Standardization of examinations in maxillofacial roentgenology. I. Standardization of methods in intraoral roentgenography

Typical errors in teeth roentgenography reproduced in experiment, indicate that considerable disproportional distortions of images of anatomical structures which are decisive for radiodiagnosis, may occur in these cases. These distortions influence the accuracy of assessment of the condition of periapical tissues, marginal parts of the alveolar process, cavity sizes, and the actual end of the root of the canal. Standardization of intraoral roentgenography is based on a strict position of the patient's head, angle of inclination and alignment of a tube. Specialized P3-1 film should be used. Its processing should strictly correspond to the instructions of a manufacturing factory otherwise the quality of an image is deteriorated and an effective equivalent dose on the vital organs is increased.     

Standardization of the Papanicolaou stain. I. A comparison of five nuclear stains.

The staining characteristics of five nuclear stains used in a Papanicolaou staining procedure were investigated. Alcohol-fixed cervical smears were stained with a modified Papanicolaou procedure using hematoxylin, alcoholic thionin bromide, alcoholic Victoria blue B, gallocyanin or the thionin Feulgen reagent (thionin-SO2) as the nuclear stain. The same anionic counterstain was used for all slides, and the optical densities of cell nuclei and cytoplasm were measured with the IBAS 2000 image analyzer. Alcoholic thionin gave the most intense nuclear stain, with a very high reproducibility of the staining pattern. Hematoxylin showed the highest coefficient of variation of the staining intensity. Both hematoxylin and gallocyanin gave some nonspecific cytoplasmic staining. Thionin-SO2 allowed a quantitative assessment of DNA, but gave a low staining intensity. Staining with the metal complex dyes interfered with subsequent staining with the pararosaniline Feulgen reagent. Alcoholic thioinin is thus recommended as a nuclear stain for cervical cytology in the Papanicolaou procedure, both for image analysis and for visual microscopy.     

General Considerations: Methods for the Standardization of Biological Stains: Part I

This is the introduction to a series of papers giving the assay methods employed in the testing of dyes submitted to the Commission on Standardization of Biological Stains. These methods are used in determining whether or not to allow the sale of any particular batch of dye as a certified stain. The present paper takes up general considerations, discussing the relative merits of various analytical methods designed both for qualitative and quantitative analysis. The advantages of determining light “absorption ratios” for qualitative purposes, and of titanous chloride reduction for quantitative purposes are pointed out. It is further indicated that in spite of all the refinements that have yet been made in chemical and optical methods of analysis, great weight must be placed on biological testing in determining the quality of any given sample.     

Standardized Viral Hemagglutination and Hemagglutination-Inhibition Tests. I. Standardization of Erythrocyte Suspensions

A spectrophotometric procedure for standardizing red blood cell suspensions for use in viral hemagglutination tests is described. The procedure is based on highly reproducible cyanmethemoglobin absorbance readings at 540 nm on any suitable spectrophotometer. Target values for milligrams of cyanmethemoglobin per 100 ml are given for the red cell suspensions of all mammalian and avian species employed in viral hemagglutination tests. By use of these values and a cyanmethemoglobin standard curve for a particular photometer, approximate 4% erythrocyte suspensions can be diluted to any lesser concentration. Coefficients of variation for the various diluted suspensions range from 4 to 7%.     

Subpicogram determination of malondialdehyde by gas-liquid chromatography with nitrogen phosphorus detector. I. Standardization

A method for the measurement of malondialdehyde (MDA) using GLC with a nitrogen phosphorus detector (GLC/NPD) is described and evaluated. The method uses 2-hydrazinobenzothiazole (HBT) which forms condensation derivatives with MDA, acetoacetaldehyde, and acetylacetone (AA). GC/MS and 13C NMR studies of the three derivatives obtained showed that they are 2-(pyrazol-1'-yl)benzothiazoles and that they can be separated by GLC/NPD. Any one of these derivatives can be used as an internal standard for the measurement of the other two. The optimal conditions for the measurement of MDA were studied. At pH 2.5 and 70 degrees C, the condensation derivative is quantitatively formed in 30 min. Its extraction is obtained by a mixture of n-hexane/isoamyl alcohol 98/2 (v/v) containing HBT-AA as internal standard. The GLC detection limit is 0.04 pmol. Inter- and intrassay coefficients of variation were 2.9 and an average of 4.0%, respectively. The method is specific, and there was no interference from other carbonyl compounds. The artifactual formation of MDA from carbohydrates during the derivatization reaction is negligible. The method is proposed as a reference method for the standardization of working solutions of MDA or MDA-generating solutions.     

Standardization of the study of maxillofacial roentgenology. II. Standardization of the methodology of orthopantomography

The main factor of a good quality of orthopantomograms is a correct position of the occlusion plane and chin support, the straightening of the cervical vertebrae, head fixation and a choice of physicochemical conditions for exposure. All these conditions ensure the standardization of orthopantomography, reducing to the minimum errors in investigations.     

