bluuebunny/crossref_metadata_2025 huggingface dataset:
Citalopram‐Induced Priapism
Authors: Dent Larry A. , Brown Waylon C. , Murney Jenny D.
Published: June 2004

Citalopram is a relatively new selective serotonin reuptake inhibitor (SSRI) that is becoming widely administered for the treatment of depression. Selective serotonin reuptake inhibitors generally are associated with mild adverse sexual side effects; however, more serious reactions may occur. A 58‐year‐old man experienced priapism several hours after inadvertently taking three tablets of citalopram 20 mg, which he had mistaken for aspirin, in addition to his usual dosage of 20 mg twice/day. Three days later, he was hospitalized and treated with intracavernous phenylephrine. He ultimately required surgical intervention. Although the citalopram overdose appears to be largely responsible for the patient developing priapism, he also was taking tamsulosin 0.4 mg/day at bedtime for benign prostatic hyperplasia. As α1‐blockers have been associated with priapism on rare occasions, tamsulosin may have been a contributing factor. The patient also had a history of priapism associated with trazodone. Health care professionals should vigilantly monitor patients who take citalopram in high dosages or in combination with other drugs associated with priapism. Patients who have a history of priapism with other drugs may be more susceptible to citalopram‐associated priapism.
Low‐Temperature, Surface‐Mediated Foaming of Polymer Films
Authors: Siripurapu S. , DeSimone J. M. , Khan S. A. , Spontak R. J.
Published: June 2004

Ultraporous thin polymer films (see Figure) are generated using physical constraints imposed by external surfaces (hard plates) and internal surfaces (hard nanoparticles and soft micelles) via foaming with supercritical CO2. The constraints serve as diffusion barriers and/or heterogeneous nucleation sites. Use of CO2‐philic copolymers further enables microcellular foaming at reduced pressures with liquid CO2.
Additive‐Driven Phase‐Selective Chemistry in Block Copolymer Thin Films: The Convergence of Top–Down and Bottom–Up Approaches
Authors: Du P. , Li M. , Douki K. , Li X. , Garcia C. B. W. , Jain A. , Smilgies D.‐M. , Fetters L. J. , Gruner S. M. , Wiesner U. , Ober C. K.
Published: June 2004

Several strategies are demonstrated for the use of additive‐driven chemistries that take place in only one type of the nanosized domains of all‐organic and organic–inorganic hybrid block copolymer thin films. Such an approach is used to examine the convergence of “top–down” and “bottom–up” fabrication via light‐driven processes. Characterization is carried out with microscopies and grazing‐incidence small‐angle X‐ray scattering (see Figure and cover).
Dynamic patterns of expression of BMP isoforms 2, 4, 5, 6, and 7 during chicken heart development
Authors: Somi Semir , Buffing Anita A.M. , Moorman Antoon F.M. , Van Den Hoff Maurice J.B.
Published: June 2004

Bone morphogentic proteins (BMPs) play an important role in cardiac development. Using an in vitro explant analysis, we show that BMPs are crucial for myocardium formation. As a first approach to identify which BMP may be involved in myocardium formation in intra‐ and extracardiac mesenchyme in vivo, a survey of the expression patterns of BMP2, ‐4, ‐5, ‐6, and ‐7 mRNA is prepared by in situ hybridization in chicken embryonic hearts from HH5 to 44. During recruitment of mesodermal cells to the outflow tract myocardium (HH10–23), BMP2, ‐4, ‐5, and ‐7 mRNA are expressed in the distal myocardial border and the flanking mesenchyme. After completion, BMP2 and ‐4 mRNA become restricted to the mesenchyme and BMP5 and ‐7 mRNA to the myocardium. At the venous pole, BMP2, ‐5, and ‐7 mRNA are expressed in the distal myocardial border of the caval vein, while BMP2, ‐5, ‐6, and ‐7 mRNA are expressed in the distal myocardium around the pulmonary vein. BMP4 mRNA is expressed in the adjacent mesenchyme at both sides. During muscularization of the atrioventricular cushions and the tricuspid valve, the cardiomyocytes that protrude into the mesenchyme express BMP2, ‐4, ‐5, and ‐7 mRNA, whereas BMP6 mRNA is expressed in the cushion mesenchyme. The myocardial protrusions formed in the mesenchymal proximal outlet septum express BMP4, ‐5, and ‐7 mRNA, while BMP2 and ‐6 mRNA are expressed in the mesenchyme. The spatiotemporal expression patterns of these BMPs in relation to myocardium formation at the distal ends and within the heart suggest a role for BMPs in myocardium formation. During delamination of the valves, BMP4 and ‐6 mRNA are expressed at the ventricular side of the forming mitral valve, BMP4 mRNA at the ventricular side of the forming tricuspid valve, and BMP2, ‐4, and ‐6 mRNA at the vascular side of the forming semilunar valves. © 2004 Wiley‐Liss, Inc.
Membrane‐transport systems in the fenestrated capillaries of the area postrema in rat and calf
Authors: Bombardi Cristiano , Grandis Annamaria , Chiocchetti Roberto , Lucchi Maria Luisa , Callegari Emilio , Bortolami Ruggero
Published: June 2004

