Decision tree analysis for factors associated with dental caries in school-aged children in Japan.

OBJECTIVE: Our study aimed to elucidate the interactive relationship between factors associated with dental caries in school children using decision tree analysis. RESEARCH DESIGN: Cross-sectional study Methods: Participants were recruited from public primary schools (9-12 years, 4th to 6th grade) and junior high schools (12-13 years, 1st grade) in Japan. A total of 1775 students (928 boys and 847 girls) were analyzed. Questionnaire survey, oral examination, and saliva test were performed. Multiple logistic regression and decision tree analysis were performed. RESULTS: Multiple logistic regression showed an association between dental caries and toothpaste use, dental attendance and the presence of Streptococcus mutans. Decision tree analysis showed that students with non-regular dental attendance were at a significantly higher risk of dental caries at the late stage of primary school. At the early stage of primary school, high levels of Streptococcus mutans and male sex were factors associated with dental caries. In students with low levels of Streptococcus mutans, using toothpaste occasionally was associated with a high risk of dental caries. CONCLUSIONS: In early primary school years, S. mutans may be a useful screening and diagnostic tool for dental caries. In students with high levels of S. mutans, sex may be associated with dental caries. Furthermore, in students with low levels of S. mutans, regular use of toothpaste should be encouraged, and in late primary school years, regular dental attendance should be encouraged to prevent dental caries.

Unilateral recurrent laryngeal nerve neuropraxia following placement of a ProSeal laryngeal mask airway in a patient with CREST syndrome.

We report a severe unilateral recurrent laryngeal nerve neuropraxia following use of the ProSeal laryngeal mask airway (PLMA) in a 71-year-old female patient with CREST syndrome. She required amputation of the 5th phalanx of foot because of gangrene due to Raynaud's syndrome. Anesthesia was induced with propofol, and a size 3 PLMA was inserted. Anesthesia was maintained with sevoflurane and nitrous oxide for 2 h and the operation was performed uneventfully. On removal of PLMA, the cuff volume was measured to 40 ml. The patient did not complain of respiratory discomfort shortly after PLMA removal. However, the next day she developed dysphagia and hoarseness. Laryngoscopic examination revealed unilateral vocal cord paralysis. Cricothyrotomy was required because of suspected silent aspiration pneumonia. The pharyngolaryngeal complications improved with a mobile vocal cord but slight hoarseness after 2 months. We considered the patient's CREST syndrome with a potential of tissue ischemia, and the high intracuff pressure of the PLMA due to nitrous oxide influx, to be the cause of severe recurrent laryngeal nerve neuropraxia in this case.

Evaluation of acrosome reactivity using the Acrobeads test in varicocele patients: findings before and after treatment.

The Acrobeads test was performed on semen samples from 43 patients with varicocele before and after varicocelectomy. Sperm motility significantly increased after surgery (p <.05), while sperm concentration and motile sperm concentration did not alter postoperatively. Sperm motion analysis using CellSoft 3000 did not demonstrate a significant change after treatment. Acrobeads score significantly increased after the procedure (p<.005). Pregnancy was achieved in 10 patients (28%). Acrobeads score in cases that achieved pregnancy was increased postoperatively (p<.005). The percentage of patients with a postoperative increase in Acrobeads score in the group that achieved pregnancy was significantly higher than that observed in the unsuccessful group (p <.05). Sperm parameters other than the Acrobeads score did not show a significant difference between the successful and unsuccessful patients. The Acrobeads test assessed postoperatively can be useful in precisely evaluating fertility potential after varicocele repair.

Hypergravity modulates behavioral nociceptive responses in rats.

Hypergravity (2G) exposure elevated the nociceptive threshold (pain suppression) concomitantly with evoked neuronal activity in the hypothalamus. Young Wistar male rats were exposed to 2G by centrifugal rotation for 10 min. Before and after 2G exposure, the nociceptive threshold was measured as the withdrawal reflex by using the von Frey type needle at a total of 8 sites of each rat (nose, four quarters, upper and lower back, tail), and then rats were sacrificed. Fos expression was examined immunohistochemically in the hypothalamic slices of the 2G-treated rats. When rats were exposed to 2G hypergravity, the nociceptive threshold was significantly elevated to approximately 150 to 250% of the 1G baseline control levels in all the examination sites. The 2G hypergravity remarkably induced Fos expression in the paraventricular and arcuate nuclei of the hypothalamus. The analgesic effects of 2G hypergravity were attenuated by naloxone pretreatment. Data indicate that hypergravity induces analgesic effects in rats, mediated through hypothalamic neuronal activity in the endogenous opioid system and hypothalamo-pituitary-adrenal axis.

