bluuebunny/crossref_metadata_2025 huggingface dataset:
In vitroeffects of fetal rat cerebrospinal fluid on viability and neuronal differentiation of PC12 cells
Authors: Nabiuni Mohammad , Rasouli Javad , Parivar Kazem , Kochesfehani Homa M , Irian Saeid , Miyan Jaleel A
Published: April 2012

Background

Fetal cerebrospinal fluid (CSF) contains many neurotrophic and growth factors and has been shown to be capable of supporting viability, proliferation and differentiation of primary cortical progenitor cells. Rat pheochromocytoma PC12 cells have been widely used as an in vitro model of neuronal differentiation since they differentiate into sympathetic neuron-like cells in response to growth factors. This study aimed to establish whether PC12 cells were responsive to fetal CSF and therefore whether they might be used to investigate CSF physiology in a stable cell line lacking the time-specific response patterns of primary cells previously described.

Methods

In vitro assays of viability, proliferation and differentiation were carried out after incubation of PC12 cells in media with and without addition of fetal rat CSF. An MTT tetrazolium assay was used to assess cell viability and/or cell proliferation. Expression of neural differentiation markers (MAP-2 and β-III tubulin) was determined by immunocytochemistry. Formation and growth of neurites was measured by image analysis.

Results

PC12 cells differentiate into neuronal cell types when exposed to bFGF. Viability and cell proliferation of PC12 cells cultured in CSF-supplemented medium from E18 rat fetuses were significantly elevated relative to the control group. Neuronal-like outgrowths from cells appeared following the application of bFGF or CSF from E17 and E19 fetuses but not E18 or E20 CSF. Beta-III tubulin was expressed in PC12 cells cultured in any media except that supplemented with E18 CSF. MAP-2 expression was found in control cultures and in those with E17 and E19 CSF. MAP2 was located in neurites except in E17 CSF when the whole cell was positive.

Conclusions

Fetal rat CSF supports viability and stimulates proliferation and neurogenic differentiation of PC12 cells in an age-dependent way, suggesting that CSF composition changes with age. This feature may be important in vivo for the promotion of normal brain development. There were significant differences in the effects on PC12 cells compared to primary cortical cells. This suggests there is an interaction in vivo between developmental stage of cells and the composition of CSF. The data presented here support an important, perhaps driving role for CSF composition, specifically neurotrophic factors, in neuronal survival, proliferation and differentiation. The effects of CSF on PC12 cells can thus be used to further investigate the role of CSF in driving development without the confounding issues of using primary cells.
Intimal lining layer macrophages but not synovial sublining macrophages display an IL-10 polarized-like phenotype in chronic synovitis
Authors: Ambarus Carmen A , Noordenbos Troy , de Hair Maria JH , Tak Paul P , Baeten Dominique LP
Published: April 2012

Introduction

Synovial tissue macrophages play a key role in chronic inflammatory arthritis, but the contribution of different macrophage subsets in this process remains largely unknown. The main in vitro polarized macrophage subsets are classically (M1) and alternatively (M2) activated macrophages, the latter comprising interleukin (IL)-4 and IL-10 polarized cells. Here, we aimed to evaluate the polarization status of synovial macrophages in spondyloarthritis (SpA) and rheumatoid arthritis (RA).

Methods

Expression of polarization markers on synovial macrophages, peripheral blood monocytes, and in vitro polarized monocyte-derived macrophages from SpA versus RA patients was assessed by immunohistochemistry and flow cytometry, respectively. The polarization status of the intimal lining layer and the synovial sublining macrophages was assessed by double immunofluorescence staining.

Results

The expression of the IL-10 polarization marker cluster of differentiation 163 (CD163) was increased in SpA compared with RA intimal lining layer, but no differences were found in other M1 and M2 markers between the diseases. Furthermore, no significant phenotypic differences in monocytes and in vitro polarized monocyte-derived macrophages were seen between SpA, RA, and healthy controls, indicating that the differential CD163 expression does not reflect a preferential M2 polarization in SpA. More detailed analysis of intimal lining layer macrophages revealed a strong co-expression of the IL-10 polarization markers CD163 and cluster of differentiation 32 (CD32) but not any of the other markers in both SpA and RA. In contrast, synovial sublining macrophages had a more heterogeneous phenotype, with a majority of cells co-expressing M1 and M2 markers.

Conclusions

The intimal lining layer but not synovial sublining macrophages display an IL-10 polarized-like phenotype, with increased CD163 expression in SpA versus RA synovitis. These differences in the distribution of the polarized macrophage subset may contribute to the outcome of chronic synovitis.
A new empirical complex electrical resistivity model
Authors: Kavian M. , Slob E. C. , Mulder W. A.
Published: April 2012

