bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of hydroxyapatite as solid signal on performance of PCL porous scaffolds for bone tissue regeneration
Authors: Guarino Vincenzo , Causa Filippo , Netti Paolo A. , Ciapetti Gabriela , Pagani Stefania , Martini Desiree , Baldini Nicola , Ambrosio Luigi
Published: March 2008

Highly porous composites made up of biodegradable poly‐ε‐caprolactone (PCL) and stoichiometric hydroxyapatite (HA) particles have been developed as substrate for bone‐tissue regeneration. The processing technique consists of phase inversion and particulate (salt crystals) leaching. Three different HA contents (13, 20 and 26 vol %) in PCL‐based composite were considered in this study. Pore microstructure with fully interconnected network and pore sizes ranging around a few hundred of μm (macroporosity) was obtained as a result of salt particles removal by leaching process. Several microns (microporosity) porosity was also created through phase inversion of polymer solution. Total porosity up to 95% was achieved. Human marrow stromal cells (MSC) were seeded onto porous PCL‐based composites for 1–5 weeks and cultured in osteogenic medium. MSC were able to adhere and grow on PCL‐based substrates with a plateau at 3–4 weeks. However, the small effect of bioactive signals on the biological response evaluated in MSC cell culture suggests a prior role of topography on the biological response. Importantly, the presence of HA as a bioactive solid signal determines an increase of mechanical properties. On the overall, the results indicated that porous PCL‐based composites are potential candidate for bone substitution with beneficial influence on structural characteristics by solid signal addition. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2008
Selection of a practical assay for the determination of the entire range of acetyl content in chitin and chitosan: UV spectrophotometry with phosphoric acid as solvent
Authors: Hein San , Ng Chuen‐How , Stevens Willem F. , Wang Kean
Published: March 2008

The rapidly expanding use of chitomaterials in biomedical applications demands accurate and precise analytical methods to determine physico‐chemical characteristics, especially the acetyl content of the sample. The analytical methods available for the determination of the acetyl content of the biomaterials are quite different in efficiency, accuracy and precision. Out of 22 analytical methods reviewed, XRD, DSC, FTIR (KBr pellet), solid state13C CP/MAS NMR, and acid hydrolysis‐HPLC and the spectrophotometry assay using phosphoric acid as solvent (PUV) were selected in this study. The validity and applicability of these methods were investigated with a wide range of chitin and chitosan samples varying acetyl content, preparation methods, and sources. The XRD, DSC, and FTIR (KBr pellet) methods showed poor accuracy with the samples of diverse preparations and sources. The PUV method was modified and accuracy of the method was examined against absolute methods: solid state13C CP/MAS NMR and acid hydrolysis‐HPLC methods. The correlations between these three methods were >0.9. Therefore, the PUV method was selected as the most generally acceptable method based on its accuracy, reliability, simplicity, and instrument availability. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Effects of corticosterone deficiency and its replacement on leydig cell steroidogenesis
Authors: Parthasarathy C. , Balasubramanian K.
Published: March 2008

Clinical and experimental studies have shown the adverse effects of glucocorticoid deficiency/metyrapone treatment on testicular Leydig cell testosterone production. However, molecular mechanisms that underlie the effects of glucocorticoid deficiency on Leydig cell steroidogenesis are not yet determined. Therefore, the present study was designed to assess the mechanism of this phenomenon. Following metyrapone‐induced corticosterone deficiency, serum testosterone, and Leydig cell 14C‐glucose oxidation were decreased. StAR mRNA and protein levels were significantly increased in Leydig cells of corticosterone‐deficient animals. mRNA levels and the specific activities of P450scc and 17β‐HSD were decreased by corticosterone deficiency, whereas the activity and mRNA of 3β‐HSD were increased. Simultaneous administration of corticosterone prevented its deficiency‐induced changes in Leydig cells. Our results show that metyrapone‐induced corticosterone deficiency impairs Leydig cell testosterone production by decreasing the activities of steroidogenic enzymes and their mRNA expression and glucose oxidation. J. Cell. Biochem. 104: 1671–1683, 2008. © 2008 Wiley‐Liss, Inc.
TGF‐β inhibits prolactin‐induced expression of β‐casein by a Smad3‐dependent mechanism
Authors: Wu Wen‐Jun , Lee Chin‐Feng , Hsin Chung‐Han , Du Jyun‐Yi , Hsu Tsai‐Ching , Lin Ting‐Hui , Yao Tsung‐You , Huang Cheng‐Hsieh , Lee Yi‐Ju
Published: March 2008

