bluuebunny/crossref_metadata_2025 huggingface dataset:
Gene expression profiling reveals that the regulation of estrogen-responsive element-independent genes by 17β-estradiol-estrogen receptor β is uncoupled from the induction of phenotypic changes in cell models
Authors: Li Xiaodong , Nott Stephanie L , Huang Yanfang , Hilf Russell , Bambara Robert A , Qiu Xing , Yakovlev Andrei , Welle Stephen , Muyan Mesut
Published: April 2008

Estrogen hormone 17β-estradiol (E2) is involved in the physiology and pathology of many tissues. E2 information is conveyed by the transcription factors estrogen receptors (ER) α and β that mediate a complex array of nuclear and non-nuclear events. The interaction of ER with specific DNA sequences, estrogen-responsive elements (EREs), constitutes a critical nuclear signaling pathway. In addition, E2-ER regulates transcription through interactions with transfactors bound to their cognate regulatory elements on DNA, hence the ERE-independent signaling pathway. However, the relative importance of the ERE-independent pathway in E2-ERβ signaling is unclear. To address this issue, we engineered an ERE-binding defective ERβ mutant (ERβEBD) by changing critical residues in the DNA-binding domain required for ERE binding. Biochemical and functional studies revealed that ERβEBD signaled exclusively through the ERE-independent pathway. Using the adenovirus infected ER-negative cancer cell models, we found that although E2-ERβEBD regulated the expression of a number of genes identified by microarrays, it was ineffective in altering cellular proliferation, motility, and death in contrast to E2-ERβ. Our results indicate that genomic responses from the ERE-independent pathway to E2-ERβ are not sufficient to alter the cellular phenotype. These findings suggest that the ERE-dependent pathway is a required signaling route for E2-ERβ to induce cellular responses.
Sub-chronic stimulation of glucocorticoid receptor impairs and mineralocorticoid receptor protects cytosolic Ca2+ responses to glucose in pancreatic β-cells
Authors: Koizumi Masaru , Yada Toshihiko
Published: April 2008

The development of diabetes associated with stress, obesity, and metabolic syndrome involves elevated plasma glucocorticoid levels. It has been shown that short-term (<1 day) exposure to glucocorticoids reduces insulin secretion from pancreatic islets by affecting several steps of glucose signaling in β-cells. However, longer term direct effects of glucocorticoids on β-cells remain to be established. In this study, single β-cells isolated from rat islets were treated with glucocorticoids, mineralocorticoids, and their receptor agonists/antagonists for 3 days in culture, followed by assessment of the β-cell responsiveness to glucose by measuring cytosolic Ca2+ concentration ([Ca2+]i) using fura-2. Following treatment with corticosterone at 10–500 ng/ml for 3 days, the first-phase [Ca2+]i response to 8.3 mM glucose in β-cells was suppressed. Simultaneous administration of RU-486, a glucocorticoid receptor (GR) antagonist, prevented this suppression. RU-486 by itself promoted the β-cell [Ca2+]i response to glucose. Conversely, dexamethasone (1000 ng/ml), a highly selective GR agonist, impaired β-cell [Ca2+]i responses to glucose. A mineralocorticoid receptor (MR) antagonist spironolactone, co-administered with corticosterone, further depressed [Ca2+]i responses to glucose, while an MR ligand aldosterone attenuated the corticosterone inhibition of [Ca2+]i responses. Neither spironolactone nor aldosterone by itself affected [Ca2+]i responses. These results indicate that long-term treatment with corticosterone impairs β-cell [Ca2+]i responses to glucose. This effect is mediated by GR and attenuated partially by simultaneous MR stimulation by corticosterone. The results show a novel function of MR to protect islet β-cells against deteriorating glucocorticoid action via GR.
Epidermal growth factor receptor activation by protein kinase C is necessary for FSH-induced meiotic resumption in porcine cumulus–oocyte complexes
Authors: Chen Xiufen , Zhou Bo , Yan Jun , Xu Baoshan , Tai Ping , Li Junxia , Peng Shiming , Zhang Meijia , Xia Guoliang
Published: April 2008

