterations in composition diminish salivary protective mechanisms, i.e. antibacterial activity, lubrication and protection of soft tissues, and maintenance of hard tissue integrity. Recent research on structure of mucins, the nature of the salivary lipids and interactions among salivary proteins should stimulate a second generation of studies on both the effects of aging per se and aberrations resulting from disease. Stimulation of compromised function and development of more effective salivary substitutes are also important areas of research.     

Dysbiosis of Salivary Microbiota in Inflammatory Bowel Disease and Its Association With Oral Immunological Biomarkers

Analysis of microbiota in various biological and environmental samples under a variety of conditions has recently become more practical due to remarkable advances in next-generation sequencing. Changes leading to specific biological states including some of the more complex diseases can now be characterized with relative ease. It is known that gut microbiota is involved in the pathogenesis of inflammatory bowel disease (IBD), mainly Crohn''s disease and ulcerative colitis, exhibiting symptoms in the gastrointestinal tract. Recent studies also showed increased frequency of oral manifestations among IBD patients, indicating aberrations in the oral microbiota. Based on these observations, we analyzed the composition of salivary microbiota of 35 IBD patients by 454 pyrosequencing of the bacterial 16S rRNA gene and compared it with that of 24 healthy controls (HCs). The results showed that Bacteroidetes was significantly increased with a concurrent decrease in Proteobacteria in the salivary microbiota of IBD patients. The dominant genera, Streptococcus, Prevotella, Neisseria, Haemophilus, Veillonella, and Gemella, were found to largely contribute to dysbiosis (dysbacteriosis) observed in the salivary microbiota of IBD patients. Analysis of immunological biomarkers in the saliva of IBD patients showed elevated levels of many inflammatory cytokines and immunoglobulin A, and a lower lysozyme level. A strong correlation was shown between lysozyme and IL-1β levels and the relative abundance of Streptococcus, Prevotella, Haemophilus and Veillonella. Our data demonstrate that dysbiosis of salivary microbiota is associated with inflammatory responses in IBD patients, suggesting that it is possibly linked to dysbiosis of their gut microbiota.     

鼻咽癌放疗后致迟发性放射性脑病34例临床分析

目的：探讨鼻咽癌放疗后致迟发性放射性脑病的临床特征。方法：对中南大学湘雅医院神经内科所收治的34例鼻咽癌放疗后致迟发性放射性脑病患者临床资料、治疗方法及预后进行回顾性研究。结果：34例迟发性放射性脑病患者的临床特征包括头痛、头晕、记忆力下降、精神异常、抽搐、复视、面瘫或面部麻木、听力下降、言语增多、肢体无力、走路不稳、肢端麻木等。头部MRIT1WI呈低信号,T2WI呈高信号,增强后呈不规则强化。34例均随访,其中死亡11例,占32.35%;现存活23例,17例伴有严重症状,生存质量差,占50%。结论：鼻咽癌放疗后致迟发性放射性脑病临床表现各异,患者预后较差,临床上需尽早诊断,积极治疗,定期随诊。     

Salivary Anionic Changes after Radiotherapy for Nasopharyngeal Carcinoma: A 1-Year Prospective Study

Objectives

To investigate the salivary anionic changes of patients with nasopharyngeal carcinoma (NPC) treated by radiotherapy.

Material and Methods

Thirty-eight patients with T1-4, N0-2, M0 NPC received conventional radiotherapy. Stimulated whole saliva was collected at baseline and 2, 6 and 12 months after radiotherapy. Salivary anions levels were measured using ion chromatography.

Results

A reduction in stimulated saliva flow and salivary pH was accompanied by sustained changes in anionic composition. At 2 months following radiotherapy, there was a significant increase in chloride, sulphate, lactate and formate levels while significant reductions in nitrate and thiocyanate levels were found. No further changes in these anion levels were observed at 6 and 12 months. No significant changes were found in phosphate, acetate, or propionate levels throughout the study period.

