Biomedical subjects

A C Johannessen

Publications and source records attributed to A C Johannessen.

81 records · Page 5Linked to original sources

PubMed1984

Enzyme histochemical characterization of mononuclear cells in human dental periapical chronic inflammatory lesions.

Cell infiltrates in sections of paraffin-embedded tissue of 36 human periapical inflammatory lesions (15 granulomas and 21 cysts) were examined by staining for acid alpha-naphthyl acetate esterase (ANAE). Thirty-four of the lesions showed ANAE reactive T lymphocytes, plasma cells and cells of the monocyte/macrophage cell line. Large granular lymphocytes (NK cells) could not be identified with certainty among the ANAE positive cells. Two specimens were free of ANAE reactive cells. Differential cell counts on sections from 15 lesions (7 granulomas and 8 cysts) showed that T lymphocytes were the predominating ANAE reactive cells (23%), followed by plasma cells (15%) and monocytes/macrophages (11%). 51% of the inflammatory cells were ANAE negative. There was no marked difference between the granulomas and the cysts. Inhibition with NaF (10-100 mM) gave a gradual reduction in number of ANAE positive cells, some macrophages being the only cells resistant to 100 mM NaF. The results suggest that both humoral and cellular immune reactions are likely to occur in periapical inflammatory lesions.

Adolescent↗

PubMed1983

Deposits of immunoglobulins and complement factor C3 in human dental periapical inflammatory lesions.

Thirty-five human dental periapical lesions were studied by immunofluorescence technique using polyclonal anti-IgG (F(ab)2), anti-IgM (F(ab)2), anti-IgA (F(ab)2), anti-IgE and anti-C3c as well as monoclonal anti-IgE. Prewashed ethanol-fixed specimens showed a great number of plasma cells staining for IgG. Cells containing IgA, IgM or IgE were also seen. Deposits of immunoglobulins and C3c suggestive of immune complexes were demonstrated using a double staining technique combining FITC-labeled immunoglobulins with TRITC-conjugated C3c. The complexes were located intracellularly in macrophages, as well as in vessel walls and in the basement membrane zone of proliferating epithelium. Immune complexes may be involved in the epithelial proliferation in those granulomas which lead to cyst formation. Monoclonal anti-IgE demonstrated plasma cells and mast cells, as well as intercellular IgE in epithelial strands of granulomas. The role of IgE in the epithelium is obscure. The study strongly indicates the involvement of hypersensitivity reactions type I and III in periapical inflammatory lesions.

Adult↗

PubMed1982

In situ characterization of cell infiltrates in human dental periapical granulomas. 1. Demonstration of receptors for the Fc region of IgG.

The aims of the present study were to demonstrate FcR activity of dental periapical granulomas and to correlate the activity with the degree of lymphoreticular cell infiltration. Cryostat sections of 46 out of 51 granulomas adsorbed sheep erythrocytes(E) sensitized with rabbit IgG antibodies (A) (EA). No adsorption occurred using erythrocytes sensitized with F(ab')2 fragments of IgG. IgG and Fc fragments of human of rabbit IgG inhibited the binding of EA, whereas F(ab')2 fragments, human IgA, IgM or albumin did not, indicating the presence of receptors for the Fc region of IgG. Periodate, neutral formaldehyde and phospholipase C abolished the FcR activity whereas neuraminidase had no effect. Comparison of sections binding EA and adjacent sections stained with haematoxylin and eosin showed that EA adhered to areas infiltrated with mononuclear cells. The degree of binding of EA coincided with the density of mononuclear cell infiltration. Point attachments between the tissue sections and the adsorbed EA could be demonstrated by scanning electron microscopy. Sections with no infiltrates did not bind EA.

Adsorption↗

PubMed1981

X-ray microanalytical studies of initial mineralization in induced heterotopic bone formation in guinea pigs.

