bluuebunny/crossref_metadata_2025 huggingface dataset:
Trust in physicians and elements of the medical interaction in patients with rheumatoid arthritis and systemic lupus erythematosus
Authors: Berrios‐rivera Javier P. , Street Richard L. , Garcia Popa‐lisseanu Maria G. , Kallen Michael A. , Richardson Marsha N. , Janssen Namieta M. , Marcus Donald M. , Reveille John D. , Warner Noranna B. , Suarez‐almazor Maria E.
Published: June 2006

Objective

To identify components of the patient‐doctor relationship associated with trust in physicians.

Methods

We assessed 102 patients with systemic lupus erythematosus (SLE) or rheumatoid arthritis (RA) seen at publicly funded hospitals in Houston, Texas. Patients completed a self‐response survey examining patient perceptions of the medical encounter and trust in their physicians. Evaluated components of physicians' behaviors included: informativeness, sensitivity to concerns, reassurance and support, patient‐centeredness, and participatory decision‐making style. Scales were scored 0 to 10, with higher numbers indicating more positive perceptions of communication.

Results

Seventy patients had RA and 32 SLE; 25% were white, 43% Latino, 31% African American, and 75% were female. Mean scores for the medical interaction and trust scales ranged from 6.2–7.1, indicating moderate degrees of positive perceptions. All components were highly and positively correlated with each other, and with trust, suggesting that these traits are all elements of a positive style of doctor‐patient communication. In multivariate analysis, ethnicity, physicians' informativeness, physicians' sensitivity to concerns, patient‐centeredness, disease activity, and patient trust in the US health care system were independent predictors of trust in physicians. A separate model examined the predictors of patient disclosure of information. Patient perceptions of physicians' patient‐centeredness and severity of disease activity were independently predictive of patient disclosure of information.

Conclusion

In patients with SLE and RA, trust in physicians is significantly associated with patients' ethnicity and their perceptions about specific components of physicians' communication style. Trust in physicians can be improved by using a patient‐centered approach, being sensitive to patient concerns, and providing adequate clinical information. Furthermore, patients appear to be more willing to disclose concerns when physicians use a patient‐centered communication style.
Differences in disease outcomes between medicaid and privately insured children: Possible health disparities in juvenile rheumatoid arthritis
Authors: Brunner Hermine I. , Taylor Janalee , Britto Maria T. , Corcoran Melinda S. , Kramer Sandy L. , Melson Paula G. , Kotagal Uma R. , Graham T. Brent , Passo Murray H.
Published: June 2006

Objective

To determine the relationship between health insurance status and disease outcome in children with juvenile rheumatoid arthritis (JRA).

Methods

JRA patients followed at a tertiary pediatric rheumatology center were assessed for the number of active joints and number of joints with limited range of motion. Disease activity, patient well‐being, and pain were measured. Disability was assessed by the Childhood Health Assessment Questionnaire, health‐related quality of life by the Pediatric Quality of Life Inventory (PedsQL) Generic Core Scale, and the PedsQL Rheumatology Module. Health care resource utilization was estimated based on the number of billing events for health services coded in administrative databases; these databases also provided information on patient health insurance status. Children insured by Medicaid or similar state programs for low‐income families were considered to have Medicaid status. Disease outcomes of children with Medicaid status was compared with that of children with private health insurance.

Results

Forty (14%) of the 295 children with JRA had Medicaid status. Patients with Medicaid status were more often of nonwhite race (P ≤ 0.04) and more frequently had a polyarticular or systemic disease course (P = 0.04) compared with other patients (n = 255). After correction for differences in disease duration, race, JRA onset, and JRA course between groups, children with Medicaid status continued to have significantly higher disability (P < 0.0003), and lower mean PedsQL Generic Core Scale scores (P < 0.05), while health resource utilization appeared similar between groups.

Conclusion

Despite apparently similar health resource utilization and joint involvement, Medicaid status is associated with significantly lower health‐related quality of life and higher disability in JRA.
Use of computerized assessment to predict neuropsychological functioning and emotional distress in patients with systemic lupus erythematosus
Authors: Roebuck‐spencer Tresa M. , Yarboro Cheryl , Nowak Miroslawa , Takada Kazuki , Jacobs Geneva , Lapteva Larissa , Weickert Thomas , Volpe Bruce , Diamond Betty , Illei Gabor , Bleiberg Joseph
Published: June 2006

Objective

Cognitive dysfunction and neuropsychiatric disturbance are common in systemic lupus erythematosus (SLE). This study addressed the ability of the Automated Neuropsychological Assessment Metrics (ANAM), a computerized cognitive testing battery consisting of cognitive subtests, a sleepiness rating scale, and a mood scale, to predict neuropsychological status in patients with SLE.

Methods

Sixty individuals with SLE and no overt neuropsychiatric symptoms were administered ANAM to determine its validity as a screening measure of cognitive dysfunction and emotional distress in SLE.

Results

Performance on ANAM was compared with results of a consecutively administered, 2‐hour battery of traditional neuropsychological tests and the Beck Depression Inventory II (BDI‐II). Individual ANAM cognitive test scores were significantly correlated with most neuropsychological tests, particularly those measuring psychomotor processing speed and executive functioning. Using logistic regression, ANAM cognitive subtests successfully predicted individuals with SLE who had probable versus no impairment after controlling for premorbid levels of cognitive ability. Sensitivity of group classification was 76.2% and specificity was 82.8%, with 80% correct classification overall. ANAM's ability to predict neuropsychological functioning remained even after controlling for subjective reports of depressed mood and current sleepiness. Further, the ANAM mood scale was significantly correlated with the BDI‐II (r = 0.67, P < 0.001), indicating its potential future use as a screening tool for emotional distress.

