Reduced methacholine-induced submandibular salivary secretion in rats with experimental periodontitis

Objective

Saliva is the first barrier to the entry of bacteria and viruses into the body and is considered a necessary instrument in oral health. Intraperitoneal injection of lipopolysaccharide endotoxins results in submandibular gland (SMG) hyposalivation. The objective of present studies was to assess if periodontitis, a chronic inflammatory disease caused by oral bacteria, alters cholinergic-induced SMG salivary secretion.

Design

An experimental periodontitis model (EP) (cotton thread ligature around the neck of the first lower molars) was used. Male Wistar rats (300–380 g) were randomly divided into 3 groups: control, 7 days-bilateral EP and 7 days-unilateral EP (to study if there were different effects at the ipsilateral and contralateral side). The following determinations were performed in SMG: (1) dose–response curves to the cholinergic agonist methacholine, (2) prostaglandin E (PGE) content, (3) inducible nitric oxide synthase (iNOS) activity and (4) histology of gland sections.

Results

The molars with EP, no matter the group, exhibited significant and similar bone loss (p < 0.001). Bilateral EP reduced methacholine-induced salivary secretion (p < 0.05, dose 1 μg/kg; p < 0.001, dose 3–30 μg/kg), increased PGE content (p < 0.01), stimulated iNOS activity (p < 0.05). Ipsilateral glands of unilateral EP animals presented lower methacholine-induced salivary secretion (p < 0.05, dose 3 μg/kg; p < 0.001, dose 10–30 μg/kg), and higher PGE content than contralaterals (p < 0.001). In turn, at 3 and 10 μg/kg of methacholine, contralateral glands showed significantly lower secretion than control animals (p < 0.001). Histological studies of glands revealed partial loss of secretor granular material and periductal oedema in the bilateral and unilateral EP groups as compared to controls.

Conclusions

As far as we know, the present results demonstrate for the first time that EP reduces methacholine-induced SMG salivary secretion.     

涎腺肌上皮癌的生物学行为及治疗

为了总结涎腺肌上皮癌的生物学行为及有效治疗，作者对１９例涎腺肌上皮癌患者进行临床分析，其临床特点为：发病部位以腮腺为最常见，其次为腭部；部分肿瘤生长迅速，广泛侵犯周围组织；颈部淋巴结转移率不很高，但血行性转移率高；治疗后极易复发；患者预后差。其生物学行为属高度恶性肿瘤。治疗以根治性切除为主，原则上不作选择性颈淋巴清扫术；放射治疗不敏感。对于局限性肿瘤复发灶及时手术可获得较好的效果。     

唾液腺肌上皮瘤的影像学分析

目的:探讨唾液腺肌上皮瘤(ME)的CT及MRI表现和临床特点。方法:回顾性分析2003年至2007年间17例肌上皮瘤患者的影像学资料。男7例,女10例;年龄23～70岁,平均46岁。结果:病灶直径均小于2.5cm。病灶位于大唾液腺者13例,位置浅表,大多与腺体包膜接触(12/13),有明显结节状强化,包膜可见;位于小唾液腺者4例,无明显强化,其中发生于软腭者1例,发生于硬腭者3例,腭板有压迫性吸收者2例(2/3)。结论:了解唾液腺肌上皮瘤的影像学表现,结合其临床表现,可以提高对ME的诊断和鉴别诊断能力。     

Parasympathectomy increases resting salivary secretion in normal and irradiated submandibular glands of rats

Fluid and ion secretion from the submandibular gland (SMG) is mainly regulated by parasympathetic nerves. This study evaluated the effect of parasympathectomy on salivary secretion from normal and irradiated rat SMGs from 1 to 24 wk after denervation. Although stimulated salivary secretion was significantly lower in denervated SMGs compared with contralateral self‐controls, the resting salivary flow rates were markedly higher in the denervated SMGs at 1, 12, and 24 wk after denervation. The levels of muscarinic acetylcholine M1 and M3 receptors, as well as of aquaporin 5, were up‐regulated. Notably, although irradiated SMGs showed significantly lower resting and stimulated salivary secretion rates than non‐irradiated SMGs, the resting salivary secretion rates of the irradiated and denervated SMGs were markedly higher than seen in the irradiated self‐control SMGs at 1, 12, and 24 wk after parasympathectomy, and were even higher than seen in the non‐irradiated sham‐operated rats. The expression of M1 and M3 receptors was similarly elevated. Taken together, our results suggest that parasympathetic denervation increases resting salivary secretion of both normal and irradiated SMGs. This approach might provide a potential modality for relieving radiation‐induced xerostomia, which is a common complication following treatment of head and neck cancer.     

