bluuebunny/crossref_metadata_2025 huggingface dataset:
CCR9 interactions support ovarian cancer cell survival and resistance to cisplatin-induced apoptosis in a PI3K-dependent and FAK-independent fashion
Authors: Johnson Erica L , Singh Rajesh , Johnson-Holiday Crystal M , Grizzle William E , Partridge Edward E , Lillard James W , Singh Shailesh
Published: June 2010

Background

Cisplatin is more often used to treat ovarian cancer (OvCa), which provides modest survival advantage primarily due to chemo-resistance and up regulated anti-apoptotic machineries in OvCa cells. Therefore, targeting the mechanisms responsible for cisplatin resistance in OvCa cell may improve therapeutic outcomes. We have shown that ovarian cancer cells express CC chemokine receptor-9 (CCR9). Others have also shown that CCL25, the only natural ligand for CCR9, up regulates anti-apoptotic proteins in immature T lymphocytes. Hence, it is plausible that CCR9-mediated cell signals might be involved in OvCa cell survival and inhibition of cisplatin-induced apoptosis. In this study, we investigated the potential role and molecular mechanisms of CCR9-mediated inhibition of cisplatin-induced apoptosis in OvCa cells.

Methods

Cell proliferation, vibrant apoptosis, and TUNEL assays were performed with or without cisplatin treatment in presence or absence of CCL25 to determine the role of the CCR9-CCL25 axis in cisplatin resistance. In situ Fast Activated cell-based ELISA (FACE) assays were performed to determine anti-apoptotic signaling molecules responsible for CCL25-CCR9 mediated survival.

Results

Our results show interactions between CCR9 and CCL25 increased anti-apoptotic signaling cascades in OvCa cells, which rescued cells from cisplatin-induced cell death. Specifically, CCL25-CCR9 interactions mediated Akt, activation as well as GSK-3β and FKHR phosphorylation in a PI3K-dependent and FAK-independent fashion.

Conclusions

Our results suggest the CCR9-CCL25 axis plays an important role in reducing cisplatin-induced apoptosis of OvCa cells.
Interleukin-18 as an in vivomediator of monocyte recruitment in rodent models of rheumatoid arthritis
Authors: Ruth Jeffrey H , Park Christy C , Amin M Asif , Lesch Charles , Marotte Hubert , Shahrara Shiva , Koch Alisa E
Published: June 2010

Introduction

The function of interleukin-18 (IL-18) was investigated in pertinent animal models of rodent rheumatoid arthritis (RA) to determine its proinflammatory and monocyte recruitment properties.

Methods

We used a modified Boyden chemotaxis system to examine monocyte recruitment to recombinant human (rhu) IL-18 in vitro. Monocyte recruitment to rhuIL-18 was then tested in vivo by using an RA synovial tissue (ST) severe combined immunodeficient (SCID) mouse chimera. We defined monocyte-specific signal-transduction pathways induced by rhuIL-18 with Western blotting analysis and linked this to in vitro monocyte chemotactic activity. Finally, the ability of IL-18 to induce a cytokine cascade during acute joint inflammatory responses was examined by inducing wild-type (Wt) and IL-18 gene-knockout mice with zymosan-induced arthritis (ZIA).

Results

We found that intragraft injected rhuIL-18 was a robust monocyte recruitment factor to both human ST and regional (inguinal) murine lymph node (LN) tissue. IL-18 gene-knockout mice also showed pronounced reductions in joint inflammation during ZIA compared with Wt mice. Many proinflammatory cytokines were reduced in IL-18 gene-knockout mouse joint homogenates during ZIA, including macrophage inflammatory protein-3α (MIP-3α/CCL20), vascular endothelial cell growth factor (VEGF), and IL-17. Signal-transduction experiments revealed that IL-18 signals through p38 and ERK½ in monocytes, and that IL-18-mediated in vitro monocyte chemotaxis can be significantly inhibited by disruption of this pathway.

Conclusions

Our data suggest that IL-18 may be produced in acute inflammatory responses and support the notion that IL-18 may serve a hierarchic position for initiating joint inflammatory responses.
A transversely isotropic medium with a tilted symmetry axis normal to the reflector
Authors: Alkhalifah Tariq , Sava Paul
Published: June 2010

The computational tools for imaging in transversely isotropic media with tilted axes of symmetry (TTI) are complex and in most cases do not have an explicit closed-form representation. Developing such tools for a TTI medium with tilt constrained to be normal to the reflector dip (DTI) reduces their complexity and allows for closed-form representations. The homogeneous-case zero-offset migration in such a medium can be performed using an isotropic operator scaled by the velocity of the medium in the tilt direction. For the nonzero-offset case, the reflection angle is always equal to the incidence angle, and thus, the velocities for the source and receiver waves at the reflection point are equal and explicitly dependent on the reflection angle. This fact allows for the development of explicit representations for angle decomposition as well as moveout formulas for analysis of extended images obtained by wave-equation migration. Although setting the tilt normal to the reflector dip may not be valid everywhere (i.e., on salt flanks), it can be used in the process of velocity model building, in which such constrains are useful and typically are used.
Relationship between low-frequency electrical properties and hydraulic permeability of low-permeability sandstones
Authors: Zisser Norbert , Kemna Andreas , Nover Georg
Published: June 2010

