scholarly journals Experiments on the Mechanism of Silver Staining

1955 ◽  
Vol s3-96 (33) ◽  
pp. 103-115
Author(s):  
A. PETERS
Keyword(s):  
Silver Staining ◽  
Protective Action ◽  
The Other ◽  
Physical Developer ◽  
Nerve Staining

The effect of a series of photographic developers on the final silver-staining picture has been investigated. Ten common developers were used, but of these only hydroquinone, chloroquinol, pyrogallol, and p-aminophenol, were found to be of general use. The other developers were either so weak in their action that the final staining was light and incomplete, or so powerful that a differentiated nerve staining was not produced. For silver staining to be effected nuclei of reduced silver should be present in the section. These nuclei act as centres for the deposition of additional silver reduced by the developer; the additional silver may either be derived from that combined with the sections during impregnation or from the developing solution itself. Whether or ot the additional silver is deposited in such a way as to produce differentiated nerve staining depends on the properties of the developer and on the composition of the developing solution. The redox- and ‘bromide’-potentials, the sulphite and hydrogen n concentrations in the developing solution, and the protective action of the tissue components of the section all play a part in determining the final staining picture. A new glycine-containing physical developer and a gold thiocyanate physical developer are described.

Nucleolar organizer activity at meiosis in wheat–rye hybrid plants

1986 ◽  
Vol 28 (2) ◽  
pp. 227-234 ◽  
Author(s):  
N. Cuñado ◽  
M. C. Cermeño ◽  
J. Orellana
Keyword(s):  
Silver Staining ◽  
Staining Method ◽  
Nucleolar Organizer ◽  
The Other ◽  
Nucleolar Organizer Regions ◽  
Binucleate Cells ◽  
Hybrid Plants ◽  
Nucleolar Organizer Activity ◽  
Silver Staining Method ◽  
Organizer Activity

Nucleoli and nucleolar organizer regions (NORs) have been studied by a silver staining method in all meiotic stages of wheat–rye hybrid plants. The maximum number of nucleoli per cell scored at meiotic prophase and tapetum binucleate cells indicates that only the NORs of 1B, 6B, and 5D wheat chromosomes are active, whereas that of chromosome IR (SAT) of rye is inactive. However, at diakinesis, metaphase and anaphase meiotic stages only chromosomes 1B and 6B show Ag-NOR as was reported previously in somatic metaphase. The absence of Ag-NOR on chromosome 5D has been imputed to its low nucleolar organizer activity, not detectable by silver staining, because of the small number of rDNA clusters it carries. On the other hand, the meiotic behaviour of chromosomes 1B and 6B has been studied at metaphase I and anaphase I, using the Ag-NORs as cytological markers.Key words: nucleolar organizer, Ag-NOR, meiosis, wheat–rye hybrids.

Oxygen toxicity in cultured aortic endothelium: selenium-induced partial protective effect

1983 ◽  
Vol 55 (2) ◽  
pp. 343-352 ◽  
Author(s):  
B. Housset ◽  
C. Ody ◽  
D. B. Rubin ◽  
G. Elemer ◽  
A. F. Junod
Keyword(s):  
Protein Content ◽  
Time Course ◽  
Protective Action ◽  
Oxygen Toxicity ◽  
Lipid Peroxides ◽  
Cell Loss ◽  
The Other ◽  
Related Effect ◽  
Fourfold Increase ◽  
Ldh Release

The time course of biochemical changes related to cell loss and damage during exposure to 95% O2 [DNA and protein content of dishes, lactate dehydrogenase (LDH) release] was studied in postconfluent endothelial cells isolated from pig aorta, cultured in standard medium and in medium supplemented with 2 X 10(-7) M selenomethionine (Se-Met). A fourfold increase in glutathione peroxidase (G-Px) was the only major enzymatic Se-related effect under both normoxic and hyperoxic conditions, the other antioxidant enzymes being little or not at all affected by this treatment. The addition of Se-Met had a clearcut protective action against the cytotoxic effect of O2 as shown by measurements of DNA and protein content of Petri dishes and of LDH release. On the other hand, the most sensitive O2-related effect, namely the decrease in [3H]thymidine incorporation into DNA, was not affected by Se-Met addition. These experiments suggest that some of the O2-related toxic effects (but not the inhibition of DNA synthesis) could be mediated by lipid peroxides, since they were, at least partly, prevented by a Se-Met-induced increase in G-Px activity.

scholarly journals Silver staining of the nucleolus organizer regions (NOR) requires clusters of sulfhydryl groups.

