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Liu FW, Huang L, Yu JH. [Research update on the relationship between gastroesophageal reflux disease and atrial fibrillation and treatment efficacy by proton-pump inhibitors]. ZHONGHUA XIN XUE GUAN BING ZA ZHI 2017; 45:250-252. [PMID: 28316184 DOI: 10.3760/cma.j.issn.0253-3758.2017.03.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Kim JY, Cho J, Kim H, Kang D, Jung HA, Lee SH, Bae S, Yu JH, Lee SK, Kim SW, Lee JE, Nam SJ, Ahn JS, Im YH, Guallar E, Park YH. Abstract P6-09-50: Impact of young age on recurrence and mortality after surgery in breast cancer: 15 years active surveillance. Cancer Res 2017. [DOI: 10.1158/1538-7445.sabcs16-p6-09-50] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Introduction:Substantial efforts have been made to find factors associated with breast cancer (BC) recurrence and mortality after BC treatment. So far TNM stage, ER, PR, and HER2 status are considered as the major predictive markers of BC recurrence and used for treatment decision. However, most of these factors were evaluated independent from other important confounders such as age, stage, and various anti-cancer treatments because they were mostly derived from clinical trials. In Korea, up to 50% of BC patients are premenopausal women, it is not clear how age at diagnosis affect the progression and outcomes of the disease considering all known prognostic factors including TNM stage, ER, PR, and HER2 status. We aim to evaluate the impact of young age on recurrence and mortality after surgery among Korean women with BC.
Methods: This is a retrospective cohort study conducted using the data from BC registry from 2000 to 2016 at Samsung Medical Cancer, Seoul, Korea. Patients who received curative BC surgery and who had histologically-confirmed invasive BC between 2000 to 2011 were included in the study. Patients who second primary cancer or double primary cancer were excluded. Information local, regional, or distant recurrence and death until May 2016 was collected using electronic medical records and National Health Statistics. Cumulative incidence rates of distant recurrence and morality at 3-years, 5-years and 10-years were calculated using a competing-risk model. Cox proportional hazards analysis were conducted with 3 different models to take into account for potential confounding factors including age, body mass index (BMI), stage and subtype at breast cancer diagnosis, chemotherapy, radiotherapy and hormone therapy.
Results:There were 7360 BC patients with curative BC surgery between 2000 and 2011, and the average follow up duration was 75.4 months. The mean age at diagnosis was 48.4 years old (Standard deviation (SD)=±10), and 6.2% (n=459) was diagnosed younger than 35. Of total, 13.3% were stage III BC and 73.4% of patients had hormone receptor positive BC. The cumulative incidence (95%CI) of recurrence at 3, 5, and 10 years was 4.4% (3.9-4.9), 7.5% (6.8-8.2), and 14.8% (12.9-16.7) respectively. The incidence of mortality at 3, 5, and 10 years was 1.8% (1.5-2.1), 3.8% (3.3-4.3), and 10.2% (9.1-11.5) respectively. Patients who were diagnosed BC under 35 years of age had 2.14 (95% confidence interval (CI):1.74-3.10) and 1.62 (95% CI:1.02-2.56) times higher risk of distant recurrence and mortality compared to patients whose age at diagnosis were between 50 to 60 after adjusting all well-known prognostic factors including stage, subtype, and BMI at diagnosis, chemotherapy, radiotherapy and hormone therapy.
Conclusions: Young age at diagnosis (<35) was the most significant predictor on BC recurrence and mortality independently from BC stage and subtype. Further study is warranted to explain biologic background for the differences in outcomes in young women with BC.
Citation Format: Kim J-Y, Cho J, Kim H, Kang D, Jung HA, Lee S-H, Bae S, Yu JH, Lee SK, Kim SW, Lee JE, Nam SJ, Ahn JS, Im Y-H, Guallar E, Park YH. Impact of young age on recurrence and mortality after surgery in breast cancer: 15 years active surveillance [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-09-50.
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Kim JY, Park D, Jung HH, Bae SY, Yu JH, Lee SK, Kim SW, Lee JE, Nam SJ, Ahn JS, Im YH, Park YH. Abstract P1-02-11: Clinical utility of serial monitoring of circulating tumor DNA (ctDNA)in patients with neoadjuvant chemotherapy (NAC) for locally advanced breast cancer (LABC). Cancer Res 2017. [DOI: 10.1158/1538-7445.sabcs16-p1-02-11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Introduction: Circulating tumor DNA (ctDNA) is a new biomarker which could guide further treatment. Characterization of tumor mutation profiles is required for informed choice of therapy, given that biological agents target specific pathways and effectiveness may be modulated by specific mutations. It would have clinical utility for neoadjuvant setting also. Thus, we assess the potency of ctDNA to predict tumor response to neoadjuvant chemotherapy(NAC) in locally advanced breast cancer(LABC).
Methods: We performed targeted deep sequencing of 30 plasma DNAs and 10 matched germline DNAs from 10 LABC patients. Serial plasma DNAs were collected at diagnosis, after 1st NAC and curative surgery. For the target enrichment, we designed RNA baits covering a total of ~202kb regions of human genome including a total of 83 cancer-related genes. We constructed the sequencing libraries according to the optimized protocol that we recently reported and sequenced on Illumina HiSeq2500 aiming a mean sequencing depth of ~10,000. After excluding unmapped reads, PCR duplicates and off-target reads, the coverage depths for plasma DNA and germline DNA samples were 2,627x and 4,833x on average, respectively. NAC response was measured by residual cancer burden(RCB) score, calculated as a continuous index combining pathologic measurements of primary tumor and nodal metastases for prediction of distant relapse-free survival.
