Serum oestradiol in women with carcinomas of the breast and uterine cervix

Endogenous oestrogens are thought to be involved in breast cancer, but few studies could show the direct relationship between hormones and pathological process of the disease. In the present study, oestradiol was estimated in the serum of pre-and postmenopausal breast cancer patients along with normal healthy controls and patients with carcinoma of the uterine cervix which is not dependent on oestrogens. Premenopausal patients with breast cancer showed higher levels of oestradiol as compared to premenopausal control women as well as cervical cancer patients. Whereas, no statistically significant differences were observed in serum oestradiol levels amongst postmenopausal groups of breast cancer, cervical cancer and normal women. The result of the study reflects the association of oestradiol as well as its difference in the pathological events of pre and postmenopausal breast cancer.     

Breast cancer in developing population: A nutrition caveat

From January 1992-January 1998, 1404 patients attended the “Breast Clinic” of R.N.T. Medical College M.B. Hospital, Udaipur. Out of these, 11% and 81% patients had breast cancer (B.C.) and benign breast cancer (B.B.D.) respectively. The oxidative load in B.C. was 2.32 times higher than controls, but comparable to B.B.D. β-Carotene deficiency was uncommon in patients, whereas vitamin A deficiency was almost equally common in both B.C. and controls. Most of the patients had almost depleted levels of α-tocopherol and ascorbic acid but their TBAR levels were in normal range. The data in the present study when compared with B.B.D. and other local normal subjects point out: a) oxidative burden in B.C. is a consequence and not the cause of the disease, (b) oxidative stress could be one of the etiological factors in tumor expression, which need not to be malignant and c) α-tocopherol and ascorbic acid are not importantly responsible for higher oxidative burden in B.C.     

y-氨基丁酸和维生素E对AA肉鸡胸肌生长的影响

目的：研究y-氨基丁酸（GABA）对肉鸡胸肌生长的影响,并进一步探讨y-氨基丁酸（GABA）和维生素E（VE）联合应用时是否具有协同作用。方法：试验将300只鸡随机分为6个试验组,每组50羽。其中试验I组为对照组,试验Ⅱ、Ⅲ、Ⅳ组日粮中分别添加25mg／kg、50mg／kg、75mg／kg的GABA,试验V、Ⅵ组日粮中分别添加50rag／kgGABA＋50mg／kgVE和50mg／kgGABA＋100mg／kgVE。在21日龄和42日龄分剐采样,显微镜下测算肌纤维直径。结论：在日粮中添加GABA对肉仔鸡体重和胸肌生长有一定的影响,且具有一定的剂量依赖性,其中以中剂量（50mg／kg）的GABA应用效果最佳。日粮中添加25mg／kg的GABA可以显著提高21日龄肉鸡胸肌肌纤维直径,促进早期肌肉生长,而一定剂量GABA（50rag／kg）与VE（50-100mg／kg）联合应用可显著降低42日龄胸肌肌纤维直径,进而改善肉品质。     

Biochemistry of Nitric Oxide

Nitric oxide (NO) a free radical having both cytoprotective as well as tumor promoting agent is formed from l-arginine by converting it to l-citrulline via nitric oxide synthase enzymes. The reaction product of nitric oxide with superoxide generates potent oxidizing agent, peroxynitrite which is the main mediator of tissue and cellular injury. Peroxynitrite is reactive towards many biomolecules which includes amino acids, nucleic acid bases; metal containing compounds, etc. NO metabolites may play a key role in mediating many of the genotoxic/carcinogenic effects as DNA damage, protein or lipid modification, etc. The basic reactions of nitric oxide can be divided as direct effect of the radical where it alone plays a role in either damaging or protecting the cell milieu and an indirect effect in which the byproducts of nitric oxide formed by convergence of two independent radical generating pathways play the role in biological reactions which mainly involve oxidative and nitrosative stress. Nitric oxide is also capable of directly interacting with mitochondria through inhibition of respiration or by permeability transition. Reaction of nitric oxide with metal ions include its direct interaction with the metals or with oxo complexes thereby reducing them to lower valent state. Excessive production of nitric oxide can be studied by inhibiting the synthetic pathway of nitric oxide using both selective or specific nitric oxide synthase inhibitor or non-selective nitric oxide synthase inhibitor with respect to isoforms of nitric oxide.     

身体活动降低罹患乳腺癌风险的生物学机制研究进展

乳腺癌是目前我国发病率较高的癌症类型,直接关系到众多女性的健康.科学预防乳腺癌的发生是控制乳腺癌发病率的重要途径.已有的流行病学研究证明,身体活动可以显著降低罹患乳腺癌的风险.通过综合近年来国际主流文献对身体活动干预乳腺癌发生的机制研究,阐述身体活动干预乳腺癌的可能的生物学途径,尤其是对乳腺癌生物标记物的干预效果,这些生物指标主要包括身体质量指数、雌/雄激素、胰岛素耐受、脂肪因子以及TNF-a、Ⅱ-6等炎症因子.女性长期进行中等强度以上的锻炼,可以通过控制体重、减少脂肪、降低循环雌激素水平、改善胰岛素耐受、调控脂肪因子以及拮抗炎症因子等生物学途径预防乳腺癌的发生.由于雌激素代谢、胰岛素敏感性、脂肪因子合成等均与脂肪组织有关,因此,通过身体活动控制体重是预防乳腺癌的核心.建议重视长期跟踪实验及对多种人群的干预研究;在实验中需对身体活动的类型及运动强度、持续时间等进行详细阐述,进一步改进评估方法.     

