bluuebunny/crossref_metadata_2025 huggingface dataset:
Holo-Transferrin and Thrombin Can Interact to Cause Brain Damage
Authors: Nakamura Takehiro , Xi Guohua , Park Jung-Weon , Hua Ya , Hoff Julian T. , Keep Richard F.
Published: January 2005

Background and Purpose—

Previous studies have suggested that delayed release of hemoglobin degradation products, particularly iron, is involved in intracerebral hemorrhage (ICH)–induced brain injury. However, a recent study found evidence of iron-induced brain injury soon after ICH. This study, therefore, examined whether another iron-containing component of blood, holo-transferrin (holo-Tf), might also induce brain injury either alone or in combination with thrombin, another factor involved in early ICH-induced brain injury.

Methods—

Male Sprague-Dawley rats received an intracerebral infusion of holo-Tf, apo (noniron–loaded)-Tf, thrombin, or a combination of Tf with thrombin into the right basal ganglia. The rats were euthanized 24 hours later for measurement of brain edema and assessment of DNA damage (single- and double-strand breaks and 8-hydroxyl-2′-deoxyguanosine immunohistochemistry). Iron distribution was examined histochemically.

Results—

Holo-Tf, apo-Tf, and the dose of thrombin used (1 U) all failed to induce brain edema when administered alone. However, the combination of holo-Tf with thrombin (but not apo-Tf with thrombin) caused brain edema, DNA damage, and intracellular iron accumulation in the ipsilateral basal ganglia.

Conclusions—

These results suggest that in addition to hemoglobin-bound iron, Tf-bound iron may contribute to ICH-induced brain injury and that thrombin may contribute to the latter by facilitating cellular iron uptake.
Genetic variation within endemic Podarcis lizards from the Balearic Islands inferred from partial Cytochrome b sequences
Authors: Picornell  , Terrasa  , Ramon  , Castro
Published: January 2005

Sequences of the cytochrome b gene were analysed for 47 samples of two species of Podarcis from the Balearic Islands (P. pityusensis from Pityuses and P. lilfordi, from Gymnesies archipelago). The average uncorrected distance between the two species studied was 9.7%. The sampled individuals from each species form reciprocally monophyletic units. Assuming an overall rate of change for cytochrome b of 2% per million years the nucleotide divergence of 9.7% ± 1.9% between P. lilfordi and P. pityusensis, could correspond to a divergence time of 4.95 ± 0.95 million years. The separation time between Gymnesies and Pityuses archipelagos according to geological hypotheses is around 5 million years, thus our results suggest the ancestors of the two present forms became isolated during this event. The most parsimonious networks suggest that currently accepted subspecies do not form monophyletic groups, and so should be reassessed. Despite our limited sampling the level of variability is much higher in P. lilfordi than P. pityusensis. Since they are sister taxa the relative age of each species is equal, therefore the differences might be due to historical population structure differences. However it seems that the forms on the islands are not genetically distinct units, implying that morphological differences are recent adaptations to their environments.
Sustained correction of disease in naive and AAV2-pretreated hemophilia B dogs: AAV2/8-mediated, liver-directed gene therapy
Authors: Wang Lili , Calcedo Roberto , Nichols Timothy C. , Bellinger Dwight A. , Dillow Aaron , Verma Inder M. , Wilson James M.
Published: January 2005

Adeno-associated virus 8 (AAV8), a new member of the AAV family isolated from nonhuman primates, is an attractive candidate for hepatic gene transfer applications because of 10- to 100-fold improved transduction efficiency in mouse liver models. Additionally, AAV8 has lesser frequency of pre-existing immunity in humans. These properties could solve some of the problems associated with AAV2 vectors. The benefits of AAV8 demonstrated in mouse models, however, have not been confirmed in larger animals. In this study, we evaluate the efficacy and safety of AAV2/8 vector in both naive and AAV2-pretreated hemophilia B dogs. Two naive hemophilia B dogs that received a single intraportal administration of AAV2/8 vector have achieved sustained expression of 10% and 26% of normal levels of canine factor IX (cFIX) for more than a year. In an AAV2-pretreated hemophilia B dog, cFIX expression increased from less than 1% to 16% of normal levels when treated with an AAV2/8 vector, and a high level of expression has lasted for more than 2 years. No significant liver toxicity or cFIX-specific antibodies have been detected in these animals. Studies here have demonstrated the safety and improved efficacy of AAV2/8 vector in large-animal models for liver-directed gene therapy.
Integrative Epidemiology: From Risk Assessment to Outcome Prediction
Authors: Spitz Margaret R. , Wu Xifeng , Mills Gordon
Published: January 2005

In this paper, we advance the concept of integrative epidemiology. Our unifying premise is that the same genes that are implicated in cancer risk may also be involved in a person's propensity to carcinogenic exposure and/or to modulation of therapeutic outcome. In the coming years, molecular epidemiology will play an increasingly prominent role in early detection of cancer and in identifying genetically high-risk subgroups that might benefit disproportionately from more intensive screening or chemoprevention interventions. Molecular epidemiology is also integral to pharmacogenetic research, by constructing genetic profiles that could be used to individualize therapy and to understand the functional consequences of chemoprevention, chemotherapy, or radiotherapy response. At the level of risk assessment, the focus might be on germline polymorphisms in candidate genes; for early detection, epigenetic events in these same or other genes may be relevant; and tumor tissue expression levels, loss of heterozygosity, genomic amplification, rearrangements, or somatic mutations in the same classes of genes may determine outcome. We will provide examples of how changes in the function of a single gene can contribute to susceptibility to carcinogenic exposure, predisposition to cancer development, patient prognosis, and prediction of outcome.
Behavior and Cancer Prevention
Authors: Gotay Carolyn C.
Published: January 2005

