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Yoshihide Nakai

Publications and source records attributed to Yoshihide Nakai.

9 recordsLinked to original sources
PubMed2006

Evaluation of psychophysiological asymmetry in patients with fibromyalgia syndrome.

Fibromyalgia syndrome (FMS) is characterized by systemic pain of unknown etiology, and is often accompanied by various psychological symptoms. In the present study, differences in surface electromyographic (SEMG) levels of the trapezius muscle, skin temperature (TEMP) and skin conductance level (SCL) were compared between the right and left side of the body in 31 FMS and 47 control subjects (Control Group). We observed significant asymmetries of SEMG level, TEMP and SCL in the FMS Group. These asymmetries might be related to central, peripheral and autonomic nervous system dysfunctions. Marked increase of SEMG levels, and a decrease of TEMP and SCL were observed at the dominant side in the FMS Group, and a negative correlation of SEMG levels with TEMP and SCL was found. These results suggest that continued antalgic postures in response to pain at the dominant side in FMS patients might lead to asymmetries of SEMG level, TEMP and SCL. Thus, a focus on pain related behaviors and muscle asymmetry might be a useful therapeutic approach.

Adult↗
PubMed2006

[GERD and sleep disorder].

The prevalence of gastroesophageal reflux disease (GERD) is increasing in Japan. Symptoms of GERD negatively affect their quality of life and sleep. There are several reasons for sleep disorder with GERD as follows. Nocturnal GERD symptoms sometimes directly avoid sleeping. Sleep apnea syndrome and GERD are sometimes concomitant. The both are sharing similar risk factor such as obesity and cause sleep disorder. When untypical symptoms of GERD are not diagnosed, patients are severely anxious about their physical condition. Then they feel stressful and sometimes get secondary depressive state including sleep disorder. We had better take care about patients' psychosocial factors and treat symptoms of GERD and sleep disorder together with holistic approach.

Adult↗
PubMed2005

Rho-kinase mediates spinal nitric oxide formation by prostaglandin E2 via EP3 subtype.

Prostaglandin E2 (PGE2), the principal pro-inflammatory prostanoid, is known to play versatile roles in pain transmission via four PGE receptor subtypes, EP1-EP4. We recently demonstrated that continuous production of nitric oxide (NO) by neuronal NO synthase (nNOS) following phosphorylation of myristoylated alanine-rich C-kinase substrate (MARCKS) and NMDA receptor NR2B subunits is essential for neuropathic pain. These phosphorylation and nNOS activity visualized by NADPH-diaphorase histochemistry were blocked by indomethacin, a PG synthesis inhibitor. To clarify the interaction between cyclooxygenase and nNOS pathways in the spinal cord, we examined the effect of EP subtype-selective agonists on NO production. NO formation was stimulated in the spinal superficial layer by EP1, EP3, and EP4 agonists. While the EP1- and the EP4-stimulated NO formation was markedly blocked by MK-801, an NMDA receptor antagonist, the EP3-stimulated one was completely inhibited by H-1152, a Rho-kinase inhibitor. Phosphorylation of MARCKS and NADPH-diaphorase activity stimulated by the EP3 agonist were also blocked by H-1152. These results suggest that PGE2 stimulates NO formation by Rho-kinase via EP3, a mechanism(s) different from EP1 and EP4.

Animals↗
PubMed2005

Plasma acylated ghrelin levels correlate with subjective symptoms of functional dyspepsia in female patients.

OBJECTIVE: Ghrelin is a brain-gut peptide that is mainly secreted from gastric endocrine cells (X/A like cells). In addition to promoting growth-hormone release and appetite, ghrelin also affects gastric motility and secretion. Circulating ghrelin levels are related to appetite and energy balance. Functional dyspepsia (FD) is a disorder characterized by the presence of chronic or recurrent symptoms of upper abdominal pain or discomfort. Although no known specific organic abnormalities are present in FD, abnormalities in gastrointestinal motility and sensitivity are thought to play a role in a substantial subgroup of patients. In addition, some patients also suffer from anorexia and body-weight loss. To investigate the role of ghrelin in the pathophysiology of FD, circulating ghrelin levels in affected patients were measured. MATERIAL AND METHODS: Eighteen Japanese female patients with functional dyspepsia and 18 healthy volunteers were recruited for the study. Acylated and desacyl forms of ghrelin were measured using commercially available enzyme-linked immunosorbent assay kits. RESULTS: Although plasma levels of acylated or desacyl ghrelin were not significantly different between healthy subjects and FD patients, plasma acylated, but not desacyl ghrelin, levels were correlated with a subjective symptom score in FD patients. In addition, the ratio of acylated to desacyl ghrelin (A/D ratio) was correlated strongly with acylated, but not desacyl, ghrelin levels. CONCLUSIONS: The correlation of circulating acylated ghrelin levels with the subjective symptom score and the A/D ratio in FD patients suggest that acylated ghrelin may play a role in the pathophysiology of FD.

