bluuebunny/crossref_metadata_2025 huggingface dataset:
SERS studies of the adsorption of 1‐phenyl‐5‐mercaptotetrazole on silver sols
Authors: Pergolese Barbara , Bigotto Adriano
Published: October 2002

Surface‐enhanced Raman scattering spectra of 1‐phenyl‐5‐mercaptotetrazole (PMT) and of the corresponding sodium salt adsorbed on silver sols were recorded in the 3700–2800 and 1800–150 cm−1 regions. The SERS spectra obtained in both cases are the same, therefore it can be deduced that PMT adsorbs on silver sol in the ionized thiol form (PMTA). Moreover, the similarity between SERS and normal Raman spectra of the corresponding silver complex (AgPMTA) is diagnostic of chemisorption of the substance on the silver surface. SERS data were interpreted with the help of the results of DFT calculations on PMTA and AgPMTA. On the basis of the description provided by the potential energy distribution of the vibrational normal modes related to the most enhanced bands in the SERS spectra, it can be deduced that PMTA interacts with the silver sol via the lone pairs of the sulphur and of one of the nitrogen atoms. The orientation of the tetrazole ring is nearly edge‐on with respect to the metal surface, whereas the molecular plane of benzene ring is inclined to it. Copyright © 2002 John Wiley & Sons, Ltd.
Raman scattering from the peroxide ion in Cs2O2
Authors: Livneh Tsachi , Band Alisa , Tenne Reshef
Published: October 2002

The Raman spectrum of Cs2O2 excited at 632.8 nm shows a single O2−2 fundamental band at wavenumber of 742.5 cm−1 and second and third overtones at 1468.5 and 2176.8 cm−1, respectively. The harmonic wavenumber ωe = 759.5 ± 0.7 cm−1 and anharmonicity constant ωexe = 8.4 ± 0.3 cm−1 were calculated directly from the measurements. These results are compared with ωe = 1151.0 ± 1.5 cm−1 and ωexe = 9.6 ± 0.5 cm−1 recently found for O2− ion in CsO2 by others. The lower ωexe of O2−2 relative to that of O2− indicates a broader (smaller curvature) anharmonic oscillator potential well. Copyright © 2002 John Wiley & Sons, Ltd.
Effects of manufacturing process variables on the physicochemical and sensory characteristics of Galician chorizo sausage
Authors: Fernández‐Fernández E , Vázquez‐Odériz M L , Romero‐Redríguez M A
Published: October 2002

Physicochemical and sensory changes were evaluated during the curing of Galician chorizo, comparing samples from three different manufacturers (each of whom uses different procedures for smoking and curing). The observed variations were in all cases largely explained by pairwise differences between one of the manufacturers (manufacturer C) and the other two and are probably attributable to the more traditional and less strictly controlled process conditions used by manufacturer C.

© 2002 Society of Chemical Industry
Influence of storage temperature and ascorbic acid addition on pomegranate juice
Authors: Martí Nuria , Pérez‐Vicente Antonio , García‐Viguera Cristina
Published: October 2002

Our recent work shows that in pomegranate juice the destructive effect of ascorbic acid on anthocyanins is not well correlated with changes in the observed colour. However, the addition of vitamin C to this juice has no additional benefit, since ascorbic acid degradation is very rapid and a slightly orange hue results, after a period of storage, in those juices to which ascorbic acid was added. Data are also included on the influence of storage temperature on juice colour stability, indicating that this parameter is more specific for colour alteration and anthocyanin degradation.

© 2001 Society of Chemical Industry
Mathematical modelling of the heat inactivation of trypsin inhibitors in soymilk at 121–154 °C
Authors: Kwok Kin‐Chor , Liang Han‐Hua , Niranjan Keshavan
Published: October 2002

Response surface methodology (RSM) was used to investigate the effects of processing temperature and time on the inactivation of trypsin inhibitors (TI) in soymilk. The factorial experimental design consisted of four levels of temperature and six levels of time in a temperature range of 121–154 °C and a time interval of 10–90 s. A quadratic polynomial equation, relating log(% TI retained) as a function of heating time and temperature, was satisfactorily fitted to the experimental data by least squares regression with r2 (correlationcoefficient) = 0.959. Within the range of heating times investigated, TI in soymilk was satisfactorily destroyed to 10% retained at 143 and 154 °C with 62 and 29 s heating time respectively.

© 2002 Society of Chemical Industry
Residual effect of CO2 on hake (Merluccius merluccius L) as a function of the period of time in controlled atmosphere storage
Authors: Ruiz‐Capillas Claudia , Moral Antonio
Published: October 2002

Whole gutted hake kept in a controlled atmosphere (60% CO2/15% O2/25% N2) for 7 and 12 days in containers in the hold of the fishing vessel and then stored conventionally in ice was compared with hake stored in ice and treated in the traditional way. The residual effect of the atmosphere containing CO2 prolonged the shelf‐life of chilled hake by 2–5 days compared with that of hake stored in ice. This residual effect of CO2 was dependent on the period of time in the controlled atmosphere; 12 days in this atmosphere was the optimum to obtain the maximum residual effect of CO2. On day 25 the legal limit of total volatile basic nitrogen (TVBN) was reached in hake previously kept under the controlled atmosphere for 12 days (CA12), and the hake was also rejected in the inspection and pH analyses. However, this lot did not reach the legal limit of trimethylamine nitrogen (TMA‐N) during the 25 days of storage. Similar results were found by a sensory panel, who rated the hake kept in controlled atmosphere storage (CA12) well.

