bluuebunny/crossref_metadata_2025 huggingface dataset:
Essentiality and toxicity of trace elements: Principles and methods for assessment of risk from human exposure to essential trace elements
Authors: Nordberg G. , Sandström B. , Becking G. , Goyer R.A.
Published: August 2002

Recommendations aimed at protecting the public from toxicity of essential elements have been developed separately from those recommendations aimed at protection from deficiency. Because of the uncertainties involved in evaluations, these recommendations have sometimes been in conflict, emphasizing the need for a new approach including a balanced consideration of nutritional as well as toxicological data.

In developing these new principles of evaluation, some basic concepts based on interindividual variability in sensitivity to deficiency and toxicity must be considered. Such variation translates into one interval of (low) daily intakes, at which there is risk of developing deficiency, and another interval of (high) dietary intakes, at which toxicity may occur. In most instances there is a third set of intakes in between, which represents the acceptable range of oral intakes (AROI) in which no adverse effects occur. It must be noted, however, that such a range cannot be found that protects all persons from adverse effects. Those persons with genetically determined sensitivity may require higher intakes to avoid deficiency, or lower intakes to avoid toxicity than those defined by AROI. AROI is defined as protecting 95% of an unselected human population from even minimal adverse effects of deficiency or toxicity. J. Trace Elem. Exp. Med. 13:141–153, 2000.
Impacts of land redistribution on land management and productivity in the Ethiopian highlands
Authors: Benin S. , Pender J.
Published: August 2002

The increasing problem of landlessness in Ethiopia has put pressure on regional governments to redistribute land. In 1997 and 1998, a major land redistribution was undertaken in the Amhara Region, reducing landlessness where implemented. While the impacts of such redistributions have been hotly debated, little empirical evidence exists concerning the actual impacts of redistribution. We find that land redistribution in the Amhara Region has had a positive impact on land productivity, by increasing access to land for farmers who are more interested or able to use purchased inputs such as fertilizer and herbicides. Our results, however, do not show much effect of the recent land redistribution or expectations of future redistribution on land improvement and management. Thus, to the extent that investments in land improvement are necessary for conservation purposes, it appears that policy change to stop land redistributions is unlikely to have a substantial impact on reducing land degradation. Credit and extension programmes and improving land rental markets, however, present better strategies for improving land management in this region of Ethiopia. Copyright © 2001 John Wiley & Sons, Ltd.
Er:YAG laser skin resurfacing using repetitive long‐pulse exposure and cryogen spray cooling: II. Theoretical analysis
Authors: Majaron Boris , Verkruysse Wim , Kelly Kristen M. , Nelson J. Stuart
Published: August 2002

Background and Objective

To analyze the effects of laser pulse duration and cryogen spray cooling (CSC) on epidermal damage and depth of collagen coagulation in skin resurfacing with repetitive Er:YAG laser irradiation.

Study Design/Materials and Methods

Evolution of temperature field in skin is calculated using a simple one‐dimensional model of sub‐ablative pulsed laser exposure and CSC. The model is solved numerically for laser pulse durations of 150 and 600 μsec, and 6 msec cryogen spurts delivered just prior to (“pre‐cooling”), or during and after (“post‐cooling”) the 600 μsec laser pulse.

Results

The model indicates a minimal influence of pulse duration on the extent of thermal effect in dermis, but less epidermal damage with 600 μsec pulses as compared to 150 μsec at the same pulse fluence. Application of pre‐ or post‐cooling reduces the peak surface temperature after laser exposure and accelerates its relaxation toward the base temperature to a different degree. However, the temperature profile in skin after 50 msec is in either example very similar to that after a lower‐energy laser pulse without CSC.

Conclusions

When applied in combination with repetitive Er:YAG laser exposure, CSC strongly affects the amount of heat available for dermal coagulation. As a result, CSC may not provide spatially selective epidermal protection in Er:YAG laser skin resurfacing. Lasers Surg. Med. 28:131–137, 2001. © 2001 Wiley‐Liss, Inc.
Long‐term results in the treatment of childhood hemangioma with the flashlamp‐pumped pulsed dye laser: An evaluation of 617 cases
Authors: Hohenleutner Silvia , Badur‐Ganter Elke , Landthaler Michael , Hohenleutner Ulrich
Published: August 2002

Background and Objective

Presenting the long‐term results of flashlamp‐pumped pulsed dye laser treatment in 617 hemangiomas to evaluate this treatment modality.

Study Design/Materials and Methods

In 548 children, 692 hemangiomas were treated with the flashlamp‐pumped pulsed dye laser (FPDL) SPTL 1B (Candela Corporation, Wayland, MA). The objective of treatment was the inhibition of further growth or the induction of regression. The treatment results were documented by the treating physician as well as by means of a questionnaire delivered to the parents. A total of 617 treatment results could be evaluated.

Results

After 1–12 treatments (mean, 2.5), we could achieve our treatment objective to stop the further growth of the lesion in 96.6% of all hemangiomas. In 13.8%, the treatment resulted in a complete remission, a significant regression was seen in 14.9%, and 67.9% of the treated lesions showed a discontinuation of growth. The percentage of complete remission was especially high in small superficial (42.6%) and superficial (19%) hemangiomas.

