bluuebunny/crossref_metadata_2025 huggingface dataset:
Support vector machines for predicting HIV protease cleavage sites in protein
Authors: Cai Yu‐Dong , Liu Xiao‐Jun , Xu Xue‐Biao , Chou Kuo‐Chen
Published: October 2002

Knowledge of the polyprotein cleavage sites by HIV protease will refine our understanding of its specificity, and the information thus acquired is useful for designing specific and efficient HIV protease inhibitors. The pace in searching for the proper inhibitors of HIV protease will be greatly expedited if one can find an accurate, robust, and rapid method for predicting the cleavage sites in proteins by HIV protease. In this article, a Support Vector Machine is applied to predict the cleavability of oligopeptides by proteases with multiple and extended specificity subsites. We selected HIV‐1 protease as the subject of the study. Two hundred ninety‐nine oligopeptides were chosen for the training set, while the other 63 oligopeptides were taken as a test set. Because of its high rate of self‐consistency (299/299=100%), a good result in the jackknife test (286/299=95%) and correct prediction rate (55/63 = 87%), it is expected that the Support Vector Machine method can be referred to as a useful assistant technique for finding effective inhibitors of HIV protease, which is one of the targets in designing potential drugs against AIDS. The principle of the Support Vector Machine method can also be applied to analyzing the specificity of other multisubsite enzymes. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 267–274, 2002
Ab initioand DFT studies on van der Waals trimers: The OCS · (CO2)2complexes
Authors: Valdés H. , Sordo J. A.
Published: October 2002

Ab initiocalculations [MP2, MP4SDTQ, and QCISD(T)] using different basis sets [6‐31G(d,p), cc‐pVXZ (X = D, T, Q), and aug‐cc‐pVDZ] and density functional theory [B3LYP/6‐31G(d,p)] calculations were carried out to study the OCS · (CO2)2van der Waals trimer. The DFT has proved inappropriate to the study of this type of systems where the dispersion forces are expected to play a relevant role. Three minima isomers (two noncyclic and one cyclic) were located and characterized. The most stable isomer exhibits a noncyclic barrel‐like structure whose bond lengths, angles, rotational constants, and dipole moment agree quite well with the corresponding experimental values of the only structure observed in recent microwave spectroscopic studies. The energetic proximity of the three isomers, with stabilization energies of 1442, 1371, and 1307 cm−1, respectively, at the CBS‐MP2/cc‐pVXZ (X = D, T, Q) level, strongly suggests that the two unobserved structures should also be detected as in the case of the (CO2)3trimer where both noncyclic and cyclic isomers have been reported to exist. The many‐body symmetry‐adapted perturbation theory is employed to analyze the nature of the interactions leading to the formation of the different structures. The three‐body contributions are small and stabilizing for the two most stable structures and almost negligible for the cyclic isomer. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 444–455, 2002; DOI 10.1002/jcc.10041
Effective atom volumes for implicit solvent models: comparison between Voronoi volumes and minimum fluctuation volumes
Authors: Schaefer Michael , Bartels Christian , Leclerc Fabrice , Karplus Martin
Published: October 2002

An essential element of implicit solvent models, such as the generalized Born method, is a knowledge of the volume associated with the individual atoms of the solute. Two approaches for determining atomic volumes for the generalized Born model are described; one is based on Voronoi polyhedra and the other, on minimizing the fluctuations in the overall volume of the solute. Volumes to be used with various parameter sets for protein and nucleic acids in the CHARMM force field are determined from a large set of known structures. The volumes resulting from the two different approaches are compared with respect to various parameters, including the size and solvent accessibility of the structures from which they are determined. The question of whether to include hydrogens in the atomic representation of the solute volume is examined. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1857–1879, 2001
Balanced arrays of strength two from block designs
Authors: Sinha Kishore , Dhar Vanshi , Saha G. M. , Kageyama Sanpei
Published: October 2002

Some constructions of balanced arrays of strength two are provided by use of rectangular designs, group divisible designs, and nested balanced incomplete block designs. Some series of such arrays are also presented as well as orthogonal arrays, with illustrations. © 2002 Wiley Periodicals, Inc. J Combin Designs 10: 303–312, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jcd.10016
Comparison of seven‐subtest and Satz‐Mogel short forms of the WAIS‐III
Authors: Kulas Joseph F. , Axelrod Bradley N.
Published: October 2002

Intellectual functioning remains an important domain of functioning to be measured. To reduce the lengthy administration time, numerous short forms of the WAIS‐III have been devised. The present study aimed to compare two methods of applying short forms of the WAIS‐3 within a clinical population. The results revealed that both item‐reduced and selected subtest short forms provide excellent predictions of full administration WAIS‐3 summary and index scores. The Satz‐Mogel short form appeared to provide higher predictive power than the seven‐subtest short forms and accounted for a higher number of cases within 6 points of the obtained scores from the full administration. However, the Satz‐Mogel short form was inferior to the seven‐subtest short forms in terms of the reliability of the index and summary IQ scores. As found in previous research, a trade‐off occurs between the predictive power and the reliability of a short form. © 2002 Wiley Periodicals, Inc. J Clin Psychol 58: 773‐782, 2002.
Prenatal sonographic diagnosis of dilated cavum vergae
Authors: Sahinoglu Zeki , Uludogan Mehmet , Delikara Mehmet N.
Published: October 2002

