bluuebunny/crossref_metadata_2025 huggingface dataset:
Flowers in the clinical setting: Infection risk or workload issue?
Authors: Gould Dinah , Gammon John , Salem Rachel Ben , Chudleigh Jane , Fontenla Marina
Published: February 2005

Healthcare-associated infection has become a topic of interest to the general public in the United Kingdom, kindled by media accounts of poor hygiene and the risks of cross-infection. In the spring of 2003, one of the broadsheet newspapers published an article debating the hygiene and infection risks associated with cut flowers brought into clinical areas. There were reports that in many wards this practice is no longer allowed because flowers are considered dirty, trigger allergies and the water is regarded as harbouring bacteria, leading to infection.

Discussion with infection control experts revealed that questions concerning the risks associated with flowers are among those most frequently asked. A literature search was undertaken to establish the evidence base, and a questionnaire study was performed with a purposive sample of 39 nurses to document how they manage flowers in the clinical setting. Empirical research studies were difficult to obtain. Early work had been undertaken to explore the added workload associated with maintaining fresh flowers and ways of reducing it. Later studies revealed that the water in flower vases and cut plants both harbour large numbers of Gram-negative pathogens.

Cross-infection and cases of clinical infection have never been documented, thus flowers have not been considered a risk, except to severely immunocompromised patients. However, scrutiny of the more general literature relating to Gram-negative sepsis indicated that cross-infection has been documented from a wide range of environmental sources and it is possible that it may take place from flowers via the hands of staff if they are not properly decontaminated. Nevertheless, these risks can be reduced by scrupulous attention to hand hygiene and commonsense measures.

Over half the nurses (n = 26, 66.6%) thought that flowers constituted an infection risk and a number of other disadvantages were cited. Most nurses (n = 31, 80%) were not in favour of flowers in the clinical setting and there was some evidence that this attitude was related to the amount of work generated, with infection and other risks used to justify it. Interest in the topic was considerable and the results can be used to stimulate discussion and emphasise the importance of controlling health-related infection.
Using ethnography (or qualitative methods) to investigate drug errors: A critique of a published study
Authors: Armitage Gerry , Holder Award , Hodgson Ian
Published: February 2005

The effects of drug errors and any consequent adverse events frequently impact on patients, their relatives and professional carers. Furthermore, the financial cost to the National Health Service is considerable (DoH, 2000; DoH, 2001; DoH, 2004). In a study of two London teaching hospitals, Vincent et al. (2001) found that 10% of patients are exposed to an adverse event, which adds a mean 8.5 days to their hospital stay. Drug errors are recurrently reported to account for between 10 and 20% of all adverse events (DoH, 2004).

In response to Department of Health policy, NHS trusts are changing their approach to the management of error to encourage more reporting. The emphasis is on openness and support, and individual and organisational learning rather than blame. Research designed to increase a knowledge of the aetiology and context of drug errors should be carefully constructed and include qualitative methods which, if implemented according to established convention, can reflect the approaches described above.

This paper will critique a recently published study that focused on nursing practice and was, in our view, inappropriately described as ethnographic. The study undoubtedly adds to the body of existing knowledge about drug errors and, crucially, if the study contributes to improved patient safety, it must, fundamentally, be valued. Nevertheless, some qualitative research conventions were broken and, as such, it is suggested, some opportunities for a broader understanding and for learning may have been lost. The critique will lead to a range of recommendations about future qualitative studies in this research domain which, it is argued, could produce a fuller picture of the context, culture and, perhaps, even the cause of error.
Recognising the challenges of collaborative, multi-site research
Authors: Girot Elizabeth A. , Goodman Benny , Ross Kath , Latter Sue , Jackson Dawn
Published: February 2005

Background: Collaborative multi-site research is gaining recognition. In particular, across stakeholders in the health and social care professions, there has been an increase in the documentation of such approaches, with the majority acknowledging the strengths and few identifying the pitfalls. Four universities in the south west of England collaborated on the design, analysis and implementation of a project scoping the staff development needs of nursing and midwifery academics to meet the National Health Service Modernisation Agenda in the United Kingdom.

Aim: This paper highlights the challenges and the lessons learned from each stage of the process of this large multi-site collaborative study. Consideration has been given to addressing the site-specific differences as well as the politics of the processes and power relations across the research team.

Discussion: From an analytical reflection across the team, there were a number of lessons learned from the process of collaboration. Initially, the main challenge was the selection of the team and lead researcher and these were its greatest success. Nevertheless, managing each individual's competing roles within the organisation remained problematic. Particular challenges included gaining consensus on the research design, the chosen sample and data collection to reflect the site-specific differences and were overcome through discussion and effective leadership. Towards the end of the study, adequately representing each institution in the findings, as well as dissemination have remained the greatest challenges.

