[Surgical treatment for patients with descending necrotizing mediastinitis].

Descending necrotizing mediastinitis (DNM) originating from deep cervical infection is a rare and serious clinical condition with a high mortality rate. Clinical feature of 5 patients undergone surgical drainage for DNM, between 2006 and 2009 were assessed. There were 3 male and 2 female patients whose age ranged from 57 to 83 years old (mean 69.8). All 5 patients had no underlying disease except for 1 patient with severe dental caries. The primary infections of these patients were tonsillitis and pharyngitis. The mean duration from onset of symptom to the referral to our hospital was 14 days (ranged 2 to approximately 41). Two patients underwent cervical drainage for upper mediastinum, and 3 patients were required mediastinal drainage by thoracotomy. There was no post-operative death. Early and aggressive surgical drainage of the neck and mediastinum by a multidisciplinary team of surgeons is very important in the treatment of DNM.

Oral toxicity to high level sodium fluoride causes impairment of autophagy.

Autophagy is a highly conserved intracellular digestion process that degrades damaged proteins and organelles but the biological roles of autophagy in pathological aspects of oral tissues remain largely unknown. We sought to elucidate the function of autophagy, especially its interplay with apoptosis and oxidative stress, in the oral toxicity induced by exposure to 5 mM sodium fluoride (NaF). Human cementoblasts (HCEM-2) in culture were exposed to 5 mM NaF for 5 min, after which cell viability and cell apoptosis were assessed using the MTS assay and an Annexin V-FITC/PI apoptosis detection kit, respectively. Quantitative RT-PCR and Western blotting were performed to characterize the expression levels of markers for autophagy, apoptosis, and oxidative stress. Senescence-resistant (SAMR1) mice were exposed to 5 mM NaF in their drinking water from 12 to 58 weeks. Micro-computed tomography was used to measure changes in their alveolar bone while immunohistochemistry and immunofluorescence staining was used to evaluate protein expression levels. HCEM-2 cells exposed to 5 mM NaF had decreased levels of autophagy, as shown by reduced expression levels of ATG5, Beclin-1 and LC3-II, elicited apoptosis, which in turn induced oxidative stress and inflammation, as manifested by elevated levels of Bax, cleaved caspase-3, SOD1 and phospho NF-κB. Treatment of mice with 5 mM NaF resulted in histological abnormalities in periodontal tissues, induced excessive oxidative stress and apoptosis, and reduced autophagy. Micro-computed tomography analysis demonstrated that 5 mM NaF caused a decrease in bone areas of mice compared with controls. Exposure to 5 mM NaF induced RANKL (receptor activator of nuclear factor κB ligand) and cathepsin K expression in periodontal tissues, while ATG5 and Beclin-1 expression was abrogated by 5 mM NaF. Taken together, our findings suggest that 5 mM NaF elicits oral toxicity that contributes to excessive apoptosis, oxidative stress, and defective autophagy, which aggravates periodontal tissue damage.

Wrinkling of molar crowns: new evidence.

We submit that wrinkling of molar crowns in Primates is a phenomenon of genetically controlled activity of the inner enamel epithelium that is grossly evident soon after initial calcification of the tooth occurs. The amount and pattern of this wrinkling are characteristic of the species before they are evident in the enamel surface itself.

The effect of Porphyromonas gingivalis infection on cytokine levels in type 2 diabetic mice.

