bluuebunny/crossref_metadata_2025 huggingface dataset:
Spondylarthritis‐associated and non–spondylarthritis‐associated B27 subtypes differ in their dependence upon tapasin for surface expression and their incorporation into the peptide loading complex
Authors: Goodall Jane C. , Ellis Lou , Hill Gaston J. S.
Published: December 2005

Objective

B27 subtypes associated with susceptibility to ankylosing spondylitis (AS), and those reported not to be associated with AS, are found to differ in the amino acids that are known in other HLA class I molecules to alter the requirements for tapasin and incorporation into the peptide loading complex. The purpose of this study was to examine the behavior of B*2704 and B*2705 in comparison with B*2706 and B*2709 during early events in HLA class I antigen expression, and determine if their behavior correlates with disease association.

Methods

Cell lines with nonfunctional tapasin were transiently transfected with different B27 subtypes and their site‐directed mutants, and surface expression analyzed by flow cytometry. The association with the peptide loading complex was determined by immunoprecipitation of heterodimeric transporter‐associated peptide and analysis of coprecipitated B27.

Results

Amino acids at positions 114, 116, and 152 in the different B27 subtypes were shown to perform key roles in defining a requirement for interaction with tapasin. Not all disease‐associated alleles were expressed optimally in the absence of tapasin; furthermore, dependence on tapasin for cell surface expression did not correlate with disease association. Although B*2706, which is not associated with disease, exhibited a number of properties different from those of the disease‐associated subtypes, these properties were not displayed by the non–disease‐associated allele B*2709.

Conclusion

These results indicate that the ability to exhibit optimal cell surface expression in the absence of tapasin is not a prerequisite for susceptibility to AS.
Toll‐like receptor 9 signaling protects against murine lupus
Authors: Wu Xiaobo , Peng Stanford L.
Published: December 2005

Objective

Hypomethylated CpG–containing DNA, which is recognized by Toll‐like receptor 9 (TLR‐9), has been strongly implicated in the pathogenesis of autoantibody‐mediated diseases such as systemic lupus erythematosus. This study was undertaken to determine the role of TLR‐9 in the MRL/+ and MRL/lpr models of murine lupus.

Methods

TLR‐9–deficient MRL mice were generated by backcrossing a TLR‐9–deficient allele against the MRL backgrounds by a speed congenic technique. Parameters of murine lupus were examined by routine methods. Regulatory T cell activity was assessed by autologous mixed lymphocyte reaction (AMLR), an in vitro assay for autoreactivity.

Results

Surprisingly, TLR‐9–deficient animals of both the MRL/+ and the MRL/lpr backgrounds developed more severe lupus, as judged by anti‐DNA and rheumatoid factor autoantibodies, total serum Ig isotypes, lymphadenopathy, inflammatory infiltrates in the salivary gland and kidney, proteinuria, and mortality, in comparison with their TLR‐9–sufficient littermates. In vitro, regulatory T cells from TLR‐9–deficient animals were impaired in their ability to suppress the AMLR.

Conclusion

In the MRL model of murine lupus, TLR‐9 signaling plays a protective role, perhaps by modulating the activity of regulatory T cells. These results contrast with findings of recent studies that implicate TLR‐9 in the pathogenesis of anti‐DNA responses, based in part on investigations in incompletely backcrossed TLR‐9–deficient MRL/lpr mice in vivo or transgenic B cells in vitro. The present results highlight the need for caution in the assessment of disease paradigms based on the study of isolated cell populations in vitro, as well as in vivo studies of knockout animals involving non‐ideal genetic models.
Prevention and reversal of nephritis in MRL/lpr mice with a single injection of C‐reactive protein
Authors: Rodriguez Wilfredo , Mold Carolyn , Marnell Lorraine L. , Hutt Julie , Silverman Gregg J. , Tran Dao , Du Clos Terry W.
Published: December 2005

Objective

C‐reactive protein (CRP) is an acute‐phase serum protein with binding reactivity to nuclear autoantigens and immunomodulatory function. The MRL/lpr mouse is an important model of human systemic lupus erythematosus (SLE). These mice develop high‐titer anti‐DNA antibodies and immune complex–mediated nephritis and exhibit progressive lymphadenopathy. The mortality rate among these mice is 50% by age 18–20 weeks; the most frequent cause of death is glomerulonephritis. The present study was undertaken to determine whether treatment of mice with CRP would affect the course of lupus nephritis.

Methods

MRL/lpr mice were treated with a single 200‐μg injection of CRP at either age 6 weeks (before disease onset) or age 13 or 15 weeks (when proteinuria had reached high levels). Proteinuria was measured weekly, and levels of anti–double‐stranded DNA autoantibodies and blood urea nitrogen were determined monthly. Glomerular immune complex deposition and renal pathology were assessed in mice ages 15 weeks and 17 weeks.

Results

Early CRP treatment markedly delayed the onset of proteinuria and lymphadenopathy, increased survival, and reduced levels of autoantibodies to DNA. Treatment of mice with active disease reversed proteinuria and prolonged survival. Renal disease was decreased in CRP‐treated mice, with a marked suppression of glomerular pathology, tubular degeneration, and interstitial inflammation, which correlated with the decrease in proteinuria and azotemia.

