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1.
Nobuyuki Suto  Toru Masuko 《Polymer》2005,46(1):167-172
The morphology of solution-grown crystals (SGCs) of syndiotactic polysthyrene (s-PS) has been investigated using transmission electron and atomic force microscopy (TEM and AFM). Well-defined s-PS SGCs were prepared from 0.005% (w/w) n-tetradecane/decahydronaphthalene solution 2:1 (v/v) by an isothermal crystallization method at 200 °C. Lattice constants for this crystal estimated by TEM with the diffraction mode are a=0.90 nm, b=2.88 nm. AFM images of the folded chains on the surface of s-PS SGC suggested their alignment parallel to the direction of the growth face of the truncated-lozenge shaped crystal. The angle between the growth faces obtained from s-PS SGCs was 130°. Since, the value of 130° correspond to the {230} angle, the primary growth face of s-PS SGC was assigned to the (230) plane.  相似文献   

2.
Recent studies indicate that β-elemene, a compound isolated from the Chinese herbal medicine Curcuma wenyujin, is capable of reversing tumor MDR, although the mechanism remains elusive. In this study, β-Elemene treatment markedly increased the intracellular accumulation of doxorubicin (DOX) and rhodamine 123 in both K562/DNR and SGC7901/ADR cells and significantly inhibited the expression of P-gp. Treatment of SGC7901/ADR cells with β-elemene led to downregulation of Akt phosphorylation and significant upregulation of the E3 ubiquitin ligases, c-Cbl and Cbl-b. Importantly, β-elemene significantly enhanced the anti-tumor activity of DOX in nude mice bearing SGC7901/ADR xenografts. Taken together, our results suggest that β-elemene may target P-gp-overexpressing leukemia and gastric cancer cells to enhance the efficacy of DOX treatment.  相似文献   

3.
Nitrile rubber (NBR)/sliding graft copolymer (SGC) composites with significantly improved strength and damping property are successfully prepared. SGC is a novel kind of supramolecular material with sliding crosslink junctions. The micromorphology analyses of NBR/SGC composites indicate that the SGC phase with particle size less than 500 nm is fairly uniformly dispersed in the NBR matrix. As SGC content increases, the loss factors (tan δ) of NBR/SGC composites increase gradually. Specifically, the tan δ of NBR/SGC (100/40) is about 1.2 times higher than that of pristine NBR rubber. The tensile strength and elongation at break of NBR/SGC composites are unexpectedly improved after the addition of SGC. The significantly improved damping performance and tensile strength can be ascribed to the pulley effect of SGC and the strong interfacial hydrogen bonds between SGC and NBR. The high damping performance and good mechanical strength make the NBR/SGC composite a promising high-performance damping material. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47188.  相似文献   

4.
Oral cancer is the most common form of head and neck squamous cell carcinoma (HNSCC) and most frequently presents as oral squamous cell carcinoma (OSCC), which is associated with an alarmingly high mortality rate. Internationally, a plethora of research to further our understanding of the molecular pathways related to oral cancer is performed. This research is of value for early diagnosis, prognosis, and the investigation of new drugs that can ameliorate the harmful effects of oral cancer and provide optimal patient outcomes with minimal long-term complications. Two pathways on which the progression of OSCC depends on are those of proliferation and apoptosis, which overlap at many junctions. Herein, we aim to review these pathways and factors related to OSCC progression. Publicly available search engines, PubMed and Google Scholar, were used with the following keywords to identify relevant literature: oral cancer, proliferation, proliferation factors, genes, mutations, and tumor suppressor. We anticipate that the use of information provided through this review will further progress translational cancer research work in the field of oral cancer.  相似文献   

5.
目的筛选胃癌中相关miRNAs,并验证其作用靶点。方法应用基因芯片技术检测3份正常胃组织标本、24份胃癌组织标本、胃癌细胞SGC7901和正常胃黏膜细胞GES-1中328个miRNAs的表达情况。采用实时荧光定量PCR对结果进行验证,并用基因克隆和Western blot方法分析miR-9的作用靶点。结果共有26个miRNAs在胃癌标本(包括24份胃癌组织和SGC7901细胞)中异常表达。其中19个下调,7个上调。实时荧光定量PCR检测出miR-9在胃癌标本中的表达水平显著下调,该结果与基因芯片检测结果一致。miR-9与RAS癌基因家族成员RAB34的表达呈负相关。结论已初步筛选了胃癌相关miRNAs。miR-9可能是胃癌中的标记性miRNAs之一,RAB34是其作用靶点。  相似文献   