This paper reviews research on the effects of behavioral risk factors on cancer incidence, as well as behavioral interventions for cancer prevention. Risk factors discussed here—tobacco use, diet, physical activity, and obesity/energy balance—are all linked with cancer etiology, and effective behavioral interventions have been developed in all of these areas. The most effective interventions appear to incorporate various components; for example, including individual as well as family activities, and involving multiple community organizations in behavior-changing activities. Behavioral theories have guided the design of these interventions, providing support that certain influences on behavior, such as self-efficacy, problem-solving skills, and social support, are important regardless of the specific behavioral target. As illustrated by the recent lowered lung cancer incidence and mortality rates for men and women, behavior change is possible and effective in cancer prevention. Clinical guidelines have been established for behavioral aspects of treatments for smoking cessation, dietary guideline compliance, physical activity, and obesity reduction, and new tools for dissemination of effective intervention materials will be helpful in increasing their use. Documenting the cost-effectiveness of behavioral interventions, using new technology interventions, and building on translational research to tailor interventions to individuals offer considerable promise for the future.
Colorectal Cancer Prevention
Authors: Hawk Ernest T. , Levin Bernard
Published: January 2005

Colorectal cancer is the second leading cause of mortality in the United States. In the United States, the cumulative lifetime risk of developing colorectal cancer for both men and women is 6%. Despite advances in the management of this disease, the 5-year survival rate in the United States in only 62%. Because only 38% of patients are diagnosed when the cancers are localized to the bowel wall, it is likely that widespread implementation of screening could significantly improve the outcome. Colorectal cancer screening is cost effective, irrespective of the methods used. In addition to currently available methods (fecal occult blood, flexible sigmoidoscopy, colonoscopy, and double contrast barium enema), computed tomographic colonography (virtual colonoscopy) and stool-based molecular screening are under development.

Four classes of chemopreventive compounds have demonstrated efficacy in reducing recurrent colorectal adenomas and/or cancer in randomized, controlled trials. They are selenium, calcium carbonate, hormone replacement therapy, and nonsteroidal anti-inflammatory drugs. The mechanisms of action of nonsteroidal anti-inflammatory drugs include inhibition of the cyclooxygenase system as well as cyclooxygenase-independent effects. Considerable effort is being expended to define chemopreventive activity, optimal dose, administration schedule, and toxicity for the coxibs in adenoma recurrence prevention trials. The threshold for tolerating toxicities is very low in asymptomatic individuals at minimally increased risk for colorectal neoplasia.
Endovascular management of infected carotid artery pseudoaneurysm complicating pharyngolaryngectomy: complete occlusion followed by early recurrence and rebleeding
Authors: Goddard Anthony J.P. , Lenthall Robert K. , Bradley Patrick J.
Published: January 2005

Carotid artery pseudoaneurysms are rare lesions and are increasingly treated by endovascular means. This paper reports the case of a patient presenting with haemorrhage due to a left external carotid artery pseudoaneurysm seven weeks after total laryngectomy for carcinoma. The lesion recurred and rebled after technically successful emergency endovascular occlusion. Subsequent aneurysmectomy and carotid sacrifice resulted in fatal hemispheric infarction. The aneurysm was demonstrated to be infected on white cell study and subsequent histopathology. We propose that infection within the aneurysm itself was a significant factor in its recurrence and rebleeding after endovascular occlusion. If infection is proven or suspected then consideration should be given to early surgical rather than endovascular intervention.
Current practice in the management of frontal sinus fractures
Authors: Swinson B.D. , Jerjes W. , Thompson G.
Published: January 2005

Fractures of the frontal sinus are seen predominantly, although not exclusively, in young men and are usually the result of road traffic accidents or falls.

These types of injury may present to either ENT, Maxillofacial, Plastic or Neurosurgery teams, and understanding of a clear management protocol is desirable for each of the specialties. The optimal management of these injuries is becoming more uniformly adopted although some areas of contention still persist. The aim of treatment has always been directed at creating a ’safe sinus’ that is not complicated by the late sequelae of infection or mucocele formation. The difficulty lies in being able to predict which patients are likely to develop these complications.

The aim of this paper is to evaluate the literature and offer a rationale for the management of these injuries.
What happens to the lateral sinus following thrombosis? A case of failed recanalization
Authors: Agada F.O. , Kortequee S. , Jenkins C.N. , Coatesworth A.P.
Published: January 2005

Recanalization of the lateral sinus thrombosis is an expected outcome in patients who respond to treatment. We report a case of persistent lateral sinus thrombosis many years after treatment for peri-sinus infection.
Pearls and pitfalls in the management of branchial cyst
Authors: Kadhim A.L. , Sheahan P. , Colreavy M.P. , Timon C.V.
Published: January 2005

Introduction: Although branchial cysts may present as asymptomatic swellings, about one-third present acutely due to inflammation. The use of fine-needle aspiration biopsy (FNAB) and computerized tomography (CT) is controversial. The treatment of inflamed cysts is also controversial.

Aims: To compare the findings of FNAB and CT between cases of branchial cysts presenting as an asymptomatic swelling, and those presenting acutely due to inflammation, and to examine the management of infected cysts.

Materials and methods: Retrospective review of the medical records of 39 adult patients with histologically proven branchial cysts treated by the senior author (C.V.T.) between 1994 and 2003.

