The Effects of Hot Isostatic Pressing (HIP) and Heat Treatment on the Microstructure and Mechanical Behavior of Electron Beam-Melted (EBM) Ti-6Al-4V Alloy and Its Susceptibility to Hydrogen.

The effects of the secondary processes of Hot Isostatic Pressing (HIP) at 920 °C and Heat Treatment (HT) at 1000 °C of Electron Beam-Melted (EBM) Ti-6Al-4V alloy on the microstructure and hydrogen embrittlement (HE) after electrochemical hydrogen charging (EC) were investigated. Comprehensive characterization, including microstructural analysis, X-ray diffraction (XRD), thermal desorption analysis, and mechanical testing, was conducted. After HIP, the ß-phase morphology changed from discontinuous Widmanstätten to a more continuous structure, 10 times and ~1.5 times larger in length and width, respectively. Following HT, the ß-phase morphology changed to a continuous "web-like" structure, ~4.5 times larger in width. Despite similar mechanical behavior in their non-hydrogenated state, the post-treated alloys exhibit increased susceptibility to HE due to enhanced hydrogen penetration into the bulk. It is shown that hydrogen content in the samples' bulk is inversely dependent on surface hydride content. It is therefore concluded that the formed hydride surface layer is crucial for inhibiting further hydrogen penetration and adsorption into the bulk and thus for reducing HE susceptibility. The lack of a hydride surface layer in the samples subject to HIP and HT highlights the importance of choosing secondary treatment process parameters that will not increase the continuous ß-phase morphology of EBM Ti-6Al-4V alloys in applications that involve electrochemical hydrogen environments.

Beam-Recoil Polarization Measurement of π

The helicity-dependent recoil proton polarizations P_{x}^{'} and P_{z}^{'} as well as the helicity-independent component P_{y} have been measured in the p(e[over →],e^{'}p[over →])π^{0} reaction at four-momentum transfer Q^{2}≃0.1 GeV^{2}, center-of-mass proton emission angle θ_{p}^{*}≃90°, and invariant mass W≃1440 MeV. This first precise measurement of double-polarization observables in the energy domain of the Roper resonance P_{11}(1440) by exploiting recoil polarimetry has allowed for the extraction of its scalar electroexcitation amplitude at an unprecedentedly low value of Q^{2}, establishing a powerful instrument for probing the interplay of quark and meson degrees of freedom in the nucleon.

Vacuoles release sucrose via tonoplast-localised SUC4-type transporters.

Arabidopsis thaliana has seven genes for functionally active sucrose transporters. Together with sucrose transporters from other dicot and monocot plants, these proteins form four separate phylogenetic groups. Group-IV includes the Arabidopsis protein SUC4 (synonym SUT4) and related proteins from monocots and dicots. These Group-IV sucrose transporters were reported to be either tonoplast- or plasma membrane-localised, and in heterologous expression systems were shown to act as sucrose/H(+) symporters. Here, we present comparative analyses of the subcellular localisation of the Arabidopsis SUC4 protein and of several other Group-IV sucrose transporters, studies on tissue specificity of the Arabidopsis SUC4 promoter, phenotypic characterisations of Atsuc4.1 mutants and AtSUC4 overexpressing (AtSUC4-OX) plants, and functional comparisons of Atsuc4.1 and AtSUC4-OX vacuoles. Our data show that SUC4-type sucrose transporters from different plant families (Brassicaceae, Cucurbitaceae and Solanaceae) localise exclusively to the tonoplast, demonstrating that vacuolar sucrose transport is a common theme of all SUC4-type proteins. AtSUC4 expression is confined to the stele of Arabidopsis roots, developing anthers and meristematic tissues in all aerial parts. Analyses of the carbohydrate content of WT and mutant seedlings revealed reduced sucrose content in AtSUC4-OX seedlings. This is in line with patch-clamp analyses of AtSUC4-OX vacuoles that characterise AtSUC4 as a sucrose/H(+) symporter directly in the tonoplast membrane.

Active leflunomide metabolite inhibits interleukin 1beta, tumour necrosis factor alpha, nitric oxide, and metalloproteinase-3 production in activated human synovial tissue cultures.

