Double jeopardy: Exploring the moderating effect of educational mismatch in the relationship between work-family conflict and depressive symptoms among Korean working women.

RATIONALE: Despite a growing body of empirical evidence on the detrimental effects of work-family conflict (WFC) on psychological health, little attention has been given to whether educational mismatch in the workplace, which refers to the perceived level of match between one's attained education and the required educational level for a position, may exacerbate these effects. OBJECTIVE: The purpose of this study was to examine the relationship between WFC, educational mismatch, and depressive symptoms in Korean working women, with a particular focus on the potential moderating effects of educational mismatch on the association between WFC and depressive symptoms. METHODS: The data utilized for this study were collected from 5174 married working women over five waves (16,610 person-observations) of the Korean Longitudinal Survey of Women and Families spanning 8 years between 2012 and 2020. Fixed effects (FE) models were estimated to account for unobserved individual-level heterogeneity. RESULTS: FE estimates indicated that WFC is associated with an increase in depressive symptoms, even after accounting for unobserved confounding factors and time-varying covariates. The interaction model provides evidence for the moderating role of educational mismatch in the association between WFC and depressive symptoms. The positive association between WFC and depressive symptoms was more pronounced among those who perceive themselves as "overeducated." The estimated coefficient for the association was about 45% larger for those who perceive themselves as "overeducated" than their "well-matched" counterparts. CONCLUSION: The study's findings suggest a robust link between WFC and depressive symptoms and further elaborate on how this association varies depending on educational mismatch. In Korea, where conservative gender role norms of female-caregiver ideology are still prevalent, WFC and educational mismatch can act as double jeopardy, exacerbating the mental health of working women.

Gender differences in the relationship between perceived discrimination and personality traits in young adulthood: Evidence using sibling fixed effects.

RATIONALE: Although perceived discrimination (PD) is known to be associated with personality traits, family background characteristics may confound this association. Moreover, little is known about whether the relationship differs by gender. OBJECTIVE: This study investigates whether the association between PD and personality traits is confounded by family background characteristics. Given gender differences in contexts and perceptions of discrimination as well as personality traits, this study also explores whether the association between PD and personality traits differs for men and women. METHODS: Using data from the National Longitudinal Study of Adolescent to Adult Health, this study examines the association between PD and Big Five personality traits among young adults. This study uses sibling fixed effects models with a lagged dependent variable to account for unobservable family-level characteristics, such as genetics, parental characteristics, family environment, and childhood social contexts. RESULTS: Sibling fixed effects estimates showed that PD was associated with lower levels of conscientiousness and extraversion and higher levels of neuroticism. There were also gender differences such that PD was associated with lower conscientiousness only for women and lower extraversion only for men. The positive association with neuroticism was apparent for both men and women. CONCLUSION: This study suggests that the association between PD and personality traits is generally not confounded by stable family-level characteristics shared by siblings. This study also documents gender differences in the relationship between PD and personality traits. Given substantial implications of personality for a broad range of outcomes, especially among young adults, the findings of this study reaffirm the commitment of the whole society to eradicate any form of discrimination.

A probable case of oral bisphosphonate-associated osteonecrosis of the jaw and recovery with parathyroid hormone treatment.

INTRODUCTION: Bisphosphonates are effective for treating osteoporosis, Paget's disease of bone, and malignancy-associated bone diseases. Bisphosphonate-associated osteonecrosis of the jaw (ONJ) is a rare but serious adverse effect of bisphosphonate therapy. Due to inhibitory actions on bone turnover, bisphosphonate therapy may result in the accumulation of microdamage. CASE SUMMARY: A 74-year-old Korean woman (height, 150 cm; weight, 51 kg) was referred to the Department of Endocrinology and Metabolism, Ajou University School of Medicine, Suwon, South Korea, for evaluation of pain and persistent abnormal exposure of jaw bone after extraction of teeth. She had been receiving weekly oral alendronate treatment for osteoporosis for ~5 years. The patient had the clinical features of bisphosphonate-associated osteonecrosis of the mandible, which was precipitated by teeth extraction ~14 months prior to the outpatient referral visit. At her clinical baseline visit, serum hormone concentrations and bone turnover markers were as follows: thyroid-stimulating hormone, 0.88 µIU/mL (reference range, 0.25-5.00 µIU/mL); 25-hydroxyvitamin D3, 20.9 (9.0-37.6) ng/mL; parathyroid hormone (PTH), 57 (11-62) pg/mL; serum osteocalcin, 8.7 (12.9-55.9) ng/mL; and urine N-telopeptide 21 (26-124) nM/mM creatinine. She had multiple systemic risk factors for ONJ, including older age, type 2 diabetes mellitus, and long duration of bisphosphonate therapy. There was no mandibular lesion improvement despite repeated surgical procedures performed within a 14-month period. Bisphosphonate therapy was discontinued and PTH therapy was started. After 2 months, exposed oral mucosa had healed. After 4 months of treatment, the pain had completely subsided, and after 6 months the patient's eating and drinking habits returned. The serum concentration of osteocalcin, a bone formation marker, which was initially suppressed (8.7 ng/mL), increased 174% (15.1 ng/mL) from baseline after 6 months of treatment with PTH. CONCLUSIONS: Here we report a probable case of oral bisphosphonate-associated ONJ featuring suppressed bone turnover. Treatment with the bone formation-stimulating agent PTH was beneficial.