Conclusion

These findings demonstrate that systemic suppression of autoimmunity is initiated by a single injection of CRP. Long‐term maintenance of CRP‐mediated protection was reversed by injection of an anti‐CD25 monoclonal antibody but not by macrophage depletion, suggesting that disease suppression is maintained by CD25‐bearing T cells.
Dissemination of a Sjögren's syndrome–associated extranodal marginal‐zone B cell lymphoma: Circulating lymphoma cells and invariant mutation pattern of nodal Ig heavy‐ and light‐chain variable‐region gene rearrangements
Authors: Hansen A. , Reiter K. , Pruss A. , Loddenkemper C. , Kaufmann O. , Jacobi A. M. , Scholze J. , Lipsky P. E. , Dörner T.
Published: December 2005

Objective

Both the genesis and outgrowth of extranodal marginal‐zone B cell lymphomas (MZLs) of the mucosa‐associated lymphoid tissue (MALT) type are generally thought to represent antigen‐driven processes. We undertook this study to analyze lymphoma progression and dissemination outside of the MALT‐type lesions.

Methods

Histopathologic and Ig heavy‐ and light‐chain variable‐region gene (VH/L) analyses were performed in sequential tissue samples from a patient with primary Sjögren's syndrome (SS) with glandular (parotid) manifestations and subsequent nodal dissemination of a low‐grade MZL.

Results

This MZL expressed a CD20+,CD27+,sIgM/κ+,IgD−,CD5−,CD10−,Bcl‐6−,CD23−,p53−,p21−,MDM2− phenotype and mutated VH1–69/D2–21/JH4α–VκA27/Jκ2 Ig rearrangements. Notably, circulating lymphoma cells from the parotid glands occurred transiently in the patient's blood, as detected by single‐cell polymerase chain reaction. In addition, 2 minor B cell clones (clones 2 and 3, with VH3–07/D3–22/JH3b–Vλ3L/Jλ2/3 and VH3–64/D3–03/JH2–VκA19/Jκ2 rearrangements, respectively) were also detected in the parotid glands and blood, and 1 of these (clone 2) was also detected in the lymph nodes. Ig VH/L analyses revealed ongoing (antigen‐driven) mutations of the glandular lymphoma rearrangements, but an invariant mutation pattern of their nodal counterparts.

Conclusion

These data indicate coexpansion and transient (re)circulation of the lymphoma clone and 2 additional glandular B cell clones in a primary SS–associated extranodal MZL. Combined histologic and molecular features of the nodal lymphoma subclone reflect a process of “follicular colonization” that eventually froze the mutation machinery after accumulation of additional (antigen‐driven) Ig VH/L mutations.
Production of lipid peroxidation products in osteoarthritic tissues: New evidence linking 4‐hydroxynonenal to cartilage degradation
Authors: Morquette Barbara , Shi Qin , Lavigne Patrick , Ranger Pierre , Fernandes Julio C. , Benderdour Mohamed
Published: December 2005

Objective

The lipid peroxidation product 4‐hydroxynonenal (HNE) is prominently produced in osteoarthritic (OA) synovial cells, but its specific contribution to cartilage destruction is not understood. This study was designed to test whether HNE signaling and binding are involved in OA cartilage degradation through type II collagen (CII) and matrix metalloproteinase 13 (MMP‐13) modulation.

Methods

HNE levels in synovial fluid and in isolated OA chondrocytes treated with free radical donors were determined by enzyme‐linked immunosorbent assay. The formation of the HNE/CII adducts was measured in cartilage explants by immunoprecipitation. Levels of CII and MMP‐13 messenger RNA and protein were determined by reverse transcription–polymerase chain reaction, Western blotting, and by the use of commercial kits.

Results

Levels of HNE/protein adducts were higher in OA synovial fluid compared with normal synovial fluid and were higher in OA chondrocytes treated with free radical donors compared with untreated cells. In cartilage explants, HNE induced CII cleavage, as established by the generation of neoepitopes. The level of HNE/CII adducts was increased in OA cartilage explants incubated with free radical donors. Modification of CII by HNE accelerated its degradation by active MMP‐13. In isolated OA chondrocytes, HNE inhibited the expression of CII and tissue inhibitor of metalloproteinases 1 and induced MMP‐13 mainly through activation of p38 MAPK. In vitro, HNE binding to MMP‐13 activated this enzyme at a molar ratio of 1:100 (MMP‐13 to HNE).

Conclusion

The increased level of HNE in OA cartilage and the ability of HNE to induce transcriptional and posttranslational modifications of CII and MMP‐13 suggest that this aldehyde could play a role in OA.
Contribution of congestive heart failure and ischemic heart disease to excess mortality in rheumatoid arthritis
Authors: Nicola Paulo J. , Crowson Cynthia S. , Maradit‐Kremers Hilal , Ballman Karla V. , Roger Véronique L. , Jacobsen Steven J. , Gabriel Sherine E.
Published: December 2005

Objective

Although mortality among patients with rheumatoid arthritis (RA) is higher than in the general population, the relative contribution of comorbid diseases to this mortality difference is not known. This study was undertaken to evaluate the contribution of congestive heart failure (CHF) and ischemic heart disease (IHD), including myocardial infarction, to the excess mortality in patients with RA, compared with that in individuals without RA.

Methods

We assembled a population‐based inception cohort of individuals living in Rochester, Minnesota, in whom RA (defined according to the criteria of the American College of Rheumatology [formerly, the American Rheumatism Association]) first developed between 1955 and 1995, and an age‐ and sex‐matched non‐RA cohort. All subjects were followed up until either death, migration from the county, or until 2001. Detailed information from the complete medical records was collected. Statistical analyses included the person‐years method, cumulative incidence, and Cox regression modeling. Attributable risk analysis techniques were used to estimate the number of RA deaths that would be prevented if the incidence of CHF was the same in patients with RA and non‐RA subjects.

