A preliminary investigation of the contribution of different tenderness factors to beef loin, tri-tip and heel tenderness

The objective of this study was to identify the relative contribution of tenderness factors for three beef muscles with similar tenderness ratings. Longissimus lumborum (LL), tensor fascia latae (TF) and gastrocnemius (GC) were collected from 10 USDA low Choice beef carcasses and assigned to a 5 or 21 days aging period (n = 60). Sarcomere length, troponin-T degradation, collagen content, mature collagen crosslink density, intramuscular lipid content and trained panel analysis were measured. Correlation and multivariate regression analysis indicated each muscle has a specific tenderness factor that contributed to the overall tenderness evaluated by trained panelists. The equations indicated LL tenderness was driven by lipid content (P < .05); TF tenderness was driven by collagen content (P < .05). GC tenderness was driven by proteolysis (P < .01), and only collagen content can be casually used as an overall tenderness predictor for all three cuts.

Decreased photosynthetic rate under high temperature in wheat is due to lipid desaturation, oxidation, acylation, and damage of organelles

BACKGROUND

High temperature is a major abiotic stress that limits wheat (Triticum aestivum L.) productivity. Variation in levels of a wide range of lipids, including stress-related molecular species, oxidative damage, cellular organization and ultrastructural changes were analyzed to provide an integrated view of the factors that underlie decreased photosynthetic rate under high temperature stress. Wheat plants of cultivar Chinese Spring were grown at optimum temperatures (25/15 °C, maximum/minimum) until the onset of the booting stage. Thereafter, plants were exposed to high temperature (35/25 °C) for 16 d.

RESULTS

Compared with optimum temperature, a lower photosynthetic rate was observed at high temperature which is an interplay between thylakoid membrane damage, thylakoid membrane lipid composition, oxidative damage of cell organelle, and stomatal and non-stomatal limitations. Triacylglycerol levels were higher under high temperature stress. Polar lipid fatty acyl unsaturation was lower at high temperature, while triacylglycerol unsaturation was the same at high temperature and optimum temperature. The changes in lipid species indicates increases in activities of desaturating, oxidizing, glycosylating and acylating enzymes under high temperature stress. Cumulative effect of high temperature stress led to generation of reactive oxygen species, cell organelle and membrane damage, and reduced antioxidant enzyme activity, and imbalance between reactive oxygen species and antioxidant defense system.

CONCLUSIONS

Taken together with recent findings demonstrating that reactive oxygen species are formed from and are removed by thylakoid lipids, the data suggest that reactive oxygen species production, reactive oxygen species removal, and changes in lipid metabolism contribute to decreased photosynthetic rate under high temperature stress.

The JAK inhibitor tofacitinib suppresses synovial JAK1-STAT signalling in rheumatoid arthritis

Objective

Tofacitinib is an oral Janus kinase (JAK) inhibitor for the treatment of rheumatoid arthritis (RA). The pathways affected by tofacitinib and the effects on gene expression in situ are unknown. Therefore, tofacitinib effects on synovial pathobiology were investigated.

Methods

A randomised, double-blind, phase II serial synovial biopsy study (A3921073; NCT00976599) in patients with RA with an inadequate methotrexate response. Patients on background methotrexate received tofacitinib 10 mg twice daily or placebo for 28 days. Synovial biopsies were performed on Days -7 and 28 and analysed by immunoassay or quantitative PCR. Clinical response was determined by disease activity score and European League Against Rheumatism (EULAR) response on Day 28 in A3921073, and at Month 3 in a long-term extension study (A3921024; NCT00413699).

Results

Tofacitinib exposure led to EULAR moderate to good responses (11/14 patients), while placebo was ineffective (1/14 patients) on Day 28. Tofacitinib treatment significantly reduced synovial mRNA expression of matrix metalloproteinase (MMP)-1 and MMP-3 (p<0.05) and chemokines CCL2, CXCL10 and CXCL13 (p<0.05). No overall changes were observed in synovial inflammation score or the presence of T cells, B cells or macrophages. Changes in synovial phosphorylation of signal transducer and activator of transcription 1 (STAT1) and STAT3 strongly correlated with 4-month clinical responses (p<0.002). Tofacitinib significantly decreased plasma CXCL10 (p<0.005) at Day 28 compared with placebo.

Conclusions

Tofacitinib reduces metalloproteinase and interferon-regulated gene expression in rheumatoid synovium, and clinical improvement correlates with reductions in STAT1 and STAT3 phosphorylation. JAK1-mediated interferon and interleukin-6 signalling likely play a key role in the synovial response.

Trial registration number

NCT00976599.

Acid-sensing ion channel 3 expressed in type B synoviocytes and chondrocytes modulates hyaluronan expression and release

BACKGROUND

Rheumatoid arthritis is an inflammatory disease marked by intra-articular decreases in pH, aberrant hyaluronan regulation and destruction of bone and cartilage. Acid-sensing ion channels (ASICs) are the primary acid sensors in the nervous system, particularly in sensory neurons and are important in nociception. ASIC3 was recently discovered in synoviocytes, non-neuronal joint cells critical to the inflammatory process.

OBJECTIVES

To investigate the role of ASIC3 in joint tissue, specifically the relationship between ASIC3 and hyaluronan and the response to decreased pH.

METHODS

Histochemical methods were used to compare morphology, hyaluronan expression and ASIC3 expression in ASIC3+/+ and ASIC3-/- mouse knee joints. Isolated fibroblast-like synoviocytes (FLS) were used to examine hyaluronan release and intracellular calcium in response to decreases in pH.

RESULTS

In tissue sections from ASIC3+/+ mice, ASIC3 localised to articular cartilage, growth plate, meniscus and type B synoviocytes. In cultured FLS, ASIC3 mRNA and protein was also expressed. In FLS cultures, pH 5.5 increased hyaluronan release in ASIC3+/+ FLS, but not ASIC3-/- FLS. In FLS from ASIC3+/+ mice, approximately 50% of cells (25/53) increased intracellular calcium while only 24% (14/59) showed an increase in ASIC3-/- FLS. Of the cells that responded to pH 5.5, there was significantly less intracellular calcium increases in ASIC3-/- FLS compared to ASIC3+/+ FLS.

CONCLUSION

ASIC3 may serve as a pH sensor in synoviocytes and be important for modulation of expression of hyaluronan within joint tissue.

Mode of action of abatacept in rheumatoid arthritis patients having failed tumour necrosis factor blockade: a histological, gene expression and dynamic magnetic resonance imaging pilot study

Objectives:

Abatacept is the only agent currently approved to treat rheumatoid arthritis (RA) that targets the co-stimulatory signal required for full T-cell activation. No studies have been conducted on its effect on the synovium, the primary site of pathology. The aim of this study was to determine the synovial effect of abatacept in patients with RA and an inadequate response to tumour necrosis factor alpha (TNFα) blocking therapy.

Methods:

This first mechanistic study incorporated both dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) and arthroscopy-acquired synovial biopsies before and 16 weeks after therapy, providing tissue for immunohistochemistry and quantitative real-time PCR analyses.

Results:

Sixteen patients (13 women) were studied; all had previously failed TNFα-blocking therapy. Fifteen patients completed the study. Synovial biopsies showed a small reduction in cellular content, which was significant only for B cells. The quantitative PCR showed a reduction in expression for most inflammatory genes (Wald statistic of p<0.01 indicating a significant treatment effect), with particular reduction in IFNγ of −52% (95% CI −73 to −15, p<0.05); this correlated well with MRI improvements. In addition, favourable changes in the osteoprotegerin and receptor activator of nuclear factor kappa B levels were noted. DCE–MRI showed a reduction of 15–40% in MRI parameters.

Conclusion:

These results indicate that abatacept reduces the inflammatory status of the synovium without disrupting cellular homeostasis. The reductions in gene expression influence bone positively and suggest a basis for the recently demonstrated radiological improvements that have been seen with abatacept treatment in patients with RA.

Synergistic benefit in inflammatory arthritis by targeting I kappaB kinase epsilon and interferon beta

OBJECTIVES

The I kappaB kinase (IKK)-related kinase IKKepsilon regulates type I interferon expression and responses as well as proinflammatory mediator production. We examined the role of IKKepsilon in arthritis and its ability to enhance the therapeutic response to systemic interferon (IFN) beta therapy in passive murine K/BxN arthritis.

METHODS

IKKepsilon(-/-), IFN alpha(approximately)beta R(-/-) and wild type mice were given K/BxN serum and treated with polyinosinic polycytidylic acid (poly(I:C)), IFN beta, or normal saline. Clinical response and histological scores were assessed. Gene expression in the paws was measured by quantitative PCR. Serum interleukin 1a receptor agonist (IL1Ra) and IL10 were measured by ELISA and multiplex bead array.