Macroscopic measurements of electrical resistivity require frequency-dependent effective models that honor the microscopic effects observable in macroscopic measurements. Effective models based on microscopic physics exist alongside with empirical models. We adopted an empirical model approach to modify an existing physical model. This provided a description of electrical resistivity as a function of not only frequency, but also water saturation. We performed two-electrode laboratory measurements of the complex resistivity on a number of fine and medium-grained unconsolidated sand packs saturated with water of three different salinities. For frequencies between 0.1 and 1 MHz, the data were fitted with the new model and compared to fits with Archie’s law. Our model described the relaxation times and DC resistivity values as negative exponential functions with increasing water saturation. All data could be accurately described as a function of frequency and water saturation with nine parameters.
Fabricating Defoes: From Anonymous Hack to Master of Fictions
Authors: Marshall Ashley
Published: April 2012

The “Defoe” to be found in the major modern biographies and the criticism of the last four decades is a radically different person and writer from earlier Defoes. Although the notion of a “constructed” author is by now an over-worked cliché, Defoe represents an especially problematic case. Dryden, Pope, and Fielding as we now conceive them are constructions built on the basis of relatively clear (if not uncontested) materials; the evidence we possess about them is open to varying interpretations, but we have a considerable amount to work with. More than any other major eighteenth-century writer, however, our Defoe is a construction—one that is both relatively recent and of dubious validity. Until the 1960s, Defoe was regarded as a sloppy hack writer who happened to write a few interesting novels. In the last fifty years, his reputation has changed drastically: critics have reconceived him as a brilliant fiction-writer, a master craftsman, and the father of the novel. Defoe is treated very much like other canonical eighteenth-century authors, but he represents a different kind of writer and a unique set of problems, and we should therefore rethink the way we regard him and interpret his writings. For a variety of reasons—having to do with the nature of his life and work, the lack of much personal record, the anonymity and attribution problems—we are simply not on solid ground, as we are with Dryden, Pope, Fielding, or Swift.
Attribution and Repetition: The Case of Defoe and the Circulating Library
Authors: Vareschi Mark
Published: April 2012

While much scholarly attention has been paid to attributing or de-attributing the texts associated with Daniel Defoe properly, less attention has been paid to the process of attribution itself and the context in which these attributions were made. This essay examines the various means through which Francis Noble and his brother John represented the authorial relationship between Defoe, Roxana, and Moll Flanders between 1775 and 1787 and analyzes these attributions within the larger discourses surrounding the Nobles’ circulating libraries. “Attribution and Repetition” provides an account of attribution as a slow and repetitive process rather than a singular moment or act.
Raising the Roof: Hymn Singing, the Anti-Methodist Response, and Early Methodist Religiosity
Authors: McInelly Brett C.
Published: April 2012

This paper explores some of the ways hymns informed the Methodist revival. I argue that the hymns can be better understood as the site of a complex negotiation between John and Charles Wesley and their followers, as the brothers attempted to steer the movement away from charges of religious enthusiasm. The emotional power the hymns unleashed required various kinds of constraint so that hymn singing fed the intense feelings of conversion in controlled ways while providing the feelings with content. The hymns achieved this, in part, by creating for singers an experience of identification (as described by Kenneth Burke); that is, singers identified with the lyrical and rhythmic qualities of the hymns, thereby confirming spiritual impulses they felt but could not always express. In addition, by questioning the rationality of mainstream Enlightenment religion, the hymns functioned, though not always successfully, to challenge the grounds on which the anti-Methodists mounted their campaign against Methodism. Like other features of the revival, such as open-air preaching and lay ministry, hymn singing generated controversy; paradoxically, this controversy provided much of the energy that ultimately sustained the Methodist movement and helped to define the faith of individual Methodists.
Collecting Trouble: Sir Hans Sloane’s Literary Reputation in Eighteenth-Century Britain
Authors: Benedict Barbara M.
Published: April 2012

This article argues that the shifts in the reputation of Sir Hans Sloane, the foremost British collector of the eighteenth century, reflect the changing reputation of collecting itself from the Restoration to the Regency. By examining the literary representations of Sloane in genres ranging from poetry to memoirs, it traces Sloane’s reputation in literary culture from that of a model physician and benefactor, to a charlatan, to a toyman, and finally, to an entrepreneur. These shifts reflect the challenges that collecting presented to culture: on the one hand, it threatened conventional valuations, and on the other, offered rich opportunities both for both self-advancement and the advancement of learning. Writers show that Sloane’s activities recast the natural world as a storehouse stuffed with collectibles and collecting as an ambiguous but national practice of imperialistic acquisition. At the same time, they find in Sloane and the fashion for collecting several dangers: it reflected the increasing power of objects to oust abstract concepts as the subjects of literary description, presented new modes of self-definition and sociability, and, above all, led to a transition from an idea of nature as full of wonders to one in which nature is a treasure-house of loot and knowledge. Whereas the Restoration had embraced the new definition of a scholar-collector as a gentleman who contributed to the public good, by the midcentury, collectors seemed self-absorbed and deluded. Yet, by the end of the century, collecting was considered laudable self-advancement. Things had changed, so that on 15 January 1759, when the British Museum opened for “study and public inspection,” Sloane, formerly a charlatan and a toyman, stood as the noble exemplar of the collector and the father of a new British identity.
Poetry, Power, Protest: Reimagining Muslim Nationhood in Northern Pakistan
Authors: Ali Nosheen
Published: April 2012

