bluuebunny/crossref_metadata_2025 huggingface dataset:
Predictors of disease course and remission in systemic juvenile idiopathic arthritis: Significance of early clinical and laboratory features
Authors: Singh‐Grewal D. , Schneider R. , Bayer N. , Feldman B. M.
Published: April 2006

Objective

To determine whether the disease course in systemic juvenile idiopathic arthritis (JIA) can be characterized as monophasic, polycyclic, or persistent, and to determine whether early clinical and laboratory characteristics can be used to predict the disease course and time to remission.

Methods

Forty‐five children with systemic JIA diagnosed between 1996 and 2000 were followed up with a standardized data collection protocol, including data on clinical and laboratory features (mean followup 4.9 years). Disease was considered inactive if the clinical and laboratory features were normal. Three definitions of remission were applied to classify disease course. Predictors of disease course were evaluated using multiple logistic regression. Predictors of time to remission were evaluated using Cox proportional hazards regression.

Results

When applying a definition of remission requiring inactive disease while not receiving any medications for a period of 3 months, 42.2%, 6.7%, and 51.1% of the patients were classified as having monophasic, polycyclic, and persistent disease, respectively. Fever and active arthritis at 3 months (R2 = 0.42, area under the receiver operating characteristics curve [AUC] = 0.76) and an erythrocyte sedimentation rate (ESR) >26 mm/hour and corticosteroid use at 6 months (R2 = 0.49, AUC = 0.92) were predictive of a nonmonophasic course. Absence of active arthritis, an ESR of <26 mm/hour, and no requirement for corticosteroid therapy at 3 and 6 months were predictors of an earlier time to remission.

Conclusion

The disease course in systemic JIA can be characterized as monophasic, polycyclic, or persistent using a definition of remission requiring 3 months of inactive disease while not receiving any therapy. Features at 3 and 6 months are predictive of the disease course and time to remission.
Impaired recognition of apoptotic neutrophils by the C1q/calreticulin and CD91 pathway in systemic lupus erythematosus
Authors: Donnelly Suzanne , Roake Wendy , Brown Simon , Young Philip , Naik Haley , Wordsworth Paul , Isenberg David A. , Reid Kenneth B. M. , Eggleton Paul
Published: April 2006

Objective

A deficiency in a subcomponent of C1q can result in increased susceptibility to autoimmune diseases such as systemic lupus erythematosus (SLE). The monocyte endocytic receptor CD91 is implicated in the endocytosis of apoptotic neutrophils via interactions with C1q and calreticulin. In this clinical study, we studied the binding of C1q to leukocytes and determined whether C1q bound specifically to calreticulin and CD91 on cells undergoing apoptosis in SLE.

Methods

Proximal antibody phage display, calreticulin‐transfected cells, and immunocytochemical and confocal techniques were used in a comprehensive analysis of direct binding of C1q to apoptotic neutrophils that were obtained from healthy individuals and from patients with SLE. In addition, apoptotic cellular systems were assessed in vitro.

Results

C1q appeared to colocalize to apoptotic blebs on the surface of leukocytes in association with both calreticulin and CD91, as determined by phage display and transfected cell studies. However, C1q did not bind to apoptotic cells isolated from SLE patients, despite the positivity of the cells for both calreticulin and CD91. Surface expression of calreticulin decreased on neutrophils as they aged, but increased on monocytes. In an apoptotic phagocytic assay, the addition of C1q and calreticulin significantly enhanced the phagocytosis of apoptotic cell debris by monocyte‐derived cells.

Conclusion

These observations indicate that neutrophils from SLE patients have a reduced ability to be recognized and removed by the C1q/calreticulin/CD91‐mediated apoptotic pathway, despite the presence of main apoptotic recognition partners. This suggests that an additional component, as yet unidentified, acts as a C1q binding partner on apoptotic cells, and this component may be lacking in cells isolated from SLE patients.
Combination treatment with methotrexate, cyclosporine, and intraarticular betamethasone compared with methotrexate and intraarticular betamethasone in early active rheumatoid arthritis: An investigator‐initiated, multicenter, randomized, double‐blind, parallel‐group, placebo‐controlled study
Authors: Hetland Merete Lund , Stengaard‐Pedersen Kristian , Junker Peter , Lottenburger Tine , Ellingsen Torkell , Andersen Lis Smedegaard , Hansen Ib , Skjødt Henrik , Pedersen Jens Kristian , Lauridsen Ulrik Birk , Svendsen Anders , Tarp Ulrik , Pødenphant Jan , Hansen Gert , Lindegaard Hanne , Carvalho Anselmo De , ØStergaard Mikkel , Hørslev‐Petersen Kim
Published: April 2006

Objective

To investigate whether disease control can be achieved in early active rheumatoid arthritis (RA) by treatment with methotrexate and intraarticular betamethasone, and whether the addition of cyclosporine to the regimen has any additional effect.

Methods

Patients (n = 160) were randomized to receive methotrexate 7.5 mg/week plus cyclosporine 2.5 mg/kg of body weight/day (combination therapy) or methotrexate plus placebo‐cyclosporine (monotherapy). At weeks 0, 2, 4, 6, and 8 and every 4 weeks thereafter, betamethasone was injected into swollen joints (maximum 4 joints or 4 ml per visit). Beginning at week 8, if synovitis was present, the methotrexate dosage was increased stepwise up to 20 mg/week, with a subsequent stepwise increase in the cyclosporine or placebo‐cyclosporine dosage up to 4 mg/kg.

