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G Romhányi

Publications and source records attributed to G Romhányi.

At least 19 recordsLinked to original sources
PubMed1983

The characteristic three-banded birefringence of ligamentum nuchae elastic fibres indicates ordered micellar texture.

The ultrastructural organization of the elastic fibres of bovine ligamentum nuchae is still controversial (Kádár 1979; Sandberg 1976; Sandberg et al. 1981; Quintarelli et al. 1973; Gosline 1976). Polarization microscopy demonstrated convincingly, contrary to a recent negative report (Aaron and Gosline 1980), an ordered birefringent micellar texture (Schmidt 1939; Romhányi 1965; Fischer 1979). The three-banded anisotropic pattern of the fibres can be explained by the optical interference of two micellar textures of opposite orientation, one arranged circularly in the surface layer and the other oriented longitudinally in the axial core of the fibres (Romhányi 1965). Analysis of the underlying molecular mechanism for the anisotropic staining reaction of these fibres with Congo red led to the conclusion that this is due to a definite structural order of specific cross-linking segments within the random network of elastin. The anisotropic staining reaction of the elastic fibres with Congo red is described as the most simple method to demonstrate the three-banded birefringent pattern of ligamentum nuchae elastic fibres even in histologic sections.

Animals↗
PubMed1982

Acid polysaccharide content of frog rod outer segments determined by metachromatic toluidine blue staining.

Sulfonation of periodate-oxidized vicinal hydroxyl groups on a polysaccharide backbone allows binding of toluidine blue (aldehyde bisulfite-toluidine blue or ABT staining) with a concurrent metachromatic shift of the dye's absorption peak from 630 nm (monomer) to 580 nm (isolated dimer interaction at vicinal sulfonate groups) or 540 nm (dye polymer interaction). A molar absorptivity of 2.358 +/- 0.134 X 10(4) at 540 nm for polymeric toluidine blue O chloride (TB) aggregates was determined by spectrophotometry of TB bound to hyaluronic acid (HA) and sulfonated glycogen (SG) in water. Microspectrophotometry of ABT stained frog rod outer segments (FROS) showed spectra similar to TB in aqueous HA and SG solutions with absorbances corresponding to 0.063 M dye bound to sugar. Given two dye molecules bound per sugar residue and a rhodopsin concentration of 3.25 mM in FROS, the above indicates 10 stainable sugars per rhodopsin are contained in these cells. Half of these sugars are sensitive to hyaluronidase digestion implying 5 glycosaminoglycan (GAG) repeating units and 5 stainable oligosaccharide sugar residues per rhodopsin in FROS. The GAGs in FROS appear to be primarily HA. Birefringence measurements at 475 nm indicate that this HA and the oligosaccharide of rhodopsin are anisotropically oriented in these cells.

Animals↗
PubMed1980

[Methods of the selective demonstration of various structural elements of the vascular wall].

Selective topo-optical and impregnation technique for the demonstration of acid mucopolysaccharides, neutral polysaccharides, collagen, elastic fibres and membranes, smooth muscle cell i.e. structural elements of the vessel wall are described. These techniques are simple and reliable and may be used for the every-day pathohistological diagnostics. Their parallel application provides further possibilities for the study of the structure and various pathological alterations of the vessel wall. It should be stressed, that on the basis of the analysis of optical effects--birefringence, dichroism, metachromasia--these techniques provide opportunity to detect early structural lesions, which by the application of conventional techniques can not be detected.

Arteries↗
PubMed1979

[Selective demonstration of amyloid deposits and methodical possibilities of analysis of their ultrastructural differences (author's transl)].

In preparations stained with congo-rot and covered with arabic gum amyloid deposits reveal intensive, positive birefringence. Collagen is isotropic or shows a mild negative birefringence. This method is most suitable for selective optical demonstration of amyloid deposits. On the base of investigations on ultrastructural stability of amyloid deposits (resistance to performic acid and induced proteolysis) two types may be distinguished: (1) amyloid deposits of labile structure (generalized, secondary amyloidosis) and (2) amyloid deposits of stable structure (generalized primary amyloidosis, local and senile amyloid deposits).

Amyloid↗
PubMed1978

Orientation of acidic polysaccharides and rhodopsin-oligosaccharides in frog retinal rod outer segments.