BACKGROUND AND OBJECTIVE: Several studies have shown that diabetes mellitus increases the severity of periodontitis. Conversely, periodontitis has been shown to have an impact on diabetes, although the underlying mechanisms of this are unclear. The aim of this study was to compare the inflammatory response to Porphyromonas gingivalis infection in normal and diabetic mice. MATERIAL AND METHODS: Porphyromonas gingivalis were inoculated adjacent to the periosteum, at a point on the midline of the skull located between the ears, in C57BL/6 (normal) and KKAy (diabetic) mice. After induction, the levels of tumor necrosis factor-alpha, interleukin-6 and adiponectin in the mice were measured using real-time polymerase chain reaction and enzyme-linked immunosorbent assay. RESULTS: The KKAy mice showed significant increases in blood glucose, serum tumor necrosis factor-alpha and interleukin-6 levels after inoculation with Porphyromonas gingivalis, and a significant decrease in adiponectin to 35.7%. Similar results were observed at the mRNA level in liver and visceral adipose tissue. CONCLUSION: These observations suggest that tumor necrosis factor-alpha, interleukin-6 and adiponectin are an integral part of the link between diabetes mellitus and Porphyromonas gingivalis infection.

HTHQ (1-O-hexyl-2,3,5-trimethylhydroquinone), an anti-lipid-peroxidative compound: its chemical and biochemical characterizations.

Recently, it has become apparent that reactive oxygen species (ROS) play many important roles in biological systems. For example, relationships between many diseases, such as cancer, cardiac infarction and arteriosclerosis, and ROS have been found. It is also well known that anti-oxidative agents scavenge ROS in biological systems, which in turn prevents ROS-related diseases. In our previous efforts to develop effective anti-oxidative compounds, we found that 1-O-hexyl-2,3,5-trimethylhydroquinone (HTHQ), which is a hydroquinone monoalkyl ether, is a potent anti-oxidative agent. Here, the scavenging activities of HTHQ against ROS, such as superoxide anion radicals, hydroxyl radicals, t-butyl peroxyl radicals and singlet oxygens, were examined by the ESR (electron spin resonance)-spin trapping method. Among ROS, HTHQ scavenged t-butyl peroxyl radicals most effectively (IC50=0.31+/-0.04 mM), showing approximately twice the activity of a well-known lipophilic anti-oxidant, D,L-alpha-tocopherol (IC50=0.67+/-0.06 mM), as measured by IC50 values defined as the 50% inhibition concentration of the generated ROS. In addition, a relatively stable ESR spectrum of free radicals due to HTHQ was observed during the reaction of HTHQ and t-butyl peroxyl radicals, indicating a direct reaction of HTHQ and t-butyl peroxyl radicals. The free radicals due to HTHQ were more stable than those derived from D,L-alpha-tocopherol under the same conditions examined. On the basis of these results, we evaluated anti-lipid-peroxidative activity of HTHQ in three systems involving micelles, liposomes and rat liver microsomes. HTHQ exhibited a similar anti-oxidative activity to that of D,L-alpha-tocopherol against lipid peroxidation in linolate micelles initiated by addition of Fe2+. On the other hand, HTHQ exhibited approximately 4.8-fold higher anti-lipid-peroxidation activity than that of D,L-alpha-tocopherol against the peroxidation in phosphatidylcholine liposomes initiated by addition of Fe2+. Furthermore, HTHQ scavenged the lipid peroxides at a rate approximately 150 times higher than that of D,L-alpha-tocopherol against Fe3+ -ADP-induced lipid peroxidation in rat liver microsomes, indicating that the anti-lipid-peroxidation activity of HTHQ might be substantially elevated in biological systems in comparison with that of D,L-alpha-tocopherol. Based on these results, we suggest that HTHQ reacts directly with peroxyl radicals, such as t-butyl peroxyl radicals and peroxides of linolate micelles, liposomes and microsomes, by scavenging them to form stable free radicals. The resulting free radicals are presumed to be reduced by several reducing mechanisms in biological systems similarly to those of D,L-alpha-tocopherol, and then the lipid-peroxidation reactions will be terminated. In conclusion, HTHQ was found to be a potent anti-lipid-peroxidative compound and its antioxidation activity to be extremely elevated in biological systems, such as that of liver microsomes via the generation of stable free radicals. We propose that HTHQ is a potent anti-oxidative agent for use in future treatments for lipid-peroxide relevant diseases.

Effects of positive pressure in odontogenic keratocysts.

