摘要:

A method for observing whole rat fetal viscera embedded in gelatin using an automatic slicing apparatus is described. Fetuses were immersed in Bouin's solution. Part of the thoracic and abdominal skin of each fetus was removed, and fetuses were immersed consecutively in sodium bicarbonate 30% in 70% ethanol, gelatin 15% in water, gelatin 30% in water, then embedded in fresh 30% gelatin. The gelatin blocks containing the fetuses were immersed in 10% formalin. After fixation, the block was sliced into 200μmserial transverse sections using a rotor-slicer at a rotation speed of 120 rpm and a cutting speed of 25 mm/sec. Complete slicing of a single fetus required about 20 min. The advantages of the method presented here include: complete fetal serial sections are produced, thin and uniform sections are obtained easily, viscera can be identified easily, and observation can be carried out at any time after slicing. The method presented can be used to detect whole fetal visceral malformations in developmental toxicity tests.

ISSN:1052-0295    

DOI:10.3109/10520299409106310

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

The present study demonstrates that rhodamine 123 penetrates the callose walls surrounding plant microspores before they are released from tetrads. The stain accumulates in active mitochondria due to the electrical potential across the mitochondria1 membrane. Accumulation of dye does not occur in mitochondria of fixed cells and fades quickly when mitochondrial activity is inhibited by exposure to carbonyl cyanide m-chlorophenyl hydrazone. Rhodamine can be used as a viability test for microspores still within tetrads, thus making it possible to determine when during development genes leading to pollen sterility are expressed. Rhodamine 123 is excited by blue (550 nm) light and can thus be used with confocal laser scanning microscopy. Anthers of Nicotiana tabacum, Oenothera villari-cae, Silene dioica and Lycopersicum esculentum were studied here.

ISSN:1052-0295    

DOI:10.3109/10520299409106311

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

An immunohistochemical assay for proliferating cell nuclear antigen (PCNA) identifies cells in all active phases of the cell cycle. In this study, PCNA methodology, which was developed primarily for mammalian tissues, was adapted to three small fish species, medaka(Ory-zias latipes), guppy(Poecilia reticulata), and western mosquitofish(Gambusia affiinis)that are used in carcinogenesis bioassays and environmental sentinel studies. Our study showed that PCNA can be identified in routinely processed, paraffin embedded specimens of these fishes. Optimum staining conditions were dependent on fixative, primary antibody, antigen retrieval processing. and protein blocking reagent. Best results were achieved using 10% neutral buffered formalin as the fixative, clone PC10 as the primary antibody, and a combination of powdered milk and bovine serum albumin as a protein block. Except for medaka specimens, antigen retrieval was not required for specimens preserved in 10% neutral buffered formalin. but was required for the other fixatives tested. In whole fish specimens, PCNA marked cells in normally proliferating tissues such as testis. ovary, primary filament epithelium of the gill, hematopoietic tissues, thymus, retina and alimentary tract. The study demonstrated the successful application of mammalian-based PCNA technology to these aquatic species. Further applications of the assay will aid in understanding the role of cell proliferation in normal, diseased, and toxicant-affected tissues of aquatic animals.

ISSN:1052-0295    

DOI:10.3109/10520299409106312

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

We describe a new technique for immunohistochemical and enzyme-histochemi-cal double staining using confocal laser scanning microscopy in the reflection mode. As an example, we investigated the immunoreactivity for Spot 35-calbindin-D28K, a vitamin D-dependent calcium binding protein, and the enzyme activity for ma+-ATPase in the rat kidney. The lead precipitation method for Ca2+-ATPase was initially used to process kidney slices. Each specimen was then dehydrated and embedded in a water soluble resin. Thin sections were cut from the resin block, and an indirect immunocolloidal gold method with silver enhancement for Spot 35-calbindin-D28Kantigen was carried out on the glass slides. Results were then observed by confocal laser scanning microscopy in the reflection mode. The three-dimensional distribution of the reaction products was detected by serial optic slice images. Lead phosphate particles, which represented the location of Ca2+-ATPase, were distributed deep in the section. The most intense signals from the silver partkles were detected from the surface slice of the section. A stereoscopic image generated from the serial optic slices clearly showed the differences in their distribution.

ISSN:1052-0295    

DOI:10.3109/10520299409106313

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

The mercury-silver (Hg-Ag) argentaffin technique, known to stain specifically proteins in the lateral components of triads/diads in striated muscle cells, was applied to the central nervous system of adult rats. Following fixation in glutaraldehyde, axons in white and gray matter were selectively stained, but not perikarya or their proximal axon and dendrites. Neural tissues were postfixed 24 hr in 5% (w/v) mercuric acetate in 2% (v/v) acetic acid in distilled water, stained for 12–24 hr in darkness at 37–43 C with ammoniacal silver nitrate solution, freshly prepared by adding concentrated ammonia to 60% (w/v) silver nitrate solution until a small amount of silver oxide precipitate remained undissolved. Samples were then washed with freshly prepared 5% (w/v) sodium sulfite and distilled water. All steps were carried out using dark-colored glass flasks. Samples were dehydrated with ethanol and embedded in Paraplast or Poly Bed. Electron microscopy showed the silver-reducing protein inside the axons. Methylation abolished Hg-Ag axonal reactivity indicating that carboxyl groups were necessary for silver staining. Proteins with solubility properties characteristic of neurofilament proteins were involved in Hg-Ag staining. In the cerebellum the plexus of parallel fibers in the molecular layer were not stained, while basket cell axonal processes reacted intensely. The method appears to distinguish neuronal protein variants related to cytotypic differences in cytoskeletal neurofilaments.

ISSN:1052-0295    

DOI:10.3109/10520299409106314

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

A method has been developed to enable correlative light microscopy (LM) and scanning electron microscopy (SEM) on the same section of wheat(Triticum aestivumL.) leaves infested by greenbug aphids(Schizaphis gra-minumRondani). Segments of infested leaf tissue were fixed, embedded in paraffin, sectioned, and affixed to slides by standard histological techniques. Serial sections were viewed by LM as temporary mounts in xylene. Sections of interest were identified and re-embedded in fingernail polish, affixed to aluminum stubs, freed of polish with ethyl acetate or acetone, and sputter-coated for SEM. SEM of re-embedded leaf sections showed excellent preservation of leaf anatomy. The same aphid tracks and regions of cell damage identified by LM were visible. SEM increased resolution and provided a much clearer sense of the three-dimensional relations involved in the interaction between plant and insect.

ISSN:1052-0295    

DOI:10.3109/10520299409106315

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

ISSN:1052-0295    

DOI:10.3109/10520299409106316

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor