bluuebunny/crossref_metadata_2025 huggingface dataset:
Antimicrobial Activity of ɛ‐Polylysine against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes in Various Food Extracts
Authors: Geornaras I. , Yoon Y. , Belk K.E. , Smith G.C. , Sofos J.N.
Published: October 2007

ABSTRACT:  This study compared the antimicrobial effects of ɛ‐polylysine (ɛ‐PL) against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes in 6 food extracts and in broth. The food extracts (10% (w/w) in distilled water) evaluated were fat‐free and whole fat milk, beef, bologna, rice, and vegetables (50:50 ratio of broccoli and cauliflower). ɛ‐PL was tested at 0.005% and 0.02% (w/v) against E. coli O157:H7 and L. monocytogenes, and 0.02% and 0.04% (w/v) against S. Typhimurium. The substrates were inoculated (5 log CFU/mL) and periodically analyzed for surviving populations during storage at 12 °C for 6 d. In general, all 3 pathogens reached 7 to 9 log CFU/mL within 2 d in control substrates (no ɛ‐PL). Immediate bactericidal effects (P < 0.05) following exposure to ɛ‐PL were obtained in the rice (all pathogens) and vegetable (E. coli O157:H7 and S. Typhimurium) extracts. During storage, antimicrobial effects of ɛ‐PL were more pronounced in the food extracts than in the broth medium. The greatest antimicrobial activity for all 3 pathogens was obtained in the rice and vegetable extracts, where counts were reduced (P < 0.05) to below the detection limit (0.0 log CFU/mL) by one or both ɛ‐PL concentrations tested. In the other food extracts (fat‐free milk, whole fat milk, beef, and bologna), both ɛ‐PL concentrations tested generally resulted in lower (P < 0.05) pathogen levels at the end of storage compared to initial counts, with better bactericidal effects exerted by the higher of the 2 ɛ‐PL concentrations. Additional research is needed to explore the potential antimicrobial effects of ɛ‐PL in real food systems.
Salts Soaking Treatment for Improving the Textural and Functional Properties of Trifoliate Yam (Dioscorea dumetorum) Hardened Tubers
Authors: Medoua G.N. , Mbome I.L. , Egbe T.A. , Mbofung C.M.F.
Published: October 2007

ABSTRACT:  Processing of Dioscorea dumetorum hardened tubers into flour could be a means of adding a longer‐term value to this tropical plant with a high nutritional potential, but which presents a postharvest hardening problem characterized by a hard‐to‐cook defect. In an attempt to investigate the changes leading to salts soaking treatment of hardened tubers, the central composite rotatable design for K= 2 was used to study the combined effect of NaCl concentration (0% to 6%) and pH (4 to 10) on tubers cooked hardness, and 6 kanwa alkaline salt concentrations (1:3 (w/v); 0%, 0.2%, 0.5%, 0.8%, 1%, and 1.5%; pH 11.3 ± 0.2) were used to study the effect of kanwa treatment on tuber cooked hardness and functional properties of resulting flours. The results showed that salts soaking treatment significantly decreased (P≤ 0.05) tubers cooked hardness, independently of the solution pH, but could not totally overcome the tubers hardening phenomenon, as a consequence of the multiple mechanisms of D. dumetorum tuber hardening. Nevertheless, kanwa concentrations of 0.8% to 1.5% could be used to tenderize hardened tubers prior to its transformation in flour. Except oil absorption capacity, initial soaking of hardened tubers in kanwa solutions significantly influenced (P≤ 0.05) the functional properties of the resulting flours. Water absorption capacity increased with increasing of kanwa concentration while the other properties evaluated (water solubility index, hydrophilic–lipophilic index, bulk density, swelling capacity, least gel‐forming concentration) decreased.
Analytic Formula for the Clear‐sky UV Index
Authors: Madronich Sasha
Published: October 2007

An approximate formula for the UV Index (UVI) under cloud‐free, unpolluted, low surface albedo conditions is:
image

where μo is the cosine of the solar zenith angle and Ω is the total vertical ozone column (in Dobson Units, DU). The dependence on μo and Ω is based on a simple physical model of biologically weighted atmospheric transmission in the UV‐B and UV‐A spectral bands, with coefficients tuned to a detailed radiative transfer model, and is accurate to 10% or better over 0–60° and 200–400 DU. Other factors (clouds, haze, ground, etc.) mostly conserve this dependence and scale simply.
Sociology and New Wars in the Era of Globalisation
Authors: Drake Michael S.
Published: October 2007

The sociology of war has used a number of analytical perspectives to explain why the end of the Cold War saw outbreaks of violence around the world in the form of ‘new wars’, rather than universal peace. Factors often considered are globalisation, nationalist ideology, political elites, the Revolution in Military Affairs, international crime and migration. Sociological analysis of these new wars often makes use of comparative historical sociology, but these are wars of state disintegration rather than of state formation. This summary undertakes a critical evaluation of different approaches, arguing that they mostly follow a model of war inherited from Clausewitz which conceives of war only as an encounter between two states and so cannot successfully explain new war, where armed forces no longer primarily fight each other but target civilians.
Media, Racism and Islamophobia: The Representation of Islam and Muslims in the Media
Authors: Saeed Amir
Published: October 2007

