bluuebunny/crossref_metadata_2025_split huggingface dataset:
CNS late‐effects after ALL therapy in childhood. Part III: Neuropsychological performance in long‐term survivors of childhood ALL: Impairments of concentration, attention, and memory*†‡
Authors: Langer Thorsten , Martus Peter , Ottensmeier Holger , Hertzberg Holger , Beck Jörn D. , Meier Walburga 
Published: August 2002

AbstractPurposeTo date, the event free survival (EFS) after treatment of childhood acute lymphoblastic leukemia (ALL) attains 80%. The survivor group is growing steadily. Therefore, the primary purpose of our study is to define the neuropsychological function and to describe which central nervous system (CNS) functions are impaired following the German ALL‐BFM and COALL protocols for CNS‐negative patients.Patients and MethodsIn a cross‐sectional multicenter study 121 subjects, long‐term survivors of childhood ALL in first continuous complete remission were investigated. Seven years ago, the subjects were treated as standard or medium risk patients according to ALL‐BFM 81, ALL‐BFM 83, or COALL 82 protocols, receiving comparable treatments. According to different CNS‐prophylaxes, two subgroups were compared in the study: the non‐cranially irradiated MTX‐group (methotrexate‐group) (n = 38) and the cranially irradiated RT‐group (radiotherapy‐group) (with MTX i.th.) (n = 83). Intellectual and cognitive abilities of these groups were evaluated using standardized psychometric techniques. The Kaufman factors Verbal Comprehension, Perceptual Organisation and Freedom from Distractibility were calculated. Demographical and clinical data collected at the time of the diagnosis were compared between both groups. The different prognoses for patients within both groups were taken into account using a defined risk factor. Analysis of variance was conducted to relate intellectual performance to age, gender, and CNS‐treatment.ResultsThe RT‐group exhibited a lower Full Scale IQ than the MTX‐group (101.2 ± 15.9 vs. 109.9 ± 14.9, P = 0.031). Particularly for the Kaufman factor Freedom from Distractibility the RT‐group showed the lower scores (96.9 ± 14.1 vs. 105.5 ± 12.6, P = 0.037). Significant interactions between gender and CNS prophylactic treatment were observed for Full Scale IQ (P = 0.008), Verbal IQ (P = 0.012), Performance IQ (P = 0.024), Verbal Comprehension (P = 0.004), and Perceptual Organisation (P = 0.032).ConclusionsCranial irradiation in combination with MTX therapy was associated with deficits in attention, concentration, and the ability of sequencing and processing, measured by the Kaufman factor Freedom from Distractibility. Our results support the strategy of avoiding prophylactic CNS irradiation in low risk patients. Med. Pediatr. Oncol. 2002;38:320–328. © 2002 Wiley‐Liss, Inc.
Perinatal exposure to infection and risk of childhood leukemia
Authors: Naumburg Estelle , Bellocco Rino , Cnattingius Sven , Jonzon Anders , Ekbom Anders 
Published: August 2002

AbstractBackgroundA population‐based case‐control study was conducted to investigate the association between childhood leukemia and infectious exposures during pregnancy and early neonatal period.ProcedureChildren born and diagnosed with leukemia between 1973 and 1989 in Sweden (578 lymphatic, 74 myeloid) were selected as cases. One control was randomly selected for each case and individually matched by sex, month, and year of birth. Children with Down's syndrome were excluded. Exposure data were blindly abstracted from antenatal, obstetric, and other standardized medical records. Odds ratios (OR) and 95% confidence intervals (CI) were calculated by conditional logistic regression.ResultsA history of maternal infection was not significantly associated with childhood leukemia, OR = 1.25 (95% CI 0.95–1.65). Maternal lower genital tract infection significantly increased the risk of childhood leukemia, OR = 1.78 (95% CI 1.17–2.72), and especially for children over 4 years of age at diagnosis, OR = 2.01 (95% CI 1.12–3.80). Neonatal infection was not associated with the risk of leukemia. The results remained unaltered after adjustment for potential confounders, and separate analyses for myeloid and lymphoid leukemia.ConclusionsWe could document an association between exposure to maternal lower genital tract infection in utero, and a subsequent risk for childhood leukemia, which indicate the importance of an early exposure. Med Pediatr Oncol 2002;38:391–397. © 2002 Wiley‐Liss, Inc.
1H and 13C NMR study of 6‐aryl‐3‐cinchopheny‐1,2,4‐triazolo[3,4‐b]‐1,3,4‐thiadiazoles
Authors: Liu Xue‐hui , Xu Hao , Fang Yi‐ou , Cui Yu‐xin , Xu Peng‐fei 
Published: August 2002