Conclusion

ANAM shows promise as a time‐ and cost‐efficient tool for screening and monitoring cognitive and emotional functioning in SLE, and can indicate when a more thorough neuropsychological investigation is warranted.
Pilot study of fitness training and exercise testing in polyarticular childhood arthritis
Authors: Singh‐grewal D. , Wright V. , Bar‐or O. , Feldman B. M.
Published: June 2006

Objective

To 1) assess the safety and feasibility of laboratory‐based exercise testing in juvenile idiopathic arthritis (JIA), 2) test the safety and feasibility of a 3‐month exercise program in JIA, 3) assess pain during exercise in JIA, 4) compare ratings of perceived effort (RPE) with heart rate (HR) achieved, and 5) estimate the training effect on metabolic efficiency of gait as measured by submaximal exercise testing.

Methods

Nine children with JIA were enrolled in a 12‐week circuit training program involving pool, stationary bicycle, treadmill, and Fitball. They underwent formal exercise testing before and after the program, underwent a full joint assessment, were administered the Childhood Health Assessment Questionnaire and Juvenile Arthritis Functional Status Index, and were assessed for overall quality of life and health‐related quality of life. A visual analog scale was used to assess pain during testing and training, and the Borg scale was used to measure RPE.

Results

Children with JIA were able to participate in exercise testing without any significant problems. Children with severe hip disease dropped out of the exercise program due to pain during the exercise sessions and worsened arthritis symptoms. Target HR was achieved and correlated with RPE in the bicycle and treadmill sessions. Submaximal exercise testing showed an improvement with a small to moderate effect size.

Conclusion

This study suggests that it is safe, feasible, and acceptable for children with arthritis, in the absence of severe hip involvement, to participate in formal exercise testing and structured fitness programs.
Raman and surface‐enhanced Raman spectroscopy investigation of vasopressin analogues containing 1‐aminocyclohexane‐1‐carboxylic acid residue
Authors: Podstawka Edyta , Sikorska Emilia , Proniewicz Leonard M. , Lammek Bernard
Published: June 2006

In this work, Raman spectroscopy (RS) was employed to characterize molecular structures of [Arg8]vasopressin (AVP) and its [Acc2,D‐Arg8]AVP, [Acc3]AVP, and [Cpa1, Acc3]AVP analogues. The RS band assignments have been proposed. To determine the mechanism of adsorption of the above‐mentioned compounds adsorbed on a colloidal silver surface, surface‐enhanced Raman spectra (SERS) were measured. The SERS spectra were used to determine relative proximity of the adsorbed functional groups of the investigated peptides and their orientation on the silver surface. The AVP and [Acc3]AVP SERS spectra (Acc: 1‐aminocyclohexane‐1‐carboxylic acid) show that the L‐tyrosine (Tyr) lies far from the metal surface, whereas the [Cpa1,Acc3]AVP spectrum (Cpa: 1‐mercaptocyclohexaneacetic acid) provides evidence that Tyr interacts with the silver surface. These results suggest the binding of the Tyr‐ionized phenolic group might be responsible for the selectivity of the analogues. We show that the aromatic ring of L‐phenylalanine (Phe) of AVP and [Acc2,D‐Arg8]AVP interacts with the silver surface. The strength of this interaction is considerably weaker for [Acc2,D‐Arg8]AVP than for AVP. This might be due either to a longer distance between the Phe ring and the silver surface, or to the almost perpendicular orientation of the Phe ring towards the surface. The carbonyl group of the L‐glutamine acid (Gln) or L‐asparagine acid (Asn) of AVP, [Acc2,D‐Arg8]AVP, and [Acc3]AVP is strongly bound to the silver surface. We have also found that all peptides adsorb on the silver surface via sulfur atoms of the disulfide bridge, adopting a “GGG” conformation, except [Cpa1,Acc3]AVP, which accepts a “TGG” geometry. © 2006 Wiley Periodicals, Inc. Biopolymers 83: 193–203, 2006

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Zeta potential as a diagnostic tool to evaluate the biomass electrostatic adhesion during ion‐exchange expanded bed application
Authors: Lin Dong‐Qiang , Zhong Li‐Na , Yao Shan‐Jing
Published: June 2006

Expanded bed adsorption is an integrative technology in downstream processing allowing the direct capture of target proteins from biomass (cells or cell debris) containing feedstocks. Potential adhesion of biomass on the surface of adsorbent, however, may hamper the application of this technique. Since the electrostatic forces dominate the interactions between biomass and adsorbent, the concept of zeta potential was introduced to characterize the biomass/adsorbent electrostatic interactions during expanded bed application. The criterion of zeta potential evaluation proposed in the previous paper (Biotechnol Bioeng, 83(2):149–157, 2003) was verified further with the experimental validation. The zeta potential of intact cells and homogenates of four microorganisms (Escherichia coli, Bacillus subtilis, Pichia pastoris, and S. cerevisiae) were measured under varying pH and salt concentration, and two ion‐exchange adsorbents (Streamline DEAE and Streamline QXL) were investigated. The biomass transmission index (BTI) from the biomass pulse response experiments was used as the indicator of biomass adhesion in expanded bed. Combining the influences from zeta potential of adsorbent (ζa), zeta potential of biomass (ζb) and biomass size (d), a good relationship was established between the zeta potential parameter (−ζaζbd) and BTI for all experimental conditions. The threshold value of parameter (−ζaζbd) can be defined as 120 mV2 µm for BTI above 0.9. This means that the systems with (−ζaζbd) < 120 show neglectable electrostatic bio‐adhesion, and would have a considerable probability of forming stable expanded beds in a biomass suspension under the particular experimental conditions. © 2006 Wiley Periodicals, Inc.
Receptor autoradiographic correlates of deafferentation‐induced reorganization in adult primate somatosensory cortex
Authors: Garraghty Preston E. , Arnold Lori L. , Wellman Cara L. , Mowery Todd M.
Published: June 2006

