Hypochlorous acid induced activation of human neutrophil and gingival crevicular fluid collagenase can be inhibited by ascorbate.

Interstitial collagenase either obtained from human neutrophils by phorbol myristate acetate (PMA) induced degranulation or isolated from human gingival crevicular fluid was found to be activated by addition of an oxidative agent, hypochlorous acid (HOCl). Collagenase released by PMA stimulated neutrophils was completely in latent form but underwent partial autoactivation during 16 h incubation at 22 degrees C in the presence of soy bean trypsin inhibitor. The partial autoactivation was potentiated to complete activation of released collagenase after addition of exogenous HOCl. Ascorbate prevented this activation of neutrophil collagenase. Isolated human gingival crevicular fluid collagenase represented an apparent Mr of 70 kD in completely latent form, whereas 70/54 kD enzyme species were detected for partially autoactive form of the enzyme. Western blot analysis of gingival crevicular fluid using a polyclonal antibody raised against purified human neutrophil collagenase revealed the same 70/54 kD molecular forms of the enzyme. The latent gingival crevicular fluid collagenase was also activated by HOCl and this activation could be prevented by ascorbate. Activation of the 70 kD latent collagenase by HOCl as well as by other non-proteolytic activators such as an organomercurial compound (phenylmercuric chloride) and a gold(I) compound (gold thioglucose) was not associated with detectable changes in apparent Mr, whereas trypsin activation resulted in fragmentation of 70 kD enzyme to 54 kD species. Our results provide further evidence for the neutrophil origin of gingival crevicular fluid collagenase and suggest that, in addition to proteolytic activation, oxidative and antioxidative agents seem to be able to regulate neutrophil collagenase activity.     

Inhibition of adsorption of oral streptococci to saliva treated hydroxyapatite by chitin derivatives.

This study estimated the effects of five chitin derivatives low molecular chitosan (LMCS), ethyleneglycol chitin (PEGT), carboxymethyl chitin (PCMT), sulphated chitosan (PSSS), and phosphorylated chitin (PPPT) on the adsorption of three oral streptococci to saliva-treated hydroxyapatite (S-HA). The adsorption was evaluated by measuring the optical density of the bacterial cell suspensions released from saliva-treated hydroxyapatite by 0.5 N HCl. The adsorption of test strains to S-HA progressively decreased in proportion to each additional volume of PEGT, PPPT, or PSSS. PPPT and PSSS quite effectively inhibited the adsorption of S. mutans onto S-HA, but were less effective against S. sanguis and S. mitis. PPPT, PSSS, and PCMT all markedly promoted the desorption of S. mutans cells pre-adsorbed onto S-HA. Pretreatment of S-HA with PPPT, PSSS, or PCMT significantly decreased the subsequent adsorption of S. mutans and S. mitis. Pretreatment of these cells with PEGT also decreased their adsorption to S-HA. These findings suggest that these chitin derivatives may change the ionic natures of the S-HA and the bacterial cell surface, resulting in a less favorable interaction.     

18q-syndrome with cleft lip and palate. A clinically diagnosed case

A case of a child with 18q-syndrome was encountered. The patient presented cleft lip and palate, narrow auditory canals, overlapping fingers, undescended testes and micropenis. Chromosome analysis demonstrated partial deletion of the long arm of one chromosome 18 in the patient and normal chromosomes in the parents. A cheiloplasty for repair of bilateral complete cleft lip was performed.     

Developmental anomaly of permanent teeth related to traumatic injury

Abstract A case is presented where a 4-year-old girl was injured in an automobile accident. The dental injury, intrusive luxation of the maxillary deciduous incisors, seemed unimportant at the time, since the child was in critical condition. The situation was first evaluated 5 years later, when the child was referred for treatment of an apical periodontitis originating from the right central incisor. The present case reflects several important aspects that were overlooked at the time of injury: the potential of intruded luxated deciduous teeth to cause developmental anomalies to the permanent dentition; the necessity of a longer follow-up period to detect such anomalies; and the need to develop effective treatment methods.     

单侧唇裂术后的鼻有解剖学研究

为探讨组织错位及组织发育不足与单侧唇裂鼻畸形的关系，对３８例伴有鼻畸形的单侧唇裂术后患者在鼻畸形修复术听健患侧鼻翼软骨大小及相对位置进行观察和测量，发现均存在患侧鼻翼软骨错位，若伴有患侧鼻软骨发育不足则鼻畸形更加严重。说明患侧鼻软骨组织错位及发育不足是造成唇裂鼻畸形的局部因素。     

颊癌中肿瘤转移抑制基因nm23mRNA的表达

通过Ｎｏｒｔｈｅｒｎ斑点杂交技术研究５２例颊癌及相关组织中肿瘤转移抑制基因ｎｍ３２－Ｈ１和ｎｍ２３－Ｈ２ｍＲＮＡ的表达。结果发现：颊癌组织中ｎｍ２３－Ｈ１和ｎｍ２３Ｈ２ｍＲＮＡ表达比正常颊粘膜、白斑、癌旁粘膜均有不同程度增高，颊癌有转移组中ｎｍ２３－Ｈ１ｍＲＮＡ表达比无转移组明显降低，转移灶中ｎｍ２３－Ｈ１ｍＲＮＡ的表达更低（Ｐ〈０．０５），ｎｍ２３－Ｈ１ｍＲＮＡ经无转移组明显降低，转移灶中ｎｍ２     

The management of the treatment and diagnosis for the calcifying odontogenic cyst]

18 Patients with calcifying odontogenic cyst underwent surgery in our Department from 1977 to 1993 were reported.8 male and 10 female aged from 11 to 52 with medium or 33 years were included.16 cases were pathologically confirmed as primary intraosseous cyst(central),and 2 as extraosseous cyst(peripheral).There was no recurrence after the local excision for preripheral calcifying odontogenic cyst and local curettage for central one.There were 3 in 6 cases of tumor typed cyst who had recurred postoperatively,two of them had recurred repeatedly and cured by means of local radiotherapy.The authors recommend that the tumor type of intraosseous calcifying odontogenic cyst be classified as a border-line tumor and treated as well as the principles of low malignant tumor.Post-operative radiotherapy could be used for recurrent cases.     

无牙颌患者的咬合垂直距离与咀嚼肌肌电关系的实验研究

作者选择了颌关系正常、能合作的15名无牙颌受试者。在4kg咬合力作用下，在不同的咬合垂直距离时，测定了颞肌及嚼肌的肌电幅值，实验结果表明，在控制咬合力状态下，无牙颌患者的咀嚼肌肌电幅值随着垂直距离增加而逐渐下降，两者间呈非常显著性负相关关系；在肌电活动变化过程中，有一相对稳定区域，由此提示，为无牙颌患者重建的咬合垂直距离有一定生理范围，约1.0mm(后牙区测点）。