Conclusions

Conventional radiotherapy has a significant and prolonged impact on certain anionic species, likely contributing to increased cariogenic properties and reduced antimicrobial capacities of saliva in NPC patients post-radiotherapy.     

Oral Microbiota and Risk for Esophageal Squamous Cell Carcinoma in a High-Risk Area of China

Poor oral health has been linked with an increased risk of esophageal squamous cell carcinoma (ESCC). We investigated whether alteration of oral microbiota is associated with ESCC risk. Fasting saliva samples were collected from 87 incident and histopathologicallly diagnosed ESCC cases, 63 subjects with dysplasia and 85 healthy controls. All subjects were also interviewed with a questionnaire. V3–V4 region of 16S rRNA was amplified and sequenced by 454-pyrosequencing platform. Carriage of each genus was compared by means of multivariate-adjusted odds ratios derived from logistic regression model. Relative abundance was compared using Metastats method. Beta diversity was estimated using Unifrac and weighted Unifrac distances. Principal coordinate analysis (PCoA) was applied to ordinate dissimilarity matrices. Multinomial logistic regression was used to compare the coordinates between different groups. ESCC subjects had an overall decreased microbial diversity compared to control and dysplasia subjects (P<0.001). Decreased carriage of genera Lautropia, Bulleidia, Catonella, Corynebacterium, Moryella, Peptococcus and Cardiobacterium were found in ESCC subjects compared to non-ESCC subjects. Multinomial logistic regression analyses on PCoA coordinates also revealed that ESCC subjects had significantly different levels for several coordinates compared to non-ESCC subjects. In conclusion, we observed a correlation between altered salivary bacterial microbiota and ESCC risk. The results of our study on the saliva microbiome are of particular interest as it reflects the shift in microbial communities. Further studies are warranted to verify this finding, and if being verified, to explore the underlying mechanisms.     

The Rapalogue,CCI-779, Improves Salivary Gland Function following Radiation

The standard of care for head and neck cancer typically includes surgical resection of the tumor followed by targeted head and neck radiation. However depending on tumor location and stage, some cases may not require surgical resection while others may be treated with chemoradiation. Unfortunately, these radiation treatments cause chronic negative side effects for patients. These side effects are associated with damage to surrounding normal salivary gland tissue and include xerostomia, changes in taste and malnutrition. The underlying mechanisms of chronic radiation-induced salivary gland dysfunction are unknown, however, in rodent models persistently elevated proliferation is correlated with reduced stimulated salivary flow. The rapalogue, CCI-779, has been used in other cell systems to induce autophagy and reduce proliferation, therefore the aim of this study was to determine if CCI-779 could be utilized to ameliorate chronic radiation-induced salivary gland dysfunction. Four to six week old Atg5^f/f; Aqp5-Cre, Atg5^+/+; Aqp5-Cre and FVB mice were treated with targeted head and neck radiation. FVB mice were treated with CCI-779, chloroquine, or DMSO post-radiation. Stimulated salivary flow rates were determined and parotid and submandibular salivary gland tissues were collected for analyses. Mice with a defect in autophagy, via a conditional knockout of Atg5 in the salivary glands, display increased compensatory proliferation in the acinar cell compartment and hypertrophy at 24-72 hours following radiation. FVB mice treated with post-therapy CCI-779 have significant improvements in salivary gland physiology as determined by stimulated salivary flow rates, proliferation indices and amylase production and secretion. Consequently, post-radiation use of CCI-779 allows for improvement of salivary gland function and reestablishment of glandular homeostasis. As CCI-779 is already FDA approved for other uses, it could have a secondary use to alleviate the chronic side effects in head and neck cancer patients who have completed anti-tumor therapy.     

