bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spectroscopic and molecular modeling studies of the interaction between cytidine and human serum albumin and its analytical application
Authors: Cui Fengling , Wang Junli , Yao Xiaojun , Wang Li , Zhang Qiangzhai , Qu Guirong 
Published: July 2007

AbstractIn this study, the interaction between cytidine and human serum albumin (HSA) was investigated for the first time by fluorescence spectroscopy in combination with UV absorption spectrum and molecular modeling under simulative physiological conditions. Experimental results indicated that cytidine had a strong ability to quench the intrinsic fluorescence of human serum albumin. The binding constants (K) at different temperatures, thermodynamic parameter enthalpy changes (ΔH) and entropy changes (ΔS) of HSA‐cytidine had been calculated according to the relevant fluorescence data, which indicated that the hydrophobic and electrostatic interactions played a major role, which was in agreement with the results of molecular modeling study. In addition, the effects of other ions on the binding constants were also studied. Furthermore, synchronous fluorescence technology was successfully applied to the determination of human serum albumin added into the cytidine solution. © 2007 Wiley Periodicals, Inc. Biopolymers 87: 174–182, 2007.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Astressin‐amide and astressin‐acid are structurally different in dimethylsulfoxide
Authors: Grace Christy Rani R. , Cervini Laura , Gulyas Jozsef , Rivier Jean , Riek Roland 
Published: July 2007

AbstractThe C‐terminally amidated CRF antagonist astressin binds to CRF‐R1 or CRF‐R2 receptors with low nanomolar affinity while the corresponding astressin‐acid has >100 times less affinity. To understand the role of the amide group in binding, the conformations of astressin‐amide and astressin‐acid were studied in DMSO using NMR techniques. The 3D NMR structures show that the backbones of both analogs prefer an α‐helical conformation, with a small kink around Gln26. However, astressin‐amide has a well‐defined helical structure from Leu27 to Ile41 and a conformation very similar to the bioactive conformation reported by our group (Grace et al., Proc Natl Acad Sci USA 2007, 104, 4858–4863). In contrast, astressin‐acid has an irregular helical conformation from Arg35 onward, including a rearrangement of the side chains in that region. This structural difference highlights the crucial role of the C‐terminal amidation for stabilization of astressin's bioactive conformation. © 2007 Wiley Periodicals, Inc. Biopolymers 87: 196–205, 2007.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Optimal design of metabolic flux analysis experiments for anchorage‐dependent mammalian cells using a cellular automaton model
Authors: Meadows Adam L. , Roy Siddhartha , Clark Douglas S. , Blanch Harvey W. 
Published: July 2007

AbstractMetabolic flux analysis (MFA) is widely used to quantify metabolic pathway activity. Typical applications involve isotopically labeled substrates, which require both metabolic and isotopic steady states for simplified data analysis. For bacterial systems, these steady states are readily achieved in chemostat cultures. However, mammalian cells are often anchorage dependent and experiments are typically conducted in batch or fed‐batch systems, such as tissue culture dishes or microcarrier‐containing bioreactors. Surface adherence may cause deviations from exponential growth, resulting in metabolically heterogeneous populations and a varying number of cellular “nearest neighbors” that may affect the observed metabolism. Here, we discuss different growth models suitable for deconvoluting these effects and their application to the design and optimization of MFA experiments employing surface‐adherent mammalian cells. We describe a stochastic two‐dimensional (2D) cellular automaton model, with empirical descriptions of cell number and non‐growing cell fraction, suitable for easy application to most anchorage‐dependent mammalian cell cultures. Model utility was verified by studying the impact of contact inhibition on the growth rate, specific extracellular flux rates, and isotopic labeling in lactate for MCF7 cells, a commonly studied breast cancer cell line. The model successfully defined the time over which exponential growth and a metabolically homogeneous growing cell population could be assumed. The cellular automaton model developed is shown to be a useful tool in designing optimal MFA experiments. Biotechnol. Bioeng. 2007; 98: 221–229. © 2007 Wiley Periodicals, Inc.
Monitoring of dissolved oxygen and cellular bioenergetics within a pancreatic substitute
Authors: Gross Jeffrey D. , Long R.C. , Constantinidis I. , Sambanis A. 
Published: July 2007

