bluuebunny/crossref_metadata_2025 huggingface dataset:
Expanding Our Understanding of the Change Message
Authors: Bernerth Jeremy
Published: April 2004

With the development of the global economy in the late 1980s and 1990s, organizations have been forced to continually reevaluate operations and strategies. As a result, the one constant in this dynamic world is the everchanging work environment. The human resource and organizational development fields have long looked to investigate what makes change efforts successful. Researchers and practitioners have both found employee readiness to be a critical factor in successful change efforts. This article provides a theoretical foundation for one of the most complete models of organizational readiness. Specifically, the Armenakis, Harris, &Feild five-message component model of organizational readiness is presented with a theoretical foundation for the importance of each of the five specified components. A case study is provided to display the need to communicate each of the message components. Implications and conclusions draw attention to the importance of taking proactive steps in creating readiness.
Imagination, Creativity, and HRD: an Aesthetic Perspective
Authors: Gibb Stephen
Published: April 2004

Human resource development is conceptualized here in terms of levels of action: representations, experience, relations, and communities. Functionality is taken as a hallmark of good human resource development in these. Yet reflecting on what works, and on innovations in human resource development, factors other than those associated with functionality seem to matter: imagination and creativity. To understand and explore these, an aesthetic perspective on human resource development is proposed. How the aesthetic exists and lives in human resource development is described here as a quadrant, with imagination and creativity existing in the form of imported metaphors, design thinking, development epistemology, and the aesthetics of organization. The implications of this combining of an under-standing of the functional and the aesthetic for theorizing and practicing human resource development are outlined.
Microdialysis—A Model for Studying Chronic Wounds
Authors: Clough Geraldine , Noble Miriam
Published: April 2004

Microdialysis has been used for more than 20 years as a method of sampling the interstitial fluid space. It has been used in both animals and human tissues, in vivo. The principle of microdialysis is based on the passive diffusion of a compound along its concentration gradient. One major advantage of this sampling technique is that it is simple, relatively cheap, and minimally invasive. Consequently, microdialysis has been employed in a variety of research and clinical settings to recover endogenous molecules and metabolites from the tissue space. It has also been used to measure the tissue penetration of xenobiotics and to follow their temporal and spatial distribution. Most recently, microdialysis has begun to be used as a diagnostic tool and its application to clinical investigation at the bedside explored. This review describes the principles of the technique of microdialysis and its current uses in both an experimental and clinical setting. It goes on to consider current methods of wound fluid sampling and the range of bioactive molecules that have been detected in wound fluid recovered using these techniques. Finally, the use of microdialysis as a novel method for sampling wound fluid in vivo and its ability to provide a fluid that is unaffected by the sampling method and that is representative of the wound environment is discussed.
Reliability and Accuracy of Techniques for Surface Area Measurements of Wounds and Scars
Authors: van Zuijlen Paul P. M. , Angeles Adam P. , Suijker Monique H. , Kreis Robert W. , Middelkoop Esther
Published: April 2004

The applicability of simple methods to measure the size of pathological skin lesions for management and research has been poorly studied to date. The interobserver reliability and accuracy (validity) was established for planimetry by photography and planimetry by tracing on a transparent sheet in this study. Drawings of 25, 50, and 75 cm2 were created on 3 locations with increasing curvature (back, thigh, and forearm) in 20 healthy volunteers. Three investigators evaluated the drawings by both planimetry techniques. Both techniques showed a good reliability (r ≥ 0.82, intraclass correlation) for 25 cm2 areas. Planimetry by photography was more reliable than planimetry by tracings for the 50 -and 75-cm2 areas and was more accurate than planimetry by tracing for all areas except for the area with the greatest curvature, the forearm. The study permits the conclusion that planimetry by photography is more suitable for surface area measurements than planimetry by tracing except for extremely curved body parts, where it is likely that effects of distortion supervene.
Decreasing Foot Pressures While Implementing Topical Negative Pressure (Vacuum-Assisted Closure) Therapy
Authors: Armstrong David G. , Lavery Lawrence A.
Published: April 2004

Over the past generation, there have been a number of significant advances in wound healing in general. Unfortunately, much of this has not translated into increased success in healing wounds on the sole of the foot. We believe that much of this therapeutic disconnect has to do with an inadequate merging of pressure off-loading technologies and active wound-healing technologies. This article discusses such a merger between removable cast walkers and topical negative pressure (also known as vacuum-assisted closure).
Recurring Wounds in a Diabetic with Multiple Medical Problems: Lower Extremity Wound Care
Authors: Kaufman Melissa W. , Wigley Darlene
Published: April 2004

Acute trauma leading to open wounds in the lower extremity of a patient with diabetes mellitus can be life threatening. Diabetes mellitus complicates and compromises wound care and tissue repair for several reasons. This case report describes the successful wound care treatment modalities used in the care of a 53-year-old male who presented with diabetes and a full-thickness lower leg wound.
The Integration of Hypnosis into a Model of Palliative Care
Authors: Marcus Joel , Elkins Gary , Mott Frank
Published: April 2004

