Michael Hansen

Magnetic resonance imaging-determined synovial membrane volume as a marker of disease activity and a predictor of progressive joint destruction in the wrists of patients with rheumatoid arthritis.

OBJECTIVE To evaluate the synovial membrane volume, determined by magnetic resonance imaging (MRI), as a marker of joint disease activity and a predictor of progressive joint destruction in rheumatoid arthritis (RA). METHODS Twenty-six patients with RA, randomized to receive disease-modifying antirheumatic drug (DMARD) therapy alone (11 patients) or DMARDs in combination with oral prednisolone (15 patients), were followed up for 1 year with contrast-enhanced MRI of the dominant wrist (months 0, 3, 6, and 12), conventional radiography (months 0 and 12), and clinical and biochemical examinations. Bone erosion (by MRI and radiography) and synovial membrane volumes (by MRI) were assessed. RESULTS Significant synovial membrane volume reductions were observed after 3 and 6 months in the DMARD + prednisolone group, and after 6 and 12 months in the DMARD-alone group (P < 0.01-0.02, by Wilcoxon-Pratt analysis). The rate of erosive progression on MRI was highly correlated with baseline scores and, particularly, with area under the curve (AUC) values of synovial membrane volume (Spearmans sigma = 0.69, P < 0.001), but not with baseline or AUC values of local or global clinical or biochemical parameters, or with prednisolone treatment. In none of 5 wrists with baseline volumes <5 cm3, but in 8 of 10 wrists with baseline volumes > or =10 cm3, erosive progression was found by MRI and/or radiography, indicating a predictive value of synovial membrane volumes. MRI was more sensitive than radiography for the detection of progressive bone destruction (22 versus 12 new bone erosions). CONCLUSION MRI-determined synovial membrane volumes are closely related to the rate of progressive joint destruction. Quantitative MRI assessment of synovitis may prove valuable as a marker of joint disease activity and a predictor of progressive joint destruction in RA.

Effect of Nicotine Chewing Gum in Combination with Group Counseling on the Cessation of Smoking

We studied the effectiveness of chewing gum containing nicotine, in combination with group counseling, for subjects who were attempting to stop smoking. We used the Horn-Russell scale, based on a smoking questionnaire, to measure dependence on cigarettes; 173 smokers were grouped as highly dependent on nicotine or as having medium to low degrees of dependence. In a randomized double-blind study, the 60 highly dependent smokers were given gum containing 4 mg of nicotine (n = 27) or 2 mg of nicotine (n = 33), and the 113 smokers with medium or low dependence were given gum containing 2 mg of nicotine (n = 60) or a placebo gum (n = 53). All smokers took part in group counseling. In the highly dependent group, abstinence from cigarettes was chemically verified after six weeks, one year, and two years; 81.5 percent, 44.4 percent, and 33.3 percent of the subjects given gum containing 4 mg of nicotine were abstinent after those follow-up periods; the rates of abstinence were 54.5 percent, 12.1 percent, and 6.1 percent, respectively, for the subjects given gum containing 2 mg of nicotine. In the group with medium or low dependence, the rates of abstinence after the same periods were 73.3 percent, 38.3 percent, and 28.3 percent for the subjects given gum containing 2 mg of nicotine and 41.5 percent, 22.6 percent, and 9.4 percent for those given placebo gum. The differences in outcomes were significant at the 5 percent level for all comparisons, with the exception of the 2-mg nicotine gum versus the placebo gum at one year. This study indicates that the effectiveness of nicotine gum is not due to a placebo effect and that it is related to dose. The use of nicotine gum in appropriate doses should be helpful to persons who are attempting to stop smoking.

Distribution of phytoplasmas in infected plants as revealed by real-time PCR and bioimaging.

