bluuebunny/crossref_metadata_2025 huggingface dataset:
Laminarin in the dietary fibre concept
Authors: Devillé Christelle , Damas Jacques , Forget Philippe , Dandrifosse Guy , Peulen Olivier
Published: May 2004

Dietary fibres consist of edible plant polysaccharides that are resistant to digestion and absorption in the human small intestine but undergo complete or partial fermentation in the colon. Seaweeds, notably Laminaria spp, are particularly rich in polysaccharides resistant to hydrolysis in the upper gastrointestinal tract and are, in consequence, considered as dietary fibres. Most of the carbohydrates from Laminaria spp are thought to be indigestible by humans. The main storage polysaccharide of these algae is laminarin, a β‐polymer of glucose. The aims of this work were, on the one hand, to compare various methods of extraction of laminarin by partial characterisation of the product obtained and, on the other hand, to study the fate of this polysaccharide and its effects in the gastrointestinal tract in order to determine its potential as a dietary fibre in human nutrition. Among four methods tested to extract laminarin, the best appeared to be a hot HCl‐based method. Human digestive enzymes did not hydrolyse laminarin, so this polysaccharide can be considered as a dietary fibre. After ingestion by rats, this polysaccharide was not found in faeces of these animals. It did not increase the intestinal transit and stool output in vivo, but it increased the contractile response of the stomach to acetylcholine in vitro. Copyright © 2004 Society of Chemical Industry
Changes in chemical composition of coconut (Cocos nucifera) water during maturation of the fruit
Authors: Jackson José C , Gordon André , Wizzard Gavin , McCook Kayanne , Rolle Rosa
Published: May 2004

Changes in chemical composition of coconut (Cocos nucifera) water, including total and soluble solids, titratable acidity (as citric acid), turbidity, ash, lipids and sugars, were investigated in four varieties of coconuts at four stages of maturity of the fruit. The most significant change was observed in the volume of nut water, which increased during development from 233 to 504 ml, with the greatest quantity found at 9 months. Fat, protein, soluble solids, acidity and turbidity also increased steadily with maturity, while pH and ash showed variation throughout maturation. The interaction of variety and stage of maturity of the fruit appeared to have a significant effect on the chemical composition of the coconut water. Copyright © 2004 Society of Chemical Industry
The effects of natural antioxidants and lighting conditions on the quality characteristics of gilt‐head sea bream fillets (Sparus aurata) packaged in a modified atmosphere
Authors: Giménez Begoña , Roncalés Pedro , Beltrán José A
Published: May 2004

The effects of lighting conditions and the application of natural antioxidants (rosemary extract and ascorbic acid) on the shelf‐life of gilt‐head sea bream fillets (Sparus aurata) packaged in a modified atmosphere (MAP) and stored at 1 ± 1 °C were studied. Lighting with low‐UV colour‐balanced lamps led to an extension of shelf‐life compared with that under supermarket fluorescent tubes, as assessed by lipid oxidation (TBARS value) and sensory evaluation. The application of antioxidants to the surface of MAP fillets delayed lipid oxidation besides improving the sensory quality. Rosemary extract was more effective than ascorbic acid in delaying lipid oxidation under both kinds of lighting. The effect of ascorbic acid was greater in the samples illuminated by low‐UV tubes than in those stored under conventional lighting. However, the effectiveness of rosemary extract was similar in both kinds of lighting conditions. Copyright © 2004 Society of Chemical Industry
Functional dry fermented sausages manufactured with high levels of n‐3 fatty acids: nutritional benefits and evaluation of oxidation
Authors: Muguerza Edurne , Ansorena Diana , Astiasarán Iciar
Published: May 2004

Dry fermented sausages including fish oil extracts rich in n‐3 fatty acids were manufactured in order to obtain functional products, and their nutritional advantages and effects on oxidation process were compared with traditional ones. Modified products were manufactured with 5.3 g kg−1 and 10.7 g kg−1 of fish oil extract. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) contents per 100 g of dry fermented sausages were 0.15 g and 0.13 g for the lower rate of addition and 0.33 g and 0.26 g, respectively, for the higher rate, compared with only 0.01 g EPA and 0.03 g DHA in the control products. No significant differences were found in the other fatty acids. A decrease in the n‐6/n‐3 ratios from 16.14 in the control to 7.78 in batch A and 5.32 in batch B was achieved. Thiobarbituric acid reactive substances values were similar in control (0.31 ppm) and in batch A products (0.34 ppm) but increased significantly in batch B products (1.22 ppm). No statistical differences were observed among batches for the content of cholesterol oxidation products (2.36–2.43 µg g−1 fat) leading to similar percentages of oxidation. 7‐Ketocholesterol, considered an indicator of oxidation, was not present in any sample. Values obtained for L* and hue (arctg b*/a*) were comparable with those of meat products. Although no effect was observed in cholesterol oxidation product formation and instrumental measurements of colour, the highest level of n‐3 fatty acid seemed to accelerate the oxidation process significantly. Copyright © 2004 Society of Chemical Industry
Tailoring donor hepatectomy per segment 4 venous drainage in right lobe live donor liver transplantation
Authors: Chan See Ching , Lo Chung Mau , Liu Chi Leung , Wong Yik , Fan Sheung Tat , Wong John
Published: May 2004

