bluuebunny/crossref_metadata_2025 huggingface dataset:
Resection for Hepatocellular Carcinoma is a Good Option in Child-Turcotte-Pugh Class A Patients With Cirrhosis Who Are Eligible for Liver Transplantation
Authors: Margarit Carlos , Escartín Alfredo , Castells Lluis , Vargas Víctor , Allende Elena , Bilbao Itxarone
Published: September 2005

The best treatment option for patients with single, early hepatocellular carcinoma (HCC) and cirrhosis, good liver function, and absence of portal hypertension remains to be established. The aim of this work was to compare the outcome of liver resection (LR) with that of liver transplantation (LT) for single, early HCC in Child-Turcotte-Pugh class A patients with cirrhosis younger than 70 years of age. Thirty-seven of 134 patients who underwent LR and 36 of 125 who underwent LT for HCC in our unit fulfilled the inclusion criteria. No differences were observed in mean tumor size (3 cm); HCV cirrhosis predominated in the LT group and older age in the LR group. Postoperative mortality was higher and hospital stay longer in the LT group. Patient survival was similar in both groups. Tumor recurrence was higher in the LR group (59% vs. 11%), extrahepatic recurrences predominated after LT and hepatic recurrences after LR. Disease-free survival was significantly better after LT. Eighteen patients presented hepatic recurrence after LR: 5 advanced and 13 early. Seventeen patients—13 with early HCC recurrence and 4 with liver failure—were potential candidates for salvage LT. However, 10 of 17 patients were older than 70 years at this time. Salvage LT could only be performed in 6 patients: 5 for HCC recurrence and 1 for liver failure. Results of salvage LT were similar to those of primary LT. In conclusion, only 27.6% of resected patients were eligible for LT. LR is a good option since it offers similar survival to LT. Salvage liver transplantation was performed in 16.2% of resected patients, with older age being the main contraindication. Outcome of salvage LT was similar to that of primary LT.
Early Hepatic Stellate Cell Activation is Associated With Advanced Fibrosis After Liver Transplantation in Recipients With Hepatitis C
Authors: Russo Mark W. , Firpi Roberto J. , Nelson David R. , Schoonhoven Robert , Shrestha Roshan , Fried Michael W.
Published: September 2005

Recurrent hepatitis C after liver transplantation is a serious problem faced by liver transplant recipients. Activation of hepatic stellate cells is an early step in hepatic fibrogenesis. The aim of this study was to evaluate hepatic stellate cell activation, early after liver transplantation, as a predictor for the subsequent development of advanced fibrosis. Forty-six patients who underwent liver transplantation for hepatitis C and protocol liver biopsies were divided into rapid fibrosers (n = 21), defined as recipients who developed bridging fibrosis or cirrhosis within 2 years of liver transplantation, and slow fibrosers (n = 25). The protocol liver biopsy obtained 4 months after transplantation was stained and quantitated for hepatic stellate cell activation with antibody to alpha smooth muscle actin. Hepatic stellate cell activity was independently associated with rapid fibrosis (odds ratio: 1.6 [95% CI: 1.1,2.2],

P

= 0.013). The c-statistics for the receiver operating characteristic curve for stellate cell activity and fibrosis were 0.78 and 0.67, respectively,

P

= 0.36. The receiver operating characteristic curve for a model including stellate cell activity, histology activity index, and alanine aminotransferase. obtained at month 4 had the best c-statistic (0.88). In recipients with stage 0 or 1 fibrosis on the month 4 liver biopsy who subsequently developed advanced fibrosis, the c-statistic for the receiver operating characteristic curves was significantly better for stellate cell activity than for stage of fibrosis (0.77 and 0.51, respectively;

P

= 0.004). In conclusion, hepatic stellate cell activation early after liver transplantation complements traditional testing for identifying liver transplant recipients with hepatitis C at greatest risk for developing advanced fibrosis.
Evaluation for liver transplantation: Adherence to AASLD referral guidelines in a large veterans affairs center
Authors: Julapalli Venodhar R. , Kramer Jennifer R. , El-Serag Hashem B.
Published: September 2005

Access of patients to liver transplantation involves three levels: referral for evaluation for transplantation, placement on a waiting list for transplantation, and receipt of a liver transplant. No study has formally evaluated access to liver transplantation at the referral level. Therefore, we sought to estimate the magnitude and determinants of consideration of liver transplantation in patients at a single, large Veterans Affairs medical center. Patients with liver disease were identified between October 2002 and September 2003, and their entire medical records were examined for encounters involving potential indications for liver transplantation according to American Association for the Study of Liver Diseases (AASLD) guidelines, mention of liver transplantation, and potential contraindications. Liver transplantation was mentioned in only 59 (20%) of 300 encounters, constituting 41 (21%) of 199 patients satisfying AASLD guidelines for referral. The significant negative independent determinants of mention of liver transplantation were older age (adjusted odds ratio [OR]: 0.31; 95% confidence interval [CI]: 0.13–0.77,