Results: Twenty-eight patients presented with an asymptomatic swelling. Eleven presented acutely with inflammation. A higher incidence of indeterminate fine needle aspirates and atypical CT features were found in the inflamed group. Initial treatment in the infected group consisted of intravenous antibiotics, followed by aspiration or surgical exploration in non-resolving cases. Interval excision after six weeks was performed in all inflamed cases without complication.

Conclusions: FNAB is recommended in all cystic neck lumps to rule out malignancy, but may be inconclusive, especially in inflamed cysts. Inflamed cysts are best treated with intravenous antibiotics, with or without aspiration or incision and drainage, followed by interval excision.
Hypotension as an isolated factor may not be sufficient to provoke hearing impairment
Authors: Pirodda Antonio , Ferri Gian Gaetano , Montana Teresa , Riggio Raffaella , Innocenti Grazia , Di Nino Gianfranco
Published: January 2005

Objective: We investigated the possible role of hypotension and related autonomic phenomena in the pathogenic mechanism of sudden sensorineural hearing loss.

Methods: Forty-nine patients belonging to the ASA I-II classes of anaesthesiological risk and submitted to a non-otological surgical procedure were examined. Each operation was performed under general anaesthesia by controlled hypotension technique. Hearing function of the patients was evaluated before and after surgery by means of a pure tone audiometry recorded by the same clinician with the same instrument.

Results: No cases of bilateral hearing worsening were recorded after surgery.

Conclusions: An induced and controlled steady hypotension under general anaesthesia did not affect the hearing function of any of the patients. It may be supposed, therefore, that an adverse effect on the cochlear oxygenation is more likely to be caused by the sympathetic changes induced by a consistent decrease of blood pressure rather than to hypotension itself.
Quantification of Antimalarial Bisthiazolium Compounds and Their Neutral Bioprecursors in Plasma by Liquid Chromatography-Electrospray Mass Spectrometry
Authors: Nicolas Olivier , Farenc Christine , Calas Michèle , Vial Henri J , Bressolle Françoise
Published: January 2005

Background: A new class of antimalarial drugs targeting membrane biogenesis during intraerythrocytic Plasmodium falciparum development has been identified. The bisthiazolium salts T3 and T4 have superior in vitro and in vivo parasite-killing properties and need to be monitored.

Methods: We used a liquid chromatography–electrospray ionization mass spectrometry method (positive mode) to quantify two bisthiazolium compounds (T3 and T4) and a related prodrug (TE4c) in human and rat plasma. Verapamil was used as internal standard. Verapamil and the TE4c compound were characterized by protonated molecules at m/z 455.7 and m/z 725.7, respectively. T3 and T4 were detected through two ions [M2+/2] at m/z 227.7 and m/z 241.8 and by their adducts with trifluoroacetic acid [M+TFA]+ at m/z 568 and m/z 596, respectively. The sample clean-up procedure involved solid-phase extraction. HPLC separation was performed on a reversed-phase column, using a water–acetonitrile gradient, with both solvents containing TFA. Stability under various conditions was also investigated.

Results: The peak-area ratios (drugs/internal standard) were linked to concentrations (6.4–1282 μg/L for T3; 6.5–1309.8 μg/L for T4; 20–2000 μg/L for TE4c) according to a quadratic equation. The accuracy ranged from 85% to 113.1%, and the imprecision from 2.2% to 15%. The mean extraction recoveries were 87%, 98%, and 80% for T3, T4, and TE4c, respectively. The lower limit of quantification was 6.4 μg/L for the two bisthiazolium compounds, whereas it was 20 μg/L for TE4c, the related lipophilic prodrug.

Conclusion: This highly specific and sensitive method is suitable for analyzing samples collected during preclinical pharmacokinetic studies in rats and to determine the percentage binding of T3 and T4 to human plasma proteins.
Very early treatment with infliximab in addition to methotrexate in early, poor‐prognosis rheumatoid arthritis reduces magnetic resonance imaging evidence of synovitis and damage, with sustained benefit after infliximab withdrawal: Results from a twelve‐month randomized, double‐blind, placebo‐controlled trial
Authors: Quinn Mark A. , Conaghan Philip G. , O'Connor Philip J. , Karim Zunaid , Greenstein Adam , Brown Andrew , Brown Clare , Fraser Alexander , Jarret Stephen , Emery Paul
Published: January 2005

Objective

Anti–tumor necrosis factor α agents are among the most effective therapies for rheumatoid arthritis (RA). However, their optimal use is yet to be determined. This 12‐month double‐blind study attempted remission induction using standard therapy with or without infliximab in patients with early, poor‐prognosis RA. The primary end point was synovitis (measured by magnetic resonance imaging [MRI]). Clinical observations continued to 24 months.

Methods

All patients had fewer than 12 months of symptoms. Assessments included full metrologic evaluation, laboratory tests, radiographs, functional evaluation using the Health Assessment Questionnaire (HAQ), and quality of life measurement using the RA Quality of Life (RAQoL) questionnaire. MRI was performed at 0, 4, 14, and 54 weeks; MR images were scored blindly. Patients received methotrexate (MTX) and were randomized to receive either infliximab or placebo for 12 months.

Results

Twenty patients were recruited (mean age 52 years, mean symptom duration 6 months, mean C‐reactive protein level 42 mg/liter, and 65% rheumatoid factor positive). At 1 year, all MRI scores were significantly better, with no new erosions in the infliximab plus MTX group; a greater percentage of infliximab plus MTX–treated patients fulfilled the American College of Rheumatology (ACR) 50% and 70% improvement criteria (78% versus 40% in the placebo plus MTX group and 67% versus 30%, respectively) and had a greater functional benefit (P < 0.05 for all comparisons). Importantly, at 1 year after stopping induction therapy, response was sustained in 70% of the patients in the infliximab plus MTX group, with a median Disease Activity Score in 28 joints (DAS28) of 2.05 (remission range). At 2 years, there were no significant between‐group differences in the DAS28, ACR response, or radiographic scores, but differences in the HAQ and RAQoL scores were maintained (P < 0.05).