RESULTS

Arthritis was almost completely blocked in wild type mice if arthritogenic K/BxN serum and the Toll-like receptor (TLR)3 ligand, poly(I:C), were coadministered at the onset of the model, but not in established disease. Mice deficient in IFN alpha(approximately)beta R had an accelerated course of arthritis, and did not respond to poly(I:C). IKKepsilon null mice had a modest decrease in clinical arthritis compared with heterozygous mice. Low doses of IFN beta that were ineffective in wild type mice significantly decreased clinical arthritis in IKKepsilon null mice. Articular chemokine gene expression was reduced in the IKKepsilon(-/-) mice with arthritis and secreted IL1Ra (sIL1Ra) mRNA was significantly increased. Serum levels of IL1Ra were increased in low dose IFN beta-treated IKKepsilon(-/-) mice.

CONCLUSIONS

Subtherapeutic doses of IFN beta enhance the anti-inflammatory effects of IKKepsilon deficiency, possibly by increasing production of IL1Ra and unmasking the antichemokine effects. Combination therapy with low dose IFN beta and an IKKepsilon inhibitor might improve efficacy of either agent alone and offers a novel approach to RA.

Assessment of rituximab's immunomodulatory synovial effects (ARISE trial). 1: clinical and synovial biomarker results

OBJECTIVE

Treatment with the anti-CD20 monoclonal antibody (mAb) rituximab is effective in rheumatoid arthritis (RA). Marked depletion of circulating B cells, seen in almost all patients, does not correlate with efficacy. The potential synovial immunomodulatory effects of rituximab have not been fully defined.

METHODS

The ARISE trial is an open label, serial synovial biopsy (pre-treatment and 8 weeks) study of rituximab, given 1 g intravenously on days 0 and 14 without peri-infusional steroids, in active RA patients on concomitant methotrexate (MTX). Synovial tissue was analysed by immunohistochemistry with digital image analysis and gene expression by real-time PCR.

RESULTS

The mean (SD) baseline DAS28 score was 6.5 (0.4), and mean MTX dose 17.3 mg/week. Of 13 patients, 11 had failed prior tumour necrosis factor (TNF) inhibitor therapy. With treatment, all patients experienced near complete depletion of circulating B cell numbers. During the 6 months after treatment, 7/13 patients achieved an American College of Rheumatology (ACR) 20% improvement (ACR20) response, 3/13 an ACR50 response and 2/13 an ACR70 response. There was a significant decrease in synovial B cells after treatment, but only a small trend towards greater reduction among clinical responders. Among the three patients with ACR50 responses there was a significant decrease in synovial immunoglobulin synthesis.

CONCLUSIONS

These data suggest that unlike those in circulation, synovial B cells are decreased but are not eliminated by rituximab therapy. Patients with higher levels of response may have more consistent depletion of synovial B cells, and may also have an alteration in synovial B cell function, as indicated by decreases in synovial immunoglobulin synthesis. Thus, effects on synovial B cells may be necessary but not sufficient for inducing clinical efficacy. Other effects, such as on primary lymph organ B cell antigen presentation or cytokine production, may be operative.

DNA mismatch repair enzyme expression in synovial tissue

BACKGROUND

Oxidative stress in RA synovial tissue can cause DNA damage and suppress the DNA mismatch repair (MMR) system in cultured synoviocytes. This mechanism includes two enzyme complexes, hMutSalpha (hMSH2/hMSH6) and hMutSbeta (hMSH2/hMSH3).

OBJECTIVE

To examine the expression and distribution of MMR enzymes in synovial tissues from patients with arthritis and from normal subjects.

METHODS

Synovial tissues from patients with RA, osteoarthritis (OA), or normal subjects were analysed by immunohistochemistry using monoclonal antibodies to hMSH2, hMSH3, and hMSH6. MMR protein expression was evaluated by computer assisted digital image analysis.

RESULTS

hMSH2, hMSH3, and hMSH6 were found in most synovial tissues evaluated, with greater levels in the intimal lining than sublining regions. In RA and OA, sublining perivascular staining for hMSH6 and hMSH3 was also prominent. Significantly higher sublining expression of hMSH2, hMSH3, and hMSH6 was seen in RA and OA than in normal synovium. Double label immunohistochemistry demonstrated that the main cells expressing MMR enzymes were CD68(+) and CD68(-) cells in the intimal lining.

CONCLUSIONS

DNA MMR enzyme expression is greatest in the synovial intimal lining layer, where maximal oxidative stress in RA occurs. Although MMR enzyme expression is greater in RA than in normal tissue, this compensatory response cannot overcome the genotoxic environment, and DNA damage accumulates.

Expression and regulation of cryopyrin and related proteins in rheumatoid arthritis synovium

BACKGROUND

Rheumatoid arthritis (RA) synovium is characterised by enhanced NF-kappaB activity and proinflammatory cytokines. Cryopyrin (CIAS-1, NALP-3, PYPAF-1) has been shown to regulate NF-kappaB and caspase-1 activation.

OBJECTIVE

To study the expression of cryopyrin, its effector molecule ASC, and its putative antagonist pyrin in RA and osteoarthritis (OA) synovium, and the main two cellular constituents of synovial lining, cultured fibroblast-like synoviocytes (FLS) and macrophages.

METHODS

FLS and macrophages were cultured in the presence of inflammatory mediators. Real time polymerase chain reaction was used to quantify message levels in synovial biopsy specimens and cells. In situ hybridisation was employed to localise expression of cryopyrin mRNA.

RESULTS

Cryopyrin mRNA was raised in RA synovium and detected in both lining and sublining regions. FLS from RA and OA tissue expressed low baseline levels of cryopyrin transcripts that were induced by tumour necrosis factor alpha (TNFalpha). In contrast, macrophages differentiated in vitro expressed relatively high cryopyrin levels, which were further induced by TNFalpha, but not by interleukin 1beta. ASC mRNA levels were comparable in RA and OA tissue, FLS, and macrophages, and were depressed by TNFalpha in macrophages. Pyrin expression was higher in RA synovium than in OA tissue, and virtually undetectable in FLS but high in macrophages where it was unchanged by TNFalpha treatment.

CONCLUSION

These results suggest that enhanced cryopyrin levels in RA synovium are due to a greater numbers of tissue macrophages, and demonstrate transcriptional regulation of cryopyrin in a chronic inflammatory disease.

Glutathione peroxidase-1 deficiency leads to increased nuclear light scattering, membrane damage, and cataract formation in gene-knockout mice

PURPOSE

Previous in vitro studies with transgenic and gene-knockout mice have shown that lenses with elevated levels of glutathione peroxidase (GPX)-1 activity are able to resist the cytotoxic effect of H(2)O(2), compared with normal lenses and lenses from GPX-1-deficient animals. The purpose of this study was to investigate the functional role of this enzyme in antioxidant mechanisms of lens in vivo by comparing lens changes of gene-knockout mice with age-matched control animals.

METHODS

In vivo lens changes were monitored by slit lamp biomicroscopy, and enucleated lenses were examined under a stereomicroscope in gene-knockout animals and age-matched control animals ranging in age from 3 weeks to 18 months. Transmission (TEM) and confocal microscopy were performed on different regions of lenses after the mice were killed at various times.

RESULTS

Slit lamp images showed an increase in nuclear light scattering (NLS) in gene-knockout mice compared with control animals. TEM revealed changes in the nucleus as early as 3 weeks of age by the appearance of waviness of fiber membranes. With increasing age, there was greater distortion of fiber membranes and distension of interfiber space at the apex of fiber cells compared with control mice. The changes in nuclear fiber membranes were even more dramatic, as observed by confocal microscopy, which was performed on thicker sections. In contrast to the changes in the lens nucleus, the morphology of the epithelium and superficial cortex remained unchanged in knockout animals during the same experimental period, consistent with slit lamp observations. Stereomicroscopy of ex vivo lenses demonstrated a significant increase in opacification in gene-knockout mice relative to control animals of the same age. This effect became evident in mice aged 5 to 9.9 months and persisted thereafter in older animals, resulting in mature cataracts after 15 months.

CONCLUSIONS

The results demonstrate the critical role of GPX-1 in antioxidant defense mechanisms of the lens nucleus. The increased NLS appears to be associated with damage to fiber membranes in the nucleus, which is particularly susceptible to oxidative challenge because of the deficiency of GPX-1. It is suggested that the lens membrane changes in the knockout animals may be due to the formation of lipid peroxides, which serve as substrates for GPX-1. Cataract development in gene-knockout mice appeared to progress from focal opacities, apparent at an earlier age, to lamellar cataracts between 6 and 10 months, and finally to complete opacification in animals older than 15 months. This is the first reported phenotype in GPX-1-knockout mice.