Successful intermittent application of the Pringle maneuver for 30 minutes during human hepatectomy: a clinical randomized study with use of a protease inhibitor.

BACKGROUND/AIMS: There is experimental evidence that the liver can safely tolerate a cycle involving application of the Pringle maneuver for 30 minutes each time. METHODOLOGY: One hundred and twenty patients who underwent elective hepatectomy were randomly assigned to two groups of intermittent occlusion (30-min or 15-min Pringle group, n=60 each). A synthetic protease inhibitor (gabexate mesilate, GM, 2 mg/kg/h) was administered to pharmacologically alleviate visceral congestion, accompanied by hepatic pedicle clamping. Intraoperative data, liver function parameters and portal plasma levels of the inflammatory cytokine, interleukin (IL)-6 (a marker reflecting the status of visceral congestion), were examined as well as the postoperative course. Additionally, ten more patients randomly underwent right hepatectomy without GM, in order to clarify the influence of this agent on the present outcomes. RESULTS: The two groups of patients were comparable in terms of preoperative assessments, hepatic inflow occlusion time, extent of resection and background liver conditions. The 30-min Pringle group showed less blood loss during surgery (p=0.02) with a tendency for better postoperative mortality and morbidity. The postoperative liver functions were similar between the two groups. The portal plasma levels of IL-6 during pedicle clamping did not differ significantly between the two groups. When GM was not used, the 30-min intermittent Pringle maneuver induced a two-fold rise in serum transaminase levels on day 1 compared with the 15-min group. CONCLUSIONS: Our study indicates that intermittent application of the Pringle maneuver for 30 minutes each time can be accomplished effectively and safely for human hepatectomy, when combined with use of a protease inhibitor.

A strong dose-response relation between serum concentrations of persistent organic pollutants and diabetes: results from the National Health and Examination Survey 1999-2002.

OBJECTIVE: Low-level exposure to some persistent organic pollutants (POPs) has recently become a focus because of their possible link with the risk of diabetes. RESEARCH DESIGN AND METHODS: Cross-sectional associations of the serum concentrations of POPs with diabetes prevalence were investigated in 2,016 adult participants in the National Health and Nutrition Examination Survey 1999-2002. Six POPs (2,2',4,4',5,5'-hexachlorobiphenyl, 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin, 1,2,3,4,6,7,8,9-octachlorodibenzo-p-dioxin, oxychlordane, p,p'-dichlorodiphenyltrichloroethane, and trans-nonachlor) were selected, because they were detectable in >or=80% of participants. RESULTS: Compared with subjects with serum concentrations below the limit of detection, after adjustment for age, sex, race and ethnicity, poverty income ratio, BMI, and waist circumference, diabetes prevalence was strongly positively associated with lipid-adjusted serum concentrations of all six POPs. When the participants were classified according to the sum of category numbers of the six POPs, adjusted odds ratios were 1.0, 14.0, 14.7, 38.3, and 37.7 (P for trend < 0.001). The association was consistent in stratified analyses and stronger in younger participants, Mexican Americans, and obese individuals. CONCLUSIONS: There were striking dose-response relations between serum concentrations of six selected POPs and the prevalence of diabetes. The strong graded association could offer a compelling challenge to future epidemiologic and toxicological research.

Common presence of non-transferrin-bound iron among patients with type 2 diabetes.

