bluuebunny/crossref_metadata_2025 huggingface dataset:
Fat cell invasion in long‐term denervated skeletal muscle
Authors: Rodrigues Antonio de Castro , Andreo Jesus Carlos , Júnior Geraldo Marco Rosa , dos Santos Nícolas Bertolaccini , Moraes Luis Henrique Rapucci , Lauris José Roberto P.
Published: October 2007

There are several differences between red and white muscles submitted to different experimental conditions, especially following denervation: a) denervation atrophy is more pronounced in red than white muscles; b) the size of the fibers in the red muscles does not vary between different parts of the muscle before and after denervation, when compared to white muscles; c) the regional difference in the white muscles initially more pronounced after denervation than red muscle; d) red muscle fibers and fibers of the deep white muscle present degenerative changes such as disordered myofibrils and sarcolemmal folds after long‐term denervation; e) myotube‐like fibers with central nuclei occur in the red muscle more rapidly than white after denervation. Denervation of skeletal muscles causes, in addition to fibers atrophy, loss of fibers with subsequent regeneration, but the extent of fat cell percentage invasion is currently unknown. The present article describes a quantitative study on fat cell invasion percentage in red m. soleus and white m. extensor digitorum longus (EDL) rat muscles at 7 weeks for up to 32 weeks postdenervation. The results indicate that the percentage of fat cells increase after denervation and it is steeper than the age‐related fat invasion in normal muscles. The fat percentage invasion is more pronounced in red compared with white muscle. All experimental groups present a statistically significant difference as regard fat cell percentage invasion. © 2007 Wiley‐Liss, Inc. Microsurgery, 2007.
Polycondensation Kinetics of Lactic Acid
Authors: Harshe Yogesh M. , Storti Giuseppe , Morbidelli Massimo , Gelosa Simone , Moscatelli Davide
Published: October 2007

The direct polycondensation of D,L‐lactic acid in the absence and presence of different catalysts at various temperatures has been studied experimentally. Two types of reactions were carried out, one under closed conditions to estimate the equilibrium constant and the other under flow of nitrogen to estimate the polymerization rate constant. A mathematical model was developed based on a suitable kinetic scheme for polycondensation reaction accounting for the rate of water removal. The effects of different operating conditions (temperature and pressure) on the average molecular weight of the polymer have been explored through experiments and model simulations.

magnified image
“Living” Free Radical Polymerization in Tubular Reactors. I. Modeling of the Complete Molecular Weight Distribution Using Probability Generating Functions
Authors: Asteasuain Mariano , Soares Matheus , Lenzi Marcelo K. , Cunningham Michael , Sarmoria Claudia , Pinto José Carlos , Brandolin Adriana
Published: October 2007

This is the first of a series of works aiming at developing a tool for designing “living” free radical polymerization processes in tubular reactors, in order to achieve tailor‐made MWDs. A mathematical model of the nitroxide‐mediated controlled free radical polymerization is built and implemented to predict the complete MWD. It is shown that this objective may be achieved accurately and efficiently by means of the probability generating function (pgf) transformation. Comparison with experimental data is good. The potential of the resulting model for optimization activities involving the complete MWD is also shown.

magnified image
Normal axonal ion channel function in large peripheral nerve fibers following chronic ciguatera sensitization
Authors: Vucic Steve , Kiernan Matthew C.
Published: October 2007

Although the acute clinical effects of ciguatera poisoning, due to ingestion of ciguatoxin, are mediated by activation of transient Na+ channels, the mechanisms underlying ciguatera sensitization remain undefined. Axonal excitability studies were performed by stimulating the median motor and sensory nerves in two patients with ciguatera sensitization. Excitability parameters were all within normal limits, thereby arguing against dysfunction of axonal membrane ion channels in large‐diameter fibers in ciguatera sensitization. Muscle Nerve, 2007
Three‐dimensional mapping of lingual myoarchitecture by diffusion tensor MRI
Authors: Kim Sungheon , Barnett Alan S. , Pierpaoli Carlo , Chi‐Fishman Gloria
Published: October 2007

This study was performed to assess the feasibility of investigating the complex lingual myoarchitecture through segmentation of muscles from diffusion tensor imaging (DTI) data. The primary eigenvectors were found to be adequate for delineating the superior and inferior longitudinalis, genioglossus, and hyoglossus. The tertiary eigenvector orientations effectively revealed the homogeneous and systematic change of muscle orientation in the tongue core. In the longitudinalis near the tongue tip, the secondary eigenvectors were oriented in the radial direction. Lingual muscles were segmented using two methods: modified directional correlation (DC) and tensor coherence (TC) methods. The DC method, based on one eigenvector, was found to be inadequate for lingual muscle segmentation, whereas the TC method, based on the tensor shape and orientation, was used successfully to segment most lingual muscles. The segmentation result was used to report the diffusion tensor properties of individual lingual muscles. Also found was a continuous change in skewness of the intrinsic tongue core from negative in the anterior region to positive in the posterior region. DTI and the proposed segmentation method provide an adequate means of imaging and visualizing the complex, compartmentalized musculature of the tongue. The potential for in vivo research and clinical applications is demonstrated. Copyright © 2007 John Wiley & Sons, Ltd.
A Hamiltonian particle method for non‐linear elastodynamics
Authors: Suzuki Yukihito , Koshizuka Seiichi
Published: October 2007