P

= 0.01), alcoholic liver disease (adjusted OR: 0.10; 95% CI: 0.02–0.57,

P

= 0.01), and black race (OR: 0.15; 95% CI: 0.02–0.96,

P

= 0.045). Most patients had potential contraindications that were inferred (but not documented) as reasons for not being evaluated for transplantation; however, a small but significant proportion (7%) had no recorded evidence of contraindications. In conclusion, we found a low rate of mention of liver transplantation in patients who satisfied AASLD guidelines for referral, particularly among patients with alcoholic liver disease and blacks. Deficiencies at the referral level may lead to disparities at further levels of access to liver transplantation. (Liver Transpl 2005.)
Recurrent primary sclerosing cholangitis after liver transplantation: A magnetic resonance cholangiography study with analyses of predictive factors
Authors: Brandsaeter Bjorn , Schrumpf Erik , Bentdal Oystein , Brabrand Kurt , Smith Hans Jorgen , Abildgaard Andreas , Clausen Ole Petter , Bjoro Kristian
Published: September 2005

Primary sclerosing cholangitis (PSC) is a well-established indication for orthotopic liver transplantation (OLT), but post-OLT bile duct strictures complicate the outcome for these patients. These strictures might represent recurrent PSC (rPSC). To estimate the risk factors for post-OLT non-anastomotic bile duct strictures in PSC patients and to find their possible etiology, we performed magnetic resonance cholangiography (MRC) and angiography (MRA) in all PSC patients who had undergone OLT and were alive (median follow-up 6.4 years, range 1.4–15.2 years). This group of PSC patients was compared to a group of 45 non-PSC patients who had also undergone OLT. A logistic regression analysis was performed to find predictors of rPSC. Bile duct strictures were found in 19/49 PSC patients and in 4/45 non-PSC patients (

P

= 0.001). In the PSC group nine patients without other possible explanations for bile duct strictures than rPSC were identified, i.e., the estimated risk of rPSC was 9/49 (18%); surprisingly similar changes were also seen in one patient without a pre-transplant PSC diagnosis. Severe liver disease due to rPSC was seen in 4/9 patients (one patient died and three are being evaluated for re-OLT). Steroid-resistant rejection was the only significant predictor for rPSC. In conclusion, our study shows that by the use of MRC we found more bile duct strictures in PSC patients post-OLT compared to controls and that steroid-resistant rejections was a predictor of such changes. (Liver Transpl 2005.)
Endothelin Activation and Postoperative Renal Failure After Human Liver Transplantation
Authors: Hetz Hubert , Bauer Michael , Lahner Daniel , Faybik Peter , Winning Johannes , Ankersmit Hendrik Jan , Bacher Andreas , Krenn Claus Georg
Published: September 2005

Renal failure is an established risk factor for impaired patient outcome after orthotopic liver transplantation (OLT). As the endothelin pathway is known to be involved in the development of acute renal failure (ARF), we designed a study to clarify its role in ARF following OLT. Twenty consecutive patients with intact kidney function scheduled for their first OLT were prospectively studied. Plasma big endothelin-1 (ET-1) levels were measured before surgery, after graft reperfusion, and on the first and second postoperative day. According to postoperative glomerular filtration rate (GFR), patients were assigned to the acute renal dysfunction group (ARDF) and the non-ARDF group. Each patient's GFR was estimated according to the 4-variable formula used in the modification of diet in renal disease before surgery, daily within the first postoperative week, and at 1, 3, 12, and 24 months after surgery. Postoperative mean big ET-1 levels correlated significantly with the maximum percent decrease of GFR within 3 days after OLT (

P

< 0.01). The proportion of patients who developed ARDF was significantly correlated to mean postoperative big ET-1 quartiles (

P

< 0.01). In the ARDF group, the percent decrease of GFR within 24 months was significantly higher (

P

< 0.05) as compared to the non-ARDF group. In conclusion, patients who develop ARDF immediately after OLT do not fully recover to baseline regarding long-term kidney function. Short-term GFR was significantly correlated with postoperative big ET-1 plasma levels, suggesting renal dysfunction is mediated by the activated endothelin system.
Inflammatory Responses in a New Mouse Model of Prolonged Hepatic Cold Ischemia Followed By Arterialized Orthotopic Liver Transplantation
Authors: Shen Xiu-Da , Gao Feng , Ke Bibo , Zhai Yuan , Lassman Charles R. , Tsuchihashi Sei-Ichiro , Farmer Douglas G. , Busuttil Ronald W. , Kupiec-Weglinski Jerzy W.
Published: September 2005

The current models of liver ischemia/reperfusion injury (IRI) in mice are largely limited to a warm ischemic component. To investigate the mechanism of hepatic “cold” IRI, we developed and validated a new mouse model of prolonged cold preservation followed by syngeneic orthotopic liver transplantation (OLT). Two hundred and forty-three OLTs with or without rearterialization and preservation in University of Wisconsin solution at 4°C were performed in Balb/c mice. The 14-day survivals in the nonarterialized OLT groups were 92% (11/12), 82% (9/11), and 8% (1/12) after 1-hour, 6-hour and 24-hour preservation, respectively. In contrast, hepatic artery reconstruction after 1-hour, 6-hour, and 24-hour preservation improved the outcome as evidenced by 2-week survival of 100% (12/12), 100% (10/10), and 33% (4/12), respectively, and diminished hepatocellular damage (serum alanine aminotransferase /histology). Moreover, 24-hour (but not 1-h) cold preservation of rearterialized OLTs increased hepatic CD4+ T-cell infiltration and proinflammatory cytokine (tumor necrosis factor-α, interleukin 2, interferon-γ) production, as well as enhanced local apoptosis, and Toll-like receptor 4/caspase 3 expression. These cardinal features of hepatic IRI validate the model. In conclusion, we have developed and validated a new mouse model of IRI in which hepatic artery reconstruction was mandatory for long-term animal survival after prolonged (24-h) OLT preservation. With the availability of genetically manipulated mouse strains, this model should provide important insights into the mechanism of antigen-independent hepatic IRI and help design much needed refined therapeutic means to combat hepatic IRI in the clinics.
Recurrent Primary Biliary Cirrhosis
Authors: Guy Jennifer E. , Qian Peiqing , Lowell Jeffrey A. , Peters Marion G.
Published: September 2005

