bluuebunny/crossref_metadata_2025 huggingface dataset:
The Gene Expression Profile in Refractory Periodontitis Patients
Authors: Kim David M. , Ramoni Marco F. , Nevins Myron , Fiorellini Joseph P.
Published: May 2006

Background: There are no specific bacterial profiles or diagnostic tests capable of identifying refractory periodontitis patients before a treatment regimen is initiated. Therefore, in this high‐risk cohort of patients who do not respond appropriately, host factors that might be partly under genetic control may play a crucial role in their susceptibility. Specifically, we tested the hypothesis that patients with refractory periodontitis have multiple upregulated and/or downregulated genes that might be important in influencing clinical risk.

Methods: Oral subepithelial connective tissues were harvested aseptically from seven refractory periodontitis and seven periodontally well‐maintained patients. An RNA isolation kit was used to isolate total RNA from tissue samples that had been stabilized in the RNA stabilizing reagent. The isolated total RNA was then subjected to gene expression profiling using the microarray to measure gene expression levels. The retrieved data were analyzed with a computer program for the differential analysis of gene expression microarray experiments. In addition, real‐time polymerase chain reaction (PCR) analysis was performed on selected samples to confirm the microarray data's gene expression patterns.

Results: A total of 68 upregulated and six downregulated genes were identified that were differentially expressed at least two‐fold out of 22,283 genes we analyzed. The selected model provided a 93% intrinsic validation along with a 93% extrinsic validation. To validate the microarray data, five upregulated genes (lactotransferrin [LTF], matrix metalloproteinase‐1 [MMP‐1], MMP‐3, interferon induced‐15 [IFI‐15], and Homo sapiens hypothetical protein MGC5566) and two downregulated genes (keratin 2A [KRT2A] and desmocollin‐1 [DSC‐1]) were randomly selected for further analysis by real‐time PCR. The relative RNA expression level of these genes measured by real‐time PCR was similar to those measured by microarrays.

Conclusion: The combined use of microarray technology with the computer program for the differential analysis of gene expression microarray experiments provided a set of candidate genes that may serve as novel therapeutic intervention points and improved diagnostic and screening procedures for high‐risk individuals.
Changes in Periodontal Disease Experience From 26 to 32 Years of Age in a Birth Cohort
Authors: Thomson W. Murray , Broadbent Jonathan M. , Poulton Richie , Beck James D.
Published: May 2006

Background: Information is lacking on the natural history of periodontitis through the third and fourth decades of life.

Methods: Periodontal examinations were conducted at 26 and 32 years of age in a longstanding prospective study of a birth cohort born in Dunedin, New Zealand, in 1972 and 1973. At each age, gingival recession (GR) and probing depth (PD) were recorded at three sites per tooth using a diagonal half‐mouth design (measurements were made in all four quadrants at 32 years of age, but longitudinal comparisons were made using only the half‐mouth data).

Results: A total of 882 individuals were examined at both ages. The mean number of measured sites fell between 26 and 32 years of age. The overall prevalence of one or more sites with ≥4 mm combined attachment loss (CAL) rose from 18.6% to 21.8%, whereas there were greater increases in the proportion with two or more sites with ≥4 mm CAL (from 8.0% to 12.6%) and one or more sites with ≥5 mm CAL (from 3.6% to 8.0%). The extent and severity of CAL also increased. A total of 403 individuals (45.7%) had an increase in CAL ≥2 mm at one or more sites, whereas 110 (12.5%) had a CAL increase ≥3 mm at one or more sites. Seen in ∼4% of sites, negative GR (i.e., gingival enlargement) had a substantial effect on PD‐based estimates. An increase in PD ≥2 mm at one or more sites was experienced by 345 individuals (39.1%), whereas 88 people (10.0%) had an increase in PD ≥3 mm at one or more sites. The greatest mean attachment loss was experienced at disto‐lingual sites on molars, and most manifested as PD increases. Notable increases in GR were seen with lower incisors and canines.

Conclusions: Periodontal loss of attachment continues among a sizable proportion of people from the third to the fourth decade of life; however, contrary to patterns in older adults, changes in the PD component are greater than the changes in the recession component. Incident attachment loss is most frequently observed at proximal sites on posterior teeth.
Gender-Specific Trends in Educational Attainment and Self-Rated Health, 1972–2002
Authors: Hill Terrence D. , Needham Belinda L.
Published: May 2006

Objectives. We tested whether self-rated health has improved over time (1972–2002) for women and men. We also considered the degree to which historical gains in educational attainment help to explain any observed trends.

Methods. Using 21 years of repeated cross-sectional data from the General Social Survey, we estimated a series of ordered logistic regression models predicting self-rated health.

Results. Our results show that women’s health status has steadily improved over the 30-year period under study, and these improvements are largely explained by gains in educational attainment. We also found that the health trend for men is nonlinear, suggesting significant fluctuations in health status over time.

