bluuebunny/crossref_metadata_2025 huggingface dataset:
Deletion of Frs2α from the ureteric epithelium causes renal hypoplasia
Authors: Sims-Lucas Sunder , Cullen-McEwen Luise , Eswarakumar Veraragavan P. , Hains David , Kish Kayle , Becknell Brian , Zhang Jue , Bertram John F. , Wang Fen , Bates Carlton M.
Published: September 2009

Fibroblast growth factor receptor 2 (Fgfr2) signaling is critical in maintaining ureteric branching architecture and mesenchymal stromal morphogenesis in the kidney. Fibroblast growth factor receptor substrate 2α (Frs2α) is a major docking protein for Fgfr2 with downstream targets including Ets variant (Etv) 4 and Etv5 in other systems. Furthermore, global deletion of Frs2α causes early embryonic lethality. The purpose of the study was to determine the role of Frs2α in mediating Fgfr2 signaling in the ureteric epithelium. To that end, we generated mice with conditional deletion of Frs2α in the ureteric epithelium ( Frs2αUB−/−) and mice with point mutations in the Frs2α binding site of Fgfr2 ( Fgfr2LR/LR). Frs2αUB−/−mice developed mild renal hypoplasia characterized by decreased ureteric branching morphogenesis but maintained normal overall branching architecture and had normal mesenchymal stromal development. Reduced nephron endowment in postnatal mutant mice was observed, corresponding with the reduction in branching morphogenesis. Furthermore, there were no apparent renal abnormalities in Fgfr2LR/LRmice. Interestingly, Etv4 and Etv5 expression was unaltered in Frs2αUB−/−mice, as was Sprouty1, an antagonist of Frs2α signaling. However, Ret and Wnt11 (molecules critical for ureteric branching morphogenesis) mRNA levels were lower in mutants vs. controls. Taken together, these findings suggest that Fgfr2 signals through adapter molecules other than Frs2α in the ureteric epithelium. Furthermore, Frs2α may transmit signals through other receptor kinases present in ureteric epithelium. Finally, the renal hypoplasia observed in Frs2αUB−/−mice is likely secondary to decreased Ret and Wnt11 expression.
Surface expression of sodium channels and transporters in rat kidney: effects of dietary sodium
Authors: Frindt Gustavo , Palmer Lawrence G.
Published: September 2009

The abundance of Na transport proteins in the luminal membrane of the rat kidney was assessed using in situ biotinylation and immunoblotting. When animals were fed an Na-deficient diet for 1 wk, the amounts of epithelial Na channel (ENaC) β-subunit (β-ENaC) and γ-subunit (γ-ENaC) and Na-Cl cotransporter (NCC) protein in the surface fraction increased relative to controls by 1.9-, 3.5-, and 1.5-fold, respectively. The amounts of the luminal Na/H exchanger (NHE3) and the luminal Na-K-2Cl cotransporter (NKCC2) did not change significantly. The increases in ENaC subunits were mimicked by administration of aldosterone for 1 wk, but the increase in NCC was not. When the animals were fed a high-Na (5% NaCl) diet for 1 wk, the surface expression of β-ENaC increased by 50%, whereas that of the other membrane proteins did not change, relative to controls. The biochemical parameter most strongly affected by dietary Na was the abundance of the 65-kDa cleaved form of γ-ENaC at the surface. This increased by 8.5-fold with Na depletion and decreased by 40% with Na loading. The overall 14-fold change reflected regulation of the total abundance of the subunit as well as the fraction of the subunit protein in the cleaved form. We conclude that cleavage of γ-ENaC and its expression at the apical surface play a major role in the regulation of renal Na reabsorption.
Regulation of the mitochondrial permeability transition in kidney proximal tubules and its alteration during hypoxia-reoxygenation
Authors: Feldkamp Thorsten , Park Jeong Soon , Pasupulati Ratna , Amora Daniela , Roeser Nancy F. , Venkatachalam M. A. , Weinberg Joel M.
Published: September 2009

Development of the mitochondrial permeability transition (MPT) can importantly contribute to lethal cell injury from both necrosis and apoptosis, but its role varies considerably with both the type of cell and type of injury, and it can be strongly opposed by the normally abundant endogenous metabolites ADP and Mg2+. To better characterize the MPT in kidney proximal tubule cells and assess its contribution to injury to them, we have refined and validated approaches to follow the process in whole kidney proximal tubules and studied its regulation in normoxic tubules and after hypoxia-reoxygenation (H/R). Physiological levels of ADP and Mg2+greatly decreased sensitivity to the MPT. Inhibition of cyclophilin D by cyclosporine A (CsA) effectively opposed the MPT only in the presence of ADP and/or Mg2+. Nonesterified fatty acids (NEFA) had a large role in the decreased resistance to the MPT seen after H/R irrespective of the available substrate or the presence of ADP, Mg2+, or CsA, but removal of NEFA was less effective at restoring normal resistance to the MPT in the presence of electron transport complex I-dependent substrates than with succinate. The data indicate that the NEFA accumulation that occurs during both hypoxia in vitro and ischemic acute kidney injury in vivo is a critical sensitizing factor for the MPT that overcomes the antagonistic effect of endogenous metabolites and cyclophilin D inhibition, particularly in the presence of complex I-dependent substrates, which predominate in vivo.
Differential regulation of E-cadherin and α-smooth muscle actin by BMP 7 in human renal proximal tubule epithelial cells and its implication in renal fibrosis
Authors: Veerasamy Mangalakumar , Nguyen Tri Q. , Motazed Reza , Pearson Alexander L. , Goldschmeding Roel , Dockrell Mark E. C.
Published: September 2009

