bluuebunny/crossref_metadata_2025 huggingface dataset:
Improved bone ingrowth and fixation with a thin calcium phosphate coating intended for complete resorption
Authors: Reigstad O. , Franke‐Stenport V. , Johansson C. B. , Wennerberg A. , Røkkum M. , Reigstad A.
Published: February 2007

Bonit® is claimed to be a resorbable electrochemically deposited calcium phosphate coating consisting mainly of brushite, which is a hydroxyapatite precursor. This study involved a comparison of Ti6Al4V screw‐shaped implants with and without a 15 ± 5 μm Bonit coating in rabbit tibia and femur, after 6 and 12 weeks of insertion. The biomechanical removal torque test showed significantly increased values for the coated implants after 12 weeks (p < 0.05) but not after 6 weeks of integration. Higher bone‐implant contact was found for the coated implants in the tibia after 6 weeks and for both tibial and femoral screws after 12 weeks (p < 0.05). There was no difference in the inflammatory reaction around the implants, and possible grains of the coating could be detected after 6 weeks, but not after 12 weeks of follow‐up. This unloaded short‐term study has shown promising results for the easily applicable and resorbable coat (Bonit) compared to uncoated titanium‐alloy implants. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Antimicrobial properties of nanocrystalline tetracalcium phosphate cements
Authors: Gbureck Uwe , Knappe Oliver , Hofmann Norbert , Barralet Jake E.
Published: February 2007

The antimicrobial properties of cements prepared from mechanically activated tetracalcium phosphate (maTTCP) were tested with the agar diffusion test using Streptococcus salivarius, Staphylococcus epidermidis, and a clinically isolated plaque mixture. All maTTCP cements showed a significantly higher antimicrobial potency as revealed by inhibition zones of ∼3–5 mm width, compared with a commercial Ca(OH)2//salicylate cement which only produced small inhibition zones around the cement specimens of 1.5 mm or less. This behavior was explained by the formation of amorphous Ca(OH)2 during setting of maTTCP cements, which is thought to have a higher solubility and may release more OH− ions than conventional Ca(OH)2//salicylate cements. In fact, the pH value in the agar gel around the specimens was higher in the case of maTTCP cements (7.8–8.7) compared with the Ca(OH)2//salicylate control (7.0–8.0). The maTTCP cements did not affect the photoactivation of resin‐based composites, and their antimicrobial activity is making them interesting candidates for the use as pulp‐capping agents, endodontic sealers, or cavity liners in dentistry. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Investigation as to the osteoinductivity of macroporous calcium phosphate cement in goats
Authors: Bodde Esther W. H. , Cammaert Camille T. R. , Wolke Joop G. C. , Spauwen Paul H. M. , Jansen John A.
Published: February 2007

For bone formation in critical‐sized or poor healing defects, osteoinductive behavior of synthetic bone grafts is crucial. Although the osteoconductive behavior of calcium phosphate (CaP) cement is generally accepted, its osteoinductive potential is less reported. In this study, osteoinduction of porous CaP cement was investigated. Four goats received each six subcutaneous placed prehardened porous CaP cement implants. Implantation time was 3 and 6 months. After explantation, histological evaluation and scoring with a histological grading scale for soft‐tissue implants were performed. The histological sections revealed that the implants degraded for more than 50% over time. The implants had lost their macroporous structure from 3 months on. A medium‐thick fibrous capsule with a few inflammatory cells surrounded the implants after 3 months. This capsule significantly decreased in thickness after 6 months. Throughout the implant ingrowth of fibrous tissue was seen with scattered foci of inflammatory cells. Cement particles were surrounded by a layer of inflammatory cells. The massive inflammatory response in the interstice was seen after 3 months, which disappeared after 6 months implantation. No bone formation was detected in any of the specimens. The fast degradation and thereby collapsing of the porous structure of our CaP cement implant might have prevented osteoinduction. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
The spectrum of additive BIB designs
Authors: Sawa M. , Matsubara K. , Matsumoto D. , Kiyama H. , Kageyama S.
Published: February 2007

In this article, the existence of additive BIB designs is discussed with direct and recursive constructions, together with investigation of a property of resolvability. Such designs can be used to construct infinite families of BIB designs. In particular, we obtain a series of B(sn,tsm, λt(tsm − 1) (sn‐m − 1)/[2(sm − 1)]) for any positive integer λ, such thatsn(sn − 1) λ ≡ 0 (modsm(sm − 1) and for any positive integertwith 2 ≤ t ≤ sn‐m, wheresis an odd prime power. Connections between additive BIB designs and other combinatorial objects such as multiply nested designs and perpendicular arrays are discussed. A construction of resolvable BIB designs withv = 4kis also proposed. © 2007 Wiley Periodicals, Inc. J Combin Designs 15: 235–254, 2007
Remarks on the second neighborhood problem
Authors: Fidler D. , Yuster R.
Published: February 2007

The second neighborhood conjecture of Seymour asserts that for any orientation G = (V,E), there exists a vertex υ ∈ V so that |N+(υ)| ≤ |N++(υ)|. The conjecture was resolved by Fisher for tournaments. In this article, we prove the second neighborhood conjecture for several additional classes of dense orientations. We also prove some approximation results, and reduce an asymptotic version of the conjecture to a finite case. © 2007 Wiley Periodicals, Inc. J Graph Theory 55: 208–220, 2007
Relationships between total domination, order, size, and maximum degree of graphs
Authors: Yeo Anders
Published: February 2007

