Electron microscopy of horseradish peroxidase uptake by papillary cells of the mouse incisor enamel organ

Horseradish peroxidase was injected into the tail veins of adult mice. Enamel organs were excised from mice killed at predetermined intervals, fixed in formaldehyde-glutaraldehyde, incubated in diaminobenzidine medium, post-fixed in OsO₄, and processed for electron microscopy. Within 5 min of peroxidase administration, the reaction product was seen extracellularly between papillary cells and between reduced ameloblasts, but not beyond the apical terminal bar apparatus. Only papillary cells took up the peroxidase intracellularly via bristle-coated vesicles. Within the papillary cells, peroxidase was also seen in tubular structures, and at 30–60 min intervals in numerous multivesicular bodies.The results demonstrate that (1) the basal terminal bar apparatus of reduced ameloblasts is permeable to peroxidase, whereas the apical is not, (2) papillary cells function in the absorption of protein from the capillaries, and (3) bristle-coated vesicles and tubular structures serve to transport absorbed protein to multivesicular bodies within papillary cells.     

固齿健周煎剂对老年小鼠的抗氧化作用

目的探讨中药固齿健周煎剂对老年小鼠的抗氧化作用。方法实验组为固齿健周煎剂灌胃的老年小鼠，对照组为灌胃等量自来水的青、老年小鼠。检测过氧化脂质、超氧化物歧化酶及过氧化氢酶。结果实验组与青、老年小鼠对照组比较差异均有显著性。结论固齿健周煎剂具有抗脂质过氧化的作用，可能对调节机体代谢功能、抗自由基损伤及恢复牙周组织健康有益     

Clinical application of angiography of oral and maxillofacial hemangiomas. Clinical analysis of seventy cases

Angiographic findings in seventy cases of maxillofacial hemangioma are reported. The tumors have been divided into four types: (1) plexiform hemangioma, (2) cavernous hemangioma with venous drainage, (3) cavernous hemangioma without venous drainage, and (4) the so-called "diffuse type" of cavernous hemangioma. The angiographic features of the four types are described, and clinical application is evaluated. The angiograms demonstrate the location, extent, blood supply, and drainage of the tumors and show whether they communicate intracranially, thus providing valuable criteria for planning and determining the mode of treatment.     

A scanning electron microscope study of monkey maturation-stage ameloblasts

The maturation-stage enamel organs of Macaca arctoides and Macaca mulatta were examined in order to determine whether the cells were similar to those of the continuously erupting rat incisor. Tooth buds of the permanent dentition were fixed in formaldehyde-glutaraldehyde and post-fixed in OsO4. The enamel organs were separated from the enamel during dehydration, critical-point-dried, metal-coated, and examined in a scanning electron microscope. The results showed that there were few differences in the morphology of maturation-stage ameloblasts of these primates compared with those of other species reported in the literature. The apical plasma membranes were either smooth- or ruffle-ended, while the later membranes had maze, microvillous, or ridge configurations, also seen in rats, and an additional configuration of interdigitating bulbous extensions. The blood vessels of the papillary layer in monkeys were about 7 micron in diameter, considerably larger than those of the rat.     

Persistent buccopharyngeal membrane in an adult

Persistence of the buccopharyngeal membrane (BPM) also called the oropharyngeal membrane is a rare congenital oropharyngeal anomaly. We report a case of an adult aboriginal male patient with a membrane that closed his oropharyngeal isthmus except for a 2 cm diameter central perforation. The patient had no symptoms related to this membrane and no other congenital anomalies were found. This finding has not previously been reported in an adult. The embryology and management of this rare condition is discussed.     

Role of calcium and PKC in salivary mucous cell exocrine secretion

Fluid and exocrine secretion of mucins by salivary mucous glands is regulated predominantly by parasympathetic activation of muscarinic receptors. A direct role for subsequent putative signaling steps, phospholipase C (PLC), increased intracellular calcium ([Ca(2+)](i)), and isoforms of protein kinase C (PKC) in mediating muscarinic exocrine secretion has not been elucidated, and these are potential therapeutic targets to enhance mucin secretion in hyposalivary patients. We found that muscarinic-induced mucin secretion by rat sublingual tubulo-acini was dependent upon PLC activation and the subsequent increase in [Ca(2+)](i), and further identified a transient PKC-independent component of secretion dependent upon Ca(2+) release from intracellular stores, whereas sustained secretion required entry of extracellular Ca(2+). Interactions among carbachol, PKC inhibitors, phorbol 12-myristate 13-acetate, and thapsigargin to modulate [Ca(2+)](i) implicated conventional PKC isoforms in mediating sustained secretion. With increasing times during carbachol perfusion of glands, in situ, PKC-α redistributed across glandular membrane compartments and underwent a rapid and persistent accumulation near the luminal borders of mucous cells. PKC-β1 displayed transient localization near luminal borders, whereas the novel PKCs, PKC-δ or PKC-ε, displayed little or no redistribution in mucous cells. Collective results implicate synergistic interactions between diacylglycerol (DAG) and increasing [Ca(2+)](i) levels to activate cPKCs in mediating sustained muscarinic-induced secretion.     

CAD/CAM-produced surgical guides: Optimizing the treatment workflow

The increased availability of devices for 3D radiological diagnosis allows the more frequent use of CAD/CAM-produced surgical guides for implant placement. The conventional workflow requires a complex logistic chain which is time-consuming and costly. In a pilot study, the workflow of directly milled surgical guides was evaluated. These surgical guides were designed based on the fusion of an optical impression and the radiological data. The clinical use showed that the surgical guides could be accurately placed on the residual dentition without tipping movements. The conventional surgical guides were used as a control for the manual check of the deviation of the implant axis. The direct transfer of the digital planning data allows the fabrication of surgical guides in an external center without the need of physical transport, which reduces the logistic effort and expense of the central fabrication of surgical guides.     

Noordhoff法修复单侧不完全性唇裂的特点分析

目的:采用Noordhoff法修复单侧不完全性唇裂,分析与常规方法的不同设计,提出在手术过程中应注意的问题。方法:通过对随机选择用Noordhoff法修复52例单侧不完全性唇裂的患儿的手术效果分析,提出Noordhoff法修复单侧不完全性唇裂手术方法的特点,阐明手术设计的思想和操作中应注意的问题。结果:52例中除其中1例因切口摔倒而裂开重新缝合外,余51例切口均I期愈合。所有患儿术后鼻、唇弓及红唇形态近期效果满意。结论:Noordhoff法手术方法的设计最大限度的利用了唇的软组织,避免了鼻翼外侧的切口,鼻唇畸形同期整复使单侧不完全性唇裂能达到较满意的效果。