Particle methods are meshless simulation techniques in which motion of continua is approximated by discrete dynamics of a finite number of particles. They have a great degree of flexibility, for instance, in dealing with complex large deformations or the fragmentation of solids. In this paper, a particle method for non‐linear elastodynamics of compressible and incompressible materials is developed based on a discretization of the Lagrangian from which the governing equations of elastodynamics are derived using the principle of least action. The discretized Lagrangian leads to a finite‐dimensional Hamiltonian system via the Legendre transformation. If the material is incompressible, the Hamiltonian system is accompanied by holonomic constraints. Depending on whether the material is compressible or incompressible, the symplectic scheme adopted for numerical time integration is either the Störmer/Verlet scheme or the RATTLE method, respectively. The resulting particle method inherits the symplectic structure possessed by the governing equations of elastodynamics. In the case of incompressible materials, incompressibility is strictly enforced at each time step. Some numerical tests indicate the excellence of the method for conservation of mechanical energy besides that of linear and angular momenta. Copyright © 2007 John Wiley & Sons, Ltd.
The theologies of transparency in Europe: the limits and possibilities of ‘fusion’ in the EU transparency regime
Authors: Billet Steven
Published: October 2007

The consideration of a transparency regime for the European Union has stimulated considerable response from the Brussels lobbying community. Somewhat predictably, the responses have congregated about two poles: one represented by a strident group of reform activists calling for complete openness with a strong legal component, the other taking a minimalist self‐regulatory approach to the most fundamental issues. The basic positions of the competing sides seem to be immovable; embraced with all the fervour of religious ‘true believers’. At first blush the possibility for a meaningful compromise seems remote. However, the submissions may offer a limited way forward based on a fusion of principles held by many on both sides of the issue.

Copyright © 2007 John Wiley & Sons, Ltd.
The determinants of corporate political strategy in Chinese transition
Authors: Tian Zhilong , Deng Xinming
Published: October 2007

Corporate political strategy (CPS) formulation in Chinese transition is an area with little empirical work. We fill this gap validly and the primary focus of this study is to examine the firm‐ and industry‐level factors influencing Chinese firms' political strategy choice. Empirical support is found for the taxonomy of corporate political strategies in Chinese transition—that is direct participation strategy, financial incentive strategy, prolocutor strategy, institution innovation strategy, government association strategy and government involvement strategy. The results indicate that there is no consistently significant firm‐ and industry‐level predictor of all six political strategies and we explore what determinants are related to each specific decision independently. We also verify the random effects of industry‐level variables and our hypotheses are tested through using general evaluation equations (GEEs). Our study aims to be helpful to point managers toward both industrial environments and internal resources to consider when making appropriate political strategy choices and thus improve Chinese firms' strategy management level. Some implications of findings are also discussed finally.

Copyright © 2007 John Wiley & Sons, Ltd.
Managed Care in the USA: origins, HMO strategies and the marketing of health services
Authors: Simonet Daniel
Published: October 2007

HMOs appeared in the 1970s in a context of increasing health‐care expenditure. These organizations now provide care to an increasing share of the general population, offering cost/effectiveness studies and sophisticated cost‐control mechanisms directed at care providers and patients. The following article reviews the history of Managed Care organizations, details the service they offer, discusses the current difficulties that have forced them to withdraw from some market segments and considers what prompted the government to intervene to protect patients' interests. The paper also describes the growing hostility of patients and physicians to Managed Care.

Copyright © 2007 John Wiley & Sons, Ltd.
But what do they really think? Identifying consumers' values relevant to adopting biotechnologically produced foods
Authors: Grantham Susan
Published: October 2007

Much has been written about the media's importance in the formation of attitudes toward new technologies such as biotechnology. However, little has been published regarding consumer‐held values that play such an important role in forming these attitudes and which ultimately play a role in whether a product is adopted. Understanding how the product will complement, or clash, with, the publics' values is crucial in developing strategic communication plans. Developing Means‐End Chains via Laddering Theory to document users' values has been a useful research method in understanding the attributes and consequences associated with a product that may lead to acceptance by the general public. The purpose of this exploratory research was to identify the values consumers held toward foods created through biotechnological methods and the supporting attributes and consequences that supported those values. The findings indicate that, in this study, consumers felt no differently toward products developed using traditional agricultural methods versus biotechnological methods because the participants overwhelmingly relied on government agencies to ensure that their food was safe. The values identified in this study may provide a common ground for communicating about biotechnologically produced foods.