Several cases of enlarged cavum vergae have been reported, but prenatal diagnosis of this condition is very rare. We report 3 cases of dilated cavum vergae diagnosed prenatally using sonography. In 1 of the 3 fetuses, ventriculomegaly and lumbar meningomyelocele were additional sonographic findings. In 1 of the 3 infants, a stereotactic cyst–peritoneal shunt was placed at 6 months of age to relieve intracranial hypertension due to progressive enlargement of the cavum vergae. The infant who had a meningomyelocele required surgical repair of this defect shortly after birth; in the third infant, the dilated cavum vergae remained asymptomatic, and no surgery was necessary. When interhemispheric cystic lesions are identified prenatally, physicians must distinguish them from pathologic cysts and determine whether associated malformations are present. Sonography is useful for both the differential diagnosis and identification of associated anomalies. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 30:378–383, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/jcu.10083
Phagocytosis of apoptotic cells by liver: A morphological study
Authors: Dini Luciana , Pagliara Patrizia , Carlà Emanuela C.
Published: October 2002

The present review deals with the morphological features of the removal of apoptotic cells by liver. The engulfment of cells undergoing apoptosis can be considered a specialized form of phagocytosis, playing a major role in the general tissue homeostasis in physiological and pathological conditions. In fact, defects of phagocytosis of apoptotic cells might have deleterious consequences for neighboring healthy cells, i.e., pathogenesis of inflammatory disease or dysregulation of the immune system. Phagocytosis of apoptotic cells by liver is a complex phenomenon, involving multiple molecular mechanisms of recognition (i.e., lectin‐like receptors and receptors for externalized phosphatydilserine) of both parenchymal (hepatocytes) and nonparenchymal (Kupffer and endothelial cells) liver cells, often operating in cooperation. The data discussed in the present review are drawn from studies of phagocytosis of apoptotic cells in the liver, carried out with in vivo and in situ adhesion experiments as well as in vitro assays. Our results indicate that the three main liver cell types (hepatocytes, Kupffer, and endothelial cells) are able to recognize and internalize apoptotic cells by means of specific receptors (galactose and mannose‐specific receptor; receptor for phosphatydilserine) and by cytoskeletal reorganization that favors the engulfment of the apoptotic cells. The “flags” for the identification of apoptotic cells by the liver are modifications of the surface of dead cells, i.e., sugar residues and phosphatydilserine exposition. Vitronectin receptor is not involved in such a recognition. The adhesions between modified cell surfaces of apoptotic cells and phagocytes generate cytoplasmatic signaling pathways that drive apoptotic cells to their final fate within the phagocytes (i.e., lysosomal digestion). Microsc. Res. Tech. 57:530–540, 2002. © 2002 Wiley‐Liss, Inc.
Calcitonin gene‐related peptide (CGRP)‐containing nerve fibers in bone tissue and their involvement in bone remodeling
Authors: Irie Kazuharu , Hara‐Irie Fumiko , Ozawa Hidehiro , Yajima Toshihiko
Published: October 2002

Bone remodeling is a process of bone renewal accomplished by osteoclastic bone resorption and osteoblastic bone formation. These two activities are regulated by systemic hormones and by local cytokines and growth factors. Moreover, the nervous system and certain neuropeptides seem to be involved in regulation of bone remodeling. In this paper, we focus on the distribution of CGRP‐containing nerve fibers and their dynamics, and discuss the role of these fibers as a possible mechanism for nervous system involvement in regulation of bone remodeling. CGRP‐immunoreactive nerve fibers are widely distributed in bone tissue, such as periosteum and bone marrow, and show apparent regional distribution with different densities. They are often associated with blood vessels and show a beaded appearance. The wide distribution of CGRP‐immunoreactive nerve fibers in bone tissue and the changes in distribution during bone development and regeneration suggest the involvement of these fibers in bone remodeling. The effect of CGRP on bone remodeling could partly be through its action on blood vessels, thereby regulating local blood flow. Moreover, in vitro biochemical data and the localization of CGRP‐immunoreactive nerve fibers in the vicinity of bone cells suggest that they are directly involved in local regulation of bone remodeling by elevating the concentration of CGRP in the microenvironment around bone cells, especially during bone growth or repair. Microsc. Res. Tech. 58:85–90, 2002. © 2002 Wiley‐Liss, Inc.
Characterization of Hox genes in the Bichir, Polypterus palmas
Authors: Ledje Christina , Kim Chang‐Bae , Ruddle Francis H.
Published: October 2002

It has been suggested that the increase in the number of Hox genes may have been one of the key events in vertebrate evolution. Invertebrates have one Hox cluster, while mammals have four. Interestingly, the number of Hox gene clusters is greater in the teleost fishes, zebrafish and medaka, than in mouse and human. The greater number of Hox clusters in the teleosts suggests that Hox gene duplication events have occurred during the radiation of ray‐finned fishes. The question is when the Hox gene duplication event(s) that lead to seven Hox clusters in the teleosts actually occurred.

We have addressed this question by studying the Hox genes in the bichir, Polypterus palmas. A preliminary PCR‐estimation of the number of Hox genes suggests that Polypterus has five different Hox9 cognate group genes, which may be an indication of more than four Hox clusters in the bichir. J. Exp. Zool. (Mol. Dev. Evol.) 294:107–111, 2002. © 2002 Wiley‐Liss, Inc.
Non‐viral vector‐mediated uptake, distribution, and stability of chimeraplasts in human airway epithelial cells
Authors: de Semir David , Petriz Jordi , Avinyó Anna , Larriba Sara , Nunes Virginia , Casals Teresa , Estivill Xavier , Aran Josep M.
Published: October 2002

Background

Chimeraplasty is a novel methodology that uses chimeric RNA/DNA oligonucleotides (chimeraplasts) to stimulate genomic DNA repair. Efficient uptake and nuclear localization of intact chimeraplasts are key parameters to achieve optimal correction of mutation defects into specific cell types.

