Prospective association between phthalate exposure in childhood and liver function in adolescence: the Ewha Birth and Growth Cohort Study.

BACKGROUND: Phthalate exposure is ubiquitous due to the widespread use of plastic products in daily life, and affects several health outcomes, including metabolic diseases. In this study, we evaluated the effects of phthalate exposure in childhood on liver function in adolescence.  METHODS: Among 164 Ewha Birth and Growth Cohort Study participants followed up during two exposure periods (when the children were aged 3-5 and 7-9 years), 126 were followed up at age 10-15 years. To investigate the relationship between phthalate exposure during the two periods and liver enzyme levels (ALT, AST, γ-GTP) in adolescence, differences between groups and the dose-response relationship were analyzed. In addition, we investigated differences in liver enzymes between groups based on the combined exposure levels (high or low) during the two periods. The interaction effect between phthalates and BMI on liver enzyme levels was evaluated, stratified by sex.  RESULTS: In the 3-5 year-old exposure period, ALT levels tended to increase as MECPP levels increased, while γ-GTP levels tended to increase as MiBP, MnBP, and ∑DBP levels increased. In addition, the group exposed to consistently high levels of phthalates at both time points had higher liver enzyme levels compared to the group that had lower exposure. In particular, the interaction effect between some phthalate metabolites and BMI in 3-5 year olds affected AST and γ-GTP levels in adolescence only in girls. CONCLUSIONS: Exposure to phthalates in daily life during childhood affects liver enzyme levels in adolescence. Elevated liver enzyme levels are associated with the development of metabolic syndrome, implying that attention should be paid to phthalate exposure during childhood.

Skin-color perception of morphed face images.

The purpose of this study was to verify the interconnection between the perception of face shape and skin color. The hypothesis of this study was that, if there is a relationship between face shape and skin-color perception, a change would be expected in skin-color perception based on the degree of similarity to a face. We conducted three experiments, designed to determine the ability to retrieve from memory the color of human-like faces with several degrees of morphing. The experiments were (i) test of memory for colors of scrambled faces, (ii) test of morphing limits, and (iii) test of further degrees of morphing and more chromatic variations, based on the information gathered from the first two experiments. The first experiment indicated that a lower degree of morphing would impact the final result. The second experiment was important to determine the appropriate degree of morphing, whereas the third experiment widened the range of chromatic staring points, thereby broadening the limits of the experiment. The color-matching results differed according to the completeness of the facial shape. We found that the presence of eyes on morphed images of faces induces the perception of faces. Moreover, it appeared that the starting chromatic point, if too distant from the original stimulus, increased the difficulty of the memory task. This study has shown the possibility of a relationship between skin color and face perception.

Association between pre-and postnatal growth and longitudinal trends in serum uric acid levels and blood pressure in children aged 3 to 7 years.

BACKGROUND: Uric acid has been identified as an important factor in the development of hypertension. If low birth weight (LBW) combined with catch-up growth (CUG) is associated with continuously elevated serum uric acid levels (SUA) level trajectories, LBW children who experience CUG may have an increased risk of hypertension later in life. Therefore, this cohort study analyzed longitudinal trends in SUA levels and changes in blood pressure in relation to pre- and postnatal growth over an extended follow-up period. METHODS: This prospective cohort study of 364 children from the Ewha Birth and Growth Cohort assessed the effects of pre- and postnatal growth status on SUA at 3, 5, and 7 years of age using a linear mixed model and the change in blood pressure over the 7-year follow-up period using a generalized linear model (analysis of covariance). CUG was defined as a change in weight (between birth and age 3) with a z-score > 0.67 for LBW subjects. The multivariate model considered sex, gestational age, and uric acid, height, and weight at 3 years of age. RESULTS: Children with LBW and CUG had higher SUA for the first 7 years of life compared to the normal birth weight group. This trend was particularly evident when comparing LBW children at term to children with normal birth weight. Within the group with LBW at term, children with greater CUG had higher SUA than children with normal birth weight, and this difference increased with age. Changes in the systolic blood pressure between 3 and 7 years of age were higher by 7.9 mmHg in children who experienced LBW and CUG compared with those who had a normal birth weight after adjusting for sex, gestational age, and height, weight, and uric acid at 3 years of age (p-value = 0.08). CONCLUSIONS: The uric acid levels and changes in systolic blood pressure were consistently higher among LBW children who experienced CUG compared with NBW children for the first 7 years of life. LBW children who experienced greater weight gain from birth to age 3 had even higher uric acid levels compared with NBW children.

