Factors affecting psychological stress in children who cooperate with dental treatment: a pilot study.

AIM: Few studies have examined psychological stress and personal anxiety in children exhibiting cooperative behaviour during dental treatment. We assessed psychological stress and personal anxiety during dental treatment in cooperative children, and investigated the influence of various factors. MATERIALS AND METHODS: We measured pre- and post-treatment salivary alpha amylase (sAA) levels of 28 children aged 8-13 years and their parents. Children completed the State-Trait Anxiety Inventory for Children (STAIC); their parents completed the STAI. The IA group included children whose sAA levels increased >10%, whereas the DA group included children whose sAA levels decreased >10%. We used regression models to calculate the power of variables to predict children's psychological stress. RESULTS: The mean anxiety trait score in the IA group was significantly higher than in the DA group (t-test, P = 0.021). For children with higher STAIC-Trait scores, the OR for increasing sAA was 1.16 (95% CI [1.02-1.31]). Parental or treatment factors did not significantly contribute to incremental sAA levels in children. CONCLUSION: Well-behaved children with high anxiety traits may experience high stress levels during dental treatment; however, parental and dental treatment factors may not affect psychological stress in these children.

Career choice and attitudes towards dental education amongst dental students in Japan and Sweden.

The purpose of this study was to identify and compare the perspectives of dental students towards their career choice and dental education in Japan and Sweden. One hundred and fourteen dental students from the Nippon Dental University, Japan and 43 dental students from the Karolinska Institutet, Sweden participated in this study. Information was derived from a self-answered questionnaire consisting of five items for career choice and six items for dental education. Chi-square test and Wilcoxon signed-rank test were used for comparison. Significant differences were detected for 10 questionnaire items between the two countries. Regarding motivation towards the career choice, 44% of Swedish students indicated interpersonal motives related to helping other people, whereas 32% of Japanese students indicated expectations of their family in the dental profession. As future career options, 64% of Japanese and 47% of Swedish students planned to work as general dentists. More Swedish students (37%) preferred specialisation than Japanese students (17%). Nearly three-quarters of the Swedish students were satisfied with the teaching faculty of their school, whilst only 32% of the Japanese students indicated content. The perspectives of dental students were different in Japan and Sweden. This study provides a description of the perspectives of Japanese and Swedish dental students and enables better understanding of career decision and dental curriculum issues.

Mild intraischemic hypothermia reduces postischemic hyperperfusion, delayed postischemic hypoperfusion, blood-brain barrier disruption, brain edema, and neuronal damage volume after temporary focal cerebral ischemia in rats.

Mild to moderate hypothermia (30-33 degrees C) reduces brain injury after brief (< 2-h) periods of focal ischemia, but its effectiveness in prolonged temporary ischemia is not fully understood. Thirty-two Sprague-Dawley rats anesthetized with 1.5% isoflurane underwent 3 h of middle cerebral artery occlusion under hypothermic (33 degrees C) or normothermic (37 degrees C) conditions followed by 3 or 21 h of reperfusion under normothermic conditions (n = 8/group). Laser-Doppler estimates of cortical blood flow showed that intraischemic hypothermia reduced both postischemic hyperperfusion (p < or = 0.01) and postischemic delayed hypoperfusion (p < or = 0.01). Hypothermia reduced the extent of blood-brain barrier (BBB) disruption as estimated from the extravasation of Evans blue dye at 6 h after the onset of ischemia (p < or = 0.01). Hypothermia also reduced the volume of both brain edema (p < or = 0.01) and neuronal damage (p < or = 0.01) as estimated from Nissl-stained slides at both 6 and 24 h after the onset of ischemia. These results demonstrate that mild intraischemic hypothermia reduces tissue injury after prolonged temporary ischemia, possibly by attenuating postischemic blood flow disturbances and by reducing vasogenic edema resulting from BBB disruption.

Mild intraischemic hypothermia suppresses consumption of endogenous antioxidants after temporary focal ischemia in rats.

