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Biomedical subjects

R Jonsson

Publications and source records attributed to R Jonsson.

178 records · Page 10Linked to original sources

Lupus band test in uninvolved oral mucosa in systemic lupus erythematosus.

In 42 patients with systemic lupus erythematosus, clinically normal oral mucosa was investigated with direct immunofluorescence technique for the presence of immunoglobulins G, A and M and complement factor C3 in the mucosal basement membrane zone (the lupus band test, LBT). Punch biopsies were performed in the posterior part of the hard palate (n = 39) or the lower labial mucosa (n = 3). The immunopathological observations were compared with clinical and serological data. The LBT was positive for IgM in 45% of the patients and trace amounts of IgM were found in another 19%. In 7 cases (17%) either IgG, IgA or C3 were found in addition to IgM and these patients all had a severe form of the disease, while the presence of IgM only was not correlated to clinical parameters.

Adult↗

Some statistical properties of the miniature endplate potentials.

I will demonstrate that series of miniature endplate potentials (m.e.p.ps) showing a high proportion of so-called giant m.e.p.ps (g.m.e.p.ps) have different statistical structures from series where the proportion of g.m.e.p.ps is low. The nature of the different structures will be discussed on the basis of two statistical models, one for the distribution of the m.e.p.p. amplitudes and one for the series of point events occurring in time.

Aminoquinolines↗

Immunofluorescent localization of fibronectin in human oral mucosa.

Fibronectin (FN) with an immunohistochemical fluorescence technique using anti-human FN and anti-rat FN sera was localized in the basement membrane of lip, buccal mucosa, palate, tongue, around ectopic sebaceous glands and around acini and ducts of labial salivary glands though in different amounts. In the mucosal lamina propria, FN was present in a net-like pattern. The highest concentrations of FN were in the palatal and tongue connective tissues. Much FN was present in the walls of small blood vessels and in perineural sheaths of peripheral nerves. No fluorescence was seen in the acini of labial salivary glands. In their striated ducts however, some cells were intensely fluorescent; the significance of this is unknown.

Basement Membrane↗

Localization of fibronectin during dentinogenesis in rat incisor.

Fibronectin (FN) was localized in the dental pulp and predentine at different stages of dentinogenesis by indirect immunofluorescence. Fibronectin was present in the basement membrane between the inner enamel epithelium and the underlying dental mesenchyme and also in mantle predentine. Fibronectin was absent from predentine during further (circumpulpal) dentine formation, indicating that the FN molecule is not directly involved in mineralization. The findings emphasize the difference between the mantle and circumpulpal dentine formation. Fibronectin was localized in the odontoblast layer at the level where the cell processes leave the cell bodies and where the odontoblasts adhere to each other by junctional complexes.

Animals↗

Histologic and sialochemical findings indicating sicca syndrome in patients with systemic lupus erythematosus.

Twenty unselected patients with systemic lupus erythematosus (SLE) were investigated with respect to symptoms and signs of salivary gland involvement. Eight of them complained of xerostomia. Whole salivary flow was measured, parotid saliva was analyzed chemically, and palatal biopsy was performed to assess the degree of inflammatory infiltration in minor salivary glands. All but one of the patients showed signs of involvement on at least one of the tests and, as a group, the patients with SLE had significantly reduced values for salivary flow and increased concentrations of sodium, protein, and carbohydrates as compared to matched healthy controls.

Adult↗

Assessment of a tissue transport-medium in preservation of tissue-fixed immunoglobulins and complement demonstrated by direct immunofluorescence. A pilot study with skin from SLE patients.

The present work was undertaken in order to test the value of a tissue transport-medium (Histocon) for direct immunofluorescence studies. For this purpose one skin biopsy was performed on each forearm of 26 patients with systemic lupus erythematosus. One of the specimens was left in ice-cold Histocon solution for 4, 8, or 20 hours, and the other was immediately quick-frozen. The results of the immunofluorescence tests with the two methods yielded similar results. It is concluded that the solution allows the preservation of tissue-fixed immunoglobulins and complement during short periods of transport.

Adult↗

Rapid quality evaluation of hybridomas using ELISPOT and cell-ELISA techniques.

