bluuebunny/crossref_metadata_2025 huggingface dataset:
Control of energy distribution of the proton beam with an oblique incidence of the laser pulse
Authors: Morita Toshimasa , Bulanov Sergei V. , Esirkepov Timur Zh. , Koga James , Yamagiwa Mitsuru
Published: March 2009

Proton acceleration in the interaction of an obliquely incident laser pulse with a double layer target consisting of a high-Z atom layer and a proton-rich layer is investigated with three-dimensional particle-in-cell simulations. The dependence of the proton beam energy spread on the laser focus position at the target surface provides a way to control the proton energy spectrum. By appropriately adjusting the size and position of the second proton layer one can minimize the proton energy spread simultaneously maximizing the proton energy.
Dissociative melting of ice VII at high pressure
Authors: Goncharov Alexander F. , Sanloup Chrystele , Goldman Nir , Crowhurst Jonathan C. , Bastea Sorin , Howard W. M. , Fried Laurence E. , Guignot Nicolas , Mezouar Mohamed , Meng Yue
Published: March 2009

We have used x-ray diffraction to determine the structure factor of water along its melting line to a static pressure of 57 GPa (570 kbar) and a temperature of more than 1500 K, conditions which correspond to the lower mantle of the Earth, and the interiors of Neptune and Uranus up to a depth of 7000 km. We have also performed corresponding first principles and classical molecular dynamics simulations. Above a pressure of 4 GPa the O–O structure factor is found to be very close to that of a simple soft sphere liquid, thus permitting us to determine the density of liquid water near the melting line. By comparing these results with the density of ice, also determined in this study, we find that the enthalpy of fusion (ΔHf) increases enormously along the melting line, reaching approximately 120 kJ/mole at 40 GPa (compared to 6 kJ/mole at 0 GPa), thus revealing significant molecular dissociation of water upon melting. We speculate that an extended two-phase region could occur in planetary processes involving the adiabatic compression of water.
Spinel LiMn2−xNixO4 cathode materials for high energy density lithium ion rechargeable batteries
Authors: Singhal Rahul , Saavedra-Aries Jose J. , Katiyar Rajesh , Ishikawa Yasuyuki , Vilkas Marius J. , Das Suprem R. , Tomar Maharaj S. , Katiyar Ram. S.
Published: March 2009

The practical limitations of fully lithium ion insertion and extraction into LiMn2O4 cathode structure without any structural instability make it unsuitable in commercial Li-ion rechargeable batteries. In this work, we showed that those partially substituted by Ni, i.e., LiMn2−xNixO4 (0≤x≤0.5), prepared by sol-gel technique, could be used as a potential candidate for high energy density and high voltage Li-ion battery applications with superior rate capabilities. The improved structural stability of the cathode was probed by x-ray diffraction and micro-Raman spectroscopy. The density-functional theoretical calculations were employed to identify the minimum energy needed for Li+ diffusion pathway and activation energy in the spinel framework with different Ni ion concentrations. Our results showed significant enhancement in the properties with 25at.% of Ni solid-solution doping in LiMn2O4 host and the experimental results are in line with the theoretical computations.
The role of carrier gases in the production of metastable argon atoms in a rf discharge
Authors: Rudinger Kenneth , Lu Zheng-Tian , Mueller Peter
Published: March 2009

We investigate the role of carrier gases in the production of metastable argon atoms in a rf-driven discharge. The effects of different carrier gases (krypton, xenon, neon, and helium), carrier gas pressures, and rf discharge powers are examined. A xenon carrier gas provides the greatest metastable population of argon, yielding an optimal fractional metastable population of argon (Ar∗/Ar) of 2×10−4 at 0.2 mTorr of xenon gas. The optimal krypton configuration yields 60% of the xenon-supported population at 1.5 times higher pressure. Neon and helium perform considerably worse probably due to their higher ionization potentials.
Extracting the hydrodynamic resistance of droplets from their behavior in microchannel networks
Authors: Labrot Vincent , Schindler Michael , Guillot Pierre , Colin Annie , Joanicot Mathieu
Published: March 2009

The overall traffic of droplets in a network of microfluidic channels is strongly influenced by the liquid properties of the moving droplets. In particular, the effective hydrodynamic resistance of individual droplets plays a key role in their global behavior. Here we propose two simple and low-cost experimental methods for measuring this parameter by analyzing the dynamics of a regular sequence of droplets injected into an “asymmetric loop” network. The choice of a droplet taking either route through the loop is influenced by the presence of previous droplets that modulate the hydrodynamic resistance of the branches they are sitting in. We propose to extract the effective resistance of a droplet from easily observable time series, namely, from the choices the droplets make at junctions and from the interdroplet distances. This becomes possible when utilizing a recently proposed theoretical model based on a number of simplifying assumptions. Here we present several sets of measurements of the hydrodynamic resistance of droplets, expressed in terms of a “resistance length.” The aim is twofold: (1) to reveal its dependence on a number of parameters, such as the viscosity, the volume of droplets, their velocity as well as the spacing between them. At the same time (2), by using a standard measurement technique, we compare the limitations of the proposed methods. As an important result of this comparison, we obtain the range of validity of the simplifying assumptions made in the theoretical model.
Management practices for control of runoff losses from cotton furrows under storm rainfall. III. Cover and wheel traffic effects on nutrients (N and P) in runoff from a black Vertosol
Authors: Silburn D. M. , Hunter H. M.
Published: March 2009

