bluuebunny/crossref_metadata_2025_split huggingface dataset:
Systemic insulin‐like growth factor‐I administration prevents cognitive impairment in diabetic rats, and brain IGF regulates learning/memory in normal adult rats
Authors: Lupien Sean B. , Bluhm Erik J. , Ishii Douglas N. 
Published: October 2003

AbstractDiabetic patients have impaired learning/memory, brain atrophy, and two‐fold increased risk of dementia. The cause of cognitive disturbances that progress to dementia is unknown. Because neurotrophic insulin‐like growth factor (IGF) levels are reduced in diabetic patients and rodents, and IGF can cross the blood‐central nervous system barrier (B‐CNS‐B), the hypothesis was tested that IGF administered systemically can prevent cognitive disturbances, independently of hyperglycemia and a generalized catabolic state. Latency to escape to a hidden platform in the Morris Water Maze is used widely to test spatial memory, a hippocampus‐dependent task. Adult rats were rendered diabetic with streptozotocin and implanted 4 weeks later with subcutaneous pumps that released either vehicle (D + Veh) or 20 μg/day IGF‐I (D + IGF). Latency to escape to the hidden platform was prolonged in (D + Veh) versus non‐diabetic rats (P < 0.003) 10.5 weeks after the onset of diabetes. Such prolongation was prevented in (D + IGF) versus (D + Veh) rats (P < 0.03). The data show that IGF‐I can act across the B‐CNS‐B to prevent loss of cognition‐related performance in the water maze independently of ongoing hyperglycemia and reduction in brain (P < 0.001) and whole body weight (P < 0.001) in diabetic rats. The hypothesis that brain IGF contributes to learning/memory was tested. An anti‐IGF antibody, or preimmune serum, was infused into the lateral ventricles in non‐diabetic rats. Learning in a passive avoidance task was impaired significantly in the IGF antibody versus preimmune serum‐treated groups on test Days 1, 2, and 3 (P = 0.04, 0.02 and 0.004, respectively). The data together are consistent with a model in which brain IGF is essential for learning/memory, and a loss of IGF activity due to diabetes may contribute to cognitive disturbances. © 2003 Wiley‐Liss, Inc.
Expression of PTEN in renal cell carcinoma and its relation to tumor behavior and growth
Authors: Shin Lee Ji , Seok Kim Hyung , Bok Kim Young , Cheol Lee Min , Soo Park Chang 
Published: October 2003

AbstractBackground and ObjectivesPTEN is a candidate tumor suppressor gene in a variety of malignant tumors, including renal cell carcinoma (RCC). PTEN regulates cell cycle progression and cell survival in vivo. However, the role of PTEN alterations and their association with tumor growth and behavior in patients with RCC has not been well established. The aim of our study was to evaluate PTEN expression in RCC and its correlation with clinicopathologic features, cell proliferation, and apoptosis.MethodsSixty‐seven RCC specimens were examined immunohistochemically with anti‐PTEN antibody. The apoptotic cells were visualized by terminal deoxynucleotidyl transferase (TdT) mediated dUTP nick‐end labeling (TUNEL) and proliferative cells were visualized by staining with Ki‐67 antibody.ResultsTwenty‐one (31.3%) of the 67 RCCs showed reduced PTEN expression. The apoptotic index (AI) varied from 0.2 to 25.5%, and the Ki‐67 index (KI) ranged from 1.6 to 69.8%. Reduced PTEN expression correlated with TNM stage (P < 0.05) and nuclear grade (P < 0.05). Tumors with reduced PTEN expression had a significantly higher KI than those with normal PTEN expression (P < 0.01). By univariate analysis, nuclear grade (P = 0.0005), TNM stage (P < 0.0001), AI (P = 0.0220), KI (P = 0.0002), and reduced PTEN expression (P < 0.0001) were associated with shortened survival. However, TNM stage was the only independent prognostic factors by multivariate analysis (P = 0.0007).ConclusionsOur results suggest that PTEN expression is frequently reduced in advanced RCC. The PTEN gene seems to be important for the growth suppression of RCC, by inhibiting cell proliferation. J. Surg. Oncol. 2003;84:166–172. © 2003 Wiley‐Liss, Inc.
Mortality for gastric cancer in elderly patients
Authors: Eguchi Teruo , Fujii Masashi , Takayama Tadatoshi 
Published: October 2003