Copyright © 2007 John Wiley & Sons, Ltd.
Liver expression of proteins controlling interferon‐mediated signalling as predictive factors in the response to therapy in patients with hepatitis C virus infection
Authors: Bautista D , Bermúdez‐Silva FJ , Lasarte JJ , Rodriguez‐Fonseca F , Baixeras E
Published: October 2007

Combination therapy with interferon‐alpha (IFNα) and ribavirin is the current treatment of choice for hepatitis C virus (HCV) infection. However, an important number of patients fail to respond to this therapeutic strategy. Factors determining IFN responsiveness are not well understood, and assessment of biomarkers that predict the response to IFN therapy in HCV patients is necessary. Several studies show that particular HCV proteins are able to block IFN function through interaction with important IFN‐signal mediators, such as signal transducers and activators of transcription (STATs). We performed immunostaining analysis of STATs in liver tissue from IFN‐responder vs. non‐responder HCV patients in order to compare the expression profile of these proteins between both groups. Tissue arrays of liver biopsies were used to study the expression of STAT1, STAT2, STAT5 and PIAS1 (protein inhibitor of activated STAT1). Robust and higher expression levels of STAT1, STAT2 and STAT5 in liver tissue from HCV patients were found when compared with samples from healthy donors. However, no significant differences were observed between IFN‐responder and ‐non‐responder groups, but rather increasing levels of STAT1, STAT2 and STAT5 paralleled the degree of liver injury. Importantly, PIAS1 expression in the nucleus of most hepatocytes in HCV tissue biopsy sections, particularly of non‐responder HCV patients, strongly indicated a regulatory effect on STAT1–DNA binding, likely affecting the IFN late signalling. In conclusion, our evidence indicates that intense PIAS1 nuclear staining, widely distributed in hepatocytes of infected livers, could be a good predictive factor of a defective response to IFN treatment, and a biomarker that is easily detectable by immunostaining during standard histopathological liver biopsy analysis. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Over‐expression of S100A2 in pancreatic cancer correlates with progression and poor prognosis
Authors: Ohuchida K , Mizumoto K , Miyasaka Y , Yu J , Cui L , Yamaguchi H , Toma H , Takahata S , Sato N , Nagai E , Yamaguchi K , Tsuneyoshi M , Tanaka M
Published: October 2007

Controversy exists regarding the clinical significance of S100A2 in the progression of tumours. In pancreatic cancer, little is known about the role of S100A2. The aim of this study was to clarify the clinical significance of S100A2 expression in pancreatic carcinogenesis. We microdissected invasive ductal carcinoma (IDC) cells from 22 lesions, pancreatic intraepithelial neoplasia (PanIN) cells from five lesions, intraductal papillary mucinous neoplasm (IPMN) cells from 38 lesions, pancreatitis‐affected epithelial (PAE) cells from 16 lesions, and normal ductal cells from 18 normal pancreatic tissues. S100A2 expression in 14 pancreatic cancer cell lines, microdissected cells and formalin‐fixed paraffin‐embedded (FFPE) samples was examined by quantitative reverse transcription‐polymerase chain reaction (qRT–PCR). Microdissection analyses revealed that IDC cells expressed higher levels of S100A2 than did IPMN, PAE or normal cells (all comparisons, p < 0.007). Cell lines from metastatic sites expressed higher levels of S100A2 than those from primary sites. PanIN cells expressed higher levels of S100A2 than normal cells (p = 0.018). IDC cells associated with poorly differentiated adenocarcinoma expressed higher levels of S100A2 than did IDC cells without poorly differentiated adenocarcinoma (p = 0.006). Analyses of FFPE samples revealed that levels of S100A2 were higher in samples from patients who survived < 1000 days after surgery than in those from patients who survived > 1000 days (p = 0.043). Immunohistochemical analysis was consistent with qRT–PCR. S100A2 may be a marker of tumour progression or prognosis in pancreatic carcinogenesis and pancreatic cancer. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Phase 1 trial of O6‐benzylguanine and BCNU in children with CNS tumors: A Children's Oncology Group study
Authors: Adams Denise M. , Zhou Tianni , Berg Stacey L. , Bernstein Mark , Neville Kathleen , Blaney Susan M.
Published: October 2007

Background

Efficacy of nitrosoureas is limited by host repair of drug‐induced alkylation. O6‐benzylguanine (O6‐BG), an inhibitor of host alkylation repair, and BCNU were studied in children with refractory/untreatable central nervous system tumors to determine dose‐limiting toxicities (DLTs) and maximum tolerated dose (MTD) of BCNU administered following O6‐BG.

Procedure

O6‐BG (120 mg/m2 IV over 1 hr) was followed by BCNU (IV over 1 hr). Cohorts of three to six patients were treated with escalating doses of BCNU. Courses were repeated every 6 weeks. Patients in Stage 1 were accrued irrespective of prior treatment. Once the MTD was exceeded, Stage II accrual was limited to less heavily pretreated patients (≤ two prior chemotherapy regimens, no prior central axis radiation, no prior bone marrow transplant, and no bone marrow involvement).

Results

Twelve patients in Stage I and 13 in Stage II (less heavily pretreated patients only) were evaluable for toxicity. The MTD of BCNU administered with O6‐BG (120 mg/m2 IV) was 58 mg/m2 in less‐heavily pretreated patients. Myelosuppression, which was cumulative in some patients receiving multiple cycles of therapy, was the predominate DLT. Twenty‐four patients were evaluable for response: after two courses of therapy, 6 had stable disease, 17 had progressive disease, and 1 patient had a minor response but progressed after four courses of therapy.