Chronic kidney diseases are characterized by progressive tubulointerstitial fibrosis, and TGFβ1 plays a crucial role in its development. Bone morphogenic protein 7 (BMP 7), another member of the TGF superfamily, antagonized the profibrotic effects of TGFβ1, including epithelial mesenchymal transition and E-cadherin loss, in the previous studies from animal models. We investigated the effect of BMP 7 on TGFβ1-mediated E-cadherin loss in two different transformed human adult proximal tubule epithelia. We found that BMP 7 not only failed to prevent TGFβ1-mediated E-cadherin loss but itself downregulated E-cadherin levels and that it had an additive effect with TGFβ1 in inducing E-cadherin loss. The downregulation of E-cadherin by BMP 7 was mediated through the Smad1/5 pathway. BMP 7-mediated E-cadherin loss was not followed by de novo α-smooth muscle actin (α-SMA) expression (a marker of myofibroblastic phenotype), which was due to the concurrent induction of Inhibitor of DNA binding 1 (Id1, a basic helix loop helix class transcriptional regulator) through a non-Smad pathway. Concurrent treatment of BMP 7 and TGFβ1 prevented TGFβ1-mediated α-SMA induction. In summary, our results suggest that E-cadherin loss, the key feature of epithelial mesenchymal transition, will not necessarily be followed by total phenotype change; rather, cells may undergo some loss of phenotypic marker in a ligand-dependent manner and participate in reparative processes. The inhibition of de novo expression of α-SMA could explain the antifibrotic effect of BMP 7. Id1 might play a crucial role in maintaining proximal tubule epithelial cell phenotype and its signaling regulation could be a potential therapeutic target.
Pulmonary perfusion heterogeneity is increased by sustained, heavy exercise in humans
Authors: Burnham K. J. , Arai T. J. , Dubowitz D. J. , Henderson A. C. , Holverda S. , Buxton R. B. , Prisk G. K. , Hopkins S. R.
Published: September 2009

Exercise presents a considerable stress to the pulmonary system and ventilation-perfusion (V̇a/Q̇) heterogeneity increases with exercise, affecting the efficiency of gas exchange. In particular, prolonged heavy exercise and maximal exercise are known to increase V̇a/Q̇ heterogeneity and these changes persist into recovery. We hypothesized that the spatial heterogeneity of pulmonary perfusion would be similarly elevated after prolonged exercise. To test this, athletic subjects ( n = 6, V̇o2max = 61 ml· kg−1·min−1) with exercising V̇a/Q̇ heterogeneity previously characterized by the multiple inert gas elimination technique (MIGET), performed 45 min of cycle exercise at ∼70% V̇o2max. MRI arterial spin labeling measures of pulmonary perfusion were acquired pre- and postexercise (at 20, 40, 60 min post) to quantify the spatial distribution in isogravitational (coronal) and gravitationally dependent (sagittal) planes. Regional proton density measurements allowed perfusion to be normalized for density and quantified in milliliters per minute per gram. Mean lung density did not change significantly in either plane after exercise ( P = 0.19). Density-normalized perfusion increased in the sagittal plane postexercise ( P = <0.01) but heterogeneity did not (all P ≥ 0.18), likely because of perfusion redistribution and vascular recruitment. Density-normalized perfusion was unchanged in the coronal plane postexercise ( P = 0.66), however, perfusion heterogeneity was significantly increased as measured by the relative dispersion [RD, pre 0.62(0.07), post 0.82(0.21), P < 0.0001] and geometric standard deviation [GSD, pre 1.74(0.14), post 2.30(0.56), P < 0.005]. These changes in heterogeneity were related to the exercise-induced changes of the log standard deviation of the ventilation distribution, an MIGET index of V̇a/Q̇ heterogeneity (RD R2 = 0.68, P < 0.05, GSD, R2 = 0.55, P = 0.09). These data are consistent with but not proof of interstitial pulmonary edema as the mechanism underlying exercise-induced increases in both spatial perfusion heterogeneity and V̇a/Q̇ heterogeneity.
Direct Activation and Temporal Response Properties of Rabbit Retinal Ganglion Cells Following Subretinal Stimulation
Authors: Tsai David , Morley John W. , Suaning Gregg J. , Lovell Nigel H.
Published: September 2009

In the last decade several groups have been developing vision prostheses to restore visual perception to the profoundly blind. Despite some promising results from human trials, further understanding of the neural mechanisms involved is crucial for improving the efficacy of these devices. One of the techniques involves placing stimulating electrodes in the subretinal space between the photoreceptor layer and the pigment epithelium to evoke neural responses in the degenerative retina. This study used cell-attached and whole cell current-clamp recordings to investigate the responses of rabbit retinal ganglion cells (RGCs) following subretinal stimulation with 25-μm-diameter electrodes. We found that direct RGC responses with short latency (≤2 ms using 0.1-ms pulses) could be reliably elicited. The thresholds for these responses were reported for on, off, and on–off RGCs over pulse widths 0.1–5.0 ms. During repetitive stimulation these direct activation responses were more readily elicited than responses arising from stimulation of the retinal network. The temporal spiking characteristics of RGCs were characterized as a function of stimulus configurations. We found that the response profiles could be generalized into four classes with distinctive properties. Our results suggest that for subretinal vision prostheses short pulses are preferable for efficacy and safety considerations, and that direct activation of RGCs will be necessary for reliable activation during high-frequency stimulation.
Experience-Dependent Intrinsic Plasticity in Interneurons of Barrel Cortex Layer IV
Authors: Sun Qian-Quan
Published: September 2009

