bluuebunny/crossref_metadata_2025 huggingface dataset:
Visualization of nitric oxide production and intracellular calcium in juxtamedullary afferent arteriolar endothelial cells
Authors: Pittner J. , Liu R. , Brown R. , Wolgast M. , Persson A. E. G.
Published: November 2003

Aim:  Nitric oxide (NO) is an important signal transmitter with multiple haemodynamic functions in the kidney. Study of these is complicated by the difficulty in measuring NO directly or visualizing its production. Recently the synthesis of a group of new NO‐sensitive fluorescent dyes, diaminofluoresceins (DAF), suitable for imaging applications has been reported. We attempted to use one DAF (DAF‐2 DA) to investigate the relationship between endothelial calcium, NO production and afferent arteriolar reactivity.

Methods:  We used the isolated, perfused juxtamedullary nephron preparation (JMN) and loaded the afferent arteriolar endothelium with Fura‐2 AM and DAF‐2 DA (4,5‐diaminofluorescein‐2‐diacetyl). After in vitro calibration of the imaging system, we measured Fura‐2 and DAF‐2 fluorescence in single endothelial cells of afferent arterioles (AA) perfused at a pressure of 100 mmHg.

Results:  Carboxy‐2‐phenyl‐4,4,5,5‐tetramethyl‐imidazoline‐1‐oxyl‐3‐oxide (carboxy‐PTIO) (10−3 m), a specific NO scavenger, decreased DAF‐2 fluorescence in the endothelium by 16.1% and the mid‐afferent arteriolar diameter by 10.2%, and increased endothelial calcium by 17.8%. Nω‐nitro‐l‐arginine methyl ester (l‐NAME) (10−4 m) decreased fluorescence intensity of DAF‐2 by 18.6%, increased cellular calcium level by 19.7% and constricted the vessels by 11.6%. Addition of carbachol (10−4 m) increased average DAF‐2 fluorescence by 22.8% and endothelial calcium concentration by 28.9%, whereas the arteriolar diameter remained essentially unchanged. Carbachol failed to increase DAF‐2 fluorescence when administered after l‐NAME pre‐treatment.

Conclusion:  We conclude that endothelial NO homeostasis is an important determinant of AA reactivity and suggest that DAF are suitable for real‐time imaging of afferent arteriolar NO production in the isolated, perfused JMN and may be used in combination with calcium‐sensitive fluorophores. We have found that NO reduction by carboxy‐PTIO or l‐NAME increases endothelial calcium, suggesting involvement of calcium signalling in an autocrine NO production feedback in the endothelium. This method should help to further clarify the role of endothelial NO in renal haemodynamics.
The role of reactive oxygen species in the regulation of tubular function
Authors: Garvin J. L. , Ortiz P. A.
Published: November 2003

The phrase reactive oxygen species covers a number of molecules and atoms, including the quintessential member of the group, O2−; singlet oxygen; H2O2; organic peroxides; and OONO−. While nitric oxide (NO) is also technically a member of the reactive oxygen species family, it is generally considered with a different class of compounds and will not be considered here. To our knowledge, there are currently no published data reporting the effects of reactive oxygen species on net transepithelial flux in the proximal nephron. However, there is evidence that OONO− regulates Na+/K+ adenosine triphosphatase (ATPase) activity as well as paracellular permeability. While it is easy to speculate that such an effect on the pump would decrease net transepithelial solute and water reabsorption, one cannot do so without knowing how other transporters are affected. O2− stimulates NaCl absorption by the thick ascending limb by activating protein kinase C and blunting the effects of NO. The effects of O2− on thick ascending limb NaCl absorption may be important for the initiation of salt‐sensitive hypertension. To our knowledge, there are no published data concerning the role of reactive oxygen species in the regulation of solute absorption in either the distal convoluted tubule or the collecting duct. However, OONO− inhibits basolateral K+ channels in the cortical collecting duct, although the net effect of such inhibition is unknown.

Conclusion:  While the regulation of tubular transport by reactive oxygen species is important to overall salt and water balance, we know very little about where and how these regulators act along the nephron.
Renal and vascular oxidative stress and salt‐sensitivity of arterial pressure
Authors: Manning R. D. , Meng S. , Tian N.
Published: November 2003

Oxidative stress occurs in a tissue or in the whole body when the total oxidant production exceeds the antioxidant capacity. Recent studies in human essential hypertension indicate that free radical production is increased and antioxidant levels are decreased, and more than one‐half of these hypertensives have a salt‐sensitive type of hypertension with progressive renal damage. Increased oxidative stress may also play a critical role in animal models of salt‐sensitive hypertension. The stroke‐prone spontaneously hypertensive rats (SHRSP) exhibits salt‐sensitivity, vascular release of superoxide is increased, and total plasma antioxidant capacity is decreased. The superoxide release in the SHRSP rats inactivates nitric oxide, and superoxide dismutase (SOD) administration returns the bioactive nitric oxide levels to normal. The deoxycorticosterone acetate (DOCA)‐salt hypertensive rat is salt‐sensitive, aortic superoxide production is increased, and renal inflammation is significant. Treatment of the DOCA‐salt rats with apocynin, an NADPH oxidase inhibitor, decreased aortic superoxide production and decreased arterial pressure. The Dahl salt‐sensitive (S) rat has increased mesenteric microvascular and renal superoxide production and increased plasma levels of H2O2. The renal protein expression of SOD is decreased in the kidney of Dahl S rats, and long‐term administration of Tempol, a superoxide mimetic, significantly decreased arterial pressure and renal damage. In conclusion, both human hypertension and experimental models of salt‐sensitive hypertension have increased superoxide release, decreased antioxidant capacity and elevated renal damage.
E‐exchange and the Boundary between Households and Organizations
Authors: Lindbeck Assar , Wikström Solveig
Published: November 2003