Results: We analyzed ctDNA and primary tumor tissues from 10 patients with LABC scheduled NAC followed by operation in Samsung Medical Center. Of ten LABCs, one excluded from analysis because of angiosarcoma of breast. Five samples were triple-negative breast cancers (BCs), 2 were HER2 positive BCs and others were ER positive BCs. In tumor response, 1 patient had pathologic complete response (pCR), 1 had RCB class I, 4 and 3 patients did RCB class II and III.
Of 83 genes, in analysis of ctDNA at BC diagnosis, we found 2 to 6 mutations in each samples and 3 mutations were detected averagely. Most common mutation was TP53 (6 patients), followed by PIK3CA mutation. By measuring these mutations in serial ctDNA, we found that ctDNA had disappeared after first cycle of NAC in patient with pCR. In two patients with RCB class I, ctDNA had decreased by more than 10 percent (the level of ctDNA(pg/ml): 455.9 to 30.4, 5.8 to 0.0) of primary plasma sample after first NAC. Two patients increased level of ctDNA had tumor response with RCB class III and one patient had distant tumor recurrence within 3 months after curative surgery. However, correlation between the level of ctDNA and initial stage was not observed.
Patient No.Initial stageSurgical stageRCB scoreRCB classct DNA at diagnosis (pg/5ml)ctDNA after 1st NAG (pg/5ml)Tumor recurrence12A11.3331455.930.4No22B00pCR446.60.0No33B2A1.31515.80.0No42A12.132246.255.4No52B11.7972107.811.6No63B3A4.09033401.15075.5Yes73A2B3.92235088.68536.7No
Conclusions: This preliminary result suggests that serial monitoring of ctDNA would be a potiential surrogate marker to predict tumor response and recurrence during NAC in LABC patients. Further results with long-term outcomes are warranted.
Citation Format: Kim J-Y, Park D, Jung HH, Bae SY, Yu JH, Lee SK, Kim SW, Lee JE, Nam SJ, Ahn JS, Im Y-H, Park YH. Clinical utility of serial monitoring of circulating tumor DNA (ctDNA)in patients with neoadjuvant chemotherapy (NAC) for locally advanced breast cancer (LABC) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-02-11.
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Bae SY, Nam SJ, Lee SK, Kim SW, Lee JE, Yu JH. Abstract P6-09-36: Tamoxifen resistance: EGFR expression in hormone receptor-positive and HER2 negative breast cancer. Cancer Res 2017. [DOI: 10.1158/1538-7445.sabcs16-p6-09-36] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Purpose: Crosstalk between growth factor receptor tyrosine kinases (RTKs) and the estrogen receptor (ER) represents one of the most important mechanisms of endocrine resistance. EGFR and HER2 have been recognized as prominent factors associated with endocrine resistance. Most previous studies did not identify subgroups by HER2 overexpression and/or included breast cancer with HER2 overexpression. Accordingly, we analyzed HR positive (HR+) tumors without HER2 overexpression (HER2-).
Methods: We analyzed the clinical data of 2,166 patients with HR+HER2- breast tumors, between January 2007 and July 2013.We included only patients who had endocrine therapy with tamoxifen. Immunostaining for EGFR was interpreted as positive when at least 10% of the tumor cells showed moderate to strong membrane staining.
Results: EGFR expression (EGFR+) was present in 109 patients (5%). EGFR expression was significantly associated with more advanced stage and higher grades. In the univariate analyses, EGFR+ tumors were associated with poorer prognosis than EGFR- tumors (5-year DFS, EGFR+ vs. EGFR-, 91.2% vs. 96.6%, P <0.001; 5-year OS, EFGR+ vs EGFR-, 93.1 % vs. 99.4%, P < 0.001). In the multivariate analysis, EGFR+ tumors had a hazard ratio of 2.63 (95% CI 1.14 -6.05) for DFS. EGFR+ tumors had a hazard ratio of 8.8 (95% CI 2.68-132.25) for OS.
Conclusion: EGFR expression could be prognostic factor in hormone receptor-positive and HER2 negative breast cancer, for tamoxifen resistance.
Citation Format: Bae SY, Nam SJ, Lee SK, Kim SW, Lee JE, Yu JH. Tamoxifen resistance: EGFR expression in hormone receptor-positive and HER2 negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-09-36.
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Liu X, Li JX, Hu JZ, Shen Y, Wan R, Xiong QM, Zhou QQ, Xie JY, Jin JJ, Yan X, Yu JH, Hong K. [Recurrent syncope related to catecholaminergic polymorphic ventricular tachycardia due to de novo RyR2-R2401H mutation]. ZHONGHUA XIN XUE GUAN BING ZA ZHI 2017; 45:39-43. [PMID: 28100344 DOI: 10.3760/cma.j.issn.0253-3758.2017.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To explore the clinical and molecular genetic features of a Chinese patient with catecholaminergic polymorphic ventricular tachycardia (CPVT). Methods: Clinical data including resting electrocardiography, echocardiography and treadmill exercise testing of a patient with CPVT admitted to our department in March 2013 were analyzed, and the peripheral venous blood samples of the patient and his family members and 400 ethnicity-matched healthy controls were obtained. All exons and exon-intron boundaries of the six CPVT-related genes including RYR2, CASQ2, TRDN, CALM1, KCNJ2 and ANKB were sequenced to detect the variants related to CPVT. The relationship between the genotypes and phenotypes was analyzed to direct the target therapy. Results: Recurrent syncope induced either by exercise or extreme frightened fear was observed in this patient. There was no positive family history of syncope or sudden death. The resting electrocardiography and echocardiography of the patient were normal, while the exercise testing revealed bidirectional and polymorphic ventricular tachycardia. A cardiac ryanodine receptor gene mutation (R2401H) was identified in this patient, while this mutation was absent in his parents and sister and 400 controls. No variant was detected in the remaining five candidate genes. Treatment with high dose of metoprolol succinate (118.75 mg/d) was effective and patient was free of syncopal attack during the 2 years follow-up. Conclusion: This is the first report on RyR2-R2401H mutation in Chinese patient with CPVT, and high dose of metoptolol is the effective therapy option for CPVT related to RyR2 mutation.