Transforming growth factor‐β (TGF‐β) is a multifunctional growth factor, affecting cell proliferation, apoptosis, and extracellular matrix homeostasis. It also plays critical roles in mammary gland development, one of which involves inhibition of the expression of milk proteins, such as β‐casein, during pregnancy. Here we further explore the underlying signaling mechanism for it. Our results show that TGF‐β suppresses prolactin‐induced expression of β‐casein mRNA and protein in primary mouse mammary epithelial cells, but its effect on protein expression is more evident. We also find out that this inhibition is not due to the effect of TGF‐β on cell apoptosis. Furthermore, inhibition of TGF‐β type I receptor kinase activity by a pharmacological inhibitor SB431542 or overexpression of dominant negative Smad3 substantially restores β‐casein expression. By contrast, inhibition of p38 and Erk that are known to be activated by TGF‐β does not alleviate the inhibitory effect of TGF‐β. These results are consistent with our other observation that Smad but not MAPK pathway is activated by TGF‐β in mammary epithelial cells. Lastly, we show that prolactin‐induced tyrosine phosphorylation of Jak2 and Stat5 as well as serine/threonine phosphorylation of p70S6K and S6 ribosomal protein are downregulated by TGF‐β, although the former event requires considerably long exposure to TGF‐β. We speculate that these events might be involved in repressing transcription and translation of β‐casein gene, respectively. Taken together, our results demonstrate that TGF‐β abrogates prolactin‐stimulated β‐casein gene expression in mammary epithelial cells through, at least in part, a Smad3‐dependent mechanism. J. Cell. Biochem. 104: 1647–1659, 2008. © 2008 Wiley‐Liss, Inc.
Timing of Doppler examination for the detection of arteriovenous fistula after percutaneous renal biopsy
Authors: Yang Chih‐Yu , Lai Ming‐Yu , Lu Cheng‐Lang , Tseng Hsiuo‐Shan , Chiou Hong‐Jen , Yang, Wu‐Chang , Ng Yee‐Yung
Published: March 2008

Percutaneous renal biopsy is frequently performed, and postbiopsy arteriovenous fistula (AVF) formation is not uncommon. In most cases, it is asymptomatic and remains undiagnosed, because Doppler examination is not performed routinely. We describe 2 cases of postbiopsy AVF of the kidney that were detected 61 and 17 months after renal biopsy, respectively. The subsequent superselective transcatheter arterial embolization was successful in both cases. An undetected AVF of the kidney can progress and lead to serious consequences. A follow‐up Doppler examination of the kidney soon after renal biopsy and 6 months later is recommended for early detection of nonresolving AVFs to prevent further complications. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008.
ER stress is involved in Aβ‐induced GSK‐3β activation and tau phosphorylation
Authors: Resende Rosa , Ferreiro Elisabete , Pereira Cláudia , Oliveira Catarina Resende
Published: March 2008

Intracellular neurofibrillary tangles, one of the characteristic hallmarks of Alzheimer's disease (AD), are mainly composed of hyperphosphorylated tau. The abnormal tau phosphorylation seems to be related to altered activity of kinases such as glycogen synthase kinase‐3β (GSK‐3β). Tau pathology is thought to be a later event during the progression of the disease, and it seems to occur as a consequence of amyloid‐beta (Aβ) peptide accumulation. The aim of this work was to investigate whether soluble Aβ1–42, particularly oligomers that correspond to the neurotoxic species involved early in the development of AD, triggers tau phosphorylation by a mechanism involving activation of tau‐kinase GSK‐3β. Several studies suggest that GSK‐3β plays a central role in signaling the downstream effects of endoplasmic reticulum (ER) stress. Therefore, the involvement of ER Ca2+ release in GSK‐3β activation and tau phosphorylation induced by Aβ1–42 oligomers was evaluated using dantrolene, an inhibitor of Ca2+ release through channels associated with ER ryanodine receptors. We observed that Aβ1–42 oligomers increase tau phosphorylation and compromises cell survival through a mechanism mediated by GSK‐3β activation. We also demonstrated that oligomeric Aβ1–42 induces ER stress and that ER Ca2+ release is involved in oligomer‐induced GSK‐3β activation and tau phosphorylation. This work suggests that GSK‐3β can be a promising target for therapeutic intervention in AD. © 2008 Wiley‐Liss, Inc.
Retrograde Wallerian degeneration of cranial corticospinal tracts in cervical spinal cord injury patients using diffusion tensor imaging
Authors: Guleria Saurabh , Gupta Rakesh K. , Saksena Sona , Chandra Anil , Srivastava R.N. , Husain Mazhar , Rathore Ramkishore , Narayana Ponnada A.
Published: March 2008

Diffusion tensor imaging (DTI) has the potential to reveal disruption of white matter microstructure in chronically injured spinal cords. We quantified fractional anisotropy (FA) and mean diffusivity (MD) to demonstrate retrograde Wallerian degeneration (WD) of cranial corticospinal tract (CST) in cervical spinal cord injury (SCI). Twenty‐two patients with complete cervical SCI in the chronic stage were studied with DTI along with 13 healthy controls. Mean FA and MD values were computed for midbrain, pons, medulla, posterior limb of internal capsule, and corona radiata. Significant reduction in the mean FA and increase in MD was observed in the cranial CST in patients with SCI compared with controls, suggesting retrograde WD. Statistically significant inverse FA and MD changes were noted in corona radiata, indicating some restoration of spared white matter tracts. Temporal changes in the DTI metrics suggest progressing degeneration in different regions of CST. These spatiotemporal changes in DTI metrics suggest continued WD in injured fibers along with simultaneous reorganization of spared white matter fibers, which may contribute to changing neurological status in chronic SCI patients. © 2008 Wiley‐Liss, Inc.
Effect of mother corm dimension and sowing time on stigma yield, daughter corms and qualitative aspects of saffron (Crocus sativus L.) in a Mediterranean environment
Authors: Gresta F. , Lombardo G. M. , Siracusa L. , Ruberto G.
Published: March 2008

BACKGROUND: Saffron is one of the most appreciated and expensive spices known and has been used from the oldest times as a dye for fabrics, a condiment to enrich food and for medicinal purposes. The aim of this study was to evaluate the effect of crop management methods on the quantitative and qualitative characteristics of the spice in southern Italy. Two sowing times (end of July and end of August) and two corm dimensions (4 and 3 cm horizontal diameter) were evaluated.