This article examines the role of poetry in illuminating and challenging the meaning of citizenship in the border region of Gilgit-Baltistan, which is located in the north of Pakistan and is internationally considered as forming part of Pakistani Kashmir. Ali discusses how poetic performances constitute a critical public arena for protesting political dispossession and for nurturing a postsectarian, religious harmony in the region. The article also complicates our understanding of the state, as several of the poets in Gilgit work for the local government. From this overlapping position as local inhabitants and state officials, they seek to create spaces of poetic reflection that can help reshape the state as well as society in Gilgit-Baltistan.
Gender, Performance, and the Politics of Space: Germany and the Veil in Popular Culture
Authors: Stehle Maria
Published: April 2012

Since the 1990s, the headscarf has played a powerful role in negotiating questions of national and cultural belonging, gender identity, and definitions of urban space in Germany. This essay examines examples of veiling depicted in popular culture and theorizes the relationship between the headscarf and gendered and racialized spaces and the headscarf’s potential as a symbol of defiance in Germany. The two examples, the television comedy Turkish for Beginners and the performances of Berlin hip-hop artist Sahira Awad, illustrate how young Muslimas (female Muslims) inhabit a precarious space as mediators between cultures. In spite of being rather prescriptive, the mediator role also opens up spaces for critical intervention in the German media landscape.
Effects of host diet and thermal state on feeding performance of the flea Xenopsylla ramesis
Authors: Korine Carmi , Krasnov Boris R. , Khokhlova Irina S. , Pinshow Berry
Published: April 2012

We examined feeding performance of the flea Xenopsylla ramesis on three different hosts: its natural, granivorous, rodent host, Sundevall’s jird (Meriones crassus); the frugivorous Egyptian fruit bat (Rousettus aegyptiacus); and an insectivorous bat, Kuhl’s pipistrelle (Pipistrellus kuhlii). Because these fleas are not known to occur on bats, we hypothesized that the fleas’ feeding performance (i.e. feeding and digestion rates) would be higher when feeding on their natural host than on either of the bats that they do not naturally parasitize. We found that mass-specific blood-meal size of both male and female fleas was significantly lower when feeding on Kuhl’s pipistrelles than on the other two species, but was not different in female fleas feeding on fruit bats or on jirds at all stages of digestion. However, more male fleas achieved higher levels of engorgement if they fed on Sundevall’s jirds than if they fed on Egyptian fruit bats. The fleas digested blood of fruit bats and jirds significantly faster than blood of Kuhl’s pipistrelle. In addition, after a single blood meal, the survival time of fleas fed on normothermic Kuhl’s pipistrelles was significantly shorter than that of fleas fed on Sundevall’s jirds and even lower when male fleas fed on Egyptian fruit bats. Thus, our prediction was partially supported: normothermic Kuhl’s pipistrelles were inferior hosts for fleas compared with Sandevall’s jirds and Egyptian fruit bats. Interestingly, the proportion of engorged fleas that fed on torpid Kuhl’s pipistrelles was significantly higher than the proportion of the fleas that fed on normothermic individuals, indicating that becoming torpid might be a liability, rather than an effective defense against parasites.
Transport of selenium across the plasma membrane of primary hepatocytes and enterocytes of rainbow trout
Authors: Misra Sougat , Kwong Raymond W. M. , Niyogi Som
Published: April 2012

Transport of essential solutes across biological membranes is one of the fundamental characteristics of living cells. Although selenium is an essential micronutrient, little is known about the cellular mechanisms of chemical species-specific selenium transport in fish. We report here the kinetic and pharmacological transport characteristics of selenite and its thiol (glutathione and l-cysteine) derivatives in primary cultures of hepatocytes and isolated enterocytes of rainbow trout. Findings from the current study suggest an apparent low-affinity linear transport system for selenite in both cell types. However, we recorded high-affinity Hill kinetics (Kd=3.61±0.28 μmol l–1) in enterocytes exposed to selenite in the presence of glutathione. The uptake of selenite in the presence of thiols was severalfold higher than uptake of selenite alone (at equimolar concentration) in both hepatocytes and enterocytes. Cellular accumulation of selenium was found to be energy independent. Interestingly, we observed a decrease in selenite transport with increasing pH, whereas selenite uptake increased with increasing pH in the presence glutathione in both cell types. The cellular uptake of selenite demonstrated a pronounced competitive interaction with a structurally similar compound, sulfite. The uptake of selenite as well as its thiol derivatives was found to be sensitive to the anion transport blocker DIDS, irrespective of the cell type. Inorganic mercury (Hg2+) elicited an inhibition of selenite transport in both cell types, but augmented the transport of reduced forms of selenite in hepatocytes. Based on the substrate choice and comparable pharmacological properties, we advocate that multiple anion transport systems are probably involved in the cellular transport of selenite in fish.
Minimum cost of transport in Asian elephants: do we really need a bigger elephant?
Authors: Langman Vaughan A. , Rowe Michael F. , Roberts Thomas J. , Langman Nathanial V. , Taylor Charles R.
Published: April 2012

