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Plastic changes in white matter have received considerable attention in relation to normal cognitive function and learning. Oligodendrocytes and myelin, which constitute the white matter in the central nervous system, can respond to neuronal activity with prolonged depolarization of membrane potential and/or an increase in the intracellular Ca(2+) concentration. Depolarization of oligodendrocytes increases the conduction velocity of an action potential along axons myelinated by the depolarized oligodendrocytes, indicating that white matter shows functional plasticity, as well as structural plasticity. However, the properties and mechanism of oligodendrocyte depolarization-induced functional plastic changes in white matter are largely unknown. Here, we investigated the functional plasticity of white matter in the hippocampus using mice with oligodendrocytes expressing channelrhodopsin-2. Using extracellular recordings of compound action potentials at the alveus of the hippocampus, we demonstrated that light-evoked depolarization of oligodendrocytes induced early- and late-onset facilitation of axonal conduction that was dependent on the magnitude of oligodendrocyte depolarization; the former lasted for approximately 10 min, whereas the latter continued for up to 3 h. Using whole-cell recordings from CA1 pyramidal cells and recordings of antidromic action potentials, we found that the early-onset short-lasting component included the synchronization of action potentials. Moreover, pharmacological analysis demonstrated that the activation of Ba(2+) -sensitive K(+) channels was involved in early- and late-onset facilitation, whereas 4-aminopyridine-sensitive K(+) channels were only involved in the early-onset component. These results demonstrate that oligodendrocyte depolarization induces short- and long-term functional plastic changes in the white matter of the hippocampus and plays active roles in brain functions., (© 2014 Wiley Periodicals, Inc.)

Background: The salutogenic model states that coping resources are defined within sociocultural and historical contexts and that various social and historical factors influence the availability of such resources. Though previous studies have suggested the need for an interregional comparison of psychological and social resources, few studies have undertaken such an investigation. The aim of this study is to investigate the associations among coping resources, sense of coherence (SOC), and health status in a comparison of urban and rural residents., Methods: General residents (aged 30-69 years) in two areas were targeted for the current study. Through a random sampling selection, 1,000 residents from each area were picked, and an anonymous questionnaire was mailed to each resident. Ultimately, 269 and 363 valid responses from the urban and rural areas, respectively, were analyzed. SOC, both social and psychological resources, and mental health were assessed. To examine relationships between SOC and resources associated with mental health, mental health was defined as a dependent variable. Hierarchical multiple regression was conducted with variables entered from sociodemographic characteristics, social and psychological resources, and SOC., Results: Regarding regional characteristics, social capital and participation in community activities were significantly greater in the rural area than in the urban area. Urban residents reported significantly higher self-esteem and optimism than rural residents. SOC showed the most significant association with mental health in both areas. Mental health was significantly associated with physical activity limitations and life stressors in both areas. However, the associations were weakened when social and psychological resources and SOC were added, which demonstrated their buffering effect on the negative influence of life stressors on health. When SOC was added, the association of self-esteem with mental health disappeared in both areas, but optimism in the urban area and humor in the rural area were directly and independently associated with mental health., Conclusions: Our findings indicate that resources available to urban and rural residents are characteristic of the area where they live, and that social and psychological resources as well as SOC are associated with better mental health. Possible directions for health support strategies, reflecting regional characteristics, are suggested.

