bluuebunny/crossref_metadata_2025 huggingface dataset:
Even‐hole‐free graphs part II: Recognition algorithm
Authors: Conforti Michele , Cornuéjols Gérard , Kapoor Ajai , Vušković Kristina
Published: August 2002

We present an algorithm that determines in polytime whether a graph contains an even hole. The algorithm is based on a decomposition theorem for even‐hole‐free graphs obtained in Part I of this work. We also give a polytime algorithm to find an even hole in a graph when one exists. © 2002 Wiley Periodicals, Inc. J Graph Theory 40: 238–266, 2002
New heads for Freud's hydra: Psychoanalysis in Los Angeles
Authors: Hale Nathan G.
Published: August 2002

This paper describes the transplantation of psychoanalysis from Europe to Los Angeles and the similarities and differences in followers, cultural attitudes, institutional organization, and patient symptoms. Psychoanalysis in both places attracted psychiatrists, psychologists, social workers, artists, writers, and movie people, all committed to “modernism” and cultural change. But special American conditions created greater institutional rigidity, medicalization, and a more diffuse patient symptomatology centered on the maternal relationship. Such conditions also fostered bitter disputes over modifications of psychoanalytic theory and practice which have only recently become less acute as the status of psychoanalysis has declined in America. © 2001 John Wiley & Sons, Inc.
Development of financial capital markets and the role of children as economic assets
Authors: Rammohan Anu
Published: August 2002

This paper examines the link between development of financial capital markets, old‐security and fertility, when child labour is prevalent. The model demonstrates that when returns from financial capital markets increase, fertility levels and investment in children's schooling are reduced, but child labour levels increase. However, the return to child labour is also an important determinant of fertility decisions. In particular if there is a child labour market, fertility decisions are determined mainly by the child wage rate and child rearing costs. Finally, the model shows that the development of financial capital markets implies a reduction in the borrowing rates and leads to an increase in schooling investments and a reduction in child labour. © 2001 John Wiley & Sons, Ltd.
Insecurity and social protection—has the World Bank got it right?
Authors: Moser Caroline
Published: August 2002

While all three WDR 2000/01 themes — opportunity, empowerment and security — are deemed to be of equal importance, security is probably the most strategic instrument for targeted poverty reduction. This paper critically discusses the two innovative frameworks introduced in the report: the twofold typology of risk and vulnerability, and the risk management framework. In so doing it highlights the lack of new instruments to strengthen informal risk reduction, that require participatory approaches, and locally defined tools, to ensure that ‘the voices of the poor’ move beyond complaints to commitments. Copyright © 2001 John Wiley & Sons, Ltd.
Radiosynthesis of a ligand for studying the glycine transporter: [11C]ALX‐5407
Authors: Ravert Hayden T. , Mathews William B. , Klitenick Mark A. , Wong Dean F. , Dannals Robert F.
Published: August 2002

[11C]ALX‐5407, R‐N[3‐(4′‐fluorophenyl)‐3‐(4′‐phenylphenoxy)propyl] sarcosine, a chiral glycine transporter 1 antagonist, was labeled with [11C]iodomethane by N‐alkylation of methyl ester protected N‐normethyl precursor, ALX‐5536, and subsequent saponification of the methyl ester protecting group. The time for synthesis, purification, and formulation was 33 minutes with an average specific radioactivity of 3909 mCi/µmol (EOS) and average decay corrected radiochemical yield of 8%. Copyright © 2001 John Wiley & Sons, Ltd.
An improved synthesis of radiolabeled 4‐(acetoxymethylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanone
Authors: Peterson Lisa A. , Spratt Thomas E. , Shan Weifeng , Wang Lijuan , Subotkowski Witold , Roth Robert
Published: August 2002

The synthesis of high specific activity tritium‐labeled 4‐(acetoxymethylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanone is reported. This compound was prepared by tritiation of 4‐(acetoxymethylnitrosamino)‐1‐[3‐(5‐bromo)‐pyridyl]‐1‐butanone (5‐BrNNKOAc) in the presence of 10% Pd/C catalyst, yielding a product with a specific activity of 11.9 Ci/mmol. This pathway represents a major improvement over previously published methods. Copyright © 2001 John Wiley & Sons, Ltd.
Labelling of octreotide using 76Br‐prosthetic groups
Authors: Yngve Ulrika , Khan Tanweera S. , Bergström Mats , Långström Bengt
Published: August 2002

A method for labelling the octapeptide octreotide (D–Phe–Cys–Phe–D–Trp–Lys–Thr–Cys–Thr(ol)) with the positron emitting 76Br (T1/2=16 h) is presented. ϵ‐Boc‐protected octreotide was conjugated to N–succinimidyl 4‐[76Br]bromobenzoate 1 and N–succinimidyl 5‐[76Br]bromo‐3‐pyridinecarboxylate 3 using microwave heating. The conjugates 4 and 5 were isolated in 50–55% radiochemical yield after the removal of the protecting Boc‐group. Compound 3 was synthesised from the corresponding trimethylstannyl‐precursor in 25% radiochemical yield. The synthesis of methyl‐4‐[76Br] bromobenzimidate 8 in 40% radiochemical yield from the precursor methyl‐4‐trimethylstannylbenzimidate is also described. Experiments were performed to react 8 with Boc‐octreotide but no product was obtained. The binding‐properties of 76Br‐conjugates 4 and 5 to meningiomas were investigated using frozen section autoradiography. Compound 5 showed better binding properties than 4. Copyright © 2001 John Wiley & Sons, Ltd.
Effective Syntheses of 2‐trimethylsilylmethyl‐3‐trimethylsilyl‐1‐propene and its 1,1‐d2‐ and 1,1,1′,1′,3,3‐ d6‐isotopomers
Authors: Hu Jun , Squires Robert R.
Published: August 2002