Including the middle hepatic vein (MHV) in the right lobe liver graft for adult-to-adult live donor liver transplantation provides more functional liver by securing adequate venous drainage. Donor outcome of this procedure in relation to different venous drainage patterns of segment 4 is unknown. Modification of graft harvesting technique by preserving segment 4b hepatic vein (V4b) in theory compensates for unfavorable venous drainage patterns. Consecutive 120 right lobe live donors were included. Computed tomography was studied in detail to assign each donor to one of the three types of the Nakamura classification of venous drainage pattern of segment 4. Type I drainage was mainly via the left hepatic vein (LHV), type II drainage was equally into the MHV and LHV, and type III drainage was predominantly into the MHV. Any distinct umbilical vein was also noted. In the early part of the series, the V4b draining into the MHV was divided to provide a long MHV stump in the graft. In the later part of the series, prominent V4b draining into the MHV was preserved in the donor as far as possible. Donor outcomes were measured by peak values of prothrombin time (PT), serum bilirubin and transaminases levels. There was no donor mortality. Type I donors (n=69) had the best outcome with peak PT of 17.9 sec (range 12.3-23.3 sec). Type II donors (n=44) had peak PT of 18.5 sec (range 15.4-24.4 sec). When V4b was preserved in type II donors (n=19), the peak PT (18.0 sec, range 15.4-20.7 sec) became significantly lower than that of type II donors who had V4b sacrificed (20.3 sec, range 16.2-24.4 sec) (P=0.001). A distinct umbilical vein (n=91, 75.8%) was insignificant for donor outcome measured by peak PT. Multivariate analysis identified that type II donors with V4b sacrificed (n=25), type III donors (n=7), and the first 50 cases had less favorable outcomes. In conclusion, unfavorable venous drainage patterns were one of the independent factors compromising postoperative donor liver function, but was circumvented by preservation of V4b. (Liver Transpl 2004;10:755-762.)
The effect of donor weight reduction on hepatic steatosis for living donor liver transplantation
Authors: Hwang Shin , Lee Sung-Gyu , Jang Se-Jin , Cho Sung-Hun , Kim Ki-Hun , Ahn Chul-Soo , Moon Deok-Bog , Ha Tae-Yong
Published: May 2004

Hepatic steatosis is often associated with overweight, so we tried body-weight reduction in potential living donors with fatty liver and/or obesity to alleviate hepatic steatosis. We advised to reducing the body weight by 5% for 9 potential living donors showing hepatic steatosis of 25-95% on initial percutaneous needle biopsy (PCNB). They lost 5.9 ± 2.0% of the initial body weight during 2-6 months and their body mass index changed from 25.3 ± 3.8 to 23.7 ± 3.4. Total amount of hepatic steatosis changed significantly from 48.9 ± 25.6% to 20.0 ± 16.2% before and after weight reduction. The proportional reduction in microvesicular steatosis was more obvious than in macrovesicular fatty changes. Six right lobe and 3 left lobe grafts were procured uneventfully from these 9 donors. All donors recovered uneventfully, and all 9 recipients survived more than 15 months to date. In conclusion, we think that short-term weight reduction of living donors will be helpful to alleviate excessive hepatic steatosis, especially in microvesicular type and can contribute to expand the pool of marginal living donors. (Liver Transpl 2004;10:721-725.)
Resection prior to liver transplantation for hepatocellular carcinoma: A strategy of optimizing the role of resection and transplantation in cirrhotic patients with preserved liver function
Authors: Poon Ronnie T. , Fan Sheung Tat
Published: May 2004

Objective

To evaluate the feasibility and postoperative course of liver transplantation (LT) in cirrhotic patients who underwent liver resection prior to LT for HCC.

Summary Background Data

Although LT provides longer survival than liver resection for treatment of small HCCs, donor shortage and long LT wait time may argue against LT. The feasibility and survival following LT after hepatic resection have not been previously examined.

Methods

Between 1991 and 2001, among 107 patients who underwent LT for HCC, 88 met Mazzafero’s criteria upon pathologic analysis of the explant. Of these, 70 underwent primary liver transplantation (PLT) and 18 liver resection prior to secondary liver transplantation (SLT) for recurrence (n = 11), deterioration of liver function (n = 4), or high risk for recurrence (n = 3). Perioperative and postoperative factors and long-term survival were compared.

Results

Comparison of PLT and SLT groups at the time of LT revealed similar median age (53 vs. 55 years), sex, and etiology of liver disease (alcohol/viral B/C/other). In the SLT group, the mean time between liver resection and listing for LT was 20 months (range 1-84 months). Overall time on LT waiting list of the two groups was similar (3 vs. 5 months). Pathologic analysis after LT revealed similar tumor size (2.2 vs. 2.3 cm) and number (1.6 vs. 1.7). Perioperative and postoperative courses were not different in terms of operative time (551 vs. 530 minutes), blood loss (1191 vs. 1282 mL), transfusion (3 vs. 2 units), ICU (9 vs. 10 days) or hospital stay (32 vs. 31 days), morbidity (51% vs. 56%) or 30-day mortality (5.7% vs. 5.6%). During a median follow-up of 32 months (3 to 158 months), 3 patients recurred after PLT and one after SLT. After transplantation, 3- and 5-year overall survivals were not different between groups (82 vs. 82% and 59 vs. 61%).

Conclusions

In selected patients, liver resection prior to transplantation does not increase the morbidity or impair long-term survival following LT. Therefore, liver resection prior to transplantation can be integrated in the treatment strategy for HCC. (Ann Surg 2003;238:885-893.) (Liver Transpl 2004;10:813-815.)
Hepatic venous congestion in living donor liver transplantation: Preoperative quantitative prediction and follow-up using computed tomography
Authors: Hwang Shin , Lee Sung-Gyu , Park Kwang-Min , Kim Ki-Hun , Ahn Chul-Soo , Lee Young-Joo , Sung Kyu-Bo , Moon Deok-Bog , Ha Tae-Yong , Cho Sung-Hun , Oh Ki-Bong , Han Ji-Min , Kim Myung-Hwan
Published: May 2004