Conclusions: While collaboration has been lauded as a way forward, this analysis of the process highlights some of the difficulties of working as a multi-site virtual team who are widely spread geographically and who have no previous connection. At different stages of the process there has been acknowledgement of the political dimensions affecting such an approach and a need to avoid the pitfalls of collaborative working in order to harness the potential of all team members, if success is to be achieved.
Developing a service-user framework to shape priorities for nursing and midwifery research
Authors: Smith Elizabeth , Ross Fiona M. , Mackenzie Ann , Masterson Abigail
Published: February 2005

Many people believe, and government policy recommends, that service users should be involved more in research agenda setting. This paper helps to provide a way of undertaking this, drawing on the approach used in a national research priority setting exercise for nursing and midwifery service delivery and organisation. A framework of service-user expectations for nursing and midwifery services was developed through a process of focus group discussions. Thirty-two participants were recruited from Community Health Councils (CHCs) because of their formal role in linking to health providers and as advocates of local communities. Discussions focused on the main gaps in nursing and midwifery services, priority areas for improvement and ways of involving service users in these developments. Nine broad expectations for nursing and midwifery services were identified and were used as a framework for the alignment of professional stakeholder data and literature and policy analysis. This enabled five priority areas for research to be identified that were important to all of these groups. Targeted sampling, information giving prior to the focus groups, careful explanation of confidentiality and the purpose of the exercise and facilitation skills were important for developing a framework that covered the wide breadth of the topic area. The process also raised important questions for nursing and midwifery research. Conceptual difficulties about balancing service-user control and researcher influence, and the authenticity of the data in representing diversity, were limitations of the approach. A final report is available at www.sdo.lshtm.ac.uk/nursingandmidwifery.
Patient consent principles and guidelines for e-consent: a New Zealand perspective
Authors: Galpottage P. A. B. , Norris A. C.
Published: February 2005

E-consent systems are attracting considerable interest as healthcare providers increasingly apply information technology and management to plan and deliver high-quality and cost-effective healthcare. These systems can ensure that patients are informed about the consequences of clinical intervention or the use to which their personal health information is put, as well as able to log the conditions of consent and create an audit trail. This article considers the nature of patient consent and the control of information before outlining the characteristics, benefits and limitations of e-consent systems. It then surveys international developments in e-consent before describing a project to develop a framework for such consent in New Zealand. The results of this project offer recommendations for further development and implementation of the framework.
Introducing a process manager in healthcare: an experience report
Authors: Perjons Erik , Wangler Benkt , Wäyrynen Jaana , Åhlfeldt Rose-Mharie
Published: February 2005

To be efficient and patient focused, healthcare units need to be process oriented and integrated with the processes and IT systems of other healthcare units. A process manager facilitates integration of different systems by using graphical and executable process models. The process manager also communicates directly with healthcare personnel via desktop computers and mobile devices. This article reports on a Swedish project where a prototype system was developed and tested with several healthcare units. The experience shows several advantages and opportunities. For example, current information about patients can be transferred automatically between healthcare units; resource intensive manual tasks can be replaced with automated tasks; and long-term process monitoring and quality assessment can be enabled. However, introducing a process manager requires attention to issues of security, ethics and legality. Healthcare units may also show differences in security awareness and IT maturity, which could obstruct the introduction of a process manager.
Structural work
Authors: Sahlins Marshall
Published: February 2005

The structural-cum-symbolic amplification of minor differences: how small-scale, interpersonal or factional disputes are turned into large-scale struggles between nations, kingdoms or their totalized like - thus making macrohistories out of microhistories and vice versa. The phenomenon depends on structural relays of various sorts that endow the opposing local parties with collective identities and the opposing collectives with local or interpersonal sentiments. In the occurrence, the small-scale struggles are transformed into abstract and irreconcilable causes-to-die-for, their outcome depending now on the larger correlation of forces. The discussion focuses on three ethnographic/historical examples: the recent Elián Gonzalez affair in the US; the nationalization of peasant disputes in the Cerdanya, Catalonia during the 17th to 19th centuries; and civil strife in Corcyra and other Greek city-states during the Peloponnesian War. The last was an important source of Hobbes’s idea of the state of nature. It shows that it takes a lot of culture to make a state of nature.
Subjectivity and cultural critique
Authors: Ortner Sherry B.
Published: February 2005

In the many works that try to bring back ‘the actor’ in some sense, there is a tendency to avoid questions of subjectivity, that is, complex ‘structures of feeling’ (in Raymond Williams’s phrase). This article returns to the work of Max Weber and Clifford Geertz to consider various issues of subjectivity, including both fundamental existential anxieties, and specific cultural and historical constructions of ‘consciousness’. The article concludes with a rereading of several recent texts on postmodern consciousness as a specific configuration of anxieties, tied in turn to formations of ‘late capitalism’.
A model of online customer behavior during the initial transaction: Moderating effects of customer characteristics
Authors: Ranaweera Chatura , McDougall Gordon , Bansal Harvir
Published: February 2005

