bluuebunny/crossref_metadata_2025 huggingface dataset:
The antioxidant resveratrol protects against chondrocyte apoptosis via effects on mitochondrial polarization and ATP production
Authors: Dave Mandar , Attur Mukundan , Palmer Glyn , Al‐Mussawir Hayf E. , Kennish Lauren , Patel Jyoti , Abramson Steven B.
Published: August 2008

Objective

To determine the effects of the antioxidant resveratrol on the functions of human chondrocytes in osteoarthritis (OA).

Methods

Chondrocytes and cartilage explants were isolated from OA patients undergoing knee replacement surgery. Effects of resveratrol in the presence or absence of interleukin‐1β (IL‐1β) stimulation were assessed by measurement of prostaglandin E2(PGE2) and leukotriene B4(LTB4) synthesis, cyclooxygenase (COX) activity, matrix metalloproteinase (MMP) expression, and proteoglycan production. To explore the mechanisms of action of resveratrol, its effects on mitochondrial function and apoptosis were examined by assessing mitochondrial membrane potential, ATP levels, cytochrome c release, and annexin V staining.

Results

Resveratrol inhibited both spontaneous and IL‐1β–induced PGE2production by >20% (P< 0.05) and by 80% (P< 0.001), respectively; similarly, LTB4production was reduced by >50% (P< 0.05). The production of PGE2was inhibited via a 70–90% suppression of COX‐2 expression and enzyme activity (P< 0.05). Resveratrol also promoted anabolic effects in OA explant cultures, by elevating proteoglycan synthesis and decreasing production of MMPs 1, 3, and 13. Pretreatment of OA chondrocytes with resveratrol blocked mitochondrial membrane depolarization, loss of mitochondrial biomass, and IL‐1β–induced ATP depletion. Similarly, IL‐1β–mediated induction of the apoptotic markers cytochrome c and annexin V was also inhibited by resveratrol. Exogenous addition of PGE2abolished the protective effects of resveratrol on mitochondrial membrane integrity, ATP levels, expression of apoptotic markers, and DNA fragmentation.

Conclusion

Resveratrol protects against IL‐1β–induced catabolic effects and prevents chondrocyte apoptosis via its inhibition of mitochondrial membrane depolarization and ATP depletion. These beneficial effects of resveratrol are due, in part, to its capacity to inhibit COX‐2–derived PGE2synthesis. Resveratrol may therefore protect against oxidant injury and apoptosis, which are main features of progressive OA.
Reduction of plasma urate levels following treatment with multiple doses of pegloticase (polyethylene glycol–conjugated uricase) in patients with treatment‐failure gout: Results of a phase II randomized study
Authors: Sundy John S. , Becker Michael A. , Baraf Herbert S. B. , Barkhuizen Andre , Moreland Larry W. , Huang William , Waltrip Royce W. , Maroli Allan N. , Horowitz Zeb ,   Pegloticase Phase 2 Study Investigators
Published: August 2008

Objective

To assess the efficacy of pegloticase in achieving and maintaining plasma urate levels of <6 mg/dl in gout patients in whom other treatments have failed, and to assess the pharmacokinetics and safety of pegloticase.

Methods

Forty‐one patients were randomized to undergo 12–14 weeks of treatment with pegloticase at 1 of 4 dosage levels: 4 mg every 2 weeks, 8 mg every 2 weeks, 8 mg every 4 weeks, or 12 mg every 4 weeks. Plasma uricase activity, plasma urate, and antipegloticase antibodies were measured, pharmacokinetic parameters were assessed, and adverse events were recorded.

Results

The mean plasma urate level was reduced to ≤6 mg/dl within 6 hours in all dosage groups, and this was sustained throughout the treatment period in the 8 mg and 12 mg dosage groups. The most effective dosage was 8 mg every 2 weeks. Twenty‐six patients received all protocol doses. The percentage of the patients in whom the primary efficacy end point (plasma urate <6 mg/dl for 80% of the study period) was achieved ranged from 50% to 88%. Gout flares occurred in 88% of the patients. The majority of adverse events (excluding gout flare) were unrelated to treatment and were mild or moderate in severity. Infusion‐day adverse events were the most common reason for study withdrawal (12 of 15 withdrawals). There were no anaphylactic reactions. Antipegloticase antibody, present in 31 of 41 patients, was associated with reduced circulating half‐life of pegloticase in some patients.

Conclusion

Pegloticase, administered in multiple doses, was effective in rapidly reducing and maintaining plasma urate levels at ≤6 mg/dl in most patients in whom conventional therapy had been unsuccessful due to lack of response, intolerability, or contraindication.
A systematic review on the effectiveness of treatment with antidepressants in fibromyalgia syndrome
Authors: Üçeyler Nurcan , Häuser Winfried , Sommer Claudia
Published: August 2008

Objective

To systematically review the efficacy of treatment of fibromyalgia syndrome (FMS) with antidepressants.

Methods

We screened Medline, PsychINFO, SCOPUS, and the Cochrane Library databases (through October 2007) and the reference sections of original studies, meta‐analyses, and evidence‐based guidelines and recommendations on antidepressants in FMS. Randomized controlled trials (RCTs) on the treatment of FMS with antidepressants were analyzed. Inclusion criteria, study characteristics, quality, and all outcome measures were investigated.

Results

Twenty‐six of 167 studies were included. The main outcome variables reviewed were pain, fatigue, sleep, depressiveness, and quality of life. Amitriptyline, studied in 13 RCTs, was efficient in reducing pain with a moderate magnitude of benefit (pain reduction by a mean of 26%, improvement in quality of life by 30%). Selective serotonin reuptake inhibitors (SSRIs) were studied in 12 RCTs, which also showed positive results, except for 2 studies on citalopram and 1 on paroxetine. Three RCTs on the dual serotonin and noradrenaline reuptake inhibitors (SNRIs) duloxetine and milnacipran and 1 of the 2 RCTs using the monoamine oxidase inhibitor moclobemide reported a positive result. The longest study duration was 12 weeks.