The relationship between low-frequency electrical properties and hydraulic permeability of rocks has been the focus of geophysical investigations for a long time because it offers a possibility for an in situ and noninvasive permeability estimation of rocks. We examined the hydraulic and low-frequency [Formula: see text] electrical properties as well as the anisotropic properties of low-permeability sandstones from a tight gas reservoir. Single-frequency electrical properties were found to be of low value for the determination of permeability for the studied samples, whereas a strong link between the spectral-induced polarization (SIP) response and permeability was found. The SIP response was transformed into a relaxation-time distribution using a Debye decomposition procedure. We observed a strong positive correlation in form of a power law between median relaxation time of the distribution and permeability, suggesting that relaxation time is a good measure of the effective hydraulic length scale. From a comparison of our results with published relationships between relaxation time and permeability, it becomes evident that the corresponding function is formation specific, requiring a separate calibration for each formation. Nevertheless, SIP offers a high potential for in situ permeability determination because estimation of permeability from relaxation time seems to be applicable for very different lithologies.
Creating realistic models based on combined forward modeling and tomographic inversion of seismic profiling data
Authors: Koulakov Ivan , Stupina Tatiana , Kopp Heidrun
Published: June 2010

Amplitudes and shapes of seismic patterns derived from tomographic images often are strongly biased with respect to real structures in the earth. In particular, tomography usually provides continuous velocity distributions, whereas major velocity changes in the earth often occur on first-order interfaces. We propose an approach that constructs a realistic structure of the earth that combines forward modeling and tomographic inversion (FM&TI). Using available a priori information, we first construct a synthetic model with realistic patterns. Then we compute synthetic times and invert them using the same tomographic code and the same parameters as in the case of observed data processing. We compare the reconstruction result with the tomographicimage of observed data inversion. If a discrepancy is observed, we correct the synthetic model and repeat the FM&TI process. After several trials, we obtain similar results of synthetic and observed data inversion. In this case, the derived synthetic model adequately represents the real structure of the earth. In a working scheme of this approach, we three authors used two different synthetic models with a realistic setup. One of us created models, but the other two performed the reconstruction with no knowledge of the models. We discovered that the synthetic models derived by FM&TI were closer to the true model than the tomographic inversion result. Our reconstruction results from modeling marine data acquired in the Musicians Seamount Province in the Pacific Ocean indicate the capacity and limitations of FM&TI.
Simulation of acoustic wavefields in heterogeneous media: A robust method for automatic suppression of numerical dispersion
Authors: Yang Dinghui , Song Guojie , Hua Biaolong , Calandra Henri
Published: June 2010

Numerical dispersion limits the application of numerical simulation methods for solving the acoustic wave equation in large-scale computation. The nearly analytic discrete method (NADM) and its improved version for suppressing numerical dispersion were developed recently. This new method is a refinement of two previous methods and further increases the ability of suppressing numerical dispersion for modeling acoustic wave propagation in 2D heterogeneous media, which uses acoustic wave displacement, particle velocity, and their gradients to restructure the acoustic wavefield via the truncated Taylor expansion and the high-order interpolation approximate method. For the method proposed, we investigate its implementation and compare it with the higher-order Lax-Wendroff correction (LWC) scheme, the original nearly analytic discrete method (NADM) and its im-proved version with regard to numerical dispersion, computational costs, and computer storage requirements. The numerical dispersion relations provided by the refined algorithm for 1D and 2D cases are analyzed, as well as the numerical results obtained by this method against the exact solution for the 2D acoustic case. Numerical results show that the refined method gives no visible numerical dispersion for very large spatial grid increments. It can simulate high-frequency wave propagation for a given grid interval and automatically suppress the numerical dispersion when the acoustic wave equation is discretized, when too few samples per wavelength are used, or when models have large velocity contrasts. Unlike the high-order LWC methods, our present method can save substantial computational costs and memory requirements because very large grid increments can be used. The refined method can be used for the simulation of large-scale wavefields.
Attenuated Proliferation and Trans-Differentiation of Prostatic Stromal Cells Indicate Suitability of Phosphodiesterase Type 5 Inhibitors for Prevention and Treatment of Benign Prostatic Hyperplasia
Authors: Zenzmaier Christoph , Sampson Natalie , Pernkopf Dominik , Plas Eugen , Untergasser Gerold , Berger Peter
Published: June 2010

Benign prostatic hyperplasia (BPH) is characterized by tissue overgrowth and stromal reorganization primarily due to cellular proliferation and fibroblast-to-myofibroblast trans-differentiation. To evaluate the potential of phosphodiesterase type 5 (PDE5) inhibitors like tadalafil for prevention and treatment of BPH, we analyzed the role of the nitric oxide/cyclic GMP (cGMP)/PDE5 pathway for cellular proliferation and TGFβ1-induced fibroblast-to-myofibroblast trans-differentiation in primary prostate stromal cells. Inhibition by tadalafil of PDE5, which is mainly expressed in the stromal compartment of the prostate, reduced proliferation of primary prostate stromal cells and to a lesser extent of primary prostate basal epithelial cells. Attenuated proliferation due to elevated intracellular cGMP levels was confirmed by inhibition of the cGMP-dependent protein kinase G by its inhibitor KT2358. Moreover, tadalafil strongly attenuated TGFβ1-induced fibroblast-to-myofibroblast trans-differentiation. The inhibitory effect on trans-differentiation was also observed after small interfering RNA-mediated PDE5 knockdown. As confirmed by the MAPK kinase 1 inhibitor PD98059, this effect was mediated via MAPK kinase 1 signaling. We conclude that BPH patients might benefit from adjuvant therapies with PDE5 inhibitors that inhibit stromal enlargement due to cell proliferation, as well as TGFβ1-induced trans-differentiation processes.
The Calcium Oscillator of GnRH-1 Neurons Is Developmentally Regulated
Authors: Constantin Stephanie , Klenke Ulrike , Wray Susan
Published: June 2010