Recent research shows that observations based on overall online consumer behavior can lead to erroneous conclusions since behavior can be substantially different among groups of individuals. This article proposes a theoretical model, which captures the main characteristics of the website and explains how the user reaction to the website, determined by a set of user characteristics, could moderate consumer perceptions of websites as well as subsequent behaviors especially in a B2C context. A comprehensive understanding of these user characteristics will enable researchers to further the understanding of online consumer behavior during the crucial initial transaction, which often raises the biggest challenge for service providers. An understanding of user characteristics will assist service providers in designing customized websites for competitive advantage.
Integrating e-commerce into existing export marketing theories: A contingency model
Authors: Karavdic Munib , Gregory Gary
Published: February 2005

Current theory on export marketing is based on the assumption that each exporting decision is made in isolation, whereby a set of factors are considered for single market entry only, without the consideration of simultaneous entry into multiple foreign markets. Because e-commerce is able to provide instantaneous access to numerous global markets, recent technological advances force us to rethink whether existing theoretical frameworks are sufficient in explaining today's export marketing strategies. A review of the recent export literature suggests that a new paradigm may be needed to take into consideration the electronic marketplace, both in the process of entering markets, and in the management of operations within those markets. The purpose of this article is to present a model that integrates e-commerce into existing theories on export marketing. Specifically, the aim is to develop a theoretical framework that: (a) extends existing export marketing theories by incorporating ecommerce strategy; (b) proposes a contingency approach to compare and contrast the relationship among environmental variables, export market strategy and export performance; and, (c) provides a clear direction for future research through the development of research propositions investigating the role of e-commerce strategy in the exporting process.
Justice or Freedom
Authors: Herzog Annabel
Published: February 2005

This article argues that Camus’s thinking, as expressed in his works of fiction and non-fiction, is based upon a contradiction between his determination to reconcile politics and ethics and his belief that they irrefutably contradict each other. Throughout his career, Camus’s concerns never diverged from his aporetic attempt to reach an ‘agreement’ between two concepts he regarded as incompatible: justice and freedom. This article demonstrates how this basic aporia led Camus to an original - albeit rather hopeless - view of the human condition. It illustrates how Camus’s aporia led him to define the role of thinkers in terms of public criticism and argues that in today’s sociopolitical reality Camus’s aporia can neither be dismissed, nor overcome.
CLL, but not normal, B cells are dependent on autocrine VEGF and α4β1 integrin for chemokine-induced motility on and through endothelium
Authors: Till Kathleen J. , Spiller David G. , Harris Robert J. , Chen Haijuan , Zuzel Mirko , Cawley John C.
Published: February 2005

Vascular endothelial cell growth factor (VEGF) is a multifunctional cytokine involved in tumor formation. In chronic lymphocytic leukemia (CLL), it is known that the malignant cells secrete VEGF and possess VEGF receptors. This suggests that an autocrine loop might be important in the pathogenesis of CLL. Here we show that, in patients with lymphadenopathy, autocrine VEGF and α4β1 integrin are involved in the chemokine-dependent motility of CLL cells on and through endothelium—processes important for the invasion of lymphoreticular tissues, a major determinant of disease outcome. In contrast, normal lymphocytes were not dependent on autocrine VEGF or α4β1 for either type of cell movement. Moreover, in contrast to normal B lymphocytes, CLL cells failed to cluster and activate αLβ2 in response to chemokines, unless VEGF receptor(s) and α4β1 were also engaged by their respective ligands. This is the first demonstration that autocrine VEGF is involved in CLL-cell motility, and that the αLβ2 on the malignant cells is functionally altered compared with that of normal B cells in not undergoing activation in response to chemokine alone. Given the importance of cell motility for tissue invasion, the present results provide a rationale for a trial of VEGF and α4 blockade in patients with CLL who have tissue disease. (Blood. 2005;105:4813-4819)
Cyclooxygenase-2 (COX-2) is frequently expressed in multiple myeloma and is an independent predictor of poor outcome
Authors: Ladetto Marco , Vallet Sonia , Trojan Andreas , Dell'Aquila Maria , Monitillo Luigia , Rosato Rosalba , Santo Loredana , Drandi Daniela , Bertola Alessandra , Falco Patrizia , Cavallo Federica , Ricca Irene , De Marco Federica , Mantoan Barbara , Bode-Lesniewska Beata , Pagliano Gloria , Francese Roberto , Rocci Alberto , Astolfi Monica , Compagno Mara , Mariani Sara , Godio Laura , Marino Lydia , Ruggeri Marina , Omedè Paola , Palumbo Antonio , Boccadoro Mario
Published: February 2005

