bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cigarette smoking and aneuploidy in human sperm
Authors: Shi Qinghua , Ko Evelyn , Barclay Leona , Hoang Tina , Rademaker Alfred , Martin RenÉe 
Published: August 2002

AbstractCigarette smoke contains chemicals which are capable of inducing aneuploidy in experimental systems. These chemicals have been shown to reach the male reproductive system, increasing oxidative DNA damage in human sperm and lowering semen quality. We have examined the association between smoking and aneuploid sperm by studying 31 Chinese men with similar demographic characteristics and lifestyle factors except for cigarette smoking. None of the men drank alcohol. These men were divided into three groups: nonsmokers (10 men), light smokers (< 20 cigarettes/day, 11 men), and heavy smokers (≥ 20 cigarettes/day, 10 men). There were no significant differences in semen parameters or in age across groups. Two multi‐color fluorescence in situ hybridizations (FISH) were performed: two‐color FISH for chromosomes 13 and 21, and three‐color FISH for the sex chromosomes using chromosome 1 as an internal autosomal control for diploidy and lack of hybridization. The mean hybridization efficiency was 99.78%. The frequency of disomy 13 was significantly higher in light and heavy smokers than in non‐smokers, while no significant differences in the frequency of disomy 21, X or Y were observed across groups. Significant inter‐donor heterogeneity in every category of disomic sperm examined was found in both light and heavy smokers, while in nonsmokers only XY disomy showed significant inter‐donor differences. Thus, we conclude that cigarette smoking may increase the risk of aneuploidy only for certain chromosomes and that men may have different susceptibilities to aneuploidy in germ cells induced by cigarette smoking. Mol. Reprod. Dev. 59: 417–421, 2001. © 2001 Wiley‐Liss, Inc.
17β‐estradiol induces spermatogonial proliferation through mitogen‐activated protein kinase (extracellular signal‐regulated kinase 1/2) activity in the lizard (Podarcis s. sicula)
Authors: Chieffi Paolo , D'Amato Luca Colucci , Guarino Fabio , Salvatore Gaetano , Angelini Francesco 
Published: August 2002

AbstractThere are always more evidences indicating that 17β‐estradiol (E2) is necessary for normal male fertility. We have used a nonmammalian vertebrate model (the lizard Podarcis s. sicula) to investigate the regulation of extracellular signal‐regulated kinase 1 and 2 (ERK1/2) activity in the testis during the annual sexual cycle and to study whether E2 exerts a role in the spermatogenesis through ERK1/2 activity. Immunocytochemistry analysis shows that ERK1/2 proteins are present in the nucleus of the spermatogonia (SPG), and in primary (I) spermatocytes (SPC). The annual E2 profile shows a progressive increase during the active spermatogenesis (from April to June) and a peak in the month of August (spermatogonial mitosis). In parallel, ERK1/2 (molecular weight 44 and 42 kDa, respectively) are highly phosphorylated during the period of active spermatogenesis and in post‐refractory period (August) compared with the winter stasis (from November to March). Present results demonstrate that E2 treatment induces spermatogonial proliferation, possibly via the activation of ERK1/2, and this effect is counteracted by the antiestrogen ICI 182‐780. Mol. Reprod. Dev. 61: 218–225, 2002. © 2002 Wiley‐Liss, Inc.
Different excitation and reception distributions with a single‐loop transmit‐receive surface coil near a head‐sized spherical phantom at 300 MHz
Authors: Collins C.M. , Yang Q.X. , Wang J.H. , Zhang X. , Liu H. , Michaeli S. , Zhu X.‐H. , Adriany G. , Vaughan J.T. , Anderson P. , Merkle H. , Ugurbil K. , Smith M.B. , Chen W. 
Published: August 2002