Copyright © 2002 Society of Chemical Industry
Inhibition of amylases present in ruminal particle‐associated micro‐organisms
Authors: Martínez T F , Díaz M , Moyano F J
Published: October 2002

The effect of different substances potentially inhibitory of ruminal amylase activity in sheep was assessed using biochemical and electrophoretic assays. Most amylase activity was detected in the particle‐associated fraction (70%) of the ruminal contents (which was selected for the assays) in comparison with the bacterial (21%) and extracellular (9%) fractions. Salts of divalent ions such as Sn2+, Hg2+, Cu2+ and Zn2+ produced 90, 82, 65 and 44% inhibition of amylase activity respectively when assayed at a relative concentration of 5 × 10−3 mol l−1. Organic acids such as tannic, formic, ascorbic and benzoic acid produced 79, 48, 43 and 37% inhibition respectively, whereas chelators such as EDTA, EGTA and 1,10‐phenanthroline produced an inhibition ranging from 32 to 37%. Substrate SDS‐PAGE zymograms allowed the identification of different amylase‐active bands in ruminal extracts, showing a wide range of relative molecular masses (from 36 to more than 100 kDa). Such zymograms also confirmed the effect of some inhibitors. The reversibility of the inhibitory effect of some of the assayed substances was assessed. ZnSO4 was the most persistent inhibitory substance even at low concentrations and, owing to its low toxicity, appears to be an adequate substance to reduce the high in vitro ruminal degradation of starch. Implications for the process of enzymatic digestion of starch are discussed.

© 2002 Society of Chemical Industry
Effects of cassava processing methods on antinutritional components and health status of children
Authors: Ojo Omorogieva , Deane Rashid
Published: October 2002

This study was conducted to evaluate cassava processing methods in Nigeria, its antinutritional components and the possible impact on the health status of children. The traditional method of cassava processing involved peeling of cassava tubers with a knife, manual grating, dewatering with logs of wood and/or stones, sieving with a cane‐woven sieve and frying in a local metal fryer on a wood fire. In contrast, the modern method involved the use of knives for peeling, a mechanical grater, a hydraulic press for dewatering, iron sieves for sieving and an improved metal fryer for frying on a coal fire. The products of both methods included gari (accounting for 70% of Nigeria's total cassava consumption) and lafun. The intake of gari and other foods in 129 3–5‐year‐old children in Benin City, Nigeria was also assessed based on a food frequency questionnaire. The children were classified into normal and protein‐deficient groups using lower/middle/upper‐arm circumference and clinical features of malnutrition. Based on the number of households in villages around Benin City who were involved in cassava processing, 90% used the traditional processing method compared with 10% using the modern method, although the latter controlled the commercial production and sale of gari. There were significantly (P < 0.05) higher intakes of protein and energy in normal compared with protein‐deficient children, but the latter group obtained higher percentages of protein and energy from gari. In addition, the correlation between the amount of gari consumed and clinical scores of malnutrition was low (R2 < 0.2). This may be due to the children consuming gari from both methods and also from different sources. The average gari intake for these children was 320 g day−1 and HCN levels may be as high as 10.24 mg day−1. Some children who are exposed to these levels with poor nutritional status and lack of access to food varieties may develop sublethal effects in the short term. The higher protein intake by the normal children may also reduce the toxicity of HCN. We conclude that methods of processing cassava have profound effects on HCN retention and chemical composition of cassava products. In addition, the modern processing method is more efficient than the traditional method, with significantly reduced processing losses, labour input and levels of HCN. The HCN content in combination with the quantity and quality of protein in the diet has significant impact on the health status of children. Therefore, in susceptible children with poor nutritional status who consume inadequately processed cassava products with limited food choice, these may predispose them to the effects of HCN and thiocyanate.

© 2002 Society of Chemical Industry
The use of FT‐IR microspectroscopic mapping to study the effects of enzymatic retting of flax (Linum usitatissimum L) stems
Authors: Himmelsbach David S , Khalili Sadia , Akin Danny E
Published: October 2002

Fourier transform infrared (FT‐IR) microspectroscopic mapping was investigated as a tool to study the effects of enzymatic retting of flax stems. The FT‐IR technique permitted the elucidation of the relative loss or changes in the distribution of key chemical components after treatment with enzymes or enzyme/chelator mixtures in association with visible changes in structure. Cross‐sections of Ariane flax stems were treated with SP 249 (a pectinase‐rich enzyme mixture from Novo Nordisk) at 0.5, 0.7 or 1.0 ml l−1 concentration in pH 5 acetate buffer for 6 h at 40 °C. Flax stems treated with 0.5 or 0.7 ml l−1 SP 249 and 50 mM oxalic acid as a chelator were also investigated by the technique. The results indicated that treatment with 0.5 ml l−1 SP 249 alone was ineffective in releasing the fibre bundles from the surrounding tissue, but the release was increased by the addition of 50 mM oxalic acid as a likely chelator for the cations of pectate salts. However, the IR spectra of the bundles indicated that an insoluble oxalate salt remained on the tissue after this treatment. Increasing the concentration of SP 249 to 0.7 ml l−1 plus 50 mM oxalic acid was effective in releasing the fibre bundles and generating some ultimate fibres with no detectable oxalate expectate salt residues. Increasing the SP 249 concentration to 1.0 ml l−1 without using oxalic acid was effective in separating the fibre bundles into ultimate (individual) fibres, leaving no pectate salt residue and only a trace of pectic esters and/or acids. The use of infrared mapping, or so‐called chemical imaging, is shown to have advantages over visible imaging alone in that it can detect and locate the chemical species present after each treatment in relation to the anatomical features of the flax stem. This analytical tool shows promise as a technique by which to study the effects of enzymatic treatment of natural fibre materials.

