bluuebunny/crossref_metadata_2025 huggingface dataset:
Psychosocial stress attenuates general sound processing and duration change detection
Authors: Simoens V. L. , Istók E. , Hyttinen S. , Hirvonen A. , Näätänen R. , Tervaniemi M.
Published: November 2006

An EEG‐compatible adaptation of the Trier Social Stress Test was developed to induce psychosocial stress in healthy subjects while investigating their auditory processing of unattended sounds and salivary levels of the stress hormone cortisol. The mismatch negativity (MMN) and N1/P2 were assessed using a multifeature paradigm, while subjects were attending to visual tasks with high or low attentional workload. Only the responses to duration change were affected by the stress manipulation. Cortisol levels during stress were inversely related to the MMN amplitudes of duration deviants. During anticipatory stress, responses to the standard tones (general sound processing) increased, but their amplitude was not correlated with cortisol levels. We found that psychosocial stressor anticipation attenuates both general and deviance‐specific sound processing, suggesting that cortisol interferes with cortical memory‐trace formation.
Green decisions: demographics and consumer understanding of environmental labels
Authors: D’Souza Clare , Taghian Mehdi , Lamb Peter , Peretiatko Roman
Published: November 2006

This research examined the demographic profiles of Australian green consumers in relation to their satisfaction of environmental labelling. It examined consumers’ understanding of labelling and empirically investigated the association of demographic profile of consumers with their attitudes towards such labels. The results indicated that some of the demographic variables were significant, which is largely consistent with earlier findings by other researchers in this area. Label dissatisfaction was higher in the older and middle age respondents. However, some respondents disagreed that labels were accurate while commenting that labels were easy to understand. The key issue arising from the findings is that in order to provide perception of accuracy in labels, it is an option to use Type I or Type III labelling on products. These labels are, arguably, more credible because they are endorsed by third party labelling experts. This would come at a cost and for green products that use third party labelling, they will also have to bear in mind to keep the prices competitive.
Developing oligodendrocytes express functional GABAB receptors that stimulate cell proliferation and migration
Authors: Luyt Karen , Slade Timothy P. , Dorward Jienchi J. , Durant Claire F. , Wu Yue , Shigemoto Ryuichi , Mundell Stuart J. , Váradi Anikó , Molnár Elek
Published: November 2006

GABAB receptors (GABABRs) are involved in early events during neuronal development. The presence of GABABRs in developing oligodendrocytes has not been established. Using immunofluorescent co‐localization, we have identified GABABR proteins in O4 marker‐positive oligodendrocyte precursor cells (OPCs) in 4‐day‐old mouse brain periventricular white matter. In culture, OPCs, differentiated oligodendrocytes (DOs) and type 2 astrocytes (ASTs) express both the GABAB1abcdf and GABAB2 subunits of the GABABR. Using semiquantitative PCR analysis with GABABR isoform‐selective primers we found that the expression level of GABAB1abd was substantially higher in OPCs or ASTs than in DOs. In contrast, the GABAB2 isoform showed a similar level of expression in OPCs and DOs, and a significantly higher level in ASTs. This indicates that the expression of GABAB1 and GABAB2 subunits are under independent control during oligodendroglial development. Activation of GABABRs using the selective agonist baclofen demonstrated that these receptors are functionally active and negatively coupled to adenylyl cyclase. Manipulation of GABABR activity had no effect on OPC migration in a conventional agarose drop assay, whereas baclofen significantly increased OPC migration in a more sensitive transwell microchamber‐based assay. Exposure of cultured OPCs to baclofen increased their proliferation, providing evidence for a functional role of GABABRs in oligodendrocyte development. The presence of GABABRs in developing oligodendrocytes provides a new mechanism for neuronal–glial interactions during development and may offer a novel target for promoting remyelination following white matter injury.
Interleukin‐6 promotes sprouting and functional recovery in lesioned organotypic hippocampal slice cultures
Authors: Hakkoum David , Stoppini Luc , Muller Dominique
Published: November 2006

Interleukin (IL)‐6 is a pro‐inflammatory cytokine now widely recognized to contribute to the molecular events that follow CNS injury. Little is known, however, about its action on axonal sprouting and regeneration in the brain. We addressed this issue using the model of transection of Schaffer collaterals in mice organotypic hippocampal slice cultures. Transection of slice cultures was associated with a marked release of IL‐6 that could be neutralized by an IL‐6 blocking antibody. We monitored functional recovery across the lesion by recording synaptic responses using a multi‐electrode array. We found that application of IL‐6 antibodies to the cultures after lesioning significantly reduced functional recovery across the lesion. Furthermore, the level of expression of the 43‐kDa growth‐associated protein (GAP‐43) was lower in slices treated with the IL‐6 neutralizing antibody than in those treated with a control IgG. Conversely, addition of exogenous IL‐6 to the culture medium resulted in a dose‐dependent enhancement of functional recovery across the lesion and a higher level of expression of GAP‐43. Co‐culture of CA3 hemi‐slices from thy1‐YFP mice with CA1 hemi‐slices from wild‐type animals confirmed that IL‐6‐treated co‐cultures exhibited an increased number of growing fluorescent fibres across the lesion site. Taken together these data indicate that IL‐6 plays an important role in CNS repair mechanisms by promoting regrowth and axon regeneration.
Therapeutic targets and potential of the novel brain‐ permeable multifunctional iron chelator–monoamine oxidase inhibitor drug, M‐30, for the treatment of Alzheimer's disease1
Authors: Avramovich‐Tirosh Yael , Amit Tamar , Bar‐Am Orit , Zheng Hailin , Fridkin Mati , Youdim Moussa B. H.
Published: November 2006

