Social Isolation, Loneliness and Their Relationships with Mental Health Status in South Korea.

OBJECTIVE: This study aims to investigate the prevalence and psychological impact of social isolation and loneliness in South Korea. Loneliness and social isolation have been regarded as a risk to both physical and mental health. However, most studies have focused on the elderly; hence, there are limited studies on the characteristics of socially isolated or lonely people considering age. METHODS: A sample of 1,700 participants was selected from three major cities in South Korea. In-person interviews were conducted to evaluate loneliness, social isolation and mental health status. RESULTS: Among the participants, the prevalence of social isolation and loneliness was 17.8% and 4.1%, respectively. Males decreased the odds of loneliness (AOR 0.49, 95% CI=0.28-0.87), while increasing the odds of social isolation (AOR 1.44, 95% CI=1.12-1.86) after adjusting for age and sex. Greater depressive and social phobic symptoms were associated with increased odds of loneliness and social isolation. CONCLUSION: Social isolation and loneliness are prevalent among Koreans and associated with depression, social phobic symptoms, and suicidality. This study provides a foundation for further research to investigate nationwide prevalence and a more in-depth analysis of loneliness and social isolation.

Distribution and perinatal transmission of bacterial vaginal infections in pregnant women without vaginal symptoms.

BACKGROUND: We evaluated the distribution and vertical transmission of bacterial vaginal infections in asymptomatic pregnant women. METHODS: We performed multiplex PCR on secretions collected on cervical swabs from pregnant women at over 36 weeks of gestation and on oral secretions collected from their neonates immediately after delivery. We detected sexually transmitted infections (STIs) with the following 6 species: Trichomonas vaginalis, Mycoplasma hominis, Mycoplasma genitalium, Chlamydia trachomatis, Neisseria gonorrhoeae, and Ureaplasma urealyticum. RESULTS: Infectious agents were detected in 64 of 455 pregnant women (14.1%) and in 11 neonates (2.4%). The rate of vertical transmission was 17.2% and all the infectious agents detected in neonates were concordant with those found in their mothers. U. urealyticum was the most frequently detected in the maternal genitalia, followed by M. hominis. Women who were in labor for a longer period of time had a higher risk of vertically transmitting STI agents to their neonates. CONCLUSIONS: Vertical transmission of bacterial STIs from mothers to their infants is possible at delivery and influenced by the duration of labor. STIs should be diagnosed in pregnant women to prevent vertical transmission from the mother to the infant at the time of delivery.

Selective cyclooxygenase inhibitors increase paclitaxel sensitivity in taxane-resistant ovarian cancer by suppressing P-glycoprotein expression.

OBJECTIVE: The purpose of this study was to investigate whether selective cyclooxygenase (COX) inhibitors promote paclitaxel-induced apoptosis in taxane-resistant ovarian cancer cells by suppressing MDR1/P-glycoprotein (P-gp) expression. METHODS: Taxane-resistant ovarian cancer cells were cultured with paclitaxel alone or combined with a selective COX inhibitors. The expression patterns of MDR1/P-gp and the ability of COX inhibitors to inhibit growth of taxane-resistant ovarian cancer cells were measured. The efficacy of prostaglandin E2 (PGE2) supplementation was measured to evaluate the mechanisms involved in suppressing MDR1 gene expression. RESULTS: P-gp was upregulated in taxane-resistant ovarian cancer cells compared to paired paclitaxel-sensitive ovarian cancer cells. An 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that selective COX inhibitors significantly enhanced the cytotoxic effects of paclitaxel in taxane-resistant ovarian cancer cells via a prostaglandin-independent mechanism. These increased apoptotic effects were further verified by measuring an increased percentage of cells in sub-G1 stage using flow cytometry. Selective COX inhibitors suppressed MDR1 and P-gp expression. Moreover, combined treatment with paclitaxel and selective COX inhibitors increased poly (ADP-ribose) polymerase (PARP) cleavage in taxane-resistant ovarian cancer cells. CONCLUSION: Selective COX inhibitors significantly promote paclitaxel-induced cell death in taxane-resistant ovarian cancer cells in a prostaglandin-independent manner. COX inhibitors could be potent therapeutic tools to promote paclitaxel sensitization of taxane-resistant ovarian cancers by suppressing MDR1/P-gp, which is responsible for the efflux of chemotherapeutic agents.

Activation of peroxisome proliferators-activated receptor δ (PPARδ) promotes blastocyst hatching in mice.

