bluuebunny/crossref_metadata_2025 huggingface dataset:
PPARγ-Independent Increase in Glucose Uptake and Adiponectin Abundance in Fat Cells
Authors: Dubuisson Olga , Dhurandhar Emily J. , Krishnapuram Rashmi , Kirk-Ballard Heather , Gupta Alok K. , Hegde Vijay , Floyd Elizabeth , Gimble Jeffrey M. , Dhurandhar Nikhil V.
Published: July 2011

Although thiazolidinediones (TZD) effectively improve hyperglycemia and increase adiponectin, a proinsulin-sensitizing adipokine, they also increase adipogenesis via peroxisome proliferator-activated receptor (PPAR)γ induction, which may be undesirable. Recent safety concerns about some TZD have prompted the search for next generation agents that can enhance glycemic control and adiponectin independent of PPARγ or adipogenesis. Reminiscent of TZD action, a human adenovirus, adenovirus 36 (Ad36), up-regulates PPARγ, induces adipogenesis, and improves systemic glycemic control in vivo. We determined whether this effect of Ad36 requires PPARγ and/or adipogenesis. Glucose uptake and relevant cell signaling were determined in mock-infected or human adenoviruses Ad36 or Ad2-infected cell types under the following conditions: 1) undifferentiated human-adipose-tissue-derived stem cells (hASC), 2) hASC differentiated as adipocytes, 3) hASC in presence or absence of a PPARγ inhibitor, 4) NIH/3T3 that have impaired PPARγ expression, and 5) PPARγ-knockout mouse embryonic fibroblasts. Mouse embryonic fibroblasts with intact PPARγ served as a positive control. Additionally, to determine natural Ad36 infection, human sera were screened for Ad36 antibodies. In undifferentiated or differentiated hASC, or despite the inhibition, down-regulation, or the absence of PPARγ, Ad36 significantly enhanced glucose uptake and PPARγ, adiponectin, glucose transporter 4, and glucose transporter 1 protein abundance, compared with mock or Ad2-infected cells. This indicated that Ad36 up-regulates glucose uptake and adiponectin secretion independent of adipogenesis or without recruiting PPARγ. In humans, natural Ad36 infection predicted greater adiponectin levels, suggesting a human relevance of these effects. In conclusion, Ad36 provides a novel template to metabolically remodel human adipose tissue to enhance glycemic control without the concomitant increase in adiposity or PPARγ induction associated with TZD actions.
Identification and Regulation of Bone Morphogenetic Protein Antagonists Associated with Preantral Follicle Development in the Ovary
Authors: Fenwick Mark A. , Mansour Yosef T. , Franks Stephen , Hardy Kate
Published: July 2011

The TGFβ superfamily comprises several bone morphogenetic proteins (BMP) capable of exerting gonadotropin-independent effects on the development of small preantral follicles. In embryonic tissues, BMP concentration gradients, partly formed by antagonistic factors, are essential for establishing phenotypic fate. By examining the expression of candidate genes whose protein products are known to interact with BMP ligands, we set out to determine which antagonists would most likely contribute toward regulation of paracrine signaling during early follicle development. Juvenile mouse ovaries of 4, 8, 12, and 21 d of age enriched with follicles at successive developmental stages were used to assess changes in candidate gene transcripts by quantitative RT-PCR. Although some antagonists were found to be positively associated with the emergence of developing follicles (Nog, Htra1, Fst, Bmper, Vwc2), two (Sostdc1, Chrd) showed a corresponding reduction in expression. At each age, twisted gastrulation homolog 1 (Twsg1), Htra1, Nbl1, and Fst were consistently highly expressed and localization of these genes by in situ hybridization, and immunohistochemistry further highlighted a clear pattern of expression in granulosa cells of developing follicles. Moreover, with the exception of Nbl1, levels of these antagonists did not change in preantral follicles exposed to FSH in vitro, suggesting regulation by local factors. The presence of multiple antagonists in the juvenile ovary and their high level of expression in follicles imply the actions of certain growth factors are subject to local modulation and further highlights another important level of intraovarian regulation of follicle development.
Deficiency in Interferon-γ Results in Reduced Body Weight and Better Glucose Tolerance in Mice
Authors: Wong Nicole , Fam Barbara C. , Cempako Gitta R. , Steinberg Gregory R. , Walder Ken , Kay Thomas W. , Proietto Joseph , Andrikopoulos Sofianos
Published: July 2011

Obesity is a chronic low-grade inflammatory disease caused by increased energy intake and reduced energy expenditure. Studies using animal models with deletion of inflammatory cytokines have produced conflicting results with some showing increased weight gain and others showing no effect or even reduced body weights. Clearly, more work is necessary to understand the role of cytokines on body weight control. The aim of this study was to determine the effect of interferon-γ deletion (IFNγ−/−) on body weight regulation and glucose metabolism. Male IFNγ−/− and wild-type C57BL/6 mice were fed a low-fat chow diet, and body weight, food intake, and energy expenditure were monitored over 20 wk. At the end of the study, ip glucose tolerance test, insulin tolerance test, basal glucose turnover, and hyperinsulinemic/euglycemic clamps were performed. Expression levels of arcuate nucleus neuropeptide Y, Agouti-related peptide, and proopiomelanocortin mRNA as well as circulating leptin levels were also determined. IFNγ−/− mice had improved glucose tolerance with reduced rate of glucose appearance and increased insulin sensitivity due to greater suppression of endogenous glucose output, which was associated with decreased hepatic glucose-6-phosphatase activity. In addition, we also observed reduced body weight associated with decreased food intake and increased physical activity. Neuropeptide Y and Agouti-related peptide mRNA expression was reduced, whereas proopiomelanocortin mRNA expression was increased, as were plasma leptin levels. Global deletion of IFNγ in mice resulted in reduced body weight associated with negative energy balance, improved glucose tolerance, and hepatic insulin sensitivity. Our findings demonstrate that IFNγ plays a critical role in the regulation of body weight and glucose metabolism.
Male Hypogonadism and Germ Cell Loss Caused by a Mutation in Polo-Like Kinase 4
Authors: Harris Rebecca M. , Weiss Jeffrey , Jameson J. Larry
Published: July 2011

