Gender differences in correlates of mental health among elderly Koreans

OBJECTIVE

. This study examined the differential impact of social roles and socioeconomic resources on the mental health of Korean men and women aged 65 years or older.

METHODS

The study sample was a weighted population of 930 people (905 survey samples) aged 65 years or older who had responded to the health behavior survey of the 2001 Korean National Health and Nutrition Examination Survey.

RESULTS

We observed striking gender differences in the correlates of poor mental health. Living alone was significantly associated with depressive symptoms and suicidal ideation in men but not in women. Living in a multigenerational family without a spouse and having a lower household income were significantly associated with poor mental health in both men and women.

DISCUSSION

We discuss the intriguing evidence of gender differences in the correlates of mental health within the context of traditional Asian society and suggest further research on social components of gender differences in mental health across diverse cultures.

Immunohistochemical detection of oxidative DNA damage induced by ischemia-reperfusion insults in gerbil hippocampus in vivo

There is much evidence to suggest that ischemic injury occurs during the reperfusion phase of ischemia-reperfusion insults, and that the injury may be due to reactive-oxygen-species (ROS)-mediated oxidative events, including lipid peroxidation and DNA damage. However, oxidative DNA damage has until now not been examined in situ. In the present study, we report for the first time observation of cell type- and region-specific oxidative DNA damages in 5 min transient ischemic model by immunohistochemical methods, using monoclonal antibody against 8-hydroxy-2'-deoxyguanosine (8-OHdG), an oxidative DNA product. The cell types containing 8-OHdG immunoreactivity were neurons, glia and endothelial cells in the hippocampus. The 8-OHdG immunoreactivity was present in the nucleus but not the cytoplasm of these cells. The level of 8-OHdG in CA1 increased significantly (P<0.05) at the end of 30 min after ischemia, but there was no increase within CA2 and CA3 areas. The 8-OHdG levels in the hippocampus increased significantly (about fourfold) after 3 h of reperfusion and remained significantly (P<0.01) elevated for at least 12 h. At 4 days after ischemia, 8-OHdG levels in the CA2 and CA3 areas decreased to levels of the sham without neuronal loss, while disappearance of 8-OHdG immunoreactivity in the CA1 coincided with neuronal death in this area. These findings strongly suggest that ischemia-induced DNA damage evolves temporally and spatially, and that oxidative DNA damage may be involved in delayed neuronal death in the CA1 region.

The alterations of N-Methyl-D-aspartate receptor expressions and oxidative DNA damage in the CA1 area at the early time after ischemia-reperfusion insult

Delayed neuronal death in the CA1 of the hippocampus following global ischemia has been evoked by both the activation of N-methyl-D-aspartate receptor (NR) and the generate reactive oxygen species in the neurons. In the present study, we investigated whether oxidative DNA damages may be correlated with NR subunits (NR1 and NR2A/B) expression following ischemia insults in vivo. Thirty minutes after ischemia-reperfusion, the intensities of both NR and 8-hydroxy-2'-deoxyguanosine (8-OHdG) immunoreactivities were markedly increased in neurons of CA1. However, NR2A/B and 8-OHdG immunoreactivities were enhanced in CA1 over 24 h after ischemia although NR1 immunoreactivity was decreased. These results suggest that oxidative stress and excitotoxicity in the CA1 may simultaneously trigger neuronal damages at early time after ischemia, and free radical damage including oxidative DNA damage may eventually promote the delayed neuronal death in this region.

Evaluation of lymph node status after neoadjuvant chemotherapy in breast cancer patients: comparison of diagnostic performance of ultrasound, MRI and ¹⁸F-FDG PET/CT

Objective:

To evaluate the diagnostic performance of ultrasound, MRI and fluorine-18 fludeoxyglucose positron emission tomography (¹⁸F-FDG PET)/CT for the diagnosis of metastatic axillary lymph node (ALN) after neoadjuvant chemotherapy (NAC) and to find out histopathological factors affecting the diagnostic performance of these imaging modalities.

Methods:

From January 2012 to November 2014, 191 consecutive patients with breast cancer who underwent NAC before surgery were retrospectively reviewed. We included 139 patients with ALN metastasis that was confirmed on fine needle aspiration or core needle biopsy at initial diagnosis.

