Pulmonary tuberculosis and lung cancer risk in current smokers: the Seoul Male Cancer Cohort Study

Authors evaluated pulmonary tuberculosis (PTB) history as a risk factor for lung cancer in current male smokers in a prospective, population-based cohort study. The subjects were the 7,009 males among the participants in the Seoul Male Cancer Cohort Study for whom there was full information on PTB history and smoking habits. With a 16-yr follow-up, 93 cases of lung cancer occurred over the 99,965 person-years of the study. The estimated relative risk (RR) of PTB history of current smokers in lung cancer after adjusting for three confounders - intake of coffee and tomatoes, and age at entry - was 1.85 (95% CI: 1.08-3.19). The observed joint RRs and attributable risks (ARs) across strata of three confounders were greater than the expected, indicating a positive interaction. Thus a history of PTB in current smokers may be another risk factor for lung cancer. Based on a synergic interaction, a heavy male smoker with a PTB history would be expected to belong to the group at high risk of lung cancer.

Abstract 4807: Soy and salty food intake and risk of stomach cancer in Seoul Male Cohort

Stomach cancer is the most common cancer among men in Korea. High prevalence of H. pylori infection and salty food intake has been suspected to be the main contributors of the high incidence of stomach cancer in Korea. Many studies reported an inverse association between soy food and risk of stomach cancer, but some studies showed that fermented soy food increased the risk of stomach cancer probably due to the high concentration of salt in it. We aimed to evaluate the association between fermented and non-fermented soy, and other salty food and the risk of stomach cancer in a prospective cohort study in Korea. Seoul Male Cohort was established in 1993. Members were recruited from the male beneficiaries of the Korean Health Insurance Company, who were aged 40-59 and living in Seoul. A lifestyle questionnaire survey was conducted through mailing. Dietary intake was measured using a quantitative food frequency questionnaire with 88 food items. Cancer occurrence was identified through data linkage to the Korean Central Cancer Registry and Korean Death Records. A total of 14,512 members were followed up until December 31, 2008, and 362 stomach cancer cases were identified. Total calorie adjusted multivariable odds ratio (aOR) and 95% confidence interval (95%CI) were calculated using logistic regression. Soybean paste stew, a very popular fermented soy food in Korea, was positively associated with the risk of stomach cancer. Men who ate soybean paste stew 2∼3 cups per week had 1.45 times higher risk of stomach cancer than men who ate less than one cup per week (95% CI = 1.11-1.92). Non-fermented soy foods, including soybean, tofu, and soy drink, were not associated with the risk of stomach cancer. The aOR of stomach cancer for the highest intake of soybean compared to the lowest intake was 1.02 (95%CI = 0.77-1.36), for the highest intake of tofu was 1.05 (95%CI = 0.75-1.46), for the highest intake of soy drink was 1.11 (95%CI = 0.84-1.47). Other salty foods, including Kimchi stew (highest vs. lowest, aOR=1.47, 95%CI=1.05-2.06), and salt-fermented radish (highest vs. lowest, aOR=1.45, 95%CI=1.11-1.90) were positively associated with the risk of Stomach cancer. However, Kimchi itself, the most popular salt-fermented vegetable in Korea, was not associated with the risk of stomach cancer (highest vs. lowest, aOR=1.06, 95%CI=0.77-1.46). In conclusion, we found no evidence of inverse association between non-fermented soy food and risk of stomach cancer. When soy is fermented, its high concentration of salt may increase the risk of stomach cancer. Most of the other salty foods may increase the risk of stomach cancer.

Citation Format: Myung-Hee Shin, Seon-Mi Hwang, Jong-Myon Bae, Moo-Song Lee, Dong-Hyun Kim, Zhong-Min Li, Yoon-Ok Ahn. Soy and salty food intake and risk of stomach cancer in Seoul Male Cohort. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4807. doi:10.1158/1538-7445.AM2013-4807

Lung cancer incidence by smoking status in Korean men: 16-years of observations in the Seoul Male Cancer Cohort study

The relative risk (RR) of smoking and mortality of lung cancer in British doctors was previously reported to have increased throughout a 40-yr period. Here, we evaluated this RR based on the incidence of lung cancer in Korean men using a longer follow-up period. We compared our data to the RR reported in a study using a 10-yr follow-up period; the subjects and methods were identical to those of the previous paper with the exception of the follow-up period, which ended on December 31, 2008. We found that the RR of smoking habits in patients with lung cancer did not increase, and that the data showed narrowing 95% confidence intervals over a longer observation in Korean men. Estimated lung cancers attributable to smoking were 55.6%. These results highlight the need for an intervention program to help patients quit smoking in Korea.

Abstract 650: Association between obesity, body composition and risk of female thyroid cancer

Obesity increases the risk of many cancers, including endometrial, colorectal, kidney, and postmenopausal breast cancer. Some reported a positive association between obesity measured in body mass index (BMI, kg/m2) and risk of thyroid cancer, but others observed no association. We aimed to examine the association between various obesity and body composition measures and the risk of female thyroid cancer in Korea. A total of 158 incident papillary thyroid cancer and 144 non-cancer controls from one university hospital in Seoul were interviewed on their life-style factors between April, 2006 and December, 2007. Controls included patients with incidental benign thyroid nodules, goiter, and other minor surgical conditions. Weight, height, and BMI were measured. Among the total participants, 93 patients and 102 controls agreed to be measured for their body composition using In-Body 3.0 (BioSpace). Diagnostic procedural thyroid stimulating hormones (TSH) levels were abstracted from the clinical records of 155 cases and 138 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) of thyroid cancer were calculated using logistic regression adjusted for age, physical exercise (total MET value), smoking, alcohol intake amount, menopausal status, and serum TSH levels. The level of obesity was not high in this population. The range of BMI was 16.6 - 36.8 kg/m2, with the mean of 23.4 ± 3.0 kg/m2. There were no differences in means of BMI, weight, height, and WC between cases and controls. The proportion of participants with BMI >= 27.5 kg/m2 was 9.5 % in cases and 6.9% in controls. The OR of thyroid cancer for BMI>=27.5 kg/m2 compared to 20<=BMI<25 was 2.67 (95%CI= 0.89- 6.83, ptrend = 0.01). When we separated body composition into lean mass and fat mass, lean mass increased (q5 vs. q1, OR = 4.05, 95%CI= 1.48 - 11.10, ptrend <0.001) while fat mass decreased (q5 vs. q1, OR = 0.32, 95%CI= 0.11 - 0.98, ptrend = 0.01) the risk of thyroid cancer. In correlation analysis, BMI was more strongly correlated with fat mass (r=0.80) than with lean mass (r=0.46). The association between BMI and risk of thyroid cancer seemed slightly stronger among premenopausal than postmenopausal women and non-alcohol drinkers than alcohol drinkers. However, the increased risk by lean mass and decreased risk by fat mass were stronger among postmenopausal than premenopausal women and alcohol drinkers than non-drinkers. In conclusion, lean mass may increase the risk of thyroid cancer. A larger, confirmatory study is warranted. Independent roles of lean and fat body mass should be considered when evaluating the association between obesity and risk of thyroid cancer, at least among a population with low grade of obesity.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 650. doi:1538-7445.AM2012-650

Reactive oxygen species-dependent necroptosis in Jurkat T cells induced by pathogenic free-living Naegleria fowleri

Naegleria fowleri, a free-living amoeba, is the causative pathogen of primary amoebic meningoencephalitis in humans and experimental mice. N. fowleri is capable of destroying tissues and host cells through lytic necrosis. However, the mechanism by which N. fowleri induces host cell death is unknown. Electron microscopy indicated that incubation of Jurkat T cells with N. fowleri trophozoites induced necrotic morphology of the Jurkat T cells. N. fowleri also induced cytoskeletal protein cleavage, extensive poly (ADP-ribose) polymerase hydrolysis and lactate dehydrogenase (LDH) release. Although no activation of caspase-3 was observed in Jurkat T cells co-incubated with amoebae, intracellular reactive oxygen species (ROS) were strongly generated by NADPH oxidase (NOX). Pretreating cells with necroptosis inhibitor necrostatin-1 or NOX inhibitor diphenyleneiodonium chloride (DPI) strongly inhibited amoeba-induced ROS generation and Jurkat cell death, whereas pan-caspase inhibitor z-VAD-fmk did not. N. fowleri-derived secretory products (NfSP) strongly induced intracellular ROS generation and cell death. Necroptotic effects of NfSP were effectively inhibited by pretreating NfSP with proteinase K. Moreover, NfSP-induced LDH release and intracellular ROS accumulation were inhibited by pretreating Jurkat T cells with DPI or necrostatin-1. These results suggest that N. fowleri induces ROS-dependent necroptosis in Jurkat T cells.