This article examines the representation of Islam and Muslims in the British press. It suggests that British Muslims are portrayed as an ‘alien other’ within the media. It suggests that this misrepresenatation can be linked to the development of a ‘racism’, namely, Islamphobia that has its roots in cultural representations of the ‘other’. In order to develop this arguement, the article provies a summary/overview of how ethnic minorities have been represented in the British press and argues that the treatment of British Muslims and Islam follows these themes of ‘deviance’ and ‘un‐Britishness’.
Protective effects of a combination of quercetin and vitamin E against cyclosporine A‐induced oxidative stress and hepatotoxicity in rats
Authors: Mostafavi–Pour Zohreh , Zal Fatemeh , Monabati Ahmad , Vessal Mahmood
Published: October 2007

Aim: Cyclosporine A (CsA) is the most widely used immunosuppressive drug in transplant surgery. It is able to generate reactive oxygen species (ROS) and cause lipid peroxidation (thiobarbituric acid‐reacting substances [TBARS]), which will directly result in CsA hepatotoxicity.

Methods: In this study, the potential of quercetin (Q) and vitamin E (E), in attenuating CsA‐induced liver dysfunction in rats was investigated. Male Sprague–Dawley rats were divided into six groups and treated with either olive oil, ethanol + olive oil, CsA, CsA + E, CsA + Q, or CsA + E + Q for both 4 and 8 weeks. Hepatotoxicity was assessed by morphological alterations in tissue architecture and by reduced serum total protein and increased serum alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase.

Results: The results indicated that CsA treatment increases TBARS and decreases activities of catalase (CAT) and glutathione peroxidase (GPx) in the rat liver. The co‐administration of E and Q with CsA treatment improved both liver morphology changes and function. A combination of these antioxidants significantly reduced TBARS and increased CAT and GPx activities in the hepatic tissue.

Conclusion: Our data demonstrates that E + Q plays a protective role against the imbalance elicited by CsA between the production of free radicals and antioxidant defence systems, and suggests that a combination of these two antioxidants may find clinical application where cellular damage is a consequence of ROS.
Solar-Assisted Small Solar Tower Trigeneration Systems
Authors: Buck R. , Friedmann S.
Published: October 2007

Solar-hybrid gas turbine power systems offer a high potential for cost reduction of solar power. Such systems were already demonstrated as test systems. For the market introduction of this technology, microturbines in combination with small solar tower plants are a promising option. The combination of a solarized microturbine with an absorption chiller was studied; the results are presented in this paper. The solar-hybrid trigeneration system consists of a small heliostat field, a receiver unit installed on a tower, a modified microturbine, and an absorption chiller. The components are described, as well as the required modifications for integration to the complete system. Several absorption chiller models were reviewed. System configurations were assessed for technical performance and cost. For a representative site, a system layout was made, using selected industrial components. The annual energy yield in power, cooling, and heat was determined. A cost assessment was made to obtain the cost of electricity and cooling power, and eventually additional heat. Various load situations for electric and cooling power were analyzed. The results indicate promising niche applications for the solar-assisted trigeneration of power, heat, and cooling. The potential for improvements in the system configuration and the components is discussed, also the next steps toward market introduction of such systems.
A Finite-Time Thermodynamic Framework for Optimizing Solar-Thermal Power Plants
Authors: McMahan A. , Klein S. A. , Reindl D. T.
Published: October 2007

Fundamental differences between the optimization strategies for power cycles used in “traditional” and solar-thermal power plants are identified using principles of finite-time thermodynamics. Optimal operating efficiencies for the power cycles in traditional and solar-thermal power plants are derived. In solar-thermal power plants, the added capital cost of a collector field shifts the optimum power cycle operating point to a higher-cycle efficiency when compared to a traditional plant. A model and method for optimizing the thermoeconomic performance of solar-thermal power plants based on the finite-time analysis is presented. The method is demonstrated by optimizing an existing organic Rankine cycle design for use with solar-thermal input. The net investment ratio (capital cost to net power) is improved by 17%, indicating the presence of opportunities for further optimization in some current solar-thermal designs.
Optimization of Economic Solar Field Design of Stationary Thermal Collectors
Authors: Weinstock Dan , Appelbaum Joseph
Published: October 2007

The optimization of solar field designs of stationary thermal collectors, taking into account shading and masking effects, may be based on energy or economic criteria. Obtaining maximum energy from a given field size or determining the required minimum field area that produces a given amount of energy are examples of energy criteria. Designing a solar plant with a minimum cost or a plant that produces minimum cost of unit energy are examples of economic criteria. These design problems may be formulated as optimization problems with objective functions and sets of constraints (equality and inequality) for which mathematical optimization techniques may be applied. This paper deals with obtaining optimal field and collector design parameters (number of rows, distance between collector rows, collector height, and collector inclination angle) that result in minimum periodic cost of a solar plant producing a given amount of annual energy. A second problem is the determination of optimal field and collector design parameters resulting in minimum cost of unit energy for the solar plant. In both cases, the optimal deployment of the collectors in the solar field as a function of the daily energy demand—cost of land and collector efficiency as parameters—is presented.
Structural Design Criteria for Steel Components of Parabolic-Trough Solar Concentrators
Authors: Giannuzzi G. M. , Majorana C. E. , Miliozzi A. , Salomoni V. A. , Nicolini D.
Published: October 2007