6.
7.
目的研究基质金属蛋白酶-2(MMP-2)反义寡核苷酸(ASODN)对人胃癌SGC7901细胞增殖及侵袭能力的影响。方法将不同浓度的硫代磷酸化修饰的MMP-2ASODN转染入人中低分化胃腺癌SGC7901细胞株,RT-PCR法检测细胞MMP-2基因mRNA的转录水平;Transwell试验检测细胞体外迁移和侵袭能力变化;MTT法检测细胞的增殖活性。结果转染MMP-2ASODN后,SGC7901细胞中MMP-2基因mRNA的转录水平显著降低,细胞的体外迁移和侵袭能力受到抑制,且抑制作用随ASODN浓度的增加而增强;而细胞的增殖活性无明显变化。结论MMP-2ASODN可抑制胃腺癌SGC7901细胞MMP-2基因mRNA的转录水平及细胞的体外迁移和侵袭能力,但与胃癌细胞的增殖活性无明显相关性。  相似文献   

8.
Cancer cachexia is a common condition in many cancer patients, particularly those with advanced disease. Cancer cachexia patients are generally less tolerant to chemotherapies and radiotherapies, largely limiting their treatment options. While the search for treatments of this condition are ongoing, standards for the efficacy of treatments have yet to be developed. Current diagnostic criteria for cancer cachexia are primarily based on loss of body mass and muscle function. However, these criteria are rather limiting, and in time, when weight loss is noticeable, it may be too late for treatment. Consequently, biomarkers for cancer cachexia would be valuable adjuncts to current diagnostic criteria, and for assessing potential treatments. Using high throughput methods such as “omics approaches”, a plethora of potential biomarkers have been identified. This article reviews and summarizes current studies of biomarkers for cancer cachexia.  相似文献   

9.
10.
Photodynamic therapy (PDT) can be a highly effective treatment for diseases ranging from actinic keratosis to cancer. While use of this therapy shows great promise in preclinical and clinical studies, understanding the molecular consequences of PDT is critical to designing better treatment protocols. A number of publications have documented alteration in angiogenic factors and growth factor receptors following PDT, which could abrogate treatment effect by inducing angiogenesis and reestablishment of the tumor vasculature. In response to these findings, work over the past decade has examined the efficacy of combining PDT with molecular targeting drugs, such as anti-angiogenic compounds, in an effort to combat these PDT-induced molecular changes. These combinatorial approaches increase rates of apoptosis, impair pro-tumorigenic signaling, and enhance tumor response. This report will examine the current understanding of PDT-induced angiogenic signaling and address molecular-based approaches to abrogate this signaling or its consequences thereby enhancing PDT efficacy.  相似文献   

11.
Endometrial cancer occurs in up to 29% of women before 40 years of age. Seventy percent of these patients are nulliparous at the time. Decision making regarding fertility preservation in early stage endometrial cancer (ES-EC) is, therefore, a big challenge since the decision between the risk of cancer progression and a chance to parenthood needs to be made. Sixty-two percent of women with complete remission of ES-EC after fertility-sparing treatment (FST) report to have a pregnancy wish which, if not for FST, they would not be able to fulfil. The aim of this review was to identify and summarise the currently established biomolecular and genetic prognostic factors that can facilitate decision making for FST in ES-EC. A comprehensive search strategy was carried out across four databases; Cochrane, Embase, MEDLINE, and PubMed; they were searched between March 1946 and 22nd December 2022. Thirty-four studies were included in this study which was conducted in line with the PRISMA criteria checklist. The final 34 articles encompassed 9165 patients. The studies were assessed using the Critical Appraisal Skills Program (CASP). PTEN and POLE alterations we found to be good prognostic factors of ES-EC, favouring FST. MSI, CTNNB1, and K-RAS alterations were found to be fair prognostic factors of ES-EC, favouring FST but carrying a risk of recurrence. PIK3CA, HER2, ARID1A, P53, L1CAM, and FGFR2 were found to be poor prognostic factors of ES-EC and therefore do not favour FST. Clinical trials with bigger cohorts are needed to further validate the fair genetic prognostic factors. Using the aforementioned good and poor genetic prognostic factors, we can make more confident decisions on FST in ES-EC.  相似文献   

12.
目的探讨神经纤毛蛋白2(Neuropilin2,NRP2)干扰质粒对胃腺癌SGC7901细胞株生长、侵袭及转移的影响。方法构建NRP2特异的小RNA干扰质粒shRNA-NRP2,采用脂质体介导的方法将质粒转染入人胃腺癌SGC7901细胞株,Western blot法检测NRP2蛋白的表达;Transwell试验检测胃癌细胞体外迁移和侵袭能力的变化;MTT试验检测胃癌细胞的增殖水平。结果 shRNA-NRP2转染SGC7901细胞后,NRP2蛋白表达明显下降,细胞的侵袭、迁移能力明显受抑制,而细胞的增殖水平无显著变化。结论 shRNA-NRP2干扰质粒可下调胃腺癌SGC7901细胞株NRP2蛋白的表达,进而抑制细胞的侵袭、转移能力,提示NRP2可能成为胃癌分子治疗的靶标。  相似文献   

