bluuebunny/crossref_metadata_2025 huggingface dataset:
Raman spectroscopy of hydrazine‐intercalated kaolinite at 77, 298, 323, 343 and 358 K
Authors: Martens Wayde N. , Ding Zhe , Frost Ray L. , Kristof János , Kloprogge J. Theo
Published: August 2002

The Raman spectrum at 298 K of hydrazine‐intercalated kaolinite shows a single band at 3620 cm−1. No other hydroxyl stretching bands are observed. Upon obtaining the spectrum at liquid nitrogen temperature the band is observed at 3616 cm−1, the same position as for the inner hydroxyl of the non‐intercalated kaolinite. Hence this band is assigned to the inner hydroxyl of kaolinite. After exposure to the atmosphere for 10 min and upon obtaining spectra at 77 K, two additional bands are observed at 3607 and 3625 cm−1. These additional bands are only observed after the onset of deintercalation. The band observed at 3625 cm−1 is assigned to the inner surface hydroxyls, hydrogen bonded to the hydrazine. The fact that the band is only observed after the onset of deintercalation suggests that the band is Raman inactive and infrared active. Raman spectroscopic analysis indicates that there are two types of hydrazine molecules as evidenced by two NH bands, (a) weakly hydrogen bonded as evidenced by two bands observed around 3300 and 3312 cm−1 and (b) a strongly hydrogen‐bonded hydrazine as evidenced by bands at 2890 and 2948 cm−1. The two NH symmetric stretching bands at around 3300 and 3312 cm−1 combined with the two NH antisymmetric stretching bands at 3361 and 3367 cm−1 suggest that there are two slightly different NH2 units in the hydrazine‐intercalated complex. Copyright © 2002 John Wiley & Sons, Ltd.
Vibrational characteristics of new double tungstates Li2MII(WO4)2 (M = Co, Ni and Cu)
Authors: Ma̧czka M. , Hanuza J. , Fuentes A. F. , Amador U.
Published: August 2002

For the first time, Raman and IR studies were performed on new double tungstates Li2MII(WO4)2 (M = Co, Ni and Cu) crystallizing in the wolframite‐type structure. The observed vibrational modes were assigned to the respective motions of atoms in the unit cell. The vibrational properties of the Cu derivative differ significantly from those of the cobalt and nickel derivatives. The differences were attributed to the differences in the crystal structures. A comparison of the results with literature data for MIIWO4 and LiMIII(WO4)2 (MII = Zn, Fe, Cu; MIII = Fe, In, Sc), crystallizing in the wolframite‐like structure, revealed a very large splitting for a few bridging modes and large shifts of the low‐wavenumber modes towards higher wavenumbers in the case of Li2MII(WO4)2. These features were assigned to different arrangements of tungsten–oxygen interactions within the infinite chains, which results in the formation of two non‐equivalent oxygen bridges in the structure of the compounds studied. Copyright © 2002 John Wiley & Sons, Ltd.
A framework for establishing and implementing corporate intelligence
Authors: Trim Peter
Published: August 2002

A commitment to corporate intelligence will assist senior management to formulate and implement strategies that counteract the actions of competitors and fraudsters.

In order that an Intelligence Unit is managed successfully it is vital for senior management to adopt a strategic approach to intelligence and security work.

An Advisory Board should be established to oversee the activities of the Director of Corporate Intelligence and provide advice and support during the early stage of the unit's development. Copyright © 2001 John Wiley & Sons, Ltd.
The effect of feeding pods of multipurpose trees (MPTs) on the degradability of dry matter and cell wall constituents of maize stover and alfalfa incubated in the rumen of sheep
Authors: Ngwa A T , Nsahlai I V , Bonsi M L K
Published: August 2002

This study evaluated the effects of feeding alfalfa and pods of tree legumes on rumen pH and ammonia concentration as well as in sacco degradability of dry matter and fibre constituents of maize stover, alfalfa hay and their neutral detergent extracts. The feeds were incubated in the rumens of five South African Merino sheep fed individually in an incomplete (5 × 4) Latin square design using five diets. The diets comprised equal proportions of pasture hay and either alfalfa (Alfalfa diet) or pods of Acacia sieberiana (Sieberiana diet), Acacia nilotica (Nilotica diet) or Leucaena leucocephala (Leucaena diet). The fifth diet was composed of pasture hay alone (Hay diet) and served as a negative control. Supplementation of hay with either legume pods or alfalfa significantly (p < 0.05) increased rumen ammonia concentration from 56 to a maximum of 86 mg l−1. The pH of the rumen fluid ranged between 6.2 and 6.5 for all diets, but variations in pH were not significant. Diet did not affect (p > 0.05) the degradability constants lag time (LT), slowly degradable fraction (B), potential degradability (PD), effective degradability (ED) and rate of degradation (C) of dry matter (DM) but significantly (p < 0.01) affected ED of the fibre constituents of the incubated feeds. The effective degradabilities of the incubated feeds differed (p < 0.001), with alfalfa and maize stover having average values of 555 and 318 g kg−1 DM respectively. The rate of degradation of alfalfa was also higher (p < 0.01) than that of maize stover. Neutral detergent extraction improved ED of the cell wall constituents of maize stover but produced the opposite effect for alfalfa. The interactions between incubation feed and extract were significant (p < 0.01) for ED and C of neutral detergent fibre and hemicellulose. The observations show that pods from tree legumes are comparable to alfalfa in the provision of rumen ammonia but limit microbial activity in the degradability of fibre constituents. They also show that maize stover and alfalfa differ in their degradabilities and that the differences may be attributed to their cell wall chemistry.