Transport of nitrogen (N) and phosphorus (P) in runoff was measured using a rainfall simulator on a cotton hill–furrow system with a range of on-ground cover (0–60%), each with and without prior wheel traffic in the furrow. Total N and P losses in runoff (kg/ha) from the bare plots on a whole-field basis (wheel and non-wheel tracks) were equivalent to 1.5% and 1%, respectively, of fertiliser applied that season (218 kg N/ha, 27 kg P/ha). This was for a single runoff event of 17 mm, about 1/10 of the total runoff expected in a season. Retaining surface cover and avoiding wheel traffic were both effective in reducing runoff losses of total N and P, especially when used together. Retaining cover gave considerably lower concentrations of total P, and of N and P associated with sediment, with no significant differences (P > 0.05) between wheel and non-wheel tracks. The majority of nutrients were transported with sediment, for P for all treatments, and for N from low cover plots. Concentrations of dissolved N, dominantly as NO3-N, were unaffected by cover on non-wheel tracks but increased with cover on wheel track plots where runoff occurred as shallow interflow. On a whole-field basis, N was mainly in dissolved form at higher covers, because most runoff came from wheel tracks where interflow occurred. Reducing the ratio of wheel tracks to non-wheel tracks will reduce runoff of N and P. Interflow or exfiltration above an infiltration throttle layer is a worst-case scenario for runoff transport of soluble, poorly sorbed chemicals such as NO3-N, which would otherwise leach and not enter runoff. To improve water quality, for both sorbed and dissolved forms, the combination of retaining cover and avoiding wheel traffic and subsoil compaction is needed. Similarly, land uses involving high nutrient inputs should be avoided on soils with shallow subsurface restrictions to infiltration, which are thus prone to interflow.
Primary (dispersed) clay and silt were slightly enriched in sediment in runoff, while primary fine and coarse sand were depleted. However, sediments were not enriched in total N and P compared with the soil surface, and organic carbon was only slightly enriched (enrichment ratio 1.06). This is typical of the behaviour of well-aggregated soils of high clay content.
Global warming-enhanced stratification and mass mortality events in the Mediterranean
Authors: Coma Rafel , Ribes Marta , Serrano Eduard , Jiménez Eroteida , Salat Jordi , Pascual Josep
Published: March 2009

Summer conditions in the Mediterranean Sea are characterized by high temperatures and low food availability. This leads to “summer dormancy” in many benthic suspension feeders due to energetic constraints. Analysis of the most recent 33-year temperature time series demonstrated enhanced stratification due to global warming, which produced a ≈40% lengthening of summer conditions. Many biological processes are expected to be affected by this trend, culminating in such events as mass mortality of invertebrates. Climatic anomalies concomitant with the occurrence of these events represent prolonged exposure to warmer summer conditions coupled with reduced food resources. Simulation of the effects of these conditions on a model organism demonstrated a biomass loss of >35%. Losses of this magnitude result in mortality similar to that noted in field observations during mass mortality events. These results indicate that temperature anomalies are the underlying cause of the events, with energetic constraints serving as the main triggering mechanism.
The spread of awareness and its impact on epidemic outbreaks
Authors: Funk Sebastian , Gilad Erez , Watkins Chris , Jansen Vincent A. A.
Published: March 2009

When a disease breaks out in a human population, changes in behavior in response to the outbreak can alter the progression of the infectious agent. In particular, people aware of a disease in their proximity can take measures to reduce their susceptibility. Even if no centralized information is provided about the presence of a disease, such awareness can arise through first-hand observation and word of mouth. To understand the effects this can have on the spread of a disease, we formulate and analyze a mathematical model for the spread of awareness in a host population, and then link this to an epidemiological model by having more informed hosts reduce their susceptibility. We find that, in a well-mixed population, this can result in a lower size of the outbreak, but does not affect the epidemic threshold. If, however, the behavioral response is treated as a local effect arising in the proximity of an outbreak, it can completely stop a disease from spreading, although only if the infection rate is below a threshold. We show that the impact of locally spreading awareness is amplified if the social network of potential infection events and the network over which individuals communicate overlap, especially so if the networks have a high level of clustering. These findings suggest that care needs to be taken both in the interpretation of disease parameters, as well as in the prediction of the fate of future outbreaks.
High-pressure polymeric phases of carbon dioxide
Authors: Sun Jian , Klug Dennis D. , Martoňák Roman , Montoya Javier Antonio , Lee Mal-Soon , Scandolo Sandro , Tosatti Erio
Published: March 2009