Expression and regulation of inducible IkappaB kinase (IKK-i) in human fibroblast-like synoviocytes

IkappaB kinase (IKK) plays a key role in the regulation of nuclear factor kappaB (NF-kappaB). We previously demonstrated the expression of two kinases, IKK1 and IKK2, in fibroblast-like synoviocytes (FLS) and determined their functional consequences for inflammatory gene expression in vitro and in vivo. Recently, a novel inducible IkappaB kinase has been described, namely, IKK-i or IKK-epsilon, which is functionally and structurally distinct from constitutively expressed IKK1 and IKK2. Therefore, we investigated the expression and regulation of this novel kinase in FLS from patients with rheumatoid arthritis and osteoarthritis. Interestingly, constitutive gene expression and protein expression were observed in all cell lines examined. TNFalpha stimulation for 24 h increased IKK-i expression 7.2 +/- 1.8-fold in FLS (P < 0.02). IL-1 also significantly increased IKK-i gene expression. Time course experiments demonstrated that IKK-i gene expression increased within 3 h of TNFalpha stimulation and persisted for at least 24 h. Dose-response studies showed that as little as 1 ng/ml of TNFalpha increased IKK-i gene expression. Constitutive IKK-1 gene expression was also noted in rheumatoid arthritis, osteoarthritis, and normal synovium. This is the first report demonstrating constitutive expression and cytokine regulation of this novel kinase in primary human synovial cells.

Inhibitor of nuclear factor kappaB kinase beta is a key regulator of synovial inflammation

OBJECTIVE

Inhibitor of nuclear factor kappaB kinase beta (IkappaB kinase beta, or IKKbeta) has emerged as a key regulator of the transcription factor nuclear factor kappaB (NF-kappaB). Since IKKbeta could have both pro- and antiinflammatory activity, we examined whether its constitutive activation was sufficient to cause a chronic inflammatory disease such as rheumatoid arthritis.

METHODS

Normal Lewis rats were evaluated for paw swelling by plethysmometry and histologic assessment after intraarticular injection of an adenoviral construct encoding the IKKbeta wild-type gene (Ad.IKKbeta-wt); controls received an adenoviral construct encoding green fluorescent protein (Ad.GFP). The rats were killed after 7 days. Additionally, rats were killed 48 hours after intraarticular injection of Ad.IKKbeta-wt or Ad.GFP for studies of IKK activity and NF-kappaB binding. For studies of the effects of inhibition of IKKbeta activity, Lewis rats were immunized with Mycobacterium tuberculosis in mineral oil. The ankle joints were injected on day 12 with an adenoviral construct encoding IKKbeta K-->M (dominant negative, IKKbeta-dn) or Ad.GFP. We evaluated paw swelling and NF-kappaB expression on day 25.

RESULTS

Intraarticular gene transfer of IKKbeta-wt into the joints of normal rats resulted in significant paw swelling and histologic evidence of synovial inflammation. Increased IKK activity was detectable in the IKKbeta-wt-injected ankle joints, coincident with enhanced NF-kappaB DNA binding activity. Intraarticular gene transfer of IKKbeta-dn significantly ameliorated the severity of adjuvant arthritis, accompanied by a significant decrease in NF-kappaB DNA expression in the joints of Ad.IKKbeta-dn-treated animals.

CONCLUSION

IKKbeta plays a key role in rodent synovial inflammation. Intraarticular gene therapy to inhibit IKKbeta activity represents an attractive strategy for the treatment of chronic arthritis.

c-Jun N-terminal kinase is required for metalloproteinase expression and joint destruction in inflammatory arthritis

Mitogen-activated protein kinase (MAPK) cascades are involved in inflammation and tissue destruction in rheumatoid arthritis (RA). In particular, c-Jun N-terminal kinase (JNK) is highly activated in RA fibroblast-like synoviocytes and synovium. However, defining the precise function of this kinase has been difficult because a selective JNK inhibitor has not been available. We now report the use of a novel selective JNK inhibitor and JNK knockout mice to determine the function of JNK in synoviocyte biology and inflammatory arthritis. The novel JNK inhibitor SP600125 (anthra[1,9-cd]pyrazol-6(2H)-one) completely blocked IL-1--induced accumulation of phospho-Jun and induction of c-Jun transcription in synoviocytes. Furthermore, AP-1 binding and collagenase mRNA accumulation were completely suppressed by SP600125. In contrast, complete inhibition of p38 had no effect, and ERK inhibition had only a modest effect. The essential role of JNK was confirmed in cultured synoviocytes from JNK1 knockout mice and JNK2 knockout mice, each of which had a partial defect in IL-1--induced AP-1 activation and collagenase-3 expression. Administration of SP600125 modestly decreased the rat paw swelling in rat adjuvant-induced arthritis. More striking was the near-complete inhibition of radiographic damage that was associated with decreased AP-1 activity and collagenase-3 gene expression. Therefore, JNK is a critical MAPK pathway for IL-1--induced collagenase gene expression in synoviocytes and in joint arthritis, indicating that JNK is an important therapeutic target for RA.

Physicochemical and microbiological properties of selected rice flour-based batters for fried chicken drumsticks

Rice flour-based batter (RFBB) formulations for chicken drumstick coating were developed as an alternative for traditional wheat flour-based batter (WFBB). Physicochemical properties and storage stability of selected RFBB were evaluated and compared to WFBB. Batter pickup of RFBB formulated in combination with oxidized corn starch and methylcellulose (MC) was not significantly different from that of WFBB. In contrast, batters with only rice and corn flour (60:40% flour weight) exhibited significantly higher pickup. Rice flour batter with 15% oxidized corn starch had the lowest batter pickup. All RFBB exhibited (P < 0.05) lower oil absorption than WFBB. The TBA values of RFBB and WFBB increased (P < 0.05) with increased frozen storage time at -40 C for 90 d. The RFBB with MC exhibited the lowest TBA values, whereas WFBB had the highest values. Microstructural analysis revealed that freezing caused structural deterioration of all batters, but the RFBB with MC exhibited less freezing tolerance than other samples. The total plate counts of immediately fried or frozen fried chicken stored for 90 d were less than 1 log cfu/g sample. The RFBB with 5% oxidized corn starch and MC can replace WFBB on fried drumsticks. Additionally, RFBB results in a healthier product due to lower fat absorption.

Anti-inflammatory effects of ABT-702, a novel non-nucleoside adenosine kinase inhibitor, in rat adjuvant arthritis

Adenosine (ADO) is a homeostatic inhibitory autocoid that is released at sites of inflammation and tissue injury, and exerts anti-inflammatory effects via multiple interactions at ADO receptor subtypes. Inhibition of ADO kinase (AK) increases extracellular ADO concentrations and AK inhibitors have demonstrated ADO-mediated anti-inflammatory effects in acute models of inflammation. To evaluate the potential utility of this approach in chronic inflammation, a novel, potent, and selective non-nucleoside AK inhibitor, ABT-702, was tested in the rat adjuvant arthritis model. Animals were immunized with complete Freund's adjuvant on day 0 and were treated with vehicle or ABT-702 (20 mg/kg/b.i.d. p.o.) beginning on day 8. ABT-702 significantly inhibited arthritis as determined by paw volume. In addition, histologic and radiographic evidence of bone and cartilage destruction was significantly decreased in the treated group. Coadministration of the ADO receptor antagonist theophylline attenuated the anti-inflammatory effects of ABT-702, suggesting that this action was mediated through endogenous ADO release. To evaluate the mechanism of chondroprotection, Northern blot and electrophoretic mobility shift assays were performed on joints samples. These studies demonstrated that ABT-702 suppressed collagenase and stromelysin gene expression in treated animals. In addition, the activator protein-1 and nuclear factor-kappaB binding activity was also decreased. Therefore, ABT-702 inhibited clinical, radiographic, and histologic evidence of chronic inflammatory arthritis. The mechanism of joint protection is likely related to suppressed transcription factor activation and matrix metalloproteinase gene expression.

Adhesion of rice flour-based batter to chicken drumsticks evaluated by laser scanning confocal microscopy and texture analysis

The convenience and appeal of battered or breaded products have resulted in a sales increase of 100% since 1980. Because of the rapid growth of the Asian-American population and increasing consumption of rice and rice products, rice flour is a logical alternative for wheat flour in traditional batter formulation. The effects of ingredients used in rice flour-based batters on adhesion characteristic for deep-fat fried chicken drumsticks were studied by laser scanning confocal microscopy (LSCM) and texture analysis. Raw chicken drumsticks were predusted with egg albumin powder before dipping into batters prepared from combinations of rice flour, yellow corn flour, oxidized cornstarch, methylcellulose, or xanthan gum. The drumsticks were fried at 175+/-5 C until the internal temperature reached at least 71 C. For LSCM, samples were fixed overnight and were sectioned by vibratome (200 microm) before viewing. Batter adhesion was determined using an attachment specifically designed for chicken drumsticks. Microstructural analysis showed that batter formulated with a 50:50 mixture of rice and corn flours adhered better to drumsticks than batter with other rice flour ratios. Xanthan gum (0.2%) or methylcellulose (0.3%) alone had poor adhesion to chicken skin. However, when combined with other ingredients, xanthan gum increased the amount of batter pick-up before frying by increasing viscosity. Egg albumin significantly facilitated batter adhesion. The results from texture analysis supported the microstructural studies. As rice flour ratio increased from 50 to 70%, the binding force decreased. Rice flour showed potential as an alternative to wheat flour for batter formulas when the appropriate levels of oxidized starch, xanthan gum, and methylcellulose were included in the formulation.