Disease-Specific Mortality and Prevalence Trends in Korea, 2002-2015.

BACKGROUND: Evaluation of mortality and prevalence trends is important for health planning and priority decision-making in health policy. This study was performed to examine disease-specific mortality and prevalence trends for diseases in Korea from 2002 to 2015. METHODS: In this study, 206 mutually exclusive diseases and injuries were classified into 21 cause clusters, which were divided into three cause groups: 1) communicable, maternal, neonatal, and nutritional conditions; 2) non-communicable diseases (NCDs); and 3) injuries. Cause specific trends for age-standardized mortality and prevalence rates were analyzed by the joinpoint regression method. RESULTS: Between 2002 and 2015, the age-standardized mortality declined to about 177 per 100,000 population, while the age-standardized prevalence rate increased to approximately 68,065 per 100,000 population. Among the 21 cause clusters, most of the disease mortality rates showed decreasing trends. However, neurological disorders, self-harm, and interpersonal violence included periods during which the mortality rates increased in 2002-2015. In addition, the trends for prevalence rates of human immunodeficiency virus infection and acquired immune deficiency syndrome, tuberculosis, transport injuries, and self-harm, and interpersonal violence differed from the overall prevalence rates. The annual percent change in prevalence rates for transport injuries increased during 2004-2007, and then decreased. The self-harm and interpersonal violence prevalence rates decreased from 2004 to 2014. CONCLUSION: Between 2002 and 2015, overall decreasing trends in the mortality rate and increasing trends in the prevalence rate were observed for all causes in Korea. Especially, NCDs represented an important part of the increasing trends in Korea. For clusters of diseases with unusual trends, proper management must be considered.

Evaluating the impact of suramin additive on CHO cells producing Fc-fusion protein.

OBJECTIVE: To examine the effects of suramin in CHO cell cultures in terms of the cell culture performance and quality of the Fc-fusion protein. RESULTS: Suramin had positive effects on the CHO cell cultures. The addition of suramin caused an increase in the viable cell density, cell viability, and titer of the Fc-fusion protein. Moreover, suramin had no impact on protein aggregation and enhanced the sialic acid contents of Fc-fusion protein by 1.18-fold. The enhanced sialylation was not caused by the increased nucleotide sugar level but by the inhibition of sialidase activity. The results showed that suramin inhibited apoptosis and had positive impacts on the productivity and quality of Fc-fusion protein. CONCLUSION: The addition of suramin increased the production of Fc-fusion protein and enhanced sialylation when added as a supplement to the media component in CHO cell cultures. This study suggested that suramin could be a beneficial additive during the biological production in terms of the productivity and quality of Fc-fusion protein.

Projection of the Years of Life Lost, Years Lived with Disability, and ​Disability-Adjusted Life Years in Korea for 2030.

BACKGROUND: Projection of future trends in disease burden can facilitate setting of priorities for health policies and resource allocation. We report here projections of disease-specific mortality and the burdens of various diseases in Korea from 2016 to 2030. METHODS: Separate age- and sex-specific projection models for 21 major cause clusters from 2016 to 2030 were developed by applying coherent functional data models based on historical trends from 2002 to 2015. The age- and sex-specific years of life lost (YLL) for each cause cluster were projected based on the projected number of deaths. Years lived with disability (YLD) projections were derived using the 2015 age- and sex-specific YLD to YLL ratio. The disability-adjusted life years (DALYs) was the sum of YLL and YLD. RESULTS: The total number of deaths is projected to increase from 275,777 in 2015 to 421,700 in 2030, while the age-standardized death rate is projected to decrease from 586.9 in 2015 to 447.3 in 2030. The largest number of deaths is projected to be a result of neoplasms (75,758 deaths for males; 44,660 deaths for females), followed by cardiovascular and circulatory diseases (34,795 deaths for males; 48,553 deaths for females). The three leading causes of DALYs for both sexes are projected to be chronic respiratory diseases, musculoskeletal disorders, and other non-communicable diseases (NCDs). CONCLUSION: We demonstrate that NCDs will continue to account for the majority of the disease burden in Korea in the future.