Oxidative damage by free radicals has been proposed as a mechanism of cerebral injury due to ischemia and reperfusion. Hypothermia protects against ischemic necrosis; however, its effect on oxidative stress has not been investigated. In this study, the effects of hypothermia on oxidative stress were studied by determining consumption of endogenous antioxidants after temporary focal ischemia in rats. Thirty-two Sprague-Dawley rats anesthetized with 1.5% isoflurane underwent 3 h of middle cerebral artery occlusion under hypothermic (33 degrees C) or normothermic (37 degrees C) conditions followed by 3 h of normothermic reperfusion. In the first study (n = 8 per group), intraischemic hypothermia suppressed the reduction of tissue concentrations of endogenous antioxidants, ascorbate (P < or = 0.05), and glutathione (P < or = 0.05) in ischemic cortex but not in caudoputamen. In a parallel study (n = 8 per group), hypothermia reduced tissue damage in ischemic frontoparietal cortex (P < or = 0.05), but not in caudoputamen. Laser-Doppler estimates of cortical blood flow showed that intraischemic hypothermia significantly attenuated early postischemic hyperperfusion (P < or = 0.01) and delayed postischemic hypoperfusion (P < or = 0.01). These results demonstrate that intraischemic mild hypothermia reduces oxidative stress and cell injury after prolonged focal ischemia followed by reperfusion. The reduction of oxidative stress by hypothermia may be related indirectly to attenuation of postischemic blood flow changes.

Effects of ouabain and EGTA on the inhibitory effect of Ca2+ on guinea pig stomach smooth muscle ('Ca reversal').

Guinea pig stomach smooth muscle is known to show sustained contraction when treated with carbachol (CCh) in Ca-free solution containing 2 X 10(-3) M EGTA ('Ca-free contraction'). After pretreatment of the muscle with a Ca antagonist (D-600, nicardipine or nifedipine), addition of 10(-4) M Ca2+ (pCa 4.0) relaxed this CCh-induced Ca-free contraction ('Ca reversal'), but without pretreatment with a Ca antagonist, Ca2+ evoked contraction. In a Ca buffer containing 2 X 10(-3) M EGTA, low concentrations of Ca2+, 10(-8)-3 X 10(-7) M (pCa 8.0-6.5), relaxed the Ca-free contraction dose dependently ('Ca reversal'), whereas concentrations higher than 10(-6) M Ca2+ (pCa 6.0-) reversed this relaxation back to contraction. EGTA at 5 X 10(-3) or 10(-2) M potentiated the Ca reversal, whereas no reversal occurred in a Ca buffer containing 10(-3) M EGTA. This Ca reversal was inhibited in K(+)-depleted, Ca-free solution and by ouabain in Ca buffer containing EGTA (5 X 10(-3) or 10(-2) M). These results show that Ca reversal of guinea pig stomach smooth muscle occurs at low concentrations of Ca2+ and that its mechanism is related to ouabain-sensitive processes, such as the function of Na(+)-K+ ATPase.

Inhibitory effects of protein kinase inhibitors and cytoskeletal inhibitors on Ca2(+)-free contraction of rat uterus.

In rat uterine smooth muscle, sustained Ca2(+)-free contraction was observed by oxytocin in Ca2(+)-free solution. This Ca2(+)-free contraction was effectively inhibited by protein kinase inhibitors and cytoskeletal inhibitors but myosin-light chain kinase (MLCK) inhibitors were not so effective. Simultaneous addition of a protein kinase inhibitor and a cytoskeletal inhibitor caused synergistic inhibition. These results suggest that the mechanism for Ca2(+)-free contraction involves some protein kinase and cytoskeletal elements rather than MLCK.

Ca(2+)-independent contraction of uterine smooth muscle induced by vanadate and its inhibition by Ca2+.

Vanadate, 30 microM, contracts uterine smooth muscle of estrogen-dominated non-pregnant rats in Ca(2+)-free medium after preincubation with 3 mM EGTA. In spite of the phosphorylation of the myosin light chain during this contraction, studies with fura-2 suggested that this contraction was not accompanied by an increase in the cytosolic Ca2+ level. Inhibitors of the myosin light chain kinase and protein kinase C partly inhibited this contraction. Vanadate seems to enter the cell through anion channels to inhibit phosphatases, resulting in phosphorylation via basal activities of the myosin light chain kinase and protein kinase C. An increase in the cytosolic free Ca2+ level resulted in relaxation of the contracting muscle in the same manner as in the oxytocin-induced Ca(2+)-free contraction.

Sex differences in masticatory muscle pain after chewing.

Neither the etiology of muscle-related temporomandibular disorders (TMD) nor the reason for the disproportionate number of women suffering from these disorders is well-established. We tested the hypothesis that physiologically relevant exercise (i.e., chewing bubble gum for 6 min) increases masticatory muscle pain in patients, but not in asymptomatic control subjects, and that female patients experience a significantly greater increase than males. Chewing increased pain in both female and male patients and, unexpectedly, also in female control subjects. One hour after chewing, the pain remained above pre-test levels for female patients but not for the other groups. Thus, sex differences in chewing-induced pain were found in control subjects but not as hypothesized in patients. Because chewing-induced masticatory muscle pain was significantly greater in female control subjects than in males, and persisted longer in female patients than in males, these results suggest greater susceptibility in women.