鼻咽癌分子标志物研究

鼻咽癌严重危害人类健康,寻找其早期诊断及预后相关的分子标志物迫在眉睫.在总结本课题组运用基因组学、转录组学、蛋白质组学和组织微阵列等高通量技术对不同分化阶段、不同组织类型和不同临床分期的鼻咽癌标本进行大规模筛选工作的基础上,结合近年国际上有关进展,初步构建了鼻咽癌不同发病阶段的分子靶标系统:a.证实SPLUNC1、p16、EBER-1、p27、RASSF1A和CDH13是鼻咽癌早期诊断的理想分子靶标;b.鼻咽癌上调基因RB1,STMN1和DSP及下调基因SERPINB6,AGTRL1和SYTL2的分类预测模型是区分正常鼻咽上皮和鼻咽癌的分子靶标;c.NGX6、Ezrin、LTF、OPN、THY1和Tiam-1是鼻咽癌侵袭与转移预测的候选分子靶标;d.Cyclin D1、Survivin和HPA是与鼻咽癌预后相关的候选分子标志物;e.证实Bcl-2、EGFR和Ki67是预测鼻咽癌放疗敏感与否的候选分子靶标;f.SAA和cox-2是监测鼻咽癌复发的候选分子标志物;g.发现BRD7、NGX6、NOR1和UBAP1的6个SNP改变是鼻咽癌遗传易感风险因子;h.建立了由139个基因组成的鼻咽癌不同临床分期分子靶标系统.这些在大样本基础上的分子靶标筛选为鼻咽癌分子分型研究奠定了重要工作基础.     

Comparison of Oral Microbial Profiles between Children with Severe Early Childhood Caries and Caries-Free Children Using the Human Oral Microbe Identification Microarray

Objective

Early childhood caries (ECC) has become a prevalent public health problem among Chinese preschool children. The bacterial microflora is considered to be an important factor in the formation and progress of dental caries. However, high-throughput and large-scale studies of the primary dentition are lacking. The present study aimed to compare oral microbial profiles between children with severe ECC (SECC) and caries-free children.

Methods

Both saliva and supragingival plaque samples were obtained from children with SECC (n = 20) and caries-free children (n = 20) aged 3 to 4 years. The samples were assayed using the Human Oral Microbe Identification Microarray (HOMIM).

Results

A total of 379 bacterial species were detected in both the saliva and supragingival plaque samples from all children. Thirteen (including Streptococcus) and two (Streptococcus and Actinomyces) bacterial species in supragingival plaque and saliva, respectively, showed significant differences in prevalence between the two groups. Of these, the frequency of Streptococcus mutans detection was significantly higher in both saliva (p = 0.026) and plaque (p = 0.006) samples from the SECC group than in those from the caries-free group.

Conclusions

The findings of our study revealed differences in the oral microbiota between the SECC and caries-free groups Several genera, including Streptococcus, Porphyromonas, and Actinomyces, are strongly associated with SECC and can be potential biomarkers of dental caries in the primary dentition.     

Genetic Variations in Radiation and Chemotherapy Drug Action Pathways and Survival in locoregionally Advanced Nasopharyngeal Carcinoma Treated with Chemoradiotherapy

Background and Purpose

Treatment outcomes vary greatly in patients with nasopharyngeal carcinoma (NPC). The purpose of this study is to evaluate the influence of radiation and chemotherapy drug action pathway gene polymorphisms on the survival of patients with locoregionally advanced NPC treated with cisplatin- and fluorouracil-based chemoradiotherapy.

Material and Methods

Four hundred twenty-one consecutive patients with locoregionally advanced NPC were prospectively recruited. We utilized a pathway approach and examined 18 polymorphisms in 13 major genes. Polymorphisms were detected using the LDR-PCR technique. Multifactor dimensionality reduction (MDR) analysis was performed to detect potential gene-gene interaction.

Results

After adjustment for clinicopathological characteristics, overall survival was significantly decreased in patients with the MPO rs2243828 CT/CC genotype (HR=2.453, 95% CI, 1.687-3.566, P<0.001). The ERCC1 rs3212986 CC (HR=1.711, 95% CI, 1.135-2.579, P=0.010), MDM2 rs2279744 GT/GG (HR=1.743, 95% CI, 1.086-2.798, P=0.021), MPO rs2243828 CT/CC (HR=3.184, 95% CI, 2.261-4.483, P<0.001) and ABCB1 rs2032582 AT/AA (HR=1.997, 95% CI, 1.086-3.670, P=0.026) genotypes were associated with poor progression-free survival. Prognostic score models based on independent prognostic factors successfully classified patients into low-, intermediate-, and high-risk groups. Furthermore, MDR analysis showed no significant interaction between polymorphisms.