1982 ◽  
Vol 30 (9) ◽  
pp. 908-911 ◽  
Author(s):  
A De Capoa ◽  
M Ferraro ◽  
P Lavia ◽  
F Pelliccia ◽  
A Finazzi-Agrò
Keyword(s):  
Heavy Metals ◽  
Silver Staining ◽  
Reducing Agents ◽  
Nucleolus Organizer ◽  
The Other ◽  
Nuclear Proteins ◽  
Staining Reaction ◽  
Nucleolus Organizer Regions ◽  
High Affinity ◽  
Per Se

Silver stainability of nucleolus organizer regions (NORs) appears to be correlated with the presence of grouped sulfhydryl (SH) side chains of proteins. In fact, heavy metals with high affinity for SH groups, such as Hg and Cu, do prevent the silver staining reaction. Ferricyanide, which is known to oxidize SH to disulfides, also prevents any further reaction with silver. On the other hand, alkali and reducing agents (mercaptoethanol, cyanide) do not affect silver stainability of the NORs. These results show that the silver staining reaction is not related to disulfide or persulfide groups and that alkali-soluble, acidic nuclear proteins per se do not play a major role in this process.

scholarly journals AN EXPERIMENTAL STUDY OF THE QUESTION OF ASPIRATION OF FOREIGN MATERIAL INTO THE AIR PASSAGES DURING INTRATRACHEAL INSUFFLATION

1911 ◽  
Vol 13 (6) ◽  
pp. 626-633
Author(s):  
T. S. Githens ◽  
S. J. Meltzer
Keyword(s):  
Experimental Study ◽  
Respiratory Tract ◽  
Protective Action ◽  
The Other ◽  
Foreign Material ◽  
Other Hand ◽  
Air Stream ◽  
Extraneous Material ◽  
Trachea And Bronchi

The foregoing experiments clearly justify the following conclusions :— Intratracheal insufflation protects the respiratory tract very efficiently against any invasion from the pharynx. The filling up of the pharynx with extraneous material, whether it be from the stomach or from the mouth, brings no danger to the trachea and bronchi. This holds true even if the animal is under deep anesthesia. On the other hand, the presence of a tube in the trachea or larynx without the protection of an effective recurrent air stream, definitely facilitates the entrance of foreign material from the pharynx into the trachea. Anesthesia, which removes the protective action of deglutition, greatly increases the danger from aspiration in these cases.

Experiments on the Mechanism of Silver Staining

1955 ◽  
Vol s3-96 (35) ◽  
pp. 301-315
Author(s):  
A. PETERS
Keyword(s):  
Silver Staining ◽  
Autocatalytic Reaction ◽  
Solution Temperature ◽  
Quantitative Results ◽  
Physical Developer

The quantitative aspects of silver staining of sections have been investigated with radioactive silver (Ag111). The concentrations of reducible silver, developed silver, and silver nuclei in the sections were determined, but it is doubtful if the values obtained for silver nuclei are significant. All three forms of silver increased with pH, time, and the concentration of silver in the impregnating solution. Temperature of impregnation had little effect on the uptake of reducible silver, but increased the developed silver, presumably by increasing the silver nuclei. An increase in the temperature of a hydroquinone-sulphite developer increased the amount of reducible silver reduced by the developer. The deposition of silver by a glycine physical developer was shown to follow a curve which was reasonably consistent with the assumption of a typical autocatalytic reaction. The uptake of silver by non-nervous tissues provided evidence that the process is not specific for nerves; the final specificity of staining is determined during development. The quantitative results are consistent with the hypothesis that the histidine in the sections is responsible for the combination of reducible silver.

scholarly journals An immunogold-silver staining method for detection of cell-surface antigens in light microscopy.