AbstractCalculations and experiments were used to examine the B1 field behavior and signal intensity distribution in a 16‐cm diameter spherical phantom excited by a 10‐cm diameter surface coil at 300 MHz. In this simple system at this high frequency very complex RF field behavior exists, resulting in different excitation and reception distributions. Included in this work is a straightforward demonstration that coil receptivity is proportional to the magnitude of the circularly polarized component of the B1 field that rotates in the direction opposite to that of nuclear precession. It is clearly apparent that even in very simple systems in head‐sized samples at this frequency it is important to consider the separate excitation and reception distributions in order to understand the signal intensity distribution. Magn Reson Med 47:1026–1028, 2002. © 2002 Wiley‐Liss, Inc.
Improved selectivity of double quantum coherence filtering for the detection of glutathione in the human brain in vivo
Authors: Trabesinger Andreas H. , Boesiger Peter 
Published: August 2002

AbstractAn improved double quantum coherence (DQC) filter for the selective in vivo detection of glutathione (GSH) in the human brain at 1.5 Tesla is presented. The goal was to minimize contamination of the DQC‐filtered GSH signal at 2.9 ppm with contributions arising from GABA. The modification consists of tailoring the frequency response of the read pulse, which converts DQC into anti‐phase single quantum coherence in such a way that the GABA β and γ resonances at 3.0 and 1.9 ppm, respectively, remain unaffected. An implementation incorporating a Dante pulse train is used for in vitro tests as well as for in vivo applications. Magn Reson Med 45:708–710, 2001. © 2001 Wiley‐Liss, Inc.
Rapid measurement of aortic wave velocity: In vivo evaluation
Authors: Kraft Kenneth A. , Itskovich Vitalii V. , Fei Ding‐Yu 
Published: August 2002

AbstractA 1D MR sequence has been developed for determining aortic flow wave velocity (WV), a metric of arterial compliance, within a single cardiac cycle. Studies were carried out on the thoracic aortas of 10 normal volunteers. Correlative WV data were also acquired from each subject using a conventional phase‐velocity 2D mapping technique. Aortic WV in this cohort was found to range from 411 to 714 cm/s and was highly correlated (R = 0.95) between the two methods. Peak blood velocity was also measured using both methods and found to agree closely. The reproducibility of WV measurements using the rapid 1D method averaged 7.6%, which is comparable or better than that achieved using existing noninvasive techniques. Magn Reson Med 46:95–102, 2001. © 2001 Wiley‐Liss, Inc.
Coil‐by‐coil image reconstruction with SMASH
Authors: McKenzie Charles A. , Ohliger Michael A. , Yeh Ernest N. , Price Mark D. , Sodickson Daniel K. 
Published: August 2002

AbstractThe SiMultaneous Acquisition of Spatial Harmonics (SMASH) technique uses linear combinations of undersampled datasets from the component coils of an RF coil array to reconstruct fully sampled composite datasets in reduced imaging times. In previously reported implementations, SMASH reconstructions were designed to reproduce the images that would otherwise be obtained by simple sums of fully gradient encoded component coil images. This strategy has left SMASH images vulnerable to phase cancellation artifacts when the sensitivities of RF coil array elements are not suitably phase‐aligned. In fully gradient encoded imaging schemes these artifacts can be eliminated using a variety of methods for combining the individual coil images, including matched filter combinations as well as sum of squares combinations. Until now, these reconstruction schemes have been unavailable to SMASH reconstructions as SMASH produced a final composite image directly from the raw component coil k‐space datasets. This article demonstrates a modification to SMASH that allows reconstruction of a full set of accelerated individual component coil images by fitting component coil sensitivity functions to a complete set of spatial harmonics tailored for each coil in the array. Standard component coil combinations applied to the individual reconstructed images produce final composite images free of phase cancellation artifacts. Magn Reson Med 46:619–623, 2001. © 2001 Wiley‐Liss, Inc.
Improved spatial harmonic selection for SMASH image reconstructions
Authors: McKenzie Charles A. , Yeh Ernest N. , Sodickson Daniel K. 
Published: August 2002