Conclusions

Four single nucleotide polymorphisms were associated with survival in patients with locoregionally advanced NPC treated with cisplatin- and fluorouracil-based chemoradiotherapy. Combining clinical prognostic factors with genetic information was valuable in identifying patients with different risk.     

Sensorineural Hearing Loss after Combined Intensity Modulated Radiation Therapy and Cisplatin-Based Chemotherapy for Nasopharyngeal Carcinoma

PURPOSE: The incidence of sensorineural hearing loss (SNHL) after treatment with combination of intensity-modulated radiation therapy (IMRT) and cisplatin-based chemotherapy in nasopharyngeal carcinoma (NPC) patients was evaluated, and relationships of SNHL with host factors, treatment-related factors, and radiation dosimetric parameters were investigated. METHODS: Fifty-one NPC patients treated with IMRT from 2004 to 2009 were analyzed. All patients received neoadjuvant, concurrent, or adjuvant use of cisplatin. Pure tone audiometry was performed during the follow-up period with a median time of 60 months, ranging from 28 to 84 months. Correlation of SNHL at low frequencies (pure tone average, 0.5-2 kHz) with a series of factors was analyzed. RESULTS: Among 102 ears, 12.7% had low-frequency SNHL and 42.2% had high-frequency (4 kHz) SNHL. The incidence of low-frequency SNHL was greater in patients with age > 40, with T-stage 4, or who received cumulative cisplatin dose (CCD) > 200 mg/m² (P = .034, .011, and .003, respectively) and in ears with secretory otitis media (SOM) (P = .002). Several dosimetric parameters were found to be correlated with SNHL. Univariate analysis showed that the minimum radiation dose to 0.1 ml highest dose volume (D0.1 ml) of the cochlea was the best radiation-related predictive parameter. Multivariate analysis indicated that CCD, SOM, and D0.1 ml of cochlea (P = .035, .012, and .022, respectively) were the factors associated with SNHL. CONCLUSION: For NPC patients treated with IMRT and chemotherapy, the incidence of treatment-related SNHL was associated with CCD, D0.1 ml of cochlea, and SOM.     

二甲双胍联合放射线照射对鼻咽癌细胞CNE-1增殖的影响

目的:探讨二甲双胍联合放射线照射对鼻咽癌细胞CNE-1增殖的影响。方法:分别给予鼻咽癌细胞CNE-1二甲双胍(5m M)、2Gy放射线照射、二甲双胍(5 m M)联合2Gy放射线照射处理后,采用MTT实验、克隆形成实验检测和比较其细胞增殖抑制率和克隆形成抑制率。结果:MTT实验结果显示:与二甲双胍组或2Gy放射线照射组相比,二甲双胍联合放射线照射组细胞增殖抑制率显著升高,差异具有统计学意义(P0.05);克隆形成实验结果显示,与二甲双胍组或2Gy放射线照射组相比,二甲双胍联合放射线照射组细胞克隆形成抑制率显著升高,差异具有统计学意义(P0.05)。结论:二甲双胍联合放射线照射能够有效的抑制鼻咽癌细胞CNE-1的增殖。     

Pyrosequencing Analysis of the Salivary Microbiota of Healthy Chinese Children and Adults