Results

At 52 weeks, 20% improvement according to the American College of Rheumatology criteria (ACR20) was achieved in 85% of the combination therapy group versus 68% of the monotherapy group (P = 0.02). The median individual overall ACR response (ACR‐N) in the 2 groups was 80.0% (interquartile range 40.1–91.8%) and 54.5% (interquartile range 2.4–87.8%), respectively (P = 0.025). At 48 and 52 weeks, ACR remission criteria were met in 35% of the combination therapy group and 28% of the monotherapy group. Progression in the Larsen score at 52 weeks was –0.2 ± 6.5 and 0.4 ± 6.9 (mean ± SD) in the combination therapy and monotherapy groups, respectively. Serum creatinine levels increased by 7%, and hypertrichosis was more prevalent, in the combination therapy group.

Conclusion

Combined treatment with methotrexate and intraarticular glucocorticoid showed excellent disease control and stopped the progression of erosions in patients with early active RA, who had a poor prognosis. Addition of cyclosporine improved the ACR20 and ACR‐N responses, whereas the ACR50 and ACR70 responses, remission rates, and radiographic changes did not differ between the 2 study groups.
Leflunomide use and the risk of interstitial lung disease in rheumatoid arthritis
Authors: Suissa Samy , Hudson Marie , Ernst Pierre
Published: April 2006

Objective

Spontaneous reports of interstitial lung disease (ILD) in patients with rheumatoid arthritis (RA) treated with leflunomide, a disease‐modifying antirheumatic drug (DMARD), have been appearing recently. To assess this risk, we conducted a population‐based epidemiologic study.

Methods

A cohort of 62,734 patients with RA to whom a DMARD had been dispensed between September 1, 1998 and December 31, 2003 was formed using the PharMetrics claims database. A nested case–control design was used, in which each case of serious ILD requiring hospitalization was matched to 100 controls according to age (calendar time) and equal or greater duration of followup, to estimate adjusted rate ratios (RRs) of serious ILD associated with DMARD use.

Results

There were 74 cases of serious ILD, which corresponds to a rate of 8.1 per 10,000 patients per year. The risk of ILD was increased with the use of leflunomide (adjusted RR 1.9 [95% confidence interval (95% CI) 1.1–3.6]). Among subjects with no previous methotrexate use and no history of ILD, the risk associated with leflunomide treatment was not elevated (RR 1.2 [95% CI 0.4–3.1]), but it was elevated among the remaining subjects (RR 2.6 [95% CI 1.2–5.6]). Patients with a history of ILD were twice as likely to have been prescribed leflunomide as any other DMARD.

Conclusion

The reports of ILD associated with leflunomide use are likely the result of channeling of high‐risk patients to leflunomide treatment, particularly those with a history of methotrexate use or preexisting ILD. Patients with no history of ILD and no previous methotrexate use show no excess risk of developing ILD with leflunomide treatment.
Functional characterization of a soluble gp130 isoform and its therapeutic capacity in an experimental model of inflammatory arthritis
Authors: Richards Peter J. , Nowell Mari A. , Horiuchi Sankichi , McLoughlin Rachel M. , Fielding Ceri A. , Grau Sandra , Yamamoto Naoki , Ehrmann Michael , Rose‐John Stefan , Williams Anwen S. , Topley Nicholas , Jones Simon A.
Published: April 2006

Objective

Soluble gp130 is the naturally occurring antagonist of the interleukin‐6 (IL‐6)/soluble IL‐6 receptor (sIL‐6R) complex and selectively inhibits IL‐6 trans‐signaling. Several isoforms of soluble gp130 have been identified, including an autoantigenic form termed gp130‐RAPS (for gp130 of the rheumatoid arthritis antigenic peptide–bearing soluble form) that is present in the serum and synovial fluid of patients with rheumatoid arthritis. The aim of this study was to evaluate the functional properties of gp130‐RAPS.

Methods

To define a role for gp130‐RAPS in arthritis, a recombinant version was generated using a baculovirus expression system, and its activities were tested in vitro and in vivo.

Results

Gp130‐RAPS was shown to bind with high affinity to the stable IL‐6/sIL‐6R complex, hyper–IL‐6, and to effectively modulate leukocyte migration in murine acute peritonitis. A single intraarticular injection of gp130‐RAPS suppressed chronic antigen‐induced arthritis in association with a reduction in local activation of signal transducer and activator of transcription 3. Although gp130‐RAPS contains the previously identified autoantigenic sequence Asn‐Ile‐Ala‐Ser‐Phe (NIASF), no increase in the prevalence of anti– gp130‐RAPS antibodies was observed in serum or synovial fluid obtained from patients with rheumatoid arthritis.

Conclusion

The use of inhibitory antibodies to block IL‐6 responses has shown considerable clinical promise. However, the results presented herein suggest that selective targeting of IL‐6 trans‐signaling may represent a viable alternative to this strategy. In this respect, our present results suggest that the soluble gp130 isoform gp130‐RAPS may be useful in the treatment of chronic inflammatory arthritis.
“Endogenous adjuvant” activity of the RNA components of lupus autoantigens Sm/RNP and Ro 60
Authors: Kelly Kindra M. , Zhuang Haoyang , Nacionales Dina C. , Scumpia Philip O. , Lyons Robert , Akaogi Jun , Lee Pui , Williams Bryan , Yamamoto Masahiro , Akira Shizuo , Satoh Minoru , Reeves Westley H.
Published: April 2006

Objective

Most lupus patients produce autoantibodies against small ribonucleoproteins such as Sm/RNP and Ro 60 (containing U1 and Y1–Y5 RNAs, respectively). We undertook this study to investigate whether the RNA components of these antigens, which contain extensive tracts of single‐ and double‐stranded RNA, signatures of viral infection, activate innate immunity.

