bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetic resonance imaging as a tool for in vivo and ex vivo anatomical phenotyping in experimental genetic models
Authors: Pitiot Alain , Pausova Zdenka , Prior Malcolm , Perrin Jennifer , Loyse Naomi , Paus Tomáš
Published: April 2007

This article describes a suite of computational approaches suitable for deriving various quantitative phenotypes from structural magnetic resonance (MR) images obtained in rodents and used subsequently in genetic studies of complex traits. We begin by introducing the basic principles of genetic studies of complex traits in experimental models. We then illustrate the use of MR‐based computational anatomy in vivo and ex vivo, and in combination with histology. This work was carried out in two inbred strains of rats, namely spontaneously hypertensive rats and Brown Norway rats; these are parental strains of the only existing panel of recombinant inbred strains of rats. The rats were scanned in vivo at two time points (at 8 and 12 weeks of age) and ex vivo (at 12 weeks of age). We describe between‐strain differences and across‐time changes in brain and kidney volumes, as well as regional variations in brain structure using surface‐ and deformation‐based approaches. We conclude by discussing the power of the population‐based computational analysis of MR images, and their fusion with histology, in studies of complex traits. Hum Brain Mapp, 2007. © 2007 Wiley‐Liss, Inc.
Fronto‐striatal dysfunction and potential compensatory mechanisms in male adolescents with fragile X syndrome
Authors: Hoeft Fumiko , Hernandez Arvel , Parthasarathy Sudharshan , Watson Christa L. , Hall Scott S. , Reiss Allan L.
Published: April 2007

Response inhibition is an important facet of executive function. Fragile X syndrome (FraX), with a known genetic etiology (fragile X mental retardation‐1 (FMR1) mutation) and deficits in response inhibition, may be an ideal condition for elucidating interactions among gene‐brain‐behavior relationships. Functional magnetic resonance imaging (fMRI) studies have shown evidence of aberrant neural activity when individuals with FraX perform executive function tasks, though the specific nature of this altered activity or possible compensatory processes has yet to be elucidated. To address this question, we examined brain activation patterns using fMRI during a go/nogo task in adolescent males with FraX and in controls. The critical comparison was made between FraX individuals and age, gender, and intelligent quotient (IQ)‐matched developmentally delayed controls; in addition to a control group of age and gender‐matched typically developing individuals. The FraX group showed reduced activation in the right ventrolateral prefrontal cortex (VLPFC) and right caudate head, and increased contralateral (left) VLPFC activation compared with both control groups. Individuals with FraX, but not controls, showed a significant positive correlation between task performance and activation in the left VLPFC. This potential compensatory activation was predicted by the interaction between FMR1 protein (FMRP) levels and right striatal dysfunction. These results suggest that right fronto‐striatal dysfunction is likely an identifiable neuro‐phenotypic feature of FraX and that activation of the left VLPFC during successful response inhibition may reflect compensatory processes. We further show that these putative compensatory processes can be predicted by a complex interaction between genetic risk and neural function. Hum Brain Mapp, 2007. © 2007 Wiley‐Liss, Inc.
Heritability of brain volume, surface area and shape: An MRI study in an extended pedigree of baboons
Authors: Rogers Jeffrey , Kochunov Peter , Lancaster Jack , Shelledy Wendy , Glahn David , Blangero John , Fox Peter
Published: April 2007

To evaluate baboons (Papio hamadryas) as a primate model for the study of the genetic control of brain size and internal structure, we performed high resolution (<500 μm) magnetic resonance imaging on 109 pedigreed baboons. Quantitative genetic analysis of these MR images using a variance components approach indicates that native (untransformed) brain volume exhibits significant heritability among these baboons (h2 = 0.52, P = 0.0049), with age and sex also accounting for substantial variation. Using global spatial normalization, we transformed all images to a standard population‐specific reference, and recalculated the heritability of brain volume. The transformed images generated heritability estimates of h2 = 0.82 (P = 0.00022) for total brain volume, h2 = 0.86 (P = 0.0006) for cerebral volume, h2 = 0.73 (P = 0.0069) for exposed surface area of the cerebrum and h2 = 0.67 (P = 0.01) for gray matter volume. Regional differences in the genetic effects on brain structure were calculated using a voxel‐based morphometry (VBM) approach. This analysis of regional variation shows that some areas of motor cortex and the superior temporal gyrus show relatively high heritability while other regions (e.g. superior parietal cortex) exhibit lower heritability. The general pattern of regional differences is similar to that observed in previous studies of humans. The present study demonstrates that there is substantial genetic variation underlying individual variation in brain size and structure among Papio baboons, and that broad patterns of genetic influence on variation in brain structure may be similar in baboons and humans. Hum Brain Mapp, 2007. © 2007 Wiley‐Liss, Inc.
Age‐period‐cohort projections of breast cancer incidence in a rapidly transitioning Chinese population
Authors: Wong Irene O.L. , Cowling Benjamin J. , Schooling Catherine Mary , Leung Gabriel M.
Published: April 2007

