bluuebunny/crossref_metadata_2025_split huggingface dataset:
Calculation of the renal perfusion and glomerular filtration rate from the renal impulse response obtained with MRI
Authors: Hermoye L. , Annet L. , Lemmerling Ph. , Peeters F. , Jamar F. , Gianello P. , Van Huffel S. , Van Beers B.E. 
Published: April 2004

AbstractThe aim of this study was to assess the importance of deconvolution for the calculation of renal perfusion and glomerular filtration rate (GFR) on the basis of concentration–time curves as measured with perfusion MRI. Six rabbits were scanned dynamically after injection of a gadolinium chelate. Concentration–time curves were generated by manually drawing regions of interest in the aorta and the renal cortex. To remove the dependency on the arterial input function, a regularized structured total least‐squares deconvolution algorithm was used to calculate the renal impulse response. This curve was fitted by the sum of two gamma variate functions, corresponding to the passage of the contrast agent in the glomeruli and the proximal convoluted tubules. Tracer kinetics models were applied to these two functions to obtain the renal perfusion and GFR. For comparison, these two parameters were also calculated on the basis of the renal concentration–time curve before deconvolution. The renal perfusion values correlated well (r = 0.9, P = 0.014) with the values calculated by a validated upslope method. The GFR values correlated well (r = 0.9, P = 0.014) with the values obtained from the clearance of 51Cr‐EDTA. A comparison of the values obtained with and without deconvolution demonstrated the necessity of deconvolution. Magn Reson Med 51:1017–1025, 2004. © 2004 Wiley‐Liss, Inc.
Quantitative description of proton exchange processes between water and endogenous and exogenous agents for WEX, CEST, and APT experiments
Authors: Zhou Jinyuan , Wilson David A. , Sun Phillip Zhe , Klaus Judith A. , van Zijl Peter C.M. 
Published: April 2004

AbstractThe proton exchange processes between water and solutes containing exchangeable protons have recently become of interest for monitoring pH effects, detecting cellular mobile proteins and peptides, and enhancing the detection sensitivity of various low‐concentration endogenous and exogenous species. In this work, the analytic expressions for water exchange (WEX) filter spectroscopy, chemical exchange‐dependent saturation transfer (CEST), and amide proton transfer (APT) experiments are derived by the use of Bloch equations with exchange terms. The effects of the initial states for the system, the difference between a steady state and a saturation state, and the relative contributions of the forward and backward exchange processes are discussed. The theory, in combination with numerical calculations, provides a useful tool for designing experimental schemes and assessing magnetization transfer (MT) processes between water protons and solvent‐exchangeable protons. As an example, the case of endogenous amide proton exchange in the rat brain at 4.7 T is analyzed in detail. Magn Reson Med 51:945–952, 2004. © 2004 Wiley‐Liss, Inc.
Reduced RF power without blurring: Correcting for modulation of refocusing flip angle in FSE sequences
Authors: Busse Reed F. 
Published: April 2004

AbstractIn order to reduce the RF power deposition of fast spin echo sequences operated at high field strength, the flip angles of the refocusing pulse train are varied from pulse to pulse using a modulated angle refocusing train method. The technique employs high flip angle pulses prior to sampling the center of k‐space in order to preserve T2 contrast, low flip angles after sampling the center of k‐space to reduce power and prolong relaxation, and a smooth transition between the high and low flip angle regimes in order to maintain the pseudosteady‐state, maximizing signal and avoiding artifact‐inducing oscillations. An analytical expression is used to predict and correct for the flip angle dependence of the signal, thus eliminating any deleterious effects of flip angle modulation on the point spread function. Analysis of resolution and SNR were performed in simulation and phantom studies. In human imaging studies, it is shown that RF energy deposition per slice in a single‐shot fast spin echo application can be reduced by up to 75%, making the sequence as practical at 3 T as it is has been at 1.5 T. Magn Reson Med 51:1031–1037, 2004. © 2004 Wiley‐Liss, Inc.
In vivo precision of quantitative shoulder cartilage measurements, and changes after spinal cord injury
Authors: Vanwanseele B. , Eckstein F. , Hadwighorst H. , Knecht H. , Spaepen A. , Stüssi E. 
Published: April 2004

