bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure and function of primitive immunoglobulin superfamily neural cell adhesion molecules: a lesson from studies on planarian
Authors: Fusaoka Eri , Inoue Takeshi , Mineta Katsuhiko , Agata Kiyokazu , Takeuchi Kosei
Published: April 2006

Precise wiring and proper remodeling of the neural network are essential for its normal function. The freshwater planarian is an attractive animal in which to study the formation and maintenance of the neural network due to its high regenerative capability and developmental plasticity. Although a recent study revealed that homologs of netrin and its receptors are required for regeneration and maintenance of the planarian central nervous system (CNS), the roles of cell adhesion in the formation and maintenance of the planarian neural network remain poorly understood. In the present study, we found primitive immunoglobulin superfamily cell adhesion molecules (IgCAMs) in a planarian that are homologous to vertebrate neural IgCAMs. We identified planarian orthologs of NCAM, L1CAM, contactin and DSCAM, and designated them DjCAM, DjLCAM, DjCTCAM and DjDSCAM, respectively. We further confirmed that they function as cell adhesion molecules using cell aggregation assays. DjCAM and DjDSCAM were found to be differentially expressed in the CNS. Functional analyses using RNA interference revealed that DjCAM is partly involved in axon formation, and that DjDSCAM plays crucial roles in neuronal cell migration, axon outgrowth, fasciculation and projection.
Atmospheric nitrogen deposition has caused nitrogen enrichment and eutrophication of lakes in the northern hemisphere
Authors: BERGSTRÖM ANN‐KRISTIN , JANSSON MATS
Published: April 2006

We compiled chemical data and phytoplankton biomass (PB) data (chlorophyll a) from unproductive lakes in 42 different regions in Europe and North America, and compared these data to inorganic nitrogen (N) deposition over these regions. We demonstrate that increased deposition of inorganic N over large areas of Europe and North America has caused elevated concentrations of inorganic N in lakes. In addition, the unproductive lakes in high N deposition areas had clearly higher PB relative to the total phosphorus (P) concentrations illustrating that the elevated inorganic N concentrations has resulted in eutrophication and increased biomass of phytoplankton. The eutrophication caused by inorganic N deposition indicates that PB yield in a majority of lakes in the northern hemisphere is (was) limited by N in their natural state. We, therefore, suggest that P limitation largely concerns lakes where the balance between N and P has been changed because of increased anthropogenic input of N.
Soil carbon balance in a clonal Eucalyptus plantation in Congo: effects of logging on carbon inputs and soil CO2 efflux
Authors: EPRON DANIEL , NOUVELLON YANN , DELEPORTE PHILIPPE , IFO SUSPENS , KAZOTTI GUY , THONGO M'BOU ARMEL , MOUVONDY WELCOME , ANDRE LAURENT SAINT , ROUPSARD OLIVIER , JOURDAN CHRISTOPHE , HAMEL OLIVIER
Published: April 2006

Soil CO2 efflux was measured in clear‐cut and intact plots in order to quantify the impact of harvest on soil respiration in an intensively managed Eucalyptus plantation, and to evaluate the increase in heterotrophic component of soil respiration because of the decomposition of harvest residues. Soil CO2 effluxes showed a pronounced seasonal trend, which was well related to the pattern of precipitation and soil water content and were always significantly lower in the clear‐cut plots than in the intact plots. On an annual basis, soil respiration represented 1.57 and 0.91 kgC m−2 yr−1 in intact and clear‐cut plots, respectively. During the first year following harvest, residues have lost 0.79 kgC m−2 yr−1. Our estimate of heterotrophic respiration was calculated assuming that it was similar to soil respiration in the clear‐cut area except that the decomposition of residues did not occur, and it was further corrected for differences in soil water content between intact and clear‐cut plots and for the cessation of leaf and fine root turnover in clear cut. Heterotrophic respiration in clear‐cut plots was estimated at 1.18 kgC m−2 yr−1 whereas it was only 0.65 kgC m−2 yr−1 in intact plots (41% of soil respiration). Assumptions and uncertainties with these calculations are discussed.
Effect of mineral trioxide aggregate on proliferation of cultured human dental pulp cells
Authors: Takita T. , Hayashi M. , Takeichi O. , Ogiso B. , Suzuki N. , Otsuka K. , Ito K.
Published: April 2006

Aim  To investigate the effect of mineral trioxide aggregate (MTA) on the proliferation of human dental pulp (HDP) cells ex‐vivo.

Methodology  Human dental pulp cells were cultured with MTA or calcium hydroxide‐containing cement (Dycal) using culture plate inserts. Control cells were cultured with culture plate inserts only. Cell proliferation was measured for up to 14 days using a Cell Counting kit, and the concentration of calcium ions released from the tested materials was assessed using a Calcium E‐test kit. To confirm that the effect of MTA was attributable to released calcium ions, cell proliferation was measured in the presence of exogenous calcium chloride as a source of calcium ions while in the absence of MTA.

