bluuebunny/crossref_metadata_2025 huggingface dataset:
Accurate prediction of the blood–brain partitioning of a large set of solutes usingab initiocalculations and genetic neural network modeling
Authors: Hemmateenejad Bahram , Miri Ramin , Safarpour Mohammad A. , Mehdipour Ahmad R.
Published: May 2006

A genetic algorithm‐based artificial neural network model has been developed for the accurate prediction of the blood–brain barrier partitioning (in logBBscale) of chemicals. A data set of 123 logBB(115 old molecules and 8 new molecules) of a diverse set of chemicals was chosen in this study. The optimum 3D geometry of the molecules was estimated by theab initiocalculations at the level of RHF/STO‐3G, and consequently, different electronic descriptors were calculated for each molecule. Indeed, logPas a measure of hydrophobicity and different topological indices were also calculated. A three‐layered artificial neural network with backpropagation of an error‐learning algorithm was employed to process the nonlinear relationship between the calculated descriptors and logBBdata. Genetic algorithm was used as a feature selection method to select the most relevant set of descriptors as the input of the network. Modeling of the logBBdata by the only quantum descriptors produced a 5:4:1 ANN structure with RMS error of validation and crossvalidation equal to 0.224 and 0.227, respectively. Better nonlinear model (RMSVand RMSCVequals to 0.097 and 0.099, respectively) was obtained by the incorporation of the logPand the principal components of the topological indices to electronic descriptors. The ultimate performances of the models were obtained by the application of the models to predict the logBBof 23 molecules that did not have contribution in the steps of model development. The best model produced RMS error of prediction 0.140, and could predict about 98% of variances in the logBBdata. © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 1125–1135, 2006
Multiple pathways in conformational transitions of the alanine dipeptide: An application of dynamic importance sampling
Authors: Jang Hyunbum , Woolf Thomas B.
Published: May 2006

We present multiple dynamic transition pathways on the two‐dimensional dihedral plane between conformational states of the alanine dipeptide. The method used in this study is dynamic importance sampling (DIMS). To perform DIMS, unbiased molecular dynamic simulations are used to generate equilibrium ensembles for the alanine dipeptide within different states. Free energy surfaces on the dihedral plane are calculated from the equilibrium simulations, and four energy minima defined from the surface are used as the starting and ending points for DIMS dynamics. The DIMS method represents an important step towards finding multiple transition pathways within complex biomolecular systems. © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 1136–1141, 2006
High efficiency of meiotic gynogenesis in sea lamprey Petromyzon marinus
Authors: Rinchard Jacques , Dabrowski Konrad , Garcia‐abiado Mary‐ann
Published: May 2006

Induction of androgenesis and gynogenesis by applying a pressure (PS) or heat shock (HS) to double the haploid chromosomal set results in progenies possessing only chromosomes from a single parent. This has never been accomplished in representatives of Agnatha. The objective of this study was to induce gynogenesis and androgenesis in sea lamprey Petromyzon marinus. For gynogenesis experiments, ultraviolet (UV)‐irradiated sperm was used to activate sea lamprey eggs and HS or PS were applied to inhibit the second meiotic division and consequently induce diploidy in the embryos. The UV irradiation of immobilized sperm was performed for 1 min at 1,719 J m−2. HS of 35±1°C for 2 min and PS of 9,000 psi for 4 min were applied at different times after egg activation (8, 12, 20, and 24 min or 8, 16, and 24 min for HS or PS, respectively). Regardless of the induction time of the HS, survivals at pre‐hatching stage were similar. In contrast, PS applied 8 min after activation appears to increase survival rate of pre‐hatched embryos in comparison to 16 and 24 min after activation. In control groups, without shock treatment (no diploidization), there were no survivors. All deformed, gynogenetic embryos were confirmed to be haploids and died prior to burying themselves in the sand. We confirmed by flow cytometry that progenies produced using both shock methods surviving to the next stage, burying in the substrate, were diploid gynogenetic. For the androgenesis experiments, UV‐irradiated eggs (1,719 J m−2 for 1 min) were fertilized with non‐treated sperm and HS was applied to restore diploidy of the eggs. Several attempts have been made to optimize the parameters used. HS of 35±1°C was applied 110, 140, 170, 200, and 230 min after activation for 2 min. Low yields of androgens were obtained and all animals died within a week after hatching. These techniques will allow to establish meiotic gynogenetic lines of sea lamprey for determining sex differentiation in this species and to analyze its hormonal and environmental regulation. J. Exp. Zool. (Mol. Dev. Evol.) 306B, 2006. © 2006 Wiley‐Liss, Inc.
Matrix‐mediated gene transfer to brain cortex and dorsal root ganglion neurones by retrograde axonal transport after dorsal column lesion
Authors: Gonzalez Ana Maria , Berry Martin , Greenlees Lydia , Logan Ann , Baird Andrew
Published: May 2006

Background

In previous studies, we showed that the immobilisation of DNAs encoding basic fibroblast growth factor, neurotrophin‐3 and brain‐derived neurotrophic factor in a gene‐activated matrix (GAM) promotes sustained survival of axotomised retinal ganglion cells after optic nerve injury. Here, we evaluated if the immobilisation of DNAs in a GAM could be an effective approach to deliver genes to axotomised dorsal root ganglion (DRG) neurones after spinal cord injury and if the matrix component of the GAM would modulate the deposition of a dense scar at the injury site.

Methods

We evaluated the expression of the thymidine kinase (TK) reporter gene in brain cortex and DRG after a bilateral T8 dorsal column (DC) lesion using PCR, RT‐PCR and in situ hybridisation analyses. Collagen‐based GAMs were implanted at the lesion site and the cellular response to the GAM was assessed using cell‐specific markers.