AbstractRecent advances in MRI have enabled the quantitative assessment of articular cartilage morphology in human joints. In this study, we tested the hypothesis that the precision of quantitative shoulder cartilage measurements is sufficient to detect changes between and within patients, and that shoulder cartilage thickness in paraplegic patients increases due to increased loading. We imaged the shoulders of seven healthy volunteers four times using a coronal 3D, fat‐suppressed, gradient‐echo sequence. The humeral head cartilage in seven paraplegic patients was evaluated soon after injury and 1 year post injury. A precision of 4.5% (root mean square (RMS) average coefficient of variation (CV) %) was found for shoulder cartilage thickness measurements in the humeral head. Whereas a significant decrease of cartilage thickness (−11%, P < 0.05) was observed in the knee, there was no significant change in articular cartilage thickness in the shoulder (−1.1%). Our data show, for the first time, that articular cartilage of the humeral head can be quantified with acceptable precision in vivo. It was demonstrated that, in contrast to the knee, the articular cartilage morphology of the humeral head changes very little (i.e., there is no significant increase or decrease in thickness) after spinal cord injury (SCI). Magn Reson Med 51:1026–1030, 2004. © 2004 Wiley‐Liss, Inc.
Association of spinal and bulbar muscular atrophy with myotonic dystrophy type 1
Authors: Jinnai Kenji , Nishimoto Keisuke , Itoh Kyoko , Hashimoto Kozo , Takahashi Keiichi 
Published: April 2004

AbstractA man with spinal and bulbar muscular atrophy (SBMA) had a short (CTG)n expansion in the myotonic dystrophy protein kinase gene as well as (CAG)n expansion in the androgen receptor gene in leukocytes. The patient had the characteristic clinical findings of SBMA, but none of myotonic dystrophy type 1 (DM1). All of his three children (a son and two daughters) had the DM1 phenotype with long (CTG)n expansions. The daughters also had heterozygous long (CAG)n expansions. Postmortem examination of the patient revealed the characteristic pathological changes of SBMA as well as muscle degeneration compatible with DM1. Gene analysis of the organs disclosed unstable long expansions of the (CTG)n repeats, in contrast to the stable (CAG)n expansions. We have assumed that SBMA and DM1 developed independently in our patient, but cannot exclude the possibility that interactive gene effects increased somatic instability. Muscle Nerve 29: 729–733, 2004
Canine inflammatory myopathy: Analysis of cellular infiltrates
Authors: Pumarola Marti , Moore Peter F. , Shelton G. Diane 
Published: April 2004

AbstractInflammatory myopathies (IMs) occur relatively frequently in dogs, and, with the exception of masticatory muscle myositis (MMM), have not been characterized. This study analyzed the distribution and types of cellular infiltrates in 21 cases of generalized IM, 3 cases of focal IM (MMM), and 1 case with features of both generalized and focal IM, using a panel of monoclonal antibodies to cell surface markers. In generalized IM, mononuclear cells showed an endomysial and perimysial distribution with invasion of non‐necrotic fibers similar to human IM. T lymphocytes with T‐cell receptor (TCR)αβ predominated. Distinct differences were seen in MMM including prominent B‐cell infiltration, dendritic cells and macrophages in greater numbers than T cells, and numerous T cells with TCRγδ. Thus, generalized IM and MMM appear to be distinct diseases with different mechanisms. Canine generalized IM may be an important animal model for human IM. Muscle Nerve 29: 782–789, 2004
Comparative behavior of polybutadiene and polynorbornene‐based latices prepared by dispersion ring‐opening metathesis polymerization with a poly(ethylene oxide) macromonomer
Authors: Chemtob Abraham , Héroguez Valérie , Gnanou Yves 
Published: April 2004

AbstractThis study critically examines the similarities and differences between poly(ethylene oxide) (PEO) stabilized latices of polynorbornene and polybutadiene. Features such as the kinetics of copolymerization of norbornene and cyclooctadiene with a macromonomer of PEO, the particles' size and morphology, the type of copolymer formed, and the stability of these latices were investigated and the results obtained are considered. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2705–2716, 2004
Effects of a brief intervention program for patients with cancer and their partners on feelings of inequity, relationship quality and psychological distress
Authors: Kuijer Roeline G. , Buunk Bram P. , de Jong G. Majella , Ybema Jan F. , Sanderman Robbert 
Published: April 2004