Oscillations in intracellular calcium levels have been described in GnRH-1 neurons in both prenatal and adult cells. However, differences have been reported in the mechanisms underlying these [Ca2+]i oscillations, dependent on the model used. The goal of this study was to address whether these changes depend on the maturation status of GnRH-1 neurons by assaying prenatal GnRH-1 cells maintained in explants, at two different developmental stages. This report documents an increase in the frequency of [Ca2+]i oscillations between 1 and 3 wk of in vitro maturation. During the early stage, [Ca2+]i oscillations are blocked by tetrodotoxin and are mainly triggered by excitatory neurotransmitters, γ-aminobutyric acid (GABA), and glutamate. In contrast, in the later stage, some cells exhibit residual tetrodotoxin-insensitive [Ca2+]i oscillations, which are sustained by action potential-independent GABA and glutamate release. The strength of these two excitatory inputs remained relatively constant during the maturation process, and the increase in frequency of [Ca2+]i oscillations observed at the later stage is due to a novel excitatory input carried by cholecystokinin. Together, these data indicate developmentally regulated release and interactions of neurotransmitters (known regulators of GnRH-1 cells in adults) and point to extrinsic factors regulating GnRH-1 cellular physiology.
Developmental Programming: Insulin Sensitizer Treatment Improves Reproductive Function in Prenatal Testosterone-Treated Female Sheep
Authors: Veiga-Lopez Almudena , Lee James S. , Padmanabhan Vasantha
Published: June 2010

Prenatal testosterone (T) excess causes reproductive and metabolic disruptions including insulin resistance, attributes of women with polycystic ovary syndrome. This study tested the hypothesis that insulin resistance contributes toward severity of reproductive disruptions in prenatally T-treated females. Pregnant sheep were injected im with 100 mg of T-propionate semiweekly from d 30–90 of gestation. Immediately after the first breeding season, a subset of controls and prenatal T-treated (TR) sheep were administered an insulin sensitizer (rosiglitazone; 8 mg/d) orally for 8 months. Untreated control and prenatal T-treated females (T group) were studied in parallel. Biochemical analyses revealed rosiglitazone to be safe for use in sheep. Glucose tolerance tests performed before and after the insulin sensitizer treatment found that insulin sensitizer decreased cumulative insulin, cumulative insulin/glucose ratio, and insulin area under the curve by about 50% and increased the insulin sensitivity index by about 70% in the TR compared with the T group. Twenty percent of TR females showed a reduced number of cycles in the second relative to first breeding season as opposed to 80% of T group females showing such deterioration. Insulin sensitizer treatment also decreased the number of aberrant cycles (≥18 d) during the second breeding season in the TR group relative to the first as opposed to the T group females showing an increase in the second breeding season relative to the first. These findings provide evidence that insulin sensitizer treatment prevents further deterioration of the reproductive axis in prenatal T-treated sheep, a finding of translational relevance to women with polycystic ovary syndrome.
Posttranslational Activation of Bone Morphogenetic Protein 2 Is Mediated by Proprotein Convertase 6 during Decidualization for Pregnancy Establishment
Authors: Heng Sophea , Paule Sarah , Hardman Belinda , Li Ying , Singh Harmeet , Rainczuk Adam , Stephens Andrew N. , Nie Guiying
Published: June 2010

Bone morphogenetic proteins (BMPs) require major posttranslational modifications to become biologically active. One such key modification is endoproteolytic cleavage of the initially synthesized nonactive precursor protein to release the mature ligand. Here we show in a physiological context of uterine stromal decidualization that BMP2 cleavage is mediated by proprotein convertase 5/6 (PC6). Decidualization is a uterine remodeling event critical for embryo implantation. Deletion or knockdown of either BMP2 or PC6 inhibits decidualization causing implantation failure and female infertility. In this study we provide biochemical and physiological evidence that PC6 proteolytically activates BMP2. We used freshly isolated primary human endometrial stromal cells and demonstrated that PC6 was the sole member of the PC family significantly up-regulated during decidualization. The precursor form of BMP2 was reduced, whereas its active form was increased during decidualization. Inhibition of PC6 activity inhibited decidualization, and this was accompanied by a total blockade of BMP2 activation. Addition of recombinant active BMP2 partially rescued the decidualization arrest caused by PC6 inhibition. PC6 processed BMP2 at the KREKR282↓ cleavage site, and mutating this site prevented the cleavage. This study thus demonstrates for the first time that the proteolytic activation and thus bioavailability of BMP2 is controlled by PC6.
The Relationship of Menopausal Status and Rapid Menopausal Transition with Carotid Intima-Media Thickness Progression in Women: A Report from the Los Angeles Atherosclerosis Study
Authors: Johnson B. Delia , Dwyer Kathleen M. , Stanczyk Frank Z. , Bittner Vera , Berga Sarah L. , Braunstein Glenn D. , Azziz Ricardo , Yang YuChing , Hale Georgina E. , Bairey Merz C. Noel
Published: June 2010

Context: The onset of menopause has been associated with an increase in cardiovascular risk factors. However, little information is available about the rapidity of the menopausal transition and its relationship to the development of preclinical cardiovascular disease (CVD).