Conclusion

Amitriptyline 25–50 mg/day reduces pain, fatigue, and depressiveness in patients with FMS and improves sleep and quality of life. Most SSRIs and the SNRIs duloxetine and milnacipran are probably also effective. Short‐term treatment of patients with FMS using amitriptyline or another of the antidepressants that were effective in RCTs can be recommended. Data on long‐term efficacy are lacking.
Efficacy and safety of infliximab in patients with ankylosing spondylitis over a two‐year period
Authors: Braun Jürgen , Deodhar Atul , Dijkmans Ben , Geusens Piet , Sieper Joachim , Williamson Paul , Xu Weichun , Visvanathan Sudha , Baker Daniel , Goldstein Neil , van der Heijde Désirée
Published: August 2008

Objective

To assess safety and efficacy of infliximab in patients with ankylosing spondylitis (AS) through 102 weeks.

Methods

Patients (n = 279) with active AS were randomized to either group 1 (n = 78; placebo through week 24 and then infliximab 5 mg/kg from weeks 24 through 96) or group 2 (n = 201; infliximab 5 mg/kg through week 96). The primary efficacy end point at week 24 (≥20% improvement in the ASsessment in Ankylosing Spondylitis International Working Group criteria [ASAS20]) was assessed with an intent‐to‐treat analysis of observed data.

Results

More patients in group 2 than group 1 achieved the ASAS20 response at week 24 (61.2% versus 19.2%; P < 0.001). By week 102, groups 1 and 2 were similar with regard to ASAS20 response (72.1% versus 73.9%); ASAS40 responses at week 102 were 45.9% versus 59.4%. No new safety issues were discerned.

Conclusion

Infliximab demonstrated sustained efficacy and safety over 2 years in this large cohort of patients with active AS.
Disease activity of rheumatoid arthritis during pregnancy: Results from a nationwide prospective study
Authors: de Man Yaël A. , Dolhain Radboud J. E. M. , van de Geijn Fleur E. , Willemsen Sten P. , Hazes Johanna M. W.
Published: August 2008

Objective

According to common knowledge and retrospective studies, approximately 75–90% of patients with rheumatoid arthritis (RA) will improve during pregnancy. Prospective data on disease activity during pregnancy are limited. Therefore, this study aimed to prospectively determine the disease activity during pregnancy in RA patients treated in an era of new treatment options.

Methods

For 84 RA patients (American College of Rheumatology criteria), a Disease Activity Score in 28 joints (DAS28) and medication use were obtained, before conception if possible, at each trimester of pregnancy and at 6, 12, and 26 weeks postpartum. Improvement and deterioration were determined by assessing changes in DAS28 and by applying the DAS28‐derived European League Against Rheumatism (EULAR) response criteria.

Results

Disease activity decreased with statistical significance (P = 0.035) during pregnancy and increased postpartum. In patients with at least moderate disease activity in the first trimester (n = 52), at least 48% had a moderate response during pregnancy according to EULAR‐defined response criteria. In patients with low disease activity in the first trimester (n = 32), disease activity was stable during pregnancy. Thirty‐nine percent of patients had at least a moderate flare postpartum according to reversed EULAR response criteria. Less medication was used during pregnancy compared with before conception and compared with postpartum.

Conclusion

This study demonstrates that patients achieve remission during pregnancy and deteriorate postpartum, although less frequently than previously described.
Generalized vibratory deficits in osteoarthritis of the hip
Authors: Shakoor Najia , Lee Kristen J. , Fogg Louis F. , Block Joel A.
Published: August 2008

Objective

Lower extremity sensory deficits, including reduced proprioception, joint kinesthesia, and, recently, vibratory sense, have been described in subjects with osteoarthritis (OA) of the knee. However, comparable deficits in OA of the hip have not previously been evaluated. Vibratory perception threshold (VPT) is a reliable measure used to assess sensory deficits and is amenable to testing multiple body sites. This study examined VPT at the upper and lower extremities of subjects with hip OA compared with subjects without hip OA.

Methods

Fourteen subjects with symptomatic and radiographic hip OA were compared with 13 age‐matched controls without hip OA. VPT was assessed using a biothesiometer. Five sites in the lower extremity and 1 site in the upper extremity (radial head) were evaluated and compared between OA and control subjects.

Results

VPT was significantly reduced at all 6 testing sites of the OA subjects compared with controls (P < 0.05 for all sites). VPT scores (mean ± SEM volts) for OA subjects and controls were as follows: first metatarsophalangeal joint (13.5 ± 1.4 versus 7.4 ± 0.7), medial malleolus (18.1 ± 2.6 versus 11.2 ± 1.7), lateral malleolus (20.9 ± 2.4 versus 10.6 ± 1.5), medial femoral condyle (22.8 ± 2.9 versus 12.6 ± 1.3), lateral femoral condyle (26.7 ± 2.6 versus 16.2 ± 1.9), and radial head (10.2 ± 0.8 versus 7.5 ± 0.6).