Methods

U1 and Y RNAs were affinity purified from K562 cells. Murine bone marrow–derived dendritic cells (DCs), human HEK 293 cells, and murine RAW264.7 cells were stimulated with U1 RNA and other known Toll‐like receptor (TLR) ligands. Expression of the interferon (IFN)–inducible gene Mx1 and other genes was quantified using real‐time polymerase chain reaction, and cytokine production was measured by enzyme‐linked immunosorbent assay. DC maturation was assessed using flow cytometry.

Results

Purified U1 and Y1–Y5 RNAs and synthetic stem‐loop II of U1 RNA stimulated type I IFN (IFN‐I) production by cell lines and murine bone marrow–derived DCs and promoted DC maturation (CD86 expression). U1 RNA–stimulated, but not TLR‐3 ligand–stimulated, IFN‐I was blocked by bafilomycin A1, indicating that immunostimulation by U1 RNA requires endosomal acidification. Myeloid differentiation factor 88–deficient cells responded poorly to U1 RNA, suggesting that an endosomal TLR, probably TLR‐7, mediates the stimulatory effects of U1 RNA. U1 RNA–induced IFN‐I and interleukin‐6 production also were protein kinase R (PKR) dependent (abrogated by 2‐aminopurine and greatly reduced in PKR−/− cells).

Conclusion

We conclude that the RNA components of the Ro 60 (Y1–Y5 RNA) and Sm/RNP (U1 RNA) small ribonucleoproteins act as endogenous adjuvants that could play a role in the pathogenesis of autoimmunity by stimulating DC maturation and IFN‐I production.
Preliminary evidence for a structural benefit of the new bisphosphonate zoledronic acid in early rheumatoid arthritis
Authors: Jarrett Stephen J. , Conaghan Philip G. , Sloan Victor S. , Papanastasiou Philemon , Ortmann Christine‐Elke , O'Connor Philip J. , Grainger Andrew J. , Emery Paul
Published: April 2006

Objective

Bisphosphonates inhibit osteoclast activity, which is central to the development of bone damage in rheumatoid arthritis (RA). The aim of this study was to assess whether treatment with zoledronic acid, compared with placebo, could achieve a ≥50% reduction in the development of new erosions on magnetic resonance imaging (MRI) in patients with early RA.

Methods

In this proof‐of‐concept study, 39 patients with early RA and clinical synovitis of the hand/wrist were randomized to receive infusions with either zoledronic acid (5 mg) or placebo, administered at baseline and week 13. Patients in both groups received methotrexate (MTX) at a dosage of 7.5–20 mg/week. MRI and plain radiography were performed at baseline and week 26.

Results

At week 26, the mean ± SD change in MRI hand and wrist erosions was 61% lower in the zoledronic acid group compared with the placebo group (0.9 ± 1.63 versus 2.3 ± 3.09; P = 0.176). The mean ± SD increase in the number of hand and wrist bones with erosions was 0.3 ± 0.75 for zoledronic acid compared with 1.4 ± 1.77 for placebo (P = 0.029). The proportion of patients in whom new MRI‐visualized bone edema developed was smaller in the zoledronic acid group compared with the placebo group (33% versus 58%; P = 0.121). The zoledronic acid group had a mean change in the number of radiographic erosions of 0.1 compared with 0.5 for the placebo group (P = 0.677). The safety profile of zoledronic acid was similar to that of placebo.

Conclusion

The results of this study suggest a structural benefit associated with zoledronic acid therapy in patients with RA, as demonstrated by consistent results in structural end points in favor of zoledronic acid plus MTX compared with MTX alone.
Radiographic joint space width in the fingers of patients with rheumatoid arthritis of less than one year's duration
Authors: Goligher Ewan C. , Duryea Jeffrey , Liang Matthew H. , Wolfe Frederick , Finckh Axel
Published: April 2006

Objective

To determine the radiographic joint space width (JSW) in undamaged metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints of patients with early rheumatoid arthritis (RA) and to identify important clinical determinants of JSW.

Methods

Radiographs of patients with RA of <1 year's duration, from an early arthritis cohort at a tertiary care rheumatology clinic, were obtained. JSW was analyzed by joint, finger, age, sex, height, and a number of other clinically relevant variables. Multivariate analysis was also performed, to account for possible confounding between variables.

Results

Thirty‐eight patients were included in the study. We found that JSW was greater in the MCP joint than the PIP joint (P < 0.0001). JSW was significantly greater in men (P < 0.0001) and increased with increasing height (P < 0.003), but was not associated with age (P < 0.21). In multivariate analyses, sex was shown to be the most important predictor of JSW.

Conclusion

In patients with early RA, MCP and PIP JSW is significantly associated with sex and height. In studies of RA in which JSW measurements are included as an outcome, these differences may need to be accounted for in the analysis.
Association of the IL4R single‐nucleotide polymorphism I50V with rapidly erosive rheumatoid arthritis
Authors: Prots Iryna , Skapenko Alla , Wendler Jörg , Mattyasovszky Stefan , Yoné Clarisse L. , Spriewald Bernd , Burkhardt Harald , Rau Rolf , Kalden Joachim R. , Lipsky Peter E. , Schulze‐Koops Hendrik
Published: April 2006

Objective

To examine whether single‐nucleotide polymorphisms (SNPs) of the interleukin‐4 receptor gene IL4R influence susceptibility to, or radiographic progression in, rheumatoid arthritis (RA).

Methods

The contribution of 2 SNPs (I50V and Q551R) in the coding region of IL4R to RA susceptibility was analyzed by allele‐specific polymerase chain reaction in a case–control study of 471 RA patients and 371 healthy controls. Patients with available radiographs of the hands and feet obtained 2 years after disease onset (n = 302) were stratified retrospectively according to radiologic outcome into an erosive and a nonerosive group to evaluate the association between IL4R SNPs and disease progression.