Results

At 1 week post‐injury, PCR analyses confirmed that DNATK was retrogradely transported from the DC lesion where the GAM was implanted to the brain cortex and to caudal DRG neurones, and RT‐PCR analyses showed expression of mRNATK. At 7 weeks post‐injury, DNATK was still be detected in the GAM and DRG. In situ hybridisation localised DNATK and mRNATK within fibroblasts, glia, endothelial and inflammatory cells invading the GAM and in DRG neurones. Interestingly, the presence of a GAM also reduced secondary cavitation and scar deposition at the lesion site.

Conclusions

These results establish that GAMs act as bridging scaffolds in DC lesions limiting cavitation and scarring and delivering genes both locally to injury‐reactive cells and distally to the cerebral cortex and to DRG neuronal somata through retrograde axonal transport. Copyright © 2006 John Wiley & Sons, Ltd.
Absence of synaptophysin near cortical neurons containing oligomer Aβ in Alzheimer's disease brain
Authors: Ishibashi Ken‐Ichi , Tomiyama Takami , Nishitsuji Kazuchika , Hara Mitsuhiro , Mori Hiroshi
Published: May 2006

Soluble amyloid β protein (Aβ) oligomers have been considered recently to be responsible for the cognitive dysfunction that sets in prior to senile plaque formation in the Alzheimer's disease (AD) brain. By using the newly prepared antibody against oligomer Aβ, rather than fibrillar or monomer Aβ, we observed that oligomer Aβ in AD brains was localized as clusters ofdot‐likeimmunostains in the neurons in a manner different from that in senile plaques. The relationship of oligomer Aβ with synaptophysin, a synaptic molecular marker, was examined because oligomer Aβ is widely believed to be related to synaptic failure. We observed that immunostainings for synaptophysin were absent near neurons bearing clusters of oligomer Aβ. The present study provides morphological evidence to support the idea that accumulated oligomer Aβ, but not fibrillar Aβ, is closely associated with synaptic failure, which is the major cause of cognitive dysfunction. © 2006 Wiley‐Liss, Inc.
Cellular composition of long‐term human spinal cord‐ and forebrain‐derived neurosphere cultures
Authors: Piao Jing‐Hua , Odeberg Jenny , Samuelsson Eva‐Britt , Kjældgaard Anders , Falci Scott , Seiger Åke , Sundström Erik , Åkesson Elisabet
Published: May 2006

In vitro expanded neural precursor cells (NPCs) may provide a stable source for cell therapy. In search of the optimal cell source for spinal cord repair, we investigated influences of gestational age, regional heterogeneity, and long‐term in vitro propagation. The cellular content of neurosphere cultures prior to and after in vitro differentiation was studied by immunocytochemistry and flow cytometry. Human forebrain and spinal cord NPCs deriving from first‐trimester tissue were cultured as neurospheres in the presence of epidermal growth factor, basic fibroblast growth factor, and ciliary neurotrophic factor. Proteins characteristic for embryonic stem cells, i.e., Tra‐1‐60, Tra‐1‐81, and SSEA‐4, were present in ≈0.5% of the cells in donor tissues and neurospheres. The proportions of nestin‐ and proliferating cell nuclear antigen‐immunoreactive (IR) cells were also maintained, whereas the CD133‐IR population increased in vitro. Glial fibrillary acidic protein‐IR cells increased in number, and in contrast the fraction of β‐tubulin III‐IR cells decreased, at and beyond passage 5 in spinal cord but not forebrain cultures. However, dissociated and in vitro‐differentiated forebrain‐ and spinal cord‐derived neurospheres generated similar proportions of neurons, astrocytes, and oligodendrocytes. Gestational age of the donor tissue, which ranged from 4.5 to 12 weeks for forebrain and from 4.5 to 9.5 weeks for spinal cord, did not affect the proportion of cells with different phenotypes in culture. Thus, cellular composition of human neurosphere cultures differs as a result of long‐term in vitro propagation and regional heterogeneity of source tissue, despite expansion under equal culture conditions. This could in turn imply that human spinal cord and forebrain NPCs present different repair potentials in in vivo settings. © 2006 Wiley‐Liss, Inc.
Glutathione peroxidase 1 and glutathione are required to protect mouse astrocytes from iron‐mediated hydrogen peroxide toxicity
Authors: Liddell Jeff R. , Hoepken Hans H. , Crack Peter J. , Robinson Stephen R. , Dringen Ralf
Published: May 2006

The enzyme glutathione peroxidase 1 (GPx1) is involved in the cellular detoxification of peroxides. To test for the consequences of GPx deficiency in astrocytes, astrocyte‐rich primary cultures from wild‐type and GPx1‐deficient [GPx1(–/–)] mice were exposed to H2O2. In GPx1(–/–) astrocytes, the clearance rate of H2O2 was slower than in wild‐type cells. In contrast to GPx1‐deficient astrocytes, wild‐type cells exhibited, within 2 min of H2O2 application, a rapid and transient accumulation of cellular glutathione disulfide that amounted to 60% of total glutathione. The peroxide treatment did not affect the viability of wild‐type astrocytes, whereas 45% of the GPx1(–/–) cells died within 8 hr. However, the viability of both types of astrocytes was strongly compromised by lowering cellular glutathione content before peroxide application. In contrast, inactivation of catalase caused substantial cell death only in GPx1(–/–) cells but not in wild‐type astrocytes. The cell death observed was prevented by the iron chelators deferoxamine, 1,10‐phenathroline, or 2,2′‐dipyridyl, whereas preincubation with ferric ammonium citrate increased the toxicity of peroxide treatments. These results demonstrate that GPx1 contributes to the rapid clearance of H2O2 by mouse astrocytes and that both GPx1 and a high concentration of glutathione are required to protect these cells from iron‐dependent peroxide damage. © 2006 Wiley‐Liss, Inc.
Study of tryptophan metabolism via serotonin in cerebrospinal fluid of patients with noncommunicating hydrocephalus using a new endoscopic technique
Authors: Comai Stefano , Longatti Pierluigi , Perin Alessandro , Bertazzo Antonella , Ragazzi Eugenio , Costa Carlo V.L. , Allegri Graziella
Published: May 2006