© 2001 Society of Chemical Industry
Telomerase activity in esophageal squamous cell carcinoma: Down‐regulation by chemotherapeutic agent
Authors: Mitsui Akira , Kuwabara Yoshiyuki , Iwase Hirotaka , Mitani Masami , Shinoda Noriyuki , Sato Atsushi , Toyama Tatsuya , Sugiura Masahiko , Suzuki Tomotaka , Kato Joji , Fujii Yoshitaka
Published: August 2002

Background and Objectives

Telomerase has been suggested as being necessary for continued cell growth and progression of cancer. Esophageal cancer and matched normal esophageal tissue from 54 patients were analyzed for telomerase activity, human telomerase reverse transcriptase (hTERT) mRNA expression, and their correlation with clinicopathological factors.

Methods

Telomeric repeat amplification protocol was used for detection of telomerase activity and real time quantitative RT‐PCR was used for hTERT mRNA. An esophageal carcinoma cell line was used to study the effect of chemotherapeutic agent on telomerase.

Results

Telomerase activity was detectable in 79.6% of the tumor and 59.3% of the normal esophageal tissue. The level of telomerase activity in the tumor was significantly higher than that in the normal tissue. A significantly higher telomerase activity was observed in tumors with extensive blood vessel invasion. A significantly lower telomerase activity was observed in tumors that showed good response to preoperative chemotherapy than those with poor response. TE‐9 cells exposed to 5‐FU showed a diminished telomerase activity preceded by a time‐dependent decrease in the mRNA expression of hTERT.

Conclusions

Telomerase activity was high in esophageal cancer tissue and showed positive correlation with blood vessel invasion. Chemotherapeutic agents may down‐regulate telomerase activity. J. Surg. Oncol. 2002;79:37–45. © 2002 Wiley‐Liss, Inc.
Does CH3 addition to C6H6 occur as reported?
Authors: Park J. , Lin M. C.
Published: August 2002

The kinetics for the CH3 + C6H6 reaction has been investigated by modeling the existing data obtained by Holt and Kerr [Int J Chem Kinet 1977, 9, 185.]. The result of the modeling suggests that the yields of CH4 measured in the UV photolysis of mixtures of (CH3CO)2, i‐C4H10, and C6H6 and employed in their analysis of the CH3 + C6H6 kinetics could be quantitatively predicted by the reactions of CH3 with i‐C4H10 and alkyl radicals present in the system, independent of the CH3 + C6H6 reaction. The CH3 + C6H6 reaction was concluded to be insignificant under the conditions employed on account of the instability of the C7H9 radical adduct and the strong CH bonds in benzene, which prevent the occurrence of the simple abstraction process. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 803–807, 2001
Kinetics of the thermal isomerization of 1,1‐dimethylcyclopropane
Authors: Kalra Bansi L. , Lewis David K.
Published: August 2002

Rate constants for the unimolecular thermal isomerization of gaseous 1,1‐dimethylcyclopropane to isomeric methylbutenes have been measured, and Arrhenius parameters determined, over a wide temperature range, 683–1132 K, using a single‐pulse shock tube and a static reactor. For the overall reaction, Ea = 61.8 ± 0.4 kcal/mol, and log10(A, s−1) = 15.04 ± 0.10. These values are in good agreement with previously reported values obtained over a much narrower temperature range. Rate constants for formation of the two major products, 2‐methylbut‐2‐ene and 3‐methylbut‐1‐ene, are given by Ea = 61.9 kcal/mol, log A = 14.80 and Ea = 61.1 kcal/mol, log A = 14.54, respectively. A comparison of the activation parameters for structural isomerizations of cyclopropane, methylcyclopropane, and 1,1‐dimethylcyclopropane confirms a trend toward lower activation energy values as hydrogen atoms in cyclopropane are replaced by CH3 groups. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 853–858, 2001
Kinetics and mechanism of the oxidation of 4‐methyl‐3‐thiosemicarbazide by acidic bromate
Authors: Jonnalagadda Sreekantha B. , Chinake Cordelia R. , Olojo Rotimi , Simoyi Reuben H.
Published: August 2002

The oxidation of 4‐methyl‐3‐thiosemicarbazide (MTSC) by bromate and bromine was studied in acidic medium. The stoichiometry of the reaction is extremely complex, and is dependent on the ratio of the initial concentrations of the oxidant to reductant. In excess MTSC and after prolonged standing, the stoichiometry was determined to be H3CN(H)CSN(H)NH2 + 3BrO3− → 2CO2 + NH4+ + SO42− + N2 + 3Br− + H+ (A). An interim stoichiometry is also obtained in which one of the CO2 molecules is replaced by HCOOH with an overall stoichiometry of 3H3CN(H)CSN(H)NH2 + 8BrO3− → CO2 + NH4+ + SO42− + HCOOH + N2 + 3Br− + 3H+ (B). Stoichiometry A and B are not very different, and so mixtures of the two were obtained. Compared to other oxidations of thiourea‐based compounds, this reaction is moderately fast and is first order in both bromate and substrate. It is autocatalytic in HOBr. The reaction is characterized by an autocatalytic sigmoidal decay in the consumption of MTSC, while in excess bromate conditions the reaction shows an induction period before autocatalytic formation of bromine. In both cases, oxybromine chemistry, which involves the initial formation of the reactive species HOBr and Br2, is dominant. The reactions of MTSC with both HOBr and Br2 are fast, and so the overall rate of oxidation is dependent upon the rates of formation of these reactive species from bromate. Our proposed mechanism involves the initial cleavage of the CN bond on the azo‐side of the molecule to release nitrogen and an activated sulfur species that quickly and rapidly rearranges to give a series of thiourea acids. These thiourea acids are then oxidized to the sulfonic acid before cleavage of the CS bond to give SO42−, CO2, and NH4+. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 237–247, 2002
Influence of nozzle‐to‐skin distance in cryogen spray cooling for dermatologic laser surgery
Authors: Aguilar Guillermo , Majaron Boris , Pope Karl , Svaasand Lars O. , Lavernia Enrique J. , Nelson J. Stuart
Published: August 2002

Background and Objective

Cryogen sprays are used for cooling human skin during various laser treatments. Since characteristics of such sprays have not been completely understood, the optimal atomizing nozzle design and operating conditions for cooling human skin remain to be determined.