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Song LL, Yu JH. [Solicosis with one micorscopic polyangitis case complicated]. ZHONGHUA LAO DONG WEI SHENG ZHI YE BING ZA ZHI = ZHONGHUA LAODONG WEISHENG ZHIYEBING ZAZHI = CHINESE JOURNAL OF INDUSTRIAL HYGIENE AND OCCUPATIONAL DISEASES 2016; 34:540-541. [PMID: 27682495 DOI: 10.3760/cma.j.issn.1001-9391.2016.07.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Yu JH, Zhai ZH. [A case of chronic myeloid leukemia caused by benzene]. ZHONGHUA LAO DONG WEI SHENG ZHI YE BING ZA ZHI = ZHONGHUA LAODONG WEISHENG ZHIYEBING ZAZHI = CHINESE JOURNAL OF INDUSTRIAL HYGIENE AND OCCUPATIONAL DISEASES 2016; 34:460. [PMID: 27514560 DOI: 10.3760/cma.j.issn.1001-9391.2016.06.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
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Fan HJ, Yu JH, Cui GM, Zhang WY, Yang X, Dong QJ. Insulin pump for the treatment of diabetes in combination with ulcerative foot infections. J BIOL REG HOMEOS AG 2016; 30:465-470. [PMID: 27358133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Ulcerative foot infection is a chronic complication frequently seen in diabetic patients, and can result in disability. To evaluate insulin pump treatment for type 2 diabetes in combination with ulcerative foot infection, we selected 168 diabetic patients who developed foot ulcers and received treatment from April 2012 to April 2014 in the Peoples Hospital of Zhengzhou, Henan, China. The patients were divided into a treatment group and a control group, 84 in each group. Besides anti-infection treatment, patients in the control group were given multiple subcutaneous insulin injection (MSII), while patients in the treatment group were given continuous subcutaneous insulin infusion (CSII). Ulcer area, fasting plasma glucose (FPG), C-reactive protein (CRP) and count of white blood cells (WBC) were recorded before treatment, one week after treatment, two weeks after treatment and four weeks after treatment; moreover, ulcer healing condition was recorded four weeks after treatment and the related factors were analyzed. Patients in the treatment group showed an obviously narrowed ulcer area two and four weeks after treatment (P less than 0.05) and significantly lowered levels of FPG, CRP and WBC in the 1st, 2nd and 3rd weeks after treatment (P less than 0.05); four weeks after treatment, 88.1% of patients in the treatment group and 66.7% in the control group had healed well, and the difference between two groups was statistically significant (χ2=5.509, P=0.019). Multi-factor logistic regression analysis indicated that levels of FPG, CRP and WBC at baseline and four weeks after treatment had a positive correlation to ulcer healing (P less than 0.05). All the above findings suggest that insulin pump can improve ulcer healing of patients suffering from diabetic foot ulcers as it effectively controls blood glucose level, restrains inflammatory reaction and prevents spreading of infection.
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Yoon TI, Kim HJ, Yu JH, Sohn G, Ko BS, Lee JW, Son BH, Ahn SH. Abstract P5-13-06: Concurrent gonadotropin-releasing hormone (GnRH) agonist administration with chemotherapy improves neoadjuvant chemotherapy responses in young premenopausal breast cancer patients. Cancer Res 2016. [DOI: 10.1158/1538-7445.sabcs15-p5-13-06] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background
Gonadotropin-releasing hormone (GnRH) agonist therapy for ovarian function preservation shows promising results. This study aimed to determine the oncologic efficacy of GnRH agonist treatment concurrent with chemotherapy in a neoadjuvant setting.
Patients and Methods
A retrospective analysis was performed on 332 cases of invasive breast cancer in patients who were <40 years old at diagnosis and received GnRH agonists concurrent with neoadjuvant chemotherapy (GnRH agonist group) or neoadjuvant chemotherapy alone (neochemotherapy-alone group) at Asan Medical Center from December 2010 to September 2014. Pathologic complete response rates (pCR) and Ki-67 changes were evaluated between the two groups. For hormone receptor (HR)-positive tumors, the clinical response and preoperative endocrine prognostic index (PEPI) score also were evaluated.
Results
The median age was 32 ± 3.9 and 36 ± 3.0 years old in the GnRH agonist group and neochemotherapy-alone group, respectively (P < .001). Adjusted for tumor size, grade, lymph node metastasis, HR status, and chemotherapy regimen, the GnRH agonist group exhibited a higher pCR rate with an odds ratio (OR) of 2.98 (95% CI, 1.37–6.34) and more decreased Ki-67 expression during treatment (P = 0.05) than the neochemotherapy-alone group. In HR-negative tumors, the GnRH agonist group showed a higher pCR rate (multivariate OR = 3.50; 95% CI, 1.37–8.95) and more decreased Ki-67 expression (P = 0.047). In HR-positive breast cancer, the pCR rate, change in Ki-67 index, and clinical response were higher and preoperative prognostic index (PEPI) scores were lower in the GnRH agonist group, but not significant between the two treatment groups.
Conclusion
Concurrent administration of GnRH agonists during neoadjuvant chemotherapy improved pCR rates and suppressed Ki-67 expression especially in HR-negative tumors.
