Microscopica acta最新文献

In quantitative neuroanatomy and neuropathology, large neuronal systems are frequently analyzed on the basis of small tissue blocks thus assuming that the volume changes of the various compartments of the tissue block can be corrected by an overall factor. 228 blocks of cerebral cortex and white matter of the frontal lobe, thalamus, and striatum were prepared from 13 human brains and embedded in paraffin. The mean shrinkage in the paraffin sections was found to be 51% for the cerebral cortex and 42% for the white matter. Therefore, an overall correction factor tissue blocks both with cerebral cortex and white matter results in an underestimation of cerebral cortex and an overestimation of white matter.

The newer DNA-binding fluorochromes DAPI (4',6-diamidino-2-phenylindole) and fluorochrome 33258 H (Hoechst) (2-[2-(4-hydroxy-phenyl)-6-benzimidazolyl]-6-(1-methyl-4-piperazyl)-benzimidazole . 3 HCl) proved useful in identifying genital strains of Chlamydia trachomatis in McCoy cells. For practical purposes, e.g. to analyse patient specimens, we recommend this technique using the fluorochromes at pH 2.0 in a final concentration of 3 micrograms/ml and non-replicative McCoy cells after fixation with alcohol-acetic acid. The application of the fluorochrome technique in demonstrating Chlamydia trachomatis-infections is recommendable because it is a) simple to perform, b) a rapid procedure, c) it corresponded well with the Giemsa staining in identifying mature inclusions, and d) it facilitates the detection of the RNA-rich early stages of chlamydial growth. For this reasons the fluorochrome technique with DAPI or 33258 H at pH 2.0 can be considered a highly specific and sensitive method for identifying Chlamydia trachomatis.

The effect of four antidiarrheal drugs (China clay, bentonite, pectin, Kaoprompt H) on the epithelia of murine small intestine and colon was studied under in vitro conditions with histological techniques. In this experiment, the drugs coarsely coated the guts' surface without outlining details or protruding into clefts. The resistance of the layers to rinsing is slightly different. None of the substances was able to protrude between the microvilli. Best intrusion was shown by pectin. The transfer of the experimental results to in vivo conditions is discussed.

This paper presents informations as to the ability of aqueous solutions of two basic dyes, such as Dahlia and Victoria blue, belonging to aminotriarylmethane group for the staining of DNA-aldehyde molecules as well as DNA-phosphate groups. It has been found that sections of rat tissues stained with aqueous solutions of these dyes after acid hydrolysis followed by drying between folds of filter paper and treatment in n-butanol for a minute and then by a very brief treatment in a mixture consisting of equal parts of n-butanol and absolute ethanol reveal well-stained nuclei. Tissue sections after acid hydrolysis when stained with aqueous solutions of these dyes and then treated with SO2 water do not reveal any colouration of the nuclei. Since both the dyes are without any primary amino group in their molecules, it has been concluded that the imino group of Dahlia and the tertiary amino group of Victoria blue with cold concentrated phosphoric acid and then stained with any of these dyes also exhibit well-stained nuclei. The absorption spectra of nuclei stained with these dyes for DNA-aldehyde molecules as well as DNA-phosphate groups reveal positions of the peaks of maximum absorption at the same wavelength, which, however, are different in the case of nuclei stained with the two dyes. The implications of these findings have been discussed.

The technique of gentle nuclear lysis for electron microscopic observation is suggested, which comprises adsorption of isolated nuclei on a positively charged pricked supporting film and sequential short-timed installation of the support with its back onto the filter paper moistened by lysing solution. The advantage of the method is slow, gradient-like, and to some extent regulated treatment allowing to visualize nuclear structures in their integrity.

A novel method is presented for the staining of cell nuclei with aqueous solutions of Janus blue, methylene blue, and Janus red in tissue sections from which RNA has been extracted selectively with cold phosphoric acid. Not only this, DNA-aldehyde molecules can also be stained when tissue sections from which RNA has been extracted are then hydrolysed in 6 N hydrochloric acid at 30 degrees C for 15 min followed by staining with Janus blue, methylene blue, and Janus red. Following staining with any of these dyes, sections can be dried between folds of filter paper and then treated with n-butanol or passed through grades of ethanol, cleared in xylene and mounted. Staining with Janus blue has been considered to be metachromatic, particularly in the sections of the rectum in which glycogen stains blue-black and the nuclei purplish. An aqueous solution of methylene blue does also stain glycogen blue with similar colour of the nuclei while with Janus red both the nuclei as well as glycogen stain red. The in situ absorption spectra of the nuclei stained with the dyes mentioned, after selective extraction of RNA, reveal peaks of maximum absorption at 560-570 nm (Janus blue), at 600 and 640 nm (methylene blue), and at 530 nm (Janus red). Those of nuclei stained for DNA-aldehyde molecules are at 560 nm (Janus blue), at 600 and 630 nm (methylene blue), and at 520 nm (Janus red). Possible significance of these findings has been discussed.

This paper reports on the use of gallamine blue (GB), a dye of the oxazine group, as a specific stain for DNA in animal tissue nuclei. The dye can be used as 1% aqueous solution in boiling distilled water at ph 1.0 to 1.5. Not only this, GB dye-reagent can also be prepared after dispersing the dye with concentrated sulphuric acid and then dissolving the friable mass in 1% cobalt chloride and then used to stain nuclei at very low pH. Although the dye does not contain any primary amino group in its molecules, it can be used as aqueous solution or as dye-reagent to stain DNA-aldehyde molecules in tissue sections which are hydrolysed in 6N HCl at 28 degrees C or at 40 degrees C for 15 and 5 min, respectively. Following staining of the DNA-aldehyde molecules, the preparations cannot be treated with SO2 water, since this treatment brings about complete leaching of the dye from the nuclei. It has, therefore, been concluded that GB staining of DNA-aldehyde molecules is due to a modified Feulgen reaction in which tertiary amino group may be involved. Moreover, GB in an aqueous solution or as a dye-reagent can be used to stain DNA-phosphate groups in tissue sections from which RNA has been extracted selectively with cold concentrated phosphoric acid. Sections from which RNA has been extracted and then hydrolysed in 6N HCl at 28 degrees C or at 40 degrees C for 15 and 5 min, respectively, can also be stained with this dye. The absorption spectra of nuclei stained following the various procedures have been presented. The paper contains a discussion on the implications of all these findings.

In these studies vasogenic brain edema has been induced by implantation of rat glioma cells RGI 2.2 into BD-IX rats while cytotoxic edema pas produced by permanent regional ischemia in the mongolian gerbil. In the gerbil sodium concentration was raised from 201 meq/kg d.w. (dry weight) [p/b (peak/background) = 0] to 269 meq/kg d.w. (p/b = 0.25; 2 hours) and 651 meq/kg d.w. [p/b = 0.71; 24 hours), whereas potassium concentration decreased from 373 meq/kg d.w. (p/b = 1.69) to 337 meq/kg d.w. (p/b = 1.65) and 152 meq/kg d.w. (p/b = 0.53). In the rat tumor sodium and potassium concentrations were 279 meq/kg d.w. (p/b = 0.44) and 510 meq/kg d.w. (p/b = 1.94). Non-tumorous tissue contained 237 meq/kg d.w. (p/b = 0) and 517 meq/kg d.w. (p/b = 1.98). In addition X-ray microanalysis could show that chlorine behaves like sodium, whereas the concentration of phosphorus and sulphur remains nearly constant. X-ray microanalysis in this case proved to be useful in the localization and quantification of different elements. The main disadvantage, however, is the reduced sensitivity for light elements, e.g. sodium, which cannot be determined in normal brain.