It is proved that epidermal growth factor (EGF)-like factors mediate gonadotropin-induced rodent oocyte maturation via EGF receptor (EGFR). However, the detail kinetics and signal pathway between FSH and EGF/EGFR is not clear in large animals. In the present study, we investigated the roles of EGFR and protein kinase C (PKC) in FSH-induced porcine oocyte meiotic resumption. Porcine cumulus–oocyte complexes were cultured in NCSU37 medium containing 10% porcine follicular fluid and germinal vesicle breakdown (meiotic resumption) was detected after different treatments. The results showed that EGF-like factor amphiregulin (AR) and EGFR mRNA were expressed in porcine cumulus cells, but not oocytes. FSH significantly induced AR mRNA expression with maximum at 4 h and activated EGFR phosphorylation at 8 h. AR (1–100 ng/ml) dose-dependently induced meiosis resumption of porcine oocyte. The specific EGFR inhibitor, AG1478, but not AG43 (the inactive analog of AG1478), completely blocked FSH, EGF, and AR-induced oocyte meiotic resumption; the inhibitory effect of AG1478 on FSH action gradually decreased when the inhibitor was added at 6 h or later and disappeared when it was added at 11 h; EGF reversed the inhibitory effect on FSH when AG1478 was added within 6 h. FSH triggered porcine oocyte meiotic resumption (at 20 h) later than that of EGF and AR (at 18 h). All these results supported that endogenously produced EGFR activator(s), possibly AR (maximum at 4 h) and EGFR activation (began at 6 h and finished within 11 h), in cumulus cells is necessary for FSH-induced porcine oocyte meiotic resumption (began at 18 h). Furthermore, PKC activator PMA mimicked but PKC inhibitor chelerythrine chloride inhibited FSH action, and AG1478 also suppressed PMA-induced porcine oocyte meiotic resumption. These data together suggested that EGFR activation, by PKC signal pathway, participates in FSH-induced porcine oocyte meiotic resumption.
IGF-II/mannose-6-phosphate receptor signaling induced cell hypertrophy and atrial natriuretic peptide/BNP expression via Gαq interaction and protein kinase C-α/CaMKII activation in H9c2 cardiomyoblast cells
Authors: Chu Chun-Hsien , Tzang Bor-Show , Chen Li-Mien , Kuo Chia-Hua , Cheng Yi-Chang , Chen Ling-Yun , Tsai Fuu-Jen , Tsai Chang-Hai , Kuo Wei-Wen , Huang Chih-Yang
Published: April 2008

The role played by IGF-II in signal transduction through the IGF-II/mannose-6-phosphate receptor (IGF2R) in heart tissue has been poorly understood. In our previous studies, we detected an increased expression of IGF-II and IGF2R in cardiomyocytes that had undergone pathological hypertrophy. We hypothesized that after binding with IGF-II, IGF2R may trigger intracellular signaling cascades involved in the progression of pathologically cardiac hypertrophy. In this study, we used immunohistochemical analysis of the human cardiovascular tissue array to detect expression of IGF2R. In our study of H9c2 cardiomyoblast cell cultures, we used the rhodamine phalloidin staining to measure the cell hypertrophy and western blot to measure the expression of cardiac hypertrophy markers atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in cells treated with IGF-II. We found that a significant association between IGF2R overexpression and myocardial infarction. The treatment of H9c2 cardiomyoblast cells with IGF-II not only induced cell hypertrophy but also increased the protein level of ANP and BNP. Using Leu27IGF-II, an analog of IGF-II which interacts selectively with the IGF2R, to specifically activate IGF2R signaling cascades, we found that binding of Leu27IGF-II to IGF2R led to an increase in the phosphorylation of protein Kinase C (PKC)-α and calcium/calmodulin-dependent protein kinase II (CaMKII) in a Gαq-dependent manner. By the inhibition of PKC-α/CaMKII activity, we found that IGF-II and Leu27IGF-II-induced cell hypertrophy and upregulation of ANP and BNP were significantly suppressed. Taken together, this study provides a new insight into the effects of the IGF2R and its downstream signaling in cardiac hypertrophy. The suppression of IGF2R signaling pathways may be a good strategy to prevent the progression of pathological hypertrophy.
Acute elevation of circulating fatty acids impairs downstream insulin signalling in rat skeletal muscle in vivo independent of effects on stress signalling
Authors: Frangioudakis Georgia , Cooney Gregory J
Published: April 2008