Results:

After NAC, 39 (28%) patients showed negative conversion of ALN on surgical specimens of sentinel lymph node (LN) or ALN. The sensitivity of ultrasound, MRI and PET/CT was 50% (48/96), 72% (70/97) and 22% (16/73), respectively. The specificity of ultrasound, MRI and PET/CT was 77% (30/39), 54% (21/39) and 85% (22/26), respectively. The Az value of combination of ultrasound and PET/CT was the highest (0.634) followed by ultrasound (0.626) and combination of ultrasound, MRI and PET/CT (0.617). The size of tumour deposit in LN and oestrogen receptor was significantly associated with the diagnostic performance of ultrasound (p < 0.001 and p = 0.009, respectively) and MRI (p = 0.045 and p = 0.036, respectively). The percentage diameter decrease, size of tumour deposit in LN, progesterone receptor, HER2 and histological grade were significantly associated with the diagnostic performance of PET/CT (p = 0.023, p = 0.002, p = 0.036, p = 0.044 and p = 0.008, respectively). On multivariate logistic regression analysis, size of tumour deposit within LN was identified as being independently associated with diagnostic performance of ultrasound [odds ratio, 13.07; 95% confidence interval (CI), 2.95–57.96] and PET/CT (odds ratio, 6.47; 95% CI, 1.407–29.737).

Conclusion:

Combination of three imaging modalities showed the highest sensitivity, and PET/CT showed the highest specificity for the evaluation of ALN metastasis after NAC. Ultrasound alone or combination of ultrasound and PET/CT showed the highest positive-predictive value. The size of tumour deposit within ALN was significantly associated with diagnostic performance of ultrasound and PET/CT.

Advances in knowledge:

This study is about the diagnostic performance of ultrasound, MRI, PET/CT and combination of each imaging modality for the evaluation of metastatic ALN after NAC. Of many histopathological factors, only the size of tumour deposit within ALN was an independent factor associated with the diagnostic performance of ultrasound and PET/CT.

Relative sparing of calretinin containing neurons in the substantia nigra of 6-OHDA treated rat parkinsonian model

A certain calcium binding protein (CaBP) has been known to exert a neuroprotective effect in various neurodegenerative diseases. Using the 6-OHDA induced rat Parkinsonian model, we examined if calretinin (CR), one of CaBP family, could play the similar role in the Parkinson's disease because CR is profusely localized in dopaminergic neurons of the substantia nigra pars compacta (SNPC) of the rat. Employing immunohistochemical analyses, we found that the survival rate of CR neurons was significantly higher than that of tyrosine hydroxylase (TH) neurons in the SNPC of the Parkinsonian rat. Furthermore double-labeled fluorescent microscopy revealed that almost all surviving TH neurons were also positive to CR. Our data suggest that CR-positive neurons are less vulnerable to 6-OHDA and CR in the dopaminergic neurons may have a protective function for survival of these neurons in the experimentally induced Parkinsonian rat.

Cerebellar alterations induced by chronic hypoxia: an immunohistochemical study using a chick embryonic model

A model of fetal aerogenic hypoxia was developed in which fertilized chicken eggs were half-painted with melted wax and incubated under normal conditions. The cerebellum of the hypoxic chick embryos at a later stage of development (E18-20) was analyzed immunochemically. Hypoxic insult resulted in considerable neurocytological deficits of the Purkinje cells and altered glial fibrillary acid protein (GFAP) immunoreactivity in the fetal cerebellum. Purkinje cells in the hypoxic embryos were marked by small cell size, poorly developed dendrites, low cell density, deletion and ectopia. On the other hand, enhanced GFAP immunoreactivity was found in astrocytes and Bergmann glia of the hypoxic embryos. Our results indicate that chronic hypoxia in the chick fetus can cause severe disorders of neuronal development as well as glial activation. We suggest that our hypoxic model of chick embryos could be an accessible animal model for further elucidating fetal hypoxia.

XY model in small-world networks

The phase transition in the XY model on one-dimensional small-world networks is investigated by means of Monte Carlo simulations. It is found that long-range order is present at finite temperatures, even for very small values of the rewiring probability, suggesting a finite-temperature transition for any nonzero rewiring probability. Nature of the phase transition is discussed in comparison with the globally coupled XY model.