Partial purification and characterization of a calcium-dependent protein kinase in rice leaves.

A protein from rice leaves, which was partially purified by sequential chromatography on DE52, MONO-Q and Superose 12, presented calcium-dependent protein kinase (CDPK) activity. This protein kinase phosphorylated the substrate, histone III-S, in a Ca(2+)-dependent manner and the half-maximum concentration of Ca2+ to protein kinase activity (EC50) was 1 microM. This phosphorylation was independent of phosphatidylserine and a phorbol ester. The apparent M(r) of the protein kinase, as determined by phosphorylation in SDS-polyacrylamide gel containing histone III-S, was 45 k. This kinase was found to react differently from other protein kinases, such as protein kinase C from rat brain or CDPK from soybean leaves, owing to the absence of a phospholipid or phorbol ester dependency. CDPK phosphorylated three endogenous proteins as detected by in vitro phosphorylation on two-dimensional PAGE.

Intraoperative mild hypothermia ameliorates postoperative cerebral blood flow impairment in patients with aneurysmal subarachnoid hemorrhage.

OBJECTIVE: Intraoperative mild hypothermia has been used during cerebral aneurysm surgery to reduce ischemic injury induced by temporary vessel occlusion and brain retraction. However, the clinical effects on cerebral hemodynamics are unclear. This study investigated the effects of intraoperative mild hypothermia on cerebral blood flow (CBF) after surgery to treat aneurysmal subarachnoid hemorrhage. METHODS: Twenty-four patients with ruptured internal carotid or middle cerebral artery aneurysms, of preoperative Hunt and Hess Grade II or III, underwent aneurysm clipping within 72 hours after the onset of subarachnoid hemorrhage. During surgery, patients were randomly assigned to either intraoperative mild hypothermia (33.5 degrees C, n = 12) or normothermia (37 degrees C, n = 12). Brain single photon emission computed tomography with 99mTc-hexamethylpropylenamine oxime or 99mTc-L,L-ethylcysteinate dimer was performed on Days 4, 7, and 14 after subarachnoid hemorrhage. Regional CBF was determined in the basal ganglia and cingulate, frontal, and frontoparietal cortices, using a semiquantitative method. RESULTS: CBF in the frontal cortex ipsilateral to the aneurysm was significantly higher in the hypothermia group than in the normothermia group on Day 4 (P<0.01) but not Day 7 or 14. There was a similar trend in the ipsilateral frontoparietal cortex, but it was not significant. There were no differences in regional CBF in the ipsilateral cingulate cortex or basal ganglia or in any contralateral region during the study period. CONCLUSION: Intraoperative mild hypothermia may reduce the severity of ischemia induced by intraoperative temporary vessel occlusion and brain retraction, thus ameliorating postoperative CBF impairment.

Use of mild intraischemic hypothermia versus mannitol to reduce infarct size after temporary middle cerebral artery occlusion in rats.

To determine which of two treatments for reducing ischemic injury after temporal focal ischemia is more effective, the effects of mild (33 degrees C) intraischemic hypothermia were compared with those of mannitol, the most commonly used neuroprotective agent. Four groups of Sprague-Dawley rats underwent 1 hour of endovascular middle cerebral artery occlusion followed by 23 hours of normothermic reperfusion. The four experimental groups were as follows: Group A, saline control; Group B, mannitol (25%, 1 g/kg); Group C, hypothermia; and Group D, hypothermia plus man-nitol. Laser-Doppler estimates of cortical blood flow showed that hypothermia did not affect blood flow during ischemia or reperfusion. Mannitol increased cortical blood flow during ischemia and reperfusion under both normothermic and hypothermic conditions (p < 0.05). Neurological deficit was significantly less severe in treated rats (Group B, p < 0.05; Group C or D, p < 0.01) than in controls (Group A). Infarct volume, measured on semiserial Nissl-stained sections, was significantly smaller in treated rats (p < 0.01) than in controls. Infarct volume was also significantly smaller in rats treated with hypothermia than in those treated with mannitol (Group C vs. Group B, p < 0.05); there was no difference between rats treated with mannitol and those treated with mannitol and hypothermia. All three treatments reduced infarct area in the ischemic penumbra; hypothermia with or without mannitol also reduced infarct area in the ischemic core. These results demonstrate that both mild intraischemic hypothermia and mannitol reduce infarct size and neurological deficit: hypothermia reduces infarct size more effectively than mannitol, and mannitol adds no significant protection to hypothermia, whereas hypothermia adds significant protection beyond that afforded by mannitol after brief focal ischemia followed by reperfusion in rats. The results suggest that mild intraischemic hypothermia alone, or in combination with mannitol, may be useful in avoiding ischemic injury from temporary vessel occlusion during cerebrovascular surgery.