Conclusion

In the vast majority of the hemangiomas, it was possible to stop further progression or induce regression by FPDL treatment. Total regression could be achieved in nearly half of the small superficial hemangiomas. Because the treatment is fast, effective, and nearly without side effects, we recommend early laser treatment especially in superficial and small childhood hemangiomas. Lasers Surg. Med. 28:273–277, 2001. © 2001 Wiley‐Liss, Inc.
Family history information on essential tremor: Potential biases related to the source of the cases
Authors: Louis Elan D. , Barnes Livia F. , Ford Blair , Ottman Ruth
Published: August 2002

The proportion of essential tremor (ET) cases that can be attributed to genetic factors is unknown; estimates range from 17–100%. One possible reason for this variability is that clinic and community cases may differ with regard to family history of ET. This is because clinic patients are self‐selected and represent as few as 0.5% of all ET cases. Our goal was to determine whether ET cases ascertained from a clinic differed from those ascertained from a community in terms of the family history information that they provided. Subjects (57 clinic, 64 community) underwent a family history interview. Clinic cases were 4.73 times more likely to report an affected relative than were community cases. We conclude that there was a substantial difference between our clinic and community ET cases in terms of the information they provided regarding their family history. Selection and reporting biases could have accounted for this difference. Because of these biases, the source of the cases must be taken into consideration when investigators are trying to synthesize the widely variable results of studies that have estimated the genetic contribution to ET. © 2001 Movement Disorder Society.
Speech Dysfluency Exacerbated by Levodopa in Parkinson's Disease
Authors: Louis Elan D. , Winfield Linda , Fahn Stanley , Ford Blair
Published: August 2002

The role of dopamine in the modulation of speech fluency is complex. In this report we describe two patients with Parkinson's disease whose speech dysfluency was exacerbated by the administration of levodopa. In doing so, we extend the observation that dopaminergic mechanisms may be involved in the regulation of speech fluency. It is important for clinicians to recognize that, in some instances, dopaminergic replacement therapy may exacerbate an underlying dysfluency syndrome in PD.
Intravenous amantadine improves levadopa‐induced dyskinesias: An acute double‐blind placebo‐controlled study
Authors: Del Dotto Paolo , Pavese Nicola , Gambaccini Gianna , Bernardini Silvia , Metman Leonard Verhagen , Chase Thomas N. , Bonuccelli Ubaldo
Published: August 2002

Experimental evidence suggests that glutamatergic receptor blockade may improve the motor response complications associated with long‐term levodopa treatment in Parkinson's disease (PD) patients. Our objective was to evaluate the acute effect of amantadine, a noncompetitive antagonist of the N‐methyl‐D‐aspartate (NMDA) receptor, on levodopa‐induced dyskinesias, and to gain further insights into the antidyskinetic mechanism of this drug. Nine PD patients with motor fluctuations and severely disabling peak of dose dyskinesias received their first morning levodopa dose, followed by a 2‐hour intravenous amantadine (200 mg) or placebo infusion, on two different days. Parkinsonian symptoms and dyskinesias were assessed every 15 minutes during the infusion and for 3 hours thereafter, while patients were taking their usual oral antiparkinsonian therapy, by means of Unified Parkinson's Disease Rating Scale (UPDRS, motor examination), tapping test, and a modified Abnormal Involuntary Movement Scale (AIMS). Intravenous amantadine acutely improved levodopa‐induced dyskinesias by 50%without any loss of the anti‐parkinsonian benefit from levodopa. This study confirms the antidyskinetic effect of amantadine and strengthens the rationale for using antiglutamatergic drugs in the treatment of parkinsonian motor fluctuations. © 2001 Movement Disorder Society.
Myoclonus of peripheral origin: Case secondary to a digital nerve lesion
Authors: Martinez M. Seijo , Fontoira M. , Celester G. , Castro del Río M. , Permuy J. , Iglesias A.
Published: August 2002

We present a patient with myoclonus of the left hand appearing 1 month after surgical correction of a stenosing tenosynovitis of the thumb. An extensive fibrosis of the external palmar digital nerve was shown, and the successful liberation of this median nerve terminal branch completely and rapidly eliminated the movement disorder. © 2001 Movement Disorder Society.
Clinical features of parkinsonian patients with the α‐synuclein (G209A) mutation
Authors: Bostantjopoulou S. , Katsarou Z. , Papadimitriou A. , Veletza V. , Hatzigeorgiou G. , Lees A.
Published: August 2002

The motor and neuropsychological abnormalities in eight Greek patients with Parkinson's disease (PD) carrying the α‐synuclein gene mutation (G209A) were studied. These patients (five men, three women) belonged to six different families. Their symptoms started between 32–50 years of age (mean ± SD, 39.7 ± 7.6 years) and they had a mean disease duration of 5.4 ± 2.1 years (range, 2–9 years) at the time of examination. Rigidity and bradykinesia predominated both at disease onset as well as in the later stages and rest tremor was relatively uncommon. Neuropsychological assessment showed that one patient was mildly demented while another had impairment in memory, visuoconstructive abilities, and executive function. Depression was present in only one patient. Our findings indicate that genetic forms of parkinsonism share common motor and cognitive characteristics with sporadic PD but raise the possibility that greater cognitive impairment and the relative rarity of tremor may be distinctive features worthy of further investigation. © 2001 Movement Disorder Society.
Microsurgical anterolateral thigh fasciocutaneous flap for facial contour correction in patients with hemifacial microsomia
Authors: Ji Ying , Li Teng , Shamburger Susan , Jin Ji , Lineaweaver William C. , Zhang Feng
Published: August 2002