Hepatic venous congestion (HVC) has not been assessed quantitatively prior to hepatectomy and its resolving mechanism has not been fully analyzed. We devised and verified a new method to predict HVC, in which HVC was estimated from delineation of middle hepatic vein (MHV) tributaries in computed tomography (CT) images. The predicted HVC was transferred to the right hepatic lobes of 20 living donors using a paper scale, and it was compared with the actual observed HVC that occurred after parenchymal transection and arterial clamping. The evolution of HVC from its emergence to resolution was followed up with CT. Volume proportions of the predicted and observed HVC were 31.7 ± 6.3% and 31.3 ± 9.4% of right lobe volume (RLV) (P = .74), respectively, which resulted in a prediction error of 3.8 ± 3.7% of RLV. We observed the changes in the HVC area of the right lobes both in donors without MHV trunk and in recipients with MHV reconstruction. After 7 days, the HVC of 33.5 ± 7.7% of RLV was changed to a computed tomography attenuation abnormality (CTAA) of 28.4 ± 5.3% of RLV in 12 donor remnant right lobes, and the HVC of 29.1 ± 11.5% of RLV was reduced to a CTAA of 9.3 ± 3.2% of RLV in 7 recipient right lobe grafts with MHV reconstruction. There was no parenchymal regeneration of the HVC area in donor remnant livers during first 7 days. In conclusion, we believe that this CT-based method for HVC prediction deserves to be applied as an inevitable part of preoperative donor evaluation. The changes in CTAA observed in the right lobes of donors and recipients indicate that MHV reconstruction can effectively decrease the HVC area. (Liver Transpl 2004;10:763-770.)
Advances in adult living donor liver transplantation: A review based on reports from the 10th anniversary of the adult-to-adult living donor liver transplantation meeting in Tokyo
Authors: Sugawara Yasuhiko , Makuuchi Masatoshi
Published: May 2004

In 1993, the Shinshu Group performed the first successful adult-to-adult living donor liver transplantation (LDLT). During the first 10 years of LDLT, many technical innovations have been reported. The major limitation of LDLT for adult recipients is the size of the graft. To overcome the problem, several graft types were designed, including left liver graft with caudate lobe, right liver, modified right liver, and right lateral sector and dual grafts. The necessity and criteria of reconstruction of middle hepatic vein is still on debate in right liver graft without trunk of middle hepatic vein. Biliary reconstruction remains a significant source of morbidity in LDLT. Donor safety must always be the primary consideration in LDLT and the selection criteria and management of the living donor must continue to be refined. On February 21, 2004, the 10th anniversary of the adult-to-adult LDLT meeting was held in Tokyo to review the accumulated experience and the presented information is summarized. (Liver Transpl 2004;10:715-720.)
Estimation of standard liver volume for liver transplantation in the Korean population
Authors: Yu Hee Chul , You Heecheon , Lee Ho , Jin Zhe-Wu , Moon Jang Il , Cho Baik Hwan
Published: May 2004

The standard liver volume (LV) of a recipient is estimated in liver transplantation to determine the minimum LV necessary for the recipient. Simple linear formulas of LV estimation were developed for the Japanese and Caucasian populations. The present study examined the applicability of the reported formulas to the Korean population. Liver density (LD) was determined by analyzing 24 healthy livers. Data of liver weight (LW), body weight (BW), body height (BH), body surface area (BSA), and age were obtained from 652 postmortem examination reports (age, 42.4 ± 16.5 years) showing normal livers. The LV of each subject was estimated by LW / LD and the relationships between LV, BW, BSA, and age were analyzed. LD was 1.04 ± 0.07 kg/L. LV / BW decreased as age increased in the children but leveled off in the adults; the rate of increase in LV along with BSA in individuals with BSA <1.2 m2 appeared less than the corresponding rate in individuals with BSA ≥1.2 m2. The Japanese formula produced underestimates for the Korean population (226.9 ± 289.4 mL), while the Caucasian formula produced random errors (−30.64 ± 281.5 mL). A better LV estimation formula was established: LV (mL) = 21.585 × BW (kg)0.732 × BH (cm)0.225 (adjusted R
2 = 0.59; SE = 275.8 mL). In conclusion, this study indicates that a nonlinear or piecewise linear model is more desirable than a simple linear model for LV estimation in children and adults, because LV / BW and LV / BSA are not constant with age and BSA. (Liver Transpl 2004;10:779-783.)
Functional characterization of hepatoma‐specific stem cell antigen‐2
Authors: He Jin , Chang Lung‐Ji
Published: May 2004

Identification of tumor‐specific antigens and genetic pathways may lead to potential diagnostic and therapeutic applications in cancer treatment. cDNA microarray has been used in cancer gene profiling, but the broad spectrum of data accruing and narrow signal‐to‐noise range of this technology have limited its use in rapid identification of highly differentially expressed tumor genes. Here, we used a modified suppression subtractive hybridization (SSH) method to isolate a small number of highly differentially expressed genes from murine hepatoma cells. For functional analysis of these hepatoma‐specific genes, we employed the small interference RNA (siRNA)‐mediated gene silencing method with lentiviral vectors, which have the advantages of high delivery efficiency and long lasting effect. Stem cell antigen‐2 (Sca‐2) was identified as one of the highest differentially expressed tumor antigens. Lentiviral siRNA successfully suppressed >90% of Sca‐2 expression and the suppression lasted longer than 3 mo. Interestingly, inhibition of Sca‐2 induced rapid hepatoma cell apoptosis, and the survival Sca‐2‐negative hepatoma cells exhibited high sensitivity to extrinsic tumor necrosis factor alpha (TNF‐α) apoptosis signal but not intrinsic apoptosis signal. Analysis of TNF receptor 1 (TNFR1) by flow cytometry and Western blotting indicated that Sca‐2 expression downregulated cell surface but not de novo synthesis of TNFR1 in the hepatoma cells. Together, our results suggested that Sca‐2 was a signal transducer situated at the nexus of surface molecules regulating death receptor‐mediated apoptosis. The technology illustrated that this method can deduce a small number of highly differentially expressed tumor genes that may have diagnostic and therapeutic potential. © 2004 Wiley‐Liss, Inc.
Identification of novel differentially expressed genes by the effect of a high‐fat n‐6 diet in experimental breast cancer
Authors: Escrich Eduard , Moral Raquel , García Gemma , Costa Irmgard , Sánchez Josep Anton , Solanas Montserrat
Published: May 2004