There exists a need for a broad and inclusive model of integration of mind-body interventions for palliative care. Symptoms relating to psychological distress and existential concerns are even more prevalent than pain and other physical symptoms among those with life-limiting conditions. The hypnotic model’s purpose is to improve the patient’s total psychological, social, and spiritual well-being. A 4-stage model of interventions is offered to assist the clinician in developing and implementing appropriate hypnotherapeutic treatment for noncurative patients. The focus of the hypnotherapy is to ameliorate the effects of pain and dyspnea to restore a level of psychological and physical wellbeing. Within this model of therapy for patients with active, progressive, far-advanced disease and a short life expectancy, the goals of the hypnotic intervention are to provide relief from pain and shortness of breath. Other focuses include assisting the patient with the psychological adjustment to their noncurative and ultimately final state.
Second-Language Acquisition, Culture Shock, and Language Stress of Adult Female Latina Students in New York
Authors: Buttaro Lucia
Published: April 2004

The purpose of this study was to identify and describe the educational, cultural, and linguistic adjustments and experiences encountered by Hispanic adult females in learning English as a second language (ESL) and the relation of these experiences to the variables of language, culture, and education of adult Hispanic females. Adult ESL learners face problems of controlling linguistic rules and of applications in various situations while attempting to deal with the shock of living in a new cultural environment.
Practical Arterial Evaluation of the Lower Extremity
Authors: Baun Jim
Published: April 2004

Sonographic examination of the lower extremity arterial system can be time-consuming and arduous if performed in its entirety on every patient who is referred to the vascular sonography laboratory. In fact, most patients can benefit from a tailored noninvasive arterial examination that integrates clinical, physiological, and imaging/Doppler modalities in answering the referring physician s questions. This study provides an algorithm for assessing the type and level of information needed for most patients arriving in the sonography suite with known or suspected peripheral arterial disease.
Congenital Malformations
Authors: Su Ching-Hui , Rouse Glen A.
Published: April 2004

The incidence of multiple congenitalmalformations amid infants of mothers withinsulindependent diabetes mellitus (type I or IDDM) isbetween 6% and 12%. This is two to five timesthe incidence in nondiabetic mothers.Congenital malformations associated with IDDMinclude craniofacial defects, holoprosencephaly,cardiac defects, caudal regression syndrome,renal agenesis, gastrointestinal defects, and asingle umbilical artery. Unfortunately, thesemalformations are not exclusive to IDDMpregnancies. Many of the same pathologies are alsoseen in trisomy 13 fetuses.
Metal‐Catalyzed Disruption of Membrane Protein and Lipid Signaling in the Pathogenesis of Neurodegenerative Disorders
Authors: MATTSON MARK P.
Published: April 2004

Abstract: Membrane lipid peroxidation and oxidative modification of various membrane and associated proteins (e.g., receptors, ion transporters and channels, and signal transduction and cytoskeletal proteins) occur in a range of neurodegenerative disorders. This membrane‐associated oxidative stress (MAOS) is promoted by redox‐active metals, most notably iron and copper. The mechanisms whereby different genetic and environmental factors initiate MAOS in specific neurological disorders are being elucidated. In Alzheimer's disease (AD), the amyloid β‐peptide generates reactive oxygen species and induces MAOS, resulting in disruption of cellular calcium homeostasis. In Parkinson's disease (PD), mitochondrial toxins and perturbed ubiquitin‐dependent proteolysis may impair ATP production and increase oxyradical production and MAOS. The inheritance of polyglutamine‐expanded huntingtin may promote neuronal degeneration in Huntington's disease (HD), in part, by increasing MAOS. Increased MAOS occurs in amyotrophic lateral sclerosis (ALS) as the result of genetic abnormalities (e.g., Cu/Zn‐superoxide dismutase mutations) or exposure to environmental toxins. Levels of iron are increased in vulnerable neuronal populations in AD and PD, and dietary and pharmacological manipulations of iron and copper modify the course of the disease in mouse models of AD and PD in ways that suggest a role for these metals in disease pathogenesis. An increasing number of pharmacological and dietary interventions are being identified that can suppress MAOS and neuronal damage and improve functional outcome in animal models of AD, PD, HD, and ALS. Novel preventative and therapeutic approaches for neurodegenerative disorders are emerging from basic research on the molecular and cellular actions of metals and MAOS in neural cells.
Redox‐Active Metals, Oxidative Stress, and Alzheimer's Disease Pathology
Authors: HUANG XUDONG , MOIR ROBERT D. , TANZI RUDOLPH E. , BUSH ASHLEY I. , ROGERS JACK T.
Published: April 2004

Abstract: Considerable evidence is mounting that dyshomeostasis of the redox‐active biometals, Cu and Fe, and oxidative stress contribute to the neuropathology of Alzheimer's disease (AD). Present data suggest that metals can interact directly with Aβ peptide, the principal component of β‐amyloid that is one of the primary lesions in AD. The binding of metals to Aβ modulates several physiochemical properties of Aβ that are thought to be central to the pathogenicity of the peptide. First, we and others have shown that metals can promote the in vitro aggregation into tinctorial Aβ amyloid. Studies have confirmed that insoluble amyloid plaques in postmortem AD brain are abnormally enriched in Cu, Fe, and Zn. Conversely, metal chelators dissolve these proteinaceous deposits from postmortem AD brain tissue and attenuate cerebral Aβ amyloid burden in APP transgenic mouse models of AD. Second, we have demonstrated that redox‐active Cu(II) and, to a lesser extent, Fe(III) are reduced in the presence of Aβ with concomitant production of reactive oxygen species (ROS), hydrogen peroxide (H2O2) and hydroxyl radical (OH•). These Aβ/metal redox reactions, which are silenced by redox‐inert Zn(II), but exacerbated by biological reducing agents, may lead directly to the widespread oxidation damages observed in AD brains. Moreover, studies have also shown that H2O2 mediates Aβ cellular toxicity and increases the production of both Aβ and amyloid precursor protein (APP). Third, the 5′ untranslated region (5′UTR) of APP mRNA has a functional iron‐response element (IRE), which is consistent with biochemical evidence that APP is a redox‐active metalloprotein. Hence, the redox interactions between Aβ, APP, and metals may be at the heart of a pathological positive feedback system wherein Aβ amyloidosis and oxidative stress promote each other. The emergence of redox‐active metals as key players in AD pathogenesis strongly argues that amyloid‐specific metal‐complexing agents and antioxidants be investigated as possible disease‐modifying agents for treating this horrible disease.
Oxidative Stress and Redox‐Active Iron in Alzheimer's Disease
Authors: HONDA KAZUHIRO , CASADESUS GEMMA , PETERSEN ROBERT B. , PERRY GEORGE , SMITH MARK A.
Published: April 2004