Phytoplasmas are cell wall-less bacteria inhabiting the phloem and utilizing it for their spread. Infected plants often show changes in growth pattern and a reduced crop yield. A quantitative real-time polymerase chain reaction (Q-PCR) assay and a bioimaging method were developed to quantify and localize phytoplasmas in situ. According to the Q-PCR assay, phytoplasmas accumulated disproportionately in source leaves of Euphorbia pulcherrima and, to a lesser extent, in petioles of source leaves and in stems. However, phytoplasma accumulation was small or nondetectable in sink organs (roots and sink leaves). For bioimaging, infected plant tissue was stained with vital fluorescence dyes and examined using confocal laser scanning microscopy. With a DNA-sensitive dye, the pathogens were detected exclusively in the phloem, where they formed dense masses in sieve tubes of Catharanthus roseus. Sieve tubes were identified by counterstaining with aniline blue for callose and multiphoton excitation. With a potentiometric dye, not all DNA-positive material was stained, suggesting that the dye stained metabolically active phytoplasmas only. Some highly infected sieve tubes contained phytoplasmas that were either inactive or dead upon staining.

The HvNAC6 transcription factor: a positive regulator of penetration resistance in barley and Arabidopsis

Pathogens induce the expression of many genes encoding plant transcription factors, though specific knowledge of the biological function of individual transcription factors remains scarce. NAC transcription factors are encoded in plants by a gene family with proposed functions in both abiotic and biotic stress adaptation, as well as in developmental processes. In this paper, we provide convincing evidence that a barley NAC transcription factor has a direct role in regulating basal defence. The gene transcript was isolated by differential display from barley leaves infected with the biotrophic powdery mildew fungus, Blumeria graminis f.sp. hordei (Bgh). The full-length cDNA clone was obtained using 5′-RACE and termed HvNAC6, due to its high similarity to the rice homologue, OsNAC6. Gene silencing of HvNAC6 during Bgh inoculation compromises penetration resistance in barley epidermal cells towards virulent Bgh. Complementing the effect of HvNAC6 gene silencing, transient overexpression of HvNAC6 increases the occurrence of penetration resistant cells towards Bgh attack. Quantitative RT-PCR shows the early and transient induction of HvNAC6 in barley epidermis upon Bgh infection. Additionally, our results show that the Arabidopsis HvNAC6 homologue ATAF1 is also induced by Bgh and the ataf1-1 mutant line shows decreased penetration resistance to this non-host pathogen. Collectively, these data suggest a conserved role of HvNAC6 and ATAF1 in the regulation of penetration resistance in monocots and dicots, respectively.

A randomised trial of differentiated prednisolone treatment in active rheumatoid arthritis. Clinical benefits and skeletal side effects.

OBJECTIVES To study benefits and skeletal side effects of carefully monitored prednisolone treatment in patients with active rheumatoid arthritis. METHODS One hundred and two patients with active rheumatoid arthritis were randomly allocated to treatment with disease modifying anti-inflammatory drug (DMARD) alone or DMARD and prednisolone in a one year follow up study. Prednisolone was given in a dose regimen adapted to the disease activity of the individual patient. The mean dose was 6 mg and the mean cumulated dose was 2160 mg. Patients were followed up with disease activity parameters, radiograph of the hands (Larsen score), and bone mineral density (BMD) of the lumbar spine, distal forearm and hand. At one year 26 patients had withdrawn from the investigation leaving 76 patients for evaluation. RESULTS The results showed that disease activity in the prednisolone treated group was reduced within two weeks. In the DMARD alone group disease activity was gradually reduced over months. At six months there was no difference between the groups as evaluated by an improvement score using a number of ACR criteria. Prednisolone in the present set up was not able to protect significantly against radiological disease progression, although there was a trend towards less progression in Larsen score in the prednisolone group, a matter that was further underlined in an intention to treat analysis. BMD data revealed a significant reduction in spinal BMD in the prednisolone group, whereas prednisolone seemed to have a protective effect against bone loss in the hand and distal forearm. CONCLUSIONS This study does not allow any firm conclusions for or against the treatment of rheumatoid arthritis with prednisolone. The data suggest that the beneficial effects of prednisolone are not as clear cut in established rheumatoid arthritis as in early disease. Furthermore the data indicate that treatment in the chosen relatively low dose does not provide sufficient control of disease. On the other hand the spinal bone loss observed in the prednisolone group does invite considerations about using higher doses.

