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Biomedical subjects

G Heyden

Publications and source records attributed to G Heyden.

At least 37 records · Page 2Linked to original sources
PubMed1987

The application of microspectrocytofluorometric measurement of Feulgen nuclear DNA content to experimental tumors of rat submandibular gland. 1. Pathogensis and nuclear DNA content.

Pellets containing 9,10-dimethyl-1,2-benzanthracene (DMBA) were inserted into the submandibular glands of 65 male Fischer rats to determine the nuclear DNA content of both metaplastic epithelium during the process of development of squamous metaplasia (noted at 1, 2, 5, 7, 9, 10, 11, 13 and 15 weeks after insertion) and tumor cells of squamous cell carcinoma 24 weeks after insertion. From the second week of insertion onward, squamous metaplasia was found in excretory duct remaining epithelium in the tissues around the pellet. Dysplasia or a lining of metaplastic epithelium with atypia adjacent to pellets (i.e., formation of an epidermal cyst) was observed 5 weeks after insertion. Coincident with this dysplasia or metaplastic epithelium with atypia, variation in the nuclear DNA content was observed, showing the emergence of octaploids and a widespread histogram pattern with many peaks. Between 7 and 15 weeks, 25%-66% of the lining metaplastic epithelium showed variation in the nuclear DNA content due to shift of a peak (major mode) to a triploid as well as a vague major mode with the appearance of octaploids, etc. Tumors of the submandibular gland were recognized at 24 weeks in 11 (55%) of 20 rats. Nine were keratinized squamous cell carcinomas and the remaining 2 were carcinosarcomas. Marked abnormalities in the nuclear DNA content were observed in 5 of the 11 rats (45.5%), 3 with keratinizing squamous cell carcinoma and 2 with carcinosarcomas. In contrast, no marked variation in the nuclear DNA content was found in 5 rats in which the tumor was associated with cysts.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1987

The application of microspectrocytofluorometric measurement of Feulgen nuclear DNA content in experimental tumors of rat submandibular gland, 2. The correlation between proliferative ability and nuclear DNA content of tumor tissue in autotransplanted areas.

We have reported that there is a difference in the variation of the nuclear DNA content of tumor cells among cases of squamous cell carcinoma induced by 9,10-dimethyl-1,2-benzanthracene (DMBA) in the rat submandibular gland. In the present investigation, the relationship between the nuclear DNA content of tumor cells in autotransplanted sections collected from primary lesions of DMBA-induced tumors and their proliferative ability in the subfascial area of the rat abdomen was examined. As a result of autotransplantation, proliferation in the autotransplanted area was observed in 6 of 14 (42.8%) cases of autotransplantation. Five of these had a keratinizing squamous cell carcinoma while the remaining one had a sarcomatoid tumor. The histological type of the tumor of the proliferative lesion in the transplanted area was very similar to that of the tumor tissues in the primary lesion or the transplanted section collected from the primary lesions. In the proliferative group, marked variation of the nuclear DNA content was observed in the tumor cells of the transplanted section. The proliferative index (PI) was high for these tumor cells in this group. There was no variation in the nuclear DNA content in the tumor cells of the nonproliferative group, and the PI was also low. These results were considered to suggest that there was a correlation between the nuclear DNA content of these experimental tumor cell and their proliferative ability in the autotransplanted area. Therefore, the determination of nuclear DNA content by this method can be used as an objective index of the proliferative ability of tumor tissue.

Animals↗
PubMed1984

Oral mucosal lesions in systemic lupus erythematosus--a clinical, histopathological and immunopathological study.

The oral mucosa was investigated in 51 patients with systemic lupus erythematosus (SLE). Lesions were seen in 23 patients (45%). Most lesions were of discoid type or erythemas; only 3 were seen in 23 patients (45%). Most lesions were of discoid type or erythemas; only 3 were ulcerations. The hard palate, buccal mucosa and vermilion border were the most frequent sites of involvement. The overall prevalence was not related to disease activity, but discoid lesions and ulcerations were only seen in patients with active disease. Histopathological investigation showed liquefactive degeneration in 6 biopsies of 10 lesions. Immunofluorescence examination was positive in all cases.