Objectives: This study sought to clarify changes in both Sense of Coherence (SOC) and social support during one year and causal relationships among upper-grade elementary school children., Methods: A one-year longitudinal survey using a self-rating questionnaire containing measures regarding individual attributes, SOC, and social support was conducted for all 403 pupils from 4th to 6th grade at a public elementary school in a suburban area of Kanagawa prefecture. Latent growth curve analysis was carried out on 237 pupils who completed all three surveys, conducted once in each semester. Firstly, to observe both overall and individual changes in SOC and social support scores, a model was constructed for each score, using the score for each semester as an observable variable, intercept (signifying the score of the first semester) and slope (signifying change of score during a year) as latent variables, and grade and sex as independent variables. Then, models of both were combined to examine causal relationships., Results: For change in SOC score, the mean slope was 0.01 (n.s.) with a variance of 2.85 (P<.05). Thus the score had no change overall, but there were pupils whose scores gradually rose or fell during the year. For change in social support score, the mean slope was -1.25 (P<.05) and its variance was 8.47 (P<.01). Therefore, the score showed an overall decrease, but there were pupils whose scores gradually rose. Grade and sex were not related to change in either score. The intercept of the social support score contributed to the slope of the SOC score (0.44, P<.001), and the intercept of the SOC score contributed to the slope of the social support score (0.34 P<0.05). Thus, a high score of social support in the first semester raised the SOC scores in the following second and third semesters, and a high score of SOC in the first semester raised subsequent social support scores. Grade and sex were not related to these associations., Conclusion: Among 237 upper-grade elementary school children, it was found that SOC overall demonstrated no change and social support decreased over one year. Pupils whose social support was abundant in the first semester had heightened SOC subsequently, and high levels of SOC in the first semester increased social support thereafter. Therefore, it was suggested that an interactive causal relationship between SOC and social support could be demonstrated by latent growth curve analysis.

Hippocampal inhibitory interneurons have a central role in the control of network activity, and excitatory synapses that they receive express Hebbian and anti-Hebbian long-term potentiation (LTP). Because many interneurons in the hippocampus express nicotinic acetylcholine receptors (nAChRs), we explored whether exposure to nicotine promotes LTP induction in these interneurons. We focussed on a subset of interneurons in the stratum oriens/alveus that were continuously activated in the presence of nicotine due to the expression of non-desensitizing non-alpha7 nAChRs. We found that, in addition to alpha2 subunit mRNAs, these interneurons were consistently positive for somatostatin and neuropeptide Y mRNAs, and showed morphological characteristics of oriens-lacunosum moleculare cells. Activation of non-alpha7 nAChRs increased intracellular Ca(2+) levels at least in part via Ca(2+) entry through their channels. Presynaptic tetanic stimulation induced N-methyl-D-aspartate receptor-independent LTP in voltage-clamped interneurons at -70 mV when in the presence, but not absence, of nicotine. Intracellular application of a Ca(2+) chelator blocked LTP induction, suggesting the requirement of Ca(2+) signal for LTP induction. The induction of LTP was still observed in the presence of ryanodine, which inhibits Ca(2+) -induced Ca(2+) release from ryanodine-sensitive intracellular stores, and the L-type Ca(2+) channel blocker nifedipine. These results suggest that Ca(2+) entry through non-alpha7 nAChR channels is critical for LTP induction. Thus, nicotine affects hippocampal network activity by promoting LTP induction in oriens-lacunosum moleculare cells via continuous activation of non-alpha7 nAChRs.

Objective: The consultation rate in Japan for mammography screening for breast cancer continues to drop. In order to examine this issue based on demand for mammography, the present study was conducted using Discrete Choice Experiments (DCEs), a type of Stated Preference (SP) method. The objectives of this study were as follows: (1) To consider what attributes of mammography screening are being potentially evaluated by general recipients in the target age group; (2) To verify the validity of the SP method by separating the sample group into sub-groups of previous mammography recipients and non-recipients, and to compare their findings; (3) To predict selection behavior by setting scenarios for screening options possibly in demand in the future., Methods: 800 subjects aged between 40 to 59 years and with no history of breast cancer were randomly selected from the general population of Tokyo. A DCE was conducted using postal self-administered survey forms. A total of 301 survey responses were obtained. Subjects were presented with a pair of hypothetical screenings, including 5 attributes regarding mammography screening, and asked which screening they would prefer to receive. For the entire sample and sub-groups, estimations for parameters were made using the conditional logit model setting the screening attributes as independent variables and the selection of whether or not to receive each screening as a dependent variable. Based on these results, short-time/high-cost and long-time/low-cost screening options were set and selection behavior was predicted., Results: The five attributes regarding mammography screening for all samples--total amount of time taken for the screening; degree of breast pain; possibility of breast cancer being missed during the screening; the effectiveness of reducing deaths caused by breast cancer; and the total cost required for the screening--were each estimated to be significant at the 5% level with coefficient signs consistent with expectations for the entire sample group. Next, comparing the estimated results of the sub-groups, a positive correlation was confirmed between behavior and preference. As for forecast of selection behavior, the percentage of respondents choosing the short-time option was predicted to be the same or higher than for those choosing long-time/low-cost option when the short-time option was offered for Yen 7500 or less., Conclusion: This study shows that subjects place significant value on attributes regarding the screening process as well as actual health outcomes. It also suggests the validity of using the SP methods in examining screening preferences. We found that short-time screening was able to compete against long-time/low-cost screening when it was offered for Yen 7500 or less. These results suggest that offering mammography screening with favorable settings could increase the demand.