By a recent minimally invasive neuroendoscopic technique, the cerebral ventricles have been reached in a quick, reliable, and harmless way, making possible the study of cerebrospinal fluid (CSF) of the lateral ventricles and, above all, the CSF adjacent to the walls of the third ventricle. Tryptophan, 5‐hydroxytryptophan, serotonin (5‐HT), and 5‐hydroxyindoleacetic acid (5‐HIAA) were measured in CSF by HPLC equipment. Twenty‐six patients affected with noncommunicating hydrocephalus were enrolled in the study and, as controls, 28 subjects not suffering from any neurological disease. The concentrations of tryptophan were higher in right ventricular CSF than in lumbar CSF (P < 0.01). 5‐HT was detectable in the CSF of the right ventricle of hydrocephalic patients. 5‐HIAA was higher in right ventricular CSF than in cisternal and lumbar CSF (P < 0.01), both in controls and in hydrocephalic patients. However, there was a higher concentration of 5‐HIAA in right ventricular (P < 0.05) and cisternal (P < 0.01) CSF in hydrocephalic patients in comparison with controls. In the CSF samples withdrawn during neuroendoscopy, 5‐HT presented the highest concentrations in the pineal recess. The highest amounts of 5‐HIAA were found in the choroid plexus, third and right ventricles, pituitary recess, and aqueduct, and the lowest in pineal recess, subarachnoid space, infundibulum, and interpeduncolar cistern. These results provide new insight into the fate of tryptophan and its metabolites via serotonin in the CSF and suggest the feasibility of the new neuroendoscopic technique for brain metabolic studies. © 2006 Wiley‐Liss, Inc.
Distributions of long dry spells in the iberian peninsula, years 1951–1990
Authors: Lana X. , Martínez M. D. , Burgueño A. , Serra C. , Martín‐Vide J. , Gómez L.
Published: May 2006

Statistical distributions of annual extreme and long dry spells for the Iberian Peninsula are investigated by using a daily database compiled from 43 rain gauges, with the recording period extending from 1951 to 1990 and with a minor lack of data. Dry spell lengths are derived for three different daily rainfall thresholds of 0.1, 1.0 and 5.0 mm/day. On one hand, the generalised extreme value (GEV) and generalised Pareto (GP) distributions are considered for modelling the series of annual extreme (AE) dry spells. On the other hand, both theoretical distributions are assumed for the partial duration (PD) series, which are derived from the dry spell lengths exceeding the 95th percentile. In both cases, a robust estimation of the three parameters of the GEV and GP distributions is obtained by L‐moments. The fit between empirical and theoretical distributions is evaluated by using the 95% confidence bands of the Kolmogorov–Smirnov test and the L‐skewness‐kurtosis distance. Even though AE spells are quite well fitted by the GEV model, the GP distribution is a better option for some rain gauges. The PD series are usually better fitted by the GP distribution, only a few cases being better modelled by the GEV distribution. The basis for climatic drought risk assessment in the Iberian Peninsula is then established for dry spell lengths associated with return periods of 2, 5, 10, 25 and 50 years and accurately reviewed by comparing with results deduced from the AE and PD sampling strategies. As a general feature, both the spatial distribution of the statistical parameters and the dry spell lengths for the different return periods depict a north to south gradient. Some local deviations of this behaviour could be due to the vicinity to the Mediterranean Sea and the Atlantic Ocean. Copyright © 2006 Royal Meteorological Society
Lessons learned from 1,000 living donor liver transplantations in a single center: How to make living donations safe
Authors: Hwang Shin , Lee Sung-Gyu , Lee Young-Joo , Sung Kyu-Bo , Park Kwang-Min , Kim Ki-Hun , Ahn Chul-Soo , Moon Deok-Bog , Hwang Gyu-Sam , Kim Kyung-Mo , Ha Tae-Yong , Kim Dong-Sik , Jung Jae-Pil , Song Gi-Won
Published: May 2006

Serious complications have occurred in a considerable proportion of living donors of liver transplants, but data from a single high-volume center has rarely been available. We analyzed the medical records of donors and recipients of the first 1,000 living donor liver transplants, performed at Asan Medical Center from December 1994 to June 2005, with a focus on donor safety. There were 107 pediatric and 893 adult transplants. The most common diagnoses were biliary atresia in pediatric recipients (63%) and hepatitis B-associated liver cirrhosis (80%) in adult recipients. Right lobe donors were strictly selected based on liver resection rate and steatosis. From 1,162 living donors, 588 right lobes, 6 extended right lobes, 7 right posterior segments, 464 left lobes, and 107 left lateral segments were obtained. Of these, 837 grafts were implanted singly, whereas 325, along with 1 cadaveric split graft, were implanted as dual grafts into 163 recipients. The 5-yr survival rates were 84.8% in pediatric recipients and 83.2% in adult recipients. There was no donor mortality, but 3.2% of donors experienced major complications. Until the end of 2001, the major donor complication rate was 6.7%, with most occurring in right liver donors. Since 2002, liver resection exceeding 65% of whole liver volume were avoided except for young donors with no hepatic steatosis, and the donor complication rate has been reduced to 1.3%. In conclusion, a majority of major living donor complications appear to be avoidable through the strict selection of living donor and graft type, intensive postoperative surveillance, and timely feedback of surgical techniques. Selection of right lobe graft should be very prudently considered if the donor right liver appears to be larger than 65% of the whole liver volume.
Liver Transpl 12:920–927, 2006.