We have used the ELISPOT assay in combination with ELISA procedures for rapid evaluation of properties of three different murine hybridoma cell lines, 104-I, -B and -G, secreting IgG1 kappa monoclonal antibodies against a 104-mer synthetic peptide from the C-terminal part of HIV-1 p24. By conventional ELISA we obtained data suggesting that the three monoclonal antibodies had different affinities. By cell-ELISA we found that the IgG1 kappa secretion rate varied between cells (4,000 to 14,000 antibody molecules/cell/min), and ELISPOT showed that only 4-5% of 104-I cells gave antigen-specific spots, indicating a cell population with diverse properties. We recommend that the ELISPOT and cell-ELISA techniques should be used routinely to supplement conventional ELISA procedures for rapid evaluation of hybridoma properties.

Animals↗

High prevalence of influenza specific antibody secreting cells in nasal mucosa.

Secretory immunoglobulin A (SIgA) provides the first line of defence against pathogens initiating infection via the mucosal route, e.g. the influenza virus. The aim of this study was to examine the basal level of influenza-specific antibody-secreting cell (ASC) in the local mucosa of the upper respiratory tract. Nineteen patients scheduled for tonsillectomy were enrolled for the study, and they had not experienced influenza during the previous year. Tonsils, blood, oral fluid and a nasal biopsy were sampled, and the basal levels of ASC and antibodies (Abs) were determined. We found low numbers of influenza-specific ASC in the blood and tonsils, but there were about 10-100 times higher numbers of specific ASC in the nasal mucosa tissue despite no recent influenza exposure. Thus, the basal level of influenza-specific ASC in the mucosa of the respiratory tract may be important in the protection against influenza infection.

Adult↗

Apoptotic effect of rituximab on peripheral blood B cells in rheumatoid arthritis.

Rituximab (RTX) has proven efficacious in the treatment of rheumatoid arthritis (RA). Herein, we assessed the apoptosis-inducing capability of RTX in vitro on RA peripheral blood B-cell subsets and also compared the effects of RTX on B cells from rheumatoid factor-positive (RF+) and RF- patients. The likely relevance of B cells in disease was assessed by measuring B-cell-modulating serum cytokines. Peripheral blood B cells were isolated and cultured with the presence or absence of RTX. The levels of apoptosis within the naïve, memory and IgD+CD27+ B-cell subpopulations were determined by cytofluorometric analysis and caspase 3/7 assays. Levels of serum cytokines were measured with a multiplex cytokine array system. RTX induced significant apoptosis in all B-cell subsets in both RA and controls. In naïve and memory B cells from RA patients, RTX induced significantly higher levels of apoptosis than in controls. RTX induced apoptosis of B cells in RF+ and RF- patients. Serum levels of interleukin-1beta (IL-1beta), IL-4, IL-10 and IL-13 were profoundly increased in RF+ patients compared to RF- patients and controls. Although our cohort was small (10 RA patients), the data suggest that RTX induces apoptosis in all investigated subsets of B cells from RA patients. Interestingly, memory B cells from RA patients were more sensitive to RTX than memory cells from normal controls, suggesting that the delay in treatment response to RTX observed in clinical trials may be due in part to memory cell depletion. The apoptotic effects of RTX were similar in RF+ and RF- patients, but serum levels of B-cell-activating cytokine levels were only elevated in RF+ but not RF- patients. These data suggest that RTX is less effective in RF- RA because B cells play a less significant role in RA pathogenesis in RF- patients.

Antibodies, Monoclonal↗

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↗

Synovial inflammation in active rheumatoid arthritis and psoriatic arthritis facilitates trapping of a variety of oral bacterial DNAs.

OBJECTIVE: To investigate the presence of oral bacterial DNAs in serum and synovial fluid (SF) of patients with active rheumatoid arthritis (RA) and psoriatic arthritis (PsA). METHODS: Serum and SF samples from 16 RA patients, 14 PsA patients, and 9 osteoarthritis (controls) patients were extracted for oral bacterial DNA. This was used in a checkerboard DNA-DNA-hybridization set up, to identify 40 different bacteria. RESULTS: Mean number +/- standard deviation (SD) of oral bacterial species in sera were 6.2 (3.2) in the RA group (p = 0.004) and 5.4 (2.7) in the PsA group (p = 0.009) compared to 2.1 (1.7) in the controls. Periodontitis associated species Porphyromonas gingivalis and Prevotella nigrescens were exclusively detected in RA and PsA. Mean number (+/- SD) of oral bacterial species in SF were 14.0 (6.8) in the RA (p = 0.001) and 19.4 (7.1) in the PsA group (p < 0.001) compared to 4.0 (1.7) in controls. P. gingivalis, Tannerella forsythensis and Prevotella intermedia were exclusively identified in RA and PsA SF. Higher means of DNAs were found in RA SF compared to RA serum (p < 0.001), and in PsA SF compared to PsA serum (p < 0.001). Higher concentrations of bacterial DNAs were found in RA and PsA compared to controls. CONCLUSION: Higher variety and concentrations of oral bacterial DNAs were found in SF compared to serum of RA and PsA patients. These findings indicate that synovial inflammation in RA and PsA may favor trapping of oral bacterial DNAs, suggesting a perpetuating effect of oral pathogens in joint disease.