Published in 2002 for SCI by John Wiley & Sons, Ltd
Rheological characteristics of suwari and kamaboko gels made of surimi from Indian major carps
Authors: Sankar Thazhakot V , Ramachandran Alappat
Published: October 2002

The gel strength, compressibility and folding characteristic of suwari (set) and kamaboko (set and cooked) gels prepared from rohu (Labeo rohita), catla (Catla catla) and mrigal (Cirrhinus mrigala) surimi were examined to understand the occurrence of suwari and modori phenomena in surimi from major freshwater carps. Suwari setting of gels did not take place at lower temperatures. Suwari gels showed good gel strength at 50 °C for rohu and at 60 °C for catla and mrigal after 30 min setting time. Incubation for 60 min decreased the gel strength at 60 °C for rohu and catla. Setting at 25 °C followed by cooking at 90 °C increased the gel strength. Increased setting temperature, however, decreased the gel strength of cooked gels. Gel strength and compressibility data were supported by folding characteristics.

© 2002 Society of Chemical Industry
LC–MS analysis of anthocyanins from purple corn cob
Authors: de Pascual‐Teresa Sonia , Santos‐Buelga Celestino , Rivas‐Gonzalo Julián C
Published: October 2002

Liquid chromatography coupled with diode array spectrophotometry and mass spectrometry detection (LC–DAS–MS) has been applied to the study of the anthocyanin composition of a commercial extract from purple corn cob used as a colourant additive in the food industry. Nine different anthocyanins were isolated using semipreparative HPLC and identified by LC–MS and hydrolytic techniques. Useful information for the identification of compounds was also obtained from their fragmentation patterns (MS–MS spectra). Six of these anthocyanins seem to be present in the original cob, namely cyanidin‐3‐glucoside, pelargonidin‐3‐glucoside, peonidin‐3‐glucoside and their respective malonyl derivatives. The other three are produced during the industrial extraction process and have been identified as the corresponding ethylmalonyl derivatives.

© 2002 Society of Chemical Industry
Formation of selected biogenic amines in carp meat
Authors: Křížek Martin , Pavlíček Tomáš , Vácha František
Published: October 2002

Changes in biogenic amine content in carp (Cyprinus carpio) muscle were studied. Fish halves and minced fish meat were stored at 3 and 15 °C. Both the temperature of storage and the type of meat processing had statistically important effects on the amine content. In another set of experiments, temperature and the preservative effects of Purac at various concentrations were tested. Purac can extend the shelf‐life of fish halves stored at 3 °C by about 5 days. Putrescine concentration is proposed as a chemical indicator of carp meat quality. Decomposition is apparent when the putrescine content in the meat exceeds 20 mg kg−1.

© 2002 Society of Chemical Industry
Evidence of low selenium concentrations in UK bread‐making wheat grain
Authors: Adams Martin L , Lombi Enzo , Zhao Fang‐Jie , McGrath Steve P
Published: October 2002

The selenium concentration of representative bread‐making wheat (Triticum aestivum L) samples was measured in national grain surveys collected in 1982 (n (number of samples) = 180), 1992 (n = 187) and 1998 (n = 85) from major wheat‐growing regions around the UK. The means and distributions of selenium concentrations over the three years were similar, with mean grain concentrations of 0.025, 0.033 and 0.025 mg kg−1 dry weight respectively and inter‐quartile ranges varying from 0.015 mg kg−1 in 1982 to 0.019 mg kg−1 in 1992 samples. No long‐term changes in the distribution of wheat selenium concentrations were found over the 17 year period. Geographical mapping of the concentrations identified an area of eastern England as having high grain concentrations compared with other UK regions. There were no significant correlations between grain selenium and grain sulphur concentrations for the national survey samples. However, at an individual field experimental site, increasing the rate of sulphur addition was found to decrease grain selenium concentration significantly. The daily UK dietary contribution of selenium from wheat‐based products was estimated and the daily intake was calculated to be 6.4 µg selenium, around one‐tenth of the UK recommended intake values for men and women.

© 2002 Society of Chemical Industry
Seasonal effects on storage proteins and gluten strength in four Swedish wheat cultivars
Authors: Johansson Eva , Nilsson Helle , Mazhar Hifza , Skerritt John , MacRitchie Finlay , Svensson Gunnar
Published: October 2002

Weather variations in Sweden result in differences in the bread‐making quality of wheat. This study investigated whether the variation in bread‐making quality caused by yearly weather fluctuations could be explained by variation in protein composition, amount of storage proteins, protein subunits and protein groups, and relative amount and size distribution of polymeric proteins. Four spring wheat (Triticum aestivum L) cultivars grown in Sweden during three different years were investigated. Bread‐making quality and gluten strength were measured using baking and glutograph tests. SDS‐PAGE, SE‐HPLC, RP‐HPLC and ELISA were applied for investigation of protein composition, amount of storage proteins, protein subunits and protein groups, and relative amount and size distribution of polymeric proteins. The bread volume within cultivars varied depending on the cultivation year. The highest gluten strength was found in 1994 and the weakest in 1991. Variation in composition or relative amount of specific storage proteins, protein subunits or protein groups could not explain the variation in gluten strength between years. Instead, a significant relationship was found between the cultivation year and the percentage of unextractable polymeric protein in the total polymeric protein. The percentage of unextractable polymeric protein in the total polymeric protein was found to be highest during years when gluten strength was also high.