The genetic etiologies of male infertility remain largely unknown. To identify genes potentially involved in spermatogenesis and male infertility, we performed genome-wide mutagenesis in mice with N-ethyl-N-nitrosourea and identified a line with dominant hypogonadism and patchy germ cell loss. Genomic mapping and DNA sequence analysis identified a novel heterozygous missense mutation in the kinase domain of Polo-like kinase 4 (Plk4), altering an isoleucine to asparagine at residue 242 (I242N). Genetic complementation studies using a gene trap line with disruption in the Plk4 locus confirmed that the putative Plk4 missense mutation was causative. Plk4 is known to be involved in centriole formation and cell cycle progression. However, a specific role in mammalian spermatogenesis has not been examined. PLK4 was highly expressed in the testes both pre- and postnatally. In the adult, PLK4 expression was first detected in stage VIII pachytene spermatocytes and was present through step 16 elongated spermatids. Because the homozygous Plk4I242N/I242N mutation was embryonic lethal, all analyses were performed using the heterozygous Plk4+/I242N mice. Testis size was reduced by 17%, and histology revealed discrete regions of germ cell loss, leaving only Sertoli cells in these defective tubules. Testis cord formation (embryonic day 13.5) was normal. Testis histology was also normal at postnatal day (P)1, but germ cell loss was detected at P10 and subsequent ages. We conclude that the I242N heterozygous mutation in PLK4 is causative for patchy germ cell loss beginning at P10, suggesting a role for PLK4 during the initiation of spermatogenesis.
Gonadotropin-Releasing Hormone Neurons Extend Complex Highly Branched Dendritic Trees Outside the Blood-Brain Barrier
Authors: Herde Michel K. , Geist Katrin , Campbell Rebecca E. , Herbison Allan E.
Published: July 2011

GnRH neurons project axons to the median eminence to control pituitary release of gonadotropins and, as such, represent the principal output neurons of the neuronal network controlling fertility. It is well established that the GnRH neurons exhibit a simple bipolar morphology with one or two long dendrites. Using adult GnRH-green fluorescent protein transgenic mice and juxtacellular cell filling, we report here that a subpopulation of GnRH neurons located in the rostral preoptic area exhibit extremely complex branching dendritic trees that fill the organum vasculosum of the lamina terminalis (OVLT). The dendritic nature of these processes was demonstrated at both light and electron microscopic levels by the presence of spines, dendritic ultrastructure, and synapses. Further, electrophysiological recordings showed that GnRH neurons were excited by glutamate as well as kisspeptin puffed onto their dendrites located within the OVLT. Using iv injection of horseradish peroxidase, a molecule unable to penetrate the blood-brain barrier (BBB), we show that GnRH neuron cell bodies and dendrites within 100 μm of the OVLT reside outside the BBB. Approximately 85% of GnRH neurons in this area express c-Fos at the time of the GnRH surge. These observations demonstrate that GnRH neurons extend complex, highly branched dendritic trees beyond the BBB into the OVLT, where they will be able to sense directly molecules circulating in the bloodstream. This indicates a new mechanism for the modulation of GnRH neurons that extends considerably the range of factors that are integrated by these neurons for the control of fertility.
Adaptation in the optical properties of the crystalline lens in the eyes of the Lessepsian migrantSiganus rivulatus
Authors: Gagnon Yakir L. , Shashar Nadav , Kröger Ronald H. H.
Published: July 2011

Vision is an important source of information for many animals. The crystalline lens plays a central role in the visual pathway and hence the ecology of fishes. In this study, we tested whether the different light regimes in the Mediterranean and Red Seas have an effect on the optical properties of the lenses in the rivulated rabbitfish, Siganus rivulatus. This species has migrated through the Suez Canal from the Red Sea and established a vital population in the Mediterranean Sea. Longitudinal spherical aberration curves and focal lengths of the fish lenses were measured by laser scans and compared between the two populations. In addition, rivulated rabbitfish from the Mediterranean Sea were exposed to colored light (yellow, green and blue) and unfiltered light for periods of 1 or 13 days to test for short-term adjustments. Lens focal length was significantly longer (3%) in the Rea Sea population. The shorter focal length of the Mediterranean population can be explained as an adaptation to the dimmer light environment, as this difference makes the Mediterranean eyes 5% more sensitive than the eyes of the Red Sea population. The difference may be due to genetic differences or, more likely, adaptive developmental plasticity. Short-term regulatory mechanisms do not seem to be involved.
A multilevel approach to examining cephalopod growth usingOctopus pallidusas a model
Authors: Semmens Jayson , Doubleday Zoë , Hoyle Kate , Pecl Gretta
Published: July 2011

