Giving social support at work may reduce inflammation on employees themselves: a participatory workplace intervention study among Japanese hospital nurses.

Previously, we reported that the participatory workplace intervention was effective in reducing stress-related inflammatory markers among 31 Japanese female nurses. During the analysis, we recognized that our intervention might have increased prosocial behaviors like giving social support to others in some participants. Based on this assumption, we ran a secondary analysis, which examined the effect of giving social support on inflammatory markers, autonomic nervous activity (ANA), and perceived job stress (PJS) before and after the intervention. A group of participants who had increased scores on giving social support (n=13) showed significant decreases in interferon-γ, interleukin-6, and interleukin-12/23p40 after the intervention. Another group of those who had decreased/unchanged in the scores (n=17) did not show changes in these markers. Regarding ANA and PJS, no significant changes were observed in both groups. This study presented insight that giving social support at work may provide health benefits towards employees themselves, via decreasing inflammation.

Effects of participatory workplace improvement program on stress-related biomarkers and self-reported stress among university hospital nurses: a preliminary study.

Although participatory workplace improvement programs are known to provide favorable effects on high stress occupations like nursing, no studies have confirmed its effect using biomarkers. The aim of this study was to determine whether a participatory workplace improvement program would decrease stress-related symptoms as evaluated by biomarkers and self-reported stress among hospital nurses. Three actions to alleviate job stress, which were determined through focus group interviews and voting, were undertaken for two months. A total of 31 female Japanese nurses underwent measurement of inflammatory markers, autonomic nervous activity (ANA), and perceived job stress (PJS) at three-time points; before the program (T1), within a week after the completion of the program (T2), and three months after the program (T3). A series of inflammatory markers (Interferon-γ, Interleukin (IL)-6, and IL-12/23p40) decreased significantly at T2, and IL-12/23p40 and IL-15 significantly decreased at T3 compared to T1, while ANA and PJS remained unchanged. Our participatory program exerted beneficial effects in reducing inflammatory responses, but not for ANA and PJS. Further investigations with a better study design, i.e., a randomized controlled trial, and a larger sample size are warranted to determine what exerted beneficial effects on inflammatory markers and why other outcomes remained unchanged.

Inhibitory effects of pine nodule extract and its component, SJ-2, on acetylcholine-induced catecholamine secretion and synthesis in bovine adrenal medullary cells.

Extract of pine nodules (matsufushi) formed by bark proliferation on the surface of trees of Pinus tabulaeformis or Pinus massoniana has been used as an analgesic for joint pain, rheumatism, neuralgia, dysmenorrhea and other complaints in Chinese traditional medicine. Here we report the effects of matsufushi extract and its components on catecholamine secretion and synthesis in cultured bovine adrenal medullary cells. We found that matsufushi extract (0.0003-0.005%) and its component, SJ-2 (5-hydroxy-3-methoxy-trans-stilbene) (0.3-100 µM), but not the other three, concentration-dependently inhibited catecholamine secretion induced by acetylcholine, a physiological secretagogue. Matsufushi extract (0.0003-0.005%) and SJ-2 (0.3-100 µM) also inhibited 45Ca2+ influx induced by acetylcholine in a concentration-dependent manner, similar to its effect on catecholamine secretion. They also suppressed 14C-catecholamine synthesis and tyrosine hydroxylase activity induced by acetylcholine. In Xenopus oocytes expressing α3ß4 nicotinic acetylcholine receptors, matsufushi extract (0.00003-0.001%) and SJ-2 (1-100 µM) directly inhibited the current evoked by acetylcholine. The present findings suggest that SJ-2, as well as matsufushi extract, inhibits acetylcholine-induced catecholamine secretion and synthesis by suppression of nicotinic acetylcholine receptor-ion channels in bovine adrenal medullary cells.

Ikarisoside A inhibits acetylcholine-induced catecholamine secretion and synthesis by suppressing nicotinic acetylcholine receptor-ion channels in cultured bovine adrenal medullary cells.