Starting from the R&D experience acquired, within the Italian context, in the field of the development of new technologies for solar energy exploitation, structural design criteria have been selected here to define a guideline for steel structures design and assessment of components of parabolic-trough solar concentrators. The main codes of practice used in Italy and in the European community have been considered and design criteria chosen to find a compromise between requirements of rules that should be followed precisely and costs. Loads, actions, and more generally, the whole design procedure has been considered in agreement with the limit state method; a new approach is critically and carefully proposed to use this method in designing and testing “special structures,” such as the one analyzed here (e.g., wind and snow actions are evaluated and newly interpreted according to both the angular position of the collectors and the characteristic effects). A method for evaluating variable loads is proposed to integrate current Italian and European rules, and a dimensional reduction for some elements due to the limit state design approach is underlined.
Computational Fluid Dynamics Simulation of a Tubular Aerosol Reactor for Solar Thermal ZnO Decomposition
Authors: Perkins Christopher , Weimer Alan
Published: October 2007

Computational fluid dynamics simulations were performed to model solar ZnO dissociation in a tubular aerosol reactor at ultrahigh temperatures (1900–2300K). Reactor aspect ratios ranged between 0.15 and 0.45, with the smallest ratio base case corresponding to a reactor diameter of 0.02286m. Gas flow rates were set such that the Ar:ZnO ratio was greater than 3:1 and the system residence time was below 2s. The system was found to exhibit highly laminar flow in all cases (Re∼10), but gas velocity profiles did not seriously affect temperature profiles. Particle heating was nearly instantaneous, a result of the high radiation heat flux from the wall. There was essentially no difference between gas and particle temperatures due to the high surface area for conductive heat exchange between the phases. Calculation of ZnO conversion showed that significant conversions (>90%) could be attained for residence times typical of rapid aerosol processing. Particle sizes of >1μm negatively affected conversion, but sizes of 10μm still gave acceptable conversion levels. Simulation of reaction of product oxygen with the reactor wall showed that a reactor constructed of an oxidation-sensitive material would not be a viable choice for a high temperature solar reactor.
Gas Temperature Measurements in High Concentration Solar Furnace Environments: Evidence of Nonequilibrium Effects
Authors: Badie J. M. , Cassan L. , Granier B. , Agudelo Florez S. , Chejne Janna F.
Published: October 2007

Temperature measurements of the gas phase surrounding the hot front during material processing at the focus of a high concentration solar furnace can be achieved by coupled emission and absorption optical spectroscopy. The emitted light results from a fluorescence phenomenon of some vapor species from the heated sample excited by absorption of the incident concentrated beam. Absorption measurements were performed on these same species with a reference beam using the sun radiation as source. These coupled techniques led to consistent results and suggested the existence of a nonequilibrium Knudsen layer near the vaporizing surface. In this paper, we report measurements performed on YO diatomic molecule issuing from a melted sample of yttrium oxide.
Thermal Modeling of PCM-Based Solar Integrated Collector Storage Water Heating System
Authors: Reddy K. S.
Published: October 2007

The thermal modeling and analysis of a transparent insulation materials (TIM) covered solar integrated collector storage (ICS) water heating system with phase-change material (PCM) is carried out in this paper. The system consists of a double rectangular enclosure of cross section 1m×1m where the top enclosure is filled with paraffin wax and that of the bottom is with water. The transient response of the PCM-water solar ICS system is studied with and without fins on the diurnal basis. The performance of the system is investigated with 4, 9, and 19 fins inside the wax having a pitch of 20cm, 10cm, and 5cm, respectively. The latent heat storage with nine fins is found to be optimum for maximum water temperature and minimum heat losses to the surroundings. The temperature of water in the ICS exceeds 50°C with a temperature drop of only 1.5–2°C during nighttime. The nine-fin solar ICS configuration attains ∼9°C higher than other configurations.
Sensitivity Analysis of Optimal Building Thermal Mass Control
Authors: Henze Gregor P. , Le Thoi H. , Florita Anthony R. , Felsmann Clemens
Published: October 2007

In order to avoid high utility demand charges from cooling during the summer and to level a building’s electrical demand profile, precooling of the building’s massive structure can be applied to shift cooling-related thermal loads in response to utility pricing signals. Several previous simulation and experimental studies have shown that proper precooling can attain considerable reduction of operating cost in buildings. This paper systematically evaluates the merits of the passive building thermal capacitance to minimize energy cost for a design day using optimal control. The evaluation is conducted by means of a sensitivity analysis utilizing a dynamic building energy simulation program coupled to a popular technical computing environment. The optimal controller predicts the required extent of precooling (zone temperature set-point depression), depending on the utility rate structure, occupancy and on-peak period duration and onset, internal gains, building mass, occupancy period temperature set-point range, and weather as characterized by diurnal temperature and relative humidity swings. In addition to quantifying the building response, energy consumption, and utility cost, this paper extracts the dominant features of the optimal precooling strategies for each of the investigated cases so that guidelines for near-optimal building thermal mass savings may be developed in the future.
Culture-Dependent and -Independent Characterization of Microbial Communities Associated with a Shallow Submarine Hydrothermal System Occurring within a Coral Reef off Taketomi Island, Japan
Authors: Hirayama Hisako , Sunamura Michinari , Takai Ken , Nunoura Takuro , Noguchi Takuro , Oida Hanako , Furushima Yasuo , Yamamoto Hiroyuki , Oomori Tamotsu , Horikoshi Koki
Published: October 2007