AbstractBackgroundThe aim of this study was to clarify the surgical outcome in elderly patients with gastric cancer.MethodsThe clinicopathological features of elderly patients (80 (3.7%), over 80 years, elderly group) were reviewed retrospectively and compared with those of younger patients (2,095 (96.3%), 23–79 years, control group).ResultsThe elderly group had a significantly higher prevalence of concomitant disease (P < 0.0001), while the prevalence of T1 primary tumor, N0 lymph node metastasis, and stage I was lower (P = 0.0125, P = 0.0004, P < 0.0001). The rates of resected cases and curative operation (R0) were significantly lower in the elderly group (P < 0.0001, P = 0.0021). The mortality from other diseases was 16.3% in elderly patients and 4.4% in control patients (P < 0.0001). The 5‐year survival of stage I and stage IV were not significantly different between the two groups (P = 0.1266 and P = 0.2490). The overall survival and disease‐specific survival for all patients in the elderly group were significantly lower than those in the control group (P < 0.0001, P = 0.0102). However, disease‐specific survival for resected cases was not significantly different between the two groups (P = 0.0725).ConclusionsIn elderly patients, the reason for the poor prognosis is the high rate of advanced stage and the high rate of death from other diseases. J. Surg. Oncol. 2003;84:132–136. © 2003 Wiley‐Liss, Inc.
Prospective evaluation of prognostic factors in patients with colorectal cancer undergoing curative resection
Authors: Fujita Shin , Shimoda Tadakazu , Yoshimura Kimio , Yamamoto Seiichiro , Akasu Takayuki , Moriya Yoshihiro 
Published: October 2003

AbstractBackground and ObjectivesStreak type, defined by the presence of white streaks at the advancing margin of tumor invasion; focal dedifferentiation, seen as undifferentiated cancer cells with an infiltrative pattern at the invasive front; and perineural invasion have been demonstrated to be prognostic factors in patients with colorectal cancer. We performed a prospective study to examine the usefulness of these features as prognostic factors.MethodsWe reviewed a total of 391 patients who underwent curative surgery for colorectal cancer between May 1997 and June 1999. Of these, 50 patients with multiple cancers were excluded, and a total of 341 patients were finally entered into the study.ResultsOf the prognostic factors investigated, depth of invasion, lymph node status, lymphatic invasion, venous invasion, growth type, streak type, focal dedifferentiation, and perineural invasion were significant prognostic factors in univariate analysis. In multivariate analysis, lymph node status, depth of invasion, and perineural invasion were significant prognostic factors. The survival of patients with perineural invasion was significantly poorer than that of patients without perineural invasion in both stage II and III cancer.ConclusionsPerineural invasion status can be used to facilitate the selection of colorectal cancer patients for adjuvant chemotherapy and should be described in routine pathology reports. J. Surg. Oncol. 2003;84:127–131. © 2003 Wiley‐Liss, Inc.
Inactivation of p16INK4a by CpG hypermethylation is not a frequent event in colorectal cancer
Authors: Norrie Mark W.A. , Hawkins Nicholas J. , Todd Alison V. , Meagher Alan P. , O'Connor Terence W. , Ward Robyn L. 
Published: October 2003

AbstractBackround and ObjectivesGene promoter hypermethylation is common in colorectal cancer and is associated with transcriptional silencing. However, the clinicopathological significance of p16INK4a gene silencing with hypermethylation is unknown. Therefore, the aim of this study was to analyze loss of p16 expression and its relationship to hypermethylation in sporadic colorectal cancer.MethodsTissue from 426 colorectal cancers underwent histological analysis. Immunohistochemistry was performed for p16 expression. Fresh tumor DNA was analyzed for microsatellite instability (MSI) and the presence of K‐ras mutations. In addition, DNA was bisulphite‐modified and analyzed for p16INK4a promoter methylation by methylation‐specific PCR.ResultsThere were 25% of tumors with p16INK4a promoter hypermethylation. These tumors were associated with older patients, right‐sidedness, MSI and were poorly differentiated, mucinous, and had intraepithelial and peritumoral lymphocytes and a Crohn's‐type lymphocytic reaction (P < 0.05). However, only right‐sidedness was significant on multivariate analysis (P < 0.001). Only 8.1% of tumors did not express p16, and this was associated with hypermethylation (P < 0.05).Conclusionp16INK4a promoter methylation, although common in colorectal cancer, does not result in a clinicopathologically distinct subgroup of tumors and infrequently results in transcriptional silencing. This suggests that p16INK4a gene inactivation does not have an important role in the pathogenesis of sporadic colorectal cancer. J. Surg. Oncol. 2003;84:143–150. © 2003 Wiley‐Liss, Inc.
Application of direct nonlinear regression from single TG curve to compounds undergoing simple and complex thermal decompositions
Authors: Rodante Fabrizio , Vecchio Stefano , Slovák Václav 
Published: October 2003

