Effects of sciatic neurectomy on the femur in growing rats: Application of peripheral quantitative computed tomography and Fourier transform infrared spectroscopy

The effects of unilateral sciatic neurectomy (USN) on the development of the femur were studied in 15 growing Wistar-derived rats (age, 5 weeks). The rats were divided into four groups: USN-operated group (right femur), USN-nonoperated group (left femur), sham-operated group (right femur), and sham-nonoperated group (left femur). Bone mineral density (BMD), bone mineral content (BMC), bone area, periosteal circumference, and endosteal circumference were measured by peripheral quantitative computed tomography (pQCT) and the mineral/matrix ratio was evaluated by Fourier transform infrared spectroscopy (FTIR). The USN-operated group showed a significant decrease in cortical BMC, bone area, and periosteal circumference compared with the other groups (P < 0.05). The cortical BMD did not vary significantly between the groups. In the cancellous bone, the USN-operated group showed a significant decrease in BMD and BMC at the metaphysis compared with the other groups (P < 0.05). The mineral/matrix ratio of the cortical bone did not differ significantly between the USN-operated and USN-nonoperated groups. These results suggest that in cortical bone, USN inhibits periosteal bone formation but has no significant effect on the mineral/matrix ratio of cortical bone in femurs. In cancellous bone, USN induces bone loss at the metaphysis. Received: Nov. 19, 1998 / Accepted: Feb. 12, 1999     

Application of the Electrotopological State Index to QSAR Analysis of Flavone Derivatives as HIV-1 Integrase Inhibitors

Purpose. A QSAR study based on electrotopological state (E-state) indices was conducted for a series of flavone HIV-1 integrase inhibitors to guide drug design. Methods. E-state indices formulated to encode electronic and topological information for each skeletal atom in a molecule (Kier and Hall Pharm. Res. 7:801–807 (1990)) were calculated using the Molconn-X program, and partial least squares (PLS) multivariate regression was used to derive QSAR models. Results. Predictive models with correlation coefficients (r²) of 0.98 (3 PLS components) and 0.99 (5 PLS components) and corresponding cross-validated correlation coefficients (c.v. r²) of 0.51 and 0.73, were obtained for inhibition of cleavage and integration, respectively, with one molecule omitted from the analysis. Conclusions. E-state indices at C6, C3, C5, C5, and O4 were found to be more important for prediction of activity than those for any of the other 12 flavone skeletal atoms that are common to the molecules in the data set.     

The mechanism of directional coronary atherectomy

An attempt was made to assess the mechanism of directional coronaryatherectomy using different methods of analysis. Quantitativecoronary angiography was used as the gold standard to assessthe immediate results of atherectomy, and a comparative quantitativeanalysis of atherectomy and balloon angioplasty was made. Todetermine whether the post-atherectomy cross-sectional areais close to a circle, we compared the area measurements obtainedby edge detection with those obtained by videodensitometry.Finally, the extent of a ‘Dotter’ effect was establishedby quantitative angiography following crossing the stenosiswith the atherectomy device. For the purpose of this study,the results of the first 113 successful atherectomy procedureswere reviewed. In matched lesions, directional atherectomy induceda greater increase in minimal luminal diameter than balloonangioplasty (1.6 mm vs 0.8 mm; P < 0.0001 However, this luminalimprovement is due to a substantial ‘Dotter’ effectinduced by the bulky atherectomy device. Following atherectomy,only a slight difference in cross-sectional area measurementsbetween edge detection and videodensitometry (mean difference:0.28 mm² was found. Histologic examination of an atherectomizedcoronary artery showed a near-circular post atherectomy areageometry. In conclusion, directional atherectomy is a very effectivedevice with a substantially better initial result than balloonangioplasty. However, insertion of this bulky device itselfcauses an important ‘Dotter’effect.     

Contributions of chronological age,age at menarche and menopaus and of anthropometric parameters to axial and peripheral bone densities

Bone mineral density (BMD) was measured in 128 normal postmenopausal women at different skeletal sites: lumbar spine and proximal femur, using dual-energy X-ray absorptiometry (DXA), and the cancellous and cortical envelopes of the distal third of radius and tibia, using precise low-dose quantitative computed tomography (QCT). Multivariate analysis included chronological age, ages related to menstrual history (menopause and menarche) and anthropometric factors, e.g. height and weight, as independent predictive variables. Weight is a much-studied predictor of bone density. At sites of high bone turnover, i.e. cancellous envelope, the effect of weight appeared overshadowed by estrogen-related parameters: age-past-menopause was the first predictor of BMD in the cancellous compartment of radius and in Ward's triangle, and the number of reproductive years was the strongest predictor of BMD in the cancellous compartment of tibia and in the spine (L2–4). This suggests that in addition to menopause, the length of menstrual life should be considered as an explanation for the variations in current bone mass in postmenopausal women.At the cortical level of radius, the effect of chronological age was predominant. At the cortical level of tibia, height and weight were the best predictors of BMD.We conclude that the influence of parameters related to menstrual history is predominant in sites with mainly cancellous tissue and that anthropometric factors constitute the best predictors of BMD in the cortical sites of weight-bearing bones.     

