显微分光扫描在细胞内物质定量分析的应用

本文扼要叙述。显微分光扫描法的基本原理,结合计算机数据处理给出了一些细胞基本参数诸如细胞核,质面积;细胞内物质吸收光谱、相对含量;细胞二维灰度图、三维含量分布图等。列举过热BGC胃癌细胞SDH含量及正常小白鼠肝细胞核内DNA含量测定,说明该测量法有较好的可靠性、重复性。并初步探讨使用该方法可能产生误差及克服误差方法等问题。     

Stimulated drug uptake in a photoreceptor cell

In many cells, organelle translocation requires structural integrity of microtubules [2,6,11,14, 5]. We have found that extracellular application of the antimicrotubular drug colchicine, which was expected to enter cells simply by diffusion, was ineffective at blocking pigment granule migration (PGM) inside fly photoreceptors. However, illumination of these receptors in the presence of colchicine resulted in complete PGM block. From a combined study using microphotometry, microfluorometry and intracellular recordings, we inferred that light permeabilized the cell to the drug. This hypothesis was supported by the observation that illumination caused the photoreceptor to take up an inert dye. The results show that target cells optically selected from a homogeneous population can be induced to take up an agent from the extracellular fluid. Remarkably, this process of light-induced drug uptake does not affect cell viability.     

Renal test dyes V.

Summary Fluorescence intensities on the renal cortex of Wistar-Furth rats were measured photometrically after an i.v. injection of FITC-dextrans with a molecular weight of 3400, 19000, 26000, 41000 or 153000. The kidney surface was illuminated by the 488 nm line of an ionized argon laser and the fluorescent patterns were recorded by a high sensitivity television camera connected with a tape recorder. Intensities of fluorescence were evaluated directly from the television record. Passages of FITC-dextrans through peritubular capillaries, early and late proximal as well as distal tubules correspond to those of lissamine green. Intensity of the dye during the tubular passage decreases with increasing molecular weight of dextran. Comparison of the tubular intensity of dextran 19000, 26000, 35000 and 41000 with that of dextran 3400 gave corresponding values of 45%, 33%, 19% and 13%, respectively. As could be expected from clearance results, dextran 153000 was only visible during its passage through the peritubular capillaries, but no tubular passage could be observed. This method permits, for the first time, the visualization and photometric quantification of glomerular filtration as a function of molecular size, i.e. glomerular permeability. Since several tubules are seen in each recorded field, it is often possible to make several analyses from the same videotaped record. The photometry of a dye bolus also allowed the measurement of local flow velocities in the proximal tubular loops. Supported by USPHS Grant HL08977 and Deutsche Forschungsgemeinschaft (SFB90)     

Nonuniform myosin expression along single fibers of chronically stimulated and contralateral rabbit tibialis anterior muscles

Using a combined histochemical and biochemical technique, single fiber analyses were performed on chronically stimulated and contralateral tibialis anterior (TA) muscles of the rabbit. The major fiber population (60%) in 30 days stimulated TA was transforming fibers (type IIC). Some of these fibers displayed a nonuniform distribution of histochemically assessed myofibrillar actomyosin ATPase (mATPase) activity. This heterogeneity of mATPase activity along the fibers was verified in longitudinal sections and by microphotometric evaluation of mATPase staining intensities in serial cross-sections. Biochemical analyses of single fiber segments revealed that these C fibers not only coexpressed fast- and slow-myosin subunits but did so nonuniformly along their length. The distribution of fast- and slow-myosin subunits in these fibers was not random but focal. Variations in myosin expression were also observed in some of the C fibers in the contralateral TA. As opposed to the transforming fibers in the stimulated TA, heterogeneities of mATPase activity and myosin subunits in these contralateral C fibers were less focal and more gradual. These findings suggest that muscle fibers in chronically stimulated TA and the contralateral muscle do not transform synchronously or uniformly along their length.     

The effects of carbonate and Mg on in vitro mineralization of demineralized dentin

The demineralized sections of dentins of rats were mineralized in vitro. The sections were observed with contact microradiography (CMR) and their mineral contents were determined with micro-photometry of CMR films. In the mineralizing solution containing no carbonate, mineral appeared to adhere only on the surface of the demineralized dentins, regardless of their structure or their chemical nature. However, once the demineralized dentins were immersed in a mineralizing solution containing carbonate, the mineralization proceeded continuounly even in mineralizing solution containing no carbonate, suggesting that the action of carbonate participates in the initiation of mineral deposition. The effect of Mg in the mineralizing solution containing carbonate was studied. Mg showed an inhibitory effect in the mineralization of matrices. This effect seemed to participate in the process of growth or increase of precipitation after the initiation.     