AbstractThis work investigated the use of nuclear magnetic resonance (NMR) spectroscopy in combination with a mathematical model of an encapsulated cell system as a method for rapidly assessing the status of a pancreatic substitute. To validate this method, an in vitro experiment was performed in which the encapsulated cells were perfused in an NMR‐compatible system and the dissolved oxygen (DO) concentration of the perfusing medium was lowered from 0.20 to 0.05 mM, then returned to 0.20 mM in a stepwise fashion. The cellular metabolic activity and bioenergetics were evaluated by measuring the oxygen consumption rate (via DO sensors) and nucleotide triphosphate levels (via 31P NMR). By incorporating a perfluorocarbon emulsion into the alginate beads, the cellular oxygenation state was monitored by measuring the average intrabead DO (AIDO) concentration by 19F NMR. The in vitro measurements were then compared with model predictions based on the measured external DO concentration and time. Model‐predicted cell growth and AIDO closely matched the experimentally acquired data. As the DO concentrations both external to and within the pancreatic substitute are needed to apply this methodology in vivo, the feasibility of measuring the DO concentration from two distinct bead populations implanted in the peritoneal cavity of mice was established. It is concluded that PFC incorporation and 19F NMR measurements, in combination with a mechanistic model of the encapsulated system, allow the tracking of the state of a pancreatic substitute in vitro and potentially in vivo. Biotechnol. Bioeng. 2007; 98: 261–270. © 2007 Wiley Periodicals, Inc.
Rectal cancer surgery without mechanical bowel preparation
Authors: Bretagnol F , Alves A , Ricci A , Valleur P , Panis Y 
Published: July 2007

Abstract

Background
Eight randomized clinical trials and two meta-analyses recently questioned the value of preoperative mechanical bowel preparation (MBP) in colorectal surgery. However, very few patients having rectal surgery were included in these studies. The aim of this study was to assess whether rectal cancer surgery can be performed safely without MBP.

Methods
The postoperative course was assessed in 52 consecutive unselected patients who underwent rectal cancer resection and sphincter preservation without MBP. This group was compared with a group of 61 matched patients in whom MBP was performed before surgery.

Results
The overall morbidity rate after rectal resection was higher in patients who had MBP than in those who did not (51 versus 31 per cent; P = 0·036). The incidence of symptomatic anastomotic leakage was similar in the two groups (8 versus 10 per cent respectively; P = 1·000). Although not significant, peritonitis occurred more frequently in the absence of MBP (2 versus 6 per cent; P = 0·294). A trend towards a higher rate of infectious complications was noted in patients who had MBP (23 versus 12 per cent; P = 0·141), but MBP was associated with a significantly higher rate of infectious extra-abdominal complications (11 versus 0 per cent; P = 0·014). Mean hospital stay was significantly longer in the MBP group (12 versus 10 days; P = 0·022).

Conclusion
Elective rectal surgery for cancer without MBP may be associated with reduced postoperative morbidity.
Photoreactivity and Photopolymerization of Silicon‐Bridged [1]Ferrocenophanes in the Presence of Terpyridine Initiators: Unprecedented Cleavage of Both Iron–Cyclopentadienyl Bonds in the Presence of Chlorosilanes
Authors: Chan Wing Yan , Lough Alan J. , Manners Ian 
Published: July 2007

AbstractThe photopolymerisation of sila[1]ferrocenophane [Fe(η‐C5H4)2SiMe2] (3) with 4,4′,4′′‐tri‐tert‐butyl‐2,2′:6′,2′′‐terpyridine (tBu3terpy) as initiator has been explored. High‐molecular‐weight polyferrocenylsilane (PFS) [{Fe(η‐C5H4)2SiMe2}n] (5) was formed in high yield when a stoichiometric amount of tBu3terpy was used at 5 °C. Photopolymerisation of ferrocenophane 3 at higher temperatures gave PFS 5 in lower yield and with a reduced molecular weight as a result of a slower propagation rate. Remarkably, when Me3SiCl was added as a capping agent before photopolymerisation, subsequent photolysis of the reaction mixture resulted in the unprecedented cleavage of both iron–Cp bonds in ferrocenophane 3: iron(II) complex [Fe(tBu3terpy)2Cl2] (7Cl) was formed and the silane fragment (C5H4SiMe3)2SiMe2 (8) was released. The iron–Cp bond cleavage reaction also proceeded in ambient light, although longer reaction times were required. In addition, the unexpected cleavage chemistry in the presence of Me3SiCl was found to be applicable to other photoactive ferrocenes such as benzoylferrocene. For benzoylferrocene and ferrocenophane 3, the presence of metal‐to‐ligand charge transfer (MLCT) character in their low‐energy transitions in the visible region probably facilitates photolytic iron–Cp bond cleavage, but this reactivity is suppressed when the strength of the iron–Cp bond is increased by the presence of electron‐donating substituents on the cyclopentadienyl rings.
Shaping immunity in healthy and diseased tissues
Authors: Borst Jannie , Ricciardi‐Castagnoli Paola 
Published: July 2007