Diffusion-weighted magnetic resonance imaging in the early evaluation of corticospinal tract injury to predict functional motor outcome in patients with deep intracerebral hemorrhage.

OBJECT: Diffusion-weighted (DW) magnetic resonance imaging was used to visualize corticospinal tract injury in patients with deep intracerebral hemorrhage (ICH), and the results were used to predict motor impairment of the extremities. METHODS: Twenty-eight patients with deep ICH (17 men and 11 women, mean age 58+/-14 years) were examined. The volume of the ICH was assessed on initial computerized tomography scans. Twelve patients had ICH volumes of 40 ml or more and were treated surgically, and 16 patients who had an ICH volume of less than 40 ml were treated medically. Initial corticospinal tract injury was classified into four grades according to the anatomical relationship between the corticospinal tract and the ICH on DW images. Motor impairment of both the upper and lower extremities was assessed at admission and 1 month poststroke by using the National Institutes of Health Stroke Scale. The extent of correlation was determined between motor impairment and corticospinal tract injury. Initial corticospinal tract injury was not correlated with the impairment of extremities at admission but was closely correlated with motor impairment of the upper (r = 0.843, p < 0.001) and lower (r = 0.868, p < 0.001) extremities at 1 month poststroke. Impairment of the upper extremities correlated better with anterior than with posterior corticospinal tract injury (r = 0.911 compared with r = 0.600), and impairment of the lower extremities correlated better with posterior than with anterior injury (r = 0.890 compared with r = 0.787). CONCLUSIONS: Early evaluation of corticospinal tract injury based on DW imaging can provide predictive value for motor functional outcome in patients with deep ICH.

Delayed induction of mild hypothermia to reduce infarct volume after temporary middle cerebral artery occlusion in rats.

Deep to moderate hypothermia (24 degrees to 30 degrees C) during focal cerebral ischemia reduces infarct volume but must be initiated before the onset of ischemia to be effective and has deleterious pulmonary, myocardial and neurological effects. It is not known whether mild hypothermia (32 degrees to 33 degrees C) protects against ischemic neuronal damage, whether hypothermia induced after the onset of ischemia has protective effects, or whether these effects are associated with alterations in cortical blood flow. In this study, mild whole-body hypothermia was induced in rats just before or 10, 30, or 60 minutes after the onset of 2 hours of temporary middle cerebral artery occlusion; rewarming began immediately after reversal of occlusion and normothermia was maintained throughout 22 hours of reperfusion. Infarct volume, measured 24 hours after the end of reperfusion, was significantly smaller in rats made hypothermic within 30 minutes after the onset of ischemia than in normothermic controls; hypothermia induced at 60 minutes of ischemia did not reduce infarct volume. Cortical blood flow, measured by laser Doppler ultrasound flowmetry, was not significantly different between groups during ischemia; however, postischemic cortical blood flow correlated positively with total infarct volume. These results indicate that mild hypothermia initiated during temporary focal ischemia in rats can reduce infarct volume without attenuating the reduction in cortical blood flow.

Endovascular suture occlusion of the middle cerebral artery in rats: effect of suture insertion distance on cerebral blood flow, infarct distribution and infarct volume.

Sprague-Dawley rats anesthetized with isoflurane, underwent MCA occlusion by intraluminal 3-0 suture insertion, either 22 mm (n = 8) or 18 mm (n = 6) beyond the CCA bifurcation or were sham-operated as controls (n = 3) for autoradiographic analysis of cerebral blood flow. Infarct volume was measured 24 hours after the onset of ischemia (22 mm, n = 11; 18 mm, n = 10); neurological examinations were performed at 6 and 24 hours. Cerebral blood flow in the MCA distribution was significantly lower in the 22 mm suture insertion group than in the 18 mm group (p < 0.05). The total infarct volume was significantly larger (197 +/- 15 versus 135 +/- 19 mm3, p < 0.05) and the coefficient of variance was significantly smaller (23.8% versus 43.9%, p < 0.05) in the 22 mm group. Border zone regions of medial caudoputamen and dorsolateral cortex were often spared in the 18 mm group but never in the 22 mm group. The neurological deficit was more severe in the 22 mm group at 24 hours (p < 0.05), but not at 6 hours. The greater blood flow reduction and the less variable histological damage in dorsolateral cortex (a watershed area between the middle and anterior cerebral arteries) and the greater histological damage in medial caudate in the 22 mm group further characterizes this focal ischemia model for two potential applications: 22 mm insertion for studies requiring extensive and reproducible infarcts; 18 mm insertion for studies requiring less severe and more variable lesions after permanent MCA occlusion.