Many aspects of octopus growth dynamics are poorly understood, particularly in relation to sub-adult or adult growth, muscle fibre dynamics and repro-somatic investment. The growth of 5 month old Octopus pallidus cultured in the laboratory was investigated under three temperature regimes over a 12 week period: seasonally increasing temperatures (14–18°C); seasonally decreasing temperatures (18–14°C); and a constant temperature mid-way between seasonal peaks (16°C). Differences in somatic growth at the whole-animal level, muscle tissue structure and rate of gonad development were investigated. Continuous exponential growth was observed, both at a group and at an individual level, and there was no detectable effect of temperature on whole-animal growth rate. Juvenile growth rate (from 1 to 156 days) was also monitored prior to the controlled experiment; exponential growth was observed, but at a significantly faster rate than in the older experimental animals, suggesting that O. pallidus exhibit a double-exponential two-phase growth pattern. There was considerable variability in size-at-age even between individuals growing under identical thermal regimes. Animals exposed to seasonally decreasing temperatures exhibited a higher rate of gonad development compared with animals exposed to increasing temperatures; however, this did not coincide with a detectable decline in somatic growth rate or mantle condition. The ongoing production of new mitochondria-poor and mitochondria-rich muscle fibres (hyperplasia) was observed, indicated by a decreased or stable mean muscle fibre diameter concurrent with an increase in whole-body size. Animals from both seasonal temperature regimes demonstrated higher rates of new mitochondria-rich fibre generation relative to those from the constant temperature regime, but this difference was not reflected in a difference in growth rate at the whole-body level. This is the first study to record ongoing hyperplasia in the muscle tissue of an octopus species, and provides further insight into the complex growth dynamics of octopus.
Gliding saves time but not energy in Malayan colugos
Authors: Byrnes Greg , Libby Thomas , Lim Norman T.-L. , Spence Andrew J.
Published: July 2011

Gliding is thought to be an economical form of locomotion. However, few data on the climbing and gliding of free-ranging gliding mammals are available. This study employed an animal-borne three-dimensional acceleration data-logging system to collect continuous data on the climbing and gliding of free-ranging Malayan colugos, Galeopterus variegatus. We combined these movement data with empirical estimates of the metabolic costs to move horizontally or vertically to test this long-standing hypothesis by determining whether the metabolic cost to climb to sufficient height to glide a given distance was less than the cost to move an equivalent distance horizontally through the canopy. On average, colugos climb a short distance to initiate glides. However, due to the high energetic cost of climbing, gliding is more energetically costly to move a given horizontal distance than would be predicted for an animal travelling the same distance through the canopy. Furthermore, because colugos spend a small fraction of their time engaged in locomotor activity, the high costs have little effect on their overall energy budget. As a result, the energetic economy hypothesis for the origins of gliding is not supported. It is likely that other ecologically relevant factors have played a greater role in the origins of gliding in colugos and other mammals.
Different effects of temperature on foraging activity schedules in sympatric Myrmecia ants
Authors: Jayatilaka Piyankarie , Narendra Ajay , Reid Samuel F. , Cooper Paul , Zeil Jochen
Published: July 2011

Animals avoid temperatures that constrain foraging by restricting activity to specific times of the day or year. However, because temperature alters the availability of food resources, it is difficult to separate temperature-dependent effects on foraging and the occupation of temporal niches. By studying two congeneric, sympatric Myrmecia ants we isolated the effect of temperature and investigated whether temperature affects foraging schedules and causes the two ants to be active at distinct times of the day or year. We monitored foraging activity and identified the ants' temperature tolerance in the laboratory by determining (1) critical thermal minima and maxima (CTmin and CTmax) and (2) the relationship between walking speed and temperature. Ants of Myrmecia croslandi were diurnal throughout the year, but ceased above-ground activity during winter. Surface temperature at the onset of foraging was 9.8–30.1°C, while their laboratory CTmin and CTmax were 10.4 and 48.5°C, respectively. Time of foraging onset was significantly influenced by surface temperature at time of sunrise and of onset. Ants of Myrmecia pyriformis were nocturnal throughout the year. Surface temperature at the onset of foraging was 5.4–26.2°C, while their laboratory CTmin and CTmax were 8.2 and 41.6°C, respectively. Time of foraging onset was not influenced by surface temperature, but solely by sunset time. We conclude that temperature determines the timing of foraging as well as the daily and seasonal foraging activity in M. croslandi, but has less obvious effects on M. pyriformis. In both species, CTmax was greater than temperatures at the natural foraging times.
Early elevation of testosterone advances migratory preparation in a songbird
Authors: Tonra Christopher M. , Marra Peter P. , Holberton Rebecca L.
Published: July 2011