© 2002 Society of Chemical Industry
Use of 1‐methylcyclopropene to extend the postharvest life of lettuce
Authors: Wills Ron B H , Ku Vivian V V , Warton Michelle A
Published: October 2002

This study examined the effect of fumigation of iceberg lettuce with 1‐methylcyclopropene (1‐MCP) at 0.1–1 µl l−1 for 1–5 h on the storage life at 5 °C in air containing 0.1 µl l−1 ethylene. 1‐MCP extended the storage life of shredded lettuce at all concentrations, with the optimal treatment being fumigation with 0.1 µl l−1 1‐MCP for 1 h at 5 °C, which resulted in an extension in storage life of about 50% over untreated lettuce. Application of this treatment to whole lettuce heads resulted in a 100% increase in storage life. 1‐MCP thus appears to be of considerable commercial potential for the lettuce industry.

© 2002 Society of Chemical Industry
Comparative evaluation of the efficacy of cereal and microbial phytases in growing pigs fed diets with marginal phosphorus supply
Authors: Zimmermann Birgit , Lantzsch Hans‐Joachim , Mosenthin Rainer , Schöner Franz‐Josef , Biesalski Hans Konrad , Drochner Winfried
Published: October 2002

Two experiments with a total of 76 growing pigs (average initial body weight 16.6 kg) were conducted to compare the efficacy of cereal phytases (wheat and rye) and supplemented microbial phytase (Natuphos®). Using the slope ratio technique, the dose–response relationship between five levels of phytase (0, 50, 100, 150 and 200 U kg−1) and the apparent absorption of phosphorus (P) within each source of phytase was calculated. Graded phytase levels in the diets were obtained by adding increasing amounts of microbial phytase or phytase‐containing wheat (Exp 1) or rye (Exp 2) to phytase‐inactivated basal diets at the expense of phytase‐inactivated wheat (Exp 1) or rye (Exp 2). Except for wheat phytase, addition of phytase to the basal diets increased (P < 0.05) apparent P absorption, with microbial phytase being more efficient (P < 0.05) than cereal phytase. There were no significant differences in apparent P absorption between the wheat‐ or rye‐based diets when either microbial or cereal phytases were supplemented from 0 to 200 U kg−1. It could be derived from the results of this study, by means of regression analysis, that the efficacy of cereal phytases was 40% compared to microbial phytase.

© 2002 Society of Chemical Industry
A response surface methodology approach to optimise pretreatments to prevent enzymatic browning in potato (Solanum tuberosum L) cubes
Authors: Reyes‐Moreno C , Parra‐Inzunza M A , Milán‐Carrillo J , Zazueta‐Niebla J A
Published: October 2002

The objective of this work was to find the best combinations of ascorbic acid concentration/soaking time (Pretreatment 1), 4‐hexylresorcinol concentration/soaking time (Pretreatment 2) and ascorbic acid concentration–4‐hexylresorcinol concentration/soaking time (Pretreatment 3) to prevent the development of enzymatic browning in raw potato cubes (10 mm × 10 mm × 10 mm). Potato variety Alpha was used as study model because of its low susceptibility to enzymatic browning. Response surface methodology was applied in all pretreatments on two response variables (Hunter L value and total colour difference) to find the best conditions for carrying out the pretreatments. The various pretreatments had variation levels for ascorbic acid (AA) concentration (1 and 3) and 4‐hexylresorcinol (4HR) concentration (2 and 3) of 1–4 and 0.04–0.20 g l−1 respectively; in all pretreatments the variation level for soaking time was 3–6 h. A central composite experimental design with two factors at five levels was used. Predictive models for Hunter L value and total colour difference were developed as a function of process or independent variables. The optimisation technique was applied to obtain maximum Hunter L values and minimum values of total colour difference. Surface superposition of these variables allowed identification of the best combinations of process variables for each pretreatment as (1) 2.9 g l−1 AA/4.8 h, (2) 0.04 g l−1 4HR/2.6 h and (3) 2.42 g l−1 AA–0.15 g l−1 4HR/5.41 h.

© 2001 Society of Chemical Industry
Kinetic study of the ruthenium(VI)‐catalyzed oxidation of benzyl alcohol by alkaline hexacyanoferrate(III)
Authors: Mucientes A. E. , Santiago F. , Almena M. C. , Poblete F. J. , Rodriguez‐Cervantes A. M.
Published: October 2002

The kinetics of the Ru(VI)‐catalyzed oxidation of benzyl alcohol by hexacyanoferrate(III), in an alkaline medium, has been studied using a spectrophotometric technique. The initial rates method was used for the kinetic analysis. The reaction is first order in [Ru(VI)], while the order changes from one to zero for both hexacyanoferrate(III) and benzyl alcohol upon increasing their concentrations. The rate data suggest a reaction mechanism based on a catalytic cycle in which ruthenate oxidizes the substrate through formation of an intermediate complex. This complex decomposes in a reversible step to produce ruthenium(IV), which is reoxidized by hexacyanoferrate(III) in a slow step. The theoretical rate law obtained is in complete agreement with all the experimental observations. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 421–429, 2002
Acute electrophysiologic effect of pulsed gallium–arsenide low energy laser irradiation on configuration of compound nerve action potential and nerve excitability
Authors: Bagis Selda , Comelekoglu Ulku , Sahin Gunsah , Buyukakilli Belgin , Erdogan Canan , Kanik Arzu
Published: October 2002