Conclusion

To our knowledge, this is the first study to evaluate sensory deficits in hip OA and to demonstrate that there is vibratory sense loss at both the upper and lower extremities in these subjects compared with controls. The noted generalized deficits may have significant implications in the neuromechanical pathophysiology of OA.
Associations of back and leg pain with health status and functional capacity of older adults: Findings from the retirement community back pain study
Authors: Hicks Gregory E. , Gaines Jean M. , Shardell Michelle , Simonsick Eleanor M.
Published: August 2008

Objective

Low back pain (LBP) is the most frequently reported musculoskeletal problem in older adults, but its impact on health status is not well understood. Our objective was to determine whether LBP and concurrent leg pain are associated with health‐related quality of life (HRQOL) and function in a cohort of older adults, and to examine care‐seeking behaviors related to LBP.

Methods

This was a population‐based, cross‐sectional survey study of 522 community‐dwelling men and women (67.4%) ages ≥62 living in 4 retirement communities in Maryland and northern Virginia. LBP status in the past year was categorized as no pain in the low back or leg, LBP only, and LBP with leg pain. HRQOL and function were measured with the Medical Outcomes Study Short Form 36 (SF‐36).

Results

A total of 26.8% of the sample reported LBP only and 21.3% reported LBP plus leg pain. Participants with LBP and LBP plus leg pain had lower scores in all SF‐36 domains, reflecting worse HRQOL (P < 0.0001). LBP and LBP plus leg pain were associated with 2‐fold greater odds of falling and increased difficulty lifting grocery bags, walking several blocks, and bathing. LBP plus leg pain was associated with difficulty in social interactions (odds ratio 10.63, 95% confidence interval 3.57–31.60). Less than half sought care for LBP and those who did had poorer health status and greater pain burden.

Conclusion

LBP is common among older adults and strongly associated with reduced HRQOL and function. These findings argue strongly for both identifying cases of LBP by health care practitioners and pursuing effective treatments for LBP given the potential consequences.
Effect of therapeutic exercise for hip osteoarthritis pain: Results of a meta‐analysis
Authors: Hernández‐Molina Gabriela , Reichenbach Stephan , Zhang Bin , Lavalley Michael , Felson David T.
Published: August 2008

Objective

Recommendations for lower extremity osteoarthritis (OA) and exercise have been primarily based on knee studies. To provide more targeted recommendations for the hip, we gathered evidence for the efficacy of exercise for hip OA from randomized controlled trials.

Methods

A bibliographic search identified trials that were randomized, controlled, completed by ≥60% of subjects, and involved an exercise group (strengthening and/or aerobic) versus a nonexercise control group for pain relief in hip OA. Two reviewers independently performed the data extraction and contacted the authors when necessary. Effect sizes (ES) of treatment versus control and the I2statistic to assess heterogeneity across trials were calculated. Trial data were combined using a random‐effects meta‐analysis.

Results

Nine trials met the inclusion criteria (1,234 subjects), 7 of which combined hip and knee OA; therefore, we contacted the authors who provided the data on hip OA patients. In comparing exercise treatment versus control, we found a beneficial effect of exercise with an ES of −0.38 (95% confidence interval [95% CI] −0.68, −0.08;P= 0.01), but with high heterogeneity (I2= 75%) among trials. Heterogeneity was caused by 1 trial consisting of an exercise intervention that was not administered in person. Removing this study left 8 trials (n = 493) with similar exercise strategy (specialized hands‐on exercise training, all of which included at least some element of muscle strengthening), and demonstrated exercise benefit with an ES of −0.46 (95% CI −0.64, −0.28;P< 0.0001).

Conclusion

Therapeutic exercise, especially with an element of strengthening, is an efficacious treatment for hip OA.
Effects of specialized footwear on joint loads in osteoarthritis of the knee
Authors: Shakoor Najia , Lidtke Roy H. , Sengupta Mondira , Fogg Louis F. , Block Joel A.
Published: August 2008

Objective

Elevated dynamic joint loads have been associated with the severity and progression of osteoarthritis (OA) of the knee. This study compared the effects of a specialized shoe (the mobility shoe) designed to lower dynamic loads at the knee with self‐chosen conventional walking shoes and with a commercially available walking shoe as a control.

Methods

Subjects with knee OA were evaluated in 2 groups. Group A (n = 28) underwent gait analyses with both their self‐chosen walking shoes and the mobility shoes. Group B (n = 20) underwent gait analyses with a control shoe and the mobility shoe. Frontal plane knee loads were compared between the different footwear conditions.

Results

Group A demonstrated an 8% reduction in the peak external knee adduction moment with the mobility shoe compared with self‐chosen walking shoes (mean ± SD 49 ± 0.80 versus 2.71 ± 0.84 %BW × H; P < 0.05). Group B demonstrated a 12% reduction in the peak external knee adduction moment with the mobility shoe compared with the control shoe (mean ± SD 2.66 ± 0.69 versus 3.07 ± 0.75 %BW × H; P < 0.05).

Conclusion

Specialized footwear can effectively reduce joint loads in subjects with knee OA, compared with self‐chosen shoes and control walking shoes. Footwear may represent a therapeutic target for the treatment of knee OA. The types of shoes worn by subjects with knee OA should be evaluated more closely in terms of their effects on the disease.
Features associated with, and the impact of, hemolytic anemia in patients with systemic lupus erythematosus: LX, results from a multiethnic cohort
Authors: Durán Sergio , Apte Mandar , Alarcón Graciela S. , Marion Miranda C. , Edberg Jeffrey C. , Kimberly Robert P. , Zhang Jie , Langefeld Carl D. , ViLá Luis M. , Reveille John D.
Published: August 2008

Objective

To examine the clinical and genetic correlates of hemolytic anemia and its impact on damage accrual and mortality in systemic lupus erythematosus (SLE) patients.