Conclusions

Based on lack of activity of this combination in adult phase II studies, no further testing of O6‐BG plus BCNU in children is planned. Strategies to decrease hematopoeitic toxicity of BCNU plus O6‐BG are required. Pediatr Blood Cancer 2008;50:549–553. © 2007 Wiley‐Liss, Inc.
Correction of chronic granulomatous disease after second unrelated‐donor umbilical cord blood transplantation
Authors: Parikh Suhag H. , Szabolcs Paul , Prasad Vinod K. , Lakshminarayanan Sonali , Martin Paul L. , Driscoll Timothy A. , Kurtzberg Joanne
Published: October 2007

Allogeneic hematopoietic stem cell transplantation (HSCT) is curative for chronic granulomatous disease (CGD), but many patients lack a suitably matched related donor. We report successful outcomes after mismatched, unrelated‐donor umbilical cord blood transplantation (uUCBT) in two boys with X‐linked CGD. Both patients experienced autologous recovery after first transplants, required second transplants to achieve durable donor engraftment, and are alive 27 and 15 months post‐transplant. Both had invasive fungal disease and received granulocyte transfusions. In conclusion, uUCBT is effective in children with CGD, but immunosuppression in the conditioning regimen may need to be increased to decrease the risk of graft rejection. Pediatr Blood Cancer © 2007 Wiley‐Liss, Inc.
Outcome of children with aplastic anemia treated with immunosuppressive therapy
Authors: Pongtanakul Bunchoo , Das Prabodh Kumar , Charpentier Karen , Dror Yigal
Published: October 2007

Background

Immunosuppressive therapy (IST) is the alternative treatment in children with aplastic anemia (AA) who do not have an HLA‐matched sibling. The aim of this study is to evaluate the outcome of children with AA treated with IST.

Methods

We retrospectively reviewed the hospital records of children with AA from 1984 to 2004, treated at our institution with antithymocyte globulin (ATG), cyclosporine (CS), and short course of prednisone.

Result

Forty‐two patients were treated with IST (24 boys, 18 girls); of whom 26% received G‐CSF. The median age at diagnosis was 8.5 years. Sixty‐nine, 19, and 12% were diagnosed with severe, very severe, and moderate AA, respectively. Twenty‐one percent had hepatitis‐associated AA. Median follow‐up time was 53.3 months. Sixty‐two percent had complete response; 19% had partial response. Two patients relapsed and received a second course of ATG; both had a partial response. The actuarial 5 years survival rate was 67.5%. Two patients developed myelodysplastic syndrome (MDS); both received long‐term G‐CSF and had partial response after two courses of IST. Fifteen percent of survivors had significant hypertension which persisted after CS was discontinued.

Conclusions

This study shows promising response in children with AA treated with IST; however, the outcome was inferior to our institutional results with hematopoietic stem cell transplantation from a sibling donor. Hypertension and MDS are late complications. Longer follow‐up, larger cohorts, and prospective studies are warranted to evaluate late complications and risk factors. Pediatr Blood Cancer 2008;50:52–57. © 2007 Wiley‐Liss, Inc.
Feasibility of metronomic maintenance chemotherapy following high‐dose chemotherapy for malignant central nervous system tumors
Authors: Choi L. Mi Rim , Rood Brian , Kamani Naynesh , La Fond Deborah , Packer Roger J. , Santi Maria Rita , MacDonald Tobey J.
Published: October 2007

Background

Children less than 5 years of age with malignant central nervous system (CNS) tumors, continue to have a high rate of morbidity and mortality following administration of conventional therapy. In an attempt to avoid the neurologic sequelae associated with craniospinal radiation, strategies such as high‐dose chemotherapy (HDCT) followed by peripheral stem cell rescue have been used successfully. Metronomic chemotherapy has also been reported as a potential new treatment strategy in solid tumors, particularly in adults.

Procedure

A retrospective chart analysis was performed on 10 patients less than 5 years of age with CNS tumors treated with metronomic chemotherapy shortly after HDCT as part of their clinical care.

Results

Metronomic chemotherapy was associated with minimal toxicity and all patients maintained a good quality of life. At the time of this report, all 10 patients are alive. Two patients have relapsed, and the remaining eight, including six patients with metastatic disease, continue to have stable clinical and radiographic disease at a mean of 20 months from the time of diagnosis.

Conclusions

Metronomic chemotherapy in this patient population is feasible and shows encouraging preliminary results, especially in patients with metastatic disease who have not received craniospinal radiation. Further investigation of this strategy in newly diagnosed patients with CNS tumors is warranted. Pediatr Blood Cancer 2008;50:970–975. © 2007 Wiley‐Liss, Inc.
Hypofractionated stereotactic radiotherapy in the management of recurrent or residual medulloblastoma/PNET
Authors: Saran Frank , Baumert Brigitta G. , Creak Antonia L. , Warrington Alan P. , Ashley Sue , Traish Daphne , Brada Michael
Published: October 2007

Purpose

To evaluate the efficacy and toxicity of hypofractionated stereotactic radiotherapy in the management of locally recurrent or residual central nervous system (CNS) primitive neuroectodermal tumors (PNETs).

Patients and Methods

Between 1991 and 2005, 12 patients with locally recurrent medulloblastoma and two patients with residual supratentorial PNET were treated with hypofractionated stereotactic conformal radiotherapy (SCRT). Nine patients were treated for first recurrence, two patients after the 2nd, and one patient after 3rd recurrence. Median age at diagnosis was 20 years (range: 4–35 years) and median age at SCRT 25 years (range: 7–41 years). Nine of 12 patients underwent resection at recurrence and 13 patients received at least one cycle of chemotherapy prior to SCRT. All received focal SCRT (30–40 Gy/6–8 #) using non‐coplanar arcs (n = 6) or fixed conformal non‐coplanar fields (n = 8).