The aim of this study was to examine the effect of an acute, physiological increase in plasma free fatty acid (FFA) on initial signalling events in rat red quadriceps muscle (RQ). Male Wistar rats received a 7% glycerol (GLYC) or 7% Intralipid/heparin (LIP) infusion for 3 h, after which they were either killed or infused with insulin at a rate of 0.5 U/kg per h for 5 min, before RQ collection. Plasma FFAs were elevated to ∼2 mM in the LIP rats only. Insulin-stimulated insulin receptor (IR) Tyr1162/Tyr1163 phosphorylation and IR substrate (IRS)-1 Tyr612 phosphorylation were increased at least twofold over basal in GLYC rats with insulin and this increase was not significantly impaired in the LIP rats. However, there was no insulin-stimulated protein kinase B (PKB) Ser473 or glycogen synthase kinase (GSK)-3β Ser9 phosphorylation in the LIP rats, compared with at least a twofold increase over basal in GLYC rats for both proteins. c-Jun N-terminal kinase, inhibitor of κ kinase β and inhibitor of nuclear factor-κB phosphorylation and total protein expression, as well as Ser307-IRS-1 phosphorylation, were not altered by lipid infusion compared with GLYC infusion. These data indicate that acute, physiological elevation in FFA has a greater impact on insulin signalling downstream of IR and IRS-1, at the level of PKB and GSK-3β, and that under these conditions stress signalling pathways are not significantly stimulated. Decreased PKB and GSK-3β phosphorylation in RQ may therefore be primary determinants of the reduced insulin action observed in situations of acute FFA oversupply.
Real-time analysis of gene regulation by glucocorticoid hormones
Authors: McMaster A , Chambers T , Meng Q-J , Grundy S , Loudon A S I , Donn R , Ray D W
Published: April 2008

There is increasing evidence that temporal factors are important in allowing cells to gain additional information from external factors, such as hormones and cytokines. We sought to discover how cell responses to glucocorticoids develop over time, and how the response kinetics vary according to ligand structure and concentration, and hence have developed a continuous gene transcription measurement system, based on an interleukin-6 (IL-6) luciferase reporter gene. We measured the time to maximal response, maximal response and integrated response, and have compared these results with a conventional, end point glucocorticoid bioassay. We studied natural glucocorticoids (corticosterone and cortisol), synthetic glucocorticoids (dexamethasone) and glucocorticoid precursors with weak, or absent bioactivity. We found a close correlation between half maximal effective concentration (EC50) for maximal response, and for integrated response, but with consistently higher EC50 for the latter. There was no relation between the concentration of ligand and the time to maximal response. A comparison between conventional end point assays and real-time measurement showed similar effects for dexamethasone and hydrocortisone, with a less effective inhibition of IL-6 seen with corticosterone. We profiled the activity of precursor steroids, and found pregnenolone, progesterone, 21-hydroxyprogesterone and 17-hydroxyprogesterone all to be ineffective in the real-time assay, but in contrast, progesterone and 21-hydroxyprogesterone showed an IL-6 inhibitory activity in the end point assay. Taken together, our data show how ligand concentration can alter the amplitude of glucocorticoid response, and also that a comparison between real-time and end point assays reveals an unexpected diversity of the function of glucocorticoid precursor steroids, with implications for human disorders associated with their overproduction.
Probabilistic assessment of small earthfill dams
Authors: Preziosi Marie-Christine
Published: April 2008

This paper focuses on a generic earthfill dam model and investigates, probabilistically, downstream and upstream slope stability, as significant limit states governing the long-term performance. Specific variables that define failure modes are identified and their probabilistic models defined. A parametric analysis is performed, using a simplified soil model, for different upstream and downstream slope gradients to evaluate notional reliabilities against slope failure. This is achieved using standard first-order second-moment reliability analysis. On the basis of these analyses, a methodology for sitespecific effects such as deterioration, maintenance patterns and the impact of climate change can be proposed.
A modern risk-based approach to reservoir regulation
Authors: Rooke David
Published: April 2008