Calpain mediates degradation of cytoskeletal proteins during Jurkat T-cell death induced by Entamoeba histolytica

Entamoeba histolytica is known to induce host cell death via activation of calpain and caspases. In this study, we investigated the specific proteases involved in the degradation of cytoskeletal proteins during Jurkat T-cell death induced by E. histolytica. Amoebic trophozoites induced marked degradation of paxillin, Cas, vimentin, vinculin and talin, as well as α- or β-spectrin, in Jurkat T cells. The cleavage effects of E. histolytica were strongly retarded by pretreatment with a calpain inhibitor, but not with a pan-caspase inhibitor. In addition, calpain knockdown with siRNA in Jurkat T cells effectively inhibited E. histolytica-induced PARP, paxillin, α-spectrin, β-spectrin and talin degradation, as compared to scrambled siRNA. These results suggest that calpain plays a crucial role in the cleavage of cytoskeletal proteins during cell death induced by E. histolytica.

Abstract 4649: Association between serum 25-hydroxyvitamin D and risk of female thyroid cancer in Korea

The incidence of female thyroid cancer is rapidly increasing in Korea. However, factors that would account for this increase are unclear other than the increase in frequency of screening. Vitamin D has shown anticarcinogenic effect on many cancers in experimental studies. Dietary and circulating vitamin D have shown inconclusive, yet promising, inverse associations with colorectal, breast, and prostate cancer in epidemiological studies. Evidences on the association between circulating vitamin D and thyroid cancer are rare. We investigated the association between serum 25-hydroxyvitamin D3 (25(OH)D3) and the risk of thyroid cancer among Korean women. A total of 158 incident thyroid cancer and 144 non-cancer control patients from one large hospital in Seoul were interviewed on their life-style factors between April, 2006 and December, 2007. Among the total participants, 91 cancer (all thyroid papillary cancer) and 105 control patients who agreed to donate their blood were included in this study. The blood of cancer patients was collected at the inpatient wards while the patients were admitted for the operation. The blood of control patients was collected at the inpatient wards or outpatient clinics of four different clinical departments. All blood samples were centrifuged within 1 hour of collection and the serum vials were stored in -80 °C. Serum 25(OH)D3 concentration was measured using radioimmunoassay (RIA). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression adjusted for the month of blood collection, body mass index, physical exercise, breast feeding, and menopausal status. The OR of thyroid cancer for the highest quintile (17.2-30.1ng/ml) of serum 25(OH)D3 concentration compared to the lowest quintile (4.0-8.7ng/ml) was 0.30 (95%CI = 0.10-0.85, ptrend=0.04). The inverse association between serum 25(OH)D3 and risk of thyroid cancer was observed in both premenopausal (OR=0.50, 95%CI=0.09-2.68) and postmenopausal women (OR=0.24, 95%CI=0.05-1.09) although statistical significance was not reached in both groups. Women with lower BMI (<23kg/m2) or with no history of breast feeding showed stronger association between serum 25(OH)D3 and risk of thyroid cancer. Our results suggest higher serum 25(OH)D3 may reduce the risk of thyroid papillary cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4649. doi:10.1158/1538-7445.AM2011-4649

Cancer survival in Seoul, Republic of Korea, 1993-1997

The Seoul cancer registry was established in 1991. Cancer is a notifiable disease, and registration of cases is done by passive and active methods. The registry contributed survival data for 56 cancer sites or types registered during 1993-1997. Follow-up information has been gleaned predominantly by passive methods with median follow-up ranging between 5-82 months for various cancers. The proportion with histologically verified diagnosis for different cancers ranged between 23-99%; death certificates only (DCOs) comprised 0-67%; 33-100% of total registered cases were included for survival analysis. The top-ranking cancers on 5-year age-standardized relative survival rates were testis and placenta (95%), thyroid (93%), non-melanoma skin (93%), corpus uteri (79%), renal pelvis (77%), cervix (76%), Hodgkin lymphoma (75%), breast (74%) and prostate (74%). Five-year relative survival by age group showed a decreasing trend with increasing age groups for cancers of the small intestine, colon, gall bladder, cervix, corpus uteri, ovary, kidney, urinary bladder and thyroid, or was fluctuating for other cancers.

Altered cardiovascular responses to tracheal intubation in patients with complete spinal cord injury: relation to time course and affected level

BACKGROUND

We determined cardiovascular responses to tracheal intubation in relation to the time since injury in patients with different levels of spinal cord injury.

METHODS

Two hundred and fourteen patients with complete cord injury were studied. They were either quadriplegics (>C7, n=71) or paraplegics (<T5, n=143), and were subdivided into six groups each according to the time since injury: <4 week (acute), 4 week-1 yr, 1-5, 5-10, 10-20, and >20 yr. Twenty patients with no cord injury served as controls. Systolic arterial pressure (SAP), heart rate (HR), and plasma catecholamine concentrations were determined.

RESULTS

Intubation did not affect SAP in the quadriplegics regardless of the time post-injury, but it significantly increased SAP in all paraplegics. Moreover, the pressor response was enhanced in the paraplegics who were 10 yr or more since injury (P<0.05). HR increased significantly in all groups; the magnitude of the increase was less only in acute quadriplegics compared with controls. Plasma concentrations of norepinephrine increased in every group except for the quadriplegics within 4 weeks of injury. The maximum increases in SAP, HR, and norepinephrine from awake baseline values were smaller in the quadriplegics than in the paraplegics (P<0.01).

CONCLUSIONS

The cardiovascular and catecholamine responses to intubation change as a function of the time elapsed and the level of the cord injury. In this study, the pressor response to tracheal intubation was abolished in the quadriplegics but not in paraplegics; indeed, it was enhanced at 10 yr or more since injury in this group.

Calpain-dependent cleavage of SHP-1 and SHP-2 is involved in the dephosphorylation of Jurkat T cells induced by Entamoeba histolytica

Host cell death induced by Entamoeba histolytica is an important mechanism for both host defence and microbial immune evasion during human amoebiasis. However, the signalling pathways underlying cell death induced by E. histolytica are not fully understood. This study investigated the involvement of the protein tyrosine phosphatases (PTPs) SHP-1 and SHP-2 in the dephosphorylation associated with E. histolytica-induced host cell death. Incubation with E. histolytica resulted in a marked decrease in protein tyrosine phosphorylation levels and degradation of SHP-1 or SHP-2 in Jurkat cells. Pre-treatment of cells with a calpain inhibitor, calpeptin, impeded the amoeba-induced dephosporylation and cleavage of SHP-1 or SHP-2. Additionally, inhibition of PTPs with phenylarsine oxide (PAO) attenuated Entamoeba-induced dephosphorylation and DNA fragmentation in Jurkat T cells. These results suggest that calpain-dependent cleavage of SHP-1 and SHP-2 may contribute to protein tyrosine dephosphorylation in Jurkat T cell death induced by E. histolytica.

Comparison of prevalence of metabolic syndrome between korean emigrants and host country residents in Japan and china-the korean emigrant study

OBJECTIVES

This study aims to compare the prevalence of metabolic syndrome between Korean emigrants (KEs) and their host country residents in Japan and China.

METHODS

The Korean Emigrant Study (KES) is a cohort study initiated in 2005 to elucidate the effect of genetic susceptibility and environmental change on hypertension, diabetes, and metabolic syndrome. Equal numbers of KEs and host country residents, aged 30 or over, were recruited from three regions; Kobe-Osaka in Japan (total number=965), Yanbian in China (n=1,019), and Changchun in China (n=949).