Novel therapeutic approaches for the treatment of neurodegenerative disorders comprise drug candidates designed specifically to act on multiple CNS targets. We have synthesized a multifunctional non‐toxic, brain permeable iron chelator drug, M‐30, possessing propargyl monoamine oxidase (MAO) inhibitory neuroprotective and iron‐chelating moieties, from our prototype iron chelator VK‐28. In the present study M‐30 was shown to possess a wide range of pharmacological activities, including pro‐survival neurorescue effects, induction of neuronal differentiation and regulation of amyloid precursor protein (APP) and β‐amyloid (Aβ) levels. M‐30 was found to decrease apoptosis of SH‐SY5Y neuroblastoma cells in a neurorescue, serum deprivation model, via reduction of the pro‐apoptotic proteins Bad and Bax, and inhibition of the apoptosis‐associated phosphorylated H2A.X protein (Ser 139) and caspase 3 activation. In addition, M‐30 induced the outgrowth of neurites, triggered cell cycle arrest in G0/G1 phase and enhanced the expression of growth associated protein‐43. Furthermore, M‐30 markedly reduced the levels of cellular APP and β‐C‐terminal fragment (β‐CTF) and the levels of the amyloidogenic Aβ peptide in the medium of SH‐SY5Y cells and Chinese hamster ovary cells stably transfected with the APP ‘Swedish’ mutation. Levels of the non‐amyloidogenic soluble APPα and α‐CTF in the medium and cell lysate respectively were coordinately increased. These properties, together with its brain selective MAO inhibitory and propargylamine‐ dependent neuroprotective effects, suggest that M‐30 might serve as an ideal drug for neurodegenerative disorders, such as Parkinson's and Alzheimer's diseases, in which oxidative stress and iron dysregulation have been implicated.
INCREASES IN WEALTH AMONG THE ELDERLY IN THE EARLY 1990s: HOW MUCH IS DUE TO SURVEY DESIGN?
Authors: Rohwedder Susann , Haider Steven J. , Hurd Michael D.
Published: November 2006

The Asset and Health Dynamics Among the Oldest Old (AHEAD) study shows a large increase in reported total wealth between 1993 and 1995. Such an increase is not found in other U.S. household surveys around that period. This paper examines one source of this difference. We find that in AHEAD 1993 ownership rates of stocks, CDs, bonds, and checking and saving accounts were under‐reported, resulting in under‐measurement of wealth in 1993 and a substantial increase in wealth from 1993 to 1995. The explanation for the under‐reporting is a combination of question sequence and wording in the AHEAD survey instrument.
WEALTH AND THE DISTRIBUTION OF INCOME: PERMANENT AND TRANSITORY EFFECTS
Authors: Tuttle M. H. , Gauger Jean
Published: November 2006

This paper examines the permanent and transitory effects of changes in wealth, the top federal marginal income tax rate, and capital gains tax rate on the distribution of Adjusted Gross Income (AGI). This paper establishes the importance of wealth in determining the distribution of AGI, and results here suggest that its effects can negate the permanent effect of a change in both tax rates. Of the two tax rates, the capital gains tax rate is the most important for AGI distribution. The marginal income tax rate is notably less important for long run behavior, but does have short run impacts.
ECONOMIC TRANSITION AND SUBJECTIVE POVERTY IN URBAN CHINA
Authors: Bishop John A. , Luo Feijun , Pan Xi
Published: November 2006

Market‐oriented economic reforms have substantially changed the Chinese economy. A policy of “allowing some to get rich earlier” clearly has benefited some regions of the country more than others. The purpose of this paper is to investigate changes in regional urban poverty during this period of policy transition. Our approach is based on survey responses to minimum needs (i.e., the “subjective method”). For the richest (Coast) and poorest regions (North West) we find unambiguous declines in poverty between 1988 and 1995 for the registered population. For the Central and South West regions we find that changes in poverty over time are sensitive to both the poverty line selected and the poverty index employed.
AN UPPER BOUND OF THE GINI INDEX IN THE ABSENCE OF MEAN INCOME INFORMATION
Authors: Ogwang Tomson
Published: November 2006

In this paper, an upper bound of the Gini index, based on grouped data, is proposed assuming that there is no information on all the group mean incomes as well as the overall mean income but the limits of the income brackets are known. An important advantage of this proposal is that conventional formulas for the upper bound of the Gini index could be applied directly by substituting the (unknown) mean income for each income bracket with the corresponding value that maximizes the grouping correction for that income bracket. The effects of varying the number and size of income brackets are investigated.
Beyond Evidence: The Complexity of Maternity Care
Authors: Enkin Murray W. , Glouberman Sholom , Groff Philip , Jadad Alejandro R. , Stern Anita
Published: November 2006

Preface:  This paper has been gestating for a long time‐‐the sixty years that I have been associated with maternity care. It was conceived during an era of medical authoritarianism, born in a time of nascent childbirth education and family‐centered maternity care, matured in a period of enthusiastic (but not unquestioning) homage to evidence‐based obstetrics, and culminated in a reluctant but comforting acceptance of uncertainty. It has passed through stages of enthusiasm, of disillusionment, and of reevaluation. It is, to use an ancient word I only recently learned, a clinamen, a swerve, a point of intellectual revision. Others in the Clinamen Collaboration share the authorship of this paper with me.