New and effective routes to synthesize 2‐trimethylsilylmethyl‐3‐trimethylsilyl‐1‐propene and its 1,1‐d2‐ and 1,1,1′,1′,3,3‐d6‐isotopomers have been developed, using the displacement reaction of lithium trimethylsilylcyanocuprate with allylic halides and tosylates. These compounds are pivotal precursors for the gas‐phase synthesis and characterization of the trimethylenemethane anion, and for negative ion photoelectron spectroscopic investigations of the singlet–triplet splitting in trimethylenemethane. Copyright © 2001 John Wiley & Sons, Ltd.
The preparation of isotopically labelled macrocyclic compounds by organic synthesis
Authors: Filer Crist N.
Published: August 2002

The preparation of isotopically labelled macrocyclic compounds is reviewed with pertinent literature references through the end of 2000. Copyright © 2001 John Wiley & Sons, Ltd.
Radiolabelling of NNC 05‐1869, a compound for treatment of diabetic neuropathy
Authors: Valsborg Jacob S. , Foged Christian
Published: August 2002

Synthesis of 3H‐, 14C‐ and 125I‐labelled NNC 05‐1869 is described. The 3H‐label was obtained by catalytic hydrogenation of a carbon–carbon double bond with tritium gas, which after purification yielded 470 µCi [3H]NNC 05‐1869 with a specific radioactivity of 36 Ci/mmol. 14C‐labelling was accomplished in three steps, including a chiral HPLC separation, starting from ethyl 3‐[carboxyl‐14C]piperidinecarboxylate (1). The overall radiochemical yield was 1.5 mCi of [carboxyl‐14C]NNC 05‐1869 (14%) with a specific radioactivity of 55 mCi/mmol. Electrophilic aromatic iododestannylation of the tin‐precursor NNC 47‐4310 with Na125I resulted in a cis/trans mixture, which was separated on RP‐HPLC to give the two isomers in 20% and 22%, yield, respectively. Copyright © 2002 John Wiley & Sons, Ltd.
Ultrastructural study of the precursor to fungiform papillae prior to the arrival of sensory nerves in the fetal rat
Authors: Iwasaki Shin‐ichi , Asami Tomoichiro , Kageyama Ikuo
Published: August 2002

The structure of precursors to fungiform papillae without taste buds, prior to the arrival of sensory nerve fibers at the papillae, was examined in the fetal rat on embryonic day 13 (E13) and 16 (E16) by light and transmission electron microscopy in an attempt to clarify the mechanism of morphogenesis of these papillae. At E13, a row of rudiments of fungiform papillae was arranged along both sides of the median sulcus of the lingual dorsal surface, and each row consisted of about 10 rudiments. There was no apparent direct contact between papillae rudiments and sensory nerves at this time. Bilaterally towards the lateral side of the tongue, adjacent to these first rudiments of fungiform papillae, a series of cord‐like invaginations of the dorsal epithelium of the tongue into the underlying connective tissue, representing additional papillary primordia parallel to the first row, was observed. The basal end of each invagination was enlarged as a round bulge, indented at its tip by a mound of fibroblasts protruding into the bulge. At E16 there was still no apparent direct contact between rudiments of fungiform papillae and sensory nerves. Each rudiment apically contained a spherical core of aggregating cells, which consisted of a dense assembly of large, oval cells unlike those in other areas of the lingual dorsal epithelium. The differentiation of these aggregated cells was unclear. The basal lamina was clearly recognizable between the epithelium of the rudiment of fungiform papillae and the underlying connective tissue. Spherical structures, which appeared to be sections of the cord‐like invaginations of the lingual epithelium that appeared on E13, were observed within the connective tissue separated from the dorsal lingual epithelium. Transverse sections of such structures revealed four concentric layers of cells: a central core, an inner shell, an outer shell, and a layer of large cells. Bundles of fibers were arranged in the central core, and the diameters of bundles varied somewhat depending on the depth of the primordia within the connective tissue and their distance from the median sulcus. Ultrastructural features of cells in the outer shell differed significantly in rudiments close to the lingual epithelium as compared to those in deeper areas of connective tissue. Around the outer shell there was a large‐cell layer consisting of one to three layers of radially elongated, oval cells that contained many variously sized, electron‐dense, round granules. Large numbers of fibroblasts formed dense aggregates around each spherical rudiment, and were separated by the basal lamina from the large‐cell epithelial layer. Progressing from deep‐lying levels of the rudiments of the papillae to levels close to the lingual surface epithelium, the central core, inner shell, and outer shell gradually disappeared from the invaginated papillary cords. J. Morphol. 250:225–235, 2001. © 2001 Wiley‐Liss, Inc.
Interaction of a designed interleukin‐10 epitope mimic with an antibody studied by isothermal titration microcalorimetry
Authors: Welfle Karin , Misselwitz Rolf , Sabat Robert , Volk Hans‐Dieter , Schneider‐Mergener Jens , Reineke Ulrich , Welfle Heinz
Published: August 2002

The mechanism of recognition of proteins and peptides by antibodies and the factors determining binding affinity and specificity are mediated by essentially the same features. However, additional effects of the usually unfolded and flexible solution structure of peptide ligands have to be considered. In an earlier study we designed and optimized six peptides (pepI to pepVI) mimicking the discontinuous binding site of interleukin‐10 for the anti‐interleukin‐10 monoclonal antibody (mab) CB/RS/1. Three of them were selected for analysis of their solution conformation by circular dichroism measurements. The peptides differ in the content of α‐helices and in the inducibility of helical secondary structures by trifluoroethanol. These properties, however, do not correlate with the binding affinity. PepVI, a 32‐mer cyclic epitope mimic, has the highest affinity to mab CB/RS/1 identified to date. CD difference spectroscopy suggests an increase of the α‐helix content of pepVI with complex formation. Binding of pepVI to mab CB/RS/1 is characterized by a large negative, favorable binding enthalpy and a smaller unfavorable loss of entropy (ΔH ° = −16.4 kcal·mol−1,TΔS ° = −6.9 kcal·mol−1) resulting in ΔG° = −9.5 kcal·mol−1at 25 °C as determined by isothermal titration calorimetry. Binding of pepVI is enthalpically driven over the entire temperature range studied (10–35 °C). Complex formation is not accompanied by proton uptake or release. A negative heat capacity change ΔCpof −0.354 kcal·mol−1·K−1was determined from the temperature dependence of ΔH °. The selection of protein mimics with the observed thermodynamic properties is promoted by the applied identification and iterative optimization procedure. Copyright © 2001 John Wiley & Sons, Ltd.