Methods

SLE patients (American College of Rheumatology [ACR] criteria) of Hispanic (Texan or Puerto Rican), African American, and Caucasian ethnicity from the LUMINA (LUpus in MInorities, NAture versus nurture) cohort were studied. Hemolytic anemia was defined as anemia with reticulocytosis (ACR criterion). The association between degrees of hemolytic anemia and socioeconomic/demographic, clinical, pharmacologic, immunologic, psychological, and behavioral variables was examined by univariable and multivariable (proportional odds model) analyses. Genetic variables (FCGR and Fas/Fas ligand polymorphisms) were examined by 2 degrees of freedom test of association and Cochran‐Armitage trend tests. The impact of hemolytic anemia on damage accrual and mortality was examined by multivariable linear and Cox regression analyses, respectively.

Results

Of 628 patients studied, 90% were women, 19% were Texan Hispanic, 16% were Puerto Rican Hispanic, 37% were African American, and 28% were Caucasian. Sixty‐five (10%) patients developed hemolytic anemia at some time during the disease course, 83% at or before diagnosis. Variables independently associated with degrees of hemolytic anemia were African American ethnicity, thrombocytopenia, and the use of azathioprine. Hemolytic anemia was associated with damage accrual after adjusting for variables known to affect this outcome; however, hemolytic anemia was not associated with mortality.

Conclusion

The association of hemolytic anemia with thrombocytopenia suggests a common mechanism in their pathophysiology. Hemolytic anemia is an early disease manifestation and is associated with African American ethnicity and the use of azathioprine; it appears to exert an impact on damage but not on mortality.
Implementation of advanced technologies in commercial monoclonal antibody production
Authors: Zhou Joe X. , Tressel Tim , Yang Xiaoming , Seewoester Thomas
Published: August 2008

Process advancements driven through innovations have been key factors that enabled successful commercialization of several human therapeutic antibodies in recent years. The production costs of these molecules are higher in comparison to traditional medicines. In order to lower the development and later manufacturing costs, recent advances in antibody production technologies target higher throughput processes with increased clinical and commercial economics. In this review, essential considerations and trends for commercial process development and optimization are described, followed by the challenges to obtain a high titer cell culture process and its subsequent impact on the purification process. One of these recent technical advances is the development and implementation of a disposable Q membrane adsorber as an alternative to a Q‐packed‐bed column in a flow‐through mode. The scientific concept and principles underlining Q membrane technology and its application are also reviewed.
Application of magnetic force‐based cell patterning for controlling cell–cell interactions in angiogenesis
Authors: Ino Kosuke , Okochi Mina , Honda Hiroyuki
Published: August 2008

To investigate the effects of cell–cell interactions on cellular function, the microenvironment surrounding cells should be precisely controlled. Here, we describe a cell patterning technique, which utilizes magnetic force and magnetite nanoparticles. This method was used to develop cell culture arrays for investigation of cell behaviors in angiogenesis. Pin holder devices that contain more than 6,000 pillars on the surface are used for fabricating the cell culture arrays by setting it on a magnet. The magnetically labeled cells were arranged by magnetic distribution. When the human umbilical vein endothelial cells are arranged at 250 µm intervals (5.9 cells/spot), the cells spread toward other cell cluster on adjacent spots in 4.5 h, and formed cord‐like structures in 8.5 h. It was shown that cell–cell interactions were successfully investigated using magnetic cell arrangement. Biotechnol. Bioeng. 2009; 102: 882–890. © 2008 Wiley Periodicals, Inc.
Dynamic compressive loading influences degradation behavior of PEG‐PLA hydrogels
Authors: Nicodemus G.D. , Shiplet K.A. , Kaltz S.R. , Bryant S.J.
Published: August 2008

Biodegradable hydrogels are attractive 3D environments for cell and tissue growth. In cartilage tissue engineering, mechanical stimulation has been shown to be an important regulator in promoting cartilage development. However, the impact of mechanical loading on the gel degradation kinetics has not been studied. In this study, we examined hydrolytically labile gels synthesized from poly(lactic acid)‐b‐poly(ethylene glycol)‐b‐poly‐(lactic acid) dimethacrylate macromers, which have been used for cartilage tissue engineering. The gels were subject to physiological loading conditions in order to examine the effects of loading on hydrogel degradation. Initially, hydrogels were formed with two different cross‐linking densities and subject to a dynamic compressive strain of 15% at 0.3, 1, or 3 Hz. Degradation behavior was assessed by mass loss, equilibrium swelling and compressive modulus as a function of degradation time. From equilibrium swelling, the pseudo‐first‐order reaction rate constants were determined as an indication of degradation kinetics. The application of dynamic loading significantly enhanced the degradation time for the low cross‐linked gels (P < 0.01) while frequency showed no statistical differences in degradation rates or bulk erosion profiles. In the higher cross‐linked gels, a 3 Hz dynamic strain significantly increased the degradation kinetics resulting in an overall faster degradation time by 6 days compared to gels subject to the 0.3 and 1 Hz loads (P < 0.0001). The bioreactor set‐up also influenced overall degradation behavior where the use of impermeable versus permeable platens resulted in significantly lower degradation rate constants for both cross‐linked gels (P < 0.001). The compressive modulus exponentially decreased with degradation time under dynamic loading. Together, our findings indicate that both loading regime and the bioreactor setup influence degradation and should be considered when designing and tuning a biodegradable hydrogel where mechanical stimulation is employed. Biotechnol. Bioeng. 2009; 102: 948–959. © 2008 Wiley Periodicals, Inc.
Flow dynamics in bioreactors containing tissue engineering scaffolds
Authors: Lawrence Benjamin J. , Devarapalli Mamatha , Madihally Sundararajan V.
Published: August 2008