Background and Objectives

We evaluated the acute electrophysiologic effects of low‐energy pulsed laser irradiation, measured by extracellular recording technique on compound action potential configuration and nerve excitability in the isolated frog sciatic nerve

Study Design/Materials and Methods

A pulsed gallium‐arsenide (GaAs) laser (wavelength, 904 nm; pulse duration, 220 nanoseconds; peak power per pulse, 27 W; spot size, 0.28 cm2; total applied energy density, 0.005–2.5 J/cm2) was used for the experiment. Sixty isolated nerves were divided into six groups (n = 10), each of which received a different repetition frequency. In each group, action potentials were recorded, before laser irradiation, which served as the control data. The extracellular action potentials were recorded for each combination of 1, 3, 5, 7, 10, 13, and 15 minutes of irradiation time and 4, 8, 16, 32, 64, 128 repetition frequency by using a BIOPAC MP 100 Acquisition System Version 3.5.7 (Santa Barbara USA). Action potential latency, duration of depolarization and repolarization, and the stimulating voltage were measured. Statistical evaluation was performed using linear correlation analysis by SPSS 9.05.

Results

Although there was no correlation between applied energy density and action potential latency, the duration of depolarization and repolarization phases (P > 0.05), there was a weak correlation between applied energy density and stimulating voltage.

Conclusions

The study showed that low‐energy GaAs irradiation at 42 different energy density between 0.005 and 2.5 J/cm2 generates no effect on action potential configuration and nerve excitability. Lasers Surg. Med. 30:376–380, 2002. © 2002 Wiley‐Liss, Inc.
Calcium solubility of dental enamel following sub‐ablative Er:YAG and Er:YSGG laser irradiation in vitro
Authors: Apel C. , Meister J. , Schmitt N. , Gräber H.‐G. , Gutknecht N.
Published: October 2002

Background and Objective

The objective of the present study was to investigate the effect of sub‐ablative Er:YAG (λ = 2.94 μm) and Er:YSGG (λ = 2.79 μm) laser radiation on the acid solubility of dental enamel. The influence of fluoride application prior to laser irradiation was additionally evaluated.

Study Design/Materials and Methods

To this end, 294 enamel specimens were prepared from bovine teeth and divided into 14 groups of 21 specimens each. The enamel samples were irradiated in their groups with the Er:YAG and the Er:YSGG laser, using energy densities of 4, 6, and 8 J/cm2 in each case. Irradiation was additionally repeated in the same way on specimens, which had previously been immersed in 1% sodium fluoride solution for 15 minutes. One group was left untreated and served as a control group. A further group was not irradiated, but only immersed in the 1% fluoride solution for 15 minutes. The enamel specimens were demineralised for 24 hours in an acetate buffer solution. The calcium content in the demineralisation solution was subsequently determined with the aid of atomic absorption spectrometry.

Results

The results indicate a decline in calcium solubility after laser irradiation. Compared to the control group, a 20% lower calcium content was detected in the demineralisation solution after irradiation with the Er:YSGG laser at 8 J/cm2. The difference between the laser‐irradiated groups and the untreated control group was, however, not statistically significant. A significantly lower calcium content was found in the demineralisation solution after fluoridation of the specimens. Additional laser radiation had no further effect on this result.

Conclusions

In summary, it can be stated that, although the erbium laser wavelengths apparently have the potential to increase acid resistance, their application solely for caries prevention would not appear to be sensible under the prevailing conditions. Lasers Surg. Med. 30:337–341, 2002. © 2002 Wiley‐Liss, Inc.
Tumorigenic effect of transcription factor hAP‐2α and the intricate link between hAP‐2α activation and squelching
Authors: Yu Yihong , Wang Yingqun , Li Min , Kannan Perry
Published: October 2002

Overexpression of human activator protein‐2α (hAP‐2α) is carcinogenic. Its aberrant regulation is the underlying tumorigenic event in the human teratocarcinoma cell line PA‐1. In this cell line excess hAP‐2α protein binds and sequesters coactivators, which interferes with the activity of other activators and with its own activity. The N‐terminus of hAP‐2α, which contains an activation domain, is critical in squelching and tumorigenicity. Mutation analyses of the N‐terminus region showed that activation and squelching were intricately linked; nevertheless, squelching could occur in the absence of activity. Cells overexpressing squelching‐proficient mutants grew efficiently on soft agar irrespective of their ability to activate transcription, which indicates that these cells are tumorigenic. Mutants that lacked both properties were nontumorigenic. These results suggest that squelching, but not activation, causes transformation and that the factors that are sequestered at this region are critical in tumorigenesis. © 2001 Wiley‐Liss, Inc.
CpG hypermethylation of promoter region and inactivation of E‐cadherin gene in human bladder cancer
Authors: Ribeiro‐Filho Leopoldo Alves , Franks Joseph , Sasaki Masahiro , Shiina Hiroaki , Li Long‐Cheng , Nojima Dana , Arap Sami , Carroll Peter , Enokida Hideki , Nakagawa Masayuki , Yonezawa Suguru , Dahiya Rajvir
Published: October 2002