Primary biliary cirrhosis (PBC) recurs after orthotopic liver transplantation (OLT) in up to one-third of patients. These patients are typically asymptomatic, can be identified by abnormal liver biochemistries, and have evidence of histologic recurrence on liver biopsy. The effect of treatment on recurrence has not been determined. This pilot study evaluates the factors associated with recurrent PBC and describes our experience using ursodeoxycholic acid treatment in this patient population. Forty-eight patients with PBC were followed for at least 1 yr post-OLT, and 27 patients (56%) developed abnormal serum alkaline phosphatase. Seventeen patients (35%) had evidence of recurrent PBC by liver biopsy. Patients with recurrent PBC had a trend toward longer warm ischemia times and more episodes of acute cellular rejection in the first year posttransplant, but this was not significant in multivariate analysis. Donor or recipient age, donor and recipient cytomegalovirus status, and dose of immunosuppression did not correlate with recurrence of PBC. Those patients diagnosed with recurrent PBC were placed on ursodeoxycholic acid, 15 mg/kg daily, with improvement in serum alkaline phosphatase in the majority. In conclusion, recurrent PBC is not infrequent post-OLT, and ursodeoxycholic acid can be used with some benefit post-OLT. Treatment effects on long-term survival are not known.
Liver Transplantation for Adult Patients with Hepatocellular Carcinoma in Korea
Authors: Hwang Shin , Lee Sung-Gyu , Joh Jae-Won , Suh Kyung-Suk , Kim Dong-Goo
Published: September 2005

Current selection criteria of liver transplantation (LT) for patients with hepatocellular carcinoma (HCC) were derived from the outcomes of cadaveric donor LT (CDLT). We tried to assess the applicability of such criteria to living donor LT (LDLT) through a comparative study between CDLT and LDLT. We analyzed the outcomes of 312 HCC patients who underwent LT at 4 Korean institutions during 1992 to 2002. There were no gross differences of tumor characteristics between CDLT group (n = 75) and LDLT group (n = 237). Overall 3-year survival rate (3-YSR) was 61.1% after CDLT and 73.2% after LDLT including 38 cases of perioperative mortality. Comparison of HCC recurrence curves did not reveal any statistical difference between these 2 groups. Patient survival period till 50% mortality after HCC recurrence was 11 months after CDLT and 7 months after LDLT. Significant risk factors for HCC recurrence were alpha-fetoprotein level, tumor size, microvascular invasion, gross major vessel invasion, bilateral tumor distribution, and histologic differentiation in the LDLT group on univariate analysis, and tumor size, gross major vessel invasion, and histologic differentiation on multivariate analysis. Milan criteria were met in 70.4%: Their 3-YSR was 89.9% after CDLT and 91.4% after LDLT with exclusion of perioperative mortality. University of California San Francisco criteria were met in 77.7%: Their 3-YSR was 88.1% after CDLT and 90.6% after LDLT. In conclusion, we think that currently available selection criteria for HCC patients can be applicable to LDLT without change of prognostic power.
Living Domino Liver Transplantation in an Adult With Congenital Absence of Portal Vein
Authors: Takeichi Takayuki , Okajima Hideaki , Suda Hiroko , Hayashida Shintarou , Iwasaki Hironori , Ramirez Manuel Zeledon , Ueno Mikako , Asonuma Katsuhiro , Inomata Yukihiro
Published: September 2005

Congenital absence of the portal vein (CAPV) is a rare malformation of the splanchnic venous system. Although CAPV is usually detected in the pediatric age group, our patient was a 35-year-old woman. She had been diagnosed with CAPV in 1996 when she was 27 years old. In 1998, she was placed on hemodialysis due to chronic renal failure. After several episodes of encephalopathy in 2002, liver transplantation (LT) was recommended to her and her family. Since there was no suitable living donor candidate, she was put on the waiting list for a deceased donor liver transplant in Japan. In 2004, her ammonia level increased to around 300 μg/dl, and she went into a coma lasting for three days. After recovering from this event, she underwent a living domino transplantation using a whole liver donated by a familial amyloid polyneuropathy (FAP) patient. Her portal vein, which had drained directly into the inferior vena cava (IVC), was transected together with a cuff of the IVC wall and anastomosed to the graft liver portal vein in an end-to-end fashion. In conclusion, liver transplantation proved to be a safe and effective way to save this patient and improve her quality of life.
Recurrent Herpes Simplex Virus Hepatitis After Liver Retransplantation Despite Acyclovir Therapy
Authors: Longerich Thomas , Eisenbach Christoph , Penzel Roland , Kremer Thomas , Flechtenmacher Christa , Helmke Burkhard , Encke Jens , Kraus Thomas , Schirmacher Peter
Published: September 2005