The capillaries of the area postrema (AP) lack the morphological peculiarity of the blood‐brain barrier (BBB), and the AP neurons are considered located outside the BBB. Using the immunofluorescent method, we have investigated the expression of membrane transport systems that are instrumental to the BBB function, such as caveolin‐1, ‐2, P‐glycoprotein, and glut‐4, in the capillary endothelium of the rat and calf AP. The expression of these molecules was verified after fibronectin immunostaining of the microvessels. Both in the rat and calf, caveolin‐1, ‐2, and P‐glycoprotein were expressed in the AP capillaries. A quantitative analysis revealed that the proportion of the capillary profiles expressing these transport systems was very close to 100% of the fibronectin immunolabelled profiles. On the contrary, none of the AP capillaries showed glut‐4 immunoreactivity. The present investigation demonstrates that the endothelial layer of the AP capillaries, in spite of the paracellular passage of polar molecules through the leaky tight junctions and fenestrations, could be an active interface which is able to control the entry of a wide range of blood‐borne compounds into the brain by means of specific mechanisms, including an efflux pump. © 2004 Wiley‐Liss, Inc.
Development of the synovial membrane in the rat temporomandibular joint as demonstrated by immunocytochemistry for heat shock protein 25
Authors: Ikeda Nobuyuki , Nozawa‐Inoue Kayoko , Takagi Ritsuo , Maeda Takeyasu
Published: June 2004

The synovial lining layer of the temporomandibular joint (TMJ) consists of macrophage‐like type A cells and fibroblast‐like type B cells. Until now, little information has been available on the development of the synovial membrane in TMJ. In the present study we examined the development of the synovial lining layer in the rat TMJ by light‐ and electron‐microscopic immunocytochemistry for heat shock protein (Hsp) 25, which is a useful marker for type B cells. At embryonic day 19 (E19), a few Hsp25‐positive cells first appeared in the upper portion of the developing condyle. During the formation of the upper articular cavity (E21 to postnatal day 1 (P1)), a few positive cells were arranged on its surface. Immunoelectron microscopy demonstrated that these cells had ultrastructural features of fibroblast‐like type B cells. In addition, some Hsp25‐positive cells moved to the deep portion by extending their cytoplasmic processes toward the articular cavity at P3. At that time, the presence of typical macrophage‐like type A cells in the lining layer was confirmed by immunoelectron microscopy. The slender processes of Hsp25‐positive cells showed a continuous covering with the synovial surface at P7, followed by a drastic increase in the Hsp25‐positive cells at P15 and later, when active jaw movement occurred. These findings suggested that the arrangement and morphological maturation of type B cells are closely related to the formation of the articular cavity in the embryonic period and the commencement of active jaw movement after birth, respectively. © 2004 Wiley‐Liss, Inc.
Expression of bone morphogenetic protein‐10 mRNA during chicken heart development
Authors: Somi Semir , Buffing Anita A.M. , Moorman Antoon F.M. , Van Den Hoff Maurice J.B.
Published: June 2004

In this communication we describe the expression pattern of BMP10 mRNA during cardiac development in chickens. BMP10 is considered an important factor in the regulation of cardiac growth and trabeculation in the murine embryo. We identified chicken Ests, which are similar to mouse and human BMP10 in the UMIST database. The cDNA clone that contained most sequences was obtained, verified by sequence analysis, and used to determine the spatiotemporal pattern of gene expression. BMP10 mRNA is initially expressed at HH10 in the myocardium of the arterial pole of the heart tube, anterior to the interventricular groove. Between HH14 and HH22, BMP10 mRNA becomes broadly expressed in the outflow tract, the distal part of the inflow tract, and the trabeculated part of the developing ventricles and atria. From HH31 onward, BMP10 mRNA expression decreases in the ventricular myocardium by first disappearing from the compact myocardium and then from the tips of the trabecules. At HH44, BMP10 mRNA is expressed only in the trabeculated myocardium of the atria and the endocardium of the ventricles. The observed expression pattern of BMP10 mRNA suggests that it may play a role in regulating the formation of the ventricular wall and trabecules. © 2004 Wiley‐Liss, Inc.
Ultrastructural evidence for co‐localization of dopamine D2 and μ‐opioid receptors in the rat dorsolateral striatum
Authors: Ambrose L.M. , Unterwald E.M. , Van Bockstaele E.J.
Published: June 2004

Previous studies have shown significant changes in dopamine and opioid receptors in the basal ganglia following administration of cocaine. Cocaine administration results in a significant increase in the number of opioid receptors in dopamine‐enriched brain regions. The aim of this study was to determine if dopamine D2 receptors (D2r) and μ‐opioid receptors (μOr) are localized to the same neurons in the dorsolateral striatum. Immunoperoxidase and immunogold‐silver labeling combined with electron microscopy was used to examine the ultrastructural localization of both receptors in the dorsolateral striatum. Approximately half of the μOr‐labeled somatodendritic processes showed immunolabeling for the D2r. Similarly, about half of the D2r‐labeled dendrites and cell bodies showed immunolabeling for the μOr. In conclusion, our results indicate that individual neurons in the rat dorsolateral striatum may be directly modulated by both dopaminergic and opioid ligands. These data also suggest that the molecular mechanism responsible for the up‐regulation of μOrs in the caudate and putamen following cocaine exposure may depend, in part, on the co‐existence of D2rs and μ‐Ors in these cells. © 2004 Wiley‐Liss, Inc.
Efficacy and safety of leflunomide in the treatment of psoriatic arthritis and psoriasis: A multinational, double‐blind, randomized, placebo‐controlled clinical trial
Authors: Kaltwasser J. Peter , Nash Peter , Gladman Dafna , Rosen Cheryl F. , Behrens Frank , Jones Peter , Wollenhaupt Jürgen , Falk Franziska G. , Mease Philip
Published: June 2004

Objective

Current treatment options for psoriatic arthritis (PsA) are limited. Leflunomide, an oral pyrimidine synthesis inhibitor, is highly effective in the treatment of rheumatoid arthritis, and small studies have suggested similar efficacy in PsA. We undertook this double‐blind, randomized, placebo‐controlled trial to evaluate the efficacy and safety of leflunomide in patients with PsA and psoriasis.