Citation Format: Yoon TI, Kim HJ, Yu JH, Sohn G, Ko BS, Lee JW, Son BH, Ahn SH. Concurrent gonadotropin-releasing hormone (GnRH) agonist administration with chemotherapy improves neoadjuvant chemotherapy responses in young premenopausal breast cancer patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-13-06.
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Song IH, Lee HJ, Park IA, Yu JH, Ahn JH, Gong G. Abstract P3-07-56: Predictive value of tertiary lymphoid structure assessed by high endothelial venule count in neoadjuvant setting of triple-negative breast cancer. Cancer Res 2016. [DOI: 10.1158/1538-7445.sabcs15-p3-07-56] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background
Tertiary lymphoid structure (TLS) is an ectopic lymph node-like structure characterized by lymphoid aggregation with high endothelial venules (HEVs), and is an important source of tumor-infiltrating lymphocytes (TILs). TILs have a strong prognostic and predictive significance, particularly in triple-negative breast cancer (TNBC). We previously analyzed expression of immune-related genes in pre-neoadjuvant chemotherapy (NAC) biopsy samples using NanoString assay and showed that gene expression of follicular helper T cell marker CXCL13, which is closely associated with TLSs, was an independent predictive factor for pathologic complete remission (pCR) in TNBC. However, measuring gene expression of biopsy sample is not easy to perform in daily pathology practice. Therefore, we evaluated TLSs by assessing hematoxylin and eosin (H&E) stained slides and immunohistochemistry, and investigated their clinical importance.
Methods
A total of 108 patients diagnosed with primary TNBC and treated with NAC (anthracycline, cyclophosphamide, and taxane) were included. The amounts of TILs and TLSs were histopathologically measured in H&E slides. Immunohistochemical studies were done in 55 cases with available tissue samples. The numbers of CD3-, CD8-, and CD20- immunopositive cells in tumor areas were counted by the image analyzer. MECA79- immunopositive HEV densities were calculated. Their relationship to CXCL13 gene expression by NanoString assay was also analyzed.
Results
The overall rate of pCR was 30.6% (33 of 108 tumors). Lower pre-NAC clinical T stage and higher level of TIL and TLS assessed by H&E slides were predictors of pCR in all cases. The mean number of MECA 79-immunopositive HEV in pre-NAC biopsy samples was 12 (range, 0-72). The amounts of TILs and TLSs, numbers of CD3-, CD8-, and CD20- positive cells, HEV density, and expression of CXCL13 showed good correlation with one another. Higher HEV density, CD20- positive cell number, and CXCL13 expression were predictors of pCR. Higher CD8- positive cell numbers and CXCL13 expression were associated with better disease-free survival rate.
Conclusion
The amount of TLSs assessed by H&E slides and MECA 79-immunopositive HEV densities was well correlated with level of TILs, numbers of CD3-, CD8-, and CD20-positive cells, and gene expression of CXCL13, and was significantly associated with pCR in TNBCs. Therefore, assessing HEV density by MECA 79 immunohistochemistry in pre-NAC biopsy samples might be an objective and valuable tool for predicting pCR of TNBC in routine pathology practice. Further investigation of mechanism of TLS development might help to improve immunotherapeutic strategy.
Citation Format: Song IH, Lee HJ, Park IA, Yu JH, Ahn J-H, Gong G. Predictive value of tertiary lymphoid structure assessed by high endothelial venule count in neoadjuvant setting of triple-negative breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-07-56.
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Hong SM, Park CW, Kim SW, Nam YJ, Yu JH, Shin JH, Yun CH, Im SH, Kim KT, Sung YC, Choi KY. NAMPT suppresses glucose deprivation-induced oxidative stress by increasing NADPH levels in breast cancer. Oncogene 2015; 35:3544-54. [PMID: 26568303 DOI: 10.1038/onc.2015.415] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 09/03/2015] [Accepted: 09/04/2015] [Indexed: 12/21/2022]
Abstract
Nicotinamide phosphoribosyltransferase (NAMPT) is a rate-limiting enzyme involved in NAD+ biosynthesis. Although NAMPT has emerged as a critical regulator of metabolic stress, the underlying mechanisms by which it regulates metabolic stress in cancer cells have not been completely elucidated. In this study, we determined that breast cancer cells expressing a high level of NAMPT were resistant to cell death induced by glucose depletion. Furthermore, NAMPT inhibition suppressed tumor growth in vivo in a xenograft model. Under glucose deprivation conditions, NAMPT inhibition was found to increase the mitochondrial reactive oxygen species (ROS) level, leading to cell death. This cell death was rescued by treatment with antioxidants or NAD+. Finally, we showed that NAMPT increased the pool of NAD+ that could be converted to NADPH through the pentose phosphate pathway and inhibited the depletion of reduced glutathione under glucose deprivation. Collectively, our results suggest a novel mechanism by which tumor cells protect themselves against glucose deprivation-induced oxidative stress by utilizing NAMPT to maintain NADPH levels.