The new information and communication technology, ICT, induces households to take over tasks from firms and government agencies, using tools and systems provided by these very same organizations. The result is often joint production activities. We argue that the importance of ICT for the exchange process between households and organizations is underestimated by only considering the consequences for the last stage of the process, i.e., the final purchase of goods and services. Our analysis of household behavior utilizes a modified version of Gary Becker’s model of the household as a combined producer‐consumer.
The Future of the Defence Firm
Authors: Hartley Keith , Sandler Todd
Published: November 2003

This paper focuses on the future of the defence firm. It forecasts that the defence firm of 2050 will be radically different, reflecting a combination of technology, economic and political factors. To provide insights into the future, the paper starts by outlining recent changes in the size, structure and organization of defence firms and industries. It concludes by suggesting that the defence firm has a future and that it will focus on systems integration with new and different forms of industrial organization and will include new entrants.
A Divided Europe? Regional Convergence and Neighbourhood Spillover Effects
Authors: Carrington Anca
Published: November 2003

While the stylised fact that, around the world, areas of rapid growth are geographically distinct from those with a poor growth performance, is easily accepted, little effort has been made in the empirical literature to incorporate location into the analysis of regional convergence in terms of economic growth. This paper provides a quantitative evaluation of the role of location in regional convergence, using the argument that growth in each region depends not only on its own characteristics but also on those of the regions that form the neighbourhood to which it belongs. Applying spatial econometrics it is found that, during the 1990s, opposing forces were exerting their influence across the EU: while regions did converge at a rate close to the 2 percent mark, neighbourhoods of regions diverged at an almost equal rate, leaving a net effect of convergence considerably smaller than the one previously reported in the literature.
Teaching reforms and the impact of paid adult support on participation and learning in mainstream schools
Authors: Howes Andrew
Published: November 2003

In the first of our three articles focusing on the role of support staff, Andrew Howes considers some of the implications for the deployment of support staff of Raising Standards and Tackling Workload: a National Agreement. He considers that the wider impact of this proposed deployment has been insufficiently explored in the Agreement. Here he reviews the literature to establish what is known about the impact of support staff in mainstream schools and what the possible outcomes might be if professional roles are reworked in the ways proposed.
‘It's more peaceful without any support’: what do deaf pupils think about the support they receive in mainstream schools?
Authors: Jarvis Joy
Published: November 2003

Our third article turns its attention to the views of young people on the support they receive in school, with deaf education supplying a particularly useful context to explore this issue. Here Joy Jarvis describes a research project carried out to establish what the pupils saw as facilitating or inhibiting their inclusion in a mainstream context. She concludes that in addition to the benefits of specialist teaching and sensitive support in class, more attention should be paid to the development of peer support.
Difficulties and support at school for children following renal transplantation: a case study
Authors: Poursanidou Konstantina , Garner Philip , Watson Alan , Stephenson Roger
Published: November 2003

In an interesting example of inter‐agency collaboration, researchers from Nottingham Trent University and Nottingham City Hospital here use a case study to shed light on some of the peer relationship issues and the support needs of young people with medical conditions. They consider that the concerns raised by the case study suggest schools need to address these proactively rather than reactively.
Supporting asylum seekers in schools
Authors: Clarke Lucy
Published: November 2003

In this article Lucy Clarke provides us with a ‘hands‐on’ view of her work with the East Oxford Schools Inclusion Project where she is a project worker supporting asylum seekers. Her post has been funded jointly by The Children's Society, Oxfordshire Social Services and Oxfordshire Local Education Authority.
Inclusion: on the move?
Authors: Gordon Mike
Published: November 2003

Mike Gordon is an ex‐president of the former National Association for Remedial Education (NARE), now NASEN. He began his teaching career in 1958 in a boys' secondary modern school in Hull. Following national service (1960–62) and a posting in Malaya, he was given responsibility for an ‘Opportunity Class’ in a co‐educational secondary modern. He was fortunate to be seconded in 1966–7 to do Alec William's (great guru) Diploma in the Education of Handicapped Children course. He was then appointed Head of Remedial Studies in a new comprehensive school in Hull. From 1970–73 Mike was a lecturer in Hull College of Education but left to teach in a social priority primary school for five years. He then moved to Scarborough to lead the area learning support service team before becoming North Yorkshire's Head of Special Teaching Support Services. In the early 1970s he obtained a Diploma in Education and an M.Ed. After retiring in 1997 he was NASEN's media officer and was then appointed as the Association's first Executive Secretary in 1999.
Factors influencing nurses’ use of nonpharmacological pain alleviation methods in paediatric patients
Authors: Pölkki Tarja , Laukkala Helena , Vehviläinen‐Julkunen Katri , Pietilä Anna‐Maija
Published: November 2003

