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.

Human type II phospholipase A2-induced Mac-1 expression on human neutrophils.

To investigate the effect of type II phospholipase A2 (PLA2-II) on neutrophil function, we assessed the Mac-1 (CD11b/CD18) expression on human neutrophils by flow cytometry after incubation of the cells with human PLA2-II. PLA2-II at a concentration of 10 microg/mL increased the Mac-1 expression by 150% compared with unstimulated cells at 30 min and after. Under these conditions PLA2-II increased the exocytosis from secretory vesicles but not from azurophilic, specific, or gelatinase granules. The results suggest that PLA2-II induces translocation of Mac-1 from the secretory vesicles to the plasma membrane. The Mac-1 induction mediated by PLA2-II was inhibited by an anti-PLA2-II antibody, which was able to inhibit the catalytic activity. However, the Mac-1 induction by PLA2-II was not inhibited by a 5-lipoxygenase, cyclooxygenase inhibitor, or a platelet-activating factor antagonist. Thus, we examined the effects of fatty acids and lysophospholipids on Mac-1 expression. Only arachidonic acid induced Mac-1 expression. These results imply that PLA2-II induces Mac-1 expression on neutrophils via production of arachidonic acid.

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.

Preparation and characterization of human rheumatoid arthritic synovial fluid phospholipase A2 produced by recombinant baculovirus-infected insect cells.

We prepared human rheumatoid arthritic synovial fluid phospholipase A2 (PLA2) [EC 3.1.1.4] from insect cells infected with a recombinant baculovirus. The PLA2 DNA was designed, changing the original codons to those used frequently in the polyhedrin gene. Sixteen oligo-deoxynucleotides ranging from 40 to 70 nucleotides were chemically synthesized and then assembled to form the whole PLA2 gene. The gene thus synthesized was then placed under the control of the polyhedrin promoter of Autographa californica nuclear polyhedrosis virus. The recombinant virus was infected into Spodoptera frugiperda cells. The infected cells secreted protein having PLA2 activity into the culture medium. The enzyme level in the medium reached about 3 mg/liter on day 4 after infection. The secreted protein was purified to a single band of 14,000 Da on SDS-PAGE, by means of cation exchange chromatography and reverse-phase HPLC. N-terminal amino acid sequence analysis revealed that the recombinant protein was recognized and cleaved at the signal sequence in the insect cell. The purified enzyme had almost the same specific enzyme activity, substrate specificity, pH optimum, Ca2+ ion dependency, and kinetic values as those of the natural enzyme.

Indication of fusion for lumbar spinal stenosis in elderly patients and its significance.

STUDY DESIGN: Selection of surgical therapy for lumbar canal stenosis in elderly patients is discussed. Decompression alone and decompression with fusion were evaluated. OBJECTIVES: To determine the indication of decompression with fusion for lumbar spinal stenosis in elderly patients. SUMMARY OF BACKGROUND DATA: Although there is no objection to posterior decompression, which is regarded as the first choice of surgical therapy for lumbar spinal stenosis in the elderly, it is debatable whether or not fusion should be used with decompression. METHODS: The presence or absence of instability was defined by Posner's method from preoperative plain radiographic lateral findings. Thirty-four elderly patients with lumbar canal stenosis were studied. Seventeen of the 34 patients were found to have instability. Ten of the 17 patients with spinal instability underwent decompression and instrumented fusion. The seven remaining patients with spinal instability underwent decompression alone. The 17 patients without spinal instability were treated by decompression alone. Preoperative symptoms, postoperative results, and changes in radiographic findings were compared among the three groups. RESULTS: The group treated by decompression and fusion showed the best results. The group treated by decompression in the presence of instability showed the worst results by the Japanese Orthopaedic Association back scores. Good results can be obtained by decompression alone only if the patients do not have instability as defined by Posner. CONCLUSIONS: The definition of instability by Posner's method proved useful for selecting elderly patients with instability for fusion treatment. Fusion with instrumentation should be performed on elderly patients with instability after decompression.

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.

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.

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.

[An autopsied case of intravascular malignant lymphomatosis with paraparesis, that presented a leukoencephalopathy-like image after spinal cord biopsy].