AbstractTen new 1,2,4‐triazolo[3,4‐b]‐1,3,4‐thiadiazole derivatives were synthesized and their NMR spectra were analyzed by 1D and 2D NMR techniques (gCOSY, gHMBC, gHMQC). Copyright © 2001 John Wiley & Sons, Ltd.
Characteristics of the cell membrane fluidity, actin fibers, and mitochondrial dysfunctions of frozen‐thawed two‐cell mouse embryos
Authors: Ahn Haek Jun , Sohn In Pyo , Kwon Hyuck Chan , Jo Do Hyun , Park Young Dong , Min Churl K. 
Published: August 2002

AbstractPhysical and chemical alterations caused by the freezing and thawing and their effects on survivals/developments in vitro were investigated. Of a total of 452 two‐cell mouse embryos, the overall survival rate of the frozen‐thawed embryos was 76.1% (344/452). The blastocyst formation of the frozen‐thawed embryos was 32.6% (44/136) compared to 74.5% (117/157) in the fresh embryos (P < 0.05). The total number of cells in a blastocyst also decreased from 96.0 ± 19.0 (n = 26) in the fresh embryos to 42.0 ± 11.34 (n = 30) in the frozen‐thawed embryos (P < 0.05). Fluorescence recovery after photobleaching (FRAP) measurement revealed about 5‐fold decrease in the cell membrane fluidity with a characteristic time constant (τ) of 1.46 ± 0.13 sec (n = 5) in the frozen‐thawed embryos as opposed to 0.28 ± 0.04 sec (n = 5) in the fresh embryos (P < 0.05). The relative amount of H2O2 in an embryo as quantified by the fluorescence intensity of 2′,7′‐dichlorofluorescein (DCF) showed 62.8 ± 23.5 (n = 24) and 34.2 ± 14.5 (n = 20) in the frozen‐thawed embryos and in the fresh embryos, respectively (P < 0.05). The distribution of actin filaments in the frozen‐thawed embryos revealed an uneven distribution, particularly discontinuities at the “actin band,” which contrasted to an even distribution shown in the fresh embryos. Mitochondrial staining by Rhodamine 123 showed that there was no significant difference between the two treatments in the number and in the distribution of viable mitochondria, but a marked aggregation was seen in the arrested embryos. No Annexin V binding was detected in two‐cell or four‐cell embryos while the binding was positive in the arrested embryos. The mitochondrial membrane potential measured by a membrane potential‐sensitive fluorescent probe 5,5′,6,6′‐tetrachloro‐1,1′,3,3′‐tetraethylbenzimidazol‐ carbocyanine iodide (JC‐1) revealed a marked depolarization in the frozen‐thawed embryos. Finally, terminal deoxynucleotidyl transferase (TdT)‐mediated dUTP‐digoxigenin nick end‐labeling (TUNEL) was employed to quantify the DNA fragmentation. In 75.0% cells of blastocysts (n = 24) in the frozen‐thawed embryos, the DNA fragmentation was detected as opposed to 37.0% in the fresh embryos (n = 20) (P < 0.05). Taken together, it is proposed that during the cryopreservation, two‐cell mouse embryos are subjected to physical and chemical alterations, including destruction of the cell membrane integrity, redistribution of actin fibers, mitochondrial depolarizations, and increased reactive oxygen species (ROS) productions, which then may trigger the apoptotic cascade leading to a decrease in the survival rate and in the developmental rate of the embryos. Mol. Reprod. Dev. 61:466–476, 2002. © 2002 Wiley‐Liss, Inc.
Ubiquitin‐dependent sperm quality control mechanism recognizes spermatozoa with DNA defects as revealed by dual ubiquitin‐TUNEL assay
Authors: Sutovsky Peter , Neuber Evelyn , Schatten Gerald 
Published: August 2002