Conclusions. Based on the linear health status trend and strong mediation pattern for women, and the nonlinear health status trend for men, women have benefited more than men, in terms of self-rated health, from increased educational attainment.
Characterization of water‐soluble organoarsenic compounds in marine sponges
Authors: Yamaoka Yukiho , Carmona Marvelisa L. , Oclarit Jose M. , Jin Kazuo , Shibata Yasuyuki
Published: May 2006

To provide a better understanding of the arsenic cycle in the marine ecosystem and marine biotechnological viewpoints, the present study is intended to identify arsenic compounds contained in marine sponges. Marine sponges were collected off the coastal waters of Magsaysay Islet within Bohol Sea near Mindanao (Philippines) and in the Seto Inland Sea (Japan) by skin‐diving. Water‐soluble arsenic compounds were extracted with methanol–water (1: 1, v/v) from freeze‐dried samples of 13 marine sponges. The extracts were analyzed using high‐performance liquid chromatography (HPLC) with an inductively coupled plasma mass spectrometer (ICP/MS) serving as an arsenic‐specific detector. All marine sponges contained arsenobetaine [(CH3)3As+ CH2COO−], 2,3‐dihydroxypropyl 5‐deoxy‐5‐(dimethylarsinoyl)‐β‐ribofuranoside (arseno‐sugar X), and 3‐glycerophosphoryl‐2‐hydroxy‐1‐[5‐deoxy‐5‐(dimethylarsinoyl)‐β‐ribofuranosyloxy]propane (arseno‐sugar X1), among which arseno‐sugarX1 was most abundant in the Jaspis spp., Suberites spp. and four Japanese sponges. Also, a linear relationship existed between total water‐soluble arsenic and arsenobetaine Copyright © 2006 John Wiley & Sons, Ltd.
Caspase inhibitors reduce severity of cartilage lesions in experimental osteoarthritis
Authors: D'Lima Darryl , Hermida Juan , Hashimoto Sanshiro , Colwell Clifford , Lotz Martin
Published: May 2006

Objective

To examine the therapeutic efficacy of caspase inhibitors in experimental osteoarthritis (OA).

Methods

Experimental OA was induced in rabbits by anterior cruciate ligament transection (ACLT). Rabbits were treated with intraarticular (IA) injections of caspase inhibitors 3 times per week starting 1 week postoperatively. Animals were killed 9 weeks after ACLT, for macroscopic, histologic, and immunohistochemical assessment of the knee joints.

Results

IA administration of the pan‐caspase inhibitor Z‐VAD‐FMK significantly reduced cartilage degradation, as assessed by macroscopic and microscopic criteria. Untreated knees showed large numbers of chondrocytes with active caspase 3 and the p85 fragment of poly(ADP‐ribose) polymerase (PARP p85) that is generated during apoptosis. The frequency of cells positive for PARP p85 and active caspase 3 was reduced in Z‐VAD‐FMK–treated knees. Inhibitors specific for caspase 3 or caspase 8 showed no significant efficacy. Caspase 1 inhibitor and the combination of caspase 3 and caspase 8 inhibitors reduced OA pathology.

Conclusion

These results provide direct support for a role of cell death in OA pathogenesis. Caspase inhibitors reduced the severity of cartilage lesions in experimental OA, suggesting that they may have disease‐modifying activity in human OA.
Primary therapist model for patients referred for rheumatoid arthritis rehabilitation: A cost‐effectiveness analysis
Authors: Li Linda C. , Maetzel Andreas , Davis Aileen M. , Lineker Sydney C. , Bombardier Claire , Coyte Peter C.
Published: May 2006

Objective

To estimate the incremental cost‐effectiveness (ICE) of services from a primary therapist compared with traditional physical therapists and/or occupational therapists for managing rheumatoid arthritis (RA), from the societal perspective.

Methods

Patients with RA were randomly assigned to the primary therapist model (PTM) or traditional treatment model (TTM) for ∼6 weeks of rehabilitation treatment. Health outcomes were expressed in terms of quality‐adjusted life years (QALYs), measured with the EuroQol instrument at baseline, 6 weeks, and 6 months. Direct and indirect costs, including visits to health professionals, use of investigative tests, hospital visits, use of medications, purchases of adaptive aids, and productivity losses incurred by patients and their caregivers, were collected monthly.

Results

Of 144 consenting patients, 111 remained in the study after the baseline assessment: 63 PTM (87.3% women, mean age 54.2 years, disease duration 10.6 years) and 48 TTM (79.2% women, mean age 56.8 years, disease duration 13.2 years). From a societal perspective, PTM generated higher QALYs (mean ± SD 0.068 ± 0.22) and resulted in a higher mean cost ($6,848 Canadian, interquartile range [IQR] $1,984–$9,320) compared with TTM (mean ± SD QALY −0.017 ± 0.24; mean costs $6,266, IQR $1,938–$10,194) in 6 months, although differences were not statistically significant. The estimated ICE ratio was $13,700 per QALY gained (95% nonparametric confidence interval −$73,500, $230,000).

Conclusion

The PTM has potential to be an alternative to traditional physical/occupational therapy, although it is premature to recommend widespread use of this model in other regions. Further research should focus on strategies to reduce costs of the model and assess the long‐term economic consequences in managing RA and other rheumatologic conditions.
Accelerating the analyses of 3‐way and 4‐way PARAFAC models utilizing multi‐dimensional wavelet compression
Authors: Cramer Jeff , Kim Yoon‐Chang , Vogt Frank , Booksh Karl
Published: May 2006