初级组蛙泳腿部动作教学中常见错误及原因分析

游泳教学腿部动作是基础，通过对初级组蛙泳腿部动作教学中常见错误动作的原因进行分析，提出练习和纠正错误动作的方法，为初级组蛙泳教学提供参考。     

分段逆向调强优化方法在乳腺癌调强放疗计划设计中的应用研究

目的:制作乳腺癌调强放疗计划时,采用分段逆向调强优化方法以达到更好的靶区剂量和保护肺、心脏等危及器官。方法:应用Eclipse8.6计划系统针对10例乳腺癌患者(肿瘤原发部位左右侧各5例)分别制定T1,T2模式调强放疗计划,处方剂量均为DT50Gy/25次。T1模式采用左乳300°、330°、0°、30°、60°、90°和120°方向射野,右乳60°、30°、0°、330°、300°、270°和240°方向射野,设置优化参数进行逆向优化和剂量运算。T2模式采用与T1模式相同的角度方向设野,第一段总剂量24Gy,分次剂量2Gy,分12次治疗,设置优化参数进行逆向优化和剂量运算;第二段总剂量26Gy,分次剂量2Gy,分13次照射,设置优化参数,采用"Base dose plan"功能选择基于第一段治疗计划以总量50Gy来逆向优化和剂量运算。将两段计划相加作为T2模式的治疗计划,通过剂量体积直方图比较两种模式下计划的靶体积和危及器官剂量分布。结果:T1、T2模式调强放疗计划的靶体积均满足临床剂量要求,对于左侧乳腺癌,适形指数分别为0.727±0.034、0.751±0.034(t=-6.20,P=0.003);对于右侧乳腺癌,适形指数分别为0.691±0.058、0.729±0.048(t=-5.39,P=0.006)。对左侧乳腺癌,T2模式的左肺V10(%)、左肺V20(%)、左肺V30(%)、全肺V10(%)、全肺V20(%)、全肺V30(%)和心脏V10(%)均大于T1模式,分别增大5.0%、2.7%、3.7%、4.6%、2.6%、3.8%和4.4%。对于右侧乳腺癌,无充分证据说明危及器官各指标有差别。结论:与T1模式相比,采用分段逆向调强优化方法能更好的优化靶区的剂量分布,但对左侧乳腺癌而言,会略微增加左肺、全肺和心脏剂量受量。     

Human cancer genetics

Cancer is a genetic disorder.Although heredi-tary cancers account for only a small fraction of all tumors,most cancers are caused by a variable mix of heredity and environment that leads to accumulations of genetic alterations and then uncontrolled cell pro-liferations(Kops et al.,2005).In addition,genetic alteration is one of the a few most important bio-logical factors that determine the diagnosis and prognosis of different cancers and dictate the treat-ment strategies for cancer patients.Fu…     

CRISPR/Cas: a Nobel Prize award-winning precise genome editing technology for gene therapy and crop improvement

Since it was first recognized in bacteria and archaea as a mechanism for innate viral immunity in the early 2010 s,clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein(Cas) has rapidly been developed into a robust, multifunctional genome editing tool with many uses. Following the discovery of the initial CRISPR/Cas-based system, the technology has been advanced to facilitate a multitude of different functions. These include development as a base editor, prime editor, epigenetic editor, and CRISPR interference(CRISPRi) and CRISPR activator(CRISPRa) gene regulators. It can also be used for chromatin and RNA targeting and imaging. Its applications have proved revolutionary across numerous biological fields, especially in biomedical and agricultural improvement. As a diagnostic tool, CRISPR has been developed to aid the detection and screening of both human and plant diseases, and has even been applied during the current coronavirus disease 2019(COVID-19) pandemic. CRISPR/Cas is also being trialed as a new form of gene therapy for treating various human diseases, including cancers, and has aided drug development. In terms of agricultural breeding, precise targeting of biological pathways via CRISPR/Cas has been key to regulating molecular biosynthesis and allowing modification of proteins, starch, oil, and other functional components for crop improvement. Adding to this, CRISPR/Cas has been shown capable of significantly enhancing both plant tolerance to environmental stresses and overall crop yield via the targeting of various agronomically important gene regulators. Looking to the future, increasing the efficiency and precision of CRISPR/Cas delivery systems and limiting off-target activity are two major challenges for wider application of the technology. This review provides an in-depth overview of current CRISPR development, including the advantages and disadvantages of the technology,recent applications, and future considerations.     

进展期胃癌新辅助化疗疗效的Meta分析

针对进展期胃癌新辅助化疗的价值在临床中的应用仍有争论,本文采用Cochrane系统评价方法,查询了国内外有关的英文及中文随机对照试验研究,以对胃癌新辅助化疗的疗效进行Meta分析,为临床决策提供依据.