The correction of facial asymmetry in complex hemifacial microsomia presents a challenging problem for reconstructive surgeons. Numerous microsurgical flaps have been introduced for reconstruction of facial asymmetry. This article reports our experience in facial soft tissue reconstruction with microsurgical anterolateral thigh fasciocutaneous flap transfer in six patients with hemifacial microsomia. This flap, which has a reliable vascular pedicle and relatively thin pliable soft tissue, can provide an ideal treatment for facial asymmetry in hemifacial microsomia. © 2002 Wiley‐Liss, Inc. MICROSURGERY 22:34–38 2002 DOI 10.1002/micr.22008
Compressible Navier–Stokes system in 1‐D
Authors: Mucha Piotr Bogusław
Published: August 2002

The compressible barotropic Navier–Stokes system in monodimensional case with a Neumann boundary condition given on a free boundary is considered. The global existence with uniformly boundedness for large initial data and a positive force is proved. The result concerning an asymptotic behavior shows that the solutions tends to the stationary solution. Copyright © 2001 John Wiley & Sons, Ltd.
On the implementation of adjacent channel interference suppression for direct digital six‐port receivers
Authors: Xu Yansheng , Bosisio Renato G.
Published: August 2002

In this paper, practical approaches to implement the suppression of adjacent channel interference for direct digital six‐port receivers using compact integrated‐circuit dispersive delay lines are described and discussed in detail. Additional interference at the receiver output due to phase errors in the implementation is analyzed and calculated. Computer simulation results are provided, and further enhancement of the effectiveness of this suppression means is discussed. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 376–379, 2002.
Cross‐polarization level reduction of broadband triangular patch antenna with dual L‐strip lines
Authors: Chiou Shr‐Hau , Lu Jui‐Han
Published: August 2002

This article presents a design for a dual L‐strip lines to excite a triangular patch antenna with a thick air substrate to obtain a wide operating bandwidth with cross‐polarization level reduction. The dual L‐strip lines are face‐to‐face with a 180°‐phase shift to cancel the cross‐polarization radiation. Experimental results show that the proposed triangular patch antenna can have wider impedance bandwidth and much reduced cross‐polarization radiation across the entire operating bandwidth, compared to the case with a single L‐strip line. The measured antenna gain of the proposed broadband patch antenna has about 2.5 dB greater than that of single L‐strip line feed design. Details of the proposed design and experimental results of the constructed prototypes are presented and discussed. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 300–303, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10301
Beltrami field phasors are eigenvectors of 6×6 linear constitutive dyadics
Authors: Lakhtakia Akhlesh
Published: August 2002

When the constitutive parameters of a linear, homogeneous, bianisotropic medium are arranged in a certain way as a 6×6 dyadic, it is shown that the eigenvectors of that dyadic may yield admissible Beltrami field phasors whose wavenumbers are directly proportional to the corresponding eigenvalues. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 127–128, 2001.
Radar image studies of an ocean‐like surface
Authors: Kim Hyunjun , Johnson Joel T.
Published: August 2002

High‐resolution radar images of a 1‐D ocean‐like surface are formed through back‐projection tomography. The surface profile is described by a Pierson–Moskowitz spectrum, and satisfies an impedance boundary condition. Backscatter results from 10 to 14 GHz excited by a tapered beam at incidence angles from 60 to 80° are considered. Radar images from approximate and numerical scattering models demonstrate dominant Bragg scattering components, small multiple interaction effects associated with the long‐wave portion of the surface spectrum, and significant polarization dependencies. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 381–384, 2001.
Complete 1H and 13C NMR assignments of chamigrenes from Aplysia dactilomela
Authors: Kaiser Carlos R. , Pitombo Liane F. , Pinto Angelo C.
Published: August 2002

Stereochemical evaluation and complete 1H and 13C NMR assignment of the chamigrenes johnstonol (1), pacifenediol (2), pacifidiene (3), pacifenol (4), isolated from the Brazilian mollusc Aplysia dactilomela, were performed using 2D NMR techniques including COSY, NOESY, HSQC and HMBC, combined with AMI calculations and 1H NMR spectrum simulations. Copyright © 2001 John Wiley & Sons, Ltd.
Structural studies of benzophenanthridine alkaloid free bases by NMR spectroscopy
Authors: Sečkářová Pavlína , Marek Radek , Dostál Jiří , Dommisse Roger , Esmans Eddy L.
Published: August 2002

The free bases of eight quaternary benzo[c]phenanthridine alkaloids (chelerythrine, sanguilutine, chelirubine, chelilutine, sanguirubine, sanguinarine, nitidine and fagaronine) were investigated by 1H and 13C NMR spectroscopy. The pseudobases (the 6‐hydroxy‐5,6‐dihydro derivatives) were found to be the only products of the alkalization of these alkaloids using sodium carbonate in DMSO‐d6 solution. This observation differs from the measurements of preparative free bases in CDCl3 solution, where the structures of the bimolecular aminoacetals were unequivocally confirmed. According to the results obtained, in biological systems, in the presence of excess of water and ions, free bases of the investigated alkaloids are assumed to adopt the pseudobase (6‐hydroxy derivative) structure. In contrast, in less polar media (C6D6, CDCl3), the formation of the bimolecular aminoacetal structure is preferred. Copyright © 2001 John Wiley & Sons, Ltd.
VLA‐6 integrin distribution and calcium signalling in capacitated boar sperm
Authors: Barboni B. , Lucidi P. , Mattioli M. , Berardinelli P.
Published: August 2002