Conclusion

Remission induction with infliximab plus MTX provided a significant reduction in MRI evidence of synovitis and erosions at 1 year. At 2 years, functional and quality of life benefits were sustained, despite withdrawal of infliximab therapy. These data may have significant implications for the optimal use of expensive biologic therapies.
Use of bone morphogenetic protein 2 and diffusion chambers to engineer cartilage tissue for the repair of defects in articular cartilage
Authors: Nawata Masashi , Wakitani Shigeyuki , Nakaya Hiroyuki , Tanigami Akira , Seki Toyokazu , Nakamura Yukio , Saito Naoto , Sano Kenji , Hidaka Eiko , Takaoka Kunio
Published: January 2005

Objective

To examine the ability of cartilage‐like tissue, generated ectopically in a diffusion chamber using recombinant human bone morphogenetic protein 2 (rHuBMP‐2), to repair cartilage defects in rats.

Methods

Muscle‐derived mesenchymal cells were prepared by dissecting thigh muscles of 19‐day postcoital rat embryos. Cells were propagated in vitro in monolayer culture for 10 days and packed within diffusion chambers (106/chamber) together with type I collagen (CI) and 0, 1, or 10 μg rHuBMP‐2, and implanted into abdominal subfascial pockets of adult rats. Tissue pellets were harvested from the diffusion chambers at 2 days to 6 weeks after implantation, and examined by histology, by reverse transcription–polymerase chain reaction (PCR) for aggrecan, CII, CIX, CX, and CXI, MyoD1, and core binding factor a1/runt‐related gene 2, and by real‐time PCR for CII. Tissue pellets generated in the chamber 5 weeks after implantation were transplanted into a full‐thickness cartilage defect made in the patellar groove of the same strain of adult rat.

Results

In the presence of 10 μg rHuBMP‐2, muscle‐derived mesenchymal cells expressed CII messenger RNA at 4 days after transplantation, and a mature cartilage mass was formed 5 weeks after transplantation in the diffusion chamber. Cartilage was not formed in the presence of 1 μg rHuBMP‐2 or in the absence of rHuBMP‐2. Defects receiving cartilage engineered with 10 μg rHuBMP‐2 were repaired and restored to normal morphologic condition within 6 months after transplantation.

Conclusion

This method of tissue engineering for repair of articular defects may preclude the need to harvest cartilage tissue prior to mosaic arthroplasty or autologous chondrocyte implantation. Further studies in large animals will be necessary to validate this technique for application in clinical practice.
Inhibition of interleukin‐1β–induced cyclooxygenase 2 expression in human synovial fibroblasts by 15‐deoxy‐Δ12,14‐prostaglandin J2 through a histone deacetylase–independent mechanism
Authors: Farrajota Katherine , Cheng Saranette , Martel‐Pelletier Johanne , Afif Hassan , Pelletier Jean‐Pierre , Li Xinfang , Ranger Pierre , Fahmi Hassan
Published: January 2005

Objective

The cyclooxygenase (COX) metabolite, 15‐deoxy‐Δ12,14‐prostaglandin J2 (15d‐PGJ2), has been reported to inhibit the expression of a number of genes involved in the pathogenesis of arthritis. However, its effects on COX‐2 remain controversial. We undertook this study to investigate the effects of 15d‐PGJ2 on interleukin‐1β (IL‐1β)–induced COX‐2 expression in human synovial fibroblasts (HSFs).

Methods

HSFs were cultured with IL‐1β in the absence or presence of 15d‐PGJ2, and the levels of COX‐2 protein and messenger RNA (mRNA) expression were evaluated using Western blotting and real‐time reverse transcriptase–polymerase chain reaction, respectively. COX‐2 promoter activity was analyzed in transient transfection experiments. Chromatin immunoprecipitation assays were performed to evaluate the level of histone acetylation and the recruitment of histone deacetylases (HDACs) 1, 2, and 3 and histone acetylase (HAT) p300 to the COX‐2 promoter.

Results

IL‐1β–induced COX‐2 protein and mRNA expression, as well as COX‐2 promoter activation, were inhibited by 15d‐PGJ2. Troglitazone, a selective peroxisome proliferator–activated receptor γ (PPARγ) ligand, enhanced COX‐2 expression, while GW9662, a specific PPARγ antagonist, relieved the suppressive effect of 15d‐PGJ2. IL‐1β–induced histone H3 acetylation was selectively blocked by 15d‐PGJ2. The reduction of histone H3 acetylation did not correlate with the recruitment of HDACs to the COX‐2 promoter. Also, treatment with the specific HDAC inhibitor, trichostatin A, did not relieve the suppressive effect of 15d‐PGJ2, indicating that HDACs are not involved in the inhibitory effect of 15d‐PGJ2. Furthermore, 15d‐PGJ2 blocked IL‐1β–induced recruitment of p300 to the COX‐2 promoter, which may be the mechanism for decreased histone H3 acetylation and COX‐2 expression. In accordance with this, overexpression of p300, but not of a mutant p300 lacking HAT activity, relieved the inhibitory effect of 15d‐PGJ2 on COX‐2 promoter activation.