Bioreactors are widely used in tissue engineering as a way to distribute nutrients within porous materials and provide physical stimulus required by many tissues. However, the fluid dynamics within the large porous structure are not well understood. In this study, we explored the effect of reactor geometry by using rectangular and circular reactors with three different inlet and outlet patterns. Geometries were simulated with and without the porous structure using the computational fluid dynamics software Comsol Multiphysics 3.4 and/or ANSYS CFX 11 respectively. Residence time distribution analysis using a step change of a tracer within the reactor revealed non‐ideal fluid distribution characteristics within the reactors. The Brinkman equation was used to model the permeability characteristics with in the chitosan porous structure. Pore size was varied from 10 to 200 µm and the number of pores per unit area was varied from 15 to 1,500 pores/mm2. Effect of cellular growth and tissue remodeling on flow distribution was also assessed by changing the pore size (85–10 µm) while keeping the number of pores per unit area constant. These results showed significant increase in pressure with reduction in pore size, which could limit the fluid flow and nutrient transport. However, measured pressure drop was marginally higher than the simulation results. Maximum shear stress was similar in both reactors and ranged ∼0.2–0.3 dynes/cm2. The simulations were validated experimentally using both a rectangular and circular bioreactor, constructed in‐house. Porous structures for the experiments were formed using 0.5% chitosan solution freeze‐dried at −80°C, and the pressure drop across the reactor was monitored. Biotechnol. Bioeng. 2009; 102: 935–947. © 2008 Wiley Periodicals, Inc.
Evaluation of metabolism using stoichiometry in fermentative biohydrogen
Authors: Lee Hyung‐Sool , Rittmann Bruce E.
Published: August 2008

We first constructed full stoichiometry, including cell synthesis, for glucose mixed‐acid fermentation at different initial substrate concentrations (0.8–6 g‐glucose/L) and pH conditions (final pH 4.0–8.6), based on experimentally determined electron‐equivalent balances. The fermentative bioH2 reactions had good electron closure (−9.8 to +12.7% for variations in glucose concentration and −3 to +2% for variations in pH), and C, H, and O errors were below 1%. From the stoichiometry, we computed the ATP yield based on known fermentation pathways. Glucose‐variation tests (final pH 4.2–5.1) gave a consistent fermentation pattern of acetate + butyrate + large H2, while pH significantly shifted the catabolic pattern: acetate + butyrate + large H2 at final pH 4.0, acetate + ethanol + modest H2 at final pH 6.8, and acetate + lactate + trivial H2 at final pH 8.6. When lactate or propionate was a dominant soluble end product, the H2 yield was very low, which is in agreement with the theory that reduced ferredoxin (Fdred) formation is required for proton reduction to H2. Also consistent with this hypothesis is that high H2 production correlated with a high ratio of butyrate to acetate. Biomass was not a dominant sink for electron equivalents in H2 formation, but became significant (12%) for the lowest glucose concentration (i.e., the most oligotrophic condition). The fermenting bacteria conserved energy similarly at ∼3 mol ATP/mol glucose (except 0.8 g‐glucose/L, which had ∼3.5 mol ATP/mol glucose) over a wide range of H2 production. The observed biomass yield did not correlate with ATP conservation; low observed biomass yields probably were caused by accelerated rates of decay or production of soluble microbial products. Biotechnol. Bioeng. 2009; 102: 749–758. © 2008 Wiley Periodicals, Inc.
Generation of New Derivatives of the Antitumor Antibiotic Mithramycin by Altering the Glycosylation Pattern through Combinatorial Biosynthesis
Authors: Pérez María , Baig Irfan , Braña Alfredo F. , Salas José A. , Rohr Jürgen , Méndez Carmen
Published: August 2008

Mithramycin is an antitumor drug produced by Streptomyces argillaceus. It consists of a tricyclic aglycone and five deoxyhexoses that form a disaccharide and a trisaccharide chain, which are important for target interaction and therefore for the antitumor activity. Using a combinatorial biosynthesis approach, we have generated nine mithramycin derivatives, seven of which are new compounds, with alterations in the glycosylation pattern. The wild‐type S. argillaceus strain and the mutant S. argillaceus M7U1, which has altered D‐oliose biosynthesis, were used as hosts to express various “sugar plasmids”, each one directing the biosynthesis of a different deoxyhexose. The newly formed compounds were purified and characterized by MS and NMR. Compared to mithramycin, they contained different sugar substitutions in the second (D‐olivose, D‐mycarose, or D‐boivinose instead of D‐oliose) and third (D‐digitoxose instead of D‐mycarose) sugar units of the trisaccharide as well as in the first (D‐amicetose instead of D‐olivose) sugar unit of the disaccharide. All compounds showed antitumor activity against different tumor cell lines. Structure–activity relationships are discussed on the basis of the number and type of deoxyhexoses present in these mithramycin derivatives.
Site‐Specific Chemical Modification of Proteins with a Prelabelled Cysteine Tag Using the Artificially Split Mxe GyrA Intein
Authors: Kurpiers Thomas , Mootz Henning D.
Published: August 2008

The selective modification of proteins with a synthetic probe is of central interest for many aspects of protein chemistry. We have recently reported a new approach in which a short cysteine‐containing tag (CysTag) fused to one part of a split intein is first modified with a sulfhydryl‐reactive probe. In a second step, protein trans‐splicing is used to link the labelled CysTag to a target protein that has been expressed in fusion with the complementary split intein fragment. Here, we present the generation and biochemical characterisation of the artificially split Mycobacterium xenopi GyrA intein. We show that this split intein is active without a renaturation step and that it provides a significant improvement for the CysTag protein‐labelling approach in terms of product yields and target protein tolerance. Two proteins with multiple cysteine residues, human growth hormone and a multidomain nonribosomal peptide synthetase, were site‐specifically modified with high yields. Our approach combines the benefits of the plethora of commercially available cysteine‐reactive probes with a straightforward route for their site‐specific incorporation even into complex and cysteine‐rich proteins.
Comparison of Design Strategies for Promotion of β‐Peptide 14‐Helix Stability in Water
Authors: Vaz Esther , Pomerantz William C. , Geyer Matthias , Gellman Samuel H. , Brunsveld Luc
Published: August 2008