Body mass is the primary determinant of an animal’s energy requirements. At their optimum walking speed, large animals have lower mass-specific energy requirements for locomotion than small ones. In animals ranging in size from 0.8 g (roach) to 260 kg (zebu steer), the minimum cost of transport (COTmin) decreases with increasing body size roughly as COTmin∝body mass (Mb)–0.316±0.023 (95% CI). Typically, the variation of COTmin with body mass is weaker at the intraspecific level as a result of physiological and geometric similarity within closely related species. The interspecific relationship estimates that an adult elephant, with twice the body mass of a mid-sized elephant, should be able to move its body approximately 23% cheaper than the smaller elephant. We sought to determine whether adult Asian and sub-adult African elephants follow a single quasi-intraspecific relationship, and extend the interspecific relationship between COTmin and body mass to 12-fold larger animals. Physiological and possibly geometric similarity between adult Asian elephants and sub-adult African elephants caused body mass to have a no effect on COTmin (COTmin∝Mb0.007±0.455). The COTmin in elephants occurred at walking speeds between 1.3 and ∼1.5 m s–1, and at Froude numbers between 0.10 and 0.24. The addition of adult Asian elephants to the interspecific relationship resulted in COTmin∝M–0.277±0.046b. The quasi-intraspecific relationship between body mass and COTmin among elephants caused the interspecific relationship to underestimate COTmin in larger elephants.
Audiogram and auditory critical ratios of two Florida manatees (Trichechus manatus latirostris)
Authors: Gaspard Joseph C. , Bauer Gordon B. , Reep Roger L. , Dziuk Kimberly , Cardwell Adrienne , Read LaToshia , Mann David A.
Published: April 2012

Manatees inhabit turbid, shallow-water environments and have been shown to have poor visual acuity. Previous studies on hearing have demonstrated that manatees possess good hearing and sound localization abilities. The goals of this research were to determine the hearing abilities of two captive subjects and measure critical ratios to understand the capacity of manatees to detect tonal signals, such as manatee vocalizations, in the presence of noise. This study was also undertaken to better understand individual variability, which has been encountered during behavioral research with manatees. Two Florida manatees (Trichechus manatus latirostris) were tested in a go/no-go paradigm using a modified staircase method, with incorporated ‘catch’ trials at a 1:1 ratio, to assess their ability to detect single-frequency tonal stimuli. The behavioral audiograms indicated that the manatees’ auditory frequency detection for tonal stimuli ranged from 0.25 to 90.5 kHz, with peak sensitivity extending from 8 to 32 kHz. Critical ratios, thresholds for tone detection in the presence of background masking noise, were determined with one-octave wide noise bands, 7–12 dB (spectrum level) above the thresholds determined for the audiogram under quiet conditions. Manatees appear to have quite low critical ratios, especially at 8 kHz, where the ratio was 18.3 dB for one manatee. This suggests that manatee hearing is sensitive in the presence of background noise and that they may have relatively narrow filters in the tested frequency range.
Head and body stabilization in blowflies walking on differently structured substrates
Authors: Kress Daniel , Egelhaaf Martin
Published: April 2012

Visually guided animals depend heavily on the quality of visual signals in order to obtain functionally relevant information about their environment. To support visual information processing, nature has evolved a large variety of physiological adaptations and behavioral strategies such as compensatory head movements. During self-movement, head rotations compensate for changes in body attitude in order to stabilize gaze. However, how walking animals cope with uneven structured substrates, which may affect body and gaze orientation, is still unknown. We used stereo high-speed video to analyze compensatory head movements of blowflies walking freely on differently structured substrates. We found that even a pronounced asperity of the ground structure, with bumps of almost the size of the animal, was largely compensated by the walking apparatus of the blowfly, which leads to body roll and pitch movements only marginally larger than those on flat substrate. Pitch and roll fluctuations of the head were smaller compared with body fluctuations on all tested substrates, emphasizing the significance of gaze stabilization during walking on structured substrates. Furthermore, we found no impairment in head and body stabilization during walks in darkness, which indicates that the control system mediating compensatory head movements works well without any visual input. Interestingly, blowflies changed their walking style in the dark and seemed to use their forelegs as tactile probes.
Prolonged fasting increases purine recycling in post-weaned northern elephant seals
Authors: Soñanez-Organis José Guadalupe , Vázquez-Medina José Pablo , Zenteno-Savín Tania , Aguilar Andres , Crocker Daniel E. , Ortiz Rudy M.
Published: April 2012