The purpose of this study was to describe the factors promoting and hindering nurses’ use of nonpharmacological methods in children's surgical pain relief, and demographic variables related to this. The data were collected by a Likert‐type questionnaire, which was completed by nurses (n = 162) who were working in one of the paediatric surgical wards located in university hospitals in Finland. The response rate was 99%. Factor analysis was used to analyse the data. According to the results, five promoting factors (nurse's competence, versatile use of pain alleviation methods, workload/time, child's age/ability to cooperate, and parental participation), as well as five hindering factors (nurse's insecurity, beliefs regarding parental roles/child's ability to express pain, heavy workload/lack of time, limited use of pain alleviation methods, and work organizational model/patient turnover rate) were found to influence the nurses’ use of nonpharmacological methods. Almost all of the nurses (98%) hoped to make progress in their career and to learn different pain alleviation methods, but less than half of them (47%) agreed that they had obtained sufficient education regarding these methods. Demographic variables such as the nurse's age, education, and work experience were significantly related to certain factors influencing the use of nonpharmacological methods. In conclusion, paediatric patients’ surgical pain relief in the hospital was affected more by the nurses’ personal characteristics, than by work‐related factors or characteristics of the child or the child's parents. The nurses had positive attitudes towards learning different pain alleviation methods, which constitute the basis for the development of pain management in paediatric patients.
A holistic‐existential approach to health promotion
Authors: Berg Geir V. , Sarvimäki Anneli
Published: November 2003

Health promotion seems to be implicit in many nursing theories, but the theoretical and philosophical basis of health promotion in nursing is not always explicitly stated. The interpretation of health promotion is closely related to the interpretation of man, health, illness and nursing. There is a need to clarify, refine and redefine health promotion in nursing because the concept is partly nonspecific and has not been used to identify a distinctive nursing focus. The aim of this study was to formulate a stipulative definition of health promotive nursing with a holistic‐existential approach. A philosophical frame of reference in combination with conceptual analysis and theoretical synthesis were used as the methodological approach. The philosophical framework served as a basis in selecting the nursing theories and influenced the analysis. Two nursing theories and one nursing model were selected due to their influence on Norwegian nursing and because of their philosophical basis. Through analysis and synthesis of the selected nursing theories, the concepts man, health, illness/disease and nursing were analysed. The paper proposes a stipulative definition of health promotion in nursing based on a holistic‐existential approach, supported by five necessary conditions. The definition and conditions needs to be further investigated by both empirical studies and by comparing with other relevant nursing theories, in order to formulate theoretical statements. The proposed definition may be the first step in a process of developing a theoretical framework of health promotive nursing with a holistic‐existential approach.
Family members’ experiences of the quality of geriatric care
Authors: Isola Arja , Backman Kaisa , Voutilainen Päivi , Rautsiala Tarja
Published: November 2003

The quality of institutional geriatric care is a topical issue in Finland. The study to be described here is part of a Finnish project on the quality assessment and development of long‐term geriatric care provided by the City of Helsinki. The health care division of the City of Helsinki authorized an outside survey of long‐term geriatric care in the hospitals providing such care in 1998. Based on the results, recommendations concerning the development of geriatric care were issued. In the years 1999–2000, a further education programme was arranged for ward nurses, chief nurses and heads of profit centres concerning leadership in long‐term geriatric nursing. A re‐survey was conducted in 2001, using the same criteria of quality assessment. The purpose of this paper is to report on the quality of institutional geriatric nursing as evaluated by family members in 2001 and to compare the responses to those obtained in 1998. The results are presented as frequency and percentage distributions, means and medians and cross‐tabulations. The responding family members were generally content with the care of their elderly relatives: 92% said they were very satisfied or satisfied with the care, and the average of the marks given for geriatric care was 8.3 (range 4–10). Family members were more content now than in 1998, when the corresponding figures were 86% and 7.3 (range 4–10). Nevertheless, the results still highlight certain aspects that should be improved and developed.
Patients' perceptions of nursing care in the hospital setting
Authors: Schmidt Lee A.
Published: November 2003

Background.  Patient satisfaction and patient satisfaction with nursing care data are routinely collected as an indicator of the quality of services delivered. Despite the widespread collection and reporting of these data, the theoretical basis of patient satisfaction and patient satisfaction with nursing care remains unclear. Without a clear theoretical base, interpretation of patient satisfaction findings is hampered and the entire line of patient satisfaction research is of questionable validity. It has been suggested that, to understand patient satisfaction, patient perceptions of their care must first be understood.

Aim.  The aim of this study was to discover patients’ perceptions of the nursing care they receive in the hospital setting.

Method.  Grounded theory method was used in this study of eight medical–surgical patients recently discharged from an academic medical centre in the south‐eastern United States of America (USA). Participants were interviewed and the verbatim transcripts analysed using the constant comparative method.

Findings.  Four categories of patient perceptions of their nursing care emerged from the data. ‘Seeing the individual patient’ captures the unique nature of the nursing care experience for each patient. ‘Explaining’ represents the informal explanations given by nursing staff as they provide care. ‘Responding’ refers to both the character and timeliness of nursing staff's responses to patient requests or symptoms. ‘Watching over’ represents the surveillance activities of nursing staff.