Multimorbidity and health-related quality of life in Koreans aged 50 or older using KNHANES 2013-2014.

BACKGROUND: Multimorbidity negatively affects health outcomes and impairs health-related quality of life (HRQoL). We assessed the prevalence of multimorbidity in Koreans aged 50 and older, taking into consideration their socioeconomic status, and estimated the loss in HRQoL due to multimorbidity. METHODS: This study is based on an analysis of data for adults aged 50 and older derived from the cross-sectional nationally representative Korean National Health and Nutrition Examination Survey conducted in 2013-14. The five most prevalent chronic diseases and disease dyads were identified. The impact of the degree of multimorbidity, sex, and socioeconomic status on the European Quality of Life 5 Dimension (EQ-5D) index score were analyzed. Marital status, educational attainment, household income, basic livelihood security benefit, and occupation were considered as socioeconomic factors. RESULTS: The analysis included 5996 adults aged 50 years and older with males comprising 46.6%. Two or more chronic diseases were present in 26.8% of the participants aged 50 and older and 37.9% of the participants aged 65 and older. The most prevalent dyadic combination was hypertension and dyslipidemia in the 50 and older group, and hypertension and osteoarthritis in the 65 and older age group. Hypertension dominated the multimorbidity combinations (four of the five most prevalent multimorbidity dyads), while a few conditions such as osteoarthritis had a relatively large influence on quality of life. In addition to the degree of multimorbidity, female and lower socioeconomic status were associated with significantly lower EQ-5D index scores. CONCLUSIONS: Integrated, holistic healthcare based on a patient-oriented perspective for earlier, more effective intervention, targeting multimorbidity is warranted. Special consideration should be given to patients with low socioeconomic status.

A prospective cohort study of the association between bisphenol A exposure and the serum levels of liver enzymes in children.

BACKGROUND: Bisphenol A (BPA) is an endocrine disrupter that acts in an estrogen-like manner. Few studies have investigated the association between urinary BPA concentrations and adverse liver function. Additionally, most studies were cross-sectional in nature and included only adults. OBJECTIVES: We evaluated BPA exposure levels and prospectively explored the association between BPA exposure and liver function in children. METHODS: Data were retrieved from the ongoing prospective Ewha Birth and Growth Cohort Study. Urinary BPA concentrations were measured in 164 children at 3-5 and 7-9 years of age. At each visit, fasting blood and urine samples were collected, and questionnaires were completed. The associations between the BPA concentrations at these ages and the serum levels of liver enzymes measured at 10-13 years of age were analyzed (n = 113). Multiple regression analysis was performed with adjustment for covariates. We also explored whether the BPA level exhibited dose-response relationships with liver enzyme levels. RESULTS: The median urinary BPA concentrations were 0.76µg/g creatinine at 3-5 years and 0.61µg/g creatinine at 7-9 years of age. The urinary BPA concentrations at the two ages were correlated significantly (r = 0.23, p < 0.01). The urinary BPA concentrations at 7-9 years, but not that at 3-5 years, was associated significantly with the serum levels of liver enzymes at 10-13 years of age (p < 0.05). Those in the top tertile of urinary BPA concentration had higher levels of liver enzymes than did others. After adjustment for covariates, dose-response relationships of the BPA level with liver enzyme levels were evident at 7-9 years, but not at 3-5 years. Notably, the effect size was larger and the dose-response relationships were more evident in boys than in girls. CONCLUSIONS: Exposure of children to even low doses of BPA may adversely affect later liver function.

The effect of contextual factors on unintentional injury hospitalization: from the Korea National Hospital Discharge Survey.