The primate somatosensory system provides an excellent model system with which to investigate adult neural plasticity. We have previously shown that transection of the median and ulnar nerves is followed by an expansion in the representation of radial nerve skin, and that this plasticity proceeds in stages. Immediately following nerve injury, new receptive fields are “unmasked” in a fraction of the affected cortex. The remaining deprived cortex regains responsiveness to tactile stimulation over the following days to weeks. Given these progressive changes, it has been suggested that different mechanisms might account for the earlier and later phases of reorganization. In the present experiments, we quantified receptor autoradiographic binding data for GABAA and GABAB, AMPA, and NMDA receptors in the primary somatosensory cortices of adult squirrel monkeys at four postnerve injury survival durations: immediately (1–3 hours), 3 days, 1 month, and 2 months. We found dramatic reductions in GABAA binding in layer IV within hours following nerve injury, and this reduction was maintained across all survival durations. This finding is consistent with the idea that the earliest reorganizational changes are due to a relaxation in tonic inhibitory mechanisms permitting the expression of formerly subthreshold receptive fields. GABAB receptor binding is decreased in layer IV by 1 month after nerve injury, while binding for AMPA receptors is increased in layer IV by this time. These findings are consistent with our previous suggestion that the second stage of reorganization proceeds via mechanisms comparable to those revealed to account for NMDA‐dependent long‐term potentiation in the hippocampus. J. Comp. Neurol. 497:636–645, 2006. © 2006 Wiley‐Liss, Inc.
Aldosterone‐sensitive neurons in the nucleus of the solitary tract: Bidirectional connections with the central nucleus of the amygdala
Authors: Geerling Joel C. , Loewy Arthur D.
Published: June 2006

The HSD2 (11‐β‐hydroxysteroid dehydrogenase type 2‐expressing) neurons in the nucleus of the solitary tract (NTS) of the rat are aldosterone‐sensitive and have been implicated in sodium appetite. The central nucleus of the amygdala (CeA) has been shown to modulate salt intake in response to aldosterone, so we investigated the connections between these two sites. A prior retrograde tracing study revealed only a minor projection from the HSD2 neurons directly to the CeA, but these experiments suggested that a more substantial projection may be relayed through the parabrachial nucleus. Small injections of cholera toxin beta subunit (CTb) into the external lateral parabrachial subnucleus (PBel) produced both retrograde cell body labeling in the HSD2 neurons and anterograde axonal labeling in the lateral subdivision of the CeA. Also, injections of either CTb orPhaseolus vulgarisleucoagglutinin into the medial subdivision of the CeA labeled a descending projection from the amygdala to the medial NTS. Axons from the medial CeA formed numerous varicosities and terminals enveloping the HSD2 neurons. Complementary CTb injections, centered in the HSD2 subregion of the NTS, retrogradely labeled neurons in the medial CeA. These bidirectional projections could form a functional circuit between the HSD2 neurons and the CeA. The HSD2 neurons may represent one of the functional inputs to the lateral CeA, and their activity may be modulated by a return projection from the medial CeA. This circuit could provide a neuroanatomical basis for the modulation of salt intake by the CeA. J. Comp. Neurol. 497:646–657, 2006. © 2006 Wiley‐Liss, Inc.
Sterile and disposable fluidic subsystem suitable for clinical high speed fluorescence‐activated cell sorting
Authors: Jayasinghe Sachintha M. , Wunderlich Joshua , McKee Angel , Newkirk Heather , Pope Steve , Zhang Jiwang , Staehling‐Hampton Karen , Li Linheng , Haug Jeffrey S.
Published: June 2006

Background:

Applications of fluorescence‐activated cell sorting (FACS) are ideally performed under aseptic conditions so that isolated cells can be successfully cultured, transplanted, or processed for the isolation of protein and nucleic acids. However, modern “off‐the shelf” flow cytometers are suboptimally designed for these purposes because nonsterile instrument hardware components directly contact sample‐harboring fluids, compromising their sterility.

Methods:

We have described the design and modular modification of a cytometer with a sterile and disposable FACS fluid handling system that meets requirements of high‐speed FACS and good manufacturing practice. This system was tested for functionality and its ability to maintain a clean and sterile fluid environment.

Results:

Our data have shown that this new fluidic subsystem completely replicated the intended function of the manufacturer's standard fluid handling system, and isolates the fluid from contaminants such as bacteria and fungus, endotoxins, mycoplasma, and helicobacter.