Murray Enkin
Women’s Mental Health Before, During, and After Pregnancy: A Population‐Based Controlled Cohort Study
Authors: Van Bussel Johan C. H. , Spitz Bernard , Demyttenaere Koen
Published: November 2006

ABSTRACT:  Background:
Common mental health disorders like depressive and anxiety disorders are frequent in antenatal and postpartum women. However, no agreement about the prevalence of these disorders and the course of women’s mental health during the transition to motherhood exists. This study compared women’s mental health before, during, and after pregnancy with a control group of nonpregnant women.
Methods:
Three hundred and twenty‐four women were assessed before, during, and after their pregnancy with the 12‐item version of the General Health Questionnaire (GHQ‐12). A control group of 324 women who did not deliver during 3 subsequent years was assessed with the GHQ‐12 at corresponding time‐points.
Results:
No differences in GHQ‐12 mean scores, prevalence, and incidence of common mental health disorders between the study and control groups were found. No differences in prevalence and incidence rates within each group were found. The presence of a common mental health disorder before pregnancy or in early pregnancy predicted common mental health disorders in the postpartum period.
Conclusions:
Common mental health disorders are frequent during pregnancy and the postpartum period, but pregnant or postpartum women are not more at risk than those who are not pregnant or who did not deliver. (BIRTH 33:4 December 2006)
Long‐Term Survival in Patients Treated with Cardiac Resynchronization Therapy: A 3‐Year Follow‐Up Study from the InSync/InSync ICD Italian Registry
Authors: GASPARINI MAURIZIO , LUNATI MAURIZIO , SANTINI MASSIMO , TRITTO MASSIMO , CURNIS ANTONIO , BOCCHIARDO MARIO , VINCENTI ANTONIO , PISTIS GIANFRANCO , VALSECCHI SERGIO , DENARO ALESSANDRA ,   On Behalf of the INSYNC/INSYNC ICD ITALIAN Registry Investigators
Published: November 2006

Background: Studies reporting the long‐term survival of patients treated with cardiac resynchronization therapy (CRT) outside the realm of randomized controlled trials are still lacking. The aim of this study was to quantify the survival of patients treated with CRT in clinical practice and to investigate the long‐term effects of CRT on clinical status and echocardiographic parameters.

Methods: The study population consisted of 317 consecutive patients with implanted CRT devices from eight Italian University/Teaching Hospitals. The patients were enrolled in a national observational registry and had a minimum follow‐up of 2 years. A visit was performed in surviving patients and mortality data were obtained by hospital file review or direct telephone contact.

Results: During the study period, 83 (26%) patients died. The rate of all‐cause mortality was significantly higher in ischemic than nonischemic patients (14% vs 8%, P = 0.002). Multivariate analysis showed that ischemic etiology (HR 1.72, CI 1.06–2.79; P = 0.028) and New York Heart Association (NYHA) class IV (HR 2.87, CI 1.24–6.64; P = 0.014) were the strongest predictors of all‐cause mortality. The effects of CRT persisted at long‐term follow‐up (for at least 2 years) in terms of NYHA class improvement, increase of left ventricular ejection fraction, decrease of QRS duration (all P = 0.0001), and reduction of left ventricular end‐diastolic and end‐systolic diameters (P = 0.024 and P = 0.011, respectively).

Conclusions: During long‐term (3 years) follow‐up after CRT, total mortality rate was 10%/year. The outcome of ischemic patients was worse mainly due to a higher rate of death from progressive heart failure. Ischemic etiology along with NYHA class IV was identified as predictors of death. Benefits of CRT in terms of clinical function and echocardiographic parameters persisted at the time of long‐term follow‐up.
Improvement of Quality of Life by Means of Antitachy Pacing: From PainFREE to the ADVANCE‐D Trial
Authors: LUNATI MAURIZIO , DEFAYE PASCAL , MERMI JOHANN , GARCIA‐ALBEROLA ARCADI , MERINO JOSÉ L. , ARENAL ANGEL , CAPPATO RICCARDO , NAVARRO XAVIER , PASSARDI MICAELA , SANTINI MASSIMO
Published: November 2006

Background: Implantable cardioverter‐defibrillators (ICD) can terminate ventricular tachyarrhythmias with shocks (painful) or antitachycardia pacing (painless). According to the results of the Pacing Fast VT Reduces Shock ThErapies Trials, antitachycardia pacing (ATP) can avoid painful shocks and also increase device longevity. The purpose of the ADVANCE‐D (Atp DeliVery for PAiNless ICD ThErapy) study is to determine the most appropriate ventricular tachycardia (VT) therapy, so as to optimize painless therapy for life‐threatening arrhythmias.

Methods and Results: The ADVANCE‐D is a prospective, multicenter, parallel, two‐arm randomized study designed to evaluate the efficacy of two different sequences of ATP therapies (burst 15 pulses, 88%, vs burst 8 pulses, 88%), during an episode of spontaneous arrhythmia classified as fast VT (FVT) in patients with a Class I or IIA indication for ICD implantation (single and dual chamber devices). The primary endpoint is to compare the efficacy of two ATP therapies for FVT episodes. The study will enroll a minimum of 900 patients within 2 years, followed‐up for 12 months. The investigation is expected to be completed in 2007.

Conclusions: The ADVANCE‐D trial is the first large randomized clinical investigation aimed to evaluate optimal programming and efficacy of ATP.
Primary Prevention of Sudden Cardiac Death: Can We Afford the Cost of Cardioverter‐Defibrillators? Data from the Search‐MI Registry‐Italian Sub‐study
Authors: BORIANI GIUSEPPE , BIFFI MAURO , RUSSO MAURIZIO , LUNATI MAURIZIO , BOTTO GIANLUCA , PROCLEMER ALESSANDRO , VERGARA GIUSEPPE , RAHUE WERNER , MARTIGNANI CRISTIAN , RICCI RENATO , SANTINI MASSIMO ,   On Behalf of the SEARCH MI Registry Italian Investigators
Published: November 2006

Background: Large randomized trials show that in appropriately selected patients with left ventricular dysfunction, implantable cardioverter‐defibrillators (ICDs) can improve overall survival at 2–5 years. Since direct implementation of the criteria used in the MADIT II and SCD‐HeFT will lead to a marked rise in ICD implants, there is a growing fear that increased use of ICDs may cause a dramatic burden to health care systems. The ICD has traditionally been seen as an expensive form of treatment, which is difficult to accept at the first look. This is mainly due to the nonlinear character of the ICD investment, characterized by high initial expenditure, followed by a deferred pay‐off in terms of clinical benefits. Cost‐effectiveness analysis may help provide a different perspective on the problem of ICD cost, as may estimation of the daily cost of ICD treatment, assuming a time horizon of 5–7 years—a particularly interesting subject for further registry studies.

