Method of intravital injection of the internal blood vessels of organs for experimental-morphological research]

Ten minutes before the injection the rat is given heparin (500 units per 1 kg weight) intradermally. To the narcotized animal, the needle with the 1 ml syringe is inserted and 3--5 ml of blood are aspirated (about 2% of the body mass). Then with the same needle another syringe of 10 ml volume containing filtrated and heated up to 40 degrees C undiluted Indian ink is injected. The amount of the Indian ink injected is 8--10 ml per 100 g of the body mass. We can consider the injection oa success if the mucose of the tongue, the skin of the concha auriculae, the sclera of the eye are promptly stained during the injection and the tail vessels are well filled.     

Apoptosis in the cells of parenchymatous organs in subacute sodium nitrate poisoning

Subacute intoxication was induced by the oral administration of sodium nitrate 200 mg/kg during 150 days to Wistar rats. After the time had been up severe damaging were found in liver, kidney, heart and thymic tissues. In the liver cells the DNA fragmentation in "scale" manner was found, but not in kidney and heart cells. Simultaneously, the Ca2+, Mg(2+)-depended endonucleases activity were increased in the liver nuclei extracts under intoxication. It was suggested that increasing of apoptosis in liver is the universal reaction to toxins.     

Labeling of cholesterol with filipin in cellular membranes of parenchymatous organs

Summary Filipin is used for ultrastructural cytochemical localization of cholesterol in biological membranes. It binds to unesterified 3-hydroxy-sterols forming 25 nm complexes which are readily recognized in freeze-fracture replicas. Since most investigations with filipin have been performed in isolated cells (tissue culture, cell suspensions etc.) we have investigated the conditions for reproducible labeling of cholesterol in membranes of parenchymatous organs. Vibratome sections of rat kidney fixed by glutaraldehyde perfusion were incubated in filipin and freeze-fracture replicas were prepared using standard techniques. The concentration of filipin, the thickness of vibratome sections and the incubation time and temperature were varied over a wide range. Optimal results were obtained with 50 m thick tissue slices incubated in 400 g/ml of filipin for 46 h at room temperature. Under these conditions lysosomes were consistently labeled while mitochondria and the endoplasmatic reticulum were negative. Peroxisomes showed a little or no labeling at all while the nuclear envelope was heavily labeled in some cells being negative in others. The method described here should be useful in investigation of the role of cholesterol in function of biological membranes in parenchymatous organs and compact tissues.     

Study of the innervation of blood vessels of the digestive organs by fluorescence microscopy]

The blood vessels of the samll intestine and the gallbladder were shown to possess a great amount of adrenergic nerve fibres which, when penetrating the thickness of the wall of the above organs, become thinner and the distributed between the tissue structures of the organs as the thinnest monoaxonal network. The method of Falck--Hillarp--Krokhina was used. Among the vessel nerves there are perivascular nerves accompanying the vessels along their total legnth, juxtavascular and intramural nervous bundles of the sumpathetic nature detected by the fluorescent-microscopy method. Large arteries are disposed in a considerably thicker network of specifically fluorescing fibres than veins and small arteries.     

Method of determining the sensitivity of Staphylococcus aureus to methicillin]

The effect of the incubation temperature, i.e. 37 and 30 degrees and the effect of addition of 5 per cent of sodium chloride to the nutrient medium was studied with respect to the results of sensitivity determination of staphylococci to methicillin by 3 methods, such as serial dilutions in liquid and solid media and replica method applied to separate colonies. With the use of all 3 methods incubation of the samples at a temperature of 30 degrees increased the rate of staphylococcal cultures resistant to methicillin. Addition of sodium chloride to the solid nutrient medium increased the level of detecting methicillin resistant cultures in the samples incubated at a temperature of 37 degrees and decreased it in the samples incubated at 30 degrees.     

Interdependent development of blood vessels and organs

The cardiovascular system is the first functional organ in the vertebrate embryo, and many organs start to develop adjacent to cells of the cardiovascular system. Endothelial cells (EC) form the inner cell lining of blood vessels and represent the major cell type that interacts with developing organs. On the one hand, EC provide organs with signals. These signals determine the location, differentiation and morphology of an organ. On the other hand, EC receive signals from the organ-specific cell types. Such signals give EC organ-specific features that the organ needs to interact with the circulatory system. This review provides the reader with specific examples of an interdependent development of organs and blood vessels.Eckhard Lammert and Ganka Nikolova were supported by the Deutsche Forschungsgemeinschaft DFG (La1216/2–1)     

Method of determining the antimicrobial activity of alcohol extracts of propolis]

It is proposed to determine the antimicrobial activity of propolys alcohol extracts by the method of subsequent dilutions in solid nutrient media. Dilution of the extracts immediately in hot agar eliminated the inhibiting effect of the extragent on the microbial growth. Opalesence appearing in the agar did not prevent estimation of the results in contrast to the method of subsequent dilutions in liquid nutrient media.     

Labeling of cholesterol with filipin in cellular membranes of parenchymatous organs. Standardization of incubation conditions

Filipin is used for ultrastructural cytochemical localization of cholesterol in biological membranes. It binds to unesterified 3 beta-hydroxy-sterols forming 25 nm complexes which are readily recognized in freeze-fracture replicas. Since most investigations with filipin have been performed in isolated cells (tissue culture, cell suspensions etc.) we have investigated the conditions for reproducible labeling of cholesterol in membranes of parenchymatous organs. Vibratome sections of rat kidney fixed by glutaraldehyde perfusion were incubated in filipin and freeze-fracture replicas were prepared using standard techniques. The concentration of filipin, the thickness of vibratome sections and the incubation time and temperature were varied over a wide range. Optimal results were obtained with 50 micron thick tissue slices incubated in 400 micrograms/ml of filipin for 46 h at room temperature. Under these conditions lysosomes were consistently labeled while mitochondria and the endoplasmatic reticulum were negative. Peroxisomes showed a little or no labeling at all while the nuclear envelope was heavily labeled in some cells being negative in others. The method described here should be useful in investigation of the role of cholesterol in function of biological membranes in parenchymatous organs and compact tissues.