Microbial communities in a shallow submarine hydrothermal system near Taketomi Island, Japan, were investigated using cultivation-based and molecular techniques. The main hydrothermal activity occurred in a craterlike basin (depth, ∼23 m) on the coral reef seafloor. The vent fluid (maximum temperature, >52°C) contained 175 μM H2S and gas bubbles mainly composed of CH4(69%) and N2(29%). A liquid serial dilution cultivation technique targeting a variety of metabolism types quantified each population in the vent fluid and in a white microbial mat located near the vent. The most abundant microorganisms cultivated from both the fluid and the mat were autotrophic sulfur oxidizers, including mesophilicThiomicrospiraspp. and thermophilicSulfurivirga caldicuralii. Methane oxidizers were the second most abundant organisms in the fluid; one novel type I methanotroph exhibited optimum growth at 37°C, and another novel type I methanotroph exhibited optimum growth at 45°C. The number of hydrogen oxidizers cultivated only from the mat was less than the number of sulfur and methane oxidizers, although a novel mesophilic hydrogen-oxidizing member of theEpsilonproteobacteriawas isolated. Various mesophilic to hyperthermophilic heterotrophs, including sulfate-reducingDesulfovibriospp., iron-reducingDeferribactersp., and sulfur-reducingThermococcusspp., were also cultivated. Culture-independent 16S rRNA gene clone analysis of the vent fluid and mat revealed highly diverse archaeal communities. In the bacterial community,S. caldicuraliiwas identified as the predominant phylotype in the fluid (clonal frequency, 25%). Both bacterial clone libraries indicated that there were bacterial communities involved in sulfur, hydrogen, and methane oxidation and sulfate reduction. Our results indicate that there are unique microbial communities that are sustained by active chemosynthetic primary production rather than by photosynthetic production in a shallow hydrothermal system where sunlight is abundant.
Sequence Characterization and Comparative Analysis of Three Plasmids Isolated from EnvironmentalVibriospp
Authors: Hazen Tracy H. , Wu Dongying , Eisen Jonathan A. , Sobecky Patricia A.
Published: October 2007

The horizontal transfer of genes by mobile genetic elements such as plasmids and phages can accelerate genome diversification ofVibriospp., affecting their physiology, pathogenicity, and ecological character. In this study, sequence analysis of three plasmids fromVibriospp. previously isolated from salt marsh sediment revealed the remarkable diversity of these elements. Plasmids p0908 (81.4 kb), p23023 (52.5 kb), and p09022 (31.0 kb) had a predicted 99, 64, and 32 protein-coding sequences and G+C contents of 49.2%, 44.7%, and 42.4%, respectively. A phylogenetic tree based on concatenation of the host 16S rRNA andrpoAnucleotide sequences indicated p23023 and p09022 were isolated from strains most closely related toV. mediterraneiandV. campbellii, respectively, while the host of p0908 forms a clade withV. fluvialisandV. furnissii. Many predicted proteins had amino acid identities to proteins of previously characterized phages and plasmids (24 to 94%). Predicted proteins with similarity to chromosomally encoded proteins included RecA, a nucleoid-associated protein (NdpA), a type IV helicase (UvrD), and multiple hypothetical proteins. Plasmid p0908 had striking similarity to enterobacteria phage P1, sharing genetic organization and amino acid identity for 23 predicted proteins. This study provides evidence of genetic exchange betweenVibrioplasmids, phages, and chromosomes among diverseVibriospp.
Obesity-related elevations in plasma leucine are associated with alterations in enzymes involved in branched-chain amino acid metabolism
Authors: She Pengxiang , Van Horn Cynthia , Reid Tanya , Hutson Susan M. , Cooney Robert N. , Lynch Christopher J.
Published: October 2007

Elevations in branched-chain amino acids (BCAAs) in human obesity were first reported in the 1960s. Such reports are of interest because of the emerging role of BCAAs as potential regulators of satiety, leptin, glucose, cell signaling, adiposity, and body weight (mTOR and PKC). To explore loss of catabolic capacity as a potential contributor to the obesity-related rises in BCAAs, we assessed the first two enzymatic steps, catalyzed by mitochondrial branched chain amino acid aminotransferase (BCATm) or the branched chain α-keto acid dehydrogenase (BCKD E1α subunit) complex, in two rodent models of obesity ( ob/ob mice and Zucker rats) and after surgical weight loss intervention in humans. Obese rodents exhibited hyperaminoacidemia including BCAAs. Whereas no obesity-related changes were observed in rodent skeletal muscle BCATm, pS293, or total BCKD E1α or BCKD kinase, in liver BCKD E1α was either unaltered or diminished by obesity, and pS293 (associated with the inactive state of BCKD) increased, along with BCKD kinase. In epididymal fat, obesity-related declines were observed in BCATm and BCKD E1α. Plasma BCAAs were diminished by an overnight fast coinciding with dissipation of the changes in adipose tissue but not in liver. BCAAs also were reduced by surgical weight loss intervention (Roux-en-Y gastric bypass) in human subjects studied longitudinally. These changes coincided with increased BCATm and BCKD E1α in omental and subcutaneous fat. Our results are consistent with the idea that tissue-specific alterations in BCAA metabolism, in liver and adipose tissue but not in muscle, may contribute to the rise in plasma BCAAs in obesity.
Interaction of BMP10 with Tcap may modulate the course of hypertensive cardiac hypertrophy
Authors: Nakano Noritsugu , Hori Hisae , Abe Minako , Shibata Hiroki , Arimura Takuro , Sasaoka Taishi , Sawabe Motoji , Chida Kouji , Arai Tomio , Nakahara Ken-ichi , Kubo Toru , Sugimoto Ken , Katsuya Tomohiro , Ogihara Toshio , Doi Yoshinori , Izumi Tohru , Kimura Akinori
Published: October 2007