It is unclear whether intrinsic excitabilities of specific interneurons are modulated by sensory experiences. Here, I examined the intrinsic excitabilities of interneurons in “sensory-spared” and “sensory-deprived” cortices of GAD67-GFP mice. The results showed that whisker trimming, begun at postnatal day 7 for 3 wk, induced significant changes in intrinsic and firing properties of fast-spiking (FS) but not regular spiking nonpyramidal (RSNP) cells. Firing threshold, spike frequency, spike adaptation index, and input resistance of FS cells were significantly altered by sensory deprivation such that FS cells became less excitable. An up-regulation of IA currents in FS cells appeared to be responsible. Along with changes in the intrinsic properties of FS cells, whisker trimming also induced a robust reduction in the number of vesicular glutamate transporter 2 positive varicosities and parvalbumin expression and the strength of thalamocortical (TC) excitatory postsynaptic currents in FS cells in the “sensory-deprived barrels.” The probability of spike induction by TC stimulus was reduced by 30% and the spike jitter was increased in sensory-deprived FS cells. These results suggest that the FS networks are selectively inhibited by sensory deprivation. The concurrent changes of intrinsic properties and expression of parvalbumin in FS but not RSNP cells with TC synapses support a contribution from the TC pathway and glutamate to sensory-induced activity-dependent intrinsic plasticity of inhibitory networks in barrel cortex.
Brain Switch for Reflex Micturition Control Detected by fMRI in Rats
Authors: Tai Changfeng , Wang Jicheng , Jin Tao , Wang Ping , Kim Seong-Gi , Roppolo James R. , de Groat William C.
Published: September 2009

The functions of the lower urinary tract are controlled by complex pathways in the brain that act like switching circuits to voluntarily or reflexly shift the activity of various pelvic organs (bladder, urethra, urethral sphincter, and pelvic floor muscles) from urine storage to micturition. In this study, functional magnetic resonance imaging (fMRI) was used to visualize the brain switching circuits controlling reflex micturition in anesthetized rats. The fMRI images confirmed the hypothesis based on previous neuroanatomical and neurophysiological studies that the brain stem switch for reflex micturition control involves both the periaqueductal gray (PAG) and the pontine micturition center (PMC). During storage, the PAG was activated by afferent input from the urinary bladder while the PMC was inactive. When bladder volume increased to the micturition threshold, the switch from storage to micturition was associated with PMC activation and enhanced PAG activity. A complex brain network that may regulate the brain stem micturition switch and control storage and voiding was also identified. Storage was accompanied by activation of the motor cortex, somatosensory cortex, cingulate cortex, retrosplenial cortex, thalamus, putamen, insula, and septal nucleus. On the other hand, micturition was associated with: 1) increased activity of the motor cortex, thalamus, and putamen; 2) a shift in the locus of activity in the cingulate and insula; and 3) the emergence of activity in the hypothalamus, substantia nigra, globus pallidus, hippocampus, and inferior colliculus. Understanding brain control of reflex micturition is important for elucidating the mechanisms underlying neurogenic bladder dysfunctions including frequency, urgency, and incontinence.
Correlation of Hepatitis C Antibody Levels in Gingival Crevicular Fluid and Saliva of Hepatitis C Seropositive Hemodialysis Patients
Authors: Açıkgöz Gökhan , Cengiz Murat İnanç , Keskiner İlker , Açıkgöz Şereften , Can Murat , Açıkgöz Aydan
Published: September 2009

Search for hepatitis C virus (HCV) in body fluids other than blood is important when assessing possible nonparenteral routes of viral transmission. However, the role of oral fluids in HCV transmission remains controversial. Our aim was to compare the prevalence of HCV antibody (HCV Ab) levels in saliva, and gingival crevicular fluid (GCF) of HCV seropositive hemodialysis patients. Serum, saliva and GCF samples were collected from thirty-nine patients. Samples were analyzed for HCV Ab using the Ortho HCV 3.0 SAVe enzyme-linked immunosorbent assay (ELISA). HCH Ab levels in saliva and GCF of all HCV-seropositive patients were statistically compared. Reported here are the results of the study designed to determine the correlation between HCV-RNA positivity in serum and the detection of antibodies in GCF and saliva. One hundred percent (100%) of the 39 patients have antibodies to HCV in their serum, 15.4% have antibodies to HCV in GCF, and saliva found out. HCV Ab seropositivity in GCF and saliva was significantly correlated (kappa = 0.462; ). This study supports the concept that GCF may be a significant source of HCV in saliva.
Rational Design of Improved Pharmabiotics
Authors: Sleator Roy D. , Hill Colin
Published: September 2009

Herein we review the most recent advances in probiotic research and applications with particular emphasis on the novel concept of patho‐biotechnology: the application of pathogen‐derived (ex vivo and in vivo) stress survival strategies for the design of more technologically robust and effective probiotic cultures with improved biotechnological and clinical applications.
Is Senna Laxative Use Associated to Cathartic Colon, Genotoxicity, or Carcinogenicity?
Authors: Morales M. A. , Hernández D. , Bustamante S. , Bachiller I. , Rojas A.
Published: September 2009