Conclusions.  The categories identified in this study may be used in efforts to further develop a formal theory of patient satisfaction with nursing care. These categories should also be tested with patients possessing a wider range of characteristics, to assess the transferability of the findings.
How the health visitor can help when problems between parents add to postnatal stress
Authors: Simons John , Reynolds Jenny , Mannion Joe , Morison Linda
Published: November 2003

Background.  Caring for a baby can provoke or intensify discord between parents, with adverse effects on their own well‐being and their parenting.

Aim.  The aim of this study was to appraise evidence obtained from 450 mothers on the quality of the parents’ relationship during the postnatal period and the value of support provided by health visitors in cases of discord.

Design.  The health visitors were based at nine clinics in an outer London borough, and had been trained on a four‐day course (the Brief Encounters course) to screen mothers for relationship problems at the 6–8‐week check and to offer support (supportive listening, practical advice, referral) if problems were revealed. Data on relationship quality were obtained by a self‐report screening scale completed at the 6–8‐week check and again at the 12‐week visit for immunizations, when the scale was included in a self‐report questionnaire on help received from the health visitor. Intervention records kept by the health visitor showed what form any support had taken. Some 6 weeks later, 25 of the 82 mothers offered support, and their health visitors, were interviewed about their experience of the intervention.

Results.  One in five mothers were identified as having a relationship problem at the 6–8‐week check. Most were offered support. One in five of the 351 mothers who completed a questionnaire at the 12‐week visit reported receiving support in improving their relationship. The follow‐up interviews showed that most mothers valued this support. Responses to a questionnaire completed by health visitors showed that most were enthusiastic about its benefits.

Conclusions.  A four‐day training course for health visitors enabled them to screen for relationship problems during the postnatal period and to provide support when required in a way that was valued by mothers. Most health visitors were enthusiastic about the value of the intervention in improving their contribution to family welfare.
Translating clinical tools in nursing practice
Authors: Dunckley Maria , Hughes Rhidian , Addington‐Hall Julia M. , Higginson Irene J.
Published: November 2003

Background.  The widespread use of clinical tools in nursing practice reflects their usefulness in guiding patient care, evaluating treatment effectiveness and conducting audit. Cultural awareness and the provision of culturally competent care is a high priority for nurses in the United Kingdom (UK), given patterns of increasing ethnic diversity. However, meeting the individual needs of patients can be difficult when language barriers hinder communication. One way to address these difficulties is to translate existing clinical tools.

Aim.  The aim of this paper is to appraise the potential for, and limitations of, translating clinical tools for use in nursing practice.

Discussion.  Drawing on a range of studies from the disciplines of health and social science, this review describes and discusses some key considerations relevant to translating clinical tools in nursing. These considerations include the need to ensure cultural equivalence, lack of familiarity with clinical tool formats in some cultures and its impact on responses, and low literacy levels in some populations.

Conclusion.  Clinical tools provide benefits in identifying patients’ problems, guiding patient care, and evaluating treatments and interventions. Translating these tools can help to bridge the language gap that hinders good communication between nurses and patients. Translated clinical tools can be of acceptable cultural equivalence and validity if high quality translation methodologies are employed, together with an awareness of culturally relevant issues when interpreting the information gained from the tools.
Lymphoma complicating common variable immunodeficiency with granulomatous disease: report of two cases
Authors: Guern Véronique Le , Roux Geneviève Le , Martin Antoine , Feuillard Jean , Cohen Pascal , Poirel Hélène , Raphaël Martine , Guillevin Loïc , Mouthon Luc
Published: November 2003

Abstract: Common variable immunodeficiency (CVID) is a primary defect that is characterized by impaired antibody production. CVID patients may develop recurrent infections, autoimmune disorders and/or systemic granulomatosis. It is well documented that CVID patients are at risk to develop malignant lymphomas. However, to the best of our knowledge, lymphoma complicating the course of CVID associated with systemic granulomatosis has never been reported. We describe two CVID patients with systemic granulomatosis who developed B‐cell lymphomas, one related to Epstein–Barr virus infection, 5 and 12 yr after CVID had been diagnosed.
First case of immune‐mediated haemolytic anaemia associated to imatinib mesylate
Authors: Zago Novaretti Marcia C. , Fonseca Guilherme H. H. , Conchon Mônika , Dorlhiac‐Llacer Pedro Enrique , de Alencar Fischer Chamone Dalton
Published: November 2003

Abstract: Imatinib mesylate is a specific inhibitor of protein tyrosine kinase activity secondary to bcr‐abl, mostly indicated for the treatment of patients with Philadelphia chromosome positive chronic myeloid leukaemia (CML). Generally, the undesirable effects of imatinib administration observed in clinical trials were of mild‐to‐moderate degree, and no haemolysis has been associated with this drug. We report here a case of immune‐mediated haemolytic anaemia associated to imatinib mesylate successfully treated with prednisone in a patient with CML. Laboratory investigation showed anaemia [haemoglobin (Hb) of 59 g/L], reticulocyte of 61 × 109/L and a positive direct antiglobulin test. Anti‐drug in vitro studies revealed a positive result with gel microcolumn assay by an adsorption mechanism. Seventy‐four days after prednisone therapy, the patient's Hb level was of 110 g/L with negative direct antiglobulin test and drug in vitro studies. This case demonstrated that patients treated with imatinib mesylate can present immune‐mediated haemolysis and adequate management of this event can be done maintaining the drug and associating corticosteroids.
Necrotising dermatitis in refractory acute myeloid leukaemia
Authors: D'Apollo N. , Saviola A. , Longo G. , Luppi M. , Emilia G. , Torelli G.
Published: November 2003