Results

Median overall survival was 29 months (95% CI: 6–51 months) and median progression‐free survival was 12 months (95% CI: 5–19 months). Local progression‐free survival at 1 and 3 years was 80% (95% CI: 55–100%) and 48% (95% CI: 11–85%). Causes of death were recurrent CNS disease (n = 7), herpes encephalitis (n = 1), and metastatic PNET outside the CNS (n = 1).

Conclusion

Hypofractionated SCRT provides effective local control with acceptable toxicity for patients with recurrent localized PNET. However, overall long‐term disease control is rare and limited by the occurrence of CSF mediated relapses, which thus could benefit from intensive systemic chemotherapy as part of the primary relapse strategy even in local recurrences. Larger multi‐national studies will be necessary to assess the value of such combined treatment approaches. Pediatr Blood Cancer 2008;50:554–560. © 2007 Wiley‐Liss, Inc.
Prescribing of sulfasalazine, azathioprine and methotrexate round pregnancy—a descriptive study
Authors: Vroom Fokaline , van Roon Eric N. , van den Berg Paul B. , Brouwers Jacobus R.B.J. , de Jong‐van den Berg Lolkje T.W.
Published: October 2007

Purpose

Continuation or discontinuation of drugs during pregnancy in chronic diseases is an issue of concern. Information on prescribing of disease modifying anti‐rheumatic drugs (DMARDs) during pregnancy is scarce. In this study, we report prescribing patterns round pregnancy of sulfasalazine (SSZ), azathioprine (AZA), methotrexate (MTX) and co‐medications among women to whom one of these DMARDs were prescribed before pregnancy.

Methods

The pregnancy‐interaction database (IADB.nl, 1994–2004), containing pharmacy dispensing data from Northern‐ Netherlands, was used. Women to whom SSZ (N = 13), AZA (N = 10) or MTX (N = 6) was prescribed before their first pregnancy were identified and described in detail.

Results

AZA and SSZ are continued during pregnancy by 60% and 38% of the women, respectively, MTX was stopped before pregnancy. Among women receiving SSZ (N = 13) as their initial DMARD, anti‐inflammatory and anti‐rheumatic drugs (69%) and analgesics (45%) were the most commonly prescribed co‐medications. Among women receiving AZA (N = 8) as their initial DMARD, corticosteroids for systemic use (100%) and intestinal anti‐inflammatory agents (88%) were the most commonly prescribed co‐medications. All women receiving intestinal anti‐inflammatory drugs before pregnancy continued this during pregnancy, in contrast to other co‐medications which were mainly discontinued.

Conclusions

Our study showed that DMARDs and co‐medication are received before, during and after pregnancy, although no specific prescription patterns were found. Administrative databases, such as the pregnancy‐IADB.nl, are useful in describing drug‐prescribing patterns for better understanding of drug prescribing around pregnancy in daily practice. Based on these data, we conclude that prescribing of DMARDs and related co‐medication is based on the individual patient. Copyright © 2007 John Wiley & Sons, Ltd.
Constitution and quantity of lysis buffer alters outcome of reverse phase protein microarrays
Authors: Winters Mary , Dabir Bhavana , Yu Minshu , Kohn Elise C.
Published: October 2007

Application of novel technology to clinical samples requires optimization of procedures. Reverse phase protein lysate arrays use femtomolar quantities of tissue lysate from clinical samples with which to profile biochemical events happening in the tumor. We analyzed the effects of different tissue solubilization buffers on frozen ovarian tumor samples in order to identify the system with the best signal intensity dynamic range, reproducibility, tissue solubility, and signal consistency. A modified RIPA‐like buffer supplemented with DTT and SDS was deemed optimal.
Titanium and zirconium complexes containing modified TREN ligands for the polymerization of 1‐alkenes—A comparative study
Authors: Sudhakar Padmanabhan
Published: October 2007

The titanium and zirconium complexes in C3 and Cs symmetric forms synthesized from corresponding aminotriols in combination with MAO polymerized 1‐hexene in a controlled manner. When the polymerization temperature was lowered, they gave high molecular weight monodisperse polyhexene with narrow polydispersities indicating quazi‐living systems. The isotactic polyhexene obtained from C3 titanium catalyst has the molecular weight of around 46,500 with PDI of 1.3 and the hemi‐isotactic polymer from Cs titanium catalyst has the molecular weight of around 617,000 with PDI of 1.3. The analogues zirconium complexes upon activation with MAO polymerize hexene to give polyhexene having molecular weight of 53,000 (C3) and 626,000 (pseudo‐Cs) with PDI ranging from 1.2 to 1.4. The MIX‐titanium catalyst prepared from the 50:50 mixture of aminotriols was also able to polymerize 1‐hexene and the GPC traces of the polyhexene suggests that even though the catalyst was formed from the mixture of aminotriols, the C3 and Cs symmetry of the catalysts retain its originality avoiding the formation of aggregates or polymeric forms. When one of the arms of aminotriol was methylated yield C2 and meso aminodiol ligands and their corresponding titanium and zirconium complexes gave higher molecular weight polyhexenes with lower PDI (C2‐Zr‐Mn: 260,000; PDI: 1.05–1.10; mesoZr‐Mn: 220,000; PDI: 1.05–1.10) possibly suggesting that these systems are close to living systems. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5470–5479, 2007
Rapid additive‐free TEMPO‐mediated stable free radical polymerizations of styrene
Authors: Dollin Michael , Szkurhan Andrea R. , Georges Michael K.
Published: October 2007