Scoring of Synovial Membrane Hypertrophy and Bone Erosions by MR Imaging in Clinically Active and Inactive Rheumatoid Arthritis of the Wrist

MRI-scores of synovial membrane hypertrophy and bone erosions of the RA-wrist are introduced. Gadolinium-DTPA enhanced magnetic resonance imaging (MRI) and conventional radiography (CR) of the wrist were performed in 16 patients with rheumatoid arthritis (RA) and 3 healthy controls. A MRI-score of synovial membrane hypertrophy was obtained by summation of gradings of synovial hypertrophy in 6 regions of the wrist. The score was significantly higher in wrists with than in wrists without clinical signs of active arthritis. The score was 0 in all healthy controls. Each bone of the wrist was assessed by MRI and CR with respect to bone erosions. Bone erosions were detected by MRI in 14 wrists in contrast to only 6 wrists by CR. In all patients the erosions were more numerous on MRI. The introduced methods may be useful quantitative measures of synovitis and early joint destruction in RA.

YKL‐40 in giant cells and macrophages from patients with giant cell arteritis

OBJECTIVE YKL-40, a mammalian member of the family 18 glycosyl hydrolases, is secreted by activated macrophages at a late stage of differentiation. Macrophages are present in inflammation of the arterial wall and are thought to participate in the pathogenesis of giant cell arteritis (GCA). The aim of this study was to evaluate whether macrophages and giant cells of patients with GCA produce YKL-40, and whether serum YKL-40 concentrations are elevated in these patients. METHODS Serum YKL-40 was determined by radioimmunoassay in 19 patients with GCA and 8 patients with polymyalgia rheumatica (PMR) who were followed up prospectively during 1 year of treatment with prednisolone. Immunohistochemical staining for YKL-40 was performed in temporal artery biopsy samples that were obtained before treatment. RESULTS In the arteritic vessels of patients with GCA, positive staining for the YKL-40 antigen was found in CD68+ giant cells and mononuclear cells located in the media. Macrophages located in the adventitia and intima were negative for YKL-40. At the time of diagnosis, patients with GCA had an increased median serum level of YKL-40 (256 microg/liter; P<0.01) compared with healthy age-matched controls (median 118 microg/liter), and the serum level of YKL-40 decreased to normal levels during prednisolone treatment (-38% after 1 month; P<0.001). Most patients with PMR had normal serum YKL-40 levels (median 158 microg/liter) and had no changes in the serum YKL-40 levels during prednisolone treatment. The observed changes in serum YKL-40 did not always parallel the changes in serum C-reactive protein levels and erythrocyte sedimentation rate during the 1-year study period. CONCLUSION YKL-40 is found in CD68+ giant cells and mononuclear cells in the media of arteritic vessels of patients with GCA, and the concentration of serum YKL-40 may reflect the local activity of these cells in the inflamed artery.

Relationship between keratinocyte adhesion and death: anoikis in acantholytic diseases

Abstract  Loss of attachment to the substratum may trigger apoptosis in epithelial cells (anoikis). It is less clear whether apoptosis may be triggered by disruption of cell-cell contacts, as happens in acantholytic diseases. Biopsy specimens were obtained from the border of skin lesions from four patients with pemphigus vulgaris (PV), four patients with pemphigus foliaceus (PF), three patients with Darier’s disease (DD), two patients with Darier’s-type Grover’s disease (GD), and two patients with benign familial pemphigus Hailey-Hailey disease (HH). Control skin was obtained from five healthy volunteers. TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling) and confocal laser scanning microscopy was employed to detect the nuclei containing fragmented DNA in apoptotic cells. In PV and PF, TUNEL-stained apoptotic keratinocytes were abundantly present in the regions of acantholysis and in the cohesive epidermis below the blisters. Apoptotic keratinocytes had pyknotic, condensed nuclei. In DD, GD and HH, the number of TUNEL-stained keratinocytes was lower, apoptotic keratinocytes were confined to the regions of dyskeratosis and acantholysis, and pyknosis was absent. In conclusion, disruption of cell-cell contacts in acantholytic skin disorders may in some cases cause apoptosis of keratinocytes. Further studies are needed to determine whether the observed differences in the pattern of apoptosis are due to targeting of different junctional elements (adherens junctions in PV and PF versus desmosomes in DD, GD and HH).

