bluuebunny/crossref_metadata_2025_split huggingface dataset:
Automated techniques for the study of lung alveolar stereological parameters with the IBAS image analyser on optical microscopy sections
Authors: Rigaut J. P. , Berggren P. , Robertson B. 
Published: August 2011

SUMMARYIn the case of lung alveoli, the good contrast of the features allows the use of a fully automated image analysing procedure, yielding many of the desirable stereological parameters which can be estimated on optical microscopy slides: alveolar volume and surface densities, a form factor and average mean integral curvature.With our program, specially designed for the IBAS image analyser (Kontron Bildanalyse, Munich, B.R.D.), the whole automated process takes an average of 28 s per field. The image analyser‐obtained stereological estimates compare well with those given by point and intersection counting methods.Some difficulties inherent in image analysers arise when measuring alveolar boundary lengths: a scheme is therefore proposed which eliminates the image‐edge errors, with no sampling bias, by comparing three different frames inside each field. A solution to the problem of estimating automatically the positive and negative tangent counts, necessary for the curvature calculations, is also proposed.Our program has been applied routinely to the study of premature newborn rabbit lung alveoli, as part of a work dealing with an evaluation of the possibility of preventing the respiratory distress syndrome by the administration of heterologous surfactant.
The correlation of light and electron microscope observations
Authors: Perrie W. T. , Webb D. M. 
Published: August 2011

SUMMARYA technique is described to allow electron microscopic investigation of a specific feature of a section on a glass slide. A section on a glass slide (previously treated with a silicone release agent) is processed as required for light microscopy. The section is then impregnated with Araldite and cured with an epoxy resin block on top of it. The section and block are removed from the slide and viewed with a light microscope. The selected area for ultrastructural study remains under continuous observation while the block is trimmed. Semi‐thin (1 μm) sections retain the original staining for light microscopy and ultra‐thin sections are stained with heavy metals in the normal manner. We show how an inflammatory lesion in a large area of muscle in a case of polymyositis may be quickly located and studied at the ultrastructural level.
A simple and efficient method for objective discrimination between pseudostratified, metaplastic and dysplastic nasal epithelium
Authors: Boysen M. , Marton P. F. , Pilström L. , Solberg L. A. , Torp T. 
Published: August 2011

SUMMARYMorphologic features may sometimes be interpreted differently by different pathologists. By introducing objective methods in the histological evaluation the subjectivity of the judgement is reduced and a higher degree of consistency achieved. In the present study three linear parameters of nasal epithelial basal cells: the largest transversal nuclear diameter, the sum of the longitudinal and transversal nucleolar axes and the basal cell width, i.e. the width of the attachment face to the basement membrane, were classified by means of three‐class rulers. From this classification weighted indices were made which were then given equal weight and transformed, so that when added up their sum, the joint index (Q) to the largest possible extent was consistent with pseudostratified/stratified cuboidal, stratified squamous and dysplastic epithelium when Q ≤ 1, 1 < Q ≤ 2 and Q > 2 respectively. Tested prospectively we found 91% agreement between the morphometric and histological classification.The method presented is extremely simple and rapid to perform, and appears to have diagnostic potential in distinguishing various types of epithelial alterations of the nasal mucosa. The method may also be useful in approaching similar problems in other epithelia.
An investigation of the degree of randomness in the dispersion of point features (triple junctions) in a plane
Authors: Stock S. R. , Hilliard J. E. 
Published: August 2011

SUMMARYThe nearest‐neighbour distance distribution was used as a criterion to investigate the dispersion of triple junctions. Comparison of the expected and measured distributions by the χ2‐test indicated that the triple junctions were probably not randomly located, contrary to an earlier conclusion based on an areal probe of the same specimen. The present results suggest that areal probes are insensitive to large deviations from randomness in the location of points in a plane.
A loop for the transfer of thin tissue sections
Authors: Deer B. C. 
Published: August 2011