Results  Mineral trioxide aggregate significantly stimulated cell proliferation after 12 days, whereas Dycal had no such effect. The number of calcium ions released from MTA was significantly higher than that released from Dycal. Following the addition of calcium chloride, cell proliferation increased in a dose‐dependent manner after 12 days. Moreover, cell proliferation showed a similar pattern whether a given concentration of calcium ions was produced by calcium chloride or by release from MTA.

Conclusions  In this ex‐vivo study, the elution components such as calcium ions from MTA had higher proliferation ability of HDP cells than control and Dycal.
Mandibular first and second molar tooth transposition: a case report
Authors: GRANT J. E. R. , ABU MEZIER N. , DIBIASE A. T.
Published: April 2006

Summary.  A case is reported of what appears to be a transposition affecting the mandibular first, second, and third molars. The possible aetiology is discussed in relation to previously published studies. In the case described the primary actilogical factor appears to intraosseous migration of the developing tooth germ.
Hurler's syndrome: dental findings in a case treated with bone marrow transplantation in infancy
Authors: HINGSTON E. J. , HUNTER M. L. , HUNTER B. , DRAGE N.
Published: April 2006

Summary. Hurler's syndrome, also known as mucopolysaccharidosis I (MPS I‐H), is a rare condition inherited as an autosomal recessive trait. It is caused by a deficiency in alpha‐l‐iduronidase, an enzyme that participates in the degradation of the glycosaminoglycans (GAGs) heparin sulphate and dermatan sulphate. Children with Hurler's syndrome appear nearly normal at birth but, left untreated, show a progressive mental and physical deterioration caused by a build‐up of GAGs in all organs of the body. Death is often caused by cardiac or respiratory failure and usually occurs before the second decade of life.

 In recent years, bone marrow transplantation (BMT) has been employed in the management of patients with Hurler's syndrome. However, the dental findings observed in these cases have not previously been reported in the dental literature. Here we report a patient aged 11 years and 6 months, presented to a Specialist Paediatric Dentistry Unit, who was successfully treated by BMT at 18 months of age.
Total antioxidant levels of saliva in children related to caries, age, and gender
Authors: TULUNOGLU Ö. , DEMIRTAS S. , TULUNOGLU I.
Published: April 2006

Summary.   Aim.  The purpose of this study was to evaluate the relationship between the physicochemical properties of saliva such as flow rate, buffering capacity, pH, calcium level, total protein, total antioxidant status, and dental caries, age, and gender.

Material and methods.  The antioxidant activity of saliva was investigated in 80 healthy children aged 7–15 years. They were divided into subgroups according to gender, age (7–10 years and 11–15 years), and caries activity (caries active = CA and caries free = CF). Unstimulated saliva samples were collected from all groups. Flow rates were determined, and samples analysed for pH, buffer capacity, calcium, total proteins, and total antioxidant status. Salivary total antioxidant activity (TAA) was estimated by an adaptation of the ABTS (2,2‐azino‐di (3‐ethylbenzthiazoline‐6‐sulphonate)) assay.

Results.  The results indicated that in general, although there was no linear association between salivary flow rate pH and buffering capacity values obtained from different groups, salivary calcium concentration values were found to be higher in caries free groups. Total protein and total antioxidant values were higher in caries active groups except those in the 11‐ to 15‐year‐old girls group.

Conclusion.  In general, total protein and total antioxidant insaliva were increased with caries activity. Calcium concentrations in saliva were higher in caries‐free children. In addition, calcium concentration increased with age. Thus, it can be concluded that a linear association exists between calcium concentration age and caries activity. More clinical and laboratory studies are needed to determine the exact relationship between the physicochemical properties of saliva such as flow rate, buffering capacity, pH, calcium level, total protein, total antioxidant status, and dental caries, age, and gender.
Knowledge levels of Korean intensive care nurses towards brain death and organ transplantation
Authors: Kim Jung Ran , Fisher Murray , Elliott Doug
Published: April 2006

Aims and objectives.  To develop and examine the reliability and validity of an instrument assessing knowledge levels of Korean intensive care unit nurses. To conduct a survey with Korean ICU nurses.

Background.  Organ donation from brain dead patients is a contentious issue in Korea following recent legal recognition of brain death, given the context of a Confucian belief system. Implementation of the new Organ Transplant Act has highlighted the importance of identifying Korean intensive care unit nurses’ knowledge regarding brain death and organ donation.

Design.  Multi‐stage multi‐method development of an original instrument with a cross‐sectional analysis survey of participants.

Method.  An 18‐item instrument was developed based on previous literature and key informant interviews, and validated by an expert panel and a pilot study. A survey was conducted with Korean intensive care unit nurses (n = 520). Principal component analysis with varimax rotation was used to determine construct validity. Item‐to‐total correlations and Cronbach's coefficient alpha were used to determine the scale's internal consistency.

Results.  Principal component analysis yielded a two‐component structure: Diagnostic testing and Co‐morbid factors of brain death. The scale demonstrated acceptable internal consistency for the two components (α = 0·74, 0·64, respectively). Most of the participants had a sound knowledge of diagnostic testing for brain death, but demonstrated a lack of knowledge regarding co‐morbid factors of brain dead patients.

Conclusions.  The knowledge scale was reliable and valid for this cohort. Further research is warranted in related areas of nursing practice.