AbstractThe fitting of coil sensitivity functions to spatial harmonics is central to image reconstructions using the simultaneous acquisition of spatial harmonics (SMASH) technique. It has previously been shown that the selection of the set of spatial harmonics used in a SMASH reconstruction can have a noticeable effect on the quality of the reconstructed image. However, a mechanism for automatic selection of the best set of harmonics in any particular situation has not been provided. In this work, a modification to the SMASH reconstruction procedure is introduced that allows the use of a weighted average of all possible harmonics in a reconstruction. The new reconstruction procedure is shown to allow automatic selection of the spatial harmonics and substantially improve SNR for both phantom and in vivo images. Magn Reson Med 46:831–836, 2001. © 2001 Wiley‐Liss, Inc.
Quality of life and well‐being of patients with myasthenia gravis
Authors: Paul Robert H. , Nash Justin M. , Cohen Ronald A. , Gilchrist James M. , Goldstein Jonathan M. 
Published: August 2002

AbstractThe cardinal symptom of myasthenia gravis (MG) is weakness of voluntary muscles, a feature that may restrict full participation in life activities. In turn, such limitations may negatively affect quality of life (QOL) and well‐being among individuals with the disease. In the present study, we administered a measure of QOL to 27 patients with generalized MG. Results revealed that functional status was negatively impacted in the domains of physical functioning, energy, and general health. However, a clinically meaningful difference was evident only on perceived ability to accomplish physical tasks. The results suggest that although MG requires accommodations in physical activities, general QOL and well‐being does not differ markedly from the general population. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 512–516, 2001
Leukemia inhibitory factor enhances regeneration in skeletal muscles after myoblast transplantation
Authors: White Jason D. , Bower John J. , Kurek John B. , Austin Lawrie 
Published: August 2002

AbstractCell‐based therapies, such as myoblast transfer therapy, are likely to become an integral part of any approach to treat myopathies such as Duchenne muscular dystrophy. Previous studies have shown that an increased level of regeneration in the host muscle enhances incorporation of donor myoblasts. Leukemia inhibitory factor (LIF) increases the number of dystrophic fibers expressing dystrophin after myoblast transplantation and enhances regeneration in injured and diseased muscle. Morphometric analysis was used to investigate whether an increased level of regeneration is induced by LIF after myoblast transplantation. We found that, in muscles treated with LIF, the number of fibers undergoing regeneration was increased. The increased incorporation of donor myoblasts and thus dystrophin expression induced by LIF may be due, at least in part, to an increased level of regeneration of dystrophic muscle. © 2001 John Wiley & Sons, Inc. Muscle and Nerve 24:695–697, 2001
The pathophysiology of tremor
Authors: Deuschl Günther , Raethjen Jan , Lindemann Michael , Krack Paul 
Published: August 2002

AbstractTremor is defined as rhythmic oscillatory activity of body parts. Four physiological basic mechanisms for such oscillatory activity have been described: mechanical oscillations; oscillations based on reflexes; oscillations due to central neuronal pacemakers; and oscillations because of disturbed feedforward or feedback loops. New methodological approaches with animal models, positron emission tomography, and mathematical analysis of electromyographic and electroencephalographic signals have provided new insights into the mechanisms underlying specific forms of tremor. Physiological tremor is due to mechanical and central components. Psychogenic tremor is considered to depend on a clonus mechanism and is thus believed to be mediated by reflex mechanisms. Symptomatic palatal tremor is most likely due to rhythmic activity of the inferior olive, and there is much evidence that essential tremor is also generated within the olivocerebellar circuits. Orthostatic tremor is likely to originate in hitherto unidentified brainstem nuclei. Rest tremor of Parkinson's disease is probably generated in the basal ganglia loop, and dystonic tremor may also originate within the basal ganglia. Cerebellar tremor is at least in part caused by a disturbance of the cerebellar feedforward control of voluntary movements, and Holmes' tremor is due to the combination of the mechanisms producing parkinsonian and cerebellar tremor. Neuropathic tremor is believed to be caused by abnormally functioning reflex pathways and a wide variety of causes underlies toxic and drug‐induced tremors. The understanding of the pathophysiology of tremor has made significant progress but many hypotheses are not yet based on sufficient data. Modern neurology needs to develop and test such hypotheses, because this is the only way to develop rational medical and surgical therapies. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 716–735, 2001
Pathology‐related differential expression regulation of NGF, GDNF, CNTF, and IL‐6 mRNAs in human vasculitic neuropathy
Authors: Yamamoto Masahiko , Ito Yasuhiro , Mitsuma Norimasa , Li Mei , Hattori Naoki , Sobue Gen 
Published: August 2002