Prostaglandins participate in a variety of female reproductive processes, including ovulation, fertilization, embryo implantation and parturition. In particular, maternal prostacyclin (PGI(2)) is critical for embryo implantation and the action of PGI(2) is not mediated via its G-protein-coupled membrane receptor, IP, but its nuclear receptor, peroxisome-proliferator-activated receptor δ (PPARδ). Recently, several studies have shown that PGI(2) enhances blastocyst development and/or hatching rate in vitro, and subsequently implantation and live birth rates in mice. However, the mechanism by which PGI(2) improves preimplantation embryo development in vitro remains unclear. Using molecular, pharmacologic and genetic approaches, we show that PGI(2)-induced PPARδ activation accelerates blastocyst hatching in mice. mRNAs for PPARδ, retinoid X receptor (heterodimeric partners of PPARδ) and PGI(2) synthase (PGIS) are temporally induced after zygotic gene activation, and their expression reaches maximum levels at the blastocyst stage, suggesting that functional complex of PPARδ can be formed in the blastocyst. Carbaprostacyclin (a stable analogue of PGI(2)) and GW501516 (a PPARδ selective agonist) significantly accelerated blastocyst hatching but did not increase total cell number of cultured blastocysts. Whereas U51605 (a PGIS inhibitor) interfered with blastocyst hatching, GW501516 restored U51605-induced retarded hatching. In contrast to the improvement of blastocyst hatching by PPARδ agonists, PPAR antagonists significantly inhibited blastocyst hatching. Furthermore, deletion of PPARδ at early stages of preimplantation mouse embryos caused delay of blastocyst hatching, but did not impair blastocyst development. Taken together, PGI(2)-induced PPARδ activation accelerates blastocyst hatching in mice.

Foot deformity in charcot marie tooth disease according to disease severity.

OBJECTIVE: To investigate the characteristics of foot deformities in patients with Charcot-Marie-Tooth (CMT) disease compared with normal persons according to severity of disease. METHOD: Sixty-two patients with CMT disease were recruited for this study. The normal control group was composed of 28 healthy people without any foot deformity. Patients were classified into a mild group and a moderate group according to the CMT neuropathy score. Ten typical radiological angles representing foot deformities such as pes equinus and pes varus were measured. The CMT group angles were compared with those of the normal control group, and those of the mild group were also compared with those of the moderate group. RESULTS: The lateral (Lat.) talo-first metatarsal angle, anteroposterior talo-first metatarsal angle, Lat. calcaneal-first metatarsal angle, Lat. naviocuboid overlap, Lat. calcaneal pitch, Lat. tibiocalcaneal angle, and Lat. talocalcaneal angle in the CMT group showed a significant difference compared to the normal control group (p<0.05). These findings revealed CMT patients have pes cavus, forefoot adduction, midfoot supination and pes varus deformity. Compared to the mild group, the moderate group significantly showed an increased Lat. calcaneal pitch and decreased Lat. calcaneal-first metatarsal angle, Lat. tibiocalcaneal angle, Lat. talocalcaneal angle, and Lat. talo-first metatarsal angle (p<0.05). These findings revealed that the pes cavus deformity of CMT patients tend to be worse with disease severity. CONCLUSION: The characteristic equinovarus foot deformity patterns in CMT patients were revealed and these deformities tended to be worse with disease severity. Radiographic measures may be useful for the investigation of foot deformities in CMT patients.

Small proline-rich protein 2 family is a cluster of genes induced by estrogenic compounds through nuclear estrogen receptors in the mouse uterus.

We have investigated the potential actions of E(2) and endocrine disruptors (EDs) with estrogenic activity, such as bisphenol A, on the regulation of the Sprr2 family of genes in the mouse uterus using real-time RT-PCR, RT-PCR and Western blotting. Most members of Sprr2 genes that are induced by E(2), such as Sprr2a, 2b and 2e, showed E(2) dose-dependent increase at mRNA levels. Sprr2 expression was considerably reduced by pretreatment with ICI 182,780, an antagonist for nuclear estrogen receptors. Progesterone moderately dampened E(2)-induced Sprr2 expression. Furthermore, EDs comparably induced the expression of Sprr2 genes in a dose-dependent manner and EDs-induced Sprr2 expression was similarly modulated by ICI 182,780 and progesterone, strongly suggesting that they are, indeed, an estrogen-responsive gene family. Collectively, dose-dependent induction of Sprr2 genes by estrogen and EDs is primarily mediated via the genomic actions of estrogen signaling in the uterus, but not in other reproductive tracts, in mice.

MiR-21 regulates adipogenic differentiation through the modulation of TGF-beta signaling in mesenchymal stem cells derived from human adipose tissue.