Parallel factor analysis (PARAFAC) is one of the most popular methods for evaluating multi‐way data sets, such as those typically acquired by hyphenated measurement techniques. One of the reasons for PARAFAC popularity is the ability to extract directly interpretable chemometric models with little a priori information and the capability to handle unknown interferents and missing values. However, PARAFAC requires long computation times that often prohibit sufficiently fast analyses for applications such as online sensing. An additional challenge faced by PARAFAC users is the handling and storage of very large, high‐dimensional data sets. Accelerating computations and reducing storage requirements in multi‐way analyses are the topics of this manuscript. This study introduces a data pre‐processing method based on multi‐dimensional wavelet transforms (WTs), which enables highly efficient data compression applied prior to data evaluation. Because multi‐dimensional WTs are linear, the intrinsic underlying linear data construction is preserved in the wavelet domain. In almost all studied examples, computation times for analyzing the much smaller, compressed data sets could be reduced so much that the additional effort for wavelet compression was more than recompensated. For 3‐way and 4‐way synthetic and experimental data sets, acceleration factors up to 50 have been achieved; these data sets could be compressed down to a few per cent of the original size. Despite the high compression, accurate and interpretable models were derived, which are in good agreement with conventionally determined PARAFAC models. This study also found that the wavelet type used for compression is an important factor determining acceleration factors, data compression ratios and model quality. Copyright © 2006 John Wiley & Sons, Ltd.
Electronic Energy Transfer in a Multiporphyrin‐Based Molecular Box
Authors: Prodi Anna , Chiorboli Claudio , Scandola Franco , Iengo Elisabetta , Alessio Enzo
Published: May 2006

The molecular box 1 comprises of two zinc‐porphyrin metallacycles connected by two free‐base 4′‐trans‐dipyridylporphyrins, axially coordinated to the zinc centers. The photophysics of 1 were studied in chloroform by emission and ultrafast absorption spectroscopy. In the molecular box, fast singlet energy transfer (main component, τ=32 ps) is observed to occur from the zinc‐porphyrin metallacycles to the free‐base chromophores. From wavelength‐dependent spectrofluorimetric data, the efficiency of the energy‐transfer (ET) process is estimated as 0.5. The lower‐than‐unity value is tentatively attributed to the possibility of a competing electron‐transfer quenching pathway. Molecular box 1 can be considered to be a simple, self‐assembling, six‐chromophore antenna system. It has an inner cavity, 11.4 Å wide, that could be used, in principle, to host a variety of guest molecules and obtain higher‐order assemblies.
The transition to parenthood: Stress, resources, and gender differences in a Chinese society
Authors: Lu Luo
Published: May 2006

This study aimed to explore the parenthood transition in a Chinese cultural context. Three hundred sixty‐four parents (201 females, 163 males) took part in this panel study conducted twice at 6 weeks before and 6 weeks after the birth of their children. Results showed that (a) in cross‐sectional analyses, parenthood stress had consistent negative effects on mental health and marital satisfaction; (b) in prospective analyses, stress still had adverse effects on postnatal mental health or marital satisfaction after controlling for their prenatal baseline levels; (c) social support and marital congruence had beneficial effects on the parenthood adjustment; (d) compared to men, women reported higher stress, more psychological symptoms, lower marital satisfaction than men, but receiving more social support. These results are discussed in relation to existing Western theories and research, as well as the distinct characteristics of the contemporary Chinese society. Possible implications for community interventions are also suggested. © 2006 Wiley Periodicals, Inc.
Cover Picture: Macromol. Theory Simul. 5/2006
Authors: Izgorodina Ekaterina I. , Coote Michelle L.
Published: May 2006

Cover: The picture on the cover shows the strong chain length dependence of the addition‐fragmentation equilibrium in cumyl dithiobenzoate mediated polymerization of styrene. This effect has important implications for kinetic modeling of the RAFT process. Further details can be found in the article by E. I. Izgorodina and M. L. Coote* on page 394.
Downstream targets of Nm23‐H1: Gene expression profiling of CAL 27 cells using DNA microarray
Authors: Bosnar Maja Herak , Bago Ružica , Gall‐Trošelj Koraljka , Streichert Thomas , Pavelić Jasminka
Published: May 2006

The human nm23‐H1 was discovered as a tumor metastasis suppressor based on its reduced expression in melanoma cell lines with low versus high metastatic potential. It encodes for one of two subunits of the nucleoside‐diphosphate kinase. Besides its role in the maintenance of the cells NTP pool, nm23 plays a key role in different cellular processes. The role of nm23‐H1 in these processes still has to be elucidated. Our goal was to identify Nm23‐H1 downstream targets by subjecting Nm23‐H1 overexpressing CAL 27 cells oral squamous cell carcinoma (OSSC) to microarray analysis. The genes with changed expression patterns could be clustered into several groups: transforming growth factor β (TGFβ) signaling pathway, cell adhesion, invasion and motility, proteasome machinery, cell‐cycle, epithelial structural and related molecules and others. Based on the expression patterns observed we presume that nm23‐H1 might have a role in OSSCs, which should be confirmed by future experiments. © 2006 Wiley‐Liss, Inc.
An α‐L‐fucosidase potentially involved in fertilization is present on Drosophila spermatozoa surface
Authors: Intra Jari , Cenni Federica , Perotti Maria‐Elisa
Published: May 2006