Several studies have shown that E‐cadherin expression is lost during malignant transformation. We hypothesized that CpG methylation in the promoter region may inactivate the expression of the E‐cadherin gene in human bladder cancer. Normal and bladder cancer samples from 51 patients were compared in terms of E‐cadherin gene expression and methylation status by immunohistochemistry, methylation‐specific polymerase chain reaction (MSP), and bisulfite genome‐sequencing techniques. Ten different CpG sites (nt 863, 865, 873, 879, 887, 892, 901, 918, 920, and 940) in the promoter region were studied. Thirty‐five of 51 (69%) bladder cancer samples lacked E‐cadherin expression, whereas only six of 51 (12%) normal bladder samples lacked E‐cadherin immunoreactivity. MSP analysis of bladder cancer samples suggested that 43 of 51 (84%) showed methylation of the promoter region, whereas only 12 of 51 (24%) normal bladder samples showed hypermethylation. Sodium bisulfite genome‐sequencing analysis revealed that of 10 CpG sites, two sites (nt 892 and nt 940) showed 100% methylation in all the cancer samples analyzed. Other CpG sites were partially methylated (47–91%). Normal tissue showed only 12% methylation (range, 1–33%) on various CpG sites. Also supporting these data, E‐cadherin–negative bladder cancer cell lines restored expression of the E‐cadherin gene after treatment with the demethylating agent 5‐aza‐2′‐deoxycytidine. The present study showed that CpG hypermethylation was an important mechanism of E‐cadherin gene inactivation in bladder cancer and also that specific CpG sites consistently presented higher methylation levels than others. These findings may provide a better strategy for the diagnosis and management of bladder cancer. © 2002 Wiley‐Liss, Inc.
Reduced Brca1 protein expression in 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine–induced rat mammary carcinomas
Authors: Okochi Eriko , Miyamoto Kazuaki , Wakazono Kuniko , Shima Hiroshi , Sugimura Takashi , Ushijima Toshikazu
Published: October 2002

Reduced expression of BRCA1 protein, caused by the hypermethylation of its gene promoter and by other mechanisms, is observed in most sporadic human breast cancers, whereas its somatic mutations are rare. In the present study, we demonstrate that immunoreactivity of Brca1 was reduced in almost all rat mammary carcinomas induced by 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP), whereas hypermethylation of its promoter, mutations in its entire coding region, and decreased mRNA expression were absent. Using two kinds of polyclonal antibodies against human BRCA1 that recognized the N and C termini, respectively, immunoreactivity of Brca1 was found to be reduced in all 17 carcinomas examined and, especially, to be almost completely lost in 8 or 10 carcinomas. The reduction was confirmed by immunoblot analysis of five mammary carcinomas and normal mammary epithelial cells. Sequencing of the Brca1 promoter region after bisulfite modification in 10 PhIP‐induced mammary carcinomas showed that the region was completely unmethylated in all of them. No mutations were detected in the entire coding region by direct sequencing of the Brca1 cDNA. Decrease in mRNA levels was not detected by quantitative real‐time reverse transcription–polymerase chain reaction. These data suggested that PhIP‐induced mammary carcinomas could model human breast cancers that show reduced BRCA1 immunoreactivity without promoter hypermethylation and with normal mRNA expression. As underlying mechanisms, alterations in posttranscriptional regulation or stability of Brca1 protein were suggested. © 2002 Wiley‐Liss, Inc.
The rise of human service chains: antecedents to acquisitions and their effects on the quality of care in US nursing homes
Authors: Banaszak‐Holl Jane , Berta Whitney B. , Bowman Dilys M. , Baum Joel A.C. , Mitchell Will
Published: October 2002

This paper studies acquisitions of nursing home facilities by chains. We first test alternative ‘cream‐skimming’ and ‘turn‐around’ arguments concerning nursing home acquisitions. We then consider post‐acquisition changes in nursing home health performance, differentiating effects of the acquisition process from those of prior strategy and performance of the acquired home and acquiring chain. Our dynamic empirical analysis of more than 5000 acquisitions by US nursing home chains from 1991 through 1997 shows that nursing home chain acquisitions are driven by a turn around logic, and that performance depends on the prior quality of the target and acquirer. Our analysis is relevant to policy on the nursing home sector, helping clarify why certain homes are acquired and how being acquired affects their residents' welfare. At a more general level, we offer insights concerning strategic factors that promote acquisition and drive expansion of service sector chains. Copyright © 2002 John Wiley & Sons, Ltd.
Five strategies for rapid firm growth and how to implement them
Authors: Mascarenhas Briance , Kumaraswamy Arun , Day Diana , Baveja Alok
Published: October 2002

Analysis of 45 rapidly growing, profitable firms reveals five strategies: (1) product proliferation, (2) mass market development, (3) increasing value to select customers, (4) distribution innovation, and (5) acquisition and consolidation. These five strategies are not restricted to high‐growth industries and arise when firms exploit market disequilibrium to the their advantage. The profitable growth strategies are based on multiple, reinforcing sources of scale, scope, and time‐based advantages. The study details the steps needed to implement each growth strategy and potential pitfalls to avoid. Copyright © 2002 John Wiley & Sons, Ltd.
Small‐Amplitude cortical myoclonus in Parkinson's disease: Physiology and clinical observations
Authors: Caviness John N. , Adler Charles H. , Beach Thomas G. , Wetjen Kristi L. , Caselli Richard J.
Published: October 2002