Methods and Results: Based on real expenditure data from 2002 to 2005, as recorded in the Search‐MI Registry‐Italian Sub‐study of patients implanted on MADIT II indications, we estimated the daily costs associated with the device and leads. Over a 5–7 year time horizon, the average daily cost was estimated to be €4.60–€6.70. Translation of these figures into U.S. market conditions suggests a daily cost of around $7.90–$11.40.

Conclusions: These findings appear useful to help evaluate the affordability of ICD in comparison with other therapeutic options in a context of limited available economic resources.
Autosomal dominant retinitis pigmentosa in Norway: a 20‐year clinical follow‐up study with molecular genetic analysis. Two novel rhodopsin mutations: 1003delG and I179F
Authors: Grøndahl Jan , Riise Ruth , Heiberg Arvid , Leren Trond , Christoffersen Terje , Bragadottir Ragnheidur
Published: November 2006

Purpose:  To examine the clinical picture and molecular genetics of 12 Norwegian families with autosomal dominant retinitis pigmentosa (adRP) in order to achieve a genotype−phenotype correlation.

Methods:  In addition to a clinical ophthalmological examination, fundus photography, dark adaptometry and electroretinography were performed. Four genes were analysed: rhodopsin (RHO); retinitis pigmentosa 1 (RP1); retinal degeneration slow/peripherin (RDS/peripherin), and inosine monophosphate dehydrogenase 1 (IMPDH1). Seven of the families had been examined about 20 years previously. A total of 63 patients or first‐degree relatives (aged 18–79 years) were examined.

Results:  Mutations were found only in the RHO gene. Seven families were given a diagnosis of classical RP. Two of them had novel mutation 1003delG, and one family had the mutation V345M. Four families had pericentral retinal dystrophy (PRD), two families with the mutation A164V and one with novel mutation I179F. One family was given a diagnosis of central and pericentral retinal dystrophy (CPRD), a special type of cone/rod dystrophy, and no mutation was found.

Conclusions:  Six of 12 families had an RHO mutation. The mutation V345M and the novel mutation 1003delG both caused classical RP, the former indicating the most unfavourable prognosis. Two of the families with PRD had the A164V mutation with a favourable prognosis, whereas the novel mutation I179F caused PRD with extremely variable expressivity.
Comparisons between Pascal dynamic contour tonometry, the TonoPen, and Goldmann applanation tonometry in patients with glaucoma
Authors: Salvetat Maria L. , Zeppieri Marco , Tosoni Claudia , Brusini Paolo
Published: November 2006

Purpose:  To compare intraocular pressure (IOP) measurements taken with Pascal dynamic contour tonometry (DCT), the TonoPen and the Goldmann applanation tonometry (GAT). The influence of central corneal thickness (CCT) on IOP measurements taken with Pascal DCT and the TonoPen was evaluated.

Methods:  One eye in each of 101 consecutive patients with primary open‐angle glaucoma (POAG) underwent ultrasonic CCT measurement and IOP evaluation with GAT, Pascal DCT and the TonoPen in random order. The agreement between results from Pascal DCT and the TonoPen and those of GAT was assessed using the Bland−Altman method. The deviation of Pascal DCT and TonoPen readings from GAT values, corrected for CCT, was calculated and correlated to CCT using a linear regression model.

Results:  The mean of the differences in IOP measurements was 3.2 ± 2.4 mmHg for Pascal DCT minus GAT readings and 0.5 ± 4.5 mmHg for TonoPen minus GAT readings. The 95% confidence interval of differences in IOP measurements was higher between TonoPen and GAT readings (− 6 to 7 mmHg) than between Pascal and GAT readings (0.1−6.8 mmHg). Pascal DCT significantly overestimated IOP compared with GAT, especially for higher IOP readings. Bland−Altman scatterplots showed reasonable inter‐method agreement between Pascal DCT and GAT measurements, and poor agreement between TonoPen and GAT measurements. The deviations of Pascal DCT and TonoPen readings from the corrected GAT values were both highly correlated with CCT values (linear regression analysis, p < 0.0001). The mean change in measured IOP for a 10‐µm increase in CCT was 0.48 mmHg for Pascal DCT and 0.74 mmHg for the TonoPen.

Conclusions:  Agreement with GAT measurements was higher for Pascal DCT than for TonoPen readings; however, Pascal DCT significantly overestimated IOP values compared with GAT. Measurements of IOP obtained with both Pascal DCT and the TonoPen appeared to be influenced by CCT, and this influence appeared to be greater for the latter.
Evaluation of selective calculus removal by a fluorescence feedback‐controlled Er:YAG laser in vitro
Authors: Krause Felix , Braun Andreas , Brede Olivier , Eberhard Jörg , Frentzen Matthias , Jepsen Søren
Published: November 2006

Objectives: To evaluate the removal of subgingival calculus and dental hard tissues depending on the threshold level of a fluorescence feedback‐controlled Er:YAG laser.