Objective: Our objective was to assess whether the rate of carotid intima-media thickness (cIMT) progression over time differs according to 1) menopausal status and 2) rapidity of the menopausal transition.

Design: We evaluated 203 community-based women aged 45–60 yr without previously diagnosed CVD who underwent three repeated measurements of cIMT as a measure of preclinical CVD over 3 yr. Menopausal status was ascertained at each visit based on menstrual cycle parameters and reproductive hormone profiles. Of these, 21 remained premenopausal, 51 transitioned, and 131 were postmenopausal throughout the observation period.

Results: Age-adjusted cIMT progression rates were similar among premenopausal, transitioning, and postmenopausal women. In the 51 transitioning women, age was not related to rate of cIMT progression. However, the rapidity of menopausal transition was related to cIMT progression: women transitioning from pre- to postmenopause within the 3-yr period had a higher rate of cIMT progression compared with women with a slower transition. Statistical adjustments for the significant covariates of systolic blood pressure, body mass index, race, cigarette smoking, or hormone therapy use did not alter the findings.

Conclusions: Among healthy women undergoing repeated cIMT measurement, a more rapid menopausal transition was associated with a higher rate of preclinical CVD progression measured by cIMT. Further work is needed to explore potential mechanisms of this effect.
Efficient importance sampling in ruin problems for multidimensional regularly varying random walks
Authors: Blanchet Jose , Liu Jingchen
Published: June 2010

We consider the problem of efficient estimation via simulation of first passage time probabilities for a multidimensional random walk with heavy-tailed increments. In addition to being a natural generalization to the problem of computing ruin probabilities in insurance - in which the focus is the maximum of a one-dimensional random walk with negative drift - this problem captures important features of large deviations for multidimensional heavy-tailed processes (such as the role played by the mean of the process in connection to the location of the target set). We develop a state-dependent importance sampling estimator for this class of multidimensional problems. Then, using techniques based on Lyapunov inequalities, we argue that our estimator is strongly efficient in the sense that therelativemean squared error of our estimator can be made arbitrarily small by increasing the number of replications, uniformly as the probability of interest approaches 0.
Prediction in a Poisson cluster model
Authors: Matsui Muneya , Mikosch Thomas
Published: June 2010

We consider a Poisson cluster model, motivated by insurance applications. At each claim arrival time, modeled by the point of a homogeneous Poisson process, we start a cluster process which represents the number or amount of payments triggered by the arrival of a claim in a portfolio. The cluster process is a Lévy or truncated compound Poisson process. Given the observations of the process over a finite interval, we consider the expected value of the number and amount of payments in a future time interval. We also give bounds for the error encountered in this prediction procedure.
Busy periods in fluid queues with multiple emptying input states
Authors: Field A. J. , Harrison P. G.
Published: June 2010

A semi-numerical method is derived to compute the Laplace transform of the equilibrium busy period probability density function in a fluid queue with constant output rate when the buffer is nonempty. The input process is controlled by a continuous-time semi-Markov chain (CTSMC) with n states such that in each state the input rate is constant. The holding time in states with net positive output rate - so-called emptying states - is assumed to be an exponentially distributed random variable, whereas in states with net positive input rate - so-called filling states - it may have an arbitrary probability distribution. The result is demonstrated by applying it to various systems, including fluid queues with two on-off input sources. The latter exercise in part shows consistency with prior results but also solves the problem in the case where there are two emptying states. Numerical results are presented for selected examples which expose discontinuities in the busy period distribution when the number of emptying states changes, e.g. as a result of increasing the fluid arrival rate in one or more states of the controlling CTSMC.
The queue with impatience: construction of the stationary workload under FIFO
Authors: Moyal Pascal
Published: June 2010

In this paper we study the stability of queueing systems with impatient customers and a single server operating under a FIFO (first-in-first-out) discipline. We first give a sufficient condition for the existence of a stationary workload in the case of impatience until the beginning of service. We then provide a weaker condition of existence on an enriched probability space using the theory of Anantharam et al. (1997), (1999). The case of impatience until the end of service is also investigated.
Exponential rate of almost-sure convergence of intrinsic martingales in supercritical branching random walks
Authors: Iksanov Alexander , Meiners Matthias
Published: June 2010

We provide sufficient conditions which ensure that the intrinsic martingale in the supercritical branching random walk converges exponentially fast to its limit. We include in particular the case of Galton-Watson processes so that our results can be seen as a generalization of a result given in the classical treatise by Asmussen and Hering (1983). As an auxiliary tool, we prove ultimate versions of two results concerning the exponential renewal measures which may be of interest in themselves and which correct, generalize, and simplify some earlier works.
Preferential duplication graphs
Authors: Cohen Netta , Jordan Jonathan , Voliotis Margaritis
Published: June 2010