Materials and Methods

Two commercial cryogenic spray nozzles are characterized by imaging the sprays and the resulting areas on a substrate, as well as by measurements of the average spray droplet diameters, velocities, temperatures, and heat transfer coefficients at the cryogen‐substrate interface; all as a function of distance from the nozzle tip.

Results

Size of spray cones and sprayed areas vary with distance and nozzle. Average droplet diameter and velocity increase with distance in the vicinity of the nozzle, slowly decreasing after a certain maximum is reached. Spray temperature decreases with distance due to the extraction of latent heat of vaporization. At larger distances, temperature increases due to complete evaporation of spray droplets. These three variables combined determine the heat transfer coefficient, which may also initially increase with distance, but eventually decreases as nozzles are moved far from the target.

Conclusions

Sprayed areas and heat extraction efficiencies produced by current commercial nozzles may be significantly modified by varying the distance between the nozzle and the sprayed surface. Lasers Surg. Med. 28:113–120, 2001. © 2001 Wiley‐Liss, Inc.
A phantom with tissue‐like optical properties in the visible and near infrared for use in photomedicine
Authors: Lualdi Manuela , Colombo Ambrogio , Farina Bruno , Tomatis Stefano , Marchesini Renato
Published: August 2002

Background and Objective

Modeling of light transport in tissue requires development of theoretical models and experimental procedures, as well as tissue‐simulating phantoms. Our purpose was to develop a phantom that matches the optical characteristics of human skin in the visible and near infrared spectral range.

Study Design/Materials and Methods

The phantom consists of a transparent silicone rubber in which Al2O3 particles and a cosmetic powder are embedded. Layers with thickness as thin as 0.1 mm can be made. The optical properties of Al2O3 particles and cosmetic powder, i.e., total attenuation, absorption and scattering coefficients, and phase function, have been determined in the visible and near infrared spectral range, by using direct and indirect techniques.

Results

By varying the concentration of scattering and absorbing particles, tissue‐like layers can be produced with predictable optical properties. In particular, mixing at suitable concentration Al2O3 particles and cosmetic powder with the silicone rubber, the optical properties of human skin have been simulated over a range of wavelengths from 400 to 1,000 nm. The comparison between the phantom diffuse reflectance spectrum and that of human skin, averaged over a sample of 260 patients, showed a good agreement.

Conclusion

The proposed technique allows to produce a stable and reproducible phantom, with accurately predictable optical properties, easy to make and to handle. This phantom is a useful tool for numerous applications involving light interaction with biologic tissue. Lasers Surg. Med. 28:237–243, 2001. © 2001 Wiley‐Liss, Inc.
Laser resurfacing with a long pulse erbium: YAG laser compared to the 950 ms pulsed CO2 laser
Authors: Rostan Elizabeth F. , Fitzpatrick Richard E. , Goldman Mitchel P.
Published: August 2002

Background and Objective:

Laser resurfacing with the 950 μs pulsed CO2 laser is an effective treatment for photodamage and acne scarring; however, the potential for prolonged erythema and delayed re‐epithelialization dissuade many patients from the procedure. With the use of erbium lasers alone, there is a decrease in the incidence and severity of these adverse sequelae; however, it is difficult to achieve the same degree of improvement as with the CO2 laser because of the more superficial depth of resurfacing. Thus, new erbium lasers have been developed with longer pulse durations to deliver increased thermal effects to tissue. It is hypothesized that with the use of these lasers, diminished erythema and faster wound healing will be observed as well as enhanced clinical outcomes.

Study Design/Materials and Methods:

Sixteen patients were randomized to receive laser resurfacing on one‐half of the face with the 950 μs pulsed CO2 laser (UPCO2) followed by short pulse erbium:YAG ablation, and to the other half with a variable pulsed erbium laser (VP Er:YAG) followed by traditional short pulse erbium laser. Patients were evaluated clinically before resurfacing and at 1, 2, 4, 8, and 12 weeks post‐operatively. Histologic samples taken at various time periods before and after resurfacing were also evaluated.

Results:

Overall clinical improvement was equal for both UPCO2 and VP Er:YAG treated sides with an average improvement in photoaging scores of 57%. Decreased erythema, less edema, and faster healing were observed on the VP Er:YAG treated side.

