bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of Lipoprotein-Associated Phospholipase A
2
in Atherosclerosis
Authors: Zalewski Andrew , Macphee Colin
Published: February 2005

The development of atherosclerotic vascular disease is invariably linked to the formation of bioactive lipid mediators and accompanying vascular inflammation. Lipoprotein-associated phospholipase A
2
(Lp-PLA
2
) is an enzyme that is produced by inflammatory cells, co-travels with circulating low-density lipoprotein (LDL), and hydrolyzes oxidized phospholipids in LDL. Its biological role has been controversial with initial reports purporting atheroprotective effects of Lp-PLA
2
thought to be a consequence of degrading platelet-activating factor and removing polar phospholipids in modified LDL. Recent studies, however, focused on pro-inflammatory role of Lp-PLA
2
mediated by products of the Lp-PLA
2
reaction (lysophosphatidylcholine and oxidized nonesterified fatty acids). These bioactive lipid mediators, which are generated in lesion-prone vasculature and to a lesser extent in the circulation (eg, in electronegative LDL), are known to elicit several inflammatory responses. The proinflammatory action of Lp-PLA
2
is also supported by a number of epidemiology studies suggesting that the circulating level of the enzyme is an independent predictor of cardiovascular events, despite some attenuation of the effect by inclusion of LDL, the primary carrier of Lp-PLA
2
, in the analysis. These observations provide a rationale to explore whether inhibiting Lp-PLA
2
activity and consequent interference with the formation of bioactive lipid mediators will abrogate inflammation associated with atherosclerosis, produce favorable changes in intermediate cardiovascular end points (eg, biomarkers, imaging, and endothelial function), and ultimately reduce cardiovascular events in high-risk patients.
Nonalcoholic Fatty Liver Disease Is Associated With Carotid Atherosclerosis
Authors: Brea Angel , Mosquera Daniel , Martín Eva , Arizti Ana , Cordero José L. , Ros Emilio
Published: February 2005

Objective—

Nonalcoholic fatty liver disease (NAFLD) frequently coexists with obesity, diabetes, and dyslipidemia. We examined whether NAFLD was associated with atherosclerosis, as measured by ultrasound in the carotid arteries.

Methods and Results—

Carotid atherosclerosis and cardiovascular risk factors were assessed in 40 patients with an ultrasound diagnosis of primary NAFLD and 40 matched population controls. The metabolic syndrome and all its individual traits, including elevated C-reactive protein, were significantly (
P
<0.005) more frequent in NAFLD patients than in control subjects. Patients with NAFLD showed more carotid atherosclerosis than controls, with mean intima-media thickness (IMT) of 0.70±0.20 mm and 0.54±0.13 mm (
P
<0.0001) and plaque prevalence of 50% and 25% (
P
=0.021), respectively. By multivariate analysis, older age (odds ratio [OR], 2.5 per 10 years; 95% CI, 1.4 to 4.4;
P
=0.002), the presence of NAFLD (OR, 8.4; 95% CI, 2.49 to 29.4;
P
=0.001), and elevated serum ferritin (OR, 3.1; 95% CI, 1.2 to 7.9;
P
=0.016) were independent predictors of an increased IMT.

Conclusions—

Patients with NAFLD show a cluster of risk factors of the metabolic syndrome and advanced carotid atherosclerosis. NAFLD appears to be a feature of the metabolic syndrome, and its detection on abdominal ultrasound should alert to the existence of an increased cardiovascular risk.
Autonomic Control of Cardiac Action Potentials
Authors: Terrenoire Cecile , Clancy Colleen E. , Cormier Joseph W. , Sampson Kevin J. , Kass Robert S.
Published: February 2005

I
Ks
, the slowly activating component of the delayed rectifier current, plays a major role in repolarization of the cardiac action potential (AP). Genetic mutations in the α- (
KCNQ1
) and β- (
KCNE1
) subunits of
I
Ks
underlie Long QT Syndrome type 1 and 5 (LQT-1 and LQT-5), respectively, and predispose carriers to the development of polymorphic ventricular arrhythmias and sudden cardiac death. β-adrenergic stimulation increases
I
Ks
and results in rate dependent AP shortening, a control system that can be disrupted by some mutations linked to LQT-1 and LQT-5. The mechanisms by which
I
Ks
regulates action potential duration (APD) during β-adrenergic stimulation at different heart rates are not known, nor are the consequences of mutation induced disruption of this regulation. Here we develop a complementary experimental and theoretical approach to address these questions. We reconstituted
I
Ks
in CHO cells (ie, KCNQ1 coexpressed with KCNE1 and the adaptator protein Yotiao) and quantitatively examined the effects of β-adrenergic stimulation on channel kinetics. We then developed theoretical models of
I
Ks
in the absence and presence of β-adrenergic stimulation. We simulated the effects of sympathetic stimulation on channel activation (speeding) and deactivation (slowing) kinetics on the whole cell action potential under different pacing conditions. The model suggests these kinetic effects are critically important in rate-dependent control of action potential duration. We also investigate the effects of two LQT-5 mutations that alter kinetics and impair sympathetic stimulation of
I
Ks
and show the likely mechanism by which they lead to tachyarrhythmias and indicate a distinct role of
I
KS
kinetics in this electrical dysfunction. The full text of this article is available online at http://circres.ahajournals.org.
Triadin Overexpression Stimulates Excitation-Contraction Coupling and Increases Predisposition to Cellular Arrhythmia in Cardiac Myocytes
Authors: Terentyev Dmitry , Cala Steven E. , Houle Timothy D. , Viatchenko-Karpinski Serge , Gyorke Inna , Terentyeva Radmila , Williams Simon C. , Gyorke Sandor
Published: February 2005