Ikarisoside A is a natural flavonol glycoside derived from plants of the genus Epimedium, which have been used in Traditional Chinese Medicine as tonics, antirheumatics, and aphrodisiacs. Here, we report the effects of ikarisoside A and three other flavonol glycosides on catecholamine secretion and synthesis in cultured bovine adrenal medullary cells. We found that ikarisoside A (1-100 µM), but not icariin, epimedin C, or epimedoside A, concentration-dependently inhibited the secretion of catecholamines induced by acetylcholine, a physiological secretagogue and agonist of nicotinic acetylcholine receptors. Ikarisoside A had little effect on catecholamine secretion induced by veratridine and 56 mM K(+). Ikarisoside A (1-100 µM) also inhibited (22)Na(+) influx and (45)Ca(2+) influx induced by acetylcholine in a concentration-dependent manner similar to that of catecholamine secretion. In Xenopus oocytes expressing α3ß4 nicotinic acetylcholine receptors, ikarisoside A (0.1-100 µM) directly inhibited the current evoked by acetylcholine. It also suppressed (14)C-catecholamine synthesis and tyrosine hydroxylase activity induced by acetylcholine at 1-100 µM and 10-100 µM, respectively. The present findings suggest that ikarisoside A inhibits acetylcholine-induced catecholamine secretion and synthesis by suppression of nicotinic acetylcholine receptor-ion channels in bovine adrenal medullary cells.

Effects of various pharmacological agents on the function of norepinephrine transporter.

The norepinephrine transporter is selectively expressed in noradrenergic nerve terminals, where it can exert spatial and temporal control over the action of norepinephrine. The norepinephrine transporter mediates the termination of neurotransmission via the reuptake of norepinephrine released into the extracellular milieu. In the present brief review, we report our recent studies about the effects of various pharmacological agents such as fasudil, nicotine, pentazocine, ketamine and genistein on norepinephrine transporter function.

Assessment of exposure to voices and noise via earphones in manufacturing industry workers in Japan.

OBJECTIVES: There is concern that sound via earphones and headphones attached to headsets used in workplaces may be a risk factor for noise-induced hearing loss (NIHL). Although there are some previous studies investigating exposure to noise from headphones, almost none have assessed the risks to workers who use earphones. We assessed exposure to noise among workers who regularly wear earphones in noisy workplaces. METHODS: The subjects of this study were 21 workers who regularly wear earphones in three manufacturing companies in Japan. The sound pressure output from earphones and personal exposure to occupational noise was measured for each worker. A noise-dosimeter was used to measure individual exposure to occupational noise. The sound pressure output from the earphones was measured by recording the electric signal with a data recorder attached to the earphones, and the recording was analyzed by playing it back in the laboratory through a sound analyzer via an ear simulator. RESULTS: The mean scores for personal exposure and earphone output LAeq were 87.9 dB and 87.6 dB, respectively. Earphone output LAeq exceeded 85 dB for two-thirds of the subjects. Nearly all the subjects lacked hearing protection devices (HPDs) on their earphones. CONCLUSIONS: The results suggest that workers who use earphones in noisy workplaces are exposed to the following NIHL risk factors: (1) they are deprived of the opportunity to fit appropriate HPDs, and (2) the sound pressure output from the earphones themselves exceeds the occupational exposure limit.

Stimulatory effect of nobiletin, a citrus polymethoxy flavone, on catecholamine synthesis through Ser19 and Ser40 phosphorylation of tyrosine hydroxylase in cultured bovine adrenal medullary cells.

We previously reported the dual effects of nobiletin, a compound of polymethoxy flavones found in citrus fruits, on catecholamine secretion in cultured bovine adrenal medullary cells. Here, we report the effects of nobiletin on catecholamine synthesis in the cells. Nobiletin increased the synthesis of (14)C-catecholamines from [(14)C]tyrosine in a time (20-30 min)- and concentration (1.0-100 µM)-dependent manner. Nobiletin (10-100 µM) also activated tyrosine hydroxylase activity. The stimulatory effect of nobiletin on (14)C-catecholamine synthesis was not observed when extracellular Ca(2+) was not present in the incubation medium. Protein kinase inhibitors including H-89, an inhibitor of cyclic AMP-dependent protein kinase, and KN-93, an inhibitor of Ca(2+)/calmodulin-dependent protein kinase II, suppressed the stimulatory effects of nobiletin on catecholamine synthesis as well as tyrosine hydroxylase activity. Nobiletin also induced the phosphorylation of tyrosine hydroxylase at Ser(19) and Ser(40). Nobiletin (1.0-100 µM) inhibited (14)C-catecholamine synthesis induced by acetylcholine. The present findings suggest that nobiletin, by itself, stimulates catecholamine synthesis through tyrosine hydroxylase phosphorylation at Ser(19) and Ser(40), whereas it inhibits catecholamine synthesis induced by acetylcholine in bovine adrenal medulla.