Cyclooxygenase 2 (COX-2) is an inflammation-associated enzyme involved in the pathogenesis of many solid tumors, but little is known about its presence and role in hematologic neoplasms. Multiple myeloma (MM) is known to involve a deregulated cytokine network with secretion of inflammatory mediators. We thus decided to investigate the involvement of COX-2 in this neoplasm. Western blotting (WB) was used to evaluate 142 bone marrow (BM) specimens, including MM and monoclonal gammopathy of undetermined significance (MGUS). Selected cases under-went further evaluation by WB on purified CD138+ cells, immunohistochemistry (IC), and real-time polymerase chain reaction (PCR) for mRNA expression. COX-2 was expressed in 11% (2 of 18) of MGUS specimens, 31% (29 of 94) of MM at diagnosis, and 47% (14 of 30) of MM with relapsed/refractory disease. COX-2 positivity was associated with a poor outcome in terms of progression-free (18 vs 36 months; P < .001) and overall survival (28 vs 52 months; P < .05). Real-time PCR showed COX-2 mRNA overexpression. IC and cell separation studies demonstrated COX-2 expression to be restricted to malignant plasma cells. This is the first report of the presence and prognostic role of COX-2 expression in MM. Future studies will assess COX-2 involvement in other hematologic tumors and its potential use as a therapeutic or chemo-preventive target in onco-hematology. (Blood. 2005; 105:4784-4791)
Spatial Distribution of Damage Caused by the 1999 Earthquakes in Turkey
Authors: Dönmez C. , Pujol S.
Published: February 2005

A team of engineering students and faculty from several universities investigated the effects of the 17 August and 12 November 1999 earthquakes in Turkey, documenting the damage in reinforced concrete structures. The team focused on the damage in Düzce, Kaynaşlı, and Bolu. This article summarizes the observations and the data gathered on the spatial distribution of the damage in reinforced concrete structures with respect to the fault rupture. The data presented are of interest because they do not reveal a clear trend between damage and distance to the fault.
Aseismic Roof Isolation System Built with Steel Oval Elements: Exploratory Study
Authors: Villaverde Roberto , Aguirre Manuel , Hamilton Charles
Published: February 2005

Presented herein are the details of and results from an experimental study conducted to assess the feasibility and effectiveness of a proposed roof isolation system whose purpose is to reduce earthquake damage in buildings. The proposed isolation system entails the detachment of a building's roof from the rest of the building through the insertion of sliding bearings and the attachment of oval-shaped steel elements between the building's roof and the structure below. The objective is to form a simple resonant oscillator with a building's roof and these oval elements, with the roof providing the mass of the oscillator and the oval elements its spring and damper. An additional intention is to make the steel oval elements undergo a large number of inelastic deformation cycles and dissipate, as a result, a large portion of the energy transmitted to a building during an earthquake. The study involves the testing of a small steel frame on a shaking table alternatively with and without the proposed roof isolation system and a comparison of the story drifts and floor accelerations attained in each case. In the conducted tests, the suggested isolation technique effectively reduces the seismic response of the frame. It is concluded, thus, that the proposed roof isolation system has the potential for the development of an inexpensive and effective way to reduce earthquake damage in some buildings and merits further study.
Extension of Modal Pushover Analysis to Compute Member Forces
Authors: Goel Rakesh K. , Chopra Anil K.
Published: February 2005

This paper extends the modal pushover analysis (MPA) procedure for estimating seismic deformation demands for buildings to compute member forces. Seismic demands are computed for six buildings, each analyzed for 20 ground motions. A comparison of seismic demands computed by the MPA and nonlinear response history analysis (RHA) demonstrates that the MPA procedure provides good estimates of the member forces. The bias (or error) in forces is generally less than that noted in earlier investigations of story drifts and is comparable to the error in the standard response spectrum analysis (RSA) for elastic buildings. The four FEMA-356 force distributions, on the other hand, provide estimates of member forces that may be one-half to one-fourth of the value from nonlinear RHA.
A Design-Oriented Approach to Strength Distribution in Single-Story Asymmetric Systems with Elements Having Strength-Dependent Stiffness
Authors: Myslimaj Bujar , Tso Wai K.
Published: February 2005

Recent studies have pointed out that the stiffness and strength of many lateral force-resisting elements (LFRE) are dependent parameters. This paper examines the implication of this finding in the distribution of design strength among LFRE. It is shown here that in order to minimize torsional response, one should use a strength/stiffness distribution combination that leads to the location of the center of strength, CV, and the center of stiffness, CR, on opposite sides of the center of mass, CM. A design-oriented strength-allocation procedure to arrive at such strength and stiffness distributions is presented. Its effectiveness in minimizing torsional response is demonstrated through comparison of seismic performance of structures having strength allocated on the basis of the proposed procedure with those following current UBC and EC8 torsional provisions.
Educational Reconnaissance of the Area Affected by the 1999 Chi-Chi Earthquake—Three Years Later
Authors: Christopoulos Constantin , Garcia Diego Lopez , Tsai Keh-Chyuan
Published: February 2005

