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排序方式: 共有2198条查询结果,搜索用时 15 毫秒
1.
Doxorubicin-conjugated biodegradable polymeric micelles having acid-cleavable linkages. 总被引:13,自引:0,他引:13
Doxorubicin was chemically conjugated to the terminal end of a di-block copolymer composed of poly(L-lactic acid) (PLLA) and methoxy-poly(ethylene glycol) (mPEG) via two acid-cleavable linkages. A hydrazone bond and a cis-acotinyl bond were formed between doxorubicin and the terminal group of PLLA segment in the block copolymer. Doxorubicin-conjugated PLLA-mPEG di-block copolymers self-assembled to form micelles in aqueous solution. The doxorubicin-conjugated micelles were about 89.1 nm in diameter and their critical micelle concentration was 1.3 microg/ml. These values were comparable with those of unconjugated micelles. In an acidic condition, the conjugated doxorubicin in the hydrazone linkage was readily cleaved, releasing doxorubicin in an intact structure. Doxorubicin-conjugated PLLA-mPEG micelles were more potent in cell cytotoxicity than free doxorubicin, suggesting that they were more easily taken up within cells with concomitant rapid release of cleaved doxorubicin into the cytoplasm from acidic endosomes. 相似文献
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Kim Myoung Hee Park Jong Hoon Park Hyoung Woo Chung In Hyuk Park Kyung Ah 《Somatic Cell and Molecular Genetics》1998,24(4):245-248
To construct the PAC and cosmid contig map spanning the HOXA cluster on human chromosome 7, we used 9 DNA markers (D7S2243, D7S3010, HOXA1, EVX1, 750, pBH8, p60, p8.0, and HOXA11), among which the final 4 were generated in this study by shotgun cloning strategy. From the libraries, 5 PAC and 35 cosmid clones were screened and as a result, an overlapping continuous array of cosmid and PAC clones covering the genomic region (about 200 kb) spanning the entire cluster were constructed. The isolated cosmids contained several consecutive HOX genes of regional group, probably sharing the regulatory processes such as alternative splicing or polyadenylation, and thus could be used as useful materials for elucidating the molecular mechanism of HOX gene expression in the future. 相似文献
4.
Yoonyoung Jang Yoon-Jung Choi Youn-Hee Lim Kyung-Shin Lee Bung-Nyun Kim Choong Ho Shin Young Ah Lee Johanna Inhyang Kim Yun-Chul Hong 《Yebang Ŭihakhoe chi》2021,54(1):37
ObjectivesBisphenol A (BPA) is used in the electrical, mechanical, medical, and food industries. Previous studies have suggested that BPA is an endocrine disruptor. Regulation of BPA has led to increased use of bisphenol F (BPF) and bisphenol S (BPS). However, few studies have investigated the associations of BPF and BPS with thyroid dysfunction in children. Our study investigated the associations of prenatal BPA and early childhood BPA, BPF, and BPS exposure with thyroid function in 6-year-old children.MethodsPrenatal BPA concentrations were measured during the second trimester of pregnancy in an established prospective birth cohort. We measured urinary BPA, BPF, and BPS concentrations and thyroid hormone levels (thyroid-stimulating hormone, total T3, and free T4) in 6-year-old children (n=574). We examined the associations between urinary bisphenol concentrations and percentage change of thyroid hormone concentrations using multivariate linear regression. We also compared thyroid hormone levels by dividing the cohort according to BPA, BPF, and BPS concentrations.ResultsThe associations between prenatal BPA and total T3 levels were statistically significant in all models, except for girls when using a crude model. The associations between urinary BPA and BPS concentrations and levels of all thyroid hormones were not statistically significant. However, we observed that lower free T4 levels (−1.94%; 95% confidence interval, −3.82 to −0.03) were associated with higher urinary BPF concentrations in girls only.ConclusionsOur findings identified significant associations between prenatal BPA exposure and total T3 levels in all children and between BPF exposure and free T4 levels in girls only. 相似文献
5.
The antioxidant activity ofArtemisia iwayomogi was determined by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical The methanol extract
ofA. iwayomogi showed strong antioxidant activity, and thus fractionated with several solvents. The antioxidant activity potential of the
individual fraction was in the order of ethyl acetate>n-butanol>water>chloroform>n-hexane fraction. The ethyl acetate andn-butanol soluble fractions exhibiting strong antioxidant activity were further purified by repeated silica gel and Sephadex
LH-20 column chromatography. Antioxidant chlorogenic acid was isolated as one of the active principles from then-butanol fraction, together with the inactive components, 1-octacosanol, scopoletin, scopolin, apigenin 7,4′-di-O-methylether luteolin 6,3′-di-O-methylether (jaceosidin), apigenin 7-methylether (genkwanin), 2,4-dihydroxy-6-methoxyacetophenone 4-O-β-D-glucopyranoside and quebrachitol. The antioxidant activity of chlorogenic acid was comparable to that of L-ascorbic acid,
which is a well known antioxidant. 相似文献
6.