A total dominating set, S, in a graph, G, has the property that every vertex in G is adjacent to a vertex in S. The total dominating number, γt(G) of a graph G is the size of a minimum total dominating set in G. Let G be a graph with no component of size one or two and with Δ(G) ≥ 3. In 6, it was shown that |E(G)| ≤ Δ(G) (|V(G)|–γt(G)) and conjectured that |E(G)| ≤ (Δ(G)+3) (|V(G)|–γt(G))/2 holds. In this article, we prove that $\leq (\Delta(G)+ 2\sqrt{\Delta}) (|V(G)| - \gamma_{t}(G))/2$ holds and that the above conjecture is false as there for every Δ exist Δ‐regular bipartite graphs G with |E(G)| ≥ (Δ+0.1 ln(Δ)) (|V(G)|–γt(G))/2. The last result also disproves a conjecture on domination numbers from 8. © 2007 Wiley Periodicals, Inc. J Graph Theory 55: 325–337, 2007
Sulfur and nitrogen supply influence growth, product appearance, and glucosinolate concentration of broccoli
Authors: Schonhof Ilona , Blankenburg Dirk , Müller Siegfried , Krumbein Angelika
Published: February 2007

The effects of insufficient and optimal sulfur (S) and nitrogen (N) supply on plant growth and glucosinolate formation were studied under controlled experimental conditions in broccoli “Monaco”. Here, we report on the interaction between S and N supply, plant growth, and quality parameters and discuss the relevance of this interaction in relation to crop‐management strategies. Broccoli plants supplied with insufficient amounts of S or N showed typical deficiency symptoms and yield decreases. In contrast, total glucosinolate concentrations were high at insufficient N supply, independent of the S level, and low at insufficient S supply in combination with an optimal N supply. This was mainly due to the presence of the alkyl glucosinolates glucoraphanin and glucoiberin. Furthermore, with S concentrations above 6 g (kg DM)–1 and an N : S ratio lower than 10:1, the glucosinolate concentrations were on average around 0.33 g (kg fresh matter)–1 and differed significantly from those plants characterized by an S concentration below 6 g (kg DM)–1 and an N : S ratio above 10:1. In addition, N : S ratios between 7:1 and 10:1 promoted plant yield and enhanced overall appearance. Therefore, to produce broccoli (and potentially other Brassicaceae) with higher crop yields and enhanced product quality in the field, it is vital to establish the optimal S and N nutritional status of the plant and to integrate this information into crop‐management strategy programs.
Some cesium and potassium salts increase the water permeability of astomatous isolated plant cuticles
Authors: Elshatshat Salem , Schreiber Lukas , Schönherr Jörg
Published: February 2007

Salts were applied as aqueous solution to the outer surfaces of astomatous isolated cuticles, and the water was allowed to evaporate. Effects of salt residues on the surfaces of cuticles on water permeability of cuticles were measured at 25°C. A surface dose of 0.2 mol m–2 Cs2CO3 and K2CO3 increased the water permeability of pear leaf cuticles by factors of 9.9 and 3.9, respectively. Na2CO3 was barely effective, and Li2CO3 as well as (NH4)2CO3 had no influence on water permeability. Potassium applied as sulfate, nitrate, or chloride had no effect on the water permeability of pear leaf cuticles, while K+ salts of weak acids (0.2 mol m–2) were effective, as they increased water permeability by factors of 5.4 (K+‐acetate), 3.9 (K2CO3), and 2.0 (K2HPO4), respectively. Sensitivity of Idesia polycarpa leaf cuticles to treatment with K2CO3 at 0.2 mol m–2 was greatest as water permeability was increased 35‐fold, while the water permeability of cuticles from other species tested (astomatous leaf cuticles from Hedera helix, Citrus aurantium, Prunus laurocerasus, Pyrus communis, and Populus canescens; fruit cuticles from Capsicum annuum and Lycopersicon esculentum) increased only by factors ranging from 1.7 to 3.9. Data are discussed in relation to swelling and ion‐exchange properties of cuticles.
Transport of phosphorus in leaf veins of Vicia faba L.
Authors: Hüve Katja , Merbach Wolfgang , Remus Rainer , Lüttschwager Dietmar , Wittenmayer Lutz , Hertel Klaus , Schurr Ulrich
Published: February 2007

The plant nutrient phosphorus (P) is spread throughout the plant within the transpiration stream after uptake in the form of phosphate via the roots. Short‐term distribution is therefore strongly dependent on transpiration rather than on sinks, so that P mainly enters adult leaves. The objective of this work was to investigate the transport of phosphate in leaf veins and its distribution within the leaf. Experiments were performed with broad bean (Vicia faba L. var. Scirocco) using radioactively labeled phosphate. In a relatively new approach, the tracer was monitored by a sensitive imaging plate using Fujifilm's Bioimaging Analyzer System. Radioactive label could be monitored in fresh leaves (without fixing) using exposure times of only 5–20 min. For this reason, the method offered the possibility to obtain several subsequent autoradiographic images of the same sample after different feeding times. Phosphate tracer quickly reached small veins, which were then more intensely labeled than the tissue between them. Within the first 15 min, intercostal fields were only slightly stained. After application of phosphate tracer onto the leaf blade, export from the leaf was pronounced and started within 30 min. Phosphorus is effectively redistributed from adult leaves to sinks such as the terminal bud or growing root tips. Using the imaging method, an impression of the high velocity and effectiveness of this process was obtained. The results furthermore imply that leaf veins may be one of the most important locations where exchange between xylem and phloem transport takes place, although exchange between xylem and phloem was also observed in the shoot axis and in the petioles.
Dynamics of 13C‐labeled mustard litter (Sinapis alba) in particle‐size and aggregate fractions in an agricultural cropland with high‐ and low‐yield areas
Authors: Kölbl Angelika , von Lützow Margit , Rumpel Cornelia , Munch Jean Charles , Kögel‐Knabner Ingrid
Published: February 2007

The application of 13C‐labeled litter enables to study decomposition processes as well as the allocation of litter‐derived carbon to different soil C pools. 13Carbon‐labeled mustard litter was used in order to compare decomposition processes in an agricultural cropland with high‐yield (HY) and low‐yield (LY) areas, the latter being characterized by a finer texture and a lower organic‐C (OC) content. After tracer application, 13C concentrations were monitored in topsoil samples in particulate organic matter (POM) and in fine mineral fractions (silt‐ and clay‐sized fractions).