AbstractWhen one member of a couple develops a serious illness, the lives of both partners are likely to be affected. Interventions directed at both partners are generally lacking, however. In the present study, a brief counseling program directed at couples confronted with cancer was evaluated. The intervention focused mainly on the exchange of social support and help between both partners and was aimed at restoring perceptions of equity. Couples were randomly assigned to an experimental group or a waiting‐list group. After the intervention, both patients and their partners reported lower levels of perceptions of underinvestment and overbenefit, and higher levels of relationship quality. Moreover, among patients psychological distress decreased after the intervention. These effects were generally maintained until follow‐up three months later. Associations between perceptions of equity and relationship quality and psychological distress were also examined. Copyright © 2003 John Wiley & Sons, Ltd.
Androgen deprivation therapy for prostate cancer: Current status and future prospects
Authors: Miyamoto Hiroshi , Messing Edward M. , Chang Chawnshang 
Published: April 2004

AbstractAndrogens play a major role in promoting the development and progression of prostate cancer. As a result, androgen ablation or blockade of androgen action through the androgen receptor (AR) has been the cornerstone of treatment of advanced prostate cancer. Different strategies involving this hormonal therapy produce a significant clinical response in most of the patients, but most responders eventually lose dependency, resulting in mortality. Thus, whether hormonal therapy contributes to the improvement of overall survival rates, especially in patients with advanced prostate cancer, remains controversial. However, patients with advanced disease clearly have a benefit from androgen deprivation‐based treatment for palliating their symptoms and for improving the quality of their lives. In order to improve overall survival, novel treatment strategies that prolong the androgen‐dependent state and that are useful for androgen‐independent disease based on specific molecular mechanisms need to be identified. © 2004 Wiley‐Liss, Inc.
Density functional theory study of formamide–formamidic acid tautomerization
Authors: Du Dongmei , Fu Aiping , Zhou Zhengyu 
Published: April 2004

AbstractThe mechanism of tautomerization reaction of formamide–formamidic acid in gas phase and in water has been completely investigated in the present study using, density functional theory (DFT) and the second‐order Møller–Plesset perturbation (MP2) method. Large basis sets 6‐311++G(d,p) have been employed to determine the equilibrium structure and vibrational frequencies. Activation energy of the non‐water F → FA reaction is 202.9 kJ/mol at B3LYP/6‐311++G(d,p) level. Extensions to situations in which tautomerization is assisted by neighboring solvent molecule(s) are considered. If a single H2O molecule is considered, three stable structures and transition states of formamide–water complexes are found. If the water locates between the HN group and the CO moiety, the activation energy decreases to 94.5 kJ/mol. If the water locates in other positions, it can cause the activation energy to increase to 2–4 kJ/mol. When two intimate H2O molecules locate between the HN group and the CO moiety, the activation energy decreases to 89.3 kJ/mol. Intimate solvent participation is thus found much more strongly affecting the activation energy than the overall thermodynamics in this case. Finally, the solution phase studies are also carried out using the Onsager reaction field model, with a range of dielectric constants from 2 to 80 at the B3LYP/6‐311++G(d,p) level. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Attitudes toward chemistry among 11th grade students in high schools in Greece
Authors: Salta Katerina , Tzougraki Chryssa 
Published: April 2004

AbstractThe development of valid and reliable instruments for attitudes' measurement has been proven crucial for the quality of research. This study is dealing with the development and validation of an attitude toward chemistry instrument. By using this instrument, 11th grade Greek students' attitudes regarding the difficulty, the interest, the usefulness of chemistry course, and the importance of chemistry were investigated. Gender and study specialization differences in students' attitudes toward chemistry were examined for this population. Report card grades for the chemistry course were used to measure students' achievement in chemistry and its correlation with students' attitudes toward chemistry was explored. © 2004 Wiley Periodicals, Inc. Sci Ed 88:535–547, 2004
Model-checking dense-time Duration Calculus
Authors: Fränzle Martin 
Published: April 2004

Abstract.

Since the seminal work of Zhou Chaochen, M. R. Hansen, and P. Sestoft on decidability of dense-time Duration Calculus [ZHS93] it is well known that decidable fragments of Duration Calculus can only be obtained through withdrawal of much of the interesting vocabulary of this logic. While this was formerly taken as an indication that key-press verification of implementations with respect to elaborate Duration Calculus specifications were also impossible, we show that the model property is well decidable for
realistic
designs which feature natural constraints on their switching dynamics.