We consider a preferential duplication model for growing random graphs, extending previous models of duplication graphs by selecting the vertex to be duplicated with probability proportional to its degree. We show that a special case of this model can be analysed using the same stochastic approximation as for vertex-reinforced random walks, and show that ‘trapping’ behaviour can occur, such that the descendants of a particular group of initial vertices come to dominate the graph.
A note on converging geometric-type processes
Authors: Finkelstein Maxim
Published: June 2010

The process of deterioration of repairable systems with each repair is modeled using converging geometric-type processes. It is proved that the expectation of the number of repairs in each interval of time is infinite. A new regularization procedure is suggested and the corresponding optimization problem is discussed.
Shushing down the epigenetic landscape towards stem cell differentiation
Authors: Ichida Justin K. , Kiskinis Evangelos , Eggan Kevin
Published: June 2010

In February 2010, researchers interested in stem cell biology gathered in Keystone, Colorado, USA to discuss their findings on the origins and behaviors of pluripotent and multipotent stem cells, and their therapeutic potential. Here, we review the presentations at that meeting and the questions that emerged concerning how a stem cell `decides' to self-renew or differentiate, what their distinct properties are and how this information can be used to develop novel therapies.
Measures to Counter Fatigue Failure in Railway Axles
Authors: Maxwell W. W. , Dudley B. R. , Cleary A. B. , Richards J. , Shaw J.
Published: June 2010

This paper reviews the experience in London Transport of fatigue cracking in railway axles, and presents the results of laboratory fatigue tests on full-scale axle specimens under simulated rotating bending. The investigation was undertaken with the aim of entirely eliminating fatigue cracking and fretting under the press fits of wheel-axle sets. Whilst cold rolling of wheel seats, which is standard L.T. practice, strongly inhibits the propagation of such fatigue cracks, it does not prevent their initiation. The introduction of a stress-relieving groove, such that the edge of the press fit overhangs the groove, leads to a marked reduction in fretting and increase in life of test specimens, and the results of a limited service test suggest that the presence of such a groove reduces the stresses under the wheel hubs to a level at which cracking is eliminated. Since the presence of a press fit near to a groove increases the stress level at the root of the groove it is desirable to cold-roll the grooves, and a suitable rolling technique employing three rollers of slightly different profile radii has been developed.
Impact of pay for performance on inequalities in health care: systematic review
Authors: Alshamsan Riyadh , Majeed Azeem , Ashworth Mark , Car Josip , Millett Christopher
Published: June 2010

Objectives:

To assess the impact of pay for performance programmes on inequalities in the quality of health care in relation to age, sex, ethnicity and socioeconomic status.

Methods:

Systematic search and appraisal of experimental or observational studies that assessed quantitatively the impact of a monetary incentive on health care inequalities. We searched published articles in English identified in the MEDLINE, EMBASE, PsycINFO and Cochrane databases.

Results:

Twenty-two studies were identified, 20 of which were conducted in the United Kingdom and examined the impact of the Quality and Outcomes Framework. Sixteen studies used practice level data rather than patient level data. Socioeconomic status was the most frequently examined inequality; age, sex and ethnic inequalities were less frequently assessed. There was some weak evidence that the use of financial incentives reduced inequalities in chronic disease management between socioeconomic groups. Inequalities in chronic disease management between age, sex and ethnic groups persisted after the use of such incentives.

Conclusions:

Inequalities in chronic disease management have largely persisted after the introduction of the Quality and Outcome Framework. Pay for performance programmes should be designed to reduce inequalities as well as improve the overall quality of care.
Ocular complications of Stevens-Johnson syndrome and toxic epidermal necrolysis
Authors: Ukponmwan Catherine U , Njinaka Itiyafe , Ehimiyen Efe T
Published: June 2010

The causative factors and ocular complications of Stevens-Johnson syndrome and toxic epidermal necrolysis are reported here. Six out of seven patients developed the syndrome secondary to ingestion of sulphadoxine/pyrimethamine while one developed it as a complication of HAART (highly active antiretroviral therapy). The ocular complications were ankyloblepharon, symblepharon, chronic conjunctivitis, corneal vascularization and conjunctivalization, and blindness. One patient died. A shift to the WHO-recommened artemisin-based combination therapy for the treatment of malaria is advised. Early referral to the ophthalmologist will help to reduce the complications.
Clinical characteristics of people with head nodding in southern Tanzania
Authors: Winkler Andrea S , Friedrich Katrin , Meindl Michael , Kidunda Aslam , Nassri Amir , Jilek-Aall Louise , Matuja William , Schmutzhard Erich
Published: June 2010

We have previously described a seizure disorder characterized by head nodding (HN). In a prospective study in southern Tanzania, we evaluated 62 patients with HN. Here, we report the patients’ clinical characteristics and those of their seizures, which indicate high seizure frequency, unsatisfactory seizure control, a high burden of cognitive impairment and disease-associated barriers to education.
Meningoencephalitis associated with hepatitis A infection: a case report and review of literature
Authors: Davoudi S , Soudbakhsh A , Emadikouchak H , Nikbakht G , Modabbernia A
Published: June 2010

Hepatitis A virus uncommonly causes neurological problems. Among these manifestations meningoencephalitis is very rare. We describe the clinical and laboratory features of a young boy with hepatitis A associated meningoencephalitis and compare it with other cases which had the same diagnoses.
Soil-transmitted helminth infection and urbanization in 880 primary school children in Nicaragua, 2005
Authors: Rosewell Alexander , Robleto Guillermo , Rodrí;guez Guillermo , Barragne-Bigot Philippe , Amador Juan José , Aldighieri Sylvain
Published: June 2010