The stable free radical polymerization (SFRP) of styrene, initiated with benzoyl peroxide in the presence of TEMPO, under bulk conditions, is demonstrated to proceed rapidly without the need for any rate enhancing additives such as camphorsulfonic acid, 2‐fluoro‐1‐methyl pyridinium p‐toluenesulfonate, or acetic anhydride. Monomer conversions as high as 70% can be achieved in 5 h or less while maintaining polydispersity indexes of 1.15. These results stand in stark contrast to earlier reactions that required 70 h to achieve similar conversions. This study demonstrates that the single largest factor governing the rates of polymerization is the molar concentration of excess TEMPO remaining in solution after initiation. A reduction in the TEMPO to BPO ratio is required when large amounts of BPO are used to target low molecular weight polystyrenes. However, when a lower molar amount of BPO is used to obtain high molecular weight polystyrenes, a higher TEMPO to BPO ratio is required. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5487–5493, 2007
Synthesis and characterization of amphiphilic block copolymers with allyl side‐groups
Authors: Hu Xiuli , Chen Xuesi , Xie Zhigang , Liu Shi , Jing Xiabin
Published: October 2007

The synthesis of a new cyclic carbonate monomer containing an allyl group was reported and its biodegradable amphiphilic block copolymer, poly(ethylene glycol)‐block‐poly(L‐lactide‐co‐5‐methyl‐5‐allyloxycarbonyl‐propylene carbonate) [PEG‐b‐P(LA‐co‐MAC)] was synthesized by ring‐opening polymerization (ROP) of L‐lactide (LA) and 5‐methyl‐5‐allyloxycarbonyl‐1,3‐dioxan‐2‐one (MAC) in the presence of poly (ethylene glycol) as a macroinitiator, with diethyl zinc as a catalyst. 13C NMR and 1H NMR were used for microstructure identification of the copolymers. The copolymer could form micelles in aqueous solution. The core of the micelles is built of the hydrophobic P(LA‐co‐MAC) chains, whereas the shell is set up by the hydrophilic PEG blocks. The micelles exhibited a homogeneous spherical morphology and unimodal size distribution. By using the cyclic carbonate monomer containing allyl side‐groups, crosslinking of the PEG‐b‐P(LA‐co‐MAC) inner core was possible. The adhesion and spreading of ECV‐304 cells on the copolymer were better than that on PLA films. Therefore, this biodegradable amphiphilic block copolymer is expected to be used as a biomaterial for drug delivery and tissue engineering. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5518–5528, 2007
The theory of nonrandom polycondensation for the description of sol–gel polymerization of alkoxisilanes
Authors: Tarasevich Konstantin V. , Kuchanov Semion I.
Published: October 2007

The earlier developed theory of nonrandom polycondensation (Kuchanov, et al. J Stat Phys 122, 875, 2006) is applied for the description of sol–gel polymerization of alkoxisilanes. The accuracy of simple approximate approaches used in literature to calculate critical conversion at the gel‐point is evaluated. The results of calculation of the characteristics of gel's polymer network governing its elastic properties are presented for the first time. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 3093–3116, 2007
Surface Chemical Analysis of Plasma‐Deposited Copolymer Films Prepared from Feed Gas Mixtures of Ethylene or Styrene with Allylamine
Authors: Swaraj Sufal , Oran Umut , Lippitz Andreas , Unger Wolfgang E. S.
Published: October 2007

Plasma deposited ethylene/allylamine and styrene/allylamine copolymer films were prepared and analyzed using XPS, NEXAFS and ToF‐SIMS. The relative partial flow rate of the each monomer was used as the variable deposition parameter, while the other deposition parameters were kept constant at optimized values for the retention of functional groups. The effect of the variation in the relative partial flow rates of co‐monomers on various chemical aspects of the films like unsaturation, nitrogen retention and branching was investigated revealing several non‐linear correlations. This observation is taken as an indication for chemical copolymerization processes during film deposition. An attempt is made to compare these non‐linear correlations with approaches which have been developed for classic radical copolymerization processes. The aging behavior of these plasma copolymer films was also studied; the results indicated a stabilization against oxidation in comparison to the aging of allylamine plasma homopolymers.

magnified image
Neuroproteomics in stem cell differentiation
Authors: Beyer Susanne , Mix Eilhard , Hoffrogge Raimund , Lünser Katja , Völker Uwe , Rolfs Arndt
Published: October 2007