Herpes virus hepatitis (HSV) represents a form of acute necrotizing hepatitis, which most frequently develops in immunocompromised patients. Therapeutic options include high-dose intravenous acyclovir and liver transplantation. We report the first case of recurrent HSV hepatitis after liver retransplantation, which occurred despite continuous administration of high-dose intravenous antiviral therapy. Because explant histology pointed to initial therapy response, we thought that the reason for recurrence might be due to acyclovir resistance. Most acyclovir resistance is caused by inactivating mutations in the herpes virus

thymidine kinase

gene. HSV infection was detected by histology and proofed by immunohistochemistry. PCR amplification of the herpes virus

thymidine kinase

gene was performed on histology specimens to demonstrate the course of viral infection in liver tissue. Genotypic resistance testing of the herpes virus was performed by sequencing the thymidine kinase amplicon. In serial biopsy, HSV-DNA sequences were only detectable when histology revealed herpes hepatitis. Whereas the primary explant exhibited the wild-type

thymidine kinase

gene, a biopsy of the second graft one month after retransplantation, which showed recurrent herpes virus hepatitis, had a single base insertion within a homopolymeric cytosine stretch. This mutation causes a frame shift leading to a premature stop codon and results in a known acyclovir-resistant herpes strain. In conclusion, we believe that testing for acyclovir-resistant herpes strains should be considered in high-risk patients in whom viral clearance is not achieved serologically to prevent fatal recurrence of disease by using antiviral drugs such as inhibitors of HSV-DNA polymerase or viral helicase primase inhibitors.
Spontaneous reactions of electron‐accepting substituted quinodimethane with substituted styrenes: Inductive and steric effects on the formation of a zwitterionic intermediate
Authors: Mitsuda Yukihiro , Uno Takahiro , Kubo Masataka , Itoh Takahito
Published: September 2005

Spontaneous reactions of an electron‐accepting substituted quinodimethane, 1‐(2,2‐dimethyl‐1,3‐dioxane‐4,6‐dione‐5‐ylidene)‐4‐(dicyanomethylene)‐2,5‐cyclohexadiene, with p‐substituted, α‐substituted, and β‐substituted styrenes were investigated. When p‐substituted styrenes were used as comonomers, no spontaneous reactions took place for styrenes with an electron‐accepting p substituent such as COOMe and CN groups, and both terpolymers and cycloadducts were formed for the other p‐substituted styrenes. When α‐substituted and β‐substituted styrenes were used as comonomers, no reactions occurred for α‐ and β‐substituted styrenes with a bulky phenyl group, and spontaneous reactions took place for those with a smaller methyl group. The reaction products were an alternating copolymer for α‐substituted styrene and both terpolymers and 5‐ethylidene‐2,5‐dimethyl‐1,3‐dioxane‐4,6‐dione for β‐substituted styrenes. The position of the methyl group in the styrenes significantly affected the product formation. This behavior in the spontaneous reactions was discussed on the basis of the ability of formation of the zwitterionic tetramethylene intermediate and its conformation, determined by polar and steric effects of the substituents in the substituted styrenes. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5195–5206, 2005
Synthesis of fluorinated oligomers for supercritical carbon dioxide applications
Authors: Bilgin N. , Baysal C. , Menceloglu Y. Z.
Published: September 2005

Syntheses of various fluorine‐based surfactants, namely fluorinated‐segment‐containing block co‐oligomers, were achieved by the radical polymerization of mainly acrylate‐based monomers. These types of surfactants serve as stabilizers for supercritical carbon dioxide (scCO2) media based applications, for which the effective solubilization of materials in the supercritical phase is generally not possible because of solubility problems faced when CO2 is involved. Initially, a difunctional fluorinated initiator was synthesized in two steps. First, 4,4′‐azobis‐4‐cyanovaleric acid was chlorinated with SOCl2, and then the product, 4,4′‐azobis‐4‐cyanovaleryl chloride, was reacted with a fluorinated alcohol to obtain the initiator for the polymerization reactions. The synthesized triblock co‐oligomers consisted of fluorinated side blocks and a hydrocarbon intermediate block. Efficient solubilization of the materials in scCO2 was observed. It was experimentally shown that the solubility efficiency was affected by specific interactions between CO2 and the oligomers, and these were determined by the nature and size of the inner block and by the chain length of the fluorinated side blocks in comparison with the inner block. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5312–5322, 2005
Dielectric relaxation behavior of poly(methyl methacrylate) under high‐pressure carbon dioxide
Authors: Hirota Shin‐Ichi , Tominaga Yoichi , Asai Shigeo , Sumita Masao
Published: September 2005

An in situ dielectric measurement for atactic poly(methyl methacrylate) (at‐PMMA) was performed under high‐pressure CO2 under various pressures and temperatures. The at‐PMMA has the acetate side group with a large dipole moment. In the glassy state, a local relaxation process (β‐process) can be observed using dielectric measurement. In the rubbery state, the micro‐Brownian motion of main chain (α‐process) occurs, and the β‐process changes into αβ‐process coordinated with the α‐process. The dielectric loss (ε″) spectrum of at‐PMMA in the glassy state is asymmetric because of the density fluctuation for the amorphous structure. The loss peak frequency shifted to higher frequencies, and the relaxation strength increased with increasing CO2 pressure. In the glassy state, the shape of ε″ spectrum became more symmetric with increasing CO2 pressure. These show that the molecular mobility enhanced by the plasticization effect of CO2 allows the dipolar side groups in the high‐density region to contribute to the relaxation process. We also found that the apparent activation energy decreased under high‐pressure CO2. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2951–2962, 2005
The psychological costs of inadequate cervical smear test results: three‐month follow‐up
Authors: French David P. , Maissi Esther , Marteau Theresa M.
Published: September 2005