Bone loss in rheumatoid arthritis : influence of disease activity, duration of the disease, functional capacity, and corticosteroid treatment

Axial and appendicular bone mass were studied in 95 patients with rheumatoid arthritis. The aims were to quantify bone mineral density (BMD) and to evaluate the importance of disease activity, duration of disease, functional capacity, and corticosteroid treatment for bone loss in patients with rheumatoid arthritis. The BMD in the lumbar spine (BMDSPINE) did not differ from age-matched healthy controls, but distal forearm BMD (BMDARM) and metacarpal BMD (BMDMCB) were significantly lower in the patients (p < 0.01 and p < 0.001, respectively). Neither BMDSPINE nor BMDMCB were related to the disease activity at the time of investigation. By contrast, BMDARM was decreased in patients with active disease. BMD in any of the three measured locations was not directly correlated to duration of the disease. However, the bone mass in the appendicular skeleton was already decreased within the first two years after the start of the disease. The overall functional capacity in terms of physical activity increased BMD in the axial skeleton. The local functional capacity in terms of grip strength was positively related to BMD in the appendicular skeleton. Patients with severe functional impairment had the lowest BMDARM. The decreased BMD in patients with rheumatoid arthritis seems primarily to be caused by an impaired physical activity which may be related to disease activity. Corticosteroids did not decrease BMD in neither the axial nor the appendicular skeleton. The antiinflammatory effect of steroids lead to clinical improvement, which may counteract the expected negative effect of these drugs on bone in rheumatoid arthritis.

Occurrence and degradation of peptidoglycan in aquatic environments

Mechanisms controlling microbial degradation of dissolved organic matter (DOM) in aquatic environments are poorly understood, although microbes are crucial to global nutrient cycling. Bacterial cell wall components may be one of the keys in understanding the presence of slowly degrading DOM in nature. We found that dominant components of bacterial cell walls (D-amino acids (D-AA), glucosamine (GluA) and diaminopimelic acid (DAPA)) comprised up to 11.4% of the dissolved organic nitrogen in 50 diverse rivers entering the Baltic Sea. Occurrence of DAPA, a characteristic component of Gram-negative (G(-)) bacteria, in the rivers suggests that G(-) bacteria rather than Gram-positive (G(+)) were the major source of the cell wall material. In laboratory studies, the degradation of whole bacterial cells, cell wall material and purified peptidoglycan was studied to characterize degradation of cell wall material by natural aquatic bacteria. Addition of whole killed G(-) and G(+) bacteria to cultures of estuarine bacteria demonstrated fragmentation and loss of cell structure of the G(+) bacteria, while the G(-) bacteria maintained an intact cell shape during the entire 69-day period. In another experiment, estuarine bacteria degraded 39-69% of GluA, D-AA and DAPA in added cell wall material of a representative G(-) bacterial species during 8 days, as compared to a 72-89% degradation of GluA, D-AA and DAPA in cell material of a G(+) bacterial species. When cultures of estuarine bacteria were enriched with purified G(-) and G(+) peptidoglycan (1 mg l(-1)), at least 49% (G(-)) and 58% (G(+)) of D-AA in the peptidoglycan was degraded. No major changes in GluA were obvious. Interpretation of the results was difficult as a portion of the purified peptidoglycan was of similar size to the bacteria and could not be differentiated from cells growing in the cultures. Addition of the purified peptidoglycan stimulated the bacterial growth, and after 6 days the cell density in the enriched cultures was 4-fold higher than in the controls. A regrowth of bacteria after addition of L-broth at 105 days caused a 50- to 75-fold increase in dissolved D-AA and GluA. Most of the D-AA and GluA were taken up during the following 10 days, indicating that cell wall constituents are dynamic compounds. Our results show that a variable portion of peptidoglycan in G(-) and G(+) bacteria can be degraded by natural bacteria, and that peptidoglycan in G(-) bacteria is more resistant to bacterial attack than that in G(+) bacteria. Thus, the presence of cell wall constituents in natural DOM may reflect the recalcitrant nature of especially G(-) peptidoglycan.