Abbreviations used:

mab CB/RS/1

monoclonal anti‐human interleukin‐10 antibody

hIL‐10

human interleukin‐10

GdnHCl

guanidine hydrochloride

TFE

trifluoroethanol

MOPS

3‐morpholinopropane sulfonic acid

PIPES

piperazine‐1,4‐bis(2‐ethanesulfonic acid)

CD

circular dichroism

ITC

isothermal titration calorimetry.
MR imaging of diffuse adenomyosis changes after GnRH analog therapy
Authors: Imaoka Izumi , Ascher Susan M. , Sugimura Kazuro , Takahashi Kentaro , Li Hong , Cuomo Felicia , Simon James , Arnold Lori L.
Published: August 2002

Purpose

To evaluate uterine changes on MRI before and after GnRH analog (GnRHa) treatment in diffuse adenomyosis.

Materials and Methods

Thirty‐one patients with MRI features suggestive of diffuse adenomyosis received GnRHa for 6 months. Diffuse adenomyosis was sub‐classified as: symmetric (symmetric/ entire widening of the junctional zone [JZ]) and asymmetric (asymmetric/ partial widening of JZ). Pre‐ and post‐high signal intensity (SI) foci and JZ width, and post‐demarcated change (interface of adenomyosis with the myometrium became more discrete with a concomitant decrease in JZ width) were analyzed.

Results

Before therapy, 15 of 18 asymmetric contained high SI foci compared to none of symmetric. After therapy, JZ width decreased (P < 0.0001). Eight asymmetric and none of symmetric showed demarcated change with resolved high SI foci.

Conclusion

Our results suggest the use of GnRHa is associated with a decrease of JZ width in adenomyosis. Asymmetric adenomyosis with high SI foci appears to be the most sensitive to hormonal therapy. J. Magn. Reson. Imaging 2002;15:285–290. © 2002 Wiley‐Liss, Inc.
Time evolution of cerebral perfusion and apparent diffusion coefficient measured by magnetic resonance imaging in a porcine stroke model
Authors: Røhl Lisbeth , Sakoh Masaharuh , Simonsen Claus Ziegler , Vestergaard‐Poulsen Peter , Sangill Ryan , Sørensen Jens Cristian , Bjarkam Carsten Reidies , Gyldensted Carsten , Østergaard Leif
Published: August 2002

Purpose

To demonstrate the feasibility of sequential diffusion‐weighted (DW) and perfusion‐weighted (PW) magnetic resonance imaging (MRI) of a recently developed porcine stroke model and to evaluate the evolution of cerebral perfusion and the apparent diffusion coefficient (ADC) over time.

Materials and Methods

In five pigs, DW imaging (DWI) and PW imaging (PWI) was carried out for 7 hours after stroke onset, starting 1 hour after middle cerebral artery occlusion (MCAO).

Results

The DWI lesion volume increased significantly with time, and final DWI lesion volume correlated well with lesion area on histological sections (r = 0.910). T2 changes could be recognized 3 hours after stroke onset. At 1 hour the ADC ratio (ischemic lesion/contralateral side) was reduced to 0.81 in the caudate‐putamen and to 0.87 in the cortex, and the cerebral blood flow ratio was reduced to 0.40 in the caudate‐putamen and 0.51 in the cortex.

Conclusion

The level of flow reduction in the caudate‐putamen and the cortex after 1 hour is in good correlation with human thresholds of irreversible and reversible ischemic damage, and accordingly, this model might be a model for mechanisms of infarct evolution and therapeutic intervention. J. Magn. Reson. Imaging 2002;15:123–129. © 2002 Wiley‐Liss, Inc.
Coronary artery imaging using contrast‐enhanced 3D segmented EPI
Authors: Deshpande Vibhas S. , Wielopolski Piotr A. , Shea Steven M. , Carr James , Zheng Jie , Li Debiao
Published: August 2002

The purpose of the work was to evaluate the effectiveness of extracellular contrast media in improving MR coronary angiography using breath‐hold segmented echo‐planar imaging (SEPI). Two protocols were designed to optimize the inversion recovery‐prepared contrast‐enhanced SEPI method. In 15 healthy volunteers, significant improvements in signal‐to‐noise ratio (SNR), contrast‐to‐noise ratio (CNR), vessel sharpness, and length of visualization were observed post‐contrast. The method with two targeted scans to cover the left and right arteries, respectively, following separate 20‐mL contrast injections, was found to yield thinner slices and longer right coronary artery (RCA) visualization than a single scan following a 40‐mL contrast injection without compromising SNR and CNR. In conclusion, extracellular contrast media substantially improves the delineation of coronary arteries with SEPI. J. Magn. Reson. Imaging 2001;13:676–681. © 2001 Wiley‐Liss, Inc.
An efficient chemical shift imaging scheme for magnetic resonance‐guided neurosurgery
Authors: Liu Haiying , Hall Walter A. , Martin Alastair J. , Truwit Charles L.
Published: August 2002