Gravity stress elevates the nociceptive threshold level with immunohistochemical changes in the rat brain.

Young Wistar male rats were exposed to 2G hypergravity by continuous centrifugation for 15 minutes. The nociceptive threshold was measured by using the von Frey type filament on the rat skin surfaces after hypergravity exposure. Following the hypergravity exposure, rats were sacrificed with anesthesia, then perfused and fixed for immunohistochemical examination. The 2G hypergravity elevated the nociceptive threshold up to 2-fold and induced analgesic effects on rats that remained for 2 hours after termination of centrifugation. Expression of Fos-immunoreactive proteins was prominently induced by 2G hypergravity in the arcuate nucleus and the paraventricular nucleus of the hypothalamus. The 15-minute flash exposure to 2G hypergravity induced pain suppression in rats, which might be attributed to change of neuronal activity in rat hypothalamus.

Determination of reduced, protein-unbound, and total concentrations of N-acetyl-L-cysteine and L-cysteine in rat plasma by postcolumn ligand substitution high-performance liquid chromatography.

A high-performance liquid chromatographic assay was developed for the quantitative determination of the sulfur-containing amino acids N-acetyl-L-cysteine (NAC) and L-cysteine (Cys) in rat plasma. The thiols were separated by reverse-phase ion-pair chromatography, and the column eluent was continuously mixed with an iodoplatinate-containing solution. The substitution of sulfur of the thiol compound with iodide was quantitatively determined by measuring changes in the absorption at 500 nm. The low-molecular-weight disulfides and mixed disulfide conjugates of thiols with proteins were entirely reduced to the original reduced compounds by dithiothreitol. By reducing these two types of disulfides separately during sample pretreatment, the reduced, protein-unbound, and total thiol concentrations could also be determined. Validation testing was performed, and no problems were encountered. The limit of detection was approximately 20 pmol of thiol on the column. The present method was used to measure the plasma concentrations of NAC and Cys in the rat after a bolus intravenous administration of NAC, focusing on disulfide formation. The binding of NAC to protein through mixed disulfide formation proceeds in a time-dependent and reversible manner. Moreover, this "stable" covalent binding might limit total drug elimination, while the unbound NAC is rapidly eliminated. Consequently, the analytical method described in this study is very useful for the determination of plasma NAC and Cys, including disulfide conjugates derived from them.

Hypergravity and opioid-mediated pain suppression in rats.

It is known that pain suppression in animals is induced by certain environmental stimulus. However, little is known about the effects of gravitational alteration on the nociceptive responses in rats. A recent study indicated that Fos protein expression was strongly induced in the vestibular-related brainstem regions of rats that were exposed to 2 G hypergravity (Gustave Dit Duflo et al., 2000). A number of studies indicate that Fos expression is induced in the brain by various kinds of stress. We showed that either long-term exposure or short-term exposure to 2 G hypergravity elevated the nociceptive threshold in the rat skin surfaces, in concomitant with Fos induction in the hypothalamus including the arcuate nucleus and paraventricular nucleus (Kumei et al., 2000). We have examined the possible involvement of beta-endorphin, an endogenous opioid, in the hypergravity-induced analgesic effects on rats and its counteraction by naloxone, an opioid receptor antagonist.

Water extract of defatted rice bran suppresses visceral fat accumulation in rats.

Rice bran has been reported to inhibit pancreatic lipase activity in vitro. This action shows that administration of rice bran may result in a decrease in plasma triglyceride levels and suppress accumulation of fat in vivo. We administered water extract of defatted rice bran (WED-rice bran) to rats to determine its effects. Single administration of WED-rice bran at a dose of 1 g/kg body weight caused a decrease in plasma triglyceride levels in fat emulsion induced hypertriglyceridemic rats. Four week administration of WED-rice bran suppressed accumulation of visceral fat and body weight gain without influencing food consumption, liver function, and renal function. These results indicate that a reduction of plasma triglycerides and suppression of visceral fat accumulation may be induced by pancreatic lipase inhibition caused by administration of WED-rice bran.

Advancement of the mandible facilitates nasal breathing in human subjects sedated with midazolam.