Breast cancer incidence should be assessed separately in different populations, as it differs substantially between Chinese and Caucasian women, and more generally in developing versus developed populations. Estimation of future trends is important for public health planning. On the basis of the recent breast cancer incidence trends, we projected future disease rates in the rapidly transitioning Chinese population of Hong Kong. We used local data on breast cancer incidence and mid‐year population figures for the years 1974–2003. We fitted Poisson age‐period‐cohort models with autoregressive priors on the age, period and cohort effects, and used projections of these effects to forecast future incidence to 2018. We found that age‐standardized breast cancer incidence would continue to rise by ∼1.1% per annum over the next 15 years, from 45.9 cases in 1999–2003 to 54.3 per 100,000 (95% credible interval: 50.9, 58.4) in 2014–2018. Recent secular incidence increases can be attributed to both ageing and intergenerational effects beginning with the postwar baby boomers, whereas there is no evidence for important changes by time period. There does not appear to be differential cohort‐related risk for pre‐ vs. postmenopausal disease. Unlike most other cancers, breast cancer risk in local women would continue to increase in the short to medium term, at a similar rate of increase compared with historical trends. This could most likely be attributed to Hong Kong's socioeconomic developmental history and continuing adoption of westernized lifestyle changes. © 2007 Wiley‐Liss, Inc.
Prostaglandin F2α stimulates motility and invasion in colorectal tumor cells
Authors: Qualtrough David , Kaidi Abderrahmane , Chell Simon , Jabbour Henry N. , Williams Ann C. , Paraskeva Christos
Published: April 2007

Increased expression of cyclooxygenase‐2 (COX‐2) and subsequent prostaglandin production is an important event in several human malignancies, including colorectal cancer. COX‐2 mediated prostanoid synthesis has been shown to play a key role in tumor progression with prostaglandin E2 (PGE2) being shown to promote tumor growth, invasion and angiogenesis. The role of the other prostaglandins produced by COX‐2 in tumors remains poorly understood. We have shown that colorectal tumor cells produce prostaglandin F2α (PGF2α) and provide evidence that PGF2α may play an important role in colorectal tumorigenesis. Our data show that PGF2α is secreted by both colorectal adenoma and carcinoma‐derived cell lines at levels in excess of those detected for PGE2. These cell lines were also found to express the PGF2α receptor (FP) indicating potential autocrine effects of PGF2α. This finding is further supported by an in vivo immunohistochemical study of FP expression in resected colon tissue. These data show epithelial expression of FP in normal colorectal mucosa and also in colorectal adenomas and carcinomas. We compared the relative abilities of PGF2α and PGE2 to induce cell motility in vitro in colorectal tumor cell lines and show the first evidence of prostaglandin‐induced cell motility in colorectal adenoma cell lines. PGF2α induced cell motility with equivalent potency to PGE2 in all the cell lines tested and was also shown to increase the invasion of carcinoma‐derived cells into reconstituted basement membrane. These data show that PGF2α may play an important role in the malignant progression of colorectal tumors. © 2007 Wiley‐Liss, Inc.
Risk of human T‐lymphotropic virus type I‐associated diseases in Jamaica with common HLA types
Authors: Goedert James J. , Li Hong‐Chuan , Gao Xiao‐Jiang , Chatterjee Nilanjan , Sonoda Shunro , Biggar Robert J. , Cranston Beverley , Kim Norma , Carrington Mary , Morgan Owen , Hanchard Barrie , Hisada Michie
Published: April 2007

Human T‐lymphotropic virus‐I (HTLV‐I) causes adult T‐cell leukemia/lymphoma (ATL) and HTLV‐associated myelopathy/tropical spastic paraparesis (HAM/TSP). We postulated a higher disease risk for people with common human leukocyte antigen (HLA) types, due to a narrower immune response against viral or neoplastic antigens, compared to people with uncommon types. HLA class‐I (A,B) and class‐II (DRB1, DQB1) allele and haplotype frequencies in 56 ATL patients, 59 HAM/TSP patients and 190 population‐based, asymptomatic HTLV‐I‐infected carriers were compared by logistic regression overall (score test) and with odds ratios (ORs) for common types (prevalence >50% of asymptomatic carriers) and by prevalence quartile. HTLV‐I proviral load between asymptomatic carriers with common versus uncommon types was compared by t‐test. ATL differed from asymptomatic carriers in overall DQB1 allele and class‐I haplotype frequencies (p ≤≤ 0.04). ATL risk was increased significantly with common HLA‐B (OR 2.25, 95% CI 1.19–4.25) and DRB1 (OR 2.11, 95% CI 1.13–3.40) alleles. Higher prevalence HLA‐B alleles were associated with higher ATL risk (OR 1.14 per quartile, ptrend = 0.02). Asymptomatic carriers with common HLA‐B alleles had marginally higher HTLV‐I proviral load (p = 0.057). HAM/TSP risk did not differ consistently with common HLA types. Thus, ATL risk, but not HAM/TSP risk, was increased with higher prevalence HLA‐B alleles. Perhaps breadth of cellular immunity affects risk of this viral leukemia/lymphoma. © 2007 Wiley‐Liss, Inc.
Immunohistochemical in situ characterization of orthopedic implants on polymethyl metacrylate embedded cutting and grinding sections
Authors: Rammelt S. , Corbeil D. , Manthey S. , Zwipp H. , Hanisch U.
Published: April 2007