Currently in Japan, discontinuing an invasive mechanical ventilator (IMV) is illegal; therefore IMV-related decision making is a crucial issue. This study examined IMV decision-making factors and psychological conflict in 50 patients with amyotrophic lateral sclerosis. The Herth Hope Index was used for the assessment of pre- and post-IMV conflict. Interviews identified some decision-making factors: patient's decision, patient's and family's mutual decision, family's decision, and emergency-induced without patient's or family's consent. Participants who experienced no IMV-related regret received sufficient prior IMV education from physicians and nurses, and time for reflection and family consultation. Their hope was similar to their pre-onset levels. Patients who received no prior IMV education accepted treatment as a natural progression. Their hope levels were lower than pre-onset. Those who received only a brief prior IMV explanation rejected the ventilator, experiencing regret if they were given an emergency IMV. Their hope levels were among the lowest. However, some of these patients managed to overcome their regret through being helped by nurses. Sufficient physician explanation and nursing advocacy for autonomous patient decision making are critical for improving hope in this patient group.

Rapid activation of nicotinic acetylcholine receptors (nAChRs) at various anatomical and cellular locations in the hippocampus differentially modulates the operation of hippocampal circuits. However, it is largely unknown how the continued presence of nicotine affects the normal operation of hippocampal circuits. Here, we used single and dual whole-cell recordings to address this question. We found that horizontally oriented interneurons in the stratum oriens/alveus continuously discharged action potentials in the presence of nicotine. In these interneurons, bath application of nicotine produced slow inward currents that were well maintained and inhibited by the non-alpha 7 antagonist dihydro-beta-erythroidine. Single-cell reverse transcription-polymerase chain reaction analysis showed that nicotine-responding interneurons were consistently positive for the alpha2 subunit mRNA. These observations suggest that in the presence of nicotine, a subset of interneurons in the stratum oriens/alveus are continuously excited due to the sustained activation of alpha2* nAChRs. These interneurons were synaptically connected to pyramidal cells, and nicotine increased inhibitory baseline currents at the synapses and suppressed phasic inhibition at the same synapses. Nicotine-induced inhibitory activity increased background noise and masked small phasic inhibition in pyramidal cells, originating from other interneurons in the stratum radiatum. Thus, the continued presence of nicotine alters the normal operation of hippocampal circuits by gating inhibitory circuits through activating a non-desensitizing alpha2 nAChR subtype on a distinct population of interneurons.

We examined the relationship between skin surface lactate concentration on working muscle and heart rate during continuous graded cycling exercise. Sixteen healthy male volunteers participated in this study. A plastic container with 100 μl 1% ethanol was put on the skin surface on the belly of rectus femoris muscle. The workloads were 300, 600, 900 and 1080 (or 990) kpm/min, and each stage was 5 min in duration. Sample collections were performed at rest, during exercise, and recovery. The lactate concentration during exercise significantly increased compared to the basal level (p<0.05 or p<0.001). Skin surface lactate concentration was found to correlate significantly with heart rate at the exercise intensity of 360 kpm/min (r=-0.52, p<0.05), 720 kpm/min (r=-0.74, p<0.01) and 900 kpm (r=-0.53, p<0.05). This study confirmed that 1) the increase in lactate concentration on the skin surface on working muscle is associated with increase in exercise intensity (heart rate), and 2) the skin surface lactate concentration on the working muscle can be used as a parameter of exercise intensity in each subject.