Due to their natural origin, apparent low oral toxicity, effectiveness, and accessibility without a medical prescription, the anthranoid laxatives are a popular remedy for constipation and are frequently used abusively. Therefore, it is important to characterize its harmful and/or toxic effects. The sennosides, main active metabolites of senna, exhibit a very low toxicity in rats, and its genotoxic activity in bacterial strains as well as mammal cells was classified as weak in those cases where it was shown to be significant. The toxicological and mutagenic status of the crude extract of senna, however, is not as well characterized, and it is necessary to do so since it is frequently, and at the same time incorrectly, believed that the chronic use of anthranoid laxatives is a risk factor for the development of colorectal cancer. The objective of this article was to review the information that arises in various scientific medical databases using key words such as senna, sen,Senna alexandrina, Cassia angustifolia, sennosides, laxative toxicity, mainly ISI and non-ISI articles of journals with an editorial committee. Web pages of products or companies that publicize or commercialize this type of laxative were not included. This analysis establishes that (1) there is no convincing evidence that the chronic use of senna has, as a consequence, a structural and/or functional alteration of the enteric nerves or the smooth intestinal muscle, (2) there is no relation between long-term administration of a senna extract and the appearance of gastrointestinal tumors or any other type in rats, (3) senna is not carcinogenic in rats even after a two-year daily dose of up to 300 mg/kg/day, and (4) the current evidence does not show that there is a genotoxic risk for patients who take laxatives containing senna extracts or sennosides.
Multistability and Self‐Similarity in the Parameter‐space of a Vibro‐impact System
Authors: de Souza Silvio L. T. , Caldas Iberê L. , Viana Ricardo L.
Published: September 2009

The dynamics of a dissipative vibro‐impact system called impact‐pair is investigated. This
system is similar to Fermi‐Ulam accelerator model and consists of an oscillating one‐dimensional
box containing a point mass moving freely between successive inelastic collisions with the rigid
walls of the box. In our numerical simulations, we observed multistable regimes, for which the
corresponding basins of attraction present a quite complicated structure with smooth boundary.
In addition, we characterize the system in a two‐dimensional parameter space by using the largest
Lyapunov exponents, identifying self‐similar periodic sets.
Effect of Hibiscus sabdariffa L. Dried Calyx Ethanol Extract on Fat Absorption‐Excretion, and Body Weight Implication in Rats
Authors: Carvajal-Zarrabal O. , Hayward-Jones P. M. , Orta-Flores Z. , Nolasco-Hipólito C. , Barradas-Dermitz D. M. , Aguilar-Uscanga M. G. , Pedroza-Hernández M. F.
Published: September 2009

The effect of Hibiscus sabdariffa L. (Hs) calyx extract on fat absorption‐excretion and body weight in rats, was investigated. Rats were fed with either a basal diet (SDC = Control diet) or the same diet supplemented with Hs extracts at 5%, 10% and 15% (SD5
, SD10
and SD15
). Only SD5
did not show significant increases in weight, food consumption and efficiency compared to SDC
. The opposite occurred in SD15
group which showed a significant decrease for these three parameters. The SD10
responses were similar to SD15, with the exception of food consumption. In both SDC
and SD5
groups, no body weight loss was observed; however, only in the latter group was there a significantly greater amount of fatty acids found in feces. A collateral effect emerging from the study is that components of Hs extract at the intermediate and greater concentrations used in this experiment could be considered possible antiobesity agents.
Spectrometric Study of the Nitrile-Ketenimine Tautomerism
Authors: Saraví Cisneros Hebe , Laurella Sergio , Ruiz Danila L. , Ponzinibbio Agustín , Allegretti Patricia E. , Furlong Jorge J. P.
Published: September 2009

Mass spectrometry is used to evaluate the occurrence of the nitrile-ketenimine tautomerism. Mass spectra of two differently substituted nitriles, ethyl-4,4-dicyano-3-methyl-3-butenoate and diethyl-2-cyano-3-methyl-2-pentenodiate are examined looking for common mass spectral behaviors. Ion fragmentation assignments for specific tautomers allow to predict the presence of the corresponding structures. Additionally, the mass spectrum and nuclear magnetic resonance spectra of ethyl-4,4-dicyano-2,2-diethyl-3-methyl-3-butenoate and that of the corresponding amination product support the occurrence of the ketenimine tautomer in the equilibrium.
High Prevalence of Human Papillomavirus Infection among Brazilian Pregnant Women with and without Human Immunodeficiency Virus Type 1
Authors: Jalil Emilia Moreira , Duarte Geraldo , El Beitune Patrícia , Simões Renata Toscano , Melli Patrícia Pereira dos Santos , Quintana Silvana Maria
Published: September 2009

Objective. To estimate HPV prevalence among pregnant women from Ribeirão Preto, Brazil, and the possible influence of HIV-1 infection on this prevalence.Methods. A cross-sectional study with 44 HIV-positive and 53 HIV-negative pregnant women was conducted. Cervicovaginal specimens were obtained from all women during gynecologic exam. HPV DNA, low and high risk HPV types, was detected using conventional PCR. Statistical analysis used Student'st-test, Mann-Whitney test, Fischer's Exact test, and prevalence ratios with 95% confidence interval.Results. HIV-positive pregnant women had higher proportion of HPV infection than HIV-negative pregnant women (79.5% versus 58.5%;P<.05). HPV positivity prevalence ratio for HIV-positive women was 1.36 (95% CI 1.04–1.8;P=.03). There was significant association between HIV viral load levels and HPV positivity (P<.05).Conclusions. Our results demonstrate higher HPV positivity in HIV-infected pregnant women. Higher values of HIV viral load were associated with HPV positivity.
Extended Spectrumβ-Lactamases among Gram-Negative Bacterial Isolates from Clinical Specimens in Three Major Hospitals in Northern Jordan
Authors: Batchoun Raymond G. , Swedan Samer F. , Shurman Abdullah M.
Published: September 2009