RESULTS

The age-adjusted prevalences of metabolic syndrome among KEs in Kobe-Osaka were significantly higher than those among Japanese (in men 24.0% vs. 15.6%, p=0.04, in women 8.4% vs. 2.7%, p=0.01), while the age-adjusted prevalences among KEs in Changchun were similar to those among Chinese (in men 11.7% vs. 16.1%, p=0.37, in women 28.3% vs. 30.1%, p=0.91). The age-adjusted prevalences were generally higher in Yanbian than other regions, and KEs had higher prevalence than Chinese in men but not in women (in men 37.9% vs. 28.3%, p=0.03, women 46.0% vs. 50.6%, p=0.44). The components with significant ethnic differences in prevalence were high blood pressure and abdominal obesity in Japan, and triglyceride in China. The most influential component in diagnosing metabolic syndrome was abdominal obesity in men and triglyceride in women.

CONCLUSION

The prevalence of metabolic syndrome was higher in KEs than in host country residents in Japan but not in China. Abdominal obesity and triglyceride are both discriminating and influential components in metabolic syndrome.

Abstract 893: Obesity, weight change, and survival of breast cancer in premenopausal and postmenopausal women Korea

Large body of evidence suggests that obesity is associated with poor survival of breast cancer. However, this association is not entirely consistent among younger or premenopausal women. We investigated the association of obesity and the survival from pre- and postmenopausal breast cancer in Korea. Breast cancer patients in this study were women who previously participated in a hospital-based case-control study. A total of 1,357 patients (937 premenopausal and 420 postmenopausal women) who were first diagnosed between 1998 and 2004 and aged between 35 and 70 were included in the study. Patients were interviewed at the time of diagnosis on the risk factors of breast cancer including current body weight, weight at 2 years prior to diagnosis, weight at age 18, and adult height. Clinical records and pathologic reports were retrieved and the information on tumor characteristics, such as TNM, stage, estrogen receptor (ER), progesterone receptor (PR), and C-erbB-2, and type of treatment were coded. Patients were followed up until Dec. 31, 2007. Deaths were confirmed through hospital cancer registry and the National Death Certificate Database. Hazard ratios (HR) were calculated using Cox's proportional hazard model.

We observed 111 deaths from all cause and 74 deaths from breast cancer. Five-year survival rate for breast cancer was 94.4% for premenopausal patients and 96.2% for postmenopausal patients. Obesity was not associated with breast cancer mortality in premenopausal patients. Compared to women with Body Mass Index (BMI) at diagnosis &lt; 25kg/m2, women with BMI &gt;= 25kg/m2 had 0.7 times risk of death from breast cancer (95% Confidence Interval (CI) = 0.3-1.4). However, obesity was positively associated with breast cancer mortality in postmenopausal patients. Compared to women with BMI at diagnosis &lt; 25kg/m2, women with BMI &gt;= 25kg/m2 had 3.1 times higher risk of death from breast cancer (95% CI = 1.1-8.7). Weight loss during the two years prior to diagnosis was associated with breast cancer mortality in premenopausal patients. Compared to women whose weight changed less than 5 % during the 2 years prior to diagnosis, women who lost more than 5% of their weight had 2.9 times higher risk of death from breast cancer (95% CI = 1.4-6.1). Women who gained more than 5% of their weight did not have increased risk of death from breast cancer (HR = 1.2, 95% CI = 0.6-2.2). There was no association between weight change and breast cancer mortality in postmenopausal patients (HR for weight loss group = 0.9, 95% CI = 0.2-3.8, HR for weight gain group = 0.9, 95% CI = 0.2-4.0).

In conclusion, obesity was associated with poorer survival of breast cancer in postmenopausal women but not in premenopausal women.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 893.

Visible-light-activated photocatalysis of malodorous dimethyl disulphide using nitrogen-enhanced TiO2

This study evaluated the feasibility of applying a visible-light-activated photocatalytic technique to cleanse air dimethyl disulphide (DMDS) at low concentration conditions (0.027-5.4 ppm), by using nitrogen-enhanced TiO2. In addition, the applicability of a backup adsorption unit for the secondary control of DMDS exiting from the photocatalytic oxidation (PCO) unit was investigated. The PCO unit functioned effectively for the control of DMDS at low concentration levels ( < or = 0.027 ppm) for long-time periods (at least 603 h). However, rapid photocatalyst deactivation levels were observed during photocatalytic processes with a higher DMDS input concentration (IC) (2.7 ppm). The photocatalyst reactivated with humidified or dried air, under visible-light irradiation, did not regain all its initial activities. The photocatalytic degradation efficiencies (PDEs) for DMDS were close to 100% for the relative humidity (RH) range of 45-55%, whereas they were between 86% and 91% and between 78% and 82% regarding the RH ranges of 10-20% and 80-90%, respectively. The PDEs via the PCO alone were close to 100% during this time period for the lowest IC conditions (0.027 ppm), whereas they decreased gradually for the other ICs. The FTIR spectra of the photocatalysts, as well as a solid-liquid extraction method, suggested the formation of sulphate groups on the catalyst surface during a photocatalytic process. Methanol was identified as a gaseous by-product. In addition, the backup adsorption unit could be effectively utilized to remove methanol, under a broad indoor pollution level (0.027-5.4 ppm), as well as DMDS exiting from the PCO units.

Anaesthetic requirement and stress hormone responses in patients undergoing lumbar spine surgery: anterior vs. posterior approach

BACKGROUND

The intensity of nociceptive stimuli reflects the severity of tissue injury. The anaesthetic requirement and stress hormonal responses were determined to learn whether they differ according to different surgical approaches (anterior vs. posterior) during the spinal surgery.

METHODS

Patients undergoing lumbar spine surgery without neurological deficits were divided into two groups: one having posterior (n=13) and the other having anterior fusion (n=13). The end-tidal sevoflurane concentrations (ET(SEVO)) required to maintain the bispectral index score at 40-50 were determined. Mean arterial pressure (MAP), heart rate (HR), central venous pressure (CVP), serum osmolality and plasma concentrations of catecholamines, cortisol and vasopressin (AVP) were measured.

RESULTS

There were no differences in MAP, HR, CVP and serum osmolality between the groups. ET(SEVO) was higher in the anterior than in the posterior group (P<0.05). The plasma concentrations of norepinephrine and cortisol increased in both groups during the surgery, whereas those of epinephrine remained unchanged. AVP concentrations increased during the surgery in the anterior group, and remained unaltered in the posterior group. The anterior group needed more analgesics (P<0.01) during the first 1 h after the operation.

CONCLUSIONS

The anterior approach required a deeper level of anaesthesia while undergoing spinal surgery and more use of post-operative analgesics than the posterior approach. It was also associated with a more pronounced AVP release during the surgery.

Mitochondrial respiration is required for activation of ERK1/2 and caspase-3 in human eosinophils stimulated with hydrogen peroxide

BACKGROUND

Eosinophils are important effector cells in the pathogenesis of allergic diseases such as bronchial asthma. Oxidative stress in the form of cellular reactive oxygen species (ROS) has been implicated in the pathogenesis of several allergic diseases. Recently, it has become evident that mitochondrial-derived ROS are important transducers of apoptosis and intracellular signaling. In this study, we investigated the role of mitochondrial ROS in the activation of extracellular signal-regulated kinases (ERK) 1 and 2-mitogen-activated protein kinase (MAPK) and caspase-3 in human eosinophils stimulated with H2O2.

METHODS

Human eosinophils were purified using immunomagnetic negative selection and then stimulated with H2O. H2O2-induced eosinophil apoptosis was measured by staining cells with annexin V. Activation of ERK1/2 MAPK and caspases was assessed by Western blotting. Eosinophils were pretreated with rotenone, an inhibitor of the mitochondrial electron transport chain, before H2O2 was added.

RESULTS

Treatment with 1 mM H2O2 induced externalization of phosphatidylserine (PS) and activation of caspases in eosinophils. H2O2-triggered PS externalization and cleavage of caspase-3 were markedly inhibited by pretreatment with the mitochondrial ROS scavenger N-acetyl-L-cysteine. In addition, H2O2 strongly induced phosphorylation of ERK1/2, but not ERK5, in eosinophils. Hydrogen peroxide-triggered activation of caspase-3 and ERK1/2 was attenuated by pretreatment with rotenone.