Conclusions:

FACS has emerged as a powerful tool used to study and manipulate stem cells. However, if stem cell discoveries are to be fully utilized in clinical transplant medicine, aseptic instrument configurations must be developed. For this purpose, we have designed a disposable sterile fluid handling system. © 2006 International Society for Analytical Cytology
Self‐Assembly and Chiroptical Properties of Chiral Dendrimers Consisting of a Hamilton Receptor Substituted Porphyrin and Depsipeptide Cyanurates
Authors: Maurer Katja , Hager Kristine , Hirsch Andreas
Published: June 2006

The synthesis and characterisation of a new type of porphyrin‐based tetrakis(Hamilton receptor) 1 is presented and the complexation of 1 with the chiral depsipeptide dendrons 7–12, with cyanuric acid functionalities as their focal points, is reported. The resulting first‐ to third‐generation chiral supramolecular dendrimers 13–18 were characterised by NMR, UV/Vis and CD spectroscopy. Chirality transfer from the depsipeptide dendrons to the porphyrin core was demonstrated by CD spectroscopy in the case of the second‐ and third‐generation complexes 15–18, whereas no chirality transfer and hence no diastereoselective formation of a chiral superstructure could be determined in the case of the first‐generation systems. The intensities of the complexes’ CD absorptions in the porphyrin region are inversely proportional to the size of the dendrons, pointing to a size‐dependent cooperativity of the fourfold complexation of the dendrons with the more effective binding of the second‐generation dendrons 9 and 10 relative to their bulkier third‐generation counterparts 11 and 12. Pronounced cooperativity during the formation of the second‐generation 1:L4 complexes (L = 9, 10) is considered to be the reason for the diastereoselective formation of a preferred chiral conformation of the Hamilton receptor 1 in the complexes 15 and 16. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
A New Type of Dendritic [60]Fullerene–Metallo‐tetraphenylporphyrin Diads (M = Zn, Co)
Authors: Kovacs Christian , Hirsch Andreas
Published: June 2006

The synthesis of unsymmetrical malonates 19–23 terminated by a metallo‐tetraphenylporphyrin (M = ZnII, CoII, CoIII) and by Newkome‐type amide dendrons of generation two and three is reported. Cyclopropanation of C60 with the second‐generation dendrons 20 and 21 leads to the formation of fullerene monoadducts 24 and 25, representing a new type of dendritic diads. The establishment of Co in the oxidation sates of +II and +III was achieved by the treatment with Na2S2O4 or with O2 in the presence of CN– and SCN–, respectively, leading to the paramagnetic complex 26 and the diamagnetic axially coordinated complexes 27. Deprotection of the tert‐butyl groups terminating the dendritic branch of the diads 24 and 25 generates the corresponding water‐soluble systems 28 and 29. Due to their amphiphilic character micellar aggregates are formed in water. DOSY NMR measurements showed that the aggregates consisting of 28 have an average diameter of approximately 7 nm in a buffered D2O solution (pH = 7.2). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Large‐scale identification of cytosolic mouse brain proteins by chromatographic prefractionation
Authors: Shin Joo‐Ho , Krapfenbauer Kurt , Lubec Gert
Published: June 2006

Proteomic studies on mouse brain protein expression are still holding center stage as the generation of a reference database for the brain proteome, a need for designing expressional studies at the protein level. We therefore decided to extend the amount of identified brain proteins by the use of prefractionation. In order to reduce the complexity of mouse brain proteome we applied chromatographic prefractionations, ion‐exchange and hydrophobic interaction chromatography, prior to 2‐DE, followed by mass spectrometric identification (2‐DE MALDI‐MS). We analyzed about 17 000 protein spots in cytosolic fractions of mouse brain and identified about 10 000 spots. A total of 1841 proteins showing different pI or Mr, representing probably post‐translational modifications or splice variants, were products of 789 different genes. Numerous proteins were clearly identified as metabolic, antioxidant, cytoskeleton, signaling, transcription/translation, nucleic acid‐binding, proteolysis‐related proteins. We additionally provided evidence for the existence of hypothetical proteins predicted from nucleic acid sequences. Moreover, observed pIs of proteins are listed thus enabling localization of proteins in a gel, information that cannot be obtained from theoretical pI's in databases. The results represent so far the largest database of mouse brain proteins and provide valuable information for the design of proteomic studies in the mouse.
Neuroproteomics – the tasks lying ahead
Authors: Becker Michael , Schindler Jens , Nothwang Hans Gerd
Published: June 2006

The brain is unquestionably the most fascinating organ. Despite tremendous progress, current knowledge falls short of being able to explain its function. An emerging approach toward improved understanding of the molecular mechanisms underlying brain function is neuroproteomics. Today's neuroscientists have access to a battery of versatile technologies both in transcriptomics and proteomics. The challenge is to choose the right strategy in order to generate new hypotheses on how the brain works. The goal of this review is therefore two‐fold: first we recall the bewildering cellular, molecular, and functional complexity in the brain, as this knowledge is fundamental to any study design. In fact, an impressive complexity on the molecular level has recently re‐emerged as a central theme in large‐scale analyses. Then we review transcriptomics and proteomics technologies, as both are complementary. Finally, we comment on the most widely used proteomics techniques and their respective strengths and drawbacks. We conclude that for the time being, neuroproteomics should focus on its strengths, namely the identification of posttranslational modifications and protein–protein interactions, as well as the characterization of highly purified subproteomes. For global expression profiling, emphasis should be put on further development to significantly increase coverage.
A Knitted Lightweight High‐performance Rotor
Authors: Hufenbach Werner
Published: June 2006

Powerful rotors capable of withstanding the highest loads are becoming increasingly required – not just by industrial and mechanical engineering applications. High‐strength textiles can assist in the construction of featherweight high‐performance rotors
Hydrogels as artificial matrices for human embryonic stem cell self‐renewal
Authors: Li Ying J. , Chung Eugene H. , Rodriguez Ryan T. , Firpo Meri T. , Healy Kevin E.
Published: June 2006