Background and Objectives. Extended spectrumβ-lactamase (ESBL) production is increasing all over the world, and organisms other thanE. coliandK. pneumoniaeare acquiring this character. ESBL production is detectable by automation, E-test, double disk diffusion (DDD), and PCR. This study aimed to determine the prevalence of ESBL production among clinical isolates of gram-negative rods, and to evaluate the effectiveness of augmentation of clavunate with Cefotaxime, Ceftazoxime, Aztreonam, Ceftriaxone, and Cefpodoxime in detecting ESBL production.Methods. 472 clinical gram-negative isolates identified by standard methods were tested for ESBL-production by (DDD) method using six cephalosporins and amoxicillin-clavulinate discs.Results. 108/472 (22.9%) of the isolates were ESBL producers, and were prevalent in tertiary care hospitals. 88.2% ofE. cloacae, 71.4% ofK. pneumoniae, 28.6% ofK. oxytoca, 12.5% ofC. freundii, 11.1% ofA. calcoacceticus, and 10.8% ofE. coliwere ESBL producers. The DDD test demonstrated some variations in the efficacy of the different cephalosporins in detecting all the ESBL producers. The inclusion of ceftizoxime discs increased the efficacy of the test. It is concluded that ESBL-producing bacteria were prevalent among our hospitalized patients, and involved genera other thanKlebsiellaandEscherichia, and the inclusion of ceftizoxime increased the efficacy of ESBL detection by the DDD test.
Pneumococcal Bacteremia Presenting as Acute Parotitis and Sepsis
Authors: Kataria Ashish , Multz Alan S.
Published: September 2009

We report a case of a 33-year-old female with history of Systemic Lupus Erythematosus (SLE) presenting with acute febrile illness and unilateral parotid gland enlargement progressing to septic shock. The chest imaging showed bilateral multilobar infiltrates and Pneumococci were identified in the blood cultures. The patient was treated with broad-spectrum antibiotics. The underlying imunosupression caused by SLE and long-term steroid treatment could have predisposed this patient to invasive Pneumococcal disease.
An Evaluation of Cellular Neural Networks for the Automatic Identification of Cephalometric Landmarks on Digital Images
Authors: Leonardi Rosalia , Giordano Daniela , Maiorana Francesco
Published: September 2009

Several efforts have been made to completely automate cephalometric analysis by automatic landmark search. However, accuracy obtained was worse than manual identification in every study. The analogue‐to‐digital conversion of X‐ray has been claimed to be the main problem. Therefore the aim of this investigation was to evaluate the accuracy of the Cellular Neural Networks approach for automatic location of cephalometric landmarks on softcopy of direct digital cephalometric X‐rays. Forty‐one, direct‐digital lateral cephalometric radiographs were obtained by a Siemens Orthophos DS Ceph and were used in this study and 10 landmarks (N, A Point, Ba, Po, Pt, B Point, Pg, PM, UIE, LIE) were the object of automatic landmark identification. The mean errors and standard deviations from the best estimate of cephalometric points were calculated for each landmark. Differences in the mean errors of automatic and manual landmarking were compared with a 1‐way analysis of variance. The analyses indicated that the differences were very small, and they were found at most within 0.59 mm. Furthermore, only few of these differences were statistically significant, but differences were so small to be in most instances clinically meaningless. Therefore the use of X‐ray files with respect to scanned X‐ray improved landmark accuracy of automatic detection. Investigations on softcopy of digital cephalometric X‐rays, to search more landmarks in order to enable a complete automatic cephalometric analysis, are strongly encouraged.
Possible Treatment Concepts for the Levodopa-Related Hyperhomocysteinemia
Authors: Müller Thomas
Published: September 2009

The saga of harmful levodopa (LD) in the treatment of Parkinson's disease (PD) resulted from outcomes of animal—and cell culture studies and the clinical observation of motor complication related to the short half life of LD. Further aspects of LD long term application, the LD associated homocysteine increase and its emerging consequences on progression, and onset of neuropsychiatric symptoms and of vascular disease are only partially considered. Therapeutic approaches for this LD-mediated neurotoxic homocysteine increase are vitamin supplementation or LD application with an inhibitor of catechol-O-methyltransferase (COMT). However, forcing central dopamine metabolism further down the methylation path by central blocking of COMT and MAO-B may reduce oxidative stress and homocysteine levels. But it may also increase N-methylation of tetrahydroisoquinolines to neurotoxic N-methylated tetrahydroisoquinolines. These compounds were observed in cerebrospinal fluid and plasma of long term LD-treated PD patients. Therefore LD application with peripheral COMT inhibition may be safer.
Association of Folate-Pathway Gene Polymorphisms with the Risk of Prostate Cancer: a Population-Based Nested Case-Control Study, Systematic Review, and Meta-analysis
Authors: Collin Simon M. , Metcalfe Chris , Zuccolo Luisa , Lewis Sarah J. , Chen Lina , Cox Angela , Davis Michael , Lane J. Athene , Donovan Jenny , Smith George Davey , Neal David E. , Hamdy Freddie C. , Gudmundsson Julius , Sulem Patrick , Rafnar Thorunn , Benediktsdottir Kristrun R. , Eeles Rosalind A. , Guy Michelle , Kote-Jarai Zsofia ,   UK Genetic Prostate Cancer Study Group, Morrison Jonathan , Al Olama Ali Amin , Stefansson Kari , Easton Douglas F. , Martin Richard M.
Published: September 2009