RESULTS: Flowering period and duration were not influenced by the studied factors, while early sowing time and greater corm dimension resulted in a greater number of flowers per m2, increased stigma yield and a greater total yield of replacement corms. Early sowing time also showed a significant positive influence on stigma quality measured as apocarotenoid content according to ISO guidelines.

CONCLUSION: The results show that, in a Mediterranean environment, appropriate crop techniques and selection of corms can result in economic levels of production and improve the quantitative and qualitative characteristics of saffron. In fact, according to their apocarotenoid contents, samples from the early (July) and late (August) sowing times belonged to the first and second ISO categories respectively. Copyright © 2008 Society of Chemical Industry
Impact of goat milk powdered formulations on mineral absorption, peak bone mass and bone loss due to ovariectomy in rats
Authors: Kruger Marlena C , Chua Wei‐Hang , Darragh Alison , Booth Chris L , Prosser Colin , Lowry Dianne
Published: March 2008

BACKGROUND: Goat milk is recognised as nutritious, with benefits to growth and skeletal development. The initial aim of this study was to investigate the effect of three different goat milk formulae—a whole milk, a skim milk and a goat milk growing‐up formula fortified with pre‐ and probiotics (Formula 1)—on mineral absorption and retention in rats. The effect of long‐term intake of the fortified formula diet on peak bone mass and post‐ovariectomy bone loss in rats was then investigated in a follow‐up study and was assessed by bone density dual‐energy X‐ray absorptiometry and biomechanical testing of bone ex vivo.

RESULTS: Goat whole milk and fortified milk formulations improved calcium and phosphorus absorption and retention. Body composition analysis showed that rats fed the fortified diet had higher body calcium and phosphorus content. The fortified diet was then tested in a long‐term feeding trial. Rats fed the fortified diet from weaning had a higher peak bone mass than rats fed a soy protein control diet. Bone mineral content (BMC) and density (BMD) of the lumbar spine were higher in rats fed the fortified diet. After ovariectomy, all rats lost bone mass, but rats fed the fortified diet maintained significantly higher BMD and BMC values throughout the trial, though still lower than those of non‐ovariectomised control rats. The fortified diet increased bone strength.

CONCLUSION: Goat milk specific nutrients supported by pre‐ and probiotics in Formula 1 may improve mineral status during growth and support attainment of peak bone mass. Copyright © 2008 Society of Chemical Industry
Nut and kernel traits and chemical composition of hazelnut (Corylus avellana L.) cultivars
Authors: Cristofori Valerio , Ferramondo Simone , Bertazza Gianpaolo , Bignami Cristina
Published: March 2008

BACKGROUND: Nut and kernel traits and chemical composition of 24 Italian and foreign hazelnut cultivars were analysed in 2002–2004 in order to study the effect of genotype and environment on nut quality. Nuts were sampled in a germplasm collection in the Italian province of Viterbo.

RESULTS: Quantitative and qualitative determinations of sugars, organic acids and lipids revealed good nutritional and health potential of the nuts, with several differences among cultivars and years. The total contents of oil and sugars ranged from 563.69 to 656.36 g kg−1 dry weight (DW) and from 39.80 to 59.51 g kg−1 DW respectively. Fatty acid profile and sugar and total phenolic contents varied with the year. Significantly higher palmitic acid concentration (6.18%) was found in the hot summer year 2003; lower saturated fatty acid concentration (8.20%) and higher unsaturated/saturated acid ratio (11.27) were observed in the coolest year (2004). These differences among years were highlighted by discriminant analysis.

CONCLUSION: The information relating to secondary components such as sugars, organic acids and phenolics was useful for discriminating among cultivars and years. Owing to the effect of these compounds on sensory attributes perceived by consumers, their concentration and the varietal differences can be considered primary determinants of nut quality and should be valued when planning the cultivar choice for new plantations. Copyright © 2008 Society of Chemical Industry
Diode-end-pumped acousto-optically Q-switched 914 nm laser and the pulsed blue light generation by intracavity frequency doubling
Authors: Gao J , Yu X , Li X D , Chen F , Zhang Z , Yu J H , Wang Y Z
Published: March 2008

A diode-end-pumped acousto-optically Q-switched Nd:YVO4 914 nm laser with 2.4 W output power is reported for the first time. With intracavity frequency doubling using a 10-mm-long LBO, a maximum 457 nm blue output power of 526 mW is achieved at a repetition rate of 20 kHz. The conversion efficiency from the corresponding Q-switched fundamental output to blue output is 42%. The peak power of the Q-switched blue pulse is up to 175 W with 150 ns pulse duration. The fluctuation of the blue output power is less than 2.0% at the maximum output power.
Integrated analytical strategies for the study of phosphorylation and glycosylation in proteins
Authors: Temporini Caterina , Calleri Enrica , Massolini Gabriella , Caccialanza Gabriele
Published: March 2008

