Polyethylene glycol embedded tissue sections for immunoelectronmicroscopy.

Several methods for tissue embedding in polyethylene glycol (PEG) were compared with regard to their applicability for pre-embedding immunoelectronmicroscopy. Existing embedding procedures gave unsatisfactory results and therefore a modified procedure was developed. This method, consisting of very brief tissue infiltration with PEG 1500, to which 3% water is added, allowed adequate tissue sectioning.

Human chorionic gonadotrophin and alpha-fetoprotein in testicular germ cell tumours: a retrospective immunohistochemical study.

A series of testicular germ cell tumours (46 seminomas and 27 non-seminomas) was studied immunohistochemically with regard to the presence of alpha FP and HCG. In three seminomas, HCG reactive syncitiotrophoblast-like giant cells (STLG) were found. Immunoreactive alpha FP did not occur in seminomas.

Gastrointestinal telangietasia as a cause of severe blood loss in systemic sclerosis.

Two patients with progressive scleroderma had severe gastrointestinal blood loss. Endoscopical examination revealed multiple telangiectase in the upper gastrointestinal tract, especially in the stomach. The telangiectases in the skin and the mucosa in systemic sclerosis are indistinguishable endoscopically and histologically from those seen in hereditary hemaorrhagic telangiectasia.

A simplified method for the rapid preparation of peroxidase-anti peroxidase (PAP) complexes.

A modified method is described for the rapid production of peroxidase-antiperoxidase complexes to be used in immunocytochemistry. In this method anti-peroxidase antibodies are precipitated from crude serum with peroxidase at equivalence and subsequently resolubilized at low pH with excess peroxidase. The complexes are isolated from unbound immunoglobulin and peroxidase by gelfiltration.

Clinical applications of the enzyme labeled antibody method. Immunoperoxidase methods in diagnostic histopathology.

Histological criteria for the definition of disease entities have largely been established with light microscopy of conventionally stained and routinely processed tissue sections. More or less specific histochemical staining procedures and more recently enzyme-histochemical and quantitative histo- and cytochemical techniques in some cases provided additional criteria. In the last decade, however, the introduction of immunofluorescence and more recently the different immunoperoxidase methods have significantly influenced the scope of contemporary histopathology.

DNA content and chromosome number of a heteroploid human tumour cell line.

In this paper investigations concerning the relation between variability of chromosome number and variability of DNA content within the cells of a tumour stemline are reported. A highly heteroploid human tumour cell line was used, which was derived from a chondrosarcoma. Flow cytometrical and scanning cytophotometrical measurements confirmed the heteroploid nature of the original cell line and of several subclones.

Evidence for predominant involvement of the B-cell system in the inflammatory process in Crohn's disease.

The cellular infiltrate in the walls of resected ileum and colon specimens obtained from patients with Crohn's disease was analysed. Mononuclear cells in tissue sections were characterized by the use of surface membrane markers and immuno-histochemical and enzyme histochemical techniques. It was found that: [1] B cells, as judged by the presence of surface membrane immunoglobulin and C3 receptors and the absence of alpha-naphthylacetate esterase and acid phosphatase activity, were the predominant type of cells in the intestinal infiltrate often found in close relation with smaller numbers of non-B cells; [2] all types of immunoglobulin-containing cells were increased in number with a shift in the ratio of IgA/IgG/IgM-containing cells in favour of the IgG- and IgM-containing cells; and [3] the histopathological reaction of the regional draining lymph nodes showed hyperplasia of B-cell areas (follicles and medulla) and small or absent T-cell areas (paracortex), consistent with a B-cell response.

Morphology and immunohistochemically-defined endocrine function of pancreatic islet cell tumours.

Thirty pancreatic islet cell tumours were histologically classified and analysed for their possible peptide hormone content using the immunohistoperoxidase method. Seven tumours contained insulin, six tumours contained gastrin and eight tumours contained glucagon. One tumour contained all three hormones.

Value of cerebrospinal fluid cytology for the diagnosis of malignancies in the central nervous system.

The authors present a retrospective analysis of the results of the cytological examinations of cerebrospinal fluid (CSF) samples and tumor-cyst aspirates deriving from 262 patients treated for malignant intracranial primary and secondary tumors, and vertebral and peridural metastastic processes. Positive preoperative CSF samples were found in 15.3% of all cases of primary cerebral malignancies (13.

Gastric and duodenal mucosa in 'healthy' individuals. An endoscopic and histopathological study of 50 volunteers.

The results of histological and immunohistochemical examination of gastric and duodenal biopsy specimens from 50 volunteers without a clinical history of gastrointestinal disease are reported. Multiple specimens of tissue from standard sites in the stomach and duodenum were carefully orientated, and serially sectioned for examination by light microscopy and for immunohistochemical characterisation of plasma cells within the lamina propria. The antrum and fundus were normal in 32 of the 50 subjects but the other 18 showed histopathological evidence of gastritis in either the antrum or fundus.

The influence of fixation on immunoperoxidase staining of plasmacells in paraffin sections of intestinal biopsy specimens.

The influence of different fixation methods on the results of immunoperoxydase staining of immunoglobulin and gastrin producing cells in gastric and duodenal mucosa was investigated. An indirect method was used on paraffin sections. It appeared that that fixatives containing sublimate gave the most consistent results, a sublimate-formaldehyde mixture being the best.

High-resolution scanning-densitometry of photographic negatives of human chromosomes. III. Determination of fluorescence emission intensities.

Principles and techniques are discussed for measuring with high topological resolution local emission in fluorescing objects, using photographic negatives. Determination of fluorescence intensities is only possible when an unequivocal relation between the original local fluorescence emission intensities of the object, and the transmittances or densities recorded in the microfluorophotograph is known. This relation is formulated in the theoretical part.

Influence of Q- and G-banding on the Feulgen-stainability of human metaphase chromosomes.

In this paper, model experiments on chicken red blood cell nuclei are described concerning the influence of methanol-acetic acid fixation and irradiation at different wavelengths, with and without prior Atebrin staining on subsequent Feulgen-stainability. In addition, data are reported on the influence on Feulgen-stainability of Giemsa-banding procedures, illumination of unstained chromosomes at 220 and 515 nm and exposure of unstained and Atebrin-stained chromosomes to illumination at 440 nm. The ASG and especially the trypsin-Giemsa technique appeared to reduce markedly Feulgen-stainability.

Fluorescamine fluorescence detection of growth hormone-producing cells in human pituitary adenomas.

Formalin-fixed and paraplast-embedded tissue specimens of human pituitary, thyroid, and pancreas were investigated using fluorescamine fluorescence and immunohistochemical methods. Growth hormone-producing cells present in normal and neoplastic pituitary tissue exhibited fluorescamine fluorescence. The other tissues examined showed no fluorescamine binding.

Sézary's syndrome: a cytogenetic, cytophotometric and autoradiographic study.

Cytophotometric, cytogenetic, and autoradiographic studies were performed in cells of three patients suffering from clinically diagnosed Sézary's syndrome with erythroderma and the presence of abnormal lymphoid cells in the peripheral blood, skin, bone marrow and lymph-nodes. Feulgen DNA cytophotometry of cells in the peripheral blood and skin lesions showed marked aneuploidy and tetraploidy. Multiple translocations were identified with a G-banding technique.