Results

The study population included 603 patients with RA and 603 subjects without RA. During followup, there was an excess of 123 deaths among patients with RA (345 RA deaths occurred, although only 222 such deaths were expected). The mortality rates among patients with RA and non‐RA subjects were 39.0 and 29.2 per 1,000 person‐years, respectively. There was a significantly higher cumulative incidence of CHF (but not IHD) in patients with RA compared with non‐RA subjects (37.1% versus 27.7% at 30 years of followup, respectively; P < 0.001). The risk of death associated with either CHF or IHD was not significantly different between patients with RA and non‐RA subjects. If the risk of developing CHF was the same in patients with RA and individuals without RA, the overall mortality rate difference between RA and non‐RA hypothetically would be reduced from 9.8 to 8.0 excess deaths per 1,000 person‐years; that is, 16 (13%) of the 123 excess deaths could be prevented.

Conclusion

CHF, rather than IHD, appears to be an important contributor to the excess overall mortality among patients with RA. CHF contributes to this excess mortality primarily through the increased incidence of CHF in RA, rather than increased mortality associated with CHF in patients with RA compared with non‐RA subjects. Eliminating the excess risk of CHF in patients with RA could significantly improve their survival.
The therapeutic effects of basic fibroblast growth factor contained in gelatin hydrogel microspheres on experimental osteoarthritis in the rabbit knee
Authors: Inoue Atsuo , Takahashi Kenji A. , Arai Yuji , Tonomura Hitoshi , Sakao Kei , Saito Masazumi , Fujioka Mikihiro , Fujiwara Hiroyoshi , Tabata Yasuhiko , Kubo Toshikazu
Published: December 2005

Objective

To investigate the therapeutic effects of basic fibroblast growth factor (bFGF) contained in gelatin hydrogel microspheres on osteoarthritis (OA) development in rabbit knee joints.

Methods

125I‐labeled bFGF contained in gelatin hydrogel microspheres was administered to the knee joints of normal rabbits to confirm the sustained‐release kinetics of bFGF in the knee joint. In addition, the expression of proteoglycan core protein messenger RNA was examined using real‐time polymerase chain reaction to confirm the anabolic effects on the cartilage treated with the sustained release of bFGF. The bFGF in gelatin hydrogel microspheres was administered to the knee joint once every 3 weeks (a total of twice) from 4 weeks after anterior cruciate ligament transection (ACLT). Ten weeks after ACLT, gross morphologic and histologic examinations were performed.

Results

Sustained release of bFGF in the knee joint continued for >7 days and induced the anabolic effects on the cartilage. Intraarticular injections of bFGF contained in gelatin hydrogel microspheres suppressed the progression of OA in the ACLT rabbit model.

Conclusion

Our findings demonstrated that sustained release of bFGF into the joint had therapeutic effects on OA development in a rabbit model. Our results suggest the potential feasibility of a new conservative treatment for OA.
Projections of US prevalence of arthritis and associated activity limitations
Authors: Hootman Jennifer M. , Helmick Charles G.
Published: December 2005

Objective

To update the projected prevalence of self‐reported, doctor‐diagnosed arthritis and arthritis‐attributable activity limitations among US adults ages 18 years and older from 2005 through 2030.

Methods

Baseline age‐ and sex‐specific prevalence rates of arthritis and activity limitation, using the latest surveillance case definitions, were estimated from the 2003 National Health Interview Survey, which is an annual, cross‐sectional, population‐based health interview survey of ∼31,000 adults. These estimates were used to calculate projected arthritis prevalence and activity limitations for 2005–2030 using future population projections obtained from the US Census Bureau.

Results

The prevalence of self‐reported, doctor‐diagnosed arthritis is projected to increase from 47.8 million in 2005 to nearly 67 million by 2030 (25% of the adult population). By 2030, 25 million (9.3% of the adult population) are projected to report arthritis‐attributable activity limitations. In 2030, >50% of arthritis cases will be among adults older than age 65 years. However, working‐age adults (45–64 years) will account for almost one‐third of cases.

Conclusion

By 2030, the number of US adults with arthritis and its associated activity limitation is expected to increase substantially, resulting in a large impact on individuals, the health care system, and society in general. The growing epidemic of obesity may also significantly contribute to the future burden of arthritis. Improving access and availability of current clinical and public health interventions aimed at improving quality of life among persons with arthritis through lifestyle changes and disease self‐management may help lessen the long‐term impact.
A new model for an etiology of rheumatoid arthritis: Smoking may trigger HLA–DR (shared epitope)–restricted immune reactions to autoantigens modified by citrullination
Authors: Klareskog Lars , Stolt Patrik , Lundberg Karin , Källberg Henrik , Bengtsson Camilla , Grunewald Johan , Rönnelid Johan , Erlandsson Harris Helena , Ulfgren Ann‐Kristin , Rantapää‐Dahlqvist Solbritt , Eklund Anders , Padyukov Leonid , Alfredsson Lars
Published: December 2005

Objective

To investigate whether smoking and HLA–DR shared epitope (SE) genes may interact in triggering immune reactions to citrulline‐modified proteins.

Methods

In a case–control study involving patients with recent‐onset rheumatoid arthritis (RA), we studied interactions between a major environmental risk factor (smoking), major susceptibility genes included in the SE of HLA–DR, and the presence of the most specific autoimmunity known for RA (i.e., antibodies to proteins modified by citrullination). Immunostaining for citrullinated proteins in cells from bronchoalveolar lavage fluid was used to investigate whether smoking is associated with citrullination in the lungs.

Results

Previous smoking was dose‐dependently associated with occurrence of anticitrulline antibodies in RA patients. The presence of SE genes was a risk factor only for anticitrulline‐positive RA, and not for anticitrulline‐negative RA. A major gene–environment interaction between smoking and HLA–DR SE genes was evident for anticitrulline‐positive RA, but not for anticitrulline‐negative RA, and the combination of smoking history and the presence of double copies of HLA–DR SE genes increased the risk for RA 21‐fold compared with the risk among nonsmokers carrying no SE genes. Positive immunostaining for citrullinated proteins was recorded in bronchoalveolar lavage cells from smokers but not in those from nonsmokers.