© 2006 AASLD.
Biliary strictures in living donor liver transplantation: Incidence, management, and technical evolution
Authors: Soejima Yuji , Taketomi Akinobu , Yoshizumi Tomoharu , Uchiyama Hideaki , Harada Noboru , Ijichi Hideki , Yonemura Yusuke , Ikeda Tetsuo , Shimada Mitsuo , Maehara Yoshihiko
Published: May 2006

Biliary complications, biliary strictures (BS) in particular, continue to be a significant cause of morbidity after LDLT despite technical refinement. In this study, we assessed the incidence of BS and their management in living donor liver transplantation (LDLT) with special reference to the type of biliary reconstruction. A total of 182 LDLTs performed at our institution for either adult (n = 157) or pediatric (n = 25) patients were included in the study. The duct-to-duct (DD) biliary reconstruction was performed for 106 cases, while the conventional Roux-en-Y hepaticojejunostomy (HJ) was utilized for the remaining 76 cases. Overall, BS developed in 46/182 (25.3%) of the cases (DD, 26.4%; HJ, 25.0%). The 1- and 3-year cumulative incidences of BS were 22.9% and 31.9%, respectively, in the DD group, and 15.2% and 29.1%, respectively, in the HJ group (

P

= not significant). The left-lobe LDLT was more prone to develop BS. Continuous anastomosis tended to be associated with the high incidence of BS in the DD group. The incidence of anastomotic leak was significantly lower in the DD group. Intervention via either precutaneous or endoscopic approach was successful in the majority of cases, although recurrence could occur in some patients. In conclusion, BS was not associated with the type of reconstruction in LDLT. The primary radiological or endoscopic interventions were satisfactory treatments of choice. Technical refinement is an important factor to reduce the incidence of BS.

Liver Transpl 12:979–986, 2006. © 2006 AASLD.
Intraoperative blood loss is a risk factor for complications in donors after living donor hepatectomy
Authors: Ibrahim Salleh , Chen Chao-Long , Lin Chih-Che , Yang Chin-Hsiang , Wang Chih-Chi , Wang Shih-Ho , Liu Yeuh-Wei , Yong Chee-Chien , Concejero Allan , Jawan Bruno , Cheng Yu-Fan
Published: May 2006

Complications in a donor are a distressing but inevitable occurrence, since graft procurement is a major undertaking. Although the technique for procurement has some similarities to hepatic resection, a donor is very unlike a patient with malignancy. The risk factors identified in these patients cannot be extrapolated to donors. Donor hepatectomy carried out from June 1995 to March 2005 in Chang Gung Memorial Hospital, Kaohsiung Medical Center was reviewed with the aim of identifying risk factors for complications. There were 204 living donor liver transplants, with 205 donor hepatectomies, as 1 living donor liver transplantation was a dual graft. Ten donors (4.88%) suffered complications. There was no difference in terms of age, gender, body weight, operation, and parenchymal time between those who had complications and those who did not. There was also no difference in liver function tests between the 2 groups of donors, but the total bilirubin was significantly higher in donors with complications. The graft weight and remnant liver volume were also similar. The proportion of donors with fatty liver was the same between the 2 groups. The mean blood loss in donors with complications was 170 ± 79 mL, and that for donors without complications was 95 ± 77 mL. There was a statistically significant greater blood loss in donors with complications (P < 0.05). The number of segments removed in donors with complications was also higher compared to donors without complications (P < 0.03). Using multivariate analysis, intraoperative blood loss and the number of segments removed were found to be independent risk factors for donor complications. Intraoperative blood loss during graft procurement must be kept low to minimize complications in donors.
Liver Transpl 12:950–957, 2006.

© 2006 AASLD.
Successful ABO-incompatible pediatric liver transplantation utilizing standard immunosuppression with selective postoperative plasmapheresis
Authors: Heffron Thomas , Welch David , Pillen Todd , Asolati Massimo , Smallwood Gregory , Hagedorn Phil , Nam Chang , Duncan Alexander , Guy Mark , Martinez Enrique , Spivey James , Douglas Patricia , Fasola Carlos , De Paolo Jill , Rodriguez John , Romero Rene
Published: May 2006

Transplanting blood group A, B, or O (ABO)-incompatible (ABO-I) liver grafts has resulted in lower patient and graft survival with an increased incidence of vascular and biliary complications and rejection. We report that, without modification of our standard immunosuppression protocol, crossing blood groups is an acceptable option for children requiring liver transplantation. In our study, ABO-I liver grafts—regardless of recipient age—have comparable long-term survival (mean follow-up of 3.25 yr) with ABO-compatible grafts without any difference in rejection, vascular or biliary complications. From January 1, 1999 to October 1, 2005, we studied 138 liver transplants in 121 children: 16 (13.2%) received an ABO incompatible liver allograft. One-year actuarial patient survival for ABO-matched grafts vs. ABO-I grafts was 93.0% and 100%, respectively, whereas graft survival was 83.4% and 92.3%. Additionally, 6 of 16 (37.5%) ABO-I transplanted children had 8 rejection episodes, whereas 47 patients (44.8%) had 121 rejection episodes in the ABO-compatible group. There were no vascular complications and 2 biliary strictures in the ABO-I group. Plasmapheresis was not used for pretransplantation desensitization and was only required in 1 posttransplantation recipient. No child was splenectomized. Six of the 16 children were older than 13 yr of age, suggesting the possibility of successfully expanding this technique to an older population. In conclusion, our outcomes may support the concept of using ABO-I grafts in a more elective setting associated with split and living donor liver transplants.
Liver Transpl 12:972–978, 2006.