Methods

A 5′‐end FITC‐labeled 68‐mer RNA/DNA oligonucleotide was complexed with the polycation polyethylenimine (PEI) and the cationic lipids Cytofectin and GenePorter. Flow cytometry was employed to evaluate chimeraplast uptake under different conditions. Intracellular chimeraplast distribution and co‐localization with endocytosis markers were assessed by confocal microscopy. Relative quantification of chimeraplast metabolism was performed by denaturing PAGE and GeneScan™ analysis.

Results

In airway epithelial cells, optimized chimeraplast uptake reached near 100% efficiency with the carriers tested. However, chimeraplast nuclear localization could only be achieved using PEI or Cytofectin. Chimeraplast/GenePorter lipoplexes were retained in the cytoplasm. PEI polyplexes and Cytofectin lipoplexes displayed different uptake rates and internalization mechanisms. Chimeraplast/PEI polyplexes were internalized at least partially by fluid‐phase endocytosis. In contrast, phagocytosis may have contributed to the internalization process of large‐sized chimeraplast/Cytofectin lipoplexes. Moreover, significant chimeraplast degradation was detected 24 h after transfection with both PEI polyplexes and Cytofectin lipoplexes, although the latter seemed to confer a higher degree of protection against nuclease degradation.

Conclusion

Both Cytofectin and PEI are efficient for chimeraplast nuclear uptake into airway epithelial cells. However, despite the distinct structures and trafficking pathways of the corresponding complexes, none of them could prevent nuclease‐mediated metabolism of the chimeric oligonucleotides. These findings should be taken into account for future investigations of chimeraplast‐mediated gene repair in airway epithelial cells. Copyright © 2002 John Wiley & Sons, Ltd.
High efficiency transfection of porcine vascular cells in vitro with a synthetic vector system
Authors: Parkes Richard , Meng Qing‐Hai , Elena Siapati K. , McEwan Jean R. , Hart Stephen L.
Published: October 2002

Background

Gene therapy strategies for the treatment of vascular disease such as the prevention of post‐angioplasty restenosis require efficient, non‐toxic transfection of vascular cells. In vitro studies in these cells contribute to vector development for in vivo use and for the evaluation of genes with therapeutic potential. The aim of this project was to evaluate a novel synthetic vector consisting of a liposome (L), an integrin targeting peptide (I), and plasmid DNA (D), which combine to form the LID vector complex.

Methods

Cultures of porcine smooth muscle cells and endothelial cells were established and then transfected with the LID vector, using the reporter genes luciferase and green fluorescent protein and the metalloprotease inhibitor TIMP‐1.

Results

The LID vector system transfected primary porcine vascular smooth muscle cells and porcine aortic endothelial cells with efficiency levels of 40% and 35%, respectively. By increasing the relative DNA concentration four‐fold, incubation periods as short as 30 min achieved the same levels of luciferase transgene expression as 4 h incubations at lower DNA concentrations. The transfection did not affect cell viability as measured by their proliferative potential. Serum levels of up to 20% in the transfection medium had no adverse affect on the efficiency of transfer and gene expression in either cell type. Transfections with the cDNA for TIMP‐1 produced protein levels that peaked at 130 ng/ml per 24 h and persisted for 14 days at 10 ng/ml per 24 h.

Conclusion

This novel vector system has potential for studies involving gene transfer to cardiovascular cells in vitro and in vivo. Copyright © 2002 John Wiley & Sons, Ltd.
A short synthesis of [14C]‐labelled levamisole and its major metabolite
Authors: Janssen Cor G.M. , Thijssen Jos B.A. , Verluyten Willy L.M.
Published: October 2002

Levamisole (I) is the levo isomer of tetramisole. It is a broad spectrum anthelmintic which is used extensively as a veterinary drug for food producing animals. Metabolism and environmental studies necessitated the synthesis of 14C‐labelled levamisole (6) and of its major metabolite (12).

14C‐Tetramisole was obtained in two steps from 14C‐thiourea. Resolution via salt formation and crystallization afforded 14C‐levamisole and 14C‐dexamisole. Racemisation followed again by resolution made it possible to improve the over‐all radiochemical yield of 14C‐levamisole to 51.0%. The compound had a specific activity of 73.6 MBq/mmol, a HPLC purity of 99.8% and an enantiomeric excess of 99.4%.