Allogenic demineralized dentin implanted in the abdominal wall of guinea pigs induced heterotopic osteoid and bone formation. Samples of this tissue were frozen at - 140 degrees C, freeze-dried at -80 degrees C, infiltrated with Spurr epoxy resin and polymerized. The sections were then studied in the scanning transmission electron microscope, and analytical studies were performed by means of energy dispersive microanalysis. Osteoblasts and young osteoid osteocytes contained more calcium than undifferentiated cells and mature osteocytes. The Ca/P ratio in the cytoplasm of these young matrix-producing cells was high. Phosphorus was found in the nuclei of all cells and to a lesser extent also in the cytoplasm of cells rich in calcium. The initial extra-cellular mineral accumulation also showed a high Ca/P ratio. Small electrondense areas in these regions exhibited an amount of calcium and a Ca/P ratio resembling those of mature mineralized bone. The initial event of the mineralization process seemed to be an accumulation of calcium first in the young matrix-producing cells and then in the surrounding osteoid matrix. The results suggested that the matrix-producing cells are actively involved in the accumulation of calcium and phosphorus both intra- and extra-cellularly.

Animals↗

PubMedDate not supplied

Oxcarbazepine-induced hyponatremia, a cross-sectional study.

In order to estimate the frequency of hyponatremia in patients treated with oxcarbazepine (OxCZ), a cross-sectional study was carried out. 21 of 41 patients being treated with the drug were found to be hyponatremic (serum sodium levels less than 135 mmol/l). None was found to be hypernatremic (serum sodium levels greater than 145 mmol/l). A non-significant trend towards increasing frequency of hyponatremia with increasing age was observed. Patients treated with dosages above 30 mg/kg/day had a significantly higher risk of becoming hyponatremic.

Adult↗

PubMedDate not supplied

Apoptosis and expression of Bax and Bcl-2 in snuff- and non-snuff associated oral squamous cell carcinomas.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is etiologically linked to tobacco and alcohol consumption. A higher frequency of p53 gene mutations was reported in snuff (toombak)-associated OSCC from the Sudan versus those from non-users (Ibrahim et al., 1999, 10). MATERIALS AND METHODS: OSCC from Sudanese toombak users (n = 13) and non-users from the Sudan (n = 6) and Norway (n = 24) were analysed for bax, bcl-2 and Ki-67 immunohistochemically. Apoptosis was evaluated by the TUNEL method. The OSCC from the Sudan had previously been studied for p53 gene mutations. RESULTS: We found a higher apoptotic rate and a higher bax expression in OSCC from Norway compared with those from the Sudan (p < 0.05) irrespective of toombak use. No significant differences were detected in apoptosis, bax, bcl-2 and Ki-67 in OSCC from the Sudan in relation to toombak use or p53 gene status. CONCLUSION: In OSCC, apoptosis was associated with bax expression and was unaffected by p53 gene status or toombak use in OSCC from the Sudan.

Apoptosis↗

PubMedDate not supplied

Maintained CD40 and loss of polarised CD40 ligand expression in oral squamous cell carcinoma.

BACKGROUND: CD40 and its ligand (CD40L) are involved in immune response and inhibition or induction of apoptosis in different tissues. Little is known about CD40 and CD40L in oral squamous cell carcinomas (OSCC). MATERIALS AND METHODS: CD40 and CD40L were immunohistochemically evaluated in fresh-frozen samples of OSCC (n = 24) and normal oral epithelium (OE, n = 10). RESULTS: A high proportion of OE-cells expressed CD40 (> 80%) and CD40L (> 90%) in the basal compartment compared to less than 1% CD40-positive and 1% CD40L-positive cells in the suprabasal cell layer, reflecting a zonal distribution. In well-differentiated and moderately-differentiated OSCC, there was a less pronounced zonal distribution of CD40 and a marked loss of CD40L compared to OE (p < 0.05). Poorly-differentiated OSCC maintained CD40 and markedly lost CD40L compared to OE (p < 0.05). Double immunostaining for CD40L and laminin in OE showed a basement membrane associated localisation of CD40L. CONCLUSION: In OSCC, loss of polarised expression of CD40L and maintained expression of CD40 might be involved in tumourigenesis and immune evasion.

Basement Membrane↗

PubMedDate not supplied

Expression of c-erbB proto-oncogene family members in squamous cell carcinoma of the head and neck.