Involvement of cysteine proteases in bFGF-induced angiogenesis in guinea pig and rat cornea

Overexpression and activation of matrix metalloprotease (MMP) have been implicated in angiogenesis. However, the involvement of cysteine proteases, such as calpains (EC 34.22.17), is obscure. Thus, the purpose of this experiment was to study the involvement of cysteine proteases in angiogenesis induced by basic fibroblast growth factor (bFGF) in guinea pig and rat corneas using cysteine protease inhibitors. Sustained-release polymers containing bFGF were implanted into guinea pig and rat corneas to induce angiogenesis. For treatment of corneal angiogenesis, polymers containing cysteine protease inhibitors, leupeptin or SJA6017, were also implanted into corneas. Using the slit lamp, the corneas were observed for nine days after polymer implantation. Soluble proteins and albumin levels were used as markers of corneal injury by angiogenesis. bFGF induced angiogenesis in guinea pig and rat corneas. In guinea pig cornea, wet weight, the amount of soluble protein and albumin was highest at four days after bFGF-containing pellet implantation. In rat cornea, the amount of soluble protein and albumin was highest at six days, and wet weight increased within four days. One hundred nmole of leupeptin showed a tendency to reduce bFGF-induced angiogenesis in guinea pig cornea, and 10 nmole of SJA6017 was effective in reducing bFGF-induced angiogenesis in rat cornea, although SJA6017 showed a stronger effect than leupeptin. Ten nmole of SJA6017 significantly reduced the number of new blood vessels. These data suggested involvement of cysteine proteases in angiogenesis in guinea pig and rat cornea.

A possible role for alpha-crystallins in lens epithelial cell differentiation

PURPOSE

To test the hypothesis that crystallin proteins may actively participate in the differentiation of lens epithelial cells into fiber cells.

METHODS

Primary epithelial cells from adult bovine lenses were cultured at 37 degrees C until reaching 95-100% confluency in approximately 4-7 days. Using osmotic lysis of pinocytic vesicles, cells were then loaded with proteins labeled or unlabeled with the fluorescent marker Texas Red (TR). Fetal bovine proteins loaded into cells were lens water soluble fractions, HPLC-purified alpha-, beta-, and gamma-crystallin fractions, or bovine serum albumin (BSA). Cultures were then monitored for morphological changes over a 7 day period.

RESULTS

Both TR-labeled and unlabeled water-soluble and a-crystallin fractions from bovine lenses resulted in morphological changes to epithelial cells during the first two h postloading. These changes included aggregation of epithelial cells into raised multilayered cell masses, as well as several cells losing attachment to the dish. The initial changes were subsequently followed by elongation of cells within the mass and an increase in size of the mass, so that by 4 days postloading the multilayered, multicellular structures could be visualized with the unaided eye. Differentiation was confirmed within these structures by expression of MIP 26, beta- and gamma-crystallin. These changes did not occur in cultures containing cells originally loaded with beta- or gamma-crystallin fractions, or with cells loaded with BSA.

CONCLUSIONS

The results support the hypothesis that alpha-crystallins may actively participate in the differentiation of lens epithelial cells into fiber cells.

Regulation of CS1 fibronectin expression and function by IL-1 in endothelial cells

VLA-4 is a critical adhesion molecule that regulates mononuclear cell trafficking to sites of inflammation. VCAM-1 is a primary ligand of VLA-4, although alternatively spliced fibronectin (FN) containing the CS1 region (CS1 FN) also binds to VLA-4. CS1 FN is expressed by rheumatoid arthritis (RA) synovial endothelial cells, but the factors that regulate CS1 FN expression are not known. We incubated human umbilical vein endothelial cells (HUVEC) with IL-1 (0.1-10 ng/ml) for 8-48 h and determined total FN and CS1 FN mRNA by Northern blot analysis. Both were constitutively expressed by HUVEC, and IL-1 increased total FN mRNA and the CS1-containing isoform (P < 0.05). IL-1 also increased CS1 FN protein expression on HUVEC as determined by Western blot analysis. An adhesion assay using (51)Cr-labeled Jurkat cells and IL-1-stimulated HUVEC was used to determine if IL-1-induced CS1 FN mediates cell binding. Cyclic CS1 peptide (10 microg/ml) blocked 49 +/- 5% of IL-1-induced Jurkat cell adhesion to HUVEC (P < 0.01), whereas anti-VCAM-1 antibody inhibited binding by only 35 +/- 5% (P < 0.01). CS1 peptide and anti-VCAM antibody treatment were not additive (50 +/- 7% inhibition), and 38 +/- 6% of new VLA-4-mediated adhesion to IL-1-treated HUVEC was due to an increase in CS1 FN. These data show that IL-1 increases CS1 FN expression by HUVEC and increases CS1-mediated cell adhesion. CS1 mimetics might have therapeutic efficacy by blocking recruitment of VLA-4-bearing cells.

Intra-articular IL-4 gene therapy in arthritis: anti-inflammatory effect and enhanced th2activity

Gene therapy has been explored as a potential method for treating chronic inflammatory diseases such as rheumatoid arthritis. To determine the efficacy of intra-articular IL-4 gene therapy in an animal model of arthritis using a retroviral vector, a retrovirus encoding rat IL-4 (DA-IL-4) was engineered, purified and concentrated to high titer (>/=109 CFU/ml). Infectivity and expression levels were demonstrated in vitro using cultured fibroblast-like synoviocytes. Efficacy was evaluated in the rat adjuvant arthritis model. DA-IL-4 or DA-beta-gal retrovirus was injected into the intra-articular joint space of the right ankle on day 12 after immunization. Three days after joint injection, the injected paw contained increased levels of IL-4 compared with control or with the contralateral uninjected paw, demonstrating successful transgene expression. Surprisingly, 8 days after treatment IL-4 levels continued to increase in the injected and contralateral paw compared with DA-beta-gal-treated animals. Serum IL-4 levels were also elevated in DA-IL-4-treated rats. RT-PCR studies demonstrated that the transgene was expressed in the injected ankle but not in the contralateral joint. IL-4 gene therapy resulted in a significant reduction in paw swelling and decreased radiographic evidence of bone destruction. This is the first demonstration of successful intra-articular retroviral gene treatment using a therapeutic gene. In addition to its anti-inflammatory effect, this study supports the potential application of intra-articular gene therapy as a method for enhancing systemic Th2 function.

Jun N-terminal kinase in rheumatoid arthritis

Potential mechanisms of joint destruction in rheumatoid arthritis (RA) were examined by studying the regulation of mitogen-activated protein kinases and collagenase gene expression in fibroblast-like synoviocytes (FLS). The three main mitogen-activated protein kinase families [p38, Jun N-terminal kinase (JNK), and extracellular signal-regulated kinases (ERKs)] were constitutively expressed in RA and osteoarthritis (OA) FLS. p38 and ERK1/2 were readily phosphorylated in both RA and OA FLS after interleukin-1 (IL-1) stimulation. JNK was phosphorylated in RA FLS but not OA FLS after IL-1 stimulation. Reverse transcription-polymerase chain reaction studies suggested that JNK2 is the major isoform of the JNK family expressed by FLS. Northern blot analysis of collagenase gene expression demonstrated that RA FLS contained significantly more collagenase mRNA than OA FLS after IL-1 stimulation. The roles of JNK and p38 kinase were evaluated with the p38/JNK inhibitor SB 203580. Low concentrations of SB 203580 (1 microM, a concentration that only inhibits p38) had no significant effect on IL-1-induced collagenase expression in RA FLS whereas 25 microM (which inhibits p38, JNK2, and c-raf) blocked collagenase mRNA accumulation. IL-1-stimulated AP-1 binding was also inhibited by 25 microM SB 203580 in RA FLS. These studies suggest that OA and RA FLS have a different pattern of JNK phosphorylation, which might lead to enhanced collagenase gene expression in RA.

NF-kappa B regulation by I kappa B kinase in primary fibroblast-like synoviocytes

NF-kappa B is a key regulator of inflammatory gene transcription and is activated in the rheumatoid arthritis (RA) synovium. In resting cells, NF-kappa B is retained as an inactive cytoplasmic complex by its inhibitor, I kappa B. Phosphorylation of I kappa B targets it for proteolytic degradation, thereby releasing NF-kappa B for nuclear translocation. Recently, two related I kappa B kinases (IKK-1 and IKK-2) were identified in immortalized cell lines that regulate NF-kappa B activation by initiating I kappa B degradation. To determine whether IKK regulates NF-kappa B in primary cells isolated from a site of human disease, we characterized IKK in cultured fibroblast-like synoviocytes (FLS) isolated from synovium of patients with RA or osteoarthritis. Immunoreactive IKK protein was found to be abundant in both RA and osteoarthritis FLS by Western blot analysis. Northern blot analysis showed that IKK-1 and IKK-2 genes were constitutively expressed in all FLS lines. IKK function in FLS extracts was determined by measuring phosphorylation of recombinant I kappa B in vitro. IKK activity in both RA and osteoarthritis FLS was strongly induced by TNF-alpha and IL-1 in a concentration-dependent manner. Activity was significantly increased within 10 min of stimulation and declined to near basal levels within 80 min. Activation of IKK in FLS was accompanied by phosphorylation and degradation of endogenous I kappa B alpha as determined by Western blot analysis. Concomitant activation and nuclear translocation of NF-kappa B was documented by EMSA and immunohistochemistry. Transfection with a dominant negative IKK-2 mutant prevented TNF-alpha-mediated NF-kappa B nuclear translocation, whereas a dominant negative IKK-1 mutant had no effect. This is the first demonstration that IKK-2 is a pivotal regulator of NF-kappa B in primary human cells.