Understanding the structural transformations of solid CO
2
from a molecular solid characterized by weak intermolecular bonding to a 3-dimensional network solid at high pressure has challenged researchers for the past decade. We employ the recently developed metadynamics method combined with ab initio calculations to provide fundamental insight into recent experimental reports on carbon dioxide in the 60–80 GPa pressure region. Pressure-induced polymeric phases and their transformation mechanisms are found. Metadynamics simulations starting from the CO
2
-II (P4
2
/mnm) at 60 GPa and 600 K proceed via an intermediate, partially polymerized phase, and finally yield a fully tetrahedral, layered structure (P-4m2). Based on the agreement between calculated and experimental Raman and X-ray patterns, the recently identified phase VI [Iota V, et al. (2007) Sixfold coordinated carbon dioxide VI.
Nature Mat
6:34–38], assumed to be disordered stishovite-like, is instead interpreted as the result of an incomplete transformation of the molecular phase into a final layered structure. In addition, an α-cristobalite-like structure (P4
1
2
1
2), is predicted to be formed from CO
2
-III (Cmca) via an intermediate Pbca structure at 80 GPa and low temperatures (<300 K). Defects in the crystals are frequently observed in the calculations at 300 K whereas at 500 to 700 K, CO
2
-III transforms to an amorphous form, consistent with experiment [Santoro M,
et al.
(2006) Amorphous silica-like carbon dioxide.
Nature
441:857–860], but the simulation yields additional structural details for this disordered solid.
Anaemia in schoolchildren in eight countries in Africa and Asia
Authors:   Partnership for Child Development. Principal investigators:, Hall Andrew , Bobrow Emily , Brooker Simon , Jukes Matthew , Nokes Kate , Lambo Jane , Guyatt Helen , Bundy Don , Adjei Sam , Wen Su-Tung , Satoto  , Subagio Hertanto , Rafiluddin Mohammed Zen , Miguel Ted , Moulin Sylvie , Johnson Joseph de Graft , Mukaka Mary , Roschnik Nathalie , Sacko Moussa , Zacher Anna , Mahumane Bonifacio , Kihamia Charles , Mwanri Lillian , Tatala Simon , Lwambo Nicholas , Siza Julius , Bao Khanh Le Nguyen , Khoi Ha Huy , Toan Nguyen Duy
Published: March 2009

Objective

To report on the haemoglobin concentrations and prevalence of anaemia in schoolchildren in eight countries in Africa and Asia.

Design

Blood samples were collected during surveys of the health of schoolchildren as a part of programmes to develop school-based health services.

Setting

Rural schools in Ghana, Indonesia, Kenya, Malawi, Mali, Mozambique, Tanzania and Vietnam.

Subjects

Nearly 14 000 children enrolled in basic education in three age ranges (7–11 years, 12–14 years and Ä15 years) which reflect the new UNICEF/WHO thresholds to define anaemia.

Results

Anaemia was found to be a severe public health problem (defined as >40% anaemic) in five African countries for children aged 7–11 years and in four of the same countries for children aged 12–14 years. Anaemia was not a public health problem in the children studied in the two Asian countries. More boys than girls were anaemic, and children who enrolled late in school were more likely to be anaemic than children who enrolled closer to the correct age. The implications of the four new thresholds defining anaemia for school-age children are examined.

Conclusions

Anaemia is a significant problem in schoolchildren in sub-Saharan Africa. School-based health services which provide treatments for simple conditions that cause blood loss, such as worms, followed by multiple micronutrient supplements including iron, have the potential to provide relief from a large burden of anaemia.
Intraindividual comparison between gadopentetate dimeglumine and gadobutrol for magnetic resonance perfusion in normal brain and intracranial tumors at 3 tesla
Authors: Giesel Frederik L. , Mehndiratta Amit , Risse Frank , Rius Maria , Zechmann Christian M. , von Tengg-Kobligk Hendrik , Gerigk Lars , Kauczor Hans-Ulrich , Politi Maria , Essig Marco , Griffiths Paul D. , Wilkinson Iain D.
Published: March 2009

Background: In vitro studies have shown that the 3-Tesla (T) magnetic resonance (MR) characteristics of high- and standard-molar gadolinium-based contrast agents differ. Such differences may indicate that high-molar (1.0 M) agents offer advantages for perfusion-weighted imaging (PWI) at 3T, as has been previously reported at 1.5T.

Purpose: To investigate possible intraindividual differences of high- versus low-molar contrast agents on PWI at 3T in patients with intracranial space-occupying lesions.

Material and Methods: Six patients with intraaxial and five patients with extraaxial tumors underwent two MR examinations at 3T, separated by at least 48 hours. On each occasion, an exogenous contrast-based, T2*-weighted, gradient-recalled echo-planar imaging (EPI) technique was used to determine the intracranial perfusion characteristics using one of two intravenous contrast agents: either 5 ml of 1.0 M gadobutrol or 10 ml of 0.5 M gadopentetate dimeglumine. The primary PWI outcome measure was region-of-interest maximal signal change (Cmax).

Results: The difference in Cmax for gray and white matter (ΔCmax) was significantly higher for gadobutrol compared to gadopentetate dimeglumine ( P<0.01). The ratio of Cmax between gray and white matter (rCmax = CmaxGray/CmaxWhite) was also significantly higher (median 24.6%, range 13.7–36.5%) for gadobutrol ( P<0.01). The ratio of Cmax between the whole tumor and whole normal side hemisphere was higher in five out of the six intraaxial tumor cases. A significantly higher ratio (ΔCmax/Cmax) in the difference between Cmax of gray and white matter (from hemisphere without brain lesion) compared to Cmax for the hemisphere containing the neoplasm (hemisphere with brain lesion) was demonstrated for gadobutrol in intraaxial tumors ( P<0.05).