Material and Methods: Twenty teeth with calculus on the root surface were treated with an Er:YAG laser. Laser settings were 140 mJ and 10 Hz. The initial fluorescence threshold level of 5 [U] was reduced at intervals of 1 [U] for every laser treatment. Areas of residual calculus (RC) were evaluated using a surface analysis software. Loss of dental hard tissues was assessed by histomorphometric analysis of undecalcified ground sections.

Results: Using a threshold value of 5 [U], the median amount of RC was 11% (0–78%). By lowering the threshold levels, the amount of RC decreased [level 1 [U]: 0% (0–26%)]. The laser‐treated root surfaces revealed a statistically significant reduction of the cementum thickness [median: 80 μm (0–250)] compared with the non‐treated opposite side [median: 90 μm (30–250)] (p<0.05).

Conclusion: The amount of RC following laser irradiation depends on the fluorescence threshold level for a feedback‐controlled Er:YAG laser. It might be suggested that this laser system may be used with a threshold level even lower than 5 [U] without removing a clinically relevant amount of root cementum.
Differential expression of periodontal ligament‐specific markers and osteogenic differentiation in human papilloma virus 16‐immortalized human gingival fibroblasts and periodontal ligament cells
Authors: Pi S.‐H. , Lee S.‐K. , Hwang Y.‐S. , Choi M.‐G. , Lee S.‐K. , Kim E.‐C.
Published: November 2006

Background and Objective:  Periodontal ligament cells and gingival fibroblasts are important in the remodeling of periodontal tissue, but human papilloma virus (HPV)16‐immortalized cell lines derived from human periodontal ligament cells and gingival fibroblasts has not been characterized. The purpose of this study was to establish and differentially characterize the immortalized cell lines from gingival fibroblasts and periodontal ligament by HPV16 transfection.

Material and Methods:  Cell growth, cell cycle analysis, western blot for cell cycle regulatory proteins and osteogenic differentiation markers, and reverse transcription–polymerase chain reaction for periodontal ligament‐specific markers were performed.

Results:  Both immortalized cell lines (immortalized gingival fibroblasts and immortalized periodontal ligament cells) grew faster than primary cultured gingival fibroblasts or periodontal ligament cells. Immortalized gingival fibroblasts and immortalized periodontal ligament cells overexpressed proteins p16 and p21, and exhibited degradation of proteins pRb and p53, which normally cause cell cycle arrest in G2/M‐phase. Western blotting and reverse transcription–polymerase chain reaction for periodontal ligament‐specific and osteogenic differentiation marker studies demonstrated that a cell line, designated IPDL, mimicked periodontal ligament gene expression for alkaline phosphatase, osteonectin, osteopontin, bone sialoprotein, bone morphogenic protein‐2, periostin, S‐100A4 and PDLs17.

Conclusion:  These results indicate that IPDL and immortalized gingival fibroblast cell lines consistently retain normal periodontal ligament and gingival fibroblast phenotypes, respectively, and periodontal ligament markers and osteogenic differentiation in IPDL are distinct from immortalized gingival fibroblast cells.
Enamel matrix derivative stimulates chondrogenic differentiation of ATDC5 cells
Authors: Narukawa M. , Suzuki N. , Takayama T. , Shoji T. , Otsuka K. , Ito K.
Published: November 2006

Background and Objectives:  Although enamel matrix derivative can promote chondrogenic differentiation of pluripotent mesenchymal precursor cells, the molecular mechanism that underlies this phenomenon is unclear. The purpose of this study was to determine the effect of enamel matrix derivative on chondrogenic differentiation. ATDC5 cells, which undergo a reproducible multistep chondrogenic differentiation, were cultured with or without enamel matrix derivative for up to 35 d.

Methods and Results:  Cell proliferation and alkaline phosphatase activity increased markedly in cells cultured in the presence of enamel matrix derivative, compared with cells cultured in its absence. Deposition of Alcian blue‐positive cartilage matrix and Alizarin red‐positive mineralized nodules also increased significantly upon treatment with enamel matrix derivative. Expression of mRNAs encoding cartilage extracellular matrix proteins (type II collagen, type X collagen and aggrecan) and chondrogenic‐related transcription factors (Sox9, Zfp60 and AJ18) were measured using the real‐time polymerase chain reaction. Type II collagen, type X collagen and aggrecan mRNA expression increased markedly with enamel matrix derivative treatment. Transcription of Sox9, an important transcription factor that mediates chondrogenic differentiation, also increased with enamel matrix derivative treatment. The KRAB/C2H2 zinc‐finger transcription factors, Zfp60 and AJ18, were transiently expressed in the prehypertrophic stage, and their expression increased with enamel matrix derivative treatment. In a western blot analysis with anti‐insulin‐like growth factor‐I and anti‐bone morphogenetic protein‐6 immunoglobulin, bands corresponding to ≈ 14, ≈ 18 and ≈ 60 kDa were found in enamel matrix derivative.

Conclusion:  Our study provides clear evidence that enamel matrix derivative promotes chondrogenic differentiation of ATDC5 cells.
Differential platelet‐activating factor synthesis by monocytes and polymorphonuclear leukocytes from subjects with localized aggressive periodontitis
Authors: Shin C. R. , Moores J. , Best A. M. , Tew J. G. , Schenkein H. A. , Barbour S. E.
Published: November 2006

Background and Objective:  Platelet‐activating factor is elevated in localized aggressive periodontitis. We previously demonstrated that the elevated level of platelet‐activating factor in localized aggressive periodontitis is at least partially attributable to low levels of platelet‐activating factor acetylhydrolase, the enzyme that catabolizes platelet‐activating factor. The objective of this study was to determine if platelet‐activating factor synthesis was also elevated in localized aggressive periodontitis. To test this, platelet‐activating factor synthesis was quantified in the monocytes and polymorphonuclear neutrophils of periodontally healthy patients and of subjects with localized aggressive periodontitis.