Drosophila is emerging as a model organism to investigate egg fertilization in insects and the possible conservation of molecular mechanisms of gamete interactions demonstrated in higher organisms. This study shows that the spermatozoa of several species of Drosophila belonging to the melanogaster group have a plasma membrane associated α‐L‐fucosidase with features in common with α‐L‐fucosidases from sperm of other animals, including mammals. The enzyme has been purified and completely characterized in D. ananassae, because of its stability in this species. The sperm α‐L‐fucosidase is an integral protein terminally mannosylated, with the catalytic site oriented toward the extracellular space. It has a Mr of 256 kDa and a multimeric structure made up by subunits of 48 and 55 kDa. Enzyme characterization included kinetic properties, pI, optimal pH, and thermal stability. A soluble form of the enzyme similar to the sperm associated α‐L‐fucosidase is secreted by the seminal vesicles. Synthetic peptides designed from the deduced product of the D. melanogaster gene encoding an α‐L‐fucosidase were used to raise a specific polyclonal antibody. Immunofluorescence labeling of spermatozoa showed that the enzyme is present in the sperm plasma membrane overlying the acrosome and the tail. Lectin cytochemistry analysis of the egg surface indicated that α‐L‐fucose terminal residues are present on the chorion with a strongly polarized localization on the micropyle. The α‐L‐fucosidase of Drosophila sperm plasma membrane appears to be potentially involved in gamete recognition by interacting with its glycoside ligands present on the egg surface at the site of sperm entry. Mol. Reprod. Dev. 1149–1158, 2006. © 2006 Wiley‐Liss, Inc.
Computer simulation of aqueous block copolymer assemblies: Length scales and methods
Authors: Ortiz Vanessa , Nielsen Steven O. , Klein Michael L. , Discher Dennis E.
Published: May 2006

Atomistic, coarse‐grain, and mesoscopic computer simulation methods applied recently to the study of block copolymer assemblies in solution are reviewed. At the atomic level, particle‐based simulations have provided insight into specific interactions such as hydrogen bonding between polymer and water. Coarse‐grain models have given a generalized view of the conformations of polymer chains in solvents of different qualities by grouping clusters of atoms into effective interaction sites. Mesoscopic self‐consistent field theory allows for the study of the phase diagram of block copolymers in water using a mean‐field continuum description. Advances in and results with these methodologies are presented along with present challenges. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1907–1918, 2006
Solution structures of the first and fourth TSR domains of F‐spondin
Authors: Pääkkönen Kimmo , Tossavainen Helena , Permi Perttu , Rakkolainen Harri , Rauvala Heikki , Raulo Erkki , Kilpeläinen Ilkka , Güntert Peter
Published: May 2006

F‐spondin is a protein mainly associated with neuronal development. It attaches to the extracellular matrix and acts in the axon guidance of the developing nervous system. F‐spondin consists of eight domains, six of which are TSR domains. The TSR domain family binds a wide range of targets. Here we present the NMR solution structures of TSR1 and TSR4. TSR domains have an unusual fold that is characterized by a long, nonglobular shape, consisting of two β‐strands and one irregular extended strand. Three disulfide bridges and stack of alternating tryptophan and arginine side‐chains stabilize the structure. TSR1 and TSR4 structures are similar to each other and to the previously determined TSR domain X‐ray structures from another protein, TSP, although TSR4 exhibits a mobile loop not seen in other structures. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Special requirements for GLP studies with ‘big’ animals
Authors: Hochheimer Norbert
Published: May 2006

The article describes the special requirements for Good Laboratory Practice (GLP) studies with farm animals. Typically, GLP studies are conducted with small laboratory animals such as mice, rats and guinea pigs; GLP studies with big animals are rarely performed. This paper highlights the differences in housing and handling for small and big animals and discusses areas specific to GLP studies with farm animals. While the article draws on observations made and regulations applicable in Germany, the information may be useful for assessing GLP studies with large animals in other countries. Copyright © 2006 John Wiley & Sons, Ltd.
What's New?
Authors: Hattemer‐Apostel Rita
Published: May 2006

The What's New? section in the Quality Assurance Journal aims to draw attention to items of importance to QA professionals. There is usually a 3‐month interval between final submission of manuscripts and distribution of the journal. For this issue, the entries in the What's New? section arise from the period of 1 December 2005 to 28 February 2006. If you feel that there is any other new information that should be brought to the attention of readers, please let us know by e‐mailing rha@verdandi.ch. Copyright © 2006 John Wiley & Sons, Ltd.
Investigation of Herzberg–Teller Franck–Condon approaches and classical simulations to include effects due to vibronic coupling in circular dichroism spectra: The case of dimethyloxirane continued
Authors: Nooijen Marcel
Published: May 2006

A recent study has shown that the inclusion of vibrational effects may be vital in first‐principles simulations of circular dichroism (CD) spectra. In the present work, we show that effects from vibronic coupling or, alternatively, Herzberg–Teller corrections, can have additional and perhaps unusually strong effects, due to delicate cancellations between positive and negative contributions in a CD spectrum. As full vibronic coupling simulations tend to be too demanding computationally for the sizeable molecules considered in CD spectroscopy, it is pertinent to investigate suitable approximations. In the first part of this study, we examine various Herzberg–Teller Franck–Condon (HT–FC) approaches that include the geometrical dependence of the rotatory strength for a 3 × 3 linear vibronic model, for which exact numerical results are easily obtained. Somewhat disappointingly, none of the HT–FC approaches investigated here yielded sufficiently satisfactory results. In a subsequent part of this study, we show that purely classical simulations, based on a vibronic model, can provide reliable spectra and appear to be well suited to address the dependence of the rotatory strength on nuclear geometry. From the classical simulations we extract average rotatory strengths for each electronic state, which are then used in subsequent gradient FC calculations to incorporate vibrational fine structure in the CD spectrum. This mixed classical/gradient FC approach is applied to the methyloxirane CD spectrum, using the statistical averaging of (model) orbital potentials–time‐dependent density functional theory (SAOP–TDDFT) vibronic model presented recently and is shown to improve substantially on the original simulation, corroborating the potential importance of vibronic coupling effects in simulations of CD spectra. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Double staining of proteins after separation in SDS gels with Ruthenium Bathophenantroline Disulfonate and Silver is compatible with MALDI‐TOF mass spectrometry
Authors: Hampel Martin , Sehnert Bettina , Karas Michael , Jäck Hans‐Martin , Mielenz Dirk
Published: May 2006