The prevalence of soil-transmitted helminthiasis is close to half the population in Central America, with the marginalized peri-urban poor disproportionately affected. Previous single province helminth surveys conducted in Nicaragua have shown Ascaris lumbricoides to be the predominant species. In 2005, we conducted a cross-sectional study of 880 children in 10 Nicaraguan primary schools located in four provinces. We aimed to establish the prevalence and intensity of soiltransmitted helminth infections and to investigate the factors associated with helminthiasis. Almost half (46%) of the children were infected with soil-transmitted helminths. Tichuris trichiura was the most common infective species (34.7%). The prevalence and intensity of helminthiasis was heterogeneous in the provinces, with children educated in peri-urban schools most affected. Healthy policies are required that favour the peri-urban poor who have inadequate and declining access to water and sanitation.
Scrub typhus in Uttarakhand, India: a common rickettsial disease in an uncommon geographical region
Authors: Ahmad Sohaib , Srivastava Saurabh , Verma Sanjiv Kumar , Puri Prashant , Shirazi Nadia
Published: June 2010

Scrub typhus is a commonly encountered rickettsial disease of the Indian subcontinent. Humans are infected accidentally and the case fatality can be significantly high if the disease is not identified in time. We report nine cases of scrub typhus from the Garhwal region of the newly created north Indian state of Uttarakhand, a region not previously known to harbour the vector. Entomological studies are needed to study the density of the vectorand to institute vector control measures in order to prevent this relatively benign, yet potentially fatal, clinical entity from spiralling into a major public health issue.
Analysis of the Size Distributions of Fetal and Maternal Cell-Free DNA by Paired-End Sequencing
Authors: Fan H Christina , Blumenfeld Yair J , Chitkara Usha , Hudgins Louanne , Quake Stephen R
Published: June 2010

BACKGROUND

Noninvasive prenatal diagnosis with cell-free DNA in maternal plasma is challenging because only a small portion of the DNA sample is derived from the fetus. A few previous studies provided size-range estimates of maternal and fetal DNA, but direct measurement of the size distributions is difficult because of the small quantity of cell-free DNA.

METHODS

We used high-throughput paired-end sequencing to directly measure the size distributions of maternal and fetal DNA in cell-free maternal plasma collected from 3 typical diploid and 4 aneuploid male pregnancies. As a control, restriction fragments of λ DNA were also sequenced.

RESULTS

Cell-free DNA had a dominant peak at approximately 162 bp and a minor peak at approximately 340 bp. Chromosome Y sequences were rarely longer than 250 bp but were present in sizes of <150 bp at a larger proportion compared with the rest of the sequences. Selective analysis of the shortest fragments generally increased the fetal DNA fraction but did not necessarily increase the sensitivity of aneuploidy detection, owing to the reduction in the number of DNA molecules being counted. Restriction fragments of λ DNA with sizes between 60 bp and 120 bp were preferentially sequenced, indicating that the shotgun sequencing work flow introduced a bias toward shorter fragments.

CONCLUSIONS

Our results confirm that fetal DNA is shorter than maternal DNA. The enrichment of fetal DNA by size selection, however, may not provide a dramatic increase in sensitivity for assays that rely on length measurement in situ because of a trade-off between the fetal DNA fraction and the number of molecules being counted.
Joking as boundary negotiation among “good old boys”: “White trash” as a social category at the bottom of the Southern working class in Alabama
Authors: Davies Catherine Evans
Published: June 2010

The point of this article is to show how the “You might be a redneck” joke cycle is appropriated to designate a lower social category within the Southern working class in Alabama, and to negotiate the boundaries between the good old boy working class “red neck” and the lower category of “white trash.” Close attention to language is important in the analysis because the jokers exaggerate features of the vernacular dialect to perform members of the lower social category. Within the tradition of the study of conversational joking (Fry, Sweet madness: A study of humor, Pacific Books, 1963; Tannen, Conversational style: Analyzing talk among friends, Oxford University Press, 1984; Davies, C. E., Joint joking: Improvisational humorous episodes in conversation: 360–371, 1984, Language and American ‘good taste’: Martha Stewart as mass-media role model, Routledge, 2003a, Journal of Pragmatics 35: 361–1385, 2003b; Norrick, Conversational joking: Humor in everyday talk, Indiana University Press, 1993; Kotthoff, Coherent keying in conversational humour: Contextualizing joint fictionalisation, John Benjamins, 1999), combined with the discourse analyis of radio talk (Coupland, Language, situation, and the relational self: Theorizing dialect-style in sociolinguistics, Cambridge University Press, 2002; Goffman, Forms of talk, The University of Pennsylvania Press, 1981), and “performance speech” (Schilling-Estes, Language in Society 27: 53–83, 1998), this study examines joking interaction on a popular morning radio talk show in Alabama that is hosted by two men, known to their audience as Jack and Bubba. The data are a set of CD recordings identified as “The Best of . . .” supplemented with additional regular shows. Examining the joking as an important part of a linguistic “presentation of self” (Goffman, The presentation of self in everyday life, Doubleday, 1959; Davies, C. E., Texas Linguistic Forum 44: 73–89, 2002), the analysis reveals how the joking between the two hosts and with members of the studio audience is rooted in sociolinguistic and cultural dimensions of the working class American South.
Adjuvant High-Dose Interferon-α for Resected Melanoma in a Patient with HIV Infection
Authors: Saba Nakhle S. , George Thomas J. , Boulmay Brian C.
Published: June 2010