Material and Methods:  Cells were labeled with [3H]acetate and treated with vehicle or stimulated with calcium ionophore A23187. Platelet‐activating factor was extracted and quantified by scintillation counting.

Results:  For both subject groups, resting monocytes and polymorphonuclear neutrophils produced platelet‐activating factor, and calcium ionophore A23187 stimulated platelet‐activating factor production in both cell types. However, calcium ionophore A23187‐activated monocytes from subjects with localized aggressive periodontitis produced less platelet‐activating factor than did activated periodontally healthy monocytes (p < 0.0001), suggesting an aberrant calcium ionophore A23187 response in monocytes from subjects with localized aggressive periodontitis. Indeed, when the data were expressed as fold induction of platelet‐activating factor synthesis in response to calcium ionophore A23187, monocytes from subjects with localized aggressive periodontitis exhibited only a fourfold increase in platelet‐activating factor synthesis, whereas calcium ionophore A23187‐stimulated monocytes from periodontally healthy, chronic periodontitis and generalized aggressive periodontitis subjects produced ≈ 12 times more platelet‐activating factor than did resting monocytes. In contrast, both resting and activated localized aggressive periodontitis polymorphonuclear neutrophils synthesized more platelet‐activating factor than did periodontally healthy polymorphonuclear neutrophils.

Conclusion:  These data suggest that high levels of platelet‐activating factor in subjects with localized aggressive periodontitis result from both increased synthesis and reduced catabolism. While localized aggressive periodontitis polymorphonuclear neutrophils contribute to increased platelet‐activating factor mass through synthesis, the contribution of monocytes is probably the result of reduced catabolism by platelet‐activating factor acetylhydrolase.
Smoking modulates interleukin‐6:interleukin‐10 and RANKL:osteoprotegerin ratios in the periodontal tissues
Authors: César‐Neto J. B. , Duarte P. M. , De Oliveira M. C. G. , Tambeli C. H. , Sallum E. A. , Nociti F. H.
Published: November 2006

Background and Objective:  This study evaluated the effect of smoking on the gene expression of interleukin‐1α, ‐1ra, ‐6, ‐8 and ‐10, tumor necrosis factor‐α, matrix metalloproteinase (MMP)‐2 and ‐8, receptor activator of NF‐κB ligand (RANKL) and osteoprotegerin, in sites with periodontitis.

Material and Methods:  Gingival biopsies were divided into three groups: the healthy group (periodontally healthy subjects; n = 10); the periodontitis group [subjects with severe chronic periodontitis who never smoked (probing depth ≥ 7 mm) (n = 25)]; and the smoking group (subjects diagnosed with severe chronic periodontitis who smoked ≥ 1 pack per day for at least 10 years; n = 25). Gene and protein expressions were analyzed by quantitative polymerase chain reaction and enzyme‐linked immunosorbent assay, respectively.

Results:  Data analysis demonstrated that, except for MMP‐8 and osteoprotegerin, the levels of all factors were increased by inflammation (p < 0.001). The levels of interleukin‐1α, ‐1ra, ‐6 and ‐8, and RANKL, were higher in smokers with periodontitis compared with controls, whereas the levels of interleukin‐10, MMP‐8 and osteoprotegerin were lower (p < 0.001). Smoking lowered the levels of interleukin‐1α, ‐8, ‐10, tumor necrosis factor‐α, MMP‐8 and osteoprotegerin, and increased the levels of interleukin‐6 and ‐1ra in sites with a comparable type of periodontitis (p < 0.001).

Conclusion:  In conclusion, smoking modulates gene expression in the periodontium, and the influence of smoking on periodontal disease may involve effects of interleukin‐6:interleukin‐10 and RANKL:osteoprotegerin ratios.
(‐)‐Epigallocatechin gallate induces apoptosis, via caspase activation, in osteoclasts differentiated from RAW 264.7 cells
Authors: Yun J.‐H. , Kim C.‐S. , Cho K.‐S. , Chai J.‐K. , Kim C.‐K. , Choi S.‐H.
Published: November 2006

Background and Objective:  Alveolar bone resorption is a characteristic feature of periodontal diseases and involves removal of both the mineral and the organic constituents of the bone matrix, a process mainly carried out by multinucleated osteoclast cells. (‐)‐Epigallocatechin gallate, the main constituent of green tea polyphenols, has been reported to induce the apoptotic cell death of osteoclasts and to modulate caspase activation in various tumor cells. In the present study, we investigated the inhibitory effect of (‐)‐epigallocatechin gallate on osteoclast survival and examined if (‐)‐epigallocatechin gallate mediates osteoclast apoptosis via caspase activation.

Material and Methods:  The effect of (‐)‐epigallocatechin gallate on osteoclast survival was examined by tartrate‐resistant acid phosphatase (TRAP) staining in osteoclasts differentiated from RAW 264.7 cells. In addition, we evaluated the apoptosis of osteoclasts by (‐)‐epigallocatechin gallate using a DNA‐fragmentation assay. Involvement of caspase in (‐)‐epigallocatechin gallate‐mediated osteoclast apoptosis was evaluated by treatment with a general caspase inhibitor, Z‐VAD‐FMK. Moreover, the effect of (‐)‐epigallocatechin gallate on the activation of caspase‐3 was assessed by a colorimetric activity assay and western blotting.