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Li Y, Du Y, Luo TY, Yang HF, Yu JH, Xu XX, Zheng HJ, Li B. Usefulness of normal saline for sealing the needle track after CT-guided lung biopsy. Clin Radiol 2015; 70:1192-7. [PMID: 26175218 DOI: 10.1016/j.crad.2015.06.081] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2014] [Revised: 04/06/2015] [Accepted: 06/05/2015] [Indexed: 10/23/2022]
Abstract
AIM To determine whether the use of normal saline for sealing the needle track can reduce the incidence of pneumothorax and chest tube placement after computed tomography (CT)-guided lung biopsy. MATERIALS AND METHODS A prospective, randomised, controlled trial enrolling 322 patients was conducted. All patients were randomly assigned to one of two groups: those in whom the needle track was not sealed with normal saline (n=161, Group A) and those who did receive normal saline (n=161, Group B). CT-guided biopsy was performed with coaxial technique. Normal saline, which ranged from 1-3 ml, was injected while the trocar needle was being withdrawn. Patient characteristics, lesion, and procedure variables were analysed as potential risk variables for occurrence of pneumothorax and chest tube placement. RESULTS The incidence of pneumothorax was 26.1% in Group A and 6.2% in Group B (p<0.001). Nine patients in Group A and one patient in Group B required chest tube placement (p=0.010). Using multiple logistic regression analysis, smaller lesion size, greater needle-pleural angle, longer lesion-pleural distance, presence of emphysema, and no sealing the needle track with normal saline were significantly associated with an increased risk of pneumothorax, and that the latter three factors were also associated with an increased risk of pneumothorax requiring chest tube placement. CONLUSION Normal saline for sealing the needle track significantly reduces the incidence of pneumothorax and prevents subsequent chest tube placement after CT-guided lung biopsy.
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Liu Y, Yuan JM, Zhang LS, Zhang YR, Cai SM, Yu JH, Xia ZF. Effects of tryptophan supplementation on growth performance, antioxidative activity, and meat quality of ducks under high stocking density. Poult Sci 2015; 94:1894-901. [PMID: 26089478 DOI: 10.3382/ps/pev155] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/22/2015] [Indexed: 11/20/2022] Open
Abstract
High stocking density (STD) could affect duck welfare and production. The objective of our study was to investigate whether dietary tryptophan (TRP) supplementation could alleviate the detrimental effects of high STD on ducks. White Pekin ducks at 4 to 6 wk of age were raised at 11 birds/m(2) and fed diets containing 0.18, 0.48, 0.78, or 1.08% TRP for 21 d. Growth performance, concentrations of TRP and metabolites in the blood and hypothalamus, antioxidative activities in serum and tissue, meat quality, serum uric acid, and urea nitrogen were measured. Weight gain and feed efficiency were significantly improved by TRP supplementation at ≥ 0.48 and ≥ 0.78% (P < 0.05 and P < 0.001, respectively). Serum TRP, hypothalamic TRP, 5-hydroxytryptamine (5-HT), 5-hydroxyindoleacitic acid (5-HIAA), and 5-HIAA/5-HT were also increased significantly (P < 0.01). These increases plateaued at 0.48% TRP, and no further improvement was obtained by adding more TRP to the diet. Dietary TRP supplementation significantly increased levels of total antioxidant capacity, glutathione peroxidase (GSH-Px), and catalase (CAT) in serum; GSH-Px in liver; and GSH-Px and CAT in breast muscle (P < 0.05). Malondialdehyde levels in breast muscle decreased (P < 0.001). Drip loss of breast muscle and pH decline at 45 min postmortem were reduced by TRP supplementation (P < 0.01 and P < 0.05, respectively). Meat color was similar among different treatments (P > 0.05). Breast muscle shear force was increased significantly when dietary TRP level increased to 1.08% (P < 0.01). For ducks raised at 11 birds/m², dietary TRP supplementation could alleviate stress and improve growth performance, antioxidative activity, and meat quality.
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Du MY, Ma RM, Lao TTH, Chen Z, Xiao H, Tian YQ, Li BL, Liang K, Zhang L, Yang MH, Li J, Li H, Yan R, Geng L, Qi WJ, Li HY, Xu J, Hu SQ, Liang GH, Yu JH. Early third trimester maternal response to glucose challenge and pregnancy outcome in Chinese women-relationship between upper distribution level and recommended diagnostic criteria. Eur J Clin Nutr 2015; 69:1133-9. [PMID: 25626407 DOI: 10.1038/ejcn.2014.293] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 12/02/2014] [Accepted: 12/19/2014] [Indexed: 11/09/2022]
Abstract
BACKGROUND/OBJECTIVES The objective of this study was to examine the relationship between upper distribution levels of glucose values in the 75-g oral glucose tolerance test (OGTT) and recommended diagnostic criteria for gestational diabetes mellitus (GDM) and adverse pregnancy outcomes. SUBJECTS/METHODS The distribution of the OGTT 2-h values of 13,501 pregnant women, which were below the World Health Organization (WHO) threshold for overt diabetes mellitus (DM), and managed in one teaching hospital in China, was reviewed and related to maternal characteristics and pregnancy outcomes. RESULTS For the entire group, the 90th and 95th percentile values of the OGTT 2-h glucose level, respectively, were close to the diagnostic cutoff values of the WHO and International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria. For adverse maternal outcomes, glucose level above the 90th percentile value was associated with increased hypertensive disorders, whereas no difference was seen with cutoff using the 95th percentile value. For perinatal outcomes, the 90th percentile was associated with increased neonatal intensive care unit admission and hypoglycemia, whereas the 95th percentile showed in addition association with phototherapy for jaundice and 5th-minute Apgar score <7. Although no differences in the incidence of adverse pregnancy outcomes were found using the different cutoffs, the >95th percentile cutoff value would have missed out 33.3-56.7% of the cases of adverse outcomes that would otherwise have been attributed to GDM. CONCLUSIONS Further studies are warranted to clarify which diagnostic criterion is most appropriate universally to identify adverse pregnancy outcomes attributed to GDM, and which could be mitigated with treatment specific for GDM.