SUMMARYThe construction and use of a simple wire loop for the transfer of thin tissue sections are described. The loop picks up, carries, and releases a drop of liquid containing the sections. The loop is opened and closed by manipulation of the forceps to which it is attached. This controls the attraction of the loop for the water drop and ensures reliable pickup and release of the sections.
The application of high resolution electron microscopy to the study of oxidation
Authors: Newcomb S. B. , Smith David J. , Stobbs W. M. 
Published: August 2011

SUMMARYHigh resolution electron microscopy has been used to examine both the similarities and differences in the growth morphologies of Fe2O3, Cr2O3 as formed on iron alloys, and MgO as formed by burning Mg in moist air. A general discussion is also given of the relative advantages and disadvantages of a variety of TEM techniques as applicable to the study of oxidation phenomena.
ALCHEMI: a new technique for locating atoms in small crystals
Authors: Spence J. C. H. , Taftø J. 
Published: August 2011

SUMMARYAtom Location by Channelling Enhanced Microanalysis (ALCHEMI) is a quantitative technique for identifying the crystallographic sites, distribution and types of substitutional impurities in many crystals. The method involves no adjustable parameters, can be applied to areas as small as a few hundred Angstroms and to impurity concentrations down to about 0·1 atomic per cent. It is capable of distinguishing neighbours in the periodic table. The method uses the incident electron beam orientation dependence of characteristic X‐ray emission and uses an energy dispersive X‐ray microanalyser fitted to a transmission electron microscope. The method does not require the specimen thickness or precise orientation to be known, and makes few assumptions about the form of the dynamical electron wavefunction, which need not be calculated or predicted. The classical problems of cation ordering in spinels, feldspars and olivine have now been studied by this method.
The relative importance of multiple inelastic scattering in the quantification of EELS
Authors: Bourdillon A. J. , Hall D. J. , Morrison C. J. , Stobbs W. M. 
Published: August 2011

SUMMARYA comparison is given of energy loss results obtained for the L and K edges of aluminium as a function of specimen thickness, crystallographic orientation and collection angle. It is demonstrated that as the thickness is increased post‐loss elastic scattering is generally important in reducing the fraction of electrons collected. The implications for the quantification of EELS data are discussed while a comparison of the Fe/C ratio in cementite demonstrates the improved consistency which can be obtained when comparing K and L losses at lower energy separation than are the losses for aluminium.
The transmission electron microscopy of oxide scale formation on Fe‐Ni‐Cr alloys
Authors: Newcomb S. B. , Stobbs W. M. 
Published: August 2011

SUMMARYThe oxidation behaviour of 10Cr and 20Cr iron alloys, with nickel contents from 0 to 34 wt% both in air and in CO/CO2, is summarized with particular emphasis on the form and chemistry of the different scales as they were observed using transmission electron microscopy. The various modes of inward oxidation are for example characterized with ‘internal’ and ‘inner’ oxidation taking place under different circumstances. The role of carbon during oxidation in a CO/CO2 atmosphere is also discussed as is the way in which a given alloy can show either chemical or mechanical passivation failure in different environments.
Cryoultramicrotomy versus plastic embedding: comparative immunocytochemistry of rat anterior pituitary cells
Authors: Hemming F. J. , Mesguich P. , Morel G. , Dubois P. M. 
Published: August 2011

SUMMARYThe anterior pituitary of the rat is used as a model for the study of the effects of freezing or plastic embedding on the maintenance of antigenicity. Rat anterior pituitaries are fixed in 2.5% glutaraldehyde in 0.1 m phosphate buffer pH 7.4. Some of the blocks are post‐fixed before being divided into two lots. One batch is frozen, while the other is dehydrated and embedded. The indirect antibody enzyme method is applied to ultrathin sections obtained by cryoultramicrotomy after freezing or by sectioning after embedding. All six pituitary hormones are detected by both methods. Comparison shows that the morphological characteristics are identical for both techniques, though ultrastructural preservation is better after embedding. Immunoreactivity is found in secretory granules and sometimes in the endoplasmic reticulum. Osmium postfixation may reduce or even abolish antigenicity in plastic‐embedded tissue. After cryoultramicrotomy, however, even after osmium fixation, antibody may be used 1000 times more diluted than after plastic embedding. Embedding preserves ultrastructure and limited antigenicity while the use of cryoultramicrotomy is a far more sensitive technique.
An ultrastructural study of cryofractured myocardial cells with special attention to the relationship between mitochondria and sarcoplasmic reticulum
Authors: Dalen Helge , Scheie Paul , Myklebust Reidar , Sætersdal Thorvald 
Published: August 2011