Northern elephant seals are naturally adapted to prolonged periods (1–2 months) of absolute food and water deprivation (fasting). In terrestrial mammals, food deprivation stimulates ATP degradation and decreases ATP synthesis, resulting in the accumulation of purines (ATP degradation byproducts). Hypoxanthine-guanine phosphoribosyl transferase (HGPRT) salvages ATP by recycling the purine degradation products derived from xanthine oxidase (XO) metabolism, which also promotes oxidant production. The contributions of HGPRT to purine recycling during prolonged food deprivation in marine mammals are not well defined. In the present study we cloned and characterized the complete and partial cDNA sequences that encode for HGPRT and xanthine oxidoreductase (XOR) in northern elephant seals. We also measured XO protein expression and circulating activity, along with xanthine and hypoxanthine plasma content in fasting northern elephant seal pups. Blood, adipose and muscle tissue samples were collected from animals after 1, 3, 5 and 7 weeks of their natural post-weaning fast. The complete HGPRT and partial XOR cDNA sequences are 771 and 345 bp long and encode proteins of 218 and 115 amino acids, respectively, with conserved domains important for their function and regulation. XOR mRNA and XO protein expression increased 3-fold and 1.7-fold with fasting, respectively, whereas HGPRT mRNA (4-fold) and protein (2-fold) expression increased after 7 weeks in adipose tissue and muscle. Plasma xanthine (3-fold) and hypoxanthine (2.5-fold) levels, and XO (1.7- to 20-fold) and HGPRT (1.5- to 1.7-fold) activities increased during the last 2 weeks of fasting. Results suggest that prolonged fasting in elephant seal pups is associated with increased capacity to recycle purines, which may contribute to ameliorating oxidant production and enhancing the supply of ATP, both of which would be beneficial during prolonged food deprivation and appear to be adaptive in this species.
Active electrolocation in pulse gymnotids: sensory consequences of objects’ mutual polarization
Authors: Aguilera Pedro A. , Pereira Ana Carolina , Caputi Ángel A.
Published: April 2012

We examined non-linear effects of the presence of one object on the electric image of another placed at the foveal region in Gymnotus omarorum. The sensory consequences of object mutual polarization on electric images were also depicted using behavioral procedures. Image measurements show that objects whose electric image is not detectable may modify the electric image of another placed closer to the fish and suggest that detection range and discrimination parameters used for one object may be affected when the presence of others enriches the scene. Behavioral experiments confirm that these changes in object images resulting from mutual polarization may be exploited for improving perception. While conductive objects close to the skin allow the fish to detect other objects placed out of the active electrodetection range, non-conductive objects may hide objects that otherwise show clear electric images. This suggests that fish movements may orient the self-generated field to exploit object mutual polarization, increasing or decreasing the active electrolocation range. In addition, images of a nearby object may be modulated by the presence of another object placed outside the detection range and the corresponding behavioral responses suggest that a moving or impedance-changing context may modify a fish’s discrimination abilities for closer objects.
Active sensing via movement shapes spatiotemporal patterns of sensory feedback
Authors: Stamper Sarah A. , Roth Eatai , Cowan Noah J. , Fortune Eric S.
Published: April 2012

Previous work has shown that animals alter their locomotor behavior to increase sensing volumes. However, an animal’s own movement also determines the spatial and temporal dynamics of sensory feedback. Because each sensory modality has unique spatiotemporal properties, movement has differential and potentially independent effects on each sensory system. Here we show that weakly electric fish dramatically adjust their locomotor behavior in relation to changes of modality-specific information in a task in which increasing sensory volume is irrelevant. We varied sensory information during a refuge-tracking task by changing illumination (vision) and conductivity (electroreception). The gain between refuge movement stimuli and fish tracking responses was functionally identical across all sensory conditions. However, there was a significant increase in the tracking error in the dark (no visual cues). This was a result of spontaneous whole-body oscillations (0.1 to 1 Hz) produced by the fish. These movements were costly: in the dark, fish swam over three times further when tracking and produced more net positive mechanical work. The magnitudes of these oscillations increased as electrosensory salience was degraded via increases in conductivity. In addition, tail bending (1.5 to 2.35 Hz), which has been reported to enhance electrosensory perception, occurred only during trials in the dark. These data show that both categories of movements – whole-body oscillations and tail bends – actively shape the spatiotemporal dynamics of electrosensory feedback.
Fracture toughness of locust cuticle
Authors: Dirks Jan-Henning , Taylor David
Published: April 2012

Insect cuticle is one of the most common biological materials, yet very little is known about its mechanical properties. Many parts of the insect exoskeleton, such as the jumping legs of locusts, have to withstand high and repeated loading without failure. This paper presents the first measurements of fracture toughness for insect cuticle using a standard engineering approach. Our results show that the fracture toughness of cuticle in locust hind legs is 4.12 MPa m1/2 and decreases with desiccation of the cuticle. Stiffness and strength of the tibia cuticle were measured using buckling and cantilever bending and increased with desiccation. A combination of the cuticle’s high toughness with a relatively low stiffness of 3.05 GPa results in a work of fracture of 5.56 kJ m–2, which is amongst the highest of any biological material, giving the insect leg an exceptional ability to tolerate defects such as cracks and damage. Interestingly, insect cuticle achieves these unique properties without using reinforcement by a mineral phase, which is often found in other biological composite materials. These findings thus might inspire the development of new biomimetic composite materials.
Developmental phenotypic plasticity in a marsupial
Authors: Riek Alexander , Geiser Fritz
Published: April 2012