Triadin 1 (TRD) is an integral membrane protein that associates with the ryanodine receptor (RyR2), calsequestrin (CASQ2) and junctin to form a macromolecular Ca signaling complex in the cardiac junctional sarcoplasmic reticulum (SR). To define the functional role of TRD, we examined the effects of adenoviral-mediated overexpression of the wild-type protein (TRD
WT
) or a TRD mutant lacking the putative CASQ2 interaction domain residues 200 to 224 (TRD
Del.200–224
) on intracellular Ca signaling in adult rat ventricular myocytes. Overexpression of TRD
WT
reduced the amplitude of I
Ca
- induced Ca transients (at 0 mV) but voltage dependency of the Ca transients was markedly widened and flattened, such that even small
I
Ca
at low and high depolarizations triggered maximal Ca transients. The frequency of spontaneous Ca sparks was significantly increased in TRD
WT
myocytes, whereas the amplitude of individual sparks was reduced. Consistent with these changes in Ca release signals, SR Ca content was decreased in TRD
WT
myocytes. Periodic electrical stimulation of TRD
WT
myocytes resulted in irregular, spontaneous Ca transients and arrhythmic oscillations of the membrane potential. Expression of TRD
Del.200–224
failed to produce any of the effects of the wild-type protein. The lipid bilayer technique was used to record the activity of single RyR2 channels using microsome samples obtained from control, TRD
WT
and TRD
Del.200–224
myocytes. Elevation of TRD
WT
levels increased the open probability of RyR2 channels, whereas expression of the mutant protein did not affect RyR2 activity. We conclude that TRD enhances cardiac excitation-contraction coupling by directly stimulating the RyR2. Interaction of TRD with RyR2 may involve amino acids 200 to 224 in C-terminal domain of TRD.
A Simple 3-Item Stroke Scale
Authors: Singer Oliver C. , Dvorak Florian , du Mesnil de Rochemont Richard , Lanfermann Heiner , Sitzer Matthias , Neumann-Haefelin Tobias
Published: February 2005

Background and Purpose—

The purpose of the study was to design a simple stroke scale that requires minimal training but reflects initial stroke severity and is predictive of middle cerebral artery (MCA) occlusion.

Methods—

The new stroke scale assessed 3 parameters: (1) level of consciousness, (2) gaze, and (3) motor function. Each item was graded 0 to 2, where 0 indicated normal findings and 2 severe abnormalities (ie, profound drowsiness or worse, forced gaze deviation, and severe hemiparesis, respectively). During a study period of 11 months, patients presenting with acute stroke symptoms (onset ≤6 hours) were examined by a stroke neurologist assessing the new scale as well as the National Institutes of Health Stroke Scale (NIHSS). In addition, 83 patients received acute magnetic resonance angiography (MRA; as part of an acute stroke protocol).

Results—

The new stroke scale was strongly associated with the NIHSS. Interobserver reliability of the new scale was high (intraclass correlation coefficient 0.947). Using post hoc analysis, a score of ≥4 predicted proximal vessel occlusion (T-segment or M1-segment occlusion of the MCA on MRA) almost as accurately (overall accuracy 0.86) as an NIHSS score of ≥14 (overall accuracy 0.93).

Conclusions—

The new stroke scale reflects acute stroke severity well and predicts proximal MCA occlusion with reasonable accuracy. However, the clinical scale needs further evaluation before it can be recommended as a tool for the triage of acute stroke patients.
William M. Feinberg Lecture: Cognitive Vitality and the Role of Stroke and Cardiovascular Disease Risk Factors
Authors: Gorelick Philip B.
Published: February 2005

Background and Purpose—

Vascular risk factors are common in the elderly, and some such as hypertension may be important predictors of cognitive impairment.

Summary of Review—

In this article, the role that vascular risk factors may play in the prevention of vascular and nonvascular forms of cognitive impairment is reviewed.

Conclusions—

Because vascular risk factors may have negative effects on brain structure and cognitive function, and because vascular risk factors may be present in midlife or possibly earlier, we may need to develop long-term intervention strategies to control or prevent vascular risk factors in an effort to preserve cognitive vitality as we age.
Things fall apart? Discourses on agency and change in organizations
Authors: Caldwell Raymond
Published: February 2005