After 568 d, approximately 5% and 10% of the initial 13C amount were found in POM fractions of LY and HY areas, respectively. Higher amounts were found in POM occluded in aggregates than in free POM. Medium‐term (0.5–2 y) storage of the initial 13C in fine silt‐ and clay‐sized fractions amounts to 10% in HY and LY soils, with faster enrichment but also faster disappearance of the 13C signal from LY soils. Amounts of 80%–90% of the added 13C were mineralized or leached in the observed period. Decomposition of free POM was faster in HY than in LY areas during the first year, but the remaining 13C amounts in occluded‐POM fractions were higher in HY soils after 568 d. High‐yield and low‐yield areas showed different 13C dynamics in fine mineral fractions. In LY soils, 13C amounts and concentrations in mineral‐associated fractions increased within 160 d after application and decreased in the following time period. In HY areas, a significant increase in 13C amounts did not occur until after 568 d. The results indicate initially faster decomposition processes in HY than in LY areas due to different soil conditions, such as soil texture and water regime. The higher silt and clay contents of LY areas seem to promote a faster aggregate formation and turnover, leading to a closer contact between POM and mineral surfaces in this area. This favors the OC storage in fine mineral fractions in the medium term. Lower aggregate formation and turnover in the coarser textured HY soil leads to a delayed C stabilization in silt‐ and clay‐sized fractions.
Effect of alternative anions (Cl–vs. SO$ _4^{2-} $) on concentrations of free amino acids in young tea plants
Authors: Ruan Jianyun , Gerendás Jóska , Haerdter Rolf , Sattelmacher Burkhard
Published: February 2007

The quality of green tea is highly dependent on the concentration of free amino acids, whose profile is dominated by the unique amino acid theanine (N5‐ethyl‐glutamine). A high quality is associated with a high amino acid–to–catechin ratio, but previous results indicated that excessive chloride (Cl–) supply is detrimental for amino acid accumulation. Several experiments were conducted to investigate the effect of chloride on growth and concentrations of free amino acids in young tea plants. Soil‐grown tea plants supplied with different levels of potassium (K) as K2SO4 or KCl exhibited increased concentrations of free amino acid in young shoots only when supplied with K2SO4, and the negative effect of KCl supply was mainly due to a reduced concentration of theanine. Concentrations of other nutrients in plant tissues were not influenced. The uptake of Cl– and its interaction with nitrogen (N) uptake were further investigated in a second experiment, in which soil‐cultivated tea plants were supplied with varying amounts of Cl–. Chloride application reduced yield of young shoots, and severity of leaf damage was related to the concentration of Cl– in leaves. Nitrogen uptake was reduced by Cl– addition. To verify whether the decrease of free amino acids was simply a result of inhibited NO$ _3^- $ assimilation, a third experiment was conducted, in which tea plants were NH$ _4^+ $‐fed in the absence or presence (equivalent to the NH$ _4^+ $ concentration) of Cl–. Again, concentrations of theanine and total free amino acids in young shoots were reduced by Cl– supply, but changes of the free–amino acid pool did not contribute to the maintenance of charge balance. However, concentration of theanine in roots, where it is synthesized, was not influenced by Cl–. Total N concentrations of roots and mature leaves, uptake rate of NH$ _4^+ $, and activity of glutamine synthetase in fibrous roots and young leaves were all unaffected by Cl– as well. It is suggested that translocation of theanine from root to shoot and its catabolism in young shoots might be influenced by Cl–.
A Caspase Inhibitor, IDN-6556, Ameliorates Early Hepatic Injury in An Ex Vivo Rat Model of Warm and Cold Ischemia†
Authors: Hoglen Niel C. , Anselmo Dean M. , Katori Masamichi , Kaldas Marian , Shen Xiu-Da , Valentino Karen L. , Lassman Charles , Busuttil Ronald W. , Kupiec-Weglinski Jerzy W. , Farmer Douglas G.
Published: February 2007

This study examined the efficacy of the caspase inhibitor, IDN-6556, in a rat model of liver ischemia-reperfusion injury. Livers from male Sprague-Dawley rats were reperfused for 120 minutes after 24 hours of 4°C cold storage in University of Wisconsin solution. Portal blood flow measurements estimated sinusoidal resistance, and bile production, alanine aminotransferase activities, and Suzuki scores were evaluated as parameters of hepatocyte/liver injury. Treated livers were exposed to 25 or 50 μM of IDN-6556 in University of Wisconsin storage solution and/or the perfusate. All treatment regimens with IDN-6556 significantly improved portal blood flow measured at 120 minutes, and significant improvements were seen as early as 30 minutes when inhibitor was also present in the perfusate (P < 0.01). All treatment groups with IDN-6556 significantly increased bile production by 3-4-fold compared with controls (P < 0.01), and reductions in alanine aminotransferase activities were seen within 90 minutes of reperfusion (P < 0.05). These data were confirmed by improved Suzuki scores (less sinusoidal congestion, necrosis, and vacuolization) in all treated groups. Livers from the IDN-6556–treated groups had markedly reduced caspase activities and TUNEL (terminal deoxynucleotidyl transferase dUTP nick-end labeling)-positive cells, suggesting reductions in apoptosis. IDN-6556 present in cold storage media ameliorated liver injury due to cold ischemia and reperfusion injury and may be a rational therapeutic approach to reduce the risk of liver ischemia in the clinical setting. Liver Transpl 13: 361–366, 2007. © 2007 AASLD.
Low Risk of Hepatitis B Virus Recurrence After Withdrawal of Long-Term Hepatitis B Immunoglobulin in Patients Receiving Maintenance Nucleos(T)Ide Analogue Therapy
Authors: Wong Stephen N. , Chu Chi-Jen , Wai Chun-Tao , Howell Terese , Moore Charles , Fontana Robert J. , Lok Anna S.F.
Published: February 2007