Conclusion:

The VP Er:YAG laser can achieve a similar degree of improvement as seen with short pulse CO2 laser resurfacing with decreased thermal tissue effects and decreased risk for adverse sequelae. Lasers Surg. Med. 29:136–141, 2001. © 2001 Wiley‐Liss, Inc.
Vegetarianism: Toward a greater understanding
Authors: Janda Swinder , Trocchia Philip J.
Published: August 2002

Vegetarianism continues to gain prominence in contemporary society. This research uses a two‐phase approach to further the understanding of this phenomenon. In the first phase, a phenomenological perspective is utilized to provide a deeper understanding of the motivations, tensions, and coping mechanisms underlying vegetarianism. The second phase builds upon this understanding and broadens the scope of the research by introducing the concept of vegetarian orientation. Here, survey methodology is employed to investigate the manner in which a person's demographic, attitudinal, and personality characteristics influence his/her vegetarian‐oriented attitudes and behaviors. Findings and their marketing implications are discussed. © 2001 John Wiley & Sons, Inc.
Molecular orbital treatment of gas‐phase ion molecule collision rates: Reactive and nonreactive collisions
Authors: Dougherty Ralph C.
Published: August 2002

I.
Introduction
142

II.
Reaction Efficiency
144

III.
Ion Polar‐Molecule Collisions
145

IV.
Momentum‐Transfer Ion‐Molecule Collisions
146

V.
Summary
151

Acknowledgments
151

References
151

This paper reviews some applications of quantum mechanical models to ion‐molecule collision processes, and presents a new theoretical approach to ion mobilities of isobaric ions. Reactive ion‐molecule collisions have been successfully modeled, using perturbation molecular orbital (PMO) theory, and ab initio quantum mechanical models. In ion polar‐molecule collisions, the Stark effect exerts a controlling influence on the collision rate. The average dipole orientation for an ion polar‐molecule collision is exactly zero. The instantaneous dipole orientation to the ion‐molecule axis in these collisions is not zero. The instantaneous angle between the dipole and the ion‐molecule axis, Θ, increases as the distance between the ion and molecule, r, decreases. The Stark effect couples collisional angular momentum of the ion‐molecule complex and rotational angular momentum of the molecule. Conversion of collisional angular momentum to rotational angular momentum causes the rotation of the molecule to increase as the ion and molecule approach each other. Changes in Θ directly follow the changes in rotational angular momentum for the molecule. In momentum transfer ion‐molecule collisions in gases, the energy difference between the frontier orbitals of the collision pair is such that a first‐order perturbation model is not appropriate. An approximate second‐order PMO equation for the reduced mobility of ions in non‐polar gases, Ko PMO, is presented and used to analyze data from the literature. Ion mobility is linearly related to Ko PMO, a function of the ion‐molecule electronic potential, ΔEIM, and the reduced mass, μIM, for the ion bath‐gas interaction. The electronic states of first‐row transition metal ions separated by ion‐mobility in helium have been assigned on the basis of their reduced mobilities. © 2001 John Wiley & Sons, Inc., Mass Spec Rev 20:142–152, 2001
Expression of prostate‐specific antigen is transcriptionally regulated by genistein in prostate cancer cells
Authors: Davis Joanne N. , Kucuk Omer , Sarkar Fazlul H.
Published: August 2002

Prostate cancer is the second‐leading cause of cancer‐related deaths in men in the United States. Unfortunately, there is no effective therapy when prostate cancer becomes metastatic and refractory to conventional treatments. For this reason, the identification and exploration of new agents that reduce prostate cancer cell growth are of paramount importance. High consumption of plant‐derived phytoestrogens is inversely associated with the incidence and mortality rate of prostate cancer. Previous studies, including our own, have shown that the phytoestrogen genistein inhibits prostate cancer cell growth in vitro and in vivo and decreases secreted and intracellular levels of the androgen‐regulated protein prostate‐specific antigen (PSA), but the role of genistein as an agonist/antagonist for hormone receptors remains unclear. To elucidate the mechanism by which genistein modulates PSA protein expression in prostate cancer cells, we investigated the effects of genistein on androgen‐mediated and estrogen‐mediated transcriptional regulation of PSA, androgen receptor (AR) mRNA and protein expression, and the ability of nuclear proteins to bind to androgen‐response elements (AREs) in LNCaP cells. We showed that genistein decreased the transcriptional activation of PSA by both androgen‐dependent and androgen‐independent methods in LNCaP cells. The reduction of androgen‐mediated transcriptional activation of PSA was correlated with decreased AR protein and mRNA levels and decreased binding to AREs. In contrast, genistein had differential effects on 17β‐estradiol–mediated PSA expressions. Low concentrations of genistein enhanced 17β‐estradiol–mediated PSA expressions, whereas high concentrations of genistein inhibited estrogen‐mediated PSA expression in LNCaP cells. Genistein did not inhibit AR protein expression in the presence of 17β‐estradiol. These results suggest that ligand‐dependent differences in the ability to activate PSA expression may contribute to the agonistic/antagonistic responses observed with genistein in prostate cancer cells. © 2002 Wiley‐Liss, Inc.
A comprehensive analysis of loss of heterozygosity caused by hemizygous deletions in renal cell carcinoma using a subtraction library
Authors: Hatano Naoya , Nishikawa Naoko S. , McElgunn Cathal , Sarkar Shubhashish , Ozawa Kazuo , Shibanaka Yasuhiko , Nakajima Motowo , Gohiji Kazuo , Kiyama Ryoiti
Published: August 2002