Conclusion

These data suggest that 15d‐PGJ2 can inhibit IL‐1β–induced COX‐2 expression by an HDAC‐independent mechanism, probably by interfering with HAT p300.
Serum hyaluronan levels and radiographic knee and hip osteoarthritis in African Americans and Caucasians in the Johnston County Osteoarthritis Project
Authors: Elliott Alan L. , Kraus Virginia B. , Luta Gheorghe , Stabler Thomas , Renner Jordan B. , Woodard Janice , Dragomir Anca D. , Helmick Charles G. , Hochberg Marc C. , Jordan Joanne M.
Published: January 2005

Objective

Serum hyaluronan (HA) has been proposed as a potential biomarker of osteoarthritis (OA). We examined associations between serum HA and radiographic OA in an ethnically diverse, population‐based sample.

Methods

Participants were selected from the Johnston County Osteoarthritis Project, using stratified simple random sampling to achieve balance according to radiographic knee OA status, ethnic group, sex, and age group. Serum HA was measured by enzyme‐linked immunosorbent assay. Radiographic OA variables included knee OA, knee OA laterality, knee OA severity, concomitant knee and hip OA, and total number of OA‐affected knee and hip joints. Analysis of covariance was used to assess differences in mean serum levels of natural log–transformed HA (ln serum HA) between groups, adjusting for ethnicity, sex, age, body mass index (BMI), and self‐reported comorbidities.

Results

Levels of ln serum HA were positively associated with all definitions of radiographic OA (P < 0.0001). Levels of ln serum HA were higher in Caucasians (P = 0.0094) and in men (P = 0.0038) and were moderately correlated with age (r = 0.35, P < 0.0001). The associations with radiographic OA, ethnicity, sex, and age remained statistically significant after adjustment (P < 0.0045). There were no interactions between ethnicity and the other covariates.

Conclusion

These cross‐sectional data support a role for serum HA as a biomarker of radiographic OA. The variations in levels of serum HA attributable to ethnicity, sex, and age were not explained by radiographic OA, BMI, or comorbidities. The lack of strong confounding between serum HA and comorbidities further supports a role for serum HA as a potential biomarker.
Interleukin‐6 receptor shedding is enhanced by interleukin‐1β and tumor necrosis factor α and is partially mediated by tumor necrosis factor α–converting enzyme in osteoblast‐like cells
Authors: Franchimont Nathalie , Lambert Cécile , Huynen Pascale , Ribbens Clio , Relic Biserka , Chariot Alain , Bours Vincent , Piette Jacques , Merville Marie‐Paule , Malaise Michel
Published: January 2005

Objective

Interleukin‐6 (IL‐6) and soluble IL‐6 receptor (sIL‐6R) activation of gp130 represents an alternative pathway for osteoclast development in inflammatory conditions. The goal of the present study was to investigate changes in sIL‐6R levels in response to the inflammatory cytokines IL‐1β and tumor necrosis factor α (TNFα) and to determine the role of TNFα‐converting enzyme (TACE) in this process.

Methods

Levels of sIL‐6R in the culture media of MG63 and SAOS‐2 osteoblast‐like cell lines after exposure to various agents were determined by immunoassay. TACE protein levels were measured by Western immunoblotting. Cells were transfected with small interfering RNA (siRNA) or with an expression plasmid for IL‐6R and TACE to determine the potential involvement of TACE in IL‐6R shedding.

Results

IL‐1β and TNFα increased the levels of sIL‐6R in the culture media of MG63 osteoblast‐like cells. This effect was not influenced by cycloheximide or 5,6‐dichlorobenzimidazole riboside but was markedly inhibited by the calcium chelator EGTA and by the TACE and matrix metalloproteinase inhibitor hydroxamate (Ru36156). IL‐1β and TNFα had no influence on the alternatively spliced form of IL‐6R RNA. Levels of sIL‐6R were reduced when MG63 cells were transiently transfected with TACE siRNA. Transfection of SAOS‐2 cells with expression plasmids for IL‐6R and TACE produced a dose‐dependent increase in sIL‐6R levels.

Conclusion

IL‐1β‐ and TNFα‐mediated induction of IL‐6R shedding in osteoblast‐like cells is at least partly dependent on TACE activation.
Role of interleukin‐8 in PiT‐1 expression and CXCR1‐mediated inorganic phosphate uptake in chondrocytes
Authors: Cecil Denise L. , Rose David M. , Terkeltaub Robert , Liu‐Bryan Ru
Published: January 2005

Objective

The proinflammatory chemokine interleukin‐8 (IL‐8) induces chondrocyte hypertrophy. Moreover, chondrocyte hypertrophy develops in situ in osteoarthritic (OA) articular cartilage and promotes dysregulated matrix repair and calcification. Growth plate chondrocyte hypertrophy is associated with expression of the type III sodium‐dependent inorganic phosphate (Pi) cotransporter phosphate transporter/retrovirus receptor 1 (PiT‐1). This study was undertaken to test the hypothesis that IL‐8 promotes chondrocyte hypertrophy by modulating chondrocyte PiT‐1 expression and sodium‐dependent Pi uptake, and to assess differential roles in this activity.

Methods

The selective IL‐8 receptor CXCR1 and the promiscuous chemokine receptor CXCR2 were used. Human knee OA cartilage, cultured normal bovine knee chondrocytes, and immortalized human articular chondrocytic CH‐8 cells were transfected with CXCR1/CXCR2 chimeric receptors in which the 40–amino acid C‐terminal cytosolic tail domains were swapped and site mutants of a CXCR1‐specific region were generated.