BACKGROUND: It has been suggested that health risks are affected by geographical area, but there are few studies on contextual effects using multilevel analysis, especially regarding unintentional injury. This study investigated trends in unintentional injury hospitalization rates over the past decade in Korea, and also examined community-level risk factors while controlling for individual-level factors. METHODS: Using data from the 2004 to 2013 Korea National Hospital Discharge Survey (KNHDS), trends in age-adjusted injury hospitalization rate were conducted using the Joinpoint Regression Program. Based on the 2013 KNHDS, we collected community-level factors by linking various data sources and selected dominant factors related to injury hospitalization through a stepwise method. Multilevel analysis was performed to assess the community-level factors while controlling for individual-level factors. RESULTS: In 2004, the age-adjusted unintentional injury hospitalization rate was 1570.1 per 100,000 population and increased to 1887.1 per 100,000 population in 2013. The average annual percent change in rate of hospitalizations due to unintentional injury was 2.31% (95% confidence interval: 1.8-2.9). It was somewhat higher for females than for males (3.25% vs. 1.64%, respectively). Both community- and individual-level factors were found to significantly influence unintentional injury hospitalization risk. As community-level risk factors, finance utilization capacity of the local government and neighborhood socioeconomic status, were independently associated with unintentional injury hospitalization after controlling for individual-level factors, and accounted for 19.9% of community-level variation in unintentional injury hospitalization. CONCLUSION: Regional differences must be considered when creating policies and interventions. Further studies are required to evaluate specific factors related to injury mechanism.

Sex differences in inflammation correlated with estrogen and estrogen receptor-ß levels in azoxymethane/dextran sodium sulfate-induced colitis-associated colorectal cancer mice.

Colorectal cancer (CRC) is a type of cancer that develops in the colon or rectum and is the second leading cause of cancer-related death worldwide. Several epidemiology studies have identified a significant sexual dimorphism in CRC, with women exhibiting a lower incidence rate and delayed onset compared to men. This study aims to investigate the sexual dimorphism in the inflammatory response in colitis-associated CRC and its relationship with estrogen and estrogen receptors. An azoxymethane (AOM)/dextran sodium sulfate (DSS) mouse model was used to induce colitis-associated CRC. Five-week-old male and female mice were randomly assigned into either the control group or the AOM/DSS CRC group, with 10 mice in each group. Colitis-associated CRC was induced by injecting AOM (10 mg/kg) and administering two-cycles of DSS treatment in the drinking water. The results revealed a significant decrease in colon length exclusively in the female group, indicating more severe colonic inflammation (P < 0.01). A significant interaction was identified between sex and AOM/DSS treatment in the female AOM/DSS group, with higher visceral fat weight compared to their male counterparts (P < 0.05). The female AOM/DSS group also exhibited elevated production of M1 macrophage-related pro-inflammatory cytokines, suggesting increased tumor-associated macrophage activity. Surprisingly, the male AOM/DSS group showed a marked increase in serum estradiol levels, while the female AOM/DSS group exhibited a decrease compared to the normal control group. Additionally, a notable upregulation of both estrogen receptor α and estrogen receptor ß expression was observed in the colon tissues of the AOM/DSS groups compared to the normal control groups, with estrogen receptor ß expression being particularly pronounced in females. Taken together, our findings suggest that a decline in endogenous estrogen and increased estrogen receptors potentially contribute to the pro-inflammatory response in early CRC by augmenting cytokine expressions associated with M1 macrophage polarization in females.

A combination of rebaudioside A and neohesperidin dihydrochalcone suppressed weight gain by regulating visceral fat and hepatic lipid metabolism in ob/ob mice.

Rebaudioside A (Reb A) and neohesperidin dihydrochalcone (NHDC) are known as intense sweeteners. This study aimed to examine the anti-obesity effects of Reb A and NHDC. C57BL/6 J-ob/ob mice were supplemented with Reb A (50 mg/kg body weight [b.w.]), NHDC (100 mg/kg b.w.), or their combination (COMB) for 4 weeks. COMB-supplemented mice showed significant reduction in b.w. gain, food efficiency ratio, and fat mass. Additionally, mice in the COMB group showed suppressed levels of genes related to adipogenesis, lipogenesis, and lipolysis in the perirenal fat and the levels of hepatic triglyceride, glutamic oxaloacetic transaminase, and glutamic pyruvic transaminase. The lipogenesis and pro-inflammatory gene expressions were also downregulated in the liver, whereas ß-oxidation related genes were upregulated in the COMB group. In addition, mice that received COMB showed distinct gut microbiota structure, enriched in Blautia and Parabacteroides, and depleted in Faecalibaculum and Mucispirillum, in relation to the control group. These results suggest that supplementation with Reb A and NHDC may be an effective treatment for obesity-related metabolic disorders. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-023-01391-1.