PURPOSE: To determine how anterior advancement of the mandible (ADM) affects spontaneous breathing through the nasal route in healthy human volunteers sedated with intravenous midazolam. METHODS: In four subjects who exhibited nasal breathing during midazolam sedation (intravenous dose: 0.09+/-0.02 mg x kg(-1), mean +/- SD), we measured respiratory rate (RR), peak nasal inspiratory airflow rate (V(nIpeak)) peak nasal expiratory airflow rate (V(nEpeak), duty ratio (Ti/Ttot) and nasal resistance (Rn) before and after ADM. Nasal resistance was calculated by dividing the difference between nasal mask and oropharyngeal pressure by airflow rate at peak nasal inspiratory airflow. RESULTS: The RR, V(nIpeak), and V(nEpeak) increased following ADM (P<0.001, respectively). On the contrary, Ti/Ttot decreased after ADM (P<0.001). Consequently, ADM decreased Rn from 30.4+/-40.8 to 5.0+/-5.6 (cm H2O x l(-1) x sec(-1)) (mean +/- SD) (P<0.001). In these four subjects, no respiratory airflow was observed through the oral route before and after ADM. CONCLUSION: Advancement of the mandible decreases nasal resistance, thereby facilitating spontaneous breathing through the nasal route in normal humans sedated with midazolam.

Flumazenil abolishes midazolam-induced increase in the work of nasal breathing.

PURPOSE: To evaluate the effects of midazolam sedation followed by flumazenil antagonism on the work of nasal breathing in normal humans. METHODS: We measured minute ventilation through the nasal route, respiratory frequency, nasal resistance (Rn) and the work of nasal breathing under three conditions: awake, during midazolam sedation, and after flumazenil antagonism in eight healthy human subjects. A custom-made, partitioned face mask enabled nasal and oral airflow to be measured separately. To calculate Rn and the work of nasal breathing, nasal mask and oropharyngeal pressure was also measured. RESULTS: Total resistive work spent on the upstream segment of the nasal route per minute (Wn) (J x min(-1)) was greater during midazolam sedation (3.6 +/- 2.9) than while awake (1.6 +/- 0.9) and after flumazenil antagonism (1.7 +/- 0.6), respectively (mean +/- SD) (P < 0.05). Total resistive work spent on the upstream segment of nasal breathing (WnNnE) (JxL(-1)) increased from 0.31 +/- 0.14 to 0.75 +/- 0.61 after midazolam administration (P < 0.05) and decreased to 0.31 +/- 0.10 after flumazenil. Following midazolam administration, a strong correlation was observed between changes in WnNnE and changes in Rn r = 0.852, P < 0.0001), whereas there was no correlation between changes in Wn and changes in Rn r = 0.159, P = 0.279). CONCLUSION: The work of breathing spent on the upstream segment of the nasal route increases during midazolam sedation and returns to baseline after flumazenil antagonism.

Nociceptive responses and immunohistochemical changes in the rat brain under gravity stress.

It is well known that exposure to various stresses leads to pain suppression in animals. However, there is no report about the effects of gravitational alteration to serve as a kind of stress. The purpose of the present study is to clarify the effect of hypergravity (2 G) on the nociceptive responses and histochemical changes in rats. We examined the level of the threshold of withdrawal reflex against the noxious [correction of noxicious] stimulation in rats that were exposed to 2 G. Data show that the 2 G exposure elevates the nociceptive threshold. We have demonstrated for the first time that gravity change induces analgesic effects on rats in concomitant with c-fos induction in the arcuate, and paraventricular nuclei of rat hypothalamus. Gravity change acts as a kind of stress in rats.

Experimental infusion phlebitis: tolerance pH of peripheral vein.

This study aims to determine the pH that peripheral veins can tolerate. Intravenous nutrient solutions with different pHs (from 4.52 to 6.71) were infused into rabbit ear veins, and the veins were examined histopathologically. After 6-hr infusion at 10 mL/kg/hr, a commercial 2.72% amino acid/7.5% glucose solution with electrolytes (AG) caused obvious phlebitic changes, such as loss of venous endothelial cells, inflammatory cell infiltration, and perivascular edema, in all 6 rabbits because of its low pH (4.52) and high titratable acidity (22 mEq/L). The phlebitis was reduced when the solution was neutralized with NaOH to pH 5.93, and was almost eliminated when the pH was neutralized to 6.49. After 8-hr infusion at 15 mL/kg/hr, AG-adjusted pH to 6.30 caused slight phlebitic changes, but AG-adjusted pH to 6.71 scarcely caused any change. Furthermore, 24-hr infusion of the pH 6.49 solution caused no histopathological changes in 3 rabbits. These results suggest that the tolerance pH for the peripheral vein is about 6.5, and that an infusion solution does not cause phlebitis due to acidity if the pH is not lower than the tolerance pH.

The effect of Lipo prostaglandin E1 on cauda equina blood flow in patients with lumbar spinal canal stenosis: myeloscopic observation.

