Publications by authors named "Shizuko Okamoto"
Background: Bipolar disorder (BP) is often associated with a change in hypothalamus- pituitary-adrenal axis function change due to chronic stress. Salivary α-amylase (sAA) levels increase in response to psychosocial stress and thus function as a marker of sympathoadrenal medullary system activity. However, sAA has been studied less often than salivary cortisol in BP patients.
View Article and Find Full Text PDFPrevious studies have reported that the hypothalamic-pituitary-adrenal axis is involved with personality traits. We examined the association between corticotropin-releasing hormone receptor (CRHR) genes and personality traits. We investigated the 12 single-nucleotide polymorphisms of intron CRHR (six in CRHR1 and six in CRHR2, respectively) in 218 healthy volunteers using TaqMan PCR assays.
View Article and Find Full Text PDFObjectives: The underlying pathogenic mechanisms and predictors of recurrence in major depressive disorder are still largely unknown. Hypothalamic-pituitary-thyroid (HPT) axis and hypothalamus-pituitary-adrenocortical (HPA) axis dysregulation are thought to be related to the development and course of depression.
Design And Setting: Over a ten-year period, we investigated whether the results of thyrotropin-releasing hormone (TRH) testing and combined dexamethasone/corticotropin-releasing hormone (DEX/CRH) testing could be correlated with the recurrence of depression in 25 outpatients with clinically remitted major depression for at least 10 years.
Article Synopsis
- Salivary α-amylase (sAA) is a potential indicator of stress response linked to the sympathoadrenal medullary system; this study examines its levels in patients with obsessive-compulsive disorder (OCD) compared to healthy individuals.
- Findings show that OCD patients exhibited significantly higher scores for anxiety and depression while having lower vigor compared to healthy controls, but no differences were observed in heart rate variability (HRV) between the two groups.
- The research indicates that OCD patients had elevated sAA levels under stress, suggesting a heightened sensitivity to stressors, potentially marking a unique characteristic of OCD.
Article Synopsis
- * Forty-five patients over 50 years old with moderate MDD were treated for 8 weeks, with 12 showing positive responses and 33 not responding to SSRIs; a comparison group of 30 healthy individuals was also included.
- * Results indicated that non-responsive patients had lower brain blood flow in certain areas compared to responders and controls, suggesting that low blood flow in the frontal cortex may be an indicator of poor SSRI response in older adults.
Article Synopsis
- Two models exist regarding ghrelin's role in stress responses: it may either contribute to stress-induced depression and anxiety or help alleviate these symptoms.
- A study measured serum ghrelin levels and mood/anxiety scores in individuals with major depressive disorder (MDD) and panic disorder, comparing treatment-resistant patients to responders and healthy controls.
- Findings showed higher ghrelin levels in treatment-resistant patients, suggesting that lower ghrelin levels may enhance the effect of antidepressant treatments in MDD and panic disorder.
Article Synopsis
- Salivary alpha-amylase (sAA) and cortisol were measured in healthy volunteers after stress tests to assess their roles in stress response, revealing distinct patterns in each biomarker.
- Participants were tested with the Trier Social Stress Test (TSST) and electric stimulation stress, showing that sAA spiked quickly and returned to normal, while cortisol rose more slowly and stayed elevated longer.
- Findings indicated no gender differences in sAA responses, but females had higher cortisol levels after the TSST, and younger participants exhibited greater sAA activity, linking cortisol levels to stress intensity.
Association of CRHR1 and CRHR2 with major depressive disorder and panic disorder in a Japanese population.
Am J Med Genet B Neuropsychiatr Genet
June 2012
Article Synopsis
- - Major depressive disorder (MDD) and panic disorder (PD) have both stress and genetic factors contributing to their development, linked to the hypothalamic-pituitary-adrenal (HPA) axis and specific receptors like CRHR1 and CRHR2.
- - A study identified specific single nucleotide polymorphisms (SNPs) in these receptors that are associated with MDD and PD, investigating a total of 178 MDD patients, 180 PD patients, and 285 healthy controls.
- - Notable findings included associations of certain SNPs (like rs110402, rs242924, and rs3779250) and haplotypes in CRHR1 with MDD, and CRHR1 SNPs also
Psychosocial stress-induced activation of salivary α-amylase (sAA) functions is as a marker of sympathoadrenal medullary system (SAM) activity. However, in contrast to salivary cortisol, sAA has been less extensively studied in panic disorder patients. The present study measured sAA and salivary cortisol levels in patients with panic disorder following electrical stimulation stress.
View Article and Find Full Text PDFSalivary alpha-amylase and cortisol responsiveness following electrical stimulation stress in major depressive disorder patients.
Prog Neuropsychopharmacol Biol Psychiatry
March 2012
Major depressive disorder (MDD) is often associated with dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis by chronic stress. In comparison, psychosocial stress-induced activation of salivary α-amylase (sAA) functions as a marker of sympathoadrenal medullary system (SAM) activity. However, in contrast to salivary cortisol, sAA has been less extensively studied in MDD patients.
View Article and Find Full Text PDFElevated salivary α-amylase and cortisol levels in unremitted and remitted depressed patients.
Int J Psychiatry Clin Pract
November 2010
Abstract Objective. Major depressive disorder (MDD) is often associated with dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis via chronic stress. Psychosocial stress-induced activation of salivary α-amylase (sAA) represents sympathoadrenal medullary system (SAM) activity, and sAA has become an emerging biomarker for sympathetic nervous system activity.
View Article and Find Full Text PDFArticle Synopsis
- Previous studies hint that hepatocyte growth factor (HGF) might be linked to depression and anxiety behaviors; this study aimed to explore its relationship with anxiety and mood scores in patients with panic disorder and healthy individuals.
- Researchers analyzed 67 panic disorder patients and 97 controls, categorizing them based on their response to treatment; despite no strong link between HGF levels and anxiety or personality scores, they found a noteworthy correlation between HGF and fatigue in controls.
- The good response patients had higher HGF levels compared to the poor response group and controls, suggesting that elevated HGF might be essential for effective antidepressant treatment in panic disorder patients.
Background/aims: Computed tomographic colonography [virtual colonoscopy (VC)] is a new imaging method that may contribute to the detection of colorectal neoplasms. The aim of this study was to investigate the clinical significance of VC for the diagnosis of colorectal tumors with special reference to their morphology.
Methodology: Sixteen patients with colorectal tumors were enrolled in this study.