AbstractNonlinear regression of the basic kinetic equation was used to determine kinetic parameters of simple and complex decomposition processes related to some pesticides and pharmaceutical substances. The method for this calculation was carried out using a single TG curve.These values were compared with those obtained with model‐fitting and model‐free methods.Nonlinear regression method is able to define a single mechanism for compounds undergoing one or few steps of decomposition processes. For compounds that undergo many steps of decomposition processes, only the mechanisms of some of them can be hypothesized. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 611–622, 2003
Kinetics and mechanism for the thermal chlorination of chloroform in the gas phase: Inclusion of HCl elimination from CHCl3
Authors: Zhu Li , Bozzelli Joseph W. 
Published: October 2003

AbstractHCl elimination from chloroform is shown to be the lowest energy channel for initiation in the thermal conversion of chloroform to CCl4, with chlorine gas in the temperature range of 573–635 K. Literature data on this reaction is surveyed and we further estimate its kinetic parameters using ab initio and density functional calculations at the G3//B3LYP/6‐311G(d,p) level. Rate constants are estimated and reported as functions of pressure and temperature using quantum RRK theory for k(E) and master equation analysis for fall‐off. The high‐pressure limit rate constant of this channel is k(CHCl3 → 1CCl2 + HCl) = 5.84 × 1040 × T−8.7 exp(−63.9 kcal/mol/RT) s−1, which is in good agreement with literature values. The reactions of 1CCl2 with itself, with CCl3, and with CHCl3 are incorporated in a detailed mechanistic analysis for the CHCl3 + Cl2 reaction system. Inclusion of these reactions does not significantly change the mechanism predictions of Cl2 concentration profiles in previous studies (Huybrechts, Hubin, and Van Mele, Int J Chem Kinet 2000, 32, 466) over the temperature range of 573–635 K; but Cl2, CHCl3, C2Cl6 species profiles are significantly different at elevated temperatures. Inclusion of the 1CCl2 + Cl2 → CCl3 + Cl reaction (abstraction and chain branching), which is found to have dramatic effects on the ability of the model to match to the experimental data, is discussed. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 647–660, 2003
Pyrolysis of liquefied petroleum gas assisted by radicals desorbed from mesh catalyst surface
Authors: Quah Eugene B. H. , Li Chun‐Zhu 
Published: October 2003

AbstractThe purpose of this study is to understand the reactions on the catalyst surface and in the gas phase during the catalytic pyrolysis of light hydrocarbons. To avoid the complexity of internal pore diffusion and heat transfer limitation, nickel mesh without pore structure was used as a catalyst for the catalytic pyrolysis of a commercial liquefied petroleum gas (LPG) sample in a quartz tube reactor and in a wire‐mesh reactor over a temperature range of 600–850°C. With a Ni mesh catalyst, no catalyst deactivation associated with coke formation was observed at high gas flow rate. Our experimental results indicate that the desorption of radicals from the catalyst surface is an important process in the catalytic pyrolysis of LPG using the Ni mesh catalyst. The desorption of radicals across the gas–catalyst interface is greatly facilitated by increasing gas flow rate passing through the mesh. The desorbed radicals would initiate and/or enhance the gas‐phase radical chain reactions and lead to improved reaction rates for the pyrolysis of LPG although the product selectivities remained unchanged. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 637–646, 2003
Spectral, kinetic, and redox properties of basic fuchsin in homogeneous aqueous and sodium dodecyl sulfate micellar media
Authors: Ramanathan N. , Priyadarsini K. I. , Guha S. N. , Mohan H. 
Published: October 2003