OBJECTIVE: Recently, we reported increased cardiovascular disease mortality among supplemental vitamin C users with type 2 diabetes in a prospective cohort study. Because vitamin C may cause oxidative stress in the presence of redox active iron, we hypothesized that non-transferrin-bound iron (NTBI), a form of iron susceptible to redox activity, may be present in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: We measured serum NTBI levels using high-performance liquid chromatography in 48 patients with known diabetes (at least 5 years duration since diagnosis), 49 patients with newly diagnosed diabetes, and 47 healthy control subjects (frequency matched on age and sex). RESULTS: NTBI was commonly present in diabetes: 59% in newly diagnosed diabetes and 92% in advanced diabetes. Mean NTBI values varied significantly between the three groups, with the highest values being observed in patients with known diabetes and the lowest in the control subjects (0.62 +/- 0.43 vs. 0.24 +/- 0.29 vs. 0.04 +/- 0.13 micromol/l Fe). Serum total iron or percent transferrin saturation were very similar among the three groups, yet NTBI was strongly associated with serum total iron (r = 0.74, P < 0.01) and percent transferrin saturation (r = 0.70, P < 0.01) among the patients with known diabetes. CONCLUSIONS: Consistent with our hypothesis, these data demonstrate the common existence of NTBI in type 2 diabetic patients with a strong gradient with severity. Prospective cohort studies are required to clarify the clinical relevance of increased NTBI levels.

Graded associations of blood lead and urinary cadmium concentrations with oxidative-stress-related markers in the U.S. population: results from the third National Health and Nutrition Examination Survey.

Although oxidative stress has been proposed as a mechanism of lead and cadmium toxicity mostly based on in vitro experiments or animal studies, it is uncertain whether this mechanism is relevant in the pathogenesis of lead- or cadmium-related diseases in the general population with low environmental exposure to lead and cadmium. We examined associations of blood lead and urinary cadmium levels with oxidative stress markers of serum gamma-glutamyltransferase (GGT), vitamin C, carotenoids, and vitamin E among 10,098 adult participants in the third U.S. National Health and Nutrition Examination Survey. After adjusting for race, sex, and age (plus serum total cholesterol in the case of serum carotenoids and vitamin E), blood lead and urinary cadmium levels both showed graded associations, positive with serum GGT and inverse with serum vitamin C, carotenoids, and vitamin E (p for trend < 0.01, respectively). These associations were consistently observed among most subgroups: non-Hispanic white, non-Hispanic black, men, women, all age groups, nondrinkers, drinkers, nonsmokers, ex-smokers, current smokers, and body mass index (< 25, 25-29.9, and > or = 30). The strong association of blood lead and urinary cadmium levels with oxidative stress markers in this population suggests that oxidative stress should be considered in the pathogenesis of lead- and cadmium-related diseases even among people with low environmental exposure to lead and cadmium.

Evaluation of a protease inhibitor in the prevention of ischemia and reperfusion injury in hepatectomy under intermittent Pringle maneuver.

BACKGROUND: The severity of ischemia and reperfusion (I/R) injury is an important determinant of patient outcome in hepatic surgery. The aim of this study was to investigate the efficacy of a protease inhibitor in alleviating I/R injury to human liver in the setting of hepatectomy under intermittent Pringle maneuver. METHODS: Sixty patients who underwent liver resection under conditions of intermittent inflow occlusion were randomly assigned to 2 groups (n = 30 each) according to the use of a synthetic protease inhibitor (gabexate mesilate or GM). GM was administered intravenously at a dosage of 2.0 mg/kg/h starting 12 hours before surgery until postoperative day 2. Preoperative and intraoperative clinical variables and postoperative outcomes were evaluated. The plasma levels of a cytokine, interleukin (IL)-6, as well as laboratory biochemical liver function parameters were analyzed to evaluate hepatic I/R injury. RESULTS: The 2 groups of patients were comparable with regard to hepatic inflow occlusion time, extent of liver resection, and background liver histology. The preoperative administration of GM (GM group) substantially alleviated hepatic I/R injury compared with the untreated control group; postoperative serum transaminase levels were significantly decreased in association with marked suppression of IL-6 levels in blood circulation during surgery. This was accompanied by a lower incidence of postoperative complications. The patients without postoperative complications had significantly lower activities of plasma IL-6 at 24 hours after surgery. CONCLUSIONS: This prospective randomized study demonstrated the hepatoprotective effect of a synthetic protease inhibitor in the setting of hepatectomy under the intermittent Pringle maneuver.

A strong secular trend in serum gamma-glutamyltransferase from 1996 to 2003 among South Korean men.

Serum gamma-glutamyltransferase (GGT) concentration, within its normal range, has recently been proposed as a reliable marker of oxidative stress. Oxidative stress plays a central pathogenic role in many metabolic and/or cardiovascular diseases, incidences of which have recently increased in South Korea. Since serum GGT has strong associations with these diseases and their risk factors, the authors hypothesized a corresponding secular trend of increasing serum GGT levels in South Korea. Study subjects were 8,072 male workers at a large steel company who were aged 24-44 years at baseline and had received annual physical examinations from 1996 to 2003. The secular trend was a 0.1066-units/liter increase in ln(GGT) level per calendar year (a 180% increase during the 7-year follow-up period) (p < 0.01). Adjustment for body mass index, alcohol consumption, smoking, exercise, and cholesterol level as time-dependent covariates did not change the results. Although cholesterol is commonly used as a marker of epidemiologic transition, there was a less dramatic secular trend in ln(serum cholesterol) level, and it disappeared after adjustment for the secular trend in serum GGT. These findings suggest that serum GGT concentration can be used as a sensitive marker of epidemiologic transition, and they portend a continuing rise in incidences of metabolic and/or cardiovascular diseases in this population in the coming years.