Conclusion

We identified an environmental factor, smoking, that in the context of HLA–DR SE genes may trigger RA‐specific immune reactions to citrullinated proteins. These data thus suggest an etiology involving a specific genotype, an environmental provocation, and the induction of specific autoimmunity, all restricted to a distinct subset of RA.
An altered immune response to Epstein‐Barr nuclear antigen 1 in pediatric systemic lupus erythematosus
Authors: McClain Micah T. , Poole Brian D. , Bruner Benjamin F. , Kaufman Kenneth M. , Harley John B. , James Judith A.
Published: December 2005

Objective

New examples support the concept that host immune responses to pathogenic organisms can act as the nidus for autoimmunity. Two such examples implicate the Epstein‐Barr virus (EBV) in systemic lupus erythematosus (SLE), i.e., data consistent with SLE anti‐Sm and anti–60‐kd Ro autoantibodies emerging from distinct humoral immune responses to Epstein‐Barr nuclear antigen 1 (EBNA‐1). We undertook this study to further test whether the humoral immune response to EBNA‐1 is a risk factor for pediatric SLE.

Methods

Sera from pediatric lupus patients and healthy matched controls were tested for anti–EBNA‐1 by Western blotting and enzyme‐linked immunosorbent assay (ELISA). To define the fine specificity of their anti–EBNA‐1 humoral immune response, fragments of EBNA‐1 and the maximally overlapping unique octapeptides of EBNA‐1 were tested by modified ELISAs.

Results

All 36 pediatric SLE patient sera tested recognized EBNA‐1, while sera from only 25 of 36 matched EBV‐positive controls targeted EBNA‐1 (P < 0.005). Epitope mapping revealed that the humoral anti–EBNA‐1 response in pediatric SLE was distinct from and less restricted than that in matched normal individuals. Meanwhile, no significant differences between SLE patient sera and control sera were observed in the responses to other herpesviruses or in binding to sequential epitopes from cytomegalovirus immediate‐early antigen or EBNA‐2.

Conclusion

Anti–EBNA‐1 antibodies are associated with pediatric‐onset SLE. Furthermore, an altered humoral immune response to EBNA‐1, characteristic of SLE, has been found and may be an important SLE susceptibility factor.
Teilfertigdecken nach DIN 1045‐1. Wichtige Punkte der Bemessung und Konstruktion
Authors: Land Hartmut
Published: December 2005

Mit der Anwendung von DIN 1045‐1, Ausgabe Juli 2001 sind eingreifende Änderungen bei der Bemessung und Konstruktion von Teilfertigdecken verbunden. Das betrifft insbesondere den Nachweis der Schubkraftaufnahme in der Fuge Fertigplatte/Ortbeton. Für diesen aufwendigen Nachweis werden die Grundlagen zusammengestellt und ein Beispiel gegeben. Detailliert werden Regelungen für die Anordnung von Gitterträgern als Verbund‐/Querkraftbewehrung sowie für die Betondeckungen aufgeführt. Auflagerausbildungen sind zukünftig einfacher ausführbar.
Bauphysik‐Preis 2005
Authors: Ozimek Claudia
Published: December 2005

Zum zweiten Mal verlieh der Verlag Ernst & Sohn in diesem Jahr den Bauphysik‐Preis, um eine besondere, innovative Planungsleistung auf einem oder mehreren Teilgebieten der Bauphysik – Wärme, Feuchte, Schall, Brand, Licht – unter Berücksichtigung der funktionalen, wirtschaftlichen und gestalterischen Rahmenbedingungen des Bauwerkes auszuzeichnen.
Die Kraftwagenhalle der Kohlengroßhandlung Einmal in Aachen
Authors: Schmidt Hartwig
Published: December 2005

Nach dem Vorbild der 1911–13 in Breslau errichteten “Jahrhunderthalle” entstand 1924 in Aachen die Kraftwagenhalle der Firma Einmal als Stahlbetonrippenkuppel – eine ungewöhnliche Halle aus Fertigteilen und Ortbeton für den Fuhrpark einer Kohlengroßhandlung.
An Efficient Enzymatic Synthesis of Benzocispentacin and Its New Six‐ and Seven‐Membered Homologues
Authors: Forró Enikő , Fülöp Ferenc
Published: December 2005

A very efficient enzymatic method was developed for the synthesis of new enantiomeric benzocispentacin and its six‐ and seven‐membered homologues through the Lipolase (lipase B from Candida antarctica) catalyzed enantioselective (E>200) ring opening of 3,4‐benzo‐6‐azabicyclo[3.2.0]heptan‐7‐one, 4,5‐benzo‐7‐azabicyclo[4.2.0]octan‐8‐one, and 5,6‐benzo‐8‐azabicyclo[5.2.0]nonan‐9‐one with H2O in iPr2O at 60 °C. The (1R,2R)‐β‐amino acids (ee≥96 %, yields≥40 %) and (1S,6S)‐, (1S,7S)‐, and (1S,8S)‐β‐lactams (ee>99 %, yields≥44 %) produced could be easily separated. The ring opening of racemic and enantiomeric β‐lactams with 18 % HCl afforded the corresponding β‐amino acid hydrochlorides.
Non‐centrosomal microtubule‐organising centres in cold‐treated cultured Drosophila cells
Authors: Cottam Deborah M. , Tucker John B. , Rogers‐Bald Margaret M. , Mackie John B. , Macintyre John , Scarborough Julie A. , Ohkura Hiroyuki , Milner Martin J.
Published: December 2005