Conclusion: Higher-concentration 1.0 M gadobutrol can offer advantages over standard 0.5 M gadopentetate dimeglumine, particularly with respect to delineation between gray and white matter and for the demarcation of highly vascularized tumor tissue on brain PWI performed at 3T.
Alternative Estimation of Human Exposure of Single-Walled Carbon Nanotubes Using Three-Dimensional Tissue-Engineered Human Lung
Authors: Stoker Emily , Purser Forrest , Kwon Soonjo , Park Young-Bin , Lee Joon Sang
Published: March 2009

Recent discoveries of various forms of carbon nanostructure have stimulated research on their applications and hold promise for applications in medicine and other related engineering areas. Although carbon nanotubes (CNTs) are already being produced on a massive scale, few studies have been performed which test the potential harmful effects of this new technology. The authors used a three-dimensional in vitro model of the human airway using a coculture of normal human bronchial epithelial cells and normal human fibroblasts for the health risk assessment of CNTs on the human respiratory systems. The authors used aqueous single-walled carbon nanotube (SWCNT) solution. The average length and diameter of nanotube ropes were about 500 nm and less than 10 nm, respectively. The authors measured the production of nitric oxide (NO) as an inflammatory marker and mitochondrial activity using MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay as a cytotoxic response of the cell layers following exposure of different concentration of aqueous SWCNT solution. The results indicated that NO production was dramatically increased and cell viability was decreased following exposure of different concentrations of SWCNTs. Transepithelial electrical resistance (TER) across the coculture layers was measured to observe the changes in airway physiological function following exposure of different concentrations of SWCNTs. TER value was dramatically decreased following exposure of 20% SWCNT (8 μg/ml). In this study, the authors presented viable alternatives to in vivo tests to evaluate the toxicity of engineered SWCNTs. Cytotoxic/inflammatory responses and barrier function of the human lung layers following exposure of SWCNTs were observed using in vitro coculture system of airway.
Hexachlorobenzene Treatment on Hepatic Mitochondrial Function Parameters and Intracellular Coproporphyrinogen Oxidase Location
Authors: Sopena Yolanda E. , Ferramola de Sancovich Ana M. , Sancovich Horacio A.
Published: March 2009

These studies try to elucidate why isocoproporphyrin appears in hexachlorobenzene-poisoned rats’ feces. Chronic exposure of hexachlorobenzene to rats produces an experimental model for human porphyria cutanea tarda. After 8 weeks of treatment, rats showed high porphyrin excreta and 50% inhibition of liver uroporphyrinogen decarboxylase activity. Uroporphyrin plus heptacarboxylic porphyrin exceeded coproporphyrin in urine, whereas in feces, isocoproporphyrin, from abnormal pentacarboxylic porphyrinogen III oxidative decarboxylation by liver coproporphyrinogen oxidase, became the main porphyrin. Trypsin-treated mitochondria showed that the outer and inner membrane permeability barrier was highly conserved after hexachlorobenzene intoxication. In digitonin-treated hexachlorobenzene mitochondria, coproporphyrinogen oxidase was free in the mitochondrial intermembrane space, whereas in normal mitochondria, 30% to 50% remained anchored to the inner membrane. Hexachlorobenzene led to a decrease in respiratory control and ADP/O ratios (uncoupled mitochondria). Albumin restored oxidative phosphorylation, indicating no irreversible inner membrane damage. Normal and hexachlorobenzene mitochondria oscillatory studies exhibited similar damping factor values, showing that hexachlorobenzene had no significant effect on membrane fluidity and elasticity. Mitochondrial uncoupling could explain the free state of the enzyme within the intermembrane space. The free state of the enzyme makes it more flexible and would allow pentacarboxylic porphyrinogen III, whose levels are increased, to compete with coproporphyrinogen III and being transformed into dehydroisocoproporphyrinogen, the liver forerunner of fecal isocoproporphyrin.
In vivo expansion of T reg cells with IL-2–mAb complexes: induction of resistance to EAE and long-term acceptance of islet allografts without immunosuppression
Authors: Webster Kylie E. , Walters Stacey , Kohler Rachel E. , Mrkvan Tomas , Boyman Onur , Surh Charles D. , Grey Shane T. , Sprent Jonathan
Published: March 2009

Via a transcription factor, Foxp3, immunoregulatory CD4+CD25+ T cells (T reg cells) play an important role in suppressing the function of other T cells. Adoptively transferring high numbers of T reg cells can reduce the intensity of the immune response, thereby providing an attractive prospect for inducing tolerance. Extending our previous findings, we describe an in vivo approach for inducing rapid expansion of T reg cells by injecting mice with interleukin (IL)-2 mixed with a particular IL-2 monoclonal antibody (mAb). Injection of these IL-2–IL-2 mAb complexes for a short period of 3 d induces a marked (>10-fold) increase in T reg cell numbers in many organs, including the liver and gut as well as the spleen and lymph nodes, and a modest increase in the thymus. The expanded T reg cells survive for 1–2 wk and are highly activated and display superior suppressive function. Pretreating with the IL-2–IL-2 mAb complexes renders the mice resistant to induction of experimental autoimmune encephalomyelitis; combined with rapamycin, the complexes can also be used to treat ongoing disease. In addition, pretreating mice with the complexes induces tolerance to fully major histocompatibility complex–incompatible pancreatic islets in the absence of immunosuppression. Tolerance is robust and the majority of grafts are accepted indefinitely. The approach described for T reg cell expansion has clinical potential for treating autoimmune disease and promoting organ transplantation.
A systematic review of telemonitoring technologies in heart failure
Authors: Maric Biljana , Kaan Annemarie , Ignaszewski Andrew , Lear Scott A.
Published: March 2009

Aims

Heart failure (HF) results in characteristic signs and symptoms including oedema and breathing difficulties. Heart failure is particularly suited to telemonitoring, because patients’ signs and symptoms can be assessed remotely by healthcare providers, and deterioration can be quickly detected and addressed. In this paper, we review studies conducted in HF telemonitoring, to describe the nature of the modality, the methods, and the results.