BACKGROUND: Leflunomide is now an approved agent for the management of adult rheumatoid arthritis (RA). Its active metabolite A771726 inhibits de novo pyrimidine biosynthesis. Although considered to be an immunosuppressive agent, its mechanism of action remains obscure. OBJECTIVES: Evaluation of the leflunomide active metabolite A771726 (LEF) effect on interleukin 1beta (IL1beta), tumour necrosis factor (TNFalpha), nitric oxide (NO), and stromelysin (metalloproteinase-3 (MMP-3)) production by activated human synovial tissue in culture. METHODS: Synovial tissue was obtained during surgery from patients undergoing total knee replacement owing to RA or osteoarthritis (OA), cut into small pieces, and cultured in Petri dishes with test materials as previously described. IL1beta, TNFalpha, NO, and MMP-3 were measured in the culture media after 48 hours incubation with different doses of LEF by methods previously described. RESULTS: LEF (0.3, 3, and 9 micro g/ml) inhibited IL1beta production in the presence of lipopolysaccharide (LPS; 3 micro g/ml) in a dose dependent manner (p<0.01) at LEF 0.3 micro g/ml. TNFalpha production in the presence of IL1beta (1 ng/ml) was also inhibited in a dose dependent manner (p<0.05 at LEF 0.3 micro g/ml). NO and MMP-3 production in the presence of LPS (3 micro g/ml) was inhibited as well (p<0.01 at LEF 1 micro g/ml and at LEF 0.3 micro g/ml, respectively). Synovial cell viability evaluated by the tetrazolium salt XTT was unaffected by the LEF concentration used. There was no qualitative difference in the response of OA and RA synovial tissue. CONCLUSION: Leflunomide may modulate the rheumatoid articular process by inhibition of local production of IL1beta, TNFalpha, NO, and MMP-3.

Clinical and immunological characteristics of elderly onset Sjögren's syndrome: a comparison with younger onset disease.

OBJECTIVE: To compare the clinical and laboratory characteristics of patients with primary Sjögren's syndrome (SS) with an elderly onset to those with a younger onset. METHODS: The study group comprised 85 consecutive patients (79 women and 6 men) attending the Sjögren's clinic. Primary SS was diagnosed according to the San Diego criteria. Elderly onset disease (EOD) was determined as the appearance of symptoms suggestive of SS after age 65. Clinical and laboratory variables for EOD were compared to those of a younger onset disease (YOD). Salivary and serum samples of all patients were examined for concentrations of interleukin 6 (IL-6) and hyaluronic acid (HA). RESULTS: Seventeen patients with SS (20%) matched the definition of EOD and their median disease onset was 71 years (range 65-80). No significant differences were noted in the clinical disease manifestations between the 2 groups of patients. Rheumatoid factor and anti-Ro(SSA) antibodies were more common in the YOD group (p = 0.012 and p = 0.023, respectively). Significant elevations of salivary IL-6 and HA levels were detected in the YOD group compared to the EOD group with SS (17.3 +/- 3.6 vs 8.8 +/- 2.1 pg/ml and 230.2 +/- 41.1 vs 128.8 +/- 33.3 ng/ml, respectively) (p < 0.0001). CONCLUSION: EOD SS has somewhat milder clinical symptoms with fewer immunological manifestations than YOD. The elevations of salivary IL-6 and HA in the younger group of SS patients support in part the differences in the inflammatory process between the 2 groups.

Down regulation of interleukin 1beta production in human osteoarthritic synovial tissue and cartilage cultures by aminoguanidine.