CONCLUSIONS

These results suggest that mitochondrial respiration is essential for activation of ERK1/2 and caspase-3 in human eosinophils stimulated with H2O2.

Angiotensin II receptor blockade blocker pre-treatment largely prevents injury from gradual renal ablation in rats

INTRODUCTION

Reduction in renal mass in rats results in progressive proteinuria, hypertension, focal-segmental glomerulosclerosis (FSG), atrophy of tubules (AT), and interstitial expansion. We reported that slow reduction of renal tissue in rats (slow ablation) ending in the removal of 1.5 kidneys is associated, over the next six months, with higher albumin excretion rates (AER) and accelerated development of FSG lesions compared to sudden equivalent renal mass reduction. It was hypothesised that slow reduction of nephron numbers allows for a process of conditioning of residual nephrons that increases their susceptibility to subsequent injury.

METHODS

To test this idea we treated Münich-Wistar rats with the angiotensin receptor blocker (ARB) losartan for six weeks during the gradual staged surgical removal of 1.5 kidneys, and compared them to sham operated controls, and parallel groups untreated by losartan.

RESULTS

Despite discontinuation of losartan over the subsequent six months, ARB pre-treatment completely prevented proteinuria and hypertension in these slow renal ablation rats. ARB pre-treatment also largely prevented the subsequent development of FSG, AT, and interstitial expansion in these animals. Both losartan-treated and untreated renal ablation groups had glomerular enlargement and compensatory hyperfiltration and this was uninfluenced by losartan.

CONCLUSION

Temporary ARB administration during gradual renal mass reduction resulted in long-term prevention of hypertension and albuminuria and greatly reduced FSG and tubular and interstitial lesions. We hypothesise that the preconditioning of residual nephrons in the gradual ablation model which facilitates their subsequent injury, is blunted by renin-angiotensin system blockade.

Cigarette smoking and risk of lung cancer in Korean men: the Seoul Male Cancer Cohort Study

Lung cancer is the leading cause of cancer deaths in Korea. The aim of this study was to estimate lung cancer risk of cigarette smoking in Korean men by a 10-yr follow-up prospective cohort study using the primary databases. The number of subjects was 14,272 men, who had full information of smoking habits among participants in the Seoul Male Cancer Cohort Study (SMCC). Total 125,053 person-years were calculated by determining the number of days from the start of followup, January 1, 1993, until the date of lung cancer diagnosis, death from another cause, or the end of follow-up, December 31, 2002, followed by converting the number of days to years. The information of outcome was obtained by the database of Korea Central Cancer Registry, Seoul Regional Cancer Registry, and Korea Statistical Office. The relative risk (RR) and its 95% confidence interval (CI) values of smoking were calculated using Cox proportional hazards regression stratified on potential confounders. During the follow-up periods, 78 cases of lung cancer occurred. The cigarette smoking is the major risk factor and increases the 4.18-fold risk of lung cancer in Korean men. In order to control lung cancer, intervention of quitting smoking is needed.

Familial association of schizophrenia symptoms retrospectively measured on a lifetime basis

OBJECTIVE

The objective of this study was to characterize the familial associations of symptoms or symptom dimensions of schizophrenia, as a component of the effort to delineate suitable phenotypic markers under the homogenous genetic control.

METHODS

Clinical symptoms of the patients were evaluated on a lifetime basis, with the Korean version of the Diagnostic Interview for Genetic Studies and the Krawieka scale. Our sample consisted of 54 sibling pairs who were concordant for Diagnostic and statistical manual of mental disorder-IV schizophrenia or schizoaffective disorder.

RESULTS

At the individual symptom level measured by the Diagnostic Interview for Genetic Studies, we observed a statistically significant degree of concordance within the sibling pairs for auditory hallucination (kappa=0.600, chi(2)=15.193, P=0.000). The within-sibling resemblance of this symptom was also indicated by the results of correlation analyses of individual items of the Krawiecka scale (partial correlation coefficient=0.423, P=0.005). Among the individual symptoms or symptom dimensions of the Krawiecka scale, the 'anxious' (partial correlation coefficient=0.469, P=0.001) and the 'affective dimension' (including the items of 'anxious' and 'depressed') (partial correlation coefficient=0.436, P=0.003) were also determined to indicate significant intra-pair correlations after controlling for potential confounding variables, such as sex, duration of illness, and age of onset.

CONCLUSIONS

The results of this study suggest that familial factors, possibly genetic factors, contribute a liability to the development of auditory hallucinations. This symptom might then prove useful as a phenotype marker in future genetic studies.

Relationship between the Source of Energy Intake and Obesity in Korean Women Using the Average of Four 3-day Dietary Records

OBJECTIVES

The aim of this study was to investigate the relationship between the contributions of macronutrients to the total energy intakes and Body Mass Indices (BMI, kg/m2) of Korean women.

METHODS

We used dietary records data from 115 healthy Korean women, ages 20 and over, who completed four 3-day dietary records between February 2003 and March 2004. For the calculation of nutrients we used a dietary assessment program developed by the Korean Nutritional Society. Macronutrient intakes were estimated by averaging individual total daily intakes in four 3-day dietary records. Subjects were categorized into three Body Mass Index (BMI) groups: underweight (BMI < 20), normal (20 < or = BMI < 25), and overweight (BMI > or = 25) group.

RESULTS

The total energy intakes were not different among the three BMI groups. Similarly, other macronutrient intakes such as protein, fat, carbohydrate, vegetable protein, animal protein, saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids were not different. From the multivariate nutrient density model, substituting polyunsaturated fatty acid for carbohydrate was positively associated with BMI in women aged 20 to 49 (beta = 2.31, p < 0.01). In women aged 50 and over, substituting animal protein for carbohydrate was positively associated with BMI (beta = 0.549, p = 0.04).

CONCLUSIONS

No single macronutrient was associated with BMI when all subjects were combined. However, when stratified by age, polyunsaturated fatty acid intake in younger women, and animal protein intake in older women, were positively associated with BMI. In the future, we recommend a larger study to confirm these results.

Trichomonas vaginalis promotes apoptosis of human neutrophils by activating caspase-3 and reducing Mcl-1 expression

Neutrophils are the predominant inflammatory cells found in the vaginal discharge of patients with Trichomonas vaginalis infection. However, it is not known whether neutrophil apoptosis is induced by live T. vaginalis. Therefore, we examined whether T. vaginalis can influence neutrophil apoptosis, and also whether caspase-3 and the Bcl-2 family members are involved in the apoptosis. Thus, human neutrophils were incubated with live T. vaginalis and neutrophil apoptosis was evaluated by Giemsa, annexin V-PI, and DiOC6 stainings. The neutrophil apoptosis was significantly higher in those incubated with T. vaginalis than in the control group. When trichomonads were pre-treated with mAb to AP65 (adhesin protein), or when trophozoites were separated from neutrophils using a Transwell chamber, neutrophil apoptosis was significantly reduced. The activation of caspase-3 was evident in neutrophils undergoing spontaneous apoptosis but was markedly enhanced during T. vaginalis-induced apoptosis. Moreover, the inhibition of caspase-3 effectively reduced T. vaginalis-induced apoptosis. Trichomonad-induced apoptosis was also associated with reduced expression of the neutrophil anti-apoptotic protein, Mcl-1. These results indicate that T. vaginalis alters Mcl-1 expression and caspase-3 activation, thereby inducing apoptosis of human neutrophils.

Rising prostate cancer rates in South Korea

BACKGROUND

Prostate cancer incidence and mortality rates in South Korea are relatively low, but rising steadily.

METHODS

We examined age-standardized incidence and mortality trends of prostate cancer in South Korea to gain further insight into prostate cancer etiology.

RESULTS

Although prostate cancer incidence has been low (7.9 per 100,000 man-years), it has increased up to 28.2% between 1996-1998 and 1999-2001. Prostate cancer mortality increased 12.7-fold over a 20-year period. Despite the increase in prostate cancer incidence and mortality rates, marked differences in rates remain for Koreans, Korean Americans, and Caucasian Americans.

