bluuebunny/crossref_metadata_2025 huggingface dataset:
Erythropoietin deficiency and anaemia in multiple system atrophy
Authors: Winkler Andrea S. , Marsden Joanne , Parton Matthew , Watkins Peter J. , Chaudhuri K. Ray
Published: August 2002

Serum erythropoietin (EPO) levels are partially controlled by the sympathetic outflow to the kidney. We have studied whether patients with multiple system atrophy (MSA), known to be associated with dysautonomia, are EPO‐deficient. Eighteen MSA patients were studied along with 32 idiopathic Parkinson's disease (PD) patients, 23 controls with iron‐deficiency anaemia, and 18 healthy individuals. Serum creatinine was normal in all groups. Mean haemoglobin (Hb) concentration in MSA patients was 13.7 ± 1.7 g/dL. Four MSA patients had unexplained anaemia (minimum Hb: 10.5 g/dL) and abnormal autonomic function tests including significant postural hypotension, whereas none of the PD patients was anaemic. Serum EPO levels were suppressed in relation to anaemia in MSA patients compared to elevated EPO levels in iron‐deficiency anaemia patients (difference of regression lines P < 0.001), indicating EPO deficiency in the anaemic MSA patients. Serum EPO levels in PD patients were within normal range. A subset of MSA patients has anaemia and postural hypotension, which may be associated with EPO deficiency. This may have therapeutic implications. © 2001 Movement Disorder Society.
Playing harp, another unusual task‐specific dystonia
Authors: Gatto Emilia Mabel , Pardal Manuel María Fernandez , Reisin Ricardo Claudio , Pardal Ana María
Published: August 2002

Herein we report a task‐specific dystonia in a 48‐year‐old woman, with an unusual association between a familial harp‐playing dystonia and essential tremor. © 2001 Movement Disorder Society.
Comparison of clinical vs. electrophysiological methods of diagnosing of essential tremor
Authors: Louis Elan D. , Pullman Seth L.
Published: August 2002

Essential tremor (ET) may be differentiated from normal or enhanced physiological tremor based on a clinical examination or electrophysiological tests such as quantitative computerized tremor analysis. There have been few head to head comparisons of the two methods. Our objective was to estimate diagnostic agreement between these two methods. Cases and controls underwent a clinical evaluation (interview and videotaped examination) and an electrophysiological evaluation (quantitative computerized tremor analysis using accelerometry and electromyography) on the same day, and diagnoses were independently assigned using clinical vs. electrophysiological criteria. Agreement between diagnoses was assessed with a concordance rate and kappa statistic (κ).Thirty‐two (59.3%) of 54 subjects were diagnosed clinically as ET (possible, probable, or definite), compared with 35 (64.8%) of 54 based on tremor analysis. The concordance rate between the two methods of diagnosis was 94.4% (51 of 54). κ was 0.88, indicating a level of agreement between diagnoses that was in the “near perfect” range. All of the subjects who received electrophysiological diagnoses of definite ET also received clinical diagnoses of ET. Conversely, all of the subjects who received clinical diagnoses of definite ET also received electrophysiological diagnoses of ET. The agreement between the clinical and electrophysiological diagnosis of ET was substantial, suggesting that study protocols that were to utilize either technique would arrive at similar diagnostic conclusions. In addition, physiological testing can quantify potentially valuable subclinical measurements as well as detect possible additional cases of ET not diagnosed as such during clinical assessments. © 2001 Movement Disorder Society.
Methods for digital video recording, storage, and communication of movement disorders
Authors: Jog Mandar S. , Grantier Linda
Published: August 2002

Video technology has now reached a level of sophistication that allows easy digitization. Digital video can be easily edited, reproduced, incorporated into databases, and posted on intra‐ and Internet sites for clinical use and demonstration purposes. Numerous methods exist for the production of digital video. This article synthesizes and simplifies the available methodologies in order to easily choose the technology that is the most appropriate for the movement disorder specialist's end use. Depending on available resources, issues such as cost, ease, and time to conversion are discussed. In addition, our experience with the use of one of the methodologies is briefly presented. © 2001 Movement Disorder Society.
Sequence variation in GAA repeat expansions may cause differential penotype display in Friedreich's ataxia
Authors: McDaniel D. Olga , Keats Bronya , Vedanarayanan V.V. , Subramony S.H.
Published: August 2002

Friedreich's ataxia, the most common autosomal recessive inherited ataxia, is characterized by progressive gait and limb ataxia. Friedreich's ataxia is known for its occurrence within the first or second decade of life and is associated with hypertrophic cardiomyopathy, and in some cases with diabetes. Genetically, it is identified by the expression of an unstable trinucleotide GAA repeat expansion located in the first intron of the X25 gene on chromosome 9. Two brothers with very late adult‐onset ataxia, and their unaffected sister, were examined for the clinical presentation of FA and for the presence of the mutated FA gene. The relationship of the expanded gene sequence to the severity of disease and age of onset were evaluated. Clinical examination revealed that the two brothers had mild ataxia and proprioceptive loss, with age of onset between 60 and 70 years of age. DNA from peripheral blood nucleated cells demonstrated a small homozygous expansion, with approximately 120–130 GAA repeats in the X25 gene in both patients. The expanded repeats were interrupted either with GAAGAG, GAAGGA, or GAAGAAAA sequences. The unaffected sister carried a normal FA genotype with 8‐uninterrupted GAA repeat, observed by sequence analysis. In addition, the levels of FA gene transcript in both brothers were relatively lower than that in the unaffected sister. No detectable cardiomyopathy or diabetes was observed. Phenotypic diversity of FA is increasingly expanding. The age of onset and the structure of GAA repeat expansion plays an important role in determining the clinical features and the differential diagnosis of FA. The confirmation of the FA gene mutation in the atypical case, broadens the clinical spectrum of FA, and supports the idea that patients with even a mild form of ataxia of late adult onset should be considered for molecular testing. © 2001 Movement Disorder Society.
Riluzole reduces hyperactivity of subthalamic neurons induced by unilateral 6‐OHDA lesion in the rat brain
Authors: Hassani Oum‐Kaltoum , Mouroux Mireille , Bohme Georg Andrees , Stutzmann Jean‐Marie , Féger Jean
Published: August 2002