The post‐translational modification (PTM) of proteins is a common biological mechanism for regulating protein localization, function, and turnover. The direct analysis of modifications is required because they are not coded by genes, and thus are not predictable. Different MS‐based proteomic strategies are used for the analysis of PTMs, such as phosphorylation and glycosylation, and are composed of a structural simplification step of the protein followed by specific isolation step to extract the classes of modified peptides (also called “sub‐proteomes”) before mass spectrometry. This specific isolation step is necessary because PTMs occur at a sub‐stoichiometric level and signal suppression of the modified fractions in the mass spectrometer occurs in the presence of the more‐abundant non‐modified counterpart. The request of innovative analytical strategies in PTM studies is the capability to localize the modification sites, give detailed structural information on the modification, and determine the isoform composition with increased selectivity, sensitivity, and throughput. This review focuses on the description of recent integrated analytical systems proposed for the analysis of PTMs in proteins, and their application to profile the glycoproteome and the phosphoproteome in biological samples. Comments on the difficulties and usefulness of the analytical strategies are given. © 2008 Wiley Periodicals, Inc. Mass Spec Rev. 27:207–236, 2008
A Rheological Approach to the Analysis of Plastication Influence on Fibers Breakage of LGF‐filled Polypropylene
Authors: Lucchetta Giovanni
Published: March 2008

Summary: Long glass fiber‐filled polypropylene composites are widely used in industry because of their low cost and high performance. To investigate the rheological properties of such composites in the molten state an in‐line slit‐die rheometer was developed and mounted on an injection molding machine. The shear viscosity of filled PP determined by the in‐line rheometer was found to strongly depend on the fiber length distribution. In particular, a linear correlation was determined between the viscosity at a constant temperature and shear rate and the average fiber length equation proposed by Huq and Azaiez. The developed model and the in‐line rheometer were then used to assess the effects of the main plastication parameters (i.e. screw rotation speed and backpressure) on fibers damage. The experiments were carried out according to a central composite design and optimal plastication conditions were determined by means of the response surface method.
Specific Interactions and Reactive Coupling Induced Dispersion of Multiwall Carbon Nanotubes in Co continuous Polyamide6/Ionomer Blends
Authors: Bose Suryasarathi , Bhattacharyya Arup R. , Khare Rupesh A. , Kulkarni Ajit R. , Pötschke Petra
Published: March 2008

Summary: An efficient strategy to achieve electrical conductivity in melt‐mixed co‐continuous blends is to restrict the conducting filler in a particular phase in the blends next to forming a percolated ‘network‐like’ structure in that particular phase. However, strong inter‐tube van der Waals' forces often lead to the aggregated structure leading to higher percolation threshold. In addition, the migration of the conducting filler during melt‐mixing and the blending sequence significantly affect the bulk conductivity of the blends. SEM observation showed fine co‐continuous structures associated with 50/50 blends of PA6/Surlyn with multiwall carbon nanotubes (MWNT). MWNT were localized in the vicinity of the ionic domains in the ionomer corresponding to a specific blending sequence when unmodified MWNT were used, however, in presence of Na‐salt of 6‐amino hexanoic acid (Na‐AHA) modified MWNT, selective clustering was not observed may be due to the confinement of MWNT in the PA6 phase. To understand these complexities the electrical conductivity of melt‐mixed blends of polyamide6/ionomer with MWNT was studied. However, it was observed that the blends with even 3 wt% unmodified MWNT showed insulating behaviour irrespective of the blending sequence adopted. In addition, the key role of a reactive modifier (Na‐AHA) in facilitating uniform dispersion and subsequent ‘network‐like’ formation by establishing specific interactions with MWNT was studied. It was found that the MWNT are selectively localized in the PA6 phase in the NA‐AHA modified blends manifesting in higher electrical conductivity (∼10−5 S/cm at 3 wt% MWNT) when using a specific blending sequence, due to melt‐interfacial reaction between the ∼NH2 functionality of Na‐AHA and the ∼COOH end groups of PA6. FTIR and Raman spectroscopic analysis also supported the existence of the specific interactions.
Screening Electromagnetic Interference Effect using Nanocomposites
Authors: Bellucci S. , Balasubramanian C. , De Bellis G. , Micciulla F. , Rinaldi G.
Published: March 2008

Summary: We carried out a systematic study of the electrical properties of carbon nanotube‐based polymeric composite materials. Our purpose was the production and characterization of a light, thin and mechanically strong new composite material able to cover electric circuits against external electromagnetic interference. As polymeric matrix we used a commercial Shell product Epon 828 epoxy resin. Two types of curing agent were used along with the resin, namely A1 and PAP8 agent: the composite was obtained using the A1 curing agent, selected for the stability of the corresponding material over a wide range of pressure values. Setting the resistivity properties of carbon nanotube‐based composites against those containing micro‐sized graphite particles as constituent we showed the advantages of using carbon nanotubes. The change in the resistivity values for carbon nanotubes‐based composites turned out to be significant, even for small changes in the added carbon nanotubes percentage. We also plan to show the composite's behavior in controlled humidity environments and for different temperatures. These results might be important for determining the most suitable “recipe” for the realization of composite materials useful to high‐fidelity circuits applications, or even in devices exposed to predominantly electromagnetic noise.
Numerical Simulation of a PA66 Flow Behaviour in a Hot Runner Gate
Authors: Gava Alberto , Lucchetta Giovanni
Published: March 2008