The term “proteome” is used to describe the entire complement of proteins in a given organism or in a system at a given time. Proteome analysis in neuroscience, also called “neuroproteomics” or “neuromics” is in its initial stage, and shows a deficit of studies in the context of brain development. It is the main objective of this review to illustrate the potential of neuroproteomics as a tool to unravel the differentiation of neural stem or progenitor cells to terminally differentiated neurons. Experimental results regarding the rat striatal progenitor model cell line ST14A are presented to illustrate the large rearrangements of the proteome during the differentiation process of neural progenitor cells and their modification by neurotrophic factors like the glial cell line‐derived neurotrophic factor (GDNF). Thereby native stem cells and cells transfected with GDNF gene were investigated at the proliferative state and at seven time points up to 72 h after induction of differentiation. In addition, the immortalized human fetal midbrain stem cell line ReNcell VM was analyzed in order to detect stem cell differentiation associated changes of the protein profile. This review gives also an outlook on technical improvements and perspectives of application of neural stem cell proteomics.
Endogeneous peptide profiling of cerebrospinal fluid by MALDI‐TOF mass spectrometry: Optimization of magnetic bead‐based peptide capture and analysis of preanalytical variables
Authors: Jimenez Connie R. , Koel‐Simmelink Marleen , Pham Thang V. , van der Voort Laura , Teunissen Charlotte E.
Published: October 2007

Cerebrospinal fluid (CSF) perfuses the brain and spinal cord. CSF contains peptides and proteins important for brain physiology and potentially also relevant to brain pathology. High‐throughput endogeneous peptide profiling by MS is an emerging approach for disease diagnosis and biomarker discovery. A magnetic bead‐based method for off‐line serum peptide capture coupled to MALDI‐TOF‐MS has been introduced recently. In this study, we optimize the peptide capture method for profiling of CSF and investigate the effect of a number of preanalytical variables. The CSF profiles contain ∼100 reliably detected peptides at m/z 800–4000 with reproducible ion intensities (average 7% CV). The investigated preanalytical variables include: time at room temperature (RT) before storage, storage temperature, freeze‐thawing cycles, and blood contamination. The CSF peptidome (<20 kDa) is relatively stable and can withstand a few hours at RT and several freeze‐thaw cycles. Several peptides sensitive to storage at −20°C, including Cystatin C, were assigned based on mass or identified by MS/MS. Hemoglobin α and β chains were detected in blood contaminated samples, at levels invisible to the eye (0.01%). These peptides may be used for quality control in a MALDI‐TOF‐MS screening strategy to select high quality samples for in‐depth proteomics analysis in disease studies.
The hippocampal protein machinery varies over the estrous cycle
Authors: Diao Wei‐Fei , Chen Wei‐Qiang , Höger Harald , Shim Ki Shuk , Pollak Arnold , Lubec Gert
Published: October 2007

Information about estrous cycle (EC) and sex‐dependent protein levels is limited. Cognitive functions vary over the EC and the aim of this study was to investigate rat protein fluctuations in the hippocampus, the main cognitive brain area for learning and memory, in the individual phases of the EC and in males and indeed protein fluctuations may reflect functional variation over the EC. Sprague‐Dawley rats were used in the studies and estrous phases were determined. Hippocampi were taken, proteins extracted, run on 2‐DE, and identified using MALDI‐TOF/TOF and nano‐LC‐ESI‐MS/MS; protein levels were quantified using Proteomweaver software. Levels of protein synthetic machinery components transcriptional activator protein PUR(α,β), elongation factor 2, heterogeneous nuclear ribonucleoprotein K, chaperones 78 kDa glucose‐regulated protein, heat shock cognate 71 kDa protein, Hsp 105, stress‐70 protein, peptidyl‐prolyl cis–trans isomerase A, prefoldin subunit 2, T‐complex protein 1 subunit alpha and subunit delta, and degradation principle proteasome subunit alpha type 1 and ubiquitin carboxyl‐terminal hydrolase isozyme L1, were different between sex and phase of the EC. We suggest that differences in the protein synthetic, chaperoning, and degradation machinery indicate different function in the individual EC phases. Results herein are relevant for further design of studies in the hippocampus at the protein level and interpretation of previous studies because EC phases will have to be respected and taken into account.
The significance of organellar proteomics for the nervous system
Authors: Miller Linda C. , Sossin Wayne S.
Published: October 2007

Organellar proteomics is a useful tool for gaining biological insights about structures in the cell. Here, we discuss the tools used in organellar proteomics and the impact of this technique in understanding nervous system function. We will review insights gained from the proteomes of nervous system‐specific organelles such as synaptic vesicles and the postsynaptic density. Moreover, we will show how comparison of proteomes between organelles isolated from the nervous system and from other tissues highlight nervous system‐specific functions using the examples of clathrin‐coated vesicles and RNA granules.
Regulation of TGF‐β1 gene transcription in human prostate cancer cells by nitric oxide
Authors: Wang Daren , Lu Shan , Dong Zhongyun
Published: October 2007

Background

Overexpression of transforming growth factor (TGF)‐β1 is associated with advanced prostate cancer. Our previous studies showed an inverse correlation between the expressions of TGF‐β1 and inducible nitric oxide synthase (iNOS) in prostatic tumors in mice. The purpose of this study was to investigate regulation of TGF‐β1 expression in human prostate cancer cells by nitric oxide (NO).

Methods

Expression of TGF‐β1 in the three well‐characterized lines of human prostate cancer cells (PC‐3MM2, LNCaP, and DU145) was determined by using the enzyme‐linked immunoabsorbance assay (ELISA), real‐time reverse‐transcriptase PCR (RT‐PCR), nuclear run‐on, and promoter activity analyses.