The 14C‐labelled metabolite of levamisole (II) was obtained from 14C‐potassium cyanate in 4 consecutive steps. Resolution via chiral HPLC afforded the desired compound in a 16.2% overall radiochemical yield. It had a specific activity of 895 MBq/mmol, a HPLC purity of 98.7% and an enantiomeric excess of 100%. Copyright © 2002 John Wiley & Sons, Ltd.
Synthesis of PNU‐159548 labelled with 14C and 2H
Authors: Felicini C. , Fontana E.
Published: October 2002

The cytotoxic antitumor compound PNU‐159548 (1) has been labelled with 14C and 2H. A three‐step sequence starting from [14‐14C]idarubicin (2a) led to radiochemically pure (>98%) [14‐14C]PNU‐159548 with a specific activity of 1.13 GBq/mmol. The synthesis of [2H4]PNU‐159548 was carried out in a similar manner starting from [1,1,2,2‐2H4]2‐bromoethanol (3b). Copyright © 2002 John Wiley & Sons, Ltd.
Synthesis of [14C]‐ and [35S]‐labelled PI‐88 for pharmacokinetic and tissue distribution studies
Authors: Ferro Vito , Li Caiping , Wang Bin , Fewings Kym , King Andrew R. , Hammond Edward , Creese Brian R.
Published: October 2002

PI‐88, uniformly labelled with [14C] was prepared by incorporating D‐[14C]glucose into the fermentation of Pichia (Hansenula) holstii NRRL Y‐2448 under controlled conditions to produce [14C]‐labelled extracellular phosphomannan. Subsequent acid catalyzed hydrolysis gave the [14C]‐labelled oligosaccharide phosphate fraction which was sulfonated with excess sulfur trioxide pyridine complex to give [14C]PI‐88. [35S]‐labelled PI‐88 was similarly prepared by the sulfonation of unlabelled oligosaccharide phosphate fraction with [35S] sulfur trioxide pyridine complex. Copyright © 2002 John Wiley & Sons, Ltd.
Vaginal dysplastic lesions in women with hysterectomy and receiving radiotherapy are linked to high‐risk human papillomavirus
Authors: Barzon Luisa , Pizzighella Sergio , Corti Luigi , Mengoli Carlo , Palù Giorgio
Published: October 2002

Patients undergoing radiotherapy for advanced cervical and endometrial cancer bear a considerable risk of developing vaginal preneoplastic lesions. Radiotherapy itself has been considered to have a role in the pathogenesis of vaginal dysplasia, although human papillomavirus (HPV) involvement has also been suggested. A series of 88 patients who underwent hysterectomy and were irradiated for gynecological cancer, including 43 with postradiation vaginal dysplasia at colposcopy and 45 without vaginal lesions, were included in this study. Detection and genotyping of HPV DNA in vaginal scraping were carried out by a PCR‐based method and compared with colposcopic and cytological findings and with other clinical and laboratory data. Forty‐two (97.7%) colposcopy‐positive subjects and 6 (13.3%) colposcopically‐negative patients were PCR‐positive for high‐risk HPV DNA (P < 0.000001). Twenty‐two out of the 43 patients with colposcopic lesions showed an abnormal Papanicolau (PAP) test. Cytologic examination was negative in all colposcopically negative women. Type 16 HPV DNA was more frequent in patients with high‐grade squamous intraepithelial lesions and in patients treated with external radiotherapy, whereas other types of high‐risk HPV were more common in patients with low‐grade lesions and in those treated with brachytherapy. When considering colposcopy as the standard for diagnosing vaginal dysplasia, HPV DNA testing was more sensitive than the PAP test. However, the specificity of the PAP test was higher with no false‐positive case. In conclusion, vaginal preneoplastic changes in women post‐hysterectomy and receiving radiotherapy for cervical, endometrial, and vaginal cancer represent an HPV‐related nosologic entity. Whereas colposcopic examination can detect these preneoplastic lesions, HPV genotyping is a sensitive, inexpensive, and noninvasive method that may complement colposcopy and the PAP test. J. Med. Virol. 67:401–405, 2002. © 2002 Wiley‐Liss, Inc.
Combined detection and genotyping of Chikungunya virus by a specific reverse transcription‐polymerase chain reaction
Authors: Hasebe F. , Parquet M.C. , Pandey B.D. , Mathenge E.G.M. , Morita K. , Balasubramaniam V. , Saat Z. , Yusop A. , Sinniah M. , Natkunam S. , Igarashi A.
Published: October 2002

A reverse transcription‐polymerase chain reaction (RT‐PCR) was developed for the detection of Chikungunya virus infection. Based on the nonstructural protein 1 (nsP1) and glycoprotein E1 (E1) genes of Chikungunya, two primer sets were designed. Total RNA were extracted from the cell culture fluid of Aedes albopictus C6/36 cells inoculated with the S27 prototype virus, isolated in Tanzania in 1953, and the Malaysian strains (MALh0198, MALh0298, and MALh0398), isolated in Malaysia in 1998. For both sets of RNA samples, the expected 354‐ and 294‐base pair (bp) cDNA fragments were amplified effectively from the nsP1 and E1 genes, respectively. Phylogenetic analysis was conducted for the Malaysian strain and other virus strains isolated from different regions in the world endemic for Chikungunya, using partial E1 gene sequence data. The Malaysian strains isolated during the epidemics of 1998 fell into a cluster with other members of the Asian genotype. J. Med Virol. 67:370–374, 2002. © 2002 Wiley‐Liss, Inc.
Norwalk‐like virus 95/96‐US strain is a major cause of gastroenteritis outbreaks in Australia
Authors: White Peter A. , Hansman Grant S. , Li Angelina , Dable Joanne , Isaacs Monica , Ferson Mark , McIver Christopher J. , Rawlinson William D.
Published: October 2002