When investigating the tissue reaction on orthopedic implants, the cellular activity at the bone–implant interface is of special interest. Preparation of undecalcified bone sections with methylmetacrylate (MMA)‐based resins allows evaluation of the host tissue reactions with the implant in situ. However, the technical workup is demanding and few reports exist on the immunohistochemical characterization of these sections. Rat (R), sheep (S), and human (H) samples were investigated. R specimens contained intramedullary rods in the rat tibia. S specimens were sheep tibiae with an external fixator. H specimens were obtained from deceased patients. Specimens were embedded in MMA‐based Technovit 9100N using cold polymerization. Sections of 10–15 μm thickness were obtained and prepared for immunohistochemical staining. Good morphological detail was preserved in all specimens providing information about mineralization, recent bone formation, and bone–implant contact. The following antibodies could reproducibly be detected specifically: Osteopontin (R, S, H), Osteonectin, Cathepsin D (R, S), von Willebrand factor (R, H), Osteocalcin, ED 1 (R), CD 3, CD 68, Keratin (H). Control procedures without adding primary antibodies showed no unspecific staining. Reliable detection of immunohistochemical markers of bone resorption, bone formation, inflammation, and angiogenesis at undecalcified sections with the implant in situ appears promising in enhancing our understanding of the cellular activity and cell–matrix interactions at the bone–implant interface. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Uptake of nickel from 316L stainless steel into contacting osteoblastic cells and metal ion interference with BMP‐2‐induced alkaline phosphatase
Authors: Mölders Martina , Felix Joachim , Bingmann Dieter , Hirner Alfred , Wiemann Martin
Published: April 2007

Bone cells contacting nickel (Ni)‐containing implant materials may be affected by Ni species via disturbed signaling pathways involved in bone cell development. Here we analyze effects of the Ni‐containing steel 316L and major metal constituents thereof on bone morphogenetic protein‐2 (BMP‐2)‐induced alkaline phosphatase (ALP) of MC3T3‐E1 cells. While cells grew normally on 316L, cellular Ni content increased 10‐fold vs. control within 4 days. With respect to the major components of 316L, Ni2+ (3–50 μM) was most inhibitory to BMP‐2‐induced ALP, whereas even 50 μM Fe3+, Cr3+, Mo5+, or Mn2+ had no such effect. In line with this, BMP‐2‐induced ALP was significantly reduced in cells on 316L. This effect was not prevented by the metal ion chelator diethylenetriaminepentaacetic acid (DTPA). Instead, DTPA abolished the stimulatory effect of BMP‐2 on ALP, pointing to chelatable metal ions involved. Zn2+, as one possible candidate, antagonized the Ni2+ inhibition of BMP‐2‐induced ALP in both MC3T3‐E1 and human bone marrow stromal cells. Results show that cells contacting 316L steel are exposed to increased concentrations of Ni which suffice to impair BMP‐2‐induced ALP activity. Zn2+, as a competitor of this inhibition, may help to restore normal osteoblastic function and bone development under these conditions. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Homogenization of long‐term monthly Spanish temperature data
Authors: Staudt M. , Esteban‐Parra M. J. , Castro‐Díez Y.
Published: April 2007

Reliable time‐series is the basic ingredient when analysing climatic changes. However, the errors in real data are frequently of the same order as the signal being sought. Therefore, the available long‐term monthly series of Spanish minimum and maximum temperatures have been compiled from the late 19th century on, in order to compile a high‐quality data set. The series are organized into climatically homogeneous regional groups and, in each group, the detection and adjustment is based on relative homogeneity and an analysis of the stationarity of the whole set of temperature‐difference series. These series are scanned with moving t, Alexandersson, and Mann–Kendall tests. The detected inhomogeneities are adjusted by weighted averages of the regional series. The method is iterative and advances in steps of detection, adjustment, and actualization. Individual inhomogeneous data are discarded and gaps are filled by similar weighted multiple means.

For the analysis of the temperature evolution in the Iberian Peninsula, each region is finally represented by one local series and the regional average. The urban effect on minimum temperatures is adjusted by an empirical method, and for Madrid also by a correction derived from new homogenized data. Generally, rigorous homogeneity cannot be achieved because the initial data quality is deficient in many cases and metadata are sparse. Nevertheless, the data homogeneity and quality has been considerably enhanced: the total error margin in a series is of the order of 0.3 °C–0.4 °C, under consideration of a worst‐case error accumulation. On the other hand, the number of inhomogeneities is considerable and their average amplitude is of the order of 1 °C reflecting the much larger error margin in the raw data. The homogenized dataset compiled constitutes an important basis for the subsequent detection of thermal changes in Spain in the last 130 years, on a clearly higher confidence level than before. Copyright © 2007 Royal Meteorological Society
A Study of the Quenching Structures of Fe‐B‐C Alloy
Authors: Fu H. , Zhou Q. , Jiang Z.
Published: April 2007

The effect of quenching temperature and cooling rate on the structures of cast Fe‐B‐C alloy containing 1.0wt.%B and 0.2wt.%C was researched. The results showed that, under the same quenching temperature, the microstructures of the metallic matrix are transformed from the mixture of the pearlite, ferrite and martensite to the martensite along with the increase of quenching cooling rate. Under the water cooling condition, excessively low or excessively high quenching temperature did not favor to obtain the single martensite matrix. In the Fe‐B‐C alloy, the stability of Fe2B was good. It still had not been dissolved while heating up to 1050oC. The dissolution of boride appeared heating at the high temperature. The higher the quenching temperature was, the more the boride dissolved obviously. Along with the dissolution of boride, the boride morphology changed from network to broken‐network and isolated shape. When the heating temperature was 1050oC, the boride transformed the isolated shape completely. Quenching at 950∼1000oC, cast Fe‐B‐C alloy transformed into the compound structures of fine lath martensite and boride in the water cooling condition.
Managerial expertise, learning potential and dynamic incentives: get more for less?
Authors: Lukas Christian
Published: April 2007