Adult↗

Salivary kallikrein in Sjögren's syndrome.

Using a chromogenic substrate (H-D-Val-Leu-Arg-pNA) salivary kallikrein levels were measured in whole saliva samples from patients suffering from Sjögren's syndrome (SS). Compared to healthy control individuals, SS patients, especially those without corticosteroid medication, exhibited significantly elevated kallikrein levels. A diurnal variation was found with the highest kallikrein activities in morning saliva. No correlation between kallikrein levels and extension of the inflammation in labial salivary glands (focus score), salivary flow rates or diagnosis (primary versus secondary SS) could be observed. A pathogenic mechanism for kallikrein in autoimmune sialadenitis is discussed.

Aged↗

Immune deposits in oral mucosa, skin and kidney in patients with systemic lupus erythematosus.

Biopsies were obtained simultaneously from normal oral mucosa, sun-protected and sun-exposed skin in patients with suspected or diagnosed systemic lupus erythematosus, in order to compare the deposition of immunoproteins. In patients with renal involvement a kidney biopsy was also studied. Immunofluorescence findings at the connective tissue-epithelial junction (lupus band test) showed a good correlation between keratinized oral mucosa and sun-protected skin in 18 sets of biopsies while sun-exposed skin frequently showed more immune reactants. No close connection could be found between the deposition of immune reactants in skin/mucosa and kidney. It is concluded that diagnostic use of the lupus band test performed on normal mucosa has the same value as that on sun-protected skin.

Adult↗

Use of a sicca symptoms questionnaire for the identification of patients with Sjögren's syndrome in a heterogeneous hospital population with various rheumatic diseases.

OBJECTIVE: A six-item questionnaire regarding sicca symptoms recently validated for primary Sjögren's syndrome (SS) was tested on 154 in-patients with a wide range of inflammatory rheumatic diseases. Patients with one or more positive responses underwent objective ocular and oral diagnostic procedures. Of 27 patients thus investigated, 19 could be classified as having SS. RESULTS: The positive answers obtained were mainly in response to 4 of the 6 questions: dry eyes, sensation of sand or gravel in the eyes, dry mouth, and drinking of liquids to aid in swallowing dry foods. Among the 19 patients found with SS, most had had earlier diagnoses of various connective tissue diseases (rheumatoid arthritis included) and most were female. CONCLUSION: In conclusion, this study indicates that the sicca symptom questionnaire may be useful when deciding which patients with inflammatory rheumatic diseases should be subjected to special investigations with regard to SS.

Aged↗

Complement regulatory proteins in the salivary glands and saliva of Sjögren's syndrome patients and healthy subjects.

OBJECTIVE: The aim of this study was to examine the presence of the complement regulatory proteins protectin (CD59), decay accelerating factor (CD55), membrane cofactor protein (CD46) and clusterin (SP-40,40) in connection with the autoimmune exocrinopathy in Sjögren's syndrome (SS). METHODS: Labial salivary gland biopsy specimens and saliva samples were obtained from SS patients and healthy subjects. The tissue expression of these proteins was assessed by ABC immunoperoxidase techniques. Saliva was analysed by immunoblotting methods. RESULTS: Tissues from healthy subjects expressed CD59 and CD46 on the apical/luminal surfaces of acinar and ductal epithelial cells. CD59, CD55, and SP-40,40 were expressed in interstitial tissues. In SS tissues, the expression of CD55, CD59, CD46 and SP-40,40 was up-regulated, following the same patterns of tissue localization as the controls. CD46 and SP-40,40 exhibited a much higher staining intensity in SS patients compared to controls. CD55, CD59 and SP-40,40 were present at high concentrations in saliva from SS patients. CONCLUSION: The presence of complement regulators in our SS patients' saliva and the high expression of these proteins in inflamed salivary gland tissue followed the inflammatory reaction. These regulators may be involved in protecting the exocrine glands from complement mediated injury.

Antibodies, Monoclonal↗