Previous investigations showed that VLA‐6 integrin present on boar sperm membrane can induce acrosome reaction upon exposure to laminin accumulated in expanded cumuli (Mattioli et al., 1998. To further investigate this novel sperm egg‐recognition system, the authors studied the distribution of VLA‐6 integrin on the membrane of boar sperm throughout capacitation and following acrosome reaction, and analyzed intracellular Ca2+ changes occurring in spermatozoa exposed to laminin. Immunofluorescent localisation of VLA‐6 revealed a low proportion (nearly 22%) of positive cells in freshly ejaculated sperm, with integrin mainly concentrated in clustered spots. After 3 hr incubation most of the spermatozoa showed integrin molecules on the membrane, with three different labeling patterns: fluorescence localised on the edge of the acrosome (58.2 ± 14.2% of the cells); fluorescence uniformly spread over the whole sperm head (5.0 ± 1.9%) and finally fluorescence concentrated in clustered spots (7.6 ± 5.6%), as recorded in freshly ejaculated sperm. Twenty‐nine percent of cells did not show any distinct fluorescence. Following acrosome reaction sperm with fluorescence on the acrosomal region virtually disappeared and the proportion of unstained cells rose from 29.2 ± 9.2 to 69.0 ± 10.1%. Electron microscopy demonstrated that VLA‐6 integrin was exclusively located on the sperm membrane of intact spermatozoa. Confocal analysis showed that laminin triggers distinct Ca2+ raises, and that sperm exposed and kept in the presence of laminin fully retained their ability to rise intracellular Ca2+ in response to zona pellucida proteins. These data indicate that boar sperm accumulate VLA‐6 integrin on the membrane and concentrate it on the acrosomal region as capacitation progresses. Probably due to this compartmentalisation, sperm exposed to laminin experience a Ca2+ raise that originates in the anterior sperm head where it is more adequate for the induction of acrosome reaction. Mol. Reprod. Dev. 59:322–329, 2001. © 2001 Wiley‐Liss, Inc.
Effects of cell cycle dependent kinases inhibitor on nuclear and cytoplasmic maturation of porcine oocytes
Authors: Marchal Réjane , Tomanek Milan , Terqui Michel , Mermillod Pascal
Published: August 2002

The aims of this study were to assess the effectiveness of roscovitine, a potent inhibitor of cell cyclin kinases, to prevent meiotic resumption in porcine oocytes, and to test the subsequent fertilisability and developmental competence of these oocytes. Roscovitine blocked porcine oocytes at the GV stage during 22–44 hr of culture. This effect was dose‐dependent, and a concentration of 25 μM was sufficient to prevent meiotic resumption in 92±5% of the oocytes after 22 hr in the presence of EGF and FSH. Cumulus expansion was also inhibited under these conditions. The histone H1 kinase activity in oocytes was inhibited in a dose‐dependent way, and maintained at a basal level with 25 μM of roscovitine. Synthesis of proteins of 29, 47 and 79 kDa, normally synthesized during maturation, was inhibited too. All these effects were fully reversible. However, the kinetics of maturation were accelerated after roscovitine removal, and the acceleration was more pronounced after 44 hr of inhibition than after 22 hr. Fertilization of oocytes blocked for 22 hr before a 44 hr maturation was decreased compared to control, but was not different from that of oocytes matured for 66 hr. The developmental competence was decreased for the oocytes cultured for 66 hr, including or not an inhibition period, but it was less reduced for oocytes maintained under inhibition for 22 hr. Roscovitine may thus protect oocytes against the aging mechanisms responsible for developmental competence loss, but not against loss of fertilisability. In conclusion, roscovitine provides a useful tool to study the morphological and biochemical basis of porcine oocyte terminal differentiation. Mol. Reprod. Dev. 60: 65–73, 2001. © 2001 Wiley‐Liss, Inc.
Organisation of the cytoskeleton during in vitro maturation of horse oocytes
Authors: Tremoleda J.L. , Schoevers E.J. , Stout T.A.E. , Colenbrander B. , Bevers M.M.
Published: August 2002

Meiotic maturation of mammalian oocytes is a complex process during which microfilaments and microtubules provide the framework for chromosomal reorganisation and cell division. The aim of this study was to use fluorescence and confocal laser scanning microscopy to examine changes in the distribution of these important cytoskeletal elements and their relationship to chromatin configuration during the maturation of horse oocytes in vitro. Oocytes were cultured in M199 supplemented with pFSH and eLH and, at 0, 12, 24, and 36 hr after the onset of culture, they were fixed for immunocytochemistry and stained with markers for microtubules (a monoclonal anti‐α‐tubulin antibody), microfilaments (AlexaFluor 488 Phalloidin) and DNA (TO‐PRO3). At the germinal vesicle stage, oocyte chromatin was amorphous and poorly condensed and the microfilaments and microtubules were distributed relatively evenly throughout the ooplasm. After germinal vesicle breakdown, the microtubules were aggregated around the now condensed chromosomes and the microfilaments had become concentrated within the oocyte cortex. During metaphase I, microtubules were detected only in the meiotic spindle, as elongated asters encompassing the aligned chromosomes, and, as maturation progressed through anaphase‐I and telophase‐I, the spindle assumed a more eccentric position and gradually rotated to assist in the separation of the homologous chromosomes and in the subsequent formation of the first polar body. During metaphase II, the meiotic spindle was a symmetrical, barrel‐shaped structure with two poles and with the chromosomes aligned along its midline. At this stage, microtubules were found intermingled with chromatin within the polar body and, although, the bulk of the microfilaments remained within the oocyte cortex, a rich domain was found overlying the spindle. Thus, during the in vitro maturation of horse oocytes both the microfilament and microtubular elements of the cytoskeleton were seen to reorganise dramatically in a fashion that appeared to enable chromosomal alignment and segregation. Mol. Reprod. Dev. 60: 260–269, 2001. © 2001 Wiley‐Liss, Inc.
Spatial/temporal correlation of BOLD and optical intrinsic signals in humans
Authors: Pouratian Nader , Sicotte Nancy , Rex David , Martin Neil A. , Becker Donald , Cannestra Andrew F. , Toga Arthur W.
Published: August 2002