We have previously shown that upon receipt of inadequate cervical smear test results, women have elevated levels of state anxiety and concern about their test results, similar to those of women receiving abnormal smear test results. The current paper reports data on the psychological impact three months after receiving an inadequate smear test result. Two groups of women who initially received a normal test result (n=184) or either a first or non‐consecutive inadequate smear test result (n=140) responded. Women with initially received inadequate smear test results no longer had higher state anxiety than women who received normal test results. However, women who initially received inadequate smear test results were still more concerned about their test results and less satisfied with the information they had received about these initial test results, even after receiving normal results from repeat cervical smear tests. Concern was strongly predicted by dissatisfaction with information provided about inadequate smear test results. These results underscore the need to improve communication about inadequate cervical smear test results. Copyright © 2005 John Wiley & Sons, Ltd.
Solids Movement in Rotary Kilns in the Slumping Regime: Model Using a Control Plane Parallel to the Steepest Descent
Authors: Gonzalez Luis M. , Romero Joaquim J. B.
Published: September 2005

A new approach is proposed to model the bulk movement of solids in rotary drums operating at low rotation speeds, in slumping and rolling regimes. The model yields an equation similar to Saeman's equation, but which is valid also for the slumping regime and active area in the rolling regime.

The model was developed for constant depth using a control surface containing the steepest descent direction, so that any contribution from sliding particles to flow rate can be neglected. By considering an appropriate virtual kiln, the model is extended to the more general, variable depth situation.
The Simulation of the Electrostatic Spray Painting Process with High‐Speed Rotary Bell Atomizers. Part I: Direct Charging
Authors: Domnick Joachim , Scheibe Andreas , Ye Qiaoyan
Published: September 2005

High‐speed rotary bell atomizers are widely used in the painting industry for high quality applications. They provide a highly uniform film thickness with reasonable transfer efficiency due to the additional electrostatic field supporting the droplet transport towards the target. A basic requirement for this type of paint atomizer is a fine and reproducible atomization of a large variety of different paints, ranging from solvent‐based materials to highly non‐Newtonian water‐borne systems. Furthermore, a broad range of paint flow rates must be covered.

The present contribution summarizes investigations aiming to completely model the electrostatically supported spray painting process by means of CFD. In part I, so‐called direct charging atomizers, where high voltage is applied directly to the rotating bell, are considered. Here, charging of the droplets takes place at the bell edge and corona effects can be neglected.

A powerful commercial code, in the present case Fluent in its current releases, has been extended to account for the electrostatic field and the space charge effect due to the charged paint droplets. As input conditions, the air flow from the shaping air orifices and measured droplet sizes and velocities close to the bell edge using phase‐Doppler anemometry and Fraunhofer diffraction were taken. Also, LDA measurements in front of the target were performed, yielding comparative data of the airflow field.

In general, numerical and experimental results are in good agreement. This is especially true for the final film thickness on the target and the transfer efficiency, i.e. the amount of paint solids finally deposited on the target. The agreement was achieved using a droplet charge of 5% of the droplet size dependent Rayleigh limit.

These results serve as a basis for a complete painting process simulation for complex work pieces, e.g. whole car bodies, in the future. This task, however, can only be successfully completed performing unsteady calculations with moving atomizers along given robot paths.
Milling of Organic Solids in a Jet Mill. Part 1: Determination of the Selection Function and Related Mechanical Material Properties
Authors: de Vegt Onno , Vromans Herman , Faassen Fried , van der Voort Maarschalk Kees
Published: September 2005

The particle size distribution of pharmaceutically active materials and other fine chemicals determines the performance of the final product to a large extent. Often milling of these particles is necessary. It is not possible to determine the milling conditions solely on the basis of the particle size distribution of the starting material, because the (mechanical) properties of the material also determine the desired milling conditions. It is often not possible to optimize milling conditions experimentally because the amount of material available is frequently highly limited. A theoretical approach towards predicting the best milling conditions is needed. The purpose of this study was to develop a method to predict the desired milling conditions given a specific (organic) solid material. The selection function and the breakage distribution function are usually the starting points in modeling the milling process. The selection function is the parameter that includes the material and mill properties. Dimensional analysis made it possible to correlate the selection function with material properties. A set of theories available in the literature enable prediction of the material properties. For different compounds (lactose, paracetamol, a steroidal compound, and two heterocyclic compounds) the selection functions were calculated. The calculations predict differences: lactose reduces slowly in size, while one of the heterocyclic compounds shows the most intense fracture.
Evolutionary plasticity of protein families: Coupling between sequence and structure variation
Authors: Panchenko Anna R. , Wolf Yuri I. , Panchenko Larisa A. , Madej Thomas
Published: September 2005