Dominant-negative p53 mutations in rheumatoid arthritis

OBJECTIVE

Studies were performed to determine if p53 mutations identified in rheumatoid arthritis (RA) synovial tissue are dominant negative.

METHODS

Site-directed mutagenesis was used to produce 2 RA-derived mutants: asparagine-->serine at codon 239 (N239S) and arginine-->stop at codon 213 R213*). HS68 dermal fibroblasts were transfected with either empty vector, wild-type p53 cDNA (wt), or the N239S or R213* mutant p53 cDNA clones. Interleukin-6 (IL-6) and bax gene expression were determined by Northern blot analysis. Bax transcription was determined using a bax promoter/reporter gene construct (bax-luc).

RESULTS

Transfection of HS68 cells with wt increased bax mRNA levels. This process was blocked by cotransfection with either mutant. The mutant p53 genes also increased IL-6 gene expression. Low levels of bax promoter activity were detected in HS68 cells co-transfected with bax-luc and empty vector, N239S, or R213*, indicating that the RA mutants lacked transcriptional activity. Transfection with wt and bax-luc led to a 10-fold increase in luciferase expression. When the wt gene was cotransfected with either of the mutants, there was a dose-dependent inhibition of bax promoter activity.

CONCLUSION

These data indicate that at least 2 of the p53 mutants identified in RA joint samples are dominant negative and suppress endogenous wild-type p53 function.

p53 overexpression in synovial tissue from patients with early and longstanding rheumatoid arthritis compared with patients with reactive arthritis and osteoarthritis

OBJECTIVE

The p53 tumor suppressor gene is overexpressed in synovial tissue (ST) from patients with longstanding rheumatoid arthritis (RA), and may contain somatic mutations. The aim of this study was to determine p53 expression in ST from RA patients in different stages of the disease, compared with disease controls.

METHODS

ST biopsy specimens were obtained from the knee joints of 31 RA patients in varying disease phases, 8 patients with reactive arthritis (ReA), 10 patients with inflammatory osteoarthritis (OA), and 6 control patients (4 with meniscus pathology, 2 with vascular insufficiency). ST was also obtained from the clinically uninvolved knee joints of 9 RA patients. Expression of p53 was determined by immunohistology with DO1 monoclonal antibody (mAb) in all patients and by Western blot analysis with DO7 mAb in a subgroup of the patients.

RESULTS

The p53 protein was detected by immunohistology in 10 of the 13 patients with early RA (duration <6 months) and in 12 of the 14 patients with longstanding RA (duration >5 years). The p53 protein was also demonstrated in clinically uninvolved knee joints. Western blots revealed immunoreactive p53 in ST extracts from all RA patients. Expression of p53 was about twice as high in ST from patients with longstanding RA as in early RA samples, but the difference did not reach statistical significance. Small amounts of p53 were also detected in ST from ReA and OA patients, although the expression in RA synovium was significantly higher. Immunohistologic analysis of normal ST gave negative results for p53.

CONCLUSION

This study shows that p53 overexpression is specific for RA, compared with OA and ReA. This phenomenon is probably secondary to increased production of wild-type p53 protein in response to DNA damage and secondary to somatic mutations caused by the genotoxic local environment in inflamed ST. Of interest, p53 overexpression can also be found in the earliest stages of RA and in clinically uninvolved joints.

AP-1 and NF-kappaB regulation in rheumatoid arthritis and murine collagen-induced arthritis

OBJECTIVE

To determine the expression and regulation of nuclear transcription factors AP-1 and NF-kappaB in rheumatoid arthritis and in collagen-induced arthritis in mice.

METHODS

AP-1 and NF-kappaB expression and function were determined in RA, OA and normal synovial tissue by electrophoretic mobility shift assay (EMSA) and immunohistochemistry. The kinetics of transcription factor expression were then examined in collagen-induced arthritis (CIA) in mice. EMSAs were performed with the nuclear extracts obtained from paws of CIA mice from 10 to 45d after immunization to determine AP-1 and NF-kappaB binding activity. The expression of collagenase-3 (MMP13) and stromelysin (MMP3) mRNA was examined by northern blot analysis.

RESULTS

Immunohistochemistry showed that NF-kappaB expression was increased in both RA and OA synovial intimal lining. AP-1 components Jun and Fos were also present in the intimal lining and was significantly greater in RA than OA. The DNA binding activities of both AP-1 and NF-kappaB were significantly higher RA patients compared with OA. In CIA, AP-1 and NF-kappaB expression increased by day 20, which was 1-2 weeks before onset of clinical arthritis. However, collagenase and stromelysin gene expression did not increase until day 35.

CONCLUSION

The DNA binding activity of AP-1 and NF-kappaB are markedly increased in both CIA and RA. In CIA, activation of AP-1 and NF-kappaB precede both clinical arthritis and metalloproteinase gene expression. NF-kappaB expression correlated better than AP-1 with metalloproteinase expression.

Localization of MIP 26 in nuclear fiber cells from aged normal and age-related nuclear cataractous human lenses

The purpose of the current study was to localize the lens membrane protein, MIP 26, in nuclear fiber cells from different regions of aged normal and age-related cataractous human lenses. Adult, juvenile, fetal and embryonic nuclear regions in aged normal and age-related nuclear cataractous lenses were morphologically and biochemically characterized using the technologies of immuno-gold (5 nm) labeling, semi-thin sections (200-500 nm), serial sections, DiI staining following by photobleaching, transmission electron microscopy and spot-blot analysis. Numbers of gold particles per micron length of plasma membrane and numbers of gold particles per square micron of cytosol in the embryonic-fetal and juvenile-adult nuclear regions were quantified. Results showed that the labeling pattern of MIP 26 localized to the cytosol was unique to senescent fiber cells from age-related cataractous lenses. Numbers of gold particles per square micron of cytosol in the embryonic-fetal nucleus of age-related cataractous lenses were significantly elevated (P<0.001) above numbers from fiber cells located within the adult or juvenile nuclei of the same lens or senescent fiber cells from aged normal lenses. Some of the cytosolic labeling in cataracts was localized to lipid vesicles, while the remaining labeling was negative for the lipid specific stain DiI. Spot blot analysis demonstrated that binding of the ant-MIP 26 serum was exclusive to large molecular weight components greater than 10 kDa, and not to small molecular weight fragments of the protein. The results of the current study supply further evidence that damage to membranes occurs in senescent fiber cells during age-related nuclear cataracts, resulting in the internalization of structures containing the membrane protein MIP 26.

Finger-like projections of plasma membrane in the most senescent fiber cells of human lenses

PURPOSE

To corroborate the findings of finger-like membrane projections in monkey and baboon lenses, in human lens fiber cells.

METHODS

Normal human lenses, two months to 76 years old, as well as age-related nuclear cataracts, were immersion fixed in 2% paraformaldehyde-0.2% glutaraldehyde in 0.1 M sodium cacodylate buffer pH 7.2 for 24 h at room temperature, cut into 200-500 microm thick sections along the equatorial axis, fixed for an additional 12-18 h at room temperature, dehydrated in an ascending ethanol series and embedded in Lowicryl K4M. Semi-thick sections (0.25-1.0 microm) were cut, absorbed onto 75 or 100 nickel slotted grids, labeled with anti-MIP 26 or phalloidin, stained with 2% uranyl acetate and viewed by transmission electron microscopy at 100 kV.

RESULTS

Transmission electron microscopy micrographs demonstrated the presence of finger-like plasma membrane projections measuring 0.16-0.25 microm in diameter and 1.0-6.5 microm in length with bulbous terminal tips in the most senescent fiber cells in two-month and older normal lenses, as well as, in nuclear cataracts. These projections appeared to overlie furrowed membrane domains in the extracellular space, as well as project into the cytosol along the cytosolic leaflet of plasma membrane.

CONCLUSIONS

The results extend the findings in monkey and baboon lenses, to the human lens, and demonstrate that these projections, which sparsely label with antiserum against MIP 26, but not filamentous actin, not only extend into the extracellular space, but also project inward into the cytosol.

Collagen induced arthritis: reversal by mercaptoethylguanidine, a novel antiinflammatory agent with a combined mechanism of action

OBJECTIVE

We recently identified mercaptoethylguanidine (MEG) as an antiinflammatory agent with a combined mechanism of action. Its effects include inhibition of the inducible isoform of nitric oxide synthase (iNOS), scavenging peroxynitrite, a cytotoxic oxidant species produced from nitric oxide (NO) and superoxide, and inhibition of cyclooxygenase (COX). We investigate the effect of MEG in collagen induced arthritis (CIA).