A splinkerette PCR-based genome walking technique for the identification of transgene integration sites in CHO cells.

Identification of recombinant gene integrations sites in the Chinese hamster ovary (CHO) cell genome is increasingly important to assure monoclonality. While next-generation sequencing (NGS) is commonly used for the gene integration site analysis, it is a time-consuming and costly technique as it analyzes the entire genome. Hence, simple, easy, and inexpensive methods to analyze transgene insertion sites are necessary. To selectively capture the integration site of transgene in the CHO genome, we applied splinkerette-PCR (spPCR). SpPCR is an adaptor ligation-based method using splinkerette adaptors that have a stable hairpin loop. Restriction enzymes with high frequencies in the CHO genome were chosen using a Python script and used for the in vitro spPCR assay development. After testing on two CHO housekeeping genes with known loci, the spPCR-based genome walking technique was successfully applied to recombinant CHO cells to identify the transgene integration site. Finally, the comparison with NGS methods exhibited that the time and cost required for the analysis can be substantially reduced. Taken together, the established technique would aid the stable cell line development process by providing a rapid and cost-effective method for transgene integration site analysis.

Newly developed care food enhances grip strength in older adults with dysphagia: a preliminary study.

BACKGROUND/OBJECTIVES: Maintaining total muscle mass in the older adults with swallowing difficulty (dysphagia) is important for preserving swallowing function. Increasing protein intake can help sustain lean body mass in the older adults. The aim of this study was to evaluate the effect of various high-protein texture-modified foods (HPTMFs) on muscle mass and perform dietary assessment in ≥ 65-yrs-old patients with dysphagia. SUBJECTS/METHODS: Participants (n = 10) received the newly developed HPTMFs (average 595.23 ± 66.75 kcal/day of energy, 54.22 ± 6.32 g/day of protein) for 10 days. Relative hand-grip strength (RHS), mid-upper arm circumference (MUAC), body composition, mini nutritional assessment (MNA), mini dietary assessment (MDA), and Euro Quality-of-Life questionnaire 5-dimensional classification (EQ-5D) were assessed. RESULTS: After 10 days, an increase in MUAC (26.36 ± 2.35 cm to 28.50 ± 3.17 cm, P = 0.013) and RHS (0.38 ± 0.24 kg/kg body weight to 0.42 ± 0.22 kg/kg body weight, P = 0.046) was observed. Although MNA, MDA, EQ-5D, subjective health status, muscle mass, and calf circumference showed a tendency to increase after intervention, no significant differences were found. CONCLUSIONS: These results suggest that the HPTMFs can be used for improving the nutritional and health status in patients with dysphagia.

Clinical features and genetic analysis of Korean patients with Loeys-Dietz syndrome.

Loeys-Dietz syndrome (LDS) is an inherited disorder that is characterized by the triad of arterial tortuosity and aneurysms, hypertelorism and a bifid uvula or cleft palate. The disease is caused by heterozygous mutations in the genes encoding transforming growth factor ß receptors 1 and 2 (TGFBR1 and TGFBR2, respectively). However, studies of patients with LDS are limited in Korea. From June 2000 to December 2010, 13 patients (10 probands) diagnosed with LDS were enrolled. The multidisciplinary data of the patients were reviewed retrospectively. The frequency of each clinical manifestation in Korean patients with LDS was compared with Western populations as described in the report by Loeys et al. Twelve (92%) of the 13 LDS patients had arterial tortuosity, 9 (69%) patients had hypertelorism and 11 (85%) patients had bifid uvula or cleft palate. Mutations in either TGFBR1 or TGFBR2 were detected in nine probands (90%). Of the mutations, five novel mutations were detected; three in TGFBR2 and two in TGFBR1. Blue sclera and atrial septal defect were not observed in the Korean patients, and the frequency of blue sclera was significantly lower in our Korean population than previously-described Western population (0 vs 40%; P=0.005). Despite the restricted number of patients in our study, we identified five novel mutations in the TGFBR1 and TGFBR2 genes and, except for blue sclera, no differences in phenotype are apparent between Korean patients and Western patients.