Constitutive expression of c-myb mRNA in the adult rat brain

In this study, we demonstrated the c-myb mRNA expression in the adult rat brain using an in situ hybridization technique. We found c-myb mRNA signals in the various regions of the forebrain and midbrain including the cerebral cortex, thalamus, hippocampus, hypothalamus, superior and inferior colliculi and central gray. In the cerebellum, a diffuse signal was found in the granular layer while some positive cells were detected in the molecular layer as well. In addition, a number of cells showed intense signals in many nuclei of the medulla oblongata. The constitutive expression of c-myb mRNA in the different kinds of neural cells suggests that this gene might be involved in the normal function of these neurons.

Oligodendroglia in the avian retina: immunocytochemical demonstration in the adult bird

Immunohistochemical techniques were used in conjunction with an avian-specific probe for oligodendrocyte (OLG) marker, the antibody for transferrin binding protein (TfBP), to study the characteristics and distribution of OLGs in the retina of chickens and quails. For comparison, other antibodies such as myelin basic protein, Rip, and those for labeling Müller cells and microglia were used. A large population of OLGs was found to be distributed throughout the retina, with the distinct pattern of a central-to-peripheral gradient. It was possible to detect a spectrum of OLG morphology that bore a resemblance to the subtype of the mammalian central nervous system. In addition to these mature OLGs, limited numbers of TfBP-positive (TfBP(+)) cells with the morphology of immature OLGs were found in the immediate vicinity of the optic head. The majority of OLGs appeared in the ganglion cell layer throughout the retina, whereas OLGs in the nerve fiber layer were seen mainly in the central zone of the retina, near the optic nerve head. Double-labeling experiments showed that OLGs were associated with myelin only in the central region, where the majority of retinal OLGs occurred, but not toward the periphery of the retina. The present study is the first comprehensive analysis of the morphological features and spatial distribution of OLGs in the adult avian retina and provides in vivo evidence for the existence of a substantial population of both mature and immature OLGs in the retina of adult birds. The putative functions of TfBP(+) OLGs including myelination and the tropic role of the ganglion cells are discussed in conjunction with the physical properties of TfBP and structural characteristics of the avascular retina of birds.

Gender Differences in the Impact of Intergenerational Support on Depressive Symptoms among Older Adults in Korea

Background: This study examined the relationship between intergenerational support patterns and depressive symptoms among older men and women in Korea. Methods: A nationally representative survey of non-institutionalized, community-dwelling older adults in Korea was used. A total of 7531 older adults (3592 men and 3939 women) was included in the analysis. Results: We observed gender differences in the impact of financial support exchanges on depressive symptoms. A lack of mutual financial support significantly increased the risk of depressive symptoms by 3.83 times (95% CI 2.34–6.24) in men and 1.73 times (95% CI 1.06–2.83) in women. Men who received financial support were more likely to experience depressive symptoms (OR (Odds Ratio), 1.81, 95% CI 1.36–2.42), whereas women who provided financial support were more likely to experience depressive symptoms (OR 2.82, 95% CI 1.21–6.56). The lack of an exchange of emotional support was significantly associated with depressive symptoms in both men (OR 1.49, 95% CI 1.17–1.90) and women (OR 1.87, 95% CI 1.50–2.34). Conclusions: We discuss the evidence of gender differences in intergenerational support exchange patterns and their impact on depressive symptoms within the context of Korean cultures and suggest that future research should be conducted on gender differences in the impact of intergenerational support on mental health across diverse societies.

Effect of repeated seizure experiences on tyrosine hydroxylase immunoreactivities in the brain of genetically epilepsy-prone rats

The genetically epilepsy-prone rat (GEPR) is a model of generalized tonic/clonic epilepsy, and has functional noradrenergic deficiencies that act as partial determinants for the seizure predisposition and expression. The present study investigated the effect of repeated seizure experiences by acoustic stimulation (110 dB, 10 times) on the immunoreactivities of tyrosine hydroxylase (TH), a rate-determining enzyme in the synthesis of norepinephrine, in brain regions of GEPRs. TH immunoreactivity in locus coeruleus, the major noradrenergic nucleus in brain, was lower in GEPRs than control Sprague-Dawley rats. It was also decreased in several regions including inferior colliculus of GEPRs. Repeated experiences of audiogenic seizures further decreased TH immunoreactivities in locus coeruleus and inferior colliculus of GEPRs. The results from the present study suggest that the lower immunoreactivities of TH in locus coeruleus and inferior colliculus contribute, at least in part, to the noradrenergic deficits in GEPRs, and repeated seizure experiences further intensified these noradrenergic deficits, which may be related to the altered seizure expression by repetitive audiogenic seizure in GEPRs.