Adult↗
PubMed2005

Fyn kinase-mediated phosphorylation of NMDA receptor NR2B subunit at Tyr1472 is essential for maintenance of neuropathic pain.

Despite abundant evidence implicating the importance of N-methyl-D-aspartate (NMDA) receptors in the spinal cord for pain transmission, the signal transduction coupled to NMDA receptor activation is largely unknown for the neuropathic pain state that lasts over periods of weeks. To address this, we prepared mice with neuropathic pain by transection of spinal nerve L5. Wild-type, NR2A-deficient, and NR2D-deficient mice developed neuropathic pain; in addition, phosphorylation of NR2B subunits of NMDA receptors at Tyr1472 was observed in the superficial dorsal horn of the spinal cord 1 week after nerve injury. Neuropathic pain and NR2B phosphorylation at Tyr1472 were attenuated by the NR2B-selective antagonist CP-101,606 and disappeared in mice lacking Fyn kinase, a Src-family tyrosine kinase. Concomitant with the NR2B phosphorylation, an increase in neuronal nitric oxide synthase activity was visualized in the superficial dorsal horn of neuropathic pain mice by NADPH diaphorase histochemistry. Electron microscopy showed that the phosphorylated NR2B was localized at the postsynaptic density in the spinal cord of mice with neuropathic pain. Indomethacin, an inhibitor of prostaglandin (PG) synthesis, and PGE receptor subtype EP1-selective antagonist reduced the NR2B phosphorylation in these mice. Conversely, EP1-selective agonist stimulated Fyn kinase-dependent nitric oxide formation in the spinal cord. The present study demonstrates that Tyr1472 phosphorylation of NR2B subunits by Fyn kinase may have dual roles in the retention of NMDA receptors in the postsynaptic density and in activation of nitric oxide synthase, and suggests that PGE2 is involved in the maintenance of neuropathic pain via the EP1 subtype.

Animals↗
PubMed2004

Separate measurement of plasma levels of acylated and desacyl ghrelin in healthy subjects using a new direct ELISA assay.

Two forms of ghrelin, acylated and desacyl, circulate in plasma. Although acylation is thought to be essential for ghrelin biological activities, recent studies have suggested that desacyl ghrelin may also possess biological activity. A new commercial ELISA system has now enabled us to measure plasma levels of each of these two ghrelin forms separately. This assay system directly measures levels using small amounts of plasma. To evaluate the utility of this assay system, we measured the plasma levels of the two forms of ghrelin in healthy volunteers. Although acylated ghrelin levels were equivalent to those measured previously by RIA, desacyl ghrelin levels were lower than those expected from the total ghrelin levels previously determined by RIA. The ratios of acylated to desacyl ghrelin significantly correlated with previously determined acylated, but not desacyl, ghrelin levels. After BMI adjustment, the levels of acylated, but not desacyl, ghrelin plasma levels were higher in female subjects than those in males. Several metabolic and hormonal parameters significantly correlated with either plasma acylated or desacyl ghrelin levels. These findings indicate that separate measurements of the two ghrelin form levels may provide valuable information on their structure, gender differences, and physiological implications.

Acylation↗
PubMed2004

Paradoxical results of psychophysiological stress profile in functional somatic syndrome: correlation between subjective tension score and objective stress response.

Mind-body interactions are important in functional somatic syndromes (FSS). Therefore, in the assessment of the psychophysiological stress response in patients with FSS, both subjective feelings and psychophysiological activity should be simultaneously measured. In this study, "Objective Tension Score" (OTS) was defined as an objective parameter of tension; it consisted of surface electromyography and skin conductance level as indicators of muscle and mental tension, respectively. "Subjective Tension Score" (STS) was defined as a subjective parameter of tension. Changes in OTS and STS in response to the stress task were investigated in 30 FSS patients and 28 controls. Objective tension was significantly hyporeactive to the stress task and STS was significantly higher in the patient group than in the control group. There was a significant negative correlation between OTS response and STS in the patient group, but no significant correlation in the control group. Our results suggested the existence of dissociation between subjective and objective responses in FSS patients. This may indicate that FSS patients had difficulty with the awareness of bodily feelings, thus supporting the concept of "alexisomia" or "escaped bodily feelings" in FSS patients.

Adult↗