The key issue is that the classical undecidability results rely on a notion of validity of a formula that refers to a class of models which is considerably richer than the possible behaviours of actual embedded real-time systems: that of finitely variable trajectories. By analysing two suitably sparser model classes we obtain model-checking procedures for rich subsets of Duration Calculus. Together with undecidability results also obtained, this sheds light upon the exact borderline between decidability and undecidability of Duration Calculi and related logics.
Use of a Nonablative Radiofrequency Device to Rejuvenate the Upper One‐Third of the Face
Authors: Bassichis Benjamin A. , Dayan Steven , Thomas J. Regan 
Published: April 2004

OBJECTIVETo evaluate the use of the ThermaCool TC nonablative radiofrequency device for rejuvenation of the upper one‐third of the face, as determined by brow elevation.STUDY DESIGN AND SETTINGTwenty‐four patients in a facial plastic surgery office were treated with the nonablative radiofrequency device. The patients had pretreatment photos, in‐office procedure, and follow‐up photos. Brow elevation measurements were used to gauge efficacy of the procedure. These results were compared to an untreated, control group of 12 patients.RESULTSCompared to the control group, the post‐treatment measurements were improved (P < 0.05). The post‐treatment measurements were also improved from pretreatment baseline (P < 0.05). Subjective results obtained from patient satisfaction questionnaires did not correlate to the objective data. The data also showed that improvement in brow elevation was not uniform in each patient.CONCLUSIONThe ThermaCool TC nonablative radiofrequency device for in‐office rejuvenation of the upper one‐third of the face procedure does provide brow elevation in a majority of patients; however, the majority of the study patients did not perceive benefit from the procedure. Patient satisfaction in facial plastic surgery must be an important part of the decision of whether or not to introduce a new device into a practice setting. (Otolaryngol Head Neck Surg 2004;130:397–406.)
Treatment of Solid Sarcomas in Immunocompetent Mice With Novel, Oncolytic Herpes Simplex Viruses
Authors: Sugiura Saiko , Goshima Fumi , Takakuwa Hiroki , Sata Tetsutaro , Nakashima Tsutomu , Nishiyama Yukihiro 
Published: April 2004

OBJECTIVEAttenuated, replication‐competent herpes simplex viruses (HSVs) have shown promise as antitumor agents for cancer therapy. In this study, we sought to develop a novel type of oncolytic HSV with more potent antitumor activity for use in localized malignant tumors.STUDY DESIGNA new, attenuated multimutated HSV (termed HL) was developed, and then a highly metastatic murine fibrosarcoma cell line, NfSa Y83, was injected into the necks or flanks of immuno‐competent C3H mice. The mice were treated with attenuated HSV mutants by intratumoral injection, and antitumor efficacy was assessed by measuring tumor dimensions and overall survival rates.RESULTSTreatment with intratumoral injection of HL resulted in marked regression of tumors. In fact, roughly 75% of flank tumors and 50% of neck tumors were completely eradicated.CONCLUSIONA novel type of attenuated HSV recombinant HL demonstrated a remarkable antitumor efficacy in a localized tumor model in mice. (Otolaryngol Head Neck Surg 2004;130:470‐8.)
Stromules and the dynamic nature of plastid morphology
Authors: Kwok E. Y. , Hanson M. R. 
Published: April 2004

SummaryInvestigation of plastids via green fluorescent protein (GFP) has led to the rediscovery of tubular extensions of the plastid membrane, termed stromules, for stroma‐filled tubules. These unique structures are challenging our understanding of plastid structure and function. Stromules are highly dynamic, branching and elongating across the plant cell. Recent experiments indicate that cytoplasmic microtubules and microfilaments control the shape and motility of stromules. Whether stromule formation involves plastid‐specific structural systems, such as the plastid division machinery, remains open to debate. Fluorescence photobleaching experiments have revealed that GFP can traffic between plastids joined by stromules. As a result, interest has grown in whether other macromolecules can also travel through these connections. Although the function of stromules is unknown, several aspects of their biology suggest they play a role in molecular exchange between plastids and other organelles.
Interphase chromosomes and the Rabl configuration: does genome size matter?
Authors: Santos A. P. , Shaw P. 
Published: April 2004