Methods

One hundred ninety patients with active PsA and psoriasis (at least 3% skin involvement) were randomized to receive leflunomide (100 mg/day loading dose for 3 days followed by 20 mg/day orally) or placebo for 24 weeks. The primary efficacy end point was the proportion of patients classified as responders by the Psoriatic Arthritis Response Criteria (PsARC). Additional efficacy (joint and skin involvement), safety, and quality‐of‐life assessments were performed.

Results

At 24 weeks, 56 of 95 leflunomide‐treated patients (58.9%; 95% confidence interval [95% CI] 48.4–68.9) and 27 of 91 placebo‐treated patients (29.7% [95% CI 20.6–40.2]) were classified as responders by the PsARC (P < 0.0001). Significant differences in favor of leflunomide were also observed in the proportions of patients achieving modified American College of Rheumatology 20% improvement criteria, improvement in the designated psoriasis target lesion, and mean changes from baseline in Psoriasis Area and Severity Index scores and quality‐of‐life assessments. Diarrhea and alanine aminotransferase increases occurred at higher rates in the leflunomide group. No cases of serious liver toxicity were observed.

Conclusion

Leflunomide is an effective treatment for PsA and psoriasis, providing a safe and convenient alternative to current therapies.
Induction of interferon‐α production in plasmacytoid dendritic cells by immune complexes containing nucleic acid released by necrotic or late apoptotic cells and lupus IgG
Authors: Lövgren Tanja , Eloranta Maija‐Leena , Båve Ullvi , Alm Gunnar V. , Rönnblom Lars
Published: June 2004

Objective

To investigate the release of interferon‐α (IFNα)–inducing material by necrotic or apoptotic cells, its properties, and the necessity of autoantibodies from systemic lupus erythematosus (SLE) patients for the interferogenic activity.

Methods

U937 monocytic leukemia cells or peripheral blood mononuclear cells (PBMCs) were rendered necrotic by freeze‐thawing or apoptotic by treatment with ultraviolet light. Cell culture supernatants from these cells and IgG from SLE patients (SLE IgG) were added to cultures of normal PBMCs or purified plasmacytoid dendritic cells (PDCs). The importance of nucleic acids for IFNα induction was investigated by RNase and DNase treatment. The IFNα levels were measured by immunoassay.

Results

Both necrotic and apoptotic U937 cells released material that, combined with SLE IgG, induced IFNα production in PDCs. The release from apoptotic cells occurred with a 16‐hour delay, in late apoptosis. Also, normal PBMCs released IFNα‐inducing material, but only during necrosis. The interferogenic activity of the necrotic material required the presence of RNA, while both RNA and DNA were important in the apoptotic material. In both cases, the presence of SLE IgG was necessary, and its activity correlated with the presence of antibodies to RNA‐binding proteins, but not anti‐DNA antibodies.

Conclusion

Necrotic and late apoptotic cells release material that, combined with SLE IgG, induces production of IFNα in PDCs. The IFNα inducers probably consist of immune complexes (ICs) containing RNA and possibly DNA as essential interferogenic components. The presence of such interferogenic ICs could explain the ongoing production of IFNα in SLE and could be of etiopathogenic importance.
Overexpression of CD70 and overstimulation of IgG synthesis by lupus T cells and T cells treated with DNA methylation inhibitors
Authors: Oelke Kurt , Lu Qianjin , Richardson Derek , Wu Ailing , Deng Chun , Hanash Samir , Richardson Bruce
Published: June 2004

Objective

Generalized DNA hypomethylation contributes to altered T cell function and gene expression in systemic lupus erythematosus (SLE). Some of the overexpressed genes participate in the disease process, but the full repertoire of genes affected is unknown. Methylation‐sensitive T cell genes were identified by treating T cells with the DNA methyltransferase inhibitor 5‐azacytidine and comparing gene expression with oligonucleotide arrays. CD70, a costimulatory ligand for B cell CD27, was one gene that reproducibly increased. We then determined whether CD70 is overexpressed on T cells treated with other DNA methylation inhibitors and on SLE T cells, and determined its functional significance.

Methods

Oligonucleotide arrays, real‐time reverse transcription–polymerase chain reaction, and flow cytometry were used to compare CD70 expression in T cells treated with 2 DNA methyltransferase inhibitors (5‐azacytidine and procainamide) and 3 ERK pathway inhibitors known to decrease DNA methyltransferase expression (U0126, PD98059, and hydralazine). The consequences of CD70 overexpression were tested by coculture of autologous T and B cells with and without anti‐CD70 and measuring IgG production by enzyme‐linked immunosorbent assay. The results were compared with those of T cells from lupus patients.

Results

SLE T cells and T cells treated with DNA methylation inhibitors overexpressed CD70 and overstimulated B cell IgG production. The increase in IgG synthesis was abrogated by anti‐CD70.

Conclusion

SLE T cells and T cells treated with DNA methyltransferase inhibitors and ERK pathway inhibitors overexpress CD70. This increased B cell costimulation and subsequent immunoglobulin overproduction may contribute to drug‐induced and idiopathic lupus.
Quadriceps weakness and its relationship to tibiofemoral and patellofemoral knee osteoarthritis in Chinese: The Beijing osteoarthritis study
Authors: Baker Kristin R. , Xu Ling , Zhang Yuqing , Nevitt Michael , Niu Jingbo , Aliabadi Piran , Yu Wei , Felson David
Published: June 2004

Objective

Weakness has been documented as a feature of tibiofemoral knee osteoarthritis (OA) and may cause disease in this compartment by shock absorption during impulse loading at heel strike, when the patellofemoral joint is not engaged. Our objective was to determine the association of muscle weakness with compartment‐specific knee OA, to evaluate sex‐specific differences in this relationship, and to determine, by evaluating asymptomatic individuals with OA, whether symptoms may produce the weakness seen in OA.