Hepatitis B virus (HBV) recurrence rates of 0-16% had been reported in patients maintained on nucleoside analogues (NA) after hepatitis B immunoglobulin (HBIG) discontinuation after orthotopic liver transplantation (OLT). However, follow-up in most studies was short. We aimed to determine the long-term risk of HBV recurrence using this strategy. All HBV patients who received ≥7 doses of intravenous HBIG after OLT, with no HBV recurrence while receiving HBIG, and who eventually discontinued HBIG and were maintained on NA, were included. HBV recurrence was defined as HBsAg-positive or HBV DNA ≥5 log copies/mL on 2 consecutive occasions. Twenty-one patients met the inclusion criteria. Immediate post-OLT prophylaxis was combination HBIG and NA in 15 patients, whereas 6 patients received HBIG monotherapy for 62-109 months before NA was added. HBIG was discontinued a median of 26 (range, 0.2-121) months after OLT. Median follow-up post-HBIG discontinuation was 40 (range, 5-51) months. Only 1 patient, who had 12 months of HBIG and was noncompliant to NA therapy, had HBV recurrence, 34 months after HBIG discontinuation. One patient had HBV DNA of 3.3 log copies/mL 47 and 48 months after HBIG discontinuation but remained HBsAg-negative. Lamivudine-resistant mutations were detected in both patients. Probability of HBV recurrence was 0% and 9% at 2 and 4 years after HBIG discontinuation. Three patients had 1-2 episodes of transiently detectable HBV DNA. All were HBV DNA and HBsAg negative on repeated tests over a period of 2-36 months. Maintenance therapy with NA after discontinuation of long-term HBIG therapy is associated with a low risk of HBV recurrence after OLT in compliant HBV patients. Liver Transpl 13:374–381, 2007. © 2007 AASLD.
De Novo Esophageal Neoplasia After Liver Transplantation
Authors: Presser Sabine J. , Schumacher Guido , Neuhaus Ruth , Thuss-Patience Peter , Stieler Jens , Neuhaus Peter
Published: February 2007

The purpose of the study was to determine the incidence, risk factors, treatment, and influence on survival of patients with de novo esophageal cancer after liver transplantation (LT). From 1988 to 2006, 1,926 patients underwent LT in our institution. A total of 9 patients (0.5%) developed a de novo esophageal cancer and 1 patient a cancer of the cardia (0.05%). A retrospective analysis was performed to reveal underlying diseases, timeframes between LT and appearance of cancer, predisposing factors, cancer therapy, complications, immunosuppressive regimens, and survival. Of our 10 patients, 7 (70%) suffered from esophageal squamous cell carcinoma (SCC) and 3 patients (30%) developed an adenocarcinoma, including the patient with cancer of the cardia. A total of 9 patients were transplanted due to alcoholic cirrhosis; 1 patient suffered from hepatocellular carcinoma in nonA-nonB hepatitis-related cirrhosis. Median time to tumor diagnosis was 51 months after transplantation. A total of 5 patients were treated conservatively with combined radiochemotherapy and 5 underwent surgical resection. Patients with radiochemotherapy showed a mean survival of 14.8 months vs. 24.8 months for the patients of the surgery group. No major postoperative complication has been observed. A total of 2 patients of the surgery group are still alive after a follow-up of 15 and 89 months. In conclusion, de novo esophageal and cancer of the cardia after LT is a rare event. In spite of immunosuppression, no increased complication rate has been observed. Patients may have a survival benefit from surgical resection. Liver Transpl 13:443–450, 2007. © 2007 AASLD.
Combined En Bloc Liver Pancreas Transplantation for Children with CF
Authors: Mekeel Kristin L. , Langham Max R. , Gonzalez-Perralta Regino , Reed Alan , Hemming Alan W.
Published: February 2007