AbstractThe mRNA levels of nerve growth factor (NGF), glial cell line–derived neurotrophic factor (GDNF), ciliary neurotrophic factor (CNTF), and interleukin‐6 (IL‐6) were examined in sural nerves of 22 patients with acute necrotizing vasculitic neuropathies. NGF, GDNF, and IL‐6 mRNAs were upregulated and CNTF mRNA was downregulated in the lesioned nerves, but their up‐ and down‐regulation levels were not correlated with each other, showing that these mRNAs were independently expressed. The expression of NGF and CNTF mRNAs was clearly correlated with the degree of infiltrated macrophages and T cells, and myelinated fiber density, respectively. These findings indicate that these neurotrophic factors are differentially expressed temporally and spatially in the vasculitic nerve lesion by an underlying pathology‐related process. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 830–833, 2001
Contractile speed and fatigue of adductor pollicis muscle in multiple sclerosis
Authors: de Ruiter Cornelis J. , Jongen Peter J.H. , van der Woude Luc H.V. , de Haan Arnold 
Published: August 2002

AbstractThe purpose of the study was to investigate differences in contractile speed, force, and fatigability of the adductor pollicis muscle between 12 patients with multiple sclerosis (MS) and 8 sedentary control subjects matched for age and gender. There were no differences between the patients with MS and control subjects with respect to the percentage of maximal muscle force that could be recruited during voluntary effort (95.5 ± 3.9% and 98.2 ± 2.0%, respectively, P = 0.10), the stimulation frequency/force and force/velocity relationships, the rates of force development and relaxation, fatigue resistance, and the recovery rate of adductor pollicis muscle. However, previous results from the same group of MS patients showed that quadriceps femoris muscle force and resistance to fatigue were reduced. Therefore, our data support the clinical experience that, in patients with MS, lower limb muscle function is more or earlier affected than upper limb muscle function. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 1173–1180, 2001
Learned voiding dysfunction (non‐neurogenic, neurogenic bladder) among adults
Authors: Groutz Asnat , Blaivas Jerry G. , Pies Christoph , Sassone A. Margherita 
Published: August 2002

AbstractData concerning learned voiding dysfunction (Hinman syndrome; non‐neurogenic, neurogenic bladder) in adults are scarce. The present study was conducted to assess the pre‐valence and clinical characteristics of this dysfunction among adults referred for evaluation of lower urinary tract symptoms. Learned voiding dysfunction was suggested by a characteristic clinical history and intermittent “free” uroflow pattern and by the absence of any detectable neurological abnormality or anatomic urethral obstruction. A definitive diagnosis was made by the demonstration of typical external urethral sphincter contractions during micturition by EMG or fluoroscopy. A urodynamic database of 1,015 consecutive adults was reviewed. Twenty‐one (2%) patients (age, 24–76 years) met our strict criteria of learned voiding dysfunction. Obstructive symptoms were the most common presenting symptoms, followed by frequency, nocturia, and urgency. Eight (35%) patients had recurrent urinary tract infections, seven of these being women. None of the patients had any clinically significant upper urinary tract damage. First sensation volume was significantly lower in women than in men. Both detrusor pressure at maximum flow and maximum detrusor pressure during voiding were found to be significantly higher in men than in women. Further differentiation between adult women and men failed to reveal any other clinically significant differences. In conclusion, by strict video‐urodynamic criteria, 2% of our patients had learned voiding dysfunction. Other patients, with presumed learned voiding dysfunction, who did not undergo video‐urodynamics were not included in the present series. Thus, the prevalence of learned voiding dysfunction among adults referred for evaluation of lower urinary tract symptoms is likely to be even higher. Neurourol. Urodynam. 20:259–268, 2001. © 2001 Wiley‐Liss, Inc.
The collection depots location problem on networks
Authors: Berman Oded , Drezner Zvi , Wesolowsky George O. 
Published: August 2002