Quantitative pharmacohistochemistry of acetylcholinesterase in neostriatum of inbred strains of mice

A quantitative pharmacohistochemical technique has been used in the present study to assay acetylcholinesterase (AChE) activity in the neostriatum of C57BL/6 and DBA/2 mice. This technique permits the measurement of enzyme activity into microscopically defined compartments and is suitable for the study of striatal AChE-containing, putatively cholinergic, neurons. Microphotometric measurements have been performed in the cytoplasm of AChE-containing perikarya and in the striatal matrix: in both compartments, AChE activity was significantly higher in DBA/2 than in C57BL/6 mice. The present data show that AChE quantitative pharmacohistochemistry is suitable for studying the enzyme activity in nervous tissue and, particularly, in the cytoplasm of individual AChE-containing neurons. In addition, interstrain comparison indicates the presence of a genetically determined higher AChE content in striatal neurons of the DBA/2 strain.     

吗丙嗪和阿霉素合用对肿瘤细胞周期及DNA合成的影响

目的：观察吗丙嗪（Ｐｒｏ）和阿霉素（Ｄｏｘ）合用对肿瘤细胞周期及ＤＮＡ合成的影响，以探讨吗丙嗪增强阿霉素抗肿瘤作用之机制。方法：采用拒染法观察Ｐｒｏ，Ｄｏｘ和Ｐｒｏ＋Ｄｏｘ对小鼠体外艾氏腹水癌细胞（ＥＡＣ）的杀伤作用；采用标记前体物参入法和显微分光光度术观察两药合用对ＥＡＣ细胞周期及ＤＮＡ合成的影响。结果：Ｐｒｏ２１．４６，４２．９２和６４．３８μｍｏｌ·Ｌ－１增强Ｄｏｘ对ＥＡＣ细胞的杀伤作用；Ｐｒｏ（２１４．５９μｍｏｌ·Ｌ－１）和Ｄｏｘ（１８．０２μｍｏｌ·Ｌ－１）合用对ＥＡＣ细胞ＤＮＡ合成有明显的抑制作用；用药后４～８ｈＧ１期细胞增加，ＤＮＡ直方图左移，各用药组细胞分裂指数无明显差异。结论：Ｐｒｏ可增强Ｄｏｘ的抗肿瘤作用，其机理可能与Ｐｒｏ加强Ｄｏｘ对ＤＮＡ合成的抑制及对Ｇ１期细胞累积作用增强有关。     

Multiple analysis of tyrosine hydroxylase and calmodulin distributions in the forebrain of the rat using a microphotometry system

Immunohistochemical distributions of tyrosine hydroxylase and calmodulin in the rat forebrain were analyzed quantitatively to confirm our previous results that the activities of central catecholamine-synthesizing enzymes are regulated by a calcium-calmodulin-dependent system. The adjacent slices of adult rat brain were stained immunohistochemically for tyrosine hydroxylase and for calmodulin, and the distributions and amounts of these proteins were measured by a fluorescence microphotometry system that was developed in our laboratory. Immunohistochemical fluorescence intensity was measured stepwise at 40 microns intervals through a 6 microns phi (on the slice) pin hole. Each stained brain slice was divided into approximately 100,000 areas, and measured for fluorescence intensity and displayed two- and three-dimensionally. Immunoreactive staining of tyrosine hydroxylase and calmodulin was observed in almost all areas of the brain, but its intensity varied. The relatively high levels of calmodulin could be observed in brain regions with high levels of tyrosine hydroxylase distribution, though high levels of tyrosine hydroxylase could not always be observed in brain regions where high levels of calmodulin were distributed. In the present study, high levels of tyrosine hydroxylase and calmodulin were distributed in the nucleus accumbens septi and the lateral part of the neostriatum regions in which the amount of dopamine was increased by the intraventricular administration of calcium. These findings suggest that the synthesis of central catecholamines is regulated by a calcium-calmodulin-dependent system.