Methods

This cross‐sectional study involved 2,472 subjects (1,475 women and 997 men) ages 60 years or older from 4 central districts of Beijing, China. For all subjects, a skyline view of each knee and an anteroposterior (AP) or posteroanterior (PA) radiograph of both knees were obtained during weight bearing. Radiographs were read by one reader for Kellgren/Lawrence (K/L) grade, joint space narrowing (JSN), and osteophytes. We defined a subject as having tibiofemoral OA when the K/L grade was ≥2 on AP/PA view, patellofemoral OA on skyline view when the osteophyte score was ≥2 (or when the JSN score was ≥2 and the osteophyte score was ≥1), and mixed OA when the knee had both patellofemoral and tibiofemoral radiographic OA. Strength was measured isometrically for each leg separately, and knee pain was evaluated by questionnaire.

Results

In women, quadriceps weakness was associated with tibiofemoral OA (odds ratio [OR] 0.7, 95% confidence interval [95% CI] 0.4–1.0), patellofemoral OA (OR 0.6, 95% CI 0.4–0.9), and mixed OA (OR 0.4, 95% CI 0.3–0.6). In men, weakness was associated with mixed OA (OR 0.5, 95% CI 0.3–0.8), and the ORs suggesting an association of patellofemoral OA with weakness were the same as those in women, although in men this trend did not reach statistical significance (P= 0.12). In men, isolated tibiofemoral disease was not associated with weakness; however, the sample size in this analysis was limited. When subjects with knee symptoms were excluded, the relationship of quadriceps weakness to OA was attenuated, with only the relationship between muscle weakness and mixed OA remaining significant.

Conclusion

There is a relationship between quadriceps weakness and knee OA in all compartments, with the strongest association in mixed disease. Pain may contribute to some of this weakness.
Molecular analysis of the MVK and TNFRSF1A genes in patients with a clinical presentation typical of the hyperimmunoglobulinemia D with periodic fever syndrome: A low‐penetrance TNFRSF1A variant in a heterozygous MVK carrier possibly influences the phenotype of hyperimmunoglobulinemia D with periodic fever syndrome or vice versa
Authors: Stojanov Silvia , Lohse Peter , Lohse Pia , Hoffmann Florian , Renner Ellen D. , Zellerer Stephanie , Kéry Anja , Shin Yoon S. , Haas Dorothea , Hoffmann Georg F. , Belohradsky Bernd H.
Published: June 2004

Objective

To describe biochemical findings and the spectrum of mevalonate kinase (MVK) gene mutations as well as an associated TNFRSF1A low‐penetrance variant in a series of patients with clinical features of the hyperimmunoglobulinemia D with periodic fever syndrome (HIDS).

Methods

The MVK gene was sequenced in 8 children and 1 adult (including 2 siblings) fulfilling the clinical criteria for HIDS. In addition, sequencing of exons 2, 3, 4, and 6 of the TNFRSF1A gene was performed in patients with only one or no MVK mutation. Mevalonate kinase (MK) enzyme activity in leukocytes and renal excretion of mevalonic acid were also measured.

Results

Mutations in the coding region of the MVK gene were detected in 6 patients, and the most common mutation was V377I. Among these patients were 2 novel mutations, both of which were located in exon 6. These novel mutations resulted in the substitution of tryptophan (TGG) by a stop codon (TGA) at amino acid position 188 (W188X) and in the exchange of valine (GTG) for alanine (GCG) at amino acid position 203 (V203A). In 1 patient, a combination of one MVK (V377I) mutation and one TNFRSF1A (R92Q) mutation was present. The patient's clinical phenotype resembled a mixture of variant‐type HIDS and tumor necrosis factor receptor–associated periodic syndrome (TRAPS). Her IgD values varied between normal and slightly increased, and the MK activity was in the low‐normal range, while urinary mevalonate concentrations were always normal.

Conclusion

The genotype findings indicate that a relatively small number of genes may be involved in the clinical manifestation of HIDS, with low‐penetrance TNFRSF1A variants possibly influencing the HIDS phenotype or MVK mutations contributing to TRAPS.
Regional differences in bronchoalveolar lavage and thoracic high‐resolution computed tomography results in dyspneic patients with systemic sclerosis
Authors: Clements Philip J. , Goldin Jonathan G. , Kleerup Eric C. , Furst Daniel E. , Elashoff Robert M. , Tashkin Donald P. , Roth Michael D.
Published: June 2004

Objective

Interstitial lung disease (ILD) is the leading cause of death in systemic sclerosis (SSc). Although early identification and treatment of alveolitis may prevent deterioration of lung function, the best approach for diagnosing active alveolitis remains controversial. This study was undertaken to investigate the utility of high‐resolution computed tomography (HRCT) of the chest, in comparison with bronchoalveolar lavage (BAL), in the diagnosis of alveolitis in these patients.

Methods

Eighteen patients with SSc and dyspnea were evaluated for ILD by pulmonary function testing and bronchoalveolar lavage (BAL), and 15 of these patients underwent chest HRCT. BAL was performed in either the middle lobe or the lingula, and also in a lower lung segment. Differential cell counts were determined by clinical cytopathology, with retrospective recounting in a blinded manner by a single technician. Active alveolitis was defined as the presence of ≥3.0% polymorphonuclear cells and/or ≥2% eosinophils in BAL fluid. BAL fluids were cultured for bacteria, mycobacteria, and fungi. HRCT scans were evaluated in a blinded manner for ground‐glass opacification and fibrosis in the lavaged lobes.

