提高医学院校文科生生物化学教学质量策略探讨

生物化学是医学院校学生一门重要的公共基础课。大多数学生认为生物化学这门课程内容庞杂、名词术语繁多、抽象难懂、学习难度大,尤其对于生物学科与化学学科基础薄弱的文科生来讲,学习过程吃力,学习效果不理想,期末挂科率较高。本研究从文科生学习生物化学遇到的困难及教师面临的教学现状出发,找出问题,探讨具体应对策略,旨在提高学生学习生物化学课的兴趣和效果。     

PTEN inhibits macrophage polarization from M1 to M2 through CCL2 and VEGF-A reduction and NHERF-1 synergism

PTEN has been studied in several tumor models as a tumor suppressor. In this study, we explored the role of PTEN in the inhibition state of polarized M2 subtype of macrophage in tumor microenvironment (TME) and the underlying mechanisms. To elucidate the potential effect in TME, RAW 264.7 macrophages and 4T1 mouse breast cancer cells were co-cultured to reconstruct tumor microenvironment. After PTEN was down-regulated with shRNA, the expression of CCL2 and VEGF-A, which are definited to promote the formation of M2 macrophages, have a dramatically increase on the level of both gene and protein in co-cultured RAW 264.7 macrophages. And at the same time, NHERF-1 (Na⁺/H⁺ exchanger regulating factor-1), another tumor suppressor has a similar tendency to PTEN. Q-PCR and WB results suggested that PTEN and NHERF-1 were consistent with one another no matter at mRNA or protein level when exposed to the same stimulus. Coimmunoprecipitation and immunofluorescence techniques confirmed that PTEN and NHERF-1 were coprecipitated, and NHERF-1 protein expression was properly reduced with rCCL2 effect. In addition, cell immunofluorescence images revealed a profound transferance, in co-cultured RAW 264.7 macrophages, an up-regulation of NHERF-1 could promote the PTEN marked expression on the cell membrane, and this form for the interaction was not negligible. These observations illustrate PTEN with a certain synergy of NHERF-1, as well as down-regulation of CCL2 suppressing M2 macrophage transformation pathway. The results suggest that the activation of PTEN and NHERF-1 may impede the evolution of macrophages beyond the M1 into M2 phenotype in tumor microenvironment.     

Molecular therapy of colorectal cancer: Progress and future directions

Colorectal cancer (CRC) remains one of the most common types of cancer and leading causes of cancer death worldwide. Although the introduction of cytotoxic drugs such as oxaliplatin, irinotecan and fluorouracil has improved the treatment of advanced CRC, the individual response to chemoradiotherapy varies tremendously from one patient to another. However, recent progress in CRC molecular therapies may provide new insight into the treatment of this disease. Currently, components of the EGFR, VEGF, Wnt and NF‐kB pathways are the most important targets for CRC therapy. This review chronicles the development of molecular CRC therapies over the past few decades. We also provide an update on the current progress of research concerning the molecular pathways leading to CRC and discuss the possible implications for CRC therapy.     

坐浴Ⅰ号防治肛肠病术后并发症的疗效观察

目的:观察自拟中药方坐浴Ⅰ号用于预防治疗肛肠病术后并发症的临床疗效。方法:164例肛肠病术后住院患者随机分为两组。观察组每日便后用坐浴Ⅰ号坐浴熏洗并常规伤口换药治疗,对照组每日便后用温水清洗患处后常规伤口换药治疗。结果:观察组显效率53.57%,总有效率95.23%,均明显高于对照组(P<0.05)。两组患者疼痛程度、出血、水肿、愈合时间等方面比较,观察组均优于对照组(P<0.05)。结论:坐浴Ⅰ号可减轻肛肠病术后并发症,缩短愈合时间,疗效确切可靠,值得临床推广使用。     

胡椒碱胶囊自乳化释药系统的处方筛选及体外质量评价

摘 要 目的： 研究胡椒碱自乳化释药系统的处方及其体外特性。方法: 通过溶解度、处方配伍试验以及伪三元相图的绘制来筛选处方,并考察空白处方、含药处方对自乳化效率的影响以及自乳化后乳滴的粒度分布,考察了胡椒碱自乳化胶囊的溶出速率和稳定性。结果: 胡椒碱自乳化胶囊的最终处方为油酸乙酯、Tween 80、Transcutol P,三者之比为30∶55∶15（w∶w∶w）,药物为辅料总量的2.5%,粒径约为90 nm,胡椒碱自乳化胶囊60 min溶出度是自制的胶囊剂6倍;低温和常温稳定性考察药物含量无明显变化。结论:所制备的胡椒碱自乳化胶囊自乳化效率高、能力强、性质稳定,体外溶出率高。     