Results

Up‐regulated PiT‐1 expression was detected in OA cartilage. IL‐8, but not IL‐1 or the CXCR2 ligand growth‐related oncogene α, induced PiT‐1 expression and increased sodium‐dependent Pi uptake by >40% in chondrocytes. The sodium/phosphate cotransport inhibitor phosphonoformic acid blocked IL‐8–induced chondrocyte hypertrophic differentiation. Signaling mediated by kinase Pyk‐2 was essential for IL‐8 induction of PitT‐1 expression and Pi uptake. Signaling through the TSYT346–349 region of the CXCR1 cytosolic tail, a region divergent from the CXCR2 cytosolic tail, was essential for IL‐8 to induce Pi uptake.

Conclusion

Our results link low‐grade IL‐8–mediated cartilaginous inflammation in OA to altered chondrocyte differentiation and disease progression through PiT‐1 expression and sodium‐dependent Pi uptake mediated by CXCR1 signaling.
Mature dendritic cells readily break tolerance in normal mice but do not lead to disease expression
Authors: Georgiev Maria , Agle Lucila M. A. , Chu Jia Li , Elkon Keith B. , Ashany Dalit
Published: January 2005

Objective

To examine the ability of mature dendritic cells (DCs) or macrophages intentionally exposed to lipopolysaccharide or apoptotic or necrotic cells to break tolerance in normal mice.

Methods

We adoptively transferred into C57BL/6 mice a variety of syngeneic myeloid antigen‐presenting cell populations exposed to different activation stimuli as well as to meals of necrotic and apoptotic cells. We studied expression of autoimmunity in the immunized mice by serologic evaluation of autoantibody production, subclass analysis of Ig production, clinical evidence of kidney disease, glomerular immune complex deposition, and renal pathology.

Results

Injection of mice with DCs incubated with apoptotic or necrotic cells, as well as, surprisingly, with DCs cultured in media alone, induced high levels of IgG autoantibodies, including anti–double‐stranded DNA (anti‐dsDNA) antibodies. In striking contrast, transfer of equivalent‐treated macrophages failed to generate IgG autoantibodies. IgG was deposited in the kidneys of mice vaccinated with DCs, but despite high levels of anti‐dsDNA antibodies, these mice did not develop overt nephritis. Serologic evaluation of the antibody response revealed that the mice primarily developed elevated levels of IgG1 antibodies, including high levels of IgG1 anti‐dsDNA.

Conclusion

The data suggest that mature myeloid DCs are able to break tolerance and induce lupus autoantibodies in normal hosts, but that other susceptibility factors must be in place to induce long‐lasting autoimmunity and clinical expression of disease.
Synovial fluid levels and serum pharmacokinetics in a large animal model following treatment with oral glucosamine at clinically relevant doses
Authors: Laverty Sheila , Sandy John D. , Celeste Christophe , Vachon Pascal , Marier Jean‐Francois , Plaas Anna H. K.
Published: January 2005

Objective

To examine the concentration of glucosamine in the synovial fluid and its pharmacokinetics in serum in a large animal model following dosing with glucosamine HCl at clinically relevant levels.

Methods

Eight adult female horses were studied. After an overnight fast, glucosamine HCl (20 mg/kg of body weight) was administered by either nasogastric (NG) intubation or intravenous (IV) injection. Blood samples were collected before dosing and at 5, 15, 30, 60, 120, 180, 240, 360, 480, and 720 minutes after dosing. Synovial fluid samples were collected from the radiocarpal joints 48 hours before dosing and at 1 and 12 hours after dosing. Glucosamine was assayed by fluorophore‐assisted carbohydrate electrophoresis.

Results

The maximum concentration of glucosamine in serum reached ∼300 μM(∼50 μg/ml) following IV dosing and ∼6 μM(∼1 μg/ml) following NG dosing. Synovial fluid concentrations reached 9–15 μMwith IV dosing and 0.3–0.7 μMwith NG dosing, and remained elevated (range 0.1–0.7 μM) in most animals even at 12 hours after dosing. Following NG dosing, the median serum maximal concentration of 6.1 μM(range 4.38–7.58) was attained between 30 minutes and 4 hours postdose. The mean apparent volume of distribution was 15.4 liters/kg, the mean bioavailability was 5.9%, and the mean elimination half‐life was 2.82 hours.

Conclusion

Clinically relevant dosing of glucosamine HCl in this large monogastric animal model results in serum and synovial fluid concentrations that are at least 500‐fold lower than those reported to modify chondrocyte anabolic and catabolic activities in tissue and cell culture experiments. We conclude that the apparent therapeutic benefit of dietary glucosamine on pain and joint space width in humans and animals may be secondary to its effects on nonarticular tissues, such as the intestinal lining, liver, or kidney, since these may be exposed to much high levels of glucosamine following ingestion.
Role of interleukin‐1 and tumor necrosis factor α in matrix degradation of human osteoarthritic cartilage
Authors: Kobayashi Masahiko , Squires Ginette R. , Mousa Aisha , Tanzer Michael , Zukor David J. , Antoniou John , Feige Ulrich , Poole A. Robin
Published: January 2005

Objective

To determine whether interleukin‐1 (IL‐1) or tumor necrosis factor α (TNFα), or both, plays a role in the excessive degradation that is observed in cultured osteoarthritic (OA) articular cartilage.

Methods

Antagonists of IL‐1 and TNFα, namely, IL‐1 receptor antagonist and the PEGylated soluble TNFα receptor I, respectively, were added at different concentrations to explant cultures of nonarthritic (5 obtained at autopsy) and OA (15 obtained at arthroplasty) articular cartilage. The cleavage of type II collagen (CII) by collagenase was measured by an immunoassay in cartilage and culture media. Proteoglycan (mainly aggrecan) content and degradation were measured by a colorimetric assay for glycosaminoglycan (GAG) content in cartilage and culture media. Reverse transcriptase–polymerase chain reaction was used to analyze gene expression of matrix metalloproteases (MMPs) 1, 3, and 13, CII, aggrecan, IL‐1, and TNFα.