In previous studies, we demonstrated that high corn oil diets promote the development of 7,12‐dimethylbenz(α)anthracene (DMBA)‐induced mammary tumors. In this study, we have investigated whether modulation of gene expression is one of the mechanisms by which this high‐fat diet exerts such effects. Female Sprague‐Dawley rats were induced with DMBA and fed normolipidic (3% corn oil) or high‐fat (20% corn oil) diet. Screening of genes differentially expressed in adenocarcinomas from the high corn oil diet group compared to the control diet group was performed with cDNA microarrays. The resulting six upregulated and nine downregulated genes were validated by Northern blot and/or reverse transcription (RT)‐polymerase chain reaction (PCR). Further investigation in a higher number of adenocarcinomas showed that in the high‐fat n‐6 diet group, where the tumor phenotype was verified to be more aggressive, the expression of submaxillary gland α‐2u globulin, vitamin D3‐upregulated protein 1 (VDUP1), H19, and the unknown function gene that codifies the expressed sequence tag (EST)‐Rn.32385 was significantly decreased in comparison with the control group (C). These results, together with the fact that VDUP1, H19, and this globulin have been associated with cell proliferation and differentiation, open a new line of research about how the underexpression of these genes contributes to the stimulating effect of a high corn oil diet on experimental mammary carcinogenesis. © 2004 Wiley‐Liss, Inc.
Dominantly‐inherited adult‐onset leukodystrophy with palatal tremor caused by a mutation in the glial fibrillary acidic protein gene
Authors: Thyagarajan Dominic , Chataway Timothy , Li Rong , Gai Wei Ping , Brenner Michael
Published: May 2004

We report on a pedigree of dominantly‐inherited, adult‐onset Alexander disease caused by the glial fibrillary acidic protein (GFAP) gene mutation, R416W. This pedigree highlights the importance of genetic analysis of the GFAP gene in leukodystrophy with palatal tremor. © 2004 Movement Disorder Society
Predictors of sudden onset of sleep in Parkinson's disease
Authors: Körner Yvonne , Meindorfner Charlotte , Möller Jens Carsten , Stiasny‐Kolster Karin , Haja Doris , Cassel Werner , Oertel Wolfgang Hermann , Krüger Hans‐Peter
Published: May 2004

With respect to the ongoing discussion of “sleep attacks” in Parkinson's disease (PD), we sought to estimate the prevalence of sudden onset of sleep (SOS) with and without preceding sleepiness in PD, to identify associated factors, and to define the role of antiparkinsonian medication in SOS. We sent a questionnaire about SOS, sleep behaviour, and medication to 12,000 PD patients. The response rate was 63%, from which 6,620 complete data sets could be analysed. A total of 42.9% of our population reported SOS, 10% of whom never experienced sleepiness before the appearance of SOS (4.3% of all), and we identified the administration of all dopaminergic drugs as a risk factor for SOS. However, SOS occurred earlier after introduction of nonergoline dopamine agonists (DA) and was more strongly associated with nonergoline DA in younger patients (below 70 years) with a shorter disease duration (up to 7 years) but, actually, medication was less efficient in predicting SOS than most other factors considered such as higher age, male sex, longer disease duration, and the report of sleep disturbances. This survey strongly suggests that SOS is a multifactorial phenomenon. Some subgroups are at particular risk of experiencing SOS under nonergoline DA, especially at the beginning of this therapy. Our results support the current notion that SOS, in part, can be attributed to PD‐specific pathology because disease duration and subjective disease severity have been shown to be predictors of SOS. We recommend the development of a standardised question to recognise SOS and to facilitate the comparison of prevalence estimates. © 2004 Movement Disorder Society
Reversible Pisa syndrome (pleurothotonus) due to the cholinesterase inhibitor galantamine: Case report
Authors: Cossu Giovanni , Melis Maurizio , Melis Giannina , Maccioni Elisabetta , Putzu Valeria , Catte Olga , Putzu Paolo Francesco
Published: May 2004

We report on a case of reversible Pisa syndrome developed after treatment with galantamine in a patient with Alzheimer's disease without previous exposure to neuroleptic or other cholinesterase inhibitors. Complete and persistent resolution of the syndrome was achieved several weeks after botulinum toxin type‐A injection. © 2004 Movement Disorder Society
Microvascular anastomosis through the tibial tunnel: A new technique in free‐tissue transfer to the leg
Authors: Muramatsu Keiichi , Shigetomi Mitsunori , Ihara Koichiro , Kawai Shinya
Published: May 2004

Free‐tissue transfer to a severely traumatized leg has a high rate of vascular complications. We present three successful cases using a new technique of microvascular anastomosis through the tibial tunnel. Because of the unavailability of anterior tibial artery due to posttraumatic vascular disease, donor vascular pedicles were passed posterior to the tibia through the tibial tunnel and anastomosed to the posterior tibial artery or its branch in an end‐to‐end fashion. The flaps survived perfectly, without any vascular complication. This technique represents a safe route, and the shortest route, to an expected anastomosis point. Our technique is indicated especially in cases with a single‐vessel leg. © 2004 Wiley‐Liss, Inc.
Delayed reflection of the energy flow at a potential step for dispersive wave packets
Authors: Ali Mehmeti F. , Régnier V.
Published: May 2004