Methods and results

Articles were obtained through a MedLine search, utilizing the term heart failure in conjunction with the terms telehealth, telecare, telemonitoring, web, Internet, remote monitoring, and self‐monitoring. Studies utilizing various modalities, including telephone touch pad, specialized hardware, and websites for participants to enter data were found, with various benefits being reported. Most studies demonstrated improvements in outcome measures, including improved quality of life and decreased hospitalizations. However, not all studies reported the same improvements and in several cases the sample sizes were relatively small.

Conclusion

Telemonitoring appears to be an acceptable method for monitoring of HF patients. Controlled, randomized studies directly comparing different modalities and evaluating their success and feasibility when used as part of routine clinical care, are now required.
A fixed-time diffusion analysis method determines that the three cheV genes of Helicobacter pylori differentially affect motility
Authors: Lowenthal Andrew C. , Simon Christopher , Fair Amber S. , Mehmood Khalid , Terry Karianne , Anastasia Stephanie , Ottemann Karen M.
Published: March 2009

Helicobacter pylori is a chemotactic bacterium that has three CheV proteins in its predicted chemotaxis signal transduction system. CheV proteins contain both CheW- and response-regulator-like domains. To determine the function of these proteins, we developed a fixed-time diffusion method that would quantify bacterial direction change without needing to define particular behaviours, to deal with the many behaviours that swimming H. pylori exhibit. We then analysed mutants that had each cheV gene deleted individually and found that the behaviour of each mutant differed substantially from wild-type and the other mutants. cheV1 and cheV2 mutants displayed smooth swimming behaviour, consistent with decreased cellular CheY-P, similar to a cheW mutant. In contrast, the cheV3 mutation had the opposite effect and the mutant cells appeared to change direction frequently. Additional analysis showed that the cheV mutants displayed aberrant behaviour as compared to the wild-type in the soft-agar chemotaxis assay. The soft-agar assay phenotype was less extreme compared to that seen in the fixed-time diffusion model, suggesting that the cheV mutants are able to partially compensate for their defects under some conditions. Each cheV mutant furthermore had defects in mouse colonization that ranged from severe to modest, consistent with a role in chemotaxis. These studies thus show that the H. pylori CheV proteins each differently affect swimming behaviour.
Localization of the GerD spore germination protein in the Bacillus subtilis spore
Authors: Mongkolthanaruk Wiyada , Robinson Carl , Moir Anne
Published: March 2009

The GerD protein of Bacillus subtilis is required for efficient spore germination in l-alanine, and for germination in the alternative germinant combination of amino acids plus sugars. Only germination via nutrient receptors is affected in the mutant. The GerD protein is predicted to be a lipoprotein that is produced in the forespore compartment of the sporulating cell. Using antibody raised against the GerD protein, Western blots of proteins from spore fractions revealed that, as might be expected, the protein was detected in the inner membrane of spores, but it was also present at a high level in spore integuments (comprising coat, cortex and germ cell wall layers), and to some extent in the soluble fraction. It is likely that the GerD protein in the outer layers of dormant spores is located in the germ cell wall, as it was detected in coat-defective spores, and in the cell wall fraction of cells that were outgrowing from spores. Which of the multiple locations of GerD is important for its function is not known, but the inner membrane association would be appropriate for any interaction with germinant receptor proteins or SleB cortex lytic enzyme. Substitution of alanine for cysteine in the conserved cleavage site of the predicted prelipoprotein signal sequence of GerD resulted in mutant spores that lacked the GerD protein entirely.
Solar disinfection (SODIS) and subsequent dark storage of Salmonella typhimurium and Shigella flexneri monitored by flow cytometry
Authors: Bosshard Franziska , Berney Michael , Scheifele Michael , Weilenmann Hans-Ulrich , Egli Thomas
Published: March 2009

Pathogenic enteric bacteria are a major cause of drinking water related morbidity and mortality in developing countries. Solar disinfection (SODIS) is an effective means to fight this problem. In the present study, SODIS of two important enteric pathogens, Shigella flexneri and Salmonella typhimurium, was investigated with a variety of viability indicators including cellular ATP levels, efflux pump activity, glucose uptake ability, and polarization and integrity of the cytoplasmic membrane. The respiratory chain of enteric bacteria was identified to be a likely target of sunlight and UVA irradiation. Furthermore, during dark storage after irradiation, the physiological state of the bacterial cells continued to deteriorate even in the absence of irradiation: apparently the cells were unable to repair damage. This strongly suggests that for S. typhimurium and Sh. flexneri, a relatively small light dose is enough to irreversibly damage the cells and that storage of bottles after irradiation does not allow regrowth of inactivated bacterial cells. In addition, we show that light dose reciprocity is an important issue when using simulated sunlight. At high irradiation intensities (>700 W m−2) light dose reciprocity failed and resulted in an overestimation of the effect, whereas reciprocity applied well around natural sunlight intensity (<400 W m−2).
Severity scores, itch scores and plasma substance P levels in atopic dermatitis treated with standard topical therapy with oral olopatadine hydrochloride
Authors: HOSOKAWA Chisato , TAKEUCHI Satoshi , FURUE Masutaka
Published: March 2009