Psychometric properties of the Korean version of the Copenhagen Burnout Inventory in Korean homecare workers for older adults

BACKGROUND

Despite the increasing number of homecare workers, a reliable and valid tool with which to measure burnout among Korean homecare workers is still lacking. The aim of this study was to examine the reliability and construct validity of the Korean version of the Copenhagen Burnout Inventory (CBI-K).

METHODS

The study population consisted of 465 homecare workers. Data were collected in 2016 through a self-administered questionnaire including the three subscales of the CBI-K, the Center for Epidemiologic Studies Depression Scale (CESD-10), a measure of work-life conflict, and questions about respondents' sociodemographic characteristics.

RESULTS

The confirmatory factor analyses results showed that the model fit indices of the refined three-factor model, in which the PB, WRB, and CRB subscales each contained six items, were acceptable (CFI = 0.924, SRMR = 0.049, RMSEA = 0.091). Furthermore, based on the results for construct reliability, discriminant validity of the refined three-factor model and job characteristics of homecare workers, we proposed that an abbreviated two-factor scale using the PB and CRB subscales could be used, with appropriate model fit indices (CFI = 0.950, SRMR = 0.047, RMSEA = 0.084). Each of the PB, WRB, and CRB subscales of CBI-K were associated with depressive symptoms even after controlling for covariates.

CONCLUSIONS

The CBI-K has adequate reliability and validity for use with homecare workers. To increase its practicality, we suggest a refined form comprising only PB and CRB subscales can be used rather than a three-factor model.

Socio-demographic and Psychological Correlates of Posttraumatic Growth among Korean Americans with a History of Traumatic Life Experiences

This study examined socio-demographic and psychological correlates of posttraumatic growth (PTG) among Korean Americans (KAs) with traumatic life experiences. A total of 286 KAs were included. Being a woman or having a lower annual household income had positive associations with PTG, while having no religion had a negative association with it. In addition, praying and visiting a mental health professional for coping with stress or for psychological problems was positively associated with PTG. Higher resilience scores increased PTG, while depressive symptoms decreased it. We suggest reinforcing help seeking behaviors and accessibility to care facilities, and gender specific strengthening programs for enhancing PTG among KAs.

Distribution of heat shock protein 108 mRNA in the chicken central nervous system

The constitutive expression of heat shock protein 108 (HSP108) mRNA is mapped in a normal chicken central nervous system using in situ hybridization technique. HSP108 mRNAs were found to be mainly localized in the small neuroglial cells of various regions of the brain, although some neuronal cells also showed positive signals. This tendency is observed to be more marked in the cerebellum; HSP108 signals were not found in the Purkinje cells, but in Bergmann glial cells and oligodendrocytes. Although neuronal cells in the deep cerebellar nuclei and the molecular layer showed occasional HSP108 signals, the expression pattern of HSP108 mRNA is different from homologous HSP90 that is mostly expressed in neurons, but rather similar to that of TfBP immunoreactivity, a new member of the HSP108 family. The constitutive neuroglial localization of HSP108 could suggest that HSP108 may play an important role in the normal metabolism of neuroglial cells in the chicken brain.

Socio-demographic and Health Behavioral Correlates of Depressive Symptoms among Korean Americans

This study identifies the associations between socio-demographic characteristics and help seeking behaviors for depressive symptoms among adult Korean Americans (KAs). Using survey data from 230 residents of the New York City, Teaneck, New Jersey, and Philadelphia areas, simple and multiple logistic regression analyses were performed to assess the association between depressive symptoms and the covariates. Women were at much lower risk of depressive symptoms than were men, even after adjusting other covariates (OR 0.45, 95% CI 0.21-0.96). Having no health insurance (OR 4.02, 95% CI 1.28-12.61) and having experience in seeking professional help for mental health problems during the last year were significantly associated with depressive symptoms (OR 2.96, 95% CI 1.29-6.80). The findings suggest more attention to the risk of depression of KA men and further efforts on understanding the unique contribution of socio-demographic factors and health-related behaviors on depressive symptoms among KAs.