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Cho HJ, Shin SC, Seo DY, Cho JM, Kang JY, Yoo TK, Yu JH, Sung LH, Moon HS. Comparison of alfuzosin 10 mg with or without propiverine 10 mg, 20 mg in men with lower urinary tract symptom and an overactive bladder: randomised, single-blind, prospective study. Int J Clin Pract 2014; 68:471-7. [PMID: 24471868 DOI: 10.1111/ijcp.12339] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
PURPOSE The efficacy and safety of treatment with alfuzosin 10 mg plus propiverine 10 or 20 mg in men with lower urinary tract symptoms (LUTS) and an overactive bladder were investigated. MATERIALS AND METHODS In this parallel-arm, prospective, multicentre, single-blind study, men who were ≥ 40 years old, had an International Prostate Symptom Score (IPSS) of ≥ 8, an Overactive Bladder Symptom Score (OABSS) of ≥ 3 and an OABSS urgency item score of ≥ 2 were randomised in a 1 : 1 :1 ratio to receive alfuzosin 10 mg alone (Group A) or with propiverine 10 mg (Group B) or 20 mg (Group C) for 8 weeks. Four and 8 weeks after commencing treatment, OABSS was measured along with IPSS, maximal urinary flow rate (Qmax ) and postvoid residual volume (PVR). Adverse events were recorded. RESULTS A total of 135 men, including 43 in Group A, 48 in Group B and 44 in Group C, completed the study. Relative to baseline, all groups demonstrated significant reductions in OABSS and the IPSS after eight treatment weeks (p < 0.005). The improvement of OABSS in Group C was significantly greater than Group A and B (Group A: 0.70 ± 1.94; Group B: 2.50 ± 2.98; Group C: 4.30 ± 3.40; p < 0.005). An observed improvement of Qmax and PVR in the three groups did not achieve statistical significance. Overall adverse event rates were higher in Group C but not significant compared with others. CONCLUSION In patients with LUTS and overactive bladder, combined therapy with alfuzosin 10 mg plus propiverine 20 mg was significantly more effective than alfuzosin monotherapy and propiverine 10 mg combined therapy in terms of improving OABSS while not significantly affecting Qmax or PVR.
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Yu JH, Shin MS, Kim DJ, Lee JR, Yoon SY, Kim SG, Koh EH, Lee WJ, Park JY, Kim MS. Enhanced carbohydrate craving in patients with poorly controlled Type 2 diabetes mellitus. Diabet Med 2013; 30:1080-6. [PMID: 23586900 DOI: 10.1111/dme.12209] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/10/2013] [Indexed: 11/27/2022]
Abstract
AIMS Although hyperphagia is a common manifestation of diabetes mellitus, data on food craving in patients with diabetes are limited. This study compared food craving in patients with Type 2 diabetes mellitus and a control group without diabetes. METHODS A total of 210 subjects (105 with Type 2 diabetes and 105 age-, sex- and BMI-matched control subjects) participated in two food craving surveys. The surveys were as follows: the General Food Cravings Questionnaire--Trait, which assesses the general trait of food craving; and the Food Cravings Questionnaire--State, which assesses the state of food craving or current desire for high-carbohydrate or high-fat foods in response to pictures of food. Follow-up Food Cravings Questionnaire--State surveys were administered approximately 3 months later to the subjects with diabetes. Survey results were analysed to assess relationships between food craving and glycaemic control. RESULTS The General Food Cravings Questionnaire--Trait scores in the group with Type 2 diabetes and the control group were not significantly different. The group with Type 2 diabetes had higher carbohydrate craving scores, but lower fat craving scores, than the control group. Carbohydrate craving scores in subjects with diabetes were positively correlated with HbA(1c). In follow-up surveys, carbohydrate craving scores declined in patients with improved glycaemic control. CONCLUSIONS The surveys showed that patients with Type 2 diabetes had higher carbohydrate cravings and lower fat cravings than the age-, sex- and BMI-matched control group. Carbohydrate craving in patients with diabetes was associated with poor glycaemic control.
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Moon HG, Han W, Kim JY, Kim SJ, Yoon JH, Oh SJ, Yu JH, Noh DY. Effect of multiple invasive foci on breast cancer outcomes according to the molecular subtypes: a report from the Korean Breast Cancer Society. Ann Oncol 2013; 24:2298-304. [PMID: 23704201 DOI: 10.1093/annonc/mdt187] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND In this study, the prognostic impact of the presence of the multifocal or multicentric tumor (MMT) and its association with molecular subtypes were investigated. PATIENTS AND METHODS We investigated the breast cancer metastasis and survival in patients with multifocal or multicentric invasive foci in the same breast. The study population includes 2882 patients in the Seoul National University Hospital Breast Care Center (SNUHBCC) dataset and 41 179 patients in Korean Breast Cancer Registry (KBCR) dataset. RESULTS From SNUHBCC dataset, we observed a significant role of MMT in developing distant metastasis and death when the tumors were triple-negative subtype. This subtype-specific prognostic importance of MMT in overall survival was also seen in KBCR dataset (HR, 1.32; 95% CI, 1.02-1.69). In tumors <2 cm, the hazard ratios (HRs) for node metastasis and death were similar along the tumor size change in triple-negative subtype, while other subtypes showed a stepwise increment, suggesting the biologic importance of small invasive foci in this subtype. CONCLUSIONS Our results demonstrate the prognostic importance of MMT in patients with triple-negative breast cancers. Small additional invasive foci in triple-negative breast cancer patients should be considered as clinically relevant tumor deposits.