The history of the concept of ‘agency’ in organizational theory over the last 50 years makes dismal reading. From a position of unbounded optimism that organizational change could be managed as a rational or planned process with a transparent agenda, we now confront restructured workplaces characterized by new forms of flexibility, hypercomplexity and chaos in which the nature, sources and consequences of change interventions have become fundamentally problematic. How did this occur and what implications does it have for our understanding of agency and change in organizations? Should we assume that rationalist concepts of centred agency are no longer viable, or should we welcome the plural and promising new forms of decentred agency emerging within organizations? This article presents a selective interdisciplinary history of competing disciplinary discourses on agency and change in organizations, classified into rationalist, contextualist, dispersalist and constructionist discourses. Although the four discourses clarify the meta-theoretical terrain of agency in relation to organizational change theories, the growing plurality of discourses challenges the social scientific ambitions of the research field to be objective, cumulative or unified. It is concluded that the future for research on agency and change in organizations is characterized by new opportunities for empirical investigation and intervention, but also by mounting threats to the epistemological rationale of objective knowledge and the efficacy of practice.
The ‘Book of Life’ in the Press
Authors: O’Mahony Patrick , Schäfer Mike Steffen
Published: February 2005

The essay compares German and Irish media coverage of human genome research in the year 2000, using qualitative and quantitative frame analysis of a print media corpus. Drawing from a media-theoretical account of science communication, the study examines four analytic dimensions: (1) the influence of global and national sources of discourse; (2) the nature of elaboration on important themes; (3) the extent of societal participation in discourse production; (4) the cultural conditions in which the discourse resonates. The analysis shows that a global discursive package, emphasizing claims of scientific achievement and medical progress, dominates media coverage in both countries. However, German coverage is more extensive and elaborate, and includes a wider range of participants. Irish coverage more often incorporates the global package without further elaboration. These findings indicate that the global package is ’localized’ differently due to national patterns of interests, German participation in human genome research, traditions of media coverage, and the domestic resonance of the issue.
Architectures of Genetic Medicine
Authors: Parthasarathy Shobita
Published: February 2005

This paper compares the development of genetic testing for breast cancer (BRCA testing) in the USA and the UK. It argues that national political cultures played an important role in how these genetic testing technologies were shaped, and that the shapes of these technologies had important implications for the users of these systems. In order to demonstrate the roles of national social and political elements in the development of new genetic testing technologies, I introduce the concept of a technology’s architecture, which is made up of components and the specific ways in which these components are assembled to fulfill particular functions. In the USA, four very different BRCA testing systems initially emerged. However, one biotechnology company, Myriad Genetics, eventually used its legal and economic position to become the sole provider of testing. It offered BRCA testing the way many other laboratory tests were provided in the USA, available to anyone through any physician. The shape of this testing service had important implications for its participants, defining the client as a consumer who could demand access to any of Myriad’s laboratory services, but could not choose among testing systems. In the UK, the government-run National Health Service provided testing through regional genetics clinics, using family history information to assess risks and triage care. Clients in the UK were defined as citizens and patients, who had the right to equal access to the testing system but could not demand any specific services.
Real-world ethics and nursing research
Authors: Johnson Martin
Published: February 2005

In this paper I argue that nursing research is losing its way. There are a number of ways in which this is happening; for example, people are spending much more time writing about methodology than getting on with the research itself and the reporting of discovery. Here, I address the extent to which we are debilitating the research enterprise through what passes as ‘ethics’ and ‘governance’.

I will refer to examples from nursing and related research to illustrate the gradual development of greater concern for the well-being of research participants and the prevention of harm. I will go on to illustrate how, in comparison to the search for knowledge in the wider world, the health professions (and in the UK nurses in particular) are making research more difficult to execute than it needs to be. In the development of defensive rules and procedures we have somehow forgotten exactly from what harms we are protecting our patients, students and staff.

For those looking for a theoretical background to my views, they are, in essence, consequential, and I hope to show that with a harms and benefits approach we could bring much common sense to the critical appraisal of previous research and the approval and conduct of nursing research now and in the future.
A pilot project to explore the feasibility and potential of a protocol to support district nurses in the assessment of older frail people with type 2 diabetes
Authors: Forbes Angus , Berry Jakki , While Alison , Hitman Graham , Sinclair Alan
Published: February 2005

A study was undertaken to explore the potential of district nurses assessing older frail people with type 2 diabetes using an explicit schedule in the form of an annual review. A pilot study following pre- and post-test (six-month interval) design explored both process and outcome variables. Twelve older people (mean age 79 years, range 70-86 years) with a diagnosis of type 2 diabetes took part.

No statistically significant differences were observed on any of the main outcome measures at the post-test assessment. These findings were explained by insufficient sample size and attrition; a failure to instigate treatment following the identification of specific diabetes-related problems, especially on the part of the GP; and the fact that the sample was reasonably well controlled at the start of the study.

The study showed that district nurses were able to administer the annual review satisfactorily but that they found execution of the protocol time-consuming. A great deal of variation was found among respondents, which pointed to different sub-groups of frailty in the older population of people with diabetes, each sub-group having different needs.