© 2006 AASLD.
Fulminant hepatic failure associated with the use of black cohosh: A case report
Authors: Lynch Christopher R. , Folkers Milan E. , Hutson William R.
Published: May 2006

With data from the Women's Health Initiative indicating that estrogen plus progesterone are associated with an increased risk of cardiovascular events, many patients and practitioners are looking for alternative therapies to manage menopausal symptoms. One alternative is black cohosh, an herbal product used primarily to treat these symptoms. In recent years there have been several case reports associating this substance with hepatitis and fulminant hepatic failure. We present a case of a woman who developed hepatic failure requiring liver transplantation from the use of this herb.

Liver Transpl 12:989–992, 2006. © 2006 AASLD.
Five-year follow-up of a hepatitis B virus-positive recipient of hepatitis B surface antigen-positive living donor liver graft
Authors: Hwang Shin , Lee Sung-Gyu , Park Kwang-Min , Kim Ki-Hun , Ahn Chul-Soo , Oh Heung-Bum , Moon Deok-Bog , Ha Tae-Yong , Lim Young-Suk , Jung Dong-Hwan
Published: May 2006

The shortage of cadaveric donor organs has led to the use of living donors and marginal cadaveric donors. To date, there have been only 2 reports on the use of hepatitis B surface antigen (HBsAg)-positive liver grafts. Here we describe the 5-yr posttransplantation sequence of a hepatitis B virus (HBV)-positive recipient who received an HBsAg-positive living donor liver graft. A 43-yr-old HBV-positive patient with hepatorenal syndrome received a living donor liver graft in October 2000 from a 27-yr-old HBsAg-positive carrier with no clinical evidence of HBV infection other than the serologic markers. The recipient recovered slowly after liver transplantation (LT). Recipient serum HBsAg was continuously positive despite anti-HBV therapy with high-dose hepatitis B immunoglobulin (HBIG) and lamivudine. The patient was also treated with famciclovir and interferon; to date, a final regimen of lamivudine and adefovir has kept liver function stable for 20 months. The recipient has lived for 64 months after transplantation. The donor has not revealed any clinical evidence of active hepatitis during follow-up. In conclusion, our result implicates that a recipient of liver graft from an HBsAg-positive carrier may survive for a long period following antiviral therapy with lamivudine and adefovir. Considering this living donor case and previously reported cases, the use of an HBsAg-positive cadaveric liver graft may deserve attention when no other donor is available.
Liver Transpl 12:993–997, 2006.

© 2006 AASLD.
Broadband Dielectric Spectroscopy Studies of Hyperbranched Polyglycerols
Authors: Garcia‐Bernabé Abel , Díaz‐Calleja Ricardo , Haag Rainer
Published: May 2006

Summary: The broadband dielectric spectroscopy of three hyperbranched polyglycerols with different molecular weights has been studied. All of the hyperbranched polyglycerols exhibited three relaxation processes, one related to glass transition (α relaxation) and two sub‐glass processes (β and γ relaxations). The relaxations were analyzed in terms of the Havriliak‐Negami equation. The two sub‐glass processes collapse with α relaxation in different scenarios at high temperatures and only a broad and apparently symmetric relaxation peak is observed. Within this temperature range, two clearly different tendencies were observed at the low and high extremes of the temperature range.

magnified image
Strained Diphosphines Built upon a Calix[4]arene Skeleton. Synthesis of a Highly Active Norbornene Polymerization Catalyst
Authors: Lejeune Manuel , Jeunesse Catherine , Matt Dominique , Sémeril David , Peruch Frédéric , Toupet Loïc , Lutz Pierre J.
Published: May 2006

Summary: The complexes cis‐P,P′‐(η5‐cylopentadienyl)‐{5,17‐dibromo‐11,23‐bis(diphenylphosphino)‐25,26,27,28‐tetrapropoxy‐calix[4]arene}nickel(II) tetrafluoroborate (1) and dibromo‐{5,17‐dibromo‐11,23‐bis(diphenylphosphino)‐25,26,27,28‐tetrapropoxycalix[4]arene}nickel(II) (2), both of which contain a constrained chelating diphosphine, were evaluated for the polymerization of norbornene. Combined with methylaluminoxane, they result in remarkably active systems for the production of high‐molar‐mass vinyl‐type polynorbornene. Turnover frequencies of up to 7.5 × 105 mol(NBE) · mol(Ni)−1 · h−1 are observed. A plausible explanation for their high performances relies on a periodic P–Ni–P bite angle enlargement that temporarily increases the steric hindrance about the catalytic centre, which in turn favours the insertion steps.

Molecular structure of 2.

image

Molecular structure of 2.
Thermoresponsive Polymeric Nanoemulsions
Authors: Koňák Čestmír , Hrubý Martin
Published: May 2006

Summary:Solutions of poly(N‐isopropylacrylamide) (PNIPA) with added sodium dodecyl sulfate (SDS) were investigated by light scattering methods at temperatures of 15–40 °C. The formation of well‐defined nanoparticles of PNIPA was observed on heating at low SDS additions. The effects of PNIPA and SDS concentrations and the molecular weight of PNIPA on nanoparticle parameters were investigated. An interpretation based on stabilization of PNIPA nuclei by SDS was suggested.