In this paper the impact of ability and learning potential on incentive contracts is analyzed. A central feature of the model is that the true ability will not be revealed. The learning potential of an agent is modeled as the magnitude of impact on the agent's expected ability that learning‐by‐doing has in a given task. Absent a managerial labor market, depending on an agent's learning potential, a monotone or non‐monotone pay structure may be optimal.

The second important result is that using agents' ability distributions as inputs to information systems, higher learning potentials lead to less costly information systems, i.e. actions can be implemented at lower costs. Additionally, it is proven that the criteria cost minimization and value maximization are equivalent in the model's context. Copyright © 2007 John Wiley & Sons, Ltd.
MSU rurality index: Development and evaluation
Authors: Weinert Clarann , Boik Robert J.
Published: April 2007

The construction and validation of a residence‐based index of the degree of rurality are reported. The MSU Rurality Index is a locally normed index and assigns a quantitative measure of rurality to each participant in a study. Data required to compute the index are minimal; only two variables need be measured. Statistical analysis effort required to compute the index is somewhat more intensive than usual, but this tradeoff between data collection and data analysis seems sensible. Data collection is generally more expensive than data analysis. The two required variables, county population and distance to emergency care, are optimally transformed to achieve normality and weighted to achieve validity. A measure of departure from normality is automatically obtained while constructing the index. A positive score reflects a rural residence and a negative score reflects an urban residence relative to the group under study. A score of zero reflects average rurality. Reliability and construct validity were examined using two data sets. The MSU Rurality Index has high test–retest reliability, is appropriately related to a set of ordered categories concerning place of residence, and is as or more strongly related to these categories than alternative indices computed from distance or population alone. The validity of the MSU Rurality Index does not appear to be compromised by its parsimony. Even though the MSU Rurality Index is based on only two variables, it was found to be associated with various health care variables as strongly or more strongly than an 11 variable county‐based index developed in Texas. ©1995 John Wiley & Sons, Inc.
Ten measurement commandments that often should be broken
Authors: Knapp Thomas R. , Brown Jean K.
Published: April 2007

Many of the measurement aspects of nursing research have been governed by rules regarding the minimum values of certain summary indexes (such as Cronbach's coefficient alpha and Cohen's kappa), the required numbers of subjects per item for factor analyses, and the like. In this article a case is made for violating these rules whenever the circumstances warrant such violations. ©1995 John Wiley & Sons, Inc.
Consistency between maternal employment attitudes and employment status
Authors: Youngblut Joanne M.
Published: April 2007

The stability of mothers' attitudes toward employment, employment status, and consistency between employment attitudes and behavior over a 15‐month period was examined. Factors such as family finances, availability of child care, and child's health status that could influence either employment attitudes or employment behavior were explored. Mothers of preterm infants (N = 98) and mothers of full‐term, healthy infants (N = 101) completed questionnaires regarding home/employment orientation, choice and satisfaction with the employment decision, and employment behavior as part of a battery of instruments administered when their infants were 3, 9, and 18 months old. Analyses indicated considerable stability in attitudes, behaviors, and consistency over a 15‐month period for mothers of both full‐term and preterm infants. Consistency groups were created based on employment status (employed versus not employed) and consistency status (consistent versus inconsistent) at each time point. Consistency groups differed on ratings of financial need and availability of child care. ©1995 John Wiley & Sons, Inc.
Influence of symptoms, lung function, mood, and social support on level of functioning of patients with COPD
Authors: Graydon Jane E. , Ross Eleanor
Published: April 2007

To explain how symptoms, lung function, mood, and social support affect level of functioning, patients (N = 143) with chronic obstructive pulmonary disease (COPD) completed measures assessing their symptoms (Bronchitis‐Emphysema Symptom Checklist), mood (Profile of Mood States), social support (Personal Resource Questionnaire), and functioning (Sickness Impact Profile). Those who were receiving oxygen therapy (n = 52) had significantly lower FEV, scores and experienced significantly poorer functioning than those who were not receiving oxygen therapy (n = 91). Results of path analyses indicated that symptoms and mood directly, and social support indirectly, influenced the functioning of those who were not receiving oxygen. For those who were receiving oxygen, only symptoms directly, and FEV, indirectly, influenced their functioning. These models need to be confirmed using other samples of patients with COPD. ©1995 John Wiley & Sons, Inc.
Psychophysiologic factors contributing to functional performance in people with COPD: Are there gender differences?
Authors: Leidy Nancy Kline , Traver Gayle A.
Published: April 2007