Abstract: Severe cutaneous infections in leukaemic patients are difficult to treat and can rapidly become fatal. We report on a case of essential thrombocythemia evolved to a myelodysplastic syndrome and finally, to an overt myeloid leukaemia, refractory to chemotherapy. In the presence of a marked neutropenia, the patients developed a wide Staphylococcus epidermidis necrotising dermatitis. The diagnosis was made possible only by a skin biopsy culture and the antibiotic treatment, based on antimicrobial susceptibility tests, rapidly resolved the infection. In neutropenic patients, appropriate laboratory tests and treatment, can lead to recovery of life‐threatening infections.
Spontaneous evolution of essential thrombocythaemia into acute megakaryoblastic leukaemia with trisomy 8, trisomy 21 and cutaneous involvement
Authors: Paolini Rossella , Bonaldi Laura , Bianchini Enzo , Ramazzina Emilio , Cella Giuseppe
Published: November 2003

Abstract: Spontaneous transformation of essential thrombocythaemia (ET) into acute leukaemia is rare. We describe a case of ET that spontaneously transformed after 19 yrs uneventful follow‐up into acute megakaryoblastic leukaemia. Cytogenetic analysis of bone marrow nucleated cells showed trisomy 8 and trisomy 21 at time of leukaemic transformation supporting the hypothesis that chromosomal abnormalities are part of the mechanism that drives the leukaemic progression independently of drug cytotoxicity. In addition, the very rare and intriguing finding of M7 FAB subtype evolution of ET was complicated by cutaneous involvement in the leukaemic process.
The lipocalin 24p3, which is an essential molecule in IL‐3 withdrawal‐induced apoptosis, is not involved in the G‐CSF withdrawal‐induced apoptosis
Authors: Kamezaki Kenjirou , Shimoda Kazuya , Numata Akihiko , Aoki Kenichi , Kato Kouji , Takase Ken , Nakajima Hideaki , Ihara Kenji , Haro Takashi , Ishikawa Fumihiko , Imamura Rie , Miyamoto Toshihiro , Nagafuji Koji , Hisashi Gondo  , Hara Toshiro , Harada Mine
Published: November 2003

Abstract: Many hematopoietic cells undergo apoptosis when deprived of specific cytokines. Lipocalin 24p3, reported to be induced in hematopoietic cells by interleukin 3 (IL‐3) depletion, induces hematopoietic cell apoptosis despite the presence of IL‐3. As granulocyte colony stimulating factor (G‐CSF) depletion also induces the apoptosis of G‐CSF‐dependent cell line cells, we examined the effect of 24p3 on the apoptotic function induced by G‐CSF depletion. 24p3 was induced by the depletion of IL‐3, but not G‐CSF, in cytokine‐dependent cell lines. Although 24p3 suppressed growth induced by IL‐3, it did not influence G‐CSF‐dependent cell growth. These observations show that 24p3 is not involved in the G‐CSF withdrawal‐induced apoptosis, although it is essential in IL‐3 withdrawal‐induced apoptosis.
Effect of interleukin‐15 on anti‐CD3/anti‐CD28 induced apoptosis of umbilical cord blood CD4+ T cells
Authors: Lin Syh‐Jae , Yu Jung‐Chuan , Cheng Po‐Jen , Hsiao Shiu‐Shan , Kuo Ming‐Ling
Published: November 2003

Abstract: Objectives: Interleukin‐15 (IL‐15) has potential therapeutic advantage for patients receiving umbilical cord blood (CB) transplantation. The present study aims to examine the ability of IL‐15 to modulate the survival, maturation, and function of anti‐CD3/anti‐CD28 stimulated CB CD4+ T cells, in comparison with responses from adult peripheral blood (APB) CD4+ T cells.

Methods: Enriched CB and APB CD4+ T cells were stimulated with anti‐CD3 and anti‐CD28 (anti‐CD3/anti‐CD28) in the presence or absence of IL‐15 (10 ng/mL) for 5 d. The percentages of apoptotic cells were assessed by propidium iodide/annexin‐V flow cytometric staining. T‐cell activation was analyzed with the expression of surface markers (CD45RO/CD69/CD25). Interferon‐γ (IFN‐γ) and tumor necrosis factor‐α (TNF‐α) production in culture supernatant was determined by enzyme‐linked immunosorbent assay.

Results: CB CD4+ T cells had a higher survival and lower apoptotic response following anti‐CD3/anti‐CD28 stimulation, compared with APB CD4+ T cells. IL‐15 enhanced apoptosis and promoted CD45RO conversion of anti‐CD3/anti‐CD28 activated CB CD4+ T cells, an effect not observed with APB CD4+ T cells. Although activated CB CD4+ T cells expressed comparable level of CD69/CD25 expression to adults, IFN‐γ production of activated CB CD4+ T cells was markedly deficient compared with that of corresponding APB CD4+ T cells. Exogenous IL‐15 further enhanced the production of IFN‐γ, but not TNF‐α, of activated CB CD4+ T cells.