It was concluded that if district nurses are going to undertake this work, their activity needs to be targeted at the groups of older people most likely to benefit. The current protocol needs further refinement and should be linked to clearer clinical action pathways with a multidisciplinary focus to ensure that the appropriate remedial therapy is instigated.
Split personalities: Role conflict between the nurse and the nurse researcher
Authors: Colbourne Linda , Sque Magi
Published: February 2005

This paper is a personal account of the nurse-nurse researcher role conflict encountered while conducting a qualitative research study. Difficulties in the transition from a clinical post to a nurse researcher role are described and the experiences of other authors dealing with such a role change are used to illustrate potential resolutions. An understanding of the concept of reflexivity is offered and a description of how this can be applied to consider the impact of ‘the self’ on the research. The paper suggests a solution to the well-known role conflict encountered by nurse researchers: including the nurse in the process of research, and being confident about taking a personal investigative approach. It is argued that drawing on the interactive skills of the nurse can benefit and not detract from the research process.
The dynamic effect on nursing of a changing health service
Authors: Cowie Audrey
Published: February 2005

This paper discusses the dynamic effects on nursing of a changing health service. Scotland's demography presents the profession with unique challenges around securing future services. The Government in Scotland's response has focused on increasing workforce numbers. Workforce dynamics will, however, impact on nursing workforce numbers as all public sector employers compete for a contracting pool of resource. Reserved UK powers for professional regulation and devolved Scottish powers for health and education, matched with specific Scottish laws, can facilitate the development of new roles and new ways of working. Many examples of role development exist and some are provided here.
Reviewing the evidence on nursing record systems
Authors: Urquhart Christine , Currell Rosemary
Published: February 2005

The aim of this article is to examine the relationship between nursing practice and the recording of practice. We outline the main findings of a Cochrane systematic review on nursing records, discussing the indications from the included studies that compared computerized nursing care planning with paper-based systems. Qualitative research on nursing records systems, and other survey evidence, is collated to answer questions on the format of the record (structured versus free text, for what type of practice), occasions when information exchange about nursing care may not and should not be recorded formally, and the effective organization of the nursing record. We conclude that more research is required to answer these questions, as it seems that computerization does not always bring the expected benefits, and outcomes for patient care are not clear.
A web-based system to monitor and predict healthcare activity
Authors: Brown Helen
Published: February 2005

The UK National Health Service is subject to variation in demand for medical services, particularly during the winter. The article describes System Watch, a real-time system developed to assist with hospital bed management in NHS Scotland by monitoring and predicting activity within hospitals and the primary care sector. System Watch gathers daily hospital numbers of emergency admissions and beds occupied by emergencies. It uses this and other information to model long- and short-term demand for emergency bed admissions and present predictions in a graphical form through a web-based user interface. The article evaluates the accuracy of predictions and the initial experience of the use of System Watch by bed managers. The results indicate that System Watch’s accuracy is sufficient for planning purposes at both health board area and hospital level. Finally, additional possible uses of System Watch are described and future developments outlined.
The Craft Consumer
Authors: Campbell Colin
Published: February 2005

This article proposes that social scientists should explicitly recognize the existence of consumers who engage in ‘craft consumption’ and, hence, of an additional image of the consumer to set alongside those of ‘the dupe’,‘the rational hero’ and the ‘postmodern identity-seeker’. The term ‘craft’ is used to refer to consumption activity in which the ‘product’ concerned is essentially both ‘made and designed by the same person’ and to which the consumer typically brings skill, knowledge, judgement and passion while being motivated by a desire for self-expression. Such genuine craft consumption is then distinguished from such closely associated practices as ‘personalization’ and ‘customization’ and identified as typically encountered in such fields as interior decorating, gardening, cooking and the selection of clothing ‘outfits’. Finally, after noting that craft consumers are more likely to be people with both wealth and cultural capital, Kopytoff’s suggestion that progressive commodification might prompt a ‘decommodifying reaction’ is taken as a starting point for some speculations concerning the reasons for the recent rise of craft consumption.
Needs, Desires and the Experience of Scarcity
Authors: Keller Margit
Published: February 2005

This article contributes to the new field of post-Soviet consumer culture studies by exploring the meanings of recreational shopping carried by the Estonian notion of s oppamine, adapted from the English word ‘shopping’. It draws on empirical data derived from 71 original interviews with Estonian-speaking consumers. Underlying these respondents’ normative judgements of their own and others’ shopping behaviour is a system of moral concepts in which ‘need’ and ‘restraint’ are continually juxtaposed against ‘desire’,‘pleasure’ and ‘excess’. This opposition, while common to a range of consumer contexts, takes a specific form in the post-Soviet conditions of Estonia, marked by a shift from a collectively experienced absence of consumer goods in general to an individually perceived scarcity - either material, in the form of the money to buy available goods, or symbolic, based on an opinion that the new commodities are insufficiently sophisticated.
Determinants of e-communication adoption: The internal push versus external pull factors
Authors: Wu Fang , Lee Yi-Kuan
Published: February 2005

Firms are engaging in the adoption and implementation of electronic communication tools to facilitate exchange between partners. Although extant studies have argued that market orientation is one of the key forces in driving a firm's adoption of innovation, the current study based on the responses of senior managers in four industries suggests otherwise in the context of e-communication adoption. In particular, we examine a firm's adoption of e-communication based on two forces: (1) internal push factors, namely customer orientation and competitor orientation, and (2) external pull factors, namely customer pressure and normative pressure. Structural equation modeling is used to test the model. Our findings indicate that external factors, particularly customer pressure and normative pressure, are far more critical in driving the intensity of e-communication adoption than internal factors. The results suggest a reactive nature of organizations' behavior towards the adoption of e-communication.
Cytotoxic minor histocompatibility antigen HA-1–specific CD8+ effector memory T cells: artificial APCs pave the way for clinical application by potent primary in vitro induction
Authors: Schilbach Karin , Kerst Gunter , Walter Steffen , Eyrich Matthias , Wernet Dorothee , Handgretinger Rupert , Xie Weidong , Rammensee Hans-Georg , Müller Ingo , Bühring Hans-Jörg , Niethammer Dietrich
Published: February 2005