Abstract: Many lines of evidence indicate that oxidative stress is one of the earliest events in the genesis of Alzheimer's disease (AD). Iron is a transition metal capable of generating hydroxyl radicals, the most potent reactive oxygen species. Consequently, a disruption in the metabolism of iron has been postulated to have a role in the pathogenesis of AD. Indeed, both senile plaques and neurofibrillary tangles, the major pathological landmarks of AD, as well as neurons in the earliest stages of the disease, show elevated iron deposition. However, it is clear that the iron bound to lesion‐associated proteins such as amyloid‐β and tau plays only a minor, late role in the disease, with the RNA‐associated iron found in the neuronal cytoplasm occurring early and being of paramount importance. In this regard, it is probably not surprising that there is significant oxidation of cytoplasmic RNA among the populations of neurons vulnerable to AD. In this review, we consider the role of iron‐induced oxidative stress as a key event in AD pathophysiology.
Brain Ferritin Iron as a Risk Factor for Age at Onset in Neurodegenerative Diseases
Authors: BARTZOKIS GEORGE , TISHLER TODD A. , SHIN IL‐SEON , LU PO H. , CUMMINGS JEFFREY L.
Published: April 2004

Abstract: Tissue iron can promote oxidative damage. Brain iron increases with age and is abnormally elevated early in the disease process in several neurodegenerative disorders, including Alzheimer's disease (AD) and Parkinson's disease (PD). Higher iron levels in males may contribute to higher risk for younger‐onset PD and recent studies have linked the presence of the hemochromatosis gene with a younger age at onset of AD. We examined whether age at onset of PD and AD was associated with increased brain ferritin iron. Ferritin iron can be measured with specificity in vivo with MRI utilizing the field‐dependent relaxation rate increase (FDRI) method. FDRI was assessed in three basal ganglia regions (caudate, putamen, and globus pallidus) and frontal lobe white matter for younger‐ and older‐onset male PD and AD patients and healthy controls. Significant increases in basal ganglia FDRI levels were observed in the younger‐onset groups of both diseases compared to their respective control groups, but were absent in the older‐onset patients. The results support the suggestion that elevated ferritin iron and its associated toxicity is a risk factor for age at onset of neurodegenerative diseases such as AD and PD. Clinical phenomena such as gender‐associated risk of developing neurodegenerative diseases and the age at onset of such diseases may be associated with brain iron levels. In vivo MRI can measure and track brain ferritin iron levels and provides an opportunity to design therapeutic interventions that target high‐risk populations early in the course of illness, possibly even before symptoms appear.
The Role of Iron in the Pathogenesis of Experimental Allergic Encephalomyelitis and Multiple Sclerosis
Authors: LEVINE STEVEN M. , CHAKRABARTY ANURADHA
Published: April 2004

Abstract: Multiple sclerosis (MS) and its animal model, experimental allergic encephalomyelitis (EAE), are autoimmune disorders resulting in demyelination in the central nervous system (CNS). Pathologically, the blood‐brain barrier becomes damaged, macrophages and T cells enter into the CNS, oligodendrocytes and myelin are destroyed, astrocytes and microglia undergo gliosis, and axons become transected. Data from several biochemical and pharmacological studies indicate that free radicals participate in the pathogenesis of EAE, and iron has been implicated as the catalyst leading to their formation. The primary focus of this article is the examination of the role of iron in the pathogenesis of MS and EAE. Particular attention will be paid to the role and distribution of iron and proteins involved with iron metabolism (e.g., transferrin, ferritin, heme oxygenase‐1, etc.) in normal and disease states of myelin. Furthermore, therapeutic interventions aimed at iron, iron‐binding proteins, and substrates or products of iron‐catalyzed reactions leading to free radical production will be discussed.
Germline stem cell number in theDrosophilaovary is regulated by redundant mechanisms that control Dpp signaling
Authors: Casanueva M. Olivia , Ferguson Edwin L.
Published: April 2004