Comparing the BOLD signal with electrophysiological maps and other perfusion‐dependent signals, such as the optical intrinsic signal (OIS), within subjects should provide insight into the etiology of the BOLD signal. Tongue activations were compared in five human subjects using BOLD fMRI, 610‐nm OIS, and the electrocortical stimulation map (ESM). Robust fMRI activations centered on the lateral inferior aspect of the central sulcus and extended into pre‐ and post‐central gyri, adjacent to ESM tongue loci. OIS and fMRI maps colocalized, although optical responses were spatially larger (P < .001 across multiple thresholds) and contained more gyral components. The timecourses of the fMRI and OIS signals were similar, appearing within 2.5 s and peaking 6–8 s after task onset. Although many processes contribute to increased 610‐nm reflectance, optical spectroscopy and fluorescent dye imaging suggest that a significant part of this signal is due to a concomitant decrease in deoxyhemoglobin and increase in oxyhemoglobin concentrations. The spatial/temporal correlation of BOLD and the positive 610‐nm response within subjects suggests that the two signals may share similar etiologies. The OIS/fMRI inconsistencies may be due to cell swelling and light‐scattering contributions to OIS and fMRI sensitivity. This study also demonstrates that fMRI maps do not precisely colocalize with ESM, rather they emphasize changes in adjacent venous/sulcal structures. Magn Reson Med 47:766–776, 2002. © 2002 Wiley‐Liss, Inc.
MR temperature measurement in liver tissue at 0.23 T with a steady‐state free precession sequence
Authors: Germain D. , Vahala E. , Ehnholm G.J. , Vaara T. , Ylihautala M. , Savart M. , Laurent A. , Tanttu J. , Saint‐Jalmes H.
Published: August 2002

MRI can be used for monitoring temperature during a thermocoagulation treatment of tumors. The aim of this study was to demonstrate the suitability of a 3D steady‐state free precession sequence (3D Fast Imaging with Steady‐State Precession, 3D TrueFISP) for MR temperature measurement at 0.23 T, and to compare it to the spin‐echo (SE) and spoiled 3D gradient‐echo (3D GRE) sequences. The optimal flip angle for the TrueFISP sequence was calculated for the best temperature sensitivity in the image signal from liver tissue, and verified from the images acquired during the thermocoagulation of excised pig liver. Factors influencing the accuracy of the measured temperatures are discussed. The TrueFISP results are compared to the calculated values of optimized SE and 3D GRE sequences. The accuracy of TrueFISP in the liver at 0.23 T, in imaging conditions used during thermocoagulation procedures, is estimated to be ±3.3°C for a voxel of 2.5 × 2.5 × 6 mm3 and acquisition time of 18 s. For the SE and GRE sequences, with similar resolution and somewhat longer imaging time, the uncertainty in the temperature is estimated to be larger by a factor of 2 and 1.2, respectively. Magn Reson Med 47:940–947, 2002. © 2002 Wiley‐Liss, Inc.
Time‐dependent effects of hormone‐deprivation therapy on prostate metabolism as detected by combined magnetic resonance imaging and 3D magnetic resonance spectroscopic imaging
Authors: Mueller‐Lisse Ullrich G. , Swanson Mark G. , Vigneron Daniel B. , Hricak Hedvig , Bessette André , Males Ryan G. , Wood Penelope J. , Noworolski Susan , Nelson Sarah J. , Barken Israel , Carroll Peter R. , Kurhanewicz John
Published: August 2002

Combined MRI and 3D spectroscopic imaging (MRI/3D‐MRSI) was used to study the metabolic effects of hormone‐deprivation therapy in 65 prostate cancer patients, who underwent either short, intermediate, or long‐term therapy, compared to 30 untreated control patients. There was a significant time‐dependent loss of the prostatic metabolites choline, creatine, citrate, and polyamines during hormone‐deprivation therapy, resulting in the complete loss of all observable metabolites (total metabolic atrophy) in 25% of patients on long‐term therapy. The amount and time‐course of metabolite loss during therapy significantly differed for healthy and malignant tissues. Citrate levels decreased faster than choline and creatine levels during therapy, resulting in an increase in the mean (choline + creatine)/citrate ratio with duration of therapy. Due to a loss of all MRSI detectable citrate, this ratio could not be used to identify cancer in 69% of patients on long‐term therapy. In the absence of citrate, however, residual prostate cancer could still be detected by elevated choline levels (choline/creatine ratio ≥1.5), or the presence of only choline in the proton spectrum. The loss of citrate and the presence of total metabolic atrophy correlated roughly with decreasing serum prostatic specific antigen levels with increasing therapy. In summary, MRI/3D‐MRSI provided both a measure of residual cancer and a time‐course of metabolic response following hormone‐deprivation therapy. Magn Reson Med 46:49–57, 2001. © 2001 Wiley‐Liss, Inc.
Pharmacokinetics and enhancement patterns of macromolecular MR contrast agents with various sizes of polyamidoamine dendrimer cores
Authors: Sato Noriko , Kobayashi Hisataka , Hiraga Akira , Saga Tsuneo , Togashi Kaori , Konishi Junji , Brechbiel Martin W.
Published: August 2002