Byung Mu Lee Ja-June Jang Joung-Soon Kim Young Chan You Sun Ah Chun Hyung Sik Kim Hyung Mee Han Mi Young Ahn Soo Hyun Byun 《Cancer science》1998,89(6):597-603
Gastric adenocarcinoma is the most prevalent cancer in South Korea, and Helicobacter pylori (H. pylori) infection is also common. This study was performed to examine the association between H. pylori infection and gastric cancer, taking into account various other factors. To investigate the association between gastric adenocarcinoma and H. pylori infection, determined by urease-positive reaction in the CLO test, a total of 175 paired specimens (175 tumor and 175 tissues adjacent to tumor) of stomach cancer patients and a total of 113 control specimens were obtained. The positive H. pylori infection rates were 78.9% (138/175) among the patients in specimens of tumor or tissues adjacent to the tumor and 41.6% (47/113) among controls in the CLO test. A positive correlation between H. pylori infection and gastric cancer was observed (age-adjusted odds ratio, 7.0; MH χ2 =34.5 with P <0.0005). These data suggest that stomach cancer patients in Korea have high infection rates of H. pylori regardless of site specificity, and this infection might be causally associated with stomach cancer. 相似文献
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Seung‐Ah Yahng Jae‐Ho Yoon Seung‐Hwan Shin Sung‐Eun Lee Byung‐Sik Cho Dong‐Gun Lee Ki‐Seong Eom Seok Lee Chang‐Ki Min Hee‐Je Kim Seok‐Goo Cho Dong‐Wook Kim Jong‐Wook Lee Woo‐Sung Min Tai‐Gyu Kim Chong‐Won Park Yoo‐Jin Kim 《European journal of haematology》2013,90(2):111-120
This study describes a retrospective analysis on the transplant outcome of 56 consecutive patients with myelodysplastic syndrome (MDS) according to their response to hypomethylating agents (HMA). While 2‐yr disease‐free survival (DFS) of patients who transformed to acute myeloid leukemia (n = 12) was 25%, that of the remaining patients with MDS according to response to HMA was 73.1%, 68.1%, 50.0%, and 20.8% in G‐COR (group of continuous response, n = 19), G‐NoC (group of no change, n = 15), G‐LOR (group of loss of response, n = 6), and G‐DP (group of disease progression, n = 4), respectively. When dichotomized as G‐COR/G‐NoC versus G‐LOR/G‐DP, significantly different 2‐yr DFS (71.0% vs. 33.3%; P = 0.004) and relapse (14.1% vs. 46.7%; P = 0.016) were demonstrated. On multivariate analysis, G‐LOR/G‐DP [hazard ratio (HR), 3.91; P = 0.008] and poor karyotype at transplantation (HR, 2.69; P = 0.017) were the significant predictors for poor DFS, as G‐LOR/G‐DP was for relapse (HR, 6.28; P = 0.011). DFS was significantly poor in patients with any of the two predictors in all MDS (81.5% vs. 34.9%; P = 0.001) or higher‐risk MDS (HrMDS) at the time of HMA (80.7% vs. 29.2%; P = 0.005). G‐COR showed a trend of better DFS compared with G‐NoC among HrMDS (74.6% vs. 36.5%; P = 0.090). These results implicate the significance of response to HMA on hematopoietic stem cell transplantation (HSCT) outcomes and support the need for future study to verify the suggested strategy of proceeding to transplantation before LOR or DP, especially for HrMDS. 相似文献
9.
Hoon Suk Park Yu Ah Hong Byung Ha Chung Hyung Wook Kim Cheol Whee Park Chul Woo Yang Dong Chan Jin Yong Soo Kim Bum Soon Choi 《Yonsei medical journal》2012,53(6):1224-1227
A 27-year-old man presented at the emergency room with hemoptysis. His blood pressure was 180/100 mm Hg, and he had no history of hypertension. Chest radiographs showed bilateral infiltration, suggestive of alveolar hemorrhage. His laboratory data were consistent with acute kidney injury. His serum creatinine level increased abruptly; therefore, renal biopsy was performed. Steroid pulse therapy was administered because of a strong suspicion of immune-mediated pulmonary renal syndrome. Renal biopsy showed proliferative endarteritis, fibrinoid necrosis, and intraluminal thrombi in the vessels without crescent formation or necrotizing lesions. Steroid pulse therapy rapidly tapered and stopped. His serum creatinine level gradually decreased with strict blood pressure control. Ten months after discharge, his blood pressure was approximately 120/80 mm Hg with a serum creatinine level of 1.98 mg/dL. Pulmonary renal syndrome is generally caused by an immune-mediated mechanism. However, malignant hypertension accompanying renal insufficiency and heart dysfunction causing end-organ damage can create a pulmonary hemorrhage, similar to pulmonary renal syndrome caused by an immune-mediated mechanism. The present case shows that hypertension, a common disease, can possibly cause pulmonary renal syndrome, a rare condition. 相似文献
10.