METHODS

Syngeneic LOU rats were immunized with native type II collagen on Day 0. After clinical signs of arthritis developed on Day 10, treatment with MEG was initiated (30 mg/kg ip tid) and continued until sacrifice on Day 28. Serum nitrite/nitrate was measured in control animals, at arthritis onset and 2 days after the start of MEG treatment. Clinical scores were obtained daily. At Day 28, radiographic scores were obtained, and joints were harvested for the measurement of mRNA for tumor necrosis factor-alpha (TNF-alpha), collagenase, and stromelysin.

RESULTS

Serum nitrite/nitrate increased from 7.9+/-0.7 mM (baseline) to 13.5+/-2.6 at arthritis onset (p < 0.05). Within 48 h of MEG treatment, nitrite/nitrate levels fell to 7.2+/-1.1 (p < 0.05). By Day 28, clinical arthritis scores (measured on a scale of 0-8) were 7.1+/-0.6 in the vehicle group compared to 1.4+/-0.6 in the MEG treated group (p < 0.0001). Radiographic scores (scale 0-6) on Day 28 were reduced from 4.9+/-0.6 to 0.6+/-0.4 (p < 0.0002) by MEG treatment. MEG reduced the synovial expression of mRNA for TNF-alpha, collagenase, and stromelysin by 72, 67, and 52%, respectively.

CONCLUSION

These data show that MEG has beneficial effects on established CIA. The mechanism of action may be related to inhibition of synovial iNOS expression or activity, inhibition of COX, scavenging of peroxynitrite, with subsequent inhibition of angiogenesis, metalloproteinase, and TNF-alpha expression.

Direct synovial gene transfer with retroviral vectors in rat adjuvant arthritis

OBJECTIVE

To evaluate the feasibility of direct in vivo gene transfer in an animal model of arthritis using a retroviral vector.

METHODS

The timing and dose of retroviral vector was examined using very high titer retroviral vector (> or = 10(9) CFU) in rat adjuvant arthritis. Retroviral vector expressing beta-galactosidase (beta-gal) or vehicle alone was injected into the right ankle of rats with adjuvant arthritis. Ankles were injected either on Day 7 (pre-arthritis), Day 10 (early arthritis), Day 15 (accelerating arthritis), or Day 28 (chronic arthritis) after adjuvant immunization. Joints were harvested 3 days later and extracts were assayed for beta-gal activity.

RESULTS

Synovial beta-gal expression was minimal in the Day 7 group and elevated in the Day 10, Day 15, and Day 28 groups. Gene transfer with retroviral vector did not exacerbate the local inflammatory response. Minimal or no beta-gal expression was observed in the contralateral uninjected paw or in the spleen, lung, liver, and kidneys. Frozen sections of retroviral vector injected joints were stained with X-gal and revealed transduced cells in the lining and superficial sublining layers. To determine the longevity of gene expression, ankle joints were injected with vector on Day 15 post-adjuvant, harvested, and assayed for beta-gal activity for up to 49 days after injection. Expression of the enzyme peaked from Day 3 to 7 and was still readily detected up to 49 days after retrovirus infection.

CONCLUSION

This is the first report of successful direct in vivo gene transfer in the rat adjuvant arthritis model using a retroviral vector. Appropriate timing of administration and very high titer retroviral vector preparations are key determinants of adequate gene transduction.

What proportion of common diagnostic tests appear redundant?

PURPOSE

To identify ancillary tests for which there are criteria defining the earliest interval at which a repeat test might be indicated, to determine how often each test is repeated earlier than these intervals and, if repeated, provides useful information.

SUBJECTS AND METHODS

We performed a retrospective cohort study of 6,007 adults discharged from a large teaching hospital during a 3-month period in 1991. We measured the proportion of commonly performed diagnostic tests that were redundant, and their associated charges.

RESULTS

Of the 6,007 patients discharged, 5,289 (88%) had at least one of 12 target tests performed. Overall, 78,798 of the target tests were performed during the study period, of which 22,237 (28%) were repeated earlier than test-specific predefined intervals. This percentage varied substantially by test (range, 2% to 62%). To assess how many early repeats were justified, we performed chart reviews in a random sample stratified by test. For two tests, nearly all the initial results in the sample were abnormal, and all repeats were considered justified. Of early repeats following a normal initial result for the remaining 10 tests, chart review found no clinical indication for 92%, and a weighted mean of 40% appeared redundant. Overall, 8.6% of these 10 tests appeared redundant; if these were not performed, the annual charge reductions would be $930,000 at our hospital, although the impact on costs would be much smaller.

CONCLUSIONS

For some tests, an important proportion are repeated too early to provide useful clinical information. Most such tests might be eliminated using computerized reminder systems.

Regulation of synoviocyte proliferation, apoptosis, and invasion by the p53 tumor suppressor gene

Recent studies show that 1) the p53 tumor suppressor protein is overexpressed by rheumatoid arthritis (RA) synovium and fibroblast-like synoviocytes (FLS) and 2) somatic mutations previously identified in human tumors are present in RA synovium and FLS. We have hypothesized that abnormalities in p53 can contribute to chronic destructive RA synovitis. To understand the functional consequences of p53 abnormalities in FLS, RA and normal FLS expressing wild-type p53 were transduced with a retroviral vector encoding the human papilloma virus 18 E6 gene, which inactivates endogenous p53 protein. Three RA and one normal FLS lines were infected with recombinant retrovirus encoding the neomycin resistance gene (neo) or E6+neo. FLS proliferation, apoptosis, and invasion was studied in E6, neo, and uninfected parental strains (PS). The growth rate for E6 was significantly increased with a sixfold increase in cell number after 7 days compared with a twofold to threefold increase in neo and PS. When FLS were treated with cytokines, proliferative response of E6, neo, and PS to interleukin-1 and transforming growth factor-beta were similar. However, response to platelet-derived growth factor was significantly greater in E6 FLS compared with neo or PS. Apoptosis was studied by incubating FLS with sodium nitroprusside as a source of nitric oxide or hydrogen peroxide for 8 hours and examining DNA fragmentation and E6 cells were significantly less susceptible to cell death. In addition, E6 FLS were more invasive into cartilage extracts than neo or PS using an in vitro cell invasion assay. These data suggest that p53 is a critical regulator of FLS proliferation, apoptosis, and invasiveness. Abnormalities of p53 function might contribute to synovial lining expansion and joint destruction in RA.

Confocal microscopy of human lens membranes in aged normal and nuclear cataracts

PURPOSE

To visualize the structure and determine the continuity of lipid membranes in lens fiber cells (LFCs) from human aged normal and cataractous lenses.

METHODS

Thick sections from human nuclear cataracts and aged normal lenses were stained with the lipophilic probe DiI, and then analyzed by confocal microscopy. Staining patterns of membranes were observed in individual optical sections or three-dimensional projections of z-series taken in longitudinal section and cross-section of LFCs from different regions within the lens nucleus.

RESULTS

DiI bound to and delineated the plasma membrane of LFCs from all regions of the lens nucleus. Three-dimensional projections of z-series from aged normal and cataractous lenses suggested that some of the stained lipid membranes were not continuous with LFC plasma membrane of cataractous lenses.

CONCLUSIONS

The results obtained using these methods demonstrated that lipid membranes, discontinuous with the plasma membrane of LFCs, were indicative of a novel process occurring predominately in cataractous human lenses.

Posttranscriptional regulation of collagenase-1 gene expression in synoviocytes by adenosine receptor stimulation

OBJECTIVE

To characterize the transcriptional and posttranscriptional regulation of collagenase-1 by adenosine receptor stimulation in interleukin-1 (IL-1)-stimulated fibroblast-like synoviocytes (FLS).

METHODS

FLS were stimulated with IL-1 and either the nonselective adenosine agonist 5'-N-ethylcarboxamidoadenosine (NECA) or the adenylate cyclase activator forskolin. Electrophoretic mobility shift assays were performed to determine AP-1 and cAMP-responsive element binding protein (CREB) activation. Transcriptional activation was determined by transfecting HS68 dermal fibroblasts with a collagenase-chloramphenicol acetyltransferase construct. Finally, collagenase messenger RNA (mRNA) half-life was determined by activating cells in the presence of IL-1, IL-1 + NECA, or IL-1 + forskolin and culturing cells in the presence of actinomycin D.

RESULTS

NECA and forskolin had no effect on AP-1 activation, c-jun or c-fos gene expression, or CREB phosphorylation. IL-1 markedly increased collagenase promoter activity, and neither NECA nor forskolin blocked this action. Studies of mRNA half-life showed that both NECA and forskolin decreased the half-life of collagenase mRNA in IL-1-stimulated FLS and HS68 cells.

CONCLUSION

The findings of this study demonstrate that NECA and forskolin decrease collagenase gene expression in FLS and dermal fibroblasts due to enhanced mRNA degradation.