Results

No differences in the genotype and allele frequencies of the I50V or Q551R SNPs were identified between the RA patients and healthy controls. In contrast, significant differences in the distribution of I50V IL4R SNP genotypes between patients with erosive and nonerosive disease were observed (χ2 = 15.68, P = 0.0004). Bone erosions at 2 years after disease onset were present in 68.1% of patients homozygous for the V50 allele compared with 37.0% of patients homozygous for the I50 allele (odds ratio 3.86, P < 0.0001). This association was independent of individual factors previously associated with severe disease, such as rheumatoid factor or the HLA–DR shared epitope. On a cellular level, the V50 allele conferred significantly reduced responsiveness to interleukin‐4, providing a possible mechanism for the association of the I50V IL4R polymorphism with early erosions in RA.

Conclusion

Our data identify the I50V IL4R SNP as a novel genetic marker in RA, showing high predictive value for early joint destruction.
Solid malignancies among patients in the Wegener's granulomatosis etanercept trial
Authors: Stone John H. , Holbrook Janet T. , Marriott Matthew A. , Tibbs Andrea K. , Sejismundo Lourdes P. , Min Y.‐I. , Specks Ulrich , Merkel Peter A. , Spiera Robert , Davis John C. , St.Clair E. William , McCune W. Joseph , Ytterberg Steven R. , Allen Nancy B. , Hoffman Gary S.
Published: April 2006

Objective

Etanercept is a soluble fusion protein designed to inhibit tumor necrosis factor (TNF). During the Wegener's Granulomatosis Etanercept Trial (WGET), a placebo‐controlled trial of etanercept given in addition to standard therapy for remission induction and maintenance, more solid malignancies were observed in the etanercept group than in the group treated with standard therapy alone. This study was undertaken to further explore the potential association between anti‐TNF therapy and the development of malignancy in these patients.

Methods

One hundred eighty patients with active WG were enrolled and followed up for a median of 27 months. At enrollment, disease characteristics, treatment history, specific medical history items, and information about previous WG treatments and risk factors for malignancy were recorded. During the trial, the occurrence of malignancies and other adverse events was recorded prospectively.

Results

All 6 solid malignancies observed during the WGET occurred in the etanercept group (P = 0.01 versus placebo group); based on a comparison of age‐ and sex‐specific incidence rates, 1.92 solid malignancies would have been expected in this group. The solid malignancies included 2 cases of mucinous adenocarcinoma of the colon, 1 each of metastatic cholangiocarcinoma, renal cell carcinoma, and breast carcinoma, and 1 recurrent liposarcoma. There were no differences between the 2 treatment groups in sex distribution, disease severity, personal or family history of cancer, or tobacco and alcohol use. The etanercept group was older at baseline and less likely to be newly diagnosed with WG at the time of randomization. Patients who developed solid tumors were older than patients who did not. All etanercept‐treated patients who developed solid tumors were also treated with cyclophosphamide during the trial. However, there were no differences between the groups in the amount of cyclophosphamide received during the trial or the percentage who had received cyclophosphamide before enrollment. There were also no differences in the mean duration of daily cyclophosphamide therapy or the maximum daily cyclophosphamide dosage before enrollment.

Conclusion

Data from the WGET, the first substantial reported experience of the combined use of etanercept and cyclophosphamide in the treatment of WG, indicate that the combination of TNF inhibition and cyclophosphamide may heighten the risk of cancer beyond that observed with cyclophosphamide alone.
Improvement of the acridine orange–protein–surfactant system for protein estimation based on aromatic ring stacking effect of sodium dodecyl benzene sulphonate
Authors: wang Fei , Yang Jinghe , Wu Xia , Wang Xiaobo , Guo Changying , Jia Zhen
Published: April 2006

The fluorescence of acridine orange (AO) is greatly quenched by the anionic surfactant sodium dodecyl benzene sulphonate (SDBS), but when protein is added into the AO–SDBS system, the fluorescence intensity of the latter is enhanced again. Based on this, a new fluorimetric method of determination of protein was developed. Under optimum conditions, the enhanced intensity of fluorescence is in proportion to the concentration of protein, such as bovine serum albumin (BSA), human serum albumin (HSA) and egg albumin (EA), over a wide range with detection limits at the 10−9 g/mL level. This method has been satisfactorily used for the determination of protein in samples. We compared results using 280 nm and 490 nm excitation wavelengths and the mechanism of the assay. Copyright © 2006 John Wiley & Sons, Ltd.
Inhibition and enhancement by organic compounds of luminol–KIO4–H2O2 chemiluminescence
Authors: Xu Hong , Duan Chun‐Feng , Lai Chun‐Ze , Lian Mei , Zhang Zhi‐Feng , Liu Li‐Juan , Cui Hua
Published: April 2006

The effects of 36 organic compounds on luminol–KIO4–H2O2 chemiluminescence (CL) were studied. It was found that most of the tested compounds could inhibit or enhance the CL intensity. The activities of such inhibitors or enhancers were related to the pH of the CL system and the number and position of functional groups such as –OH and –NH2 on aromatic rings. The mechanism of the CL inhibition and enhancement was considered. Based on the CL inhibition or enhancement, the possibility of analytical applications was explored. The results demonstrated that numerous compounds were detectable at the ng/mL level using the CL system. Copyright © 2006 John Wiley & Sons, Ltd.
A comparison of the presumptive luminol test for blood with four non‐chemiluminescent forensic techniques
Authors: Webb Joanne L. , Creamer Jonathan I. , Quickenden Terence I.
Published: April 2006