Adjuvant interferon (IFN)-α remains the standard adjuvant therapy for intermediate and high-risk melanoma after definitive surgical resection. Data addressing the role and safety of adjuvant immunotherapy in HIV-infected patients with melanoma are lacking. We report on an HIV+ patient who received IFN-α as adjuvant treatment for high-risk melanoma. To our knowledge, this is the first reported case of such an approach.
GATA4 protects granulosa cell tumors from TRAIL-induced apoptosis
Authors: Kyrönlahti Antti , Kauppinen Marjut , Lind Essi , Unkila-Kallio Leila , Butzow Ralf , Klefström Juha , Wilson David B , Anttonen Mikko , Heikinheimo Markku
Published: June 2010

Disturbances in granulosa cell apoptosis have been implicated in the pathogenesis of human granulosa cell tumors (GCTs). Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a potent cytokine that induces apoptosis in a variety of malignancies without toxic effects on benign cells. The aim of this study was to investigate the expression and functionality of the TRAIL receptors DR4 and DR5 in human GCTs. Additionally, we examined the role of GATA4, a transcription factor expressed in normal and malignant granulosa cells, in TRAIL-induced GCT apoptosis. For this purpose, a tissue microarray of 80 primary and 12 recurrent GCTs was subjected to immunohistochemistry for DR4 and DR5, and freshly isolated primary GCT cultures were utilized to evaluate the functional effects of TRAIL on GCT cells. To clarify the role of GATA4 in the regulation of TRAIL-induced apoptosis, a human GCT-derived cell line (KGN) was transduced with lentiviral vectors expressing small hairpin RNAs targeting GATA4 or transfected with adenovirus expressing either wild-type or dominant negative mutant GATA4. We found that receptors DR4 and DR5 are expressed in a vast majority of GCTs as well as in primary GCT cultures, and that TRAIL induces apoptosis in the primary GCT cultures. Moreover, we showed that overexpressing GATA4 protects GCTs from TRAIL-induced apoptosis in vitro, whereas disrupting GATA4 function induces apoptosis and potentiates the apoptotic effect of TRAIL administration. Our results demonstrate that the TRAIL pathway is functional in GCT cells, and suggest that transcription factor GATA4 may function as a survival factor in this ovarian malignancy.
Age- and cell-related gene expression of aromatase and estrogen receptors in the rat testis
Authors: Bois C , Delalande C , Nurmio M , Parvinen M , Zanatta L , Toppari J , Carreau S
Published: June 2010

Spermatogenesis is a complex and coordinated process leading to the formation of spermatozoa. This event, which is under the control of numerous endocrine and paracrine factors, seems to also be controlled by estrogens which exert their effects via nuclear estrogen receptors (ESRs) ESR1 and ESR2. Estrogens are synthesized by aromatase which is biologically expressed in the rat testis. The objective of our study was to clarify the gene expression patterns of aromatase and ESRs according to age and in the two compartments of the adult rat testis. In the adult, transcripts of aromatase vary according to the germ cell type and to the stages of seminiferous epithelium, a maximum being observed at stage I. The ESR1 gene is highly expressed in the adult testis and in stages from VIIc–d to XIV. Moreover, both ESR mRNA levels are higher in purified round spermatids than in pachytene spermatocytes, suggesting a putative role of estrogens in the haploid steps of spermatogenesis. The variability of the results in the expression of both ESRs led us to explore the putative presence of variants in the rat testis. Concerning ESR1, we have shown the presence of the full-length form and of one isoform with exon 4 deleted. For ESR2, besides the wild type, three isoforms were observed: one with exon 3 deleted, another with an insertion of 54 nucleotides, and the last one with both modifications. Therefore, the stage-regulated expression of aromatase and ESR1 genes in the rat testis suggests a likely role of estrogens in spermatogenesis.
Design development of an electrocoagulation reactor for molasses process wastewater treatment
Authors: Gadd A. S. , Ryan D. R. , Kavanagh J. M. , Barton G. W.
Published: June 2010

The impact of electrode corrosion behaviour, reactor geometry and current density on electrocoagulation efficiency were investigated for the treatment of molasses process wastewater. Two laboratory-scale vertical plate electrocoagulation reactors were used for this investigation: the first being a low aspect ratio bath reactor with a low specific electrode area, while the other was a high aspect ratio column reactor with a high specific electrode area. Anomalous anodic dissolution and cathodic corrosion of the aluminium electrodes both contributed significantly to overall metal consumption. Increasing specific electrode area and aspect ratio each led to improved treatment efficiency, whereas the impact of current density was more complicated involving the combined influences of several competing effects. The space-time yields of coagulant and bubbles (both functions of specific electrode area, current density and current efficiency) were found to influence mixing within the reactor and thus treatment efficiency.
An experimentally validated immersed boundary model of fluid–biofilm interaction
Authors: Dan Vo Garret , Brindle Eric , Heys Jeffrey
Published: June 2010