An efficient magnetic resonance spectroscopic imaging (MRSI) or chemical shift imaging (CSI) technique based on multiple spin echoes (MSE) has been implemented, validated, and used in both phantom and in vivo MR‐guided neurosurgical applications. The key concept of the method is to employ MSE to significantly speed up the data collection rate for mapping hydrogen‐containing metabolites. Using an echo train length (ETL) of three per excitation to simultaneously fill three consecutive k‐space areas, the total scan time for a spectroscopic image matrix size of 32 × 32 has been shortened to approximately 11 minutes. An interecho spacing time of 273 msec was used to null the phase anomalies of lactate double peaks due to the J‐coupling. This allowed a sufficient long data sampling time to achieve 4 Hz spectral resolution. Performing CSI intraopertively during an MR‐guided neurosurgical procedure was shown to be feasible at 1.5 T. More importantly, it was shown that more relevant information can be obtained regarding neurochemistry about a targeted lesion, in addition to conventional MR morphological imaging noninvasively. In 25 MR‐guided neurosurgical cases, the alleviated choline signal has been found to be consistent with the existence of rapid tumor cell proliferation in the corresponding area. The actual neurobiopsy guided by the spectroscopic imaging method demonstrated that it could provide valuable information in specifying the optimal site in a biopsy procedure, especially in the case involving a nonenhancing tumor. The multiecho scheme has made the CSI technique efficient enough to be routinely used in MR‐guided surgical procedures at 1.5 T and also allows the possibility of taking full advantage of MRI capability. J. Magn. Reson. Imaging 2001;14:1–7. © 2001 Wiley‐Liss, Inc.
Osteodensitometry of human heel bones by MR spin‐echo imaging: Comparison with MR gradient‐echo imaging and quantitative computed tomography
Authors: Machann Jürgen , Raible Armin , Schnatterbeck Peter , Lutz Otto , Claussen Claus D. , Schick Fritz
Published: August 2002

The aim of the study was to investigate whether quantitative magnetic resonance (MR) fast spin‐echo (FSE) imaging with moderate spatial resolution enables osteodensitometry in peripheral yellow bone marrow. Signal intensities in T1‐weighted FSE images from yellow bone marrow indicate the amount of adipose tissue per volume. The signal intensity in marrow regions with spongy bone was assessed and compared to signal intensity of pure fatty marrow (100%). Heel bones of 30 patients with suspected osteoporosis were analyzed and the FSE images were compared with results from parallel MR gradient‐echo (GE) imaging and quantitative computed tomography (QCT) examinations. High correlation was found between FSE imaging and QCT [r = 0.91 in the dorsal region of interest (ROI); r = 0.86 in ventral ROI]. Linear correlation coefficients between GE imaging and QCT were slightly lower in the dorsal part (r = –0.86) and considerably lower in the ventral part (r = –0.68). Correlation between the two MR techniques amounted to r = –0.72/–0.61 (dorsal/ventral). The high correlation between FSE imaging and bone mineral density (BMD) allows possible clinical applications of FSE imaging for diagnosis of osteoporosis. Further improvements of the accuracy using reference phantoms might be possible. J. Magn. Reson. Imaging 2001;14:147–155. © 2001 Wiley‐Liss, Inc.
Determination of saccharides in fruit juices by capillary electrophoresis and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Žídková Jitka , Chmelík Josef
Published: August 2002

A fast method for the detection of cheap sweeteners is presented. Detecting the adulteration of foods rich in carbohydrates is complicated by the presence of variety of commercial sweeteners that are designed to match exactly the major carbohydrate profiles of these foods. Electrophoretic and mass spectrometric assays for the determination of fruit juice authenticity were developed. Capillary zone electrophoresis with indirect detection was employed to detect adulteration of juices demonstrated by the ratio of the concentrations of major low molecular mass saccharides (glucose, fructose and sucrose). Traces of oligosaccharides, which are not present in the sugar profiles of citrus fruits but are present in inexpensive sweeteners, were evaluated as the other group of target compounds. The fast determination of oligomeric starch hydrolysates in a complex matrix was tested by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) and applied to orange juice. MALDI‐TOFMS was shown to be a suitable method for the identification of adulteration of fruit juices by starch hydrolysates. The effects of the presence of salts and low molecular mass saccharides on the detection of oligosaccharides by MALDI‐TOFMS were studied. Low molecular mass saccharides and organic acids decrease the detectability of oligosaccharides by MALDI‐TOFMS, but the concentration of maltooligosaccharides present in juices sweetened with starch hydrolysates is high enough to be detected with good sensitivity. Copyright © 2001 John Wiley & Sons, Ltd.
Investigation of different combinations of derivatization, separation methods and electrospray ionization mass spectrometry for standard oligosaccharides and glycans from ovalbumin
Authors: Saba Julian A. , Shen Xiaodong , Jamieson James C. , Perreault Hélène
Published: August 2002

Derivatization procedures using 1‐phenyl‐3‐methyl‐5‐pyrazolone (PMP) and 2‐aminonaphthalene trisulfone (ANTS) were selected among a number of well known methods for labelling carbohydrates. PMP derivatives were selected owing to our laboratory's previous high‐performance liquid chromatography/electrospray ionization mass spectrometry (HPLC/ESI‐MS) experience with these, whereas the ANTS‐labelled compounds were prepared for fluorophore‐assisted carbohydrate electrophoresis (FACE) separation. ANTS‐oligosaccharide standards were characterized to study their ionization patterns. Reversed‐phase and normal‐phase HPLC systems were coupled on‐line with ESI‐MS. Each necessitated its own mobile phase system which, in turn, imposed some important changes in the ionization conditions used and/or on the ionization patterns and spectra obtained. Following characterization of the intact glycoprotein ovalbumin with ESI‐MS, its glycans were detached using the enzyme PNGase‐F. The glycans were subjected to PMP and ANTS derivatization. It was very difficult to separate ANTS derivatives by reversed‐phase HPLC owing to lack of retention, and normal‐phase HPLC offered reasonable retention with limited separation. PMP compounds overall yielded better normal‐ and reversed‐phase separations and improved sensitivity over the ANTS‐labelled sugars, for which negative mode ESI had to be used. The combination of ESI of intact ovalbumin and ESI of PMP‐glycans gave rise to the detection of over 20 different glycoforms, excluding the possible presence of structural isomers for each sugar composition detected. Copyright © 2001 John Wiley & Sons, Ltd.
Regiospecific analysis of neutral ether lipids by liquid chromatography/electrospray ionization/single quadrupole mass spectrometry: validation with synthetic compounds
Authors: Hartvigsen Karsten , Ravandi Amir , Bukhave Klaus , Hølmer Gunhild , Kuksis Arnis
Published: August 2002