Relevance to clinical practice.  Effective education for intensive care unit nurses is necessary to increase the organ donor pool in Korea.
Does access to bed‐chair pressure sensors reduce physical restraint use in the rehabilitative care setting?
Authors: Kwok Timothy , Mok Francis , Chien Wai Tong , Tam Eric
Published: April 2006

Background.  The common use of physical restraints in older people in hospitals and nursing homes has been associated with injurious falls, decreased mobility and disorientation. By offering access to bed‐chair pressure sensors in hospitalized patients with perceived fall risk, nurses may be less inclined to resort to physical restraints, thereby improving clinical outcomes.

Aims and objectives.  To investigate whether the access of bed‐chair pressure sensors reduces physical restraint use in geriatric rehabilitation wards.

Design.  Randomized controlled trial.

Methods.  Consecutively, patients admitted to two geriatric wards specialized in stroke rehabilitation in a convalescent hospital in Hong Kong, and who were perceived by nurses to be at risk of falls were randomly assigned to intervention and control groups. For the intervention group subjects, nurses were given access to bed‐chair pressure sensors. These sensors were not available to control group subjects, as in usual practice. The trial continued until discharge. The primary outcomes were the proportion of subjects restrained by trunk restraint, bedrails or chair‐board and the proportion of trial days in which each type of physical restraint was applied. The secondary outcomes were the proportions of those who improved in the mobility and transfer domains of modified Barthel index on discharge and of those who fell.

Results.  One hundred and eighty subjects were randomized. Fifty (55·6%) out of the 90 intervention group subjects received the intervention. There was no significant difference between the intervention and control groups in the proportions and duration of having the three types of physical restraints. There was also no group difference in the chance of improving in mobility and transfer ability, and of having a fall.

Conclusion.  Access to bed‐chair pressure sensor device neither reduced the use of physical restraints nor improved the clinical outcomes of older patients with perceived fall risk.

Relevance to clinical practice.  The provision of bed‐chair pressure sensors may only be effective in reducing physical restraints when it is combined with an organized physical restraint reduction programme.
Governing time in operating rooms
Authors: Riley Robin , Manias Elizabeth
Published: April 2006

Aim. This paper examines how time is controlled and governed in operating rooms through interpersonal communication between nurses and doctors.

Background. Time is a valuable commodity in organizations with improvements often directed towards maximizing efficiencies. As a consequence, time can be a source of tension and interpersonal conflict as individuals compete for control of its use.

Methods. The data in this paper emanate from an ethnographic study that explored a range of communication practices in operating room nursing. Participants comprised 11 operating room nurses. Data were collected over two years in three different institutional settings and involved participant observation, interviews and the keeping of a personal diary. A deconstructive analysis of the data was undertaken.

Results. Results are discussed in terms of the practices, in which clinicians are engaged in, to govern and control their use of time. The four practices presented in this paper include; questioning judgment and timing, controlling speed, estimating surgeons’ use of time and coping with different perceptions of time.

Conclusions. Time and speed were hotly contested by nurses. They used their personal knowledge of individual surgeon's habits of time to govern and control practice. Nurses thought about surgeons in terms of time and developed commonly accepted understandings about the length of surgical procedures. They used this knowledge to manage the scheduling of operations in the departments and to control the workflow in individual operating rooms. Knowledge of individual surgeons was a source of power for operating room nurses.

Relevance to clinical practice. Nurses have more power in the operating room than might be imagined but they exercise this power in subtle ways. If operating rooms are to work effectively, the operating room team must understand each others' work better.
Translating person‐centred care: a case study of preceptor nurses and their teaching practices in acute care areas
Authors: McCarthy Bridie
Published: April 2006

Aims and objectives.  The research aims to explore how preceptors interpret, operationalize, document and teach person‐centred care as they guide students within an acute surgical environment.

Background.  Person‐centred care is a term that is widely used in the nursing literature; however, its interpretation in nursing practice remains virtually unexplored. This is of great significance to nurses in general but to Irish nurses in particular on whom this study is focused. As preceptor nurses have been identified as key people in the education of clinical students, it was considered important to explore how clinical preceptors promote person‐centred care to current undergraduate nursing students.

Design and method.  Using a case study design and a qualitative approach, six preceptors were chosen to participate in this study. Data were collected by means of participant observation, review of nursing care records and semi‐structured interviews. Data were analysed in two stages. The first stage involved the identification of themes. In the second stage data were analysed using a number of propositions to examine and explain what was gleaned from the data in the context of what was originally identified in the literature.

Results.  Findings highlighted that preceptors had a limited conception of person‐centred care. Measures of care reflected the medical model of nursing. Beyond that, preceptors expressed care in terms of good manners or respectful etiquette. Preceptors also had limited appreciation of what learning entails and were sceptical about classroom theory other than what they considered essential for safe practice.

Conclusions.  This study highlights that preceptors need both internal and external support to implement the changes advocated by the Commission in Nursing in 1998, the Nursing Education Forum in 2000, the Department of Health and Children in 2001 and An Bord Altranais in 2003.