Purpose: The purpose of this paper is to describe the relationship between job stress, stress coping ability and performance among Japanese nurses., Design/methodology/approach: Health risk and organization environment as job stress factors, sense of coherence (SOC) as stress coping ability and medical risk indicator and sickness-absence days as a performance proxy were used to investigate the relationship between stress and performance. Length of professional experience also was included in the investigation., Findings: The findings suggest a possibility that enriching nurses' professional experiences reduces medical risk. There is also a possibility that raising the SOC, while improving organization environment, contributes to reducing sickness-absence., Research Limitations/implications: A cross-sectional study of nurses in a single institution was used. In order to generalize the study's results, it will be necessary to conduct multi-institutional longitudinal studies., Originality/value: The present study shows key factors affecting medical risk and sickness-absence leading to a reduced nursing performance.

This study describes the current status of peer support through an online community among patients with breast cancer, and examines how the support differs through the patients' usage of the community. Self-reported questionnaires distributed to 465 patients through Internet were analyzed. Analysis indicated the peer support among patients was categorized according to the following 5 factors: "emotional support, helper-therapy," "emotional expression," "conflict," "advice," and "insight, universality." Even the patients who only read the postings of other patients received benefits from the community.

The realization of positive life influences resulting from the experience of chronic illness has been conceptualized as "benefit-finding". This study of individuals with rheumatoid arthritis in Japan aimed to describe the nature of benefit finding; examine its predictive social factors and evaluate its impact on mental health. A web-based questionnaire was conducted, with valid responses obtained from 364 persons aged 20-59 years. The results indicated that a majority of the participants reported engaging in some type of benefit-finding. "Developing compassion towards others" and "an appreciation of things not previously important" were the most commonly reported. The patients reporting larger emotional support networks and those performing more self-care activities reported achieving higher levels of benefit-finding. Of all the factors examined, benefit-finding was the most significant predictor of mental health. These results expand the base of knowledge regarding living with rheumatoid arthritis and offer practical suggestions for the promotion of well-being.

We report two cases of a rapidly progressive fatal overwhelming pneumococcal infection. Patient 1 was a 67-year-old man with a 24-h history of fever and malaise and was transferred to our department. He was severely ill, tachypneic, and felt a chill. A purpuric discoloration with ecchymosis of the skin was noted over the body. The chest X-ray findings demonstrated thickening of the bronchovascular bundle in the right lower lung field, which later revealed the presence of bronchopneumonia. Laboratory studies revealed the presence of metabolic acidosis and disseminated intravascular coagulation. After presentation, rapid deterioration occurred followed by cardiopulmonary arrest. Despite cardiopulmonary resuscitation, the patient died only 3 h after presentation. The isolates from the patient's blood revealed penicillin-susceptible Streptococcus pneumoniae, serotype 4. Patient 2 was a 30-year-old woman with a prior history of uneventful pregnancies was transferred to our department with a 2-day history of fever, nausea, headache, and malaise. Although she was in the 19th week of pregnancy at the time, she suffered a miscarriage just prior to admission. Upon presentation to our department, she demonstrated unstable vital signs, diminished consciousness, anuria, and icterus. Purpuric discoloration with ecchymosis of the skin was noted in over most of her body, including the distal extremities. The chest X-ray findings were close to normal. Initial laboratory studies revealed the presence of severe metabolic acidosis and disseminated intravascular coagulation with multiple organ failure. Despite aggressive cardiopulmonary support, normal neurological responses disappeared on the 2nd day following admission and the patient died on the 16th day after admission. The patient's isolates from blood and vaginal swabs both later revealed penicillin-susceptible Streptococcus pneumoniae, serotype 12F. The presentation of rapidly progressive septic shock should raise the treating physician's suspicion of overwhelming pneumococcal infection, which has limited management options.