Cystic fibrosis (CF) is an inherited genetic defect in epithelial chloride transport that results a multisystem disease affecting the sweat glands and the pulmonary and digestive systems. Although pulmonary disease remains the primary cause of morbidity and mortality in these patients, up to 8% may develop focal biliary cirrhosis and portal hypertension. Liver transplantation is an accepted therapy for these patients. About 85% of CF patients develop pancreatic exocrine insufficiency and up to 34% will develop diabetes requiring insulin. We describe a series of 9 patients who underwent liver transplantation (6 transplantation of liver only [LO], and 3 combined en bloc liver-pancreas [LP] transplantation) for CF-related liver disease at our institution,. All 9 patients had pretransplant pancreatic exocrine insufficiency requiring enzyme supplementation. Of the 9, 5 patients (55%) had preoperative insulin dependent diabetes, including all 3 patients who underwent liver pancreas transplantation. Liver-pancreas transplants were performed en bloc. One-year patient survival for both LO and LP patients was 100%. Five-year patient survival was 83% for the LO patients and 100% for the LP patients. All LP patients are off insulin and do not require pancreatic enzyme supplementation. All patients receiving LO continue to need exogenous pancreatic enzyme supplementation. In the 6 patients who received LO, 2 were insulin dependent prior to surgery, and they remain insulin dependent after transplant. Of the 4 patients who received LO who were not insulin dependent pretransplant, 3 have now developed insulin-dependent diabetes. Patients receiving LO were more likely to be diabetic and require exogenous pancreatic enzymes after transplant than those receiving LP (83% vs. 0%, P = 0.04, and 100% vs. 0%, P = 0.01, respectively). In conclusion, patients with CF and end-stage liver disease requiring liver transplantation may benefit from combined liver-pancreas transplantation. Liver Transpl 13:406–409, 2007. © 2007 AASLD.
Early Immunological Monitoring After Pediatric Liver Transplantation
Authors: Gras Jérémie , Wieërs Grégoire , Vaerman Jean-Luc , Truong Dinh Quang , Sokal Etienne , Otte Jean-Bernard , Délépaut Béatrice , Cornet Anne , de Ville de Goyet Jean , Latinne Dominique , Reding Raymond
Published: February 2007

Cytokine deviation may be a factor contributing to graft acceptance. We analyze, in the context of liver transplantation, circulating cytokine levels and their mRNA precursors in liver biopsy samples to study a putative correlation with early immunologic outcome. Forty primary pediatric liver recipients were submitted to a prospective immune monitoring protocol, including 8 of 40 patients with an early, biopsy-proven acute rejection episode. The 32 patients with graft acceptance showed markedly increased interleukin (IL)-10 blood levels at 2 hours after reperfusion on days 1 and 4 after transplantation as compared with baseline, whereas patients with graft rejection only exhibited increased IL-10 levels at 2 hours. A good correlation was observed between IL-10 peripheral levels and levels ascertained by IL-10 reverse transcriptase–polymerase chain reaction at 2 hours and on day 7. Patients with graft acceptance also showed a decrease in interferon gamma (IFN-γ) at 1 and 2 hours after reperfusion on days 1, 4, 7, 14, and 28 after transplantation. One patient with graft tolerance who had subsequent immunosuppression withdrawal after posttransplantation lymphoproliferative disease showed a similar intraoperative IL-10 pattern, whereas posttransplantation tumor necrosis factor alpha and IFN-γ levels greatly decreased. The occurrence of cytokine immune deviation may therefore be related to early graft acceptance in children who receive liver transplants. Liver Transpl 13:426–433, 2007. © 2007 AASLD.
Expanded Criteria for Liver Transplantation in Patients with Hepatocellular Carcinoma
Authors: Onaca Nicholas , Davis Gary L. , Goldstein Robert M. , Jennings Linda W. , Klintmalm Göran B.
Published: February 2007

Hepatocellular carcinoma (HCC) is a common indication for liver transplantation (LT). Currently, deceased donor LT is approved by the United Network for Organ Sharing for patients with HCC who meet the Milan criteria of a single tumor up to 5 cm or up to 3 tumors up to 3 cm as determined by imaging studies. We analyzed data in the International Registry of Hepatic Tumors in Liver Transplantation from 1,206 patients with HCC. Tumor size and number were determined by gross pathologic examination. Kaplan-Meier recurrence-free survival in patients with a single tumor ≤5 cm or 2-3 lesions all ≤3 cm in diameter was 84.7% at 1 year and 61.8% at 5 years. Overall, patients whose tumor or tumors exceeded these limits had worse survival (67.2% at 1 year and 42.8% at 5 years, P < 0.001); however, not all patients in this group did poorly. Patients with 2-4 tumors ≤5 cm or single lesions ≤6 cm had recurrence-free survival equivalent to patients with a single tumor of 3.1-5.0 cm or 2-3 lesions all ≤3 cm in diameter. These data suggest that current criteria for selecting tumor patients for LT may be too restrictive and could be expanded. Liver Transpl 13:391–399, 2007. © 2007 AASLD.
Screening for Portopulmonary Hypertension
Authors: Perkins James D.
Published: February 2007

Portopulmonary hypertension (POPH) is the elevation of pulmonary artery pressure due to increased resistance to pulmonary blood flow in the setting of portal hypertension. Increased mortality has occurred with attempted liver transplantation in such patients and thus, screening for POPH is advised. We examined the relationship between screening echocardiography and right heart catheterization determinations of pressure, flow, volume, and resistance. A prospective, echocardiography-catheterization algorithm was followed from 1996 to 2005. Consecutive transplantation candidates underwent Doppler echocardiography to determine right ventricular systolic pressure (RVSP). Of 1,235 patients, 101 with RVSP >50 mm Hg underwent catheterization to measure mean pulmonary artery pressure (MPAP), flow via cardiac output (CO), central volume via pulmonary artery occlusion pressure (PAOP), and resistance via calculated pulmonary vascular resistance (PVR). Bland-Altman analysis suggested marked discordance between echocardiography-derived RVSP and catheterization results. All-cause pulmonary hypertension (MPAP >25 mm Hg) was documented in 90/101 (90%) patients. Using current pressure and resistance diagnostic guidelines (MPAP >25 mm Hg, PVR ≥240 dynes/s/cm−5), POPH was documented in 66/101 (65%) patients. Elevated MPAP was due to increased CO and/or PAOP in 35/101 (35%) patients with normal resistance (PVR <240 dynes/s/cm−5). The transpulmonary gradient (MPAP-PAOP) further characterized POPH in the presence of increased volume. Model for end stage liver disease (MELD) scores correlated poorly with MPAP and PVR.