Relevance to clinical practice.  Person‐centred care is a relatively new concept in nursing and recommended for practice. Preceptors need facilitation with its implementation. In an effort to promote changes in the delivery of health care, it is suggested that university‐based lecturers empower students to practice evidence‐based nursing as students and subsequently as qualified nurses.
The use of placebo in clinical nursing research
Authors: Chan Carmen WH , Thompson David R
Published: April 2006

Aims.  This paper reviews placebo and placebo effects and their measurement and application to nursing. Ethical and methodological issues are also discussed. Implications for nursing and recommendations for future study are offered.

Background.  Placebos have been used for decades in clinical trials but discussion about conceptual, methodological and ethical issues has been comparatively scarce.

Conclusion.  It is concluded that true placebo effects are difficult to measure and control and the use of credible placebo is sometimes impractical in clinical nursing research. This leads to the increased use of usual care as a control by researchers. However, more information should be reported in studies that use this approach, including the specification of usual care, its monitoring and patient adherence.

Relevance to clinical practice.  Where its use is considered ethical, safe and feasible, a placebo arm should be included in studies of efficacy to distinguish between active and inactive treatment.
An exploration of factors which constrain nurses from research participation
Authors: Roxburgh Michelle
Published: April 2006

Aim. The aim of this study was to explore practising nurses’ views on factors which they perceived constrained them from research participation.

Background. Many studies reviewed in the literature have taken a quantitative approach and have concentrated on why nurses do not use research findings in their practice. Of these studies a few included constraints to research use. However, with the development of national research strategies for nursing and the drive for the profession to develop its own research base, there is a need to understand what constrains clinically practising nurses from taking up opportunities to either develop their own research or participate in research studies.

Design and method. Data were collected during June and July 2004 by means of two focus groups (n = 7) followed by single interviews (n = 7). Analysis was undertaken using a thematic approach aided by N‐Vivo 2.0.

Results and discussion. In this study, findings revealed six key themes perceived by nurses to constrain from research participation: ‘Level of support nurses require to be research active’, ‘Nurses’ attitudes to undertaking/participating in research’, ‘The extent of nurses knowledge about research’, ‘Skills to undertake research’ and ‘Level of educational preparation relating to undertaking/participating in research’.

Conclusions. In this study, nurses were generally receptive to participating in research. However, they felt constrained because of lack of time, lack of peer support and limited knowledge and skills of the research process.

Relevance to clinical practice. What is already known on this topic: studies into nurses and research have predominantly taken a quantitative approach; many studies have aimed to elicit the extent of nurses’ use of research findings. What this study adds: this study adds a qualitative perspective; although findings are not generalizable, they support quantitative study findings into this subject; identifies constraints that require to be overcome for practising nurses to actively get involved in research studies.
Plasma ribavirin concentrations during treatment of recurrent hepatitis C with peginterferon α‐2b and ribavirin combination after liver transplantation
Authors: Dumortier J. , Ducos E. , Scoazec J.‐Y. , Chevallier P. , Boillot O. , Gagnieu M.‐C.
Published: April 2006

Summary.  After liver transplantation (LT) for hepatitis C virus (HCV)‐related cirrhosis, recurrence of HCV infection is universal. The efficacy of antiviral therapy in this indication is usually reduced because of its poor tolerability. We present herein the results of plasma measurement of ribavirin levels in transplanted patients when using increasing dosage of ribavirin, in comparison with a control cohort of nontransplanted patients. Seventeen control patients (nine women and eight men, median age 51.5 years) were compared with 12 liver transplant patients (2 women and 10 men, median age 55 years). In 76% of patients, HCV infection was genotype 1. All patients were treated by a combination of ribavirin and pegylated‐interferon α‐2b. A total of 54 blood samples were taken (1.8 per patient) for ribavirin level measurement. A virological response was obtained in 8/17 patients in the control group and in 6/12 LT patients. Ribavirin dose was lower in the LT group (8.79 vs 12.98 mg/kg/day), but plasma levels were the same in both groups (2.23 vs 2.43 mg/L for LT and non‐LT groups, respectively). This was probably related to impaired renal function in the LT group (serum creatinine: 112.6 vs 73.6 μmol/L). No discontinuation of ribavirin therapy was observed and haemoglobin level was the same in both groups (109.5 g/L in LT patients vs 119.5 g/L in the control group). These results strongly support the interest in plasma measurement of ribavirin concentration during antiviral therapy in LT patients. Ribavirin dosage might be adapted without compromising its efficacy.
Dominant‐negative interference with defence signalling by truncation mutations of the tomato Cf‐9 disease resistance gene
Authors: Barker Claire L. , Baillie Brett K. , Hammond‐Kosack Kim E. , Jones Jonathan D. G. , Jones David A.
Published: April 2006