Biofllms are colonies of microorganisms that live on wetted surfaces in a matrix consisting of polysaccharides, proteins, and nucleic acids. According to the National Institute of Health (NIH), biofilms play a role in over 80 percent of microbial infections in the body and these infections are remarkably difficult to treat with antimicrobial compounds. The objective here is to understand and predict the physical interaction between a biofilm and the surrounding fluid flow. We have developed a biofilm–fluid interaction model, based on the lmmersed Boundary Method, to simulate the interaction between the biofilm and a moving fluid. The model predictions of biofilm deformation quantitatively agree with experimental measurements for a range of biofilms using a simple immersed elastic solid to model the biofilm matrix. An immersed viscoelastic solid model is also developed and compared with experimental measurements. The results show that the viscoelastic behaviour inherent in the immersed boundary method (even when using a simple immersed elastic solid) is sufficient for some biofilms, but a slightly viscoelastic solid gives more general agreement with experimental measurements.
Short-term effect of ammonia concentration and salinity on activity of ammonia oxidizing bacteria
Authors: Claros J. , Jiménez E. , Borrás L. , Aguado D. , Seco A. , Ferrer J. , Serralta J.
Published: June 2010

A continuously aerated SHARON (single reactor high activity ammonia removal over nitrite) system has been operated to achieve partial nitritation. Two sets of batch experiments were carried out to study the effect of ammonia concentration and salinity on the activity of ammonia-oxidizing bacteria (AOB). Activity of AOB raised as free ammonia concentration was increased reaching its maximum value at 4.5 mg NH3-N l−1. The half saturation constant for free ammonia was determined (KNH3 = 0.32 mg NH3-N l−1). Activity decreased at TAN (total ammonium–nitrogen) concentration over 2,000 mg NH4-N l−1. No free ammonia inhibition was detected. The effect of salinity was studied by adding different concentrations of different salts to the biomass. No significant differences were observed between the experiments carried out with a salt containing or not containing NH4. These results support that AOB are inhibited by salinity, not by free ammonia. A mathematical expression to represent this inhibition is proposed. To compare substrate affinity and salinity inhibitory effect on different AOB populations, similar experiments were carried out with biomass from a biological nutrient removal pilot plant. The AOB activity reached its maximum value at 0.008 mg NH3-N l−1 and decreased at TAN concentration over 400 mg NH4-N l−1. These differences can be explained by the different AOB predominating species: Nitrosomonas europaea and N. eutropha in the SHARON biomass and Nitrosomonas oligotropha in the pilot plant.
Detection of Vibrio cholerae and Vibrio parahaemolyticus by molecular and culture based methods from source water to household container-stored water at the point-of-use in South African rural communities
Authors: Ntema V. M. , Potgieter N. , Barnard T. G.
Published: June 2010

Detection methods for Vibrio cholerae and Vibrio parahaemolyticus which included the culture based approach with polymerase chain reaction (PCR) confirmation, PCR detection without enrichment and PCR with a pre-enrichment were developed and their performance evaluated. PCR assays targeted the SodB (V. cholerae species), Flae (V. parahaemolyticus species), 16S rRNA (Vibrio and Enterobacteriacea species) genes (Multiplex 1) and V. cholerae O1 and V. cholerae O139 rfb genes, ctxA (cholera toxin) gene and 16S rRNA gene (Multiplex 2). These methods were used to determine the occurrence of selected Vibrios in source water as well as in household container-stored water. The combination of filtration, enrichment and PCR method provided a sensitive and specific method for the detection of selected Vibrios in water samples. The PCR with a pre-enrichment method detected as few as 4–10 cfu/100 mL of selected Vibrios and PCR detection without the enrichment method detected as few as 40–100 cfu/100 mL of selected Vibrios. The inclusion of an enrichment period allows detection of culturable bacteria. As an application of the developed methods, V. cholerae and V. parahaemolyticus were detected in the source water used by the population and in the water-storage containers. The results indicate that Vibrio species in the containers could have originated from the source water and survive in biofilms inside the containers.
Arsenic hyperaccumulation by Pteris vittata and Pityrogramma calomelanos: a comparative study of uptake efficiency in arsenic-treated soils and waters
Authors: Yong J. W. H. , Tan S. N. , Ng Y. F. , Low K. K. K. , Peh S. F. , Chua J. C. , Lim A. A. B.
Published: June 2010

This work comprised of the comparative study of arsenic (As) uptake efficiency by Pteris vittata and Pityrogramma calomelanos grown in (i) As amended soils (0–600 ppm) and (ii) As tainted water (40 ppb) using a new compact continuous flow phytofiltration system in a tropical greenhouse. The As hyperaccumulation efficiency was dependent on the growth medium for the two fern species. The highest level of As detected in the fronds of P. vittata was 19,300 ± 190 ppm (dry weight basis) and 11,600 ± 230 ppm for Pityrogramma calomelanos, after growing for 78 days in soils amended with As. In the compact continuous flow As phytofiltration system experiments, Pityrogramma calomelanos was found to perform better than P. vittata in phytofiltrating As contaminated water under waterlogged conditions. During the 167 h of phytofiltration experiment, the removal efficiency was approximately 99% and 67% for Pityrogramma calomelanos and P. vittata systems respectively, based on an initial 40 ppb As. Pityrogramma calomelanos also required a shorter acclimatization time than P. vittata under waterlogged conditions.