Summary: In actual hot runner systems for the injection moulding process, the control of polymers in gate is passive, which means that the melt temperature distribution and associated flow conductance is governed by a balance of heat convection by the flowing melt with heat conduction from the hot melt to the cold mould. This paper examines the rheological and thermal behaviour of a PA66 during freeze‐off and melt flow activation. Numerical simulations were carried out according to the Finite Volume Method as implemented in the Ansys CFX® code. Rheological and thermal data were obtained from a careful material characterization conducted on a capillary rheometer and a differential scanning calorimetry (DSC). The analyses indicated that relatively small changes in melt temperature and injection pressure can substantially increase the flow conductance and dynamically control both the gate freezing and the onset of melt flow in the subsequent cycle. Therefore, simple gate thermal actuators were designed and numerically implemented to active control the plastic melt flow. This numerical approach can be used to design and optimize the active control of hot runners gate when the use of mechanical actuation (i.e. valve gates) is not suitable due to excessive cost, critical maintenance or miniaturization of the entire system.
Toughening of Poly(ethylene terephtalate) (PET) Bottle Wastes by Modified Styrene‐Butadiene Rubber (SBR) Elastomer
Authors: Jazani O. Moini , Azar A. Aref
Published: March 2008

Summary: Modified SBR was blended with dried PET bottle wastes in an internal mixer. During the process mechanical and morphological properties were studied. When PET bottle wastes were blended with unmodified SBR, the final blend had a rough morphology and low impact strength. In contrary, blending of PET with modified SBR lead to smooth and fine morphology. Utilizing grafted SBR in PET blends creates an enormous difference in particle size and morphology, which is a result of powerful interactions and effective chemical bonding between the components of the blend. The final product had high impact strength in comparison with PET and unmodified SBR blend. These results are mainly related to formation in situ of PET/SBR graft copolymer in interface, which is produced by chemical reaction among active maleic anhydride groups and active PET groups.
Physico‐Mechanical Characteristics of Some EPDM/Plasticized PVC Blends
Authors: Stelescu Maria‐Daniela
Published: March 2008

Summary: In this study were prepared blends based on ethylene propylene terpolymer rubber (EPDM) and plasticized poly (vinyl chloride) (PVC). These blends are immiscible and need to be compatibilized. The following compatibilization methods were used: (1) addition of a compatibilization agent; there were used: maleinized EPDM, maleinized polyethylene (PE), chlorinated polyethylene (CPE) and maleinized polypropylene (PP); chlorinated polyethylene has proved to be the most efficient; the amount of the added CPE giving the best physico‐mechanical characteristics was of 7,5 parts to 100 polymer parts; (2) reactive compatibilization, using crosslinked copolymer formation strategy; three different crosslinking systems were used: (a) common method with sulphur and accelerators, (b) crosslinking with benzoyl peroxide and trimethylpropane trimethacrylate (TMPT DL 75), (c) vulcanization with phenol resin and tin chloride. The best physico‐mechanical characteristics were obtained with the EPDM/plasticized PVC blends crosslinked with 8 phr phenol resin. Such types of polymer blends can be processed by methods specific for plastics, removing thus vulcanization operation required in case of elastomers. These blends can be used in the manufacture of hoses, gaskets, footwear constituents etc.
Gamma Irradiation Effects on Mechanical and Thermal Properties and Biodegradation of Poly(3‐hydroxybutyrate) Based Films
Authors: Hermida Élida B. , Mega Verónica I. , Yashchuk Oxana , Fernández Víctor , Eisenberg Patricia , Miyazaki Silvia S.
Published: March 2008

Summary: Their biodegradable properties make polyhydroxyalkanoates (PHAs) ideal candidates for innovative applications. Many studies have been primarily oriented to poly(3‐hydroxybutyrate) (PHB) and poly(3‐hydroxybutyrate‐co‐3‐valerate) (PHBV) and afterwards to blends of PHAs with synthetic biodegradable polymers, such as poly(ε‐caprolactone) (PCL). Medical and pharmaceutical devices require sterilization and γ irradiation could provide a proper alternative since it assures storage stability and microbiological safety. This contribution presents the effect of γ irradiation on the mechanical and thermal properties and on the biodegradation of PHB, PHBV and a commercial PHB/PCL blend. Samples, prepared by compression moulding, were irradiated in air at a constant dose rate of 10 kGy/h, from 10 to 179 kGy. Polymer chain scission was assessed by changes in the molecular weight, thermal properties and tensile behaviour. The correlation between absorbed dose and changes in the mechanical properties and biodegradation is discussed in detail. The optimum dose to guarantee microbiological sterilization without damage of the structure or meaningful loss of the mechanical properties is also reported.
Late free‐flap salvage with catheter‐directed thrombolysis
Authors: Trussler Andrew P. , Watson James P. , Crisera Christopher A.
Published: March 2008