The timing of events associated with spring migration can be an important determinant of fitness for migratory birds. The need to prepare and maintain physical condition for migration is one demand that must be met for early arrival on breeding areas, and this demand is compounded by the energetic demands of the physiological transition to breeding. Here, we examined whether migratory birds, specifically males, can adequately meet both of these demands by elevating the sex steroid testosterone early during migratory preparation. To test this, we used a captive experiment in which we photostimulated male dark-eyed juncos (Junco hyemalis) and manipulated circulating testosterone. We predicted males with elevated testosterone would prepare to migrate and breed faster than control males or males where the ability of testosterone to bind with receptors, or be converted to estradiol, was inhibited (testosterone inhibited). We measured migratory preparation using mass, food intake, fat deposits and nocturnal activity (Zugunruhe). To estimate breeding preparation, we measured the diameter of the cloacal protuberance (CP). We found that males in the testosterone treatment group began migratory preparation approximately 10 days before controls. There was no difference in the magnitude of peak migratory condition between testosterone-implanted birds and controls. Males implanted with testosterone also reached the onset of breeding preparation faster and had larger peak CP diameter compared with controls. Testosterone-inhibited birds showed no signs of migratory preparation and only a weak increase in CP diameter. These results demonstrate that early elevation of testosterone during migratory preparation could incur benefits for males in terms of the ability to depart earlier from non-breeding areas and arrive in a more advanced breeding condition. This experiment demonstrates that there may be important physiological underpinnings to known winter to breeding season carry-over effects in migratory birds.
Effects of temperature on the respiration of brooded larvae from tropical reef corals
Authors: Edmunds Peter J. , Cumbo Vivian , Fan Tung-Yung
Published: July 2011

This study describes the effects of temperature on the respiration of brooded larvae of scleractinian corals, and evaluates the implications of these effects relative to seawater temperature when peak larval release occurs. Respiration rates of larvae from Pocillopora damicornis, Seriatopora hystrix and Stylophora pistillata were quantified in darkness as oxygen uptake during 1–3 h exposures to five temperatures between 26.4 and 29.6°C. To assess the biological significance of these experiments, the temperature of the seawater into which larvae of P. damicornis and S. hystrix were released was measured for 32–34 months over 5 years between 2003 and 2008. Mean respiration varied from 0.029 to 0.116 nmol O2 larva–1 min–1, and was related parabolically to temperature with a positive threshold at 28.0°C. The temperature coefficients (Q10) for the ascending portion of these relationships (Q10=15–76) indicate that the temperature dependency is stronger than can be explained by kinetics alone, and probably reflects behavioral and developmental effects. Larval release occurred year-round in synchrony with the lunar periodicity when seawater temperature ranged from 21.8 to 30.7°C, and more than half of the sampled larvae were released at 27.5–28.9°C. The coincidence on the temperature scale of peak larval release with the thermal threshold for respiration suggests that high metabolic rates have selective value for pelagic coral larvae. The large and rapid effects of temperature on larval respiration have implications for studies of the effects of climate change on coral reproduction, particularly when seawater temperature exceeds ∼28°C, when our results predict that larval respiration will be greatly reduced.
Ammonia sensing by neuroepithelial cells and ventilatory responses to ammonia in rainbow trout
Authors: Zhang Li , Nurse Colin A. , Jonz Michael G. , Wood Chris M.
Published: July 2011

Ammonia, the third respiratory gas in teleost fish, acts as an acute stimulant to ventilation in ammoniotelic rainbow trout. We investigated whether this sensitivity is maintained in trout chronically exposed (1+ months) to high environmental ammonia [HEA, 250 μmol l–1 (NH4)2SO4] in the water, and whether gill neuroepithelial cells (NECs) are involved in ammonia sensing. Hyperventilation was induced both by acute external (NH4)2SO4 exposure [250 or 500 μmol l–1 (NH4)2SO4] and by intra-arterial (NH4)2SO4 injection (580 μmol kg–1 of ammonia) in control trout, but these responses were abolished in chronic HEA animals. Hyperventilation in response to acute ammonia exposure persisted after bilateral removal of each of the four gill arch pairs separately or after combined removal of arches III and IV, but was delayed by removal of gill arch I, and eliminated by combined removal of arches I and II. NECs, identified by immunolabeling against 5-HT, were mainly organized in two lines along the filament epithelium in all four gill arches. In control trout, NECs were slightly smaller but more abundant on arches I and II than on arches III and IV. Chronic HEA exposure reduced the density of the NECs on all four arches, and their size on arches I and II only. Fura-2 fluorescence imaging was used to measure intracellular free calcium ion concentration ([Ca2+]i) responses in single NECs in short-term (24–48 h) culture in vitro. [Ca2+]i was elevated to a comparable extent by perfusion of 30 mmol l–1 KCl and 1 mmol l–1 NH4Cl, and these [Ca2+]i responses presented in two different forms, suggesting that ammonia may be sensed by multiple mechanisms. The [Ca2+]i responses to high ammonia were attenuated in NECs isolated from trout chronically exposed to HEA, especially in ones from gill arch I, but responses to high K+ were unchanged. We conclude that the hyperventilatory response to ammonia is lost after chronic waterborne HEA exposure, and that NECs, especially the ones located in gill arches I and II, are probably ammonia chemoreceptors that participate in ventilatory modulation in trout.
Streamlining behaviour of the red urchin Strongylocentrotus franciscanus in response to flow
Authors: Stewart Hannah L. , Britton-Simmons Kevin H.
Published: July 2011