AbstractAbout one hundred immunologists recently met in Capo Caccia, Sardinia, for the first of three events that will comprise the EMBO Conference Series, organised by the ENII, on Molecular and Cellular Mechanisms of Immune Regulation. The 2007 Conference focused on how immunity is shaped in healthy and diseased tissues.
The Influence of the Gas Diffusion Layer on Water Management in Polymer Electrolyte Fuel Cells
Authors: Holmström N. , Ihonen J. , Lundblad A. , Lindbergh G. 
Published: July 2007

AbstractPerformance losses due to flooding of gas diffusion layers (GDLs) and flow fields as well as membrane dehydration are two of the major problems in PEFC. In this investigation, the effect of GDL on the cell water management in PEFC is studied using segmented and single cell experiments. The behaviour of four different commercial GDLs was investigated at both high and low inlet humidity conditions by galvanostatic fuel cell experiments. The influence of varying reactant humidity and gas composition was studied. The results at high inlet humidity show that none of the studied GDLs are significantly flooded on the anode side. On the other hand, when some of the GDLs are used on the cathode side they are flooded, leading to increased mass transfer losses. The results at low inlet humidity conditions show that the characteristics of the GDL influence the membrane hydration. It is also shown that inlet humidity on the anode side has a major effect on flooding at the cathode.
Second primary head and neck tumor risk in patients with cervical cancer—SEER data analysis
Authors: Rose Ragin Camille C. , Taioli Emanuela 
Published: July 2007

AbstractBackground.Human papillomavirus (HPV) causes >99% of cervical carcinomas and is associated with approximately 25% of head and neck squamous cell carcinomas (HNSCCs). The role of HPV infection in HNSCC development after a first diagnosis of cervical cancer is unknown.Methods.Using the National Cancer Institute's Surveillance, Epidemiology, and End Results data, the authors compared the risk of second primary cancer (SPC) HNSCC in patients with cervical cancer with the general population and with females with other primary cancers.Results.The lifetime risk of SPC HNSCC for patients with cervical cancer was higher than in the general population (standardized incidence ratio [SIR]: 1.7). When compared with that in females with other cancers, the risk of anogenital and oropharyngeal SPC was in excess, but not of SPC in the oral cavity.Conclusion.Patients with cervical cancer develop an excess SPC HNSCC in comparison with females with other cancers. A possible role of HPV is suggested. © 2007 Wiley Periodicals, Inc. Head Neck, 2008
In vitro radiation‐induced expression of XPC mRNA as a possible biomarker for developing adverse reactions during radiotherapy
Authors: Wiebalk Katrin , Schmezer Peter , Kropp Silke , Chang‐Claude Jenny , Celebi Oktay , Debus Jürgen , Bartsch Helmut , Popanda Odilia 
Published: July 2007