We study Klein–Gordon equations with constant coefficients and different dispersion relations on two one‐dimensional semi‐infinite media coupled with transmission conditions. We obtain lower and upper bounds of the reflected part of the energy flow at the connecting point when the frequency band involved in the initial signal is sufficiently narrow. We detect a phenomenon of delayed reflection for low frequency wave packets, which is in accordance with the recent experiments of Haibel and Nimtz. The result is then generalized for a star‐shaped network of n semi‐infinite branches connected at one point. Copyright © 2004 John Wiley & Sons, Ltd.
Maximum‐weight‐basis preconditioners
Authors: Boman Erik G. , Chen Doron , Hendrickson Bruce , Toledo Sivan
Published: May 2004

This paper analyses a novel method for constructing preconditioners for diagonally dominant symmetric positive‐definite matrices. The method discussed here is based on a simple idea: we construct M by simply dropping offdiagonal non‐zeros from A and modifying the diagonal elements to maintain a certain row‐sum property. The preconditioners are extensions of Vaidya's augmented maximum‐spanning‐tree preconditioners. The preconditioners presented here were also mentioned by Vaidya in an unpublished manuscript, but without a complete analysis.

The preconditioners that we present have only O(n+t2) nonzeros, where n is the dimension of the matrix and 1⩽t⩽n is a parameter that one can choose. Their construction is efficient and guarantees that the condition number of the preconditioned system is O(n2/t2) if the number of nonzeros per row in the matrix is bounded by a constant.

We have developed an efficient algorithm to construct these preconditioners and we have implemented it. We used our implementation to solve a simple model problem; we show the combinatorial structure of the preconditioners and we present encouraging convergence results. Copyright © 2004 John Wiley & Sons, Ltd.
Mixed plate bending elements based on least‐squares formulation
Authors: Pontaza J. P. , Reddy J. N.
Published: May 2004

A finite element formulation for the bending of thin and thick plates based on least‐squares variational principles is presented. Finite element models for both the classical plate theory and the first‐order shear deformation plate theory (also known as the Kirchhoff and Mindlin plate theories, respectively) are considered. High‐order nodal expansions are used to construct the discrete finite element model based on the least‐squares formulation. Exponentially fast decay of the least‐squares functional, which is constructed using the L2 norms of the equations residuals, is verified for increasing order of the nodal expansions. Numerical examples for the bending of circular, rectangular and skew plates with various boundary conditions and plate thickness are presented to demonstrate the predictive capability and robustness of the new plate bending elements. Plate bending elements based on this formulation are shown to be insensitive to both shear‐locking and geometric distortions. Copyright © 2004 John Wiley & Sons, Ltd.
Multi‐precision Laplace transform inversion
Authors: Abate J. , Valkó P. P.
Published: May 2004

For the numerical inversion of Laplace transforms we suggest to use multi‐precision computing with the level of precision determined by the algorithm. We present two such procedures. The Gaver–Wynn–Rho (GWR) algorithm is based on a special sequence acceleration of the Gaver functionals and requires the evaluation of the transform only on the real line. The fixed Talbot (FT) method is based on the deformation of the contour of the Bromwich inversion integral and requires complex arithmetic. Both GWR and FT have only one free parameter: M, which is the number of terms in the summation. Both algorithms provide increasing accuracy as M increases and can be realized in a few lines using current Computer Algebra Systems. Copyright © 2004 John Wiley & Sons, Ltd.
New green fluorescent polyvinylcarbazole copolymer with 1,8‐naphthalimide side chains as chemosensor for iron cations
Authors: Grabchev Ivo , Chovelon Jean‐Marc , Bojinov Vladimir
Published: May 2004

The synthesis and basic photophysical characteristics of a novel green fluorescent polyvinylcarbazole polymer containing 4‐N,N‐dimethylaminoethyleneamino‐1,8‐naphthalimide side chains has been described. The ability to sense metal cations has been monitored by fluorescence emission spectroscopy. It is shown that the fluorescent intensity is very sensitive to the Fe2+ cations and the copolymer can be used as an homogeneous and heterogeneous fluorescent sensor for Fe2+ cations. Copyright © 2004 John Wiley & Sons, Ltd.
Characterization of doped polypyrrole–poly(methylthienyl methacrylate) films via pyrolysis mass spectrometry
Authors: Athar Imran , Hacaloğlu Jale , Toppare Levent
Published: May 2004

This work presents the characterization of p‐toluene sulfonate doped polypyrrole–poly(methylthienyl methacrylate) films synthesized by electrochemical polymerization of pyrrole on a poly(methylthienyl methacrylate) coated anode. Pyrolysis mass spectrometry was used to characterize the polymer. The study was focused on the influence of each of the components on the thermal degradation behaviour of the other. The results indicated that decomposition of the matrix polymer, ie poly(methylthienyl methacrylate), had occurred during the polymerization of pyrrole. Copyright © 2004 Society of Chemical Industry
Preparation and properties of styrene–ethylene/butylene–styrene (SEBS)–clay hybrids
Authors: Chang Young‐Wook , Shin Jae‐Yong , Ryu Sung Hun
Published: May 2004

Styrene–ethylene/butylene–styrene triblock copolymer (SEBS)–clay hybrids were prepared by melt blending SEBS and organoclay using an internal mixer. Maleic anhydride modified SEBS (SEBS–MA) was used as a compatibilizer. X‐ray diffraction and transmission electron microscopy revealed that silicate layers of the clay were partially exfoliated and dispersed at a nanometer scale in the polymer matrix. Enhanced mechanical properties of these hybrids were observed from tensile and dynamic mechanical tests. Thermal degradation temperature of the hybrids was increased compared with pristine SEBS. Copyright © 2004 Society of Chemical Industry
Reinforcement of elastomeric polypropylene by nanoclay fillers
Authors: Vu Yen T , Rajan Guru S , Mark James E , Myers Charles L
Published: May 2004