Results

Nine of the 18 patients had active alveolitis recorded in both lavaged segments, while in 4 patients it was recorded in only 1 segment (lower lobe in 3). Following repeat differential cell counting, 3 patients were reclassified as having active alveolitis and 1 as having no alveolitis. Culture of BAL fluid identified clinically unsuspected infection in 3 patients. For the right middle lung lobe or lingula there was excellent agreement between ground‐glass opacification and the finding of alveolitis on BAL from segments in the same lung regions, but this was not observed for the lower lobes. The correlation between fibrosis on HRCT and the presence of alveolitis on BAL was significant for the lower lobes but not the middle lung fields.

Conclusion

BAL of the middle lobe or lingula may underestimate the presence of active alveolitis. Similarly, while ground‐glass opacification on HRCT accurately predicted alveolitis in the middle lung fields, HRCT did not detect all sites of inflammation and did not identify infectious etiologies. These data suggest that, in addition to HRCT, BAL with lavage, differential cell counting, and culture from at least 2 segments of lung be performed for diagnosing SSc alveolitis.
Strong association of a functional polymorphism in the monocyte chemoattractant protein 1 promoter gene with lupus nephritis
Authors: Tucci Marco , Barnes Elena V. , Sobel Eric S. , Croker Byron P. , Segal Mark S. , Reeves Westley H. , Richards Hanno B.
Published: June 2004

Objective

Lupus nephritis (LN) is a major contributor to morbidity and mortality in patients with systemic lupus erythematosus (SLE). There is evidence that polymorphisms in the genes of inflammatory mediators may predispose to the development of LN in patients with SLE. In this study, we examined the role of a functional monocyte chemoattractant protein 1 (MCP‐1) polymorphism in SLE and LN.

Methods

DNA and paired urine and serum samples were obtained from 134 SLE patients (≥4 American College of Rheumatology criteria for SLE; 49 with and 85 without LN) and 118 controls. MCP‐1 genomic variants were detected by polymerase chain reaction followed by restriction enzyme–fragment analysis. Urinary and serum MCP‐1 levels and MCP‐1 production by peripheral blood macrophages were measured by enzyme‐linked immunosorbent assay.

Results

The A/A genotype was more common in controls than in SLE patients (P = 0.0002), whereas both the A/G (P = 0.009) and G/G (P = 0.0212) genotypes were more frequent in SLE patients. The A/A genotype was observed in only 23% of the patients with LN compared with 58% of those without LN (P < 0.0001). MCP‐1 production by peripheral blood mononuclear cells from patients with the A/G and G/G phenotypes was markedly higher than the production by cells from patients with the A/A genotype. Urinary levels of MCP‐1 were significantly higher in patients with LN.

Conclusion

These results suggest that an A/G or G/G genotype may predispose to the development of SLE and further indicate that SLE patients with these genotypes may be at higher risk of developing LN. Moreover, measurement of urinary levels of MCP‐1 may be a useful tool for the detection and management of LN.
Increased interleukin‐18 expression in bone marrow of a patient with systemic juvenile idiopathic arthritis and unrecognized macrophage‐activation syndrome
Authors: Maeno Nobuaki , Takei Syuji , Imanaka Hiroyuki , Yamamoto Kimie , Kuriwaki Kazumi , Kawano Yoshifumi , Oda Hiroshi
Published: June 2004

The aberrant induction of proinflammatory cytokines is considered to be crucial in the pathogenesis of systemic juvenile idiopathic arthritis and adult‐onset Still's disease. Interleukin‐18 (IL‐18) in particular has been reported to be a candidate for the key cytokine in both diseases; however, the origin of IL‐18 is unclear. To clarify the origin, we investigated specimens from various organs obtained during autopsy of a child with systemic JIA and macrophage activation syndrome, using immunohistochemical staining. Our results showed a high number of cells expressing IL‐18 in the bone marrow but not in the other organs. This finding suggests that bone marrow is the origin of increased serum IL‐18 and raises the possibility that other proinflammatory cytokines are also induced by IL‐18 in bone marrow in this disease. Bone marrow may be an essential organ in the pathogenesis of systemic JIA.
Initiation of degenerative joint damage by experimental bleeding combined with loading of the joint: A possible mechanism of hemophilic arthropathy
Authors: Hooiveld Michel J. J. , Roosendaal Goris , Jacobs Kim M. G. , Vianen Marieke E. , van den Berg H. Marijke , Bijlsma Johannes W. J. , Lafeber Floris P. J. G.
Published: June 2004

Objective

To investigate the effect of a limited number of experimental joint bleedings, combined with loading of the affected joint, on the development of progressive degenerative joint damage.

Methods

The right knee of 8 mature beagle dogs was injected with freshly collected autologous blood 3 times per week for 4 weeks, to mimic a limited number of joint hemorrhages occurring over a short period. To ensure loading of the experimental joint, the contralateral control knee of the animals was fixed to the trunk 4 hours per day, 3 days per week. Ten weeks after the last injection, cartilage tissue and synovium were collected from both knees to analyze features of joint degeneration. Cartilage was prepared for analysis of proteoglycan turnover (synthesis, retention, release, and content) and histologic features. Synovium was prepared for histologic analysis.

Results

The rate of proteoglycan synthesis was significantly increased, characteristic of degenerative cartilage damage as seen in osteoarthritis. Release of newly formed proteoglycans (as a measure of retention) and total loss of proteoglycans from the cartilage matrix were increased. Cartilage matrix integrity was adversely altered, as shown by histologic damage. Histologic analysis also revealed signs of synovial inflammation. These effects were not observed 10 weeks after the experimental bleedings in joints that did not undergo forced loading.