The available experimental data support the hypothesis that the cap cells(CpCs) at the anterior tip of the germarium form an environmental niche for germline stem cells (GSCs) of the Drosophila ovary. Each GSC undergoes an asymmetric self-renewal division that gives rise to both a GSC,which remains associated with the CpCs, and a more posterior located cystoblast (CB). The CB upregulates expression of the novel gene, bag of marbles (bam), which is necessary for germline differentiation. Decapentaplegic (Dpp), a BMP2/4 homologue, has been postulated to act as a highly localized niche signal that maintains a GSC fate solely by repressing bam transcription. Here, we further examine the role of Dpp in GSC maintenance. In contrast to the above model, we find that an enhancer trap inserted near the Dpp target gene, Daughters against Dpp(Dad), is expressed in additional somatic cells within the germarium,suggesting that Dpp protein may be distributed throughout the anterior germarium. However, Dad-lacZ expression within the germline is present only in GSCs and to a lower level in CBs, suggesting there are mechanisms that actively restrict Dpp signaling in germ cells. We demonstrate that one function of Bam is to block Dpp signaling downstream of Dpp receptor activation, thus establishing the existence of a negative feedback loop between the action of the two genes. Moreover, in females doubly mutant for bam and the ubiquitin protein ligase Smurf, the number of germ cells responsive to Dpp is greatly increased relative to the number observed in either single mutant. These data indicate that there are multiple,genetically redundant mechanisms that act within the germline to downregulate Dpp signaling in the Cb and its descendants, and raise the possibility that a Cb and its descendants must become refractory to Dpp signaling in order for germline differentiation to occur.
Apaf1-dependent programmed cell death is required for inner ear morphogenesis and growth
Authors: Cecconi Francesco , Roth Kevin A. , Dolgov Oleg , Munarriz Eliana , Anokhin Konstantin , Gruss Peter , Salminen Marjo
Published: April 2004

During inner ear development programmed cell death occurs in specific areas of the otic epithelium but the significance of it and the molecules involved have remained unclear. We undertook an analysis of mouse mutants in which genes encoding apoptosis-associated molecules have been inactivated. Disruption of the Apaf1 gene led to a dramatic decrease in apoptosis in the inner ear epithelium, severe morphogenetic defects and a significant size reduction of the membranous labyrinth, demonstrating that an Apaf1-dependent apoptotic pathway is necessary for normal inner ear development. This pathway most probably operates through the apoptosome complex because caspase 9 mutant mice suffered similar defects. Inactivation of the Bcl2-like (Bcl2l) gene led to an overall increase in the number of cells undergoing apoptosis but did not cause any major morphogenetic defects. In contrast, decreased apoptosis was observed in specific locations that suffered from developmental deficits, indicating that proapoptotic isoform(s) produced from Bcl2l might have roles in inner ear development. In Apaf1-/-/Bcl2l-/-double mutant embryos, no cell death could be detected in the otic epithelium,demonstrating that the cell death regulated by the anti-apoptotic Bcl2l isoform, Bcl-XL in the otic epithelium is Apaf1-dependent. Furthermore, the otic vesicle failed to close completely in all double mutant embryos analyzed. These results indicate important roles for both Apaf1 and Bcl2l in inner ear development.
Preservation of reproductive behaviors during modest cooling: rapid cold-hardening fine-tunes organismal response
Authors: Shreve Scott M. , Kelty Jonathan D. , Lee Richard E.
Published: April 2004

The primary objectives of this study were to determine (1) whether rapid cold-hardening (RCH) preserves reproductive behaviors during modest cooling,(2) whether increased mating success at a lower temperature comes at the cost of decreased performance at a higher temperature and (3) whether RCH is associated with an elevated metabolic rate. Drosophila melanogaster(Diptera: Drosphilidae) were rapidly cold-hardened by a 2-h exposure to 16°C prior to experiments. A temperature decrease of only 7°C(23°C to 16°C) prevented half (11/22) of the control pairs of D. melanogaster from engaging in any courtship activity. By contrast, most RCH pairs courted (17/20). Additionally, the 7°C transfer prevented mating in every pair of control flies, whereas more than half (11/20) of the RCH pairs mated. There was no evidence of impaired courtship or mating performance when RCH pairs were tested at 23°C. Finally, RCH is apparently not an energy-demanding process because no increase in the metabolic rate was detected during its induction. Overall, these data demonstrate that RCH serves to constantly fine-tune an insect's physiological state to match slight changes in environmental temperature. Furthermore, the RCH response is not restricted to cryoprotection and survival in the cold but also preserves more subtle behaviors, such as courtship, at moderate to high temperatures throughout the year.
Echolocation clicks of two free-ranging, oceanic delphinids with different food preferences: false killer whales Pseudorca crassidensand Risso's dolphins Grampus griseus
Authors: Madsen P. T. , Kerr I. , Payne R.
Published: April 2004

Toothed whales (Odontoceti, Cetacea) navigate and locate prey by means of active echolocation. Studies on captive animals have accumulated a large body of knowledge concerning the production, reception and processing of sound in odontocete biosonars, but there is little information about the properties and use of biosonar clicks of free-ranging animals in offshore habitats. This study presents the first source parameter estimates of biosonar clicks from two free-ranging oceanic delphinids, the opportunistically foraging Pseudorca crassidens and the cephalopod eating Grampus griseus. Pseudorca produces short duration (30 μs), broadband(Q=2–3) signals with peak frequencies around 40 kHz, centroid frequencies of 30–70 kHz, and source levels between 201–225 dB re. 1 μPa (peak to peak, pp). Grampus also produces short (40 μs),broadband (Q=2–3) signals with peak frequencies around 50 kHz,centroid frequencies of 60–90 kHz, and source levels between 202 and 222 dB re. 1 μPa (pp). On-axis clicks from both species had centroid frequencies in the frequency range of most sensitive hearing, and lower peak frequencies and higher source levels than reported from captive animals. It is demonstrated that sound production in these two free-ranging echolocators is dynamic, and that free-ranging animals may not always employ biosonar signals comparable to the extreme signal properties reported from captive animals in long-range detection tasks. Similarities in source parameters suggest that evolutionary factors other than prey type determine the properties of biosonar signals of the two species. Modelling shows that interspecific detection ranges of prey types differ from 80 to 300 m for Grampus and Pseudorca, respectively.
Comparison of Specific Gravity and Creatinine for Normalizing Urinary Reproductive Hormone Concentrations
Authors: Miller Rebecca C , Brindle Eleanor , Holman Darryl J , Shofer Jane , Klein Nancy A , Soules Michael R , O’Connor Kathleen A
Published: April 2004

Background: Specific gravity (SG) may perform as well as creatinine (CR) correction for adjusting urinary hormone concentrations, as well as offer some advantages. We compared the two methods and applied them to US and Bangladeshi specimens to evaluate their use in different populations.