Intracystic fluid pressure is thought to be involved in odontogenic cyst growth. In this study, we investigated the effects of positive pressure on the expression of interleukin-1alpha (IL-1alpha), matrix metalloproteinases (MMPs), and prostaglandin E2 (PGE2) in odontogenic keratocysts to determine whether this pressure stimulates inflammatory cytokine production and signaling of osteoclastogenic events. Positive pressure enhanced the expression of IL-1alpha mRNA and protein in odontogenic keratocyst epithelial cells, and increased the secretion of MMP-1, MMP-2, MMP-3, and PGE2 in a co-culture of odontogenic keratocyst fibroblasts and the epithelial cells. The pressure-induced secretions were inhibited by an interleukin-1 receptor antagonist. Recombinant human interleukin-1alpha (rhIL-1alpha) increased the secretion of MMP-1, MMP-2, MMP-3, and PGE2 in the fibroblasts. Furthermore, in the fibroblasts, rhIL-1alpha enhanced the expression of macrophage colony-stimulating factor (M-CSF) mRNA, and rhIL-1alpha-induced PGE2 increased the expression of nuclear factor kappaB ligand (RANKL) mRNA. Thus, positive pressure may play a crucial role in odontogenic keratocyst growth via stimulating the expression of IL-1alpha in epithelial cells.

Interleukin-1alpha enhances type I collagen-induced activation of matrix metalloproteinase-2 in odontogenic keratocyst fibroblasts.

Interleukin-1alpha (IL-1alpha) is strongly expressed in odontogenic keratocysts. In this study, we investigated the effects of IL-1alpha on the activation of matrix metalloproteinase-2 (MMP-2) in the fibroblasts isolated from odontogenic keratocysts. Odontogenic keratocyst fibroblasts secreted a latent form of MMP-2 (proMMP-2) spontaneously. Type I collagen induced the activation of the proMMP-2, and recombinant human IL-1alpha (rhIL-1alpha) further enhanced the type I collagen-induced activation of proMMP-2 in a dose-dependent manner. The rhIL-1alpha-induced activation of proMMP-2 was inhibited by anti-human IL-1alpha antibody. A reverse-transcription/polymerase chain-reaction (RT-PCR) and Western immunoblotting demonstrated that the expression of membrane-type 1 matrix metalloproteinase (MT1-MMP) mRNA and protein was increased in the fibroblasts when the cells were cultured on type I collagen, and the expression was further enhanced by rhIL-1alpha. Thus, IL-1alpha may up-regulate proMMP-2 activation by increasing the expression of MT1-MMP in the fibroblasts isolated from odontogenic keratocysts synergistically with type I collagen.

Interleukin-1alpha-dependent regulation of matrix metalloproteinase-9(MMP-9) secretion and activation in the epithelial cells of odontogenic jaw cysts.

Interleukin-1alpha (IL-1alpha) and matrix metalloproteinase-9 (MMP-9) are thought to be involved in odontogenic cyst expansion. In this study, we investigated the effects of IL-1alpha on the secretion and activation of MMP-9 in odontogenic jaw cysts. An active form of MMP-9 was present in odontogenic keratocyst (6 of 8 cases) fluids more frequently than dentigerous cyst (3 of 10 cases) and radicular cyst (3 of 10 cases) fluids, although proMMP-9 was present in all cyst fluids. Odontogenic keratocyst fragments in explant culture secreted a larger amount of IL-1alpha than dentigerous cyst and radicular cyst fragments in explant culture, and spontaneously secreted both proMMP-9 and an active form of MMP-9. The fragments of dentigerous cysts and radicular cysts secreted a small amount of proMMP-9, but no active form of MMP-9. Exogenously added recombinant human IL-1alpha (rhlL-1alpha) increased the secretion and activation of proMMP-9 in the fragments of dentigerous cysts and radicular cysts. The epithelial cells isolated from odontogenic keratocysts secreted IL-1alpha and proMMP-9 without stimulation. Under the cultivation on a fibronectin-coated dish, rhIL-1alpha increased the secretion of proMMP-9 from the epithelial cells in a dose-dependent manner. Moreover, rhIL-1alpha induced the secretion of proMMP-3 and plasminogen activator urokinase (u-PA) from the epithelial cells, and converted the secreted proMMP-3 to the active form in the presence of plasminogen. The secreted proMMP-9 was also activated in the presence of rhIL-1alpha and plasminogen. Hence, our results suggest that IL-1alpha may up-regulate not only proMMP-9 secretion but also proMMP-9 activation by inducing proMMP-3 and u-PA production in the cyst epithelial cells by autocrine/paracrine regulatory mechanisms.