Human embryonic stem cells (hESCs) have the potential to differentiate into all cell types in the body and hold great promise for regenerative medicine; however, large‐scale expansion of undifferentiated hESCs remains a major challenge. Self‐renewal of hESCs requires culturing these cells on either mouse or human fibroblast cells (i.e., a feeder layer of cells), or on artificial extracellular matrices (ECMs) while supplementing the media with soluble growth factors. Here we report a completely synthetic ECM system composed of a semi‐interpenetrating polymer network (sIPN), a polymer hydrogel, which was designed to allow the independent manipulation of cell adhesion ligand presentation and matrix stiffness. In the short term, hESCs that were cultured on the sIPN adhered to the surface, remained viable, maintained the morphology, and expressed the markers of undifferentiated hESCs. This was the first demonstration that a completely synthetic ECM can support short‐term self‐renewal of hESCs. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Increased osteoblast functions among nanophase titania/poly(lactide‐co‐glycolide) composites of the highest nanometer surface roughness
Authors: Liu Huinan , Slamovich Elliott B. , Webster Thomas J.
Published: June 2006

Currently, the scientific challenges for bone tissue engineering lie in the development of suitable scaffold materials that can improve bone cell adhesion, proliferation, and differentiation. The design of nanophase titania/poly(lactide‐co‐glycolide) (PLGA) composites offers an exciting approach to combine the advantages of a degradable polymer with nanosize ceramic particles to optimize the physical and biological properties necessary for bone regeneration. Moreover, because of the presence of nanosized ceramics, such composites can be formulated to match the surface roughness of bone. For these reasons, the objective of the present in vitro study was to investigate osteoblast (bone‐forming cell) adhesion and long‐term functions on nanophase titania/PLGA composites that mimic the surface roughness of bone. Various sonication powers were applied in this study to manipulate titania dispersions in PLGA and consequently control their surface roughness. Most importantly, results correlated better osteoblast adhesion and long‐term functions (such as collagen, alkaline phosphatase activity, and calcium‐containing mineral deposition) among nanophase titania/PLGA composites that had surface roughness values closer to natural bone. In this manner, this present study demonstrated that the nanophase titania/PLGA composites sonicated to have nanometer surface roughness values can improve osteoblast functions necessary for enhanced bone tissue engineering applications. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Evidence that both 1α,25‐dihydroxyvitamin D3 and 24‐hydroxylated D3 enhance human osteoblast differentiation and mineralization
Authors: van Driel M. , Koedam M. , Buurman C.J. , Roelse M. , Weyts F. , Chiba H. , Uitterlinden A.G. , Pols H.A.P. , van Leeuwen J.P.T.M.
Published: June 2006

Vitamin D plays a major role in the regulation of mineral homeostasis and affects bone metabolism. So far, detailed knowledge on the vitamin D endocrine system in human bone cells is limited. Here we investigated the direct effects of 1α,25‐(OH)2D3 on osteoblast differentiation and mineralization. Also, we studied the impact of 24‐hydroxylation, generally considered as the first step in the degradation pathway of vitamin D, as well as the role of the nuclear and presumed membrane vitamin D receptor (VDR). For this we used a human osteoblast cell line (SV‐HFO) that has the potency to differentiate during culture forming a mineralized extracellular matrix in a 3‐week period. Transcriptional analyses demonstrated that both 1α,25‐(OH)2D3 and the 24‐hydroxylated metabolites 24R,25‐(OH)2D3 and 1α,24R,25‐(OH)3D3 induced gene transcription. All metabolites dose‐dependently increased alkaline phosphatase (ALP) activity and osteocalcin (OC) production (protein and RNA), and directly enhanced mineralization. 1α,24R,25‐(OH)3D3 stimulated ALP activity and OC production most potently, while for mineralization it was equipotent to 1α,25‐(OH)2D3. The nuclear VDR antagonist ZK159222 almost completely blocked the effects of all metabolites. Interestingly, 1β,25‐(OH)2D3, an inhibitor of membrane effects of 1α,25‐(OH)2D3 in the intestine, induced gene transcription and increased ALP activity, OC expression and mineralization. In conclusion, not only 1α,25‐(OH)2D3, but also the presumed 24‐hydroxylated “degradation” products stimulate differentiation of human osteoblasts. 1α,25‐(OH)2D3 as well as the 24‐hydroxylated metabolites directly enhance mineralization, with the nuclear VDR playing a central role. The intestinal antagonist 1β,25‐(OH)2D3 acts in bone as an agonist and directly stimulates mineralization in a nuclear VDR‐dependent way. J. Cell. Biochem. 99: 922–935, 2006. © 2006 Wiley‐Liss, Inc.
Multifaceted interaction between the androgen and Wnt signaling pathways and the implication for prostate cancer
Authors: Terry Stéphane , Yang Xuezhen , Chen Min‐Wei , Vacherot Francis , Buttyan Ralph
Published: June 2006