Minor salivary gland secretion in children and adults

The minor salivary glands are of great importance in the physiology and pathology of the oral cavity. So far, studies of the minor glands have concentrated on adults. In the present study, minor salivary gland secretion was studied in the buccal and labial mucosa of 3-year-old children, adolescents and young adults. In addition, the number of glands per surface area was assessed in the labial mucosa. A total of 90 individuals were included, 30 in each age-group. Saliva was collected on filter paper discs and the salivary secretion rate was measured using a Periotron 8000. The number of secreting labial glands was assessed on PAS-stained filter paper discs under a microscope. Salivary secretion in the buccal mucosa was found to be age-related, with a statistically significant lower rate of secretion (P=0.003) in the 3-year-olds (mean 7.7 microl x cm(-2) x min(-1)) compared with the young adults (11.9 microl x cm(-2) x min(-1)). No significant differences between the sexes were noted. For the labial glands, no age- or sex-related differences were found. In all age-groups, salivary secretion was significantly higher in the buccal than in the labial mucosal area. A statistically significant difference in number of secreting glands was found between all age-groups, with a decreasing number of glands per surface unit with age. The number of glands was significantly lower in males compared with females in the group of adults. The lower rate of buccal salivary secretion in the young children may imply that the oral mucosa is more vulnerable to external injury and that caries protection on the buccal molar surfaces is lower. Previous studies indicate that adults with a reduced rate of minor salivary gland secretion are more susceptible to caries.     

影响涎腺粘液表皮样癌术后复发的临床病理因素分析

目的 探讨影响涎腺粘液表皮样癌病人术后复发的临床病理因素。方法 回顾经本院手术并获得五年以上随访或不足五年而出现复发的涎腺粘波表皮样癌77例，对各项临床病理指标进行单因素似然比检验及多因素Logistic回归分析，资料的统计学处理全部通过SPSS软件完成。结果 本组涎腺粘液表皮样癌术后复发有其自身的特点。在单因素分析中，性别、分化程度、原发灶的处理方式、小涎腺粘液表皮样癌侵犯骨的处理等因素均与术后复发相关。性别、分化程度、原发灶的处理方式做为影响术后复发的主要因素进入Logistic回归方程，所得回归方程对术后复发的分类能力可达84．4％。结论 性别、分化程度、原发灶的处理方式是影响涎腺粘液表皮样癌术后复发的主要因素。     

Prognostic factors in malignant tumours of the salivary glands

Salivary gland tumours are a relatively rare group of lesions best managed in specialist centres. We review some of the factors that influence their prognosis. Clinical stage is the most important, with large malignancies having a poor prognosis regardless of histological grade and other features such as perineural invasion. Even high grade neoplasms may do well when they are small. A helpful guide to the management of salivary cancers is the “4 cm” rule.     

*辣椒素对移植颌下腺"休眠期"腺体分泌功能的影响

目的观察辣椒素在移植颌下腺“休眠期”内对腺体分泌功能及防止导管阻塞中的作用。方法接受血管化自体颌下腺移植并获得手术成功的重症角结膜干燥症患者42例（45侧患眼）,在术后“休眠期”内应用两种不同剂型的辣椒素刺激,并与酸、咀嚼及红外线理疗等其他刺激方法对照。以手术侧眼睛的施墨试验结果表示移植腺体的分泌功能,观察其作用效果及作用时间。结果辣椒素含漱剂、辣椒素霜剂及红外线理疗均可明显促进“休眠期”内移植腺体的分泌,辣椒素刺激的效果更为明显,而酸和咀嚼刺激对移植腺体的分泌无明显影响。结论辣椒素刺激可以作为“休眠期”促进移植腺体分泌、预防导管阻塞的有效手段之一;辣椒素霜剂应用方便,刺激性较小,临床应用时宜作为首选剂型。     

Chitosan-containing gum chewing accelerates antibacterial effect with an increase in salivary secretion

OBJECTIVES: This study was designed to confirm the mechanical efficacy of chewing chitosan-containing gum to suppress the growth of oral bacteria compared to a mouth rinse, and to demonstrate the increased salivary secretion due to chewing chitosan-containing gum. METHOD: Twelve healthy subjects were recruited from among the staff and students of Nagasaki University School of Dentistry. For the slab of gum study, the subjects chewed chitosan-containing gum for 5 min and then rested for 5 min. For the testing of the chitosan mouth rinse solution, the subjects gargled 10 mL of solution for 30s followed by resting for 9 min 30s. These protocols were continuously repeated five times for 50 min on the same day. For the salivary secretion experiment, the gum chewing was repeated three times per day for 2 days. RESULTS: The amount of oral bacteria in the subjects who chewed chitosan-containing gum significantly decreased during all three sampling times except at 60 min for total bacteria in comparison to those in the rinse group. Chitosan-containing gum chewing also significantly increased the secretion of saliva. CONCLUSIONS: Chitosan-containing gum chewing has a greater antibacterial effect and it also increases salivary secretion. The present findings strongly indicate that the application of natural materials such as chitosan is useful for both oral health and the quality of life.