Methods: Pearson correlations between serum concentrations and SG, CR, and uncorrected urinary concentrations were compared using paired daily urine and serum specimens from one menstrual cycle from 30 US women. Corrected urinary estrone conjugate and pregnanediol glucuronide concentrations were compared with serum estradiol and progesterone. Urine specimens across one menstrual cycle from 13 Bangladeshi women were used to evaluate the applicability of both methods to a nonindustrialized population. Linear mixed-effects models were used to compare CR and SG values in the Bangladeshi vs US specimens.

Results: There was no significant difference between SG-corrected vs serum and CR-corrected vs serum correlations for either assay. Usable CR results were obtained for all US specimens, but 37% of the Bangladeshi specimens were below the CR assay limit of detection. The Bangladeshi sample had significantly lower CR and higher inter- and intrasubject CR variability than the US sample.

Conclusions: SG is a potentially useful alternative to CR correction for normalizing urinary steroid hormone concentrations, particularly in settings where CR values are highly variable or unusually low.
New measurement of 239+240Pu concentration in the IAEA reference materials SOIL-6 and IAEA-375
Authors: Chang Zhiyuan , Zhao Min , Jiang Songsheng , Li Jinghnai , Zhao Yonggang , Li Auli , Diao Lijun
Published: April 2004

Under an IAEA project for upgrading of the reference materials, a new measurement of 239+240Pu in the IAEA reference materials, SOIL-6 and IAEA-375, were performed. The extraction chromatography and a low background α-spectrometer were used for separation of plutonium and determination of 239+240Pu activity in the SOIL-6 and IAEA-375 samples. Homogeneity of SOIL-6 and IAEA-375 materials was checked by both F- and t-tests. The result showed that both materials could be considered to be sufficiently homogenous for weight of 30-50g. Activity concentration (C
A) of 239+240Pu in the SOIL-6 and IAEA-375 materials were determined to be (0.96±10.030) and (0.285±0.017)Bqkg-1 at 95% confidence level, respectively, at June 2002. The both present values of 239+240Pu C
A agree with the IAEA recommended in 95% confidence interval, but the both present values have high precision. Since the recommended values for SOIL-6 and IAEA-375 materials were issued about 20 and 10 years ago and error range of their recommended values were large, our obtained results might be useful in upgrading of the recommended values.
Physiological and Metabolic Interpretation of Diffusion‐Weighted Imaging Changes During Cerebral Ischemia
Authors: Hilger Thomas , Hoehn Mathias
Published: April 2004

Diffusion‐weighted imaging (DWI) has become one of the most important imaging modalities for the characterization of acute stroke. In this review article the connection between DWI and independent non‐MR parameters is evaluated, thereby providing the background for the physiological and metabolic interpretation of DWI changes. The pathophysiological consequences reflected by DWI changes are determined by the duration and intensity of an ischemic event. Reversible changes in water diffusion of tissue are triggered at a cerebral blood flow decrease to approximately 35–40 mL/100g*min. More severe hemodynamic disturbances (<20 mL/100g*min) obviously result in irreversible tissue damage. Furthermore, a distinct relative decrease of the apparent diffusion coefficient (ADC) to 90% of control indicates tissue acidosis, and it has been shown that, under certain conditions, the ADC reflects the current energy state of the brain, as validated by the distribution of ATP. A close correlation between the depletion of ATP and an ADC decrease to 77% of control was found for the acute phase of both permanent and transient cerebral ischemia. The correlation of diffusion changes with final tissue damage revealed that ADC can reliably predict histopathological damage during the early acute phase of cerebral ischemia and after transient recovery. However, in the intermediate phase, while histology showed further cellular degeneration, ADC obviously does not reflect the tissue status. Depending on the individual situation, a moderate ADC decrease to ca. 70–80% of control must not necessarily result in irreversible tissue damage, whereas more severe decline to ca. 60% of control presumably transforms to necrosis.
Polymerization of α‐Olefins Using Benzamidinate Zirconium Complexes Supported on Mesoporous Silica Materials
Authors: Ray Biswajit , Volkis Victoria , Lisovskii Anatoly , Eisen Moris S.
Published: April 2004

The polymerization of ethylene and propylene were studied using an anchored dimethyl benzamidinate zirconium complex. As supports, mesoporous silicas MCM‐41 and HMS were utilized. These inorganic materials were reacted with methylalumoxane to serve as the cocatalyst and to avoid the deactivation of the active cationic complex. The reaction of the octahedral benzamidinate zirconium complex with the supported cocatalysts results in the formation of active catalytic systems for the polymerization of olefins. The polymer properties were found to depend on the nature of the supports. The activity of the heterogeneous catalysts and the polymer characteristics were compared with those obtained with the homogeneous catalyst.
Synthetic flux‐promoting polyether models: Cation flux dependence on polyoxyethylene chain length
Authors: Espínola Carmen G. , Delgado Mercedes , Martín Julio D.
Published: April 2004