Results

Expression of both TGF‐β1 protein and mRNA was inhibited in both dose‐ and time‐dependent manners by NO donors sodium nitroprusside (SNP), S‐nitroso‐N‐acetylpenicilamine (SNAP), S‐nitrosoglutathione (GSNO), and (±)‐(E)‐methyl‐2‐[(E)‐hydroxyimino]‐5‐nitro‐6‐methoxy‐3‐hexeneamide (NOR‐1) and by transfection of iNOS. The inhibitory effects of SNP and iNOS on TGF‐β1 expression were reduced in cells treated with NO scavengers N‐dithiocarboxysarcosine (DTCS), 2‐phenyl‐4,4,5,5‐tetramethylimidazoline‐1‐oxyl‐3‐oxide (PTIO), and hemoglobin, or with the iNOS inhibitor N‐methyl‐arginine (NMA). SNP downregulated the in vitro transcription of TGF‐β1 mRNA, inhibited TGF‐β1 promoter activity, but had no significant effects on TGF‐β1 mRNA stability.

Conclusion

These results show that NO downregulates TGF‐β1 expression in prostate cancer cells at transcription level by suppressing the de novo synthesis of TGF‐β1 mRNA. Prostate 67: 1825–1833, 2007. © 2007 Wiley‐Liss, Inc.
Counterfeit medicines: a cause for concern in the UK?
Authors: Chaplin Steve
Published: October 2007

Much publicity has recently been given to several counterfeit medicines found in the UK supply chain. Steve Chaplin describes the scale of the problem and the measures being taken to improve detection and prevention. Copyright © 2007 Wiley Interface Ltd
ADOPT: evidence for change?
Authors: Burrill Peter
Published: October 2007

A randomised controlled trial published in a peer‐reviewed journal is considered to be the ‘gold standard’ of information about the effectiveness of a treatment; however, critical appraisal of trials is required in order to judge the value and implications of the results. Here, the author presents an appraisal of the ADOPT study, which compared the efficacy of rosiglitazone, metformin and glibenclamide in the treatment of type 2 diabetes.

Glycaemic durability of rosiglitazone, metformin, or glyburide monotherapy (the ADOPT study). N Engl J Med 2006;355:2427–43. Copyright © 2007 Wiley Interface Ltd
Anisotropic packing of C70 molecules in carbon nanotubes
Authors: Verberck B. , Michel K. H.
Published: October 2007

The optimal orientation of a C70 molecule encapsulated in a single‐walled carbon nanotube (SWCNT) depends on the tube radius. We compare discrete atomistic calculations with the results of a continuous tube approximation. We accurately determine the optimal molecular orientation as a function of the tube radius; for low (7 Å) and high (7.2 Å) tube radii, lying and standing molecular orientations are recovered, respectively. In between, we observe a transition regime. We determine the optimal intermolecular distance for a chain of on‐axis C70 molecules inside a SWCNT. Finally, we discuss the consequences of our results, agreeing well with recent X‐ray diffraction experiments, on the eventual formation of a double‐walled carbon nanotube. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of the substrate loading on the quality and diameter distribution of SWCNT in alcohol‐CVD
Authors: Bachmatiuk A. , Borowiak‐Palen E. , Rümmeli M. H. , Gemming T. , Kalenczuk R. J.
Published: October 2007

The optimization of singlewalled carbon nanotubes (SWCNT) synthesis via chemical vapour deposition (CVD) with the use of ethanol vapor as the carbon source is presented. Alcohol CVD process for SWCNT synthesis was performed with regards to the diameter distribution and quality of the sample. In particular the influence of the concentration of the catalyst support (here MgO) was investigated. The manipulation of this process parameter led to the synthesis of bulk quantity and high purity SWCNT. We have found that an increase in the MgO concentration with respect to the catalyst showed limited dependence on the diameter distribution but did show a significant influence on the sample quality for the optimum conditions. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Data Analysis in Combinatorial Experiments: Applying Supervised Principal Component Technique to Investigate the Relationship Between ToF‐SIMS Spectra and the Composition Distribution of Ternary Metallic Alloy Thin Films
Authors: Dell'Anna Rossana , Lazzeri Paolo , Canteri Roberto , Long Christian J. , Hattrick‐Simpers Jason , Takeuchi Ichiro , Anderle Mariano
Published: October 2007

We apply a semi‐supervised technique called Supervised Principal Component (SPC) to explore the relationship between the composition of a thin film combinatorial library and the peaks of Time‐Of‐Flight Secondary Ion Mass Spectrometry (ToF‐SIMS) spectra acquired from the library. SPC is first used to select a subset of the available multivariate features (the peak intensities of the ToF‐SIMS spectra) based on their association with the outcome variable (the elemental concentration of the thin film samples). Next, using only the selected features, SPC creates optimal linear models which map the ToF‐SIMS data onto the composition data. The models for the first two of the considered elemental concentrations use only eight of the 55 available ToF‐SIMS peaks, making interpretation of the model much simpler than for a model which uses all 55 available peaks. The percentage of explained variance (R2) in concentration data is in both cases about 0.80. These results are obtained during the model validation phase, performed on test data, which are exclusively used for this purpose. The model for the third considered element did not produce significant results due to the poor variability of the dataset. This work illustrates for the first time that using a multivariate analysis technique, one can establish the relationship between ToF‐SIMS measurements and stoichiometric data in a combinatorial experiment. More generally, the described feature selection approach provides an example of how combinatorial experiments can be useful for accelerating the understanding of the chemical–physical behaviors under investigation.