Some recent developments in immunocytochemistry

Factors affecting the formation of membranous substances in the palates of elderly persons requiring nursing care

OBJECTIVE

To determine the causative factor behind the formation of membranous substances in the mouths of elderly patients requiring nursing care.

BACKGROUND

Membranous substances are sometimes observed in the mouths of elderly persons requiring nursing care, and these can lead to bleeding, infection and asphyxiation.

MATERIALS AND METHODS

In April 2007, samples were collected from 70 patients at C Hospital, Aichi Prefecture, Japan, who were 65 years or older (median age, 81.1 ± 7.7 years). Sixteen of the subjects were confirmed to have a membranous substance containing a keratin degeneration product that had been derived from stratified squamous epithelium. The samples were examined microscopically, and the presence of epithelial components was confirmed through immunohistochemical staining with anti-cytokeratin-1 antibodies.

RESULTS

Decision tree analysis and logistic regression suggest that the leading contributors to the formation of the membranous substances were the method of ingesting nutrients, dryness of the tongue dorsum and open mouth. These three factors are related to elderly persons requiring nursing care with impaired oral cavity function, and it was suggested that dryness of the oral mucosa was the major factor behind the membrane formation.

Indirect immunofluorescent labeling of viable cells

A recognized flow cytometry procedure for standard indirect antibody staining for cellular analysis and cell sorting is discussed. A protocol for cell surface or intracellular antibody staining of viable cells is provided.

Establishment of anti-rat-Cu,Zn-superoxide dismutase monoclonal antibodies applied to a highly sensitive immunoassay and immunohistochemistry system

The superoxide anion has been implicated in a wide range of diseases. The major protector against superoxide anion in the cell cytosol is Cu,Zn-superoxide dismutase (Cu,Zn-SOD). In this study, anti rat Cu,Zn-SOD was established in murine monoclonal antibodies for the first time. These antibodies were applied to both a highly sensitive EIA system in serum and immunohistochemical methods for detection in gastric mucosa tissues. The proposed EIA method had a high sensitivity within the assay range, 10-300 pg/mL, good percentage, 96.9 +/- 5.60%, and good reproducibility; within-day assay CV = 8.6-10.2%, between-day assay CV = 6.5-11.7%. Inmmunohistochemically, Cu,Zn-SOD localized in the esophagus epithelial cells, gastric oxyntic cells, surface of the gastric lumen side in the small intestine and colonic epithelial cells. The establishment of anti-rat CuZn-SOD monoclonal antibody allows both specific analysis of immunoquantitation in rat Cu,Zn-SOD and highly specific detection of Cu,Zn-SOD location by immunohistochemical methods.

Development and application of immunocytochemical staining techniques: a review

Since the field of immunocytochemistry was pioneered almost half a century ago, over 30 different immunostaining methods have been developed. Most laboratory investigators, however, are aware of only a few of the more popular techniques. This article, therefore, reviews and places in historical perspective many of the less common methodologies. A discussion of the progression of immunostaining methodology from purely immunologic techniques (employing only antigens, antibodies, and free enzymatic preparations) to procedures that use non-immunologic substances (such as avidin, biotin, and protein A) is presented. Basic principles of immunostaining, including specimen preparation, fixation, control procedures, interpretation, and problems unique to cytopathology, are also discussed. Schematic diagrams that illustrate the nature and arrangement of the immunochemical reagents employed in most of these techniques are provided in order to demonstrate how various materials can be combined to create a desired staining effect.

Dipeptidyl peptidase (DPP) IV in rat organs. Comparison of immunohistochemistry and activity histochemistry