AbstractRepair of radiation‐induced DNA damage is believed to play a critical role in developing adverse reactions during radiotherapy. Ionizing radiation induces transcription of several DNA repair genes including XPC as a part of the p53‐transmitted stress response. XPC gene induction was measured to analyze whether it predicts occurrence of therapy‐related acute side effects. Prostate cancer patients (n = 406) receiving radiotherapy were monitored for development of acute adverse effects using common toxicity criteria. For gene induction analysis, lymphocytes from 99 patients were selected according to their observed grade of clinical side effects. Cells were irradiated in vitro with 5 Gy and analyzed after 4 hr for XPC gene induction using reverse transcription and quantitative real‐time PCR. Analysis of modulation of XPC induction by personal, clinical or lifestyle factors was included. Inter‐individual induction of XPC expression by ionizing radiation varied up to 20‐fold (0.29–5.77) and was significantly higher in current or exsmokers than in never‐smokers (p value: 0.008). Patients with XPC induction above the 90th percentile compared to those with lower induction levels were at increased risk of suffering from adverse reactions during radiotherapy (odds ratio 5.3, 95% confidence interval 1.2–24.5; adjusted for smoking). In summary, XPC mRNA levels induced by ionizing radiation were shown for the first time to be strongly affected by smoking and to be associated with an approximately 5‐fold increased risk for developing acute side effects of radiotherapy. The predictive value of DNA damage‐induced XPC levels as a possible biomarker for radiosensitivity has to be further investigated. © 2007 Wiley‐Liss, Inc.
Clinicopathological characteristics of patients with hepatocellular carcinoma after hepatectomy: Relationship with status of viral hepatitis
Authors: Nanashima Atsushi , Abo Takafumi , Sumida Yorihisa , Takeshita Hiroaki , Hidaka Shigekazu , Furukawa Katsurou , Sawai Terumitsu , Yasutake Toru , Masuda Junichi , Morisaki Tomohito , Nagayasu Takeshi 
Published: July 2007

AbstractBackground and ObjectivesViral hepatitis may modulate the status of liver dysfunction, tumor biology, and postoperative course in patients with hepatocellular carcinoma (HCC).MethodsTo determine the characteristics of HCC in different types of viral hepatitis, we conducted a comparative analysis of clinicopathological features and outcomes in 243 Japanese HCC patients following hepatic resection. Patients were divided into four groups; non‐B‐non‐C group, hepatitis B (HBV) group, hepatitis C (HCV) group, and co‐infection with HB, and HC (HBCV) group.ResultsLiver function was worst and prevalence of cirrhosis was highest in HBCV group than in compare to HBV and non‐B‐non‐C group. The prevalence rates of intrahepatic metastasis, tumor vascular involvement, and low curability in HBCV group were higher than in the other groups. Uncontrolled ascites and hepatic failure were significantly more common in HBCV group than other groups. The disease‐free and overall survival rates of non‐B‐non‐C group were better than those of the other groups; both survival rates were the worst in HBCV group than the other groups.ConclusionsHCC patients with co‐infection of HBV and HCV had poorer liver function and more advanced tumors compared with the other groups. This might explain the poor prognosis of such patients. J. Surg. Oncol. 2007;96:487–492. © 2007 Wiley‐Liss, Inc.
Computable metrization
Authors: Grubba Tanja , Schröder Matthias , Weihrauch Klaus 
Published: July 2007

AbstractEvery second‐countable regular topological space X is metrizable. For a given “computable” topological space satisfying an axiom of computable regularity M. Schröder [10] has constructed a computable metric. In this article we study whether this metric space (X, d) can be considered computationally as a subspace of some computable metric space [15]. While Schröder's construction is “pointless”, i. e., only sets of a countable base but no concrete points are known, for a computable metric space a concrete dense set of computable points is needed. But there may be no computable points in X. By converging sequences of basis sets instead of Cauchy sequences of points we construct a metric completion ($ \tilde X $, $ \tilde d $) of a space (X, d) together with a canonical representation $ \tilde X $, $ \tilde \delta $. We show that there is a computable embedding of (X, d) in ($ \tilde X $, $ \tilde d $) with computable inverse. Finally, we construct a notation of a dense set of points in ($ \tilde X $, $ \tilde d $) with computable mutual distances and prove that the Cauchy representation of the resulting computable metric space is equivalent to $ \tilde \delta $. Therefore, every computably regular space has a computable homeomorphic embedding in a computable metric space, which topologically is its completion. By the way we prove a computable Urysohn lemma. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Interaction of Sheep Bone Marrow Stromal Cells With Biodegradable Polyurethane Bone Substitutes
Authors: Schlickewei Carsten , Verrier Sophie , Lippross Sebastian , Pearce Simon , Alini Mauro , Gogolewski Sylwester 
Published: July 2007