Recently, it has been demonstrated that glial cells express a variety of ion channels and neurotransmitter receptors and can modulate the neuronal activities. We focused on interneuron/peri-interneuronal glial cell pairs in the hippocampus to investigate the direct interactions between these cells. The periinterneuronal astrocytes suppressed the excitatory postsynaptic currents in an adjacent interneuron through the presynaptic mechanism. Moreover, peri-interneuronal astrocytes activation modulated the interneuronal firing pattern with time dependent manner. These results indicate that peri-interneuronal astrocytes play important roles in the modulation of hippocampal excitability.

Aim: The aim of this study was to explore quantitatively which working conditions influence the occurrence of medical near-miss errors related to intravenous medication at a hospital in Japan., Background: Although working conditions such as stress, fatigue and inexperience have been reported to contribute to medical errors, countermeasures to these conditions have been delayed, and working conditions have deteriorated in many Japanese medical sites., Methods: A self-reporting questionnaire analysing working conditions that can lead to near-miss errors relating to intravenous medication was sent to 90 nurses working in four wards of one Japanese hospital in 2001. Eighty-eight subjects responded (response rate: 97.8%). Among 534 person-days in which 88 nurses attended works, 525 person-days of data were used for the analyses., Results: Among 525 person-days, the number of near-miss errors was 94 (17.9%). There was no significant difference in the occurrence of near-miss errors among the three shifts (day shift, 19.2%; evening shift, 19.2%; night shift, 12.5%). During the day shift, errors were reported at a significantly higher frequency when the nursing services were delayed longer due to workload. During the evening shift, errors were reported when the nursing services were delayed longer due to workload and when years of experience at the current ward were shorter. In addition, nurses whose perceived level of fatigue before work was lower during the day shift, and nurses whose years of experience as a nurse were longer and who had longer sleep duration during the evening shift experienced near-miss errors with a significantly higher frequency than other nurses. These latter factors could be important conditions that encourage the detection of errors before they occur., Conclusions: Workload and lack of experience at the current ward are two conditions that can lead to errors. Furthermore, lack of fatigue and long experience as a nurse may help encourage the detection of errors before they occur. It is important to improve working conditions so that health care workers can detect errors before patients are harmed and decrease the number of errors that occur.

Purpose: In community and workplace health plans, the Perceived Health Competence Scale (PHCS) is employed as an index of health competency. The purpose of this research was to examine the reliability and validity of a modified Japanese PHCS., Methods: Interviews were sought with 3,000 randomly selected Japanese individuals using a two-step stratified method. Valid PHCS responses were obtained from 1,910 individuals, yielding a 63.7% response rate. Reliability was assessed using Cronbach's alpha coefficient (henceforth, alpha) to evaluate internal consistency, and by employing item-total correlation and alpha coefficient analyses to assess the effect of removal of variables from the model. To examine content validity, we assessed the correlation between the PHCS score and four respondent attribute characteristics, that is, sex, age, the presence of chronic disease, and the existence of chronic disease at age 18. The correlation between PHCS score and commonly employed healthy lifestyle indices was examined to assess construct validity. General linear model statistical analysis was employed., Results: The modified Japanese PHCS demonstrated a satisfactory alpha coefficient of 0.869. Moreover, reliability was confirmed by item-total correlation and alpha coefficient analyses after removal of variables from the model. Differences in PHCS scores were seen between individuals 60 years and older, and younger individuals. These with current chronic disease, or who had had a chronic disease at age 18, tended to have lower PHCS scores. After controlling for the presence of current or age 18 chronic disease, age, and sex, significant correlations were seen between PHCS scores and tobacco use, dietary habits, and exercise, but not alcohol use or frequency of medical consultation., Conclusion: This study supports the reliability and validity, and hence supports the use, of the modified Japanese PHCS. Future longitudinal research is needed to evaluate the predictive power of modified Japanese PHCS scores, to examine factors influencing the development of perceived health competence, and to assess the effects of interventions on perceived health competence.