SUMMARYA comparative study of various cryofracturing techniques has been conducted on the mammallian myocardial cell. Quench freezing of fresh or fixed tissue in melting Freon 22 resulted in severe cellular damage due to ice crystallization. Fixation with Karnovsky's fixative prior to quenching had no modifying effect on the size and distribution of the ice crystals. The crystals were orientated primarily in the direction of the long axis of the myofibrils, manifested as empty tube‐like structures in the scanning electron microscope (SEM). Regular cross‐bridging often seen at the Z‐band levels indicated that ice crystals, at least in some portions of the cells, were confined within the sarcomere. Within the same cell the size of the ice crystals could vary considerably.Treatment of the tissue with polyvinylpyrrolidone (PVP) prior to rapid freezing had no noticeable cryoprotective effect. The surface of the thin layer of PVP surrounding the freeze dried tissue appeared amorphous in the SEM. However, the first evidence of ice crystallization was found a few micrometres under the surface.The freezing artefacts were completely circumvented if the cryofracturing was carried out on ethanol‐impregnated or on critical point dried material. While the first method resulted in a smooth fracture plane passing through the cell structures, the intracellular fracture plane of the critical point dried material followed the surface of the cell organelles.Separation of the cell organelles caused by freezing or by critical point drying revealed thread‐like structures extending from the mitochondrial surface. Re‐examination of SEM‐processed material in the transmission electron microscope (TEM) revealed that these structures were part of the sarcoplasmic reticulum (SR), and that a close contact between the SR and the outer mitochondrial membrane existed. TEM of conventional prepared material revealed that strands of electron‐dense material, here named ‘mito‐reticular junctional fibres’, bridged the narrow gap between the mitochondrial surface and the SR. It is suggested that these fibres have a specific anchoring function.
The effects of embedding in water‐soluble plastics on the final dimensions of liver sections
Authors: Hanstede J. G. , Gerrits P. O. 
Published: August 2011

SUMMARYThis paper describes the morphometric changes liver samples undergo in the course of fixation, dehydration, infiltration and embedding in different mixtures of water‐soluble plastics. The plastics used were: three different mixtures of glycolmethacrylate (GMA) and the commercially available material JB4.Buffered formaldehyde fixation did not produce significant morphometric changes in the liver specimens. Dehydration obviously affects the volume of the liver specimen (linear shrinkage about 9.3%). The dehydration is followed by an infiltration phase. During this phase a slight swelling (linear, 2–5%) occurs. The final polymerization of the plastic resulted in a further linear shrinkage of 1–2%.The influence of different technical factors on the stretching of sections of pure plastic and of plastic embedded liver appeared to be considerable. The difference in stretching between 2 and 3 μm sections has been studied. A significant influence of temperature upon section stretching was noted. Sections of all plastic mixtures stretched at a temperature of 293 K showed 3% more linear stretch than at a temperature of 333 K. Differences between the four plastic mixtures are discussed.Correction factors must be used in morphometrical and stereological investigations (see for review: Weibel, 1979). It was concluded that in the application of water‐soluble plastics as embedding media it is essential to apply a standardized procedure, particularly in the cutting and stretching phase.
Quantitative determination of elements by energy dispersive X‐ray microanalysis and atomic absorption spectrometry in egg cells of Lymnaea stagnalis
Authors: Elbers P. F. 
Published: August 2011