CONCLUSIONS

The rising rates of prostate cancer in South Korea cannot be attributed entirely to PSA screening due to the low PSA screening prevalence; this trend is most likely related to increased westernization among Koreans. Interdisciplinary epidemiological studies incorporating the collection of biological samples are needed to clarify the extent to which lifestyle and genetic factors contribute to the observed racial disparity.

Deafferentation-disconnection neglect induced by posterior cerebral artery infarction

OBJECTIVE

To investigate patients with posterior cerebral artery (PCA) infarctions to learn whether hemispatial neglect is more frequent and severe after right than left PCA infarction; whether visual field defects (VFDs) influence the presence or severity of hemispatial neglect; and the anatomic loci of lesions that are associated with hemispatial neglect.

METHODS

The authors recruited 45 patients with PCA infarction that involved only the occipital lobe or the occipital lobe plus other areas served by the PCA. All subjects received seven neglect tests within 2 months after onset.

RESULTS

Overall, the frequency of hemispatial neglect was 42.2%. The frequency did not significantly differ between the right (48.0%) and left (35.0%) PCA groups, but the severity of hemispatial neglect was significantly greater in the right group. VFD alone did not influence the frequency or severity of neglect after controlling other variables. Isolated occipital lesions were rarely associated with hemispatial neglect, and it was only the occipital plus splenial lesion that significantly influenced the frequency and severity of neglect.

CONCLUSIONS

This study suggests that after excluding such confounding factors as aphasia or hemiplegia, neglect frequency does not differ between the right and left posterior cerebral artery (PCA) groups, but the severity of neglect is greater after right PCA infarctions; even in the acute stage of PCA infarction; visual field defect from an isolated occipital lesion does not cause hemispatial neglect; and the injury to both the occipital lobe and the splenium of the corpus callosum is important for producing hemispatial neglect with PCA infarction.

Effect modification by vitamin C on the relation between gastric cancer and Helicobacter pylori

A hospital-based case-control study of 295 cases with histologically confirmed gastric cancer and age and sex-matched controls was conducted to evaluate the effect of dietary vitamin C intake upon the relation between Helicobacter pylori infection and gastric cancer in Korea in 1997-1998. Anti-H. pylori IgG was detected by ELISA. A food frequency questionnaire, and a questionnaire on demographic factors, including past medical history, smoking, alcohol consumption, and life style was also administered. The prevalences of H. pylori IgG in cases and controls were 80.7% and 71.2%, respectively, and the odds ratio (OR) of H. pylori for gastric cancer was 1.68 (95% confidence interval (CI): 1.14, 2.44), after adjusting for age, sex, educational level, and a past medical history of gastritis or gastric ulcer. In a stratified analysis, H. pylori seropositivity was found to be a significant risk factor for gastric cancer in the low vitamin C intake group (OR = 4.68; 95% CI: 1.97, 11.1), but not in the high vitamin C intake group (OR = 0.72; 95% CI: 0.32, 1.65). Vitamin C intake was found to modify the relation between H. pylori and gastric cancer.

Genetic polymorphism of CYP17 and breast cancer risk in Korean women

CYP17 gene is involved in steroidogenesis and steroid metabolism. Epidemiologic results on the association between the CYP17 polymorphism and breast cancer risk have been inconsistent. We examined the association between the MspAI polymorphism at +27 relative to the start of transcription in the 5'-untranslated region of CYP17 gene and breast cancer risk in Korean women. Four hundred and sixty-two incident cases and 337 controls were recruited from three teaching hospitals in Seoul during 1994-2001. Polymorphism of the CYP17 gene was determined by a single base extension assay. Demographic and lifestyle characteristics were identified using structured questionnaire. Age-adjusted (aOR) and multivariate odds ratios (& mgr;OR) and 95% confidence intervals (CI) were estimated by unconditional logistic regression. The proportions of A1/A1, A1/A2 and A2/A2 genotypes among controls were 20.8%, 45.1% and 34.1%, respectively. Compared to the A1/A1 genotype, A1/A2 or A2/A2 genotype was not statistically significantly associated with overall breast cancer risk (i.e., mOR = 1.01, 95% CI = 0.69-1.47 and mOR = 0.76, 95% CI = 0.51-1.14, respectively). However, a significant association between CYP17 A2/A2 genotype and breast cancer was observed among women aged 50 years or less (mOR = 0.58, 95% CI = 0.34-0.99, P =0.04) and leaner women (body mass index < 22 kg/ m2) (mOR = 0.48, 95% CI = 0.23-0.97, P = 0.04). Our results suggest that genetic polymorphism in 5'-untranslated region of CYP17 might play a role in breast cancer development in Korean women among younger women aged less than 50 or leaner women with body mass index less than 22 kg/m2.

Clinical Outcomes of Pneumococcal Pneumonia Caused by Antibiotic-Resistant Strains in Asian Countries: A Study by the Asian Network for Surveillance of Resistant Pathogens

To evaluate the clinical outcomes of pneumococcal pneumonia caused by antibiotic-resistant strains in Asian countries, we performed a prospective observational study of 233 cases of adult pneumococcal pneumonia in 9 Asian countries from January 2000 to June 2001. Among 233 isolates, 128 (55%) were not susceptible to penicillin (25.3% were intermediately susceptible, and 29.6% were resistant). Clinical severity of pneumococcal pneumonia was not significantly different between antibiotic-resistant and antibiotic-susceptible groups. Mortality rates among patients with pneumococcal pneumonia caused by penicillin-, cephalosporin-, or macrolide-resistant strains were not higher than those with antibiotic-susceptible pneumococcal pneumonia. Bacteremia and mechanical ventilation were significant risk factors for death, but any kind of antibiotic resistance was not associated with increased mortality due to pneumococcal pneumonia. Outcome of pneumococcal pneumonia was not significantly affected by drug resistance, and current antimicrobial regimens are mostly effective in the treatment of pneumococcal pneumonia, despite the widespread emergence of in vitro resistance.

Effect of Kaikasaponin III Obtained fromPueraria thunbergianaFlowers on Serum and Hepatic Lipid Peroxides and Tissue Factor Activity in the Streptozotocin-Induced Diabetic Rat

We investigated the effect of kaikasaponin III (KS-III) on Phase I and II enzymes and tissue factor (TF) activity to elucidate the pharmacological actions of this immunosuppressive saponin in the diabetic rat. This compound was obtained from the flower of Pueraria thunbergiana (Leguminosae) by chromatographic isolation. This crude drug (Puerariae Flos) has been used as a therapeutic agent for diabetes mellitus in traditional Korean medicine. KS-III prolonged the bleeding time and plasma clotting time in streptozotocin (STZ)-treated rats and increased the TF activity, suggesting that this compound has anti-thrombosis activity in STZ-induced rats. It also inhibited the formation of malondialdehyde (MDA) and hydroxy radicals in serum and liver, but promoted superoxide dismutase (SOD) activity. Low MDA concentrations and low xanthine oxidase and aldehyde oxidase activities were observed in the KS-III-treated rats, suggesting that such Phase I enzyme activities are the major source of lipid peroxidation. However, KS-III increased Phase II enzyme activities such as SOD, glutathione peroxidase, and catalase, suggesting the activation of free radical-scavenging enzymes. These results suggest that KS-III may exhibit its hypoglycemic and hypolipidemic effects by up-regulating or down-regulating antioxidant mechanisms via the changes in Phase I and II enzyme activities.

Hormone replacement therapy in postmenopausal women with Alzheimer's disease: a randomized, prospective study

OBJECTIVE

To compare the therapeutic efficacy of hormone replacement therapy (HRT) and tacrine in Alzheimer's disease.

DESIGN

Six-month, randomized, open-label study.

SETTING

University hospital.

PATIENT(S)

Fifty-five women with mild to moderate Alzheimer's disease were randomly assigned to tacrine (n = 26) or HRT (n = 29).