Hepatitis C virus (HCV) infection as a risk factor for spontaneous intracerebral hemorrhage: hospital based case-control study.

Hepatitis C Virus (HCV) infection was investigated as a risk factor for intracerebral hemorrhage (ICH) by HCV antibody screening in 462 patients with ICH and 462 control patients with cerebral infarction matched by age and sex. Laboratory examinations of hemostatic parameters and cholesterol level were also performed in patients with ICH. HCV infection was significantly more frequent in patients with ICH than controls (8.7% vs 3.5%, P< 0.01). ICH patients with HCV infection had significantly higher L-alanine:2-oxoglutarate aminotransferase level (P< 0.001), lower cholesterol level (P< 0.05), lower platelet count (P< 0.05), and longer prothrombin time (P< 0.01) than ICH patients without HCV infection, although most of these values were within the normal range. These results demonstrate that HCV infection is a risk factor for spontaneous ICH. Subclinical clotting disorder and/or vessel wall friability resulting from hypocholesteremia may be associated with ICH in patients with HCV infection.

[A case of sigmoid colon perforation by a V-P shunt tube resulting in pneumocephalus].

A 47-year-old male presented with headache 3 years after V-P shunt procedure. Initial CT revealed pneumocephalus, and a shunt tube migration into the sigmoid colon was detected by contrast medium injection into the shunt tube. The patient's condition was complicated with bacterial meningitis, and the infected shunt tube was removed. After chemotherapy, the V-P shunt was reinstalled. This is the first case showing pneumocephalus occurring as an initial symptom of bowel perforation by a V-P shunt tube. In this case, the abdominal tip of the shunt tube had been anchored at the same place for 6 months before bowel perforation. This finding may support the hypothesis that fibrous encasement of a shunt tube may trigger abdominal complications, as previously suggested.

[The effect of Japanese herbal medicine on MRSA carrier in neurosurgery].

Since the management of methicillin-resistant staphylococcus aureus (MRSA) carriers is not established, these patients are isolated individually, limited in activity, and delayed in rehabilitation. In this study, the effect of Japanese herbal medicine on MRSA carriers was examined. In the control group, MRSA carriers were isolated individually. In the treatment group, one of the Japanese herbal medicines "Juzentaihotou" or "Hotyuekkitou" was given in addition to isolating the patient. It was shown in cultures that Japanese herbal medicines had effectively changed MRSA carriers to negative. They also shortened the duration required to bring about the change of MRSA carriers to negative. As a result, the total number of MRSA carriers was reduced. These results suggested that Japanese herbal medicines may be useful for the management of MRSA carriers in neurosurgery.

[A case of tentorial meningioma presented with pure word deafness].

It has been known that an isolation of Wernicke's area from auditory input results in pure word deafness. In this report, a 73-year-old female case with tentorial meningioma suffering from pure word deafness is reported. The patient initially presented with hydrocephalus, and was treated with a ventriculo-peritoneal(V-P) shunt. A year after the V-P shunt, she suffered from a symptom of deafness. On admission, her repetition and auditory comprehension were severely impaired, while reading and visual comprehension were almost normal. Auditory brain stem response(ABR) revealed normal latency between wave I and V, while wave VI and VII was disappeared. Middle latency response(MLR) showed no wave peak. On MRI, tentorial meningioma compressed bilateral medial geniculate bodies, but not auditory radiation or temporal lobe. 99mTc-HMPAO single photon emission computed tomography(SPECT) showed hypoperfusion in the left temporal lobe, considered as a diaschisis resulting from the isolation of left temporal lobe from auditory input via bilateral medial geniculate bodies.

Protein Kinases from Soybean and Rice Leaves.

Two protein kinases, one from soybeans and the other from rice leaves, were partially purified by sequential chromagography. These protein kinases, which had molecular masses of 47 and 50kDa, respectively, were found to be activated by calcium and phospha- tidylserine and catalyze the phosphorylation of serine residue(s) of histone III-S.