In this work we examine how protein structural changes are coupled with sequence variation in the course of evolution of a family of homologs. The sequence–structure correlation analysis performed on 81 homologous protein families shows that the majority of them exhibit statistically significant linear correlation between the measures of sequence and structural similarity. We observed, however, that there are cases where structural variability cannot be mainly explained by sequence variation, such as protein families with a number of disulfide bonds. To understand whether structures from different families and/or folds evolve in the same manner, we compared the degrees of structural change per unit of sequence change (“the evolutionary plasticity of structure”) between those families with a significant linear correlation. Using rigorous statistical procedures we find that, with a few exceptions, evolutionary plasticity does not show a statistically significant difference between protein families. Similar sequence–structure analysis performed for protein loop regions shows that evolutionary plasticity of loop regions is greater than for the protein core. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Grouping of amino acid types and extraction of amino acid properties from multiple sequence alignments using variance maximization
Authors: Wrabl James O. , Grishin Nick V.
Published: September 2005

Understanding of amino acid type co‐occurrence in trusted multiple sequence alignments is a prerequisite for improved sequence alignment and remote homology detection algorithms. Two objective approaches were used to investigate co‐occurrence, both based on variance maximization of the weighted residue frequencies in columns taken from a large alignment database. The first approach discretely grouped amino acid types, and the second approach extracted orthogonal properties of amino acids using principal components analysis. The grouping results corresponded to amino acid physical properties such as side chain hydrophobicity, size, or backbone flexibility, and an optimal arrangement of approximately eight groups was observed. However, interpretation of the orthogonal properties was more complex. Although the principal components accounting for the largest variances exhibited modest correlations with hydrophobicity and conservation of glycine, in general principal components did not correspond to physical properties of amino acids. Although not intuitive, these amino acid mathematical properties were demonstrated to be robust and to improve local pairwise alignment accuracy, relative to 20 amino acid frequencies alone, for a simple test case. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Prediction of folding pathway and kinetics among plant hemoglobins using an average distance map method
Authors: Nakajima Shunsuke , Álvarez‐Salgado Emma , Kikuchi Takeshi , Arredondo‐Peter Raúl
Published: September 2005

Computational methods, such as the ADM (average distance map) method, have been developed to predict folding of homologous proteins. In this work we used the ADM method to predict the folding pathway and kinetics among selected plant nonsymbiotic (nsHb), symbiotic (Lb), and truncated (tHb) hemoglobins (Hbs). Results predicted that (1) folding of plant Hbs occurs throughout the formation of compact folding modules mostly formed by helices A, B, and C, and E, F, G, and H (folding modules A/C and E/H, respectively), and (2) primitive (moss) nsHbs fold in the C→N direction, evolved (monocot and dicot) nsHbs fold either in the C→N or N→C direction, and Lbs and plant tHbs fold in the C→N direction. We also predicted relative folding rates of plant Hbs from qualitative analyses of the stability of subdomains and classified plant Hbs into fast and moderate folding. ADM analysis of nsHbs predicted that prehelix A plays a role during folding of the N‐terminal domain of Ceratodon nsHb, and that CD‐loop plays a role in folding of primitive (Physcomitrella and Ceratodon) but not evolved nsHbs. Modeling of the rice Hb1 A/C and E/H modules showed that module E/H overlaps to the Mycobacterium tuberculosis HbO two‐on‐two folding. This observation suggests that module E/H is an ancient tertiary structure in plant Hbs. Proteins 2005. © 2005 Wiley‐Liss, Inc.
A new catalog of protein β‐sheets
Authors: Parisien Marc , Major François
Published: September 2005

Systematic protein folding studies depend on protein three‐dimensional structure annotation, the assignment of amino acid structural types from atomic coordinates. Significant stabilizing factors between adjacent β‐sheet peptide chains have recently been characterized and were not considered during the development of previously published annotation methods. To produce an accurate β‐sheet domain catalog and to encompass the full β‐sheet spectacle, we developed a method, β‐Spider, which evaluates a packing energy between adjacent peptide chains in accordance with the newly discovered stabilizing factors. While considering important energetic factors, our approach also minimizes the use of subjective criteria, such as (ϕ,ψ) boundaries and sets of H‐bonding motifs that are used in other existing methods. As a result of the application of β‐Spider to a set of available high‐resolution X‐ray crystal structures, we present here a new β‐sheet catalog that differs considerably from the one produced by the most acclaimed DSSP method. The catalog includes new H‐bonding motifs that were never reported. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Cover Picture: Guided Growth of Large‐Scale, Horizontally Aligned Arrays of Single‐Walled Carbon Nanotubes and Their Use in Thin‐Film Transistors (Small 11/2005)
Authors: Kocabas Coskun , Hur Seung‐Hyun , Gaur Anshu , Meitl Matthew A. , Shim Moonsub , Rogers John A.
Published: September 2005

The cover picture illustrates a self‐aligned array of single‐walled carbon nanotubes (SWNTs) formed by chemical vapor deposition on a miscut single‐crystal quartz wafer. The background picture schematically illustrates aligned SWNTs on the quartz crystal surface. The top right image shows a scanning electron microscopy image of a dense array of aligned SWNTs. The top left image shows source and drain electrodes of a type of thin‐film transistor that uses an aligned array of SWNTs as the semiconducting material. For more information, please read the Full Paper “Guided Growth of Large‐Scale, Horizontally Aligned Arrays of Single‐Walled Carbon Nanotubes and Their Use in Thin‐Film Transistors” by J. A. Rogers and co‐workers on page 1110 ff.
Uterine artery Doppler at 11–14 weeks of gestation to screen for hypertensive disorders and associated complications in an unselected population
Authors: Gómez O. , Martínez J. M. , Figueras F. , Del Río M. , Borobio V. , Puerto B. , Coll O. , Cararach V. , Vanrell J. A.
Published: September 2005

Objectives

To establish reference values for the first‐trimester uterine artery (UtA) pulsatility index (PI) and to investigate the role of UtA Doppler in the early prediction of hypertensive disorders and their associated complications in an unselected Mediterranean population.

