Immunohistochemical localization of type I collagen, fibronectin and tenascin C during embryonic osteogenesis in the dentary of mandibles and tibias in rats.

Type I collagen, fibronectin and tenascin C play an important role in regulating early osteoblast differentiation, but the temporal and spatial relationship of their localization during embryonic osteogenesis in vivo is notknown. The present study was designed to localize these three molecules in the dentary of mandibles and tibias in rat embryos using immunohistochemistry. Serial paraffin sections were cut and adjacent sections were processed for von Kossa staining or immunohistochemistry for type I collagen, fibronectin and tenascin C.

Canal enlargement by Er:YAG laser using a cone-shaped irradiation tip.

To solve the problem of mechanical instrumentation, we developed a cone-shaped laser irradiation tip. This tip delivers 80% of the energy of the laser laterally and 20% of the energy forward. The tip was equipped with a water nozzle.

Induction of necrosis factor-alpha and interleukin-6 in mice in vivo and in murine peritoneal macrophages and human whole blood cells in vitro by Micrococcus luteus teichuronic acids.

Earlier studies showed that Micrococcus luteus cells and cell walls induced anaphylactoid reactions leading to death, in some instances within 1 h, in C3H/HeN mice primed with muramyl dipeptide (MDP). They also induced serum cytokines in the surviving mice. The present study investigated the structural components responsible for these activities.

The time-course of acid excretion, levels of fluorescence dependent on cellular nicotinamide adenine nucleotide and glycolytic intermediates of Streptococcus mutans cells exposed and not exposed to air in the presence of glucose and sorbitol.

The aim of this study was to examine glucose and sorbitol metabolism in Streptococcus mutans cells exposed and not exposed to air at the coexistence of these compounds by measuring acid excretion, levels of fluorescence dependent on cellular NADH and glycolytic intermediates. An aliquot of bacterial cells grown under strictly anaerobic conditions (anaerobic cells) was exposed temporarily to air (aerobic cells). When glucose was added to the anaerobic cells metabolizing sorbitol, the acid excretion was increased.

Enhancement of hepatocyte growth factor (scatter factor) production by human gingival fibroblasts in culture stimulated with Porphyromonas gingivalis fimbriae.

Hepatocyte growth factor (HGF), also known as scatter factor (SF), is a motogen, mitogen and morphogen produced by mesenchymal cells that mainly acts on epithelial cells and is involved in osteoclast stimulation. This study examined the possible enhanced production of HGF/SF by human gingival fibroblasts upon stimulation with killed cells of Porphyromonas gingivalis strain 381 and its representative bioactive cellular components, fimbriae and lipopolysaccharide (LPS). P.

Pathways for amino acid metabolism by Prevotella intermedia and Prevotella nigrescens.

Pathways for amino acid metabolism by Prevotella intermedia and Prevotella nigrescens were investigated. Prevotella strains grew anaerobically in tryptone-based medium and their growth increased upon the addition of aspartate to the medium. Washed cells of tryptone-grown strains metabolized aspartate to succinate, acetate, fumarate, malate, formate and ammonia, while from tryptone they produced isobutyrate and isovalerate in addition to the end products from aspartate.

Rate-limiting steps of glucose and sorbitol metabolism in Streptococcus mutans cells exposed to air.

It has been supposed that rate of sorbitol metabolism in the air-exposed streptococcal cells could be limited by the low capacity to regenerate nicotinamide adenine dinucleotide (NAD) from reduced NAD (NADH) following inactivation of pyruvate formate-lyase by oxygen. The rate-limiting steps, however, have not been identified. The aim of this study was to examine the effect of temporary exposure of the streptococcal cells to air on the intracellular flux of glucose and sorbitol metabolism by measuring acid excretion, fluorescence dependent on cellular level of NADH, glycolytic intermediates and enzyme activities.

Glucose metabolism by Prevotella intermedia and Prevotella nigrescens.

Glucose metabolism by Prevotella intermedia and Prevotella nigrescens were investigated. Glucose increased the anaerobic growth of these bacteria and promoted the accumulation of intracellular polysaccharide. The polysaccharide was confirmed to be glycogen-like glucan by the absorption spectrum of iodinepolysaccharide complex and the sugar composition.