Conclusion

Experimental joint bleedings when combined with loading of the affected joint resulted in features of progressive degenerative joint damage, whereas similar joint hemorrhages without joint loading did not. This might reflect a possible mechanism of joint damage in hemophilia.
T cell receptors recognizing type II collagen in HLA–DR–transgenic mice characterized by highly restricted Vβ usage
Authors: He Xiaowen , Rosloniec Edward F. , Myers Linda K. , McColgan William Lewis , Gumanovskaya Marina , Kang Andrew H. , Stuart John M.
Published: June 2004

Objective

To determine the T cell receptor (TCR) structure recognizing type II collagen (CII) in HLA–DR–transgenic mice, and to examine the role of T cells with certain Vβ‐chains in collagen‐induced arthritis (CIA).

Methods

T cell hybridomas were established from DR1‐ and DR4‐transgenic mice and selected for their responses to CII and CII peptide containing the T cell determinants. RNA was extracted and reverse transcribed into complementary DNA, which was then amplified using appropriate Vβ‐ and Vα‐subfamily–specific primers. The polymerase chain reaction products were purified and directly sequenced. To determine the role of T cells with certain Vβ‐chains in CIA, Vβ‐subfamily–specific antibodies were administered and the development and characteristics of arthritis were determined.

Results

TCRs of 23 clonally distinct T cell hybridomas that were derived from DR1‐transgenic mice and that were reactive to the CII peptide containing the immunodominant determinant were analyzed. These hybridomas predominantly used the TCR Vβ14 and Vβ8 gene segments (70% and 30%, respectively). The same restriction in Vβ usage was also found in CII‐reactive T cell hybridomas from DR4‐transgenic mice. There was also restricted use of Vα genes, although this was less marked than that of Vβ. In contrast, the hybridomas expressed a diverse third complementarity‐determining region. Deletion of both Vβ14‐bearing and Vβ8‐bearing T cells significantly reduced the incidence and severity of CIA.

Conclusion

These data demonstrate that DR1 and DR4 not only bind and present the same CII immunodominant peptide, but also stimulate a highly restricted subset of T cells.
Ascorbic acid increases the severity of spontaneous knee osteoarthritis in a guinea pig model
Authors: Kraus Virginia B. , Huebner Janet L. , Stabler Thomas , Flahiff Charlene M. , Setton Lori A. , Fink Christian , Vilim Vladimir , Clark Amy G.
Published: June 2004

Objective

To determine whether ascorbic acid might be of benefit for the treatment of spontaneous osteoarthritis (OA) when administered over a long period of time.

Methods

We investigated the effects of 8 months' exposure to low, medium, and high doses of ascorbic acid on the in vivo development of histologic knee OA in the male Hartley guinea pig. The low dose represented the minimum amount needed to prevent scurvy. The medium dose was the amount present in standard laboratory guinea pig chow and resulted in plasma levels comparable with those achieved in a person consuming 200 mg/day (5 fruits and vegetables daily). The high dose was the amount shown in a previous study of the guinea pig to slow the progression of surgically induced OA.

Results

We found an association between ascorbic acid supplementation and increased cartilage collagen content but, in contrast to findings in a previous study of surgically induced OA in the guinea pig, ascorbic acid worsened the severity of spontaneous OA. Active transforming growth factor β (TGFβ) was expressed in marginal osteophytes, whose size and number were significantly increased with increasing intake of ascorbic acid. Synovial fluid levels of cartilage oligomeric matrix protein, a biomarker of cartilage turnover, corroborated the histologic findings.

Conclusion

Ascorbic acid has been shown to activate latent TGFβ. Prolonged intraarticular exposure to TGFβ has been shown to cause OA‐like changes. We found expression of active TGFβ in osteophytes, a prominent feature of the joint histology seen in association with ascorbic acid treatment. Thus, the deleterious effects of prolonged ascorbic acid exposure may be mediated in part by TGFβ. This worsening of OA with ascorbic acid supplementation suggests that ascorbic acid intake should not be supplemented above the currently recommended dietary allowance (90 mg/day for men and 75 mg/day for women).
Juvenile rheumatoid arthritis affected sibpairs: Extent of clinical phenotype concordance
Authors: Moroldo Marta B. , Chaudhari Minakshi , Shear Edith , Thompson Susan D. , Glass David N. , Giannini Edward H.
Published: June 2004

Objective

To investigate the clinical phenotypes and demographic characteristics of 183 affected sibling pairs (ASPs) with juvenile rheumatoid arthritis (JRA) and to determine whether there are differences between the clinical phenotypes of the ASP cohort compared with patients with sporadic disease and whether there is greater sharing of specific clinical features within versus between sibpairs.

Methods

Details of the JRA Affected Sibpair Registry operations have been described previously. The frequencies of phenotypes in the 2 cohorts were tabulated, summary statistics were determined, and comparisons were made by chi‐square test or t‐test. Sibling risk, sibling risk ratios (λs), and odds ratios were calculated to assess familial aggregation of several different clinical manifestations.

Results

The most common onset type among the 164 nontwin ASPs was pauciarticular (65% overall). Fifty‐three percent of the ASPs were concordant for pauciarticular‐onset JRA; 19% were concordant for a polyarticular disease onset. Among subjects with polyarticular‐onset disease, significantly more joints were involved at onset in simplex patients than in ASPs (P = 0.008). The difference in age at JRA onset within sibpairs (sibling 1 versus sibling 2) was not significantly different. ASPs developed disease at a mean real‐time difference of 5.1 years apart. Familial aggregation was found for tenosynovitis (λs 29.5), leukocytosis (λs 25), rheumatoid factor (λs 11.0), anemia (λs 1.7), and antinuclear antibodies (λs 1.3).