OBJECTIVE: To evaluate the effect of aminoguanidine (AG) on de novo interleukin 1beta (IL1beta), nitric oxide (NO), and interleukin 1 receptor antagonist (IL1ra) production by osteoarthritic human synovial tissue and articular cartilage cultures. METHODS: Synovial tissue and cartilage, obtained during surgery from 29 patients undergoing total knee or hip replacement for osteoarthritis, were cut into small pieces and cultured in the presence or absence of lipopolysaccharide (LPS) and test materials. IL1beta, IL1ra, and NO were determined in culture media. The inducible nitric oxide synthase inhibitor, AG, was added to cultures in various concentrations (0.3-3 mmol/l). RESULTS: In synovial tissue cultures AG (0.3, 1, and 3 mmol/l) decreased LPS (1 microg/ml) stimulated IL1beta and NO release in the media in a dose dependent manner (p<0.05 at 1 mmol/l and p<0.05 at 0.3 mmol/l, respectively). In articular cartilage cultures AG (0.3, 1, and 3 mmol/l) decreased LPS (1 microg/ml) stimulated IL1beta and NO release in the media in a dose dependent manner (p<0.05 at 1 mmol/l and p<0.01 at 0.3 mmol/l, respectively). Hydrocortisone (5 microg/ml) also significantly decreased LPS stimulated IL1beta release in media of synovial tissue and cartilage cultures and NO in media of synovial cultures. AG (0.3, 1, and 3 mmol/l) decreased LPS (1 microg/ml) stimulated IL1ra levels in media of synovial tissue cultures in a dose dependent manner (p<0.05 at 1 mmol/l) but increased LPS (1 microg/ml) stimulated IL1ra release in media of cartilage cultures (p<0.01 at 3 mmol/l). The NO donor, nitroprusside (10, 30, 100, and 300 microg/ml) stimulated IL1beta release in media of synovial tissue cultures in a dose dependent manner (p<0.01 at 100 microg/ml). AG and nitroprusside at the concentrations used had no toxic effect on human synovial cells. CONCLUSIONS: NO synthase inhibitors may modulate osteoarthritis and articular inflammatory processes not only by decreasing NO synthesis but also by their effects on ILbeta and IL1ra production.

Safety and efficacy of an improved antiseptic catheter impregnated intraluminally with chlorhexidine.

The safety and efficacy of a second-generation improved antiseptic catheter impregnated with silver sulfadiazine and increased levels of chlorhexidine on its outer surface and chlorhexidine alone on its luminal surfaces was compared in vitro and in vivo to standard antiseptic catheters impregnated with these antimicrobials on their outer surfaces only. In rat and pig intravenous models, the improved antiseptic catheter was significantly more effective in resisting both outer surface and luminal colonization compared with the standard antiseptic or control catheters. There was no evidence of tissue toxicity in any group.

Serum levels of IL-10, IL-6, IL-1ra, and sIL-2R in patients with psoriatic arthritis.

Our objective was to evaluate the levels of interleukin-6 (IL-6), soluble receptors of IL-2 (sIL-2R), IL-10, and IL-1 receptor antagonists (IL-1ra) in the serum of patients with psoriatic arthritis (PsA) and to assess the correlation between these levels and parameters of clinical activity of skin and joint disease. In total, 34 patients with PsA and ten healthy volunteers participated in the study. Assessment of joint disease included duration of morning stiffness, number of tender and swollen joints, right and left grip, the presence of inflammatory spinal back pain, and Schober test. Current severity of skin disease was graded according to the psoriasis area and severity index (PASI). Erythrocyte sedimentation rate (ESR) was determined as a marker of disease activity. Serum levels of IL-6, sIL-2R, IL-1ra, and IL-10 were measured by an enzyme immunoassay kit. Significantly higher serum levels of IL-6, sIL-2R, IL-1ra, and IL-10 were found in patients with PsA in comparison with healthy volunteers. A statistically significant correlation was found between levels of sIL-2R and PASI, whereas no association was found with clinical parameters of joint severity. Levels of IL-lra correlated with the number of tender and swollen joints. No correlation was found between levels of IL-6, IL-10, and clinical parameters of skin and joint severity. In the group of patients with PsA, serum levels of sIL-2R clearly correlated with severity of skin disease, whereas levels of IL-1ra were associated with joint severity.

Serum levels of hyaluronic acid in patients with psoriatic arthritis.