1986 ◽  
Vol 34 (7) ◽  
pp. 935-939 ◽  
Author(s):  
M De Waele ◽  
J De Mey ◽  
W Renmans ◽  
C Labeur ◽  
P Reynaert ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Cell Surface ◽  
Light Microscopy ◽  
Silver Staining ◽  
Surface Antigens ◽  
Cell Suspensions ◽  
T Cell Subsets ◽  
Staining Procedure ◽  
Cell Surface Antigens ◽  
Physical Developer

An immunogold-silver staining technique for detection of cell-surface antigens in cell suspensions was developed. Leukocyte cell suspensions were first incubated with monoclonal antibodies directed against cell-surface antigens and then with colloidal gold-labeled goat anti-mouse antibodies. Cytocentrifuge preparations of the cell suspensions were immersed in a physical developer containing silver lactate and hydroquinone as reducing substance. The preparations were then counterstained and mounted. In light microscopy, cells reacting with the monoclonal antibodies showed dark granules on their surface membrane. An optimal morphology, as revealed by a May-Grünwald-Giemsa counterstain, permitted accurate cell identification. The labeling was influenced by the gold particle diameter and the concentration of the gold reagents, by the duration of incubation in the physical developer, and by the composition and temperature of this medium. The T-cell subsets enumerated with this method in the peripheral blood of normal adults were identical to those found with other methods. The sensitivity of the technique was comparable with that of immunofluorescence microscopy. This immunogold-silver staining procedure proved to be a reliable tool for detection of cell-surface antigens in light microscopy.

The Mechanism of Renomedullary Antihypertensive Action: Haemodynamic Studies in Hydronephrotic Rats with One-Kidney Renal-Clip Hypertension

1978 ◽  
Vol 54 (4) ◽  
pp. 361-367
Author(s):  
D. Sušić ◽  
J. C. Sparks ◽  
E. A. MacHado ◽  
D. Kentera
Keyword(s):  
Plasma Volume ◽  
Protective Action ◽  
Peripheral Resistance ◽  
Volume Overload ◽  
Renal Medulla ◽  
Plasma Renin ◽  
The Other ◽  
Excretory Function ◽  
Antihypertensive Action ◽  
Hydronephrotic Kidney

1. The protective action of the renal medulla was studied in one-kidney renal-clip hypertension in rats with unilateral hereditary hydronephrosis and almost complete atrophy of the medulla of the affected kidney. 2. Rats were unilaterally nephrectomized. The first group had a normal kidney remaining, and the animals from the second and third groups were left with a hydronephrotic kidney and received renomedullary and renocortical autotransplants respectively. Two weeks later all rats were made hypertensive by placing a silver clip (0·2 mm) on the renal artery. 3. From the fourth day after clipping until the end of the experiment blood pressure was found to be significantly (P < 0·01) lower in rats with medullary transplants than in the other groups. No differences in renal excretory function, plasma volume and plasma renin activity were found between the groups either before or during development of hypertension (5 and 21 days after clipping). Early in the course of hypertension (5 days) cardiac output was significantly (P < 0·05) lower in the rats with medullary transplants than in the other groups, although an increase in plasma volume was noted in all three groups. At that time no difference in total peripheral resistance was found between the groups. 4. The results are consistent with the hypothesis that the renomedullary antihypertensive substance(s) mitigates hypertension by preventing a hypertensive haemodynamic response to sodium/volume overload.

scholarly journals Evolutionary cytogenetics of the Hoplias lacerdae, Miranda Ribeiro, 1908 group: a particular pathway concerning the other Erythrinidae fish

2007 ◽  
Vol 67 (4 suppl) ◽  
pp. 897-903 ◽  
Author(s):  
S. Morelli ◽  
MR. Vicari ◽  
LAC. Bertollo
Keyword(s):  
Silver Staining ◽  
Chromosome Pair ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
The Other ◽  
Rdna Sites ◽  
Group A ◽  
Morphologic Data ◽  
Erythrinidae Fish