SummaryIt is now well established that the cereals share a common gene order or gene synteny. However, the cereal species encompass an enormous range of genome size, with wheat being one of the largest and rice one of the smallest. Here we describe the current state of knowledge of interphase chromosome structure within the cereal species. In wheat and its close relatives, the interphase chromosomes adopt a highly regular Rabl configuration, with the two chromosome arms lying next to each other and the centromeres and telomeres located at opposite poles of the nuclei. By contrast, the chromosomes in most rice nuclei clearly do not show a Rabl configuration. Surprisingly, the chromosomes in the endoreduplicated xylem vessel cells of rice do adopt a Rabl configuration. To explain this observation, we propose that endoreduplication may occur immediately after chromosome segregation in these cells, and that the new chromatin interactions, particularly at the centromeres, in the endoreduplicated chromosomes may stabilize the anaphase chromosome configuration.
The role of diagnosis in patients failing peripheral blood progenitor cell mobilization
Authors: Koenigsmann Michael , Jentsch‐Ullrich Kathleen , Mohren Martin , Becker Elke , Heim Marcell , Franke Astrid 
Published: April 2004

BACKGROUND: Failure to mobilize PBPCs for auto‐logous transplantation has mostly been attributed to previous therapy and poses therapeutic problems.STUDY DESIGN AND METHODS: The role of underlying disease was analyzed in 17 of 73 (23%) patients with PBPC mobilization failure, and secondary mobilization with high‐dose filgrastim was attempted.RESULTS: Of 16 patients with acute leukemia, 13 (81%) mobilized poorly. In contrast, of 57 patients with non‐Hodgkin's lymphoma, Hodgkin's lymphoma, multiple myeloma, and solid tumor, 53 (93%, p < 0.001) showed good PBPC mobilization. Relapsed disease did not predispose to poor mobilization. As secondary mobilization attempt, 7 patients received 25 µg per kg per day filgrastim without chemotherapy leading to a 3.7 ± 2.8‐fold (SD) increase in the maximum number of circulating CD34+ cells (p = 0.104). PBPC apheresis yielded 3.3 (±0.5) × 106 CD34+ cells per kg of body weight in 5 patients. Four poor mobilizers received 50 µg per kg per day filgrastim as second or third mobilization attempt. Circulating CD34+ cells in these patients increased by 1.5 (±0.7) compared with the primary G–CSF application.CONCLUSION: Selective PBPC mobilization failure was seen in patients with acute leukemia whereas remarkably good mobilization was seen in other malignancies. Increasing the filgrastim dose to 25 µg per kg per day may allow PBPC collection in patients failing PBPC mobilization.
Empirical use of antisecretory drug therapy delays diagnosis of upper gastrointestinal adenocarcinoma but does not effect outcome
Authors: Panter S. J. , O'Flanagan H. , Bramble M. G. , Hungin A. P. S. 
Published: April 2004

SummaryBackground : Upper gastrointestinal cancer carries a poor prognosis. Although the incidence of gastric adenocarcinoma is falling, oesophageal adenocarcinoma is increasing. This has been attributed to an increasing prevalence of gastro‐oesophageal reflux disease, commonly treated empirically in primary care with antisecretory drugs. Treatment has been associated with delayed diagnosis but it is unclear if this influences prognosis.Aims : To ascertain the effect of antisecretory drugs on time to diagnosis, symptoms, tumour stage and outcome.Methods : A retrospective cohort study of primary care records for 747 patients diagnosed with upper gastrointestinal adenocarcinoma at South Tees NHS Trust between 1991 and 2001.Results : Mean time from the onset of symptoms to diagnosis was 30 weeks. Mean and median times at the primary care stage were longer than at the hospital stage for both oesophageal and gastric cancer (P < 0.0001). Patients with benign symptoms prescribed antisecretory drugs were referred later than those not on antisecretory drugs (P < 0.0001), as were patients with alarm symptoms (P = 0.0008). Prior use of antisecretory drugs delayed diagnosis by 17.6 weeks (mean) but had no effect on tumour stage at diagnosis or survival.Conclusion : Prior antisecretory drug therapy was associated with delayed diagnosis of upper gastrointestinal adenocarcinoma irrespective of presenting symptoms. Concerns that delays might adversely affect tumour stage or long‐term survival were not substantiated.