AbstractEffect of anionic surfactant on the optical absorption spectra and redox reaction of basic fuchsin, a cationic dye, has been studied. Increase in the absorbance of the dye band at 546 nm with sodium dodecyl sulfate (SDS) is assigned to the incorporation of the dye in the surfactant micelles with critical micellar concentration (CMC) of 7.3 × 10−3 mol dm−3. At low surfactant concentration (<5 × 10−3 mol dm−3) decrease in the absorbance of the dye band at 546 nm is attributed to the formation of a dye–surfactant complex (1:1). The environment, in terms of dielectric constant, experienced by basic fuchsin inside the surfactant micelles has been estimated. The association constant (KA) for the formation of dye–SDS complex and the binding constant (KB) for the micellization of dye are determined. Stopped‐flow studies, in the premicellar region, indicated simultaneous depletion of dye absorption and formation of new band at 490 nm with a distinct isosbestic point at 520 nm and the rate constant for this region increased with increasing SDS concentration. The reaction of hydrated electron with the dye and the decay of the semireduced dye are observed to be slowed down in the presence of SDS. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 629–636, 2003
The thioredoxin system—From science to clinic
Authors: Gromer Stephan , Urig Sabine , Becker Katja 
Published: October 2003

AbstractThe thioredoxin system—formed by thioredoxin reductase and its characteristic substrate thioredoxin—is an important constituent of the intracellular redox milieu. Interactions with many different metabolic pathways such as DNA‐synthesis, selenium metabolism, and the antioxidative network as well as significant species differences render this system an attractive target for chemotherapeutic approaches in many fields of medicine—ranging from infectious diseases to cancer therapy. In this review we will present and evaluate the preclinical and clinical results available today. Current trends in drug development are emphasized. © 2003 Wiley Periodicals, Inc. Med Res Rev, 24, No. 1, 40–89, 2004
Chemistry, biological activity, and chemotherapeutic potential of betulinic acid for the prevention and treatment of cancer and HIV infection
Authors: Cichewicz Robert H. , Kouzi Samir A. 
Published: October 2003

Abstract3β‐Hydroxy‐lup‐20(29)‐en‐28‐oic acid (betulinic acid) is a pentacyclic lupane‐type triterpene that is widely distributed throughout the plant kingdom. A variety of biological activities have been ascribed to betulinic acid including anti‐inflammatory and in vitro antimalarial effects. However, betulinic acid is most highly regarded for its anti‐HIV‐1 activity and specific cytotoxicity against a variety of tumor cell lines. Interest in developing even more potent anti‐HIV agents based on betulinic acid has led to the discovery of a host of highly active derivatives exhibiting greater potencies and better therapeutic indices than some current clinical anti‐HIV agents. While its mechanism of action has not been fully determined, it has been shown that some betulinic acid analogs disrupt viral fusion to the cell in a post‐binding step through interaction with the viral glycoprotein gp41 whereas others disrupt assembly and budding of the HIV‐1 virus. With regard to its anticancer properties, betulinic acid was previously reported to exhibit selective cytotoxicity against several melanoma‐derived cell lines. However, more recent work has demonstrated that betulinic acid is cytotoxic against other non‐melanoma (neuroectodermal and malignant brain tumor) human tumor varieties. Betulinic acid appears to function by means of inducing apoptosis in cells irrespective of their p53 status. Because of its selective cytotoxicity against tumor cells and favorable therapeutic index, even at doses up to 500 mg/kg body weight, betulinic acid is a very promising new chemotherapeutic agent for the treatment of HIV infection and cancer. © 2003 Wiley Periodicals, Inc. Med Res Rev, 24, No. 1, 90–114, 2004
Clinical significance of urokinase‐type plasminogen activator receptor (uPAR) expression in cancer
Authors: de Bock Charles Edo , Wang Yao 
Published: October 2003

AbstractThe involvement of the urokinase‐type plasminogen activator (uPA) system in particular has been extensively studied in the pathogenesis of cancer. The molecular role of the uPA receptor (uPAR) is well characterized with its participation in cell migration and extracellular matrix (ECM) degradation. Over‐expression of uPAR in cancer has been demonstrated in many studies and is considered an attractive target for anticancer agents. We and others have down‐regulated uPAR expression in an attempt to inhibit cancer metastasis based on its molecular role. Uniquely, uPAR which is a glycosyl phosphatidylinositol anchored protein is not only bound to the cell surface but also has a soluble form, suPAR. There is now accumulated clinical and experimental evidence supporting the significant role of uPAR and its soluble counterpart in a number of solid cancers. The expression of uPAR can be associated with tumor cells or stromal cells or both. Differences observed in the expression of uPAR using immunohistochemistry (IHC) are likely explained by the use of different antibodies and techniques rather than true cellular differences and are reviewed here. This review summarizes the clinical relevance of uPAR and its soluble form in the prognosis and diagnosis of different cancers. © 2003 Wiley Periodicals, Inc. Med Res Rev, 24, No. 1, 13–39, 2004
Intracellular cargo delivery using tat peptide and derivatives
Authors: Zhao Ming , Weissleder Ralph 
Published: October 2003