Induction of cytotoxic T lymphocytes (CTLs) for treatment of relapsed leukemia after allogeneic stem-cell transplantation is hindered by the laborious and time-consuming procedure of generating dendritic cells for antigen presentation. Artificial antigen-presenting cells (aAPCs) offer the advantage of being readily available in sufficient numbers, thus allowing for a highly standardized in vitro induction of CTLs. We generated aAPCs coated with anti-CD28 antibody (Ab) and either high-density (HD) or low-density (LD) major histocompatibility complex (MHC) class I molecules loaded with HA-1H, a nonapeptide derived from the hematopoiesis-restricted minor histocompatibility antigen HA-1. HD- and LD-aAPCs potently induced HA-1H–specific CD8+ CTLs from untouched CD8+ T cells of healthy donors. CTLs were subsequently purified by magnetic-activated cell sorting. HD- as well as LD-aAPC–induced CTLs exerted high HA-1H–specific cytotoxicity, resembled Tc1 effector memory cells, survived a long time in vitro, and were expanded by a factor varying between 8.2 × 104 and 51 × 104. The T-cell receptor (TCR) repertoire of HA-1H tetramer–positive CTLs was oligoclonal with a prominent usage of Vβ6. The TCR repertoire of tetramer-positive CTLs was distinct from and more restricted than that of tetramer-negative cells. These findings indicate that aAPCs are attractive tools for the ex vivo generation of HA-1H–specific CTLs suitable for immunotherapy of relapsed leukemia.
Macrophage galactose-type C-type lectins as novel markers for alternatively activated macrophages elicited by parasitic infections and allergic airway inflammation
Authors: Raes Geert , Brys Lea , Dahal Bhola K , Brandt Jef , Grooten Johan , Brombacher Frank , Vanham Guido , Noël Wim , Bogaert Pieter , Boonefaes Tom , Kindt Anne , Van den Bergh Rafaël , Leenen Pieter J M , De Baetselier Patrick , Ghassabeh Gholamreza Hassanzadeh
Published: February 2005

Molecular markers, especially surface markers associated with type II, cytokine-dependent, alternatively activated macrophages (aaMF), remain scarce. Besides the earlier documented markers, macrophage mannose receptor and arginase 1, we demonstrated recently that murine aaMF are characterized by increased expression of found in inflammatory zone 1 (FIZZ1) and the secretory lectin Ym. We now document that expression of the two members of the mouse macrophage galactose-type C-type lectin gene family (mMGL1 and mMGL2) is induced in diverse populations of aaMF, including peritoneal macrophages elicited during infection with the protozoan Trypanosoma brucei brucei or the Helminth Taenia crassiceps and alveolar macrophages elicited in a mouse model of allergic asthma. In addition, we demonstrate that in vitro, interleukin-4 (IL-4) and IL-13 up-regulate mMGL1 and mMGL2 expression and that in vivo, induction of mMGL1 and mMGL2 is dependent on IL-4 receptor signaling. Moreover, we show that expression of MGL on human monocytes is also up-regulated by IL-4. Hence, macrophage galactose-type C-type lectins represent novel surface markers for murine and human aaMF.
Drift Capacity of Reinforced Concrete Columns with Light Transverse Reinforcement
Authors: Elwood Kenneth J. , Moehle Jack P.
Published: February 2005

Existing reinforced concrete columns with light transverse reinforcement are vulnerable to shear failure during seismic response. Shear strength models, modeling the degradation of shear strength with increasing displacement ductility demand, have been widely used to evaluate the interstory drift capacity of such columns. The application of a shear strength model to determine the drift capacities for a database of 50 shear-critical columns demonstrates significant inaccuracies with such a method. An empirical drift capacity model based on the shear-critical column database provides a better estimate of the interstory drift at shear failure. The new drift capacity model identifies the most critical parameters affecting the drift capacity of shear-critical columns, namely, transverse reinforcement ratio, shear stress demand, and axial load ratio.
Shear-Wave Velocity of Surficial Geologic Sediments in Northern California: Statistical Distributions and Depth Dependence
Authors: Holzer Thomas L. , Bennett Michael J. , Noce Thomas E. , Tinsley John C.
Published: February 2005

Shear-wave velocities of shallow surficial geologic units were measured at 210 sites in a 140-km2 area in the greater Oakland, California, area near the margin of San Francisco Bay. Differences between average values of shear-wave velocity for each geologic unit computed by alternative approaches were in general smaller than the observed variability. Averages estimated by arithmetic mean, geometric mean, and slowness differed by 1 to 8%, while coefficients of variation ranged from 14 to 25%. With the exception of the younger Bay mud that underlies San Francisco Bay, velocities of the geologic units are approximately constant with depth. This suggests that shear-wave velocities measured at different depths in these surficial geologic units do not need to be normalized to account for overburden stress in order to compute average values. The depth dependence of the velocity of the younger Bay mud most likely is caused by consolidation. Velocities of each geologic unit are consistent with a normal statistical distribution. Average values increase with geologic age, as has been previously reported. Velocities below the water table are about 7% less than those above it.
Nonlinear Site Amplification as Function of 30 m Shear Wave Velocity
Authors: Choi Yoojoong , Stewart Jonathan P.
Published: February 2005