The purpose of this study was to compare the functional performance profiles of men and women with chronic obstructive pulmonary disease, describe the extent to which physiologic impairment, physical symptoms, and psychosocial resources contribute in a cumulative manner to performance, and outline the extent to which these contributions differ across gender. Secondary data analyses were employed. Although women (n = 45) reported more functional difficulty than men (n = 44) in 9 of 12 Sickness Impact Profile categories, the differences were not significant. Using hierarchical regression procedures, physiologic, symptomatic, and interactive variables predicted total (R2 = .64) and physical performance (R2 = .52), while symptomatic and psychosocial variables predicted psychosocial performance (R2 = .53). Results indicate that models of functional performance may be different for men and women. ©1995 John Wiley & Sons, Inc.
The effect of chronic obstructive pulmonary disease on quality of life
Authors: Anderson Kathryn L.
Published: April 2007

Lazarus and Folkman's (1984) theory of stress, coping, and adaptation served as the framework for a path model of quality of life in chronic obstructive pulmonary disease (COPD). It was hypothesized that psychosocial variables (depression, anxiety, self‐esteem, optimism, and social support) would mediate the effects of demographic (age, socioeconomic status) and disease (dyspnea, disease severity, and functional status) variables on life quality in COPD. Interview, pulmonary function, and 6‐minute walk test data obtained from 126 subjects with COPD resulted in support for the majority of the hypothesized relationships. Variables having direct effects on life quality were self‐esteem, depression, social support, and age. Anxiety and optimism did not have their hypothesized effects on quality of life, suggesting the need to reconsider their importance in influencing life quality in COPD. ©1995 John Wiley & Sons, Inc.
Matching versus cultural competence in research: Methodological considerations
Authors: Sawyer Linda , Regev Hanna , Proctor Susan , Nelson Martha , Messias Deanne , Barnes Donelle , Meleis Afaf Ibrahim
Published: April 2007

Researcher/participant matching has been used in nursing research as a strategy for the development of culturally competent knowledge. In this manuscript, the complexities inherent in matching in nursing research are discussed. In raising and discussing issues and questions related to matching, we argue that although matching may be one of the strategies used to generate culturally competent knowledge, it is frequently too complex for operationalization. Therefore, we propose that researchers reflect on questions related to their knowledge of culture, their cultural sensitivity, and the nature of collaboration during every phase of the research. Reflecting on and responding to these questions in every research project may facilitate the development of more culturally competent knowledge. ©1995 John Wiley & Sons, Inc.
Triangles and crystals: On the geometry of qualitative research
Authors: Sandelowski Margarete
Published: April 2007

Triangulation has become increasingly appealing to researchers in nursing as a device to grasp the complexity of human phenomena, operationalize the holistic elan of nursing, and to accommodate both qualitative and quantitative approaches to inquiry. Yet, a misplaced ecumenicism, definitional drift, and conceptual misappropriation are evident in discussions of triangulation, which has become a technique for everything. Moreover, the triangle is somewhat lacking as image and metaphor for qualitative inquiry. As an idea and technique (in)formed by the triangle, triangulation should be used only to refer to a distinctive strategy for confirmation employed within research paradigms in which convergent and consensual validity are valued, and in which it is deemed appropriate to use information from one source to corroborate another. ©1995 John Wiley & Sons, Inc.
Presentation of acute promyelocytic leukemia as granulocytic sarcoma
Authors: Worch Jennifer , Ritter Jörg , Frühwald Michael C.
Published: April 2007

Granulocytic sarcoma (GS) is a localized tumor composed of immature myeloid cells. This extramedullary tumor can present before, concurrent with or after the diagnosis of acute myeloid leukemia. GS is extremely uncommon in acute promyelocytic leukemia (APL). As a proportion of patients never develop systemic disease, correct and timely diagnosis may be rather difficult, but is a prerequisite for optimal outcome. GS should be considered in the differential diagnosis of children with unusual bone lesions. We describe a patient with GS who presented with symptoms mimicking osteomyelytis or rheumatoid disease. Pediatr Blood Cancer 2008;50:657–660. © 2007 Wiley‐Liss, Inc.
Use of desmopressin in elderly patients in Denmark
Authors: Callréus Torbjörn
Published: April 2007

Purpose

Against the background of the approval of the use of desmopressin in the treatment of nocturia in adults, the aim of the present study was to describe patterns of its use in elderly patients in Denmark from 2000 to 2004.

Methods

Data were obtained from the Danish Register of Medicinal Product Statistics on nationwide sales of desmopressin and two commonly used measures of drug utilisation: 1‐year prevalence (number of patients treated at least once during 1 year/1000 inhabitants) and therapeutic intensity (Daily Defined Doses (DDD)/1000 inhabitants/day).

Results

In 2002, the 1‐year prevalence rose ranging from a 5‐fold increase among men aged 60–69 years to a 14‐fold increased prevalence in men ≥90 years. In women, relative increases of the same magnitude were noted. Similarly, marked increases of the therapeutic intensities were observed in both men and women in 2002, this was followed by steady growth in most age groups. By the end of the study period in 2004, the highest therapeutic intensities were observed in men (1.06 DDD/1000 inhabitants/day) and women (0.92 DDD/1000 inhabitants/day) aged 80–89 years.