The Environment Agency (EA) was tested to the full by the floods in England and Wales during summer 2007. The EA's Review of 2007 Summer Floods highlights several lessons that can be learned and issues that can be addressed to improve future performance. It also outlines steps to be taken by government. This paper reviews the last EA biennial report, places the issues in the context of climate change and explains the legislative changes that the EA believes necessary to build on the UK's already impressive reservoir safety record.
New Water-Soluble Polymer for Drilling Fluids
Authors: Bielewicz Danuta , Kraj Lucja , Bortel Edgar , Witek Ewa
Published: April 2008

The new water-soluble polymer designed for improving of drilling muds used in oil-well borings, is constituted by two comonomers from which the one is a sulfonic group containing electrolyte, the other is afforded by a non dissociating water-soluble compound.

The polymer designed as CAA-5 diminishes effectively the filtration even if the concentration used is very low, not exceeding 0,25%-w/w. As a consequence that polymer renders it possible to prepare mud containing a small number of components in presence of as little as 2%-wgt of bentonite. The system proves to be stable towards 10% wgt of monovalent salts. The additional of biopolymer XCD improves the stability against bivalent salts. After heating of the mud up to 70°C (158°F) over 16 hours the fluid was increased not significantly.

By the use of CAA-5 it was possible to prepare a drilling mud MMH (Mixed Metal Hydroxide) distinguished by good rheological and filtrational parameters. At low concentration the CAA-5 polymer is an effective flocculant in muds containing a large number of components, being highly mineralized.

The CAA-5 polymer can also be applied as an auxiliary agent in slurries used in geotechnical entertainments (drainage rows, screens etc.). Such an suspensions undergoes a degradation caused by calcium hypochlorite.

In the paper are presented results on applying of CAA-5 polymer to drilling fluids.
Periodic Effect of Pressure and Temperature on Flow Phenomena in Porous Media
Authors: Lakatos I. , Tóth J. , Lakatos-Szabó J. , Rayes B. H. , Hlatki M. , Vágó Á.
Published: April 2008

The paper deals with the effect of pressure and temperature fluctuation characteristic in underground gas storage facilities on gas permeability of natural sandstone cores. Primary aim of the laboratory studies was to develop an appropriate method which might simultaneously restrict water imbibition and improve rock stability in vicinity of both producing and injection gas wells. The hypothetical method is based on hydrophobization of rock surface by different silicone compounds and asphaltenes or asphaltene-containing natural hydrocarbons. The paper provides new information for behavior of treated and non-treated cores, particularly for their gas permeability as a function of cycle number, absolute gas permeability and type of treating agents. It is also demonstrated that water content (saturation) of the porous media fundamentally influences the adsorption of asphaltenes, and hence, the efficiency of hydrophobization, wettability alteration. Despite substantial progress in the topic, some questions remained open and these "white spots" must be answered if a reliable and efficient well treatment methods should be developed for stabilization of gas wells operating in gas fields and underground gas storage facilities.
Ultra Light Well Architecture in Ultradeep Waters: Application of the "BARBI Concept" Reduces CAPEX
Authors: Bianco Luis C. B. , Barata Paulo A. , Rosa Fabio S. N. , Aragäo Ätila F. L. , Santos Paulo S. Batista , Stepkowski Alejandro T.
Published: April 2008

The BARBI Concept was a result of an integrated project targeted to drilling and production operations in deep and ultradeep waters, with the main goal of reducing the well construction costs and enhancing productivity. Based on the new available technologies for drilling and completion, improvements on the well design were made. Time reduction on the execution was attained by the decrease on the number of drilling phases, speeding up well construction by the extensive use of rotary steerable tool, use of expandable sand screens and synthetic base mud for the drilling and completion phases, and simplification on the operational procedures. The increase in well productivity was a result of the lower formation damage due to the design fluid and the use of larger screens ID that led to a more uniform oil influx, which potentially delays the water breakthrough. Substantial cost reduction on the CAPEX was achieved and this paper discusses the application of the new concept in horizontal well construction that is being applied in Campos Basin.
Assessing the Validity of a Single-Item HIV Risk Stage-of-Change Measure
Authors: Napper Lucy E. , Branson Catherine M. , Fisher Dennis G. , Reynolds Grace L. , Wood Michelle M.
Published: April 2008