SUMMARYMagnesium, phosphorus, potassium, calcium and iron in Lymnaea stagnalis egg cells at the four cell embryonic stage were quantitatively analysed by energy dispersive X‐ray analysis. The accuracy of the results was confirmed by atomic absorption spectroscopy using the graphite tube atomizer. It is shown that at 20 kV acceleration voltage the Hall equation can be applied in X‐ray microanalysis of air‐dried biological specimens of up to 8 μm thickness when calibration standards of nearly the same thickness and elemental composition are used.In the past few years considerable effort has been devoted to the X‐ray microanalysis of cells and subcellular structures in tissues. Special interest went to the determination of local concentrations of low atomic weight elements in the cells (Gupta et al., 1978). These elements partly occur in the form of mobile ions and their concentration distribution is easily disturbed by preparative procedures. Only cryogenic methods, like freeze‐sectioning (Echlin & Moreton, 1974) and freeze‐fracturing (Zs‐Nagy et al., 1977) are able to meet these problems of preparation.With single cells, e.g. invertebrate egg cells or amoebae, the situation is somewhat less complicated because these cells can be handled individually. A number of problems in cell biology, e.g. ion movement during the cell cycle, may be solved by analysis of the ion content of whole cells. Dried down Lymnaea egg cells at SEM accelerating voltages can be considered as semi‐thick specimens in which the local mass per unit area will show some variation. In order to convert X‐ray data from these specimens to concentrations, semi‐thick calibration standards should be prepared with essentially the same matrix composition as the biological material. Under such circumstances the equation
Polylysine as an adhesive for the attachment of nanoplankton to substrates for electron microscopy
Authors: Marchant Harvey J. , Thomas David P. 
Published: August 2011

SUMMARYNanoplankton can be readily attached to polylysine‐coated substrates for examination by transmission and scanning electron microscopy. This simple technique gives high yields of organisms which are consistently better preserved and less obscured by detritus than samples dried directly on to substrates.
Estimating length density and quantifying anisotropy in skeletal muscle capillaries
Authors: Mathieu Odile , Cruz‐Orive Luis‐M. , Hoppeler Hans , Weibel Ewald R. 
Published: August 2011

SUMMARYThe accurate estimation of stereological parameters defined on anisotropic structures is a long‐standing problem. In this paper we seek to estimate the capillary length density Jv in skeletal muscle tissue. A well‐known model for directional anisotropy in space, namely the ‘spherical normal’ or ‘Fisher axial distribution’ model, is found to fit the relevant data satisfactorily. Based on this model, a short‐cut estimation method is proposed and illustrated with a numerical example. This method essentially consists in taking the ratio of mean capillary profile counts, as obtained from transversal and longitudinal sections of the muscle tissue, and making use of a table or a graph given in the paper to estimate Jv. The conditions under which the methods are applicable and practicable are discussed in detail. Apart from an accurate estimation of Jv, an important feature of our method is the possibility of quantifying the degree of anisotropy by a coefficient K (called the concentration parameter of the Fisher axial distribution), which enjoys both a biological significance and a sound statistical basis.
Inter‐animal variation and its influence on the overall precision of morphometric estimates based on nested sampling designs
Authors: Gupta Madhu , Mayhew T. M. , Bedi K. S. , Sharma A. K. , White F. H. 
Published: August 2011

SUMMARYThis paper provides additional experimental evidence that biological variation between individuals is likely to be the major factor influencing the overall precision and efficiency of nested sampling schemes for morphometric analysis of thin sections.Four distinct experimental systems (two based on nervous tissue and two on epithelia) have been investigated. Morphometric estimates were obtained from measurements made on micrographs generated by sampling tissues at several levels. Sources of sampling variation were isolated so that the contributions to overall variance made by inter‐animal differences could be evaluated.In each case, biological variation was the cardinal component of total observed variance between animals. Relative contributions ranged from 53% to 78%. Examining more animals would be the most efficient way of reducing the variance of the group mean in these sampling designs.
Refractometry of fungi
Authors: Joseph S. 
Published: August 2011