Findings from a reconnaissance effort to the area affected by the 1999 Chi-Chi earthquake in Taiwan are reported in this paper. The reconnaissance team comprised eight graduate students from the three U.S. earthquake engineering research centers (MAE, MCEER, and PEER). The mission provided an opportunity to assess, three years later, the response of the engineering community to this major earthquake that caused extensive loss of life and property. This educational reconnaissance effort was hosted by Taiwan's National Center for Research in Earthquake Engineering (NCREE) in May 2002. Researchers from NCREE first presented extensive information on the observed failures, the repairs and reconstruction, as well as the lessons learned and changes in future engineering practice before an intensive site visit. In this paper, observations on the performance/repair/retrofit and reconstruction of residential buildings and bridges are reported. Although most bridge structures were retrofitted or rebuilt with state-of-the-art engineered solutions, most low-rise mixed commercial-residential buildings were retrofitted with non-engineered techniques often conceived and carried out by local contractors. Furthermore, the structural configuration of the mixed commercial-residential building that suffered the most serious damage is still rather commonly applied in Taiwan. The organization and the educational value of this reconnaissance experience are also discussed.
Evolution of Design Code Requirements for Exterior Elements and Connections
Authors: Sielaff Brian J. , Nielsen Richard J. , Schmeckpeper Edwin R.
Published: February 2005

Seismic design requirements for precast concrete cladding panel connections have evolved significantly over the past fifty years. This paper summarizes the pertinent requirements from the Uniform Building Code from 1967 to 1997, and the International Building Code 2000. A hypothetical design illustrates how emphasis in the code has evolved for both lateral force requirements and story drift displacement requirements arriving at a balance of moderate lateral force and displacement requirements. The numerical results are based on a hypothetical case of panel connections for a ten-story moment-resisting steel frame structure built in seismic Zone 4. This historical summary is of value to designers who deal with the seismic rehabilitation of precast panel connections.
Conditional Expression of a Glucocorticoid Receptor Transgene in Thymocytes Reveals a Role for Thymic-Derived Glucocorticoids in Thymopoiesis in Vivo
Authors: Pazirandeh Ahmad , Jondal Mikael , Okret Sam
Published: February 2005

We and others have previously reported that thymic epithelial cells produce glucocorticoids (GCs). In vitro studies have also suggested that thymic-derived GCs play a role in the development of thymocytes. However, until now it has not yet been established whether thymic-derived GCs play a role in thymopoiesis in vivo. To investigate this, we conditionally overexpressed the GC receptor (GR) in thymocytes using transgenic mice with a tetracycline-inducible expression system. The influence of systemic GCs was excluded by adrenalectomizing the transgenic mice before the GR induction. Conditional expression of transgenic GR in the thymocytes of adrenalectomized transgenic mice led to a decrease in the thymocyte number. This was associated with increased thymocyte apoptosis. The effect of thymic-derived GCs on the thymocytes was confirmed after transgenic GR induction in a thymic organ culture system. Finally, the GR antagonist RU486 increased thymocyte number in adrenalectomized mice in vivo and prevented a reduction in thymocyte number in thymic organ culture after transgenic GR induction. These observations further confirmed a role for the thymic-derived GCs in regulating thymocyte homeostasis in vivo.
Dynamics of forward filtration combustion at the pore‐network level
Authors: Lu Chuan , Yortsos Yannis C.
Published: February 2005

A pore‐network model is developed, based on a dual lattice, to study the dynamics of forward filtration combustion (FC) in porous media at the pore‐network scale. A novel moving coordinate method is also implemented that allows for the long‐term profiles to be obtained in a straightforward manner. The model is used to reproduce recent analytical work, including the multiplicity of steady states for the nonadiabatic case, and to study a number of other effects. Particular emphasis is placed on the effect of the heterogeneity in the microstructure, introduced by the randomness in the pore radius. It is found that the local disorder leads to less oxidant consumption, as compared to the homogeneous case. This underprediction increases with an increase in the disorder, a decrease in the thermal conductivity, and a decrease in the spatial correlation. Temporary local extinction can result for sufficiently large injection rates. As a result of the heterogeneity, the spatially averaged reaction rate is generally different from the rate calculated based on the microscale Arrhenius expression, using the averaged variables, with discrepancies of a factor of 2 or higher not uncommon. Although this effect depends on the parameter values, it can be a cause of concern when the fronts at the small scale are sufficiently distorted. Coupling of fronts occurs in a layered system, when there is sufficient oxidant supply. These results show that the microscale geometry can have a strong influence on the overall macroscopic behavior of the process. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Composite sheets with biodegradable polymers and paper, the effect of paper strengthening agents on strength enhancement, and an evaluation of biodegradability
Authors: Kanie O. , Tanaka H. , Mayumi A. , Kitaoka T. , Wariishi H.
Published: February 2005