An abnormal increase in the activity of neurons of the subthalamic nucleus is a key pathophysiological feature of Parkinson's disease. We sought to determine whether riluzole, a sodium channel inhibitor that interferes with glutamatergic neurotransmission, affects neuronal activity in this brain region. Intravenous administration of riluzole reduced the discharge rate of subthalamic neurons in rats with 6‐OHDA‐induced lesions of the midbrain. By contrast, no effect was observed in nonlesioned control animals. This property may contribute to the neuroprotective effects of riluzole in animal models of PD through the modulation of the glutamatergic inputs these neurons feedback to nigral dopaminergic neurons. © 2001 Movement Disorder Society.
Thalamic deep brain stimulation: Effects on the nontarget limbs
Authors: Ondo William , Dat Vuong Kevin , Almaguer Michael , Jankovic Joseph , Simpson Richard K.
Published: August 2002

Unilateral thalamic ventral intermediate (VIM) deep brain stimulation (DBS) is now accepted as an effective treatment for essential tremor (ET) and tremor related to Parkinson's disease (PD). The effects of unilateral placement on the side ipsilateral to the surgical site have not been carefully evaluated. To systematically assess the effects ipsilateral to the surgical side and to determine the effects of device inactivation on the baseline tremor, we evaluated tremor in 73 patients approximately 3 months after their unilateral thalamic placement. Assessment included blinded and unblinded ratings using the Unified Parkinson's Disease Rating Scale for PD patients and a modified Tremor Rating Scale in ET patients. All measures of tremor contralateral to the implantation site improved significantly and robustly in both PD and ET. Implantation did not worsen tremor by any measure on the ipsilateral side. There was mild ipsilateral improvement as measured by lower observed tremor scores in ET (6.0 ± 1.8 to 5.0 ± 1.9, P < 0.005), but not PD. There was no rebound augmentation of tremor in either hand after the devices were deactivated in either group. We conclude that VIM DBS may mildly improve ipsilateral ET, and that concerns about meaningful ipsilateral tremor augmentation after device deactivation are not warranted. © 2001 Movement Disorder Society.
Effects of liposome‐mediated gene transfer of VEGF in ischemic rat gracilis muscle
Authors: Neumeister Michael W. , Song Yao‐Hua , Mowlavi Arian , Suchy Hans , Mathur Aruna
Published: August 2002

The purpose of the current study was to determine the effects of vascular endothelial growth factor (VEGF) on muscle flap survival and vascularity in a rat gracilis ischemia‐reperfusion model. A total of 12 adult male Wistar rats were divided into two groups (n = 6). The experimental group received the plasmid encoding VEGF165 cDNA plus lipofectamine (cationic liposome) injected directly to the gracilis muscle following 4 h of ischemia. The control group received lipofectamine only. The viability and vascularity of the flaps were evaluated after 7 days of reperfusion. The data demonstrated that the VEGF plasmid‐ and lipofectamine‐treated muscle flaps had significantly greater total survival and capillary count 7 days after reperfusion compared with the flaps treated only with lipofectamine. These results indicate that VEGF exerts a protective effect on ischemic skeletal muscle flaps. © 2001 Wiley‐Liss, Inc. MICROSURGERY 21:58–62 2001
Unique continuation for systems with Lamé principal part
Authors: Weck Norbert
Published: August 2002

We generalize a result concerning unique continuation for the system of linearized isotropic elasticity by admitting first‐order perturbations. The proof is based on elementary weighted L2‐inequalities. Furthermore, we extend our result to a generalization of the Lamé system in the context of alternating differential forms. Copyright © 2001 John Wiley & Sons, Ltd.
On optimal control problems connected with eigenvalue variational inequalities
Authors: Bock Igor
Published: August 2002

The eigenvalue optimization problem for a variational inequality over the convex cone is to be dealt with. The control variable appears in the operator of the unilateral problem. The existence theorem for the maximum first eigenvalue optimization problem is stated and verified. The necessary optimality condition is derived. The applications to the optimal design of unilaterally supported beams and plates are presented. The variable thickness of a construction plays the role of a design variable. The convergence of the finite elements approximation is proved. Copyright © 2001 John Wiley & Sons, Ltd.
Numerical modeling of omnidirectional slotted‐waveguide antennas
Authors: Wang H. Y. , Zhang S. Q. , Sangster A. J.
Published: August 2002

Slotted‐waveguide antennas with omni‐directional radiation patterns are analyzed using the method of moments and a full‐wall electromagnetic simulator based on the finite‐difference time‐domain (FDTD) method. The resonant and radiation properties of the antennas have been examined. The simulated results are shown to be in good agreement with those obtained from measurements. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 374–377, 2001.
Theoretical investigations on the propagation characteristics of transmission lines on substrates with very high dielectric constant
Authors: Seixas D. L. A. , Conrado L. F. M. , Carvalho M. C. R.
Published: August 2002

The propagation characteristics of enclosed microstrip‐slot and coplanar waveguide‐slot lines printed on substrates with a very high dielectric constant (εr=40, εr=80, and εr=100, respectively) are investigated for a wide range of geometric parameters. The analysis of the lines was performed using the finite‐element method. The numerical results show the dependence of the transmission‐line parameters with transversal dimensions and frequency. Also, it was verified that the substrate thickness and enclosure width are the relevant parameters which limit single‐mode operation. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 275–278, 2002.
A novel miniaturized microstrip bandpass filter using a meander‐line resonator
Authors: Qing X. M. , Chia Y. W. M. , Sun J.
Published: August 2002