This work was motivated by subtidal observations of red urchins (Strongylocentrotus franciscanus) moving their spines into streamlined positions as water current increased in the field. Trials in a flume across flow speeds from 0 to 65 cm s–1 enabled us to observe the change in overall shape of the urchins and quantify the decrease in spine angle that occurred as flow speeds increased. The effect of this behaviour on drag and lift was measured with physical models made from urchin tests with spines in the `up' position (typical in stagnant and slow velocities) and in the `down' position (typical of posture in high velocities). Streamlining spines decreased the drag, but increased the lift experienced by urchin models at flow speeds between 10 and 40 cm s–1, current velocities that are commonly encountered by these animals in the field in Washington, USA. Total force (combination of drag and lift) was similar for `up' and `down' models at all flow speeds, lift comprising the majority of the force for `down' models, and drag slightly higher for `up' models. Live urchins in the field routinely adopt a streamlined `down' posture in flow, suggesting that they may be better able to cope with lift than drag. This behaviour, although affecting hydrodynamic forces and enabling S. franciscanus to remain attached to the substratum in high currents, may lead to reduced capture of drift kelp, which is entrapped on upright spines and then eaten, delivery of which is positively related to flow speed. Urchins living in deep subtidal habitats rely on drift kelp capture but must stay attached to the substratum to be successful in a habitat. Therefore, this streamlining behaviour may be an important factor enabling S. franciscanus to persist in deep, high-current areas.
Sound production and mechanism in Heniochus chrysostomus (Chaetodontidae)
Authors: Parmentier Eric , Boyle Kelly S. , Berten Laetitia , Brié Christophe , Lecchini David
Published: July 2011

The diversity in calls and sonic mechanisms appears to be important in Chaetodontidae. Calls in Chaetodon multicinctus seem to include tail slap, jump, pelvic fin flick and dorsal–anal fin erection behaviors. Pulsatile sounds are associated with dorsal elevation of the head, anterior extension of the ventral pectoral girdle and dorsal elevation of the caudal skeleton in Forcipiger flavissiumus. In Hemitaurichthys polylepis, extrinsic swimbladder muscles could be involved in sounds originating from the swimbladder and correspond to the inward buckling of tissues situated dorsally in front of the swimbladder. These examples suggest that this mode of communication could be present in other members of the family. Sounds made by the pennant bannerfish (Heniochus chrysostomus) were recorded for the first time on coral reefs and when fish were hand held. In hand-held fishes, three types of calls were recorded: isolated pulses (51%), trains of four to 11 pulses (19%) and trains preceded by an isolated pulse (29%). Call frequencies were harmonic and had a fundamental frequency between 130 and 180 Hz. The fundamental frequency, sound amplitude and sound duration were not related to fish size. Data from morphology, sound analysis and electromyography recordings highlight that the calls are made by extrinsic sonic drumming muscles in association with the articulated bones of the ribcage. The pennant bannerfish system differs from other Chaetodontidae in terms of sound characteristics, associated body movements and, consequently, mechanism.
Studies on the Selectivity between Glycosylation and Intermolecular Aglycone Transfer of Thioglucoside in Synthesis of Lactose Derivatives
Authors: Kato Marie , Hirai Go , Sodeoka Mikiko
Published: July 2011

Glycosylation reaction of 2,3-di-O-benzoyl-protected galactosyl donors with ethyl thioglucoside acceptor to prepare lactose derivatives was investigated. The presence of benzyl ether moieties at the 4 and 6 positions of the donor drove the glycosylation reaction to completion and blocked the intermolecular aglycone transfer reaction with thioglucoside. On the other hand, the presence of benzoyl moieties at those positions promoted the intermolecular aglycone transfer reaction with thioglucoside.
Dispersion of Carbon Nanotubes in Water by Noncovalent Wrapping with Peptides Screened by Phage Display
Authors: Ejima Hirotaka , Matsumiya Kisei , Yui Hiroharu , Serizawa Takeshi
Published: July 2011

12-mer peptides, which were originally identified by affinity screening for carbon nanotubes (CNTs) and poly(phenylenevinylene) (PPV) from phage-displayed peptide libraries, were used as dispersants for single-walled CNTs (SWNTs). The amounts dispersed were then compared under the same experimental conditions. Among the various peptides, Mps01 (HNAYWHWPPSMT) showed the highest dispersion capability. Gly scanning revealed that the Trp and Pro residues were crucial for dispersion. Atomic force microscopy (AFM) confirmed that the majority of dispersed SWNTs were debundled and isolated via Mps01 wrapping. AFM height analysis also suggested that the majority of SWNTs were covered by a monolayer of Mps01.
Development of pH-Sensitive Spin-crossover Iron(II) Complex Films, [FeII(diAMsar)]–Nafion: Manipulation of the Spin State by Proton Concentration
Authors: Kamebuchi Hajime , Jo Taketomo , Shimizu Hideharu , Okazawa Atsushi , Enomoto Masaya , Kojima Norimichi
Published: July 2011

We newly synthesized transparent films composed of pH-sensitive spin-crossover complex [FeII(diAMsar)] (diAMsar: 1,8-diaminosarcophagine) and an ion-exchange polymer, Nafion, having different colors corresponding to proton concentration. The UV–vis spectroscopic measurements revealed that the films, which were provided under pH 4, 7, and 10 conditions, showed the spin state depending on pH.
Comparison of Electrochemical Impedance Spectroscopy between Illumination and Dark Conditions
Authors: Adachi Motonari , Noda Kei , Tanino Ryo , Adachi Jun , Tsuchiya Katsumi , Mori Yasushige , Uchida Fumio
Published: July 2011

