Guy Heyden

Histochemical investigation of malignant cells

SummaryBy means of a modified histochemical method for demonstrating glucose-6-phosphate dehydrogenase activity in an atmosphere saturated with oxygen it proved possible to record malignant cells in tissue sections and cell cultures. Tests were performed on potentially malignant and established malignant human epithelial lesions, on different stages of experimental squamous cell carcinomas in the rat and on cell cultures of malignant cells. Clinically healthy epithelium, benign lesions and cell cultures of benign cells served as controls. The occurrence of strongly positive cytoplasmic enzyme reactions in malignant cells may be termed metabolic atypia. In experimental carcinogenesis this form of atypia seemed to procede visible morphologic atypia (dysplasia). Further studies are in progress to evaluate the utilization of the histochemical recordings, in addition to ordinary histologic analyses, in routine differential diagnostic work.

Intravascular papillary endothelial hyperplasia in the oral mucosa

An intraluminal reactive hyperplastic lesion from the lower labial mucosa of an adult male patient is described. It has been termed intravascular papillary endothelial hyperplasia and may have arisen in an organizing thrombosed vein. The importance of distinguishing it from a malignant vascular neoplasm is stressed, and the differential diagnosis is discussed.

The predominant microflora of the palatal mucosa in an elderly island population

The prevalence and microbiology of macrophotographically documented denture stomatitis were studied in denture wearers participating in an interdisciplinary health-monitoring project (Koster Health Project) on the Koster islands, Sweden. Upper dentures were used by 26.6% of the adult population, and 59.2% of the denture wearers had stomatitis. Denture stomatitis type I was identified as sialadenitis. The more severe forms of denture stomatitis (types II and III) demonstrated increased recovery of microorganisms in the palatal mucosa in addition to sialadenitis. Only one proband showed increased growth of fungi. Hemophilus spp. and Bacteroides spp. were the predominating microorganisms in stomatitis types II and III. Shifts in the normal oral flora are suggested to be an important factor for the development of denture stomatitis. It is concluded that bacterial colonization on the palatal mucosa may play an important role in denture stomatitis in this relatively healthy population.

Quantification of burn induced extravasation of Evans blue albumin based on digital image analysis

The present study evaluated a non-invasive method based on digital image colour analysis that allows near-continuous quantification of extravasated Evans blue albumin after burn injury. A full-thickness burn was induced in the abdominal skin of rats, followed by injection of Evans blue dye. Tissue content of Evans blue were quantified using spectrophotometry, and compared with digital colour analysis. The non-invasive technique demonstrated a good correlation when compared to invasive spectrophotometry, but is superior by allowing near continuous measurement in the same subject and may be of value for evaluation of effective burn oedema-reducing treatment.

Histological and histochemical studies on combined heat-Roentgen treatment of a C3H mouse mammary carcinoma.

SummaryAn experimental model comprising the effects of heat and roentgen treatment, 42.5° C and 800 r, combined or alone, on mouse mammary tumour cells was utilized in order to study the reliability of histological and histochemical analyses in evaluations of the therapeutic effects. It was found that fixed, cold-microtome sections revealed morphological characteristics similar to those found in conventional paraffin sections. The different treatments produced various degrees of cell damage, including nuclear changes, with a particular pattern in the combined heat-roentgen therapy. Histochemical recordings of lipids and carbohydrates alone were not conclusive in the therapy evaluations. Enzyme histochemical studies on oxido-reductases seemed to be the most sensitive of the light-microscopic methods. Tests on hydrolases revealed increased, unspecific nuclear staining reactions with the lead method for acid phosphatase after therapy. With the azo-dye technique the enzyme activity was reflecting delayed treatment effects on the tumour cells and variations in the amount of macrophages. It was concluded that combined histological and histochemical analyses are essential in light-microscopic evaluations of the therapeutic effects.In accordance with earlier data, the combined heat-roentgen therapy produced the most marked tissue effects. Heating alone was more deleterious to the malignant cells than roentgen alone.