Immunohistochemistry and activity histochemistry were used to study the localization of dipeptidyl peptidase (DPP) IV in rats. For immunohistochemistry, polyclonal as well as monoclonal anti-DPP IV antibodies were employed. The pattern of DPP IV immunoreactivity, determined with polyclonal anti-DPP IV antibody, corresponds to the histochemical pattern found for the enzymic activity of DPP IV. Immunoreactivity was present, in addition, in nerve cells, lateral membranes of certain surface epithelia, e.g., Fallopian tube, uterus and vesicular gland, in the luminal cytoplasm of e.g., vesicular gland epithelium, and in mucous cells of Brunner's gland. The monoclonal antibodies against DPP IV recognized four different epitopes (A-D) of the DPP IV molecule, and revealed that certain epitopes were not detectable by immunohistochemistry in some organs. Generally, the staining intensities for epitopes A, B, C and D decreased in that order. Usually, the monoclonal antibodies against epitopes A and B showed similar reaction patterns to those as obtained with the polyclonal antibody. Epitope D was recognized in the lumen of the duct system of exocrine glands and the intestine. Furthermore, high reactivity of this epitope was detected in goblet cells of the intestine, where no DPP IV activity was present.

Application of frozen thin sectioning immunogold staining to the study of the developing neuroepithelial basal lamina

In order to examine the deposition of basal lamina components in the developing neuroepithelium, a technique for frozen thin sectioning and immunogold staining of early embryonic tissue was developed. Different fixatives and buffer systems were evaluated to determine which best retained immunoreactivity and satisfactory ultrastructure of day 9 and 10 mouse embryos. Fixation in sodium phosphate and sodium bicarbonate buffers did not retain antigenicity, and incubations in TBS (trishydroxymethyl-aminomethane buffered saline) in an effort to 'restore' immunoreactivity were similarly unsuccessful. Fixation in sodium cacodylate buffer, however, did retain the antigenicity of basal lamina components; the pattern of type IV collagen and laminin distribution was clearly determined. These results represent the first report of on-grid immunocytochemistry of early embryonic material.

The morphogenesis of the human Paneth cell. An immunocytochemical ultrastructural study

In human duodenal mucosa Paneth cells originate away from the base of crypts and migrate towards the base during maturation. The earliest cells in the Paneth cell lineage could be identified by labelling of lysozyme in the Golgi apparatus. Specific labelling for lysozyme was present in the rough endoplasmic reticulum, Golgi apparatus, condensing vacuoles, granules and many lysosomes of mature Paneth cells. The maturation of the Paneth cell is accompanied by an increase in the content of lysozyme in the secretory granules and with senescence lysozyme diffuses into the cytoplasm.

Some improvement in tissue preparation and colloidal-gold immunolabeling for electron microscopy

The application of freeze-substitution (FS) and freeze-drying (FD) techniques and the protein A-gold-antibody complex immunocytochemical methods are described. The two tissue-preparation techniques produced excellent ultrastructure and topographical fixation of antigens when compared with conventional tissue-preparation techniques. In the FS preparation, however, occasional extragranular immunolabeling was recognized. This may suggest the leakage of antigens from the secretory granules. The FD procedure was considered the best, since such labeling was almost negligible. The protein A-gold-antibody complexes are easily prepared and label the antigens clearly. If the protein A-coated gold particles are saturated with antibodies, there is no interaction between gold particles. Thus, multiple antigens can be determined even in single secretory granules. In fact, we demonstrated intragranular colocalization of immunoreactive oxytocin, labeled with 50-nm gold particles, and immunoreactive methionine-enkephalin, labeled with 15-nm gold particles, in the axonal terminals of the FD-prepared rat neurohypophysis. This study demonstrates the value of the use of gold-antibody complexes for immunocytochemical labeling on FS- or FD-treated tissues.

Immunocytochemical detection of basement membrane antigens in the histopathological evaluation of laryngeal dysplasia and neoplasia

Immunocytochemical detection of intrinsic components of the basement membrane (type IV collagen and laminin) was performed in biopsies of carcinoma in situ, dysplasia and hyperplasia of the laryngeal mucosa. We found a distinct and continuous basement membrane, containing both laminin and type IV collagen, at the border between epithelial cells and mesenchymal stroma in normal as well as in hyperplastic and dysplastic mucosa. In contrast, irregular discontinuities were found in some cases of carcinoma in situ and in invasive carcinoma. In addition, immunoreactivity for intracytoplasmic basement membrane components was noticed occasionally in neoplastic epithelial cells. In areas of inflammation, infiltration of leucocytes into the epithelium was occasionally accompanied by sharply defined small interruptions of the basement membrane. Our results indicate that immunohistochemical detection of basement membrane components can be of value for the demonstration of microinvasive growth in laryngeal cancer.