Four macromolecular contrast agents are synthesized to visualize small vessels by MRI using generation‐3 (G3D), ‐4 (G4D), ‐5 (G5D), and ‐6 (G6D) polyamidoamine dendrimers conjugated to chelated gadolinium (Gd). The pharmacokinetics, enhancement patterns, and the ability of these constructs to visualize fine vessels is evaluated by dynamic MRI in relationship to their size. Gd‐G6D and ‐G5D exhibit a prolonged high vascular (ventricular) signal intensity (SI) with high ventricle‐to‐organ SI ratios. The initial high vascular SI with Gd‐G4D decreases to a value as low as that obtained with Gd‐G3D and Gd‐dimeglumine‐diethylenetriaminepentaacetic acid (Gd‐DTPA). Gd‐G5D, ‐G4D, and ‐G3D show high renal SIs, and Gd‐DTPA prominently enhances the skin. Gd‐G6D and ‐G5D present fine vasculature significantly more clearly than Gd‐G3D and ‐DTPA (P < 0.005). As the molecular size increases, the excretion of the 153Gd‐conjugates is retarded. In conclusion, Gd‐G6D and ‐G5D are retained in the blood and present fine vessels with high quality and detail, and should be adequate for visualizing small tumor vasculature. Magn Reson Med 46:1169–1173, 2001. © 2001 Wiley‐Liss, Inc.
Laboratory diagnosis of metabolic myopathies
Authors: Vladutiu Georgirene D.
Published: August 2002

The metabolic myopathies are a heterogeneous group of disorders inherited by a variety of modes that include gene defects in both the nuclear and mitochondrial genomes. Many factors impact on the expression of the pathogenic mutations that cause these disorders including genetic background, environmental factors, and coexisting disorders. Molecular technology has greatly improved the ability to make definitive diagnoses in many of the metabolic myopathies in the last decade and particularly has demonstrated that the wide diversity in the severity of mutations contributes to understanding genotype–phenotype correlations. In some cases, molecular testing obviates the necessity to perform an invasive muscle biopsy. However, it is also clear that the diagnostic yield from molecular testing is incomplete and particularly low among the mitochondrial myopathies as a group, ranging from ∼6% to 19% in well‐classified high‐risk groups. Therefore, it is often essential to combine clinical, biochemical, histopathologic, and molecular data for each patient in order to arrive at a definitive diagnosis. The approach to the laboratory diagnosis of metabolic myopathies is described emphasizing both noninvasive and invasive testing, highlighting the molecular methodologies with the benefits and disadvantages of each technology, and documenting how to determine whether patients have coexisting disorders. © 2002 Wiley Periodicals, Inc. Muscle Nerve 25: 000–000, 2002
Localization of ulnar neuropathy with conduction block across the elbow
Authors: Herrmann David N. , Preston David C. , McIntosh Kristi A. , Logigian Eric L.
Published: August 2002

We performed short segment incremental stimulation on 13 consecutive patients with ulnar neuropathy across the elbow (UNE) and conduction block. Conduction block occurred proximal to the medial epicondyle in 62%, at the epicondyle in 23%, and below the elbow in 15%. The ulnar nerve may be more prone to external compression above the elbow than previously recognized. Short segment incremental studies are useful to identify conduction block above the elbow in such patients. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 698–700, 2001
Response to high‐intensity eccentric muscle contractions in persons with myopathic disease
Authors: Kilmer David D. , Aitkens Susan G. , Wright Nancy C. , McCrory Megan A.
Published: August 2002

Although the response to intense eccentric muscle contractions is well described in normal subjects, concern exists about possible untoward effects in persons with myopathic diseases. We investigated 14 subjects with slowly progressive muscular dystrophies including myotonic muscular dystrophy (n = 9), facioscapulohumeral dystrophy (n = 2), limb‐girdle syndrome (n = 2), and Becker muscular dystrophy (n = 1). Control subjects consisted of 18 able‐bodied persons. Subjects performed two sets of eight maximal‐effort eccentric repetitions of the elbow flexors, with measurement of maximal concentric strength, serum creatine kinase, resting and flexed arm angle, arm circumference, and soreness at days 0, 3, and 7. Although the myopathic group had less initial strength, both groups demonstrated a similar response to the protocol over 7 days. Both groups had a significant rise in serum creatine kinase, which was still elevated at 7 days (P < 0.05). The control group demonstrated a slightly greater injury response in terms of soreness, resting and flexed arm angles, and arm swelling. Both groups of subjects appeared to respond similarly to an acute bout of eccentric contractions. However, the potential long‐term effects of this type of exercise in persons with myopathic diseases remains unknown. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 1181–1187, 2001
Inflammatory myopathy associated with mixed connective tissue disease and scleroderma renal crisis
Authors: Greenberg Steven A. , Amato Anthony A.
Published: August 2002

Mixed connective tissue disease is a rheumatological syndrome with neuromuscular manifestations that may include inflammatory myopathy and carpal tunnel syndrome. We report a patient who presented with an inflammatory myopathy and bilateral carpal tunnel syndrome prior to the diagnosis of a connective tissue disorder. Early in the course of treatment, a syndrome of acute renal failure developed. Knowledge of this syndrome, scleroderma renal crisis, and its possible relation to corticosteroid treatment is important to clinicians involved in the management of patients with inflammatory myopathies. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 1562–1566, 2001
Isolated brachialis wasting: An unusual presentation of neuralgic amyotrophy
Authors: Watson Bradley V. , Rose‐Innes Andrew , Engstrom John W. , Brown John D.
Published: August 2002