Androgen action in prostate and prostate cancer cells is dependent upon the androgen receptor (AR) protein that transcriptionally regulates the expression of androgen‐dependent genes in the presence of a steroid ligand. Whereas the overall schema of androgen action mediated by this receptor protein appears to be relatively simple, androgen signaling is now known to be influenced by several other cell signal transduction pathways and here we review the evidence that the canonical Wnt signaling pathway also modulates androgen signaling at multiple levels. Wnt is a complex signaling pathway whose endpoint involves activation of transcription from LEF‐1/TCF transcription factors and it is known to be involved in the development and progression of numerous human epithelial tumors including prostate cancer. β‐catenin protein, a particularly critical molecular component of canonical Wnt signaling is now known to promote androgen signaling through its ability to bind to the AR protein in a ligand‐dependent fashion and to enhance the ability of liganded AR to activate transcription of androgen‐regulated genes. Under certain conditions, glycogen synthase kinase‐3β (GSK‐3β), a protein serine/threonine kinase that regulates β‐catenin degradation within the Wnt signaling pathway, can also phosphorylate AR and suppress its ability to activate transcription. Finally, it was recently found that the human AR gene itself is a target of LEF‐1/TCF‐mediated transcription and that AR mRNA is highly upregulated by activation of Wnt signaling in prostate cancer cells. Paradoxically, Wnt activation also appears to stimulate Akt activity promoting an MDM‐2‐mediated degradation process that reduces AR protein levels in Wnt‐stimulated prostate cancer cells. Collectively, this information indicates that the multifaceted nature of the interaction between the Wnt and the androgen signaling pathways likely has numerous consequences for the development, growth, and progression of prostate cancer. J. Cell. Biochem. 99: 402–410, 2006. © 2006 Wiley‐Liss, Inc.
Regulation of osteoblast differentiation by Nurr1 in MC3T3‐E1 cell line and mouse calvarial osteoblasts
Authors: Lee Mi Kyeong , Choi Hosoon , Gil Minchan , Nikodem Vera M.
Published: June 2006

The orphan nuclear receptor Nurr1 is primarily expressed in the central nervous system. It has been shown that Nurr1 is necessary for terminal differentiation of dopaminergic (DA) neurons in ventral midbrain. The receptor, however, is also expressed in other organs including bone, even though the role of Nurr1 is not yet understood. Therefore, we investigated the role of Nurr1 in osteoblast differentiation in MC3T3‐E1 cells and calvarial osteoblasts derived from Nurr1 null newborn pups. Our results revealed that reduced Nurr1 expression, using Nurr1 siRNA in MC3T3‐E1 cells, affected the expression of osteoblast differentiation marker genes, osteocalcin (OCN) and collagen type I alpha 1 (COL1A1), as measured by quantitative real‐time PCR. The activity of alkaline phosphatase (ALP), another osteoblast differentiation marker gene, was also decreased in Nurr1 siRNA‐treated MC3T3‐E1 cells. In addition, Nurr1 overexpression increased OCN and COL1A1 expression. Furthermore, consistent with these results, during osteoblast differentiation, the expression of osteoblast marker genes was decreased in primary cultured mouse calvarial osteoblasts derived from Nurr1 null mice. Collectively, our results suggest that Nurr1 is important for osteoblast differentiation. J. Cell. Biochem. 99: 986–994, 2006. © 2006 Wiley‐Liss, Inc.
PGE2 amplifies the effects of IL‐1β on vascular smooth muscle cell de‐differentiation: A consequence of the versatility of PGE2 receptors 3 due to the emerging expression of adenylyl cyclase 8
Authors: Clément Nathalie , Glorian Martine , Raymondjean Michel , Andréani Marise , Limon Isabelle
Published: June 2006

Transition of vascular smooth muscle cells from a contractile/quiescent to a secretory/proliferative phenotype is one of the critical steps in atherosclerosis and is instigated by pro‐inflammatory cytokines released from macrophages that have infiltrated into the vascular wall. In most inflammatory diseases, cell activation induced by these compounds leads to a massive production of type E2 prostaglandin (PGE2) which often takes over and even potentiates the pro‐inflammatory cytokine‐related effects. To evaluate PGE2 incidence on atheroma plaque development, we investigated whether and how this compound could enhance the de‐differentiation of smooth muscle cells initially induced by interleukin‐1β (IL‐1β). To address this issue, we took advantage of vascular smooth muscle cells in primary culture and tracked two markers: PLA2 secretion and α‐actin filament disorganization. In such a context, we found that PGE2 synergizes with IL‐1β to further enhance the phenotype transition of smooth muscle cells, through cAMP‐protein kinase A. As indicated by pharmacological studies, the full PGE2‐dependent potentiation of IL‐1β induced PLA2 secretion is associated with a change of regulation exerted by the subtypes 3 Gi‐coupled PGE2 receptors toward adenylyl cyclase(s) activated by the subtype 4 Gs‐linked PGE2 receptor. Whereas on contractile cells, stimulated subtypes 3 inhibit type 4‐dependent PLA2 secretion, this negative regulation is switched to positive on IL‐1β‐treated cells. Using real time PCR, pharmacological tools and small interfering RNA (siRNA), we demonstrated that the different integration of PGE2 signals depends on the upregulation of calcium/calmodulin stimulable adenylyl cyclase 8. J. Cell. Physiol. 208: 495–505, 2006. © 2006 Wiley‐Liss, Inc.
Dysregulation of NGF‐signaling and Egr‐1 expression by Tat in neuronal cell culture
Authors: Darbinian‐Sarkissian Nune , Czernik Marta , Peruzzi Francesca , Gordon Jennifer , Rappaport Jay , Reiss Krzysztof , Khalili Kamel , Amini Shohreh
Published: June 2006