Results

Antagonists of IL‐1 and TNFα inhibited the increase in CII cleavage by collagenase as well as the increase in GAG release observed in OA cartilage compared with normal cartilage. Inhibition was significant in tissue from some patients but not from others, although significant inhibition was observed when all the results were analyzed together. An increase in the GAG content in cartilage was seen in 4 of 15 cases. However, this increase was not significant when all the data were combined. Preliminary results indicated no effect of these antagonists on nonarthritic cartilage from 3 different donors. Independent analyses of gene expression in cultured cartilage from 9 other OA patients revealed that IL‐1 or TNFα blockade, either alone and/or in combination, frequently down‐regulated MMP‐1, MMP‐3, and MMP‐13 expression. Expression of IL‐1 and TNFα was inhibited by either antagonist or by the combination in essentially half the cases. The combined blockade up‐regulated aggrecan and CII gene expression in approximately half the cases.

Conclusion

These results suggest that the autocrine/paracrine activities of TNFα and IL‐1 in articular cartilage may play important roles in cartilage matrix degradation in OA patients but not in all patients. Inhibition of either or both of these cytokines may offer a useful therapeutic approach to the management of OA by reducing gene expression of MMPs involved in cartilage matrix degradation and favoring its repair.
A locus on chromosome 9p predisposes to a specific disease manifestation, acute anterior uveitis, in ankylosing spondylitis, a genetically complex, multisystem, inflammatory disease
Authors: Martin Tammy M. , Zhang Ge , Luo Jingchun , Jin Li , Doyle Trudy M. , Rajska Barbara M. , Coffman Jessica E. , Smith Justine R. , Becker Matthias D. , Mackensen Friederike , Khan Muhammad A. , Levinson Ralph D. , Schumacher H. Ralph , Wade N. Kevin , Rosenbaum James T. , Reveille John D.
Published: January 2005

Objective

Uveitis or intraocular inflammation is a major cause of visual loss. Acute anterior uveitis (AAU) affects ∼40% of patients with ankylosing spondylitis (AS) but also affects patients with no evidence of spondylarthritis. We sought to determine whether a unique genetic region could be implicated in a specific manifestation—AAU—of a multisystem, inflammatory, genetically complex disease, AS.

Methods

Individuals from families multiplex for AAU were genotyped at 400 markers representing the ABI PRISM linkage map MD‐10, and at the HLA–B, DRB1, DQA1, DQB1, and DPB1 alleles. Among the family members with AAU, 76 affected sibpairs were analyzed (6 without concomitant AS, 12 discordant for AS, and 58 concordant for AS). Two‐point and multipoint nonparametric linkage analyses were performed, and 1‐parameter allele‐sharing model logarithm of odds (LOD) scores were determined.

Results

As previously reported for AS, linkage at the major histocompatibility complex region (chromosome 6p21) was evident, exhibiting the highest multipoint LOD score (4.96 at marker HLA–B). Strong linkage was seen at a region on chromosome 9p21–9p24, with a LOD score of 3.72 at marker D9S157. When compared with a companion cohort of AS families, the linkage at this region was found in association with AAU but not with AS. A third region on chromosome 1q23–1q31 was observed to have suggestive linkage (LOD 2.05 at marker D1S238), which overlaps with a region associated with AS.

Conclusion

This is the first study in which a genetic region for AAU has been identified by genome‐wide scan. Even though AS was highly prevalent in this cohort of families, a locus at chromosome 9p21–9p24 was identified that uniquely associates with AAU. Identifying the genetic perturbation at this region may advance our understanding of the mechanisms involved in tissue‐specific pathology of complex inflammatory diseases.
Lipid peroxidation is enhanced in patients with systemic lupus erythematosus and is associated with arterial and renal disease manifestations
Authors: Frostegård Johan , Svenungsson Elisabet , Wu Ruihua , Gunnarsson Iva , Lundberg Ingrid E. , Klareskog Lars , Hörkkö Sohvi , Witztum Joseph L.
Published: January 2005

Objective

Cardiovascular disease with premature atherosclerosis is common in patients with systemic lupus erythematosus (SLE). We previously identified elevated levels of oxidized low‐density lipoprotein (OxLDL) together with elevated levels of autoantibodies related to OxLDL as risk factors for cardiovascular disease in female patients with SLE. Autoantibodies to OxLDL are common in SLE and cross‐react with anticardiolipin antibodies (aCL). We therefore hypothesized that lipid peroxidation is enhanced in patients with SLE in general.

Methods

One hundred forty‐seven female patients with SLE and 60 age‐ and sex‐matched controls were compared. A monoclonal antibody to oxidized phospholipids, EO6, was used to determine oxidation epitopes on LDL. Anti‐OxLDL and autoantibodies to malondialdehyde (MDA)–modified LDL, cardiolipin, and oxidized aCL were determined by chemiluminescence technique.

Results

As determined by binding of EO6, patients with SLE had a higher level of oxidized phospholipids on LDL (P = 0.005) compared with controls. The level of OxLDL (e.g., oxidized phospholipid/apolipoprotein B) was associated with arterial disease (P = 0.006) and renal manifestations (P = 0.04). As reported previously, levels of aCL, autoantibodies to OxLDL, and autoantibodies to MDA‐modified LDL were enhanced and were closely correlated in SLE. Anticardiolipin antibodies from these SLE patients recognized mainly oxidized forms of cardiolipin, indicating that antigenic epitopes on cardiolipin are related to lipid peroxidation in patients with SLE.