Describing the biogeography of bacterial communities within the human body is critical for establishing healthy baselines from which to detect differences associated with diseases. Little is known, however, about the baseline of normal salivary microbiota from healthy Chinese children and adults. With parallel barcoded 454 pyrosequencing, the bacterial diversity and richness of saliva were thoroughly investigated from ten healthy Chinese children and adults. The overall taxonomic distribution of our metagenomic data demonstrated that the diversity of salivary microbiota from children was more complex than adults, while the composition and richness of salivary microbiota were similar in children and adults, especially for predominant bacteria. A large number of bacterial phylotypes were shared by healthy children and adults, indicating the existence of a core salivary microbiome. In children and adults, the vast majority of sequences in salivary microbiota belonged to Streptococcus, Prevotella, Neisseria, Haemophilus, Porphyromonas, Gemella, Rothia, Granulicatella, Fusobacterium, Actinomyces, Veillonella, and Aggregatibacter, which constituted the major components of normal salivary microbiota. With the exception of Actinomyces, the other seven non-predominant bacteria including Moraxella, Leptotrichia, Peptostreptococcus, Eubacterium, and members of Neisseriaceae, Flavobacteriaceae, and SR1 showed significant differences between children and adults (p?<?0.05). We first established the framework of normal salivary microbiota from healthy Chinese children and adults. Our data represent a critical step for determining the diversity of healthy microbiota in Chinese children and adults, and our data established a platform for additional large-scale studies focusing on the interactions between health and diseases in the future.     

Effect of Prolonged Radiotherapy Treatment Time on Survival Outcomes after Intensity-Modulated Radiation Therapy in Nasopharyngeal Carcinoma

Purpose

To estimate the influence of prolonged radiation treatment time (RTT) on survival outcomes in nasopharyngeal carcinoma after continuous intensity-modulated radiation therapy.

Methods and Materials

Retrospectively review 321 patients with NPC treated between October 2009 and December 2010 and all of them underwent simultaneous accelerated intensity-modulated radiation therapy. The fractionated dose was 2–2.47 Gy/F (median 2.27 Gy), and the total dose for nasopharyngeal region was 64–74 Gy/ 28–33 fractions. The association of prolonged RTT and treatment interruption with PFS, LRFS and DFFS were assessed by univariate analysis and multivariate analysis. Survival analyses were carried out using Kaplan–Meier methodology and the log-rank test was used to assess the difference. The Cox regression proportional hazard model was used for multivariate analyses and evaluating the prognostic parameters for PFS, LRFS and DFFS.

Results

Univariate analysis revealed no significant associations between prolonged RTT and PFS, LRFS, DFFS when dichotomized using various cut-off values (all P>0.05). In multivariate analysis, RTT (range, 36–63 days) as a continuous variable, had no influence on any survival outcome as well (P>0.05). T and N classification were independent prognostic factors for PFS, LRFS and DFFS (all P<0.05, except T classification for LRFS, P = 0.057). Age was an independent prognostic factor for PFS (hazard ratio [HR], 1.033; P = 0.008) and DFFS (HR, 1.032; P = 0.043).

Conclusion

We conclude that no such association between survival outcomes and radiation treatment duration (range: 36–63 days) can be found in the present retrospective study, however, we have to remind that prolongation in treatment should be limited in clinical application and interruptions caused by any reason should be minimized as much as possible.     

鸦胆子油乳联合放疗治疗鼻咽癌的临床疗效观察

目的:探讨鸦胆子油乳联合放疗治疗鼻咽癌的临床疗效及安全性。方法:将在我科就诊的154例鼻咽癌患者随机分为对照组和治疗组,治疗组患者在常规放射治疗的基础上联合鸦胆子油乳治疗,而对照组患者单纯接受常规放射治疗。待治疗结束后,观察并比较两组患者的临床疗效、血液学指标及不良反应的发生情况。结果:对照组和治疗组的临床有效率分别为63.16%、82.05%,治疗组的临床有效率明显高于对照组,两组间比较有统计学差异(P0.05)。治疗后,治疗组患者的血液学指标如白细胞计数、红细胞计数、血红蛋白水平、CD4+/CD8+等均显著高于对照组,不良反应如恶心呕吐、张口困难、吞咽困难、声音嘶哑、口腔炎均明显低于对照组,差异具有统计学意义(P0.05)。结论:鸦胆子油乳联合放射治疗能够有效提高鼻咽癌患者的临床疗效,并且降低放疗所致的各种不良反应,值得临床推广应用。