Several new loci were identified by a comprehensive analysis of loss of heterozygosity (LOH) using a subtraction library between matched normal and renal cell carcinoma (RCC) tissues. A total of 187 clones from the library, with a complexity of 1×104, were mapped, and 44 clusters of the mapped loci were subjected to LOH analysis using microsatellite markers. A total of 27 loci, which exhibited frequencies of LOH of at least 10% among 44 tumors, mostly clear‐cell RCC, included several loci that were reported previously, such as, the von Hippel‐Lindau gene, adenomatous polyposis coli, and interferon regulatory factor‐1, as well as new loci, at 5q32‐q34, 6q21‐q22, 8p12, and others. These loci exhibited LOH among 11.8–93.8% of tumors, and most, if not all, were derived from the sites of hemizyous deletions. The minimum regions of LOH of chromosomes 5, 6, and 8 were 9.0, 10.3, and 0.775 Mb, respectively. The average distance between the cloned fragments on the chromosomes was 2.2 Mb in 187 clones, indicating that the minimum LOH size expected from this subtraction analysis was roughly 50 kb. Therefore, the strategy described here provides comprehensive analysis of LOH sites, which were mostly caused by hemizygous deletions. © 2001 Wiley‐Liss, Inc.
Secondary nonresponsiveness to botulinum toxin type A in patients with oromandibular dystonia
Authors: Adler Charles H. , Factor Stewart A. , Brin Mitchell , Sethi Kapil D.
Published: August 2002

Intramuscular injection of botulinum toxin type A is the treatment of choice for most cases of oromandibular dystonia. We report on five patients with oromandibular dystonia that developed secondary nonresponsiveness to botulinum toxin type A following multiple injections over a 6‐year period. © 2002 Movement Disorder Society.
Levodopa‐induced ocular dyskinesias in Parkinson's disease
Authors: Linazasoro Gurutz , Van Blercom Nadege , Lasa Asier , Indakoetxea Begoña , Ruiz Javier
Published: August 2002

Levodopa‐induced ocular dyskinesias are very uncommon. Usually they occur simultaneously with limb peak‐dose choreatic dyskinesias. We report on a patient with leftward and upward deviations of gaze during the peak effect of levodopa, and hypothesize that a severe dopaminergic denervation in the caudate nucleus is needed for the appearance of these levodopa‐induce ocular dyskinesias. © 2001 Movement Disorder Society.
Parkinson's disease with late Pick's dementia
Authors: Henderson Jasmine M. , Gai Wei Ping , Hely Mariese A. , Reid Wayne G.J. , Walker Grant L. , Halliday Glenda M.
Published: August 2002

We report a case in which typical clinical features of idiopathic Parkinson's disease existed for seven years prior to the development of significant behavioral and cognitive changes and severe dementia. The patient presented with right‐sided resting tremor, bradykinesia, and rigidity, which were highly responsive to levodopa. Serial neuropsychological evaluation revealed no evidence of dementia until late in the disease. The patient deteriorated rapidly eight years into the disease, requiring full care. She died 16 years after symptom onset and post‐mortem neuropathological analysis revealed Lewy body Parkinson's disease and Pick's disease. To our knowledge, this is the first non‐familial case with this combination of clinical history and pathologically confirmed disease to be reported in the literature. The absence of a family history of any neurological disease sets this case apart from the recently described genetic cases of frontotemporal dementia with Parkinsonism linked to chromosome 17. In addition, the relatively late onset of dementia in frontotemporal dementia is atypical. While there is considerable debate regarding the cause of dementia in idiopathic Parkinson's disease, our case illustrates that Pick's disease is one such cause. © 2001 Movement Disorder Society.
Stiff leg syndrome: Case report
Authors: Gürol Mahmut Edip , Ertas Mustafa , Hanagasi Hasmet Ayhan , Sahin Hüseyin Alparslan , Gürsoy Gençay , Emre Murat
Published: August 2002

We report on a 28‐year‐old woman with insulin‐resistant diabetes mellitus with a 5‐year history of progressive stiffness and painful spasms of the right leg, exaggerated by sudden auditory and tactile stimuli or by emotional stress. There were no signs of truncal rigidity or exaggerated lumbar lordosis. Anti‐glutamic acid decarboxylase antibodies were positive in her serum. She improved substantially with clonazepam 4 mg/day. She presented with electrophysiological findings not previously reported in stiff leg syndrome, which may suggest increased inhibition in the uninvolved upper extremities. © 2001 Movement Disorder Society.
The Stokes equations with Fourier boundary conditions on a wall with asperities
Authors: Amirat Youcef , Climent Blanca , Fernández‐Cara Enrique , Simon Jacques
Published: August 2002

We study the effect of the rugosity of a wall on the solution of the Stokes system complemented with Fourier boundary conditions. We consider the case of small periodic asperities of size ε. We prove that the velocity field, pressure and drag, respectively, converge to the velocity field, pressure and drag of a homogenized Stokes problem, where a different friction coefficient appears. This shows that, contrarily to the case of Dirichlet boundary conditions, rugosity is dominant here. Copyright © 2001 John Wiley & Sons, Ltd.
Radiation efficiency analysis on small antenna by Wheeler cap method
Authors: Chair R. , Luk K. M. , Lee K. F.
Published: August 2002

There have recently been extensive studies of small‐size microstrip antennas. Some of these small antennas maintain gains of 5–6 dBi, whereas others have gains of 0–1.5 dBi. One important antenna parameter is the radiation efficiency. There have been very few studies on this parameter for small microstrip antennas. This letter presents measurements of several of these structures introduced earlier, with the use of the Wheeler cap method. The highest efficiency measured was about 96%. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 112–113, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10247
Analysis of an optical satellite communication system with stabilized microwave reference note transmission
Authors: Tsao Shyh‐Lin , Yu Hao‐Chih , Lin Yi‐Chih
Published: August 2002

A new optical satellite communication system with a local oscillator in the transmitter and one in the receiver station is presented. A new microwave–photonic receiver for picking up the stabilized microwave reference note is proposed. The system, which transmits a 2.5‐Gbps FSK signal, is analyzed. Satellite vibration, beam divergence, atmosphere absorption, and scattering are considered. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 149–151, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10260
Analysis of guided modes in photonic crystal fibers using the finite‐difference time‐domain method
Authors: Qiu Min
Published: August 2002