The tomato Cf‐9 gene confers resistance to races of the leaf mould fungus Cladosporium fulvum that carry the Avr9 avirulence gene. Cf‐9 was isolated by transposon tagging using a modified maize Dissociation (Ds) element. This generated an allelic series of Ds‐induced mutations of Cf‐9, of which two were found to confer novel phenotypes in a screen for mutants affecting wild‐type Cf‐9 function in trans. Genetic and molecular analysis of these mutants suggested semidominant, Avr9‐dependent, negative‐interfering mutations involving Ds insertions in a defined subregion of Cf‐9. Interference was associated with expression of the 5′‐end of Cf‐9 upstream of the Ds insertions in these mutants, suggesting that truncated Cf‐9 proteins were the likely cause of interference. Transgenic tomato lines harbouring Cf‐9 constructs with premature stop codons in positions similar to the Ds insertions also showed interference, indicating that the presence of Ds was not required for interference to occur. Interestingly, interference in these transgenic lines was completely dominant and was associated with a pronounced developmental phenotype that was dependent on co‐expression of Cf‐9, Avr9 and a truncated Cf‐9 transgene. However, interference with a weakly autoactive Hcr9 gene was Avr9‐independent and did not cause a developmental phenotype, suggesting that localized restoration of Cf‐9/Avr9‐dependent cell death was responsible for the developmental phenotype. The restricted region in which truncation of Cf‐9 results in dominant‐negative interference suggests that leucine‐rich repeats (LRR) 16–19 of Cf‐9 may mediate dimerization of Cf‐9 and LRRs 20–23 may mediate interactions with downstream partner proteins required for Cf‐9 signalling, or vice versa.
The CCAAT binding factor can mediate interactions between CONSTANS‐like proteins and DNA
Authors: Ben‐Naim Orna , Eshed Ravit , Parnis Anna , Teper‐Bamnolker Paula , Shalit Akiva , Coupland George , Samach Alon , Lifschitz Eliezer
Published: April 2006

CONSTANS‐Like (COL) proteins are plant‐specific nuclear regulators of gene expression but do not contain a known DNA‐binding motif. We tested whether a common DNA‐binding protein can deliver these proteins to specific cis‐acting elements. We screened for proteins that interact with two members of a subgroup of COL proteins. These COL proteins were Tomato COL1 (TCOL1), which does not seem to be involved in the control of flowering time, and theArabidopsis thalianaCONSTANS (AtCO) protein which mediates photoperiodic induction of flowering. We show that the C‐terminal plant‐specific CCT (CO, CO‐like, TIMING OF CAB EXPRESSION 1) domain of both proteins binds the trimeric CCAAT binding factor (CBF) via its HAP5/NF‐YC component. Chromatin immunoprecipitation demonstrated that TCOL is recruited to the CCAAT motifs of the yeastCYC1andHEM1promoters by HAP5. In Arabidopsis, each of the three CBF components is encoded by several different genes that are highly transcribed. Under warm long days, high levels of expression of a tomatoHAP5(THAP5a) gene can reduce the flowering time of Arabidopsis. A mutation in the CCT domain of TCOL1 disrupts the interaction with THAP5 and the analogous mutation in AtCO impairs its function and delays flowering. CBFs are therefore likely to recruit COL proteins to their DNA target motifsin planta.
Silk decorations: controversy and consensus
Authors: Bruce M. J.
Published: April 2006

Although the occurrence of silk decorations has been noted in scientific literature for over 100 years, there is still little consensus as to their function. This is despite the proliferation of studies examining the five major hypotheses: (1) protection against predators, (2) increasing foraging success, (3) prevention of damage to the web, (4) providing shade and (5) mechanical support for the web. The first three of these hypotheses have received the most attention, and thus generated the most evidence (for and against) suggesting that web decorations are a type of visual signal. However, the effect of this signal on prey and predator receivers is unclear as the evidence is contradictory. Thus, the function of silk decorations may be context specific, depending on factors such as predators, prey, background colour and ambient light. A better understanding of how predators and prey see and process visual information from silk decorations, coupled with experiments examining the mechanisms behind the various hypotheses, are crucial in illuminating their function and resolving the controversy.
Maternal serum activin A and the prediction of intrauterine growth restriction
Authors: BARKEHALL‐THOMAS Andrea , TONG Stephen , BAKER Lesleigh S. , EDWARDS Andrew , WALLACE Euan M.
Published: April 2006

Background:  Differentiating between the small healthy fetus and the high risk growth restricted fetus remains a significant obstetric challenge. It has been previously shown that maternal activin A levels are increased in association with fetal growth restriction.

Aim:  To evaluate maternal serum activin A as a marker of fetal growth restriction.

Methods:  Prospective cohort study of 62 women referred for fetal assessment because of a clinical suspicion of a small for gestation fetus. Maternal serum levels of activin A were measured with an ELISA.

Results:  Activin A levels, expressed as median (95% CI) MoMs, were similar in the women with a normal‐sized fetus and in those with a healthy small for gestational age fetus, 1.14 (95% CI 1.0–1.5) and 1.31 (95% CI 0.8–2.1), respectively (P = 0.97). Compared to the women with a normal‐sized fetus or a healthy small fetus, activin A levels were significantly elevated in the women who had an intrauterine fetal growth restriction fetus 2.37 (95% CI 1.6–3.7; P = 0.01 compared to normal and P = 0.04 compared to healthy small).