Although neuralgic amyotrophy can selectively affect discrete components of the brachial plexus including individual peripheral nerves, involvement of an individual nerve fascicle is rare. Discrete fascicular musculocutaneous neuropathy as a manifestation of neuralgic amyotrophy has not previously been reported to our knowledge. We report two cases of otherwise typical neuralgic amyotrophy with isolated brachialis muscle wasting. Abnormal spontaneous activity, motor unit remodeling, or both, was observed only in the brachialis muscle. Lateral antebrachial cutaneous nerve conduction studies were normal. These cases serve to broaden the spectrum of the clinical presentation of neuralgic amyotrophy. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 1699–1702, 2001
Solution of the unsaturated soil moisture equation using repeated transforms
Authors: Fityus S. G. , Smith D. W.
Published: August 2002

An alternative method of solution for the linearized ‘theta‐based’ form of the Richards equation of unsaturated flow is developed in two spatial dimensions. The Laplace and Fourier transformations are employed to reduce the Richards equation to an ordinary differential equation in terms of a transformed moisture content and the transform variables, s and ξ. Separate analytic solutions to the transformed equation are developed for initial states which are either in equilibrium or dis‐equilibrium. The solutions are assembled into a finite layer formulation satisfying continuity of soil suction, thereby facilitating the analysis of horizontally stratified soil profiles. Solution techniques are outlined for various boundary conditions including prescribed constant moisture content, prescribed constant flux and flux as a function of moisture change. Example solutions are compared with linearized finite element solutions. The agreement is found to be good. An adaptation of the method for treating the quasilinearized Richards equation with variable diffusivity is also described. Comparisons of quasilinear solutions with some earlier semi‐analytical, finite element and finite difference results are also favourable. Copyright © 2001 John Wiley & Sons, Ltd.
A simple linear time algorithm for finding a maximum independent set of circular arcs using intervals alone
Authors: Manacher Glenn K. , Mankus Terrance A.
Published: August 2002

We exhibit an algorithm for finding a maximum independent set (MIS) for n presorted, unweighted circular arcs in time 0(n). Unlike previous algorithms, this is achieved by means of trivial postprocessing of the output of a straightforward algorithm for finding an MIS for a set of unweighted intervals. © 2002 Wiley Periodicals, Inc.
Minimum linear gossip graphs and maximal linear (Δ, k)‐gossip graphs
Authors: Fraigniaud Pierre , Peters Joseph G.
Published: August 2002

Gossiping is an information dissemination problem in which each node of a communication network has a unique piece of information that must be transmitted to all other nodes using two‐way communications between pairs of nodes along the communication links of the network. In this paper, we study gossiping using a linear‐cost model of communication which includes a start‐up time and a propagation time which is proportional to the amount of information transmitted. A minimum linear gossip graph is a graph (modeling a network), with the minimum possible number of links, in which gossiping can be completed in minimum time under the linear‐cost model. For networks with an even number of nodes, we prove that the structure of minimum linear gossip graphs is independent of the relative values of the start‐up and unit propagation times. We prove that this is not true when the number of nodes is odd. We present four infinite families of minimum linear gossip graphs. We also present minimum linear gossip graphs for all even numbers of nodes n ≤ 32 except n = 22. A linear (Δ, k)‐gossip graph is a graph with maximum degree Δ in which gossiping can be completed in k rounds with minimum propagation time. We present three infinite families of maximal linear (Δ, k)‐gossip graphs, that is, linear (Δ, k)‐gossip graphs with a maximum number of nodes. We show that not all minimum broadcast graphs are maximal linear (Δ, k)‐gossip graphs. © 2001 John Wiley & Sons, Inc.
The capacitated arc routing problem with intermediate facilities
Authors: Ghiani Gianpaolo , Improta Gennaro , Laporte Gilbert
Published: August 2002

This article introduces the Capacitated Arc Routing with Intermediate Facilities (CARPIF), a variant of the classical Capacitated Arc Routing Problem (CARP) in which the vehicle may unload or replenish at intermediate facilities. Two lower bounds are developed for the CARPIF: The first is based on the Rural Postman Problem (RPP) and the second one uses a relaxation of an integer linear formulation of the problem. Two upper bounds are also developed, based on the solution of an RPP and of a CARP. Computational results on a set of benchmark instances confirm the quality of the proposed bounds. © 2001 John Wiley & Sons, Inc.
GABA influences the development of the ventromedial nucleus of the hypothalamus
Authors: Dellovade Tammy L. , Davis Aline M. , Ferguson Carolyn , Sieghart Werner , Homanics Gregg E. , Tobet Stuart A.
Published: August 2002