Polypropylene (PP) was prepared by metallocene catalysts so as to have a stereoblock structure, with isotactic sequences long enough to give crystallites functioning as crosslinks, but small enough in number to have the atactic chains predominate in a surrounding elastomeric matrix. The resulting thermoplastic elastomer was then blended with organically modified clays to document the conditions required to exfoliate the clay layers in a way to maximize the chances for good reinforcement. Some experiments included the use of modified PP as a compatibilizing agent or a commercial silica, for reference purposes. The clays were clearly superior to the silica, which was found to be ineffective for reinforcing this elastomer. The nanoclay fillers did provide improvements in modulus but not toughness, because of corresponding decreases in extensibility. Resistance to creep also remained a problem, presumably due to the clay layers interfering with the growth of the crystallites needed to form a robust network structure. Copyright © 2004 Society of Chemical Industry
Synthesis and properties of new aromatic polyimides based on 2,2′‐dibromo‐4,4′,5,5′‐benzophenone tetracarboxylic dianhydride
Authors: Banihashemi Ahmad , Tamami Bahman , Abdolmaleki Amir
Published: May 2004

New polyimides with enhanced thermal stability and high solubility were synthesized in common organic solvents from a new dianhydride, 2,2′‐dibromo‐4,4′,5,5′‐benzophenone tetracarboxylic dianhydride (DBBTDA). DBBTDA was used as monomer to synthesize polyimides by using various aromatic diamines. The polymers were characterized by IR and NMR spectroscopy and elemental analysis. These polyimides had good inherent viscosities in N‐methyl‐2‐pyrrolidinone (NMP) and also high solubility and excellent thermo‐oxidative stability, with 5 % weight loss in the range 433 to 597 °C. Copyright © 2004 Society of Chemical Industry
Synthesis and properties of novel crosslinkable second‐order nonlinear optical polymers based on 2,3,4,5,6‐pentafluorostyrene
Authors: Wang Yao , Wang Xinjiao , Chuai Xiaohong , Fu Na , Cui Zhanchen , Yi Maobin , Zhang Daming , Yang Bai
Published: May 2004

Two crosslinkable second‐order nonlinear optical polymers were prepared by copolymerization of 2,3,4,5,6‐pentafluorostyrene, styrene (St), glycidyl methacrylate (GMA) and 1‐(4‐nitrophenyl)‐2‐(4‐{[2‐(methacryloyloxy) ethyl] ethylamino}‐phenyl) diazene (DR1M) via the sealed‐tube reaction technique. These polymers were characterized using 1H, 13C and 19F NMR spectroscopy, gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The crosslinkable polymers have high molecular weights, good organosolubility, excellent film‐forming properties and high glass transition (106–110 °C) and thermal decomposition temperatures (290–350 °C) after being crosslinked. Furthermore, the polymer films possess not only high values (12–16 pm V−1) of electro‐optical coefficient (r33) at 1.3 µm wavelength but also low optical loss (1.7 dB cm−1) at 1.55 µm wavelength, which is of interest for applications in electro‐optical devices. Copyright © 2004 Society of Chemical Industry
Nascent morphology of polyethylene polymerized on flat model catalysts
Authors: Loos J , Lemstra PJ , van Kimmenade EME , Niemantsverdriet JW , Höhne GWH , Thüne PC
Published: May 2004

The morphology and the thermal behavior of nascent polyethylene (PE) polymerized on flat models for the Phillips CrOx/SiO2 catalyst were investigated using low‐voltage scanning electron microscopy (LVSEM) and differential scanning calorimetry (DSC). Ethylene polymerizations were performed at 25 °C and 70 °C in gas phase. For the applied polymerization conditions, microscopy observations reveal that the formation of the macromolecules at the active catalyst sites, and their subsequent crystallization on the catalyst, result in homogeneous polymer layers having a thickness of the order of micrometers. The surface morphology of the nascent samples consists of spherical entities having a diameter less than one micrometer. Pillar‐like objects form the internal structure of the PE films. Because these entities are only loosely connected, high porosity is observed within the entire film. Thermal analysis of the samples shows that melting temperature and crystallinity of the nascent PE samples polymerized at 25 °C are noticeably higher than after melting and recrystallization. Samples polymerized at 70 °C, however, do not show these features. Copyright © 2004 Society of Chemical Industry
Synthesis of soluble branched polyimides derived from an ABB′ monomer
Authors: Wang Kun‐Li , Jikei Mitsutoshi , Kakimoto Masa‐aki
Published: May 2004