The taxonomy/systematics of the Erythrinidae fish is still imprecise, with several doubts on their relationships. Karyotypes and chromosomal characteristics of some species of the Hoplias lacerdae group (Erythrinidae), from different Brazilian hydrographic basins and pisciculture stations, were analyzed in the present study, using conventional Giemsa staining, C-banding, silver staining, Mithramycin and Distamycin/DAPI fluorochromes, and fluorescent in situ hybridization (FISH). A diploid chromosome number of 2n = 50 and karyotypes composed of meta- and submetacentric chromosomes without sex-related differences were found. Only one active NOR (Nucleolar Organizer Region) site was found, which was identified by silver staining (Ag-NOR) and FISH, located on the chromosome pair 11, although additional 45S rDNA sites were also mapped on other chromosome pairs only by FISH. The Ag-NOR of the chromosome pair 11 was found to be GC-rich, appearing positive after Mithramycin staining. Mithramycin-positive/DAPI-negative sites were also observed in the centromeric/pericentomeric regions of the chromosome pairs 4, 6, 15, and 19, which have also affinity to silver nitrate. However, these four sites were not detected by FISH with the rDNA probe, indicating to be only argentophilic GC-rich heterochromatic regions. Chromosome data show that the karyotype evolution in Hoplias lacerdae group is relatively conserved and follows a particular pathway concerning the other Erythrinidae fishes, such as Hoplias malabaricus, Hoplerythrinus unitaeniatus, and Erythrinus erythrinus, in which polytypic karyotypes are found. Thus, the H. lacerdae group shows chromosome features that are not closely related to those of the congeneric H. malabaricus group. These finds, together with genetic and morphologic data, are important tools to be considered in a major revision of the Erythrinidae family, as well as for conservation programs.

scholarly journals Purification and some kinetic properties of rat liver glucosamine synthetase

1971 ◽  
Vol 121 (4) ◽  
pp. 701-709 ◽  
Author(s):  
P. J. Winterburn ◽  
C. F. Phelps
Keyword(s):  
Rat Liver ◽  
Rate Equation ◽  
Protective Action ◽  
The Other ◽  
Kinetic Properties ◽  
Ph Optimum ◽  
Ph Values ◽  
Catalysed Reaction ◽  
Ping Pong ◽  
Feedback Inhibitor

1. Glucosamine synthetase (l-glutamine–d-fructose 6-phosphate aminotransferase, EC 2.6.1.16) was purified about 300-fold from rat liver by two techniques. One procedure utilized the protective action of fructose 6-phosphate and gave a relatively stable preparation, the other yielded an unstable enzyme (half-life of about 20h), free of contaminant activities, on which kinetic experiments were performed. Although the properties of the two preparations showed slight differences, the unstabilized form could be converted into the stabilized form. 2. During preparation the enzyme retained its sensitivity to the feedback inhibitor, UDP-N-acetylglucosamine. 3. The reversibility of the enzyme-catalysed reaction could not be demonstrated. There was no apparent requirement for a cofactor. 4. The pH optimum was at 7.5, at which pH the reaction obeyed a Ping Pong Bi Bi rate equation. At pH values outside the range 6.9–7.6 and at temperatures below 29°C the velocity was described by an ordered Bi Bi rate equation. 5. The molecular weight of the enzyme, determined by two procedures, was 360000–400000. 6. The aminotransferase was unable to utilize ammonia as a substrate.

scholarly journals A STUDY OF THE PROTECTIVE ACTION OF SNAKE VENOM UPON BLOOD CORPUSCLES

1905 ◽  
Vol 7 (2) ◽  
pp. 191-222 ◽  
Author(s):  
Hideyo Noguchi
Keyword(s):  
Snake Venom ◽  
Salt Solution ◽  
Protective Property ◽  
Protective Action ◽  
Strong Solutions ◽  
The Other ◽  
Cobra Venom ◽  
Chemical Agents ◽  
Other Hand ◽  
Physical And Chemical

Washed blood corpuscles of certain species of animals in a concentration of about 5 per cent suspended in salt solution containing above 4 per cent of cobra venom undergo changes in their resistance to certain physical and chemical agents. They become non-haemolyzable by water, ether, saponin, and quite strong solutions of lecithin, provided always that the excess of venom has not been entirely removed. On the other hand, certain acids and alkalis, excepting ammonia, lake the venomized corpuscles more easily than they lake normal corpuscles. Venom solutions of 2 per cent and less exert no protective property upon blood corpuscles, but they induce changes in the corpuscles whereby they are rendered more easily laked by the same physical and chemical agents.

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