Sensitive peptide mass spectrometry techniques are increasingly used to identify molecular components of intracellular signaling networks. The detection of low abundant, electrophoretically separated proteins requires sensitive SDS gel protein stains, such as silver or fluorescent Ruthenium dyes. Both silver or Ruthenium based fluorescent dyes such as Ruthenium II Tris bathophenanthroline disulfonate (RuBPS) have unique advantages and disadvantages: some proteins stain better with silver whereas others stain better with Ruthenium dyes. Here, we demonstrate that RuBPS‐stained stained proteins after separation in SDS gels can be re‐stained with silver and that proteins from double‐stained gels can still be subjected to MALDI‐TOF mass spectrometry without adverse effects. Thus, our new double‐staining technique not only produces a permanent record of RuBPS‐stained gels, but more importantly, offers also an optimal staining procedure for electrophoretically separated proteins.
A performance analysis of a four‐leg inverter in two AC motor drives with independent vector control
Authors: Oka Kazuo , Matsuse Kouki
Published: May 2006

This paper presents a performance analysis of a four‐leg inverter (FLI) in driving two motors with vector control.

We show that an expanded two‐arm modulation (ETAM) known as a modulation method of a five‐leg inverter is applicable for the four‐leg inverter and we theoretically analyze a performance analysis of the four‐leg inverter in driving two motors with vector control. © 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Anatomical characteristics of individual roots within the fine‐root architecture of Chamaecyparis obtusa (Sieb. & Zucc.) in organic and mineral soil layers
Authors: Hishi Takuo , Tateno Ryunosuke , Takeda Hiroshi
Published: May 2006

Nutrient availability and temporal variation of physical stress are usually higher in organic soil layers than in mineral soils. Individual roots within the fine‐root system adjust anatomical, morphological, and turnover characteristics to soil conditions, for example nutrient availability and physical stresses. We investigated anatomical traits, including cork formation and passage and protoxylem cell numbers, in cross‐sections of individual fine roots of the conifer Chamaecyparis obtusa (Siebold & Zucc.) growing under different soil conditions. The fine‐root systems in different soil layers were compared by sampling ingrowth cores buried for 1 year and filled with organic and mineral soil substrates. The number of exodermal passage cells was lower in roots from organic soils than in those from mineral soils, suggesting that apical roots tend to be more stress‐tolerant in the organic layer than in mineral soils. In contrast, both root tip and specific root tip density were higher in roots from organic soils than in those from mineral soil layers. The proportion of roots with two strands of protoxylem (diarch) was greater in organic (90%) than in mineral (25%) soils. Thus, although the absorptivity of individual apical roots decreases in organic layers, the absorptivity of the entire fine‐root system of C. obtusa may be increased as a result of the increase in apical root density and the proportion of ephemeral roots. We found that the fine‐root system had simultaneous plasticity in density, anatomy, and architecture in response to complex soil conditions.
Factors distinguishing suicide attempters from suicide ideators in a community sample: social issues and physical health problems
Authors: FAIRWEATHER A. K. , ANSTEY K. J. , RODGERS B. , BUTTERWORTH P.
Published: May 2006

Background. Few studies have focused on factors that uniquely distinguish suicide attempters from suicide ideators. This study assesses prevalence of suicide attempts among suicide ideators within a community sample; explores demographics, employment status, mental and physical health conditions, personality, life stresses and social environment as factors that may distinguish these groups; examines effects of age and gender upon suicide attempts and associated factors; and investigates the increase in suicide attempts when multiple factors related to this behaviour are present.

Method. Data were drawn from the PATH Through Life Project, a community survey of 7485 people in Canberra, Australia. A subsample of 522 suicide ideators were used for this study.

Results. Logistic regression was used to identify factors associated with suicide attempts. Physical medical conditions (OR 1·95) and negative interactions with friends (OR 1·20) were associated with an increased likelihood of suicide attempts among suicide ideators. Age and gender interaction effects for suicide attempts were found involving physical medical condition and mastery among men (OR 3·78 and 0·83 respectively) and not being employed for those aged 40–44 years (OR 8·94). A cumulative effect was found when multiple factors associated with suicide attempts were present, and the probability of an attempt was significantly elevated.

Conclusions. Factors distinguishing those who attempt suicide from suicide ideators involve being unemployed, physical ill health and relationship difficulties. Contrary to expectation, this study found that ideators and attempters experience comparable levels of depression and anxiety.
The temporal relationship of the onsets of alcohol dependence and major depression: using a genetically informative study design
Authors: KUO PO-HSIU , GARDNER CHARLES O. , KENDLER KENNETH S. , PRESCOTT CAROL A.
Published: May 2006

Background. Although alcohol dependence (AD) and major depression (MD) are highly co-morbid, their causal relationship is unclear. In this longitudinal study, we used a genetically informative population-based twin sample to examine the age-at-onset distributions and the temporal relationship of AD and MD.

Method. Our sample included 7477 twins, whose diagnoses of AD and MD and age-at-onset information were obtained from structured interviews. Individual-level survival analyses were conducted based on 2603 monozygotic (MZ) twins, and co-twin diagnosis was included in models as an index of familiar liability to AD and MD.

Results. The age-at-onset distributions of AD and MD differed substantially. Most onsets of AD were in young adulthood, whereas MD had a flatter distribution across age. Most subjects, especially women, had an onset of MD preceding AD. Prior MD significantly affected risk for developing AD, and this risk decreased over time. By contrast, preceding AD had negligible effects on the risk for future MD. Familial risk was transmitted within disorders but there was little evidence of additional familial liability shared across disorders.