Electrochemical impedance spectroscopy (EIS) is an excellent method to determine simultaneously many parameters concerning electron-transport processes in dye-sensitized solar cells under the same conditions as those for the cell in operation. A number of studies analyzed the electron-transport processes based on EIS measurements under dark conditions, although the photocurrent density–voltage (I–V) measurements were carried out under one-sun illumination conditions. The result of EIS measurement obtained under dark conditions, however, is quite different from that obtained under illumination. The EIS measurement should thus be carried out under the same illumination conditions as the I–V measurement is performed to obtain properly analyzed results in regard to the electron-transport processes. The main factor contributing to such difference between dark and illumination conditions was elucidated to be the difference in the electron density in the steady-state cell performance between dark and illumination conditions.
After Midnight: A Regression Discontinuity Design in Length of Postpartum Hospital Stays
Authors: Almond Douglas , Doyle Joseph J
Published: July 2011

Estimates of moral hazard in health insurance markets can be confounded by adverse selection. This paper considers a plausibly exogenous source of variation in insurance coverage for childbirth in California. We find that additional health insurance coverage induces substantial extensions in length of hospital stay for mother and newborn. However, remaining in the hospital longer has no effect on readmissions or mortality, and the estimates are precise. Our results suggest that for uncomplicated births, minimum insurance mandates incur substantial costs without detectable health benefits. (JEL D82, G22, I12, I18, J13)
Implementing Anti-Discrimination Policies in Statistical Profiling Models
Authors: Pope Devin G , Sydnor Justin R
Published: July 2011

How should statistical models used for assigning prices or eligibility be implemented when there is concern about discrimination? In many settings, factors such as race, gender, and age are prohibited. However, the use of variables that correlate with these omitted characteristics (e.g., zip codes, credit scores) is often contentious. We provide a framework to address these issues and propose a method that can eliminate proxy effects while maintaining predictive accuracy relative to an approach that restricts the use of contentious variables outright. We illustrate the value of our proposed method using data from the Worker Profiling and Reemployment Services system. (JEL C53, J15, J65, J71)
Effect of moderate-to-severe chronic kidney disease on flow-mediated dilation and progenitor cells
Authors: Kuczmarski James M , Darocki Mark D , DuPont Jennifer J , Sikes Robert A , Cooper Carlton R , Farquhar William B , Edwards David G
Published: July 2011

A reduction in progenitor cell populations that help preserve vascular continuity and induce vascularization may accentuate endothelial cell apoptosis and dysfunction, ultimately contributing to organ failure and increased cardiovascular disease in chronic kidney disease (CKD). We hypothesized that CD45+ myeloid and CD34+ hematopoietic circulating progenitor cell (CPC) subpopulations would be reduced, peripheral blood mononuclear cell (PBMNC) colony-forming units (CFU) would be impaired, and flow-mediated dilation (FMD) would be impaired in patients with moderate-to-severe CKD as compared with healthy controls. Eleven moderate-to-severe CKD patients (mean estimated glomerular filtration rate [eGFR]: 36 ± 5) and 14 healthy controls were studied; blood was drawn and FMD was assessed by brachial artery FMD. CPCs were quantified via flow cytometry, and isolated PBMNCs were cultured for the colony-forming assay. CKD patients had significantly impaired FMD; lower CD34+, CD34+/KDR+, CD34+/CD45− and CD34+/KDR+/CD45− hematopoietic CPCs; lower CD45+, CD45+/KDR+, CD34+/CD45+ and CD34+/KDR+/CD45+ myeloid CPCs; and impaired CFUs as compared with healthy controls. Regression analysis revealed that CD34+, CD34+/KDR+ and CD34+/CD45− hematopoietic CPCs were associated positively with eGFR and negatively with blood urea nitrogen and serum creatinine. The CD45+/KDR+ myeloid CPCs also were associated positively with eGFR and negatively with serum creatinine. CD34+ hematopoietic CPCs and CD45+/KDR+ as well as CD34+/CD45+ myeloid CPCs were associated positively with FMD. In conclusion, myeloid and hematopoietic CPCs are reduced and associated with renal function as well as FMD in CKD. Therefore, reductions in CPCs may be a potential mechanism by which vascular integrity is compromised, increasing cardiovascular disease risk and contributing to renal disease progression in CKD.
Dietary kakrol (Momordica dioica Roxb.) flesh inhibits triacylglycerol absorption and lowers the risk for development of fatty liver in rats
Authors: Sato Masao , Ueda Takatoshi , Nagata Kazuko , Shiratake Sawako , Tomoyori Hiroko , Kawakami Mitsuo , Ozaki Yukio , Okubo Hiroshi , Shirouchi Bungo , Imaizumi Katsumi
Published: July 2011

Kakrol ( Momordica dioica Roxb.) is a cucurbitaceous vegetable native to India and Bangladesh. Bitter gourd ( Momordica charantia Linn.), a species related to kakrol, has been shown to have pharmacological properties including antidiabetic and antisteatotic effects. In this study, we investigated the effect of dietary kakrol on lipid metabolism in rats. Sprague-Dawley rats were fed AIN-76 formula diets containing 3% freeze-dried powders of whole kakrol or bitter gourd for two weeks. Results showed significantly lowered liver cholesterol and triacylglycerol levels in rats fed on both diets. Fecal lipid excretion increased in rats fed the kakrol diet, and lymphatic transport of triacylglycerol and phospholipids decreased in rats fed the kakrol diet after permanent lymph cannulation. Furthermore, n-butanol extract from kakrol caused a significant concentration-dependent decrease in the pancreatic lipase activity in vitro. These results indicate that the mechanisms of action on lipid metabolism in kakrol and bitter gourd are different and that dietary kakrol reduces liver lipids by inhibiting lipid absorption.
Patient-derived outcome measures for HIV services in the developed world: a systematic review
Authors: Land L , Nixon S , Ross J D C
Published: July 2011