We report a novel miniaturized microstrip bandpass filter with a meander‐line resonator which exhibits a much smaller size. A very compact prototype, having a size of about λg0/8×λg0/8 at a center frequency of 2.445 GHz, was designed and fabricated for a 2.4 GHz bluetooth application. The measurement results of the proposed filter are in good agreement with the simulation results. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 319–321, 2002.
Surface mount filter with a triple‐mode ceramic cavity
Authors: Tikhov Yuri , Kim Jeong Phill
Published: August 2002

We consider a novel surface mount ceramic filter for wireless communication systems. The high permittivity ceramic filling of the basic triple‐mode waveguide cavity makes proposed bandpass filters physically small. Integrated microstrip to ceramic waveguide transitions provide effective connection of the filter into a planar circuit. The theory is based on the singular integral equation method in conjunction with generalized scattering matrix technique. The principal feature of the simulation algorithm consists of utilization of weighted Gegenbauer polynomials as the basis functions for the Galerkin's procedure. A design example is shown for L‐band filter. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 373–377, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10326
Constrained optimization for color pattern recognition with a nonzero order joint transform correlator
Authors: Wu Chih‐Sung , Chen Chulung , Fang Jian‐Shuen
Published: August 2002

In this article, we apply a novel method on color pattern recognition with the nonzero order joint transform correlator. By the special arrangement of separated RGB channels of objects and reference images at the input plane, we can predict the location of correlation outputs. Furthermore, by the use of power‐spectrum subtraction strategy, the zero‐order part can be removed. The test pattern is a frog. The desired correlation peak is found to be quite distinctive and sharp. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 385–388, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10330
Beam‐switched rhombic antenna
Authors: Fusco V. F. , Li R.
Published: August 2002

In this paper, we show how a rhombic antenna can be operated in a degenerate fashion in order to produce a switched beam. The antenna demonstrator designed to operate at 1 GHz is shown to beam scan in elevation by about 10°, controlled only by the use of a switched 500 Ω resistor. Under these conditions, the antenna exhibits a sending end impedance variation of 1.6:1. This type of antenna could find application for use in low‐cost vehicular and asset‐tracking applications. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 84–86, 2001.
Characterization of polypropylene thin‐film microstrip lines at millimeter and submillimeter wavelengths
Authors: Nagel M. , Dekorsy T. , Brucherseifer M. , Haring Bolívar P. , Kurz H.
Published: August 2002

We report on the characteristics of thin‐film microstrip lines with adhesive polypropylene tape as dielectric. The attenuation and dispersion have been measured in a frequency range between 30 and 800 GHz by electro‐optical sampling. A 31‐μm‐wide PP microstrip line exhibits a low attenuation of 0.09 dB/mm and an effective permittivity εr, eff of 1.85, both at 30 GHz. Both the excellent dielectric properties as well as the high planarity appear very attractive for future waveguide structures. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 97–100, 2001.
Efficient determination of current densities induced in the human body from measured low‐frequency inhomogeneous magnetic fields
Authors: Ruoß Hans‐Oliver , Spreitzer Wolfgang , Nishizawa Shinichiro , Messy Sven , Klar Michael
Published: August 2002

An efficient numerical source model is proposed to calculate the induced current densities in the human body from measured low‐frequency inhomogeneous magnetic fields emitted by electronic devices (e.g., household appliances or power tools). Due to the complex geometrical structure and complicated construction of the devices, an efficient equivalent‐source formulation using magnetic elementary dipoles is determined to characterize the field source. Consequently, the validity of the proposed equivalent‐source model is confirmed, and the induced current density in the human body is calculated for several kinds of appliances. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 211–213, 2001.
Design of a large effective‐area nonzero‐dispersion fiber for DWDM systems
Authors: Survaiya S. P. , Shevgaonkar R. K.
Published: August 2002

In this paper, we analyze and propose an optimum index profile which can give a larger core effective area with nonzero‐dispersion characteristics. The index profile is modeled by an exponentially modulated linear chirp profile function. A linear finite‐element method (LFEM) is used for computing the transmission characteristics of an optical fiber having an arbitrary refractive‐index profile. The optimum index profile can give a core effective area of 117 μm2. The dispersion varies linearly from 2.5 to 4.5 ps/nm⋅km with a dispersion slope of 0.065 ps/nm2⋅km over the 1.53–1.56 μm wavelength range. Sensitivity analysis for the designed fiber characteristics is also studied. The bend loss is about 0.001 dB/m for a bend radius of 100 mm. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 238–244, 2001.
FDTD and TLM analysis of a PIFA using an irregularly graded space connection
Authors: Geng Hui , Hira M. , Shiozawa T.
Published: August 2002

This letter presents an optimization procedure for the synthesis of a planar inverted‐F antenna (PIFA). The procedure uses the combing method to exploit the advantages of the FDTD and TLM algorithms. A proposed connection interface between the FDTD and TLM with irregularly graded space was introduced in the synthesis for an optimal shape. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 259–263, 2001.
A low‐cost L‐probe patch antenna array
Authors: Wong H. , Luk K. M.
Published: August 2002

Using L‐probe patch antennas as elements, a simple series‐fed eight‐element array antenna is designed and tested. An impedance bandwidth of 8% (SWR≦1.5) and an average gain of 14.5 dBi have been achieved. The radiation pattern is stable across the passband with low cross polarization. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 280–282, 2001.
Analysis of circular waveguides with soft and hard surfaces realized by strip‐loaded walls using asymptotic boundary conditions
Authors: Kishk Ahmed A. , Morgan Michael
Published: August 2002