Methods

A prospective study including 1091 consecutive singleton pregnancies undergoing routine early ultrasound screening at 11–14 weeks of gestation was performed. The left and right UtA were examined by color and pulsed Doppler transvaginally. The mean PI and the presence of bilateral protodiastolic notching were cross‐sectionally recorded. Reference ranges were calculated and the pregnancies were followed for occurrence of pre‐eclampsia, gestational hypertension, intrauterine growth restriction, placental abruption and stillbirth. The sensitivity and predictive values of a mean UtA‐PI > 95th percentile and the presence of bilateral notching in the prediction of these pregnancy complications were calculated.

Results

A total of 999 women were finally included. Both the mean UtA‐PI and the prevalence of bilateral notches showed a significant linear decrease between 11 and 14 weeks' gestation. Sixty‐seven (6.7%) pregnancies developed at least one of the formerly described complications, including 22 (2.2%) cases of pre‐eclampsia and 37 (3.7%) cases with intrauterine growth restriction. Compared with women with a normal outcome, complicated pregnancies showed a significantly higher mean PI (2.04 vs. 1.75; P < 0.05, t‐test) and a higher prevalence of bilateral notching (58% vs. 41%; P < 0.05, Chi‐square test). Using the 95th percentile in mean UtA‐PI as a cut‐off, 23.9% (95% CI, 13.7–34.1) of complicated pregnancies and 30.8% (95% CI, 5.68–55.85) of severe cases were identified.

Conclusions

Our results suggest that pregnancies with an increased risk of developing hypertensive disorders and related complications already have an abnormally increased UtA‐PI in early pregnancy. However, the use of a single uterine Doppler measurement for screening purposes in unselected early pregnancy populations has limited clinical value. The use of UtA‐PI combined with other screening tests needs to be determined by further investigation. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
Abnormal umbilical‐portal‐hepatic venous system in two siblings: a sign for congenital cholangiodysplasia
Authors: Hofstaetter C. , Blaas H.‐G. , Isaksen C. , Bolz A.‐G. , Eik‐Nes S. H.
Published: September 2005

We report on two siblings who presented prenatally with a ductus venosus (DV) that was abnormally located between the middle hepatic vein (mHV) and the proximal inferior vena cava (IVC), and with hepatomegaly. The first case presented with polyhydramnios at 33 weeks and therapeutic amniocentesis resulted in premature delivery soon after admission. The neonate died 19 days later and autopsy revealed congenital cholangiodysplasia. The second fetus presented for routine screening at 19 weeks of gestation and was found to have similar abnormalities of the venous system, suggesting the same origin of disease. Termination of pregnancy was performed and autopsy revealed congenital cholangiodysplasia. Our observations suggest that an abnormal umbilical‐portal‐hepatic venous system may be associated with a congenital malformation of the liver. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
Thrombophilia and fetal germinal matrix‐intraventricular hemorrhage: does it matter?
Authors: Ramenghi L. A. , Fumagalli M. , Righini A. , Triulzi F. , Kustermann A. , Mosca F.
Published: September 2005

Germinal matrix‐intraventricular hemorrhage (GMH‐IVH) in the fetus is very rare and the role of thrombophilia in its pathogenesis is unclear. We report on the prenatal diagnosis by magnetic resonance imaging of GMH‐IVH in a 24‐week fetus. The newborn presented posthemorrhagic ventriculomegaly and was found to be heterozygous for two thrombophilic patterns, factor V Leiden and methylenetetrahydrofolate reductase mutation. The combination of this hypercoagulable state and prenatal GMH‐IVH is discussed together with the opportunity of testing these infants for thrombophilia. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
Residential treatment of adolescents with severe behavioural problems
Authors: Scholte E.M. , van der Ploeg J.D.
Published: September 2005

The development of adolescents with severe behavioural problems receiving residential treatment in Holland was empirically studied during 1 year. Treatment methods included a standard program comprising behavioural modification and three specific treatment programs: psychodynamic treatment, structured community living and adventurous learning. The development of the youngsters who remained in the programs () was compared with the development of the youngsters who prematurely dropped out (). All programs had positive developmental outcomes, adventurous learning and structured community living yielded the most behavioural improvement and the standard program the least, and psychodynamic treatment lay in between. Despite the positive developmental outcomes, for many of the youngsters prolongation of the treatment was still needed after 1 year. Requirements for outcome research in residential care are discussed.
Population structure of Merluccius merluccius along the Iberian Peninsula coast
Authors: Castillo Ana G.F. , Alvarez Paula , Garcia-Vazquez Eva
Published: September 2005