Chromogranin A (CGA) in the gastro-entero-pancreatic (GEP) endocrine system. I. CGA in the mammalian endocrine pancreas

Chromogranin A (CGA), a protein at first detected in the adrenal medulla, has recently been found also in other organs, e.g. the endocrine pancreas. However, immunohistochemical findings concerning the cellular source of pancreatic CGA were controversial. Therefore, the endocrine pancreas of 10 mammalian species (man, tupaia, mole, cat, dog, pig, guinea pig, rabbit, rat) was investigated immunohistochemically for CGA-like immunoreactivities on serial semithin plastic sections using a high-titer polyclonal antiserum against bovine CGA. The results show that basically all pancreatic endocrine cell types are CGA-immunoreactive; however, every species has its own pattern of CGA-immunoreactive cell types. Other findings of the present studies indicate that the physiological function of CGA in pancreatic endocrine cells is related to the storage mechanisms of peptide hormones. Finally, a methodological approach is given to obtain not only qualitative but also semi-quantitative data during immunohistochemical investigations.

The immunobiology of basal cell carcinoma: an in situ monoclonal antibody study

A semi-quantitative, immunoperoxidase monoclonal antibody technique was used to study the mononuclear cells surrounding 32 basal cell carcinoma specimens from 30 patients. Tumours were analysed in subgroups based on recurrence, size and ulceration. T cell counts were high (greater than 3 out of 4) for all groups while T helper/inducer and T suppressor/cytotoxic cell counts were equal (approx. 2). Macrophage counts were low for all groups, about I X 2, while B cell and Ia positive cell counts were high (greater than 3). T/B cell and T helper/suppressor cell ratios approached one for the tumours as a whole as well as the sub-groups. The relative importance and contribution of cell mediated vs. humoral immunity in keeping basal cell carcinomas in check is discussed.

Use of the peroxidase-antiperoxidase technique for differential staining of multiple cell types in the rat pancreatic islet

Multiple staining of the endocrine cells of the pancreatic islet was studied in tissue obtained from adult rats. After fixation in Bouin's fluid and processing for light microscopy, the unlabeled peroxidase-antiperoxidase (PAP) technique was performed. Successful staining procedures used variations of the PAP technique with 3,3'-diaminobenzidine (DAB) and 4-chloro-1-naphthol (CN) as chromagens. The purpose of this study was to stain as many of the four primary cell types (A-cells, B-cells, D-cells, PP-cells) as possible either simultaneously or sequentially using photomicroscopy. At optimum antibody titer, there was minimal nonspecific background staining which made it possible to differentiate cell types by intensity of the chromagen. Any two cell types can be shown by using DAB with the first antibody and CN with the second. To demonstrate three cell types simultaneously, three methods which altered dilutions and chromagens were used. The first method consisted of decreasing dilutions of primary antibody with DAB and CN as the chromagens. The second method involved repetitive DAB applications resulting in three intensities of brown. The third method used a DAB immersion after the second cell type was stained. This produced a color differential so the third cell type could be distinguished with CN. To demonstrate the three cell types sequentially, a masking technique was introduced with photomicroscopy. In order to block the preceding complex, the previous cell type (demonstrated by CN) was restained with DAB at an increased dilution. The next cell type was then stained with CN. These four methods were tried in attempts to stain four cell types in the same tissue section.

Homogeneity among mitochondria revealed by a constant proportion of their enzymes

The homogeneity or heterogeneity at the enzyme level of mitochondria has not been directly demonstrated and is important for many studies. To clarify this point, carbamoyl phosphate synthase (ammonia), glutamate dehydrogenase and mitochondrial adenosine triphosphatase (F1) were located in rat liver by immunolabeling using protein A-gold. Measurements of the number of gold particles per square micron of cross sectional images of mitochondria permit to assess the relative molecular concentration of the three enzymes and, most interestingly, it presents the first evidence that different mitochondria in rat liver cells have the same relative proportion of the three enzymes. Since they have vastly different half-lives, bulk or unregulated autophagy as the main mechanism regulating the turnover of these enzymes seems unlikely.