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Biomedical subjects

R Nilsen

Publications and source records attributed to R Nilsen.

At least 91 records · Page 5Linked to original sources
PubMed1981

Localization of the C3b receptors in human renal glomeruli.

Cryostat sections of human kidney were incubated with C3b containing immune complexes. The complexes were horseradish peroxidase (HRP) and F(ab')2 fragments of rabbit IgG anti-HRP incubated in C4-deficient guinea pig serum. The peroxidase activity was revealed histochemically. The sections were studied using light and electron microscopy. The bound complexes were localized to the foot processes of the visceral epithelial cells and to the surface of the parietal epithelial cells facing Bowman's space. No receptors could be demonstrated on the endothelial or mesangial cells.

Antigen-Antibody Complex↗
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↗
PubMed1980

Electronmicroscopic study of mineralization in induced heterotopic bone formation in guinea pigs.

Mineralization of heterotopic bone was studied in a bone induction model using allogenic demineralized dentin implanted in the abdominal wall of guinea pigs. There was a high yield of newly formed osteoid and bone as well as some cartilage together with areas of resorption of the dentin, and fibroblast proliferation. The osteoid contained many matrix vesicles II and less of lysosome-like type I vesicles. Early cartilage formation had more type I vesicles. The implanted dentin contained no matrix vesicles. The first signs of mineralization occurred mainly as irregular clusters of mineral crystals in the matrix close to the surface of collagen fibrils. Crystal-like figures were also found inside some type II matrix vesicles, although most of these vesicles in the mineralization zone had no crystals. The type I vesicles of both bone and cartilage exhibited often crystals near the outer membrane. The mineralizing bone showed a reduction in the size and number of proteoglycan particles. Remineralization of the implanted dentin was also often found and the mineralization pattern resembled the mineralization of bone except for the absence of matrix vesicles. Electron diffraction of selected areas showed that the crystals in the new bone and the mineralized dentin were hydroxyapatite.

Animals↗
PubMed1980

Microfilaments in cells associated with induced heterotopic bone formation in guinea pigs. An immunofluorescence and ultrastructural study.

Sera from patients with active chronic hepatitis were used to demonstrate actin microfilaments in cells of a bone-induced model. Demineralized and freeze-dried allogenic dentine was implanted in the abdominal muscles of Guinea pigs. After 21 and 28 days the tissue was excised and showed: a) resorption areas of the dentine contained dentinoclasts and macrophages. b) osteoid and bone and c) areas of fibroblastic proliferation. Osteoblasts and young osteocytes showed the strongest fluorescent staining. Electron microscopy of these cells demonstrated abundant 5-7 nm microfilaments interpreted as actin in the outer parts and cell projections, in which some microtubules also were observed. Fewer microfilaments were present in mature osteocytes although the cell projections in mineralized bone also showed microfilaments. Microfilaments were also found in some dentinoclasts where the actin was located in projections from the ruffled border protruding into the dentine. The localization in the ruffled border corresponded to the distribution of the fluorescent staining of actin. The high amount of actin in osteoblasts and osteocytes may be correlated to the synthesis and transport of the new matrix components. The microfilaments in the clear sealing zone of dentinoclasts were considered to have a function in the sealing of the ruffled border.

Actins↗
PubMed1979

Benign cementoblastoma.

A review of 44 patients with benign cementoblastomas is presented. An additional case is reported. This patient appears to be of particular interest due to radiographic records 18 months prior to admission. In this period the tumor appeared to grow very slowly.

Adolescent↗
PubMed1979

Ameloblastic fibroma.

Four cases of ameloblastic fibroma appearing in the posterior maxilla and the cupsid area of the mandibula are presented. One of the lesions appeared in the wall of a cyst and another was found in connection with a cyst. The treatment is conservative but the tumor needs close follow up for possible recurrence.

Adolescent↗
PubMed1979

Incomplete branchial arch syndromes, branchial cleft cyst and vascular hamartoma in a patient with multiple neurofibromatosis.

A case report with simultaneous occurrence of neurofibromatosis, incomplete branchial arch syndromes, a branchial cleft cyst and a pseudocyst in connection with a vascular hamartoma anterior to the right ear of a 38-year-old woman is presented. A possible common pathogenesis of the vascular hamartoma and the incomplete branchial arch syndromes as well as that of the neurofibromatosis is suggested. The pseudocyst is interpreted as a branchial cleft cyst showing inflammatory changes due to a pharyngitis shortly before the preauricular tumor appeared.

Adult↗
PubMed1979

Acquired epidermolysis bullosa treated with a gold compound.