Many short β‐peptides adopt well‐defined conformations in organic solvents, but specialized stabilizing elements are required for folding to occur in aqueous solution. Several different strategies to stabilize the 14‐helical secondary structure in water have been developed, and here we provide a direct comparison of three such strategies. We have synthesized and characterized β‐peptide heptamers in which variously a salt bridge between side chains, a covalent link between side chains, or two cyclically constrained residues have been incorporated to promote 14‐helicity. The incorporation of a salt bridge does not generate significant 14‐helicity in water, according to CD and 2D NMR data. In contrast, incorporation either of a lactam bridge between side chains or of cyclic residues results in stable 14‐helices in water. The β‐peptides featuring trans‐2‐aminocyclohexanecarboxylic acid (ACHC) residues show the highest 14‐helical backbone stability, with hardly any sensitivity to pH or ionic strength. The β‐peptides featuring side‐chain‐to‐side‐chain cyclization show lower 14‐helical backbone stability and higher sensitivity to pH and ionic strength, but increased order between the side chains because of the cyclization.
Small‐Molecule Negative Modulators of Adrenomedullin: Design, Synthesis, and 3D‐QSAR Study
Authors: Roldós Virginia , Martín‐Santamaría Sonsoles , Julián Miguel , Martínez Alfredo , Choulier Laurence , Altschuh Danièle , de Pascual‐Teresa Beatriz , Ramos Ana
Published: August 2008

Adrenomedullin (AM) is a peptidic hormone that was isolated in 1993, the function of which is related to several diseases such as diabetes, hypertension, and cancer. Compound 1 is one of the first nonpeptidic small‐molecule negative modulators of AM, identified in a high‐throughput screen carried out at the National Cancer Institute. Herein we report the synthesis of a series of analogues of 1. The ability of the synthesized compounds to disrupt the binding between AM and its monoclonal antibody has been measured, together with surface plasmon resonance (SPR)‐based binding assays as implemented with Biacore technology. These data were used to derive a three‐dimensional quantitative structure–activity relationship (3D‐QSAR) model, with a q2 (LOO) value of 0.8240. This study has allowed us to identify relevant features for effective binding to AM: the presence of a hydrogen‐bond donor group and an aromatic ring. Evaluation of the ability of selected compounds to modify cAMP production in Rat2 cells showed that the presence of a free carboxylic acid is essential for negative AM modulation.
Apoptosis‐Inducing High .NO Concentrations Are Not Sustained Either in Nascent or in Developed Cancers
Authors: Heller Adam
Published: August 2008

Nitric oxide (.NO) induces apoptosis at high concentrations by S‐nitrosating proteins such as glyceraldehyde‐3‐phosphate dehydrogenase. This literature analysis revealed that failure to sustain high .NO concentrations is common to all cancers. In cervical, gastric, colorectal, breast, and lung cancer, the cause of this failure is the inadequate expression of inducible nitric oxide synthase (iNOS), resulting from the inhibition of iNOS expression by TGF‐β1 at the mRNA level. In bladder, renal, and prostate cancer, the reason for the insufficient .NO levels is the depletion of arginine, resulting from arginase overexpression. Arginase competes with iNOS for arginine, catalyzing its hydrolysis to ornithine and urea. In gliomas and ovarian sarcomas, low .NO levels are caused by inhibition of iNOS by N‐chlorotaurine, produced by infiltrating neutrophils. Stimulated neutrophils express myeloperoxidase, catalyzing H2O2 oxidation of Cl− to HOCl, which N‐chlorinates taurine at its concentration of 19 mM in neutrophils. In squamous cell carcinomas of the skin, ovarian cancers, lymphomas, Hodgkin's disease, and breast cancers, low .NO concentrations arise from the inhibition of iNOS by N‐bromotaurine, produced by eosinophil‐peroxidase‐expressing infiltrating eosinophils. Eosinophil peroxidase catalyzes the H2O2 oxidation of Br− to HOBr, which N‐brominates taurine to N‐bromotaurine at its concentration of 15 mM in eosinophils. In microvascularized tumors, the .NO concentration is further depleted; .NO is rapidly consumed by red blood cells (RBCs) through S‐nitrosation of RBC glutathione and hemoglobin, and by oxidation to nitrate by RBC oxyhemoglobin. Angiogenesis‐inhibiting antibodies are currently used to treat cancers; their mode of action is not, as previously thought, reduction of the tumor O2 or nutrient supply. They actually decrease the loss of .NO to RBCs.
Treatment of unresectable cholangiocarcinoma using yttrium‐90 microspheres
Authors: Ibrahim Saad M. , Mulcahy Mary F. , Lewandowski Robert J. , Sato Kent T. , Ryu Robert K. , Masterson Elizabeth J. , Newman Steven B. , Benson Al , Omary Reed A. , Salem Riad
Published: August 2008

BACKGROUND.

The objective of this report was to present data from an open‐label cohort study in which patients with intrahepatic cholangiocarcinoma (ICC) underwent radioembolization with yttrium‐90 (90Y) microspheres.

METHODS.