Norwalk‐like viruses (NLVs) were detected using a nested reverse transcriptase‐polymerase chain reaction (RT‐PCR) with primers directed to the RNA polymerase region. Samples were examined from 11 separate outbreaks of gastroenteritis and five sporadic cases of childhood gastroenteritis between 1997 and 2000. Phylogenetic analysis of the 298 bp sequences showed that all strains belong to NLV genogroup II and the majority of the sequenced isolates (30/36) were members of the 95/96‐US subset of strains associated with outbreaks recorded worldwide between 1995 and 1996. This was confirmed by analysis of the full length capsid region of a representative Australian isolate. This study demonstrates the usefulness of targeting primers for NLVs to the predominant circulating genotype(s) and confirms the spread of this subtype globally, including the Southern Hemisphere. J. Med. Virol. 68:113–118, 2002. © 2002 Wiley‐Liss, Inc.
Electromagnetic field representations and computations in complex structures II: alternative Green's functions
Authors: Felsen Leopold B. , Mongiardo Mauro , Russer Peter
Published: October 2002

In this second paper of the three‐part sequence, we deal with alternative Green's function (GF) representations for the subdomain (SD) problem in the complexity architecture of Part I [1]. The relevant GFs for systematic analytic modelling are those associated with at least partially vector and co‐ordinate separable boundary conditions. Such ‘canonical’ GFs, when ‘matched’ to a real problem, can form background kernels which simplify the numerical complexity of real‐problem exact integral equations. The analytic machinery involves Sturm–Liouville (SL) theory for the reduced one‐dimensional (1D) spectral GF problems resulting from separation of variables in various co‐ordinates, set in its most general form in the complex spectral wavenumber domain. Spectral synthesis in the complex spectral wavenumber planes for 2D and 3D co‐ordinate‐separable full GFs lays the foundation for direct construction (via contour deformations, branch point, and pole residue evaluations) of alternative field representations, and their correspondingly different wave‐physical phenomenologies. Illustrative examples show the connection between the canonical GFs and their network representations. Copyright © 2002 John Wiley & Sons, Ltd.
TLM representation of the hyperbolic heat conduction equation
Authors: Pulko S. H. , Wilkinson A. J. , Saidane A.
Published: October 2002

Many heat transfer situations are adequately described by the parabolic thermal diffusion equation. However, in situations in which very rapid heating occurs or in slower heating regimes for particular materials, the hyperbolic heat conduction equation is a better representation. Here, a parameterized nodal structure for transmission line modelling (TLM) representation of hyperbolic heat conduction processes is devised. A TLM model based on the nodal structure is implemented and temperature field predicted by the model are compared with analytical results for the same physical situation. Copyright © 2002 John Wiley & Sons, Ltd.
Specific up‐regulation of GADD153/CHOP in 1‐methyl‐4‐phenyl‐pyridinium‐treated SH‐SY5Y cells
Authors: Conn Kelly J. , Gao Wen‐Wu , Ullman M. David , McKeon‐O'Malley Catherine , Eisenhauer Patricia B. , Fine Richard E. , Wells John M.
Published: October 2002

Growth arrest DNA damage‐inducible 153 (GADD153) expression was increased in 1‐methyl‐4‐phenyl‐pyridinium (MPP+)‐treated human SH‐SY5Y neuroblastoma cells as determined by gene microarray analysis. GADD153 expression increased after 24 hr of MPP+ (1 mM) exposure and preceded activation of caspase 3. Comparison of GADD153 expression among cultures treated with other toxins whose primary mode of action is either via mitochondrial impairment (rotenone) or via oxidative stress (6‐hydroxydopamine or hydrogen peroxide) showed that GADD153 was uniquely up‐regulated by MPP+. Together these data suggest that a cellular mechanism distinct from mitochondrial impairment or oxidative stress contributes significantly to the up‐regulation of GADD153 by MPP+ and that GADD153 may function as an inducer of apoptosis following MPP+ exposure. Published 2002 Wiley‐Liss, Inc.
Elevation of brain glutathione by γ‐glutamylcysteine ethyl ester protects against peroxynitrite‐induced oxidative stress
Authors: Drake Jennifer , Kanski Jaroslaw , Varadarajan Sridhar , Tsoras Maria , Butterfield D. Allan
Published: October 2002

Elevation of glutathione (GSH) has been recognized as an important method for modulating levels of reactive oxygen species (ROS) in the brain. We investigated the antioxidant properties of γ‐glu‐cys‐ethyl ester (GCEE) in vitro and its ability to increase GSH levels upon in vivo i.p. injection. GCEE displays antioxidant activity similar to GSH as assessed by various in vitro indices such as hydroxyl radical scavenging, dichlorofluorescein fluorescence (DCF), protein specific spin labeling, glutamine synthetase (GS) activity, and protein carbonyls. Intraperitoneal injection of GCEE to gerbils resulted in a 41% increase in brain total GSH levels in vivo as determined by the DTNB‐GSH reductase recycling method. Gerbils injected with buthionine sulfoximine (BSO), an inhibitor of γ‐glutamylcysteine synthetase, had 40% less total brain glutathione. Gerbils injected with BSO followed by a GCEE injection had GSH levels similar to vehicle‐injected controls, suggesting that GCEE upregulates GSH biosynthesis by providing γ‐glutamylcysteine and not cysteine. Cortical synaptosomes from GCEE‐injected animals were less susceptible to peroxynitrite‐induced oxidative damage as assessed by DCF fluorescence, protein‐specific spin labeling, and GS activity. These experiments suggest that GCEE is effective in increasing brain GSH levels and may potentially play an important therapeutic role in attenuating oxidative stress in neurodegenerative diseases associated with oxidative stress such as Alzheimer disease. © 2002 Wiley‐Liss, Inc.
Regulation of the ferritin H subunit by vitamin B12 (cobalamin) in rat spinal cord
Authors: Cairo Gaetano , Ronchi Raffaella , Buccellato Francesca R. , Veber Daniela , Santambrogio Paolo , Scalabrino Giuseppe
Published: October 2002