In conclusion

, right heart catheterization is necessary to confirm POPH and frequently identifies other reasons for pulmonary hypertension (

e.g.,

high flow and increased central volume) in liver transplantation candidates. Severity of POPH correlates poorly with MELD scores. (Hepatology 2006;44:1502-1510.) © 2007 AASLD.
Early Noncardiogenic Pulmonary Edema and the Use of PEEP and Prone Ventilation After Emergency Liver Transplantation
Authors: Sykes E. , Cosgrove J. F. , Nesbitt I. D. , O'Suilleabhain C. B.
Published: February 2007

Noncardiogenic pulmonary edema in liver transplant recipients is usually secondary to TRALI (transfusion related acute lung injury) or liver ischemic-reperfusion injury. If persistent, the resultant hypoxemia is associated with increased ventilator days, prolonged length of stay (intensive care and hospital) and increased 28-day mortality. Ventilation strategies for the management of hypoxemia in acute lung injury include moderate to high levels of PEEP (positive and expiratory pressure) and prone ventilation (PV). Such strategies have theoretical adverse effects on graft perfusion. Evidence does however exist to demonstrate that maintenance of cardiac output and correct positioning of the prone patient to allow abdominal excursion can negate the deleterious effects of PEEP and PV. A liver transplant recipient became profoundly hypoxemic on our intensive care unit following the onset of noncardiogenic pulmonary edema. A risk-benefit assessment performed at the time deemed that the potential adverse effects of PEEP and PV were outweighed by the life-threatening nature of hypoxemia. The patient's condition improved following prone positioning and application of PEEP (10-15 cm H2O). We conclude that such ventilation strategies are appropriate in hypoxemic liver transplant recipients if an appropriate risk-benefit assessment is performed. Liver Transpl 13:459–462, 2007. © 2007 AASLD.
Synthesis of Poly(L‐lactide)‐Functionalized Multiwalled Carbon Nanotubes by Ring‐Opening Polymerization
Authors: Chen Guang‐Xin , Kim Hun‐Sik , Park Byung Hyun , Yoon Jin‐San
Published: February 2007

MWNTs are modified to possess hydroxy groups and are used as coinitiators to polymerize L‐lactide by the surface‐initiated ring‐opening polymerization. FT‐IR and TEM observations reveal that the PLLA is covalently attached to the MWNTs (MWNT‐g‐PLLA), and the weight gain as a result of the functionalization is determined by TGA analysis. Two kinds of solvents, namely DMF and toluene, are used to carry out the two series of polymerizations at 140 and 70 °C, respectively, for 2–20 h. The amount of grafted PLLA increases with the reaction time either in DMF or in toluene, but it increases more significantly in DMF at 140 than in toluene at 70 °C, with the reaction time being the same. The grafted PLLA layer on the MWNT is more uniform when the reaction is performed in DMF than in toluene, and some bare surfaces are observed in the TEM image of the MWNT‐g‐PLLA prepared in toluene. The MWNT‐g‐PLLAs are well dispersed in the organic solvents as well as in the PLLA matrix. Incorporation of MWNT‐g‐PLLA greatly improves the tensile modulus and strength without a significant loss of the elongation at break. The specific interaction between the MWNT‐g‐PLLA and the polymer matrix is quantified by way of the Flory‐Huggins interaction parameter, B, which is determined by combining the melting point depression and the binary interaction model.

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Non‐Isothermal Crystallisation Kinetics of In Situ Prepared Poly(ε‐caprolactone)/Surface‐Treated SiO2 Nanocomposites
Authors: Vassiliou Alexandros A. , Papageorgiou George Z. , Achilias Dimitrios S. , Bikiaris Dimitrios N.
Published: February 2007

Poly(ε‐caprolactone)/silica nanocomposites were prepared by the in situ technique. The molecular weight of the polymer was slightly reduced on increasing the amount of filler. Most likely, the silica nanoparticles affected the action of the polymerisation catalyst. Furthermore, it was found that especially for high filler content the silica nanoparticles showed a trend to form aggregates. The non‐isothermal crystallisation of these hybrid organic/inorganic materials was studied. The crystallisation rates seemed to increase upon increasing the content of silica nanoparticles in the composites. When the silica content was above 5 wt.‐%, the molecular weight of the polymer in the hybrids decreased, and the increase in the crystallisation rates was attributed to both the nucleating effect of the nanoparticles and the lower molecular weight. The modified Avrami and Ozawa model were used to study the crystallisation kinetics. It was found that both of the models gave satisfactory results. The nucleation activity of the filler was estimated. The effective activation energy for the non‐isothermal crystallisation was calculated using the isoconversion method of Friedman and the results were compared to those from Kissinger's method. The activation energy was found to decrease upon increasing the filler content, showing that the crystallisation is favoured.

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Melt Crystallization and Morphology of Poly(p‐phenylene sulfide) under High Pressure
Authors: Lu Jun , Huang Rui , Oh Il‐Kwon
Published: February 2007

The high‐pressure melt‐crystallization behaviors of poly(p‐phenylene sulfide) (PPS) were investigated using WAXD, DSC, TEM and SEM. PPS extended‐chain crystals with c‐axis thickness exceeding 4.5 µm were formed at high pressure. The DSC results showed that the melting temperature and melting enthalpy of high‐pressure crystallized PPS samples were up to 327.53 °C and 94.96 J · g−1, respectively, which were higher than the values of ideal PPS perfect crystals used by some researchers, and the melting enthalpy of the samples fluctuated regularly during the thickening growth of the PPS crystals. Other characteristic morphologies obtained at high pressure, i.e. spherulites and rod‐like crystals, were also presented with the SEM measurements.