A novel ABB′ monomer, an isomeric mixture of 4‐[4‐(2,4‐diaminophenoxy)phenoxy]phthalic acid 2‐methyl ester, was successfully prepared. The direct polycondensation of the ABB′ monomer was carried out to form polyamic acid monomethyl ester as a precursor with an inherent viscosity of 0.30 dL/g and a number‐average molecular weight of 12,000. The degree of branching of the precursor, determined by 1H NMR, was 0.07. The low degree of branching was caused by the differences in the reactivities of the amino groups. The shape factor was calculated to be 0.72. End‐modified reactions with acetyl chloride, benzoyl chloride, and phthalic anhydride were carried out. After the chemical imidization of the end‐modified precursors, end‐modified polyimides were successfully prepared. The end‐modified polyimides were soluble in dimethyl sulfoxide, dimethylformamide (DMF), and N‐methyl‐2‐pyrrolidinone. On the basis of thermogravimetry and differential scanning calorimetry measurements of the polyimides, the 5 wt % thermal loss temperatures were determined to be 400–520 °C, and the glass‐transition temperatures were determined to be 200–258 °C. According to the X‐ray diffraction measurements, the end‐modified polyimides were amorphous. A strong but brittle film was prepared from an acetamide end‐modified polyimide solution, via casting from a DMF solution, with a tensile strength of 46 MPa, an elongation at break of 4%, and a modulus of 1.3 GPa. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3200–3211, 2004
Self‐assembly and photovoltaic properties of multilayer films based on partially doped polyaniline and poly(4‐carboxyphenyl)acetylene
Authors: Guijun Yao , Boqiu Wang , Yuping Dong , Maofeng Zhang , Zhaohui Yang , Qiaoling Yao , Yip Lam Jacky Wing , Benzhong Tang
Published: May 2004

Multilayer self‐assembled films, consisting of partially doped polyaniline (PAN) as a polycation and water‐soluble poly(4‐carboxyphenyl)acetylene (PCPA) as a polyanion, were fabricated through electrostatic attraction. These ultrathin PCPA/PAN films were relatively stable toward aqueous electrolyte solutions and polar organic solvents, and the photoelectric conversion properties of the self‐assembled PCPA/PAN films could be measured with traditional three‐electrode cells in 0.5 M KCl aqueous solutions. With an increase in the bilayer number, the photocurrent rose, and it reached its maximum at eight bilayers. A further increase led to a current drop due to an increase in the recombination probability and weak visible‐light transmission. When neutral PAN films were used, the photocurrent increased consecutively within 15 bilayers, and this indicated that the PAN molecules in the neutral state were stronger electron donors than those in the partially doped state. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3224–3229, 2004
Synthesis, optical properties, and electroluminescence of conjugated poly(p‐phenylenevinylene) derivatives containing 1,3,4‐oxadiazole and pyridine rings in the main chain
Authors: Mikroyannidis John A. , Barberis Vasilios P. , Ding Liming , Karasz Frank E.
Published: May 2004

Three new poly(p‐phenylenevinylene) derivatives—PO, POD, and POP—with oxadiazole and pyridine rings along the main chain were synthesized via Heck coupling. The polymers were amorphous and dissolved readily in common organic solvents. They showed relatively low glass‐transition temperatures (up to 42 °C) and satisfactory thermal stability. Solutions of the polymers emitted blue‐greenish light with photoluminescence (PL) emission maxima around 460 nm and PL quantum yields of 0.28–0.49. Thin films of the polymers displayed PL emission maxima at 461–521 nm, and their tendency to form aggregates was significantly influenced by the chemical structure. Light‐emitting diodes with polymers PO and POP, with an indium tin oxide/poly(ethylenedioxythiophene) (PEDOT)/polymer/Ca configuration, emitted yellow and green light, respectively, and this could be attributed to excimer emission. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3212–3223, 2004
Cationic polymerization of styrene in a neutral ionic liquid
Authors: Biedroń Tadeusz , Kubisa Przemysław
Published: May 2004

The cationic polymerization of styrene in a neutral ionic liquid, 1‐butyl‐3‐methylimidazolium hexafluorophosphate, with a 1‐phenetyl chloride/TiCl4 initiating system is reported. The polymerization proceeds to a high conversion, but an analysis of the matrix‐assisted laser desorption/ionization time‐of‐flight spectra of the polymers indicates that chain transfer is significant, leading to a lack of control over the molecular weight and molecular weight distribution. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3230–3235, 2004
pH‐Responsive ampholytic terpolymers of acrylamide, sodium 3‐acrylamido‐3‐methylbutanoate, and (3‐acrylamidopropyl)trimethylammonium chloride. I. Synthesis and characterization
Authors: Fevola Michael J. , Bridges J. Kasey , Kellum Matthew G. , Hester Roger D. , Mccormick Charles L.
Published: May 2004

Low‐charge‐density ampholytic terpolymers composed of acrylamide, sodium 3‐acrylamido‐3‐methylbutanoate (NaAMB), and (3‐acrylamidopropyl)trimethylammonium chloride were prepared via free‐radical polymerization in 0.5 M NaCl to yield terpolymers with random charge distributions. NaOOCH was used as a chain‐transfer agent during the polymerization to eliminate the effects of the monomer feed composition on the degree of polymerization (DP) and to suppress gel effects and broadening of the molecular weight distribution. The terpolymer compositions were obtained via 13C NMR spectroscopy, and the residual counterion content was determined via elemental analysis for Na+ and Cl−. The molecular weights (MWs) and polydispersity indices (PDIs) were determined via size exclusion chromatography/multi‐angle laser light scattering (SEC–MALLS); the terpolymer MWs ranged from 1.3–1.6 × 106 g/mol, corresponding to DPs of 1.6–1.9 × 104 repeat units, with all terpolymers exhibiting PDIs of less than 2.0. Intrinsic viscosities determined from SEC–MALLS data and the Flory–Fox relationship were compared to intrinsic viscosities determined via low‐shear dilute‐solution viscometry and were found to agree rather well. Data from the SEC–MALLS analysis were used to analyze the radius of gyration/molecular weight (Rg–M) relationships and the Mark–Houwink–Sakurada intrinsic viscosity/molecular weight ([η]–M) relationships for the terpolymers. The Rg–M and [η]–M relationships revealed that most of the terpolymers exhibited little or no excluded volume effects under size exclusion chromatography conditions. Potentiometric titration of terpolymer solutions in deionized water showed that the apparent pKa value of the poly[acrylamide‐co‐sodium 3‐acrylamido‐3‐methylbutanoate‐co‐(3‐acrylamidopropyl)trimethylammonium chloride] terpolymers increased with increasing NaAMB content in the terpolymers and increasing ratios of anionic monomer to cationic monomer at a constant terpolymer charge density. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3236–3251, 2004
Lineage relationship between LNCaP and LNCaP‐derived prostate cancer cell lines
Authors: Liu Alvin Y. , Brubaker Kristen D. , Goo Young Ah , Quinn Janna E. , Kral Sabine , Sorensen Carrie M. , Vessella Robert L. , Belldegrun Arie S. , Hood Leroy E.
Published: May 2004