Cobalamin‐deficient (Cbl‐D) central neuropathy is a pure myelinolytic disease, in which gliosis is also observed. Iron is abundant in the mammalian central nervous system, where it is required for various essential functions including myelinogenesis. It is predominantly located in the white matter and oligodendrocytes, which also actively synthesize the major iron proteins (e.g., ferritin, transferrin). We investigated the expression of the main proteins of iron metabolism in the spinal cord (SC) of totally gastrectomized Cbl‐D rats 2 months after surgery (i.e., when the Cbl‐D status has become severe). There were no significant changes in iron content, the activity of iron regulatory proteins, or the expression of transferrin or its receptor in the SC. We observed a significant decrease in the levels of both H and L ferritin subunits, with a more marked reduction in the latter. Post‐operative cobalamin replacement therapy normalized only the H‐ferritin subunits, and only in the SC. Our results therefore suggest that permanent cobalamin deficiency affects iron metabolism in the rat SC preferentially from a functional point of view, because H‐ferritin is known to be involved in the uptake and release of iron. © 2002 Wiley‐Liss, Inc.
p35/Cdk5 pathway mediates soluble amyloid‐β peptide‐induced tau phosphorylation in vitro
Authors: Town Terrence , Zolton Joseph , Shaffner Reed , Schnell Billy , Crescentini Robert , Wu Yajuan , Zeng Jin , DelleDonne Anthony , Obregon Demian , Tan Jun , Mullan Mike
Published: October 2002

Alzheimer's disease (AD) is pathologically characterized by deposition of amyloid‐β peptides (Aβ) as senile plaques and by the occurrence of neurofibrillary tangles (NFTs) composed primarily of hyperphosphorylated tau protein. Activation of cyclin‐dependent kinase 5 (Cdk5) via its potent activator p25 has recently been shown to promote phosphorylation of tau at AD‐specific phosphoepitopes, and increased cleavage of p35 to p25 has been demonstrated in AD patients, suggesting that Cdk5 may represent a pathogenic tau protein kinase. We were interested in the potential effect of soluble forms of Aβ on Cdk5‐mediated AD‐like tau phosphorylation, insofar as previous studies of human biopsies and aged canine and primate brains have shown that dystrophic neurites appear before the formation of neuritic plaques. We transfected N2a cells with a p35 vector (N2a/p35 cells) and, after differentiation, challenged these cells with Aβ1–42 peptide in soluble form (sAβ1–42). Results show that sAβ1–42 at relatively low levels (1–5 μM) dose‐dependently increases tau phosphorylation at AD‐specific phosphoepitopes in differentiated N2a/p35 cells compared with controls, an effect that is blocked by antisense oligonucleotides against p35. sAβ1–42‐induced tau phosphorylation is concomitant with an increase in both p25 to p35 ratio and Cdk5 activity (but not protein levels). Additionally, blockade of L‐type calcium channels or inhibition of calpain completely abolishes this effect. Taken together, these data indicate that sAβ is a potent activator of the p25/Cdk5 pathway, resulting in promotion of AD‐like tau phosphorylation in vitro. © 2002 Wiley‐Liss, Inc.
Adenoviral expression of protein‐L‐isoaspartyl methyltransferase (PIMT) partially attenuates the biochemical changes in PIMT‐deficient mice
Authors: Ogawara Midori , Takahashi Mayumi , Shimizu Takahiko , Nakajima Mitsunari , Setoguchi Yasuhiro , Shirasawa Takuji
Published: October 2002

Protein‐L‐isoaspartyl methyltransferase (PIMT) is a putative protein repair enzyme, which methylates the α‐carboxyl group of atypical L‐isoaspartyl residues in aged proteins and converts them to normal L‐aspartyl residues. Two splicing variants, PIMT‐I and PIMT‐II, have been reported, although their biological functions and specific subcellular substrates are still to be defined. We and another group have previously showed that PIMT‐deficient mice succumbed to fatal epileptic seizures associated with an abnormal accumulation of isoaspartate (IsoAsp) in the brain. In the present study, we prepared two recombinant adenovirus vectors that contained PIMT‐I or PIMT‐II, respectively, in order to investigate the differential biological roles of PIMT‐I and PIMT‐II. These recombinant viruses differentially conferred PIMT‐I or PIMT‐II expressions in cultured neurons. Biochemical analyses showed that either of PIMT‐I or PIMT‐II effectively repaired the damaged proteins in PIMT‐deficient neurons, but the concomitant expression failed to show an additive effect in the repair of IsoAsp. These results suggested that PIMT‐I and PIMT‐II might share a common biological function and/or subcellular substrates. In addition, we administered an adeno‐PIMT‐I vector into the brain of PIMT‐deficient mice at embryonic day 14.5 by an exo‐utero method to assess the biological effects in vivo. The result showed that recombinant adeno‐PIMT improved the symptoms of PIMT‐deficient mice in vivo, but only partially repaired IsoAsp in damaged proteins. The gene therapy presented in this report provided a better prognosis for the survival of PIMT‐deficient mice than the previously reported anti‐epileptic drug therapy. The results suggested a new reagent for gene therapy applicable to ageing‐associated neurodegenerative disorders. © 2002 Wiley‐Liss, Inc.
Software, shareware and freeware: multiplex commitment to an electronic social exchange system
Authors: Liao‐Troth Matthew A. , Griffith Terri L.
Published: October 2002