Climate change is likely to substantially affect the distribution ranges of species. However, little is known about how different mammalian taxa respond morphologically and physiologically to a rapid change of climate. Our objective was to provide the first quantitative data on the effect of continuous cold exposure during development on morphological and functional variables of a marsupial. Fat-tailed dunnarts (Sminthopsis crassicaudata, Dasyuridae) were reared at an ambient temperature (Ta) of 16°C [cold-reared (CR)] or 22°C [warm-reared (WR)] until they reached adult age (>200 days). Body and head length of CR animals were significantly longer than in WR animals (mean ± s.e.m.; body: CR 80.8±6 mm, WR 76.4±5 mm; head: CR 29.4±3 mm, WR 27.5±2 mm), but other body attributes were not significantly different. Use of torpor was more frequent, torpor bout duration was longer and average daily metabolic rate and percentage of savings when using torpor were significantly higher (P<0.01) in CR than in WR animals at 16°C Ta but not at 24°C. Furthermore, resting metabolic rates measured at 16°C Ta were significantly lower in CR than WR animals; at 30°C Ta values were similar. Our results do not conform to Allen’s rule, but to some extent they do conform to Bergmann’s rule. However, the data demonstrate that a relatively moderate cold exposure from birth until adulthood induces marked changes in the morphology and thermal energetics of small marsupials. Such short-term phenotypic responses without the need for long-term selection are likely important for the ability to cope with different climates over a wide range of distribution, but will also play a crucial role in enhancing the survival of species during climate change.
Morin exerts antiosteoarthritic properties: an in vitro and in vivo study
Authors: Chen Wei-Ping , Hu Peng-Fei , Bao Jia-Peng , Wu Li-Dong
Published: April 2012

Morin is a flavonoid isolated from members of the Moraceae family. Morin has been reported to possess antioxidative and anticarcinogenic activities. However, the antiosteoarthritic properties of morin have not been investigated. In this study, we evaluate the antiarthritic properties of morin through in vitro and in vivo studies. We examined the effects of morin on the expression levels of matrix metalloproteinase (MMP)-3, MMP-13 and tissue inhibitors of metalloproteinase (TIMP)-1 in interleukin-1 β (IL-1 β)-induced rat chondrocytes by realtime polymerase chain reaction and Western blotting. The effects of morin on the phosphorylation of mitogen-activated protein kinases were also investigated. The in vivo antiosteoarthritic effects of morin were evaluated in the rat model of anterior cruciate ligament transection (ACLT)-induced osteoarthritis (OA). We found that morin inhibited the expression of MMP-3 and MMP-13 and increased the expression of TIMP-1 in IL-1 β-induced rat chondrocytes. In addition, morin inhibited IL-1 β-induced phosphorylation of extracellular signal-regulated kinase and p38. For the in vivo study in a rat model of OA induced by ACLT, in which morin was orally administered to rat, the results show that morin suppressed cartilage degradation. Our results suggest that morin may be considered as a possible therapeutic agent for the treatment of OA.
Osteogenic activity of silymarin through enhancement of alkaline phosphatase and osteocalcin in osteoblasts and tibia-fractured mice
Authors: Kim Jung-Lye , Park Sin-Hye , Jeong Daewon , Nam Ju-Suk , Kang Young-Hee
Published: April 2012

Bone-remodeling imbalance induced by increased bone resorption and osteoclast formation is known to cause skeletal diseases such as osteoporosis. There has been growing interest in the anabolic natural agents that enhance bone formation. Silymarin is flavonolignans extracted from blessed milk thistle. Several studies suggest that silymarin possesses antihepatotoxic properties and anticancer effects against carcinoma cells. This study investigated promoting effects of silymarin on differentiation and mineralization of osteoblastic MC3T3-E1 mouse cells and on bone mineral density (BMD) by in vivo fracture experiments. Osteoblasts were treated with 1–20 μmol/L silymarin for 15 days in a differentiating medium. In addition, this study explored signaling pathways implicated in the osteoblastogenesis of silymarin. It was found that silymarin stimulated alkaline phosphatase (ALP) activity and calcium nodule formation in a dose-dependent manner with a substantial effect on osteoblast proliferation. Silymarin treatment enhanced collagen secretion, osteocalcin transcription and bone morphogenetic protein (BMP) expression. The BMP inhibitor noggin suppressed the silymarin-promoted ALP activity in differentiated osteoblasts, suggesting that its osteoblastogenic actions entail the BMP pathway. This was proved by increased SMAD1/5/8 phosphorylation and runt-related transcription factor 2 (Runx2) expression in the presence of silymarin. In 21-day fracture-healing experiments, fractured and silymarin (10 mg/kg)-treated C57BL/6 mice showed better bone healing than fractured mice. Silymarin supplementation improved tibial bone strength with elevated BMD and serum levels of osteogenic ALP and osteocalcin. Taken together, these results demonstrate, for the first time, that silymarin has a potential to enhance osteoblastogenesis through accelerating BMP/SMAD/Runx2 signal pathways and to improve fracture healing and bone strength in mouse tibiae.
Renal transplant ultrasound: a pictorial review
Authors: Belfield Jane C , Griffin Colin P , Powell Steven
Published: April 2012