AbstractDefective mammalian spermatozoa become ubiquitinated during epididymal passage, a mechanism that may mark the abnormal spermatozoa for proteolytic destruction (Sutovsky et al.,2001a: J Cell Sci 114:1665–1675). It is not known how such spermatozoa are recognized by the epididymal ubiquitination pathway and whether there is a selection against certain types of sperm defects. We examined the relationship between sperm ubiqutination, lifelong sperm morphology and sperm DNA defects using a single chanel, ubiquitin‐activated flow cytometric assay, and a dual, ubiquitin‐TUNEL assay. Semen samples from nine service sires of good‐to‐average fertility were screened. A positive correlation was found between sperm ubiquitination and the average frequency of morphological semen abnormalities from field evaluations performed throughout the reproductive life of individual sires. Sample correlation coefficients were r = 0.65 for primary (head and tail) and r = 0.60 for total semen abnormalities in the single channel assay. In a dual assay, we found a high, positive correlation (r = 0.93) between the ubiquitin‐positive sperm and the TUNEL positive sperm. Substantial correlations (r = 0.47–0.64) were observed when the measurements from these two respective assays were compared for individual sires. While anti‐ubiquitin antibodies recognized most of the TUNEL‐positive sperm cells, the TUNEL‐positive spermatozoa represented only a subset (∼20–40%) of all ubiquitin‐positive cells. It appears that the ubiquitin‐dependent sperm quality control, residing in the epididymal epithelium, has the ability to detect spermatozoa with apoptotic or necrotic DNA, while spermatozoa with defects other than DNA fragmentation are also recognized and ubiquitinated.Mol. Reprod. Dev. 61: 406–413, 2002. © 2002 Wiley‐Liss, Inc.
Mitogen activated protein kinase plays a significant role in metaphase II arrest, spindle morphology, and maintenance of maturation promoting factor activity in bovine oocytes
Authors: Gordo Ana Carla , He Chang Li , Smith Sallie , Fissore Rafael A. 
Published: August 2002

AbstractMammalian oocytes are arrested at the G2/M transition of the first meiotic division from which, after reaching full size and subsequent to an LH surge, they undergo final maturation. Oocyte maturation, which involves germinal vesicle breakdown, progression through metaphase I (MI), and arrest at MII, is triggered and regulated by the coordinated action of two kinases, maturation promoting factor (MPF) and mitogen activated protein kinase (MAPK). The importance of the role of MPF in mammalian oocyte maturation is well established, while the role of MAPK, although well understood in mouse oocytes, has not been fully elucidated in oocytes of large domestic species, especially bovine oocytes. Here we show that injection of MKP‐1 mRNA, which encodes a dual specificity MAPK phosphatase, into germinal vesicle stage bovine oocytes prevents the activation of MAPK during maturation. Despite the lack of MAPK activity, MKP‐1‐injected oocytes resume and progress through meiosis, although they are unable to arrest at MII stage and, by 22–26‐hour post‐maturation, exhibit decondensed pronucleus‐like chromatin, a clear sign of parthenogenetic activation. MKP‐1‐injected bovine oocytes exhibit normal activation of MPF activity; however, by 18‐hour post‐maturation, MPF activity starts to decline and by 22–26 hr MPF activity is absent. MKP‐1‐injected oocytes also show disorganized MII spindles with poorly aligned chromosomes. In summary, our results demonstrate that in bovine oocytes MAPK activity is required for MII arrest, maintenance of MPF activity, and spindle organization. Mol. Reprod. Dev. 59:106–114, 2001. © 2001 Wiley‐Liss, Inc.
Infection markers and early signs of neonatal encephalopathy in the term infant
Authors: Shalak Lina F. , Perlman Jeffrey M. 
Published: August 2002