Conclusion

After approval in 2002 of the use of desmopressin in the management of nocturia in adults, a substantial increased utilisation was observed in patients ≥80 years. Given the high prevalence of risk factors for hyponatremia in these elderly patients, the pattern of utilisation is noteworthy and may need to be reviewed. Copyright © 2007 John Wiley & Sons, Ltd.
Antidepressants in children and adolescents—changes in utilisation after safety warnings
Authors: Dean Angela J. , Hendy Anna , McGuire Treasure
Published: April 2007

Background

Antidepressants, in particular selective serotonin reuptake inhibitors, are one of the most commonly used classes of psychotropic drug in children and adolescents. Beginning in June 2003, evidence emerged suggesting that antidepressants may increase risk of suicidal behaviour in young people. This evidence was accompanied by national and international guidelines cautioning against use of many antidepressants in young people. This study aimed to assess whether these safety warnings have impacted upon antidepressant utilisation rates.

Method

This study was based at a metropolitan health service incorporating children's and adult hospitals. Total service utilisation of antidepressants was extracted from pharmacy software for the period January 2002 to December 2005. Monthly utilisation rates were computed for adults and children's services as defined daily doses (DDD) per occupied bed days. Changes in utilisation over time were examined for children and adults.

Results

There was a significant relationship between time and antidepressant utilisation in children and adolescents, where antidepressant use decreased over time (R = 0.474; t = −3.66; p < 0.01), and in particular, use of SSRIs (R = 0.461; t = −3.52; p < 0.01). In contrast, use of SSRIs (R = 0.587; t = 4.91; p < 0.001) and all antidepressants (R = 0.327; t = 2.35; p < 0.05) increased over time in adults.

Conclusions

National and international warnings about safety of antidepressants in children and adolescents appear to have influenced local utilisation of these medications in young people but not in adults. Further research is required to determine optimal utilisation rates. Copyright © 2007 John Wiley & Sons, Ltd.
Completely discontinuous organic/ inorganic hybrid nanocomposites by self‐curing of nanobuilding blocks constructed from reactions of [HMe2SiOSiO1.5]8 with vinylcyclohexene
Authors: Takamura Norihiro , Viculis Lisa , Zhang Chunxin , Laine Richard M
Published: April 2007

The reaction of 4‐vinyl‐1‐cylcohexene with [HMe2SiOSiO1.5]8 provides tetra‐ and octa‐2‐cyclohexenylethyloctasilsesquioxanes. The tetrabifunctional [cyclohexenylethylMe2SiOSiO1.5]4‐[HMe2SiOSiO1.5]4 (average degree of functionalization) melts near 80 °C and can be cast and then cured (by thermal hydrosilylation) into transparent nanocomposite shapes. These materials, while not nanoporous, offer dielectric constants of 2.8–2.9 at 100 kHz to 3 MHz, and are air stable to temperatures ≥ 400 °C. The resulting materials appear (by X‐ray diffraction) to be partially ordered after curing. The octafunctional material also melts at low temperatures (ca 120 °C) and can be copolymerized with hydridosiloxanes to give similar materials with lower thermal stability. The synthesis and characterization of the starting materials is described, as well as thermal curing studies and properties characterization of the resultant nanocomposites. Copyright © 2007 Society of Chemical Industry
Molecular modeling study on surface, thermal, mechanical and gas diffusion properties of chitosan
Authors: Prathab B. , Aminabhavi Tejraj M.
Published: April 2007

The motivation of this work is to provide reliable and accurate modeling studies of the physical (surface, thermal, mechanical and gas diffusion) properties of chitosan (CS) polymer. Our computational efforts have been devoted to make a comparison of the structural bulk properties of CS with similar type of polymers such as chitin and cellulose through cohesive energy density, solubility parameter, hydrogen bonding, and free volume distribution calculations. Atomistic modeling on CS polymer using molecular mechanics (MM) and molecular dynamics (MD) simulations has been carried out in three dimensionally periodic and effective two dimensionally periodic condensed phases. From the equilibrated structures, surface energies were computed. The equilibrium structure of the films shows an interior region of mass density close to the value in the bulk state. Various components of energetic interactions have been examined in detail to acquire a better insight into the interactions between bulk structure and the film surface. MD simulation (NPT ensemble) has also been used to obtain polymer specific volume as a function of temperature. It is demonstrated that these V–T curves can be used to locate the volumetric glass transition temperature (Tg) reliably. The mechanical properties of CS have been obtained using the strain deformation method. Diffusion coefficients of O2, N2, and CO2 gas molecules at 300 K in CS have been estimated. The calculated properties of CS are comparable with the experimental values reported in the literature. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1260–1270, 2007
Monitoring the efficacy and metabolism of phenylcarbamates in sugar beet and black nightshade by chlorophyll fluorescence parameters
Authors: Abbaspoor Majid , Streibig Jens C
Published: April 2007

Desmedipham, phenmedipham and a 50% mixture of the two decreased the maximum quantum efficiency of photosystem II (Fv/Fm) and the relative changes at the J step (Fvj) immediately after spraying in both sugar beet and black nightshade grown in the greenhouse. Sugar beet recovered more rapidly from phenmedipham and the mixture than from desmedipham. Desmedipham and the mixture irreversibly affected Fv/Fm and Fvj in black nightshade at much lower doses than in sugar beet. Black nightshade recovered from phenmedipham injury at the highest dose in the first experiment (120 g AI ha−1) but not in the second experiment (500 g AI ha−1). The dry matter dose–response relationships and the energy pipeline presentation confirmed the same trend. There was a relatively good correlation between Fvj taken 1 day after spraying and dry matter taken 2 or 3 weeks after spraying. The differential speed of herbicide metabolism between weed and crop plays an important role in herbicide selectivity and can be studied by using appropriate chlorophyll a fluorescence parameters. Copyright © 2007 Society of Chemical Industry
Interaction of S413‐PV cell penetrating peptide with model membranes: relevance to peptide translocation across biological membranes
Authors: Mano Miguel , Henriques Ana , Paiva Artur , Prieto Manuel , Gavilanes Francisco , Simões Sérgio , De Lima Maria C. Pedroso
Published: April 2007