Conclusions. Risk for developing AD was substantially increased by a prior episode of MD. The association was only partially accounted for by familial factors, providing support for a direct causal effect such as self-medication. The etiologic path from AD to MD was insignificant.
Tunneling magnetoresistance in (001)-oriented FeCo∕MgO∕FeCo magnetic tunneling junctions grown by sputtering deposition
Authors: Moriyama T. , Ni C. , Wang W. G. , Zhang X. , Xiao John Q.
Published: May 2006

Magnetic tunneling junctions (MTJs) with MgO tunnel barrier have been fabricated on both oriented and nonoriented buffer layers on Si(001) substrate by magnetron sputtering. FeCo∕MgO∕FeCo MTJs fabricated on oriented buffer layers show larger tunneling magnetoresistance (TMR) value up to 84% without high temperature postannealing, whereas those MTJs on nonoriented buffer layers show 45% of TMR. The high-resolution transmission electron microscopy images reveal an excellent morphology and very coherent crystal structure with FeCo(001)[110]∕MgO(001)[100]∕FeCo(001)[110] orientation. The results indicate that high TMR can be achieved without high temperature postannealing by sputtering deposition on appropriate oriented buffer layers.
Conductive atomic force microscopy studies of thin SiO2 layer degradation
Authors: Fiorenza Patrick , Polspoel Wouter , Vandervorst Wilfried
Published: May 2006

The dielectric degradation of ultrathin (∼2nm) silicon dioxide (SiO2) layers has been investigated by constant and ramped voltage stresses with the conductive atomic force microscopy (CAFM). CAFM imaging shows clearly the lateral degradation propagation and its saturation. Current-voltage characteristics, performed at nanometer scale, show the trap creation rate in function of the stress condition. The critical trap density has been found.
Low-current-induced electrical hysteresis in Nd0.7Ca0.3MnO3
Authors: Hsu Daniel , Lin J. G. , Wu W. F.
Published: May 2006

The electrical characteristics of Nd0.7Ca0.3MnO3 were investigated by measuring voltage versus current (V-I) at various temperatures. The V-I curves of the Nd0.7Ca0.3MnO3 sample change from linear to nonlinear behavior at temperatures below the charge ordering (CO) temperature (TCO∼200K). An unexpected and reproducible electrical hysteresis loop is observed in the linear region below the Curie temperature (TC∼110K); it is associated with the “tearing” of a two-domain structure of weak and strong CO state. The required current for this hysteresis is of the order of microamperes, which is appropriate for the low-current memory devices.
60
mW
continuous-wave operation of InGaN laser diodes made by plasma-assisted molecular-beam epitaxy
Authors: Skierbiszewski C. , Wiśniewski P. , Siekacz M. , Perlin P. , Feduniewicz-Zmuda A. , Nowak G. , Grzegory I. , Leszczyński M. , Porowski S.
Published: May 2006

We demonstrate continuous-wave operation at 411nm of InGaN multi-quantum-well laser diodes (LDs) made by plasma-assisted molecular-beam epitaxy (PAMBE). The threshold current density and voltage for these LDs are 4.2kA∕cm2 and 5.3V, respectively. High optical output power of 60mW is achieved. The LDs are fabricated on low-dislocation-density bulk GaN substrates, at growth conditions which resemble liquid-phase epitaxy. We show that use of such substrates eliminates spiral growth, which is the dominant growth mechanism for PAMBE on high-dislocation-density substrates. Therefore, PAMBE opens new perspectives for next generation of InGaN LDs.
Aspects of the ecology of swamp antechinus (Antechinus minimus maritimus) on a Bass Strait island
Authors: Sale M. G. , Ward S. J. , Arnould J. P. Y.
Published: May 2006

The swamp antechinus (Antechinus minimus maritimus) is a small insectivorous marsupial inhabiting closed heath and tussock grassland in south-eastern Australia. The species is considered ‘Near Threatened’ on the Australian mainland. Populations persist on coastal islands off Wilsons Promontory, but their current status is unknown. This study investigated the density, diet and reproduction of the swamp antechinus on Kanowna Island. Data were collected by live trapping in different vegetation types during four trips between August 2003 and January 2004. Higher animal densities (47–129 ha–1) were found for Kanowna Island than for previously studied mainland populations (1–18 ha–1). Examination of scats showed that this species eats a wide variety of prey types, with moth larvae a major dietary component, particularly during the breeding season. Births were estimated to have occurred between 28 June and 8 August, which is a longer period than reported for other populations of this species. Factors including reduced predation, restricted dispersal and increased food availability may be responsible for supporting this dense population.
A hybrid two-component system protein of a prominent human gut symbiont couples glycan sensing
in vivo
to carbohydrate metabolism
Authors: Sonnenburg Erica D. , Sonnenburg Justin L. , Manchester Jill K. , Hansen Elizabeth E. , Chiang Herbert C. , Gordon Jeffrey I.
Published: May 2006