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Jung CH, Lee WJ, Hwang JY, Yu JH, Shin MS, Lee MJ, Jang JE, Leem J, Park JY, Kim HK. Assessment of the fatty liver index as an indicator of hepatic steatosis for predicting incident diabetes independently of insulin resistance in a Korean population. Diabet Med 2013; 30:428-35. [PMID: 23278318 DOI: 10.1111/dme.12104] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Revised: 10/24/2012] [Accepted: 12/18/2012] [Indexed: 02/06/2023]
Abstract
AIMS Fatty liver disease, especially non-alcoholic fatty liver disease, is considered to be the hepatic manifestation of the metabolic syndrome, both closely associated with insulin resistance. Furthermore, fatty liver disease assessed by ultrasonography is known to be a predictor of the development of Type 2 diabetes mellitus. However, it remains unclear whether fatty liver disease plays a role in the pathogenesis of Type 2 diabetes independently of insulin resistance. In this study, we investigated whether fatty liver disease assessed by the fatty liver index can predict the development of Type 2 diabetes independently of systemic insulin resistance. METHODS We examined the clinical and laboratory data of 7860 subjects without diabetes who underwent general routine health evaluations at the Asan Medical Center in 2007 and had returned for follow-up examinations in 2011. Fatty liver index was calculated using an equation that considers serum triglyceride levels, γ-glutamyltransferase, waist circumference and BMI. RESULTS During a 4-year period, 457 incident diabetes cases (5.8%) were identified. The odds ratios for the development of Type 2 diabetes were significantly higher in the group with a fatty liver index ≥ 60 (fatty liver index-positive) than in the group with a fatty liver index < 20 (fatty liver index-negative) after adjusting for various confounding variables including homeostasis model assessment of insulin resistance. Odds ratios were significant regardless of the insulin resistance status at baseline. CONCLUSIONS Our results suggest that fatty liver index as a simple surrogate indicator of hepatic steatosis is valuable in identifying subjects at high risk for Type 2 diabetes. In addition, fatty liver disease itself contributes to the development of Type 2 diabetes independently of systemic insulin resistance.
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Li Y, Du Y, Yang HF, Yu JH, Xu XX. Re: CT-guided percutaneous core needle biopsy for small (≤20 mm) pulmonary lesions. A reply. Clin Radiol 2013; 68:e354. [PMID: 23510621 DOI: 10.1016/j.crad.2013.02.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2013] [Accepted: 02/06/2013] [Indexed: 10/27/2022]
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Cho JY, Ahn SH, Lee JW, Yu JH, Koh BS, Kim HJ, Lee JW, Son BH, Gong GY, Kim HH. Abstract P3-01-02: Correlation of Mammographic breast density and tumor characteristics in Korean breast cancer patients. Cancer Res 2012. [DOI: 10.1158/0008-5472.sabcs12-p3-01-02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Introduction: Western studies have demonstrated high breast density as a strong risk factor for breast cancer, it is poorly understood whether breast density affects the diverse phenotypes of breast cancer. We examined the association between various tumor characteristics and mammographic breast density in women with breast cancer.
Methods: We conducted a cross-sectional analysis in 910 Korean women diagnosed with breast cancer to evaluate the associations between breast density and tumor size, lymph node status, lymphovascular invasion, histologic grade, estrogen receptor, progesterone receptor, HER2. Breast density was classified as fatty (percent density less than 50% by a computer-assisted thresholding program, named “Cumulus™”; n = 470) or dense (percent density 50% or more; n = 440) for the cancer-free breast at the time of operation. Logistic regression was used to examine whether the relationships were modified by adjustment for body mass index, age at diagnosis, age at first birth, menopausal status, history of breast-feeding, and breast cancer staging.
Results: Total 910 patients were involved, the mean age and median age at the operation was 48 years old (range 20–82), and the mean percent density was 48.09 (SD = 9.62 %: normally distributed, Kolmogorov-Smirnov test p = 0.32). Crude analysis shows that tumor size over than 0.5cm were more likely to have dense breasts compared with women with a tumor size <=0.5 cm (OR = 3.21, 95% CI = 1.59–6.45, p = 0.001 for tumor sizes 0.6–1.0cm; OR = 2.02, 95% CI = 1.09–3.74, p = 0.03 for tumor sizes 1.1–1.5cm; OR = 1.8, 95% CI = 0.97–3.33, p = 0.06 for tumor sizes 1.6–2.0cm; and OR = 1.64, 95% CI = 0.92–2.94, p = 0.1 for tumor sizes 2.1cm or more). PD and histologic grade shows reverse association between histologic grade 1 and grade 2,3. Progesteron receptor positive patients tend to have more dense(OR = 1.27, 95% CI=0.97–1.66, p = 0.07) breast than receptor negative patients, although after adjustment of age the statistical significant disappeared. Percent density was not significantly associated with, ER (p = 0.74), HER2 (p = 0.72).
Conclusion: These results suggest that breast density is associated with tumor size and histologic grade and progesterone receptor positivity. Additional studies are needed to address whether these associations are due to just density masking the detection of some tumors, biological causation, or both.
Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-01-02.
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Chrobak CP, Van Zeeland MA, Moyer RA, Yu JH. Restoring transmission of irradiated image fiber bundles. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:10E514. [PMID: 23127021 DOI: 10.1063/1.4733544] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Image fiber bundles are employed in fusion experiments and other high radiation environments where they are used to transmit an image from an unprotected objective lens to a radiation shielded camera. Due to their exposure to neutron and gamma radiation the transmission of these expensive image fiber bundles can rapidly degrade, especially at the shorter visible wavelengths, and require costly replacement. A cost-effective, non-destructive heat treatment process in which entire fiber bundles are heated gradually in air to 150°-200°C and held for tens of hours has been shown to recover much of the transmission lost due to the radiation induced absorption. The restoration process can be repeated multiple times without a loss in effectiveness, although some physical degradation of inter-fiber alignment has been observed. The results and the apparatus used for the successful restoration of the transmission of multiple image fiber bundles across their entire wavelength band will be presented.