Introduction: Despite high success rates with free‐tissue transfer, flap loss continues to be a devastating event. Flap salvage is often successful if vascular complications are recognized and treated early. However, delayed presentation of flap compromise is an ominous predictor of flap loss. Late free‐flap salvage has been described with poor long‐term results. Catheter‐directed thrombolysis (CDT) has only been described in context with free‐tissue transfer in a case of distal bypass salvage. Objectives: The authors examined the efficacy of highly selective CDT in late salvage of free‐flaps with vascular compromise. Methods: Two patients underwent highly selective CDT after delayed presentation (>5 days) of flap compromise. Patient 1 is a 59‐year‐old woman who underwent delayed breast reconstruction with a free TRAM flap and presented with arterial thrombosis 12 days postoperatively. Patient 2 is a 53‐year‐old man who underwent fibular osteocutaneous free‐flap reconstruction of a floor of mouth defect who developed venous thrombosis 6 days postoperatively. Patient 2 underwent two attempted operative anastamotic revisions with thrombectomies and local thrombolysis prior to CDT. Results: The average time of presentation was 9 days, with the average time to CDT being 9.5 days. Patient 1 had an arterial thrombosis, whereas Patient 2 had a venous thrombosis. Both patients underwent successful thrombolysis after super‐selective angiograms. Continuous infusions of thrombolytic agents were used in both patients for ∼24 h. Average length of stay postCDT was 7 days with no perioperative complications. Long‐term follow‐up demonstrated complete flap salvage with no soft tissue loss. Conclusion: Despite extremely delayed presentation, aggressive CDT was successful in both breast, and head and neck reconstructions with excellent long‐term flap results. CDT appears to be a useful modality in managing difficult cases of free‐flap salvage. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
Myotilin overexpression enhances myopathology in the LGMD1A mouse model
Authors: Garvey Sean M. , Liu Yutao , Miller Sara E. , Hauser Michael A.
Published: March 2008

Missense mutations in the myotilin gene cause limb‐girdle muscular dystrophy type 1A (LGMD1A). We set out to examine the effect of overexpression of wild‐type myotilin in an LGMD1A mouse model by crossing wild‐type and mutant transgenic mice. Compared to single‐transgenic mutant mice, double‐transgenic mice overexpressing myotilin showed more severe muscle degeneration, enhanced myofibrillar aggregation, and earlier onset of aggregation. These data suggest that strategies aimed at lowering total myotilin levels in LGMD1A patients may be an effective therapeutic approach. Muscle Nerve, 2008
Sensitive detection of phosphopeptides by matrix‐assisted laser desorption/ionization mass spectrometry: use of alkylphosphonic acids as matrix additives
Authors: Kuyama Hiroki , Sonomura Kazuhiro , Nishimura Osamu
Published: March 2008

Matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) has been one of the most powerful tools for analyzing protein phosphorylation. However, it is frequently difficult to detect phosphopeptides with high sensitivity by MALDI‐MS. In our investigation of matrix/matrix‐additive substances for improving the phosphopeptide ion response in MALDI‐MS, we found that the addition of low‐concentration alkylphosphonic acid to the matrix/analyte solution significantly enhanced the signal of phosphopeptides. In this study, the combination of methanediphosphonic acid and 2,5‐dihydroxybenzoic acid gave the best results. In addition to enhancing the signal of the phosphopeptides, alkylphosphonic acid almost completely eliminated the signals of sodium and potassium ion adducts. We report herein sensitive detection of phosphopeptides by MALDI‐MS with the use of alkylphosphonic acids as matrix additives. Copyright © 2008 John Wiley & Sons, Ltd.
Bewegliche Brücken für den Straßenverkehr in Deutschland
Authors: Fiedler Erich
Published: March 2008

In Deutschland gibt es etwa 120000 feste Straßenbrücken – hingegen sind nur etwa 130 bewegliche Brücken für den Straßenverkehr in Nutzung. Im Rahmen der Veröffentlichung wird diese Brückengattung mit teilweise sehr interessanten technischen Lösungen vorgestellt. Es werden Klappbrücken mit Waagebalken, Klappbrücken mit tief liegendem Gegengewicht, Hubbrücken und Drehbrücken behandelt, wobei zu jeder Kategorie einige namhafte, ausgeführte Bauwerke beschrieben werden. Abschließend werden bestimmte technische Daten, die einen Überblick zum jeweiligen Bauwerk geben sollen, von fast allen in Deutschland bestehenden beweglichen Brücken tabellarisch erfasst.
Role for Limited Neck Exploration in Young Adults with Apparently Sporadic Primary Hyperparathyroidism
Authors: Adam Laura A. , Smith Brian J. , Calva‐Cerqueira Daniel , Howe James R. , Lal Geeta
Published: March 2008

Background

The risk of multiglandular disease (MGD) dictates the extent of exploration in patients with primary hyperparathyroidism (PHPT). Historically, young patients with PHPT were more likely to have MGD, but the existing literature is sparse and conflicting. We hypothesized that young adults (ages 16–40 years) without familial PHPT have a disease process similar to that in older patients.

Methods

A 22‐year retrospective chart review was performed on patients who underwent neck exploration for PHPT at our tertiary care center. Altogether, 708 charts were reviewed for demographics, family history, laboratory values, operative findings, pathology, and outcomes.

Results

As a group, young adults comprised 14.0% of the total population and were more likely to have preexisting familial disorders of PHPT (p < 0.01), therapeutic failure (p < 0.01), failure to identify an abnormal parathyroid at operation (p < 0.01), and higher reoperative rates (p = 0.02); they were less likely to have single‐gland disease (p = 0.04). Young adults without a family history of the disease demonstrated no disease differences except for a higher rate of symptoms (p < 0.01). Additional analysis found that patients with a family history of hypercalcemia, a sole family member with PHPT, or nephrolithiasis (“possible” family history) were more likely to have MGD (relative risk 2.0).