AbstractEfficient delivery of therapeutic and diagnostic agents across the plasma membrane is crucial in developing novel therapies. Membrane permeating peptides, in particular HIV‐1 tat peptide and its derivatives, have enabled the intracellular delivery of cargos of various sizes and physicochemical properties. This review summarizes the current knowledge of tat‐derived cell permeating peptides in the transduction of exogenous molecules/complexes. © 2003 Wiley Periodicals, Inc. Med Res Rev, 24, No. 1, 1–12, 2004
Update on HIV resistance and resistance testing
Authors: Sebastian Joseph , Faruki Hawazin 
Published: October 2003

AbstractThe introduction of highly active antiretroviral therapy, including a combination of antivirals directed at various steps in the viral life cycle, has led to significant decreases in morbidity and mortality associated with human immunodeficiency virus (HIV‐1) infections. Despite the availability of numerous antivirals, many extensively treated patients gradually loose the ability to control viral replication because of development of antiviral resistance. Laboratory tests have been developed and validated to assist in recognizing such resistance and to help predict which antivirals may be more likely to control viral replication in a given patient. Both genotypic and phenotypic assays have been developed to assess HIV‐1 antiviral resistance. The assay methodologies, including the advantages and disadvantages of each method, as well as the limitations of each method are reviewed. The ability to predict likely drug response from a genotype or a phenotype is continually evolving, and the more recently discovered mutation/drug resistance associations are discussed in terms of their implications for HIV resistance assays. To provide additional options for those who have developed resistance to all currently available drugs, new antivirals, such as the fusion inhibitors, are being developed. These new classes of antivirals block the HIV viral life cycle at sites other than reverse transcriptase and protease. Unique and novel resistance assays are being developed to measure HIV resistance to these new drugs. © 2003 Wiley Periodicals, Inc. Med Res Rev, 24, No. 1, 115–125, 2004
On the competitive growth of two sand heaps
Authors: Kuttler Christina 
Published: October 2003

AbstractA simple quasistationary model for the growth of 1D sand heaps in form of a non‐linear system of ordinary differential equations is presented. The basic assumption for the model is the instantaneous deposition of the matter which is poured by punctiform sources. Existence and uniqueness of the solution is shown, and the qualitative evolution, especially the overrun phenomenon, is described. Copyright © 2003 John Wiley & Sons, Ltd.
Pseudo‐reflection phenomena for singularities in thin elastic shells
Authors: Karamian‐Surville P. , Sanchez‐Hubert J. , Sanchez Palencia E. 
Published: October 2003

AbstractWe consider problems of statics of thin elastic shells with hyperbolic middle surface subjected to boundary conditions ensuring the geometric rigidity of the surface. The asymptotic behaviour of the solutions when the relative thickness tends to zero is then given by the membrane approximation. It is a hyperbolic problem propagating singularities along the characteristics. We address here the reflection phenomena when the propagated singularities arrive to a boundary. As the boundary conditions are not the classical ones for a hyperbolic system, there are various cases of reflection. Roughly speaking, singularities provoked elsewhere are not reflected at all at a free boundary, whereas at a fixed (or clamped) boundary the reflected singularity is less singular than the incident one. Reflection of singularities provoked along a non‐characteristic curve C are also considered. Copyright © 2003 John Wiley & Sons, Ltd.
Conservation laws for Lotka–Volterra models
Authors: Schimming Rainer 
Published: October 2003

AbstractWe derive necessary and sufficient conditions on a Lotka–Volterra model to admit a conservation law of Volterra's type. The result and the proof for the corresponding linear algebra problem are given in graph‐theoretical terms; they refer to the directed graph which is defined by the coefficients of the differential equation system. Copyright © 2003 John Wiley & Sons, Ltd.
Modelling and optimal control of coupled structural acoustic systems with piezoelectric elements
Authors: Litvinov W. G. , Kröplin B. 
Published: October 2003

AbstractWe construct a model of a shell with piezoelectric elements (patches) that take into account the mutual influence of deformations and electric fields. Coupled problems for the shell with piezoelectric patches and an acoustic field, are studied and results on the existence and the uniqueness are obtained. For this system we consider an optimal control problem on noise attenuation and obtain results on the existence, the uniqueness, necessary and sufficient conditions of optimality. Copyright © 2003 John Wiley & Sons, Ltd.