Using topo-optical staining reactions, the presence and molecular order of three structural components of outer segments of frog retina were studied. These components included (1) an acidic polysaccharide texture, (2) free aldehyde groups which arise during formalin fixation and (3) the oligosaccharide chains of rhodopsin. Quantitative measurements of the dye binding and birefringence effects arising from the individual structural components in rod outer segments were made. Results indicated that all three structural components had a rather well-defined orientation within the ROS. The spherulites phagocytized from the apical ends of ROSs by the pigment epithelium also demonstrate preferred orientation of the three structural components investigated.

Aldehydes↗
PubMed1977

Optical studies on the molecular-sterical mechanism of metachromasia.

We have investigated how the stereochemical situation of the dye binding negative side groups on polysaccharides influences metachromatic staining effects. We found that selective binding of toluidine blue (pH = 1.0) in the places of substituted (acidified) vicinal OH groups C2 and C3 resulted in the clearest metachromasia with the strongest anisotropy effects and with a bright clear green polarization color. On the other hand, selective toluidine blue binding in the places of C6 of the carbohydrate rings of the polysaccharide chains resulted in orthochromatic basophilia and lack of birefringence. After transformation of all OH side groups into negatively charged groups, metachromatic staining was found mixed with an orthochromatic hue and a birefringence effect weaker than in the case of staining on the vicinal OH groups only. The need of poststaining stabilization of the labile metachromatic staining reactions is emphasized.

Animals↗
PubMed1976

[Demonstration of bacteria and fungi in tissues by topo-optic aldehyde bisulfite toluidine blue (ABT) reaction].

Reaction with aldehyd-bisulfit-toluidinblue (ABT)--as a selective topo-optical reaction for vicinal OH-and amino-OH groups, appears to be suitable for demonstration of bacteria in tissues. Cell membranes and capsules of bacteria and fungi contain large quantity of carbo-hydrates, therefore they show strong basophilic staining after ABT reaction. Double refringement brought about by orientated dye-binding seems to be the sign of the linear arrangement of polysaccharides composing cell membranes and capsules of bacteria. Practical importance of the reaction is shown on examples. Diagnostic advantages of it are also discussed.

Animals↗
PubMed1976

[Selective demonstration of amloid deposits and methodical possibilities for the analysis of ultrastructural differences].

In preparations stained by congo-rot and covered with arabic gumm amyloid deposits reveal intensive, positive bi refringement, collagen is isotrop, or shows a mild bi refringement. This method is most suitable for selective optical demonstration of amyloid deposits. On the base of investigation of ultrastructural stability of amyloid deposits (resistency to performiat and induced proteolysis) two types of them may be distinguished: I. amyloid deposits of labile structure (generalized, secondary amyloidosis) and 2. amyloid deposits of stabile structure (generalized primary amyloidosis, local and senile amyloid deposits).

Amyloid↗
PubMed1976

Viability of extracorporeally perfused dog livers.

The possibility of structural and functional preservation of the isolated liver has been studied in dog experiments. A sterile liver preparation left in situ was worked out, having practically no ischaemic period, except during perfusion. Nevertheless, well-defined lesions (perivascular and interstitial oedema, dissociated contraction of the smooth muscle elements of the veins, cellula accumulation in the sinusoids) appeared, accompanied by a gradual reduction (microcirculatory disorders, enzyme derailment) of the function of hepatocytes.

Animals↗
PubMed1975

Aldehyde bisulfite-toluidine blue (ABT) staining as a topo-optical reaction for demonstration of linear order of vicinal OH groups in biological structures.

The aldehyde-bisulfite-toluidine blue reaction followed by poststaining stabilization with potassium ferricyanide (ABT) is described as a topo-optical, oriented staining reaction of the vicinal OH groups of complex carbohydrates in biological structures such as polysaccharides, glycoproteins and glycolipids. The birefringence as induced by the oriented dye binding as a result of ABT is indicative of linear order of the vicinal OH groups and, in turn, provides information on the ultrastructural pattern of carbohydrate moieties in biological substances, which pattern is often not demonstrable by other ultrastructural methods. The possibilities of this new approach to the ultrastructural analysis of complex carbohydrates with ABT in a great number of biological substances is demonstrated and its practical value in histopathology discussed.

Aldehydes↗