This review sought to establish the themes and approaches used in the measurement of patient satisfaction regarded by HIV service users as crucial to improving service quality. It also investigated how feedback has been measured previously and whether a gold standard instrument exists that is generalizable across HIV inpatient and clinic settings. Twelve databases and other sources yielded 1474 titles. Using a clinically-focused question and pre-defined inclusion and exclusion criteria, 32 articles were retrieved and reviewed for quality using a quality appraisal checklist. Two reviewers used a data extraction form to identify and verify key patient experiences. Thematic analysis revealed that clinic staffs' current knowledge of HIV was an essential factor in positive feedback. Treating patients with dignity and respecting their autonomy and confidentiality were also important. Developments in treatment, extended life expectancy and quality of life have altered patients' experience and level of satisfaction. Three instruments developed to assess patient satisfaction with HIV care were identified but there was no gold standard method of measuring it. There is a need to develop a specific, valid instrument that is easy to complete and analyse, and the data should be used to inform the redesign of services to promote a dynamic model of care.
In-hospital mortality rates and HIV: a medical ward review, Lilongwe, Malawi
Authors: Akinkuotu A , Roemer E , Richardson A , Namarika D C , Munthali C , Bahling A , Hoffman I F , Hosseinipour M C
Published: July 2011

In order to determine inpatient hospital mortality rates, causes of mortality and characteristics of inpatients at Kamuzu Central Hospital (KCH) in Lilongwe, Malawi, we conducted a prospective observational study of all patients admitted to KCH medical ward from 20 September 2008 to April 2, 2009. All admission diagnoses, HIV status and antiretroviral therapy (ART) use were recorded. Patients' vital status was determined at discharge. A descriptive analysis and two logistic regression models were used for the analysis. Of the 1895 enrolled patients, the overall hospital mortality rate was 14.6%, substantially higher among known HIV-infected patients (24.2% versus 10.8%, P = 0.0009) and men (17.1% versus 12%, P = 0.033). Patients with multiple diagnoses had significantly higher mortality (odds ratio [OR] 2.33; 95% confidence interval [CI] 1.47, 3.71). Most patients (62.3%) had unknown HIV status at admission. Among HIV-infected patients, ART use did not reduce hospital mortality or alter the spectrum of diseases. The majority of diagnoses were infectious (63.4%). The high inpatient mortality rate, especially among HIV-infected patients combined with the limited spectrum of diagnoses, emphasizes the need for improved inpatient management and diagnostic services. Expansion of HIV testing is warranted. Despite the rollout of ART, there remains a significant need for treatment of HIV-infected individuals.
Finding cases of Trichomonas vaginalis infection in England
Authors: Mahto M , Evans-Jones J , Zia S , Robinson T I , Rothburn M M , Mallinson H
Published: July 2011

We describe the use of a new molecular assay for Trichomonas vaginalis (TV), the Gen-Probe Aptima TV (ATV) in female attendees at community clinics, a genitourinary (GU) medicine clinic and a prison GU medicine service. Positivity rates at community clinics and GU medicine were 0/382 (0%) and 3/358 (0.8%, 95% confidence interval [CI] 0–1.7%), respectively. Positivity was significantly higher, 29/269 (10.8%, 95% CI 7.1–14.5%), odds ratio (OR) 14.3 (4.11 < OR < 59.55), in those tested at the prison. A questionnaire survey of English GU medicine clinics and data from the UK Health Protection Agency (HPA) for England both demonstrated the large variation in case rates by region and testing methods employed. Higher rates were seen in women, in prison GU medicine services and in London GU medicine clinics. The ATV assay is now CE-marked (Conformité Européenne) and so a larger prospective study of its potential application is warranted.
An RSU by any other name: thoughts on the naming of secure units
Authors: Jones Christopher
Published: July 2011

Names are powerful symbols which contribute to internal and external perceptions of an individual or institution. This paper discusses the names given to Regional Secure Units established following the Butler Report, and discusses some of the reasons underlying the choice of name. Understanding the derivation of names can assist understanding of the development of forensic psychiatry as a separate specialty and awareness of its history.
Myophosphorylase deficiency (McArdle disease) in a patient with normal pregnancy and normal pregnancy outcome
Authors: Giles Warwick , Maher Catherine
Published: July 2011

McArdle disease is a rare, mostly autosomal recessive disorder of deficient myophosphorylation of glycogen in skeletal muscles. Recent knowledge regarding this condition means that women of childbearing age with McArdle disease can expect to labour normally without ill effect. We report a case of a 30-year-old woman in her first pregnancy who had an episode of exercise-induced myoglobinuria with a significant rise in serum creatine kinase (CK) levels in early pregnancy who then laboured normally but did require a caesarean section for a malposition of the fetal head.
The management challenges of non-preeclampsia-related nephrotic syndrome in pregnancy
Authors: Côté Anne Marie , Sauvé Nadine
Published: July 2011