STUDY DESIGN: Myeloscopic examination was performed to observe the cauda equina in patients with lumbar spinal canal stenosis before and after treatment with Lipo prostaglandin E1, a strong peripheral vasodilator. OBJECTIVES: The purpose of this study was to clarify the effects of Lipo prostaglandin E1 on blood flow in the cauda equina in patients with lumbar spinal canal stenosis. SETTING: Japan, Kagoshima METHODS: We performed myeloscopic observations of morphological changes in blood vessels running along the cauda equina in 11 patients with lumbar spinal canal stenosis before and after treatment with Lipo prostaglandin E1. RESULTS: In six of these patients, dilation of the running blood vessels was observed immediately after administration. In all of the patients who exhibited a dilation of vessels on the surface of the cauda equina, intermittent claudication and lower extremity pain and/or numbness lessened immediately after examination. However, none of the patients who exhibited no morphological changes in the vessels along the cauda equina after administration of Lipo prostaglandin E1 experienced any improvement of symptoms at the time of examination. CONCLUSION: Results of this study suggest that Lipo prostaglandin E1 may enhance blood flow in the cauda equina and improve clinical symptoms in some patients with lumbar spinal stenosis.

Cytosolic phospholipase A2, increased and activated in the eosinophils of patients with hypereosinophilic syndrome in vivo, is involved in the augmented release of leukotriene C4.

OBJECTIVE: Eosinophils from patients with hypereosinophilic syndrome (HES) showed augmented release of leukotriene C4 (LTC4) by stimulation with A23187. In the present study, we investigated the involvement of cytosolic phospholipase A2 (cPLA2) in this phenomenon. METHODS: Eosinophils from normal and HES donors (2.5 x 10(6) cells/ml) were incubated with A23187 (0.03-3 microM) for 60 min in the presence or absence of a cPLA2 inhibitor, AACOCF3. The LTC4 released from eosinophils was measured by enzyme immunoassay. Distribution of cPLA2 and 5-lipoxygenase (5-LO) proteins within the eosinophils were detected by Western immunoblotting. RESULTS: The level of LTC4 released from the HES eosinophils by stimulation with A23187 was higher than that from normal eosinophils. The A23187-induced LTC4 release was inhibited by AACOCF3 in a dose-dependent manner. The amounts of cPLA2 seemed to be increased in the non-stimulated HES eosinophils by an analysis of immunoblotting. To be noticed was that cPLA2 was detected as a phosphorylated and membrane-bound form in the HES eosinophils, but not in the normal eosinophils. In contrast, localization of 5-LO within the eosinophils under A23187 stimulation was not different between normal and HES donors, while the amounts of 5-LO also seemed to be increased in the HES eosinophils. CONCLUSIONS: These results suggest that cPLA2, increased and activated (phosphorylated and membrane-translocated) in vivo, is involved in the augmented release of LTC4 from the HES eosinophils.

Effects of long-term ursodeoxycholate administration on expression levels of secretory low-molecular-weight phospholipases A2 and mucin genes in gallbladders and biliary composition in patients with multiple cholesterol stones.

Group IIA phospholipase A2 (PLA2), a secretory low-molecular-weight PLA2, may play a critical role in the process of gallbladder mucosal inflammation in multiple cholesterol stones, which in turn may produce biliary pronucleating proteins as well as mucin. On the other hand, ursodeoxycholate (UDC) decreases biliary levels of various pronucleating proteins, possibly because of its membrane-protective effects on the inflamed gallbladder mucosa. To elucidate that beneficial effect of UDC, the expression levels of low-molecular-weight PLA2s, group IIA PLA2 (PLA2-IIA), and group V PLA2 (PLA2-V), and mucin core polypeptide genes in the gallbladders were studied for UDC-treated patients and untreated patients with multiple cholesterol stones. Furthermore, the results were correlated with alterations in biliary composition. With long-term administration of UDC, the PLA2-IIA protein mass (2.7 +/- 0.5 vs. 5.0 +/- 0.4 ng/mg x protein [mean +/- SEM]; P < .01) and steady-state mRNA level, as well as the PLA2-V mRNA level, were significantly decreased in the gallbladders, where the prostaglandin E2 (PGE2) level was concomitantly decreased (190.7 +/- 27.9 vs. 393.6 +/- 55.3 pg/mg x protein; P < .01). In the gallbladder bile, the immunoradiometrically determined PLA2-IIA levels were significantly decreased in the UDC-treated patients (43 +/- 4 ng/dL; P < .01) in comparison with untreated patients (78 +/- 6 ng/dL). Significant decreases were similarly found for total protein, mucin, and free arachidonate concentrations, as well as nucleation activity in the bile. The degree of the changes was found to be rather small in solitary stones. In contrast to the decreased mucin concentration, however, there were no significant changes in the expression levels of mucin core polypeptide genes (MUC1-MUC6) between the UDC-treated and untreated patients. Long-term UDC administration was observed to lower the increased PLA2-IIA protein mass and mRNA level, as well as the PLA2-V mRNA level, in the gallbladders of patients with multiple cholesterol stones, which in turn may be of therapeutic importance in improving the gallbladder mucosal inflammation. Effects of UDC on secretory low-molecular-weight PLA2s as inflammatory mediators may relate to the reported efficacy of UDC treatment in cholesterol gallstone disease.