Autoradiographic study of iron-binding sites in the rat brain: distribution and relationship to aging

Specific binding of 59Fe to various brain structures was investigated in rats using nanomolar concentrations of 59FeCl3 and quantitative autoradiography. Saturation studies revealed high affinity binding (kd in the nanomolar range) with binding sites density (Bmax) which varied in different brain regions from 462 fmol per mg tissue in the central thalamic nuclei to over 4 pmol per mg tissue in the cerebral peduncle. Binding was seen in both white and gray matter structures. Bmax values for frontal cortex, dentate gyrus, and substantia nigra were significantly lower in older rats. The distribution of 59Fe binding sites was not consistent with the distribution of brain iron as reported by other investigators. 59Fe binding was reduced significantly in the presence of free radicals. These observations suggest that high affinity binding sites for iron are localized differentially in various brain structures and may play an important role in the translocation and storage of potentially harmful ferric cations in brain. The finding that the capacity of the brain tissue to bind iron diminished with age in discrete brain regions suggests that in the aged animal, the removal of "free" iron from the cellular domain may be impaired in such regions, leading to increased susceptibility to iron-enhanced lipid peroxidation and cell death.     

麻黄中生物碱类有效成分的非水毛细管电泳含量测定

目的 利用非水毛细管电泳(NACE)法对麻黄中各生物碱类有效成分进行含量测定，并比较不同提取方法中各组份含量差异。方法 采用50mmol／L醋酸铵的甲醇溶液，未加入任何其他添加剂，检测波长为210nm。结果 各组份在8min内达基线分离。伪麻黄碱在9．8～147．0μg／mL，去甲基麻黄碱在6．8～102．0μg／mL，麻黄碱在9．4～141．0μg／mL，去甲基伪麻黄碱在4．8～72．0μg／mL，甲基麻黄碱在6．8～102．0μg／mL分别有良好的线性关系。各麻黄碱类回收率在95．0％～100．4％。结论 为麻黄中各生物碱类有效成分的含量测定提供了一种快速、准确和灵敏的测定方法。     

反相高效液相色谱法测定发酵液中梅岭霉素

目的:建立了发酵液中梅岭霉素的定量测定方法。方法:反相高效液相色谱法,Hypersil-C_(18)柱(4 mm×125mm,5μm),流动相为乙腈-水(78:22),流速1.2mL·min~(-1),检测波长238 nm,室温测定。结果:在1O.2～163.2μg·mL~(-1)范围内梅岭霉素浓度与峰面积呈良好线性关系,r=0.999 7,回归方程为Y=25.44X+2.72。样品的日间 RSD≤1.8％,高中低浓度样品的日内RSD≤2.5％(n=8)。平均回收率为96.9％(n=8,RSD<3.0％)。结论:本方法快速、准确、简便、稳定,为定量分析提供了可靠的依据。     

小青龙汤配方颗粒与传统饮片中芍药苷含量的比较

目的 比较小青龙汤配方颗粒与传统饮片中芍药苷的含量。方法 采用高效液相色谱法进行分析比较研究。结果 该测定方法精密度、稳定性和重复性良好，平均回收率为101．78％，RSD=0．85％。结论 两种剂型中芍药苷的含量无明显差异。     

肝组织多药耐药基因高表达与结肠癌肝转移的相关性研究

目的　探索早期检测肝组织多药性耐药基因对结肠癌肝转移的预测价值。方法　取裸鼠 4 0只 ,用人结肠癌SW4 80细胞系制作裸鼠原位结肠癌肝转移模型。模型建立的第 10天肝活检取左右肝叶各2mm3 组织 ,用实时荧光定量PCR方法检测多药耐药基因 (multidrugresistancegene,mdr- 1mRNA)的表达 ;模型建立的第 5周观察裸鼠肝脏是否形成肉眼转移灶。结果　经实时荧光定量RT -PCR检测肝活检组织mdr- 1基因 ,在存活的 36只裸鼠中 2 2例高表达 ,平均CT值 (Cyclethreshold ,即反应管内的荧光信号到达设定的域值时所经历的循环数 )为 2 5 90 1,平均拷贝数为 4 2 7× 10 7/ugRNA ,并高表达的 2 2只裸鼠均有肉眼肝转移灶形成 (10 0 % ) ;mdr - 1基因低表达 (平均CT值 33 36 8,平均拷贝数 2 11× 10 5)及无表达的 14只裸鼠中 ,仅 1例形成肉眼肝转移灶 (7 1% ) ,其余 13例均无肉眼肝转移灶形成 (P <0 0 1)。结论　结肠癌肝活检肿瘤细胞mdr- 1mRNA基因高表达与异时的肝转移灶形成有明显的相关性 ,提示检测结肠癌肝组织多药性耐药基因的高表达可以预测异时的肝转移灶形成。