A comparison of the Ghent and revised Ghent nosologies for the diagnosis of Marfan syndrome in an adult Korean population.

Recently, a revised Ghent nosology has been established for the diagnosis of Marfan syndrome (MFS) that puts more weight on the aortic root aneurysm and ectopia lentis. We compared the application of the Ghent and revised Ghent nosologies in adult Korean patients for whom there is suspicion of MFS. From January 1995 to June 2010, we enrolled 106 patients older than 20 years for whom there was suspicion of MFS, and who had undergone genetic analysis of the fibrillin-1 gene (FBN1). Of 106 patients, 86 patients (81%) fulfilled the criteria of the Ghent nosology, and 84 patients (79%) met the criteria of the revised Ghent nosology. The two patients who met the Ghent nosology criteria, but not the criteria of the revised Ghent nosology were diagnosed with Loeys-Dietz syndrome and MASS phenotype. The level of agreement between both nosologies was very high (κ = 0.94, 95% confidence interval: 0.86 to 1.0). Marfan-like syndromes were diagnosed in 30% (6/20 patients) with negative Ghent and revised Ghent criteria and no FBN1 mutations. These results suggest that adult Korean patients who fulfill the old Ghent criteria almost all fulfill the new criteria for the diagnosis of MFS.

Congenital web of the common bile duct combined with multiple intrahepatic duct stricture: a case report of successful radiological intervention

Congenital web formations are extremely rare anomalies of the extrahepatic biliary tree. We herein report a case of common bile duct septum combined with multiple intrahepatic bile duct strictures in a 74-year-old female patient who was successfully treated with radiological intervention. The patient initially visited the hospital because of upper abdominal pain. Imaging studies revealed multifocal strictures with dilatation in both intra- and extrahepatic ducts; the final clinical diagnosis was congenital common bile duct web combined with multiple intrahepatic duct strictures. Surgical treatment was not indicated because multiple biliary strictures were untreatable, and the disease was clinically diagnosed as benign. The multiple strictures were extensively dilated twice through bilateral percutaneous transhepatic biliary drainage (PTBD) for 2 months. After 1 month of observation, PTBD catheters were successfully removed. The patient is doing well at 6 months after completion of the radiological intervention, with the maintenance of normal liver function. Congenital web of the bile duct is very rare, and its treatment may vary depending on the patterns of biliary stenosis. In cases where surgical intervention is not indicated for congenital web and its associated disease, radiological intervention with balloon dilatation can be a viable therapeutic option.

Pedunculated mucinous cystic neoplasm of the liver: a case report.

In 2010, the World Health Organization classified mucin-producing bile duct tumors of the liver into two distinct entities; mucinous cystic neoplasm of the liver (MCN-L) and intraductal papillary mucinous neoplasm of the bile duct. We present the case of a patient with MCN-L having a uniquely pedunculated shape. A 32-year-old woman was referred to our institution with a diagnosis of biliary cystic neoplasm. She had undergone left salpingo-oophorectomy for ovarian cancer 15 years ago. Imaging studies showed an 8 cm-sized well defined, multiloculated cystic lesion suggesting a mucinous cystic neoplasm. The cystic mass was pedunculated at the liver capsule and pathologically diagnosed as MCN-L. The mass was resected with partial hepatectomy. The patient recovered uneventfully. She was discharged 7 days postoperatively. The patient has been doing well for 6 months after the operation. The patient will be followed up annually because of the favorable postresection prognosis of MCN-L.

Establishment of a glycoengineered CHO cell line for enhancing antennary structure and sialylation of CTLA4-Ig.