Prespawning hake caught in eight locations around the Iberian Peninsula were genetically analysed. The distribution of variation at five microsatellite loci suggests that the species follows a population model of isolation by distance in this geographical area. Three different areas can be identified: the Mediterranean Sea, the Portuguese coast, and the Cantabric Sea. The lack of differentiation between samples caught in the VIIIa,b,d and in the VIIIc ICES Areas suggests that, based on genetic information, the boundary between northern and southern stocks of European hake should be reconsidered.
The role of neurotrophins in the maintenance of the spinal cord motor neurons and the dorsal root ganglia proprioceptive sensory neurons
Authors: Stephens Heather E. , Belliveau Anne C. , Gupta Jagdish S. , Mirkovic Slobodan , Kablar Boris
Published: September 2005

The aim of this study was to approach the question of neuronal dependence on neurotrophins during embryonic development in mice in a way other than gene targeting. We employed amyogenic mouse embryos and fetuses that develop without any skeletal myoblasts or skeletal muscle and consequently lose motor and proprioceptive neurons. We hypothesized that if, in spite of the complete inability to maintain motor and proprioceptive neurons, the remaining spinal and dorsal root ganglia tissues of amyogenic fetuses still contain any of the neurotrophins, that particular neurotrophin alone is not sufficient for the maintenance of motor and proprioceptive neurons. Moreover, if the remaining spinal and dorsal root ganglia tissues still contain any of the neurotrophins, that particular neurotrophin alone may be sufficient for the maintenance of the remaining neurons (i.e., mostly non‐muscle‐ and a few muscle‐innervating neurons). To test the role of the spinal cord and dorsal root ganglia tissues in the maintenance of its neurons, we performed immunohistochemistry employing double‐mutant and control tissues and antibodies against neurotrophins and their receptors. Our data suggested that: (a) during the peak of motor neuron cell death, the spinal cord and dorsal root ganglia distribution of neurotrophins was not altered; (b) the distribution of BDNF, NT‐4/5, TrkB and TrkC, and not NT‐3, was necessary for the maintenance of the spinal cord motor neurons; (c) the distribution of BDNF, NT‐4/5 and TrkC, and not NT‐3 and Trk B, was necessary for the maintenance of the DRG proprioceptive neurons; (d) NT‐3 was responsible for the maintenance of the remaining neurons and glia in the spinal cord and dorsal root ganglia (possibly via TrkB).
what is the role of biomechanics in cardiac surgery?
Authors: pietrabissa riccardo , luisi vincenzo stefano
Published: September 2005

cardiac surgery is a discipline aimed at restoring the best cardiac function of diseased hearts. it is often necessary to implant devices, and surgical tools are of great help in achieving faster and safer procedures. paediatric cardiac surgery is a more recent specialization of cardiac surgery. in paediatric cardiac surgery, the problem is usually related to congenital malformations, consisting in the main of anatomical abnormalities which produce, among other problems, poor oxygenation of the blood, high cardiac afterload, cardiac failure, hemodynamic problems during growth, and so on. the paediatric cardiac surgeon uses his skill and experience to determine the optimal correction in each individual case. in many cases, however, it is not easy to predict the effects of the given surgical procedure that, for success, depends on many different parameters.
in vitro experiments and in vivo implants to evaluate a new silicone-based polyurethane material for replacement of small vessels
Authors: soldani giorgio , bernabei massimo , losi paola , crucean adrian , chiappino dante , burchielli silvia , bernini fabio
Published: September 2005

the idea underscoring our proposed development is to take advantage of the good properties of both polyurethanes (pu) and silicones (pdms). the attributes which make polyurethanes attractive as materials for biomedical applications are their excellent physical–chemical properties, and their relatively good biocompatibility. against their use is the phenomenon of biodegradation that occurs after long-term implantation. silicones, on the other end, are known to have long-term biostability and good haemocompatibility subsequent to their use in several biomedical settings.
assessment by computational and in vitro studies of the blood flow rate through modified blalock-taussig shunts
Authors: pennati giancarlo , migliavacca francesco , gervaso francesca , dubini gabriele
Published: September 2005

surgical repairs of many severe congenital cardiac malformations, such as the procedures used to redirect the flow of blood in the setting of absent or suboptimal perfusions, are performed either using direct vascular anastomosis, or by the insertion of interpositioned prosthetic shunts. examples of these applications can be found when considering those cardiac malformations characterized by the common physiological feature of having a single pumping ventricle, usually due to the incomplete and rudimentary form of the complementary ventricle. in this situation, since the circulation depends on the functionally single ventricle, pulmonary perfusion can be derived from the systemic circulation through a synthetic tube (gore-tex®, falstaff, az, usa), usually connected between the brachiocephalic or subclavian arteries and the right or left pulmonary arteries. this arrangement is called the modified blalock-taussig shunt (fig. 1, left). the effect is to produce parallel circulations (fig. 1, right). survival at this stage is closely dependent on the balance between systemic and pulmonary flows, and thus on the fluid-dynamics through the interposition shunt, which is often the sole source of pulmonary perfusion.
surgical experience with the modified blalock-taussig shunt: what we might learn from mathematical and laboratory studies?
Authors: borini italo , marasini maurizio , cervo giuseppe , calza giovani , lerzo franco , virgone alfredo , zannini lucio
Published: September 2005

clinical experience in the treatment of patients with functionally univentricular hearts has shown the fontan operation to be much less than a perfect therapy. even in ideal patients, acquired elevation of the venous pressures in the systemic circulation, especially in the regions drained by the inferior caval vein, is only a matter of time. for this reason the treatment of this complex form of congenital heart disease is still the object of active scientific debate, as well as considerable ongoing medical and basic research.