Bacteroides thetaiotaomicron
is a prominent member of our normal adult intestinal microbial community and a useful model for studying the foundations of human–bacterial mutualism in our densely populated distal gut microbiota. A central question is how members of this microbiota sense nutrients and implement an appropriate metabolic response.
B. thetaiotaomicron
contains a large number of glycoside hydrolases not represented in our own proteome, plus a markedly expanded collection of hybrid two-component system (HTCS) proteins that incorporate all domains found in classical two-component environmental sensors into one polypeptide. To understand the role of HTCS in nutrient sensing, we used
B. thetaiotaomicron
GeneChips to characterize their expression in gnotobiotic mice consuming polysaccharide-rich or -deficient diets. One HTCS, BT3172, was selected for further analysis because it is induced
in vivo
by polysaccharides, and its absence reduces
B. thetaiotaomicron
fitness in polysaccharide-rich diet-fed mice. Functional genomic and biochemical analyses of WT and BT3172-deficient strains
in vivo
and
in vitro
disclosed that α-mannosides induce BT3172 expression, which in turn induces expression of secreted α-mannosidases. Yeast two-hybrid screens revealed that the cytoplasmic portion of BT3172's sensor domain serves as a scaffold for recruiting glucose-6-phosphate isomerase and dehydrogenase. These interactions are a unique feature of BT3172 and specific for the cytoplasmic face of its sensor domain. Loss of BT3172 reduces glycolytic pathway activity
in vitro
and
in vivo
. Thus, this HTCS functions as a metabolic reaction center, coupling nutrient sensing to dynamic regulation of monosaccharide metabolism. An expanded repertoire of HTCS proteins with diversified sensor domains may be one reason for
B. thetaiotaomicron
's success in our intestinal ecosystem.
ORGAN-SPECIFIC ESTROGEN-INDUCED RNA SYNTHESIS RESOLVED BY DNA-RNA HYBRIDIZATION IN THE DOMESTIC FOWL
Authors: Hahn William E. , Schjeide O. A. , Gorbman Aubrey
Published: May 2006

In the domestic fowl and other oviparous vertebrates, estrogens induce hepatic synthesis of yolk proteins. The oviduct also increases in size and produces ovalbumin when estrogens are administered. DNA-RNA hybridization assays indicate that within 105 minutes following treatment with estrone the liver of immature pullets contains most, if not all, of the liver RNA species that are present in the livers of the laying hen. Because of limitations of the nucleic acid hybridization technique, which remain to be clearly defined, it is not known whether the hepatic RNA populations in estrone-treated pullets and laying hens are completely homologous or differ in some important way. The results indicate that the genomic response in the avian liver to exogenous estrone is „normal” (relative to the laying hen) and further suggest that the hepatic response to estrogen is primarily pertinent to vitellinogenesis.

DNA-RNA hybridization assays on total RNA also indicate that estrogen-induced RNA species in the liver are not homologous to estrogen-evoked RNA species of the oviduct. Therefore, in these two target organs estrogen-evoked RNA synthesis appears to be in part organ-specific. These data indicate that the specificity of hormone action can be explained in part on the basis of induced synthesis of specific RNA molecules. Whether these alterations in transcription are due to indirect hormonal action or are the result of a primary action of estrogens or estrogen-binding site complexes on the genome and/or its repressors remains a basic question.
THE INFLUENCE OF SHORT-RANGE INTERACTIONS ON PROTEIN CONFORMATION, II. A MODEL FOR PREDICTING THE α-HELICAL REGIONS OF PROTEINS
Authors: Kotelchuck D. , Scheraga H. A.
Published: May 2006

On the basis of earlier energy computations, the various single peptide units in proteins were designated as helix-making or helix-breaking.
1
With the use of these designations, empirical rules for distinguishing between α-helical and non-α-helical regions of proteins have been formulated. These rules include conditions for initiation and termination of a helical segment which, when combined with changes in the designation of three peptide units, correctly identify the helical or nonhelical character of over three fourths of the individual peptide units in four proteins of known amino acid sequence and structure: myoglobin, lysozyme, tosyl-α-chymotrypsin, and ribonuclease-A. The model is discussed, some of its predictions are checked, and further predictions about the structure of various proteins are made.
ANTIBODIES TO A UNIQUE REGION IN LYSOZYME PROVOKED BY A SYNTHETIC ANTIGEN CONJUGATE
Authors: Arnon Ruth , Sela Michael
Published: May 2006

A synthetic conjugate, prepared by covalent binding of a lysozyme fragment (sequence 64-83, denoted „loop” peptide) to a synthetic branched polypeptide, elicited in rabbits the formation of antibodies with specificity directed against a unique region in native lysozyme. These anti-„loop” antibodies were isolated immunospecifically on a lysozyme-cellulose immunoadsorbent. Antibodies with a similar specificity were isolated from antilysozyme sera with an immunoadsorbent prepared from the same „loop” peptide. The capacity of the anti-„loop” antibodies to distinguish between the „loop” peptide, containing a disulfide bridge, and the open-chain peptide derived from it suggests that they are directed against a conformation-dependent determinant.
THE CYTOPLASMIC RNA OF HELA CELLS: NEW DISCRETE SPECIES ASSOCIATED WITH MITOCHONDRIA
Authors: Vesco Cesare , Penman Sheldon
Published: May 2006

Two new species of cytoplasmic RNA with approximate sedimentation values of 12
S
and 21
S
, and which appear associated with mitochondria, are described. The species are unmethylated, are relatively metabolically stable, and have a 43 per cent G + C content. Their synthesis is uniquely resistant to inhibition by UV irradiation. The 12
S
and 21
S
RNA do not appear to be components of polysome-like structures.
CIRCULAR DICHROISM OF NUCLEOSIDE DERIVATIVES, VI. THE OPTICALLY ACTIVE BANDS OF ADENINE NUCLEOSIDE DERIVATIVES
Authors: Miles Daniel W. , Robins Morris J. , Robins Roland K. , Eyring Henry
Published: May 2006