In this paper we describe a new type of non‐centrosomal microtubule‐organising centre (MTOC), which is induced by cold treatment of certain cultured Drosophila cells and allows rapid reassembly of microtubule (MT) arrays. Prolonged cooling of two types of cultured Drosophila cells, muscle cells in primary culture and a wing imaginal disc cell line Cl.8+ results in disassembly of MT arrays and induces the formation of clusters of short MTs that have not been described before. Upon rewarming, the clusters are lost and the MT array is re‐established within 1 h. In Cl.8+ cells, γ‐tubulin‐containing centrosomes are detected, both in cell extensions and in the expected juxtanuclear position, and γ‐tubulin co‐localises with the cold‐induced MT clusters. The MT plus‐end‐binding protein, Drosophila EB1, decorates growing tips of MTs extending from clusters. We conclude that the cold‐induced MT clusters represent acentrosomal MTOCs, allowing rapid reassembly of MT arrays following exposure to cold. Cell Motil. Cytoskeleton 63, 2006. © 2005 Wiley‐Liss, Inc.
Aroyl‐Pyrrolyl Hydroxyamides: Influence of Pyrrole C4‐Phenylacetyl Substitution on Histone Deacetylase Inhibition
Authors: Mai Antonello , Massa Silvio , Valente Sergio , Simeoni Silvia , Ragno Rino , Bottoni Patrizia , Scatena Roberto , Brosch Gerald
Published: December 2005

The novel aroyl‐pyrrolyl hydroxyamides 4 a–a′ are analogues of the lead compound 3‐(1‐methyl‐4‐phenylacetyl‐1H‐pyrrol‐2‐yl)‐N‐hydroxy‐2‐propenamide (2) and are active as HDAC inhibitors. The benzene ring of 2 was substituted with a wide range of electron‐donating and electron‐withdrawing groups, and the effect was evaluated on three HDACs from maize, namely HD2, HD1‐B (a class I HDAC), and HD1‐A (a class II HDAC). Inhibition studies show that the benzene 3′ and, to a lesser extent, 4′ positions of 2 were the most suitable for the introduction of substituents, with the 3′‐chloro (in 4 b) and the 3′‐methyl (in 4 k) derivatives being the most potent compounds, reaching the same activity as SAHA. Inhibition data for 4 b,k against mouse HDAC1 were consistent with those observed in the maize enzyme. The substituent insertion on the benzene ring of 2 (compounds 4 a–a′) abated the slight (3‐fold) selectivity for class II HDACs displayed by 2. Compound 4 b showed interesting, dose‐dependent antiproliferative and cytodifferentiation properties against human acute promyelocytic leukemia HL‐60 cells.
Group IIA phospholipase A2 is coexpressed with SNAP‐25 in mature taste receptor cells of rat circumvallate papillae
Authors: Oike Hideaki , Matsumoto Ichiro , Abe Keiko
Published: December 2005

The taste buds are composed of heterogeneous cell populations with diverse properties and at different stages of maturity. It is important to define the relationships between cell properties and cell maturity to understand the molecular events involved in intracellular taste signaling. In the present study, in situ hybridization analysis indicated that group IIA phospholipase A2 (PLA2‐IIA) is expressed in a subset of taste bud cells. Immunohistochemical studies showed that PLA2‐IIA was expressed in a subset of cells expressing phospholipase Cβ2, a molecule essential for taste signaling in taste receptor cells, and also that some PLA2‐IIA‐positive cells expressed gustducin (Ggust), a bitter‐taste‐signaling molecule. Although PLA2‐IIA and Ggust were expressed at similar frequencies in taste buds, bromodeoxyuridine (BrdU) chase experiments indicated that the expression of Ggust began 2 days after BrdU injection, whereas the expression of PLA2‐IIA commenced after 4 days. In addition, PLA2‐IIA was coexpressed with SNAP‐25, a synaptosomal‐associated protein. These results indicated that PLA2‐IIA is expressed in mature taste receptor cells that possess exocytotic machinery. J. Comp. Neurol. 494:876–886, 2006. © 2005 Wiley‐Liss, Inc.
Kainic acid‐induced recurrent mossy fiber innervation of dentate gyrus inhibitory interneurons: Possible anatomical substrate of granule cell hyperinhibition in chronically epileptic rats
Authors: Sloviter Robert S. , Zappone Colin A. , Harvey Brian D. , Frotscher Michael
Published: December 2005

Kainic acid‐induced neuron loss in the hippocampal dentate gyrus may cause epileptogenic hyperexcitability by triggering the formation of recurrent excitatory connections among normally unconnected granule cells. We tested this hypothesis by assessing granule cell excitability repeatedly within the same awake rats at different stages of the synaptic reorganization process initiated by kainate‐induced status epilepticus (SE). Granule cells were maximally hyperexcitable to afferent stimulation immediately after SE and became gradually less excitable during the first month post‐SE. The chronic epileptic state was characterized by granule cell hyperinhibition, i.e., abnormally increased paired‐pulse suppression and an abnormally high resistance to generating epileptiform discharges in response to afferent stimulation. Focal application of the γ‐aminobutyric acid type A (GABAA) receptor antagonist bicuculline methiodide within the dentate gyrus abolished the abnormally increased paired‐pulse suppression recorded in chronically hyperinhibited rats. Combined Timm staining and parvalbumin immunocytochemistry revealed dense innervation of dentate inhibitory interneurons by newly formed, Timm‐positive, mossy fiber terminals. Ultrastructural analysis by conventional and postembedding GABA immunocytochemical electron microscopy confirmed that abnormal mossy fiber terminals of the dentate inner molecular layer formed frequent asymmetrical synapses with inhibitory interneurons and with GABA‐immunopositive dendrites as well as with GABA‐immunonegative dendrites of presumed granule cells. These results in chronically epileptic rats demonstrate that dentate granule cells are maximally hyperexcitable immediately after SE, prior to mossy fiber sprouting, and that synaptic reorganization following kainate‐induced injury is temporally associated with GABAA receptor‐dependent granule cell hyperinhibition rather than a hypothesized progressive hyperexcitability. The anatomical data provide evidence of a possible anatomical substrate for the chronically hyperinhibited state. J. Comp. Neurol. 494:944–960, 2006. © 2005 Wiley‐Liss, Inc.
Cell proliferation in the forebrain and midbrain of the sea lamprey
Authors: Villar‐Cheda Begoña , Pérez‐Costas Emma , Meléndez‐Ferro Miguel , Abalo Xesús Manoel , Rodríguez‐Muñoz Rolando , Anadón Ramón , Rodicio María Celina
Published: December 2005