The proposed mechanism of nanoparticle formation.

image

The proposed mechanism of nanoparticle formation.
Expectation and the placebo effect in Parkinson's disease patients with subthalamic nucleus deep brain stimulation
Authors: Mercado Rodrigo , Constantoyannis Constantine , Mandat Tomasz , Kumar Ajit , Schulzer Michael , Stoessl A. Jon , Honey Christopher R.
Published: May 2006

To determine whether the degree to which a patient with Parkinson's disease expects therapeutic benefit from subthalamic nucleus–deep brain stimulation (STN‐DBS) influences the magnitude of his or her improved motor response, 10 patients with idiopathic Parkinson's and bilateral STN‐DBS were tested after a 12‐hour period off medication and stimulation. Four consecutive UPDRS III scores were performed in the following conditions: (a) stimulation OFF, patient aware; (b) stimulation OFF, patient blind; (c) stimulation ON, patient aware; and (d) stimulation ON, patient blind. Statistical significance (P = 0.0001) was observed when comparing main effect ON versus OFF (mean ON: 32.55; mean OFF: 49.15). When the stimulation was OFF, patients aware of this condition had higher UPDRS motor scores than when they were blinded (mean: 50.7 vs. 47.6). With the stimulation ON, UPDRS motor scores were lower when the patients were aware of the stimulation compared with when they were blinded (mean: 30.6 vs. 34.5). The interaction between these levels was significant (P = 0.049). This variation was important for bradykinesia and was not significant for tremor and rigidity. The authors conclude that the information about the condition of the stimulation enhanced the final clinical effect in opposite directions. The results presented support the role of expectation and placebo effects in STN‐DBS in Parkinson's disease patients. © 2006 Movement Disorder Society
Two cases of ischemia associated with subthalamic nucleus stimulator implantation for advanced Parkinson's disease
Authors: Novak Kevin E. , Nenonene Emmanuel K. , Bernstein Lawrence P. , Vergenz Sandra , Medalle Gina , Prager Jordan M. , Eller Theodore W. , Cozzens Jeffrey W. , Rezak Michael
Published: May 2006

Deep brain stimulation is generally a safe and effective method of alleviating motor impairment in advanced‐stage Parkinson's disease patients. However, adverse events of surgery have been noted, such as hemorrhage, infection, seizures, and device failure. In this report, we describe 2 cases of the unusual adverse event of ischemia associated with subthalamic nucleus stimulator implantation. We present the intraoperative neurological symptoms, microelectrode recording data, imaging findings, and other correlated events. In the first case, the clinical effects of ischemia were evident intraoperatively and coincided with silence during microelectrode recording from the ischemic region. In the second case, the timing of the ischemic event could not be determined precisely but also was associated with a difficult mapping. Subcortical ischemia may be an underrecognized event that confounds neurophysiological mapping of deep brain structures and affects clinical outcomes. © 2006 Movement Disorder Society
Striatal dopa and glucose metabolism in PD patients with freezing of gait
Authors: Bartels Anna L. , de Jong Bauke M. , Giladi Nir , Schaafsma Joanna D. , Maguire R. Paul , Veenma Lammy , Pruim Jan , Balash Yacov , Youdim Moussa B.H. , Leenders Klaus L.
Published: May 2006

In Parkinson's disease (PD), freezing suggests sudden and transient blocks of motor behavior during initiating or continuous repetitive movements. Its underlying pathophysiology remains unclear. The objective of this study is to compare striatal dopamine metabolism and cerebral glucose metabolism between PD patients with and without freezing of gait (FOG). A total of 10 PD patients with FOG at off and 7 PD patients without FOG underwent brain positron emission tomography with 18[F]‐6‐fluoro‐levodopa (FDOPA) and 18[F]‐fluordesoxyglucose (FDG). Striatum decarboxylase activity was expressed by metabolic influx constants of the striatum related to the occipital lobe (Kocc). FDG uptake in caudate and putamen was normalized to global FDG uptake. Region of interest (ROI) analysis of striatal regions was used, as well as voxel‐based analysis by statistical parametric mapping (SPM). ROI analysis did not reveal differences in striatal FDOPA and FDG uptake between the groups. SPM showed lower putaminal FDOPA uptake (P = 0.05 uncorrected) with increased FDG uptake (P = 0.01 uncorrected) in freezing PD, whereas caudate uptake of the two tracers was reduced. Freezing‐related cortical FDG decrease was found in (right) parietal regions. In conclusion, in freezing PD, caudate uptake of FDG and FDOPA was reduced, whereas putamen FDOPA decrease was associated with FDG increase. Right hemisphere circuitry seemed to be more affected in freezing patients. © 2006 Movement Disorder Society
Boundary value problem for theN‐dimensional time periodic Vlasov–Poisson system
Authors: Bostan M.
Published: May 2006

In this work, we study the existence of time periodic weak solution for theN‐dimensional Vlasov–Poisson system with boundary conditions. We start by constructing time periodic solutions with compact support in momentum and bounded electric field for a regularized system. Then, thea prioriestimates follow by computations involving the conservation laws of mass, momentum and energy. One of the key point is to impose a geometric hypothesis on the domain: we suppose that its boundary is strictly star‐shaped with respect to some point of the domain. These results apply for both classical or relativistic case and for systems with several species of particles. Copyright © 2006 John Wiley & Sons, Ltd.
Predictive value of initial urodynamic pattern on urinary continence in patients with myelomeningocele
Authors: Kessler Thomas M. , Lackner Jakob , Kiss Gustav , Rehder Peter , Madersbacher Helmut
Published: May 2006

Aims

To investigate whether the initial urodynamic pattern may predict urinary continence and the need for adjunctive incontinence surgery in patients with myelomeningocele.