Elevated wall stress by hypertension induces an adaptive myocardial hypertrophy via releasing prohypertrophic hormones such as angiotensin II. In this study, we investigated the involvement of bone morphogenetic protein-10 (BMP10) in hypertension-induced cardiac hypertrophy. Expression of BMP10 was increased in the hypertrophied ventricles from hypertensive rats. BMP10 localized on cell surface and at stretch-sensing Z disc of cardiomyocytes, where BMP10 interacted with a protein called titin-cap (Tcap). A rare variant of the human BMP10 gene, Thr326Ile, was found to be associated with hypertensive dilated cardiomyopathy. The variant BMP10 demonstrated decreased binding to Tcap and increased extracellular secretion. Conditioned medium from cells transfected with wild-type or variant BMP10 induced hypertrophy in rat neonatal cardiomyocytes, except that medium from variant BMP10-carrying cells showed an enhanced effect reflecting the increased secretion. These observations suggested that hypertension induced expression of prohypertrophic BMP10, and the hypertrophic effect of BMP10 was modulated, at least in part, by its binding to Tcap at the Z disc.
Adaptation and Information Transmission in Fly Motion Detection
Authors: Safran Moshe N. , Flanagin Virginia L. , Borst Alexander , Sompolinsky Haim
Published: October 2007

In this work, we studied the adaptation of H1, a motion-sensitive neuron in the fly visual system, to the variance of randomly fluctuating velocity stimuli. We ask two questions. 1) Which components of the motion detection system undergo genuine adaptational changes in response to the variance of the fluctuating velocity signal? 2) What are the consequences of this adaptation for the information processing capabilities of the neuron? To address these questions, we characterized the adaptation of H1 by estimating the changes in the parameters of an associated Reichardt motion detection model under various stimulus conditions. The strongest stimulus dependence was exhibited by the temporal kernel of the motion detector and was parametrized by changes in the model's high-pass time constant (τH). This time constant shortened considerably with increasing velocity fluctuations. We showed that this adaptive process contributes significantly to the shortening of the velocity response time-course but not to velocity gain control. To assess the contribution of time-constant adaptation to information transmission, we compared the information rates generated by our adaptive model motion detector with model simulations in which τH was held fixed at its unadapted value for all stimulus conditions. We found that for intermediate stimulus conditions, fixing τH at its unadapted value led to higher information rates, suggesting that time-constant adaptation does not optimize total information rates about velocity trajectories. We also found that, over the wide range of stimulus conditions tested here, H1 information rates are dependent on the amplitude of velocity fluctuations.
Inhibitory Feedback Shapes Bipolar Cell Responses in the Rabbit Retina
Authors: Molnar Alyosha , Werblin Frank
Published: October 2007

Retinal bipolar cells can be divided into on and off types based on the polarity of their response to light. Bipolar activity is further shaped by inhibitory inputs, characterized here by the events that occur immediately after the onset of a light step: 1) in most off bipolar cells, excitatory current decreased, whereas inhibitory current increased. These currents reinforced each other, enhancing the light response. 2) In about half of the on cone bipolar cells, the excitatory current increased, whereas inhibitory current decreased, also reinforcing the light response. Both of these reinforcing interactions were mediated by glycinergic inhibition. 3) In the remaining on cone bipolar cells, excitation and inhibition both increased, but inhibition was delayed so that these cells responded transiently. 4) Finally, in rod bipolar cells, excitation and inhibition both increased so that inhibition suppressed excitation, reducing the light response at all time scales. The suppressive inhibition seen in on cone and rod bipolar cells was mediated by GABA. Thus morphologically diverse bipolar cells receive only four main types of inhibitory input, and the majority of “inhibitory” inputs actually serve to enhance excitation.
No Potassium, No Acid: K+Channels and Gastric Acid Secretion
Authors: Heitzmann Dirk , Warth Richard
Published: October 2007

The gastric H+-K+-ATPase pumps H+into the lumen and takes up K+in parallel. In the acid-producing parietal cells, luminal KCNE2/KCNQ1 K+channels play a pivotal role in replenishing K+in the luminal fluid. Inactivation of KCNE2/KCNQ1 channels abrogates gastric acid secretion and dramatically modifies the architecture of gastric mucosa.
Extracellular Calcium and cAMP: Second Messengers as “Third Messengers”?
Authors: Hofer Aldebaran M. , Lefkimmiatis Konstantinos
Published: October 2007