SUMMARYImmersion refractometry is based on matching the refractive index of the medium to that of the cytoplasm of the cell, in which case the latter will have minimum contrast in the phase contrast microscope and will practically disappear. The cytoplasm is then said to be at the match point with the medium. Since the refractive index of a solution is related to its concentration by the formula n ‐ no =αC, the values for the refractive indices can be expressed in terms of the concentration of solids (g/100 ml) which in fact has been done throughout this work. The properties of a suitable immersion medium, its preparation and interpretation of numerical results have been discussed. Refractometric measurements were carried out on fungal hyphae and spores. The solid concentration in hyphae varies according to their age, physiological state and function. In general the highest values are found at sites of physiological activity, such as growth and reproduction, and may range from 11% to 30% of solid concentration. The solid concentration of mature, resting spores was found to be in the range of 45–54%, with the exception of a powdery mildew spores in which the concentration of solids was 30–32%.The germination of spores is preceded by a fall in the concentration of solids, and subsequent swelling before the emergence of the germ tube. When the solid concentration in pregerminating spore has fallen to about 20–30%, metabolic activity can take place and germination can occur.
Experimental lymphatic metastasis
Authors: Carr Ian 
Published: August 2011

SUMMARYA model of lymphatic metastasis of cancer has been established by injecting tumour cells into the rat footpad and examining the draining popliteal lymph node. The node can probably destroy only a few tumour cells; thereafter metastasis is progressive and lethal. The tumour cells penetrate the lymphatic endothelium, in the footpad either by moving singly between intact endothelial cells, by destroying the endothelium, or by passing in clumps between the endothelial cells. Tumour cells may then be obtained from the lymph by cannulation of the lymphatic trunk. These experiments pose the question: is local lymphatic chemotherapy useful in treating lymphatic metastasis?
A high‐resolution staining method for examination of mammalian cell surfaces in the light microscope
Authors: Junker Steffen 
Published: August 2011

SUMMARYA simple light‐microscopic method for the examination of fine details on cell surfaces is described. When cell specimens on platinum‐coated glass or plastic surfaces are stained with 3,3′‐diaminobenzidine tetrahydrochloride and hydrogen peroxide, fine cytoplasmic processes that cannot be detected using conventional staining techniques for the light microscope are revealed. It is suggested the new technique be applied instead of the scanning electron microscope when the limited resolution of the light microscope is sufficient.
A statistical method for the analysis of quantitative thin‐film X‐ray microanalytical data
Authors: Blake D. F. , Isaacs A. M. , Kushler R. H. 
Published: August 2011

SUMMARYA series of equations is presented through which thin‐film X‐ray microanalytical data may be characterized statistically. Test statistics based on the Gaussian distribution are then presented, together with examples of the use and evaluation of an empirically derived Mg/Ca working curve.
Particle sizes and their distributions estimated from line‐ and point‐sampled intercepts. Including graphical unfolding
Authors: Gundersen H. J. G. , Jensen E. B. 
Published: August 2011

SUMMARYInformation about particle size is currently obtained almost exclusively by the use of stereological methods which lead to estimates of the number distribution of linear particle size. The main point of this presentation is to stress the freedom to choose more appropriate parameters for size among a host of options, including particle surface area and volume. Moreover, particle size information may often be considered advantageously in terms of particle distributions based on structural characteristics rather than number distributions. Some of these other distribution types are correctly represented in samples of intercept lengths obtained by line‐ and point‐sampling, respectively. The known and quite simple theory of sampling intercepts is summarized and developed further in several different directions, including a derivation of the distribution of intercept length in ellipsoids, graphical unfolding procedures, and mean size estimators. The potential of the approach is illustrated—but not exhausted—by the existence of a general mean size estimator based on minimal assumptions regarding particle shape.