Examination of signal transduction pathways that modulate neuronal cell differentiation and protection against apoptosis has revealed a central role for the MAPK/Erk cascade. The activation of MAPK/Erk through the TrkA NGF signaling pathway is critical for growth and survival of neuronal cells. Here, we investigate the impact of HIV‐1 Tat on the NGF‐signaling pathway in SK‐N‐MC neuroblastoma cells. Expression of Tat decreased cell growth and induced apoptosis. Our results revealed dysregulation of various steps involved in the NGF pathway including suppression of MAPK, and inhibition of the promoter activity of Egr‐1, a key pleiotropic mediator of the expression of genes involved in cell growth upon expression of Tat in SK‐N‐MC cells. Similarly, exposure of SK‐N‐MC to conditioned media derived from cells expressing Tat decreased phosphorylation of MAPK and reduced the level of Egr‐1 protein expression in SK‐N‐MC cells. Furthermore, MAPK was able to phosphorylate Purα, a cellular protein that plays an important role in neuronal cell function and differentiation, and this was inhibited by Tat. The ability of Purα to interact with a GA/GC‐rich sequence positioned upstream from the transcription start site of the Egr‐1 promoter provided a rationale to examine Egr‐1 expression. Expression of Tat decreased NGF‐induced Egr‐1 levels in SK‐N‐MC cells and reduced binding of Purα to the Egr‐1 promoter. All of these observations support a model where the interplay between Tat and Purα dysregulates the NGF pathway including the MAPK/Erk network, resulting in reduced expression and activity of Egr‐1 in neuronal cells. J. Cell. Physiol. 208: 506–515, 2006. © 2006 Wiley‐Liss, Inc.
Superoxide dismutase 1 protects retinal cells from oxidative damage
Authors: Dong Aling , Shen JiKui , Krause Melissa , Akiyama Hideo , Hackett Sean F. , Lai Hong , Campochiaro Peter A.
Published: June 2006

Bolstering the endogenous oxidative damage defense system is a good strategy for development of treatments to combat neurodegenerative diseases in which oxidative damage plays a role. A first step in such treatment development is to determine the role of various components of the defense system in cells that degenerate. In this study, we sought to determine the role of superoxide dismutase 1 (SOD1) in two models of oxidative damage‐induced retinal degeneration. In one model, paraquat is injected into the vitreous cavity and then enters retinal cells and generates reactive oxygen species (ROS) that cause progressive retinal damage. Assessment of retinal function with serial electroretinograms (ERGs) showed that sod1−/− mice were much more sensitive than sod1+/+ mice to the damaging effects of paraquat, while sod1+/− mice showed intermediate sensitivity. Compared to sod1+/+ mice, sod1−/− mice showed greater paraquat‐induced oxidative damage and apoptosis. In the second model, mice were exposed to hyperoxia for several weeks, and sod1−/− mice showed significantly greater reductions in ERG amplitudes than sod1+/+ mice. In both of these models, transgenic mice carrying a sod1 transgene driven by a β‐actin promoter showed less oxidative stress‐induced reduction in ERG amplitudes. These data demonstrate that SOD1 protects retinal cells against paraquat‐ and hyperoxia‐induced oxidative damage and suggest that overexpression of SOD1 should be considered as one component of ocular gene therapy to prevent oxidative damage‐induced retinal degeneration. J. Cell. Physiol. 208: 516–526, 2006. © 2006 Wiley‐Liss, Inc.
The p53 tumor suppressor participates in multiple cell cycle checkpoints
Authors: Giono Luciana E. , Manfredi James J.
Published: June 2006

The process of cell division is highly ordered and regulated. Checkpoints exist to delay progression into the next cell cycle phase only when the previous step is fully completed. The ultimate goal is to guarantee that the two daughter cells inherit a complete and faithful copy of the genome. Checkpoints can become activated due to DNA damage, exogenous stress signals, defects during the replication of DNA, or failure of chromosomes to attach to the mitotic spindle. Abrogation of cell cycle checkpoints can result in death for a unicellular organism or uncontrolled proliferation and tumorigenesis in metazoans (Nyberg et al., 2002). The tumor suppressor p53 plays a critical role in each of these cell cycle checkpoints and is reviewed here. J. Cell. Physiol. 209: 13–20, 2006. © 2006 Wiley‐Liss, Inc.
Leukemogenic AML1‐ETO fusion protein upregulates expression of connexin 43: The role in AML1‐ETO‐induced growth arrest in leukemic cells
Authors: Li Xi , Xu Ya‐Bei , Wang Qiong , Lu Ying , Zheng Ying , Wang Ying‐Chao , Lübbert Michael , Zhao Ke‐Wen , Chen Guo‐Qiang
Published: June 2006

AML1‐ETO, a fusion protein generated by the chromosomal translocation t(8;21), is frequently associated with acute myeloid leukemia (AML). In addition to blocking differentiation, AML1‐ETO is also shown to induce growth arrest in AML cells, which is unfavorable for leukemogenesis harboring the t(8;21) translocation. However, its precise mechanism is still unclear. Here we provide the first demonstration that the conditional expression of AML1‐ETO by the ecdysone‐inducible system dramatically increases the expression of connexin 43 (CX43), together with growth arrest at G1 phase in leukemic U937 cells. We also show that the CX43 induction inhibits the proliferation of U937 cells at G1 phase, while the suppression of CX43 expression by small interfering RNA (siRNA) effectively overcomes the growth‐inhibitory effect of AML1‐ETO in leukemic cells. Furthermore, either AML1‐ETO or CX43 induction elevates cell‐cycle negative regulator P27kip1 protein by inhibiting its degradation, which is antagonized by siRNA against CX43. Taken together, our data indicate that CX43 plays a role in AML1‐ETO‐induced growth arrest possibly through the accumulation of P27kip1 protein. The potential mutation or/and epigenetic alterations of CX43 and its related gene(s) deserve to be explored in AML1‐ETO‐positive AML patients. J. Cell. Physiol. 208: 594–601, 2006. © 2006 Wiley‐Liss, Inc.
Cdk9 phosphorylates p53 on serine 392 independently of CKII
Authors: Claudio Pier Paolo , Cui Jianqi , Ghafouri Mohammad , Mariano Chiara , White Martyn K. , Safak Mahmut , Sheffield Joel B. , Giordano Antonio , Khalili Kamel , Amini Shohreh , Sawaya Bassel E.
Published: June 2006