We studied the occurrence of small‐amplitude myo‐ clonus in 20 idiopathic Parkinson's disease patients who had no evidence of dementia as defined by criteria in the Diagnostic and Statistical Manual of Mental Disorders, fourth edition. Parkinson's disease was diagnosed by United Kingdom Brain Bank criteria, and clinical assessment was performed with the Unified Parkinson's Disease Rating Scale motor score, Hoehn and Yahr staging, and the Mini‐Mental State Examination. Clinical assessment showed a range of mild‐to‐moderate disease severity. All patients underwent polygraphic electro–encephalographic‐electromyographic (EMG) recording with back‐averaging, somatosensory evoked potential testing, and attempted elicitation of long‐latency EMG responses. Multichannel surface EMG recording during muscle activation showed irregular, multifocal, brief (<50 msec) myoclonus EMG discharges. Back‐averaging consistently showed a focal, short‐latency, electroencephalographic transient prior to the myoclonus EMG discharge. Cortical somatosensory evoked potential waves were not enlarged, and long‐latency EMG responses at rest were not present. The small‐amplitude myoclonus in such cases arises from an abnormal discharge from the sensorimotor cortex. The mechanism of this cortical myoclonus in Parkinson's disease has differences from the more common “cortical reflex myoclonus” physiology. Advanced parkinsonism is not a requirement for manifestation of this myoclonus type. Although the myoclonus occurred without dementia in these cases, its relationship to the subsequent development of cognitive impairment remains to be defined. © 2002 Movement Disorder Society
Secondary paroxysmal dyskinesias
Authors: Blakeley Jaishri , Jankovic Joseph
Published: October 2002

Paroxysmal dyskinesias (PxDs) are involuntary, episodic movements that include paroxysmal kinesigenic (PKD), paroxysmal nonkinesigenic (PNKD), and paroxysmal hypnogenic (PHD) varieties. Although most PxDs are primary (idiopathic or genetic), we found 17 of our 76 patients with PxD (22%) to have an identifiable cause for their PxD (10 men; mean age, 41.4 years). Causes included peripheral trauma (in three patients), vascular lesions (in four), central trauma (in four), kernicterus (in two), multiple sclerosis (in one), cytomegalovirus encephalitis (in one), meningovascular syphilis (in one), and migraine (in one). The latency from insult to symptom onset ranged from days (trauma) to 18 years (kernicterus), with a mean of 3 years. Nine patients had PNKD, two had PKD, five had mixed PKD/PNKD, and one had PHD. Hemidystonia was the most common expression of the paroxysmal movement disorder, present in 11 patients. Both of the patients with PKD had symptom durations of <5 minutes. Symptom duration ranged from 10 seconds to 15 days for PNKD and from 5 minutes to 45 minutes for mixed PKD/PNKD. There were no uniformly effective therapies, but anticonvulsant drugs, clonazepam, and botulinum toxin injections were the most beneficial. Awareness of the variable phenomenology and the spectrum of causes associated with secondary PxD will allow for more timely diagnosis and early intervention. © 2002 Movement Disorder Society
Tourettism and dystonia after subcortical stroke
Authors: Kwak Carolyn H. , Jankovic Joseph
Published: October 2002

The term “tourettism” has been used to describe Tourette syndrome (TS)‐like symptoms secondary to some specific cause. Tics associated with attention deficit hyperactivity disorder (ADHD), obsessive–compulsive disorder (OCD), or both, are commonly present in TS, but this constellation of symptoms has been rarely attributed to stroke. We describe two boys who suffered a subcortical stroke and subsequently developed hemidystonia, tics, and behavioral comorbidities. Both had right hemispheric stroke involving the basal ganglia at 8 years of age, and in both the latency from the stroke to the onset of left hemidystonia was 2 weeks. In addition to ADHD and OCD, both exhibited cranial‐cervical motor tics but no phonic tics. The temporal relationship between the stroke and subsequent TS‐like symptoms, as well as the absence of phonic tics and family history of TS symptoms in our patients, argues in favor of a cause and effect relationship, and the observed association provides evidence for an anatomic substrate for TS and related symptoms. © 2002 Movement Disorder Society
Chloroquine resistance in the malarial parasite, Plasmodium falciparum
Authors: Ursos Lyann M.B. , Roepe Paul D.
Published: October 2002

Malarial parasites remain a health problem of staggering proportions. Worldwide, they infect about 500 million, incapacitate tens of millions, and kill approximately 2.5 million (mostly children) annually. Four species infect humans, but most deaths are caused by one particular species, Plasmodium falciparum. The rising number of malarial deaths is due in part to increased drug resistance in P. falciparum. There are many varieties of antimalarial drug resistance, and there may very well be several molecular level contributions to each variety. This is because there are a number of different drugs with different mechanisms of action in use, and more than one molecular event may sometimes be relevant for resistance to any one class of drugs. Thus, “multidrug” resistance in a clinical setting likely entails complex combinations of overlapping resistance pathways, each specific for one class of drug, that then add together to confer the particular multidrug resistance phenotype. Nonetheless, rapid progress has been made in recent years in elucidating mechanisms of resistance to specific classes of antimalarial drugs. As one example, resistance to the antimalarial drug chloroquine, which has been the mainstay therapy for decades, is becoming well understood. This article focuses on recent advances in determining the molecular mechanism of chloroquine resistance, with particular attention to the biochemistry and biophysics of the P. falciparum digestive vacuole, wherein changes in pH have recently been found to be associated with chloroquine resistance. © 2002 Wiley Periodicals, Inc. Med Res Rev, 22, No. 5, 465–491, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/med.10016
Experimental study of a broadband U‐slot triangular patch antenna
Authors: Jang Yong‐Woong
Published: October 2002