Soft and hard walls are realized for a circular waveguide with walls coated by a uniform dielectric layer of appropriate thickness and loaded with conducting strips. The strips are oriented along the waveguide axis (z‐axis) for hard surfaces or φ‐directed for soft surfaces in a periodic form. The simple approximate asymptotic strip boundary condition (ASBC) is used to analyze the structure. For the dominant mode, when the waveguide walls are hard or soft, a linear field distribution across the waveguide cross section can be obtained. Then the waveguide can be used as an antenna with good linear polarization. The characteristics of such waveguides are presented with sample radiation patterns as compared with hollow waveguide radiation patterns. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 433–436, 2001.
Pulmonary abnormalities at long‐term follow‐up of patients with Langerhans cell histiocytosis
Authors: Bernstrand Cecilia , Cederlund Kerstin , Sandstedt Bengt , Åhström Lars , Lundell Marie , Dahlquist Gisela , Henter Jan‐Inge
Published: August 2002

Background

In Langerhans cell histiocytosis (LCH) pulmonary involvement, which is often initially asymptomatic, may contribute to significant morbidity and mortality. To determine the long‐term prognosis, a cross‐sectional study was undertaken.

Procedure

Forty‐one patients with ≥5 years follow‐up after the diagnosis of LCH were interviewed and underwent physical examination, blood tests, a chest X‐ray and a high‐resolution CT (HRCT) of the lungs. All patients included had been referred to the Department of Pediatrics at the Karolinska Hospital in Stockholm between July 1962 and February 1990 (median follow‐up 16 years). Biopsies from all patients were reviewed and confirmed to be consistent with LCH. Information on previous clinical features including treatment and the results of chest X‐rays were also collected for risk factor analysis.

Results

Radiographic abnormalities of the lungs (cysts and/or emphysema), found in 10/41 (24%) at follow‐up, were classified into five groups according to the extent of the cysts. These patients had more often suffered from multisystem than from single‐system disease (P = 0.01), were significantly older at diagnosis (P < 0.001), and had been more heavily treated with chemotherapy and/or radiotherapy. They were also more frequently smokers (P < 0.0001) and 7/10 (70%) had suffered lung involvement at diagnosis. At the time of diagnosis of the pulmonary involvement, 4/10 (40%) patients had respiratory symptoms, but only 2/10 (20%) had symptoms at follow‐up.

Conclusions

Ten (24%) of the 41 patients had abnormal findings on radiological examination of the lungs at long‐term follow‐up and seven are or had been smokers. It is of great importance that patients with LCH be informed about smoking‐related pulmonary morbidity. Prolonged monitoring of the lungs for smokers and patients with known pulmonary involvement is recommended. Med. Pediatr. Oncol. 36:459–468, 2001. © 2001 Wiley‐Liss, Inc.
Expression of cytokeratin‐18‐related tissue polypeptide‐specific (TPS) antigen in Wilms tumor
Authors: Rebhandl Winfried , Handisurya Alessandra , Memaran Nima , Felberbauer Franz Xaver , Aberle Judith , Paya Kurosh , Strobl Birgit , Horcher Ernst
Published: August 2002

Background

So far, there is no approved tumour marker for diagnosis or follow‐up in Wilms tumour (WT). Tissue polypeptide‐specific antigen (TPS), a cytokeratin 18 proteolytic fragment, has been suggested to be of value in the clinical management of WT patients. Cytokeratin 18 fragments are an early indicator of apoptosis and cytokeratin 18 might influence tumour cell behaviour. We investigated TPS expression in specimens of WT and other paediatric renal malignancies

Procedure

Immunoreactivity of WT sections (n = 9), clear cell sarcomas (CCSK, n = 3), and a renal cell carcinoma (RCC), and two pediatric kidney tumour cell lines (WT: SK‐NEP‐1 and rhabdoid tumour of the kidney: G‐401) were investigated using the monoclonal antibody M3. Additionally, immunoblotting and RT‐PCR analysis were performed. Cell culture supernatants were evaluated for TPS release. Serum TPS was measured in five patients at diagnosis, during chemotherapy and after surgical resection.

Results

Moderate to strong immunoreactivity for TPS was found in tubular and blastemal components of nearly all (8/9) WT specimens. This was confirmed by Western‐blotting. Cystic and epithelial‐like portions of CCSKs and RCC showed distinct reactivity (3/3). The supernatant of G‐401 but not of SK‐NEP‐1 showed a time‐ and cell number‐dependent increase of TPS release. Interestingly, TPS synthesis was demonstrated in SK‐NEP‐1 cells. Median preoperative serum TPS was elevated (293 U/l) compared to healthy children and lowest after surgical resection (49.5 U/l).

Conclusions

This is the first study demonstrating the synthesis and release of TPS by WTs and other paediatric renal malignancies. Considering the elevated levels of TPS in serum of these patients, a further investigation of this marker by larger clinical trials seems to be justified. Med Pediatr Oncol 2001;37:357–364. © 2001 Wiley‐Liss, Inc.
Intensive timed sequential remission induction chemotherapy with high‐dose cytarabine for childhood acute myeloid leukemia
Authors: Loeb David M. , Bowers Daniel C. , Civin Curt I. , Friedman Alan D.
Published: August 2002

Background

Timed sequential chemotherapy and high‐dose cytarabine (cytosine arabinoside, Ara‐C; HDAC) are both effective treatments for acute myeloid leukemia (AML). We review our institutional experience with timed sequential induction chemotherapy consisting of daunorubicin/Ara‐C/‐thioguanine (DAT) or idarubicin/Ara‐C/‐thioguanine (IAT) followed on day 14 by HDAC regardless of the degree of marrow aplasia for children with newly diagnosed AML.

Procedure

Children presenting with newly diagnosed AML were treated with induction chemotherapy consisting of idarubicin (12 mg/m/day on days 1–3 or daunorubicin at 45 mg/m2/day for the first five patients), Ara‐C (100 mg/m2/day by continuous infusion on days 1–7), and thioguanine (100 mg/m2/day on days 1–7). HDAC (1 g/m2/dose every 12 hr for 10 doses) was administered beginning on day 14, regardless of the results of bone marrow examination.