Presumptive blood detection tests are used by forensic investigators to detect trace amounts of blood or to investigate suspicious stains. Through the years, a number of articles have been published on the popular techniques of the day. However, there is no single paper that critiques and compares the five most common presumptive blood detection tests currently in use: luminol, phenolphthalein (Kastle–Meyer), leucomalachite green, Hemastix® and the forensic light source. The present authors aimed to compare the above techniques with regard to their sensitivity, ease of use and safety. The luminol test was determined to be the most sensitive of the techniques, while Hemastix® is a suitable alternative when the luminol test is not appropriate. Copyright © 2006 John Wiley & Sons, Ltd.
Azobenzene as Conformational Switch in Model Peptides
Authors: Renner Christian , Moroder Luis
Published: April 2006

The photoinduced isomerization of azobenzene between the extended (trans) and compact (cis) conformations is reversibly triggered by light of two differing wavelengths. The resulting changes in molecular geometry have been extensively utilized to photoswitch transformations in chemical species reversibly for applications in optoelectronic devises as well as to photocontrol conformational states in (bio)polymers. The high isomerization yield, remarkable photostability and ultrafast kinetics (few ps) of azobenzene are well suited for the design of small, defined model systems that allow detailed folding studies to be carried out both experimentally and theoretically on the same molecules. In our and other laboratories such systems were recently obtained with cyclic peptides of defined conformational preferences as well as with α‐helical and β‐hairpin peptides. These should, by comparison of simulation and experiment, permit an assessment and improvement of the theoretical description on the one hand and a detailed interpretation of the ultrafast conformational dynamics on the other. The phototriggered changes in conformational states lead to concurrent changes in biophysical properties that can be exploited in the photocontrol of biochemical and biological events, as exemplarily discussed with redox‐active cyclic bis‐cysteinyl peptides and receptor ligands.
FTIR Studies of Iron–Carbonyl Intermediates in Allylic Alcohol Photoisomerization
Authors: Chong Thiam Seong , Tan Sze Tat , Fan Wai Yip
Published: April 2006

The 532 or 355 nm laser‐induced photoisomerization of allylic alcohols to aldehydes catalyzed by [Fe3(CO)12] or [Fe(CO)4PPh3] in hexane was investigated. The Fourier transform infrared (FTIR) absorption spectra of iron–carbonyl intermediate species such as [Fe(CO)5], [Fe(CO)4(R‐C3H4OH)], and more importantly the π‐allyl iron–carbonyl hydride species [FeH(CO)3(R‐C3H3OH)] (R=H, Me, Ph) were recorded during the catalytic process using [Fe3(CO)12] as the catalytic precursor. When [Fe(CO)4PPh3] was photolyzed with 355 nm, [FeH(CO)3(R‐C3H3OH)] was also generated indicating the common occurrence of the species in these two systems. The π‐allyl hydride species is long believed to be a key intermediates and its detection here lends support to the π‐allyl mechanism of the photoisomerization of allyl alcohols.
Pyrimidinyl Nitronyl Nitroxides
Authors: Brough Peter , Pécaut Jacques , Rassat André , Rey Paul
Published: April 2006

The chemistry of 2,2,4,4‐substituted pentane derivatives has been investigated with the aim of providing a flexible and versatile synthetic route to pyrimidinyl nitronyl nitroxides, in which the bis‐N‐oxy fragment is incorporated in a six‐membered ring. The synthesis of 2,4‐diamino‐2,4‐dimethylpentane and 2,4‐bis(hydroxylamino)‐2,4‐dimethylpentane, convenient precursors of these nitroxides, is described and full characterization of a series of pyrimidinyl nitronyl nitroxides is reported, along with a preliminary study of their coordination properties.
Synthesis and Structural Model of an α(2,6)‐Sialyl‐T Glycosylated MUC1 Eicosapeptide under Physiological Conditions
Authors: Dziadek Sebastian , Griesinger Christian , Kunz Horst , Reinscheid Uwe M.
Published: April 2006

To study the effect of O‐glycosylation on the conformational propensities of a peptide backbone, a 20‐residue peptide (GSTAPPAHGVTSAPDTRPAP) representing the full length tandem repeat sequence of the human mucin MUC1 and its analogue glycosylated with the (2,6)‐sialyl‐T antigen on Thr11, were prepared and investigated by NMR and molecular modeling. The peptides contain both the GVTSAP sequence, which is an effective substrate for GalNAc transferases, and the PDTRP fragment, a known epitope recognized by several anti‐MUC1 monoclonal antibodies. It has been shown that glycosylation of threonine in the GVTSAP sequence is a prerequisite for subsequent glycosylation of the serine at GVTSAP. Furthermore, carbohydrates serve as additional epitopes for MUC1 antibodies. Investigation of the solution structure of the sialyl‐T glycoeicosapeptide in a H2O/D2O mixture (9:1) under physiological conditions (25 °C and pH 6.5) revealed that the attachment of the saccharide side‐chain affects the conformational equilibrium of the peptide backbone near the glycosylated Thr11 residue. For the GVTSA region, an extended, rod‐like secondary structure was found by restrained molecular dynamics simulation. The APDTR region formed a turn structure which is more flexibly organized. Taken together, the joined sequence GVTSAPDTR represents the largest structural model of MUC1 derived glycopeptides analyzed so far.
Identification of organ‐specific T cell populations by analysis of multiparameter flow cytometry data using DNA‐chip analysis software
Authors: Hofmann Matthias , Zerwes Hans‐Günter
Published: April 2006

Background:

The analysis of cells from multiple experimental groups by multiparameter flow cytometry leads to the generation of complex data sets, for which adequate analysis tools are not commonly available. We report here that software designed for transcriptomics applications can be used in multiparameter flow cytometry.