Alterations in the lipid content of rat palatal epithelium during carcinogenesis

SummaryThe hard palates of 150 female albino rats of the Sprague-Dawley strain were painted 3 times a week either with the fat-soluble carcinogen 7,12-dimethylbenz(a)anthracene (DMBA) for 11 months with inhibited secretion of saliva or with the water-soluble carcinogen 4-nitrochinoline N-oxide (4NQO) for 8 months with intact salivary secretion. Specimens were taken regularly from the mucosa of the hard palate, and the content of lipids in the epithelium was studied histochemically and biochemically during the carcinogenesis.Changes in the lipid content could be observed histochemically as there was a focal loss of lipid stainability in the epithelium during the more advanced stages of carcinogenesis with severe epithelial dysplasia, carcinoma in situ and early invasive carcinoma.The biochemical method used (TLC) could not, however, verify the histologically observed changes in the lipid content of the epithelium, probably because the changes were very local.

Follicular choristoma of the gingiva: A peculiar lesion

Abstract In a 9-year-old girl a tumorlike nodular projection lingual to the lower permanent incisors contained sebaceous cells, hair follicles with hairs, a small keratocyst, melanocytes, and lymphocytes and plasmocytes, and, associated with disintegrated sebaceous cells, a foreign-body giant-cell reaction. The “tumor” is termed a follicular choristoma .

A NEW ROUTINE IN HISTOPATHOLOGY

The positive artifacts are informative in diagnostic work, but the negative ones are usually detrimental in thatthey interfere with the interpretation of tissue changes. Positive artifacts may be exemplified by the nuclear staining reactions in histology, and by the coloured precipitates, indicating enzyme activities, in histochemistry. Negative artifacts may be represented by the loss of stainable substances and by morphological defects usually from chemical and thermal damage during paraflin embedding, and diffusion problems and mechanical defects during freezing and thawing of tissues in enzyme histochemical studies. The methods used today in routine histopathology are extensively based on fixation and paraffin embedding of the tissues. Most of the procedures have been unchanged for many decades. The reluctance to introduce variations in the laboratory routine maintains the continuity of criteria for morphologic evaluation of tissue changes and thus simplifies the training of pathologists.

Histochemical tests on lipids in the oral and skin epithelia in the mouse

SummaryThe present study concerns the application of a new tissue transport medium, Histocon, in lipid histochemical analysis of biopsies. It was generally found that this medium visibly retained more lipids quantitatively than did a fixation of the tissues. The lipid “preserving” capacity of Histocon seemed to be superior even to the use of fresh frozen specimens. These beneficial effects may be due to membrane stabilizing factors in the transport medium.Two types of lipids were usually found when comparing oral mucosa with epidermis. The mucosa was characterized chiefly by phospholipids with an increasing concentration gradient towards the stratum granulosum. The skin showed, in addition to the similar phospholipid gradient, also the presence of unsaturated hydrophobic lipids in the stratum corneum and granulosum.

Computer analysis in oral lichenoid reactions

To improve diagnostic procedures and facilitate clinical decision-making, computer-assisted image analysis was performed on color slides from 30 patients with histopathologically verified oral lichenoid reactions. Areas from white hyperkeratotic and adjacent red inflamed areas of the lesions were selected and subjected to image analysis. The digitization of the color slides was done by means of an image scanner, and the digital information was transmitted to a personal computer for subsequent feature extraction and analysis. The different oral lesions were characterized as the difference in mean values between white hyperkeratotic and red inflamed areas, respectively, compared with clinically normal tissue. Statistical analyses were made on three different color systems: Red-Green-Blue (RGB), normalized red-green-blue (rgb), and Intensity-Hue-Saturation (IHS). The results showed statistically significant differences in all color systems for both the hyperkeratotic areas and adjacent inflammatory reactions. A linear correlation was obtained when the results of the image analysis of color variations were compared with a clinical score system for hyperkeratosis and inflammation evaluated by two investigators independently.