A better understanding of the molecular mechanisms that govern human adipose tissue-derived mesenchymal stem cells (hASCs) differentiation could improve hASCs-based cell therapy and provide new insights into a number of diseases, including obesity. In this study, we examined the roles of microRNA-21 (miR-21) in adipogenic differentiation of hASCs. We found that miR-21 expression was transiently increased after induction of adipogenic differentiation, peaked at 3 days, and returned to the baseline level 8 days. Lentiviral overexpression of miR-21 enhanced adipogenic differentiation. Overexpression of miR-21 decreased both protein and mRNA levels of TGFBR2. The expression of TGFBR2 was decreased during adipogenic differentiation of hASCs in concordance with an increase in the level of miR-21. In contrast, inhibiting miR-21 with 2'-O-methyl-antisense microRNA increased TGFBR2 protein levels in hASCs, accompanied by decreased adipogenic differentiation. The activity of a luciferase construct containing the miR-21 target site from the TGFBR2 3'UTR was lower in LV-miR21-infected hASCs than in LV-miLacZ infected cells. TGF-beta-induced inhibition of adipogenic differentiation was significantly decreased in miR-21 overexpressing cells compared with control lentivirus-transduced cells. RNA interference-mediated downregulation of SMAD3, but not of SMAD2, increased adipogenic differentiation. Overexpression and inhibition of miR-21 altered SMAD3 phosphorylation without affecting total levels of SMAD3 protein. Our data are the first to demonstrate that the role of miR-21 in the adipogenic differentiation of hASCs is mediated through the modulation of TGF-beta signaling. This study improves our knowledge of the molecular mechanisms governing hASCs differentiation, which may underlie the development of obesity or other metabolic diseases.

Saponins derived from the roots of Platycodon grandiflorum inhibit HT-1080 cell invasion and MMPs activities: regulation of NF-kappaB activation via ROS signal pathway.

The chemopreventive effects of saponin derived from Platycodon grandiflorum (Changkil saponin; CKS) on tumor invasion and migration and the possible mechanisms involved in this protection were investigated in HT-1080 tumor cells. In this study, we found that CKS reduced 12-O-tetradecanoylphorbol-13-acetate (PMA)-enhanced Matrix metalloproteinases (MMP)-9 and MMP-2 activation in a dose-dependant manner and further inhibited HT-1080 cell invasion and migration. In addition, CKS suppressed PMA-enhanced expression of MMP-9 protein, mRNA and transcription activity levels through suppression of nuclear factor (NF)-kappaB activation without changing tissue inhibitor of metalloproteinase (TIMP)-1 level. CKS also reduced PMA-enhanced MMP-2 active forms through suppression of membrane-type 1 MMP (MT1-MMP) level, but did not alter MMP-2 and TIMP-2 levels. Moreover, reactive oxygen species (ROS) production induced by PMA was partly decreased in the presence of CKS and this suppression of ROS production may be related to diminish NF-kappaB activity. Therefore, our results suggested that the inhibitory effects of CKS on MMP-2 and MMP-9 activation, relation of tumor invasion and migration in vitro possibly involve mechanisms related to its ability to suppress PMA-enhanced NF-kappaB activation through ROS signaling pathway. Overall, CKS may be a valuable anti-invasive drug candidate for cancer therapy.

Effects of packing on the postoperative hearing after middle ear surgery.

CONCLUSION: The changes of hearing by packing after middle ear surgery should be anticipated and carefully interpreted. OBJECTIVES: To evaluate the amount and patterns of hearing loss resulting from packing in middle ear cavity (MEC) and external auditory canal (EAC) after middle ear surgery. METHOD: We obtained pure tone thresholds by bone (BC) and air conduction (AC) up to 12 weeks after middle ear surgery in 17 patients who had minimal middle ear pathology. To observe the effects of packing only in the EAC as in cases of explorative tympanotomy or stapes surgery, BC and AC threshold were obtained after packing only in the EAC in 18 volunteers. The changes of BC and AC thresholds in terms of pure tone average (PTA) and high frequency PTA were analyzed. RESULTS: PTA by AC increased significantly by a maximal value of 38.7 dB at the second postoperative day, by 35.0 dB at 1 week after middle ear surgery. PTA by BC also increased maximally at the second postoperative day by 4.8 dB. The elevation of BC threshold at high frequencies (2, 3, 4 kHz) was more pronounced. Packing of EAC without MEC packing resulted in elevation of AC threshold by 43.0 dB, with similar patterns of BC threshold changes as MEC and EAC packing.