A reversed‐phase high‐performance liquid chromatography (HPLC) method with on‐line electrospray ionization/collision‐induced dissociation/mass spectrometry (ESI/CID/MS) is presented for the regiospecific analysis of synthetic reference compounds of neutral ether lipids. The reference compounds were characterized by chromatographic retention times, full mass spectra, and fragmentation patterns as an aid to clarify the regiospecificity of ether lipids from natural sources. The results clearly show that single quadrupole mass spectroscopic analysis may elucidate the regiospecific structure of neutral ether lipids. Ether lipid reference compounds were characterized by five to six major ions in the positive ion mode. The 1‐O‐alkyl‐sn‐glycerols were analyzed as the diacetoyl derivative, and showed the [M − acetoyl]+ ion as an important diagnostic ion. The diagnostic ions of directly analyzed 1‐O‐alkyl‐2‐acyl‐sn‐glycerols and 1‐O‐alkyl‐3‐acyl‐sn‐glycerols were the [M − alkyl]+, [M + H − H2O]+ and [M + H]+ ions. Regiospecific characterization of the fatty acid position was evident from the relative ion intensities, as the sn‐2 species had relatively high [M + H]+ ion intensities compared with [M + H − H2O]+, whereas the reverse situation characterized the sn‐3 species. Furthermore, corresponding sn‐2 and sn‐3 species were separated by the chromatographic system. However, loss of water was promoted as fatty acid unsaturation was raised, which may complicate interpretation of the mass spectra. The diagnostic ions of directly analyzed 1‐O‐alkyl‐2,3‐diacyl‐sn‐glycerols were the [M − alkyl]+, [M − sn‐2‐acyl]+ and [M − sn‐3‐acyl]+ ions. Regiospecific characterization of the fatty acid identity and position was evident from the relative ion intensities, as fragmentation of the sn‐2 fatty acids was preferred to the sn‐3 fatty acids; however, loss of fatty acids was also promoted by higher degrees of unsaturation. Therefore, both structural and positional effects of the fatty acids affect the spectra of the neutral ether lipids. Fragmentation patterns and optimal capillary exit voltages are suggested for each neutral ether lipid class. The present study demonstrates that reversed‐phase HPLC and positive ion ESI/CID/MS provide direct and unambiguous information about the configuration and identity of molecular species in neutral 1‐O‐alkyl‐sn‐glycerol classes. Copyright © 2001 John Wiley & Sons, Ltd.
Characterizing closely spaced, complex disulfide bond patterns in peptides and proteins by liquid chromatography/electrospray ionization tandem mass spectrometry
Authors: Yen Ten‐Yang , Yan Hui , Macher Bruce A.
Published: August 2002

Identifying the Cys residues involved in disulfide linkages of peptides and proteins that contain complex disulfide bond patterns is a significant analytical challenge. This is especially true when the Cys residues involved in the disulfide bonds are closely spaced in the primary sequence. Peptides and proteins that contain free Cys residues located near disulfide bonds present the additional problem of disulfide shuffling via the thiol–disulfide exchange reaction. In this paper, we report a convenient method to identify complex disulfide patterns in peptides and proteins using liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI‐MS/MS) in combination with partial reduction by tris(2‐carboxyethyl)phosphine (TCEP). The method was validated using well‐characterized peptides and proteins including endothelin, insulin, α‐conotoxin SI and immunoglobulin G (IgG2a, mouse). Peptide or protein digests were treated with TCEP in the presence of an alkylation reagent, maleimide‐biotin (M‐biotin) orN‐ethylmaleimide (NEM), followed by complete reduction with dithiothreitol and alkylation by iodoacetamide (IAM). Subsequently, peptides that contained alkylated Cys were analyzed by capillary LC/ESI‐MS/MS to determine which Cys residues were modified with M‐biotin/NEM or IAM. The presence of the alkylating reagent (M‐biotin or NEM) during TCEP reduction was found to minimize the occurrence of the thiol–disulfide exchange reaction. A critical feature of the method is the stepwise reduction of the disulfide bonds and the orderly, sequential use of specific alkylating reagents. Copyright © 2001 John Wiley & Sons, Ltd.
Optimization of congener‐specific analysis of 40 polybrominated diphenyl ethers by gas chromatography/mass spectrometry
Authors: Eljarrat E. , Lacorte S. , Barceló D.
Published: August 2002

The analysis by gas chromatography coupled with mass spectrometry (GC/MS) of 40 different congeners of polybrominated diphenyl ethers (PBDEs) containing 1–7 bromine atoms is described. Two different MS approaches were used, negative chemical ionization (NCI‐MS) and electron ionization (EI‐MS). Operating parameters such as electron energy and source temperature were optimized in order to obtain the maximum sensitivity in the EI‐MS study. For NCI‐MS analyses, the effects of the moderating gas (methane or ammonia), source temperature and system pressure were studied. The quality parameters of the two approaches tested were compared. NCI‐MS gave detection limits between 30 fg and 1.72 pg, whereas EI‐MS gave detection limits between 0.53 and 32.09 pg. The main advantage of EI‐MS is that it provides better structural information. Moreover, the use of EI‐MS allowed the use of an isotope dilution method for quantification, making the analysis more reliable at trace levels. Copyright © 2001 John Wiley & Sons, Ltd.
Monitoring the response to antiretroviral therapy in HIV‐1 group O infected patients using two new RT‐PCR assays
Authors: de Mendoza Carmen , Lu Wei , Machuca Ana , Sainz María , Castilla Jesús , Soriano Vincent
Published: August 2002