Conclusions:  These data confirm that circulating activin A is increased in association with fetal growth restriction. However, a single blood sample for activin A will not efficiently discern between healthy and compromised small fetuses.
Activin‐A secretion is increased in the eutopic endometrium from women with essndometriosis
Authors: ROMBAUTS Luk , DONOGHUE Jacqui , CANN Leonie , JONES Rebecca L. , HEALY David L.
Published: April 2006

Background:  Activin is a well‐characterised growth and differentiation factor and an important inflammatory mediator. Activin is secreted by normal endometrial glands and stroma and is expressed by endometrial leucocytes. It is also known that the eutopic endometrium from women with endometriosis is functionally different to that from women without endometriosis. In this study, we hypothesise that the endometrial secretion of activin is altered in women with endometriosis.

Aims:  To determine whether the expression of inhibin/activin subunits and the secretion of activin‐A is different in eutopic endometrium from women with and without endometriosis.

Methods:  Endometrial biopsies were obtained from premenopausal, regularly menstruating women with and without endometriosis. Staining intensity for the different inhibin/activin subunits was compared in endometrial and endometriotic biopsies. Activin‐A secretion was studied using endometrial explants and endometrial glandular and stromal monolayer cell cultures.

Results:  The α‐ and βA‐subunits of inhibin/activin were more abundant in eutopic glandular cells from patients with minimal to mild endometriosis compared to women without endometriosis. In patients with endometriosis, the βB‐subunit was more abundant in eutopic stromal cells and endometrial leucocytes. Comparison of paired endometrial and endometriotic biopsies from the same patient did not reveal significant differences for any of the inhibin/activin subunits or activin receptors. Activin‐A secretion by glandular and stromal endometrial cells was sevenfold and threefold higher, respectively, in women with endometriosis compared to women without endometriosis.

Conclusions:  The expression of inhibin/activin subunits in eutopic endometrium is altered in women with endometriosis, leading to higher levels of activin‐A secretion by both glandular cells and stromal cells.
Regenerative Medicine for Cardiovascular Disorders‐New Milestones: Adult Stem Cells
Authors: Akar A. Ruchan , Durdu Serkan , Corapcioglu Tumer , Ozyurda Umit
Published: April 2006

Abstract:  Cardiovascular disorders are the leading causes of mortality and morbidity in the developed world. Cell‐based modalities have received considerable scientific attention over the last decade for their potential use in this clinical arena. This review was intended as a brief overview on the subject of therapeutic potential of adult stem cells in cardiovascular medicine with basic science findings and the current status of clinical applications. The historical perspective and basic concepts are reviewed and a description of current applications and potential adverse effects in cardiovascular medicine is given. Future improvements on cell‐based therapies will likely provide remarkable improvement in survival and quality of life for millions of patients with cardiovascular disorders.
In Vivo Recellularization of Plain Decellularized Xenografts With Specific Cell Characterization in the Systemic Circulation: Histological and Immunohistochemical Study
Authors: Takagi Kazuyoshi , Fukunaga Shuji , Nishi Akinori , Shojima Takahiro , Yoshikawa Kazuhiro , Hori Hidetsugu , Akashi Hidetoshi , Aoyagi Shigeaki
Published: April 2006

Abstract:  Decellularized biological scaffolds have been used for the tissue engineering of heart valves with good results in the pulmonary circulation. However, little information is available on the recellularization of plain decellularized biological scaffolds in the systemic circulation. The aim of this study was to determine whether plain decellularized xenografts (PDXs) can recellularize with specific cell characterization in the systemic circulation. The xenogenic aortic valved conduit grafts of rabbits were implanted in the abdominal aorta of dogs after decellularization. The grafts were explanted at 4, 12, or 24 weeks after implantation for histological, immunohistochemical examination, scanning electron microscope, and Western blot analysis. Although the valvular structures were completely lost after implantation, supravalvular conduits showed normal shapes and endothelialization. The PDXs were repopulated with basic vascular cell components in approximate natural proportions without immunological responses. The PDXs had been recellularized with specific cell characterization in the systemic circulation.
Cultivation of Endothelial Progenitor Cells on Fibrin Matrix and Layering on Dacron/Polytetrafluoroethylene Vascular Grafts
Authors: Sreerekha Perumcherry Raman , Krishnan Lissy K.
Published: April 2006

Abstract:  Completely biological tissue‐engineered vascular graft is an upcoming substitute for damaged blood vessel, but its clinical use is currently limited due to poor mechanical strength. Therefore, at present, polymeric small‐diameter vascular grafts lined with endothelial cells (ECs) to reduce graft thrombosis may be a more viable option. Successful construction of EC‐seeded artificial grafts faces some challenges such as (i) retention of endothelial lining; and (ii) availability of differentiated autologous cells. Biomaterial surfaces that are modified by depositing extracellular matrix (ECM) components may stabilize cells in the lumen against forces of blood flow. Adult stem cells such as endothelial progenitor cells (EPCs) circulate in the blood and they usually attach to the exposed matrix at the injured blood vessel site. Depending on the signaling capabilities of ECM, cells may differentiate into ECs,, and if a similar composition of the matrix is provided in vitro, EPCs isolated from blood might get differentiated and thus autologous cells for tissue engineering may be obtained. In this in vitro study, ECM scaffold consisting of biomolecules such as fibrin, fibronectin, and gelatin along with growth factors is found to have supported differentiation of EPC into EC. Further, the ECM precoated on Dacron and polytetrafluoroethylene is found to have supported the formation of EC monolayer that synthesized nitric oxide, and resisted shear stress. Thus, biomimetic fibrin composite is found to be suitable not only to seed cells on currently available artificial grafts but also to obtain differentiated EC from EPC.
Hemodynamics of a Pulsatile Left Ventricular Assist Device Driven by a Counterpulsation Pump in a Mock Circulation
Authors: Khir Ashraf William , Swalen Marcel J. , Segers Patrick , Verdonck Pascal , Pepper John R.
Published: April 2006