This study examined the validity of a single-item measure of HIV risk stage of change that HIV prevention contractors were required to collect by the California State Office of AIDS. The single-item measure was compared to the more conventional University of Rhode Island Change Assessment (URICA). Participants were members of Los Angeles County-defined behavioral risk groups recruited from a mobile HIV testing program ( N = 123). The study found low correspondence between participants' stage of change on the single-item and the URICA, suggesting that they do not assess the same construct, and that the single item may not provide a valid measure. The current data suggests that the single-item measure should be revised or abandoned in favor of more conventional stage-of-change measures.
An Evaluation of Youth Empowerment Tobacco Prevention Programs in the Southwest
Authors: Marr-Lyon Lisa , Young Kathleen , Quintero Gilbert
Published: April 2008

Evaluation research pertaining to the development of assessment instruments that fully capture the facets of empowerment prevention perspectives among youth are sparse. With funding from the American Legacy Foundation, the University of New Mexico Center for Health Promotion and Disease Prevention, in partnership with the New Mexico State Department of Health, developed a measure of individual empowerment. Drawing from the various bodies of literature in adolescent development, substance abuse prevention, and program/coalition building, a questionnaire was developed to capture facets of individual empowerment as it pertains to tobacco prevention efforts among youth within New Mexico. Utilizing a sample of 112 youth participants, principal axis factor analysis with Varimax rotation revealed four valid sub-scales entitled active participation, empowerment efficacy, external organizational involvement, and participant satisfaction. Internal consistency reliabilities were satisfactory with Cronbach's alpha ranging from .78 to .84. Regression mediation analysis revealed that active participation mediated the relationship of empowerment efficacy and self-esteem. Challenges associated with conceptualizing and assessing empowerment among youth are discussed.
Early in Reperfusion Following Myocardial Ischemia, Leukocyte Activation Is Necessary for Venular Adhesion But Not Capillary Retention
Authors: Ritter Leslie S. , Wilson Donald S. , Williams Stuart K. , Copeland Jack G. , McDonagh Paul F.
Published: April 2008

Objective: The pathobiology of leukocyte sequestration in the coronary microcircu‐lation following ischemia is unclear. We examined the location(s) and persistence of leukocyte sequestration of unactivated and preactivated blood in the coronary microcirculation early during reperfusion following ischemia.

Methods: Isolated rat hearts were subjected to 30 min of 37°C, no‐flow ischemia. Hearts were initially reperfused with diluted whole blood containing fluorescent leukocytes (DWB*). At 5, 20, and 35 min of reperfusion (R), the deposition of leukocytes in the coronary capillaries and venules was observed directly using intravital fluorescence microscopy. Four groups were studied: a nonischemic control group (Gr I), and postischemic groups reperfused with DWB* treated with vehicle (Gr II) or preactivated with 10−8 M N‐formylmethionyl‐leucyl‐phenylala‐nine (fMLP) (Gr III) or 10−6 M fMLP (Gr IV).

Results: At R5, postischemic reperfusion with unactivated blood caused a significant trapping of leukocytes in coronary capillaries (Gr I = 2.2 ± 0.4 versus Gr II = 5.6 ± 0.6 leukocytes per capillary field, P < 0.05). Hearts in Gr IV exhibited significantly greater leukocyte retention in capillaries compared to all other groups at R5 (R5, Gr IV = 8.8 leukocytes per capillary field, P < 0.05) and at R35. At R5, although more leukocytes were observed adhered to the venules in Gr II compared to Gr I, the difference was not statistically significant (Gr I = 1.7 ± 0.7 versus Gr II = 3.4 ± 0.5 leukocytes per 100 |μm venule, P = 0.23). DWB* preactivated with the lower concentration of fMLP (10−8 M) resulted in a significant increase in venular leukocyte adhesion at R5 compared to Gr I and Gr II (Gr III 6.1 ± 0.5, P < 0.05). After 35 min of reperfusion, a greater percentage of leukocytes remained in the capillaries than in the venules.