Alveolar soft-part sarcoma of the cheek: report of a case with a review of the literature.

An alveolar soft-part sarcoma (ASPS) occurring in the cheek is described, with a review of the literature. The subject was a 25-year-old woman who presented with a large swelling in the left cheek. The lesion, initially diagnosed as a benign tumor on radiographic and computed tomographic examinations, was surgically excised.

Coptidis rhizoma inhibits growth and proteases of oral bacteria.

Objective: The aim of this study was to investigate the antibacterial effect of Coptidis Rhizoma (CR), a traditional medicinal plant, on oral bacteria.

Materials And Methods: CR extract was prepared by boiling CR in water for 2 h. Alkaloids contained in CR extract were assayed by high performance liquid chromatography (HPLC).

Response properties of slowly and rapidly adapting periodontal mechanosensitive neurones in the primary somatosensory cortex of the cat.

Periodontal mechanosensitive neurones in the primary somatosensory (SI) cortex are classified as either slowly or rapidly adapting. The responses of cortical neurones and their projection pathways were studied using mechanical and electrical stimulation of the teeth and electrical stimulation of the thalamic posteromedial ventral (VPM) nuclei and contralateral SI cortex. A total of 247 periodontal mechanosensitive units were recorded from the SI cortex in 35 anaesthetized cats, distributed mainly in area 3b: 14% were slowly adapting and 86% rapidly adapting units; 62% of the slowly adapting and 9% of the rapidly adapting units were single-tooth units sensitive to stimulation of only one tooth.

Expression of apoptotic signaling proteins in leukoplakia and oral lichen planus: quantitative and topographical studies.

Although the pathogenesis of leukoplakia has been unclear, carcinogenic transformation is postulated to result from alterations of apoptotic signal transduction proteins in epithelial cells. The pathogenesis of oral lichen planus (OLP) has also been unclear, but apoptotic changes of the epithelial cells in OLP have been reported. In the present study, we used a histochemical approach to describe human keratinocyte-expression of several apoptotic signaling proteins in leukoplakia, in OLP, and in normal oral mucosa as a control.

Bone mineral density of alveolar bone in rats during pregnancy and lactation.

Background: The present study was designed to investigate the effect of pregnancy and lactation on the bone mineral density (BMD) of alveolar bone in rats fed diets containing different amounts of calcium (Ca). The effects of different levels of Ca intake by the mothers on the BMD of alveolar bone in their pups were also examined.

Methods: Ten-week-old female Wistar rats were housed with male rats for breeding and were divided into 3 groups fed diets containing 0.

Involvement of nitric oxide in parasympathetic and antidromic vasodilatations in cat lower lip.

The involvement of nitric oxide (NO) in the lower lip vasodilatations mediated via parasympathetic and antidromic mechanisms was examined in alpha-chloralose/urethane-anesthetized cats, with the two types of blood flow responses being recorded separately (by laser Doppler flowmeter) from the two sides of the lower lip. The central cut end of the lingual nerve (LN) or the peripheral cut end of the inferior alveolar nerve (IAN) was electrically stimulated to elicit parasympathetic or antidromic vasodilatation, respectively, in the lower lip. N(G)-nitro-L-arginine methyl ester (L-NAME), but not N(G)-nitro-D-arginine methyl ester (D-NAME) (each at 30 mg/kg), markedly reduced the increases in lip blood flow evoked by stimulation, the reduction being to a similar degree irrespective of whether LN or IAN was stimulated.

Metabolic pathways for cytotoxic end product formation from glutamate- and aspartate-containing peptides by Porphyromonas gingivalis.

Metabolic pathways involved in the formation of cytotoxic end products by Porphyromonas gingivalis were studied. The washed cells of P. gingivalis ATCC 33277 utilized peptides but not single amino acids.

Parasympathetic reflex vasodilatation in rat submandibular gland.

The present study was designed to investigate 1) whether parasympathetic reflex vasodilatation occurs in the submandibular gland (SMG) in deeply urethan-anesthetized, cervically vagotomized, and sympathectomized rats when the central cut end of the lingual nerve (LN) is electrically stimulated and 2) to what extent the neural mechanisms underlying such responses are the same as those involved in the response to direct stimulation of the chorda-LN (CLN). Stimulation of each nerve separately elicited a marked blood flow increase in SMG. Section of the chorda tympani abolished the SMG blood flow response but had no effect on the lip blood flow increase evoked by LN stimulation.