The purpose of this study was to evaluate the serum levels of hyaluronic acid (HA) in a group of patients with psoriatic arthritis (PsA), with special emphasis on the relationships between HA levels and clinical parameters of joint and skin activity. Thirty-four patients with PsA, 34 patients with rheumatoid arthritis (RA) and 49 healthy volunteers participated in the study. Assessment of joint disease in patients with PsA included duration of morning stiffness, number of tender and swollen joints, right and left grip, the presence of inflammatory back pain and Schober's test. The current severity of skin involvement was graded according to the Psoriasis Area Severity Index (PASI). Serum levels of HA were measured by a radiometric assay. The mean HA serum levels of patients with PsA and RA were significantly increased in comparison with healthy controls (107 +/- 39.6 microg/dl in patients with PsA, whereas in patients with RA it was 168 +/- 32.4 microg/dl and 36.7 +/- 5.5 microg/dl in healthy controls). A highly significant correlation was found between levels of HA and index of skin involvement, but no association was found between HA levels and clinical parameters of joint severity. We conclude that in this cohort of patients with PsA, HA levels clearly reflected psoriatic skin involvement although it did not correlate with joint disease.

Hydroxychloroquine treatment for primary Sjögren's syndrome: its effect on salivary and serum inflammatory markers.

OBJECTIVE: To evaluate the effect of hydroxychloroquine treatment on interleukin 6 (IL6), hyaluronic acid (HA), and soluble interleukin 2 receptor (sIL2R) concentrations in the saliva and serum of patients with primary Sjögren's syndrome (SS). METHODS: Fourteen SS patients treated with hydroxychloroquine 200 mg/day for 12 months were investigated in an open prospective study. Clinical parameters of efficacy and routine biochemical and haematological data to assess drug safety and tolerability were determined every three months. Salivary and serum IL6, sIL2R, and HA values were determined at study entry, 6 and 12 months, using ELISA and radiometric assays. RESULTS: After hydroxychloroquine treatment, salivary IL6 concentrations decreased from 13.2 (1.2) to 7.3 (1.1) pg/ml (mean (SEM)) (p < 0.0001). Similarly, salivary HA concentrations were also reduced from 577.8 (120) to 200 (34) ng/ml (mean (SEM) (p < 0.003). Serum IL6 concentrations decreased from 5.4 (0.6) to 2.9 (0.2) pg/ml (mean (SEM) (p < 0.001), while serum HA concentrations remained unchanged. No change has been detected in salivary or serum sIL2R concentrations after 12 months of treatment with hydroxychloroquine. Treatment also resulted in significant reduction in erythrocyte sedimentation rate, serum gamma globulin, and C reactive protein values while only partial clinical improvement was noted in some patients. A more pronounced decrease of salivary IL6 and HA levels was found in the two patients in whom a reduction in the swelling of the parotid gland was noted. CONCLUSION: In this open label study of hydroxychloroquine treatment for SS a significant reduction of some salivary inflammatory markers was seen at the end of 12 months. Although during the treatment period only a partial clinical effect could be noted, the findings suggest that a double blind controlled study of hydroxychloroquine in SS is indicated.

Salivary and serum soluble interleukin-2 receptor in primary Sjögren's syndrome.

Salivary and serum concentrations of soluble interleukin-2 receptor (sIL-2R) were studied in a group of patients with Sjögren's syndrome and a group suffering from dry mouth. Salivary sIL-2R levels was significantly higher (57.9+/-15.1 vs 16.7+/-4.7 pg/ml) (p < 0.05) in the group of 26 patients with Sjögren's syndrome than in the dry-mouth group. Both the salivary and the serum sIL-2R of normal controls were below the level of detection. No significantly statistical differences were noted between the concentrations of serum sIL-2R in either abnormal groups. No correlations were found between salivary or serum sIL-2R and the erythrocyte sedimentation rate, C-reactive protein, the presence of various autoantibodies or the focus score from lip biopsies in the group of patients with Sjögren's syndrome. The results show that, although the salivary sIL-2R does not actually reflect the extent of inflammation, it might have an important role in the diagnosis of Sjögren's syndrome.

Anti-interleukin-1 effects of diacerein and rhein in human osteoarthritic synovial tissue and cartilage cultures.