Results

Thirteen children received timed sequential HDAC. Only one child received HDAC later than Day 18. Eleven of the children achieved a complete remission. All patients experienced grade 4 hematologic toxicity, and all had fever as well. There were 11 children with documented infections. Ten had grade 3 or 4 GI toxicity. One patient died of sepsis.

Conclusions

HDAC administered as a part of timed sequential therapy yields an excellent remission induction rate with manageable toxicity. Med Pediatr Oncol 2001;37:365–371. © 2001 Wiley‐Liss, Inc.
37Cl/35Cl and 13C/12C isotope effects on the fluorine shielding in several two‐carbon chlorofluorocarbons
Authors: Tordeux Marc , Wakselman Claude , Jarjayes Olivier , Béguin Claude G.
Published: August 2002

Isotope effects on the chemical shift (IECS) of 19F bonded through two or three bonds to the isotopes 35Cl and 37Cl are reported for a wide range of two‐carbon chlorofluorocarbons (and, for a few cases, with the isotopes 79Br and 81Br, for two‐carbon bromofluorocarbons). These IECS through two bonds were found to range, for one chlorine atom, from −5.0 to −7.6 ppb for aliphatic compounds and from −4.5 to −6.4 ppb for olefinic compounds. The IECS through three bonds were found to be less than −1.15 ppb. No deviation from additivity was detected for the IECS when several equivalent chlorine atoms are present. The broadening of the 19F lines, due to scalar relaxation arising from 19F–37/35Cl spin–spin interactions, ranges from 0.32 to 2.50 Hz in our series and are related to the 2J(Cl, 19F)T1(Cl) term. IECS of 19F bonded through one or two bonds to the isotopes 13C and 12C are also reported for the same series. Several correlations, related to structural information, can be made and discussed between these IECS [13/12C IECS through two bonds as a function of 1J(13C, 19F) spin–spin coupling constants and 13/12C IECS as a function of 37/35Cl IECS]. 37/35Cl IECS can also be observed on 13C satellites of 19F spectra. For non‐symmetrical compounds, the dependence of these signals on the 37/35Cl IECS is the same as that for the main 19F signal; however, for the centrosymmetrical compounds, the main 19F signal appears to be sensitive to all the chlorine atoms, whereas the 13C satellites seem to be sensitive only to the directly bonded chlorine. Copyright © 2001 John Wiley & Sons, Ltd.
Gradient‐enhanced 1D HMQC‐ and HSQC‐relayed experiments with maximum sensitivity
Authors: Parella Teodor , Belloc Jordi
Published: August 2002

The incorporation of pulsed‐field gradients for coherence selection into 1D proton‐detected pulse sequences provides clean spectra free of cancellation artifacts but, frequently, at the expense of a sensitivity loss by a theoretical factor of 2 due to the rejection of another contributed pathway. A series of slightly modified gradient‐enhanced 1D carbon‐selective HMQC‐ and HSQC‐relayed experiments are proposed to obtain maximum signal‐to‐noise ratios in the same overall acquisition time. In contrast to the implementation of this so‐called PEP approach in multi‐dimensional experiments, the proposed 1D experiments do not have extra requirements for data acquisition or data processing with respect to the original ones and the excellent spectral quality due to of gradient‐selected experiments is preserved. Copyright © 2001 John Wiley & Sons, Ltd.
Principal component analysis in studies of substituent‐induced chemical shifts of 1,4‐disubstituted benzenes
Authors: Canto Eduardo L. , Tasic Ljubica , Bruns Roy E. , Rittner Roberto
Published: August 2002

Chemometric analyses of 1,4‐disubstituted benzene aromatic carbon atom NMR chemical shifts, bearing 14 substituents (X) within a complete series involving the same substituents as fixed groups (Y), are reported. The substituent effects of (i) strong electron donors (NMe2, NH2 and OMe), (ii) halogens (F, Cl and Br), (iii) electron acceptors (CF3, CN and NO2), (iv) acceptors of the carbonyl type [C(O)OEt, C(O)Me and CHO] and (v) neutral groups (H and Me) were studied using principal component analysis (PCA). The charge alterations (Δq) induced by introducing a substituent X at C‐1 were also analyzed by the means of PCA of data obtained from theoretical calculations (AM1 method). The correlations among the substituent chemical shifts (SCS) and among the charge alterations (Δq) and the dependence of SCS on charge alterations were analyzed by regression analyses applied to the scores of the first principal components (PC1) obtained in the PCA of the SCS and Δq values. Copyright © 2001 John Wiley & Sons, Ltd.
Electronic structure of nitrogen–chlorine bonds in some compounds studied by NQR spectroscopy and DFT calculations
Authors: Poleshchuk O. Kh. , Makiej K. , Ostafin M. , Nogaj B.
Published: August 2002

35Cl‐NQR frequencies of 1,3,5‐trichloro‐1,3,5‐triazine‐2,4,6‐(1H,3H,5H)‐trione and 1,3‐dichloro‐5,5‐dimethylhydantoin were measured at 77 K. The asymmetry parameters of electric field gradient (EFG) tensors on 35Cl nuclei were also determined with nutation 35Cl‐NQR spectroscopy in zero magnetic field. The calculated quadrupole coupling constants and asymmetry parameters for 14N and 35Cl nuclei were compared with the corresponding experimental values for several compounds containing N—Cl bonds. The electronic structure of the N—Cl bond in these compounds is discussed in terms of the terminology of lone pairs, hybrid orbitals and NAO charges. Copyright © 2001 John Wiley & Sons, Ltd.
Unnaturally configured 13‐epi steroids: full 1H and 13C assignments and ring C–D conformations from 1H, 1H vicinal couplings
Authors: Fielding Lee , Diepeveen Yolande , Fletcher Dan , Hamilton Niall
Published: August 2002