Adenosine inhibits neutrophil degranulation in activated human whole blood: involvement of adenosine A2 and A3 receptors

Adenosine, acting via A2 receptors, is a potent inhibitor of neutrophil oxidative burst, but its effects and mechanisms of action on neutrophil degranulation have been less well characterized. We, therefore, investigated the effects of adenosine and its receptor-specific analogues on neutrophil degranulation in stimulated human whole blood. Adenosine dose-dependently inhibited the LPS- and TNF-alpha-induced release of the azurophilic granule proteins bactericidal/permeability-increasing protein, elastase, and defensins to approximately the same extent, with a maximum inhibition of 70 to 80% and an IC50 ranging from 14 to 24 microM. The inhibitory effects of adenosine were partially blocked by the A2 receptor antagonist 3,7-dimethyl-1-propargylxanthine, the A1/A2 antagonist 8(p-sulfophenyl)theophyline, and the A1/A3 antagonist xanthine amine congener, but not by the A1 antagonist 1,3-dipropyl-8-cyclopentylxanthine. The highly selective A3 agonist N6-(3-iodobenzyl)-adenosine-5'-N-methyluronamide and the nonselective agonist 2-chloroadenosine reduced degranulation more potently than the A1 agonist N6-cyclopentyladenosine. The inhibitory effects of N6-(3-iodobenzyl)-adenosine-5'-N-methyluronamide and 2-chloroadenosine were strongly reversed by xanthine amine congener, but were not affected by 8(p-sulfophenyl)theophyline. In addition, the adenosine kinase inhibitor GP515 attenuated degranulation via an adenosine-mediated mechanism. These data indicate that adenosine acts via A2 as well as A3 receptors to inhibit neutrophil degranulation and add to the anti-inflammatory potential of adenosine and adenosine-regulating agents in neutrophil-mediated tissue injury.

Adenosine inhibits neutrophil degranulation in activated human whole blood: involvement of adenosine A2 and A3 receptors

Adenosine, acting via A2 receptors, is a potent inhibitor of neutrophil oxidative burst, but its effects and mechanisms of action on neutrophil degranulation have been less well characterized. We, therefore, investigated the effects of adenosine and its receptor-specific analogues on neutrophil degranulation in stimulated human whole blood. Adenosine dose-dependently inhibited the LPS- and TNF-alpha-induced release of the azurophilic granule proteins bactericidal/permeability-increasing protein, elastase, and defensins to approximately the same extent, with a maximum inhibition of 70 to 80% and an IC50 ranging from 14 to 24 microM. The inhibitory effects of adenosine were partially blocked by the A2 receptor antagonist 3,7-dimethyl-1-propargylxanthine, the A1/A2 antagonist 8(p-sulfophenyl)theophyline, and the A1/A3 antagonist xanthine amine congener, but not by the A1 antagonist 1,3-dipropyl-8-cyclopentylxanthine. The highly selective A3 agonist N6-(3-iodobenzyl)-adenosine-5'-N-methyluronamide and the nonselective agonist 2-chloroadenosine reduced degranulation more potently than the A1 agonist N6-cyclopentyladenosine. The inhibitory effects of N6-(3-iodobenzyl)-adenosine-5'-N-methyluronamide and 2-chloroadenosine were strongly reversed by xanthine amine congener, but were not affected by 8(p-sulfophenyl)theophyline. In addition, the adenosine kinase inhibitor GP515 attenuated degranulation via an adenosine-mediated mechanism. These data indicate that adenosine acts via A2 as well as A3 receptors to inhibit neutrophil degranulation and add to the anti-inflammatory potential of adenosine and adenosine-regulating agents in neutrophil-mediated tissue injury.

Confocal microscopy of cataracts from animal model systems: relevance to human nuclear cataract

A recent study demonstrated that cytosolic lipid membrane structures, independent of the plasma membrane, preferentially occurred in human cataractous lenses. Animal model systems of cataractogenesis (selenite treated rats: galactose fed rats; buthionine-sulfoxime treated mice; Emory mice) were screened for possible relevant structures using the lipid membrane probe DiI and confocal microscopy. Well delineated plasma membranes of lens fiber cells with independent cytosolic staining structures were only observed in the selenite model system. These cytosolic structures were not observed in aged matched control lenses or within the transparent cortical regions of selenite treated animals with intense nuclear opacification. These results suggested that the morphological changes in DiI staining structures seen in the nucleus of the human cataractous lens were best approximated by those seen in the selenite model system.

Apoptosis in rheumatoid arthritis: p53 overexpression in rheumatoid arthritis synovium

DNA damage induces p53 tumor suppressor gene expression and protein production, which in turn facilitates DNA repair or apoptosis. Wild-type p53 protein has a short half-life, so it is rarely detected in non-neoplastic tissue. Because DNA fragmentation is abundant in the intimal lining in rheumatoid arthritis (RA) synovial tissue (ST) using in situ end-labeling (Firestein GS, Yeo M, Zvaifler NJ: Apoptosis in rheumatoid arthritis synovium. J Clin Invest 1995, 96:1631-1638), we assessed ST p53 expression. Immunohistochemical analysis of fixed RA synovium using antibody PAb 1801 showed prominent p53 staining in the cytoplasm and nuclei of intimal lining cells. Noninflammatory and osteoarthritis (OA) ST had significantly less p53 in the lining. These data were confirmed by Western blot analysis of ST extracts, with abundant p53 found in RA compared with OA. p53 expression in cultured fibroblast-like synoviocytes (FLS) was then examined. Flow cytometry on permeabilized cells showed that RA FLS constitutively express p53 protein. Western blots showed that RA FLS expressed significantly more p53 than either OA FLS or dermal fibroblasts. Immunohistochemistry of FLS cultured in chamber slides localized the p53 to the cytoplasm of most resting FLS, with nuclear staining in only 10.7 +/- 2.4%. Exposure to hydrogen peroxide for increased nuclear staining to 70.7 +/- 12.8% after 8 hours (P = 0.003). These data indicate that p53 is overexpressed in RA ST in the intimal lining, which is the primary site of DNA damage, and is constitutively expressed by FLS.

Inhibition of synoviocyte collagenase gene expression by adenosine receptor stimulation

OBJECTIVE

To characterize the regulation of matrix metalloproteinases (MMPs) by adenosine.

METHODS

Cultured fibroblast-like synoviocytes (FLS) were stimulated with interleukin-1 (IL-1) in the presence or absence of adenosine receptor agonists. Immunoreactive MMPs were measured using specific enzyme-linked immunosorbent assays, and gene expression was assessed by Northern blot analysis.

RESULTS

The nonselective adenosine receptor agonist 5'-N-ethylcarboxamidoadenosine (NECA) decreased collagenase production by IL-1-stimulated synoviocytes from 196 +/- 28 ng/ml (mean +/- SEM) to 66 +/- 9 ng/ml (P < 0.001). There was minimal effect on stromelysin production (decrease from 107 +/- 16 ng/ml to 97 +/- 15 ng/ml). Selective adenosine receptor agonists implicated the A2b adenosine receptor in this activity, and reverse transcriptase-polymerase chain reaction studies confirmed that FLS express this receptor. Northern blot analysis demonstrated that the mechanism of action was pre-translational since NECA decreased collagenase, but not stromelysin or tissue inhibitor of metalloproteinases 1 (TIMP-1), messenger RNA levels. Cyclic AMP levels were increased by NECA, and a direct adenylate cyclase activator (forskolin) also suppressed collagenase gene expression. These data suggest that cAMP mediates the inhibitory effect of NECA on collagenase production.

CONCLUSION

Stimulation of the A2b receptor on FLS decreases collagenase gene expression, with little or no effect on stromelysin and TIMP-1. The combination of antiinflammatory and MMP-regulating properties of adenosine or adenosine-regulating agents suggest that treatment based on this approach might be useful in rheumatoid arthritis.

EM immunolocalization of alpha-crystallins: association with the plasma membrane from normal and cataractous human lenses

PURPOSE

To integrate past biochemical findings with past morphological observations of area insoluble material isolated from cataract and aged normal lenses, by determining the spatial distribution of alpha-crystallins associated with the plasma membrane (PM) of nuclear cataractous and age matched normal human lenses.

METHODS

Lenses were homogenized, pelleted and washed several times in 0.05M Tris-Cl (pH 7.2) containing 100mM KCl, 1 mM MgCl2 and 2mM beta-mercaptoethanol, followed by several washes in 8M urea. Urea insoluble pellets (UIP) were labeled before fixation and embedding with rabbit serum raised against alpha-crystallins, followed by goat anti-rabbit IgG conjugated to 5nm gold. Approximately 300 gold particles associated with the PM were counted, for each lens, on several electron microscopy (EM) micrographs. The number of gold particles/um of PM, number of individual vs clusters of gold particles were determined.