Patients and Methods

One hundred and twenty‐three patients with myelomeningocele were included in our retrospective study. The patients were divided based on the urodynamic pattern at initial evaluation into four categories: overactive detrusor with overactive (spastic) sphincter (group 1, n = 43), overactive detrusor with underactive/acontractile sphincter (group 2, n = 37), underactive/acontractile detrusor with overactive (spastic) sphincter (group 3, n = 8), and underactive/acontractile detrusor with underactive/acontractile sphincter (group 4, n = 35). Urinary continence status at the last follow‐up and the need for adjunctive incontinence surgery were compared between the four groups.

Results

Mean follow‐up was 10 years and mean age at the last follow‐up 17 years. A socially acceptable continence status (continent or socially dry) was achieved in 74% and was significantly different among the four groups (P = 0.023): 86% and 87% of the patients in group 1 and 3 became continent or socially dry, but only 57% and 74% of those in group 2 and 4, respectively. Although none of the patients in group 3 underwent adjunctive incontinence surgery compared to about 25% in the other groups, statistically the difference was not significant (P = 0.48).

Conclusions

The initial urodynamic pattern is very useful in counseling families by predicting urinary continence in patients with myelomeningocele. The chances of becoming continent or at least socially dry are best for patients with overactive (spastic) sphincter. Neurourol. Urodynam. 25:361–367, 2006. © 2006 Wiley‐Liss, Inc.
Dopaminergic mechanisms controlling urethral function in rats
Authors: Ogawa Teruyuki , Seki Satoshi , Masuda Hitoshi , Igawa Yasuhiko , Nishizawa Osamu , Kuno Sadako , Chancellor Michael B. , de Groat William C. , Yoshimura Naoki
Published: May 2006

Aims

To investigate the role of dopamine receptor subtypes in the control of urethral activity.

Methods

Simultaneous recordings of intravesical and urethral perfusion pressure (UPP) were performed in rats under urethane anesthesia. Changes in coordinated activity of the bladder and urethral sphincter were examined following intravenous (i.v.), intrathecal (i.t.), or intracerebroventricular (i.c.v.) administration of dopamine D1‐ and D2‐like receptor agonists (SKF38393 and quinpirole, respectively) and antagonists (SCH23390 and remoxipride, respectively).

Results

Quinpirole (0.03, 0.1, and 0.3 mg/kg i.v.) dose‐dependently decreased baseline urethral pressure to 45.33 ± 5.8, 33.7 ± 3.3 (P < 0.05, n = 6), and 27.7 ± 3.3 cm H2O (P < 0.05, n = 5) from the control value (46.0 ± 4.0 cm H2O), respectively. i.c.v. injection of quinpirole (1 µg) decreased baseline urethral pressure to 33.6 ± 5.0 cm H2O (P < 0.05, n = 4) from the control value (51.4 ± 4.9 cm H2O) in contrast to the insignificant effects of i.t. administration of the drug (3 µg). The decrement of baseline pressure induced by quinpirole (0.1 mg/kg i.v.) was suppressed by α‐bungarotoxin (BGT), a neuromuscular blocking agent. SCH23390 (1 and 3 mg/kg, i.v.) dose‐dependently decreased the frequency of high frequency oscillation (HFO) of the urethral sphincter. SKF38393 or remoxipride did not have significant effects on any parameters of bladder and urethral activity.

Conclusions

These results indicate that activation of D2‐like dopamine receptors at a supraspinal site can suppress activity of the striated muscle urethral sphincter. Thus, decreased urethral resistance induced by D2 dopamine receptor activation might aggravate urge incontinence symptoms often seen in patients with Parkinson's disease (PD). Neurourol. Urodynam. © 2006 Wiley‐Liss, Inc.
Analysis of prognostic factors regarding the outcome after a transurethral resection for symptomatic benign prostatic enlargement
Authors: Seki Narihito , Takei Mineo , Yamaguchi Akito , Naito Seiji
Published: May 2006

Aims

To identify preoperative predictive variables regarding treatment outcomes following transurethral resection of the prostate (TURP) of patients with symptomatic benign prostatic enlargement (BPE).

Methods

A retrospective study was conducted in 384 patients of 1,397 men who had undergone TURP for symptomatic BPE. All the patients had completed the evaluation of International Prostate Symptom Score (I‐PSS), and quality of life (QOL) index, and had undergone full urodynamics before the surgery. Outcomes were assessed at 12 months after surgery. The association between baseline variables and the improvement in outcome variables was statistically analyzed.

Results

Preoperative urodynamic abnormalities included bladder outlet obstruction (BOO) in 315 (82.0%), detrusor underactivity in 91 (23.7%), and detrusor overactivity (DO) in 160 (41.7%). Multivariate analysis showed that the presence of DO and a higher degree of BOO were both associated with postoperative improvement both in I‐PSS and the QOL. The initial level of storage symptoms correlated with an improvement in the QOL.

Conclusions

The association between those variables obtained by preoperatively performed urodynamic analysis and the degree of improvement in lower urinary tract symptom and QOL following TURP was statistically elucidated in a large number of patients with symptomatic BPE. A higher degree of baseline BOO positively predicts the postoperative improvement in I‐PSS and QOL, while the baseline DO negatively predict it. Neurourol. Urodynam. © 2006 Wiley‐Liss, Inc.
PACAP 38 is involved in the non‐adrenergic non‐cholinergic inhibitory neurotransmission in the pig urinary bladder neck
Authors: Hernández Medardo , Barahona María Victoria , Recio Paz , Bustamante Salvador , Benedito Sara , Rivera Luis , García‐Sacristán Albino , Prieto Dolores , Orensanz Luis M.
Published: May 2006

Aims

To investigate the role played by pituitary adenylate cyclase activating polypeptide 38 (PACAP 38) in the non‐adrenergic non‐cholinergic (NANC) neurotransmission of the pig urinary bladder neck.