Conclusions: IL‐15 preferentially resulted in an activation‐enhancing effect on CB CD4+ T cells, accompanied by increased apoptosis. Our finding may have therapeutic implications while designing IL‐15 immunotherapy for patients receiving CB transplant.
Flavones inhibit proliferation and increase mediator content in human leukemic mast cells (HMC‐1)
Authors: Alexandrakis Michael , Letourneau Richard , Kempuraj Durajisamy , Grzybowska Kristiana Kandere , Huang Man , Christodoulou Spyridon , Boucher William , Seretakis Dimitris , Theoharides Theoharis C.
Published: November 2003

Abstract: Objective: Mast cells are involved in allergic and inflammatory reactions. These cells are also increased in the bone marrow, skin, and other organs in systemic mastocytosis. Flavonoids are naturally occurring molecules with antioxidant, cytoprotective, and anti‐inflammatory activities. Some flavonoids, like quercetin, inhibit the growth of certain malignant cells in culture. Quercetin also inhibits histamine release and induces accumulation of secretory granules in rat basophilic leukemia cells.

Method: We investigated the effect of five flavonoids: flavone, kaempferol, morin, myricetin, and quercetin at 1, 10, and 100 μm on proliferation and secretory mediator content (β‐hexosaminidase, histamine, and tryptase) in human leukemic mast cells (HMC‐1), the doubling time of which was about 2 d.

Results: Flavone and kaempferol at 100 μm inhibited cell proliferation over 80% on either day 3, 4, or 5 of culture. Quercetin showed this level of inhibition only on day 5, myricetin inhibited by 50% at days 3–5, whereas morin's inhibition was <20%. All flavonoids (except morin) at 100 μm increased histamine and tryptase content, but not β‐hexosaminidase, equally at days 3 and 4 of culture quercetin also increased the development of secretory granules.

Conclusion: These results indicate that certain flavonoids can inhibit HMC‐1 proliferation, induce secretory granule development and the accumulation of mediators.
Methods for Rapidly Measuring the Lodging Resistance of Wheat Cultivars
Authors: Berry P. M. , Spink J. , Sterling M. , Pickett A. A.
Published: November 2003

Lodging resistance ratings for winter wheat cultivars are frequently based upon observations of lodging. This is an unreliable method because of the frequent occurrence of years without significant lodging events. It also does not distinguish between stem and root lodging resistance. This paper describes the development and testing of instrumentation and procedures for two field‐based methods to rapidly assess stem and root lodging resistance. Both methods used a specifically designed instrument for measuring the resistance of shoots against rotational displacement. Stem lodging resistance was assessed when the soil was dry and strong, whereas resistance to root lodging was assessed after the soil had been weakened by irrigation. Tests were carried out on 14 winter wheat cultivars grown at two sites in the UK during 2002. Both methods were able to detect statistically significant differences between the cultivars for their resistance to stem and root lodging. A comparison of these results with observations of lodging in the field showed that the methods accounted for about 60 and 50 % of the stem and root lodging respectively.
Possible Residual Effects of Gibberellic Acid and Gibberellin Biosynthesis Inhibitors on Sprouting, Early Bulbil Formation and Tuber Yield in Chinese Yam
Authors: Kim S. K. , Lee S. C. , Kim K. M. , Lee B. H. , Lee I. J.
Published: November 2003

The residual effect of gibberellic acid (GA) and plant growth retardants [mepiquat chloride (MC) and trinexapac‐ethyl (TNE)], on Chinese yam plants was examined. Bulbil formation in MC and TNE‐treated tubers was earlier than that of the control and GA treatment. Bulbils in GA‐treated tubers increased the ratio of bulbil size (>4 mm) compared with the control. The highest GA treatment was fivefold more increased than that of the control. Bulbil yield per hectare was significantly increased by the elevated GA application compared with the control. The more MC concentration was elevated the more the ratio of bulbil size (>4 mm) increased. Bulbil yield was highest in the MC concentration (400 p.p.m.). The more TNE concentration was elevated the more the ratio of bulbil size (>4 mm) increased. Similar to MC treatment, TNE treatment showed the effect of bulbil enlargement in all the concentrations. This suggests that MC is the most effective growth retardant to induce bulbil enlargement and formation, and to increase bulbil and tuber yield in Chinese yams.
Exchange Rate Exposure at the Firm and Industry Level
Authors: Doukas John A. , Hall Patricia H. , Lang Larry H. P.
Published: November 2003