Calcium and cyclic AMP are familiar second messengers that typically become elevated inside cells on activation of cell surface receptors. This article will explore emerging evidence that transport of these signaling molecules across the plasma membrane allows them to be recycled as “third messengers,” extending their ability to convey information in a domain outside the cell.
Nutrition-induced ketosis alters metabolic and signaling gene networks in liver of periparturient dairy cows
Authors: Loor Juan J. , Everts Robin E. , Bionaz Massimo , Dann Heather M. , Morin Dawn E. , Oliveira Rosane , Rodriguez-Zas Sandra L. , Drackley James K. , Lewin Harris A.
Published: October 2007

Dairy cows are highly susceptible after parturition to developing liver lipidosis and ketosis, which are costly diseases to farmers. A bovine microarray platform consisting of 13,257-annotated oligonucleotides was used to study hepatic gene networks underlying nutrition-induced ketosis. On day 5 postpartum, 14 Holstein cows were randomly assigned to ketosis-induction ( n = 7) or control ( n = 7) groups. Cows in the ketosis-induction group were fed at 50% of day 4 intake until they developed signs of clinical ketosis, and cows in the control group were fed ad libitum throughout the treatment period. Liver was biopsied at 10–14 (ketosis) or 14 days postpartum (controls). Feed restriction increased blood concentrations of nonesterified fatty acids and β-hydroxybutyrate, but decreased glucose. Liver triacylglycerol concentration also increased. A total of 2,415 genes were altered by ketosis (false discovery rate = 0.05). Ingenuity Pathway Analysis revealed downregulation of genes associated with oxidative phosphorylation, protein ubiquitination, and ubiquinone biosynthesis with ketosis. Other molecular adaptations included upregulation of genes and nuclear receptors associated with cytokine signaling, fatty acid uptake/transport, and fatty acid oxidation. Genes downregulated during ketosis included several associated with cholesterol metabolism, growth hormone signaling, proton transport, and fatty acid desaturation. Feed restriction and ketosis resulted in previously unrecognized alterations in gene network expression underlying key cellular functions and discrete metabolic events. These responses might help explain well-documented physiological adaptations to reduced feed intake in early postpartum cows and, thus, provide molecular targets that might be useful in prevention and treatment of liver lipidosis and ketosis.
Functional Internal Complexity of Amygdala: Focus on Gene Activity Mapping After Behavioral Training and Drugs of Abuse
Authors: Knapska Ewelina , Radwanska Kasia , Werka Tomasz , Kaczmarek Leszek
Published: October 2007

The amygdala is a heterogeneous brain structure implicated in processing of emotions and storing the emotional aspects of memories. Gene activity markers such as c-Fos have been shown to reflect both neuronal activation and neuronal plasticity. Herein, we analyze the expression patterns of gene activity markers in the amygdala in response to either behavioral training or treatment with drugs of abuse and then we confront the results with data on other approaches to internal complexity of the amygdala. c-Fos has been the most often studied in the amygdala, showing specific expression patterns in response to various treatments, most probably reflecting functional specializations among amygdala subdivisions. In the basolateral amygdala, c-Fos expression appears to be consistent with the proposed role of this nucleus in a plasticity of the current stimulus-value associations. Within the medial part of the central amygdala, c-Fos correlates with acquisition of alimentary/gustatory behaviors. On the other hand, in the lateral subdivision of the central amygdala, c-Fos expression relates to attention and vigilance. In the medial amygdala, c-Fos appears to be evoked by emotional novelty of the experimental situation. The data on the other major subdivisions of the amygdala are scarce. In conclusion, the studies on the gene activity markers, confronted with other approaches involving neuroanatomy, physiology, and the lesion method, have revealed novel aspects of the amygdala, especially pointing to functional heterogeneity of this brain region that does not fit very well into contemporarily active debate on serial versus parallel information processing within the amygdala.
Hedgehog Signaling in Development and Homeostasis of the Gastrointestinal Tract
Authors: van den Brink Gijs R.
Published: October 2007

The Hedgehog family of secreted morphogenetic proteins acts through a complex evolutionary conserved signaling pathway to regulate patterning events during development and in the adult organism. In this review I discuss the role of Hedgehog signaling in the development, postnatal maintenance, and carcinogenesis of the gastrointestinal tract. Three mammalian hedgehog genes, sonic hedgehog (Shh), indian hedgehog (Ihh), and desert hedgehog (Dhh) have been identified. Shh and Ihh are important endodermal signals in the endodermal-mesodermal cross-talk that patterns the developing gut tube along different axes. Mutations in Shh, Ihh, and downstream signaling molecules lead to a variety of gross malformations of the murine gastrointestinal tract including esophageal atresia, tracheoesophageal fistula, annular pancreas, midgut malrotation, and duodenal and anal atresia. These congenital malformations are also found in varying constellations in humans, suggesting a possible role for defective Hedgehog signaling in these patients. In the adult, Hedgehog signaling regulates homeostasis in several endoderm-derived epithelia, for example, the stomach, intestine, and pancreas. Finally, growth of carcinomas of the proximal gastrointestinal tract such as esophageal, gastric, biliary duct, and pancreatic cancers may depend on Hedgehog signaling offering a potential avenue for novel therapy for these aggressive cancers.
Predictors of Survival in Dementia with Lewy Bodies and Parkinson Dementia
Authors: Jellinger Kurt A. , Wenning Gregor K. , Seppi Klaus
Published: October 2007