Folate-pathway gene polymorphisms have been implicated in several cancers and investigated inconclusively in relation to prostate cancer. We conducted a systematic review, which identified nine case-control studies (eight included, one excluded). We also included data from four genome-wide association studies and from a case-control study nested within the UK population–based Prostate Testing for Cancer and Treatment study. We investigated by meta-analysis the effects of eight polymorphisms: MTHFR C677T (rs1801133; 12 studies; 10,745 cases; 40,158 controls), MTHFR A1298C (rs1801131; 5 studies; 3,176 cases; 4,829 controls), MTR A2756G (rs1805087; 8 studies; 7,810 cases; 37,543 controls), MTRR A66G (rs1801394; 4 studies; 3,032 cases; 4,515 controls), MTHFD1 G1958A (rs2236225; 6 studies; 7,493 cases; 36,941 controls), SLC19A1/RFC1 G80A (rs1051266; 4 studies; 6,222 cases; 35,821 controls), SHMT1 C1420T (rs1979277; 2 studies; 2,689 cases; 4,110 controls), and FOLH1 T1561C (rs202676; 5 studies; 6,314 cases; 35,190 controls). The majority (10 of 13) of eligible studies had 100% Caucasian subjects; only one study had <90% Caucasian subjects. We found weak evidence of dominant effects of two alleles: MTR 2756A>G [random effects pooled odds ratio, 1.06 (1.00-1.12); P = 0.06 (P = 0.59 for heterogeneity across studies)] and SHMT1 1420C>T [random effects pooled odds ratio, 1.11 (1.00-1.22); P = 0.05 (P = 0.38 for heterogeneity across studies)]. We found no effect of MTHFR 677C>T or any of the other alleles in dominant, recessive or additive models, or in comparing a/a versus A/A homozygous. Neither did we find any difference in effects on advanced or localized cancers. Our meta-analysis suggests that known common folate-pathway single nucleotide polymorphisms do not have significant effects on susceptibility to prostate cancer.(Cancer Epidemiol Biomarkers Prev 2009;18(9):2528–39)
Protective effect of glutathione against oxidative injury in intestinal epithelial cells of piglet in vitro
Authors: Chen Qun , Zhang Shu-Ming , Liu Hai-Yan , Li Ying-Qiu
Published: September 2009

Oxidative stress of intestinal epithelium is involved in inflammatory bowel disease. To investigate protective effects of glutathione (GSH) on xanthine/xanthine oxidase (X/XO)-induced oxidative injury in intestinal epithelial cells (IECs). We employed in vitro cell culture supplemented with X/XO. IECs were cultured for 72 h, and then divided into seven groups with various concentrations of X/XO and GSH supplementation in the medium. Agarose gel electrophoresis lanes indicated that X/XO induced DNA injury by the high concentration of XO (40, 70 U/L)-treated groups. The X/XO supplementation significantly increased the production of malondialdehyde (MDA) in a dose-dependent manner. There was a slight increase in total radical-trapping antioxidant potential (TRAP) value by the low concentration of XO (10U/L) alone-treated group (P > 0.05) while supplementation of a high concentration of XO (40, 70 U/L) significantly decreased TRAP value compared with XO (10 U/L) and the control group (P < 0.05). Addition of GSH decreased the production of MDA and DNA fragmentations (P < 0.05), but enhanced TRAP value (P < 0.05). These results suggest that IECs of piglet have the ability of enduring mild oxidative stress induced by a low concentration of XO. Although high concentrations of XO resulted in oxidation injury and lipid peroxidation in the IECs, additions of GSH to the medium showed significant protection against the X/XO-induced oxidative stress.
Genetic diversity of a captive population of black muntjac revealed by a set of high polymorphism across-species microsatellites
Authors: Ni Xiao-Wei , Meng Kai , Wu Hai-Long , Zhu Guo-Ping
Published: September 2009

Eleven high polymorphic across-species loci were used to test the usefulness in the individual identification and parentage determination of black muntjac and to detect the genetic variation in a captive population of the animal. Discrimination power for individual locus ranged from 0.845 to 0.949 with the cumulative discrimination power across the eleven loci being up to 1. The combined exclusion probability across the eleven polymorphic loci in the absence and presence of genetic information on the second parent was 0.999 and 1, respectively. These results indicated that the eleven microsatellites would be highly diagnostic in individual identification and parentage testing for the species. The application of these polymorphic loci to evaluate population genetic variation indicated that the genetic diversity of the captive population (5.4 and 0.68 for A and He, respectively; n = 14) was significantly lower than that of the source population (7 and 0.785 for A and He, respectively; n=16). This supported our previous results discovered by mtDNA d-loop, i.e., the genetic diversity of the captive population had obviously declined over less than 20 years due to the paucity of founders. However, difference of observation heterozygosity between the captive and the source populations was not significant. These results indicated that loss of nuclear diversity in the captive population was first evidenced by A but not Ho. In order to retard the potential inbreeding effect, we suggested that some more wild animals should be introduced into the captive population and that a pedigree-based breeding program should be established.
Opportunistic predation on bats by the tawny owl Strix aluco
Authors: Lesiński Grzegorz , Ignaczak Maurycy , Manias Jarosław
Published: September 2009