This Letter describes a U‐shaped aperture‐coupled U‐slot triangular patch antenna fed by microstrip feed line. Because a thick aperture substrate with a dual U‐slot patch radiator are used in the design, a high level of coupling to the feed line results. The measured bandwidth of approximately 84.9% (VSWR ≤ 2.0) and a gain of 6.5 dBi have been obtained. The experimental far‐field patterns are stable across the passband. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 34: 325–327, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10451
Radiotherapy for medulloblastoma in children: A perspective on current international clinical research efforts
Authors: Freeman Carolyn R. , Taylor Roger E. , Kortmann Rolf‐Dieter , Carrie Christian
Published: October 2002

Background

The North America and four European pediatric cooperative groups have undertaken prospective studies for medulloblastoma continuously since the 1970s. In this article, we will review the results of these studies with respect specifically to the use of radiotherapy, and trace the developments that have led up to the present trials for patients with this tumor.

Procedure

Published and unpublished data from the North American CCG and POG and now COG studies, from the UKCCG and SIOP groups, as well as from the French and German groups were reviewed. Issues of especial interest included radiotherapy dose and dose fractionation schedules, scheduling of chemotherapy and radiotherapy, and technical aspects of treatment with radiotherapy that might impact on outcome.

Results and Conclusions

Much progress has been made in the management of medulloblastoma in childhood as a consequence of the studies undertaken sequentially by these groups over the past two decades. It now seems clear that chemotherapy plays an important role for all patients. In patients with average risk disease, the use of chemotherapy has allowed a reduction in the dose of radiotherapy to the craniospinal axis and the combination of chemotherapy with radiotherapy appears to have brought about a significant improvement in disease‐free and overall survival in this patient population. Patients with high‐risk disease fare better now than in the past as a consequence of the routine use of aggressive chemotherapy and preliminary data suggest that the use of higher doses of radiation as in the POG studies is associated with a particularly favorable outcome. Accurate delivery of radiotherapy is essential for optimal results. The avail‐ability of better tools at the treating centres and quality control as an integral part of cooperative studies are likely to bring about further improvements in outcome in the future. Med Pediatr Oncol 2002;39:99–108. © 2002 Wiley‐Liss, Inc.
Long‐term survival of children with neuroblastoma prior to the neuroblastoma screening project in Germany
Authors: Burkhardt‐Hammer Tatjana , Spix Claudia , Brenner Hermann , Kaatsch Peter , Berthold Frank , Hero Barbara , Michaelis Jörg
Published: October 2002

Background

In the last decades, prognosis of children with neuroblastoma has improved only slightly. Traditional estimates of survival reflect the survival experience of children diagnosed many years ago, and may thus not capture more recent progress in prognosis. We applied a new method of survival analysis, denoted period analysis, to provide more up‐to‐date estimates of long‐term prognosis. We selected the cases diagnosed before the German neuroblastoma screening project in 1995, allowing to assess the method by comparing the 1994 projected survival estimates with the observations made today (2000).

Procedure

The data comes from the population based German Childhood Cancer Registry. We included all 1,353 children diagnosed with neuroblastoma below age 15 between 1980 and 1994. We derived 5‐, 10‐, and 15‐year survival estimates using traditional analysis or period analysis as needed. Where possible we compared the period analysis estimates with the later obtained actual estimates. We showed trends in survival for the sample as a whole and for prognostic subgroups.

Results

Survival probabilities increased over time especially in the subgroups with poor prognosis. Short‐term survival probabilities improved more than long‐term survival probabilities. Evaluation of the period‐analysis estimates showed them to provide accurate and timely projections of prognosis of newly diagnosed patients.

Conclusions

The results suggest major improvements in prognosis of children with neuroblastoma, even prior to the start of the German neuroblastoma screening project, especially in advanced disease. This could have been disclosed with the application of the period analysis method in 1995 even then with considerable accuracy. We recommend a more widespread application of this method especially in population‐based cancer registries. Med Pediatr Oncol 2002;39:156–162. © 2002 Wiley‐Liss, Inc.
Transient transmission of a transgene in mouse offspring following in vivo transfection of male germ cells
Authors: Celebi Catherine , Auvray Pierrick , Benvegnu Thierry , Plusquellec Daniel , JÉgou Bernard , Guillaudeux Thierry
Published: October 2002

Sperm‐mediated gene transfer in vertebrates has undergone various developments over the last few years, in different laboratories. In the present study, we microinjected a circular plasmid, carrying the lacZ reporter gene mixed with noncommercial cationic lipids, into the seminiferous tubules of anesthetized adult mice. Histochemical analysis was used to estimate the transfection efficiency 48–96 hr and 40 days after injection. As early as 48–96 hr post‐injection, an efficient transfection was revealed by a β‐galactosidase expression within both immature and differentiated germ cells. By 40 days post‐injection, the specific LacZ expression was restricted to the most immature germ cells in the basal portion of the seminiferous tubules. At this time, some injected males were mated with wild‐type females and the progeny were analyzed by PCR and Southern blot. We showed that the transgene was transmitted to the offspring but remained episomal, as it was found in the tail of the young animals but not at adulthood. Therefore, the plasmid seemed to be lost during the numerous germ cells divisions. This plasmid stayed in some tissues, such as skeletal muscle and cardiac muscle. No integrative forms have yet been found with the use of a circular DNA. Mol. Reprod. Dev. 62:477–482, 2002. © 2002 Wiley‐Liss, Inc.