Structure-activity relationship of polyphenols on inhibition of chemical mediator release from rat peritoneal exudate cells.

The effect of phenolic compounds in foodstuffs on histamine and leukotriene B4 (LTB4) release from rat peritoneal exudate cells and their antioxidative activity were examined to assess their antiallergenic activities. Among them, triphenols such as pyrogallol and gallic acid inhibited histamine release from the cells, but diphenols did not. On the other hand, o- and p-diphenols such as catechol and hydroquinone with strong antioxidative activity inhibited LTB4 release as strongly as pyrogallol, but an m-derivative resorcinol with weak antioxidative activity did not. Though carboxylated compounds and their noncarboxylated counterparts were antioxidative, the former exerted a much weaker inhibitory effect on the LTB4 release than the latter. In flavonols, only myricetin with a triphenolic B ring strongly inhibited histamine release, but all flavonols strongly suppressed LTB4 release irrespective of the number of OH groups in the B ring. Among flavonoids with an o-diphenolic B ring, flavonol and flavone with a C4-carbonyl group strongly inhibited LTB4 release, whereas the activity of anthocyan without C4-carbonyl was much weaker than the above compounds. These results suggest that triphenolic structure is essential for the inhibition of histamine release. On the other hand, antioxidative activity and membrane permeability of phenolic compounds seemed to be essential for the inhibition of LTB4 release. In addition, the C4-carbonyl group seemed to be important for strongly inhibiting LTB4 release.

Os odontoideum with posterior atlantoaxial instability.

Nine patients who had os odontoideum with posterior atlantoaxial instability are reviewed. Three parameters were measured on the lateral radiographs: the distance from the os odontoideum to the spinous process of the axis in extension (Dext), the distance from the os odontoideum to the posterior arch of the atlas (Datl), and the degree of instability (Inst). Patients were classified into four groups: Group I, local symptoms (N = 3); Group II, transient myelopathy (N = 0); Group III, progressive myelopathy (N = 6); and Group IV, cerebral symptoms (N = 0). The development of cervical myelopathy was not related to degree of instability but to distance from the os to the spinous process of the axis (Dext). Dext was more than 16 mm in Group I and less than or equal to 16 mm in Group III. Five of six patients in Group III underwent myelography. Based on myelographic findings, Group III was further subdivided into two groups, Group IIIA (N = 2) and Group IIIB (N = 3), according to the following characteristics: In Group IIIA, the distance from the os to the posterior arch of the atlas was more than 13 mm, and the spinal cord was impinged between the os odontoideum and the lamina of the axis in extension and reduced in flexion. In Group IIIB, Datl was less than or equal to 13 mm, and the spinal cord was compressed at the level of the atlas during flexion and extension. Stenotic Datl of 13 mm or less specifically defined severe cervical myelopathy. Surgical treatment for cervical myelopathy in os odontoideum with posterior instability is suggested as follows: in the absence of canal stenosis of the atlas (Group IIIA), atlantoaxial fusion in a reduced position is indicated; when associated with canal stenosis of the atlas (Group IIIB), laminectomy of the atlas followed by occiput-to-C2 arthrodesis is indispensable.

Relation between size of odontogenic jaw cysts and the pressure of fluid within.