Conclusions

In this largest single‐institution study of young adults with sporadic PHPT, we conclude that sporadic PHPT in young adults represents a disease entity similar to that in older patients, with no increased risk for MGD, and hence they can be managed with a similar surgical approach. Further studies are needed to assess the role of a “possible” family history as a risk factor for MGD.
Sphincter‐Preserving Operations Following Preoperative Chemoradiation: An Alternative to Abdominoperineal Resection for Lower Rectal Cancer?
Authors: Huh Jung Wook , Jung Eun Joo , Park Yoon Ah , Lee Kang Young , Sohn Seung‐Kook
Published: March 2008

Background

Sphincter‐preserving operations (SPO) for lower rectal cancer are on the rise. In the study reported here, we compared the oncologic outcomes of patients who underwent sphincter‐preserving operations following preoperative chemoradiation for lower rectal cancer with the outcome for patients who underwent abdominoperineal resection (APR).

Methods

This prospective study included 87 patients who underwent proctectomy with curative intent for locally advanced rectal cancer that was located less than 6 cm from the anal verge. Forty‐four patients had APR with no preoperative treatment. Forty‐three patients underwent concurrent chemoradiation therapy (CCRT) consisting of preoperative 5‐fluorouracil–based chemotherapy and pelvic radiation (4500–5040 cGy); this was followed 6 weeks later by surgery (SPO/CCRT). The oncologic outcomes between the two groups were compared, and factors affecting survival were evaluated.

Results

The median follow‐up period was 56.2 months. The overall postoperative complication rates did not significantly differ between SPO/CCRT and APR (32.6% versus 34.2%; p = 0.879). Also, there were no significant differences in the overall recurrence rate (20.9% versus 20.5%; p = 0.956) and 5‐year overall survival rate (70.8% versus 62.9%; p = 0.189) between the two groups. By multivariate analysis, only the pathologic N stage was significantly associated with overall survival (p < 0.001).

Conclusions

Sphincter‐preserving operation with CCRT could be another option for the treatment of locally advanced lower rectal cancer in patients who are clinically considered for APR, with no deterioration of oncologic outcomes. For patients undergoing curative resection for lower rectal cancer, the pathologic N stage can provide valuable prognostic information about survival.
Laparoscopic Adrenalectomy for Metachronous Metastasis from Renal Cell Carcinoma
Authors: Bonnet Stéphane , Gaujoux Sébastien , Leconte Mahaut , Thillois Jean‐Marc , Tissier Frédérique , Dousset Bertrand
Published: March 2008

Background

Metachronous adrenal metastases (AM) from renal cell carcinoma (RCC) are rare. We report our experience of surgical resection in this setting, with particular respect to laparoscopic approach and long‐term outcome.

Methods

A retrospective review of 11 patients who underwent adrenalectomy for metachronous AM from RCC was conducted between 2002 and 2005 in a tertiary referral center.

Results

CT scan findings were those of an adrenal mass ranging from 2 to 13 cm in diameter with a basal density of 12 to 28 Hounsfield Units and strong heterogeneous enhancement following contrast injection. The surgical procedure consisted of controlateral (n = 5), ipsilateral (n = 2), and bilateral (n = 1) laparoscopic adrenalectomy, whereas three patients underwent controlateral open adrenalectomy for adrenal mass >10 cm. Nine patients were recurrence‐free with a median follow‐up of 34 months. In the remaining two patients, lung metastases were discovered at postoperative months 28 and 11, respectively. The former patient is alive and free of disease recurrence 32 months after lung metastasis resection, whereas the latter is currently being treated with sunitinib.

Conclusions

This study confirms that prolonged overall and disease free‐survival can be achieved in selected patient after laparosocpic adrenalectomy for AM from RCC
Applying Modern Error Theory to the Problem of Missed Injuries in Trauma
Authors: Clarke D. L. , Gouveia J. , Thomson S. R. , Muckart D. J. J.
Published: March 2008

Background

Modern theory of human error has helped reduce the incidence of adverse events in commercial aviation. It remains unclear whether these lessons are applicable to adverse events in trauma surgery. Missed injuries in a large metropolitan surgical service were prospectively audited and analyzed using a modern error taxonomy to define its applicability to trauma.

Methods

A prospective database of all patients who experienced a missed injury during a 6‐month period in a busy surgical service was maintained from July 2006. A missed injury was defined as one that escaped detection from primary assessment to operative exploration. Each missed injury was recorded and categorized. The clinical significance of the error and the level of physician responsible was documented. Errors were divided into planning or execution errors, acts of omission or commission, or violations, slips, and lapses.

Results

A total of 1,024 trauma patients were treated by the surgical services over the 6‐month period from July to December 2006 in Pietermaritzburg. Thirty‐four patients (2.5%) with missed injuries were identified during this period. There were 29 men and 5 women with an average age of 29 years (range: 21–67 years). In 14 patients, errors were related to inadequate clinical assessment. In 11 patients errors involved the misinterpretation of, or failure to respond to radiological imaging. There were 9 cases in which an injury was missed during surgical exploration. Overall mortality was 27% (9 patients). In 5 cases death was directly attributable to the missed injury. The level of the physicians making the error was consultant surgeon (4 cases), resident in training (15 cases), career medical officer (2 cases), referring doctor (6 cases).