We develop empirical relationships to predict nonlinear (i.e., amplitude-dependant) amplification factors for 5% damped response spectral acceleration as a continuous function of average shear wave velocity in the upper 30 m, Vs-30. We evaluate amplification factors as residuals between spectral accelerations from recordings and modified rock attenuation relationships for active regions. Amplification at low- and mid-periods is shown to increase with decreasing Vs-30 and to exhibit nonlinearity that is dependent on Vs-30. The degree of nonlinearity is large for NEHRP Category E (Vs-30<180 m/s) but decreases rapidly with Vs-30, and is small for Vs-30>∼300 m/s. The results can be used as Vs-30-based site factors with attenuation relationships. The results also provide an independent check of site factors published in the NEHRP Provisions, and apparent bias in some of the existing NEHRP factors is identified. Moreover, the results provide evidence that data dispersion is dependent on Vs-30.
In Vitro Growth and Ovulation of Follicles from Ovaries of Estrogen Receptor (ER)α and ERβ Null Mice Indicate a Role for ERβ in Follicular Maturation
Authors: Emmen Judith M. A. , Couse John F. , Elmore Susan A. , Yates Mariana M. , Kissling Grace E. , Korach Kenneth S.
Published: February 2005

Both estrogen receptor (ER) α and β are expressed within the ovary and lack of either of these receptors affects ovarian function. In this study, the role of ERα and ERβ in folliculogenesis and ovulation was further analyzed. Evaluation of ovarian follicle populations in wild-type and ERβ knockout (βERKO) ovaries revealed reduced late antral growth and ovulatory capacity of βERKO follicles, indicated by reduced numbers of large antral follicles and corpora lutea and increased atresia of large antral follicles. An in vitro culture system was used to study growth, rupture, and luteinization of wild-type, ERα knockout (αERKO) and βERKO ovarian follicles. αERKO follicles exhibited wild-type-like growth and ovulation rates but an increased capacity to synthesize estradiol. In contrast, βERKO follicles showed a significant lack of progression from early antral to large antral stage, decreased estradiol production, and reduced ovulation. Expression patterns of several genes involved in follicle maturation and ovulation were analyzed in follicles grown in vitro. Ar, Pgr, and Has2 mRNA expression levels were the same among the three genotypes. However, βERKO follicles showed reduced expression of Cyp19 mRNA during follicle maturation and reduced Lhcgr and Ptgs2 mRNA expression after human chorionic gonadotropin stimulus. Luteinization occurs normally in αERKO and βERKO follicles, shown by increased progesterone secretion and increased cdkn1b mRNA expression after human chorionic gonadotropin. Collectively, these data indicate that ERβ, but not ERα, plays a direct role in folliculogenesis. ERβ appears to facilitate follicle maturation from the early antral to the preovulatory stage.
Electrochemical synthesis and characterization of polycarbazole
Authors: Macit H. , Sen S. , Saçak M.
Published: February 2005

Electroinitiated polymerization of carbazole was achieved in acetonitrile by direct electron transfer via constant potential electrolysis based on anodic peak potentials. The anodic peak potential of carbazole was determined by cyclic voltammetry to be + 1.4V. It has been observed that polymer yield increased with some factors, such as time, monomer concentration, and polymerization potential. Conducting polycarbazole material obtained on a platinum anode electrode was characterized by FT‐IR, TGA, and conductance measurements. The conductivities of samples were measured to be about 10−3–10−4 S/cm by the four‐probe method. Temperature‐dependence of electrical resistance values of polycarbazole between 30°–125°C suggest that it can be used as a thermal sensor. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 894–898, 2005
Antibacterial activity of polymers with norfloxacin moieties against native and norfloxacin‐tolerance‐induced bacteria
Authors: Kim Mal‐Nam , Lim A Hyon , Yoon Jin‐San
Published: February 2005

Antimicrobial characteristics were investigated for norfloxacin against 18 bacteria (4 gram‐positive bacteria and 14 gram‐negative bacteria) with the minimum inhibition concentration (MIC) test. Among the bacteria tested, B. cereus, V. fluvialis, and V. parahaemolyticus formed norfloxacin‐tolerant colonies. The release of ultraviolet‐absorbing substances from the cells in contact with norfloxacin was examined for the native bacteria and for the norfloxacin‐tolerance‐induced ones. Norfloxacin was grafted to polypropylene‐graft‐maleic anhydride (MAPP) and poly(styrene‐co‐maleic anhydride) (MAPS) to synthesize polymeric antimicrobial agents. The bioactivity of MAPP–norfloxacin and MAPS–norfloxacin was evaluated and compared with that of neat norfloxacin with the shake flask test and the MIC test. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 936–943, 2005
Cell lineage labels in the early amphibian embryo
Authors: Slack Jonathan M. W.
Published: February 2005