The presence of bats in the diet of tawny owls inhabiting the entrance parts of a large bat hibernation site in central Poland was compared in two periods. In the years 1985–1988 the median total number of hibernating bats per survey (522) was nearly 3 times lower than in the years 2002–2008 (1455). Along this trend the share of bats in tawny owls' diet increased respectively from 21.9% of vertebrate prey items to 36.5%. In areas without large bat concentrations they usually comprise up to 1% of vertebrate prey. This finding could be an evidence of an opportunistic feature of bat predation by owls.
Ectoparasites and gastrointestinal helminths of chickens of three agro-climatic zones in Oromia Region, Ethiopia
Authors: Tolossa Yacob , Shafi Ziad , Basu Asoke
Published: September 2009

A survey for ectoparasites and gastrointestinal helminths was conducted in 150 chickens raised in a traditional backyard production system. The chickens were randomly selected from six sites in three agro-climatic zones in central Ethiopia, namely Bekoji and Chancho (highland), Woliso and Teji (midland), and Metehara and Zeway Dugda (lowland). The study indicated that in the three agro-climatic zones 126 (84%), 108 (72%) and 97 (64.67%) of the examined chickens were harbouring ectoparasites, nematodes and cestodes respectively. Out of 10 species of ectoparasites, Menacanthus stramineus (40%) was the most frequent species. Postmortem examinations revealed the presence of four species of nematodes (Ascaridia galli, Heterakis gallinarum, Subulura brumpti and Capillaria caudinflata) and four species of cestodes (Raillietina echinobothrida, R. tetragona, R. cesticillus and Choanotaenia infundibulum). The ectoparasite infestation was found to be sex specific in chicken, being significantly higher (P<0.05) in males. On the other hand, endoparasitic infection showed no such difference (P>0.05). No difference was found among the three agro-climatic zones in the frequency of ectoparasite and nematode infection. However, a significant difference (P<0.05) in the frequency of cestode infection among the three zones was observed.
Cephalic salivary gland ultrastructure of worker and queen eusocial bees (Hymenoptera, Apidae)
Authors: Poiani Silvana Beani , da Cruz-Landim Carminda
Published: September 2009

Eusocial bees present a pair of functional salivary glands in head, the cephalic salivary glands. These glands from workers and queens of two eusocial bee species, Apis mellifera and Scaptotrigona postica, were examined at different life stages using routine transmission electron microscopy techniques to correlate morphology and gland functions. Ultrastructural features of worker and queen glands ducts and secretory units were descriptively compared between species. The duct cells present basal plasma membrane invaginations reaching the apical region. Intercellular space and invaginations contain material of similar electron-density to the basal lamina, suggesting that substances might be directly absorbed from the hemolymph to the gland lumen. The secretory cells are rich in smooth endoplasmic reticulum, mitochondria, Golgi, and vesicles typical of lipid secretion. Secretory cells in S. postica become flattened with age in contrast to A. mellifera, where cells remained cuboidal. Mitochondria are associated with secretory vesicles and may become lipid deposits. A possible role of worker and queen secretion is discussed, taking changes in caste gland morphology and their function in the colony into account.
Can we predict the distribution of heathland butterflies with heathland bird data?
Authors: Maes Dirk , Anselin Anny , van Swaay Chris , Sierdsema Henk , De Bruyn Luc , Vermeersch Glenn , Van Dyck Hans
Published: September 2009

National or regional conservation strategies are usually based on available species distribution maps. However, very few taxonomic groups achieve a full coverage of the focal region. Distribution data of well-mapped taxonomic groups could help predict the distribution of less well-mapped groups and thus fill gaps in distribution maps. Here, we predict the distribution of five heathland butterflies in Flanders (north Belgium) using typical heathland bird distribution data as predictor variables. We compare predictions with those using only biotope or a combination of both biotope and bird data as variables. In addition, we test the transferability of 'bird', biotope and combined models to the Netherlands, an ecologically similar region. Transferability was tested in three separate sandy regions in the Netherlands at different distances from the region in which the models were built. For each of the five heathland butterflies, we applied logistic regressions on ten random model sets and tested the models on ten random evaluation sets within Flanders. We used the area under the curve (AUC) of the receiver-operating characteristics (ROC) plots to estimate model accuracy. Overall, bird models performed significantly better than biotope models but were not significantly different from the combined models in Flanders. In the Netherlands, the transferred biotope and the combined models performed better than the transferred 'bird models'. We conclude that on a local scale, birds can, to some extent, serve as proxies for biotope quality, but that biotope models are more robust when transferred to another region.
Mechanical Properties of the Coir Fiber-reinforced Polypropylene Composites: Effect of the Incorporation of Jute Fiber
Authors: Haydaruzzaman  , Khan A.H. , Hossain M.A. , Khan Mubarak A. , Khan Ruhul A.
Published: September 2009

Coir yarn-reinforced polypropylene (PP)-based unidirectional composites were prepared by compression molding. Coir yarn content in the composite was optimized and 20% yarn content showed higher mechanical properties. Jute yarns (20%—100%) were incorporated into the coir-based composites. It was found that 20% coir and 80% jute-reinforced PP matrix composites performed the best results. All the materials (coir, jute, and PP) were irradiated with gamma radiation from 400 to 1000 krad. PP-based composites (20% coir and 80% jute) showed the highest mechanical properties at 600 krad of total gamma dose. Starch (2—10% in aqueous solution) was used as stiffening agent for the yarns and it was found better unidirectional position of the yarns inside composite over the untreated composite. It was reported that composites prepared with 5% starch treated yarns (coir and jute) for 5 min soaking time demonstrated the best results. Scanning electron microscopy, thermal degradation, water uptake, and electrical properties were also studied.
Enhancing Fracture Toughness of Glass/Epoxy Composites by Using Rubber Particles Together with Silica Nanoparticles
Authors: Tsai Jia-Lin , Huang Bao-Hung , Cheng Yi-Lieh
Published: September 2009