A 54-year-old woman was hospitalized because of paraparesis, sensory disturbance of the lower extremities, and dysuria. Laboratory data included an erythrocyte sedimentation rate (ESR) of 16 mm/h and lactate dehydrogenase (LDH) level of 459 IU/l. Myelogram showed an enlarged spinal cord at the L1 level, and spinal MRI revealed a high signal area on T2-weighted images. Spinal cord biopsy by thoraco-lumbar laminectomy showed thickening of the pia mater and neovascularization, but no malignant cells. Immediately after the operation, the patient displayed progressive mental deterioration. Cranial MRI showed widespread high signal areas in the cerebral white matter on T2-weighted images which resembled those of leukoencephalopathy. Steroid therapy was tried but was ineffective. Ten months after the onset of symptoms, a brief period of regression of both clinical symptoms and MRI appearances occurred following the administration of Inosiplex, subsequent progressive deterioration led to death 14 months after the onset of symptoms. LDH, C-reactive protein (CRP), and cerebrospinal fluid (CSF) protein were all elevated during the deterioration of her general status. Postmortem examination revealed a large tumor mass of the left adrenal gland which extended to the Th12, L1, and L2 vertebrae and remarkable brain edema. Microscopic mononuclear tumor cells were widespread but confined to the lumens of small vessels of the brain, spinal cord, spinal root and right adrenal gland, almost as if they were occluded. Cerebral white matter presented widespread multiple small infarcts and extensive myelin thinning. In addition to the left adrenal gland, interstitial invasions of tumor cells were discovered in the kidneys, iliopsoas muscles, oviducts, myocardium, lymph nodes, and thyroid gland.(ABSTRACT TRUNCATED AT 250 WORDS)

[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.

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.

[Familial Creutzfeldt-Jakob disease with the heterozygous point mutation at codon 200 of the prion protein gene (Glu-->Lys)--report of CJD200 brothers of Yamanashi Prefecture origin].

We report two brothers with familial Creutzfeldt Jakob disease (CJD) having a heterozygous point mutation at codon 200 of the prion protein gene (Glu-->Lys): CJD200. The brothers were born in Kitakoma-gun, Yamanashi Prefecture. Patient 1, a 62-year-old man, developed CJD in 1995 and died nine months later. Patient 2, his brother, developed CJD200 at the age of 58 in 1982 and died 13 months later. They both exhibited rapidly progressive dementia with myoclonus and periodic synchronous discharges on electroencephalograms and became bedridden with three or four months. DNA analysis of peripheral blood cells of patient I showed a point mutation in the prion protein gene at codon 200: GAG-->AAG (Glu-->Lys). Five families with CJD200, 11 patients, have been reported in Japan to date, and nine of the patients from four families were born in Yamanashi Prefecture and vicinity. Our patients were born in the same area. We suspect that there is a cluster of CJD200 in Yamanashi Prefecture and vicinity. In Europe and America the phenotype of CJD200 has been reported to be heterogeneous, whereas the clinical features in Japanese cases are fairly homogeneous. We suspect that these patients have a common ancestor with a codon 200 mutation, and that that explains why the phenotypes are homogeneous.

[IBL-type lymphadenopathy after infection of rubella virus].

A 52-year-old woman presented slight fever, diffuse papular skin rash and painful cervical lymph node swelling. Her lymph node swelling generally up to 3 cm in diameter, with petechiae on the lower legs and hepato-splenomegaly within a few weeks. ESR was 45 mm/h, Hb 10.0 g/dl, RBC 345 x 10(4)/microliter, WBC 22,600/microliter (atypical lymphocyte 47%), PLT 1.0 x 10(4)/microliter, GPT 91 U/L, gamma-globulin 34.3%, EBV-VCA x 2,560, EBNA x 20, and anti-rubella antibody x 512. The biopsied cervical lymph node showed histologic features of effacement of nodal architecture by an exuberant vascular proliferation accompanied with infiltration of the immunoblasts, and was diagnosed as immunoblastic lymphadenopathy (IBL)-type lymphadenopathy. The pulse therapy of methylprednisolone and high dose of gamma-globulin improved lymphadenopathy, thrombocytopenia and anemia. IBL-type lymphadenopathy after infection of rubella virus may be different from true IBL, but is important to discuss the pathogenesis of IBL.

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.

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.