New methods of marking cells enable single clones to be followed during embryonic development. They can be used for the construction of fate maps and for the investigation of induction and determination.
Uteroferrin: A protein in search of a function
Authors: Roberts R. Michael , Bazer Fuller W.
Published: February 2005

Uteroferrin, a purple‐colored, iron‐containing acid phosphatase, with many of the properties of a lysosomal hydrolase, transports iron from the mother to the conceptus in pregnant pigs. Uteroferrin, however, is but one member of what may be a broad class of iron‐containing phosphatases with unusual spectral properties which result from a novel type of di‐iron active site. The biological function of uteroferrin is unknown. We argue here that the in vivo function of uteroferrin, despite its undoubted ability to act as a potent acid phosphatase, is that of a transplacental iron transporter.
Mitogenic polypeptides control ion flux in responsive cells
Authors: Glaser Luis , Whiteley Brian , Rothenberg Paul , Cassel Dan
Published: February 2005

Polypeptide growth factors (mitogens) which stimulate proliferation of fibroblasts and epithelial cells also rapidly activate transmembrane ion transport systems. The mitogen‐induced Na+ influx is due to the activation of a Na+/H+ antiport. Recent methodological developments allow, for the first time, precise measurements of the factors that control activation of the Na+/H+ antiport by these agents, and provide the tools needed to assess the physiological significance of this exchange mechanism.
Molecular biology of plasminogen activators and recombinant DNA progress
Authors: Cederholm‐Williams S. A.
Published: February 2005

Plasminogen activators are enzymes with multiple roles. They play vital parts in maintaining the functional integrity of the vascular system and they are also involved in processes of tissue reorganization. In this review, the molecular properties of these enzymes that make them ideal targets for genetic and biochemical engineering to satisfy a potential therapeutic role are described.
Retroviral DNA integration
Authors: Skalka Anna Marie , Leis Jonathan
Published: February 2005

The synthesis and integration of DNA into the genome of its host cell is a normal step in the replication of the retroviruses. Previous studies have provided details concerning the structure of viral DNA and viral and host integration sites. More recent genetic and biochemical results have expanded our understanding considerably: it should soon be possible to describe the exact viral DNA sequence recognized during the integration reaction for several viruses. In addition, at least one of the viral proteins and enzymatic activities required in the reaction has been identified. Analysis of this apparently efficient and highly specific site‐directed recombination event in eukaryotic cells promises to provide insights of both fundamental and practical interest.
Embryonic neuronal transplantation
Authors: Fine Alan
Published: February 2005

Foetal neurones transplanted within the adult mammalian central nervous system survive and differentiate. Study of such transplants has yielded insights into the function, development and plasticity of brain structures, and suggests promising new therapies for a number of neurological disorders.
The role of E. coli single‐stranded DNA binding protein in DNA metabolism
Authors: Chase John W.
Published: February 2005

Single‐stranded DNA binding proteins have been known for some time to be crucial in many DNA metabolic reactions in both prokaryotes and eukaryotes. Despite a wealth of studies on these proteins we still do not understand their biochemical mechanism of action. Recent studies of the Escherichia coli single stranded DNA binding protein (SSB) are beginning to provide some insight into how this and similar proteins might function.
On the status of the Z‐DNA question for animal chromosomes
Authors: Hill Ronald J.
Published: February 2005

The Z‐conformation, recently elucidated in crystals of synthetic alternating dG‐dC polymers, is a dramatically different structure for DNA. Despite suggestive locations of alternating purine‐pyrimidine tracts in chromosomes and intriguing functional hypotheses, unequivocal demonstrations of the Z‐conformation in vivo are not proving easy. Perhaps the Z‐conformation should be considered largely as a dynamic structure transiently forming in torsionally stressed chromatin.
Control mechanisms for vitellogenin synthesis in mosquitoes
Authors: Borovsky Dov
Published: February 2005

Earlier investigations of the hormonal control of vitellogenin (egg‐yolk protein) synthesis in mosquitoes relied on microsurgical manipulations to identify organs that secrete the various hormones that stimulate or inhibit vitellogenesis. Advances in the last 10 years, using radioimmunoassays, HPLC, mass spectrometry and tissue‐culture incubations, have shown that the control mechanism involves a complex interaction between ecdysteroids, juvenile hormones and peptide hormones.
Problems and paradigms: Domains, compartments and determinative switches in Drosophila development
Authors: Gubb D.
Published: February 2005

In BioEssays, vol. I. no. 5, p. 227, P. A. Lawrence discussed the selector gene hypothesis and its implications for development. In the following article, D. Gubb presents an alternative view of the genetic control of development.
What the papers say: Fibronectin in early embryonic development of the vertebrate
Authors: Thiery Jean Paul
Published: February 2005

During development some cells are migratory whilst others are stationary. However, the same cell may change its behaviour depending upon its environment. Recent evidence has implicated the extracellular matrix protein fibronectin in the regulation of migratory behaviour. As the structure of this molecule becomes elucidated, it is also becoming possible to interpret this regulation in precise molecular terms.
Torsional stress in eukaryotic chromatin
Authors: Scott Walter A.
Published: February 2005