We observe the behavior of 37 authors of shared (i.e., non‐commercial) software for the Apple Newton in terms of multiplex commitment (committed to multiple related targets) and the helping behaviors directed at these multiple related targets. The behavior of these shared software authors show a pattern of commitment to related targets consistent with our expectations of multiplex commitment and relationships to two helping behaviors (the number of shared software programs produced, and the degree of sacrifice expected with that shared software). The related targets of commitment were the users of the software, other shared software authors, and the newsgroup that served as the electronic social exchange system, but not the FTP site that enabled the exchange or the Listserv that served as an additional electronic social exchange system. Copyright © 2002 John Wiley & Sons, Ltd.
Getting ready for the digital economy: Net Readiness in New Zealand industries
Authors: Clark Delwyn N.
Published: October 2002

This paper focuses on measures of readiness for success in the digital economy.

Scorecards for measuring preparedness for the Internet‐based economy are discussed.

The New Zealand context and environment for E‐Commerce is introduced.

Key results from a novel study of Net Readiness in eight New Zealand industries are presented.

Further Net Readiness research is proposed to provide international comparisons and explore industry‐specific factors, size and links to corporate performance.

Copyright © 2002 John Wiley & Sons, Ltd.
Application of high‐pressure treatment in the mashing of white malt in the elaboration process of beer
Authors: Pérez‐Lamela C , Ledward D A , Reed R J R , Simal‐Gándara J
Published: October 2002

In this study, high‐pressure treatment (HPT) was applied to the mashing stage of beer production, which involves drying and milling of white malt and subsequent mixing with water. The following parameters were evaluated after pressurisation: β‐glucanase activity, starch gelatinisation and sugar extraction. Evaluation of starch hydrolysis from the malted barley endosperm after HPT was performed by measuring β‐glucanase activity after pressurisation; this enzyme breaks down gums and β‐glucans in wort and is desirable to obtain a good‐quality beer. Soaked malt samples pressurised at 200–600 MPa showed no increase in this activity compared with controls. Conversion of milled malt was evaluated indirectly by measuring the gelatinisation of starch, which began at 400 MPa. Soluble sugars were also measured in pressurised samples from the mashed liquid to investigate saccharification during the mashing stage. After 400 or 600 MPa treatment for 20 min, both the sucrose (g per 100 ml) and extract (l ° kg−1) values were the same as those found in mashed samples following the standard procedure used in the brewing industry (65 °C,90 min). Starch gelatinisation was analysed at different high pressures (200–600 MPa) and it was shown that gelatinisation began at 400 MPa. The HPT time would have to be shorter to make the process commercially attractive.

© 2002 Society of Chemical Industry
Detection of orange juice adulteration by tangelo juice using multivariate analysis of polymethoxylated flavones and carotenoids
Authors: Pan Geoffrey G , Kilmartin Paul A , Smith Bronwen G , Melton Laurence D
Published: October 2002

Reverse phase HPLC has been applied to quantify levels of polymethoxylated flavones and carotenoids in orange and tangelo juices. Lower levels of sinensetin and tetramethyl‐o‐scutellarein and higher levels of heptamethoxyflavone and tangeretin relative to nobiletin indicated the addition of tangelo to orange juice. β‐Cryptoxanthin and its esters, identified by positive ion electrospray mass spectrometry, were present in larger amounts relative to β‐carotene in tangelo than in orange juice. Using canonical discriminant analysis, the addition of 100 g kg−1 tangelo to orange juice can be detected.

© 2002 Society of Chemical Industry
Monoacylglycerols derived from butter oil by Penicillium roquefortii in suspension cultures
Authors: Liu Qin‐Tao , Clench Malcolm R , Kinderlerer Judith L
Published: October 2002

Structural isomers of monoacylglycerols (monoglycerides, MAGs) were identified and compared after degradation of butter oil by two strains of Penicillium roquefortii and a commercial lipase from P roquefortii (EC 3.1.1.3) at pH 7.0 and 10 °C. The conditions were selected as they were comparable with those used in the manufacture of blue mould‐ripened cheese. The commercial lipase was selected to compare with the fungal strains in terms of acyl migration. Results showed that the main isomers formed by lipolysis with the commercial lipase were sn‐2 MAGs (64  mol%), whilst spores and emerging mycelia of P roquefortii produced mainly sn‐1(3) MAGs (83–90 mol%). The work reported here may lead to further assessment of different MAG structural isomers as natural preservatives in foods and dairy products.

© 2002 Society of Chemical Industry
Enhancement of the flavour development of dry fermented sausages by using a protease (Pronase E) and a cell‐free extract of Penicillium camemberti
Authors: Bruna José M , Fernández Manuela , Ordóñez Juan A , de la Hoz Lorenzo
Published: October 2002

The present work was an attempt to improve the organoleptic properties of dry fermented sausages by enhancing the release of amino acids and their further transformation into ammonia, ketoacids and some volatile compounds responsible for the ripened flavour. For this purpose a protease (Pronase E from Streptomyces griseus) and a cell‐free extract (CFE) of a Penicillium camemberti strain selected for its L‐amino‐oxidase activity were used. The addition of Pronase E alone led to a large increase in the content of free amino acids. The CFE showed deaminative activity, which gave rise to the accumulation of some important volatile compounds such as 2‐methylpropanal and 2‐ and 3‐methylbutanal. Organoleptic analysis reflected an improvement in the quality of the sausages, especially when the two treatments were combined.