AbstractRecent evidence points to an association between intrauterine infection and cerebral palsy (CP) in the preterm as well as the term infant. The mechanisms that link these two conditions are unclear. Chorioamnionitis is a common clinical problem complicating 5–10% of pregnancies, whereas the incidence of CP attributed to intrapartum asphyxia is rare. Chorioamnionitis may result in brain injury as a result of interruption of placental blood flow (asphyxia), or via fever and/ or the cytokine release associated with infection. This review will attempt to establish the link between perinatal infection and brain damage in term infants. The characteristics of the perinatal inflammatory response, the potential mechanisms of brain injury associated with infection, and the clinical characteristics of neonatal encephalopathy will be discussed. MRDD Research Reviews 2002;8:14–19. © 2002 Wiley‐Liss, Inc.
Why does MTR change with neuronal depolarization?
Authors: Stanisz Greg J. , Yoon Richard S. , Joy Michael L. G. , Henkelman R. Mark 
Published: August 2002

AbstractT1 and T2 relaxation, and magnetization transfer (MT) of the rat brain were measured during experimentally induced spreading depression (SD). All measured MR parameters changed during SD: T1 relaxation increased by approximately 13%, whereas the T2 increase was substantially larger (88%). MT results showed an MT ratio (MTR) decrease of 9%. The lack of change in the MT exchange rate indicated that the MT processes between water and macromolecular protons are not affected by neuronal depolarization. The observed decrease in MTR was only caused by changes in T1 and T2 relaxation. Magn Reson Med 47:472–475, 2002. © 2002 Wiley‐Liss, Inc.
Localized two‐dimensional shift correlated MR spectroscopy of human brain
Authors: Thomas M. Albert , Yue Kenneth , Binesh Nader , Davanzo Pablo , Kumar Anand , Siegel Benjamin , Frye Mark , Curran John , Lufkin Robert , Martin Paul , Guze Barry 
Published: August 2002

AbstractA two‐dimensional (2D) chemical shift correlated MR spectroscopic (COSY) sequence integrated into a new volume localization technique (90°–180°–90°) is proposed for whole‐body MR spectroscopy (MRS). Using the product operator formalism, a theoretical calculation of the volume localization as well as the coherence transfer efficiencies in 2D MRS is presented. Phantom model solutions were used to test and optimize the efficiency of the proposed sequence. A combination of different MRI transmit/receive RF coils was used: a head MRI coil and a 3″ surface coil receive combined with a body coil transmit. The J cross‐peaks due to N‐acetyl aspartate (NAA), glutamate/glutamine (Glx), myo‐inositol (mI), creatine (Cr), choline (Ch), aspartate (Asp), γ‐aminobutyrate (GABA), taurine (Tau), glutathione (GSH), threonine (Thr), and macromolecules (MM) were identified. The cross‐peak intensities excited by the proposed 2D sequence were asymmetric with respect to the diagonal peaks. Localized COSY (L‐COSY) spectra of cerebral prefrontal and occipital gray/white matter regions in 15 healthy controls are presented. Magn Reson Med 46:58–67, 2001. © 2001 Wiley‐Liss, Inc.
Measurement of tissue oxygen extraction ratios from venous blood T2: Increased precision and validation of principle
Authors: Golay Xavier , Silvennoinen M. Johanna , Zhou Jinyuan , Clingman Chekesha S. , Kauppinen Risto A. , Pekar James J. , van Zij Peter C.M. 
Published: August 2002