AbstractSummary: Autogenous cancellous bone graft is often used in clinical practice to promote bone healing in large, critical‐size defects. Bone harvesting has numerous drawbacks which calls for new alternatives. Potentially, an alternative to bone grafting may be offered by a tissue engineering approach that utilizes a suitable scaffold seeded with osteogenic cells. In this study the interaction of sheep bone marrow stromal cells with biodegradable microporous polyurethane scaffolds designed as bone substitutes was investigated. The scaffolds were produced from the same polyurethane but had two different pore sizes in the ranges of 140–400 µm and 200–600 µm. The scaffolds were impregnated with platelet‐rich plasma or fibrin to evaluate whether impregnation affects cell attachment, growth and proliferation. It has been found that scaffolds promote attachment, differentiation and proliferation of sheep bone marrow stromal cells. The cells adhered well to the scaffold's surface and infiltrated its porous structure. The DNA content and the mRNA expression increased with time of culture. Histological and immunohistochemical stainings showed that the cells were viable and differentiated into osteoblasts. There was an evident effect of the scaffolds' pore size on cell attachment and proliferation. Cell growth was more efficient in the scaffolds with smaller pore sizes than in the scaffolds with larger pores. Scaffolds with larger pores underwent calcification. No calcium was found in the scaffolds with smaller pore sizes. The pore size had no effect on cell morphology. The stromal cells differentiated into osteoblasts, which process was more pronounced in the scaffolds with larger pores. Impregnation of the scaffolds with fibrin or platelet‐rich plasma facilitated cell growth and proliferation. This effect was more pronounced for scaffolds impregnated with platelet‐rich plasma than for scaffolds impregnated with fibrin.
Effects of Laminin For Osteogenesis in Porous Hydroxyapatite
Authors: Yoshikawa Masataka , Tsuji Norimasa , Shimomura Yasunori , Hayashi Hiroyuki , Ohgushi Hajime 
Published: July 2007

AbstractSummery: As a tooth is composed of hard tissue covering pulp, it may be suitable for tooth regeneration to use porous cylindrical hydroxyapatite (HA) scaffolds with a hollow center. Generally, in vivo examination, bone marrow cell suspension for osteogenesis in cell/HA composite scaffold without subculture is prepared at a density of 1 × 107 cells/ml or higher. In dentistry, stem cells would be obtained from tooth pulp. For dentine formation, a smaller number of stem cells must be used. In this study, a suspension of rat bone marrow cells at 1 × 106 cells/ml of density was prepared to estimate the adhesive effect of laminin. After immersion of HA scaffold in laminin solution, bone marrow cells were seeded in the pores of the HA scaffolds by immersion in the cell suspension for preparing the cell/HA composite scaffolds. The specimens were respectively implanted in the dorsal subcutis of 7‐week‐old male Fischer 344 rats for 4 weeks for histological examination. Comparing with the results of in vivo examination, alkaline phosphatase activity of bone marrow cells on laminin‐coated plate with and without dexamethasone cultured for 2 weeks was measured in vitro. It was considered that laminin contributed to bone formation in pores of a scaffold.
In Vitro Investigation on Interaction of Ranitidine Hydrochloride in the Presence of Cross‐Linked Carboxymethyl Cellulose Sodium.
Authors: Grimling B. , Pluta J. 
Published: July 2007

AbstractSummary: The adsorbance of ranitidine hydrochloride – drug selective H2 histamine receptor inhibitor used In the treatment of gastric and duodenal ulcer was investigated in the presence of croscarmellose, a cross‐ linked polymer of polysaccharide character used as a swelling additive in oral pharmaceutical formulations – capsules, tablets and granules.The evaluation of adsorbance capability was carried out by means of a statistical method in in vitro conditions, taking into account environmental pH, concentration of the investigated drug as well as the properties of the polymer. Obtained results prove that the analyzed active agent is adsorbed on polymer at all the investigated pH ranges and the capability of polymer binding depends on environmental pH. The highest binding capability was revealed in samples with pH of 7.6, (adsorbance capacity k = 0.6958) while the lowest binding capability was observed at pH 1.5 (adsorbance capacity k = 0.0005) in the presence of croscarmellose sodium. Level of adsorption depends on the analyzed drug concentration and adsorption on polymer in increasing concentration and pH environment.