Results:  (‐)‐Epigallocatechin gallate significantly inhibited, in a dose‐dependent manner, the survival of osteoclasts differentiated from RAW 264.7 cells and induced the apoptosis of osteoclasts. Treatment with (‐)‐epigallocatechin gallate resulted in DNA fragmentation and induced the activation of caspase‐3 in RAW 264.7 cell‐derived osteoclasts. Additional treatment with Z‐VAD‐FMK suppressed these effects of (‐)‐epigallocatechin gallate.

Conclusion:  From these findings, we could suggest that (‐)‐epigallocatechin gallate might prevent alveolar bone resorption by inhibiting osteoclast survival through the caspase‐mediated apoptosis.
Effects of zinc deficiency on oral and periodontal diseases in rats
Authors: Orbak R. , Kara C. , Özbek E. , Tezel A. , Demir T.
Published: November 2006

Background and Objective:  The aim of this study was to investigate the alterations of oral and periodontal tissues in zinc‐deficient rats compared with control rats.

Material and Methods:  The study was carried out on 14 Sprague‐Dawley rats, cessation of lactation on the 24th day after birth. Rats were randomly divided into two groups. Group I rats were fed with a zinc‐deficient diet and group II rats were fed with a zinc‐containing diet. At the end of the fourth week on experimental diets, alterations of the oral tissues in both groups were recorded. In addition, the gingival index (GI‐Löe‐Silness), plaque index (PI‐Silness‐Löe) and periodontal pocket depth scores were recorded in order to assess periodontal tissue health in the rats. Then, blood samples were taken and the serum zinc levels measured by atomic absorption spectrophotometry. At the end of the experiment, oral tissue samples were investigated by light microscopy. Finally, the results of the two groups were compared by using the Student's t‐test.

Results:  The effects of zinc deficiency were observed at 10–16 d in rats. Although body weight, body length and tail length were retarded in zinc‐deficient rats, they were advanced in rats fed with a zinc‐containing diet. The mean plaque index and gingival index for group II rats were significantly lower than for group I rats (p < 0.001), but there was no significant difference regarding pocket depth between the two groups of rats (p > 0.05). Aphthous ulcer was often seen in the study group, where it was observed on the alveolar mucosa with a high rate of 29.9%. According to histological findings, there was no difference related to the epithelial keratinization of the hard palate between the two groups. However, hyperkeratosis was found on the dorsal surface of the tongue in zinc‐deficient rats.

Conclusion:  The findings indicated that oral health was better in group II rats (those fed with a zinc‐containing diet) than in group I (zinc‐deficient) rats. Hyperkeratinization was more prominent in zinc‐deficient rats. We suggest that zinc deficiency is a potential risk factor for oral and periodontal diseases.
Drug reward and intake in lines of mice selectively bred for divergent exploration of a hole board apparatus
Authors: Kliethermes C. L. , Kamens H. M. , Crabbe J. C.
Published: November 2006

Individuals characterized as high‐novelty seekers are more likely to abuse drugs than are low‐novelty seekers, and it is possible that the biological substrates underlying novelty seeking and drug abuse are similar. We selectively bred replicate lines of mice from a B6D2 F3 hybrid stock for high exploratory behavior (HEB) or low exploratory behavior (LEB) as measured by the number of head dips on a hole board. To determine whether common genes might influence exploratory behavior and behaviors relevant to drug abuse, we tested HEB and LEB mice for conditioned place preference produced by ethanol and d‐amphetamine and also examined oral methamphetamine intake. After four generations of selection, HEB and LEB mice did not differ in the magnitude of place preference for ethanol, but LEB mice showed a greater place preference for an amphetamine‐paired location than did HEB mice. However, this difference did not replicate in mice tested from the fifth generation of selection. The selected lines also did not differ in sensitization to the locomotor stimulant effects of d‐amphetamine that developed across the conditioning trials. Finally, HEB and LEB mice consumed equivalently low amounts of methamphetamine. These results suggest that common genes do not influence head dipping and several behaviors potentially relevant to drug abuse.
Calciphylaxis: no therapeutic concepts for a poorly understood syndrome?
Authors: Meissner Markus , Gille Jens , Kaufmann Roland
Published: November 2006

Calciphylaxis is a very uncommon and severe disease which mainly appears in patients with chronic renal insufficiency. It presents with ischemia and necrosis of the skin, subcutaneous adipose tissue, muscles and rarely viscera.The pathogenetic mechanisms inducing calciphylaxis are for the most part unknown.The mortality rate of 80% in the first year is very high. Patients experience marked pain, recurrent infections and the constant risk of secondary sepsis. Even multidisciplinary therapeutic strategies are limited, although there are recent case reports providing promising new therapeutic options including sodium thiosulfate and cinacalcet. This review summarizes the important aspects of diagnosis, pathogenesis, prevention and the possible therapeutic strategies of this intriguing, rare and often fatal disease.
Grafting of thrombopoietin‐mimetic peptides into cystine knot miniproteins yields high‐affinity thrombopoietin antagonists and agonists
Authors: Krause Sebastian , Schmoldt Hans‐Ulrich , Wentzel Alexander , Ballmaier Matthias , Friedrich Karlheinz , Kolmar Harald
Published: November 2006

Thrombopoietin is the primary regulator of platelet production. We exploited two naturally occurring miniproteins of the inhibitor cystine knot family as stable and rigid scaffolds for the incorporation of peptide sequences that have been shown to act as high‐affinity thrombopoietin antagonists. Several miniproteins that antagonistically block thrombopoietin‐mediated receptor activation were identified using a microscale reporter assay. Covalent miniprotein dimerization yielded potent bivalent c‐Mpl receptor agonists with EC50 values in the low nanomolar or picomolar range. One selected miniprotein‐derived thrombopoietin agonist was almost as active as natural thrombopoietin with regard to stimulation of megakaryocyte colony formation from human bone marrow mononuclear cells, and elicited doubling of platelet counts in mice. Our data suggest that dimeric cystine knot miniproteins have considerable potential for the future development of small and stable receptor agonists. This approach may provide a promising strategy for pharmaceutical interference with other receptors activated by ligand‐induced dimerization.
Proteolytic processing of the receptor‐type protein tyrosine phosphatase PTPBR7
Authors: Dilaver Gönül , van de Vorstenbosch Rinske , Tárrega Céline , Ríos Pablo , Pulido Rafael , van Aerde Karlijn , Fransen Jack , Hendriks Wiljan
Published: November 2006