Expression of major bone extracellular matrix proteins during embryonic osteogenesis in rat mandibles.

It is not known how bone proteins appear in the matrix before and after calcification during embryonic osteogenesis. The present study was designed to investigate expressions of the five major bone extracellular matrix proteins--i.e.

Nifedipine-induced inhibition of parasympathetic-mediated vasodilation in the orofacial areas of the cat.

In anesthetized cats, we 1) compared the effects of antihypertensive agents (nifedipine, clonidine, phentolamine, propranolol, and nitroprusside) on the parasympathetic vasodilations elicited by lingual nerve (LN) stimulation in the lower lip and tongue and 2) investigated the mechanisms underlying the inhibitory effect of nifedipine on parasympathetic lower lip vasodilation. At the doses used, each antihypertensive agent reduced systemic arterial blood pressure by approximately 20 mmHg; however, the parasympathetic vasodilation elicited by LN stimulation was significantly reduced only by nifedipine. This inhibitory effect of nifedipine was not seen when LN was stimulated during ongoing repetitive stimulation of the superior cervical sympathetic trunk at 1-Hz frequency.

Phenytoin and its metabolite, 5-(4-hydroxyphenyl)-5-phenylhydantoin, show bone resorption in cultured neonatal mouse calvaria.

The effects of phenytoin and its major metabolite, 5-(4-hydroxyphenyl)-5-phenylhydantoin (HPPH), on bone resorption of neonatal mouse calvaria were examined in vitro. Both phenytoin and HPPH induced significant bone resorption as compared to the controls after 72 h in culture. This effect may be the cause of phenytoin-induced bone loss in vivo.

Proteolysis of human monocyte CD14 by cysteine proteinases (gingipains) from Porphyromonas gingivalis leading to lipopolysaccharide hyporesponsiveness.

Cysteine proteinases (gingipains) elaborated from Porphyromonas gingivalis exhibit enzymatic activities against a broad range of host proteins and are considered key virulence factors in the onset and development of adult periodontitis and host defense evasion. In this study, we examined the ability of arginine-specific gingipains (high molecular mass Arg-specific gingipain (HRGP) and Arg-specific gingipain 2) and lysine-specific gingipain (KGP) to cleave monocyte CD14, the main receptor for bacterial cell surface components such as LPS. Binding of anti-CD14 mAb MY4 to human monocytes was almost completely abolished by 0.

Response of zygomaticomaxillary suture to experimental malocclusion in rats.

The purpose of this study was to examine the response of the zygomaticomaxillary suture (ZMS) to experimental malocclusion in rats. Thirty-two male Wistar rats were divided into two groups. Malocclusion was produced in the experimental group (n = 20) by gluing a wire, 1 mm in diameter, on the upper left first molar.

A histopathological study of lymphoepithelial island formation in labial salivary glands in patients with primary Sjögren's syndrome.

The proliferative status of lymphoepithelial islands in the labial salivary glands of primary Sjögren's syndrome (pSS) patients was investigated by counting the number of argyrophilic nucleolar organizer regions (AgNORs) in epithelial cells constituting the islands. The islands were classified into four groups and evaluated in terms of total area and three discrete zones of the islands. In each pSS group, the mean AgNOR number per total island epithelial cell nucleus was significantly higher than in control ductal epithelial cells.

Clear cell odontogenic tumor in the mandible: report of a case with duct-like appearances and dentinoid induction.

A case of clear-cell odontogenic tumor with unusual histological features is presented. A 61-year-old Japanese man was admitted because of swelling of the left premolar-molar region of the mandible. Radiological examination revealed a multilocular radiolucency with irregular margins.

Scattering of laser light directed onto the labial surface of extracted human upper central incisors.

The purpose of this study was to evaluate the scatter of light through human teeth with laser Doppler flowmetry. An optical probe (probe 1), which mounted two optical fibers (one for light illumination and another for the measurement of backscattered light intensity) was placed on the labial surface of the extracted teeth. Another optical probe (probe 2) for the measurement of transmitted-light intensity was placed either on the mesial, distal, or palatal surface or in the canal of the teeth.