[Guillain-Barré syndrome with nerve conduction blocks at multiple common entrapment sites that rapidly disappeared after plasmapheresis].

Nerve conduction blocks (NCBs) in Guillain-Barré syndrome (GBS) are frequently found at the distal terminals, proximal segments, and common entrapment sites of peripheral nerves. NCBs at distal terminals and proximal segments are considered to be due to vulnerability of the sites to the humoral factors of GBS because of relative blood-nerve barrier deficiencies. In contrast, it is not clear whether NCBs at common entrapment sites in GBS are due to a vulnerability to humoral influences or to direct mechanical compression injuries. We report a case of a 22-year-old man with GBS. His electrophysiologic examination revealed NCBs at multiple common entrapment sites. All conduction blocks rapidly disappeared after plasmapheresis, in parallel with clinical improvement. The patient was ambulatory throughout the clinical course, suggesting that his common entrapment sites remained free from compression injuries. Rapid improvement by plasmapheresis suggested that there were no demyelinative histologic changes in the NCB sites. Such NCBs may be caused by some humoral factor that is removed by plasmapheresis. Therefore, the common entrapment sites in our patient may have been especially vulnerable to the humoral factor of GBS.

Synergistic effect of type II phospholipase A2 and platelet-activating factor on Mac-1 surface expression and exocytosis of gelatinase granules in human neutrophils: evidence for the 5-lipoxygenase-dependent mechanism.

Stimulation of human neutrophils with inflammatory mediators such as TNF-alpha or platelet-activating factor (PAF) induces translocation of adhesion molecule Mac-1 (CD11b/CD18) from secretory vesicles to the plasma membrane. Type II phospholipase A2 (PLA2-II) also induces translocation of Mac-1 from secretory vesicles. However, there are more Mac-1 molecules in gelatinase granules and specific granules than in secretory vesicles. Therefore, different combinations of PLA2-II and other mediators were examined for their ability to induce gelatinase granules and specific granules to induce Mac-1 surface expression. The combination of PLA2-II and PAF synergistically increased Mac-1 surface expression, and the effect was greater than the combinations of PLA2-II with TNF-alpha, IL-8, or FMLP. Additionally, the combination of PLA2-II and PAF induced exocytosis of both secretory vesicles and gelatinase granules, which did not occur with either PLA2-II alone or PAF alone. The induction was accompanied by marked production of leukotriene B4. AA861, an inhibitor of 5-lipoxygenase, did not inhibit exocytosis of secretory vesicles but did inhibit exocytosis of gelatinase granules and decrease Mac-1 surface expression. It was also found that Ca2+ influx is essential for 5-lipoxygenase activation, because Ni2+, which blocks the influx of extracellular Ca2+, inhibited the production of leukotriene B4. These results suggest that stimulation by the combination of PLA2-II and PAF, unlike stimulation by each mediator alone, causes exocytosis of gelatinase granules via the 5-lipoxygenase pathway, resulting in a synergistic increase in neutrophil Mac-1 surface expression during inflammatory processes.

Antibodies against type II phospholipase A2 prevent renal injury due to ischemia and reperfusion in rats.

This study was performed to determine the involvement of type II phospholipase A2 (PLA2-II) in renal injury caused by ischemia and reperfusion. Ischemia and reperfusion significantly elevated levels of blood urea nitrogen and serum creatinine in rats. These increases were significantly reduced by i.v. administration of rabbit IgG F(ab')2 fragments against rat PLA2-II. Increased levels of acid-stable PLA2 activity in the kidney were caused by ischemia and reperfusion, and were suppressed by administration of anti-PLA2-II F(ab')2. Increased levels of myeloperoxidase activity, a marker of neutrophil infiltration, in the kidney were also reduced after anti-PLA2-II F(ab')2 treatment. These results suggest that PLA2-II plays a pivotal role in pathogenesis of ischemia and reperfusion injury through induction of neutrophil infiltration.