OBJECTIVE: The etiology of osteoarthritis (OA) is still a matter of debate. Several factors are known to be involved in the destruction of the articular cartilage. Interleukin-1 (IL-1) plays an important role in the pathogenesis of osteoarthritis (OA) either directly or through the stimulation of catabolic factors, such as nitric oxide (NO). The objective of this study was to evaluate the effect of diacerein, a new anti-OA agent and its active metabolite, rhein, on the production and function of IL-1beta, nitric oxide (NO) and receptor agonist (IL-1ra) in human OA cartilage and synovial tissue cultures. DESIGN: Synovial tissue and cartilage derived from OA patients were kept in culture for 48-72 hours in the presence of 1 microg/ml of lipopolysaccharide (LPS) with or without diacerein (10(-7)-10(-5) M), rhein (10(-7)-10(-5) M) and hydrocortisone (5 microg/ml). IL-1beta, IL-1ra, NO productions and 35S uptake were measured in culture media. In some experiments the resulting supernatants from synovial tissue cultures were added to cartilage. RESULTS: Diacerein and rhein, as well as hydrocortisone, significantly inhibited LPS-induced IL-1beta production by synovial tissue and cartilage. They also significantly reversed the inhibitory effect of LPS on cartilage 35S uptake. Culture media from synovial tissue containing LPS+diacerein (10(-6) M) or +rhein (10(-6) M) had a significantly less inhibitory effect on cartilage synthesis than culture media containing LPS only. Diacerein and rhein decreased NO release in synovial tissue and cartilage media and increased IL-1ra levels in cartilage culture media. CONCLUSION: An inhibitory effect of diacerein and rhein at therapeutic concentrations on both IL-1beta secretion and function in human synovial tissue and cartilage is suggested. Diacerein and rhein effects on NO production by LPS-stimulated OA synovial tissue and cartilage may both contribute and elucidate their anti-OA properties.

Increased salivary interleukin-6 levels in patients with primary Sjögren's syndrome.

This study's purpose was to evaluate salivary interleukin-6 (IL-6) levels in patients with primary Sjögren's syndrome (SS). Salivary and serum IL-6 concentrations were evaluated by ELISA in 36 patients with SS and compared with 19 patients complaining of dry mouth and with normal controls. Salivary IL-6 levels were significantly elevated (P < 0.01) in the 36 patients with SS as compared to the 19 patients with dry mouth (200.5 +/- 43.6 and 12.6 +/- 6.8 pg/ml, respectively). No significant differences were noted in the serum IL-6 levels between these two groups (105.8 +/- 17.1 and 84.8 +/- 17.1 pg/ml, respectively). Both salivary and serum IL-6 levels in the normal controls were below the level of detection of the assay. Positive correlation (r = 0.8613, P < 0.0001) was found between salivary IL-6 levels and the focus score of labial biopsies in SS patients. Elevated salivary IL-6 levels appear to be a consequence of local production and may reflect the component of salivary gland inflammation in SS.

Fluoxetine and amitriptyline inhibit nitric oxide, prostaglandin E2, and hyaluronic acid production in human synovial cells and synovial tissue cultures.

OBJECTIVE: To evaluate the effects of fluoxetine and amitriptyline on nitric oxide (NO), prostaglandin E2 (PGE2), and hyaluronic acid (HA) production in human synovial cells and synovial tissue cultures. METHODS: Human synovial cells, synovial tissue, and cartilage were cultured in the presence or absence of cytokines, lipopolysaccharides (LPS), fluoxetine, or amitriptyline. Production of NO, PGE2, and HA was determined in culture media. Sulfated glycosaminoglycan (S-GAG) synthesis was evaluated in cartilage by 35S incorporation. RESULTS: Fluoxetine (0.3 microg/ml, 1 microg/ml, and 3 microg/ml) inhibited NO release by 56%, 62%, and 71%, respectively, in the media of synovial cells stimulated by interleukin-1alpha (IL-1alpha; 1 ng/ml) plus tumor necrosis factor alpha (TNFalpha; 30 ng/ml). Amitriptyline (0.3 microg/ml, 1 microg/ml, and 3 microg/ml) caused a 16%, 27.3%, and 51.4% inhibition of NO release. Fluoxetine and amitriptyline (0.3 microg/ml, 1 microg/ml, and 3 microg/ml) significantly (P<0.05) inhibited PGE2 release in the media of human synovial cells in the presence of IL-1alpha plus TNFalpha, in a dose-dependent manner (up to 88% inhibition). Fluoxetine (0.3 microg/ml, 1 microg/ml, and 3 microg/ml) and amitriptyline (1 microg/ml and 3 microg/ml) significantly (P<0.05) inhibited PGE2 release in the media of human synovial tissue in the presence of LPS. Fluoxetine and amitriptyline (0.3 microg/ml, 1 microg/ml, and 3 microg/ml) also significantly (P<0.05) inhibited HA production by human synovial cells in the presence of IL-1beta plus TNFalpha. Fluoxetine and amitriptyline (1 microg/ml) partially reversed IL-1beta-induced inhibition of 35S-GAG synthesis by human cartilage cultures (P<0.05). Neither fluoxetine nor amitriptyline had a toxic effect on cells in the concentrations used. CONCLUSION: Inhibition of NO and PGE2 production by connective tissue cells is a mechanism by which some antidepressant medications may affect pain, articular inflammation, and joint damage.