Intracystic fluid pressure may have a crucial role in the growth of odontogenic jaw cysts. In this study, we investigated the relation between the size of the cyst and the pressure of the fluid within odontogenic keratocysts, dentigerous cysts, and radicular cysts. The radiolucent area of the cyst on a panoramic radiograph was linearly related to the volume in the cavity, and the correlation coefficient (gamma) was 0.70 (n = 25, P < 0.001). Intracystic fluid pressure correlated negatively with the radiolucent area in odontogenic keratocysts (gamma = -0.76, n = 9, P = 0.02), dentigerous cysts (gamma = -0.54, n = 16, P = 0.03), and radicular cysts (gamma = -0.69, n = 10, P = 0.03). The values of [(intracystic fluid pressure (mmHg)) x (radiolucent area (cm(2)))] did not differ significantly among the three types of cyst. Intracystic fluid pressure may therefore be negatively related to the size of all three types of cyst.

[Granuloma formation in mice by liposomes of new glycolipid containing mycolic acids, "trehalose 2,3,6'-trimycolate"].

After intravenous administration of liposomes containing a novel glycolipid, trehalose 2,3,6'-trimycolate, isolated from Rhodococcus aurantiacus, the granuloma formation was observed distinctively in the lungs, spleen and liver of ICR mice. The concentration of the glycolipid in liposomes influenced profoundly on the inducibility for granulomas and the liposomes containing 10 mol% of trehalose 2,3,6'-trimycolate showed the highest activity for the granuloma formation in mice without a significant loss of body weight of mice with a less toxicity. EggPC liposomes are of more highly inducible for the granuloma formation in mice than eggPC:PS (7:3, mol ratio) liposomes or eggPC:Chol (9:1, mol ratio) liposomes, suggesting that cholesterol in liposomes was not necessarily essential for inducing granulomas in mice. Among the various PC liposomes, synthetic dimyristoyl-phosphatidylcholine (DMPC) or dipalmitoylphosphatidylcholine (DPPC) liposomes were of highly inducible, although a high responsiveness was also observed with natural lecithines such as egg or soy PC. However, distearoylphosphatidylcholine (DSPC) liposomes did not show any activity for the granuloma formation in any organs of mice. Organ responsiveness differed significantly in the micelle forms injected. Glycolipid entrapped with eggPC-Chol liposomes showed a lower lung index below 1.0, in contrast to w/o/w micelles containing Freunds' incomplete adjuvant, which showed a higher granuloma formation in the lungs. It was also noted that the toxicity of glycolipid containing liposomes was comparatively lower than the toxicity of glycolipid containing w/o/w micelles, indicating that the liposomes appeared to be more suitable for the induction of the immunomodifying activities of mycolic acid-containing glycolipids than w/o/w micelles.

Comparison of lidocaine with and without bupivacaine for local dental anesthesia.

The purpose of this study was to investigate the effectiveness of a combination of bupivacaine and lidocaine and that of lidocaine alone for local dental anesthesia. First, on different days, healthy volunteers were given 2% lidocaine with 1/80,000 epinephrine or 2% lidocaine with 1/80,000 epinephrine + 0.5% bupivacaine, after which pain was produced with a pulp tester. No difference was found in the time until onset of anesthetic effect between the preparations. However, the duration of anesthetic effect was longer with both lidocaine and bupivacaine than with lidocaine alone. Next, patients undergoing dental surgery were given one of the anesthetic preparations, after which serum concentrations of the anesthetics and epinephrine were measured. The maximal serum concentration of lidocaine was higher and was reached sooner after injection in patients receiving lidocaine alone (1.74 microgram/ml after 5 min) than in patients receiving both anesthetics (0.85 microgram/ml after 3 min). The mean maximal serum concentration of lidocaine was higher in patients receiving lidocaine alone (1.77 +/- 0.03 microgram/ml) than in those receiving both anesthetics (0.99 +/- 0.45 microgram/ml). Furthermore, the mean plasma concentration of epinephrine 1 min after injection was significantly higher in patients receiving lidocaine alone (0.671 ng/ml) than in patients receiving both lidocaine and bupivacaine (0.323 ng/ml). The results of this study suggest that the combination of lidocaine with epinephrine and bupivacaine produces lower systemic levels of the anesthetic and epinephrine and a longer duration of activity than lidocaine with epinephrine alone for local dental anesthesia.