Failure to recognise infection caused by human immunodeficiency virus type 1 (HIV‐1) group O variants has been described using both serological and genetic procedures. Moreover, monitoring the response to antiretroviral therapy is a difficult task in patients infected with HIV‐1 group O since commercial tests are not available so far for the quantitation of this virus. In this study, the virological response to antiretroviral therapy were assessed in five HIV‐1 group O‐infected patients living in Spain by using two new and different RT‐PCR methods (MUPROVAMA and LCx). Twenty‐four plasma samples belonging to these five patients were selected. As reference, p24 antigenaemia levels and CD4+ cell counts were used. All samples yielded positive viral load values using MUPROVAMA (range: 138 to 595,500 HIV‐RNA copies/ml) and 23 of 24 using LCx (range: < 178 to 98,356 HIV‐RNA copies/ml). Overall, the results obtained using both assays showed a good correlation among themselves, and in respect to p24 antigenaemia and CD4+ cell counts. However, the values provided by LCx were significantly lower (0.33 logs on average) than those provided by MUPROVAMA. In conclusion, both the highly sensitive MUPROVAMA and LCx Quantitative assays might represent an useful tool for guiding the decision on when start treatment and for monitoring the response to antiretroviral therapy in HIV‐1 group O‐infected patients. J. Med. Virol. 64:217–222, 2001. © 2001 Wiley‐Liss, Inc.
Human immunodeficiency virus‐1 specific and natural cellular immunity in HIV seronegative subjects with multiple sexual exposures to virus
Authors: Nicastri Emanuele , Ercoli Lucia , Sarmati Loredana , d'Ettorre Gabriella , Iudicone Paola , Massetti Paola , Vullo Vincenzo , Andreoni Massimo
Published: August 2002

The probability of HIV infection by sexual contact, although it varies greatly, appears to be lower than that of infection by other routes of exposure. The aim of this study was to evaluate immunological determinants involved in protection against HIV infection in subjects with multiple and repeated sexual exposures to the virus. Twenty‐two subjects were studied for CD8+ cell anti‐HIV suppression activity and serum neutralizing activity against the HIV strain of their own partners, β‐chemokine production, and natural killer cell activity. CD8+ cell anti‐HIV activity and neutralizing activity of sera were found in 13 (76%) and 12 (70.5%) out of 17 HIV‐1 negative subjects, respectively. Six individuals had a relevant immune response against HIV: three subjects with a high CD8+ cell antiviral suppression activity and three individuals with sera neutralizing activity titer >1:10. These last three subjects had the highest β‐chemokine levels, a very prolonged period of multiple sexual intercourse (>6 years) and a seropositive partner with a high viral load. A partial reduction of neutralizing activity titer was observed when pre‐incubating the sera with anti‐β‐chemokine neutralizing antibodies. A spontaneous natural killer cell activity was suppressed in the majority of HIV‐1 negative subjects with sexual exposure in comparison with normal individuals. The protection from sexual HIV transmission appears to be the result of a network of different humoral and cellular factors. J. Med. Virol. 64:232–237, 2001. © 2001 Wiley‐Liss, Inc.
Quantitative analysis of specific Th1/Th2 helper cell responses and IgG subtype antibodies in interferon‐α‐treated patients with chronic hepatitis C
Authors: Hempel Gerd , Galle Peter R. , Löhr Hanns F.
Published: August 2002

This study aimed to characterise the immune mechanisms relevant to viral clearance in interferon (IFN)‐α‐treated chronic hepatitis C virus (HCV) infection. Proliferative responses of peripheral blood mononuclear cells from sustained complete IFN‐α therapy responders (n = 8), nonresponders (n = 13), untreated patients (n = 10), and healthy controls (n = 5) were measured retrospectively upon stimulation with recombinant HCV‐antigens (core, helicase, NS3, NS4, and NS5) and the secretion of IFN‐γ and interleukins (IL‐4, IL‐5, IL‐10, and IL‐12) were tested by ELISA. Furthermore, IFN‐γ as well as IL‐10 secreting CD4+ T cells were quantitated by intracellular cytokine staining. Anti‐HCV core and NS3‐specific IgG subclass antibodies were quantitated in the corresponding patient sera. Sustained therapy responders had more frequent and stronger NS3 and helicase‐specific cellular immune responses than nonresponders, untreated HCV patients and healthy controls. Independent from therapy outcome HCV‐stimulated T cells in IFN‐α treated patients secreted preferentially IFN‐γ The Th2 cytokines IL‐4 and IL‐10 were even decreased in nonresponders, while the IL‐12 secretion was not influenced. With respect to the humoral immune response sustained complete responders showed significantly reduced IFN‐γ independent anti‐HCV‐core and ‐NS3 IgG1 antibody synthesis. In conclusion, vigorous NS3‐specific T‐helper cell responses were associated with viral clearance in IFN‐α recipients; however, the cytokine and antibody analysis argues against a Th1/Th2 imbalance as a major factor that influence the therapy outcome. J. Med. Virol. 64:340–349, 2001. © 2001 Wiley‐Liss, Inc.
Analysis of the relationship between immunogenicity and immunity for viral subunit vaccines
Authors: Wilson J.N. , Nokes D.J. , Dimmock N.J.
Published: August 2002