Composite sheets composed of biodegradable polymers (BP) and paper were prepared, and their physical and biodegradable properties were investigated. The paper sheets were soaked in BP emulsions and cured at 100°C for 20 min. The wet strength of composite sheets with the same basis weight increased significantly with increasing BP content, although dry strength increased only moderately. A 0.5% addition of a common wet paper‐strengthening agent, poly(amidoamine‐epichlorohydrin) (PAE) resin, enhanced the wet strength, which reached 9.3 MPa, of composite sheets consisting of a BP : paper ratio of 20 : 80. Further enhancement was achieved by the addition of polyvinylamines (PVAm). The wet tensile strength of composite sheets consisting of BP and paper (20 : 80) increased by 27% with the addition of 0.2% PVAm and 0.5% PAE, whereas it was enhanced by only 3–4% with the addition of 0.7% PAE. The biodegradability of the composite sheets was somewhat retarded by the addition of PAE and PVAm. However, a 90% weight loss was observed 60 days after placing composite sheet samples in soil. A similar weight loss was observed after 45 days for composites without additives and after 30 days for base paper alone. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 861–866, 2005
Morphology of membranes formed by the isothermal precipitation of polyamide solutions from water/formic acid systems
Authors: Shih Chien‐Hsueh , Gryte Carl C. , Cheng Liao‐Ping
Published: February 2005

Membranes were prepared by the direct and isothermal immersion of polyamide solutions in a formic acid/water bath. A crystalline polycaprolactam homopolymer, nylon 6, and a largely amorphous terpolymer of nylon 6, nylon 66, and nylon 610 were precipitated from solutions to form complex morphologies on the top and bottom surfaces and cross sections of the membranes. Terpolymer membranes exhibited the characteristics of a liquid–liquid phase‐separation process. According to the conditions of the solution and bath, nylon 6 precipitated to form membranes that showed dominance of crystallization or liquid–liquid phase separation. By precipitation from a solution containing a high concentration of a nonsolvent into a bath containing a high concentration of formic acid, skinless nylon 6 microporous membranes were formed. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 944–960, 2005
Current views of collagen degeradation. Progress towards understanding the resorption of connective tissues
Authors: Murphy Gillian , Reynolds John J.
Published: February 2005

Collagen is the most abundant vertebrate protein and forms a stable fibrous architecture in connective tissues, such as bone, cartilage, skin and tendon. Much recent research has been directed towards an understanding of the molecular and cellular mechanisms involved in the synthesis and degradation of collagen, because a change in the normal balance, or an increased destruction of collagen, can cause loss of function of specialized tissues. This short review attempts to summarize present knowledge about the proteolytic destruction of collagen and the exciting new work on the factors that are emerging as important controlling agents. An understanding of the regulatory processes is yielding some important clues regarding the levels at which they can fail in pathological conditions and we speculate about evolving strategies for preventing uncontrolled resorption.
The role of growth factors in haemopoiesis
Authors: Dexter T. M. , Heyworth C. , Whetton A. D.
Published: February 2005

Many of the haemopoietic cell growth factors have now been purified to homogeneity and their structural genes cloned. Methods are also now available for obtaining pure populations of haemopoietic cells. The use of such cells, in combination with pure growth factors, has provided intriguing information about the biological activities and mode of action of the factors in faciliating survival, proliferation and differentiation of the haemopoietic cells.
Chloroplast DNA and molecular phylogeny
Authors: Palmer Jeffrey D.
Published: February 2005

The small, relatively constant size and conservative evolution of chloroplast DNA (cpDNA) make it an ideal molecule for tracing the evolutionary history of plant species. At lower taxonomic levels, cpDNA variation is easily and conveniently assayed by comparing restriction patterns and maps, while at higher taxonomic levels, DNA sequencing and inversion analysis are the methods of choice for comparing chloroplast genomes. The study of cpDNA variation has already yielded important new insights into the origin and evolution of many agriculturally important crop plants, and promises to significantly enhance our phylogenetic understanding of the major lines of descent among land plants and algae.
The cellular and molecular basis of the Lyt‐1+2− T cell‐mediated tumor‐eradicating mechanism in vivo
Authors: Fujiwara Hiromi , Hamaoka Toshiyuki
Published: February 2005

This article reviews recent findings that bear on the mechanism(s) of tumor‐specific Lyt‐1+2− T cell‐mediated tumor eradication in vivo A tumor‐immune Lyt‐1+2− T cell subset has been identified which is distinct from T cells mediating in vitro cytotoxicity (Lyt‐1+2+/1−2+). The Lyt‐1+2− cells have a crucial role in rejecting tumor cells when adoptively transferred into T cell‐deprived B cell mice. This indicates that Lyt‐1+2− T cells do not necessarily require recruitment of the host's cytotoxic T cell precursors for implementation of in vivo immunity. Instead, this T cell subset exerts its anti‐tumor effect in collaboration with macrophages as shown with an in vivo tumor cell culture system utilizing a diffusion chamber. A pathway of Lyt‐1+2− T cell‐macrophage interaction leading to tumor cell killing is discussed in terms of its probable relevance to the eradication of tumor cell masses consisting of tumor cells expressing quantitatively and/or qualitatively different tumor antigens.
Roots: The discovery of chloroplast DNA
Authors: Kirk John T. O.
Published: February 2005