Timing and side effects of flumazenil for dental outpatients receiving intravenous sedation with midazolam.

We studied the timing and side effects of flumazenil treatment for 10 healthy volunteers and 46 dental outpatients who received intravenous sedation with midazolam. For the volunteers, vital signs were monitored before and after intravenous injection of midazolam and flumazenil. In addition, grip strength, signs and symptoms, and performance on the Romberg's test and addition tests were evaluated 30 min and 60 min after midazolam injection as well as after flumazenil injection. There were no significant changes in vital signs before, immediately after, or 50 min after injection of flumazenil, the latter time corresponding to the half-life of the drug. Thus, awakening from sedation was associated with no effects on the cardiovascular or respiratory systems. Distinct effects of flumazenil were demonstrated by the Romberg's test and the assessment of sedation status. Flumazenil had no effect on the outcome of the addition test. For the outpatients, sedation status and signs and symptoms were studied in patients undergoing procedures lasting 30 min or less (group S) and those undergoing procedures lasting 31 to 60 min (group L). Three patients in group S and one in group L had signs and symptoms of resedation. After treatment with flumazenil, abnormalities such as excitability and nausea were reported by only two patients in group L. One patient in group S had drowsiness that did not resolve after injection of flumazenil and continued until the following day. Our results indicate that flumazenil should be given at least 60 min after intravenous sedation with midazolam in dental outpatients. Moreover, caution should be exercised with regard to the potential side effects of flumazenil.

Improvement in the therapeutic efficacy of an asthma-inducing sea squirt antigen termed DIIIa by its polymerization in hyposensitization of sea squirt allergy.

Polymerization using glutaraldehyde markedly improved the apparently low efficacy of an asthma-inducing sea squirt antigen, DIIa (MW 9,980), in hyposensitization therapy on patients with sea squirt allergy. A product (poly-DIIa-G) comparable to Gi-rep (MW 106,000) in MW-distribution showed high therapeutic efficacy comparable to the most effective therapeutic antigen, Ei-M, which was paralleled by a significant increase in the allergen-specific IgG titer in most of the successfully hyposensitized patients as assayed using Ei-M as the target antigen. Another product (poly-DIIa-E) comparable to Ei-M (MW 22,800) in MW also showed a high but slightly lower therapeutic efficacy relative to poly-DIIIa-G with an apparent increase in the specific IgG titer in some patients. However, no significant change in the IgG titer was detected in most patients unsuccessfully treated with intact DIIIa. On the other hand, no significant change was detected in the IgE titer specific to the target antigen in the patients, except in a few cases where the change was independent of the therapeutic effect. The apparent correlation between the increase in the specific IgG titer and the enhancement of the therapeutic effect suggested that polymerization enhanced the immunogenicity of DIIIa and resulted in a significant improvement in the therapeutic efficacy through an additional induction of the specific IgG capable of competing, as a blocking antibody, with the specific IgE for an asthma-inducing antigen, like DIIIa, in patients treated with the polymerized antigens.

[Analysing noise levels in dental environment. Air turbine sound response to various physical factors].

Dental Air Turbine sound depends on the mechanical performance such as rotation and it is impossible to neglect connections of the sound with fluid mechanics and acoustics. Turbine sound must be considered from the standpoint of the sound pressure level and frequency component. In this study, the sound samples was measured and analysed in octave band spectrum. Turbine sound has three resonance bands of the frequency with the range from 0 to 1,600 Hz and the resonance band increased as air pressure increased. The frequency of the second resonance band decreased as the cutting load and cutting point diameter increased. Damping of the second resonance band frequency shifted downward by polishing point.