AbstractIt has recently been shown that parenchymal oxygen extraction ratios (OERs) can be quantified using the absolute T2 of venous blood draining from this tissue (Oja et al., J Cereb Blood Flow Metab 1999;19:1289–1295). Here, a modified Carr‐Purcell‐Meiboom‐Gill (CPMG) multiecho experiment was used to increase the efficiency and precision of this approach and to test the applicability of the two‐compartment exchange model for spin‐echo BOLD effects in pure venous blood. Relaxation measurements on bovine blood as a function of CPMG interecho spacing, oxygen saturation, and hematocrit provided the baseline relaxation and susceptibility shift parameters necessary to directly relate OER to T2 of venous blood in vivo. Using an interecho spacing of 25 ms, the results on visual activation studies in eight volunteers showed T2(CPMG) values increasing from 128 ± 9 ms to 174 ± 18 ms upon activation, corresponding to local OER values of 0.38 ± 0.04 and 0.18 ± 0.05 during baseline activity and visual stimulation, respectively. These OER values are in good agreement with literature data on venous oxygenation and numbers determined previously using a single‐echo approach, while the measured T2s are about 20–40 ms longer. Magn Reson Med 46:282–291, 2001. © 2001 Wiley‐Liss, Inc.
Possible pathogenic role of muscle cell dysfunction in motor neuron death in spinal muscular atrophy
Authors: Guettier‐Sigrist Séverine , Hugel Bénédicte , Coupin Gilliane , Freyssinet Jean‐Marie , Poindron Philippe , Warter Jean‐Marie 
Published: August 2002

AbstractWe have previously shown that myofibers formed by fusion of muscle satellite cells from spinal muscular atrophy (SMA) I or II undergo degeneration 1 to 3 weeks after innervation by rat embryonic spinal cord explants, whereas normal myofibers survive for several months. In the “muscle component” of the coculture, the only cells responsible for the degeneration are the SMA muscle satellite cells. Moreover, SMA muscle satellite cells do not fuse as rapidly as do normal muscle satellite cells. To determine whether death of muscle cells precedes that of motor neurons, we studied the origin and kinetics of release of apoptotic microparticles. In SMA cocultures, motor neuron apoptosis occurred before myofiber degeneration becomes visible, indicating that SMA myofibers were unable to sustain survival of motor neurons. In normal cocultures, motor neuron apoptosis occurred 4 days after innervation. However, it did not continue beyond 2 days. These results strengthen the hypothesis that SMA is due to a defect in neurotrophic muscle cell function. © 2002 Wiley Periodicals, Inc. Muscle Nerve 25: 000–000, 2002
Passive stiffness is increased in soleus muscle of desmin knockout mouse
Authors: Anderson Judith , Li Zhenlin , Goubel Francis 
Published: August 2002

AbstractThe effects of an absence of desmin on passive stiffness of skeletal muscle were analyzed using soleus muscles from desmin knockout mice. Stiffness was evaluated by analyzing the passive tension induced by a ramp‐and‐hold extension test. This test showed that passive resistance to stretch was largely increased for muscles lacking desmin. This study could facilitate interpretation of changes in muscle mechanics observed in humans affected by desmin‐related myopathies. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 1090–1092, 2001
Determination of rock mass strength properties by homogenization
Authors: Pouya A. , Ghoreychi M. 
Published: August 2002

AbstractA method for determining fractured rock mass properties is presented here on the basis of homogenization approach. The rock mass is considered to be a heterogeneous medium composed of intact rock and of fractures. Its constitutive model is studied numerically using finite element method and assimilating the fractures to joint elements (Coste, Comportement Thermo‐Hydro‐Mécanique des massifs rocheux fracturés. Thèse de Doctorat, Ecole Nationale des Ponts et Chaussées, Paris, 1997). The method has been applied to a granite formation in France. Geological data on different families of fractures have been used for the statistical representation of the fractures. A mesh‐generating tool for the medium with high density of fractures has been developed. The mechanical behaviour of the rock mass (elasticity, ultimate strength and hardening law) has been determined assuming linear elasticity and Mohr–Coulomb strength criterion both for the intact rock and the fractures. Evolution of the mechanical strength in different directions has been determined as a function of the mean stress, thanks to various numerical simulations. The mechanical strength appears to be anisotropic due to the preferential orientation of the fractures. The numerical results allowed us to determine an oriented strength criterion for the homogenized rock mass. A 2D constitutive law for the homogenized medium has been deduced from numerical data. A 3D extension of this model is also presented. Copyright © 2001 John Wiley & Sons, Ltd.
Analysis of undrained cavity expansion in elasto‐plastic soils with non‐linear elasticity
Authors: Cao Lai Fa , Teh Cee Ing , Chang Ming‐Fang 
Published: August 2002