The single‐copy mouse gene Ptprr gives rise to different protein tyrosine phosphatase (PTP) isoforms in neuronal cells through the use of distinct promoters, alternative splicing, and multiple translation initiation sites. Here, we examined the array of post‐translational modifications imposed on the PTPRR protein isoforms PTPBR7, PTP‐SL, PTPPBSγ42 and PTPPBSγ37, which have distinct N‐terminal segments and localize to different parts of the cell. All isoforms were found to be short‐lived, constitutively phosphorylated proteins. In addition, the transmembrane isoform, PTPBR7, was subject to N‐terminal proteolytic processing, in between amino acid position 136 and 137, resulting in an additional, 65‐kDa transmembrane PTPRR isoform. Unlike for some other receptor‐type PTPs, the proteolytically produced N‐terminal ectodomain does not remain associated with this PTPRR‐65. Shedding of PTPBR7‐derived polypeptides at the cell surface further adds to the molecular complexity of PTPRR biology.
Specific TSC22 domain transcripts are hypertonically induced and alternatively spliced to protect mouse kidney cells during osmotic stress
Authors: Fiol Diego F. , Mak Sally K. , Kültz Dietmar
Published: November 2006

We recently cloned a novel osmotic stress transcription factor 1 (OSTF1) from gills of euryhaline tilapia (Oreochromis mossambicus) and demonstrated that acute hyperosmotic stress transiently increases OSTF1 mRNA and protein abundance [Fiol DF, Kültz D (2005) Proc Natl Acad Sci USA102, 927–932]. In this study, a genome‐wide search was conducted to identify nine distinct mouse transforming growth factor (TGF)‐β‐stimulated clone 22 domain (TSC22D) transcripts, including glucocorticoid‐induced leucine zipper (GILZ), that are orthologs of OSTF1. These nine TSC22D transcripts are encoded at four loci on chromosomes 14 (TSC22D1, two splice variants), 3 (TSC22D2, four splice variants), X (TSC22D3, two splice variants), and 5 (TSC22D4). All nine mouse TSC22D transcripts are expressed in renal cortex, medulla and papilla, and in the mIMCD3 cell line. The two TSC22D3 transcripts (including GILZ) are upregulated by aldosterone but not by hyperosmolality in mIMCD3 cells. In contrast, TSC22D4 is stably upregulated by hyperosmolality in mIMCD3 cells and increased in renal papilla compared with cortex. Moreover, all four TSC22D2 transcripts are transiently upregulated by hyperosmolality and resemble tilapia OSTF1 in this regard. All TSC22D2 transcripts depend on hypertonicity as the signal for their upregulation and are unresponsive to increases in cell‐permeable osmolytes. mRNA stabilization is the mechanism for TSC22D2 upregulation by hyperosmolality. Overexpression of TSC22D2–4 in mIMCD3 cells confers protection towards osmotic stress, as evidenced by a 2.7‐fold increase in cell survival after 3 days at 600 mOsmol·kg−1. Based on variable responsiveness to aldosterone and hyperosmolality in kidney cells we conclude that mouse TSC22D genes have diverse physiological functions. TSC22D2 and TSC22D4 are involved in adaptation of renal cells to hypertonicity suggesting that they represent important elements of osmosensory signal transduction in mouse kidney cells.
A Recombinant Protein LHRH‐PE40 for Tumour Therapy: Preclinical Safety Studies
Authors: Li Jun , Sun Yunxia , Zhang Jinkun
Published: November 2006

Abstract: LHRH‐PE40, a recombinant DNA‐derived protein composed of LHRH and Pseudomonas aeruginosa exotoxin A, is being developed for the treatment of malignant tumours. This experiment was designed to assess its preclinical safety. Reproductive toxicity studies, pharmacokinetic studies, single‐ and repeat‐dose intraperitoneal or intravenous toxicity studies in mice, rats and monkeys were conducted to assess the toxicity of LHRH‐PE40. In intravenous single‐dose studies in mice, the LD50 was 731.26 μg/kg and 676.03 μg/kg in male and female mice respectively. In single‐dose studies and repeat‐dose range‐finding studies in rats, dose‐limited severe vascular leakage syndromes occurred. In repeat‐dose long‐term studies, except drug‐related vascular leakage syndromes, other drug‐related changes included decreased testis weight and testis atrophy. In single‐dose and repeat‐dose studies in monkeys, dose‐limited acute tubular necrosis of the kidneys was the chief finding. In reproductive studies, drug‐related changes were decreased food intakes, decreased testis weight and uterus weight, decreased foetus weight and increased foetus mortality, increased maternal and F1 offspring mortality and decreased maternal and F1 offspring body weight. Pharmacokinetic studies showed a similar half‐time of distribution and clearance in mice and monkeys. Tissue distribution showed a high concentration in the kidneys and a low concentration in the brain. LHRH‐PE40 induced vascular leak syndromes in rats and acute tubular necrosis in monkeys. It also led to testicle atrophy in rats and overt productive toxicity to parents and F1 generations in mice. Because of these findings, it should be monitored carefully in human clinical trials for things such as respiratory, urinary and reproductive toxicities.