A novel class of cyclic polyoxyethylene derivatives incorporating a polybenzylated oxane system has been prepared via ruthenium‐catalyzed ring‐closing metathesis. These polyethers were incorporated into phospholipid vesicles and shown to facilitate transmembrane sodium transport. Maximum efficiency in sodium flux occurred when polyoxygenated chain lengths were similar to the leaflet thickness in bilayers. It is proposed that polyethers dimerize in order to function. The association constants of these polyethers with alkali metal cations and methyl ammonium ion have been evaluated using Cram's picrate extraction method.
Biomedical Applications of Diffusion‐Weighted NMR Techniques
Authors: Cohen Jack S.
Published: April 2004

MRI is a well‐established tool in clinical diagnosis, but it lacks the specificity that would allow clear distinctions between many disease conditions. That is mainly because it is a spatial tool that lacks functional information. There are several other NMR techniques that could be used to provide functional information and thus improve the specificity of MR diagnostics. One of these is the use of diffusion‐weighted (DW) MRI, which provides information about the diffusion of water in tissue. Preliminary animal and clinical results indicate that changes of the diffusion properties in tumors might provide early prediction of response or non‐reponse to therapy. Another useful adjunct to MRI is the application of NMR spectroscopy (or MRS), which provides spectroscopic information mainly on the metabolic components of the tissue. However, notwithstanding many years of research, proton MRS has not so far proved a useful adjunct to MRI for the physician. This is mainly because of (a) the presence of the huge solvent water peak and (b) the mixture of both intra‐ and extracellular metabolic components in the tissue. A further extension of MRS would be the use of DWMRS, which is the application of the DW technique to the spectroscopic components of tissue other than water. Using DWMRS we are able to observe only the intracellular metabolic components and their changes due to drug treatment. In this article we will explore the potential of these DW methods as applied to (a) perfused cells, (b) brain tumors in mice, and (c) human brain tumors.
Strategies for stereocontrol at C1 or C2 in syntheses of α‐glucosaminides
Authors: Fraser‐Reid Bert , Anilkumar G. , Nair Latha G. , Olsson Lars , Martin Mercedes Garcia , Daniels Jacquitta K.
Published: April 2004

The C1 and C2 stereocenters of α‐glucosaminides can be prepared by establishing the stereocenters in either order. For the former, a C2‐azido glucosyl donor is prepared first, and the restraining effect of a 4,6‐O‐benzylidene ring is used to induce α‐coupling. For the latter, the C1 linkage is prepared first by use of an n‐pentenyl‐manno‐1,2‐orthoester donor which ensures (a) clean α‐coupling and (b) a convenient C2‐ester. The C2‐ester is replaced with a triflate leaving group, and nucleophilic displacement is effected by use of a hypervalent silicon azide.
Self‐consistent hybrid approach for simulating electron transfer reactions in condensed phases
Authors: Wang Haobin , Thoss Michael
Published: April 2004

The recently proposed self‐consistent hybrid method is presented as a numerical tool for simulating quantum dynamics in complex systems. This method is based on an iterative convergence procedure for a dynamical hybrid approach. In this approach the overall system is partitioned into a core and a reservoir. The former is treated via a numerically exact quantum mechanical method, and the latter is treated via a more approximate method. Self‐consistent iterations are then carried out, with the number of core degrees of freedom and other variational parameters increased systematically to achieve numerical convergence for the overall quantum dynamics. The details of treating the core and the reservoir, as well as the convergence procedure, are discussed for several examples of electron transfer reactions in condensed phases. It is shown that the self‐consistent hybrid method provides an accurate and practical way of simulating quantum dissipative dynamics in a wide range of physical regimes.
On the relative rate of hydrolysis of a series of ketals and their proton affinities
Authors: Li Shigui , Dory Yves L. , Deslongchamps Pierre
Published: April 2004

The relative rates of hydrolysis of a series of cyclic and acyclic ketals was studied. Their reactivity toward acid hydrolysis is explained by considering the ease of protonation and the cleavage of the C—O bond. The experimental work and the theoretical calculations of the proton affinities of the ketals suggest that the rate‐limiting step of hydrolysis of ketals is a concerted protonation and cleavage of the C—O bond. The relative proton affinity is considered to be a direct consequence of the ease of proper lone pair orbital alignment on the oxygen atoms of the various ketals.
Two‐way interactions between ocean biota and climate mediated by biogeochemical cycles
Authors: Gildor Hezi , Follows Michael J.
Published: April 2004

Some of the two‐way interactions between ocean biota and climate are mediated by biogeochemical cycles that link the different components of the climate system. As suggested by proxy records extracted from ice and ocean cores, by recent measurements, and by numerical models, such two‐way interactions were likely major players in past climate variability on glacial—interglacial timescales, and may act to amplify or moderate an anthropogenically induced climate change in the near future. At present, our lack of understanding of these interactions hampers our ability to anticipate the consequences of possible anthropogenic climate change. In this article, we highlight some of the possible feedbacks between ocean biota and climate, reviewing some key biogeochemical processes and discussing mechanisms of two‐way interactions. We also outline the need and strategies for continuing research aimed at advancing our understanding of these feedbacks and discuss their significance.
Studies on Pseudomonas aeruginosa cd1 nitrite reductase: The association and dissociation reactions of the d1‐heme
Authors: Wilson Emma K. , Bellelli Andrea , Arese Marzia , Cutruzzolà Francesca , Brunori Maurizio , Aoyagi Katsuhiro , Smith Kevin M.
Published: April 2004

