A quantitative study of the effects of different grades of polyvinyl alcohol on the activities of certain enzymes in unfixed tissue sections

1978 ◽  
Vol 10 (4) ◽  
pp. 453-463 ◽  
Author(s):  
B. Henderson ◽  
N. Loveridge ◽  
W. R. Robertson

1984 ◽  
Vol 16 (2) ◽  
pp. 111-122 ◽  
Author(s):  
Patricia A. Ealey ◽  
B. Henderson ◽  
N. Loveridge


1985 ◽  
Vol 33 (8) ◽  
pp. 755-761 ◽  
Author(s):  
K Valnes ◽  
P Brandtzaeg

Polyvinyl alcohol (PVA) mounting medium containing paraphenylenediamine (PPD), n-propyl gallate (NPG), or 1,4-diazobicyclo(2,2,2)-octane (DABCO) was compared with PVA alone or buffered glycerol with regard to capacity for preservation of immunofluorescence preparations. The results were based on staining of an artificial substrate with homogeneous antigen distribution followed by microphotometric determination of the initial light emission from bound fluorescein isothiocyanate (FITC)-labeled antibody and the subsequent fluorescence fading during 3-min exposure to blue excitation light. At a concentration of 0.2-2.0 g/liter and 6 g/liter, respectively, PPD and NPG were shown to effectively retard fluorescence fading without notably decreasing the initial emission intensity; two requisites were that the modified PVA used must be rather fresh and that the mounted preparations be examined within a few days. Although addition of DABCO (6 g/liter) afforded a mounting medium that tolerated storage before use better, but both PPD and NPG were more advantageous in practice. The retarding effect of PPD on fading of FITC emission was confirmed by performance testing on human tissue sections. Remounting in PVA alone is recommended for prolonged storage of sections that have been mounted in PVA modified with one of the above-mentioned compounds.



2006 ◽  
Vol 18 (5) ◽  
pp. 525 ◽  
Author(s):  
R. Chávez-Genaro ◽  
P. Lombide ◽  
G. Anesetti

In mammals, pregnancy induces a transient and extensive degeneration of uterine sympathetic innervation. We used the models of unilateral oviduct ligation and in oculo myometrium transplant in pregnant rats to address the role of stretching forces and/or hormone milieu in the loss of sympathetic innervation. The sympathetic fibres of the uterine horn and in oculo myometrial transplants were quantified on tissue sections processed by the glyoxylic acid technique. In normal pregnant rats, the density of uterine horn innervation was significantly reduced at late pregnancy and recovery took place during post partum. The empty horn of pregnant rats showed no significant changes in density of myometrial innervation during pregnancy or post partum. In oculo myometrial transplants were organotypically reinnervated in virgin animals. When the transplants were exposed to gestational hormonal milieu, few or no fibres were observed to the end of pregnancy; however, a significant increase at post partum was observed. Results showed that both the effects of stretching and the hormone milieu derived from the fetus–placenta complex play a role as inductors of changes on sympathetic myometrial innervation during pregnancy and support the idea that immature muscular uterine fibres are more susceptible to the effects of pregnancy than those originating from adult animals.





Author(s):  
Teruo Someya ◽  
Jinzo Kobayashi

Recent progress in the electron-mirror microscopy (EMM), e.g., an improvement of its resolving power together with an increase of the magnification makes it useful for investigating the ferroelectric domain physics. English has recently observed the domain texture in the surface layer of BaTiO3. The present authors ) have developed a theory by which one can evaluate small one-dimensional electric fields and/or topographic step heights in the crystal surfaces from their EMM pictures. This theory was applied to a quantitative study of the surface pattern of BaTiO3).



Author(s):  
George H. Herbener ◽  
Antonio Nanci ◽  
Moise Bendayan

Protein A-gold immunocytochemistry is a two-step, post-embedding labeling procedure which may be applied to tissue sections to localize intra- and extracellular proteins. The key requisite for immunocytochemistry is the availability of the appropriate antibody to react in an immune response with the antigenic sites on the protein of interest. During the second step, protein A-gold complex is reacted with the antibody. This is a non- specific reaction in that protein A will combine with most IgG antibodies. The ‘label’ visualized in the electron microscope is colloidal gold. Since labeling is restricted to the surface of the tissue section and since colloidal gold is particulate, labeling density, i.e., the number of gold particles per unit area of tissue section, may be quantitated with ease and accuracy.



Author(s):  
W. E. Rigsby ◽  
D. M. Hinton ◽  
V. J. Hurst ◽  
P. C. McCaskey

Crystalline intracellular inclusions are rarely seen in mammalian tissues and are often difficult to positively identify. Lymph node and liver tissue samples were obtained from two cows which had been rejected at the slaughter house due to the abnormal appearance of these organs in the animals. The samples were fixed in formaldehyde and some of the fixed material was embedded in paraffin. Examination of the paraffin sections with polarized light microscopy revealed the presence of numerous crystals in both hepatic and lymph tissue sections. Tissue sections were then deparaffinized in xylene, mounted, carbon coated, and examined in a Phillips 505T SEM equipped with a Tracor Northern X-ray Energy Dispersive Spectroscopy (EDS) system. Crystals were obscured by cellular components and membranes so that EDS spectra were only obtainable from whole cells. Tissue samples which had been fixed but not paraffin-embedded were dehydrated, embedded in Spurrs plastic, and sectioned.



Author(s):  
Bert Ph. M. Menco

Vertebrate olfactory receptor cells are specialized neurons that have numerous long tapering cilia. The distal parts of these cilia line the interface between the external odorous environment and the luminal surface of the olfactory epithelium. The length and number of these cilia results in a large surface area that presumably increases the chance that an odor molecule will meet a receptor cell. Advanced methods of cryoprepration and immuno-gold labeling were particularly useful to preserve the delicate ultrastructural and immunocytochemical features of olfactory cilia required for localization of molecules involved in olfactory signal-transduction. We subjected olfactory tissues to freeze-substitution in acetone (unfixed tissues) or methanol (fixed tissues) followed by low temperature embedding in Lowicryl K11M for that purpose. Tissue sections were immunoreacted with several antibodies against proteins that are presumably important in olfactory signal-transduction.



Author(s):  
Jeffrey P. Chang ◽  
Jaang J. Wang

Flat embeddment of certain specimens for electron microscopy is necessary for three classes of biological materials: namely monolayer cells, tissue sections of paraffin or plastics, as well as cell concentrations, exfoliated cells, and cell smears. The present report concerns a flat-embedding technique which can be applied to all these three classes of materials and which is a modified and improved version of Chang's original methodology.Preparation of coverglasses and microslides. Chemically cleaned coverglasses, 11 × 22 mm or other sizes, are laid in rows on black paper. Ink-mark one coner for identifying the spray-side of the glass for growing cells. Lightly spray with Teflon monomer (Heddy/Contact Inductries, Paterson, NO 07524, U.S.A.) from a pressurized can. Bake the sprayed glasses at 500°F for 45 min on Cover-Glass Ceramic Racks (A. Thomas Co. Philadelphia), for Teflon to polymerize.Monolayer Cells. After sterilization, the Teflon-treated coverglasses, with cells attached, are treated or fixed in situ in Columbia staining dishes (A. Thomas Co., Philadelphia) for subsequent processing.



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