An efficient finite‐difference time‐domain method is proposed for the full‐wave analysis of guided modes in photonic crystal fibers. The three‐dimensional hybrid guided modes can be calculated by a two‐dimensional mesh, if one assumes that the propagation constant along the z‐direction (propagation direction) is fixed. Furthermore, only real variables are used in the present method. Therefore, the computation time and computer memory are significantly reduced. The results for a honeycomb‐based silica–air photonic crystal fiber are in very good agreement with the results from the plane‐wave expansion method. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 327–330, 2001.
Leukemias related to treatment with DNA topoisomerase II inhibitors*
Authors: Felix Carolyn A.
Published: August 2002

The epipodophyllotoxins etoposide and teniposide and other DNA topoisomerase II inhibitors including anthracyclines and dactinomycin are highly efficacious anticancer drugs. All are associated with a distinct form of leukemia characterized by chromosomal translocations as a treatment complication. Most of the translocations disrupt a breakpoint cluster region (bcr) of the MLL gene at chromosome band 11q23. Other characteristic translocations also may occur. The normal function of the nuclear enzyme DNA topoisomerase II is to catalyze changes in DNA topology between relaxed and supercoiled states by transiently cleaving and re‐ligating both strands of the double helix. Anticancer drugs that are DNA topoisomerase II inhibitors are cytotoxic because they form complexes with DNA and DNA topoisomerase II. The complexes decrease the re‐ligation rate, disrupt the cleavage‐re‐ligation equilibrium, and have a net effect of increasing cleavage. The increased cleavage damages the DNA and leads to chromosomal breakage. Cells with irreparable DNA damage die by apoptosis. The association of DNA topoisomerase II inhibitors with leukemia suggests that the drug‐induced, DNA topoisomerase II‐mediated chromosomal breakage may be relevant to translocations in addition to this anti‐neoplastic, cytotoxic action. Epidemiological studies, genomic translocation breakpoint cloning and in vitro DNA topoisomerase II cleavage assays together lead to a model for treatment‐related leukemia in which DNA topoisomerase II causes chromosomal breakage and translocations form when the breakage is repaired. Med. Pediatr. Oncol. 36:525–535, 2001. © 2001 Wiley‐Liss, Inc.
Genetic predisposition and treatment‐related leukemia*
Authors: Perentesis Jhon Peter
Published: August 2002

Treatment‐related leukemias are one of the most devastating late complications of cancer therapy. Patients with rare cancer predisposition syndromes including neurofibromatosis type 1 and inherited p53 mutations are at an increased risk for this complication. Other patients may have increased susceptibility because they possess common genetic polymorphisms in drug‐metabolizing enzymes that result in impaired detoxification of chemotherapy or inefficient repair of drug‐induced genetic damage. We review studies that have identified a potential role for polymorphisms in the genes encoding the glutathione‐S‐transferases (GSTs), NAD(P) H: quinone oxidoreductase, myeloperoxidase, N‐acetyltransferase (NATs), cytochrome P450 (CYP) 1A1 and 3A4, methylenetetrahydrofolate reductase (MTHFR), cystathionine‐beta‐synthase (CBS), and others in the etiology of primary or secondary acute leukemias, and therapy‐related complications. The identification of high risk polymorphisms and use of pharmacogenetically‐guided therapies holds promise to improve the outcome of cancer therapy and reduce the risk of treatment‐related leukemias. Med. Pediatr. Oncol. 36:541–548, 2001. © 2001 Wiley‐Liss, Inc.
Genetic factors determining cutaneous basal cell carcinoma phenotype*
Authors: Ramachandran Sudarshan , Fryer Anthony A. , Strange Richard C.
Published: August 2002

Background

Basal cell carcinoma (BCC) patients demonstrate considerable phenotypic diversity. The basis of this heterogeneity is poorly understood. We have shown that presentational phenotypes are associated with BCC numbers. Thus, patients with a cluster of new BCC at any presentation comprise a subgroup, termed MPP, that is at increased risk of developing numerous lesions. Patients with more than one cluster (multiple cluster MPP) are at particular risk.

Procedure

We determined in a cohort of BCC cases, whether: (i) tumor accrual was altered after clustering; and (ii) multiple cluster MPP is associated with characteristics linked with sensitivity to UV or, GSTT1, GSTM1, GSTM3, GSTP1, MC1R, CYP2D6, TNF‐α, and VDR genotypes previously associated with BCC presentational phenotypes.

Results

(i) After clustering BCC accrual increased; and (ii) exposure to UV in single and multiple cluster MPP cases were similar. In multiple cluster cases, mean age at first presentation with a single tumor occurred earlier and, the frequencies of CYP2D6 EM (94.4%) and GSTT1 null (41.2%) were significantly greater (P = 0.028 and P = 0.004) than in single cluster cases (67.1 and 14.3%). The odds ratios for these associations with the multiple cluster MPP were large; 15.5 and 7.39, respectively.

Conclusions

The finding of clusters of new, primary BCC is a critical event that is followed by markedly increased accrual of further tumors. Clustering occurs at a relatively late age and may be associated with a failure in immune surveillance. We propose the MPP is not the consequence of excessive UV exposure but reflects the presence of a distinct BCC subgroup defined by a combination of risk genes. Med. Pediatr. Oncol. 36:559–563, 2001. © 2001 Wiley‐Liss, Inc.
Proinflammatory cytokines mediate the systemic inflammatory response associated with high‐dose cytarabine treatment in children
Authors: Ek Torben , Jarfelt Marianne , Mellander Lotta , Abrahamsson Jonas
Published: August 2002

Background

Treatment with high‐dose cytarabine (1‐β‐D‐arabinofuranosylcytosine) is often associated with an acute febrile reaction sometimes including abdominal pain, myalgia, and rash. The similarity of these symptoms to those caused by hypersecretion of cytokines in the systemic inflammatory response syndrome (SIRS) prompted us to investigate the plasma levels of proinflammatory cytokines during treatment of children with high‐dose cytarabine.