Cell proliferation in the forebrain and midbrain of the sea lamprey (Petromyzon marinus L.) was investigated by proliferation cell nuclear antigen (PCNA) immunocytochemistry, with BrdU labeling as a complementary technique. Correspondence between proliferation regions and areas of early neuronal differentiation was also assessed using antibodies against HNK‐1 early differentiation marker. The brain of late embryos shows a homogeneously thick ventricular zone (VZ) containing PCNA‐immunoreactive (PCNA‐ir) nuclei. In early prolarvae, several discontinuities formed by PCNA‐negative cells, and differences among regions in VZ thickness, become apparent. In late prolarvae and early larvae, these differences in VZ thickness and appearance, as well as the presence of PCNA‐negative discontinuities, allowed us to correlate proliferation domains and neuroanatomical regions. In larvae, the number of PCNA‐ir cells in the VZs diminish gradually, although a few PCNA‐ir cells are present in the ependyma of most regions. In late larvae, proliferation becomes confined to a few ventricular areas (medial pallium, caudal habenula, ventral preoptic recess near the optic nerve, and tuberal portion of the posterior hypothalamic recess). During metamorphosis there appears to be no proliferation, but in upstream adults a few PCNA‐ir cells are observed in the most caudal habenula. The characteristics of the proliferative regions revealed in lamprey with PCNA immunocytochemistry show notable differences from those observed in other vertebrates, and these differences may be related to the peculiar life cycle of lampreys. J. Comp. Neurol. 494:986–1006, 2006. © 2005 Wiley‐Liss, Inc.
Cholinergic axons in the rat ventral tegmental area synapse preferentially onto mesoaccumbens dopamine neurons
Authors: Omelchenko Natalia , Sesack Susan R.
Published: December 2005

Cholinergic afferents to the ventral tegmental area (VTA) contribute substantially to the regulation of motivated behaviors and the rewarding properties of nicotine. These actions are believed to involve connections with dopamine (DA) neurons projecting to the nucleus accumbens (NAc). However, this direct synaptic link has never been investigated, nor is it known whether cholinergic inputs innervate other populations of DA and γ‐aminobutyric acid (GABA) neurons, including those projecting to the prefrontal cortex (PFC). We addressed these questions by using electron microscopic analysis of retrograde tract‐tracing and immunocytochemistry for the vesicular acetylcholine transporter (VAChT) and for tyrosine hydroxylase (TH) and GABA. In tissue labeled for TH, VAChT+terminals frequently synapsed onto DA mesoaccumbens neurons but only seldom contacted DA mesoprefrontal cells. In tissue labeled for GABA, one‐third of VAChT+terminals innervated GABA‐labeled dendrites, including both mesoaccumbens and mesoprefrontal populations. VAChT+synapses onto DA and mesoaccumbens neurons were more commonly of the asymmetric (presumed excitatory) morphological type, whereas VAChT+synapses onto GABA cells were more frequently symmetric (presumed inhibitory or modulatory). These findings suggest that cholinergic inputs to the VTA mediate complex synaptic actions, with a major portion of this effect likely to involve an excitatory influence on DA mesoaccumbens neurons. As such, the results suggest that natural and drug rewards operating through cholinergic afferents to the VTA have a direct synaptic link to the mesoaccumbens DA neurons that modulate approach behaviors. J. Comp. Neurol. 494:863–875, 2006. © 2005 Wiley‐Liss, Inc.
Connections of the lateral and medial divisions of the goldfish telencephalic pallium
Authors: Northcutt R. Glenn
Published: December 2005

Biotinylated dextran amine and fluorescent carbocyanine dye (DiI) were used to examine connections of the lateral (Dl) and medial (Dm) divisions of the goldfish pallium. Besides numerous intrinsic telencephalic connections to Dl and Dm, major ascending projections to these pallial divisions arise in the preglomerular complex of the posterior tuberculum, rather than in the dorsal thalamus. The rostral subnucleus of the lateral preglomerular nucleus receives auditory input via the medial pretoral nucleus, lateral line input via the ventrolateral toral nucleus, and visual input via the optic tectum, and it projects to both Dl and Dm. The anterior preglomerular nucleus and caudal subnucleus of the lateral preglomerular nucleus receive auditory input via the central toral nucleus and project to Dm. This pallial division also receives chemosensory information via the medial preglomerular nucleus. The central posterior (CP) nucleus, which receives both auditory and visual inputs, also projects to Dm and is the only dorsal thalamic nucleus projecting to the pallium. Thus, both Dl and Dm clearly receive multisensory inputs. Major projections of CP and projections of all other dorsal thalamic nuclei are to the subpallium, however. Descending projections of Dl are primarily to the preoptic area and the caudal hypothalamus, whereas descending projections of Dm are more extensive and particularly heavy to the anterior tuber and nucleus diffusus of the hypothalamus. The topography and connections of Dl are remarkably similar to those of the hippocampus of tetrapods, whereas the topography and connections of Dm are similar to those of the amygdala. J. Comp. Neurol. 494:903–943, 2006. © 2005 Wiley‐Liss, Inc.
Developmental pattern of NADPH‐diaphorase positive neurons in chick optic tectum is sensitive to changes in visual stimulation
Authors: Scicolone Gabriel , Ortalli Ana Laura , Alvarez Gabriela , López‐Costa Juan José , Rapacioli Melina , Ferrán José Luis , Sanchez Viviana , Flores Vladimir
Published: December 2005