Abstract: The BCM (CardialCare, Minneapolis, MN, U.S.A.) is a pusher‐plate pulsatile left ventricular assist device (LVAD) that is operated by counterpulsation pumps. The purpose of this work was to assess the fluid dynamics associated with operating the BCM in a mock circulation, and also to examine the similarities between hemodynamic parameters produced by this device in vitro and those produced by the left ventricle (LV) in vivo. The BCM was connected to a true size silicon rubber aorta and operated by an intra‐aortic balloon pump. We examined the performance of the device at two system pressures (6.5 and 8 kPa); at three heart rates (60, 80, and 100 bpm); and at three pumping frequencies (1:1, 1:2, 1:3). Pressure and flow were measured in the upper descending aorta, and wave intensity analysis was used to calculate the peak intensity and energy of the compression and expansion waves. Pressure and flow waveforms produced by the BCM LVAD in vitro under different loading conditions were similar to those observed in vivo under similar loadings. Pusher‐plate‐type LVADs can produce compression and expansion waves similar to those generated by healthy LV in vivo.
INTER‐ AND INTRASPECIFIC VARIATION OF THE PSEUDO‐NITZSCHIA DELICATISSIMA COMPLEX (BACILLARIOPHYCEAE) ILLUSTRATED BY RRNA PROBES, MORPHOLOGICAL DATA AND PHYLOGENETIC ANALYSES1
Authors: Lundholm Nina , Moestrup Øjvind , Kotaki Yuichi , Hoef‐Emden Kerstin , Scholin Chris , Miller Peter
Published: April 2006

A study of 25 cultures tentatively identified as Pseudo‐nitzschia delicatissima (Cleve) Heiden, and originating from geographically widely distributed locations, showed both morphological and genetic variation among strains. Use of rRNA‐targeted DNA probes on 17 different strains showed large variation in the hybridization patterns. Detailed morphological studies placed the isolates into three groups. The sample on which the neotype of P. delicatissima is based was also examined, and used to establish the morphological identity of P. delicatissima. Phylogenetic analyses of 16 strains, based on sequences of internal transcriber spacer 1 (ITS1), 5.8S and ITS2 of the nuclear‐encoded rDNA, supported the morphological observations and the hybridization studies, and revealed large genetic variation among strains. A combination of the morphological and molecular findings resulted in the description of two new species, P. decipiens sp. nov. and P. dolorosa sp. nov. P. dolorosa has a mixture of one or two rows of poroids in the striae whereas P. delicatissima always has two rows. In addition, P. dolorosa has wider valves and a lower density of poroids. P. decipiens differs from P. delicatissima by a higher density of striae on the valve face as well as a higher density of poroids on the girdle bands. Among the strains referred to P. delicatissima, an epitype was selected. Large genetic variation was found among the P. delicatissima strains and a subdivision into two major clades represent cryptic species.
Internal Transcribed Spacer Dimorphism and Diversity in Dientamoeba fragilis
Authors: WINDSOR JEFFREY J. , MACFARLANE LORNA , CLARK C. GRAHAM
Published: April 2006

ABSTRACT. The internal transcribed spacer (ITS) region of the ribosomal RNA operon is frequently used for detecting sequence variation among closely related species as it is usually homogeneous within strains but evolves more rapidly than ribosomal RNA coding regions. We have studied this region in both genotypes of the human intestinal parasite Dientamoeba fragilis. In contrast to most organisms, we have identified extensive variation between copies of the sequence within the same strain. The ITS occurs in 2 major forms in each genotype but additional heterogeneity is also present within each form. The significance of this finding is unclear, but the only precedent for such variation is in the Apicomplexa, which have multiple dispersed ribosomal RNA operons in contrast to the tandem arrays found in most other eukaryotes.
Analytical Characterization of a Magnesia–Graphite Refractory
Authors: De Aza Antonio H. , Valle Francisco J. , Ortega Pilar , Pena Pilar , De Aza Salvador
Published: April 2006