AbstractIn this paper we investigate the collection depots location problem on a network. A facility needs to be located to serve a set of customers. Each service consists of a trip to the customer, collecting materials, dropping the materials at one of the available collection depots and returning to the facility to wait for the next call. Two objectives are considered: minimizing the weighted sum of distances and minimizing the maximum distance. The properties of the solutions to these problems are described. © 2002 John Wiley & Sons, Inc. Naval Research Logistics, 49: 15–24, 2002; DOI 10.1002/nav.10000
A branch and bound algorithm for computing optimal replacement policies in consecutive k‐out‐of‐n‐systems
Authors: Flynn James , Chung Chia‐Shin 
Published: August 2002

AbstractThis paper presents a branch and bound algorithm for computing optimal replacement policies in a discrete‐time, infinite‐horizon, dynamic programming model of a binary coherent system with n statistically independent components, and then specializes the algorithm to consecutive k‐out‐of‐n systems. The objective is to minimize the long‐run expected average undiscounted cost per period. (Costs arise when the system fails and when failed components are replaced.) An earlier paper established the optimality of following a critical component policy (CCP), i.e., a policy specified by a critical component set and the rule: Replace a component if and only if it is failed and in the critical component set. Computing an optimal CCP is a optimization problem with n binary variables and a nonlinear objective function. Our branch and bound algorithm for solving this problem has memory storage requirement O(n) for consecutive k‐out‐of‐n systems. Extensive computational experiments on such systems involving over 350,000 test problems with n ranging from 10 to 150 find this algorithm to be effective when n ≤ 40 or k is near n. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 49: 288–302, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/nav.10017
Asymptotically optimal component assembly plans in repairable systems and server allocation in parallel multiserver queues
Authors: Dinopoulou V.D. , Melolidakis C. 
Published: August 2002

AbstractT identical exponential lifetime components out of which G are initially functioning (and B are not) are to be allocated to N subsystems, which are connected either in parallel or in series. Subsystem i, i = 1,…, N, functions when at least Ki of its components function and the whole system is maintained by a single repairman. Component repair times are identical independent exponentials and repaired components are as good as new. The problem of the determination of the assembly plan that will maximize the system reliability at any (arbitrary) time instant t is solved when the component failure rate is sufficiently small. For the parallel configuration, the optimal assembly plan allocates as many components as possible to the subsystem with the smallest Ki and allocates functioning components to subsystems in increasing order of the Ki's. For the series configuration, the optimal assembly plan allocates both the surplus and the functioning components equally to all subsystems whenever possible, and when not possible it favors subsystems in decreasing order of the Ki's. The solution is interpreted in the context of the optimal allocation of processors and an initial number of jobs in a problem of routing time consuming jobs to parallel multiprocessor queues. © John Wiley & Sons, Inc. Naval Research Logistics 48: 732–746, 2001
Multiple common due dates
Authors: Dickman Bernard , Wilamowsky Yonah , Epstein Sheldon 
Published: August 2002

AbstractCommon due date problems have been extensively discussed in the scheduling literature. Initially, these problems discussed finding a common due date for a set of jobs on a single machine. These single machine problems were later extended to finding the common due date on a set of parallel machines. This paper further extends the single machine problem to finding multiple common due dates on a single machine. For a basic and important class of penalty functions, we show that this problem is comparable to the parallel machine problem. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48: 293–298, 2001