Stimulation of norepinephrine transporter function by fasudil, a Rho kinase inhibitor, in cultured bovine adrenal medullary cells.

Norepinephrine transporter (NET) regulates noradrenergic synaptic transmission by controlling extracellular levels of norepinephrine (NE). The small GTPase, RhoA, and its downstream effector Rho kinase (ROCK) are involved in the regulation of actin cytoskeleton and focal adhesion/stress fiber formation, which may play an important role in various functions of the sympathetic nervous system. We report here the effect of fasudil, a ROCK inhibitor, on the functions of NET in cultured bovine adrenal medullary cells as a model of sympathetic neurons. Treatment of bovine adrenal medullary cells with fasudil caused an increase in [(3)H]NE uptake in time (8-120 h) and concentration (10-100 µM)-dependent manner. Another ROCK inhibitor, Y-27632 (10-100 µM, 1 day), also increased [(3)H]NE uptake by the cells. Kinetics analysis of the effect of fasudil on NE transport showed a significant increase in the V (max) of NE transport with little change in K (m). When both extracellular and intracellular Ca(2+) were removed by the deprivation of extracellular Ca(2+) and BAPTA-AM, a cell-permeable Ca(2+) chelator, [(3)H]NE uptake induced by fasudil was completely abolished. Nocodazole, an inhibitor of microtubule polymerization, but not cytochalasin D, an inhibitor of actin polymerization, suppressed the stimulatory effect of fasudil on [(3)H]NE uptake. The present findings suggest that the ROCK inhibitor fasudil up-regulates NET function in a Ca(2+)-dependent and/or nocodazole-sensitive pathway in adrenal medullary cells.

Effects of menopausal hot flashes on mental workload.

This study examined the differences in psychophysiological responses during mental task performance between women with (Group S) and without (Group A) menopausal hot flashes. Twelve women who reported experiencing daily moderate or severe menopausal hot flashes (Group S) and twelve women who reported having no hot flashes (Group A) participated in a mental arithmetic (Task) and a control (Non-task) experiment that occurred twice during 30 min. Although Group S experienced frequent hot flashes during mental arithmetic task, no significant differences between the two groups emerged for the percentage of correct responses and reaction time, and cardiovascular and thermoregulatory responses. However, the STAI state anxiety score was significantly higher in Group S than in Group A during both rest and mental tasks, and stress-related cortisol secretion showed a tendency to increase in Group S compared with Group A after task. The present study indicates that there were no significant differences in physiological responses and cognitive performance between women with and without menopausal hot flashes during mental arithmetic, but women with menopausal hot flashes might perceive higher psychological stress during rest and mental arithmetic tasks than asymptomatic women.

Mental workload under time pressure can trigger frequent hot flashes in menopausal women.

The aim of this study is to examine the relationship between mental workload and occurrence of hot flashes. Twelve women with moderate to severe menopausal hot flashes participated in the study. Subjects participated in both a mental arithmetic task (Task) and control (Non-task) experiments. We measured heart rate, heart rate variability, blood pressure, near infrared spectroscopy, skin temperature, and skin potential level. The incidence of hot flashes was greater in Task than in Non-task. No significant differences between before, during and after hot flashes emerged for the percentage of correct responses and reaction time. However, the percentage of correct responses for two subjects among the ten who experienced hot flashes in Task substantially declined during hot flashes. Chest skin temperatures increased in both Task and Non-task during hot flashes, and regional oxygen saturation was significantly higher in Non-task than in Task. The present study suggested that mental workload under time pressure might be a risk factor for menopausal hot flashes, and the performance of most people who experienced hot flashes was not affected by hot flashes, however, work-related difficulties due to cognitive disturbance during hot flashes might arise in some people.

Frequency characteristics of electro-hydraulic vibrator.

Frequency characteristics of an electro-hydraulic vibrator were measured using two kinds of test signals. First, sine signals had theoretically 1.0 m/s2 (root-mean-square) in the frequency range from 1 to 16 Hz at single axis. The frequency characteristics were flat from 1 to 12 Hz, but 14, 16 Hz was considerably poor. Second, the vibrator was excited when using a complex signal consisting of 12 components in the frequency range from 1 to 12 Hz at single axis. The overall acceleration was 3 and 1 m/s2. Flat characteristics were seen in the tested frequency range. Acceleration distortion was recognized in a higher frequency than the target frequency. This second method is effective for the efficiency of experimental procedure.