The dissociation and association reactions of the d1‐heme, the prosthetic group characteristic of cd1 nitrite reductases (NiRs), have been investigated to assess the stability of the native enzyme. At pH 5.0 and 37 °C, the rate constant for the dissociation of the ferric d1‐heme from native NiR purified from Pseudomonas aeruginosa is 4.7 ± 1.4 × 10−4 s−1. However, when the d1‐heme is in the ferrous state no dissociation is observed, consistent with the shortening and strengthening of the proximal bond upon reduction of the iron. Recombinant wild‐type protein and two single point mutants (Y10N and Y10F), which are expressed as semi‐apo proteins and were reconstituted with synthetic d1‐heme, display the same slow dissociation rate as the native enzyme. Therefore the stability of the d1‐heme bound in the crevice provided by the eight‐bladed ß propeller domain is not altered by the act of reconstitution or by these two point mutations. The association reaction between the ferric d1‐heme and semi‐apo NiR is second‐order and governed by an apparent rate constant of 3.3 × 106 M−1 s−1 at neutral pH and 25 °C. Interestingly, the combination rate constant is an order of magnitude slower than that reported for iron protoporphyrin IX and apomyoglobins or apohemoglobins. This difference appears to be a property of the d1‐heme and not of the protein since association rate constants of CO‐protoheme‐Fe(II) and dicyanoprotoheme‐Fe(III) with semi‐apo NiR are 5 × 107 M−1 s−1 and 6 × 107 M−1 s−1, respectively. These results are discussed with reference to the structure of the d1‐heme binding site, as inferred from the known 3D structure of P. aeruginosa NiR.
Adaptive control for a radio‐controlled helicopter in a vertical flying stand
Authors: Dzul Alejandro , Lozano Rogelio , Castillo Pedro
Published: April 2004

In this paper, we focus on the design and implementation of a controller for a two degree‐of‐freedom system. This system is composed of a small‐scale helicopter which is mounted on a vertical platform. The model is based on Lagrangian formulation and the controller is obtained by classical pole‐placement techniques for the yaw dynamics and adaptive pole‐placement for the altitude dynamics. Experimental results show the performance of such a controller. Copyright © 2004 John Wiley & Sons, Ltd.
Ferroelectric Lithography of Multicomponent Nanostructures
Authors: Kalinin S. V. , Bonnell D. A. , Alvarez T. , Lei X. , Hu Z. , Shao R. , Ferris J. H.
Published: April 2004

A novel approach to fabricating multicomponent nanostructures is demonstrated. Atomic polarization in ferroelectric perovskites is manipulated to control electronic structure and local chemical reactivity (see Figure). Several paradigms for ferroelectric domain patterning are presented. Complex structures consisting of semiconductors, metals, and functional organic/biological molecules are produced.
Paucity of TEL‐AML 1 translocation, by multiplex RT‐PCR, in B‐lineage acute lymphoblastic leukemia (ALL) in Indian patients
Authors: Sazawal S. , Bhatia K. , Gutierrez M.I. , Saxena R. , Arya L.S. , Bhargava M.
Published: April 2004

A total of 69 patients of B lineage ALL, 35 children (32 males, 3 females) and 34 young adults (27 males, 7 females) were studied by multiplex RT‐PCR to determine the relative frequency of t(9;22), t(12;21), t(1;19), and t(4;11,). Translocation (9;22) was seen in 1/35 (2.8%) and t(1;19) in 2/35 (5.7%) children. None of the children showed t(12;21) and t(4;11) translocations. In young adults, t(9;22) and t(1;19) were seen in 5/34 (14.7%) and 2/34 (5.8%) patients, respectively. None of the latter showed t(12;21) or t(4;11) translocations. Thus, there appears to be a significant under representation of the fusion transcripts for TEL‐AML, a good prognostic marker, in this study, unlike in the West, where it is seen in 35% of children with ALL. This, together with the generally increased leukemic burden seen in Indian patients, may explain in part, the poor treatment outcome reported. Am. J. Hematol. 76:80–82, 2004. © 2004 Wiley‐Liss, Inc.
Second malignant neoplasms in childhood acute lymphoblastic leukemia: Primitive neuroectodermal tumor of the chest wall with germline p53 mutation as a second malignant neoplasm
Authors: Suarez Carlos R. , Bertolone Salvatore J. , Raj Ashok B. , Coventry Susan
Published: April 2004

About 80% of children treated for acute lymphoblastic leukemia (ALL) will be long‐term survivors. Second malignant neoplasm (SMNs) are a devastating sequelae observed on these children, with an estimated cumulative risk of 2–3.3% fifteen years after diagnosis. Primitive neuroectodermal tumor of bone (PNET) is rarely observed as a SMN following treatment of childhood ALL. The authors described the occurrence of a chest wall PNET of the bone at the site of a central line placement associated with both germ‐line and tumor cell p53 mutation in a 8‐year‐old boy 1 year after completing therapy for standard risk ALL. A review of the literature of 25,051 children treated for ALL discovered 230 SMNs (0.99%), and only one case of PNET of the bone was noted among this group. The occurrence of a SMN in children treated for ALL is a rare event. Such an occurrence, in particular the development of an unusual SMN, should be evaluated for a germline p53 mutation. Am. J. Hematol. 76:52–56, 2004. © 2004 Wiley‐Liss, Inc.
R147W mutation of PROC gene is common in venous thrombotic patients in Taiwanese Chinese
Authors: Tsay Woei , Shen Ming‐Ching
Published: April 2004