The prevention of viral infection by vaccination relies on stimulating an appropriate immune response in order to reduce the probability with which a virus can establish an infection. Post‐vaccination antibody responses have therefore been associated with reducing the probability with which an individual can be infected (i.e., the vaccine's “impact”). Quantifying this relationship is essential in evaluating new vaccines, especially since comparisons between vaccines, and vaccine licensure, may be dependent on antibody responses alone. In this paper two principal questions are identified which need to be addressed in the evaluation of subunit vaccines: i) how do specific antibody levels relate to complete protection from infection or disease and ii) how do antigenic subunits interact in developing protection when combined together in a single vaccine. The aim is to identify explicitly certain assumptions that are frequently made implicitly in the discussion of vaccine action. First, antibody levels are related to levels of protection through a novel statistical analysis of incidence data from a published hepatitis B vaccine trial. The antibody response observed after influenza A virus infection is discussed in relation to the selection of neutralisation escape variants. Finally, by way of example, a theoretical situation is examined and three simple models of subunit vaccine action are constructed in order to describe how antibody levels may be related to population level phenomena such as the elimination of an infection by mass vaccination. J. Med. Virol. 64:560–568, 2001. © 2001 Wiley‐Liss, Inc.
Low cell dosage of lymphoblastoid human cell lines EBV+ is associated to chronic hepatitis in a minority of inoculated nu/nu mice
Authors: Bertolini Luisa , Iacovacci Silvia , Bosman Cesare , Carloni Guido , Monaco Vincenzo , Bangrazi Caterina , Serafino Annalucia , Gualandi Giampiero , Prantera Giorgio , Fruscalzo Alberto
Published: August 2002

It has been suggested that an atypical course of primary infection by EBV and the reactivation of EBV infection in transplanted patients may induce hepatitis. We explored the possibility to dissect the infectious activity from the ability to promote B lymphocyte proliferation in vivo by injecting in nu/nu mice a low number (2 × 106–0.05 × 106) of cells from CE a normal human bone marrow–derived B cell line. This line carries an endogenous EBV in episomal and linear forms. Twenty nu/nu mice were inoculated subcutaneously with the B cell line CE and a matched group with the cell line RAG obtained by EBV in vitro infection of normal human peripheral blood. The mice injected with the CE line did not develop a lymphoproliferative disease, but 5 of them displayed typical histopathological lesions of chronic hepatitis without involvement of other organs. Similar results were obtained in 2 out of 20 animals in the RAG group. A close association between liver lesions and a previous EBV infection, by putative circulating B lymphoblastoid cells releasing their EBV, was established by PCR and by in situ hybridization with BamHI “W” DNA probe. This latter probe detected the presence of about 15% of positive cells only in affected livers. In addition, the rare detection in some hepatocytes of “A” type Cowdry bodies would suggest the occurrence of continuous EBV replication although at a very low level. These data show that we succeeded in dissecting the infectious from the proliferative activity of the endogenous EBV carrier CE cell line. This provides in addition a promising model for chronic EBV‐associated hepatitis. J. Med. Virol. 66:70–81, 2002. © 2002 Wiley‐Liss, Inc.
Early acquisition of TT virus in infants: Possible minor role of maternal transmission
Authors: Lin Ho‐Hsiung , Kao Jia‐Horng , Lee Ping‐Ing , Chen Ding‐Shinn
Published: August 2002

This study assessed the prevalence of TT virus (TTV) viremia in pregnant women and evaluated the role of maternal transmission in early acquisition of TTV in infants in Taiwan. Two groups of pregnant women were screened for TTV using polymerase chain reaction. The first group included 135 healthy pregnant women attending the obstetrics department for routine prenatal care and the second group from 25 GB virus‐C/hepatitis G virus (GBV‐C/HGV)‐infected mothers. In both groups, when TTV infection was found in mothers, serial serum samples were collected for the infants at regular intervals until 1 year of age and were tested for TTV DNA. The results showed that 40% (54/135) of the women undergoing routine prenatal care and 56% (14/25) of GBV‐C/HGV‐infected pregnant women were positive for TTV DNA (P = 0.137). Of the 54 TTV‐infected mothers in the routine prenatal group, 29 and their 30 infants received regular follow‐up. The positive rate of TTV DNA in infants was 40% (12/30) in the routine prenatal group and 29% (4/14) in the group with GBV‐C/HGV‐infected mothers (P = 0.463). All but 2 of the 16 TTV‐infected infants had normal serum alanine aminotransferase levels during follow‐up. The phylogenetic analysis in 7 mother‐infant pairs showed that the homology was diverse in each pair and a close genetic relatedness was found in 2 mother‐infant pairs. In conclusion, TTV viremia is common in pregnant Taiwanese women and their infants. However, the results suggest that maternal transmission may play only a minor role in early acquisition of TTV in infants. J. Med. Virol. 66:285–290, 2002. © 2002 Wiley‐Liss, Inc.
Factors predictive of response to interferon‐α therapy in hepatitis C virus type 1b infection
Authors: Yeh Byung‐Il , Han Kwang‐Hyub , Lee Hyean‐Woo , Sohn Joon Hyung , Ryu Wang‐Shick , Yoon Do‐Jun , Yoon Joonho , Kim Hyun‐Won , Kong In Deok , Chang Sei Jin , Choi Jong‐Whan
Published: August 2002