Methods:

Lymphocytes isolated from nine different mouse organs were stained and subjected to 10‐parameter flow cytometry. The resulting data set contained 594 different T cell subsets per organ per mouse and was organized into a so‐called flow cytometry array (FCA).

Results:

Computation of a hierarchical tree revealed that lymph nodes and spleen were populated by similar T cell subsets, while T cells from peripheral organs displayed a diverse subset composition. Furthermore, organ‐specific T cell subsets were identified.

Conclusions:

This new FCA concept in flow cytomics proved to be a valuable tool for the fast and unbiased analysis of complex multiparameter flow cytometry data sets. It can be used for assessing disease progression and therapeutic intervention, and for the association of disease‐related biomarkers on the protein level. © 2006 International Society for Analytical Cytology
Redox‐Active Coordination Polymers from Esterified Hexavanadate Units and Divalent Metal Cations
Authors: Han Jong Woo , Hardcastle Kenneth I. , Hill Craig L.
Published: April 2006

The redox‐active bis(pyridyl)‐capped hexavanadate [V6O13{(OCH2)3C(4‐CONHC5H4N)}2]2– (1) reacts with divalent first‐row transition‐metal cations (MnII, CoII, NiII, or ZnII) to yield crystalline linear zwitterionic coordination polymers (1M). The zwitterionic coordination chains are connected to each other by hydrogen bonds to form a 3D network. Microporous channels are formed along the packing axes of the 2D networks. All four compounds exhibit almost identical cell parameters, space group (P) and crystal morphology. The materials have been characterized by X‐ray crystallography, 1H and 51V NMR, IR, UV/Vis, elemental analysis, and TGA. All compounds 1M are reversibly reduced by chemical reductants such as phenylhydrazine and NaBH4 in CCl4 in which the hexavanadates are insoluble. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Study on pharmacokinetics and tissue distribution of norvancomycin in rats by CE with electrochemical detection
Authors: Zhou Tianshu , Wu Fang , Shi Guoyue , Wang Aifang , Hu Qin , Wang Xiaochun , Fang Yuzhi
Published: April 2006

In this paper, we developed a sensitive and simple method to study the pharmacokinetics and tissue distribution of norvancomycin (NVCM) in experimental animals by using CE with electrochemical detection. Pharmacokinetics investigation was performed by the collection of blood samples at timed intervals following administration of NVCM. Pharmacokinetic parameters were calculated by the 3P87 pharmacokinetic program. The elimination half‐life of NVCM was 42.4742 min with a clearance rate of 0.0233 mL·kg−1·min−1. Additionally, drug distribution was studied by measuring the NVCM levels in kidney, lung, stomach, intestine, spleen, heart, liver, and cerebrum. Electrophoresis conditions such as buffer solution, working potential, separation voltage, and sampling time were also discussed. The linear range was from 0.8 to 540 μg/mL with a correlation coefficient of 0.9991. The detection limit was 0.3 μg/mL. This method was for the first time applied to study the pharmacokinetics and tissue distributions of NVCM in experimental animals.
Free‐solution electrophoresis of DNA modified with drag‐tags at both ends
Authors: Meagher Robert J. , McCormick Laurette C. , Haynes Russell D. , Won Jong‐In , Lin Jennifer S. , Slater Gary W. , Barron Annelise E.
Published: April 2006

In end‐labeled free‐solution electrophoresis (ELFSE), DNA molecules are labeled with a frictional modifier or “drag‐tag”, allowing their size‐based electrophoretic separation in free solution. Among the interesting observations from early work with dsDNA using streptavidin as a drag‐tag was that the drag induced by including a streptavidin label at both ends was significantly more than double that from a single streptavidin (Heller, C. et al.., J. Chromatogr. A 1998, 806, 113–121). This finding was assumed to be in error, and subsequent work focused on experiments in which only a single drag‐tag is appended to one end of the DNA molecule. Recent theoretical work (McCormick, L. C., Slater, G. W., Electrophoresis 2005, 26, 1659–1667) has examined the contribution of end‐effects to the free‐solution electrophoretic mobility of charged‐uncharged polymer conjugates, reopening the question of enhanced drag from placing a drag‐tag at both ends. In this study, this effect is investigated experimentally, using custom‐synthesized ssDNA oligonucleotides allowing the attachment of drag‐tags to one or both ends, as well as dsDNA PCR products generated with primers appropriate for the attachment of drag‐tags at one or both ends. A range of sizes of drag‐tags are used, including synthetic polypeptoid drag‐tags as well as genetically engineered protein polymer drag‐tags. The enhanced drag arising from labeling both ends has been confirmed, with 6–9% additional drag for the ssDNA and 10–23% additional drag for the dsDNA arising from labeling both ends than would be expected from simply doubling the size of the drag‐tag at one end. The experimental results for ssDNA labeled at both ends are compared to the predictions of the recent theory of end‐effects, with reasonably good quantitative agreement. These experimental findings demonstrate the feasibility of enhancing ELFSE separations by labeling both ends of the DNA molecule, leading to greater resolving power and a wider range of applications for this technique.
Nonaqueous versus aqueous capillary electrophoresis of α‐helical polypeptides: Effect of secondary structure on separation selectivity
Authors: Psurek Arndt , Feuerstein Sophie , Willbold Dieter , Scriba Gerhard K. E.
Published: April 2006