INTERVENTION(S)

In the tacrine group, an initial dose of 40 mg/day was increased up to 160 mg/day. In the HRT group, conjugated equine estrogen was given to patients without uteri (n = 3) or together with micronized progesterone to patients with uteri (n = 26).

MAIN OUTCOME MEASURE(S)

Mini-Mental State Examination (MMSE), Hopkins Verbal Learning Test, Boston Naming Test, Controlled Oral Word Association Test, Geriatric Depression Scale, Hamilton Depression Scale (HDS), and Instrumental Activities of Daily Living (IADL).

RESULT(S)

Thirty-three patients who completed the outcome measures (tacrine, 17; HRT, 16) were included in an intent-to-treat analysis. The results did not differ between groups except for IADL, which rated more highly after HRT. Apolipoprotein E genotype effects were assessed. MMSE and HDS scores were improved after tacrine treatment in epsilon 4-negative patients.

CONCLUSION(S)

Overall efficacy of estrogen plus progesterone combination was similar to tacrine for cognition and mood, but greater for ADL. In epsilon 4-negative patients, tacrine is preferable for cognition and mood.

Intake of dairy products, calcium, and vitamin d and risk of breast cancer

BACKGROUND

Laboratory data suggest that calcium and vitamin D, found at high levels in dairy products, might reduce breast carcinogenesis. However, epidemiologic studies regarding dairy products and breast cancer have yielded inconsistent results. We examined data from a large, long-term cohort study to evaluate whether high intake of dairy products, calcium, or vitamin D is associated with reduced risk of breast cancer.

METHODS

We followed 88 691 women in the Nurses' Health Study cohort from the date of return of their food-frequency questionnaire in 1980 until May 31, 1996. Dietary information was collected in 1980 and updated in 1984, 1986, 1990, and 1994. We identified 3482 women (premenopausal = 827, postmenopausal = 2345, and uncertain menopausal status = 310) with incident invasive breast cancer. We used pooled logistic regression to estimate multivariable relative risks (RRs) using 2-year time increments. The RRs and 95% confidence intervals (CIs) were calculated for each category of intake compared with the lowest intake group. All statistical tests were two-sided.

RESULTS

Intakes of dairy products, calcium, or vitamin D were not statistically significantly associated with breast cancer risk in postmenopausal women. In premenopausal women, however, consumption of dairy products, especially of low-fat dairy foods and skim/low-fat milk, was inversely associated with risk of breast cancer. The multivariable RRs comparing highest (>1 serving/day) and lowest (<or=3 servings/month) intake categories were 0.68 (95% CI = 0.55 to 0.86) for low-fat dairy foods and 0.72 (95% CI = 0.56 to 0.91) for skim/low-fat milk. Dairy calcium (>800 mg/day versus <or=200 mg/day; RR = 0.69, 95% CI = 0.48 to 0.98), total vitamin D (>500 IU/day versus <or=150 IU/day; RR = 0.72, 95% CI = 0.55 to 0.94), and lactose (quintile 5 versus quintile 1; RR = 0.68, 95% CI = 0.54 to 0.86] also had inverse associations with premenopausal breast cancer risk. By taking into account supplemental calcium and vitamin D intake, we found that association with calcium was due mainly to dairy sources whereas the association with vitamin D may be independent of dairy intake.

CONCLUSIONS

We found no association between intake of dairy products and breast cancer in postmenopausal women. Among premenopausal women, high intake of low-fat dairy foods, especially skim/low-fat milk, was associated with reduced risk of breast cancer. Similar inverse associations were seen with components (calcium and vitamin D) of dairy foods, but their independent associations with breast cancer are difficult to distinguish.

Proportion of Death Certificate Only Cases and Its Related Factors, Kwangju Cancer Registry (KCR)

PURPOSE

To ascertain the factors associated with the proportion of death certificate only (DCO) cases contained in the Kwangju Cancer Registry (KCR) that are not as yet in the good range.

MATERIALS AND METHODS

The distribution of DCO cases was analyzed by sex, age, cancer site, histological verification (HV) as well as the physician's death certificate status.

RESULTS

All cases (n=4,243) in Kwangju diagnosed as having cancer between 1997 and 1998 were registered with the KCR. Death certificates (n=2,390) reporting cancer as the causes of death were collected from the National Statistics Office and reviewed with hospital data linkage and a total of 590 cases were registered as DCO. DCOs accounted for 12.2% (male 12.8%, female 11.5%) of all registrations in Kwangju, 1997~1998. The proportion of DCO cases was high in subjects under 15 (male13.5%,female 9.4%) as well as those 75 and over (male 20.3%, female 27.2%). For cancer sites, the proportion of DCO cases was high (over 10%) for liver, bronchus-lung, esophagus and pancreas and low (under 3%) for skin, bladder, uteri cervix and breast. The proportion of DCO cases was inversely associated with HV%. When the death certificate was issued by physician, the possibility of DCO decreased.

CONCLUSION

The proportion of DCO is positively associated with increasing age and negatively associated with HV% and the issuance of a physician's death certificate. These findings suggest that further socio-cultural efforts are required to reduce the DCO proportion.

Single dose radiation is more effective for the UV-induced activation and proliferation of melanocytes than fractionated dose radiation

PURPOSE

To establish whether the effect of fractionating radiation modifies the effects of ultraviolet (UV) radiation on epidermal melanocytes, we compared the clinical and histological effects of single high dose radiation against repeated intermediate to low dose radiation on epidermal melanocytes.

METHODS

Three minimal erythema UV doses (MED) were administered to three sites on the buttocks of healthy volunteers. One site was irradiated with 0.5 MED UV every day for 6 consecutive days, another site was irradiated with 1 MED UV every second day, and a third site received a single dose of radiation with 3 MED UV. The treatment was replicated on the other buttock. For the evaluation of UV-induced erythema and pigmentation, erythema and melanin indices were measured at 2 and 14 days post-irradiation. For purposes of histological evaluation, tissue specimens taken from each irradiated site at 2 and 14 days post-irradiation and were stained with monoclonal antibodies against Mel-5, HMB-45 and tyrosinase. Fontana-Masson silver staining, DOPA staining and split DOPA reactions were also performed.

RESULTS

At 14 days post-irradiation, UV radiation induced melanocyte activation, proliferation and melanogenesis in proportion to the radiation dose administered to each fraction. The most prominent responses were observed after single high doses of radiation.

CONCLUSION

When the total administered dose is identical, fractionation of radiation dose diminishes the effects of UV radiation on epidermal melanocytes. Furthermore, long, uninterrupted doses of UV radiation were found to more effective in inducing melanogenesis and melanocyte activation.

Aging- and photoaging-dependent changes of enzymic and nonenzymic antioxidants in the epidermis and dermis of human skin in vivo

This is a comprehensive study of the changes in major antioxidant enzymes and antioxidant molecules during intrinsic aging and photoaging processes in the epidermis and dermis of human skin in vivo. We show that the activities of superoxide dismutase and glutathione peroxidase are not changed during these processes in human skin in vivo. Interestingly, the activity of catalase was significantly increased in the epidermis of photoaged (163%) and naturally aged (118%) skin (n = 9), but it was significantly lower in the dermis of photoaged (67% of the young skin level) and naturally aged (55%) skin compared with young (n = 7) skin. The activity of glutathione reductase was significantly higher (121%) in naturally aged epidermis. The concentration of alpha-tocopherol was significantly lower in the epidermis of photoaged (56% of young skin level) and aged (61%) skin, but this was not found to be the case in the dermis. Ascorbic acid levels were lower in both epidermis (69% and 61%) and dermis (63% and 70%) of photoaged and naturally aged skin, respectively. Gluta thione concentrations were also lower. Uric acid did not show any significant changes. Our results suggest that the components of the antioxidant defense system in human skin are probably regulated in a complex manner during the intrinsic aging and photoaging processes.

A triterpene glucosyl ester from the roots of Rubus crataegifolius

Along with five known triterpene glycosides, a new triterpene glucosyl ester, named crataegioside, was isolated from the roots of Rubus crataegifolius Bunge. The structure was established as ilexosapogenin A 28-O-beta-D-glucopyranosyl ester by chemical and spectroscopic methods.