13.
Breast cancer is the most common worldwide neoplasia in women. The totality of etiology factors of breast cancer is unknown and thus an effective preventive strategy has not been developed. Risk factors associated to breast cancer can be grouped into three broad categories: a) family history (hereditary) factors, b) endocrine and reproductive factors and c) environmental and life-style factors including diet. Animal models of chemical induced mammary carcinogenesis with 7, 12-dimethylbenz[a]anthracene and N-methyl-N-nitrosourea have been useful in the study of biology, treatment and prevention of breast cancer. In this review we show the usefulness and advantages of animal models in the study of nutritional factors associated with breast cancer in order to propose new prevention strategies. We review briefly different experimental approaches as well as some physiologic effects and mechanisms of some nutritional factors studied with animal models of mammary carcinogenesis. Nutritional factors reviewed were: a) energy restriction and high-fat intake, b) soy and phytoestrogens, c) retinoids and carotenoids, d) conjugated linoleic acid, and e) brown seaweed and iodine.  相似文献   

14.
One of the major challenges in the treatment of cancer are differential responses of patients to existing standard of care anti-cancer drugs. These differential responses may, in part, be due to a diverse range of genomic, epigenomic, proteomic, and metabolic alterations among individuals suffering from the same type of cancer. Precision medicine is an emerging approach in cancer therapeutics that takes into account specific molecular alterations, environmental factors as well as lifestyle of individual patients. This approach allows clinicians and researchers to select or predict treatments that would most likely benefit the patient based on their individual tumor characteristics. One class of precision medicine tools are predictive, in vitro drug-response assays designed to test the sensitivity of patient tumor cells to existing or novel therapies. These assays have the potential to rapidly identify the most effective treatments for cancer patients and thus hold great promise in the field of precision medicine. In this review, we have highlighted several drug-response assays developed in ovarian cancer and discussed the current challenges and future prospects of these assays in the clinical management of this disease.  相似文献   

15.
The current state of research and production of a novel class of crystal-glass materials, slag-glass ceramics (SGC) is reviewed. The composition and mechanical and physical properties of SGC materials are given. Utilization of the wastes from metallurgy and other industries for SGC synthesis and the prospects for potential use of SGC are discussed.Translated from Steklo i Keramika, No. 12, pp. 8–13, December, 1996  相似文献   

16.
The standard genetic code (SGC) is a set of rules according to which 64 codons are assigned to 20 canonical amino acids and stop coding signal. As a consequence, the SGC is redundant because there is a greater number of codons than the number of encoded labels. This redundancy implies the existence of codons that encode the same genetic information. The size and organization of such synonymous codon blocks are important characteristics of the SGC structure whose evolution is still unclear. Therefore, we studied possible evolutionary mechanisms of the codon block structure. We conducted computer simulations assuming that coding systems at early stages of the SGC evolution were sets of ambiguous codon assignments with high entropy. We included three types of reading systems characterized by different inaccuracy and pattern of codon recognition. In contrast to the previous study, we allowed for evolution of the reading systems and their competition. The simulations performed under minimization of translational errors and reduction of coding ambiguity produced the coding system resistant to these errors. The reading system similar to that present in the SGC dominated the others very quickly. The survived system was also characterized by low entropy and possessed properties similar to that in the SGC. Our simulation show that the unambiguous SGC could emerged from a code with a lower level of ambiguity and the number of tRNAs increased during the evolution.  相似文献   

17.
Patients with advanced breast cancer are at high risk of developing bone metastasis. Despite treatment advances for primary breast cancer, metastatic bone disease remains incurable with a low relative survival. Hence, new therapeutic approaches are required to improve survival and treatment outcome for these patients. Bone is among the most frequent sites of metastasis in breast cancer. Once in the bone, disseminated tumor cells can acquire a dormant state and remain quiescent until they resume growth, resulting in overt metastasis. At this stage the disease is characterized by excessive, osteoclast-mediated osteolysis. Cells of the bone microenvironment including osteoclasts, osteoblasts and endothelial cells contribute to the initiation and progression of breast cancer bone metastasis. Direct cell-to-cell contact as well as soluble factors regulate the crosstalk between disseminated breast cancer cells and bone cells. In this complex signaling network interleukins (ILs) have been identified as key regulators since both, cancer cells and bone cells secrete ILs and express corresponding receptors. ILs regulate differentiation and function of bone cells, with several ILs being reported to act pro-osteoclastogenic. Consistently, the expression level of ILs (e.g., in serum) has been associated with poor prognosis in breast cancer. In this review we discuss the role of the most extensively investigated ILs during the establishment of breast cancer bone metastasis and highlight their potential as therapeutic targets in preventing metastatic outgrowth in bone.  相似文献   