Methods

Urothelium‐denuded bladder neck strips were dissected and mounted in organ baths containing a physiological saline solution (PSS) at 37°C and gassed with 5% CO2and 95% O2, for isometric force recording. The relaxations to transmural nerve stimulation (EFS) or PACAP 38 were performed on strips precontracted with 1 µM phenylephrine (PhE). EFS experiments were carried out in the absence and the presence of guanethidine (10 µM), atropine (0.1 µM), and NG‐nitro‐l‐arginine (L‐NOARG, 100 µM), to block noradrenergic neurotransmission, muscarinic receptors, and nitric oxide (NO) synthase, respectively.

Results

EFS (2–16 Hz, 1 ms duration, 20 sec trains, 75 mA current output) evoked frequency‐dependent relaxations which were reduced by the VIP/PACAP receptor antagonist PACAP (6–38) (3 µM), and by the neurotoxin of the capsaicin‐sensitive primary afferents capsaicin (10 µM), and abolished by the neuronal voltage‐activated Na+channel blocker tetrodotoxin (TTX, 1 µM). The vasoactive intestinal peptide (VIP) receptor antagonist [Lys1, Pro2,5, Arg3,4, Tyr6]‐VIP (3 µM) failed to modify the EFS‐induced relaxations. PACAP 38 (1 nM–1 µM) induced concentration‐dependent relaxations which were reduced by PACAP (6–38), TTX and by the neuronal voltage‐gated Ca2+channel inhibitor ω‐conotoxin GVIA (ω‐CgTX, 1 µM).

Conclusions

The results suggest that PACAP 38, mainly released from capsaicin‐sensitive primary afferents, is involved in the NANC inhibitory neurotransmission of the pig urinary bladder neck, producing relaxation through neuronal and muscle VIP/PACAP receptor activation. Neurourol. Urodynam. © 2006 Wiley‐Liss, Inc.
Gene expression analysis of dendritic/Langerhans cells and Langerhans cell histiocytosis
Authors: Rust R , Kluiver J , Visser L , Harms G , Blokzijl T , Kamps W , Poppema S , van den Berg A
Published: May 2006

Langerhans cell histiocytosis (LCH) is a neoplastic disorder that results in clonal proliferation of cells with a Langerhans cell (LC) phenotype. The pathogenesis of LCH is still poorly understood. In the present study, serial analysis of gene expression (SAGE) was applied to LCs generated from umbilical cord blood CD34+ progenitor cells to identify LC‐specific genes and the expression of these genes in LCH was investigated. Besides the expression of several genes known to be highly expressed in LCs and LCH such as CD1a, LYZ, and CD207, high expression of genes not previously reported to be expressed in LCs, such as GSN, MMP12, CCL17, and CCL22, was also identified. Further analysis of these genes by quantitative RT‐PCR revealed high expression of FSCN1 and GSN in all 12 LCH cases analysed; of CD207, MMP12, CCL22, and CD1a in the majority of these cases; and CCL17 in three of the 12 cases. Immunohistochemistry confirmed protein expression in the majority of cases. The expression of MMP12 was most abundant in multi‐system LCH, which is the LCH type with the worst prognosis. This suggests that expression of MMP12 may play a role in the progression of LCH. These data reveal new insight into the pathology of LCH and provide new starting points for further investigation of this clonal proliferative disorder. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Clinical proteomics: Study of a cryogel
Authors: Robert Daniel , Barelli Stefano , Crettaz David , Bart Pierre‐Alexandre , Schifferli Jürg A. , Betticher Daniel , Tissot Jean‐Daniel
Published: May 2006

Cryoproteins are proteins precipitating at low temperature. Usually, the precipitate contains immunoglobulins (Igs), and are therefore called cryoglobulins. Very rarely, Igs do not precipitate, but, upon cooling, form a gel. Here, we report a case of cryogel observed in a patient presenting with Waldenström's disease. Using proteomic tools, a monoclonal IgM was identified as being the cause of the gel formation. Furthermore, addition of H2O before incubation at 4°C demonstrated that the monoclonal IgM was precipitable as a type I cryoglobulin (hypocryoglobulin).
New preparative procedure for photoluminescent metallopolymers having a biphenyl‐2,2′‐diyl iridium(III) unit bound to a phosphine copolymer ligand
Authors: Koga Yuji , Ueno Keita , Matsubara Kouki
Published: May 2006

We first prepared polymer‐bound photoluminescent iridium complexes bearing a cyclometalated 2,2′‐biphenylene ligand via an easy procedure in which the metallopolymer was synthesized by the reaction of a metal precursor with a polymer ligand. The iridium compound, [Ir(cod)(biph)Cl]2 (where cod and biph are 1,5‐cyclooctadiene and biphenyl‐2,2′‐diyl, respectively), was used as the iridium material, and a copolymer built by the radical copolymerization of 4‐styryldiphenylphosphine and methyl methacrylate was employed as the polymer ligand. The obtained metallopolymers were highly crosslinked by iridium atoms forming PIrP bonds. The content of the iridium was experimentally clarified to be in the range of 0.06–0.6 mmol/g of the polymer. Photoluminescence of the iridium polymer in the solid state was observed at 597 nm when the polymer was irradiated at 350 nm. As the Ir content in the copolymer increased to 0.2 mmol/g, the intensity of the luminescence also increased, but more iridium content decreased the intensity. Furthermore, the intensity of the photoluminescence in these photoluminescent polymers depended on the molecular weight of the copolymer ligands. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4204–4213, 2006