纳米锶磷灰石的体外细胞毒性研究

目的对纳米锶磷灰石进行体外细胞毒性试验,评价其生物安全性,为将其应用于骨折临床修复奠定基础。方法将不同浓度的纳米锶磷灰石浸提液与小鼠成纤维细胞L929体外共培养2d、4d、7d,倒置相差显微镜下观察细胞的形态变化;用四氮唑盐比色法(MTT)检测,计算细胞相对增殖度,用六级毒性分类法进行评级。结果培养期细胞贴壁生长,形态良好,随着培养天数的增加细胞大量增殖,毒级为0～1级。相同时间点不同浓度的纳米锶磷灰石浸提液的吸光度值无明显差异性(p>0.05)。结论初步证实纳米锶磷灰石具有人体应用的生物安全基础,无细胞毒性。     

脂蛋白残粒RLP-c检测的临床意义

目的 探讨脂蛋白残粒RLP-c作为新的脂质指标的临床意义。方法 采用免疫分离法测定正常对照组(NC)、冠心病组(CHD)和2型糖尿病组(T2DM)的RLP-c水平,并比较RLP-c与其他脂质指标的相关性。结果 CHD组和T2DM组RLP-c水平明显高于NC组(P<0.01),其水平与甘油三脂(TG)和极低密度脂蛋白胆固醇(VLDL-c)高度相关(P<0.01)。结论 RLP-c可用于对动脉粥样硬化的危险性评估。     

马齿苋活性成分体内外抗癌作用的初步筛选

目的 观察马齿苋活性成分对人肺腺癌细胞系(A-549 cell)、人喉表皮样癌细胞系(Hep-2 cell)、人宫颈癌细胞系(Hela cell)和人恶性胚胎横纹肌瘤细胞系(RD cell)生长的影响.方法 体外培养条件下用不同浓度的马齿苋活性成分处理4种癌细胞,通过溴化二甲噻唑二苯四氮唑(MTT)试验法测定癌细胞的增殖;同时处理S180荷瘤小鼠,观察荷瘤小鼠的体重、瘤重、死亡率和抑瘤率.结果 马齿苋生物碱对离体培养的A-549肺癌细胞、Hela细胞和Hep-2细胞的增殖均具有明显抑制作用,马齿苋多糖对Hela细胞有较强的抑制作用, 马齿苋脂肪酸对Hep-2细胞有一定的抑制作用,马齿苋黄酮对RD细胞有很强的抑制作用,并存在浓度剂量效应,高浓度抑制作用强.结论 马齿苋活性成分能选择性地杀伤癌细胞,有进一步研究的潜在价值.     

正常人外周血淋巴细胞 IL—2受体免疫放射测定

采用~(125)I 标记小鼠抗人IL—2受体(P55)的抗Tac(CD_(25))单克隆抗体,成功地建立了人IL—2受体的免疫放射分析法,动态观察了人外周血淋巴细胞经PHA 刺激24、48和72h 后IL—2受体表达的时间曲线,通过Scatchard 作图分析表明~(125)I—抗Tac 单克隆抗体与PHA 活化的上述三个时间点的T 淋巴细胞的最大结合容量(B_(max))分别为43000位点/细胞、54000位点/细胞和61000位点/细胞。本研究为临床IL—2受体检测提供一种简便的免疫放射测定法。     

ReProComet: a new in vitro method to assess DNA damage in mammalian sperm.

The increasing request of chemical safety assessment demands for the validation of alternative methods to reduce the resort to animal experimentation. Methods that evaluate reproductive toxicity are among those requiring the largest use of animals. Presently, no validated in vitro alternative exists for the assessment of reproductive toxicity. Mammalian sperm are sensitive targets of DNA-reactive chemicals, which form premutagenic adducts. Here, we propose a new method based on comet assay to detect DNA damage induced by potential germ cell mutagens in bull sperm available from assisted reproduction practices. In somatic cells, chemical-induced adducts can be revealed by comet assay that detects DNA breaks produced during adduct repair. Mature sperm, however, are devoid of repair enzymes, and adducts are processed only after fertilization. For this reason, comet assay is not sensitive to detect DNA lesions induced in sperm by most chemicals. To overcome such limitation, we developed a modified comet assay based on the addition of a protein extract from HeLa cells to agarose-embedded sperm on microscopic slides. To test the method, sperm were treated in vitro with methyl methanesulfonate (MMS) or melphalan (MLP) and comet assay was conducted both with and without protein supplementation. No effect of MMS or MLP was detected without protein supplementation; on the contrary, a clear-cut dose-dependent effect was measured after addition of the cell extract. These results represent a proof of concept of a novel in vitro mutagenicity test on sperm that could offer a promising approach to complement previously validated in vivo germ cell genotoxicity assays.     