Atopic dermatitis (AD) is a common chronic or chronically relapsing, severely pruritic, eczematous skin disease. Recently, substance P (SP) has been demonstrated to be one of the important neuropeptides for mediating itch–scratch and stress–scratch cycles. In this study, we examined the severity scores, itch scores and plasma SP levels in 19 patients with AD treated with standard topical therapy with or without an oral antihistamine, olopatadine hydrochloride, for 4 weeks. The standard therapy decreased SCORAD scores, itch behavioral rating scores and plasma SP levels at post‐treatment in the mass, but the topical therapy with olopatadine was more effective than the topical therapy alone, suggesting a potential additive effect.
Effects of Propionibacterium acnes on various mRNA expression levels in normal human epidermal keratinocytes in vitro
Authors: AKAZA Narifumi , AKAMATSU Hirohiko , KISHI Masataka , MIZUTANI Hiroshi , ISHII Izumi , NAKATA Satoru , MATSUNAGA Kayoko
Published: March 2009

Propionibacterium acnes is one of the most significant pathogenic factors of acne vulgaris. This bacteria relates to acne by various pathways. It has also been reported that P. acnes influences pro‐inflammatory cytokine production in keratinocytes in vitro. However, the influence on the differentiation of keratinocytes by P. acnes has not been studied extensively. We analyzed the expression of keratinocyte differentiation‐specific markers, keratins, and pro‐inflammatory cytokines in normal human epidermal keratinocytes (NHEK) exposed to P. acnes in vitro. All P. acnes strains used in this study increased transglutaminase (TGase), keratin 17 (K17) and interleukin (IL) mRNA expression levels in NHEK, and decreased K1 and K10 expression levels. Some P. acnes strains increased involucrin and K6 mRNA expression levels in NHEK and decreased filaggrin, K6 and K16 expression levels in vitro. This experiment clarified that P. acnes influences the differentiation of NHEK in vitro. As a result, P. acnes influenced the expression of not only pro‐inflammatory cytokines but also some keratinocyte differentiation‐specific markers and keratins in NHEK. Our results suggest that P. acnes relates to acne pathogenesis by not only the induction of inflammation but also in the differentiation of keratinocytes. Moreover, it was considered that the reaction of NHEK to P. acnes may be different depending on the type of bacteria.
Successful treatment of Rosai–Dorfman disease with low‐dose oral corticosteroid
Authors: OKA Masahiro , KAMO Tsuneyoshi , GOTO Noriko , NAGANO Tohru , HIRAYAMA Yuji , NIBU Ken‐ichi , NISHIGORI Chikako
Published: March 2009

We present herein a Japanese case of Rosai–Dorfman disease (RDD) in which cutaneous manifestations completely remitted after treatment with low‐dose oral corticosteroid. A 69‐year‐old Japanese man presented with a 1‐year history of enlarged submandibular lymph nodes and subsequent nasal and pharyngeal bleeding. RDD was diagnosed based on biopsy results from a lymph node in the left parotid region. The patient had also noted several skin eruptions that repeatedly appeared and disappeared on the face and arms. Biopsies were taken from skin eruptions on the face and cuboidal fossa. Both biopsy specimens showed dense, well‐demarcated infiltration of histiocytes, lymphocytes and multinucleated giant cells from just under the epidermis to the subcutaneous tissue. These histiocytes were positive for CD68 and S‐100, but negative for CD1a, and some displayed emperipolesis. Given the histopathological findings and the fact that the patient was suffering from RDD, skin lesions were diagnosed as cutaneous manifestations of RDD. Cutaneous lesions gradually began to persist concomitant with enlargement of extranodal lymphadenopathy in the nasopharyngeal area. Increasing respiratory obstruction prompted a trial with oral prednisolone commencing at 0.4 mg/kg per day. Both the lymphadenopathy and skin lesions responded quickly. Within 3 months, all his skin lesions disappeared completely with almost complete resolution of lymphadenopathy. Twelve months after the beginning of oral prednisolone therapy, slight recurrence of mucosal and cutaneous lesions appeared, but disappeared quickly with an increase in prednisolone to 0.3 mg/kg per day. Low‐dose prednisolone appeared very effective in the case of RDD.
Evidence that PKA activity is constitutively activated in human GH‐secreting adenoma cells in a patient with Carney complex harbouring a PRKAR1A mutation
Authors: Takano Koji , Yasufuku‐Takano Junko , Morita Koji , Mori Shigetoshi , Takei Mao , Osamura Robert Yoshiyuki , Teramoto Akira , Fujita Toshiro
Published: March 2009

Context  The GHRH–protein kinase A (PKA) signalling pathway is essential for cell proliferation and GH synthesis/secretion in somatotrophs. An inactivating mutation of PRKAR1A is one of the causes of somatotrophinoma in Carney complex (CNC). The basal PKA activity of somatotroph adenoma cells from CNC has not been evaluated because of a limited amount of available tissue.

Objective  This study examined how the PRKAR1A mutation affects the PKA signalling pathway in a human somatotrophinoma with a PRKAR1A mutation.

Design and setting  Somatotrophinoma cells from a 40‐year‐old male patient with CNC were used. The patient had a novel somatic heterozygous germline frameshift mutation (227delT) in PRKAR1A leading to a premature stop codon. The tumour showed loss of heterozygosity (LOH) at 17q23–24. Primary cultured adenoma cells were subjected to electrophysiological experiments to evaluate PKA signalling in individual cells.