Conclusion

This study confirms the findings of earlier studies showing that a high proportion of ASPs overall show concordance of disease‐onset type, except for the subset of patients with systemic disease, and that nontwin ASPs do not develop disease at the same point in real time. We conclude that JRA and its clinical manifestations do not differ substantially between ASPs and the simplex population. The exception is the number of affected joints at JRA onset among patients with polyarticular‐onset disease. Familial aggregation of clinical features among ASPs adds strong evidence for a genetic background in this disease.
Local expression of the serum amyloid A and formyl peptide receptor–like 1 genes in synovial tissue is associated with matrix metalloproteinase production in patients with inflammatory arthritis
Authors: O'Hara Rosemary , Murphy Evelyn P. , Whitehead Alexander S. , FitzGerald Oliver , Bresnihan Barry
Published: June 2004

Objective

To evaluate the regulation of acute‐phase serum amyloid A (A‐SAA) production in inflamed synovial tissue, and to elucidate a possible pathophysiologic role in the induction of matrix metalloproteinase (MMP) release by fibroblast‐like synoviocytes (FLS).

Methods

Synovial tissue samples were obtained by arthroscopic biopsy from the knee joints of patients with inflammatory arthritis. Primary cultures of FLS from patients with rheumatoid arthritis (RA), psoriatic arthritis, sarcoid arthritis, and undifferentiated arthritis were established. Total RNA was extracted from FLS and analyzed by reverse transcription–polymerase chain reaction (PCR) using specific primers for A‐SAA and formyl peptide receptor–like 1 (FPRL1), an A‐SAA receptor. Southern blot analysis confirmed the PCR products generated. Immunohistochemical analysis demonstrated the expression of A‐SAA protein production by several synovial cell populations, and immunofluorescence analysis confirmed A‐SAA colocalization with the macrophage marker CD68. Primary FLS cultures stimulated with recombinant human A‐SAA resulted in dose‐dependent MMP‐1 and MMP‐3 production, as measured by an enzyme‐linked immunosorbent assay.

Results

A‐SAA messenger RNA (mRNA) and FPRL1 mRNA were present in FLS, macrophages, and endothelial cells isolated from the synovial tissue of patients with RA and other categories of inflammatory arthritis. A‐SAA expression was regulated by proinflammatory cytokines and occurred in association with FPRL1 expression in FLS and endothelial cells, which is consistent with a biologic role at the sites of inflammation. Recombinant human A‐SAA induced both MMP‐1 and MMP‐3 secretion by FLS. The mean fold increases in A‐SAA–induced MMP‐1 and MMP‐3 production were 2.6 and 10.6, respectively, compared with 7.6‐fold and 41.9‐fold increases in interleukin‐1β–induced MMP‐1 and MMP‐3 production.

Conclusion

The up‐regulation of the A‐SAA and FPRL1 genes in inflamed synovial tissue suggests an important role in the pathophysiology of inflammatory arthritis. A‐SAA induces the production of MMPs. Therapeutic targeting of A‐SAA, or FPRL1, may modulate pathophysiologic pathways that are associated with matrix degradation in patients with RA and other forms of progressive inflammatory arthritis.
Local activation of STAT‐1 and STAT‐3 in the inflamed synovium during zymosan‐induced arthritis: Exacerbation of joint inflammation in STAT‐1 gene–knockout mice
Authors: de Hooge Alfons S. K. , van de Loo Fons A. J. , Koenders Marije I. , Bennink Miranda B. , Arntz Onno J. , Kolbe Thomas , van den Berg Wim B.
Published: June 2004

Objective

STAT proteins play an important role in cytokine signaling. Some investigators have reported preferential activation of STAT‐1, and others have reported preferential activation of STAT‐3, in response to endogenous interleukin‐6 (IL‐6), in patients with rheumatoid arthritis. The present study was undertaken to investigate synovial STAT‐1 and STAT‐3 activation in an experimental animal model of arthritis.

Methods

Zymosan was injected intraarticularly into naive wild‐type (WT), IL‐6−/−, and STAT‐1−/− mice to induce arthritis. Western blots of synovial lysates were probed with phosphospecific antibodies to detect STAT‐1/STAT‐3 activation. Inflammation was assessed histologically. Synovial gene expression of the STAT‐induced feedback inhibitors suppressor of cytokine signaling 1 (SOCS‐1) and SOCS‐3 in WT and STAT‐1−/− mice was investigated by reverse transcriptase–polymerase chain reaction.

Results

STAT‐3 was activated in inflamed synovium of WT mice throughout the course of disease, whereas activated STAT‐1 was observed only during the chronic phase. In IL‐6−/− mice, STAT activation was limited to STAT‐3 on day 1. Although macrophage influx was not inhibited, disease went into remission after day 7 in IL‐6−/− mice. STAT‐1 deficiency resulted in exacerbation of chronic joint inflammation and granuloma formation. In STAT‐1−/− mice, STAT‐3 activation in the inflamed joints was unaltered as compared with WT mice. However, synovial SOCS‐1, but not SOCS‐3, gene expression was markedly reduced in STAT‐1−/− mice.

Conclusion

The results in the IL‐6−/− mice suggest that STAT‐3 is involved in the chronicity of ZIA. Exacerbation of arthritis in STAT‐1−/− mice suggests an opposing effect of STAT‐1, i.e., suppression of joint inflammation. The expression of SOCS‐1 could be the underlying mechanism by which STAT‐1 controls joint inflammation.
Treatment of rheumatoid arthritis with humanized anti–interleukin‐6 receptor antibody: A multicenter, double‐blind, placebo‐controlled trial
Authors: Nishimoto Norihiro , Yoshizaki Kazuyuki , Miyasaka Nobuyuki , Yamamoto Kazuhiko , Kawai Shinichi , Takeuchi Tsutomu , Hashimoto Jun , Azuma Junichi , Kishimoto Tadamitsu
Published: June 2004

Objective

Interleukin‐6 (IL‐6) is a pleiotropic cytokine that regulates the immune response, inflammation, and hematopoiesis. Overproduction of IL‐6 plays pathologic roles in rheumatoid arthritis (RA), and the blockade of IL‐6 may be therapeutically effective for the disease. This study was undertaken to evaluate the safety and efficacy of a humanized anti–IL‐6 receptor antibody, MRA, in patients with RA.