The region that becomes the ventromedial nucleus of the hypothalamus (VMH) is surrounded by cells and fibers containing immunoreactive gamma‐aminobutyric acid (GABA) by embryonic day 13 (E13), several days before the nucleus emerges in Nissl stains. As GABA plays many roles during neural development, we hypothesized that it influences VMH development, perhaps by providing boundary information for migrating neurons. To test this hypothesis we examined the VMH in embryonic mice in which the β3 subunit of the GABAA‐receptor, a receptor subunit that is normally highly expressed in this nucleus, was disrupted by gene targeting. In β3 −/− embryos the VMH was significantly larger, and the distribution of cells containing immunoreactive estrogen receptor‐α was expanded compared to controls. Using in vitro brain slices from wild‐type C57BL/6J mice killed at E15 we found that treatment with the GABAA antagonist bicuculline increased the number of cells migrating per video field analyzed in the VMH. In addition, treatment with either bicuculline or the GABAA agonist muscimol altered the orientation of cell migration in particular regions of this nucleus. These data suggest that GABA is important for the organization of cells during VMH formation. © 2001 John Wiley & Sons, Inc. J Neurobiol 49: 264–276, 2001
Short‐ and long‐chain natural polyamines play specific roles in adult cricket neuroblast proliferation and neuron differentiation in vitro
Authors: Cayre Myriam , Malaterre Jordane , Strambi Colette , Charpin Pierre , Ternaux Jean‐Pierre , Strambi Alain
Published: August 2002

In the house cricket (Acheta domesticus) mushroom bodies, neurogenesis still occurs during adulthood. Using in vitro approaches, the respective roles of natural polyamines in neurogenesis were examined. Mushroom body neuroblast proliferation was assayed in organotypic culture using 5‐bromo, 2′‐deoxyuridine labeling. The number of labeled cells was significantly increased when putrescine was added to culture medium, whereas spermidine and spermine supplementation did not alter cell proliferation. Conversely, in vitro morphometric studies on mushroom body neurons cultured in a defined medium showed that putrescine addition failed to alter any morphological character of these interneurons, whereas addition of the long‐chain polyamines, spermidine and spermine, stimulated neuron differentiation. These two polyamines significantly increased total neurite length; moreover, spermidine‐treated cells exhibited more branches than the controls. The present data demonstrate that putrescine has a mitogenic effect on mushroom body neuronal precursors, and that spermidine and spermine, which failed to induce neuroblast proliferation, act on neuronal differentiation, inducing neurite outgrowth. Our results indicate that short‐ and long‐chain polyamines play specific roles during neurogenesis, and provide a basis for further studies on neuronal precursor proliferation and differentiation. © 2001 John Wiley & Sons, Inc. J Neurobiol 48: 315–324, 2001
Computation and presentation of graphs displaying closure hierarchies of Jordan and Kronecker structures
Authors: Elmroth Erik , Johansson Pedher , Kågström Bo
Published: August 2002

StratiGraph, a Java‐based tool for computation and presentation of closure hierarchies of Jordan and Kronecker structures is presented. The tool is based on recent theoretical results on stratifications of orbits and bundles of matrices and matrix pencils. A stratification reveals the complete hierarchy of nearby structures, information critical for explaining the qualitative behaviour of linear systems under perturbations. StratiGraph facilitates the application of these theories and visualizes the resulting hierarchy as a graph. Nodes in the graph represent orbits or bundles of matrices or matrix pencils. Edges represent covering relations in the closure hierarchy. Given a Jordan or Kronecker structure, a user can obtain the complete information of nearby structures simply by mouse clicks on nodes of interest. This contribution gives an overview of the StratiGraph tool, presents its main functionalities and other features, and illustrates its use by sample applications. Copyright © 2001 John Wiley & Sons, Ltd.
Sparse self‐stress matrices for the finite element force method
Authors: Soyer E. , Topcu A.
Published: August 2002

A basic problem in the finite element force method is that of obtaining a sparse and banded self‐stress matrix and a sparse and banded structure flexibility matrix.Traditionally the self‐stress matrix is obtained through the application of algebraic procedures to the equilibrium matrix. The self‐stress matrix for an indeterminate structure is not unique, and it is possible to obtain another self‐stress matrix from an existing one through algebraic operations and grouping of redundants. The purpose of this paper is to describe and test an algorithm, called REDUC, which combines the vectors of the self‐stress matrix obtained from the LU procedure of the force method. The rows of the transpose of this matrix are combined by using a special form of the Gaussian elimination technique. A plane frame example is presented to demonstrate the algorithm at work. The algorithm REDUC is applied to a plane truss and physical interpretation of the resulting self‐stress matrix highlights the grouping of redundants, improved sparsity and bandwidth. Improvements in the conditioning and bandwidth of the structure flexibility matrix are also observed. The algorithm yields results similar to those of the turn‐back LU procedure, but requires less computation time and programming effort. Copyright © 2001 John Wiley & Sons, Ltd.
Quadrilateral elements for the solution of elasto‐plastic finite strain problems
Authors: César de Sá José M. A. , Areias Pedro M. A. , Natal Jorge Renato M.
Published: August 2002

In this paper two plane strain quadrilateral elements with two and four variables, are proposed. These elements are applied to the analysis of finite strain elasto‐plastic problems. The elements are based on the enhanced strain and B‐bar methodologies and possess a stabilizing term. The pressure and dilatation fields are assumed to be constant in each element's domain and the deformation gradient is enriched with additional variables, as in the enhanced strain methodology. The formulation is deduced from a four‐field functional, based on the imposition of two constraints: annulment of the enhanced part of the deformation gradient and the relation between the assumed dilatation and the deformation gradient determinant. The discretized form of equilibrium is presented, and the analytical linearization is deduced, to ensure the asymptotically quadratic rate of convergence in the Newton–Raphson method. The proposed formulation for the enhanced terms is carried out in the isoparametric domain and does not need the usually adopted procedure of evaluating the Jacobian matrix in the centre of the element. The elements are very effective for the particular class of problems analysed and do not present any locking or instability tendencies, as illustrated by various representative examples. Copyright © 2001 John Wiley & Sons, Ltd.