Six steroids with inverted stereochemistry at C‐13 (13‐epi) were studied. Measurement of vicinal proton–proton couplings was facilitated by a 1D TOCSY experiment, which provided efficient deconvolution of the ring D protons from other signals. A simple semi‐quantitative analysis of the ring D couplings was found to be sufficient to determine the conformation of ring D. Examples of 13α, 14β half‐chair, 17β envelope and 16β envelope conformations were found. Copyright © 2001 John Wiley & Sons, Ltd.
Translactonization of erythromycin A during oximation: mixture analysis and reaction monitoring by NMR
Authors: Grover Rajesh K. , Joshi B. S. , Batra S. , Roy Raja , Bhaduri A. P.
Published: August 2002

Oximation of erythromycin A with hydroxylamine hydrochloride and sodium acetate in methanol led to the formation of pseudoerythromycin A enol ether with erythromycin A oxime as analysed by detailed two‐dimensional NMR spectroscopy in the mixture along with traces of 8,9‐anhydroerythromycin A 6,9‐hemiketal and erythromycin A 6,9:9,12‐spiroketal. The formation of the degraded products was established by performing in situ 13C NMR spectroscopy. The analysis suggests that pseudoerythromycin A enol ether is formed by the translactonization of erythromycin A enol ether which forms as a result of acid degradation. Copyright © 2001 John Wiley & Sons, Ltd.
Unambiguous signal assignments of 1H and 13C NMR spectra for chlorinated benzenes using 37Cl/35Cl isotope effects
Authors: Matsubara Koshi
Published: August 2002

One‐bond 37Cl/35Cl isotope effects on 13C NMR chemical shifts were used to assign the 1H and 13C NMR spectra of bis(4‐chlorophenyl)sulfone, 4,5‐dichlorophthalic acid and 2,2′‐thiobis(4,6‐dichlorophenol). The chlorine‐bonded carbons showed characteristic peaks separated by about 4 ppb with a 3 : 1 area ratio, corresponding to the natural abundance of 35Cl and 37Cl. The determination of the chlorine‐bonded carbon signals based on the isotope effects was useful when the empirical additivity rules of the chemical shifts and several 2D NMR techniques were insufficient for a complete definitive assignment. Copyright © 2001 John Wiley & Sons, Ltd.
Structure determination of daphjamilin, a new bicoumarin glycoside, by NMR spectroscopy
Authors: Riaz Muhammad , Malik Abdul
Published: August 2002

Daphjamilin, a new dimeric coumarin glycoside, was isolated from the roots of Daphne oleoides and assigned the structure 7‐O‐α‐L‐rhamnosyl‐8‐[2‐oxo‐2H‐1‐benzopyran‐7′‐(hydroxy)‐6′‐yl]‐2H‐1‐benzopyran‐2‐one by extensive NMR studies. Copyright © 2001 John Wiley & Sons, Ltd.
Cycle time as a variable in homonuclear decoupling in solids: use of CRAMPS to determine minor constituent impurities in organic crystals to ≤0.005%
Authors: Gerstein Bernard C. , Kimura Hideaki
Published: August 2002

The use of proton CRAMPS NMR with varying cycle time and gain is shown to avoid the problems of dynamic range and probe background, and to allow residual solvent in some organic crystals such as durene to determined with an accuracy of ≤0.005%. Copyright © 2001 John Wiley & Sons, Ltd.
Diastereoselective synthesis and 1H and 13C NMR study of 4‐acetyl‐2,6‐diaroyl‐3,5‐diaryl‐4‐ethoxycarbonylthiane‐1,1‐dioxides
Authors: Renuga S. , Selvaraj S. , Perumal S. , Lycka A. , Gnanadeebam M.
Published: August 2002

Conjugate addition of ethyl acetoacetate to 2,2′‐sulfonylbis(1,3‐diarylprop‐2‐en‐1‐ones) afforded a diastereom‐eric mixture (in a ratio of ∼65:35) of 4‐acetyl‐2,6‐diaroyl‐3,5‐diaryl‐4‐ethoxycarbonylthiane‐1,1‐dioxides differing in configuration at C‐4. The stereochemistry of the diastereomeric thianes was established by 1H, 13C and 2D NMR spectroscopic techniques such as H,H‐COSY, C,H‐COSY and NOESY. Copyright © 2001 John Wiley & Sons, Ltd.
Structure elucidation of three new acetylated flavonoid glycosides from Centaurium spicatum
Authors: Shahat Abdelaaty A. , Apers Sandra , Miert Sabine Van , Claeys Magda , Pieters Luc , Vlietinck Arnold
Published: August 2002

Three new acetylated flavonol glycosides, quercetin 3‐O‐(2,3,4‐triacetyl‐α‐rhamnopyranosyl)‐(1 → 6)‐β‐galactopyranoside, quercetin 3‐O‐[(2,3,4‐triacetyl‐α‐rhamnopyranosyl)‐(1 → 6)]‐3‐acetyl‐β‐galactopyranoside and quercetin 3‐O‐[(2,3,4‐triacetyl‐α‐rhamnopyranosyl)‐(1 → 6)]‐4‐acetyl‐β‐galactopyranoside, were isolated from Centaurium spicatum (L.) Fritsch (Gentianaceae). Structure elucidation, especially the localization of the acetyl groups, and complete 1H and 13C NMR assignments of these biologically active compounds were carried out using one‐ and two‐dimensional NMR methods, including 1H and 13C NMR, DEPT‐135 and DEPT‐90 and gradient‐assisted experiments such as DQF‐COSY, TOCSY, HSQC and HMBC experiments. Copyright © 2001 John Wiley & Sons, Ltd.
Stereochemical and conformational studies on pharmaceutical compounds by NMR and molecular modelling
Authors: Sharman Gary J. , Jones Ian C.
Published: August 2002