Procedure

Sixteen children treated for hematological malignancies and in clinical remission were studied during treatment with six infusions of cytarabine given every 12 hr at a dose of 2 g/m2. Blood samples for analysis of tumor necrosis factor‐α (TNF‐α), interferon‐γ (IFN‐γ), interleukin‐1γ (IL‐1γ), interleukin‐6 (IL‐6), interleukin‐8 (IL‐8), interleukin‐10 (IL‐10) and interleukin‐1 receptor antagonist (IL‐1ra) were obtained prior to treatment and subsequently at 12, 36 and 60 hr. Additional samples were collected as soon as fever occurred.

Results

Thirteen of 16 patients developed fever at a median time of 30 hr following start of treatment. At 12 hr levels of TNF‐α were elevated followed by a rise in IL‐6, IFN‐α, and IL‐1ra, peaking at the onset of fever. Thereafter these levels slowly declined whereas low IL‐10 levels became detectable.

Conclusions

We conclude that high‐dose cytarabine treatment often induces release of TNF‐α followed by the sequential release of other proinflammatory cytokines. Most likely these cytokines mediate the development of symptoms comprising the cytarabine syndrome. Med Pediatr Oncol 2001;37:459–464. © 2001 Wiley‐Liss, Inc.
Sequence‐specific 13C NMR assignments in a neurotoxin (candoxin) from Bungarus candidus
Authors: Rani Parvathy V. , Chary K. V. R. , Manjunatha Kini R. , Govil G.
Published: August 2002

We report 13C NMR assignments of a weak neurotoxin called candoxin, using heteronuclear single quantum correlation (HSQC) experiments with their natural abundance in the protein. Almost complete sequence‐specific 13C NMR assignments were achieved. Chemical shift indices of 13Cα, 13Cβ and 1Hα were used to characterize the secondary structural segments in the protein. A consensus plot of chemical shift indices revealed five β‐strands as the major structural elements in the toxin. Copyright © 2001 John Wiley & Sons, Ltd.
Dynamic NMR: combined use of 1D selective EXSY and complete lineshape analysis of spectra subjected to reference deconvolution and linear prediction or the maximum entropy method
Authors: Vassilev Nikolay G. , Dimitrov Valentin S.
Published: August 2002

In dynamic NMR lineshape analysis and in handling other curve‐fitting problems, the quality of the adjusted parameters improves if the iterative procedure is constrained by introducing additional conditions. It is demonstrated on a simple model of a two‐site exchange system that in the complete lineshape analysis of spectra subjected to reference deconvolution and linear prediction or the maximum entropy method in combination with 1D EXSY experiments, the unknown parameters can be reduced to only one, the rate constant. This approach ensures excellent results for the activation parameters. It is also shown that 1D selective EXSY (1D SEXSY) experiments using E‐BURP pulses could successfully be used as a substitute to the more (experimentally) demanding 2D EXSY measurements. Copyright © 2001 John Wiley & Sons, Ltd.
Quantitative 13C NMR method using the DEPT pulse sequence for the determination of the geographical origin (DOP) of olive oils
Authors: Vlahov G. , Schiavone C. , Simone N.
Published: August 2002

Nuclear magnetic resonance (NMR) spectroscopy is applied to measure the high‐field (500 MHz) 13C spectra at natural abundance in olive oil samples in order to ascertain the suitability of NMR for discriminating oils from different Italian geographical areas of production and, in particular, from areas labelled with the ‘Denomination of Protected Origin’ (DOP). The NMR methodology, which uses the distortionless enhancement by polarization transfer (DEPT) pulse sequence for improving the signal‐to‐noise ratio of 13C spectra, is optimized for the acquisition, processing and integration parameters to validate the quantitative measurements of the intensities of 13C resonances of the whole olive oil spectrum. Principal components analysis, which is applied to the 13C intensity data, correlates the oil samples from the same geographical area provided the composition of the olive oil is monovarietal. The correlation is obtained from properties related to the fatty acid composition of the triglyceride fraction of olive oils. Copyright © 2001 John Wiley & Sons, Ltd.
Variable‐temperature high‐pressure investigation of the cobalt‐59 NMR spectroscopy of aqueous K3[Co(CN)6]
Authors: Gillies D. G. , Sutcliffe L. H. , Williams A. J.
Published: August 2002