18.
Gastric cancer (GC) is one of the most common cancers and a leading cause of cancer deaths around the world. Chemotherapy is one of the most effective treatments for cancer patients, and has remarkably enhanced survival rates. However, it has many side effects. Recently, microRNAs (miRNAs) have been intensively studied as potential biomarkers for cancer diagnosis and treatment monitoring. However, definitive biomarkers in chemotherapy-induced peripheral neuropathy (CIPN) are still lacking. The aim of this study was to identify the factors significant for neurological adverse events in GC patients receiving XELOX (oxaliplatin and capecitabine) chemotherapy. The results show that XELOX chemotherapy induces changes in the expression of hsa-miR-200c-3p, hsa-miR-885-5p, and hsa-miR-378f. Validation by qRT-PCR demonstrated that hsa-miR-378f was significantly downregulated in CIPN. Hsa-miR-378f was identified as showing a statistically significant correlation in GC patients receiving XELOX chemotherapy according to the analysis of differentially expressed (DE) miRNAs. Furthermore, 34 potential target genes were predicted using a web-based database for miRNA target prognostication and functional annotations. The identified genes are related to the peptidyl-serine phosphorylation and regulation of alternative mRNA splicing with enrichment in the gastric cancer, neurotrophin, MAPK, and AMPK signaling pathways. Collectively, these results provide information useful for developing promising strategies for the treatment of XELOX-chemotherapy-induced peripheral neuropathy.  相似文献   

19.
Breast cancer (BC) is the most frequently diagnosed cancer in women for which numerous diagnostic and therapeutic options have been developed. Namely, the targeted treatment of BC, for the most part, relies on the expression of growth factors and hormone receptors by these cancer cells. Despite this, close to 30% of BC patients may experience relapse due to the presence of minimal residual disease (MRD) consisting of surviving disseminated tumour cells (DTCs) from the primary tumour which can colonise a secondary site. This can lead to either detectable metastasis or DTCs entering a dormant state for a prolonged period where they are undetectable. In the latter, cells can re-emerge from their dormant state due to intrinsic and microenvironmental cues leading to relapse and metastatic outgrowth. Pre- and clinical studies propose that targeting dormant DTCs may inhibit metastasis, but the choice between keeping them dormant or forcing their “awakening” is still controversial. This review will focus on cancer cells’ microenvironmental cues and metabolic and molecular properties, which lead to dormancy, relapse, and metastatic latency in BC. Furthermore, we will focus on the role of autophagy, long non-coding RNAs (lncRNAs), miRNAs, and exosomes in influencing the induction of dormancy and awakening of dormant BC cells. In addition, we have analysed BC treatment from a viewpoint of autophagy, lncRNAs, miRNAs, and exosomes. We propose the targeted modulation of these processes and molecules as modern aspects of precision medicine for BC treatment, improving both novel and traditional BC treatment options. Understanding these pathways and processes may ultimately improve BC patient prognosis, patient survival, and treatment response.  相似文献   

20.
In recent years, the effectiveness of antimicrobials in the treatment of Pseudomonas aeruginosa infections has gradually decreased. This pathogen can be observed in several clinical cases, such as pneumonia, urinary tract infections, sepsis, in immunocompromised hosts, such as neutropenic cancer, burns, and AIDS patients. Furthermore, Pseudomonas aeruginosa causes diseases in both livestock and pets. The highly flexible and versatile genome of P. aeruginosa allows it to have a high rate of pathogenicity. The numerous secreted virulence factors, resulting from its numerous secretion systems, the multi-resistance to different classes of antibiotics, and the ability to produce biofilms are pathogenicity factors that cause numerous problems in the fight against P. aeruginosa infections and that must be better understood for an effective treatment. Infections by P. aeruginosa represent, therefore, a major health problem and, as resistance genes can be disseminated between the microbiotas associated with humans, animals, and the environment, this issue needs be addressed on the basis of an One Health approach. This review intends to bring together and describe in detail the molecular and metabolic pathways in P. aeruginosa’s pathogenesis, to contribute for the development of a more targeted therapy against this pathogen.  相似文献   

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