Nephrotic syndrome in a pregnant woman may be challenging, especially when the onset is early in pregnancy or with severe manifestations. Preeclampsia is the most common cause of nephrotic syndrome in pregnancy; however, this review will focus on the management of other renal causes. The aim of this pragmatic review is to address clinical issues that clinicians looking after women with nephrotic syndrome may encounter during pregnancy and the postpartum period. First, we discuss some general issues regarding nephrotic syndrome and its impact on maternal and fetal outcomes in pregnancy, and then we review the maternal management of nephrotic syndrome in pregnancy and during the postpartum period.
Unity in Diversity: Electronic Patient Record Use in Multidisciplinary Practice
Authors: Oborn Eivor , Barrett Michael , Davidson Elizabeth
Published: July 2011

In this paper we examine the use of electronic patient records (EPR) by clinical specialists in their development of multidisciplinary care for diagnosis and treatment of breast cancer. We develop a practice theory lens to investigate EPR use across multidisciplinary team practice. Our findings suggest that there are oppositional tendencies towards diversity in EPR use and unity which emerges across multidisciplinary work, and this influences the outcomes of EPR use. The value of this perspective is illustrated through the analysis of a year-long, longitudinal case study of a multidisciplinary team of surgeons, oncologists, pathologists, radiologists, and nurse specialists adopting a new EPR. Each group adapted their use of the EPR to their diverse specialist practices, but they nonetheless orientated their use of the EPR to each others' practices sufficiently to support unity in multidisciplinary teamwork. Multidisciplinary practice elements were also reconfigured in an episode of explicit negotiations, resulting in significant changes in EPR use within team meetings. Our study contributes to the growing literature that questions the feasibility and necessity of achieving high levels of standardized, uniform health information technology use in healthcare.
Value of Local Cash Reuse: Inventory Models for Medium-Size Depository Institutions Under the New Federal Reserve Policy
Authors: Zhu Yunxia , Dawande Milind , Sriskandarajah Chelliah
Published: July 2011

The effective local reuse of physical cash by depository institutions (DIs) is the primary goal of the new cash recirculation policy of the Federal Reserve System (Fed) of the United States. These guidelines, implemented since July 2007, encourage the reuse of cash by (i) penalizing a DI for the practice of cross shipping, the near-simultaneous deposit of used cash to—and withdrawal of fit cash from—the Fed; and (ii) offering a custodial inventory program that enables a DI to transfer fit cash to the Fed's books, but physically hold it within the DI's secured facility. The effective management of the inventory of cash under these new guidelines is both a challenging and important issue for DIs. We introduce two new multiperiod models—designed specifically to capture the operations of a medium-size DI—that emerge from the DI's objective to minimize the total cost incurred in managing the inventory of cash over a finite planning horizon. The Basic Model (BM) captures the DI's mode of operations if it chooses not to locally reuse cash and, instead, incur the cross-shipping penalty. Using two important structural properties, we provide a polynomial-time dynamic programming algorithm for BM. The Reuse Model (RM) represents the DI's actions when it locally recirculates cash. We first prove the hardness of RM and then develop an integer programming formulation. A comprehensive test bed—based on our interaction with a leading secure-logistics provider—helps us to develop several useful insights into the relative impacts of the DI-specific parameters and the Fed's cross-shipping fee on the effective management of cash. In particular, we show that the Value of Local Reuse for a DI, measured as the percentage cost saving between the optimal solutions of BM and RM, is substantial, and we analyze the forces that influence the volume of cross shipping. We also develop a rolling-horizon procedure to adapt the optimal solutions of BM and RM for obtaining near-optimal real-time solutions in the presence of a modest amount of uncertainty. Finally, we provide a comparative analysis of a DI's decisions under the Fed's mechanism and those under a socially optimal mechanism.
Computing Bid Prices for Revenue Management Under Customer Choice Behavior
Authors: Chaneton Juan M. , Vulcano Gustavo
Published: July 2011

We consider a choice-based, network revenue management (RM) problem in a setting where heterogeneous customers consider an assortment of products offered by a firm (e.g., different flight times, fare classes, and/or routes). Individual choice decisions are modeled through an ordered list of preferences, and minimal assumptions are made about the statistical properties of this demand sequence. The firm manages the availability of products using a bid-price control strategy, and would like to optimize the control parameters. We formulate a continuous demand and capacity model for this problem that allows for the partial acceptance of requests. The model admits a simple calculation of the sample path gradient of the revenue function. This gradient is then used to construct a stochastic steepest ascent algorithm. We show that the algorithm converges (w.p.1) to a stationary point of the expected revenue function under mild conditions. The procedure is relatively efficient from a computational standpoint, and in our synthetic and real-data experiments performs comparably to or even better than other choice-based methods that are incompatible with the current infrastructure of RM systems. These features make it an interesting candidate to be pursued for real-world applications.
Cognitive mechanisms underlying relapse to nicotine
Authors: Lester Robin A.J.
Published: July 2011

Much of the addictive power of nicotine in humans may be attributable to learned contextual associations, such that these secondary cues become potent predictive incentives for both maintaining and driving relapse to drug use, even after long periods of abstinence. Here, I review the evidence that chronic nicotine in vivo can induce persistent neuronal changes in excitability within the hippocampal circuitry, with a specific emphasis on the dentate gyrus as an initiator of drug use. The relevance of these early homeostatic (can be fully reversed by acute application of nicotine) neuroadaptations on withdrawal from nicotine is then related to known cognitive deficits also produced following chronic nicotine. I briefly discuss how the hippocampus may influence other parts of the reward circuitry to affect chronic drug use and how periods of drug cessation and/or withdrawal may convert these short-term changes into permanent alterations within the brain that may drive craving and/or relapse many years of abstinence.