Tissues hematoxylin-eosin tissue

Fig. (8). Increased infiltration of CD3, CD4 and CDS positive cells into the s.c. rechallenge tumor following CVS treatment [44]. BALB/c mice were injected s.c. with 5 x lCr Meth A cells in the right and left flanks on day 0 and 9, respectively. CVS (50 mg/kg) (B,D,F,H) or PBS (A,C,E,G)was injected i.t. into the primary tumor 3 times every 2 days from day 2. Recnallenge tumor sections, including subcutaneous tissues, were obtained 2 days after tumor rechallenge and stained with hematoxylin-eosin (A,B) or immunohistochemically (C-H). a Subcutaneous muscle layer, b interstitial space, c tumor tissue.

Interobserver variation in the grading of VIN has been observed when using hematoxylin-eosin only, MIB-1 monoclonal antibody alone, or combined hematoxylin-eosin and MIB-1 antibody (van Beurden et al., 1999). This antibody is the most versatile proliferation worker for the sections of formalin-fixed and paraffin-embedded tissues. Normal vulvar skin and VIN lesions are fixed with formalin and embedded in paraffin according to standard procedures. 

After the determination of organ weights and macroscopic examinations the tissues are processed for histo-pathological evaluations. For this they are fixed in formalin or equivalent solutions, or they are frozen (important for the diagnosis of increased fat content in a tissue, e.g. in the liver, organic solvents would dissolved the fat) trimmed to small parts, put into paraffin blocks, cut with a microtome, and stained (hematoxylin-eosin, or special staining for fat and/or collagen etc.). 

Fig. 2 Major vestibular (Bartholin s) gland of a cow. Section stained with alcian blue - hematoxylin - eosin. C, connective tissue D, excretory duct M. bulboglandularis muscle fibers L, lobule. The bar represents 1 mm. 

The site of calcium accumulation in tissues is readily identifiable on hematoxylin-eosin slides because the protein in the calcified area develops a strong affinity for hematoxylin. But sometimes special stains must be used to identify calcium. Among those techniques, the von Kossa staining method is one of the most popular. The method is based on the precipitation of silver salt by the anionic groups present in the calcium deposit. Calcium can be demonstrated directly either by microincineration or by visualization of the hydroxyapatite crystals with the aid of the electron microscope. 

There are several forms of eosin that are commercially available. One of the most popular types, eosin Y, is soluble in both water and alcohol. As opposed to hematoxylin, eosin is an anionic stain that forms a complex with acidophilic sites such as the cytoplasm, connective tissue fibers, and collagen fibers, which will be stained red or pink (Cormack, 2001). Usually acetic acid is added to eosin solutions to act as an accelerant to enhance staining. 

When an excessive amount of emulsion is administered to the hepatic artery, the excess can be leaked to the vein. The W/O/W and O/W emulsions with and without FARM were administered via the tail veins of male Wistar rats and the acute toxicities of the emulsions were evaluated (Flino et al., 1997). Fifteen days after administration or after they died, the rats were dissected. Macroscopic pathological appearances and optical microscopic changes in hematoxylin-eosin (HE)-stained tissues of lung, stomach, and thymus gland were observed. 

One month after implantation, the rats were humanely killed, and the back was dissected to expose the implanted polymer films. The films containing tissue were fixed with 10% buffered formalin and sectioned with a microtome. The thin-sectioned specimen was stained with hematoxylin-eosin and examined under a light microscope. 

For light microscopic examination, liver tissue was fixed in 10 % buffered formalin, embedded in paraffin, sectioned and stained with hematoxylin and eosin. In some cases, preparations were stained with PTAH (phosphotungstic acid-haematoxylin), by the Van Gieson method and the PAS (periodic acid-Schiff)... 

Most mycologists consider it fruitless to directly examine clinical specimens for the yeast form of Sporothrix schenckii. The number of yeast cells in the specimen is typically very limited, and their small size and shape are not distinctive. The yeast form of S. schenckii is not easily seen in sections of tissue stained with hematoxylin and eosin. 

Figure 10.7 Demonstration of protein dots and tissue on single slide. This specimen was subjected to antigen retrieval prior to immunostaining, and a complete hematoxylin and eosin counterstain. 

To obtain tissue preparations whose constituents were maintained as closely as possible to their state in vivo, the material had to be fixed, i.e. the enzymes inactivated so that cell structures were instantaneously preserved, an almost unattainable ideal. Formalin was the favored fixative, but others (e.g. picric acid), were also employed. Different methods of fixation caused sections to have different appearances. Further artifacts were introduced because of the need to dehydrate the preparations so that they could be stained by dyes, many of which were lipid-soluble organic molecules. Paraffin wax was used to impregnate the fixed, dehydrated material. The block of tissue was then sectioned, originally by hand with a cut-throat razor, and later by a mechanical microtome. The sections were stained and mounted in balsam for examination. Hematoxylin (basophilic) and eosin (acidophilic) (H and E staining) were the commonest stains, giving blue nuclei and pink cytoplasm. Eosinophils in the blood were recognized in this way. 

Histology. Whole mussels were fixed for 1-2 days in Helly s fluid (10) and stored in 70% ethanol. Tissue was blocked at 2 mm thickness, embedded in paraffin, sectioned at about 7 ym, stained with hematoxylin and eosin, and mounted on glass slides using standard procedures. 

Figure 3.1 Cross section of the rat colon (A) in comparison to small intestine (B). Tissues were fixed with 10% formalin, stained with 0.125% hematoxylin and 0.25% eosin, and observed with a microscope (x 20).

The presence of necrotic, inflammatory, and/or nontumorigenic tissue should be determined by a pathologist by reviewing the hematoxylin- and eosin-stained 5-pm section prepared in step 1. 

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