Methods

In a multicenter, double‐blind, placebo‐controlled trial, 164 patients with refractory RA were randomized to receive either MRA (4 mg/kg body weight or 8 mg/kg body weight) or placebo. MRA was administered intravenously every 4 weeks for a total of 3 months. The clinical responses were measured using the American College of Rheumatology (ACR) criteria.

Results

Treatment with MRA reduced disease activity in a dose‐dependent manner. At 3 months, 78% of patients in the 8‐mg group, 57% in the 4‐mg group, and 11% in the placebo group achieved at least a 20% improvement in disease activity according to the ACR criteria (an ACR20 response) (P < 0.001 for 8‐mg group versus placebo). Forty percent of patients in the 8‐mg group and 1.9% in the placebo group achieved an ACR50 response (P < 0.001). The overall incidences of adverse events were 56%, 59%, and 51% in the placebo, 4‐mg, and 8‐mg groups, respectively, and the adverse events were not dose dependent. A blood cholesterol increase was observed in 44.0% of the patients. Liver function disorders and decreases in white blood cell counts were also observed, but these were mild and transient. There was no increase in antinuclear antibodies or anti‐DNA antibodies. Anti‐MRA antibodies were detected in 2 patients.

Conclusion

Treatment with MRA was generally well tolerated and significantly reduced the disease activity of RA.
17β‐estradiol regulates cytokine release through modulation of CD16 expression in monocytes and monocyte‐derived macrophages
Authors: Kramer P. R. , Kramer S. F. , Guan G.
Published: June 2004

Objective

Macrophages release cytokines, such as tumor necrosis factor α (TNFα), interleukin‐1 (IL‐1), and IL‐6, which modulate the symptoms of rheumatoid arthritis (RA). Macrophage release of these cytokines can be modulated by estrogen. Fcγ receptor type IIIA (CD16a) is a receptor expressed on macrophages that selectively binds IgG molecules, an important rheumatoid factor in RA. Binding of CD16 by anti‐CD16 monoclonal antibodies stimulates macrophage cytokine release. We undertook this study to test the hypothesis that decreased concentrations of estrogen (17β‐estradiol) directly cause an increase in CD16 expression, resulting in increased release of proinflammatory cytokines from monocytes and/or macrophages upon receptor binding.

Methods

THP‐1 cells and female human primary monocytes and monocyte‐derived macrophages were treated with no 17β‐estradiol, physiologic levels (1 × 10−8M) of 17β‐estradiol, or 1 × 10−8M 17β‐estradiol followed by withdrawal of 17β‐estradiol. Surface expression of CD16 and CD16 messenger RNA was measured using fluorescence‐activated cell sorting (FACS) and semiquantitative reverse transcription–polymerase chain reaction, respectively. Cytokine release from 17β‐estradiol–treated or untreated monocytes was then quantitated by enzyme‐linked immunosorbent assay and FACS after crosslinking the receptor with anti‐CD16 antibodies.

Results

CD16 transcript significantly increased in macrophage‐like THP‐1 cells and in primary, peripheral blood macrophages in the absence of 17β‐estradiol, and the observed increase in message was dependent on transcription. CD16 receptor levels on CD14+, transforming growth factor β–treated primary monocytes also increased in cells deprived of 17β‐estradiol. Analysis of the cytokines released showed that CD16 crosslinking stimulated significant increases in TNFα, IL‐1β, and IL‐6 due to the absence of estrogen.

Conclusion

Estrogen can modulate proinflammatory cytokine release from activated monocytes and/or macrophages, in part through modulation of CD16 expression.
Correlation of polymorphic variation in the promoter region of the interleukin‐1β gene with secretion of interleukin‐1β protein
Authors: Hall Stephanie K. , Perregaux David G. , Gabel Christopher A. , Woodworth Thasia , Durham L. Kathryn , Huizinga T. W. F. , Breedveld F. C. , Seymour Albert B.
Published: June 2004

Objective

Significant variation in interleukin‐1β (IL‐1β) protein secretion between subjects has been observed when using a lipopolysaccharide (LPS)/ATP–mediated ex vivo blood stimulation assay. To explore the potential relationships between genetic polymorphisms in the IL1B cytokine gene and cellular responses to inflammatory stimuli such as LPS, we investigated the hypothesis that polymorphisms within the promoter and exon 5 of the IL1B gene contribute to the observed differences in IL‐1β protein secretion.

Methods

The IL1B gene polymorphisms C−511T, T−31C, and C3954T were tested for association with LPS‐induced secretion of IL‐1β protein as measured by an ex vivo blood stimulation assay. Samples from 2 independent study populations (n = 31 and n = 25) were available for use in the ex vivo assay after consent was obtained to analyze the DNA.

Results

A specific haplotype, composed of the T allele at −511 and the C allele at −31, was significantly associated with a 2–3‐fold increase in LPS‐induced IL‐1β protein secretion. This association was observed in both of the independent study populations (P = 0.0084 and P = 0.0017).

Conclusion

These data suggest that polymorphisms within the promoter region of the IL1B gene contribute to observed differences in LPS‐induced IL‐1β protein secretion.