Interferon‐α (IFN‐α) has been used to treat hepatitis C Virus (HCV)‐induced infection but has been effective in only about half of all patients. It is suggested that the different responses to IFN‐α treatment in HCV infection may be influenced by HCV genotypes, HCV RNA titer at the beginning of IFN‐α therapy, and the sequences of the interferon sensitivity determining region (ISDR). However, there have also been reports showing that these have no relation to an IFN‐α effect. In a previous study, it was found that the nucleotide sequence variation in the hypervariable region (HVR) 1 of the HCV could predict the effect of IFN‐α. In the present investigation, an attempt was made to determine the predictive factors of IFN‐α therapy. Twenty‐six patients with HCV infection were treated with IFN‐α. Among these, 13 patients recovered after 3 to 6 months of IFN‐α treatment, although the other 13 patients showed no response after 6 months of treatment with IFN‐α. In order to determine the predictive factors of IFN‐α therapy, the ALT levels, HCV genotypes, HCV serum titer, and the quasispecies of HVR 1 were compared between responders and non‐responders. It is suggested that the variation in the HVR 1 and HCV serum titer can be used to predict the effect of IFN‐α. J. Med. Virol. 66:481–187, 2002. © 2002 Wiley‐Liss, Inc.
Comparative analysis of two coxsackievirus B3 strains: Putative influence of virus‐receptor interactions on pathogenesis
Authors: Selinka H.‐C. , Wolde A. , Pasch A. , Klingel K. , Schnorr J.‐J. , Küpper J.‐H. , Lindberg A.M. , Kandolf R.
Published: August 2002

Strain‐specific differences in the interaction of coxsackievirus B3 (CVB3) with the coxsackievirus‐adenovirus receptor (CAR) and the decay‐accelerating factor (DAF) co‐receptor proteins were investigated using a non‐haemagglutinating (CVB3) and a haemagglutinating (CVB3‐HA) strain of CVB3. A panel of receptor‐transfected hamster CHO cells, expressing either CAR (CHOCAR cells), DAF (CHODAF cells), or both receptor proteins (CHODC cells) were used to study the interplay of CAR and DAF receptor molecules with regard to binding and infection with CVB3 and CVB3‐HA. Despite clear differences in their binding phenotypes, both virus strains were found to primarily depend on the CAR receptor protein for initialization of productive infections. Cytopathic effects induced by CVB3‐HA were influenced by co‐expression of DAF receptor proteins. The cardiotropic potential of both virus strains was investigated in A.BY/SnJ mice. Despite comparable virus replication of both CVB3 strains in individual myocytes, the number of infected heart muscle cells was significantly lower in CVB3‐HA infected mice. Infections of pancreata correlated with myocardial infections. Together these data suggest that even small differences in virus‐receptor interactions, influencing virus binding and virus spread, may have an impact on the pathogenesis of CVB‐induced diseases. J. Med. Virol. 67:224–233, 2002. © 2002 Wiley‐Liss, Inc.
New TLM nodes with PML absorbing boundary conditions for the characterization of axially symmetric antennas
Authors: Le Maguer S.
Published: August 2002

An efficient TLM algorithm for investigating body of revolution antennas is presented. This method requires a 2D‐mesh since azimuthal dependence of fields is known and introduced in the TLM scheme. Three major TLM nodes are presented (SCN (14 Voltages), HSCN (11 Voltages) and HHSCN (10 Voltages)) including their respective PML schemes (absorbing boundary conditions). For some cases, this method is found to be more attractive in terms of computer cost than the FDTD equivalent approach (BoR‐FDTD). Finally, the results found via antenna applications show the accuracy of the method. Copyright © 2001 John Wiley & Sons, Ltd.
Fast modelling of deeply and fully etched gratings based on the Bloch–Floquet theorem
Authors: Giorgio Agostino , Gina Perri Anna , Nicola Armenise Mario
Published: August 2002

A model of deeply and fully etched gratings (also identified as one‐dimensional waveguide photonic bandgap structures), based on the Bloch–Floquet theorem, has been developed to perform a complete analysis of the electromagnetic (e.m.) wave propagation in the structure, assumed of finite extension, i.e. to determine mode propagation constants, electromagnetic field harmonics and total field distribution, transmission and reflection coefficients, total forward and backward power flow in the structure, guided power and total losses.

Comparisons with other accurate numerical methods confirm the accuracy of the new one, whose main advantages are the quickness and the possibility to determine a great amount of information and figures of merit in a few seconds (for each operating wavelength). Moreover, the model allows the designer a complete view of the physical and geometrical device features, so it permits to draw design rules for optimization of photonic bandgap (PBG) waveguide device design. Copyright © 2001 John Wiley & Sons, Ltd.
Contact with astroglial membranes induces axonal and dendritic growth of human CNS model neurons and affects the distribution of the growth‐associated proteins MAP1B and GAP43
Authors: Piontek Jörg , Régnier‐Vigouroux Anne , Brandt Roland
Published: August 2002

The development of morphological complexity of CNS neurons is thought to be regulated by extracellular factors and cellular contact. To analyze the role of contact with astroglia in this process and to determine the intraneuronal mechanisms involved, an in vitro system was developed where terminally differentiated and polar human CNS model neurons (NT2‐N neurons) were cultured on a layer of mouse astrocytes or isolated membrane fractions in chemically defined medium. Morphometric analysis revealed that physical contact with living astrocytes increased the lengths of axonal and dendritic processes and lead to an increased number of branch points. Contact with astrocytes also resulted in a redistribution of the growth‐associated proteins MAP1b and GAP‐43 toward the growth cones of NT2‐N neurons. Astrocyte‐contact did not lead to a maturation of the neurons as would be detected by an increased expression of tau isoforms containing the adult‐specific exons 2 and 3. Culture on immobilized membrane fractions prepared from astrocytes also increased the morphological complexity of the neurons in a qualitatively similar manner. The results indicate that physical contact with astrocyte membranes increases the morphological complexity of CNS model neurons through a mechanism that involves a redistribution of growth‐associated proteins to neuronal growth cones. NT2‐N neurons may provide a useful cellular model to analyze cytoskeletal mechanisms during the development of terminally differentiated and polar human neurons. © 2002 Wiley‐Liss, Inc.