The chick retinotectal system is a suitable model to investigate the mechanisms involved in the establishment of synaptic connections in whose refinement nitric oxide was implicated. The purpose of this work was to describe the developmental pattern of the nitric oxide synthase (NOS)‐positive neurons as well as to determine if it is sensitive to changes in visual stimulation. The NADPH‐diaphorase histochemical method was used to describe and quantify NOS neurons in normally stimulated and subnormally stimulated chickens. Nine types of NOS neurons were identified; seven of them express NOS until adulthood, while two of them show only a transient expression. The developmental pattern of NOS neurons follows the process of laminar segregation. It can be divided into three phases. The first includes the onset of NOS expression in periventricular neurons and the formation of a deep network of NOS fibers during early development. These neurons do not show any significant change in subnormally stimulated animals. The second phase includes the appearance of two transient NOS populations of bipolar neurons that occupy the intermediate layers during the optic fibers ingrowth. One of them significantly changes in subnormally stimulated chicks. The third phase occurs when the transitory expression of bipolar neurons decreases. It includes NOS expression in six neuronal populations that innervate the superficial retinorecipient layers. Most of these cells suffer plastic changes in subnormally stimulated chicks. The diversity of neuronal types with regard to their morphology, location, and sensitivity to visual stimulation strongly suggests that they serve different functions. J. Comp. Neurol. 494:1007–1030, 2006. © 2005 Wiley‐Liss, Inc.
Radical Addition Reactions of Phosphorus Hydrides: Tuning the Reactivity of Phosphorus Hydrides, the Use of Microwaves and Horner–Wadsworth–Emmons‐Type Reactions
Authors: Jessop Christopher M. , Parsons Andrew F. , Routledge Anne , Irvine Derek J.
Published: December 2005

The reactivity of phosphorus hydrides in radical addition reactions are compared, and the substituents on phosphorus are shown to affect the efficiency of the reactions. The change in reactivity is attributed to the different bond dissociation energies of the P–H bonds, which have been calculated. Phosphorus hydrides with particularly weak P–H bonds are shown to undergo radical additions by microwave irradiation, in the absence of conventional initiators. These radical addition reactions produce phosphonothioates, phosphinothioates and phosphane sulfides, which react in HWE‐type reactions, to afford substituted alkenes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
A tree‐based model for allele‐sharing‐based linkage analysis in human complex diseases
Authors: Xu W. , Schulze T.G. , DePaulo J.R. , Bull S.B. , McMahon F.J. , Greenwood C.M.T.
Published: December 2005

By adapting a well‐known affected‐relative‐pair linkage model that can incorporate covariate or sub‐phenotype information [Olson, 1999: Am J Hum Genet 65:1760–1769], we have developed a recursive‐partitioning (RP) algorithm (tree‐based model) for identifying phenotype and covariate groupings that interact with the evidence for linkage. This strategy is designed to identify subgroups of affected relative pairs demonstrating increased evidence for linkage, where subgroups are defined by pair‐level or family‐level covariates. After growing a full tree, we identified optimal tree size through a form of tree pruning and chose the best covariate at each split by using bootstrap algorithms. Simulation studies showed that power to detect linkage can increase in the presence of gene‐environment interactions, depending on the magnitude of the interaction. As expected, however, power can decrease by examining more covariates, despite the pruning to optimize tree size. The RP model correctly identifies tree structure in a large proportion of simulations. We applied the RP model to a dataset of families with bipolar affective disorder (BPAD) where linkage regions on chromosome 18 have been previously identified. Using the all‐pairs score in Genehunter, the NPL tests showed no regions with strong linkage evidence on chromosome 18. However, using the RP model, several suggestive regions were found on chromosome 18. Two covariates appeared to influence the degree of linkage: the type II BPAD subtype and a pattern of displaying mania before or after a depressive episode. The RP model has the potential to identify previously unknown gene‐environmental interactions; here we have demonstrated the practical utility and potential this new methodology holds. Genet. Epidemiol. 2006. © 2005 Wiley‐Liss, Inc.
Efficient activation of aflatoxin B1 by cytochrome P450 2A13, an enzyme predominantly expressed in human respiratory tract
Authors: He Xiao‐Yang , Tang Lili , Wang Shou‐Lin , Cai Qing‐Song , Wang Jia‐Sheng , Hong Jun‐Yan
Published: December 2005