Adult↗
PubMed1982

Experimental induction of irreversible precancerous changes in the palatal epithelium of the rat.

The development of irreversible precancerous changes in the palatal mucosa of the rat was studied macroscopically and histologically after painting the palate 3 times a week with 0.5% 4-nitroquinoline-N-oxide for 1-22 weeks. Control animals were painted with the solvent propylene glycol. After the application periods, the spontaneous development of premalignant epithelial changes and carcinomas was recorded by repeated biopsy procedures. Short application periods (1-6 weeks) were consistently followed by prolonged expectancy periods (51-80 weeks) before the development of carcinomas. Comparably long application periods (more than 12 weeks), however, induced carcinomas after relatively short expectancy periods (8-21 weeks). The total experimental periods (application plus expectancy periods) for animals painted for more than 12 weeks were frequently less than 1/2 of that for animals painted for 1-6 weeks. All experimentally induced tumours represented highly differentiated squamous cell carcinomas with excessive keratin formation. They were consistently preceded by different stages of epithelial dysplasia. Advanced carcinomatous changes were frequently not visible macroscopically. Irreversible precancerous transformation had already occurred in epithelium at early hyperplastic, non-dysplastic stages.

4-Nitroquinoline-1-oxide↗
PubMed1982

A clinical, histomorphological and histochemical study on snuff-induced lesions of varying severity.

The oral lesions in 50 habitual snuff-dippers were graded on a four-point scale. The patients' tobacco and drinking habits were studied by means of a questionnaire. From each patient a biopsy was taken for histomorphological and histochemical analysis. A correlation between snuff habits and the clinical degrees was found, as well as between the snuff habits and certain superficial and deeply located cell changes. The incidence of keratinized lesions, sialadenitis and slight dysplasia (based on subjective evaluation under a light microscope) was higher than previously reported. Presence of dysplastic changes could not be predicted by means of the parameters which characterise the snuff habit or from the clinical grade. The histomorphological and histochemical results were interpreted as showing that the mucosa react to snuff inducing hyperplasia in the basal cell layers. In the surface layer indications of lethal damage were found. The overall stromal reaction to snuff was weak. However, the salivary glands and excretory ducts exhibited degenerative changes which were found to be more severe than the pathological changes in the surface epithelium.

Adult↗
PubMed1982

Apical periodontitis induced by selected bacterial strains in root canals of immunized and nonimmunized monkeys.

Experimental infections in root canals with Streptococcus faecalis ss. liquefaciens (Strep-MC4). Actinomyces bovis (Act-MC6) and Bacteroides oralis (Bact-MC3) were studied in four immunized and five nonimmunized monkeys. The immunization was performed using antigens of the homologous strains. The antibody level was checked by gel diffusion. In 56 root canals of the immunized animals and 60 root canals of the nonimmunized animals, viable cells of the three bacterial strains were enclosed in equal amounts of various combinations. After 6 months, samples from the root canals were subjected to qualitative and quantitative bacteriologic analyses and the apical area was radiographically and histologically examined. The analyses revealed no significant difference between the two groups of monkeys, although the viable cell recovery was slightly higher in most of the root canals of nonimmunized monkeys. The cell proportion of the strains within the different bacterial combinations was equal in root canals of the two groups of animals. The radiographic and histologic examinations revealed no significant difference between the two groups of animals regarding the number of teeth with periapical lesions. The radiographic examination, however, showed a more distinct limitation of the process in the immunized than in the nonimmunized monkeys. Histologically the lesions were more encapsulated and had a sparser cell infiltration in immunized than in nonimmunized monkeys. In the latter, inflammatory cells had often infiltrated the bone. Mixed infections gave a more severe periapical reaction than single strain infections in both animal groups.

Actinomyces↗
PubMed1981

Enzyme histochemical studies of human spermatozoa correlated with the spermiogram.