Postmenopausal Women With Colles'' Fracture Have Lower Values of Bone Mineral Density Than Controls as Measured by Quantitative Ultrasound and Densitometry

Measurement of ultrasonographic parameters provides information concerning not only bone density but also bone architecture. We investigated the usefulness of ultrasonographic parameters and bone mineral density (BMD) to evaluate the probability of Colles' fracture. Two-hundred eighty-nine postmenopausal women (62.3 +/- 8.7 yr) with (n = 76) and without (n = 213) Colles' fracture were studied. BMD of lumbar spine and proximal femur was evaluated in all women by dual-energy X-ray absorptiometry (DXA) and speed of sound (SOS), broadband ultrasound attenuation (BUA), and stiffness in the calcaneus were measured by a Sahara ultrasonometer (Hologic). Patients suffering from Colles' fracture had lower values of BMD adjusted by height at the lumbar spine, L2-L4 (0.797 g/cm2 vs 0.860 g/cm2), femoral neck (0.685 g/cm2 vs 0.712 g/cm2 ), SOS (1518 m/sg vs 1525 m/sg), and stiffness (74.6 vs 77.7) (p < 0.05). Nevertheless, BUA values were similar in both groups. After stepwise logistic regression analysis, the area found under receiver operating characteristic (ROC) curves was 0.60 for L2L4 and 0.63 for a formula combining L2L4 and height. Our data suggest that patients suffering from Colles' fracture have lower values of BMD by DXA, SOS, and stiffness. However, the ability of these techniques to discriminate is low because the values for the area under ROC curve are 0.60 for L2-L4 and 0.63 for a formula derived of the combination of L2-L4 and height.     

Development of HPLC plasma assays for CAM 4515 and CAM 4750, two new nonpeptide tachykinin antagonists, and application to bioavailability studies

CAM 4515 and CAM 4750 are new nonpeptide tachykinin NK₁ receptor antagonists with different lipophilicities. Two separate, simple, and sensitive HPLC methods for the quantitation of these two compounds in plasma and the evaluation of their oral bioavailability in rats were developed and validated. Extraction of CAM 4515 from plasma involved protein precipitation with acetonitrile, while that for CAM 4750 involved a one-step liquid-liquid extraction with methylene chloride. The analytes in extracts were chromatographed on a C18 column using two different separation buffers, 47% 0.02 M sodium citrate (pH 3.5)-53% acetonitrile for CAM 4515 and 59% 0.02 M potassium phosphate dibasic (pH 7.0)-41% acetonitrile for CAM 4750, and both compounds were detected by fluorescence (excitation 278 nm; emission 342 nm). Stability profiles of both drugs at −20°C or room temperature in plasma and in reconstituted buffers were good. The limit of quantitation for both drugs was 5 ng ml⁻¹ with good linearity from 5 to 1000 ng ml⁻¹ using 100–200 μl of plasma. Excellent precision (relative standard deviation < 8.3%) and accuracy (relative error ± 9.2%) were observed for both CAM 4515 and CAM 4750. Oral bioavailability studies were conducted for each compound in rats receiving a p.o. dose of 20 mg kg⁻¹ and an i.v. dose of 5 mg kg⁻¹. The absolute oral bioavailability of CAM 4750 (80%) was estimated to be 40-fold greater than that of CAM 4515 (2%). The experimental results suggest that incorporation of a pyridine group into the structural backbone may greatly improve bioavailability.     

Quantitative observation by enzyme cytochemistry of human rectal adenocarcinoma cells killed by LAK cells

Activity of succinic dehydrogenase(SDH)and acid phosphatase(AcPase)of effector-target cells during the process of LAK cells killing HR8348 cells was estimated by enzyme cyto-chemistry technique.SHD positive granules and AePase gray level were assayed with MIAS-300image analyser.The results showed:(1)After cocultivation of effector and target cells for vari-ous times,the activity of AcPase of HR8348 cells was apparently higher than that of the controlgroup,and it increased following prolonged coincubation.SDH activity of target cells increasedmarkedly within 30 and 60 rain cocultivation,but became low after 90 min treatment.(2)Ac-Pase content within LAK cells at 60,90,120,180 and 240 rain cocultivation was significantlyhigher than that of control group(P<0.01).The phenomenon of high AcPase and SDH activitywithin effector-target cells indicates that the function of the two types of cells was in an activestate.At the early stage of effector-target combining,the increase of SDH with HR8348 cellsmay be related to defensive function of the target cells.Higher AcPase activity of target cells in-dicates the activation of lysosomal enzyme which serves as the material basis for autolysis of thecells.     

白细胞介素1α对鼠甲状腺细胞增殖的影响

采用四氮唑蓝（MTT）比色法检测TSH存在和缺乏时白细胞介素1α（IL－1α）对鼠FRTL-5细胞增殖的影响。结果提示，在无TSH条件下IL-1α20～2000kU／L对FRTL－5细胞无明显促增殖作用；在TSH存在时IL－1α20和200kU／L对FRTL－5细胞增殖亦无明显抑制作用，IL－1α2000kU／L则可显著抑制TSH介导的FRTL－5细胞增殖。