We analyzed the genetic defects of 21 unrelated patients with venous thrombosis in whom hereditary protein C deficiency was diagnosed. Eleven mutations were detected in 18 families, while no mutation was detectable in the other three families. Among these mutations, a common genetic mutation of protein C (PROC) gene recurred in 43% (nine propositi from these 21 families). This C6152T mutation at exon 7 resulted in a missense mutation, Arg147Trp (R147W). Each propositus or family carrier had another specific polymorphism T66C at exon 2, which did not change the proline at position (−21). The haplotype analysis strongly suggested a founder effect. The first thrombotic attack was significantly younger in patients with multiple genetic defects or combined with other risk factors than those without precipitating factors. We further studied the prevalence rate of R147W mutations in normal populations through PCR amplification and dot hybridization. Three different cohorts got similar results. The prevalence rate of R147W in health controls is 0.85% [95% confidence interval (CI) 0.35–1.35]. Analysis of plasma protein C levels of all patients or carriers suggested that R147W was a type II deficiency. The odds ratio of thrombosis of R147W is 5.1 (95% CI 1.7–14.8). Taken together, R147W mutation is a significant thrombotic risk factor and is the most common defect of PROC gene in Taiwanese patients with protein C deficiency. This finding is important for screening thrombophilic families in Chinese populations. Am. J. Hematol. 76:8–13, 2004. © 2004 Wiley‐Liss, Inc.
Allogeneic hematopoietic stem cell transplantation for seven children with X‐linked hyper‐IgM syndrome: A single center experience
Authors: Tomizawa Daisuke , Imai Kohsuke , Ito Sukeyuki , Kajiwara Michiko , Minegishi Yoshiyuki , Nagasawa Masayuki , Morio Tomohiro , Nonoyama Shigeaki , Mizutani Shuki
Published: April 2004

X‐linked hyper‐IgM syndrome (XHIM), or hyper‐IgM syndrome type 1 (HIGM1), is a rare primary immunodeficiency disorder susceptible to recurrent bacterial infection and opportunistic infection such as Pneumocystis carinii and Cryptosporidium parvum. The long‐term outcome is quite poor, and allogeneic hematopoietic stem cell transplantation (HSCT) offers the only cure. Seven patients with XHIM, from age 3 to 19 years (mean 11.3 years), underwent allogeneic HSCT in our institution. Details of pre‐ and post‐transplantation data and transplantation procedure were analyzed retrospectively. The donors were HLA‐identical siblings for three patients and HLA‐identical unrelated donors for four patients. All but one received conventional conditioning regimen consisting of busulfan and cyclophosphamide and prophylaxis for graft‐versus‐host disease (GVHD) consisting of cyclosporine and methotrexate. Five out of seven patients are alive and well with normal CD40L expression, and four of these five are free of intravenous immunoglobulin supplementation. The two patients who died had prolonged episodes of severe and recurrent infections and organ damage. We conclude that conventional allogeneic HSCT from HLA matched related or unrelated donors is curative and feasible for XHIM patients, if performed before significant infections and organ damage occur. For the high‐risk patients, an alternative approach including nonmyeloablative HSCT may be more feasible. Am. J. Hematol. 76:33–39, 2004. © 2004 Wiley‐Liss, Inc.
Cytotoxic T‐lymphocyte antigen‐4 (CTLA‐4) gene polymorphism and susceptibility to non‐Hodgkin's lymphoma
Authors: Monne Maria , Piras Giovanna , Palmas Angelo , Arru Luigi , Murineddu Marco , Latte Giancarlo , Noli Annalisa , Gabbas Attilio
Published: April 2004

The CTLA‐4 molecule plays an important role in immune regulation by downregulating activation of T cells. Polymorphisms in the CTLA‐4 gene have been shown to be associated to a number of autoimmune diseases including blood disorders. In this study, the intragenic polymorphisms of the CTLA‐4 gene at position −318*C/T, +49*A/G, and the dinucleotide (AT)n repeat polymorphism in exon 3 were analyzed in patients with non‐Hodgkin's lymphoma. Genotype and haplotype analysis showed that the exon 1+49*AA genotype was over‐represented among patients with NHL (P = 0.002), whereas no difference was observed for the −318*C/T promoter and the (AT)n polymorphisms (P > 0.05). The data obtained indicate that the CTLA‐4+49A/G polymorphism may have a role in genetic susceptibility to NHL. Am. J. Hematol. 76:14–18, 2004. © 2004 Wiley‐Liss, Inc.
Thalidomide in POEMS syndrome: Case report
Authors: Sinisalo Marjatta , Hietaharju Aki , Sauranen Jukka , Wirta Ole
Published: April 2004

We report a patient with incapacitating POEMS syndrome characterized by serum monoclonal protein, polyneuropathy, organomegaly, endocrinopathy, mesangiocapillary glomerulonephritis, massive ascites formation, and pulmonary hypertension. A dramatic improvement in the clinical condition occurred after administration of thalidomide, a drug with known anti‐angiogenetic, anti‐proliferative, and anti‐cytokine properties. Am. J. Hematol. 76:66–68, 2004. © 2004 Wiley‐Liss, Inc.