NMR and molecular modelling were used to determine the stereochemistry of two pairs of pharmaceutical compounds. In both cases, an unexpected conformation complicated the analysis of one isomer, but the insight provided by molecular modelling allowed the NMR data to be interpreted and the identity proved. This study highlights the difficulty of predicting conformation, even for what might be expected to be straightforward systems. Copyright © 2001 John Wiley & Sons, Ltd.
Dipole‐stabilized carbanions in series of cyclic aldonitrones: Part 4. 13C, 14N and 7Li NMR spectra of dipole‐stabilized organolithiums derived from a cyclic aldonitrone
Authors: Voinov Maxim A. , Salnikov Georgy E. , Genaev Alexander M. , Mamatyuk Victor I. , Shakirov Makhmut M. , Grigor'ev Igor A.
Published: August 2002

13C, 14N and 7Li NMR spectra of a lithiation product of the cyclic aldonitrone 1,2,2,5,5‐pentamethyl‐3‐imidazoline 3‐oxide were obtained. The 13C NMR spectrum of the lithiated particle exhibits the resonances of the C‐4 and C‐5 atoms (δ213 ppm and 73 ppm, respectively) shifted to high frequency relative to the signals of the corresponding nuclei of the starting nitrone (δC‐4 132 ppm and δC‐5 60 ppm). The 14N NMR spectrum of the particle shows the resonance of the N‐3 atom (−115 ppm) at lower frequency in comparison with −74 ppm for the starting nitrone. The calculated chemical shift changes are in good agreement with those observed experimentally. The electronic structure of the lithiated particle is discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Complete 1H and 13C resonance assignments of glycosidic conjugates of non‐amidated and amidated bile acids
Authors: Iida Takashi , Kasuga Yuka , Arakawa Masayuki , Mushiake Kumiko , Ikegawa Shigeo , Goto Junichi , Nambara Toshio
Published: August 2002

Complete 1H and 13C resonance assignments on the basis of 1D and 2D NMR were made for seven naturally occurring variants of the 3α‐, 6α‐ and 7β‐O‐β‐D‐glycosidic conjugates (glucosides, N‐acetylglucosaminides and glucuronides) of non‐amidated and glycine‐ and taurine‐amidated bile acids related to lithocholic, hyodeoxycholic, chenodeoxycholic, ursodeoxycolic, deoxycholic and cholic acids. The 1H and 13C NMR signals serving to characterize each of the glycosidic conjugates of bile acids and the effects of the O‐β‐D‐glucosidation, O‐β‐D‐N‐acetylglucosaminidation and O‐β‐D‐glucuronidation at the 3‐, 6‐ or 7‐position in the 5β‐steroid nucleus on the 1H and 13C resonances were clarified and used in the structural elucidation of these bile acid glycosides. Copyright © 2001 John Wiley & Sons, Ltd.
Temperature calibration of a high‐resolution magic‐angle spinning NMR probe for analysis of tissue samples
Authors: Nicholls Andrew W. , Mortishire‐Smith Russell J.
Published: August 2002

The increase in tissue sample temperature caused by the spinning of a rotor in high‐resolution magic‐angle spinning (HRMAS) NMR spectroscopy was investigated using two literature NMR thermometers. The classical methanol thermometer was used to calibrate the temperature difference between the set temperature and the actual sample temperature. At spin speeds of 2, 4, 6 and 8 kHz, a mean increase in sample temperature over the set temperature of 0.8 ± 0.1, 2.2 ± 0.1, 5.0 ± 0.1 and 7.9 ± 0.2 K, respectively, was noted. This calibration was used to gauge the accuracy of the literature glucose thermometer, which was shown to have a mean increase over the set temperature of −0.3 ± 0.1, 1.2 ± 0.2, 3.0 ± 0.2 and 6.1 ±0.1 K at 2, 4, 6 and 8 kHz, respectively. By correcting for the errors measured in this study, a more accurate determination and adjustment of sample temperature in HRMAS NMR spectroscopic analyses of intact tissues is now possible. Copyright © 2001 John Wiley & Sons, Ltd.
Identification and complete 1H and 13C spectral assignments for the triterpene fern‐9(11)‐en‐28‐oic acid
Authors: Reynolds William F. , McLean Stewart , Burke Sharon J. , Jacobs Helen
Published: August 2002

The structure of the triterpene fern‐9(11)‐en‐28‐oic acid (1), was determined by concerted application of 2D methods, which also provided full 1H and 13C spectral assignments. Compound 1 is a rare triterpene which has been isolated once before, as its methyl ester. Earlier errors in 13C spectral assignments are corrected. Copyright © 2001 John Wiley & Sons, Ltd.
Essential role of ZP molecules in tubal transport of embryos in mice
Authors: Kim Chang Hun , Seo Byoung Boo , Yamanouchi Keitaro , Kuromaru Masamich , Sawasaki Toru , Hinsch Elvira , Hinsch Klaus‐Dieter , Naito Kunihiko , Tachi Chikashi , Tojo Hideaki
Published: August 2002

Our understandings of the molecular and cellular mechanisms underlying tubal transport of embryos are poor. This study describes the essential role of the molecules on the zona pellucida (ZP) in the tubal transport of mouse embryos. The bovine and porcine embryos that were interspecifically transferred to the mouse oviduct were selectively retained in the oviduct and rarely transported to the uterus. Antiserum ZP3‐9 against synthetic peptides that are specific for mouse ZP3, significantly interfered with tubal transport of the treated embryos. The treatment of mouse embryos with antiserum ZP2‐20 against the synthetic peptides, deduced from the sequences that are conserved in the structure of ZP2 from mouse and human, also inhibited their tubal transport. Among various proteolytic and glycosidic enzymes, treatments with trypsin and β‐glucosidase prior to transfer to the oviduct, significantly interfered with the tubal transport of the enzyme‐treated mouse embryos. We hypothesize that species‐specific epitopes on the ZP may be recognized by the oviductal cilia and/or the epithelial cells of ducts for tubal transport. Mol. Reprod. Dev. 61: 327–334, 2002. © 2002 Wiley‐Liss, Inc.
Partial characterization of the factor in theca‐cell conditioned medium that inhibits the progression of FSH‐induced meiosis of bovine oocytes surrounded by cumulus cells connected to the membrana granulosa
Authors: van Tol H.T.A. , Bevers M.M.
Published: August 2002