Cell penetrating peptides (CPPs) have been successfully used to mediate the intracellular delivery of a wide variety of molecules of pharmacological interest both in vitro and in vivo, although the mechanisms by which the cellular uptake occurs remain unclear and controversial. Following our previous work demonstrating that the cellular uptake of the S413‐PV CPP occurs mainly through an endocytosis‐independent mechanism, we performed a detailed biophysical characterization of the interaction of this peptide with model membranes. We demonstrate that the interactions of the S413‐PV peptide with membranes are essentially of electrostatic nature. As a consequence of its interaction with negatively charged model membranes, the S413‐PV peptide becomes buried into the lipid bilayer, which occurs concomitantly with significant peptide conformational changes that are consistent with the formation of a helical structure. Comparative studies using two related peptides demonstrate that the conformational changes and the extent of cell penetration are dependent on the peptide sequence, indicating that the helical structure acquired by the S413‐PV peptide is relevant for its nonendocytic uptake. Overall, our data suggest that the cellular uptake of the S413‐PV CPP is a consequence of its direct translocation through cell membranes, following conformational changes induced by peptide‐membrane interactions. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.
Mobility and density of ions in chitosan–orthophosphoric acid–ammonium nitrate electrolytes
Authors: Majid S. R. , Arof A. K.
Published: April 2007

An important factor that contributes significantly to the conductivity of a material is the number density and mobility of the mobile species. In this work the number density of mobile ions, n, was calculated using the Rice and Roth model and the random walk formulation. The value of n as calculated using the Rice and Roth model depends on the activation energy and mean free path of the ions whereas calculation using the random walk formulation depends on the hopping rates of the ions. Our results show that the values of n calculated using the random walk formulation is more than one order of magnitude larger than that calculated using the Rice and Roth model. Unlike mobility, the values of n do not show significant changes with temperature. This suggests that mobility influences the conductivity of the polymer at elevated temperatures. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Singlet oxygen generation in porous silicon with fullerenes
Authors: Pikulev V. B. , Kuznetsov S. N. , Saren A. A. , Gardin Yu. E. , Gurtov V. A.
Published: April 2007

We have studied light‐induced processes in ultra‐thin porous silicon (por‐Si) impregnated with fullerene C60. After insertion of C60 molecules a photoluminescence (PL) is quenched for more than one order of magnitude. No additional EPR defects were detected under fullerene insertion as it was revealed in por‐Si powder. Under illumination in oxygen the PL intensity could be restored to nearly initial level or to yet more. Recovery degree was dependent on oxidation state of por‐Si before C60 insertion. As was observed by ellipsometry a PL recovery is accompanied with oxidation of porous layer. Observed phenomenon is related with known ability of C60 to produce singlet oxygen. We suppose that generation efficiency of fullerenes to produce singlet oxygen is enhanced by energy transfer from photoexcited nanocrystallites. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Further results on porous silicon optical waveguides at 1.55 µm
Authors: Pirasteh P. , Charrier J. , Dumeige Y. , Joubert P. , Haesaert S. , Haji L.
Published: April 2007

We present our recent results on planar and buried waveguides on porous silicon or on oxidized porous silicon. Optical losses were measured and also near‐field observations of guided modes were carried out. Some single mode waveguides with low losses (2 dB/cm) were obtained. The principal contributions of the losses are discussed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Beam‐type collisional activation of polypeptide cations that survive ion/ion electron transfer
Authors: Han Hongling , Xia Yu , McLuckey Scott A.
Published: April 2007

Doubly protonated peptides that undergo an electron transfer reaction without dissociation in a linear ion trap can be subjected to beam‐type collisional activation upon transfer from the linear ion trap into an adjacent mass analyzer, as demonstrated here with a hybrid triple quadrupole/linear ion trap system. The activation can be promoted by use of a DC offset difference between the ion trap used for reaction and the ion trap into which the products are injected of 12–16 V, which gives rise to energetic collisions between the transferred ions and the collision/bath gas employed in the linear ion trap used for ion/ion reactions. Such a process can be executed routinely on hybrid linear ion trap/triple quadrupole tandem mass spectrometers and is demonstrated here with several model peptides as well as a few dozen tryptic peptides. Collisional activation of the peptide precursor ions that survive electron transfer frequently provides structural information that is absent from the precursor ions that fragment spontaneously upon electron transfer. The degree to which additional structural information is obtained by collisional activation of the surviving singly charged peptide ions depends upon peptide size. Little or no additional structural information is obtained from small peptides (<8 residues) due to the high electron transfer dissociation (ETD) efficiencies noted for these peptides as well as the extensive sequence information that tends to be forthcoming from ETD of such species. Collisional activation of the surviving electron transfer products provided greatest benefit for peptides of 8–15 residues. Copyright © 2007 John Wiley & Sons, Ltd.
Higher‐order sliding‐mode observer for state estimation and input reconstruction in nonlinear systems
Authors: Fridman Leonid , Shtessel Yuri , Edwards Christopher , Yan Xing‐Gang
Published: April 2007