Twenty‐four patients with histologically proven ICC were treated. The planned target dose was 120 Gray. Patients were stratified according to Eastern Cooperation Oncology Group (ECOG) performance status, tumor morphology (infiltrative vs peripheral), tumor distribution (solitary vs multifocal), and the presence or absence of portal vein thrombosis (PVT). Before and after the procedure, the following variables were assessed: 1) biochemical and clinical toxicity, 2) imaging (computed tomography/magnetic resonance imaging) response according to World Health Organization and European Association for the Study of Liver Disease (EASL) criteria, and 3) median survival after the first treatment using Kaplan‐Meier methodology.

RESULTS.

In total, 48 90Y treatments were administered to hepatic segments or lobes. Fatigue and transient abdominal pain were reported in 18 patients (75%) and 10 patients (42%), respectively. One patient (4%) developed grade 3 bilirubin toxicity. One patient (4%) developed a treatment‐related gastroduodenal ulcer. On imaging follow‐up of 22 patients, tumors demonstrated a partial response in 6 patients (27%), stable disease in 15 patients (68%), and progressive disease in 1 patient (5%). By using EASL guidelines, 17 patients (77%) showed >50% tumor necrosis on imaging follow‐up. Two patients (9%) demonstrated 100% tumor necrosis. The median overall survival for the entire cohort (n = 24) was 14.9 months. The median survival for patients with an ECOG performance status of 0, 1, and 2 was 31.8 months, 6.1 months, and 1 month, respectively (P < .0001); the median survival for patients without and with PVT was 31.8 months and 5.7 months, respectively (P = .0003); and the median survival for patients with peripheral versus periductal‐infiltrative tumors was 31.8 months and 5.7 months, respectively (P = .0005).

CONCLUSIONS.

Radioembolization with 90Y may be a therapeutic option for the treatment of unresectable ICC. Cancer 2008. © 2008 American Cancer Society.
Early treatment of high‐risk chronic lymphocytic leukemia with alemtuzumab and rituximab
Authors: Zent Clive S. , Call Timothy G. , Shanafelt Tait D. , Tschumper Renee C. , Jelinek Diane F. , Bowen Deborah A. , Secreto Charla R. , LaPlant Betsy R. , Kabat Brian F. , Kay Neil E.
Published: August 2008

BACKGROUND.

Patients with chronic lymphocytic leukemia (CLL) usually are treated only for progressive disease. However, the discovery of biologic predictors of a high risk of disease progression, together with the development of newer, more targeted therapies, could change this paradigm. In this phase 2 study, the authors tested the safety and efficacy of early treatment for patients with high‐risk CLL using alemtuzumab and rituximab.

METHODS.

Patients were eligible for treatment if they were 1) previously untreated, 2) had no National Cancer Institute‐Working Group 1996 criteria for treatment, and 3) had at least 1 marker of high‐risk disease 17p13−, 11q22−, or a combination of unmutated IgVH and CD38+/ZAP70+). Treatment consisted of subcutaneous alemtuzumab (initial dose escalation followed by 30 mg on Monday, Wednesday, and Friday for 4 weeks) and intravenous rituximab (375 mg/m2 per week ×4 doses). All patients received Pneumocystis pneumonia and herpes virus prophylaxis and were monitored for cytomegalovirus reactivation.

RESULTS.

Twenty‐seven of 30 patients (90%) responded to therapy with 11 (37%) complete responses (CRs). Five patients (17%) patients who had a CR had no detectable minimal residual disease. The median response duration was 14.4 months, and only 9 patients required retreatment for progressive disease at the time of the current report (median follow‐up, 17.6 months). Study patients had a significantly longer time from diagnosis to first treatment for CLL according to conventional indications than a comparison cohort with similar biologic risk profiles.

CONCLUSIONS.

The therapy regimen used was safe and effective for early treatment of patients with high‐risk CLL. Further studies will be required to determine whether this early treatment strategy decreases morbidity and mortality for high‐risk CLL. Cancer 2008. © 2008 American Cancer Society.
Donor–Acceptor Systems: Energy Transfer from CdS Quantum Dots/Rods to Nile Red Dye
Authors: Sadhu Suparna , Patra Amitava
Published: August 2008

We demonstrate strong evidence of shape‐dependent efficient resonance energy transfer between CdS quantum dots (QDs) and quantum rods (QRs) (donor) to Nile Red dye (acceptor). We also report a simple solution‐based method for the preparation of high quality CdS QDs and CdS QRs at relatively low temperature. The observed quenching of PL intensities are 78.8 % and 63.8 % for CdS QDs and QRs, respectively in the presence of Nile Red dye. The calculated energy‐transfer efficiencies are 45 % and 19 % from QDs and QRs to dyes, respectively. The energy transfer varies with changing the shape of the nanoparticles. The estimated Förster distances (R0) are 37.8 and 33.8 Å for CdS QDs and QRs, respectively. In the present study, the estimated distances (r) between one donor and one acceptor are 39.1 and 43.1 Å for QDs and QRs, respectively, using the efficiency of Förster resonance energy transfer (FRET) which depends on the inverse sixth power of the distance of separations between one nanocrystal and one dye molecule. Considering single donor and multiple acceptors interactions, the calculated average distances (rn) between the donor and acceptor are 47.7 and 53.9 Å for QD’s and QR’s, respectively. The steady‐state and time‐resolved spectroscopic analysis of nanoassemblies confirm the formation of one donor and multiple acceptors.
Inflamed adipose tissue, insulin resistance and vascular injury
Authors: Andersson Christian X. , Gustafson Birgit , Hammarstedt Ann , Hedjazifar Shahram , Smith Ulf
Published: August 2008

Type 2 diabetes is the most common metabolic disorder today and has reached epidemic proportions in many countries. Insulin resistance and inflammation play a central role in the pathogenesis of type 2 diabetes and are present long before the onset of the disease. During this time, many of the complications associated with type 2 diabetes are initiated. Of major concern is the two‐ to fourfold increase in cardiovascular morbidity and mortality in this group compared to a nondiabetic population. Obesity, characterized by enlarged fat cells, and insulin resistance are, like type 2 diabetes, associated with impaired adipogenesis and a low‐grade chronic inflammation that to a large extent emanates from the adipose tissue. Both these processes contribute to unfavourable alterations of the circulating levels of several bioactive molecules (adipokines) that are secreted from the adipose tissue, many of which have documented inhibitory effects on insulin sensitivity in the liver and peripheral tissues and, in addition, have negative effects on the cardiovascular system.