A factor, secreted by theca cells, inhibits FSH induced resumption of meiosis in bovine oocytes that are surrounded by cumulus cells which are attached to a piece of the membrana granulosa (COCGs). In order to characterize this factor, theca cell conditioned medium (CMt) was heat‐treated, filtered through a 5 kD spin off filter, charcoal treated, chloroform extracted and protease treated. To investigate whether the meiosis inhibiting factor produced by theca cells was also present in follicular fluid (FF), the same traetments were done with 50% bovine follicular fluid (bFF). COCGs, originating from 2 to 8 mm follicles of bovine ovaries collected at a slaughterhouse, were cultured in groups of 15 per 600 µl medium supplemented with 0.05 IU ml FSH for 22 hr at 39°C in a humidified atmosphere of 5% CO2. After culture the oocytes were denuded, stained with orcein, and the nuclear status assessed. Heat treatment did not affect the meiosis arresting capacity of CMt since a similar proportion of the oocytes remained at the GV stage after 22 hr of culture in heat treated CMt as compared to the proportion of oocytes in the GV stage after culture in untreated CMt. Filtering through a 5 kD spin‐off filter revealed that the meiosis inhibiting action was maintained in the <5 kD fraction, although there was a significant (P < 0.05) loss of inhibiting activity compared to nonfiltered CMt. No significant decrease was observed in the meiosis arresting capacity of the <5 kD fraction after charcoal or protease treatment. Extraction of the <5 kD fraction with chloroform also did not affect the theca cell produced factor. The effect of the theca cell factor on the progression of meiosis of the oocytes that resumed meiosis, as demonstrated by a very low percentage of the oocytes that matured up to the M2 stage, was not affected following any of the treatments. With regard to bFF, the results show a lower percentage of the oocytes in the GV stage after culture in 50% bFF as compared to culture in CMt, but progression of meiosis was clearly inhibited as demonstrated by a significant higher proportion of the oocytes blocked in the M1 stage after resumption of meiosis. In general, with regard to meiotic inhibition, bFF showed the same pattern as CMt following the various treatments. It is concluded that the theca cell secreted factor which inhibits the FSH‐induced resumption of meiosis in COCGs is a small, stable, polar molecule which is not a peptide. Mol. Reprod. Dev. 60:418‐424, © 2001 Wiley‐Liss, Inc.
Oscillating dual‐equilibrium steady‐state angiography
Authors: Overall William R. , Conolly Steven M. , Nishimura Dwight G. , Hu Bob S.
Published: August 2002

A novel technique of generating noncontrast angiograms is presented. This method, called oscillating dual‐equilibrium steady‐state angiography (ODESSA), utilizes a modified steady‐state free precession (SSFP) pulse sequence. The SSFP sequence is modified such that flowing material reaches a steady state which oscillates between two equilibrium values, while stationary material attains a single, nonoscillatory steady state. Subtraction of adjacent echoes results in large, uniform signal from all flowing spins and zero signal from stationary spins. Venous signal can be suppressed based on its reduced T2. ODESSA arterial signal is more than three times larger than that of traditional phase‐contrast angiography (PCA) in the same scan time, and also compares favorably with other techniques of MR angiography (MRA). Pulse sequences are implemented in 2D, 3D, and volumetric‐projection modes. Angiograms of the lower leg, generated in as few as 5 s, show high arterial signal‐to‐noise ratio (SNR) and full suppression of other tissues. Magn Reson Med 47:513–522, 2002. © 2002 Wiley‐Liss, Inc.
Bayesian technique for investigating linearity in event‐related BOLD fMRI
Authors: Kershaw Jeff , Kashikura Kenichi , Zhang Xiaojiang , Abe Sumiko , Kanno Iwao
Published: August 2002

Event‐related BOLD fMRI data is modeled as a linear time‐invariant system. Together with Bayesian inference techniques, a statistical test is developed for rigorously detecting linearity/nonlinearity in the BOLD response system. The test is applied to data collected from eight subjects using an event‐related paradigm with a switching checkerboard as the visual stimulus. Analyzed as a group, the results clearly find the response to be nonlinear. When each subject is analyzed individually, however, the results are predominantly nonlinear, but there is some evidence to suggest that there may be a crossover from a linear to a nonlinear regime and vice versa. This could be important when estimating physiological parameters for individuals. Additionally, estimates of the hemodynamic response function and corresponding response were obtained, but there was no consistent appearance of a poststimulus undershoot in the event‐related BOLD response. Magn Reson Med 45:1081–1094, 2001. © 2001 Wiley‐Liss, Inc.
Comments on “Gradient‐Induced Acoustic and Magnetic Field Fluctuations in a 4T Whole‐Body MR Imager”
Authors: Barnett Alan
Published: August 2002

The results published in the article Gradient‐Induced Acoustic and Magnetic Field Fluctuations in a 4T Whole‐Body MR Imager by Wu et al. (Magn Reson Med 2000;44:532–536) appear to be consistent with the response of a time‐stationary linear system. Since a linear system is more simply described than a nonlinear system, the authors are urged to reanalyze their data to test the linear‐system hypothesis. Magn Reson Med 46:207, 2001. Published 2001 Wiley‐Liss, Inc.