In the space of three years–from 1962 to 1964 – the proposition that chloroplasts contain their own DNA made the transition from being a controversial hypothesis to an accepted dogma. The crucial evidence came from biochemical analyses of the organelles themselves and from cytological studies. These discoveries revolutionized our views on the distribution of genetic information within the cell, and gave rise to the vigorous new field of chloroplast molecular biology. It is nevertheless ironic to recall that of the biochemical papers published on this topic in 1962–64, the one which was probably the most influential in creating the new paradigm was in fact quite wrong, and attributed to the chloroplast, DNA species which did not in reality belong to this organelle at all.
Problems and paradigms: Physiological analysis of bone appetite (Osteophagia)
Authors: Denton D. A. , Blair‐West J. R. , McKinley M. J. , Nelson J. F.
Published: February 2005

The vegetation eaten by animals on large areas of several continents is deficient in phosphate and deleterious effects on physiology, particularly reproduction, ensue. Records on bone chewing behaviour by both pastoral andwild game animals extend over two centuries. In laboratory investigation of this apt behaviour it has been shown that the appetite for bones is innate and specific and cued predominantly by olfactory stimuli. It is suppressed by rapidly increasing the plasma phosphate concentration to normal but not influenced by increasing the phosphate concentration in cerebrospinal fluid. The central organization of this genetically programmed behaviour appears to differ from systems subserving thirst and sodium appetite.
Neurofilaments: Abundant but mysterious neuronal structures
Authors: Shaw Gerry
Published: February 2005

Neurofilaments are by far the most obvious elements of the neuronal cytoskeleton. Their subunits are biochemically among the most abundant neuron specific components, particularly in axons. Clearly they must be important to the neuron or they would not be so numerous But what do they do?.
The elucidation of the human mitochondrial genome: A historical perspective
Authors: Attardi Giuseppe
Published: February 2005

The progressive unraveling over the past fifteen years of the structure and function of the human mitochondrial genome, taken as a prototype of all vertebrate mitochondrial genomes, has been marked by a series of startling discoveries. The history of these developments is one in which prediction often turned out to be wrong, and in which solidly established dogmas were violated. The unique features of this genome have forced a revision of our ideas about the universality of the genetic code and of the decoding mechanism, the minimal structural requirements for rRNA, tRNA and mRNA function and the mode and control of gene expression.
Cell migrations during morphogenesis: Some clues from the slug of Dictyostelium discoideum
Authors: Williams Keith L. , Vardy Phil. H. , Segel Lee A.
Published: February 2005

Starvation induces free‐living Dictyostelium discoideum amoebae to form slugs that typically contain 100,000 cells. Only recently have sufficient clues become available to suggest how coordinated cell actions might result in slug movement. We propose a “squeeze‐pull” model that involves circumferential cells squeezing forward a cellular core, followed by pulling up of the rear. This model takes into account the different classes of cells in the slug; it is proposed that prestalk cells are engines and prespore cells are the cargo.
Interstrand duplexes in nuclear RNA
Authors: Pogo A. Oscar , Miller Kenton S.
Published: February 2005

Nuclear intermolecular duplexes appear to be a general feature of nucleated cells. Most of these duplexes are formed between large RNA as well as between large and small RNA molecules. A significant portion of the large molecules belong to a special class of RNA that is restricted to the nucleus and, therefore, not designated for export. These molecules are assembled with proteins and form a structure of a higher order. The possibility that these molecules and a set of small nuclear RNAs are components of a complex machine, “the transportosome”, which functions in nucleocytoplasmic traffic, is discussed.
Testicular leydig cells: Differentiated cells responding to multiple hormonal control and producing varied products
Authors: Melner Michael H.
Published: February 2005

Leydig cells, traditionally known as the steroidogenic workhorses of the testis, are now known to synthesize significant amounts of non‐steroid products including some potent bioactive proteins and peptides. These products are currently being investigated for their potential role in the paracrine regulation of spermatogenesis in the nearby seminiferous tubules and in the autocrine regulation of Leydig cell function.
Low energy pulsing electromagnetic fields modify biomedical processes
Authors: Bassett C. A. L.
Published: February 2005

Low‐energy, pulsed electromagnetic fields (PEMFs) have reversed therapeutically resistant pathologic processes in the musculo‐skeletal system. Their development as a non‐thermal therapeutic agent is based on 30 years of study of the electro‐biological properties of connective tissues. Specific energy characteristics in applied PEMFs produce selected biological effects by modifying synthetic and other behavioral patterns of target cells; some mechanisms of action are defined. The technology appears safe and effective in clinical treatment of un‐united fractures, avascular necrosis of bone, and chronic, refractory tendinitis. An expanding, rational use in biomedical science is predicted.
Tryptophan synthetase: Its charmed history
Authors: Yanofsky Charles
Published: February 2005

Tryptophan synthetase was initially selected as a subject for investigation of the relationship between gene structure and protein structure. Early studies with this enzyme first demonstrated the existence in mutants of immunologically cross‐reacting material (CRM) and the restoration of a wild‐type enzyme by genetic suppression. Fine structure analyses with E. coli tryptophan synthetase missense mutants proved the colinearity of gene structure and catalytic capabilities of this enzyme have been subjects for numerous studies.
Bone development and repair
Authors: Caplan Arnold I.
Published: February 2005