© 2002 Society of Chemical Industry
Accounting for co‐extractable compounds (blank correction) in spectrophotometric measurement of extractable and total‐bound proanthocyanidin in Leucaena spp
Authors: Dalzell Scott A , Kerven Graham L
Published: October 2002

Methods to account for the spectral interference of co‐extractable compounds (blank correction) in the spectrophotometric analysis of both extractable and bound proanthocyanidin (PA) using the proanthocyanidin (butanol/HCl) assay were evaluated. Crude extractable and bound PA sample matrices of PA‐free Leucaena magnifica were used. Extractable PA blanks generated in heated 95% butanol/5% H2O reagent underestimated the optical density (absorbance) of co‐extractable compounds by 24% (P < 0.01), whereas unheated 95% butanol/5% HCl blanks, incubated at room temperature, accurately measured the absorbance of the background matrix (P < 0.01). Current procedures that estimate bound PA concentrations using the proanthocyanidin assay produce intensely coloured background matrices. Recovery measurements from total‐bound PA extracts spiked with 1071 and 2142 µg anthocyanidin per tube indicated that existing analytical procedures that do not account for the spectral interference of co‐extractable compounds overestimated (P < 0.01) bound PA concentrations by 69 and 38% respectively. An innovative technique that generated an internal correction factor for each sample, using wavelength‐scanning spectrophotometry and non‐linear curve‐fitting computer software, was developed. This procedure recovered 100% of added anthocyanidins from bound PA matrices.

© 2002 Society of Chemical Industry
Dynamic rheology of wheat flour dough. II. Assessment of dough strength and bread‐making quality
Authors: Khatkar Bhupendar S , Schofield J David
Published: October 2002

Controlled stress rheometry revealed that differences in wheat flour dough strengths could be observed by means of dynamic rheological measurements in the region of higher stress amplitude (ie >100 Pa). At lower stress amplitude (τo) the values of elastic modulus G′ for weak doughs were higher than those for strong doughs, but they decreased substantially beyond 100 Pa stress amplitude (τo), such that the G′ values for strong doughs crossed over the G′ values for weak doughs. Beyond a critical value of stress amplitude (ie 100 Pa), true differences in dough strengths could be seen on the basis of their elastic characteristics, because at large deformations protein–protein interactions played a more dominant role in the rheological behaviour of flour doughs. Dynamic rheological analysis demonstrated a very weak inverse relationship (R2 = 0.16) between the G′ values of flour doughs and loaf volume data for 12 wheat cultivars of diverse bread‐making performance. However, the G′ values of glutens showed significant positive relationships with bread‐making performance, explaining 73% of the variation in loaf volume.

© 2002 Society of Chemical Industry
Effects of malting on β‐glucanase and phytase activity in barley grain
Authors: Rimsten Lena , Haraldsson Ann‐Katrin , Andersson Roger , Alminger Marie , Sandberg Ann‐Sofie , Åman Per
Published: October 2002

The effects of malting on β‐glucan and phytate were investigated in one naked and one covered barley by a full factorial experiment with three factors (steeping temperature, moisture content and germination temperature) each with two levels. Analysis of total content of β‐glucan in the malted samples showed small changes after steeping at the high temperature (48 °C), while steeping at the lower temperature (15 °C) gave a significantly lower content. This trend was even stronger for β‐glucan unextractable at 38 °C. Analysis of the activity of β‐glucanase for the samples steeped at 15 °C showed a strong increase over the time of germination, while those steeped at 48 °C had a much slower development. The other two factors influenced the outcome to a small extent, mainly because the steeping temperature was the most important factor overall where any changes in β‐glucan and β‐glucanase were observed. When β‐glucan was extracted at 100 °C, a larger yield was obtained, and this was influenced by the steeping temperature in a much stronger way than for β‐glucan extracted at 38 °C. Determination of average molecular weight for β‐glucan extracted at 100 °C gave a lower value for samples steeped at 15 than at 48 °C. The design did not have any large effects on phytate degradation and phytase activity. However, it indicated that selective control of the enzymes might be possible, since phytase activity was barely affected by the parameters studied, while β‐glucanase was heavily affected.

© 2002 Society of Chemical Industry
Effect of adding natural antioxidants on colour stability of paprika
Authors: Ladrón de Guevara R G , González M , García‐Meseguer M J , Nieto J M , Amo M , Varón R
Published: October 2002

We analysed the effect of adding rosemary and tocopherol extracts, two natural antioxidants, on the colour stability of paprika stored at different temperatures and degrees of relative humidity. Any possible synergistic effect of their joint use was also investigated. The experimental data concerning colour loss, as determined by the ASTA 20.1 method, fitted first‐ and second‐order kinetics, which provided the rate constants of colour loss and half‐lives of the samples. The first finding concerned the antagonistic effect between storage temperature and humidity. The antioxidants had a clear protective effect on colour stability in all the conditions assayed, the superior effect of one or the other depending on the storage temperature. A synergistic effect of both antioxidants at temperatures between 25 and 40 °C was evident. The experimental data referring to colour loss for most of the storage conditions assayed fitted second‐order kinetics best.

© 2002 Society of Chemical Industry