柱前衍生化RP-HPLC法测定夜宁颗粒中二苯乙烯苷的含量

摘 要 目的： 建立柱前衍生化RP HPLC法测定夜宁颗粒中二苯乙烯苷含量的方法。方法: 采用丹酰氯作为衍生化试剂,色谱柱为Wondasil-C₈色谱柱( 250 mm×4.6 mm,5 μm), 以（30 mM的乙酸铵用磷酸调节pH至3.5）-乙腈（78∶22）为流动相,柱温为30℃,流速为1.0ml·min^-1,荧光检测器检测（激发波长为370 nm,发射波长为560 nm）,进样量为20 μl。结果: 制剂中其他成分无干扰,二苯乙烯苷在0.071～27.280 mg·ml^-1范围内线性关系良好,r=0.999 9,平均回收率为99.04% ,RSD为0.1 %（n=9）。结论:所用方法简便快捷,灵敏度高,准确性好,可作为夜宁颗粒质量控制方法的依据。     

EGCG Blocked Phenylephrin-Induced Hypertrophy in H9C2 Cardiomyocytes,by Activating AMPK-Dependent Pathway

AMP-activated protein kinase (AMPK) is a key regulator of energy metabolism. Previous studies have shown that activation of AMPK results in suppression of cardiac myocyte hypertrophy via inhibition of the p70S6 kinase (p70S6K) and eukaryotic elongation factor-2 (eEF2) signaling pathways. Epigallocatechin-3-gallate (EGCG), the major polyphenol found in green tea, possesses multiple protective effects on the cardiovascular system including cardiac hypertrophy. However, the molecular mechanisms has not been well investigated. In this study, we found that EGCG could significantly reduce natriuretic peptides type A (Nppa), brain natriuretic polypeptide (BNP) mRNA expression and decrease cell surface area in H9C2 cardiomyocytes stimulated with phenylephrine (PE). Moreover, we showed that AMPK is activated in H9C2 cardiomyocytes by EGCG, and AMPK-dependent pathway participates in the inhibitory effects of EGCG on cardiac hypertrophy. Taken together, our findings provide the first evidence that the effect of EGCG against cardiac hypertrophy may be attributed to its activation on AMPK-dependent signaling pathway, suggesting the therapeutic potential of EGCG on the prevention of cardiac remodeling in patients with pressure overload hypertrophy.     

Complement factors C1q, C3 and C5b-9 in the posterior sclera of guinea pigs with negative lens-defocused myopia

AIM

To investigate the expression of complement factors in the posterior scleral fibroblasts of guinea pigs with negative lens-defocused myopia.

METHODS

Eighteen guinea pigs were assigned randomly to two groups: the negative lens-defocused group (NLD group, n=9) and the normal control without treatment group (NC group, n=9). The effect of myopic induction was compared in three subgroups: eyes treated with a -10.00 D negative lens in the NLD group (NL group), eyes treated with a plano (0 D) lens in the NLD group (PL group), and untreated right eyes in the NC group (NC group). The following analyses were conducted at four weeks: examination of the refractive error via retinoscopy, assessment of complement C5b-9 expression in the posterior scleral fibroblasts using immunohistochemistry, and measurements of complement C1q and C3 protein levels in the posterior sclera by Western blot.

RESULTS

After an induction period of four weeks, a significant myopic shift was detected in the eyes of the NL group, relative to that of the PL and NC groups (P<0.05). Data analysis showed a significant increase in the percentage of C5b-9 immunopositive fibroblasts in the posterior sclera of the NL group eyes, compared to the PL group (q=11.50, P<0.001). Significantly higher levels of C1q (q=4.94, P=0.01) and C3 (q=4.07, P=0.03) protein were detected in the posterior sclera of NL group eyes, compared to the PL group. There were no significant difference between the PL and NC groups for C5b-9 (q=2.44, P=0.10), C1q (q=1.55, P=0.53) and C3 (q=0.98, P=0.77) in the posterior sclera.

CONCLUSION

The data from present study provide evidence of the up-regulation of C5b-9, C1q and C3 in the posterior scleral fibroblasts in a NLD myopic animal model. The results suggest that the complement system may be involved in the development of myopia.