scholarly journals Tissue fixation and staining by osmium tetraoxide: a possible role for alkaloids.

1981 ◽  
Vol 29 (11) ◽  
pp. 1347-1348 ◽  
Author(s):  
M J Wright ◽  
M Schröder ◽  
A J Nielson
Keyword(s):  
Normal Tissue ◽  
In Vitro Studies ◽  
Plant Tissues ◽  
Tissue Fixation ◽  
Osmium Tetraoxide

In vitro studies on the reactions of osmium tetraoxide, OsO4, with isoquinoline, pyridine, quinuclidine, and a series of structurally related alkaloids suggest that these species, under the conditions of normal tissue staining and fixation, are potentially osmiophilic. The structure of the products and their reactions with unsaturated substrates are described. The relevance of these results to the process of tissue staining and fixation of plant tissues containing alkaloids by OsO4 is discussed.

Tissue fixation and staining with osmium tetroxide: the role of phenolic compounds.

1978 ◽  
Vol 26 (2) ◽  
pp. 138-140 ◽  
Author(s):  
A J Nielson ◽  
W P Griffith
Keyword(s):  
Phenolic Compounds ◽  
Electron Density ◽  
Normal Tissue ◽  
Osmium Tetroxide ◽  
Direct Interaction ◽  
Plant Tissues ◽  
Tissue Fixation ◽  
Chelate Complexes ◽  
Animal Tissues

It has been postulated that phenol-containing areas of plant and animal tissues were osmiophilic, but proof of direct interaction between osmium tetroxide and phenolic materials, or the nature of such reactions, has been lacking. We find that, under conditions similar to those of normal tissue fixation, osmium tetroxide reacts rapidly with those phenols containing o-dihydroxy groups (including such species found in plant tissues) to give very stable chelate complexes. We conclude that these complexes are responsible for the observed electron-density in phenol-containing areas of tissue treated with osmium tetroxide, so that such phenols are indeed osmiophilic.

scholarly journals Tissue fixation by osmium tetroxide. A possible role for proteins.

1979 ◽  
Vol 27 (5) ◽  
pp. 997-999 ◽  
Author(s):  
A J Nielson ◽  
W P Griffith
Keyword(s):  
Normal Tissue ◽  
Osmium Tetroxide ◽  
Chemical Nature ◽  
Side Chain ◽  
Cross Linking ◽  
Tissue Fixation ◽  
Reaction Products ◽  
Cholesteryl Acetate ◽  
Unsaturated Lipids

The osmiophilia, under the conditions of normal tissue fixation, of the histidine, lysine, tryptophan, cysteine and methionine side chain of proteins is suggested by in vitro studies on blocked amino acids representative of such protein side chains, and the chemical nature of the reaction products elucidated. The chemical feasibility of inter- or intramolecular cross-linking of protein by OsO4 at these and other sites is demonstrated, as in the cross-linking of protein with unsaturated lipids such as methyl oleate, methyl linoleate and linolenate, and cholesteryl acetate. The relevance of these results to the process of tissue fixation by OsO4 is discussed.

The role of silicon in forages: A quantitative X-Ray study

1987 ◽  
Vol 45 ◽  
pp. 416-417
Author(s):  
Janet H. Woodward ◽  
D. E. Akin
Keyword(s):  
Sodium Acetate ◽  
Dry Matter ◽  
Acetate Buffer ◽  
Plant Tissues ◽  
Sodium Acetate Buffer ◽  
X Ray ◽  
Dry Matter Digestibility ◽  
Percent Composition

Silicon (Si) is distributed throughout plant tissues, but its role in forages has not been clarified. Although Si has been suggested as an antiquality factor which limits the digestibility of structural carbohydrates, other research indicates that its presence in plants does not affect digestibility. We employed x-ray microanalysis to evaluate Si as an antiquality factor at specific sites of two cultivars of bermuda grass (Cynodon dactvlon (L.) Pers.). “Coastal” and “Tifton-78” were chosen for this study because previous work in our lab has shown that, although these two grasses are similar ultrastructurally, they differ in in vitro dry matter digestibility and in percent composition of Si.Two millimeter leaf sections of Tifton-7 8 (Tift-7 8) and Coastal (CBG) were incubated for 72 hr in 2.5% (w/v) cellulase in 0.05 M sodium acetate buffer, pH 5.0. For controls, sections were incubated in the sodium acetate buffer or were not treated.

In vitro - studies with antler bone cells: Structure forming capacity, osteocalcin production and influence of sex steroids

2006 ◽  
Vol 15 (04) ◽  
pp. 245-257 ◽  
Author(s):  
H. J. Rolf ◽  
K. G. Wiese ◽  
H. Siggelkow ◽  
H. Schliephake ◽  
G. A. Bubernik
Keyword(s):  
Sex Steroids ◽  
Bone Cells ◽  
In Vitro Studies ◽  
Osteocalcin Production

In Vitro Studies on the Mechanism of the Antifibrino-lytic Action of E-Aminocaproic Acid (EACA)

1968 ◽  
Vol 19 (03/04) ◽  
pp. 584-592 ◽  
Author(s):  
Hanna Lukasiewicz ◽  
S Niewiarowski
Keyword(s):  
Aminocaproic Acid ◽  
Test Tube ◽  
In Vitro Studies ◽  
Lytic Action ◽  
Human Plasminogen ◽  
Experimental Findings ◽  
Fibrin Clots

Summary and Conclusion1. It has been found that EACA does not inhibit activation of human plasminogen into plasmin by SK and UK in a concentration of 5 × 10–2 M. The activation of bovine plasminogen by SK and UK is inhibited by this concentration of EACA but not by a lower one.2. EACA in concentrations of 1,5 × 10–1 – 10–4 M does not inhibit casein proteolysis by plasmin. The proteolysis of fibrinogen and fibrin measured by the release of TCA soluble tyrosine is inhibited by EACA in concentrations of 1,5 × 10–1 – 10–2 M.3. The lysis of non-stabilized clots by plasmin measured in a test tube was inhibited by an EACA concentration of 5 × 10–3 – 5 × 10–4 M. The lysis of stabilized clots by plasmin was inhibited by an EACA concentration of 10–5 M.4. On the basis of experimental findings and data given in literature the authors postulate that the mechanism of the antifibrinolytic effects of EACA consists mainly in a modification of plasmin action on fibrin. These effects are dependent on the structure of the fibrin clots.

The Venom of the Boomslang (Dispholidus Typus): In Vivo and in Vitro Studies

1969 ◽  
Vol 21 (02) ◽  
pp. 234-244 ◽  
Author(s):  
N Mackay ◽  
J.C Ferguson ◽  
Antonia Bagshawe ◽  
A.T.T Forrester ◽  
G.P Mcnicol
Keyword(s):  
In Vitro Studies

SummaryAn account is given of the effects of boomslang venom in man. Evidence was found of a fibrinolytic state apparently secondary to the coagulant action of the venom. These features rapidly responded to the administration of specific antivenom. In vitro studies, using a homogenate of boomslang parotids, confirmed the coagulant properties of the venom and showed them to be of much greater potency than the proteolytic actions.

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