AbstractA large strain analysis of undrained expansion of a spherical/cylindrical cavity in a soil modelled as non‐linear elastic modified Cam clay material is presented. The stress–strain response of the soil is assumed to obey non‐linear elasticity until yielding. A power‐law characteristic or a hyperbolic stress–strain curve is used to describe the gradual reduction of soil stiffness with shear strain. It is assumed that, after yielding, the elasto‐plastic behaviour of the soil can be described by the modified Cam clay model. Based on a closed‐form stress–strain response in undrained condition, a numerical solution is obtained with the aid of simple numerical integration technique. The results show that the stresses and the pore pressure in the soil around an expanded cavity are significantly affected by the non‐linear elasticity, especially if the soil is overconsolidated. The difference between large strain and small strain solutions in the elastic zone is not significant. The stresses and the pore pressure at the cavity wall can be expressed as an approximate closed‐form solution. Copyright © 2001 John Wiley & Sons, Ltd.
Two‐stage component test plans for testing the reliability of a series system
Authors: Vellaisamy P. , Sankar S. 
Published: August 2002

AbstractA system reliability is often evaluated by individual tests of components that constitute the system. These component test plans have advantages over complete system based tests in terms of time and cost. In this paper, we consider the series system with n components, where the lifetime of the i‐th component follows exponential distribution with parameter λi. Assuming test costs for the components are different, we develop an efficient algorithm to design a two‐stage component test plan that satisfies the usual probability requirements on the system reliability and in addition minimizes the maximum expected cost. For the case of prior information in the form of upper bounds on λi's, we use the genetic algorithm to solve the associated optimization problems which are otherwise difficult to solve using mathematical programming techniques. The two‐stage component test plans are cost effective compared to single‐stage plans developed by Rajgopal and Mazumdar. We demonstrate through several numerical examples that our approach has the potential to reduce the overall testing costs significantly. © 2002 John Wiley & Sons, Inc. Naval Research Logistics, 49: 95–116, 2002; DOI 10.1002/nav.1051
A new kind of fictitious play
Authors: Washburn Alan 
Published: August 2002

AbstractGass, Zafra, and Qiu (1996) introduce a modified version of fictitious play for matrix games where only the more successful player's strategy is retained. This paper introduces additional modifications that appear to converge faster. © 2001 John Wiley & Sons, Inc.* Naval Research Logistics 48: 270–280, 2001
Tricarboxylic acid cycle of glia in the in vivo human brain
Authors: Blüml S. , Moreno‐Torres A. , Shic F. , Nguy C.‐H. , Ross B. D. 
Published: August 2002

AbstractIn the brain, acetate is exclusively oxidized by glia. To determine the contribution of glial metabolism to the tricarboxylic acid cycle (TCA), 1‐13C‐acetate was infused in six studies in three normal adult subjects and ­one epileptic receiving valproic acid for seizure control. Ten grams of 99% 1‐13C labeled acetate were infused intravenously as a 3.3% w/v solution over 60 min, during which in vivo 13C MR spectra of the brain were acquired. As expected, 13C label rapidly enriched cerebral bicarbonate, glutamate and glutamine C5. The mean rate of acetate oxidation calculated from steady‐state 13C enrichment of bicarbonate in fasted normal subjects was 0.13 ± 0.03 µmol/g/min (n = 4), approximately 20% of the total cerebral TCA cycle rate. Copyright © 2002 John Wiley & Sons, Ltd.