Gender differences in exposure and vulnerability to psychosocial and behavioral factors of suicide attempt among Korean adolescents

INTRODUCTION

This study examined gender differences in suicide attempts and their association with exposure and vulnerability to psychosocial, behavioral, and structural factors among Korean adolescents.

METHODS

Data of 74 854 adolescents, taken from the 2010 Korea Youth Risk Behavior Survey, were used. Logistic regression analysis was used to assess the contribution of differential exposure to psychosocial, behavioral, and structural factors for gender differences of suicidal attempt.

RESULTS

Gender differences were observed in the degree of exposure to the various factors. Females were more likely to report psychosocial problems, whereas males were more likely to report experience of smoking and drinking alcohol and to engage in vigorous physical activity. Stress and unhappiness were significantly associated with suicide attempts in both males and females, and gender differences in these variables were nonsignificant. Depressive symptoms were associated with a higher risk of suicide attempts, and this relationship was significantly stronger for males. The effects of cigarette smoking and risky drinking were significantly stronger in females.

DISCUSSION

Greater exposure to perceived stress, feelings of unhappiness, depression, and higher vulnerability of smoking and heavy drinking accounted for higher suicide attempts of female adolescents. Higher exposure to health-related behaviors and greater vulnerability to depressive symptoms in male were also noted. In conclusion, differences in exposure and vulnerability to psychosocial and behavioral factors may partly explain gender differences in suicide attempts among Korean adolescents.

Social Networking Site Usage and Its Impact on Depressive Symptoms among Older Men and Women in South Korea

Background: We examined the rate of social networking site (SNS) usage and the relationship between SNS usage and depressive symptoms among older men and women in South Korea. Methods: The data were obtained from the Living Profiles of Older People Survey (LPOPS), which comprises a nationally representative sample of non-institutionalized Korean older adults living in the community. A total of 10,073 older persons (4286 men and 5787 women) were included in the analysis. Results: A total of 26.0% of the total study population reported to use social network sites. Of the men and women, 32.6 and 21.1%, respectively, used SNS. A higher educational level and higher equivalent household income, lower number of chronic illnesses, no limitation in daily activities, living with others, and having good relationships with friends and neighbors were associated with higher SNS usage among older men and women. SNS usage was significantly associated with reduced depression scores in older men, but not in women. Conclusions: The difference in SNS usage between older men and women might be partially explained by differential exposure to digital technologies and disadvantages in education and economic opportunities. Education programs for digitalization and opportunities to engage with technology need to be provided.

Activation of microglia in kainic acid induced rat retinal apoptosis

We applied a variety of methods to follow the course of kainic acid (KA) induced retinal apoptosis, especially with regard to the spatial and temporal aspects. At 24 h after KA injection, a massive cell increase, which showed terminal transferase-mediated dUTP nick-end-labeling technique positive signals, was observed in all of the retinal layers, with the exception of the outer nuclear and photoreceptor layers. Electron microscopy further confirmed that these cells might be apoptotic body ingesting phagocytes, whose function seemed to correlate with bcl-2 mRNA up-regulation. When histochemical studies were performed to determine the cellular identity of the phagocytes, the microglia were thought to be the one and only type of phagocytes involved in the KA-induced retinal apoptosis. In conclusion, we demonstrated that after KA injection, microglia were the only phagocytes to participate in clearing apoptotic debris from the inner retinal layers, and that their function might correlate with the change in expression of the bcl-2 gene family.

Are substance P neurons of the paraventricular nucleus related to the osmotic regulation in the Mongolian gerbil?

In recent years, the gerbil has been used as an experimental animal for study osmotic regulation, because of its inherent high degree of water re-uptake in kidney. Many evidences to explain this characteristic accumulated on the kidney level, it do not, however, manifest what concerns on hypothalmo-hypophyseal level. In this study, we have focused on the difference between the colchicine treated gerbil and rat in distributions of substance P (SP), which is known to have antidiuretic property. Unlike rat, in which a few SP+ neuron is present, SP+ neurons were abundantly observed in the paraventricular nucleus (PVN) of the gerbil. Furthermore SP+ cells in PVN were manifested in dehydrated gerbils, in spite of non-colchicine treatment. Therefore, we suggest that the abundant SP+ neurons in PVN may be a clue to address the neuroendocrinal mechanism concerning the high degree of osmotic regulation in this animal.