The CE separation of α‐helical polypeptides composed of 14–31 amino acid residues has been investigated using aqueous and nonaqueous BGEs. The running buffers were optimized with respect to pH. Generally, higher separation selectivities were observed in nonaqueous electrolytes. This may be explained by a change in the secondary structure when changing from water to organic solvents. Circular dichroism spectra revealed a significant increase in helical structures in methanol‐based buffers compared to aqueous buffers. This change in secondary structure of the polypeptides contributed primarily to the different separation selectivity observed in aqueous CE and NACE. For small oligopeptides of two to five amino acid residues no significant effect of the solvent was observed in some cases while in other cases a reversal of the migration order occurred when changing from aqueous to nonaqueous buffers. As these peptides cannot adopt secondary structures the effect may be attributed to a shift of the pKa values in organic solvents compared to water.
Breast cancer proteomics by laser capture microdissection, sample pooling, 54‐cm IPG IEF, and differential iodine radioisotope detection
Authors: Neubauer Hans , Clare Susan E. , Kurek Raffael , Fehm Tanja , Wallwiener Diethelm , Sotlar Karl , Nordheim Alfred , Wozny Wojciech , Schwall Gerhard P. , Poznanović Slobodan , Sastri Chaturvedula , Hunzinger Christian , Stegmann Werner , Schrattenholz André , Cahill Michael A.
Published: April 2006

The presence of progesterone receptor (PR) in estrogen receptor (ER)‐positive breast cancer is associated with a good prognosis, and indicates that tumors are likely to respond to tamoxifen. However, ER+/PR− tumors respond less well. To reveal the potential molecular mechanism of this phenomenon, we sought to identify differential protein abundances between invasive ductal carcinoma cells from cryopreserved ER+/PR+ and ER+/PR− mammary tumor specimens. Because current proteomics methods are hampered in the examination of most primary human tumor samples by the extreme tissue heterogeneity, we used laser capture microdissection (LCM) to isolate tumor cells and developed a sample pooling strategy to analyze small sample protein lysates. Proteins from LCM‐harvested tumors were pooled into four sub‐pools from each condition of three tumors/sub‐pool, and proteins from respective paired sub‐pools were co‐electrophoresed by 2‐DE using 54‐cm IEF over pH 4–9. Abundance ratios were accurately quantified by a differential multiplex radioactive ProteoTope method at low attomole levels (∼3.6 &μ;g protein per labeling reaction, <180 ng per multiplex protein sample per 54‐cm gel). Applying this approach, differentially displayed proteins were identified by MS using comigrating non‐radioactively labeled tumor proteins. They include decreased cytochrome b5 and transgelin, and more abundant CRABP‐II, cyclophilin A, Neudesin, and hemoglobin in ER+/PR+ tumors versus ER+/PR−providing a possible explanation for differential susceptibility against tamoxifen as a result of deregulated cytochrome b5‐dependent metabolism. This study demonstrates the potential of ProteoTope and LCM to enable extremely sensitive and precise differential analyses from well‐defined primary clinical specimen.
Sample pretreatment on a microchip with an integrated electrospray emitter
Authors: Lindberg Peter , Dahlin Andreas P. , Bergström Sara K. , Thorslund Sara , Andrén Per E. , Nikolajeff Fredrik , Bergquist Jonas
Published: April 2006

This study presents a microbead‐packed PDMS microchip with an integrated electrospray emitter for sample pretreatment prior to sheathless ESI‐MS. We prove the concept of analytical functions integrated onto a cm‐sized area of a single bulk material. The microchip consists of two PDMS substrates replicated from SU‐8 fabricated silicon wafer masters, bonded together after oxidation by corona discharge treatment. The channel within the microchip contains a grid structure that was used to trap 5 µm hypercross‐linked polystyrene beads. The beads acted as a medium for sample desalting and enrichment. Electrical contact for the sheathless ESI process was achieved by coating the integrated emitter with conductive graphite powder after applying a thin layer of PDMS as glue. The coating as well as the bond of the PDMS structures showed excellent durability. A continuous spray was obtained from the microchip for over 800 h in a long‐term electrospray stability experiment. Desalting and enrichment of neuropeptides from a physiological salt solution was successful by loading the sample onto the packed beads, followed by a washing and an eluting step. The results were obtained and evaluated using a TOF MS. An LOD of approximately 20 fmol (loaded onto the beads) for angiotensin II was obtained from a sample of neuropeptides dissolved in physiological salt solution.
Biomarker discovery by CE‐MS enables sequence analysis via MS/MS with platform‐independent separation
Authors: Zürbig Petra , Renfrow Matthew B. , Schiffer Eric , Novak Jan , Walden Michael , Wittke Stefan , Just Ingo , Pelzing Matthias , Neusüß Christian , Theodorescu Dan , Root Karen E. , Ross Mark M. , Mischak Harald
Published: April 2006

CE‐MS is a successful proteomic platform for the definition of biomarkers in different body fluids. Besides the biomarker defining experimental parameters, CE migration time and molecular weight, especially biomarker's sequence identity is an indispensable cornerstone for deeper insights into the pathophysiological pathways of diseases or for made‐to‐measure therapeutic drug design. Therefore, this report presents a detailed discussion of different peptide sequencing platforms consisting of high performance separation method either coupled on‐line or off‐line to different MS/MS devices, such as MALDI‐TOF‐TOF, ESI‐IT, ESI‐QTOF and Fourier transform ion cyclotron resonance, for sequencing indicative peptides. This comparison demonstrates the unique feature of CE‐MS technology to serve as a reliable basis for the assignment of peptide sequence data obtained using different separation MS/MS methods to the biomarker defining parameters, CE migration time and molecular weight. Discovery of potential biomarkers by CE‐MS enables sequence analysis via MS/MS with platform‐independent sample separation. This is due to the fact that the number of basic and neutral polar amino acids of biomarkers sequences distinctly correlates with their CE‐MS migration time/molecular weight coordinates. This uniqueness facilitates the independent entry of different sequencing platforms for peptide sequencing of CE‐MS‐defined biomarkers from highly complex mixtures.
Simultaneous enantioseparation and sensitive detection of eight β‐blockers using capillary electrochromatography‐electrospray ionization‐mass spectrometry
Authors: Zheng Jack , Shamsi Shahab A.
Published: April 2006