The circular dichroism data on 17 adenine nucleosides show that the 260- and 207-mμ absorption systems of the adenine chromophore each contain at least two electronic transitions. The CD maxima are commonly found at around 260, 220, and 200 mμ, and occasionally at 240 mμ. Solvent studies suggest that these CD bands arise from pi-pi
*
transitions. A weak absorption band that obeys the McConnell criteria of an
n
-pi
*
band is resolved at about 290 mμ in hydrocarbon solvents. This band exhibits very little rotatory power.
DONOR-ACCEPTOR INTERACTIONS OF NITROGEN
Authors: Kimura J. E. , Szent-Györgyi A.
Published: May 2006

The nitrogen atoms of organic molecules readily enter into donor-acceptor interactions, giving off an electron from their lone pair. Under favorable conditions the acceptor can form free radicals. S and O atoms behave likewise but less intensely.
RIEMANNIAN MANIFOLDS ADMITTING A CONFORMAL TRANSFORMATION GROUP
Authors: Yano Kentaro
Published: May 2006

Let
M
be a Riemannian manifold with constant scalar curvature
K
which admits an infinitesimal conformal transformation. A necessary and sufficient condition in order that it be isometric with a sphere is obtained.

Inequalities giving upper and lower bounds for
K
are also derived.
THE CONDENSATION OF THE ADENYLATES OF THE AMINO ACIDS COMMON TO PROTEIN
Authors: Krampitz Gottfried , Fox Sidney W.
Published: May 2006

Simultaneous formation of the adenylates of the 18 amino acids common to protein, followed by cocondensation, has yielded polymers containing all of those amino acids. The condensation occurred rapidly at room temperature above pH 7. The activated amino acids were reacted with thermally synthesized polyanhydro-α-amino acids to yield polymers of substantially increased size. The modified polyamino acids form micron-sized particles which demonstrate internal synthesis by growth and budding. These particles are stable over a wide range of pH.

From thermal polyamino acids alone, answers have earlier been obtained, in principle, to questions of the primordial origin of enzymes, cellular structure, membranes, systematic anhydroamino acid sequences, and propagation of microsystems. Such a model is largely heterotrophic; the mixed adenylate condensation provides, in principle, a partial answer to the origin of syntheses of peptide bonds within protocellular structures.
HYPERFINE STRUCTURE FROM THE FOUR PYRROLE NITROGENS OF HEME
Authors: Scholes Charles P.
Published: May 2006

Hemin and hematin have been incorporated into single crystals of the condensed-ring planar hydrocarbon perylene, the approximate molecular ratio of heme to aromatic being 10
-3
. X-ray diffraction and electron paramagnetic resonance (EPR) measurements indicate that these mixed crystals maintain their integrity when subjected to cryogenic temperatures and then returned to room temperature. EPR X-band orientation studies of single crystals at liquid helium temperature have revealed the following two important features: (1) presence of ligand hyperfine structure, which can be used to quantitate the distribution of unpaired metal electron on the ligands and (2) removal of the immediate fourfold symmetry of the ligand field about the metal, as evidenced by the rhombic character of the high-spin ferric system.

The ligand hyperfine splittings have been interpreted as arising chiefly from an isotropic Fermi contact interaction. The observed splittings then indicate that 2.7 per cent of an unpaired spin is in each nitrogen 2
s
orbital. The
g
-values have been interpreted in terms of the spin-Hamiltonian: [Formula: see text] which gives

g
x,y

= 6.00 ± 24
E
/
D
and

g
z

= 2.00 - 34(
E
/
D
)
2
. For various hemin and hematin sites these formulae for the
g
-values are nicely obeyed when
E
/
D
is in the range 0.015 to 0.03.
NUCLEOSIDE TRIPHOSPHATE POOLS AND THE REGULATION OF RNA SYNTHESIS IN
E. coli
Authors: Edlin G. , Stent G. S.
Published: May 2006

Amino acid starvation of “stringent RNA control” (RC
str
) strains of
Escherichia coli
(
E. coli
) results in the cessation of net protein and net RNA synthesis, whereas “relaxed RNA control” (RC
rel
) strains continue net RNA synthesis under the same conditions of amino acid starvation. This report tests further the hypothesis that net RNA synthesis is markedly reduced during amino acid starvation of RC
str
strains as a result of reduction in the supply of substrates of the RNA polymerase. Bacterial ribonucleoside triphosphate pool levels were measured before and after the arrest of protein synthesis in RC
str
and RC
rel
strains. Protein synthesis was inhibited either by addition of trimethoprim to the medium or by the use of a mutant having a temperature-sensitive valyl-tRNA synthetase. The ribonucleoside triphosphate pool levels do not decline significantly during inhibition of protein synthesis in RC
str
strains under either condition, and there is no apparent correlation between the measured pool levels and the residual rate of net RNA synthesis in RC
str
and RC
rel
strains. Thus, these data argue against the hypothesis that the regulation of RNA synthesis is mediated by the availability of substrates of the RNA polymerase.
DNA-DEPENDENT RNA-DIRECTED PROTEIN SYNTHESIS
in vitro
, I. EXTENT OF GENOME TRANSCRIPTION
Authors: Bryan R. N. , Sugiura M. , Hayashi M.
Published: May 2006

We have described an
in vitro
system which couples UTP incorporation into RNA by DNA-dependent RNA polymerase with RNA-directed amino acid incorporation into polypeptides. Using the technique of DNA-RNA hybridization, we have demonstrated that the whole ΦX-174 genome is transcribed during concomitant protein synthesis.