Enhanced inflammatory cytokine production at ischemia/reperfusion in human liver resection.

BACKGROUND/AIMS: Clinical implications of acute reactant cytokine responses remain to be clarified in the setting of ischemia/reperfusion of human liver during liver resection and transplantation. METHODOLOGY: In serial samples of portal and systemic venous blood we examined acute inflammatory cytokine activities at the time points--before i), at the end of clamping ii), and one hour iii) and day 1 iv) after continuous hepatic inflow occlusion in 25 patients undergoing elective hepatectomy (15 major and 10 minor). Responses of tumor necrosis factor-alpha, interleukin-1 beta, interleukin-6 and interleukin-8 were compared with intraoperative parameters such as the duration of hepatic inflow occlusion and portal venous pressure during the occlusion, postoperative hepatocyte injury markers such as serum transaminases and bilirubin and also related complications. RESULTS: Portal interleukin-6 levels were significantly elevated during hepatic inflow occlusion, as compared with the systemic events (P < 0.02, at time point ii), but there were no differences in the interleukin-8 levels between the portal and systemic circulation. The increase in portal interleukin-6 levels during liver resection (time points, ii and iii) significantly correlated with the duration of hepatic inflow occlusion (48 +/- 9 min, mean +/- SD), portal venous pressure (500 +/- 127 mmH2O), and postoperative serum levels of transaminases (day 1; S-ALT, 705 +/- 1023 U/L; S-AST 892 +/- 1255 U/L) and maximum bilirubin (2.6 +/- 2.5 mg/dL). Interleukin-8 levels in the portal circulation showed no such correlation, but the levels in systemic blood showed significant positive relationships with the intra- and postoperative parameters. One patient who died had an enhanced generation of the cytokines in the presence of an elevated portal venous pressure. CONCLUSIONS: These observations suggest that overproduction of acute reactant cytokines (interleukin-6 from the portal system and interleukin-8 from the systemic circulation) in hepatic ischemia/reperfusion relates positively with postoperative hepatocyte injury in humans. We propose that hepatectomy done under a prolonged continuous inflow occlusion should be reconsidered when an enhanced generation of acute cytokines is anticipated, especially in case of a markedly high portal pressure during hepatic pedicle clamping.

Hepatocyte protection by a protease inhibitor against ischemia/reperfusion injury of human liver.

BACKGROUND: Total clamping of the hepatic pedicle can induce profound hepatic ischemia/reperfusion (I/R) injury, which remains a potentially lethal problem after hepatectomy. STUDY DESIGN: The purpose of this study was to evaluate the efficacy of a protease inhibitor in ameliorating I/R injury of the human liver. In a prospective, randomized, clinical study, 66 patients who underwent liver resection under conditions of continuous inflow occlusion were randomly assigned to three groups: 25 patients were given a synthetic protease inhibitor (gabexate mesilate [GM], 2.0 mg/kg/hr) intravenously starting 24 hours before surgery until postoperative day 3 (preop GM group); 16 were similarly given GM at the beginning of surgery (intraop GM group); and 25 served as controls (without GM group). Laboratory data and intraoperative and postoperative variables were analyzed and plasma levels of cytokines--tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and interleukin-6 (IL-6)--were measured to determine the relationship between surgical stress and hepatic I/R injury. RESULTS: The three groups of patients were similar in terms of age, gender, preoperative assessments, hepatic inflow occlusion time (approximately 50 minutes), extent of resection (proportion of major and minor hepatectomy), and background liver conditions. Preoperative administration of gabexate mesilate (preop GM group) substantially ameliorated hepatic I/R injury as compared with the other patients (intraop and without GM groups); postoperative serum transaminase levels were notably decreased in association with marked suppression of IL-6 levels in blood circulation during liver surgery. This was accompanied by a lower rate of postoperative complications and no mortality. Gabexate mesilate pretreatment abrogated the positive correlation between postreperfusion hepatocyte injury and hepatic ischemia time. CONCLUSIONS: Preoperative administration of GM is useful for preventing I/R injury of the human liver, accompanied by suppression of the plasma proinflammatory cytokine IL-6.