A 20-year-old man with acquired epidermolysis bullosa of 3 years' duration was treated intramuscularly with gold sodium thiomalate. After a total dose of 1 000 mg gold sodium thiomalate, administered over a period of 9 months, the patient has shown an almost complete remission, without any apparent side effects of the chrysotherapy.

Adult↗
PubMed1978

Benign fibrous xanthoma of the parotid gland: a case report.

A fibrous xanthoma of the parotid gland is reported, the literature is reviewed with a discussion of the classification of such tumours. The present case is possibly the first report of a typical benign fibrous xanthoma of the parotid gland.

Female↗
PubMed1978

Oral lesions of epidermolysis bullosa acquisita.

Oral lesions with histologic evidence of subepidermal bullae are described in a patient with epidermolysis bullosa acquisita (EBA). Deposition of IgA, IgG, and C3 in the basement membrane zone and vasculitis with C3 deposits in vessel walls suggest the possible role of immune complexes in the pathogenesis of the disease.

Adult↗
PubMed1978

Necrotizing sialometaplasia.

Two cases of necrotizing sialometaplasia are reported together with a review of the literature. This self-limiting benign lesion is easily confused with malignant tumors. The lesions are characterized histologically by an extensive necrosis of the salivary gland tissue together with squamous metaplasia of the ducts. The present report of two females who had intense pain in the initial phase differs from previous reports concerning age and symptoms. The importance of rather extensive biopsy specimens is stressed. Antibiotic treatment appears to be insignificant. A clinical history of allergy and a dominance of eosinophilic granulocytes in the inflammatory exudate in both cases may indicate an allergic etiology.

Adult↗
PubMed1978

Epidermolysis bullosa acquisita and Crohn's disease.

A patient with epidermolysis bullosa acquisita (EBA) associated with Crohn's disease is presented. The clinical, histological and immunological findings were in keeping with previous reports. However, clinically normal skin and mucosa exhibited deposits of IgG and C3 in the basement-membrane zone. These deposits remained unchanged during the treatment period. It is therefore suggested that immunological mechanisms are implicated in pathogenesis of the disease.

Adult↗
PubMedDate not supplied

Toombak use and cigarette smoking in the Sudan: estimates of prevalence in the Nile state.

BACKGROUND: Survey data on the prevalence of use of oral snuff (toombak) and cigarette consumption according to various demographic factors are needed in the Sudan. METHODS: A house to house cross-sectional survey of a random population sample of 4,535 households was performed. Of the 23,367 household members identified, 21,648 (92.6%) eligible individuals were questioned about tobacco use. RESULTS: Among children and adolescents (4-17 years) prevalence of tobacco use was quite low (2%, range 1-2%), but there was an abrupt increase up to 25% in late adolescence. Among the adult population aged 18 years and older the prevalences of toombak use (34%) and cigarette smoking (12%) among males were significantly higher than among females (2.5 and 0.9%, respectively). The prevalence of toombak use among the male population aged 18 years and older was significantly higher in the rural than in the urban areas (35% vs 24%), while cigarette smoking had a higher prevalence in urban areas (18% vs 12%). The highest rates of toombak use were found in rural areas among the male population ages 30 years and older (mean 46.6%, range 45-47%). CONCLUSIONS: In view of the high prevalence of tobacco use, especially of toombak, among the population surveyed, there is an urgent need to educate the public on the health consequences of these habits.

Adolescent↗
PubMedDate not supplied

Comparison of parasitological and immunological methods in the diagnosis of leishmaniasis in Ethiopia.

The sensitivity and specificity of parasite demonstration methods (smear, culture and histology) and serological assays (enzyme-linked immunosorbent assay [ELISA], direct agglutination test and immunoblot) were compared in the diagnosis of leishmaniasis in Ethiopia. Culture was found to be the most sensitive diagnostic method, followed by ELISA, for the diagnosis of cutaneous leishmaniasis (CL). When the clinical type of CL was taken into consideration, serological and parasitological methods were equally good for the diagnosis of diffuse cutaneous leishmaniasis. Overall, the serological assays were not sensitive enough to diagnose all the parasitologically confirmed cases of localized cutaneous leishmaniasis. Both groups of diagnostic methods performed equally well in the diagnosis of visceral leishmaniasis patients. In cases of CL where clinical diagnosis was a problem and histology could not give a definitive diagnosis due to the absence of demonstrable parasites, one of the serological assays, preferably ELISA, was very useful in establishing the final diagnosis.

Adolescent↗