Renal transplantation is considered the optimal treatment in patients with end-stage renal disease. Ultrasound is usually the first choice imaging modality for evaluating renal transplant anatomy and perfusion. It is important to be aware of how to image a renal transplant, the normal sonographic appearances and relevant pathological processes. Renal transplant ultrasound imaging includes duplex vascular evaluation and the operator must have a sound knowledge of both normal and abnormal Doppler waveforms. Complications following renal transplantation are usually assessed with ultrasound. The time frame in which complications can occur stretches from the immediate postoperative period to months or years following transplantation. A knowledge of the anticipated complications relative to that timescale helps to focus the examination. This pictorial review aims to demonstrate the appearances of the normal renal transplant as well as potential complications. These include vascular (renal vein thrombosis, renal artery stenosis, pseudoaneurysm and arteriovenous fistulae), parenchymal (acute rejection, acute tubular necrosis and malignancy) and urological (ureteric stricture and renal calculi) complications.
A short PPR protein required for the splicing of specific group II introns in angiosperm chloroplasts
Authors: Khrouchtchova Anastassia , Monde Rita-Ann , Barkan Alice
Published: April 2012

A maize gene designated thylakoid assembly 8 (tha8) emerged from a screen for nuclear mutations that cause defects in the biogenesis of chloroplast thylakoid membranes. The tha8 gene encodes an unusual member of the pentatricopeptide repeat (PPR) family, a family of helical repeat proteins that participate in various aspects of organellar RNA metabolism. THA8 localizes to chloroplasts, where it associates specifically with the ycf3-2 and trnA group II introns. The splicing of ycf3-2 is eliminated in tha8 mutants, and trnA splicing is strongly compromised. Reverse-genetic analysis of the tha8 ortholog in Arabidopsis thaliana showed that these molecular functions are conserved, although null alleles are embryo lethal in Arabidopsis and seedling lethal in maize. Whereas most PPR proteins have more than 10 PPR motifs, THA8 belongs to a subfamily of plant PPR proteins with only four PPR motifs and little else. THA8 is the first member of this subfamily with a defined molecular function, and illustrates that even small PPR proteins have the potential to mediate specific intermolecular interactions in vivo.
Social Sharing of Information Goods: Implications for Pricing and Profits
Authors: Galbreth Michael R. , Ghosh Bikram , Shor Mikhael
Published: April 2012

Social sharing of information goods—wherein a single good is purchased and shared through a network of acquaintances such as friends or coworkers—is a significant concern for the providers of these goods. The effect of social sharing on firm pricing and profits depends critically on two elements: the structure of the underlying consumer network and the mechanism used by groups to decide whether to purchase at a given price. We examine the effect of social sharing under different network structures (decentralized, centralized, and complete), which reflect a range of market conditions. Moreover, we draw from the mechanism design literature to examine several approaches to group decision making. Our results suggest that a firm can benefit from increased social sharing if the level of sharing is already high, enabling a pricing strategy targeted primarily at sharing groups rather than individuals. However, the point at which sharing becomes marginally beneficial for a firm depends on both the distribution of group sizes (which derives from the network structure) and the group decision mechanism. Additional insights are obtained when we extend the model to capture homophily in group formation and the potential that a subset of consumers will never share for ethical reasons.
Optimal Admission and Scholarship Decisions: Choosing Customized Marketing Offers to Attract a Desirable Mix of Customers
Authors: Belloni Alexandre , Lovett Mitchell J. , Boulding William , Staelin Richard
Published: April 2012

Each year in the postsecondary education industry, schools offer admission to nearly 3 million new students and scholarships totaling nearly $100 billion. This is a large, understudied targeted marketing and price discrimination problem. This problem falls into a broader class of configuration utility problems (CUPs), which typically require an approach tailored to exploit the particular setting. This paper provides such an approach for the admission and scholarship decisions problem. The approach accounts for the key distinguishing feature of this industry—schools value the average features of the matriculating students such as percent female, percent from different regions of the world, average test scores, and average grade point average. Thus, as in any CUP, the value of one object (i.e., student) cannot be separated from the composition of all of the objects (other students in the enrolling class). This goal of achieving a class with a desirable set of average characteristics greatly complicates the optimization problem and does not allow the application of standard approaches. We develop a new approach that solves this more complex optimization problem using an empirical system to estimate each student's choice and the focal school's utility function. We test the approach in a field study of an MBA scholarship process and implement adjusted scholarship decisions. Using a holdout sample, we provide evidence that the methodology can lead to improvements over current management decisions. Finally, by comparing our solution to what management would do on its own, we provide insight into how to improve management decisions in this setting.
Network Traces on Penetration: Uncovering Degree Distribution from Adoption Data
Authors: Dover Yaniv , Goldenberg Jacob , Shapira Daniel
Published: April 2012

We show how networks modify the diffusion curve by affecting its symmetry. We demonstrate that a network's degree distribution has a significant impact on the contagion properties of the subsequent adoption process, and we propose a method for uncovering the degree distribution of the adopter network underlying the dissemination process, based exclusively on limited early-stage penetration data. In this paper we propose and empirically validate a unified network-based growth model that links network structure and penetration patterns. Specifically, using external sources of information, we confirm that each network degree distribution identified by the model matches the actual social network that is underlying the dissemination process. We also show empirically that the same method can be used to forecast adoption using an estimation of the degree distribution and the diffusion parameters at an early stage (15%) of the penetration process. We confirm that these forecasts are significantly superior to those of three benchmark models of diffusion.