The research aims to investigate the interlaminar fracture toughness of glass fiber/epoxy composites, which consist of the silica nanoparticles and the rubber particles. Two kinds of rubber particles, one is the reactive liquid rubber (CTBN) and the other is the core-shell rubber (CSR), were employed to modify the fracture toughness of epoxy resin. In general, the disadvantage of adding rubber particles into polymeric resin is the dramatic reduction of stiffness although the toughness could be modified accordingly. In order to enhance the fracture toughness of the fiber composites without sacrificing their stiffness, the silica nanoparticles in conjunction with the rubber particles were introduced into the epoxy matrix to form a hybrid nanocomposite. Experimental results obtained from tensile tests on bulk epoxy confirm the presumption that the reduction of the epoxy stiffness because of the presence of rubber particles can be effectively compensated by the silica nanoparticles. Furthermore, the fracture tests conducted on the double cantilever beam specimens revealed that the inclusion of silica nanoparticles together with the CSR particle can appreciably increase the fracture toughness of the glass/epoxy composites up to 82%. On the other hand, when the epoxy matrices were modified with CTBN rubber particles and silica nanoparticles, the improvement of the interlaminar fracture toughness was around 48%. It is noted that the role of the silica nanoparticles on the fracture toughness of fiber composites with rubber-modified epoxy matrix is different. For the CSR-modified epoxy matrix, the contribution of silica nanoparticle on the fracture toughness is destructive. In contrast, for the CTBN-modified epoxy matrix, the silica nanoparticles can synchronously improve the fracture toughness of composites.
Modeling VARTM Processes with Hybrid Media Incorporating Gravity Effects
Authors: Yoon Myung-Keun , Chen Haifeng , Simacek Pavel , Heider Dirk , Gillespie John W.
Published: September 2009

Vacuum-assisted resin transfer molding (VARTM) processes are increasingly used in manufacturing scale-up composite applications. Accordingly, gravity can significantly influence the flow behavior in tall-structure composite manufacturing processes. The present study developed a closed-form analytic solution incorporating gravity effects with the equivalent parameter approach in order to predict the resin flow behavior in a tall structure resin infusion. A hybrid model was used that consists of thin distribution media and a fibrous preform. An analytic solution was developed and validated with experiments as well as numerical methods in terms of the resin flow front shape, lag length, and the flow front location with time for the horizontal, upward, and downward infusion cases. The flow front locations were monitored using time domain reflectometry sensors embedded in the fabric layers. The lag length was constant in the horizontal infusion case, but decreased and increased in the upward and downward infusion cases, respectively, as resin progressed. The downward infusion case showed the fastest fill time, which corresponds to the previous results using a homogenous model. However, the flow became unstable at a certain location where the local flow front speeds increased suddenly along the distribution media. These phenomena were not observed in a model with homogenous media but were observed in a model with hybrid media, only in the downward infusion cases. The analytic solution also identified the stable flow conditions with the mold angles. The results obtained in the present study can be used to estimate stable process conditions in designing VARTM processes for manufacturing large-scale tall composite structures.
Wood Flour — Recycled Polyol Based Polyurethane Lightweight Composites
Authors: Rácz Ilona , Andersen Endre , Aranguren Mirta I. , Marcovich Norma E.
Published: September 2009

This work is focused on the production and characterization of lightweight polyurethane (PU) composites reinforced with pine wood flour (WF), which can have applications in car interior panels, construction, and acoustic insulation. A crosslinked PU formulated from a recycled polyol was used as matrix. The mechanical performance of the reinforced composites was studied through tensile, three point bending, and dynamic mechanical tests. The strength, modulus, and storage modulus increased with filler concentration.The addition of Al(OH)3 did not reduce the flammability of the composites with low WF concentrations; however, some improvements were found in the case of composites prepared with 20 wt% WF.
Investigating Silica Nanoparticle Effect on Dynamic and Quasi-static Compressive Strengths of Glass Fiber/Epoxy Nanocomposites
Authors: Tsai Jia-Lin , Cheng Yi-Lieh
Published: September 2009

The research is aimed to investigate the compressive strengths of glass/epoxy nanocomposites, containing various loadings of spherical silica nanoparticles. Through a sol—gel technique, the silica particles with a diameter of 25 nm were exfoliated uniformly into the epoxy resin. Subsequently, by inserting the silica—epoxy mixture into the unidirectional glass fiber through a vacuum hand lay-up process, the glass fiber/epoxy composite laminates with 10, 20, and 30 wt% of silica nanoparticles were fabricated. Quasi-static and dynamic compression tests were conducted on the brick composite specimens with fiber orientations of 0°, 5°, 10°, 15°, and 90° using a hydraulic MTS machine and a split Hopkinson pressure bar, respectively. Observations on the failure specimens indicated that for fiber orientations less than 15°, the fiber microbuckling is the dominant failure mechanism. On the other hand, for the 90° samples, the out-of-plane shear failure is the main failure mechanism. In addition, it was denoted that as the silica contents increase, the compressive strengths of the glass/epoxy composites are improved accordingly. The enhancing mechanism in the compressive strengths can be properly explicated using the microbuckling model.