Although bone development during embryogenesis and bone repair after injury have a number of features which appear similar, they are distinctly different processes which involve separate controlling elements and cuing parameters. Repair of bone is influenced by bioactive factors which reside in bone itself; some of these factors are not present when embryonic mesenchymal cells first differentiate. For example, a bone protein which induces the conversion of mesenchymal cells into cartilage cells is not present in the embryo at the site where cartilage first differentiates into the anlagen for future bone. Ultimately, the sequence of cellular and molecular events which controls the success of bone repair is dependent on the prior embryologic and developmental packaging of bioactive factors into bone and the release of these factors at a bone break site. The success of the reparative events depends not only upon the release of these bone‐derived factors but also on systemic factors and the identity and numbers of responding cells at the repair site.
The control of transcription in Saccharomyces cerevisiae
Authors: Stanway Clive , Kingsman Alan J. , Kingsman Susan M.
Published: February 2005

The control of mRNA synthesis in the unicellular eukaryote Saccharomyces cerevisiae involves a number of promoter elements, including an upstream activation site (UAS), an RNA initiation element (RIE) and, for some genes, a form of negative element. The UAS is involved in the activation and regulation of transcription, whilst the RIE, which comprises a transcription initiation site (or I site), and often a TATA box, is responsible for the accurate positioning of the 5′ end of the mRNA. The mechanism whereby these promoter elements interact involves specific protein‐DNA binding events and possibly alterations in chromatin structure.
A potential Z‐DNA‐forming sequence is an essential upstream element of a plant promoter
Authors: An Gynheung
Published: February 2005

The fine‐structure analyses of the nopaline synthase (nos) promoter which is active constitutively in a wide range of plant tissues reveal that a portion of the upstream essential region for maximal transcription is a potential Z‐DNA‐forming element. Z‐DNA sequences are found in almost all plant‐promoter regions, suggesting that these structural elements may play important roles in plant gene expression.
Kinetic isotope effects and ‘metabolic switching’ in cytochrome P450‐catalyzed reactions
Authors: Miwa Gerald T. , Lu Anthony Y. H.
Published: February 2005

The mechanistic significance of a kinetic isotope effect on a cytochrome P‐450catalyzed reaction depends, fundamentally, on the nature of the interaction of the substrate with the active site of the enzyme as well as on the nature of the chemistry of the reaction catalyzed. Consequently, kinetic isotope effects can be used to extract information on the topology of the enzyme and the mechanism of substrate oxidation. Kinetic isotope effect studies are sometimes accompanied by ‘metabolic switching’ or a change in metabolic pathway, catalyzed either by the same enzyme or by a different enzyme. For the specific case where ‘metabolic switching’ gives rise to a change in regional specificity for the cytochrome P‐450 catalyzed metabolism of a compound, this change can be explained in terms of the topological constraints on substrate binding imposed by the active site of the enzyme.
Disulphide bonds and protein stability
Authors: Creighton Thomas E.
Published: February 2005

The properties of disulphide bonds relevant to their roles in stabilizing protein conformation are reviewed. Natural disulphides can stabilize folded conformations substantially, in some cases to much greater extents than would be expected from just entropic effects on the unfolded state. The linkage relationship between conformational stability and disulphide stability is illustrated. Disulphides will not, however, increase protein stability if the disulphides are not maintained in the unfolded state or if instability is caused by processes, such as chemical modification or proteolysis, that are not linked to unfolding, either local or global. This is part of the reason why some recent attempts to increase protein stability by introducing new disulphides have had only modest success. Other reasons appear to be the severe energetic constraints on disulphide bond geometry and, in some cases, unfavourable effects of introducing Cys residues by mutation.
Analysis, design and modification of loop regions in proteins
Authors: Thornton J. M. , Sibanda B. L. , Edwards M. S. , Barlow D. J.
Published: February 2005

Loop regions in proteins have traditionally been described as ‘random coil’, although they are known to adopt well‐defined conformations in most globular proteins. In this contribution we summarize the results of detailed analysis of the structures and sequences of these loop regions in proteins of known three‐dimensional structure. We also describe how these results can be used as an aid to protein design, modification and modelling.
Engineering of antibodies
Authors: Verhoeyen Martine , Riechmann Lutz
Published: February 2005

Human monoclonal antibodies are extremely difficult to obtain by hybridoma technology. As an alternative, ‘human‐like’ antibodies have been produced by recombinant DNA technology. The first such engineered antibodies consisted of chimaeric proteins, in which murine variable regions were linked to human constant regions. More recently ‘human’ antibodies have been ‘reshaped’ by transplanting the binding site of a murine antibody into a human antibody. Further‐more antibodies have been dissected into groups of domains (Fab's, Fc's) and for example, Fab's have been joined to enzymes resulting in antibody‐enzyme chimaeras. In addition to their potential clinical applications, engineered antibodies will prove invaluable in studies of structure/function relationships of variable and constant regions.