Our empirical analysis indicates that under heavily right-skewed degree distribution conditions (such as scale-free networks), the majority of adopters (in some cases, up to 75%) join the process after the sales peak. This strong asymmetry is a result of the unique interaction between the dissemination process and the degree distribution of its underlying network.
Error Prevention Strategies for Strong Iodine Solution; Do Not Use an Insulin Pen for Multiple Patients
Authors: Cohen Michael R. , Smetzer Judy L.
Published: April 2012

These medication errors have occurred in health care facilities at least once. They will happen again—perhaps where you work. Through education and alertness of personnel and procedural safeguards, they can be avoided. You should consider publishing accounts of errors in your newsletters and/or presenting them at your inservice training programs.

Your assistance is required to continue this feature. The reports described here were received through the Institute for Safe Medication Practices (ISMP) Medication Errors Reporting Program. Any reports published by ISMP will be anonymous. Comments are also invited; the writers' names will be published if desired. ISMP may be contacted at the address shown below.

Errors, close calls, or hazardous conditions may be reported directly to ISMP through the ISMP Web site ( www.ismp.org ), by calling 800-FAIL-SAFE, or via e-mail at ismpinfo@ismp.org . ISMP guarantees the confidentiality and security of the information received and respects reporters' wishes as to the level of detail included in publications.
Pimecrolimus (Topical): Rosacea
Authors: Generali Joyce A. , Cada Dennis J.
Published: April 2012

This Hospital Pharmacy feature is extracted from Off-Label Drug Facts, a quarterly publication available from Wolters Kluwer Health. Off-Label Drug Facts is a practitioner-oriented resource for information about specific drug uses that are unapproved by the US Food and Drug Administration. This new guide to the literature enables the health care professional or clinician to quickly identify published studies on off-label uses and determine if a specific use is rational in a patient care scenario. References direct the reader to the full literature for more comprehensive information before patient care decisions are made. Direct questions or comments regarding Off-Label Drug Uses to jgeneral@kumc.edu .
Symptomatic Bradycardia, Syncope, and Prolonged QTc Interval Associated with Dronedarone Therapy
Authors: Eppert Heather Draper , Goddard Kara B.
Published: April 2012

Objective

To report a case of symptomatic bradycardia, prolonged QT interval, and syncope associated with dronedarone in a patient with atrial fibrillation who was maintained in sinus rhythm.

Case Summary

A 58-year-old man presented to the emergency department with a chief complaint of chest pain and “passing out.” Three months prior, dronedarone had been initiated for maintenance of sinus rhythm. An initial electrocardiogram (ECG) revealed normal sinus rhythm with a prolonged corrected QT (QTc) interval of 645 ms. Upon hospital admission, dronedarone was discontinued. Approximately 17 hours after hospitalization and 35 hours after the last ingested dronedarone dose, a repeat ECG revealed a QTc interval of 457 ms, and the patient reported symptomatic improvement. The patient was discharged home after a 3-day hospital stay without further event. The Naranjo Adverse Drug Reaction Probability Scale indicated a probable relationship between the patient's symptoms and dronedarone.

Discussion

Dronedarone is an antiarrhythmic drug that exhibits multiple mechanisms of action, including potassium, sodium, and calcium channel blockade, in addition to antiadrenegic activity. In clinical evaluations of dronedarone therapy, dronedarone was associated with a mean decrease in resting heart rate and potential to prolong the QT interval by 10 ms. These effects may result in clinically significant outcomes, as was observed in this patient.

Conclusions

This case of symptomatic bradycardia and prolonged QTc interval emphasizes the importance of monitoring the heart rate and ECG in patients prescribed dronedarone, particularly in those on concomitant drug therapy that may precipitate these events.
Extended Stability of Magnesium Sulfate Infusions Prepared in Polyolefin Bags
Authors: Sayre Brian E. , Prettyman Terrence , Kaushal Gagan
Published: April 2012

Purpose

To investigate the stability of extemporaneously compounded 50 g per 600 mL magnesium sulfate parenteral solution diluted in Lactated Ringer's solution.

Methods

The sterile preparations of magnesium sulfate were compounded in accordance with USP <797> standards. To carry out the stability testing, these products were stored under 3 different temperature conditions of −20°C, 2°C to 6°C, and 22°C to 25°C. Under the stability studies, pH, particulate matter, and the active content were monitored for 30 days.

Results

Magnesium sulfate infusions are stable for 30 days when stored at −20°C or 2°C to 6 °C and stable for 30 days under all the temperature conditions studied. These data demonstrate that magnesium sulfate infusions have an extended physical and chemical stability after preparation.

Conclusions

The stability analysis results show that the shelf-life observed was far better than their recommended expiration dates. This will allow the hospitals to give longer dating to magnesium sulfate preparations, provided they are prepared in a sterile environment and are in compliance with USP <797> guidelines.