In this paper, a higher‐order sliding‐mode observer is proposed to estimate exactly the observable states and asymptotically the unobservable ones in multi‐input–multi‐output nonlinear systems with unknown inputs and stable internal dynamics. In addition the unknown inputs can be identified asymptotically. Numerical examples illustrate the efficacy of the proposed observer. Copyright © 2007 John Wiley & Sons, Ltd.
Bayesian modelling of tuberculosis clustering from DNA fingerprint data
Authors: Scott Allison N. , Joseph Lawrence , Bélisle Patrick , Behr Marcel A. , Schwartzman Kevin
Published: April 2007

A combination of continuous and categorical tests, none of which is a gold standard, is often available for classification of subject status in epidemiologic studies. For example, tuberculosis (TB) molecular epidemiology uses select mycobacterial DNA sequences to provide clues
about which cases of active TB are likely clustered, implying recent transmission between these cases, versus reactivation of previously acquired infection. The proportion of recently transmitted cases is important to public health, as different control methods are implemented as transmission rates increase. Standard typing methods include IS6110 restriction fragment length polymorphism (IS6110 RFLP), but recently developed polymerase chain reaction based genotyping modalities, including mycobacterial interspersed repetitive unit‐variable‐number tandem repeat and spoligotyping provide quicker results. In addition, it has recently been suggested that results from IS6110 RFLP can be used to create a continuous measure of genetic relatedness, called the nearest genetic distance. Whichever method is used, estimation of cluster rates is rendered difficult by the lack of a gold standard method for classifying cases as clustered or not. Since many of these methods are relatively new, their properties have not been extensively investigated. Misclassification errors subsequently lead to sub‐optimal estimation of risk factors for clustering. Here we show how Bayesian latent class models can be used in such situations, for example to simultaneously analyse Mycobacterium tuberculosis DNA data from all three of the above methods. Using the data collected at the Public Health Unit in Montreal, we estimate the proportion of clustered cases and the operating characteristics of each method using information from all three methods combined, including both continuous and dichotomous measures from IS6110 RFLP. A misclassification‐adjusted regression model provides estimates of the effects of risk factors on the clustering probabilities. We also discuss how one must carefully interpret any inferences that arise from a combination of continuous and dichotomous tests. Copyright © 2007 John Wiley & Sons, Ltd.
Signal transduction mechanisms regulating ion fluxes in the sea urchin sperm
Authors: Beltrán Carmen , Galindo Blanca Estela , Rodríguez‐Miranda Esmeralda , Sánchez Daniel
Published: April 2007

Ion permeability changes involving ion channels and transporters are essential for fertilization, since they are key elements in sperm‐egg signaling and environmental sensing. Changes modulated by external factors and components from the outer layer of the homologous egg, like the sperm‐activating peptides and the fucose‐sulfate glycoconjugate, trigger complex signaling systems in the sperm that modulate how sperm swim, find the egg and fertilize it. These signaling systems depend on plasma membrane ion permeability and involve an alteration of second messenger levels, changes of membrane potential and intracellular Ca2+, Na+ and pH, along with changes in sperm morphology in the case of the acrosome reaction (AR). New procedures to elucidate the signaling pathways implicated in sperm ion transport have expanded the opportunities to dissect sperm‐egg signaling revealing how sperm ion channels participate in activation, motility, chemotaxis, and the AR. The sperm signaling pathways involve a large variety of ion channels and transporters, which are discretely localized and finely orchestrated to play specific roles that define the elaborate performance of sperm and allow a successful fertilization. In this review we will focus on the signaling molecules involved in the final aim of the sperm, to reach and fertilize the egg.
Biostratigraphy and deposition environments of the Middle-Late Miocene volcanosedimentary section in the Dzhilinda basin, Western Transbaikalia
Authors: Chernyaeva G.P. , Lyamina N.A. , Rasskazov S.V. , Rezanov I.N. , Savinova V.V.
Published: April 2007

We report results of an integrated study of volcanosedimentary rocks of the Middle-Late Miocene Dzhilinda Formation consisting of the prevolcanic sedimentary Lower Dzhilinda and volcanosedimentary Upper Dzhilinda subformations. The section was studied in three wells drilled near Lake Mukhal (Khoigot paleovalley, Vitim upland). The Dzhilinda sediments contain ubiquitous Alveolophora jouseana (Moiss.) Moiss. typical of Miocene environments. Deposition occurred in two main stages represented by different water (diatoms) and land (spores and pollen) plant communities. The upsection successive changes in diatom species are attendant with changes in pollen and spore assemblages. The K-Ar ages of lavas indicate that the mostly sedimentary lower section of the Dzhilinda Formation deposited between 12 and 14 Ma and the more volcanic upper section, with a lacustrine lens at base, formed at about 10.8–9.5 Ma. The isotope dating of volcanic rocks agrees with the ages inferred from the diatom and spore-pollen analyses. The prevolcanic Lower Dzhilinda subformation deposited during the Middle Miocene climate optimum. The stratigraphy, lithology and facies of sediments suggest that the Dzhilinda deposition was associated with the development of a deep freshwater lake in the conditions of active tectonism and volcanism.