The bulk of the DNA in eukaryotic chromatin behaves as if it is topologically relaxed; however, a subfraction can be shown to be under suercoil tension. Endonuclease S1 cuts at specific hypersentive sites in chromatin (in the promoter regions of active genes) and this enzyme cuts in the same region in supercoiled plasmids, but not in relaxed or linearized molecules. A subfraction of the minichromosomes formed after SV40 infection or microinjection of plasmid DNA into oocytes contains supercoil tension and this subfraction is thought to play an important role in transcription.
Roots: Molecular basis of biological regulation: Origins from feedback inhibition and allostery
Authors: Pardee Arthur B.
Published: February 2005

One observes regulation at every biological level. Organisms, cells, and biochemical processes operate efficiently, normally wasting neither material nor energy, and adjusting their functions to external influences. Nature evidently has evolved mechanisms specifically dedicated to regulation at many levels. What is the molecular basis of this control?

In the 1950s these molecular control mechanisms began to be explored seriously. The discoveries of feedback inhibition of enzyme activity were important because they gave an initial example of how regulation is achieved at the molecular level. We showed that certain enzymes are composed of two parts, one for catalysis and another distinct part present only to regulate this catalysis. Catalytic activity can be either stimulated or inhibited when a small molecule in the environment combines with the enzyme's regulatory site. In particular, a final product of a metabolic pathway generates a feedback loop which automatically limits its own excessive production, by combining with the regulatory site of an early enzyme in that pathway. Later studies showed that catalytic and regulatory structures of some enzymes could be separated physically.

The discovery of regulatory sites and their interaction with molecules unrelated to their substrates was the basis for the generalized allosteric concept. This concept extends the regulatory site idea to a wide variety of processes such as control of gene expression, hormone action, and cellular growth.
The physiology of pancreatic acinar cells: Questions and perspectives on the secretory process
Authors: Romagnoli Paolo
Published: February 2005

The two theories of pancreatic enzyme secretion, those of exocytosis and transmembrane flow, are described. Data thought to support the theory of transmembrane flow of single molecules from pancreatic acinar cells are first reviewed, and the conditions which could allow these data to be explained by the theory of exocytosis of enzyme quanta, i.e. secretory granules, are then discussed.

The evidence suggesting short‐term modulation of the composition of pancreatic juice is also considered, and its possible explanations at the organ and cellular level are discussed, in the light of suggested theories on enzyme secretion pathways.
Sequence information required for bacterial protein export
Authors: Benson Spencer A.
Published: February 2005

Genetic analysis of the signals within bacterial exported proteins have shown that the information required for proper localization is contained in both the amino‐terminal signal sequence and the mature protein. Several types of signal sequence mutations can be isolated, suggesting that the signal sequence may be involved in more than one step in the export process. Export information within the mature portion of the protein is present at several locations.
Evolution of resistance to penicillin and cephalosporin antibiotics
Authors: Normark Staffan , Lindberg Frederik
Published: February 2005

Bacterial resistance mechanisms to the antibiotics known as β‐lactams, which include the penicillins and cephalosporins, can take several forms but frequently involve the production of β‐lactamases from either plasmid‐ or chromosomally‐encoded loci. Gram negative bacteria express a β‐lactamase from evolutionarily related chromosomal ampC genes. Genetic analysis of both inducible and constitutively expressed AmpC β‐lactamases provide insights into the mechanisms regulating production of the enzyme. Evolutionary relationships between the genes of different species are discussed, as well as the regulatory mechanisms that in both laboratory mutants and clinical isolates lead to overproduction of β‐lactamase.
Methionine or not methionine at the beginning of a protein
Authors: Sherman Fred , Stewart John W. , Tsunasawa Susumu
Published: February 2005

Methionine aminopeptidases with a universal specificity have been revealed from the sequences of the amino‐terminal region of mutant forms of yeast iso‐1‐cytochrome c and from a systematic examination of the literature for amino‐terminal sequences formed at initiation sites. The aminopeptidase removes amino‐terminal residues of methionine when they precede certain amino acids, with a specificity that appears to be determined mainly by the residue adjacent to the methionine residue at the amino terminus. The result with the mutationally altered iso‐1‐cytochromes c and the results from published sequences of other proteins from a wide range of prokaryotes and eukaryotes suggest that the aminopeptidase usually cleaves amino‐terminal methionine when it precedes residues of alanine, cysteine, glycine, proline, serine, threonine and valine but not when it precedes residues of arginine, asparagine, aspartic acid, glutamine, glutamic acid, isoleucine, leucine, lysine or methionine. We suggest that the specificity is almost always determined simply by the size of the side chain of the penultimate residue; methionine is usually cleaved from residues with a side chain having a radius of gyration of 1·29 Å or less, but is not cleaved from residues with larger side chains.
The uptake and accumulation of proteins by the cell nucleus
Authors: Feldherr Carl M.
Published: February 2005

Evidence has recently been obtained suggesting that the accumulation of specific endogenous proteins by the nucleus is due both to facilitated transport across the envelope and intranuclear binding. Using recombinant DNA methodology, polypeptide domains containing the signals required for nuclear accumulation have been identified in several karyophilic proteins.