BACKGROUND

LNCaP and its derivative cell lines, which include C4‐2 (and the related C4‐2B) and CL1, are used as models of prostate cancer. Unlike LNCaP, the other cell lines show features of progressed disease such as metastatic capability and hormone independence. Analyses were done to determine if C4‐2 or CL1 cells were selected from pre‐existent subpopulations in LNCaP.

METHODS

Prostate cancer cells were characterized by cluster designation (CD) phenotyping. Specific cell populations were sorted by flow cytometry. DNA array analysis was used to probe differential gene expression.

RESULTS

CD phenotyping showed that CL1 and C4‐2 (and C4‐2B) were very dissimilar, and C4‐2 was more similar to LNCaP. One common difference between LNCaP and its derivatives was CD26, in which virtually all C4‐2 or CL1 cells were CD26+ but only ∼10% of LNCaP cells were CD26+. The CD26+ subpopulation of LNCaP was isolated and cultured in vitro. After culture, a high percentage of the cells (descended from the sorted cells) were CD26+, in contrast to those sorted by CD13 or CD44. The cultured CD13 and CD44 populations did not show a high percentage of CD13+ and CD44+ cells, respectively. CD13 and CD44 are markers, in addition to CD26, for CL1 but not for C4‐2.

CONCLUSIONS

C4‐2 arose probably from CD26+ LNCaP cells, while CL1 arose de novo. © 2004 Wiley‐Liss, Inc.
Evidence of pluripotent human prostate stem cells in a human prostate primary xenograft model
Authors: Huss Wendy J. , Gray Danny R. , Werdin Eric S. , Funkhouser William K. , Smith Gary J.
Published: May 2004

INTRODUCTION

The phenotypic plasticity of the human prostate stem cell within human prostate tissue was examined to determine the response of the stem cell to changes in the androgenic environment.

METHODS

Prostate xenografts were transplanted into athymic nu/nu mice implanted with testosterone pellets, allowed to establish for 1 month time point, the hosts were castrated and pellets removed, and following 1 month of androgen deprivation, the hosts were stimulated with androgen for 2 days to induce proliferation of the residual population of stem cells (2‐month time point).

RESULTS

Glands in benign xenografts harvested at the 1‐ and 2‐month time points contained basal cell layers that expressed p63 and high molecular weight cytokeratin, and in which essentially all of the cellular proliferation was localized, consistent with the proposed localization of the prostate stem cell. Benign glandular structures in the xenografts were populated by basal, secretory epithelial, neuroendocrine (NE), or squamous cells overlaying the basal cell layer, whereas, adenocarcinoma glands in the xenografts resembled the original prostate cancer (CaP) tissue.

CONCLUSIONS

In this human prostate primary xenograft model, the residual stem cell population that survives transplantation, or androgen deprivation, maintains significant pluripotentiality as demonstrated by the capacity to generate progeny that differentiate along multiple lineages in response to microenvironmental signals, particularly along the secretory epithelial lineage in response to androgen, and along the NE cell lineage in response to androgen deprivation. © 2004 Wiley‐Liss, Inc.
Up‐regulation of cathepsin X in prostate cancer and prostatic intraepithelial neoplasia
Authors: Nägler Dorit K. , Krüger Sabine , Kellner Angela , Ziomek Edmund , Menard Robert , Buhtz Peter , Krams Matthias , Roessner Albert , Kellner Udo
Published: May 2004

BACKGROUND

Evidence is accumulating that several proteases are involved in prostate cancer progression. A locus which is often amplified in prostate cancer is the chromosomal region 20q13. Interestingly, one of the genes encoding the cysteine protease cathepsin X maps to this region. The aim of this study was to assess the expression pattern of cathepsin X in malignant and non‐malignant prostatic tissue samples.

METHODS

Matched malignant and non‐malignant tissue specimens were obtained from 56 men after radical prostatectomy. Cathepsin X was quantified at both protein and mRNA levels using several detection methods: Western blotting, immunohistochemistry, quantitative RT‐PCR, and in situ hybridization. Furthermore, genomic DNA was analyzed by PCR for possible gene amplification.

RESULTS

Immunohistochemical analysis of formalin‐fixed, paraffin‐embedded sections of radical prostatectomy specimens was performed utilizing a polyclonal antibody against human procathepsin X and revealed staining of acinar basal cells in normal prostate glands. Prostatic intraepithelial neoplasias (PINs) and prostate carcinomas stained highly positive for cathepsin X, showing a significant difference to the staining of normal prostate glands. In contrast, relatively weak and heterogenous staining was observed for cathepsins F, B, and L. Up‐regulation of cathepsin X at the protein level was confirmed by Western blotting. No statistically significant difference was observed at the mRNA level. PCR of genomic DNA revealed that cathepsin X up‐regulation most likely occurs in the absence of genomic amplification.

CONCLUSIONS

The high expression levels of cathepsin X both in PIN and invasive adenocarcinomas of the prostate suggest that cathepsin X may play a role in the early tumorigenesis of prostate cancer. Further studies are needed to define the utility of this cysteine protease as a diagnostic marker for the early detection of prostate cancer. © 2004 Wiley‐Liss, Inc.