The worldwide human exposure to aflatoxin B1 (AFB1), particularly in developing countries, remains to be a serious public health concern. Although AFB1 is best known as a hepatocarcinogen, epidemiological studies have shown a positive association between human lung cancer occurrence and inhalation exposure to AFB1. Cytochrome P450 (CYP)‐catalyzed metabolic activation is required for AFB1 to exert its carcinogenicity. Previous studies have identified CYP1A2 and CYP3A4 as the major enzymes for AFB1 activation in human liver. However, the key CYP enzymes in human lung that can efficiently activate AFB1in situ are unknown. In the present study, we demonstrate that CYP2A13, an enzyme predominantly expressed in human respiratory tract, has a significant activity in metabolizing AFB1 to its carcinogenic/toxic AFB1‐8,9‐epoxide and AFM1‐8,9‐epoxide at both low (15 μM) and high (150 μM) substrate concentrations. Under the same conditions, there was no detectable AFB1 epoxide formation by CYP2A6, which was also reported to be involved in the metabolic activation of AFB1. Consistent with the activity data, there was an ∼800‐fold difference in LC50 values of AFB1 (48‐hr treatment) between Chinese hamster ovary (CHO) cells expressing CYP2A13 and CYP2A6 (50 nM versus 39 μM). We further demonstrate that amino acid residues Ala117 and His372 in CYP2A13 protein are important for AFB1 epoxidation and its related cytotoxicity. Our results suggest that CYP2A13‐catalyzed metabolic activation in situ may play a critical role in human lung carcinogenesis related to inhalation exposure to AFB1. © 2005 Wiley‐Liss, Inc.
In vivo imaging of tumor response to therapy using a dual‐modality imaging strategy
Authors: Medarova Zdravka , Pham Wellington , Kim Young , Dai Guangping , Moore Anna
Published: December 2005

In vivo assessment of the outcome of cancer therapy is hampered by the paucity of imaging probes that target tumors specifically and noninvasively. The importance of such probes increases with the continuous development of chemotherapeutics and the necessity to evaluate their effectiveness in a clinical setting. We have recently reported on a dual‐modality imaging probe specifically targeting the underglycosylated mucin‐1 tumor‐specific antigen (uMUC‐1), which is one of the early hallmarks of tumorigenesis in a wide variety of tumors. This probe consists of crosslinked superparamagnetic iron oxide nanoparticles (CLIO) for MR imaging, modified with Cy5.5 dye (for near infrared optical fluorescence imaging (NIRF)), and has peptides (EPPT), specifically recognizing uMUC‐1, attached to the nanoparticle's dextran coat. In the present study, we demonstrated that this probe could not only detect orthotopically implanted preclinical models of adenocarcinomas but could also track tumor response to chemotherapy in vivo in real time. Considering the high cost associated with the development and testing of new cancer therapeutics and the need for accurate, noninvasive assessment of their effectiveness, we believe that the developed probe represents a valuable research tool relevant to clinical discovery. © 2005 Wiley‐Liss, Inc.
Molecular biology of Hodgkin's and Reed/Sternberg cells in Hodgkin's lymphoma
Authors: Bräuninger Andreas , Schmitz Roland , Bechtel Dörte , Renné Christoph , Hansmann Martin‐Leo , Küppers Ralf
Published: December 2005

Hodgkin's and Reed/Sternberg (HRS) cells, the tumour cells in classical Hodgkin's lymphoma (HL), represent transformed B cells in nearly all cases. The detection of destructive somatic mutations in the rearranged immunoglobulin (Ig) genes of HRS cells in classical HL indicated that they originate from preapoptotic germinal centre (GC) B cells that lost the capacity to express a high‐affinity B‐cell receptor (BCR). Several aberrantly activated signalling pathways and transcription factors have been identified that contribute to the rescue of HRS cells from apoptosis. Among the deregulated signalling pathways, activation of multiple receptor tyrosine kinases in HRS cells appears to be a specific feature of HL. In about 40% of cases of classical HL the HRS cells are infected by Epstein‐Barr virus (EBV), indicating an important role of EBV in HL pathogenesis. Interestingly, nearly all cases of HL with destructive Ig gene mutations eliminating BCR expression (e.g. nonsense mutations) are EBV‐positive, suggesting that EBV‐encoded genes have a particular function to prevent apoptosis of HRS‐cell precursors that acquired such crippling mutations. This idea is further supported by the recent demonstration that isolated human GC B cells harbouring crippled Ig genes can be rescued by EBV from cell death, giving rise to lymphoblastoid cell lines. The molecular analysis of composite Hodgkin's and non‐Hodgkin's lymphomas indicated that many cases develop from a common GC B‐cell precursor in a multistep transformation process with both shared and distinct oncogenic events. © 2005 Wiley‐Liss, Inc.
The topoisomerase II–Hsp90 complex: A new chemotherapeutic target?
Authors: Barker Catherine R. , Hamlett Jane , Pennington Stephen R. , Burrows Francis , Lundgren Karen , Lough Rachel , Watson Alastair J.M. , Jenkins John R.
Published: December 2005

The modulation of DNA topology by topoisomerase II plays a crucial role during chromosome condensation and segregation in mitosis and has thus become a highly attractive target for chemotherapeutic drugs. However, these drugs are highly toxic, and so new approaches are required. One such strategy is to target topoisomerase II‐interacting proteins. Here we report the identification of potential topoisomerase II‐associated proteins using immunoprecipitation, followed by 1‐D and 2‐D gel electrophoresis and MALDI‐TOF mass spectrometry. A total of 23 proteins were identified and, of these, 17 were further validated as topoisomerase IIα‐associated proteins by coimmunoprecipitation and Western blot. Six of the interacting proteins were cellular chaperones, including 3 members of the heat shock protein‐90 (Hsp90) family, and so the effect of Hsp90 modulation on the antitumor activity of topoisomerase II drugs was tested using the sulforhodamine B assay, clonogenic assays and a xenograft model. The Hsp90 inhibitors geldanamycin, 17‐AAG (17‐allylamino‐17‐demethoxygeldanamycin) and radicicol significantly enhanced the activity of the topoisomerase II poisons etoposide and mitoxantrone in vitro and in vivo. Thus, our method of identifying topoisomerase II‐interacting proteins appears to be effective, and at least 1 novel topoisomerase IIα‐associated protein, Hsp90, may represent a valid drug target in the context of topoisomerase II‐directed chemotherapy. © 2005 Wiley‐Liss, Inc.