The tumor suppressor p53 is an important cellular protein, which controls cell cycle progression. Phosphorylation is one of the mechanisms by which p53 is regulated. Here we report the interaction of p53 with another key regulator, cdk9, which together with cyclin T1 forms the positive transcription elongation complex, p‐TEFb. This complex cooperates with the HIV‐1 Tat protein to cause the phosphorylation of the carboxyl terminal domain (CTD) of RNA polymerase II and this facilitates the elongation of HIV‐1 transcription. We demonstrate that cdk9 phosphorylates p53 on serine 392 through their direct physical interaction. Results from protein–protein interaction assays revealed that cdk9 interacts with the C‐terminal domain (aa 361–393) of p53, while p53 interacts with the N‐terminal domain of cdk9. Transfection and protein binding assays (EMSA and ChIP) demonstrated the ability of p53 to bind and activate the cdk9 promoter. Interestingly, cdk9 phosphorylates serine 392 of p53, which could be also phosphorylated by casein kinase II. Kinase assays demonstrated that cdk9 phosphorylates p53 independently of CKII. These studies demonstrate the existence of a feedback‐loop between p53 and cdk9, pinpointing a novel mechanism by which p53 regulates the basal transcriptional machinery. J. Cell. Physiol. 208: 602–612, 2006. © 2006 Wiley‐Liss, Inc.
Integrin cytoplasmic domain‐associated protein‐1 (ICAP‐1) interacts with the ROCK‐I kinase at the plasma membrane
Authors: Stroeken Peter J.M. , Alvarez Belén , Rheenen Jacco van , Wijnands Yvonne M. , Geerts Dirk , Jalink Kees , Roos Ed
Published: June 2006

The integrin cytoplasmic domain‐associated protein‐1 (ICAP‐1) binds via its C‐terminal PTB (phosphotyrosine‐binding) domain to the cytoplasmic tails of β1 but not other integrins. Using the yeast two‐hybrid assay, we found that ICAP‐1 binds the ROCK‐I kinase, an effector of the RhoA GTPase. By coimmunoprecipitation we show that ICAP‐1 and ROCK form complexes in cells and that ICAP‐1 contains two binding sites for ROCK. In cells transfected with both ICAP‐1 and ROCK, the proteins colocalized at the cell membrane predominantly in lamellipodia and membrane ruffles, but also in retraction fibers. ROCK was not found at these sites when ICAP‐1 was not co‐transfected, indicating that ICAP‐1 translocated ROCK. In lamellipodia ICAP‐1 and ROCK colocalized with endogenous β1 integrins and this colocalization was also observed with the isolated ICAP‐1 PTB domain. The plasma membrane localization of ROCK did not depend on β1 integrin ligation or ROCK kinase activity, and in truncated ROCK proteins it required the presence of the ICAP‐1‐binding domain. To show that the interaction was direct, we measured fluorescence resonance energy transfer (FRET) between cyan fluorescent protein (CFP) fused to ICAP‐1 and yellow fluorescent protein (YFP) fused to ROCK. FRET was observed in lamellipodia in cells that were induced to spread. These results indicate that ICAP‐1‐mediated binding of ROCK to β1 integrin serves to localize the ROCK‐I kinase to both the leading edge and the trailing edge where ROCK affects cell migration. J. Cell. Physiol. 208: 620–628, 2006. © 2006 Wiley‐Liss, Inc.
Exacerbated tissue destruction in DSS‐induced acute colitis of OPN‐null mice is associated with downregulation of TNF‐α expression and non‐programmed cell death
Authors: da Silva Andre Paes Batista , Pollett Aaron , Rittling Susan R. , Denhardt David T. , Sodek Jaro , Zohar Ron
Published: June 2006

Osteopontin (OPN), a pro‐inflammatory mediator, is constitutively expressed in normal gut and is upregulated in inflammatory colitis. To determine the significance of OPN in inflammatory bowel disease, we studied the development of acute, experimental colitis induced by dextran sulfate sodium (DSS) in OPN‐null and wild‐type (WT) mice. OPN expression was markedly increased in WT diseased colons, while a higher disease activity index, including spleen enlargement, bowel shortening, and mucosal destruction, was observed in OPN‐null mice. Although peripheral blood neutrophil numbers were lower in DSS‐treated OPN‐null mice, tissue myeloperoxidase levels, reflecting enhanced neutrophil activity, were increased in the diseased colons. In comparison, lymphocyte numbers in peripheral blood were increased earlier than in DSS‐treated WT mice. Despite a significantly greater spleen enlargement, flow cytometric analysis of splenocytes from the DSS‐treated OPN‐null mice revealed lower numbers of differentiated macrophages and (CD4+ and CD8α+) lymphocytes. Whereas pro‐inflammatory cytokines, including G‐CSF, RANTES, MIP1α, and TNF‐α, were increased <10‐fold in DSS‐treated WT splenocytes, expression of these cytokines was dramatically suppressed in the DSS‐treated OPN‐null splenocytes as well as gut tissues. The suppressed TNF‐α response in OPN‐null mice was reflected in a marked increase in non‐apoptotic cell death in diseased colons. Collectively, these studies demonstrate that OPN is required for mucosal protection in acute inflammatory colitis. J. Cell. Physiol. 208: 629–639, 2006. © 2006 Wiley‐Liss, Inc.