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Xu M, Tynan GR, Diamond PH, Manz P, Holland C, Fedorczak N, Thakur SC, Yu JH, Zhao KJ, Dong JQ, Cheng J, Hong WY, Yan LW, Yang QW, Song XM, Huang Y, Cai LZ, Zhong WL, Shi ZB, Ding XT, Duan XR, Liu Y. Frequency-resolved nonlinear turbulent energy transfer into zonal flows in strongly heated L-mode plasmas in the HL-2A tokamak. PHYSICAL REVIEW LETTERS 2012; 108:245001. [PMID: 23004280 DOI: 10.1103/physrevlett.108.245001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Indexed: 06/01/2023]
Abstract
The absolute rate of nonlinear energy transfer among broadband turbulence, low-frequency zonal flows (ZFs) and geodesic acoustic modes (GAMs) was measured for the first time in fusion-grade plasmas using two independent methods across a range of heating powers. The results show that turbulent kinetic energy from intermediate frequencies (20-80 kHz) was transferred into ZFs and GAMs, as well as into fluctuations at higher frequencies (>80 kHz). As the heating power was increased, the energy transfer from turbulence into GAMs and the GAM amplitudes increased, peaked and then decreased, while the energy transfer into the ZFs and the ZFs themselves increased monotonically with heating power. Thus there exists a competition between ZFs and GAMs for the transfer of turbulent energy, and the transfer into ZFs becomes dominant as the heating power is increased. The poloidal-radial Reynolds stress and the mean radial electric field profiles were also measured at different heating powers and found to be consistent with the energy transfer measurement. The results suggest that ZFs play an important role in the low-to-high (L-H) plasma confinement transition.
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Kim HJ, Yi OV, Koh BS, Yu JH, Lee JW, Son BH, Ahn SH. P3-09-06: Changes of Serum Vitamin D According to the Breast Cancer Treatment. Cancer Res 2011. [DOI: 10.1158/0008-5472.sabcs11-p3-09-06] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: Vitamin D deficiency is associated with increased breast cancer risk and decreased breast cancer survival. The purpose of this study was to determine the effect of breast cancer adjuvant treatment to the vitamin D status, as measured by the serum hydroxyvitamin D (25OHD) in breast cancer patients.
Patients and Methods: For 589 patients who was diagnosed as a non metastatic breast cancer in 2009 at the asan medical center, blood was prospectively analyzed in batches for serum 25 OHD level at basal and at 6 and 12month. We excluded the patients who took a vitamin D supplementation and got a neoadjuvant chemotherapy. Vitamin D sufficiency was defined as serum as 30ng/ml or greater, insufficiency as 20 to 29 ng/ml and insufficiency as less than 20ng/ml.
Results: At baseline, mean serum 25OHD was greater in summer (April to Oct) than Winter(Nov to May) (28.2ng/ml vs 32.9ng/ml respectively, p=0.000). The patients who did not get a chemotherapy and antihormonal therapy as baseline, the patient with chemotherapy showed decreased serum 25OHD level than who without chemotherapy in 6 month but not in 12 month (p=0.003, vs p=0.156 respectively). The patients who had taken anti-hormonal therapy showed significant increasing serum 25OHD in 6 month and 12 months (p=0.000 both). For the patients who got both chemotherapy and anti-hormonal therapy, the changes of serum 25OHD level is smaller than the patients who got a chemotherapy only.
For the patients who got a chemotherapy, 57% of patients were vitamin D sufficient at baseline, but 27% of patients in 6 month and 49% in 12 month (p=0.001).
Conclusion: Vitamin D status was worsen during chemotherapy but recovered after chemotherapy. Anti hormonal therapy make the serum vitamin D level increased. The translational research about the effect of chemotherapy and anti-hormonal therapy to the vitamin D status should be warranted.
Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-09-06.
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Manz P, Xu M, Müller SH, Fedorczak N, Thakur SC, Yu JH, Tynan GR. Plasma blob generation due to cooperative elliptic instability. PHYSICAL REVIEW LETTERS 2011; 107:195004. [PMID: 22181616 DOI: 10.1103/physrevlett.107.195004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Indexed: 05/31/2023]
Abstract
Using fast-camera measurements the generation mechanism of plasma blobs is investigated in the linear device CSDX. During the ejection of plasma blobs the plasma is dominated by an m=1 mode, which is a counterrotating vortex pair. These flows are known to be subject to the cooperative elliptic instability, which is characterized by a cooperative disturbance of the vortex cores and results in a three-dimensional breakdown of two-dimensional flows. The first experimental evidence of a cooperative elliptic instability preceding the blob-ejection is provided in terms of the qualitative evolution of the vortex geometries and internal wave patterns.
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Xu M, Tynan GR, Diamond PH, Holland C, Yu JH, Yan Z. Generation of a sheared plasma rotation by emission, propagation, and absorption of drift wave packets. PHYSICAL REVIEW LETTERS 2011; 107:055003. [PMID: 21867076 DOI: 10.1103/physrevlett.107.055003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Indexed: 05/31/2023]
Abstract
Collisional electron drift wave turbulence generates drift wave packet structures with density and vorticity fluctuations in the central plasma pressure gradient region of a linear plasma device. Tracking these packets reveals that they follow an outward directed spiral-shaped trajectory in the (r,θ) plane, are azimuthally stretched, and develop anisotropy as they approach an axisymmetric, radially sheared azimuthal flow located at the plasma boundary. Nonlinear energy transfer measurements and time-delay analysis confirm that structure absorption amplifies the sheared flow. Similar mechanisms likely operate at the edge of confined toroidal plasmas and should lead to the amplification of sheared flows at the boundary of these devices as well.
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