Results  GHRH did not increase the nonselective cation current or the voltage‐gated calcium current in these adenoma cells, in contrast to nonadenomatous somatotroph cells in which these currents increase through the PKA pathway. Application of a PKA inhibitor inhibited the basal currents in these adenoma cells, results that were not observed in nonadenomatous somatotrophs. These data indicate that the basal currents are already increased and cannot be further increased by GHRH.

Conclusions  The results demonstrate that PKA is activated at the basal state in these adenoma cells. The data also show that both the nonselective cation current and the voltage‐gated calcium current, vital regulators of GH secretion downstream of PKA, are maximally increased in these cells. These maximally increased currents probably account for the excessive GH secretion.
Enhancing invertebrate food resources for skylarks in cereal ecosystems: how useful are in‐crop agri‐environment scheme management options?
Authors: Smith Barbara , Holland John , Jones Naomi , Moreby Stephen , Morris Anthony J. , Southway Sue
Published: March 2009

UK agri‐environment schemes rarely address within‐crop biodiversity yet this habitat is used almost exclusively by some taxa. With the removal of set‐aside, maximizing the ecological services provided by in‐crop management options is critical. Field trials of small undrilled patches in the cropped area have been shown to increase skylark Alauda arvensis numbers and breeding productivity. This response may reflect a benefit for lower trophic levels, such as the invertebrates and arable plants on which birds feed. The technique has now been adopted as an option in the Environmental Stewardship scheme in England.

Two within‐field management techniques (undrilled patches and wide‐spaced rows) were compared with standard row spacing on 10 conventionally managed farms growing winter wheat in northern and eastern England in 2002 and 2003. The effect of the treatments on invertebrate abundance, particularly invertebrates known to be important food for birds, was compared and the link between cover of arable weeds and invertebrate abundance was assessed. The diet of chicks located on the treatments was compared by faecal analysis.

On a field scale, the treatments did not consistently increase invertebrate numbers. Invertebrates either colonized or avoided undrilled patches in the crop. The extent to which patches were colonized was dependent on vegetation cover, with the invertebrate assemblage structure responding strongly to broadleaved weed cover and, to a lesser extent, grass cover.

The diet of skylark chicks did not differ between nests located in the two treatments.

 Synthesis and applications. Neither undrilled patches nor wide‐spaced rows benefited invertebrate populations at the field scale. The value of undrilled patches for invertebrates would be enhanced by promoting weed cover, particularly broadleaved weeds; this could be achieved by creating the patches in the spring using cultivation and avoiding spraying with broad‐spectrum herbicides. Higher numbers of non‐pernicious weeds could provide food and refuge for invertebrates which are a food source for skylarks and other farmland birds that forage in the crop.
Super‐stretched pachytene chromosomes for fluorescence in situ hybridization mapping and immunodetection of DNA methylation
Authors: Koo Dal‐Hoe , Jiang Jiming
Published: March 2009

Meiotic pachytene chromosome‐based fluorescence in situ hybridization (FISH) mapping is one of the most important tools in plant molecular cytogenetic research. Here we report a simple technique that allows stretching of pachytene chromosomes of maize to up to at least 20 times their original size. A modified Carnoy’s II fixative (6:1:3 ethanol:chloroform:acetic acid) was used in the procedure, and proved to be key for super‐stretching of pachytene chromosomes. We demonstrate that super‐stretched pachytene chromosomes provide unprecedented resolution for chromosome‐based FISH mapping. DNA probes separated by as little as 50 kb can be resolved on super‐stretched chromosomes. A combination of FISH with immunofluorescent detection of 5‐methyl cytosine on super‐stretched pachytene chromosomes provides a powerful tool to reveal DNA methylation of specific chromosomal domains, especially those associated with highly repetitive DNA sequences.
Re‐induction of obese body weight occurs more rapidly and at lower caloric intake in beagles
Authors: Nagaoka D. , Mitsuhashi Y. , Angell R. , Bigley K. E. , Bauer J. E.
Published: March 2009

For the purpose of investigating the mechanism of obesity‐induction/re‐induction including weight‐cycling in beagles, a study was conducted using commercially available dog food combined with human food to mimic at home‐snacking and diet‐supplementation behaviours. Adult female beagles, which had free access to water and exercise, were used (n = 9). All dogs were initially offered two times their daily calculated number of calories using a dry extruded diet plus blend of canola and soybean oils and allowed to eat ad libitum. After 3 weeks, Pecan shortbread cookies were added to the diet mixture. Obesity was induced during a 19‐week period with 1875–2250 kcal/day consumed, on average, during this period. The dogs were then subjected to a weight‐loss regimen while consuming 490–730 kcal/day. After weight loss, a similar degree of obesity was re‐induced for 17 weeks even though dogs consumed only 1125–1250 kcal/day. Body weight, body condition scores, kcal consumption and food efficiency were recorded. Results indicated that less time and fewer kcal were required to re‐induce the same degree of obesity compared with the initial obesity induction. Human snack foods appeared to stimulate appetite and thus contribute to the obese state. Food efficiency was also increased during the obesity‐reinduction period compared with the induction period. This information may help pet owners better understand the need to limit table scraps and human‐type food snacks in dogs prone to obesity as well as weight maintenance after weight loss.
Carotid vascular remodelling in patients with autosomal dominant polycystic kidney disease
Authors: RONG SHU , JIN XIUCAI , YE CHAOYANG , CHEN JIABIN , MEI CHANGLIN
Published: March 2009

Aim:  To study carotid vascular wall remodelling in patients with autosomal dominant polycystic kidney disease (ADPKD) using integrated backscatter signal (IBS) analysis.