Previous work on the exposure of firms to exchange rate risk has primarily focused on U.S. firms and, surprisingly, found stock returns were not significantly affected by exchange‐rate fluctuations. The equity market premium for exposure to currency risk was also found to be insignificant. In this paper we examine the relation between Japanese stock returns and unanticipated exchange‐rate changes for 1,079 firms traded on the Tokyo stock exchange over the 1975–1995 period. Second, we investigate whether exchange‐rate risk is priced in the Japanese equity market using both unconditional and conditional multifactor asset pricing testing procedures. We find a significant relation between contemporaneous stock returns and unanticipated yen fluctuations. The exposure effect on multinationals and high‐exporting firms, however, is found to be greater in comparison to low‐exporting and domestic firms. Lagged‐exchange rate changes on firm value are found to be statistically insignificant implying that investors are able to assess the impact of exchange‐rate changes on firm value with no significant delay. The industry level analysis corroborates the cross‐sectional findings for Japanese firms in that they are sensitive to contemporaneous unexpected exchange‐rate fluctuations. The co‐movement between stock returns and changes in the foreign value of the yen is found to be positively associated with the degree of the firm's foreign economic involvement and inversely related to its size and debt to asset ratio. Asset pricing tests show that currency risk is priced. We find corroborating evidence in support of the view that currency exposure is time varying. Our results indicate that the foreign exchange‐rate risk premium is a significant component of Japanese stock returns. The combined evidence from the currency exposure and asset pricing analyses, suggests that currency risk is priced and, therefoe, has implications for corporate and portfolio managers.
What Explains the Bid‐Ask Spread Decline after Nasdaq Reforms?
Authors: He Yan , Wu Chunchi
Published: November 2003

This paper examines whether the decrease in bid‐ask spreads on Nasdaq after the 1997 reforms is due to a decrease in market‐making costs and/or an increase in market competition for order flows. Unlike previous studies, we jointly examine how competition and trading costs affect bid‐ask spreads. In addition, we separate the effects of informed trading and liquidity costs on bid‐ask spreads. Informed trading cost is directly estimated for each Nasdaq stock using a Bayesian theoretic model. Empirical results show that market‐making costs and competition significantly affect bid‐ask spreads. The post‐reform decrease in bid‐ask spreads is largely due to both an increase in competition and a decrease in informed trading and liquidity costs on Nasdaq.
A Monitoring Role for Deviations from Absolute Priority in Bankruptcy Resolution
Authors: Layish Dina Naples
Published: November 2003

Firms that have successfully reorganized under Chapter 11 of the bankruptcy laws of the United States frequently award shares of common stock in the reorganized firm to pre‐bankruptcy shareholders, even though pre‐bankruptcy creditors’ claims are not fully satisfied. Using a sample of large publicly traded firms, these deviations from absolute priority (DAPR) are found to be positively related to the severity of agency costs within a financially distressed firm. US bankruptcy laws may exacerbate these agency costs by granting exclusivity to management during the reorganization period. Firms in which outside shareholders are more concentrated have a lower occurrence of DAPR indicating that blockholders provide an effective monitoring mechanism for controlling managerial behavior during reorganization. On the other hand, firms without this monitoring mechanism have a higher probability of DAPR indicating that creditors attempt to control managerial behavior by providing them with some sort of financial compensation via their equity holding in the firm. Finally, the evidence indicates that DAPR can be used to mitigate the hold‐up problem resulting from voting rights granted to both junior and senior claimants of the firm by US bankruptcy laws.
Effects of perchlorate on myofibrillar calcium sensitivity in rat skinned skeletal muscles
Authors: KHAMMARI A. , BAUDET S. , NOIREAUD J.
Published: November 2003

The effects of perchlorate (1–20 mm) on myofibrillar calcium responsiveness have been tested in Triton X‐100‐skinned fibre bundles from rat soleus (slow‐twitch) and extensor digitorum longus (fast‐twitch) skeletal muscles. In extensor digitorum longus and soleus, perchlorate dose‐dependently shifted the pCa (‐log[Ca2+])/tension relationship towards lower free calcium concentration (sensitizing effect) and maximal tension was unchanged. The degree of sensitization was greater in extensor digitorum longus than in soleus bundles. Reversibility after exposure to 12 mm perchlorate was complete in soleus but not in extensor digitorum longus muscles. In fact, the ‘return’ pCa/tension relationship in extensor digitorum longus was shifted to higher free calcium concentration (desensitizing effect) compared with control. Perchlorate (12 mm) also enhanced myofibrillar calcium responsiveness of frog semitendinosus skinned skeletal fibres. Assuming a passive distribution of perchlorate across the sarcolemma, this sensitizing effect is probably not involved in perchlorate‐induced potentiation of contractile responses of intact muscles and thereby supports the specificity of perchlorate as an agonist of the excitation/calcium release sequence in skeletal muscle fibres.
K+ balance in humans during exercise
Authors: HALLÉN J.
Published: November 2003

Onset of exercise leads to a sudden increase in [K+] in venous plasma from the exercising muscles. Delayed by about 10 s, the arterial [K+] rises nearly at the same rate as the venous concentration. At exercise intensities below 100% of Vo2 max, both venous and arterial [K+] stabilize at a steady‐state value. At higher intensities, venous and arterial plasma [K+] continue to rise until exhaustion. During the first 5 min of exercise the contracting muscles always lose K+, with a peak in loss rate after 1–2 min. During steady state, the loss rate is minimized or may even be reduced to zero. The loss is caused by an exercise‐induced efflux of K+ from the contracting cells which exceeds the exercise‐induced influx mediated by the Na, K pump. The Na, K pump is stimulated by catecholamines in vitro and in resting tissue in vivo. However, the loss rate of K+ from steady‐state exercising muscles does not show any increase during β‐adrenergic blockade or decrease during β‐adrenergic stimulation. This is probably due to a compensatory change in intracellular [Na+]. During low exercise intensity, arterial [K+] does not increase after 1–2 min, while the exercising muscles lose K+, showing that the extracellular pool of K+ is redistributed. During β‐adrenergic blockade this redistribution is impaired so that the rise in plasma [K+] is accentuated. Conversely α‐adrenergic blockade reduces the exercise‐induced hyperkalaemia. Hence, the adrenergic system plays an important role in regulation of whole‐body K+ balance during exercise, but its significance in exercising muscles is not clear.
Sodium channel slow inactivation and the distribution of sodium channels on skeletal muscle fibres enable the performance properties of different skeletal muscle fibre types
Authors: RUFF R. L.
Published: November 2003