Spectrophotometry of Dyes: 1. Methyl Green. 2. Pyronin

Comparisons of absorption peaks of seven samples of methyl green showed that two different types of the dye were represented. One type (2 samples) had the visible peak near 617 mμ; the other (4 samples) near 630 mμ, while one sample was intermediate in spectral characteristics. Using these findings as a means of differentiating between heptamethyl and hexamethylethyl pararosanil-in is suggested. The Y and B forms of pyronin were found to be readily distinguishable by comparing their absorption maxima (Y, 546 mμ, B, 557-8 mμ). A check on the application of Beer's law of dilution showed that it held (1-3 mg./liter) for pyronin and that the relative effect of dilution was a slow increase with pyronin but a rapid decrease with methyl green.     

Spectrophotometry of Dyes: 1. Methyl Green. 2. Pyronin

Comparisons of absorption peaks of seven samples of methyl green showed that two different types of the dye were represented. One type (2 samples) had the visible peak near 617 mμ; the other (4 samples) near 630 mμ, while one sample was intermediate in spectral characteristics. Using these findings as a means of differentiating between heptamethyl and hexamethylethyl pararosanil-in is suggested. The Y and B forms of pyronin were found to be readily distinguishable by comparing their absorption maxima (Y, 546 mμ, B, 557-8 mμ). A check on the application of Beer's law of dilution showed that it held (1-3 mg./liter) for pyronin and that the relative effect of dilution was a slow increase with pyronin but a rapid decrease with methyl green.     

Zinc-iodide-osmium procedures as markers of subcellular structures. I. Standardization of staining of transmitter containing vesicles

In the present investigation certain stain properties of the zinc iodide-osmium tetroxide mixture were investigated. It was observed that the type of reaction of certain cell structures with a ZIO mixture largely depended on several factors, namely, the pH of the mixture, aldehyde prefixation and type (s) of buffer (s) used. The standardization of these parameters led to the development of four procedures, each one of them with distinct stain properties. A nomenclature to designate these methods is proposed. The following procedures were applied to material processed for electron microscopy: 1. C.4.4-ZIO-4 degree -18 h: the ZIO mixture was prepared in citric acid-disodium phosphate buffer pH 4.4 and the tissue was incubated at 4 degree C during 18 H; 2. K-P.7.4-C.4.4-ZIO-4 degree -18 h: the tissue was prefixed in Karnovsky fixative prepared in phosphate buffer pH 7.4 and then incubated in C.4.4-ZIO at 4 degree C during 18 h; 3. V.7.4-ZIO-4 degree -18 H: the ZIO was prepared in veronal buffer pH 7.4 and incubation of the tissue was at 4 degree during 18 H; 4.K-P.7.4-V.7.4-ZIO-4 degree -18 h: the tissue was prefixed in Karnovsky fixative prepared in phosphate buffer pH 7.4 and then incubated in V.7.4-ZIO at 4 degree C during 18 h. The chromaffin cells and the cholinergic endings of the rat adrenal medulla and the vas deferens nerves were studied. C.4.4-ZIO-4 degree -18 h: This procedure stained adrenaline and noradrenaline storing granules. Synaptic vesicles at cholinergic endings were not stained. K-P.7.4.4-ZIO-4 degree -18 h: One type of chromaffin granule (probably storing noradrenaline) and both, the small and the granulated synaptic vesicles of cholinergic endings were deeply stained with this method. The aminergic fibres of the vas deferens reacted synaptic vesicles at cholinergic endings were not stained. K-P.7.4.4-ZIO-4 degree -18 h: One type of chromaffin granule (probably storing noradrenaline) and both, the small and the granulated synaptic vesicles of cholinergic endings were deeply stained with this method. The aminergic fibres of the vas deferens reacted synaptic vesicles at cholinergic endings were not stained. K-P.7.4.4-ZIO-4 degree -18 h: One type of chromaffin granule (probably storing noradrenaline) and both, the small and the granulated synaptic vesicles of cholinergic endings were deeply stained with this method. The aminergic fibres of the vas deferens reacted negatively. V.7.4-ZIO-4 degree -18 H: Both types of chromaffin granules and only the small synaptic vesicles of cholinergic endings were revealed with this procedure. In addition, some compartments of the Golgi complex were also stained. K-P.7.4-V.7.4-ZIO-4 degree -18 h: This method did not stain adrenaline and noradrenaline storing granules. Cholinergic synaptic vesicles appeared stained. However, the most striking stain property of this procedure was the staining of many cell organelles. The probable mechanisms by which different factors affect the ZIO reaction are discussed.     

遗传学专业术语不规范化的现象探研—I.同名异义现象

对现行的遗传学教材中存在的专业术语同名异义现象进行探研,针对Y连锁遗传、限性遗传、从性遗传、单倍体、多倍性和累加作用等专业术语存在的表达不清,相互矛盾,同名异义等问题,进行分析探讨,并提出Y连锁遗传不能与限性遗传相混淆,限性遗传和从性遗传的基因是位于常染色体上,但二者存在区别。单倍体是指具有配子染色体数目的个体,但并不等同于一倍体。建议多倍体用染色体基数来表达,如三倍体用3X表示。 累加作用是指数量性状遗传基因间的相互累加作用。