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Cover Picture: Macromol. Chem. Phys. 4/2007
Authors: Han Seung‐Jin , Kim Bumsu , Suh Kyung‐Do
Published: February 2007

Cover: The picture shows a flexible carbon nanotube (CNT) composite film fabricated by a novel technique with poly(acrylonitrile) (PAN) nanoparticles coated with functionalized multiwall carbon nanotubes (fMCNTs). The conductivity and the electromagnetic interference (EMI) shielding effectiveness of the films were investigated. This technique may be used to improve the dispersity of fMCNTs in the polymer matrix for enhancing the electrical properties of the CNT composite films. Further details can be found in the Full Paper by S.‐J. Han, B. Kim, and K.‐D. Suh* on page 377.
Microwave‐Assisted Single‐Step Synthesis of Poly(lactic acid) by Direct Polycondensation of Lactic Acid
Authors: Nagahata Ritsuko , Sano Daisuke , Suzuki Hidematsu , Takeuchi Kazuhiko
Published: February 2007

The microwave‐assisted direct polycondensation of LA to synthesize PLA has been studied. Microwave irradiation strikingly accelerates the polymerization rate of LA compared to conventional heating. By use of a binary catalyst of SnCl2/p‐TsOH, PLA with a $\overline M _{\rm w}$ of 16 000 is obtained within 30 min under a reduced pressure of around 30 mmHg. MALDI‐TOF MS measurements reveal that the PLA formed is mainly composed of linear polymer and macrocyclics.

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Pancreatic ductal adenocarcinomas induced in syrian hamsters by N‐nitrosobis (2‐oxopropyl) amine contain a c‐Ki‐ras oncogene with a point‐mutated codon 12
Authors: Fujii Hideki , Egami Hiroshi , Chaney William , Pour Parviz , Pelling Jill
Published: February 2007

We have used the polymerase chain reaction and dideoxynucleotide sequencing to amplify and sequence exons 1 and 2 of the c‐Ki‐ras proto‐oncogene from the normal Syrian golden hamster. Similar methods were employed to screen for the presence of point mutations in the c‐Ki‐ras oncogene in primary hamster pancreatic ductal adenocarcinomas (PDC) induced by N‐nitrosobis(2‐oxopropyl)amine (BOP). A GGT to GAT point mutation was detected in codon 12 of the c‐Ki‐ras gene in 10 primary hamster PDCs. This same point mutation was present in two nonclonal cell lines, PC‐1 and PC‐1‐0, established from tumors that were produced in hamsters by subcutaneously implanting a preparation of minced BOP‐induced PDC. Two clonal cell lines, CI‐3 and CI‐7, were cloned from the PC‐1 cell line, and these cell lines also carried the GAT point mutation at codon 12. This point mutation was the same as that detected in > 75% of adenocarcinomas from the human exocrine pancreas. Thus, our findings provide further validation for the use of the BOP‐induced hamster PDC model as a relevant experimental model for human pancreas cancer: not only did the hamster pancreatic ductal adenocarcinomas closely resemble their human counterpart in histopathological morphology and sequential development, but they also contained the same point mutation in codon 12 of the c‐Ki‐ras oncogene, as has been reported for human pancreatic adenocarcinomas.
Preferential methylation of the Ha‐ras proto‐oncogene by methylnitrosourea in rat mammary glands
Authors: Lu Shi‐Jiang , Milligan Jamie R. , Archer Michael C.
Published: February 2007

Activation of the Ha‐ras proto‐oncogene, but not the Ki‐ras or N‐ras genes, has been found in mammary gland carcinomas induced in female rats by a single dose of methylnitrosourea (MNU). Here we show that a 10‐kb restriction fragment containing the Ha‐ras gene was extensively methylated by MNU in DNA isolated from mammary glands of female rats 4 h after carcinogen treatment. Fragments of similar size containing either the Ki‐ras or N‐ras genes were methylated less extensively. The extent of methylation of the three ras genes by MNU correlated with their transcriptional activity. These results suggest that the extent of interaction of a carcinogen with an oncogene, which depends on its transcriptional activity, may be a factor in determining whether the gene is mutated during the initiation of carcinogenesis.
Protein synthesis—dependent cytoplasmic translocation of p53 protein after serum stimulation of growth‐arrested MCF‐7 cells
Authors: Takahashi Kazuhide , Sumimoto Hidetoshi , Suzuki Katsuo , Ono Tetsuo
Published: February 2007

p53 protein was localized in the cytoplasm of growing and in the nucleus of growth‐arrested MCF‐7 cells. While the absolute amount and rate of synthesis of p53 in growing and arrested cells were nearly the same, the protein in growing cells was phosphorylated to a greater extent than in arrested cells. The abilities of the cytoplasmic and nuclear p53 proteins to bind to DNA sequences specific for p53 protein binding did not differ remarkably despite their differential phosphorylation levels. Serum‐induced translocation of the p53 protein from the nucleus to the cytoplasm, as well as DNA and protein synthesis, were inhibited by cycloheximide. These results suggest that the DNA synthesis—associated cytoplasmic translocation of p53 protein in response to serum stimulation depends on de novo protein synthesis and not on alteration of the protein's ability to bind to specific DNA sequences. © 1993 Wiley‐Liss, Inc.
Changes in gap‐junction permeability, phosphorylation, and number mediated by phorbol ester and non‐phorbol‐ester tumor promoters in rat liver epithelial cells
Authors: Matesic Diane F. , Rupp Heather L. , Bonney William J. , Ruch Randall J. , Trosko James E.
Published: February 2007