Apoptosis and megakaryocytic differentiation during ex vivo expansion of human cord blood CD34+ cells using thrombopoietin

Thrombopoietin (TPO), the primary regulator of megakaryocytopoiesis, plays important roles in early haematopoiesis. Previously, we have demonstrated that TPO induces a characteristic pattern of apoptosis during ex vivo expansion of cord blood (CB) CD34+ cells. In this study, we have demonstrated that the TPO-induced apoptotic cells belong to the megakaryocytic (MK) lineage and that initially expanding MK progenitors declined along with the appearance of TPO-induced apoptosis. Human CB CD34+ cells were expanded in serum-free conditions with TPO. Multidimensional flow cytometry using simultaneous measurement of apoptosis and immunophenotyping showed that the TPO-induced apoptotic cells appeared in CD61+ fractions. Immunocytochemical analysis of the fluorescent activated cell-sorted fractions showed that the apoptosis-associated CD44low fraction expressed CD61. Clonogenic assay revealed 7.4 +/- 0.50-fold increase of total megakaryocyte colony-forming units (CFU-MKs) during the initial 9 d. Thereafter, the number of CFU-MKs decreased in parallel with the increase of apoptosis. When the MK colonies were subdivided according to size, the proportion of large colonies progressively decreased, while that of medium and small colonies increased. In particular, from d 6 small colonies became predominant. These results suggested that the MK progenitors matured as they expanded during ex vivo expansion with TPO and then proceeded to apoptosis.

Prevalences of symptoms of asthma and other allergic diseases in korean children: a nationwide questionnaire survey

The purpose of this study was to estimate the national prevalence of childhood asthma and other allergic diseases in Korea, and to determine potential risk factors for the diseases. Stratified random samples of 42,886 were selected from 34 elementary (6-12 yr olds) and 34 middle schools (12-15 yr olds) nationwide, and 38,955 were in the final analysis. The Korean-translated modified version of the International Study of Asthma and Allergies in Childhood questionnaire was used in this cross-sectional survey. Twelve-month prevalences of the symptoms of asthma, rhinoconjunctivitis, and flexural eczema were 8.7%, 10.5%, 7.3% in 6-12 yr olds, and 8.2%, 10.0%, 3.9% in 12-15 yr olds, respectively. For allergic conjunctivitis, food allergy, and drug allergy, the prevalences in 6-12 yr olds were 11.2%, 6.5%, and 1.5%, respectively. Asthma and flexural eczema decreased significantly with age. Other significant risk factors were also noted. For 6-12 yr-old asthma, adjusted odds ratio (aOR) of body mass index was 1.21 with 95% confidence interval (CI) 1.0-1.48, aOR of passive smoking was 1.37 with 95%CI 1.24-1.51, aOR of carpet use was 1.28 with 95%CI 1.10-1.49. For 6-12 yr-old eczema, aOR of affluence was 1.22 with 95%CI 1.07-1.39. The control of obesity and passive smoking would be the most important preventive measures of allergic diseases.

Cysteine protease secreted by Paragonimus westermani attenuates effector functions of human eosinophils stimulated with immunoglobulin G

An immunoglobulin G (IgG)-coated surface, such as that found on helminth parasites, is one of the most effective physiologic stimuli for eosinophil activation. The cysteine proteases secreted by tissue-invasive helminth larvae play an important role in evasion of the immune response by degrading the host immunoglobulins. In this study, we investigated whether cysteine proteases in the excretory-secretory product (ESP) produced by Paragonimus westermani newly excysted metacercariae (PwNEM), which cause pulmonary or extrapulmonary paragonimiasis in human beings, could modify effector functions of human eosinophils stimulated with IgG. We coated 96-well plates with human IgG in the absence or presence of the ESP produced by PwNEM. When eosinophils were incubated in the wells coated with IgG in the presence of the ESP, eosinophil degranulation and superoxide production were significantly reduced compared with results for cells incubated in wells coated with IgG alone. This inhibitory effect of the ESP on IgG-induced superoxide production was dose dependent and was significantly abolished by pretreatment of the ESP with heat. These findings suggest that the cysteine proteases secreted by PwNEM attenuate both activation and degranulation of eosinophils stimulated with IgG. Thus, the cysteine proteases produced by tissue-invasive helminth larvae play crucial roles in evasion of IgG-dependent eosinophil helminthotoxicity and in reduction of eosinophil-associated tissue inflammation during the migratory period.

Incidence pattern of colorectal cancer in Korea by subsite of origin

It has been suggested that colorectal cancer might not be one homogenous disease entity, based on the distinctive characteristics of its subsite of origin. Incidence data on 4,987 colorectal cancer were obtained from the Seoul Cancer Registry between 1993 and 1995. Age, sex, and subsite-specific incidence rates were compared. The age-standardized annual incidence rates of total colorectal cancer were 26.1 and 18.0 per 100,000 for men and women, respectively. There were no appreciable difference in the rates of colon and rectal cancer for either sex (colon vs rectum: 12.8 vs. 13.2 for men, 9.3 vs. 8.6 for women). The incidence rate of right colon was slightly higher in men than in women, and this discrepancy became even greater in left colon (men vs women: 3.5 vs. 3.0 for right colon, 4.7 vs. 2.9 for left colon). When the incidence rate of right colon was compared with that of left colon, women had a higher rate in the right colon among the elderly, aged 60 yr and over and a lower rate at age 40 yr or less, while the opposite was observed for men. More analytic approaches are needed to identify which factors are related with these descriptive results in colorectal cancer incidence.

Proteolytic activity of cysteine protease in excretory-secretory product of Paragonimus westermani newly excysted metacercariae pivotally regulates IL-8 production of human eosinophils

This study investigated the effect of the excretory-secretory product (ESP) of Paragonimus westermani newly excysted metacercariae (PwNEM) on IL-8 production of human mature eosinophils. Treatment of eosinophils with lower concentrations (0.3 and 1 microg/ml) of the ESP significantly (P < 0.01) induced IL-8 production, whereas treatment of cells with higher concentrations (3 and 10 microg/ml) did not. This effect of the ESP was concentration-dependent. Interestingly, the amount of IL-8 production released into the culture supernatants was inversely correlated with the rate of eosinophil survival. When eosinophils were cultured with the same concentrations of the ESP for 24 h, the ESP resulted in eosinophil death in a dose-dependent manner. To investigate whether high proteolytic activity of proteases in the ESP could cause little production of IL-8, 10 microg/ml of ESP was pretreated with heat at 100 degrees C for 10 min or 56 degrees C for 30 min to reduce its proteolytic activity. IL-8 production of eosinophils incubated with heat-treated ESP was markedly increased comparable to that of cells treated with the lowest concentration used in this study. These findings suggest that the protease in the ESP of PwNEM pivotally regulates IL-8 production by controlling of eosinophil survival, depending on the amount of ESP released in vivo. Thus, the cysteine protease in the ESP of PwNEM could provide a novel role to control recruitment of inflammatory cells in larval-infected lesions in human paragonimiasis.

Prevalence and risk factors of silent cerebral infarction in apparently normal adults

Cerebrovascular disease is a major cause of death and disability in adults. Silent cerebral infarction (SCI) portends more severe cerebral infarctions or may lead to insidious progressive brain damage resulting in vascular dementia. This study was designed to evaluate the prevalence and risk factors of SCI in an apparently normal adult population. Nine hundred ninety-four consecutive symptom-free adults (mean age 49.0+/-7.7; men:women 830:164) who underwent brain magnetic resonance imaging at the Center for Health Promotion at Samsung Medical Center were assessed. All were neurologically normal in history and physical examination. A total of 121 SCI lesions was observed in 58 subjects. The lesion prevalence adjusted for patient age was 5.1%. There was no gender difference in prevalence. Ninety-nine lesions were <1 cm in diameter, 15 were between 1 and 2 cm, 3 were between 2 and 3 cm, and 4 were >3 cm in diameter. The most frequent site of the SCI lesion was basal ganglia, after which the periventricular white matter, cerebral cortex, and thalamus were the most frequent sites. Old age, hypertension, a history of coronary artery disease, evidence of cardiomegaly in chest radiographs, and high fasting glucose/hemoglobin A1c levels were associated with SCI on univariate analysis. Multivariate analysis demonstrated old age and hypertension to be independent risk factors for SCI, and mild alcohol consumption was revealed as an independent protective factor against SCI.