Cobalt‐59 NMR measurements were made on an aqueous solution of K3[Co(CN)6] with pressure as the main variable. We determined the effect of temperature and pressure (up to 5 kbar) on (i) the cobalt‐59 chemical shift, (ii) the carbon–cobalt‐59 isotope shift, (iii) the cobalt‐59–carbon‐13 coupling constant and (iv) the cobalt‐59 spin–lattice relaxation time. The marked effects of temperature and pressure on the chemical shift can be attributed to changes in the cobalt–carbon bond distance and are consistent with a radius of 2.5 Å for the [Co(CN)6]3− ion. Analysis of the slightly non‐linear dependence of the chemical shift on pressure has, for the first time, allowed the dependence of (∂δ/∂p)T and (∂δ/∂T)p on temperature and pressure to be evaluated. For a given temperature change, the fractional change in (∂δ/∂p)T is independent of pressure and, for a given pressure change, independent of temperature. The ion is more compressible at high temperatures. The same explanation can be applied to the small effect of temperature on the carbon‐13 induced isotope shift and this has confirmed previous theoretical work. The lack of a pressure dependence for the cobalt‐59 spin–lattice relaxation time is attributed to a dominant quadrupolar mechanism arising from the motion of one or more water molecules in the solvent sheath surrounding the ion. This motion induces an electric field gradient at the cobalt nucleus. This conclusion is supported by nitrogen‐14 and carbon‐13 using {K3[Co(13CN)6]} NMR relaxation studies made at ambient pressure over a range of temperatures and at different radiofrequencies: these showed that, unlike the cobalt‐59 nucleus, these nuclei are relaxed by a molecular re‐orientational process. The nitrogen‐14 and carbon‐13 data independently provide values of 18 ps for τc at 298 K and 16 kJ mol−1 for the associated activation enthalpy for the re‐orientation of the [Co(CN)6]3− ion in water. Copyright © 2001 John Wiley & Sons, Ltd.
Multinuclear magnetic resonance study of some imidovanadium complexes
Authors: Gudat Dietrich , Fischbeck Uwe , Tabellion Frank , Billen Martin , Preuss Fritz
Published: August 2002

14N NMR studies were carried out for a series of mononuclear and dinuclear vanadium complexes with different types of nitrogen ligands (terminal and µ‐imido, amido, nitrido, amine). Some complexes containing ancillary phosphine moieties were also characterized by 31P NMR spectroscopy. The observed shieldings for terminal and bridging imido ligands are intermediate between those of nitrido and amido moieties, and the latter appear less shielded than coordinated tertiary amines. The ranges for individual ligand types are sufficiently resolved to allow the use of nitrogen chemical shifts as a structure assignment tool. The 14N NMR signals of terminal and bridging imido nitrogens displayed marked differences in their lineshapes which could be used as an additional criterion for signal assignment. Examination of substituent influences revealed the absence of a general parallelism between δ14N and δ51V, but gave evidence for parallel relationships between both quantities for complexes with formal 12VE and 16VE electron counts. Determination of 1J(51V,14N) and 1J(51V,31P) coupling constants in mononuclear complexes was feasible from simulation of 14N and 31P lineshapes and suggested that imido ligands exhibit generally greater couplings to vanadium than amido ligands. Analysis of the 31P {1H,14N} NMR spectrum allowed us to determine 2J(51V,31P) for the vanadacycle cyclo(tBuN—PC(tBu)—VCl3—). It was shown that both couplings can be employed for the acquisition of two‐dimensional 31P,51V shift correlations. Copyright © 2001 John Wiley & Sons, Ltd.
Application of NMR spectroscopy to monitoring MELAS treatment: A case report
Authors: Möller Harald E. , Wiedermann Dirk , Kurlemann Gerhard , Hilbich Thorsten , Schuierer Gerhard
Published: August 2002

1H magnetic resonance spectroscopy (MRS) of the brain and 31P MRS and saturation transfer of resting skeletal muscle were used to investigate intracellular metabolites and fluxes through the creatine kinase (CK) reaction in a patient with the syndrome of mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes (MELAS). Acute cortical lesions were characterized by severely elevated lactate levels and reduced concentrations of N‐acetylaspartyl compounds, glutamate, and myo‐inositol. Similar but less extreme alterations were also observed in gray matter regions that appeared normal on magnetic resonance images. Investigation of the gastrocnemius muscle at rest demonstrated a reduced phosphocreatine level, elevated concentrations of inorganic phosphate and free adenosine 5′‐diphosphate, and an abnormally low phosphorylation potential. Besides a moderately increased muscular phosphocreatine concentration, none of the metabolic disturbances detected on MRS improved with oral creatine supplementation. Forward and reverse fluxes through the CK reaction did not significantly change upon creatine treatment. Follow‐up MRS investigations may thus provide objective markers of treatment response in vivo without the hazards or inconvenience of biopsy. © 2002 Wiley Periodicals, Inc. Muscle Nerve 25: 000–000, 2002
Creatine transporter and mitochondrial creatine kinase protein content in myopathies
Authors: Tarnopolsky M.A. , Parshad A. , Walzel B. , Schlattner U. , Wallimann T.
Published: August 2002

Total creatine or phosphocreatine, or both, are reduced in the skeletal muscle of patients with inflammatory myopathy, mitochondrial myopathy, and muscular dystrophy/congenital myopathy. We used Western blotting techniques to measure skeletal muscle creatine transporter protein and sarcomeric mitochondrial creatine kinase (mtCK) protein content in patients with inflammatory myopathy (N = 8), mitochondrial myopathy (N = 5), muscular dystrophy (N = 7), and congenital myopathy (N = 3), as compared to a control group without a neuromuscular diagnosis (N = 8). Creatine transporter protein content was lower for all groups compared to control subjects (P < 0.05; P < 0.01 for congenital myopathy). Mitochondrial CK (mtCK) was lower for inflammatory myopathy (P < 0.05), higher for mitochondrial myopathy (P < 0.05), not different for muscular dystrophy, and markedly lower for the congenital myopathy group (P < 0.01), compared to control subjects. Together, these data suggest that the reduction in total creatine or phosphocreatine in patients with certain myopathies is correlated with creatine transporter and not mtCK protein content. This further supports the belief that creatine monohydrate supplementation may benefit patients with low muscle creatine stores, although the reduction in creatine transporter protein may have implications for dosing. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 682–688, 2001