Background: Relatively few studies have directly addressed the interaction dynamics and consequences of a companion's presence in the medical visit, and their findings have been contradictory., Objectives: To examine how patient's contribution to the medical dialogue, with or without the presence of a visit companion, is related to the perception of the medical visit as patient-centered., Design: Observational study using pre- and postvisit questionnaires and audiotape recording of medical visits., Participants: One hundred and fifty-five patients aged 65 or over; 63 in medical visits that included the presence of a companion and 82 in visits that did not include a companion., Main Outcome Measure: Patient ratings of visit patient-centeredness., Results: Long visits (greater than 10 minutes long) and visits in which patients were verbally active were rated as more patient-centered by patients than other visits. Since patients were generally less verbally active in visits that included a companion, accompanied visits, especially if they were less than 10 minutes long, received lower patient-centered ratings than others. The presence of a companion was not related to length of the visit, suggesting that the verbal activity of the companion was off-set by decreased verbal activity of the patient., Conclusions: Our results have suggested that patients are more likely to perceive their physician and visit as patient-centered when they have an opportunity to engage directly in the medical dialogue. A minimal amount of "talk-time" for patients themselves should be safeguarded even in a short visit, when a companion is present.

To investigate the effect of work and organizational characteristics on workers' health status, with job dissatisfaction and intentions to leave as "organizational health", we conducted a longitudinal study using a questionnaire survey in call centers of an information service company from July to August in 2001 and 2002. The response rates were 96.2% and 92.0%, respectively. For the statistical analysis, the completed data of 296 technical support staff, which was more than 80% of the data, was used. We identified seven subscales composed of 29 items of work and organizational characteristics as scales of "organizational characteristics" and "work and workplace characteristics". The results of hierarchical multiple regression analysis showed quantitative and qualitative job-overload influenced psychological health status and poor supervisor support influenced all outcome variables. Moreover, "organizational characteristics" influenced cumulative fatigue and job dissatisfaction, showing an indirect effect with poor supervisor support and coworker support. This study suggests that measures of work and organizational characteristics are useful interventions for "organizational health".

The effects of hypoxia and hypoxic training on 8-hydroxydeoxyguanosine (8-OHdG), reduced glutathione (GSH), and oxidized glutathione (GSSG) levels and on glutathione reductase (GR) activity in the liver of rats were evaluated. Rats were divided into 3 groups: a hypoxia and exercise (HE) group, a hypoxia and sedentary (HS) group, and a normoxia and sedentary (NS) group. The liver 8-OHdG levels were lower in the HE and HS groups compared with the NS group (P <.05). No significant difference between in the liver 8-OHdG levels in the HE and HS groups were found. However, the liver GSH level in the HS group was lower than that in the NS group (P <.05), and the HE group had significantly higher levels of liver GSH than the HS group (P <.01). The activity of liver GR in the HS group was lower than that of the NS group (P <.05). Moreover, the liver GR activity of the HE group was significantly higher than that of the HS group (P <.01). No significant difference in liver GR activity between the HE and NS groups was noted. In conclusion, the present study confirmed that moderate hypoxia and hypoxic training attenuated liver DNA damage and decreased liver GSH levels and GR activity. These results indicate that moderate hypoxia and hypoxic training result in decreased oxidative stress.

A 65-year-old man was a diagnosed with meningitis and bacteremia, as Streptococcus pneumoniae was isolated from spinal fluid and blood cultures. After three weeks of antibiotic therapy, computed tomography revealed a ruptured aneurysm of the descending thoracic aorta. The aneurysm had appeared during the first episode of meningitis but had remained silent for two years. The patient underwent in situ Dacron graft replacement and his postoperative course was uneventful with no infectious complication.