Excretory-secretory product of Paragonimus westermani newly excysted metacercariae inhibits superoxide production of granulocytes stimulated with IgG

It is well known that the cysteine proteases in excretory-secretory product (ESP) of Paragonimus westermani newly excysted metacercariae (PwNEM) are capable of degrading IgG in vitro. Recent evidence suggests that the IgG-coated surface, such as found on parasites, is one of the most effective physiologic stimuli for granulocyte activation. Therefore, this study was designed to investigate the effect of excretory-secretory product (ESP) of PwNEM on superoxide production of granulocytes stimulated with IgG. The 96-well plates were coated with human IgG (0, 10, 30, 100 micrograms/ml) in the absence or presence of ESP. When granulocytes were incubated in the wells coated with human IgG in the presence of ESP, the level of superoxide production of granulocytes was reduced to about 90% when compared to the cells incubated in the wells coated with IgG alone. This inhibitory effect of the ESP on IgG-induced superoxide production of granulocytes was concentration-dependent. These results suggest that ESP secreted by PwNEM may be important in the control of effector functions of granulocytes stimulated with IgG in human paragonimiasis.

Excretory-secretory product of newly excysted metacercariae of Paragonimus westermani directly induces eosinophil apoptosis

Eosinophils are important effector cells in host defense against parasites. Excretory-secretory product (ESP) produced by helminthic worms plays important roles in the uptake of nutrients, migration in the host tissue, and in immune modulation. However, little is known about the ability of the ESP to directly trigger eosinophil apoptosis. This study investigated whether the ESP of newly excysted metacercariae of Paragonimus westermani could induce apoptosis in human eosinophils. Apoptosis was assayed by staining the cells with FITC-annexin V, and the cells were analyzed by flow cytometry. It was found that the ESP of newly excysted metacercariae of P. westermani induced a direct time- and concentration-dependent increase in the rate of constitutive apoptosis in mature human eosinophils. Eosinophil apoptosis was first apparent 3 hr after treatment with the ESP and continued to increase after 6 hr of incubation with respect to the cells cultured in the absence of the ESP. While only 2.8% of the eosinophils incubated in the medium for 3 hr were apoptotic, 7.6%, 10.9% and 22.6% of the eosinophils treated with 10, 30 and 100 micrograms/ml ESP were apoptotic, respectively. This result suggests that the ESP of newly excysted metacercariae of P. westermani directly induce eosinophil apoptosis, which may be important for the survival of the parasites and the reduction of eosinophilic inflammation in vivo.

Age-dependent infectivity of orally transferred juvenile Fasciola hepatica

Juvenile Fasciola hepatica is infective when administered orally. To determine whether the age of juveniles is a factor in infectivity by oral transfer, experimental mice were challenged orally with immature F. hepatica that had been grown in donor mice for 12, 14, 16, and 18 days. Experimental mice were examined for infections 12 16 days after the oral transfers. The infection success in experimental mice decreased with the age of juveniles. The worm recovery also decreased according to the age of juveniles. None of the juveniles was infective when grown for longer than 11 days. Once infected, orally transferred worms continued to grow. Juvenile age was a significant factor in determining the infectivity of orally transferred juvenile F. hepatica.

Evaluation of the completeness of cancer case ascertainment in the Seoul male cohort study: application of the capture-recapture method

Since the completeness of case ascertainment is directly related to the validity of a study, the evaluation of completeness is an essential feature of a cohort study. To estimate the completeness of cancer case ascertainment during a three year period (Jan. 1, 1993, to Dec. 31, 1995) in which the Seoul Male Cohort was followed up, we applied capture-recapture method. Data were obtained from the cancer registries, medical records and death certificates, with cases identified from each source numbering 103, 105, and 38, respectively. After eliminating duplicate cases, the total number was 141, and by using a log-linear model, the number of cases not detected by any of the three data sources was estimated to be 16. For all cancers, the estimated completeness of follow-up was 89.9%.

Serum concentration of the soluble interleukin-2 receptor in vitiligo patients

Serum levels of sIL-2R can be used to monitor in vivo immune activation and its elevation have been shown to be correlated with T cell mediated immune disease such as atopic dermatitis, psoriasis, lymphoma and systemic sclerosis. Vitiligo is the disease of depigmentation caused by destruction of melanocytes, and there have been extensive studies on the immune pathogenesis. If the pathogenesis of vitiligo is correlated with the activation of T lymphocytes, the change of IL-2R will be detected compared with that of normal control. Therefore we sought the change in sIL-2R to determine whether T lymphocytes from patients with vitiligo show abnormal biological behavior. The quantitation of sIL-2R was done by sandwich enzyme-linked immunosorbent assay (ELISA) from the sera of 79 vitiligo patients and 40 normal controls. The results were summarized as following. The sIL-2R level in vitiligo patients (671.91 +/- 368.59 U/ml) was significantly increased compared with that of controls (370.8 +/- 71.8 U/ml; P < 0.005). According to clinical types, sIL-2R level in focal type of vitiligo patients was significantly higher than those in other types (segmental or generalized; P < 0.05). The sIL-2R level in patients less than 1 year duration was significantly higher than in patients more than 1 year duration (P < 0.05). The sIL-2R levels were not significantly different between active and inactive group. There was no significant differences among sIL-2R levels according to sex or age of onset. Our study showed that sIL-2R level was higher in vitiligo patients compared with that of normal controls, so the activation of T lymphocytes would be an important component in the pathogenesis of vitiligo. The higher sIL-2R levels in recent onset group would suggest that sIL-2R level might be an acute immunologic marker in vitiligo patients.

Infection status of Paragonimus westermani metacercariae in crayfish (Cambaroides similis) collected from Bogildo (Islet), Wando-gun, Chollanam-do, Korea

During the period from October 1996 to November 1998, the infection status of Paragonimus westermani metacercariae in freshwater crayfish (Cambaroides similis) collected from Bogildo (islet). Wando-gun, Chollanam-do, which is known for an endemic area of P. westermani in Korea, were examined. The average infection rate of Paragonimus metacercariae in crayfish was 88.6%, and mean number of metacercariae per infected crayfish was 30.2. This metacercarial density was the highest in the group of weight in 7.1-9.0 g. These results suggest that the natural life cycle of P. westermani is still well-preserved in Bogildo.

Genetic variance of Trichomonas vaginalis isolates by Southern hybridization

In the present study, genomic DNAs were purified from Korean isolates (KT8, KT6, KT-Kim and KT-Lee) and foreign strains (CDC85, IR78 and NYH 286) of Trichomonas vaginalis, and hybridized with a probe based on the repetitive sequence cloned from T. vaginalis to observe the genetic differences. By Southern hybridization, all isolates of T. vaginalis except the NYH286 strain had 11 bands. Therefore all isolates examined were distinguishable into 3 groups according to their banding patterns; i) KT8, KT6 and KT-Kim isolates had 11 identical bands such as 1 kb, 1.2 kb, 1.6 kb, 1.9 kb, 2.3 kb, 2.7 kb, 3.2 kb, 3.4 kb, 3.8 kb, 4.9 kb and 6.0 kb. ii) The metronidazole-resistant IR78 strain had the same bands as KT-Lee isolate at bands of 1 kb, 1.2 kb, 1.6 kb, 1.8 kb, 2.1 kb, 2.5 kb, 2.7 kb, 2.9 kb, 3.4 kb, 5.0 kb and 6.0 kb. Bands of CDC85, metronidazole-resistant strain, were similar to those of IR78 and KT-Lee, except that 3.2 kb replaced 2.9 kb. iii) NYH286 particularly had 12 bands and band patterns were similar to IR78 with a few exceptions as follows: i) 6.2 kb in place of 6.0 kb, ii) 2.0 kb and 2.2 kb instead of 2.1 kb. Through the results obtained, genetic variance of T. vaginalis isolates was demonstrated by Southern hybridization.