Here we review current knowledge of the adipose tissue as an endocrine organ, the local and systemic effects of a chronic state of low‐grade inflammation residing in the adipose tissue, and, in particular, the effects of inflammation and circulating adipokines on the vascular wall. Copyright © 2008 John Wiley & Sons, Ltd.
Variable Coordination Modes of Benzaldehyde Thiosemicarbazones – Synthesis, Structure, and Electrochemical Properties of Some Ruthenium Complexes
Authors: Dutta Swati , Basuli Falguni , Castineiras Alfonso , Peng Shie‐Ming , Lee Gene‐Hsiang , Bhattacharya Samaresh
Published: August 2008

Reaction of benzaldehyde thiosemicarbazones [H2LR, where H2 stands for the two protons, the hydrazinic proton, and the phenyl proton at the ortho position, with respect to the imine function and R (R = OCH3, CH3, H, Cl, and NO2) for the para substituent] with [Ru(PPh3)2(CO)2Cl2], carried out in refluxing ethanol, afforded monomeric complexes of type [Ru(PPh3)2(CO)(HLR)(H)]. The crystal structure of the [Ru(PPh3)2(CO)(HLNO2)(H)] complex was determined. The thiosemicarbazone ligand is coordinated to the ruthenium center as a bidentate N,S‐donor ligand forming a four‐membered chelate ring. When the reaction of the thiosemicarbazones with [Ru(PPh3)2(CO)2Cl2] was carried out in refluxing toluene, a family of dimeric complexes of type [Ru2(PPh3)2(CO)2(LR)2] were obtained. The crystal structure of [Ru2(PPh3)2(CO)2(LCl)2] was determined. Each thiosemicarbazone ligand is coordinated to one ruthenium atom, by dissociation of the two protons, as a dianionic tridentate C,N,S‐donor ligand, and at the same time the sulfur atom is also bonded to the second ruthenium center. 1H NMR spectra of the complexes of both types are in excellent agreement with their compositions. All the dimeric and monomeric complexes are diamagnetic (low‐spin d6, S = 0) and show intense absorptions in the visible and ultraviolet regions. Cyclic voltammetry of the [Ru(PPh3)2(CO)(HLR)(H)] and [Ru2(PPh3)2(CO)2(LR)2] complexes show the ruthenium(II)–ruthenium(III) oxidation within 0.48–0.73 V vs. SCE followed by a ruthenium(III)–ruthenium(IV) oxidation within 1.09–1.47 V vs. SCE. Potentials of both the oxidations are found to correlate linearly with the electron‐withdrawing character of the substituent R. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Rational Assembly of High‐Spin Polynuclear Magnetic Complexes into Coordination Networks: the Case of a [Mn4] Single‐Molecule Magnet Building Block
Authors: Roubeau Olivier , Clérac Rodolphe
Published: August 2008

The synthesis of transition‐metal high‐spin complexes and of infinite coordination networks of these high‐spin carriers now represents a recognized subdiscipline of coordination chemistry. This new research trend has been particularly encouraged by the discoveries that molecular and one‐dimensional coordination aggregates may behave as nanomagnets, as illustrated by the so‐called single‐molecule magnets (SMMs) and single‐chain magnets (SCMs). While the synthesis of isolated polynuclear high‐spin complexes still rely mostly on serendipitous assembly with appropriate ligands, the synthesis of SCMs or extended networks of high‐spin complexes demands a more designed and controlled bottom‐up assembly of precursor complexes and bridging species selected for their coordination abilities. In this context, the case of a [Mn4] SMM is unique in the literature, as one‐, two‐, and three‐dimensional networks have been rationally designed by using this SMM unit as a building block, giving rise to original magnetic properties. This review gathers all reported systems that we know of, having the corresponding [Mn4O6] core, either in isolated complexes or in frameworks. Their structures and, when relevant, the synthetic strategy and magnetic properties are described. The demonstrated and potential outcomes, in terms of physical properties, of such coordination assemblies of high‐spin complexes are then discussed. These are highlighted through examples with other building blocks, to broaden the scope of possible strategies and building blocks, and thus provide a basis for the further development of this promising area. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Tetranuclear and Octanuclear Cobalt(II) Citrate Cluster Single Molecule Magnets
Authors: Moubaraki Boujemaa , Murray Keith S. , Hudson Timothy A. , Robson Richard
Published: August 2008

In a follow‐up study of the cobalt(II) member 1 of a family of isostructural cubane clusters of type [C(NH2)3]8[MII4(cit)4]·8H2O (cit = citrate, M = Mg, Mn, Fe, Co, Ni, Zn) by measuring AC magnetic susceptibilities, as a function of frequency, this compound clearly displays behaviour typical of magnetization reversal and slow magnetic relaxation (ΔE = 13.1 K, τo = 8.4 × 10–7 s). A related octanuclear cluster [Co8(C4O7)4(H2O)12]·24H2O (2) that contains a [Co4(C4O7)4] cubane moiety, behaves likewise (ΔE = 20.5 K, τo = 1.0 × 10–7 s).(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)