Magnesia–graphite refractories are currently essential for the iron and steel industry. As a result, their physico‐chemical characterization is crucial with a view to predicting their service life. In this work, a methodology for the complete analytical characterization of such materials has been developed. Magnesia–graphite refractories generally contain elemental phases (C, Si, and Al), non‐oxide and oxide inorganic phases (SiC, MgO, and Al2O3), organic phase (binders), and various additives and impurities. Consequently, their chemical characterization is especially difficult and requires the joint use of the following techniques: X‐ray diffraction, differential thermal and thermogravimetric analyses, inductively coupled plasma–atomic emission spectroscopy, flame emission, Fourier transform infrared spectrometry, gravimetry, and C/S elemental analyzer (LECO). The data obtained by the different techniques match satisfactorily and provide validity to the methodology developed. The results obtained for each element analyzed, and the precision of each determination method used, are quite acceptable.
Exercise economy does not change after acclimatization to moderate to very high altitude
Authors: Lundby C. , Calbet J. A. L. , Sander M. , Van Hall G. , Mazzeo R. S. , Stray‐Gundersen J. , Stager J. M. , Chapman R. F. , Saltin B. , Levine B. D.
Published: April 2006

For more than 60 years, muscle mechanical efficiency has been thought to remain unchanged with acclimatization to high altitude. However, recent work has suggested that muscle mechanical efficiency may in fact be improved upon return from prolonged exposure to high altitude. The purpose of the present work is to resolve this apparent conflict in the literature. In a collaboration between four research centers, we have included data from independent high‐altitude studies performed at varying altitudes and including a total of 153 subjects ranging from sea‐level (SL) residents to high‐altitude natives, and from sedentary to world‐class athletes. In study A (n=109), living for 20–22 h/day at 2500 m combined with training between 1250 and 2800 m caused no differences in running economy at fixed speeds despite low typical error measurements. In study B, SL residents (n=8) sojourning for 8 weeks at 4100 m and residents native to this altitude (n=7) performed cycle ergometer exercise in ambient air and in acute normoxia. Muscle oxygen uptake and mechanical efficiency were unchanged between SL and acclimatization and between the two groups. In study C (n=20), during 21 days of exposure to 4300 m altitude, no changes in systemic or leg VO2 were found during cycle ergometer exercise. However, at the substantially higher altitude of 5260 m decreases in submaximal VO2 were found in nine subjects with acute hypoxic exposure, as well as after 9 weeks of acclimatization. As VO2 was already reduced in acute hypoxia this suggests, at least in this condition, that the reduction is not related to anatomical or physiological adaptations to high altitude but to oxygen lack because of severe hypoxia altering substrate utilization. In conclusion, results from several, independent investigations indicate that exercise economy remains unchanged after acclimatization to high altitude.
PCR‐RFLP and AP‐PCR of rbcL and ITS of rDNA Show That ×Taxodiomeria peizhongii (Taxodium×Cryptomeria) Is not an Intergeneric Hybrid
Authors: Ling Yan , Lu Wei‐Feng , Lu Fan , Wang Yu‐Guo , Chen Jia‐Kuan , Zhang Wen‐Ju
Published: April 2006

×Taxodiomeria peizhongii Z. J. Ye, J. J. Zhang et S. H. Pan was regarded as a new intergeneric hybrid between Taxodium mucronatum Tenore (as the female donor) and Cryptomeria fortunei Hooibrenk ex Otto et Dietr (as the male donor). To confirm the authenticity of the intergeneric hybrid, we analyzed the rbcL gene and the internal transcribed spacer (ITS) of 26S‐18S ribosomal RNA gene of the three species using polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) and arbitrarily primed PCR (AP‐PCR), and obtained the following results: i) Taxodiomeria peizhongii had the same RFLP maps of the rbcL gene and the ITS as Taxodium mucronatum, but was different from C. fortunei; ii) a 311‐bp PCR amplification product was obtained in C. fortunei by AP‐PCR of ITS, but was not found in Taxodiomeria peizhongii. Our results have demonstrated that C. fortunei did not provide any genome for Taxodiomeria peizhongii, implying that T. peizhongii is not an intergeneric hybrid between the two species.

(Managing editor: Wei Wang)
The (54Fe+58Ni)/56Ni ratio as a second parameter for Type Ia supernova properties
Authors: Mazzali Paolo A. , Podsiadlowski Philipp
Published: April 2006

A variation of the relative content of (54Fe+58Ni) versus 56Ni may be responsible for the observed scatter of Type Ia supernovae (SNe Ia) about a mean relation between their intrinsic brightness and the shape of their light curve. Synthetic light curves are computed from parametrized Chandrasekhar-mass explosion models of constant kinetic energy, where the ejecta are divided into an inner nuclear statistical equilibrium (NSE) zone, composed of (54Fe+58Ni) inside and 56Ni outside, an outer zone with intermediate-mass elements, and a CO zone. Both the size of the NSE zone and the fraction of (54Fe+58Ni) versus 56Ni are varied systematically. Models with the same original NSE content but different (54Fe+58Ni)/56Ni ratios reach different peak brightness but have similar light curve shapes. Synthetic spectra indicate that the V-band decline rate is not affected by the (54Fe+58Ni)/56Ni ratio. While the 56Ni mass and the total NSE mass are the dominant parameters that determine the peak luminosity and the shape of the light curve, respectively, a variation in the (54Fe+58Ni)/56Ni ratio, which may depend on the metallicity of the progenitor is likely to account for a significant part of the observed scatter of local SNe Ia about the mean brightness–decline rate relation.