RESULTS

Micrographs from both normal and cataractous human lenses clearly demonstrated the association of alpha-crystallins with the PM. Also apparent was the abundant labeling of the PM for cataractous lenses as compared to normal lenses. Quantification of the gold labeling revealed that not only was there an increase in the amount of labeling/um of PM in cataract lenses, but there was also an increased percentage of gold in clusters. These clusters were not only more numerous in cataractous lenses, but also contained a greater number of gold/cluster.

CONCLUSIONS

These findings provide morphological evidence that the PM in nuclear cataract lenses is associated with large aggregates of alpha-crystallin.

cDNA cloning and characterization of A3i, an alternatively spliced rat A3 adenosine receptor variant

A cDNA encoding variant form of the A3 adenosine (Ado) receptor was isolated from rat by reverse transcription of brain mRNA followed by PCR. The full-length receptor (A3i) cDNA encodes 337 amino acids and shares complete sequence identity with the rat A3 Ado receptor, except for the presence of a seventeen amino acid insert located in the second intracellular domain. In contrast to the rat A3 receptor, stable expression of A3i in CHO cells resulted in poor coupling to Gi proteins. Analysis of receptor transcripts by RT-PCR suggests that the A3 Ado receptor mRNAs are products of alternative splicing. Sequence analysis of A3 genomic DNA identified a 1.7 kb intron that is likely alternatively spliced to produce the A3 and A3i receptors.

Relationship between medication errors and adverse drug events

OBJECTIVE

To evaluate the frequency of medication errors using a multidisciplinary approach, to classify these errors by type, and to determine how often medication errors are associated with adverse drug events (ADEs) and potential ADEs.

DESIGN

Medication errors were detected using self-report by pharmacists, nurse review of all patient charts, and review of all medication sheets. Incidents that were thought to represent ADEs or potential ADEs were identified through spontaneous reporting from nursing or pharmacy personnel, solicited reporting from nurses, and daily chart review by the study nurse. Incidents were subsequently classified by two independent reviewers as ADEs or potential ADEs.

SETTING

Three medical units at an urban tertiary care hospital.

PATIENTS

A cohort of 379 consecutive admissions during a 51-day period (1,704 patient-days).

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

Over the study period, 10,070 medication orders were written, and 530 medications errors were identified (5.3 errors/100 orders), for a mean of 0.3 medication errors per patient-day, or 1.4 per admission. Of the medication errors, 53% involved at least one missing dose of a medication; 15% involved other dose errors, 8% frequency errors, and 5% route errors. During the same period, 25 ADEs and 35 potential ADEs were found. Of the 25 ADEs, five (20%) were associated with medication errors; all were judged preventable. Thus, five of 530 medication errors (0.9%) resulted in ADEs. Physician computer order entry could have prevented 84% of non-missing dose medication errors, 86% of potential ADEs, and 60% of preventable ADEs.

CONCLUSIONS

Medication errors are common, although relatively few result in ADEs. However, those that do are preventable, many through physician computer order entry.

Synovial interleukin-1 receptor antagonist and interleukin-1 balance in rheumatoid arthritis

OBJECTIVE

To quantify interleukin-1 receptor antagonist (IL-1ra) and IL-1 production and gene expression by rheumatoid arthritis (RA) synovial tissue (ST) cells.

METHODS

IL-1 alpha, IL-1 beta, and IL-1ra protein levels were measured by enzyme-linked immunosorbent assay in fresh and cultured ST cells, purified synovial macrophages, and fibroblast-like synoviocytes (FLS). The relative expression of the secreted form of IL-1ra (sIL-1ra) and the alternatively spliced intracellular form (icIL-1ra) was determined by reverse transcription polymerase chain reaction (RT-PCR) techniques.

RESULTS

IL-1 alpha, IL-1 beta, and IL-1ra were present in fresh and cultured ST cell samples of synovium from RA and osteoarthritis patients. IL-1ra:IL-1 ratios ranged from 1.2 to 3.6, which is below the 10-100-fold excess of IL-1ra needed to inhibit IL-1 bioactivity. Isolated CD14+ synovial macrophages secreted IL-1ra, but the amount was much less than that of alveolar or in vitro-derived macrophages. Cultured FLS contained intracellular IL-1ra but secreted little IL-1ra into the culture supernatants. RT-PCR showed that icIL-1ra mRNA was more abundant than sIL-1ra mRNA in FLS and unfractionated ST cells.

CONCLUSION

IL-1ra production by RA ST cells is deficient relative to total production of IL-1.

Mechanisms of methotrexate action in rheumatoid arthritis. Selective decrease in synovial collagenase gene expression

OBJECTIVE

To measure the effect of methotrexate (MTX) treatment in rheumatoid arthritis (RA) on the expression of synovial collagenase, stromelysin, and tissue inhibitor of metalloproteinase 1 (TIMP-1) gene expression in a prospective study.

METHODS

Serial percutaneous synovial biopsies (pretreatment and after 3-4 months) were performed on the knees of 8 patients (7 with RA, 1 with seronegative arthritis) who were beginning oral MTX therapy. Synovial gene expression was determined by quantitative in situ hybridization using computer-assisted image analysis.

RESULTS

After therapy, patients had decreased joint counts, morning stiffness, and erythrocyte sedimentation rates. Synovial inflammation in the biopsy tissues was slightly decreased after therapy. In situ hybridization on pretreatment and posttreatment frozen sections was performed to quantify synovial messenger RNA (mRNA) levels. Collagenase gene expression significantly decreased after MTX therapy (P = 0.006) even though cell density in the region was unchanged. TIMP-1 and stromelysin mRNA levels were not changed by MTX therapy. To study the mechanism of MTX action in vitro, MTX-treated and control fibroblast-like synoviocytes were stimulated with interleukin-1 beta (IL-1 beta). MTX did not alter collagenase or TIMP-1 mRNA levels after IL-1 exposure.

CONCLUSION

MTX therapy decreases collagenase gene expression but not TIMP-1 or stromelysin gene expression in the synovium. This action is probably an indirect effect due to an alteration in the synovial cytokine milieu, rather than a direct effect on gene expression.

Impact of computerized physician order entry on physician time

We examined the effect of computerized physician order entry on housestaff time use patterns, using time motion techniques. For both medical and surgical house officers, writing orders on the computer took about twice as long (p < 0.001), or 44 minutes for medical and 73 minutes for surgical house officers. Medical house officers recovered about half this time because some administrative tasks--e.g. looking for charts--were made easier. Within types of orders, sets of stereotyped orders took much less time with order entry, but one-time orders took longer. We have since developed strategies to make it easier to enter one-time orders.

The effect of swainsonine on the phagocytosis of rod outer segments by rat RPE

From studies using inhibitors such as tunicamycin and castanospermine, it has been suggested that plasma membrane glycoproteins may function as receptors in the phagocytosis of rod outer segments (ROS) by the retinal pigment epithelium (RPE). The exact structure of the oligosaccharide side chain of the glycoprotein may not be critical for this process. We have employed another inhibitor, swainsonine, which inhibits mannosidase II, a terminal enzyme in the protein glycosylation pathway, which results in membrane glycoproteins having hybrid-type oligosaccharide chains and fewer complex oligosaccharide chains. We have examined the ability of cultured rat RPE explants to phagocytize fluorescein isothiocyanate (FITC) labelled ROS or latex beads in the presence and absence of swainsonine. A significant (p less than 0.05) reduction in the phagocytosis of FITC-ROS was found between the swainsonine treated (37.7 +/- 4.1%) and untreated (85.4 +/- 2.7%) RPE explants. The nonspecific uptake of latex beads in both swainsonine treated (85.3 +/- 2.4%) and untreated (89.3 +/- 2.0%) RPE explants indicate that the RPE cells retained their ability to phagocytize. Major differences in spectrophotometric analysis of WGA-stained blots were an absence of a peak at 201 kD, a doublet at 86 kD and an overall reduction in all peak absorbances in the swainsonine treatments as compared to the untreated controls. These results suggest that the alterations in RPE glycoprotein formation due to swainsonine alter the ability of RPE to phagocytize ROS.

Growth of Listeria monocytogenes Inoculated in Waste Fluids Collected from a Slaughterhouse

Cells of Listeria monocytogenes Scott A were artificially inoculated (26-378 CFU/ml) in waste fluids collected from a lamb slaughtering operation, and their growth was determined at 8 and 35°C. Samples tested included residual fluid from carcass rinsing (after hide and offal removal); a mixture of waste fluids from the floor (collected during the entire slaughtering and washing process); and a standard floor drain sample (drawn from the floor drain 5 min after clean-up was complete). Growth of L. monocytogenes within 24 h of incubation of the various waste fluids was more rapid at 35 (1-4 logs) than at 8°C (0.5-2 logs). Average generation times of L. monocytogenes growth at 8°C were in the range of 12.3 to 35.1 h, depending on waste fluid, while at 35°C generation times were in the range of 1.1-6.4 h. Therefore, waste fluids in slaughterhouse facilities can support growth of L. monocytogenes , which may then be introduced on carcasses and retail meat cuts. Thus, slaughterhouse temperatures should be as low as possible and cleaning and sanitation should be frequent in order to minimize carcass and retail meat contamination with the pathogen.