Elevated tear interleukin-6 levels in patients with Sjögren syndrome.

OBJECTIVE: The purpose of the study was to investigate interleukin-6 (IL-6) levels in the tear fluid and sera of patients with Sjögren syndrome (SS). PARTICIPANTS: Twelve patients with primary SS and 12 normal control subjects participated. INTERVENTION: Tear fluid and sera were obtained from the study and the control groups. Evaluation of tear fluid and sera IL-6 levels was done by using a quantitative enzyme-linked immunosorbent assay kit. All assays were carried out blindly with respect to diagnosis. MAIN OUTCOME MEASURES: Tear fluid IL-6 levels were measured. RESULTS: The mean concentration (+/- standard error) of IL-6 in the tears of patients with SS was elevated significantly compared to that of normal control subjects (88.6+/-16.2 vs. 42.1+/-10.6 pg/ml; P < 0.05). No significant differences were noted in the serum IL-6 levels between the two groups. A significant correlation (r = 0.742, P = 0.006) was found between tear fluid IL-6 levels and the focus score of lip biopsy specimens in patients with SS. CONCLUSION: Tear fluid IL-6 levels may serve as an important marker for tear gland involvement in SS.

Salivary and serum hyaluronic acid concentrations in patients with Sjögren's syndrome.

OBJECTIVE: To evaluate salivary hyaluronic acid (HA) concentration in patients with primary Sjögren's syndrome (SS). METHODS: Salivary and serum HA concentrations were evaluated using a radiometric assay. Thirty nine patients with SS served as the study group and their results were compared with 19 patients having clinical symptoms and signs of dry mouth and with 10 normal controls. RESULTS: Salivary HA concentrations were significantly increased (p < 0.05) in the 39 patients with SS compared with the 19 patients with dry mouth and the 10 normal controls (240.7 (38.5) v 99.8 (14.6) and 91.3 (7.9) ng/ml, respectively) (mean (SEM)). No significant differences were noted in the serum HA concentrations between the three groups (42 (3.9) v 36.3 (4.1) and 32 (4.3) ng/ml, respectively) (mean (SEM)). No correlation could be found between salivary HA concentrations and the focus score of lip biopsies, nor between salivary HA concentrations and erythrocyte sedimentation rate or other serological tests. CONCLUSION: Increased salivary HA concentrations can serve as a marker of local inflammation and may be of value in the diagnosis of SS.

Elevated levels of hyaluronic acid in the sera of women with fibromyalgia.

OBJECTIVE: To evaluate serum levels of hyaluronic acid (HA) in patients with fibromyalgia (FM). METHODS: HA serum levels were evaluated by a radiometric assay in 42 women with FM (ACR criteria), 27 female patients with rheumatoid arthritis (RA) and 36 healthy female controls matched for age. RESULTS: HA serum levels (mean microg/l +/- SEM) were 41 +/- 8.7 in healthy controls; 113 +/- 15.9 in RA: and 420 +/- 26 in FM. CONCLUSION: HA serum levels in women with FM were significantly elevated compared to healthy controls and patients with RA. This observation suggests that FM is associated with a biochemical abnormality and that serum HA could be a laboratory marker for its diagnosis.