The activities of NADH2-diaphorase, leucine aminopeptidase, and acid phosphatase were studied histochemically in spermatozoa and seminal plasma of 28 ejaculates from 13 men with proven fertility and in 31 ejaculates from 29 men living in infertile marriages. The enzyme activities were correlated with the spermiogram. The NADH2-diaphorase activity was located exclusively in the midpiece of the spermatozoa, while the activities of leucine aminopeptidase and acid phosphatase seemed to be located only on the surface. A positive correlation was found between the NADH2-diaphorase activity and the spermatozoal motility, density, and morphology.

Acid Phosphatase↗
PubMed1981

Influence on periapical tissues of indigenous oral bacteria and necrotic pulp tissue in monkeys.

In nine monkeys (Macaca fascicularis) the pulps of 78 teeth were aseptically necrotized. Twenty-six of the pulp chambers were kept bacteria-free by sealing, while 52 were infected by the indigenous oral flora. The results were recorded clinically, radiographically and microbiologically at the beginning of the experiment and after 6-7 months. The final examination also included histologic recordings. The initially noninfected root canals were all sterile at the final samplings, indicating that the risk of contamination (including hematogenous) of root canals of this animal is very slight. It was shown that noninfected necrotic pulp tissue did not induce inflammatory reactions in the apical tissues. By contrast, teeth with infected pulp tissue showed inflammatory reactions clinically (12/52 teeth) and radiographically (47/52 teeth). Facultatively anaerobic streptococci, coliform rods and obligately anaerobic bacterial strains were most frequently found. In the final samples the number of obligately anaerobic strains increased. Some microorganisms which were isolated in the initial samples were not detected in the final samples. All infected teeth histologically examined showed strong inflammatory reactions in the periapical region.

Animals↗
PubMed1980

Gingival tissue reactions to orthodontic closure of extraction sites. Histologic and histochemical studies.

The formation of a hyperplastic gingival tissue with invagination was observed in the extraction areas in seven patients aged 12 to 17 years who, after extraction of the maxillary first premolars, were undergoing orthodontic treatment with an edgewise appliance. This tissue was excised when about 2 mm. of the space remained to be closed. Histologic and histochemical analyses of the biopsy areas demonstrated hyperplasia and increased metabolism in the invaginated epithelium as well as increased production of glucose aminoglycans in the surrounding connective tissue. Loss of collagen was noted in the same regions. There was evidence of bone remodeling rather than only bone resorption in the biopsy area. It was concluded that stimulation from the orthodontic forces was responsible for the hyperplastic tissue reaction and that the increased amounts of glucose aminoglycans may be responsible for possible relapses.

Adolescent↗
PubMed1980

Premonitory stages of recurrent aphthous stomatitis. I. Histological and enzyme histochemical investigations.

Biopsy specimens were repeatedly excised from 10 patients with minor and major recurrent aphthous ulcers (RAS). All lesions represented premonitory stages of RAS. The histological and enzyme histochemical investigations were indicative of an early degeneration of individual, suprabasal epithelial cells. The metabolically negative, vacuolated cells were surrounded by cells with normal enzyme activity. No inflammatory reactions were recorded in the connective tissue at this stage. At more advanced stages of the disease the distribution of vacuolated cells within the oral epithelium increased and at the same time an inflammatory reaction in the connective tissue appeared. The vacuolated cells seemed to coalesce and form minor, intraepithelial vesicles. The findings of early intraepithelial degeneration of individual cells in stratum spinosum are compatible with both a viral and an immunological etiology of RAS.

Dihydrolipoamide Dehydrogenase↗
PubMed1979

Periapical surgery.

A retrospective study of 572 teeth treated with periapical surgery was undertaken in order to evaluate the influence of preoperative, operative and postoperative factors in the healing process as well as the operation method used. It was also the aim to assess whether the histophatological diagnosis of biopsies taken at the operation could be correlated to healing. Statistical analyses by the AID method and conventional cross-classification methods were performed. Factors of importance were found to be the extent of the destrucion, the operation method used, the bone surrounding the destruction, the quality of the orthograde root filling, the age of the patient, and the marginal bone buccally. The operation method was of importance in large destructions where root fillings were considered as not having properly sealed the canals, and when treating inflamed cysts. The histopathological diagnosis could not be ascribed any definite prognostic value.

Adolescent↗