Conclusion

In general, patients with SLE (particularly those with cardiovascular disease) had more oxidized epitopes on LDL compared with controls. Furthermore, aCL in these patients recognized epitopes generated during lipid peroxidation. Thus, “neo” self antigens on lipoproteins, generated during oxidation, are present in SLE and may be of importance for the development of premature cardiovascular disease and possibly also for other autoimmune phenomena observed in SLE.
Cartilage glycosaminoglycan loss in the acute phase after an anterior cruciate ligament injury: Delayed gadolinium‐enhanced magnetic resonance imaging of cartilage and synovial fluid analysis
Authors: Tiderius Carl Johan , Olsson Lars Eric , Nyquist Fredrik , Dahlberg Leif
Published: January 2005

Objective

To examine the glycosaminoglycan (GAG) content in cartilage and that in synovial fluid and determine whether they are associated, in patients with an acute anterior cruciate ligament (ACL) injury.

Methods

Twenty‐four patients (14 of whom were male) with a mean age of 27 years (range 17–40 years) were assessed with delayed gadolinium‐enhanced magnetic resonance imaging (MRI) of cartilage an average of 3 weeks after an ACL rupture and compared with 24 healthy volunteers. Two hours after an intravenous injection of Gd‐DTPA2− (0.3 mmoles/kg body weight), quantitative measurements of the T1 relaxation time (T1Gd [T1 relaxation time in the presence of Gd‐DTPA]) were made in lateral and medial femoral weight‐bearing cartilage. In the patients, synovial fluid was aspirated immediately before the MRI, and GAG was analyzed using dye precipitation with Alcian blue.

Results

Fifteen of the 24 patients had an isolated bone bruise in the lateral femoral condyle, where the cartilage T1Gd was shorter than that in the controls (mean ± SD 385 ± 83 msec and 445 ± 41 msec, respectively; P = 0.004), consistent with decreased GAG content. However, the T1Gd was also decreased in the medial femoral cartilage, where bone bruises were rare (376 ± 76 msec in patients versus 428 ± 38 msec in controls; P = 0.006). The mean ± SD synovial fluid GAG concentration in patients was 157 ± 86 μg/ml and showed a positive correlation with the T1Gd (r = 0.49, P = 0.02).

Conclusion

This study indicates that an ACL injury causes posttraumatic edema of the lateral femoral cartilage but initializes a generalized biochemical change within the knee that leads to GAG loss from both lateral and medial femoral cartilage. In cartilage with a high GAG content (long T1Gd), more GAG is released into the synovial fluid, suggesting that cartilage quality is a factor to consider when interpreting cartilage biomarkers of metabolism.
Effect of inhibition of matrix metalloproteinases on cartilage loss in vitro and in a guinea pig model of osteoarthritis
Authors: Sabatini Massimo , Lesur Christophe , Thomas Marie , Chomel Agnès , Anract Philippe , de Nanteuil Guillaume , Pastoureau Philippe
Published: January 2005

Objective

To study the effects of a matrix metalloproteinase (MMP) inhibitor (S‐34219) on osteoarthritis (OA) cartilage cultures and in the meniscectomized guinea pig model of OA.

Methods

The inhibitory activity of S‐34219 on MMPs and aggrecanase was studied by fluorimetry and immunoassay, respectively. The effects of S‐34219 on proteoglycan and collagen degradation were studied in cultures of rabbit and human cartilage. Medial meniscectomy was performed on 29 Hartley male guinea pigs, and these animals were randomly allocated to 1 of 3 groups: a control meniscectomized group (MNXc) receiving the vehicle, or a meniscectomized group receiving either 10 mg/kg or 20 mg/kg S‐34219, administered twice per day by oral gavage for 12 weeks from day 1 after surgery. An additional group comprised sham‐operated animals. Tibial cartilage from the operated left knee was processed for histologic assessment of OA lesions.

Results

The 50% inhibitory concentration (IC50) of S‐34219 on MMPs 1, 2, 3, 8, 9, and 13 was 55, 0.1, 0.5, 0.1, 0.03, and 0.2 nM, respectively; the IC50 on aggrecanase 1 was 190 nM. In cultured rabbit cartilage, 100 nM S‐34219 strongly inhibited MMP‐dependent degradation of collagen and proteoglycans. A concentration 100 times higher was needed to inhibit aggrecanase‐dependent degradation. In cultures of human OA cartilage, 100 nM S‐34219 inhibited spontaneous type II collagen degradation by 66% and proteoglycan degradation by only 22%. For in vivo studies, treated groups were compared with the MNXc group and the results, expressed as the percentage variation versus MNXc, were as follows: in the 10 and 20 mg/kg groups, a significant decrease (P < 0.05) in global histologic score (−12% and −14%, respectively) was observed, and this was associated with a significant increase (P < 0.05) in cartilage thickness (+19% and +18%, respectively). Neither dose level changed the proteoglycan content.

Conclusion

In both treated animal groups, S‐34219 significantly prevented the loss of cartilage thickness, probably by inhibiting collagen breakdown that normally leads to the erosion of fibrillated superficial areas. The absence of a protective effect on glycosaminoglycan loss, both in vitro and in vivo, suggests that aggrecanases may have an important role in cartilage loss. This study reinforces the relevance of these models for testing chondroprotective drugs, and the potential role of dual inhibitors of collagenase and aggrecanase as disease‐modifying drugs in the management of OA.