The exact role of oncogenes and proto-oncogenes in the development of squamous cell carcinoma of the head and neck (SCCHN) is still debatable. The expression of the c-erbB-2, c-erbB-3 and c-erbB-4 members of the epidermal growth factor receptor family was examined in 16 fresh frozen tissue specimens of SCCHN using avidin-biotin complex immunohistochemistry, with monoclonal and/or polyclonal antibodies directed against each. Eight fresh frozen tissue specimens of normal oral mucosa were included as controls. Of the SCCHN examined, mixed membrane/cytoplasmic staining (moderate to intense) of c-erbB-2 was found in 14/16 cases (88%). When present in the specimen, immunopositive staining of c-erbB-2 was seen in some of the oral surface epithelial cell layers (basal, intermediate and/or superficial) as well as the tumour islands. Weak cytoplasmic staining of c-erbB-3 and c-erbB-4 was found in 13/16 (81%) and 11/16 (69%) cases respectively. When present in the specimen, c-erbB-3 and cerbB-4 immunopositive staining was seen in some of the oral surface epithelial cell layers (basal, intermediate and/or superficial) as well as the tumour islands. For the positive carcinomas for c-erbB-2, c-erbB-3 and c-erbB-4, the epithelium located near the carcinomas showed weak mixed membrane/cytoplasmic staining of c-erbB-2 in 5/14 cases (36%), weak cytoplasmic staining of c-erbB-3 in 7/13 cases (54%) and of c-erbB-4 in 3/11 cases (27%). All the normal control oral mucosa showed the same pattern of staining for c-erbB-2, c-erbB-3 and c-erbB-4 found in the epithelium located near the carcinomas. Only expression of c-erbB-2 was found to correlate with the increase in the tumour stage, while co-expression of c-erbB-2, c-erbB-3 and c-erbB-4 was found to correlate with the patient survival time in 25% of the carcinomas examined. The present study shows that a) expression of c-erbB-2, but not c-erbB-3 and c-erbB-4 correlates with the increase of the tumour stage b) co-expression of c-erbB-2, c-erbB-3 and c-erbB4 correlates with decreased survival time in some of the cases of SCCHN, but not the majority c) co-expression of the c-erbB family in normal oral mucosa as well as in the carcinoma may question whether the increased tendency for development of the disease is due to co-expression of c-erbB proto-oncogenes in head and neck lesions.

Adult↗

PubMedDate not supplied

Expression of keratin 13, 14 and 19 in oral hyperplastic and dysplastic lesions from Sudanese and Swedish snuff-dippers: association with human papillomavirus infection.

Changes in the expression of keratins (Ks), indicating disturbed tissue differentiation, is one possible marker of malignant potential in stratified squamous epithelia. The presence of human papillomaviruses (HPVs) in the epithelium of the uterine cervix is increasingly regarded as a marker of risk for cervical cancer: However, a similar role in oral cancer and precancer remains controversial. To address these questions, potentially malignant oral mucosal lesions from Sudanese (9 hyperplasias/40 dysplasias) and Swedish (15 hyperplasias) snuff-dippers were examined by immunohistochemistry for expression of K types 13, 14 and 19 using monoclonal antibodies directed against each. HPV infection was searched for by in situ hybridization (ISH) using the cocktail HPV OmniProbe and the ViraType probe. For the Sudanese lesions, moderate to intense expression of both K13 (basal, basal/intermediate, basal/intermediate/superficial and intermediate/superficial cell layers) and K14 (basal, basal/intermediate cell layers) was found in 49/49 (100%). For the Swedish lesions, weak to moderate expression of K13 (basal, basal/intermediate cell layers) was found in 12/15 (80%) and 10/15 (67%), respectively. In the Sudanese lesions, expression of K13 showed a distinct pattern through the oral mucosa and its verrucous projections, with an increase towards the superficial cell layers of dysplastic, but not hyperplastic epithelium. K19 was expressed in the basal cell layer in 16/49 (33%) of the Sudanese lesions, while all the Swedish lesions were negative. HPV was found in only 2 Sudanese cases, both of which harboured both type 6 and type 11: both these cases demonstrated mild epithelial dysplasia, The present study shows that a) there is a high prevalence of expression of both K13 and K14 in oral lesions from Sudanese toombak dippers indicating dysregulation of keratinocyte maturation b) one-third of the Sudanese oral lesions expressed K19, regarded as a basal keratin representing epithelial dedifferentiation, which may prove to be a valuable risk marker in follow-up studies c) HPV genome is found infrequently in oral lesions from Sudanese toombak-dippers, suggesting that these viruses may not play a prominent role in the early stages of carcinogenesis in these subjects. These markers were less often expressed in the Swedish lesions, consistent with their much lower rate of malignant transformation.

Adult↗