The feasibility of using vancomycin chiral stationary phase (CSP) and polar organic eluent is investigated for simultaneous enantioseparation of eight β‐blockers using CEC coupled to ESI mass spectrometric detection (ESI‐MS). The internally tapered capillaries were utilized to pack CEC‐MS columns. As compared to externally tapered columns, the use of internally tapered columns demonstrated enhanced stability, durability, and reproducibility. A mixture containing methanol/ACN/acetic acid/triethylamine at 70:30:1.6:0.2 v/v/v/v was considered as optimum mobile phase since it provided a good compromise between resolution and analysis time. As expected, sheath liquid and ESI‐MS parameters mainly influenced the detection sensitivity. Interestingly, structural information of β‐blockers was available by varying the MS fragmentor voltage using in‐house CID in the scan mode. In order to maximize the chiral/achiral resolution, various column‐coupling approaches using teicoplanin as complementary CSP to vancomycin were tested. Several changes in the elution order of β‐blockers were observed using multimodal CSPs with some improvement in chiral or achiral resolution. The quantitative aspects of the CEC‐MS method were demonstrated using R‐ and S‐talinolol as internal standards. The calibration curves of β‐blockers showed good linearity in the range of 3–600 µM. The enantiomer of β‐blockers at a concentration of 30 nM was detectable. Furthermore, both 0.1 and 1% of the S‐enantiomer could be precisely quantified in the presence of 99.9 and 99% of the R‐isomer of β‐blocker.
Progress in capillary electrophoresis coupled to matrix‐assisted laser desorption/ionization – time of flight mass spectrometry
Authors: Huck Christian W. , Bakry Rania , Huber Lukas A. , Bonn Günther K.
Published: April 2006

In this review the most important techniques developed to hyphenate CE to MALDI‐TOF‐MS are summarized. The principles of the different interfaces and ways to solve the hyphenation problem are explained and discussed in detail. The most important applications especially in the proteomic field are reviewed, and the advantages of CE‐MALDI‐TOF‐MS for the analysis of these compounds compared to other techniques such as ESI‐MS are exhaustingly discussed from a critical point of view. CE coupled to MALDI‐TOF‐MS has started to overpass traditionally used CE‐coupling techniques, especially CE‐ESI‐MS, offering the possibility to analyze samples of interest even weeks after CE analysis and using multiplexing systems for high‐sample throughput.
A population‐based study of the association between coronary artery bypass graft surgery (CABG) and cognitive decline: the Cache County study
Authors: Lyketsos Constantine G. , Toone Leslie , Tschanz JoAnn , Corcoran Christopher , Norton Maria , Zandi Peter , Munger Ron , Breitner John C.S. , Welsh‐Bohmer Kathleen
Published: April 2006

Background

The relationship between coronary artery bypass graft (CABG) surgery and cognitive decline remains uncertain, in particular with regard to whether there is delayed cognitive decline associated with this procedure.

Methods

This was a population‐based cohort study involving participants in the Cache County Study of Memory Health and Aging. At baseline the study enrolled 5,092 persons age 65 and older and followed them up three years later and again four years after that. Individuals who reported having undergone CABG surgery at study baseline or had this surgery in between follow‐up waves were compared to individuals who never reported having the surgery. The main outcome measure was the Modified Mini Mental State (3MS). Multilevel models were used to examine the relationship between CABG surgery and cognitive decline over time.

Results

Study participants who had CABG surgery evidenced 0.95 points of greater decline relative to baseline on the 3MS at the first follow‐up interview after CABG, and an average of 1.9 points of greater decline at the second follow‐up interview, than those without CABG (t = −2.51, df = 2,316, p = 0.0121), after adjusting for several covariates, including number of vascular conditions. This decline was restricted to individuals who were more than five years past the procedure and was not evident in the early years after the surgery.

Conclusions

CABG surgery is associated with accelerated cognitive decline more than five years after the procedure in a long‐lived population. This decline is small and its clinical significance is uncertain. We could not find an association between CABG and decline in the first five post‐operative years. Copyright © 2006 John Wiley & Sons, Ltd.
Correlational study of the Chinese version of the executive interview (C‐EXIT25) to other cognitive measures in a psychogeriatric population in Hong Kong Chinese
Authors: Chan Sau Man Sandra , Chiu Fung Kum Helen , Lam Chiu Wa Linda
Published: April 2006

Objectives

This study is designed to pilot test the feasibility and correlational properties of the adapted Chinese version of Executive Interview (C‐EXIT25) to other cognitive measures in a psychogeriatric population in Hong Kong Chinese.

Method

Eighty‐five community dwelling elders from different levels of residential care facilities were assessed with C‐EXIT25, Cantonese version of Mini‐Mental State Examination (C‐MMSE), Chinese version of Mattis Dementia Rating Scale (CDRS) and Nelson's Modified Card Sorting Test (MCST).

Results

The C‐EXIT25 has high internal consistency (Cronbach's α = 0.7995) and inter‐rater reliability (r = 0.91). The C‐EXIT25 has superior correlational property to performance indices of MCST than the C‐MMSE and CDRS, after adjusting for age, gender and educational level. It also discriminates among subjects at different stages on Clinical Dementia Rating.

Conclusions

The C‐EXIT25 is a potentially feasible and valid bedside tool for assessment of executive cognitive functions in the psychogeriatric population in Hong Kong Chinese. Copyright © 2006 John Wiley & Sons, Ltd.