Methods:  Included in the study were: 60 ADPKD patients with preserved renal function, including 32 patient with hypertension and 28 with normotension; 25 patients with essential hypertension; and 30 healthy volunteers. Carotid intima‐media thickness (IMT) was measured by 2‐D conventional ultrasonography. Acoustic tissue characterization of the carotid wall was assessed by IBS analysis, and the percentage of regions considered as fibromatosis was calculated in all groups.

Results:  Carotid IMT in hypertensive ADPKD patients (0.8 ± 0.05 vs 0.68 ± 0.02 mm, P < 0.01 and 0.8 ± 0.05 vs 0.56 ± 0.04 mm, P < 0.01 respectively) and patients with essential hypertension (0.79 ± 0.03 vs 0.68 ± 0.02 mm, P < 0.01 and 0.79 ± 0.03 vs 0.56 ± 0.0 4 mm, P < 0.01 respectively) was significantly greater than that of normotensive patients and healthy subjects. Carotid IMT in normotensive ADPKD patients was also significantly greater than that in healthy subjects (0.68 ± 0.02 vs 0.56 ± 0.04 mm, P < 0.01). Calibrated IBS (C‐IBS) in hypertensive ADPKD patients was significantly greater than that in patients with essential hypertension and normotensive ADPKD patients (−21.2 ± 1.51 dB vs −23.1 ± 1.61 dB, P < 0.05; −21.2 ± 1.51 dB vs −24.5 ± 1.34 dB, P < 0.01). C‐IBS in normotensive ADPKD patients was significantly greater than that in healthy subjects (−24.5 ± 1.34 dB vs −26.2 ± 1.69 dB, P < 0.01). The percentage of regions that could be considered as fibromatosis in hypertensive ADPKD patients was significantly greater than that in patients with essential hypertension and normotensive ADPKD patients (30.0% vs 22.4%, P < 0.05; 30.0% vs 17.9%, P < 0.01). The percentage of regions that could be considered as fibromatosis in normotensive ADPKD patients was significantly greater than that in healthy subjects (15.2% vs 10.3%, P < 0.01).

Conclusion:  Carotid remodelling occurs in the early stage of ADPKD and can be aggravated by hypertension. Fibrosis contributes to the vascular rearrangement.
Rosai–Dorfman disease presenting as a solitary mediastinal mass
Authors: Hida Akira I. , Yagi Shin‐ichi , Obase Yasushi , Nishimura Hirotake , Akiyama Takashi , Irei Isao , Hamazaki Shuji , Oka Mikio , Sadahira Yoshito
Published: March 2009

Rosai–Dorfman disease (RDD) involving an extranodal site is a diagnostic challenge. Reported herein is the case of a 67‐year‐old man who presented with a solitary superior mediastinal mass. The lesion was clinically suspected of malignancy including lymphoma because of its high uptake during a 67Ga‐scintigram and 18F‐fluorodeoxyglucose–positron emission tomography. There was no evidence of spread of the disease. Histology of thoracoscopic biopsy specimens indicated granulomatous lesion with infiltration of lymphocytes, plasma cells, and histiocytes with lymphocytes engulfed in their cytoplasm. The lesion did not contain lymph node or thymic elements. On immunohistochemistry the histiocytes were positive for S‐100 protein, CD68, and CD163 but were negative for CD1a. These findings suggested a diagnosis of RDD. Despite lack of intervention, the lesion remained almost the same size for 3 years. To the best of the authors' knowledge this is the first case of RDD presenting as a solitary mediastinal mass.
Autoantibody to heterogeneous nuclear ribonucleoprotein‐A2 (RA33) in juvenile idiopathic arthritis: Clinical significance
Authors: Tomoum Hoda Y. , Mostafa Gehan A. , El‐Shahat Esraa M. F.
Published: March 2009

Background:  Objective biomarkers are needed for early diagnosis of juvenile idiopathic arthritis (JIA). Anti‐A33 antibodies are considered good markers for adult rheumatoid arthritis (RA), but little information is available on their occurrence in JIA. The aim of the present study was therefore to investigate the value of anti‐RA33 for diagnosis of JIA (both early and established disease), and its relation to markers of disease activity, and bone resorption.

Subjects:  This case–control study was conducted on 34 children with JIA. Ten patients with arthritis of short duration (<6 weeks) were included, as undifferentiated arthritis. Forty‐four age‐ and sex‐ matched healthy children served as controls. Beside evaluation and assessment of disease activity, urinary calcium, serum parathyroid hormone and serum anti‐RA33 were measured in included subjects. Joints were examined radiologically and modified Larsen index (LI) was estimated.

Results:  During follow up, eight of the patients with undifferentiated arthritis were diagnosed as having early JIA. Patients with JIA (early and established cases) had higher anti‐RA33 levels than the control group (z = 6.04, 3.95, respectively). A total of 66.7% of the patients were positive for anti‐RA33, results were comparable in early and established cases. Anti‐RA33 values were correlated to disease activity (clinical and laboratory), to laboratory markers (urinary calcium, parathyroid hormone levels) and radiological evidence (LI) of bone resorption (r = 0.95, 0.63, 0.94, respectively).

Conclusion:  Anti‐RA33 is detected in two‐thirds of JIA patients and occurs with comparable frequency early in the disease. Its levels are correlated to disease activity and markers of bone resorption and it seems to convey diagnostic and prognostic insights for appropriate management.