Cytotoxic T-lymphocyte-associated protein 4-Ig (CTLA4-Ig) produced using Chinese hamster ovary (CHO) cell lines is a fusion protein of CTLA4 and the Fc region of antibody. In the present study, we identified and overexpressed genes capable of increasing sialic acid levels in CTLA4-Ig to develop cell lines using glycoengineering technology. CTLA4-Ig was produced using CHO cells overexpressing N-acetylglucosaminyltransferase (GnT) and α2,6-sialyltransferase (α2,6-ST). The conditions were wild type (WT), overexpression (GnT-IV, GnT-V, and α2,6-ST), and co-overexpression (GnT-IV and α2,6-ST, and GnT-V and α2,6-ST). GnT-IV and GnT-V were transfected into CHO cells to determine tri-antennary structure formation in CTLA4-Ig. CHOGnT-IV (cells overexpressing GnT-IV) showed the highest tri-antennary structures of glycans. Compared to CHOWT, neutral and mono-sialylated glycans decreased (-10.9% and -18.6%, respectively), while bi- and tri-sialylated N-glycans increased (4.1% and 85.7%, respectively) in CHOGnT-IV∙ST (cells co-overexpressing GnT-IV and α2,6-ST). The sum of the relative quantities of neutral N-glycans decreased from 32.0% to 28.5%, while that of sialylated N-glycans increased from 68.0% to 71.5% in CHOGnT-IV∙ST. These results are the first to demonstrate the co-overexpression of especially GnT-IV and α2,6-ST, which is an effective strategy to increase sialic acid levels and the tri-antennary structure of CTLA4-Ig produced using CHO cell lines.

DNA Double-Strand Breaks Affect Chromosomal Rearrangements during Methotrexate-Mediated Gene Amplification in Chinese Hamster Ovary Cells.

Methotrexate (MTX)-mediated gene amplification has been widely used in Chinese hamster ovary (CHO) cells for the biomanufacturing of therapeutic proteins. Although many studies have reported chromosomal instability and extensive chromosomal rearrangements in MTX-mediated gene-amplified cells, which may be associated with cell line instability issues, the mechanisms of chromosomal rearrangement formation remain poorly understood. We tested the impact of DNA double-strand breaks (DSBs) on chromosomal rearrangements using bleomycin, a DSB-inducing reagent. Bleomycin-treated CHO-DUK cells, which are one of the host cell lines deficient in dihydrofolate reductase (Dhfr) activity, exhibited a substantial number of cells containing radial formations or non-radial formations with chromosomal rearrangements, suggesting that DSBs may be associated with chromosomal rearrangements. To confirm the causes of DSBs during gene amplification, we tested the effects of MTX treatment and the removal of nucleotide base precursors on DSB formation in Dhfr-deficient (i.e., CHO-DUK) and Dhfr-expressing (i.e., CHO-K1) cells. Immunocytochemistry demonstrated that MTX treatment did not induce DSBs per se, but a nucleotide shortage caused by the MTX-mediated inhibition of Dhfr activity resulted in DSBs. Our data suggest that a nucleotide shortage caused by MTX-mediated Dhfr inhibition in production cell lines is the primary cause of a marked increase in DSBs, resulting in extensive chromosomal rearrangements after gene amplification processes.

Reduced peak atrial systolic mitral annular velocity predicts the development of nonvalvular atrial fibrillation.

We investigated whether the echocardiographic parameters of the left atrium (LA) can predict the development of nonvalvular atrial fibrillation (AF). Among 14,062 patients (>20 years old) who underwent an echocardiographic examination were evaluated, 2,606 patients who underwent follow-up ECG with an interval of >6 months were investigated. Newly developed AF was noted in 42 (1.6%) patients with follow-up duration of 31.8 +/- 8.9 months. Cox regression analysis revealed that a higher left atrial volume index (hazard ratio [HR]=1.06; 95% confidence interval [CI] 1.03-1.09, P < 0.001), relative wall thickness (RWT) of>or=0.407 (HR=2.74, 95% CI 1.39-5.41, P=0.004), a reduced peak atrial systolic mitral annular velocity (HR=0.845, 95% CI 0.72-0.99, P=0.037), and an advanced age (HR=1.04, 95% CI 1.01-1.07, P=0.009) were independently related to the development of nonvalvular AF. Therefore, reduced A', which is parameter of LA contractile function, might be an important predictor for the development of nonvalvular AF.