Conclusions

Missed injuries are uncommon and are made by all grades of staff. They are associated with increased morbidity and mortality. Understanding the pattern of these errors may help develop error‐reduction strategies. Current taxonomies help in understanding the error process, but efforts must be made to develop innovative mechanisms that reduce the potential for error.
Sexually dimorphic effects of maternal separation stress on corticotrophin‐releasing factor and vasopressin systems in the adult rat brain
Authors: Desbonnet Lieve , Garrett Lillian , Daly Emma , McDermott Kieran W. , Dinan Timothy G.
Published: March 2008

Neonatal maternal separation has been widely used to model the well‐established causal relationship between stress in early life and the later development of depression. As corticotrophin‐releasing factor (CRF) and vasopressin (AVP) have been implicated in depression, we aimed to determine the long‐term effects of maternal separation stress on these neuropeptide systems, and also to explore whether these effects are gender‐dependent. Immunohistochemical staining of CRF, AVP and c‐Fos was used to assess whether these neuropeptide systems were affected following an acute swim stress in male and female maternally separated rats.

There was an increase in CRF‐immunoreactivity (IR) (p < 0.05), and an increased co‐localisation of c‐Fos and CRF (p < 0.05) following stress, in the paraventricular nucleus of the hypothalamus (PVN) of maternally separated female rats only. We found no differences in CRF in the hypothalamus of maternally separated and control male rats. However, male maternally separated rats exhibited decreases in AVP‐IR in both the non‐stressed and stressed groups relative to controls (p < 0.001). These data provide further evidence of the involvement of the neuropeptides CRF and AVP in the long‐term maladaptive effects of maternal separation stress in early life. The enhanced CRF response to stress in MS females relative to males suggests that maternal separation stress results in a more reactive neuroendocrinological stress system in females, than in males. Furthermore, the sexually dimorphic effects of maternal separation on these neuropeptides indicate that gender is an important factor influencing the trajectory of early life stress effects on CRF and AVP systems in the brain.
The nutraceutical role of thePhaseolus vulgarisα-amylase inhibitor
Authors: Obiro Wokadala Cuthbert , Zhang Tao , Jiang Bo
Published: March 2008

The present review assesses the potential of thePhaseolus vulgarisα-amylase inhibitor isoform 1 (α-AI1) starch blockers as a widely used remedy against obesity and diabetes. Consumption of the α-amylase inhibitor causes marginal intraluminal α-amylase activity facilitated by the inhibitor's appropriate structural, physico-chemical and functional properties. As a result there is decreased postprandial plasma hyperglycaemia and insulin levels, increased resistance of starch to digestion and increased activity of colorectal bacteria. The efficacy and safety of the amylase inhibitor extracts, however, depend on the processing and extraction techniques used. The extracts are potential ingredients in foods for increased carbohydrate tolerance in diabetics, decreased energy intake for reducing obesity and for increased resistant starch. Research developments in the distribution and biosynthesis of the α-amylase inhibitor, relevant physico-chemical properties, the molecular starch-blocking mechanism, anti-obesity and anti-diabetes effects, safety of extracts and the need for research into their potential anti-colorectal cancer effect are discussed.
Force Microscopy: Applications in Biology and Medicine. Edited by Bhanu P. Jena and J.K. Heinrich Hörber
Authors: Anderson Lloyd L.
Published: March 2008

Force Microscopy: Applications in Biology and Medicine. Edited by Bhanu P. Jena and J.K. Heinrich Hörber. John Wiley & Sons, Inc., Hoboken, NJ; 2006, 300 pages. ISBN 978-0-471-39628-4

The excitement of man's imagination and discovery by the scope of imaging tools, whether tele- or micro-, from 1015 to 10−15 m, ranges from the limits of the known universe to the atomic level. Light and electron microscopy opened vistas of biology and medicine with discovery of the unit of life, the cell and viruses. In the mid-1980s development of scanning probe microscopy allowed studies on live cells at the near-nanometer level. Thus, results from studies using the atomic force microscope (AFM) have given birth to a new field, “NanoCellBiology”, by providing investigators a three-dimensional view of the structure and dynamics of live cells and biomolecules at near-angstrom resolution. Applications of force microscopy to the study of physiological processes of living cells combined with biochemical and molecular biology are yielding rapid advances on how normal and diseased cells function. This exciting book contains 15 chapters by invited experts that examine cell secretory machinery and the discovery of a new cellular structure—the porosome—involved in cell secretion, properties of microbial and cell plant surfaces, cellular interactions of nanodrug delivery systems, intermolecular forces and avidity modulation of leukocyte adhesion molecules, micromechanical properties of lipid bilayers and vesicles, imaging of soft surfaces, high-speed action of biomolecules in motion, cytogenetic applications, and the study of macromolecular interactions in hemostasis and thrombosis.
Assessment of genetic diversity ofGuizotia abyssinica(L.f.) Cass. (Asteraceae) from Ethiopia using amplified fragment length polymorphism
Authors: Geleta Mulatu , Bryngelsson Tomas , Bekele Endashaw , Dagne Kifle
Published: March 2008

Seventeen populations of niger (Guizotia abyssinica), representing all regions in Ethiopia where this crop is grown, were investigated using the amplified fragment length polymorphism (AFLP) technique, in order to determine the extent and distribution of its genetic diversity. A total of 539 AFLP loci were scored using seven primer combinations applied to 170 individual plants. Of these, 90% were polymorphic and all the individuals investigated were genetically unique. Despite the fact that most of the variation was within populations, populations were differentiated at a significant level (analysis of molecular variance;P < 0.001). There were no significant differences between populations in relation to the extent and altitude of cultivation. A significant positive correlation was revealed between Nei's standard genetic distance and geographic distance. Cluster analysis and principal coordinate analysis revealed that populations from the same regions were clustered together in most cases. Further collection of niger germplasm from areas underrepresented in gene bank collections is recommended.