The effects of three tumor promoters on gap‐junction permeability; connexin 43 and 26 mRNA levels, protein levels, and phosphorylation; and the numbers of gap‐junctional membrane plaques were studied in the rat liver epithelial cell line WB‐F344 to determine whether changes in these parameters correlated with the inhibition of gap‐junction function. 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA; 10 ng/mL), dieldrin (10 μg/mL), and heptachlor epoxide (10 μg/mL) inhibited gap‐junctional intercellular communication (GJIC) assayed by fluorescent dye transfer by 80–90% after a 5‐min exposure and by more than 90% within 1 h. Decreases in steady‐state connexin 43 mRNA levels were detected by northern blot analysis within 1 h and paralleled changes in steady‐state β‐actin mRNA, but these changes did not occur rapidly enough to account for the rapid loss of gap‐junction function. A substantial loss in the number of connexin 43 immunostained gap‐junctional membrane plaques was detected after a 15‐min exposure to all three promoters, but little change had occurred at 5 min. Western blot analyses using connexin 43‐specific antibodies showed changes in the degree of connexin 43 phosphorylation for all three tumor promoters. TPA induced the appearance of a fourth connexin 43‐im‐munoreactive band (P3) and a concomitant decrease in the relative intensity of the unphosphorylated (P0) band within 5 min of treatment. P3, in addition to bands P1 and P2, disappeared after treatment with alkaline phosphatase. In contrast, dieldrin and heptachlor epoxide induced loss of P2 with a concomitant increase in the relative staining intensity of P0 within 1 h of exposure, but no changes were seen after 5 min. Connexin 43 phosphorylation levels recovered in parallel with the recovery of GJIC for all three tumor promoters. Connexin 26 mRNA levels showed little change after a 1‐h exposure to the three promoters, but reductions in connexin 26 immunofluorescent staining were observed. These results suggest that (i) TPA‐induced hyperphosphorylation of connexin 43 occurred fast enough to account for inhibition of GJIC, (ii) dieldrin and heptachlor epoxide modulated connexin phosphorylation in a manner different from TPA by promoting hypophosphorylation of connexin 43, (iii) redistribution of plasma membrane gap‐junctional plaques after treatment with phorbol ester and non‐phorbol‐ester tumor promoters occurred subsequent to changes in gap‐junction permeability, and (iv) changes in connexin mRNA levels could not account for the losses in fluorescent dye coupling induced by these promoters. © 1994 Wiley‐Liss, Inc.
Partial restoration of pre‐transformation levels of lysyl oxidase and transin mRNAs in phenotypic ras revertants
Authors: Oberhuber Hermann , Seliger Barbara , Schäfer Reinhold
Published: February 2007

Neoplastic transformation mediated by ras oncogenes is associated with deregulated expression of genes encoding, for example, various proteases, lysyl oxidase, and smooth‐muscle α‐actin. To define the role of these genes in the initiation or maintenance of the ras‐transformed state, we compared their steady‐state mRNA levels in two different sets of preneoplastic fibroblast lines, ras‐transformed clones, and phenotypic revertants derived from them. Compared with the preneoplastic fibroblasts, the ras‐transformed derivatives exhibited elevated levels of cathepsin L (major excreted protein), transin (stromelysin I, matrix metalloproteinase–3), and collagenase I (matrix metalloproteinase–1) mRNA but undetectable levels of lysyl oxidase mRNA. Partial restoration of lysyl oxidase transcription was observed in four of five phenotypic revertants derived from rat FE‐8 and NIHpEJcI3 cells. The elevated levels of transin mRNA found in NIHpEJcI3 cells were diminished to the pretransformation level in interferon revertants but were not reduced in phenotypic rat FE‐8 revertants expressing a high level of the ras oncoprotein. High steady‐state levels of collagenase I mRNA were dependent on ras expression but were not closely associated with the transformed phenotype. High levels of cathepsin L mRNA were associated with neither high ras expression nor neoplastic transformation. The downregulation of smooth‐muscle α‐actin, characteristic of transformed cell lines, was not reversible in phenotypic revertants. © 1995 Wiley‐Liss Inc.
Organisational susceptibility to fraud and theft, organizational size and the effectiveness of management controls: some UK evidence
Authors: Barnes Paul , Webb Jill
Published: February 2007

This paper examines the principal determinants of an organization's susceptibility to theft and fraud in the context of a rational economic framework in which the level of protection is determined by the minimization of cost. The empirical study shows that, adjusting for differences in organizational type and industrial sector, both organizational susceptibility and the size of a typical theft or fraud increase with organizational size. Access to resources and the manner in which the theft or fraud is perpetrated are also important determinants of the money lost. However, they are unaffected by management controls or the nature of their violation. Copyright © 2007 John Wiley & Sons, Ltd.
New Institutional Economics' contribution to strategic groups analysis
Authors: Tywoniak Stephane , Galvin Peter , Davies Jennifer
Published: February 2007

Rather than consider the two broad strands of strategic group research—performance‐based and behavior‐based studies—as competing approaches, we argue that they relate to complementary levels of analysis. We present a four‐level framework for analyzing structures within industries drawn from New Institutional Economics (NIE) which covers different approaches to strategic group formation from institutional isomorphism and embeddedness through to the firm‐level effects of certain resource deployments. We apply an institutional approach to a case study of the Australian banking industry and supplement this with a quantitative approach based around key strategic variables. This analysis suggests that distinct groups have emerged due to the institutional environment and the different regulatory environments experienced by various banks in the industry. Copyright © 2007 John Wiley & Sons, Ltd.