Na+ currents (INa) and membrane capacitance were studied with the loose patch voltage clamp technique and action potential properties were studied with a two‐electrode voltage clamp on the end‐plate, at the end‐plate border and on extrajunctional membrane of skeletal muscle fibres. Slow inactivation regulates the available INa and is operative at the resting potential of both rat and human fibres. At the resting potential, slow inactivation causes a greater reduction in INa in fast‐ than in slow‐twitch fibres. The relative resistance of slow‐twitch fibres to slow inactivation may enable slow‐twitch fibres to remain tonically active. Na+ channel inactivation may provide a peripheral mechanism that limits the duration that fast‐twitch fibres can fire at high rates to prevent injury associated with prolonged high‐frequency contraction. Consequently, slow inactivation may enable fast‐twitch fibres to operate phasically at high rates or slow‐twitch fibres to fire continuously at lower rates. For both fast‐ and slow‐twitch fibres, INa normalized to membrane area was greatest on the end‐plate, intermediate on the end‐plate border and smallest on extrajunctional membrane. When normalized to membrane capacitance, INa was the same on the end‐plate and the end‐plate border and smallest on extrajunctional membrane. For a given membrane region, INa was larger on fast‐ than on slow‐twitch fibres. The higher density of Na+ channels near the end‐plate increased the safety factor for neuromuscular transmission by lowering the action potential threshold and increasing the action potential rate of rise at the end‐plate.
High‐ and low‐frequency fatigue revisited
Authors: JONES D. A.
Published: November 2003

Changes in excitation–contraction coupling have long been recognized as possible causes of the failure in function which occurs in fatigued muscle. High‐frequency fatigue is characterized by an excessive loss of force at high frequencies of stimulation and rapid recovery when the frequency is reduced. Frequencies in excess of 50 Hz are rarely seen with voluntary activation of human muscle, and for this reason there has been some doubt as to whether high‐frequency fatigue is a significant feature of normal activity. Recent experiments have shown that with 30 Hz stimulation there is a more rapid loss of force if the muscle is held isometric in a shortened position, and the fatigue is rapidly reversed if the muscle is re‐extended, even under ischaemic conditions. These findings are consistent with the accumulation of K+ in the t‐tubules and interfibre spaces of the muscle. Low‐frequency fatigue is characterized by a relative loss of force at low frequencies of stimulation and a slow recovery over the course of hours or even days. There is evidence from intracellular measurements that low‐frequency fatigue is due to a reduction in Ca2+ release. However, there is a possibility that in the fatiguing exercise, the end sarcomeres of the fibre overextend and damage those in the middle section of the fibre. In this situation the active sarcomeres would be working at a shorter length than predicted from the overall fibre length and the force–frequency curve will be shifted to the right. Measurements of the length–tension relationship of muscles damaged by stretching are consistent with this happening.
Ion channels in the sarcoplasmic reticulum of striated muscle
Authors: DULHUNTY A. F. , JUNANKAR P. R. , EAGER K. R. , AHERN G. P. , LAVE D. R.
Published: November 2003

This review provides a summary of current concepts about the structure and single‐channel properties of ryanodine receptor calcium release channels and counter ion channels that facilitate Ca2+ release and reuptake by the sarcoplasmic reticulum. Some recent results, obtained with single ryanodine receptor ion channels incorporated into lipid bilayers from terminal cisternae vesicles of rabbit skeletal muscle and sheep ventricular myocardium, are described. The ryanodine receptor is the major Ca2+ release channel in skeletal and cardiac muscle and has been studied in far greater detail than other sarcoplasmic reticulum ion channel proteins. Several ryanodine receptor genes have been cloned and sequenced, and isoforms of the protein have been detected in muscle and in endoplasmic reticulum of brain and many other tissues from mammals, lower vertebrates, nematodes and drosophila. The proteins from all species are tetramers of a peptide with a molecular mass of ≈560 kDa, containing ≈5000 amino acids, with a similar maximum single‐channel conductance of 500–800 pS for monovalent cations at 250 mm. Results presented here include: Ca2+ activation and adaptation of activity in skeletal ryanodine receptors with rapid changes in [Ca2+] controlled by perfusion; activation by FK506 and regulation of cooperative gating of skeletal ryanodine receptor channel activity by FK506‐binding proteins; activation and block of cardiac ryanodine receptors by addition of reactive disulphides and by bilayer voltage. Effects of phosphorylation, calmodulin, triadin, calsequestrin and interactions with the α1 subunit of the dihydropyridine receptor on ryanodine receptor activity are summarized. Potassium and chloride channels in skeletal muscle sarcoplasmic reticulum, are described.