Retrospective analysis of 243 autopsy-confirmed cases of dementia with Lewy bodies (DLB) and Parkinson disease with dementia (PDD) showed an average age at symptom onset of 67 years and a median survival of 5 years from symptom onset. Older age at onset, fluctuating cognition, and hallucinations at onset predicted shorter survival; initial parkinsonism with delayed dementia significantly improved survival. Associated Alzheimer pathology also shortened survival. When adjusted for age, gender, and Alzheimer pathology, fluctuating dementia at symptom onset was identified as best predictor of poor outcome.
Congenital Intracranial Teratoma with Massive Macrocephaly and Skull Rupture
Authors: Bolat Filiz , Kayaselcuk Fazilet , Tarim Ebru , Kilicdag Esra , Bal Nebil
Published: October 2007

Objective: Congenital intracranial tumors are rare and only account for 0.5–1.5% of all pediatric brain tumors. Teratoma is the most frequently encountered intracranial tumor at birth. Massive congenital intracranial teratoma is an extremely rare neoplasm with a poor prognosis. They grow rapidly and cause extensive destruction in the brain. Herein we report a massive intracranial teratoma causing skull rupture. Case Report: A fetus with a congenital intracranial teratoma presenting with a disproportionately enlarged head at 25 weeks of gestation is presented. Since it was the first admission of the mother to a medical expert for a prenatal examination, there was noprevious follow-up data. Prenatal ultrasonography demonstrated a huge, heterogeneous intracranial mass, and midline structures and ventricles could not be observed. No heartbeat was detected. Autopsy was perforated, and histopathologic examination of the samples taken from the intracranial mass revealed an immature teratoma. Conclusion: Although congenital intracranial teratomas are rare, they may reach enormous sizes. Regular follow-up of the fetus may lead to early diagnosis of immature intracranial teratomas and prevent the mother from having further complications either due to intrauterine fetal death orpsychological trauma of giving birth to a heavily malformed baby.
Chorioangiomatosis Presenting with Severe Anemia and Heart Failure in a Newborn
Authors: Ozer Esra Arun , Duman Nuray , Kumral Abdullah , Yilmaz Sebnem , Oren Hale , Kir Mustafa , Ozer Erdener , Ozkan Hasan
Published: October 2007

Although chorioangiomas are the most common placental tumors, multiple chorioangiomas (or chorioangiomatosis) are extremely rare. We report a female newborn at 37 weeks of gestation presenting with severe anemia, thrombocytopenia, heart failure, and intrauterine growth retardation. The pathological examination of the placenta revealed chorioangiomatosis explaining the pathophysiology of the symptoms presented. The patient was treated successfully with erythrocyte and thrombocyte transfusions and was discharged after full recovery. We conclude that evaluating placental lesions may be of great value in explaining severe problems during the fetal and the neonatal period and thus prevents performing unnecessary clinical investigations.
Fetal Facial Profile in Pallister-Killian Syndrome
Authors: Liberati Marco , Melchiorre Karen , D’Emilio Ilenia , Guanciali-Franchi Paolo Emilio , Iezzi Irene , Rotmensch Sigfried , Celentano Claudio
Published: October 2007

Pallister-Killian syndrome (PKS) is a sporadic chromosomal anomaly, caused by a tissue-specific mosaic distribution of an additional isochromosome 12p. About 60 cases of prenatal diagnosis of PKS have been reported. Only 1 case of PKS is described on the basis of prenatal screening, presenting increased nuchal translucency. An abnormal fetal facial profile is described prenatally as sonographic evidence of PKS. We report a case of prenatal diagnosis in a fetus undergoing second-level scan due to positive triple screen with ultrasound features of PKS.
Prenatally Diagnosed Fetal Brain Injuries with Known Antenatal Etiologies
Authors: Gávai Márta , Hargitai Beáta , Váradi Valéria , Belics Zoran , Csapó Zsolt , Hajdú Júlia , Hauzman Erik , Berkes Enikõ , Papp Zoltán
Published: October 2007

Periventricular leukomalacia of pre- or postnatal onset is responsible for severe neurological and intellectual impairment and cerebral palsy later in life. The etiology is multifactorial, involving hypoxic-ischemic insults of various origin. The disorder is characterized by multiple necrotic foci of the white matter found most frequently adjacent to the lateral ventricles. In the past, intrapartum factors were thought to be the major cause of neonatal brain damage, but recent investigations highlighted the role of antenatal risk factors. We present 4 cases of antenatally diagnosed brain injury with known and unusual etiology.
Effects of Antenatal Betamethasone on Human Fetal Branch Pulmonary Artery Flow Velocity Waveforms
Authors: Bartha José L. , Largo-Heinrich Marta , Machado María J. , González-Bugatto Fernando , Hervías-Vivancos Blas
Published: October 2007

Objective: To evaluate the effect of antenatal betamethasone on fetal branch pulmonary artery flow velocity waveforms. Methods: Betamethasone 12 mg i.m. in 2 injections 24 h apart was given to 25 pregnant women at risk of preterm delivery. Pulsatility (PI) and resistance (RI) indexes were measured at the proximal, middle and distal segments of the fetal pulmonary artery before and repeatedly 1, 2 and 7 days after the first dose. ANOVA for repeated measures and the general linear model were used to statistically analyze the results. Results: Blood flow resistance decreased after betamethasone treatment at both the middle (p = 0.001 and p = 0.02 for RI and PI, respectively) and the proximal (p = 0.03 for RI) segments returning to basal values after 7 days. Conclusions: Antenatal betamethasone decreases fetal branch pulmonary artery vascular resistance.
Perinatal Outcome in Breech Presentation Depending on the Mode of Vaginal Delivery
Authors: Vranješ Maja , Habek Dubravko
Published: October 2007

Aim: To compare the influence of different modes of vaginal delivery in breech presentation on perinatal outcome. Materials and Methods: During the period 2000–2005, perinatal outcome of newborns was compared in 144 vaginal breech deliveries divided into 5 groups depending on the mode of delivery used (Bracht, Thiessen, Müller, Mauriceau-Levret-Veit-Smellie (MLVS), classical arm release). Neonates transferred to the neonatal intensive care unit were further divided into 2 groups – premature infants and term neonates – in order to follow their perinatal outcome separately. In addition, maternal demographic and antenatal parameters were observed. Results: Of 144 deliveries, the most often used mode was Bracht (78.47%), followed by Thiessen (9.03%), Müller (8.33%), MLVS (3.47%) and classical arm release (0.69%). 77.08% of pregnancies were term and 22.92% premature urgent or precipitate deliveries (22–37 gestational weeks). Apgar score >7 at 5 min was noted in Thiessen (100%), followed by Bracht (90.26%), Müller (75%), MLVS (80%) along with arterial cord blood pH value. 40 neonates were transferred to the neonatal intensive care unit. They were delivered by Thiessen (7.69%), Bracht (28.32%), Müller (33.33%), MLVS (40%) and classical arm release (100%). 60% of those transferred were premature infants and 40% term neonates transferred mostly on account of perinatal maladaptation or perinatal hypoxia. Apgar scores and arterial cord blood pH value of newborns transferred to the neonatal intensive care unit (NICU) were better when less aggressive modes of vaginal delivery were used. 92% of neonates delivered by the Thiessen mode required no other medical care; this percentage decreased in other more active modes (p < 0.001) and was 72% versus other active groups (p < 0.01) for the Bracht mode. Conclusion: Less-traumatizing actions during vaginal delivery of breech presentation have less harmful consequences and therefore better perinatal outcome. Incidence of AS <7 and lower arterial cord blood pH value rise with the aggressiveness of the mode of vaginal delivery used.
Prenatal Diagnosis of Monocephalic Bifacial Tetraophthalmic Diprosopus (Conjoined Twin)
Authors: Dhaifalah I. , Curtisova V. , Santavy J.
Published: October 2007

A case of diprosopus twinning which is rare conjoined twinning is reported prenatally at 22 weeks’ gestation. 2D ultrasound examinations showed duplication of the craniofacial structures with four hemispheres, two cerebella and two thalami. There were three orbits two external ears, two noses, fused adjacent maxilla and two oral cavities with two fused oral opening and two jaws. The woman did not consent to any further investigations and the pregnancy was terminated. The postmortem examination confirmed the diagnosis in a male fetus with a crown-rump length of 155 mm, weighing 450 g. The body appeared normal except for a small poorly formed rudiment of a supernumerary digit next to the thumb of the right hand. The ultrasound examination and postmortem finding of this case is described with a short review of the literature.
Blockade of Estrogen Receptors Decreases CNS and Pituitary Prostaglandin Synthase Expression in Fetal Sheep
Authors: Schaub Christine E. , Keller-Wood Maureen , Wood Charles E.
Published: October 2007

Background/Aims: Both prostaglandin E2 (PGE2) and estradiol stimulate fetal ACTH secretion and augment fetal ACTH responses to stress. We have reported that estradiol increases prostaglandin endoperoxide synthase-2 (PGHS-2), and we have proposed that there is a positive feedback relationship between estrogen and fetal hypothalamus-pituitary-adrenal (HPA) axis activity that is dependent upon PGHS activity in the fetal brain. The present study was designed to test the hypothesis that blockade of estrogen receptors in the fetal brain decrease PGHS-2 expression and reduces fetal HPA axis activity. Methods: In study 1, six time-dated pregnant ewes with chronically-catheterized twin fetuses were used. In each pregnancy, one twin was treated intracerebroventricularly (icv) with the estrogen receptor antagonist ICI 182,780 (25 µg/day; n = 6) while the other twin served as an age-matched control. In study 2, plasma samples were drawn from 10 singleton chronically-catheterized fetuses on alternating days until the time of spontaneous parturition. Results: ICI infusion caused significantly decreased PGHS-2 mRNA abundance in fetal central nervous system and pituitary, with the greatest decreases occurring in hippocampus and pituitary. There were no statistically significant changes in PGHS-1 mRNA. ICI infusion did not significantly change fetal plasma concentrations of pro-opiomelanocortin (POMC), ACTH, or cortisol in fetuses 130–134 days ges- tation (study 1) but did decrease the preparturient rise in plasma pro-opiomelanocortin concentrations in study 2. Conclusion: We conclude that PGHS-2 expression in the late-gestation fetal brain is in part stimulated by circulating estrogens in fetal plasma. Blockade of CNS estrogen receptors reduces preparturient plasma concentrations of POMC, but does not reduce fetal HPA axis activity in 130–134 day fetal sheep.