Conclusions: These direct observations suggest that early in reperfusion after ischemia, both leukocyte and endothelial activation are necessary for venular adhesion, but that ischemia‐induced coronary microvascular alterations are sufficient to promote leukocyte retention in coronary capillaries. These results also indicate that during 35 min of reperfusion, the degree of leukocyte washout is greater in the venules than in the capillaries. These results suggest that the mechanisms contributing to leukocyte retention early in reperfusion following myocardial ischemia are, indeed, different in the capillaries and venules and that the mechanisms affecting retention in capillaries are more persistent than those in the venules.
Blood Vessel Growth in the Endometrium
Authors: Goodger Anne M. , Rogers Peter A.W.
Published: April 2008

Angiogenesis, or formation of new blood vessels by sprout formation from existing vessels, is generally considered to be the only mechanism by which blood vessel growth occurs. This traditional concept of angiogenesis has been derived largely from observations of experimental systems. Relatively fewer studies on angiogenesis have been carried out using normal angiogenic situations where vessel growth occurs in a controlled three‐dimensional fashion throughout the tissue. Recent advances in the treatment of infertility and outpatient gynecological procedures have led to greater accessibility to normal human endometrium, thus providing new opportunities to study the process of angiogenesis in a physiological context. However, to date, it appears that very little work had been done in relation to endometrial angiogenesis apart from the location of numerous angiogenic and other growth factors with potential to influence angiogenesis in the endometrium, and here there have been few attempts to link these observations with actual angiogenic events. The purpose of this review is to summarize the literature regarding angiogenesis in the endometrium, including work from our own laboratory, and to suggest that blood vessel growth in the endometrium may occur by a mechanism that differs from classical angiogenesis.
Use of Ruthenium Red Staining to Detect Mast Cell Degranulation In Vivo
Authors: Shepherd Rebecca K. , Duling Brian R.
Published: April 2008

Objective: To establish a method of detecting mast cell degranulation in tissues during in vivo microscopy.

Methods: Hamster tissues were prepared for intravital microscopy. Ruthenium red (RR) was superfused over the cheek pouch at concentrations of 0.0001–0.01% to determine the optimal concentration. Mast cells were stimulated with compound 48/80, as well as with vasoactive agents not known to be stimulatory to mast cells, following which, mast cell staining was observed. Mesenteries were stained with Toluidine Blue (TB) or RR and mast cell degranulation was assessed during treatment with compound 48/80, or control.

Results: During superfusion with varying concentrations of RR, a dose dependence for background staining of unstimulated cells was observed. A RR concentration of 0.001% was optimal for in vivo detection of mast cell degranulation. Mast cells exposed to 0.001% RR were stained following stimulation with compound 48/80 but not after treatment with KC1 or acetylcholine. The latter agents are not known to stimulate mast cells. Thus, arteriolar vasomotor responses, per se, did not appear to play a role in mast cell RR uptake. Comparable results were obtained with RR versus TB in control or 48/80‐treated mesenteries.

Conclusions: This RR technique facilitates rapid detection of mast cell degranulation in vivo and provides an opportunity to assess both mast cell and microvascular function simultaneously.
A Role for Dietary Copper in Nitric Oxide‐Mediated Vasodilation
Authors: Schuschke Dale A. , Saari Jack T. , Miller Frederick N.
Published: April 2008

Objective: This study was designed to investigate the role of dietary copper in nitric oxide‐mediated arteriolar dilation.

Methods: Male weanling Sprague—Dawley rats were fed a purified diet that was either copper‐adequate (6.0 μg Cu per g diet) or copper‐deficient (0.3 μg Cu per g diet) for a period of 4 weeks. Each rat was anesthetized with pentobarbital and its cremaster muscle was positioned in a Krebs'‐fdled bath to which graded concentrations of vasoactive agents were added. In the first series, responses to norepineph‐rine (NE 10−9‐10−6 M) and acetylcholine (ACH 10−7‐10−4 M) were compared in third‐order arterioles. Second, the dilator response to 10−5 M ACH in the absence and presence of 240 U/ml Cu, Zn‐superoxide dismutase (SOD) was determined. Third, arteriolar dilation was determined in response to NO‐independent stimulation of soluble guanylate cyclase with hydrogen peroxide (10−7‐10−5 M) and to dibutyryl cGMP (10−6‐10−4 M), dibutyryl cAMP (10−6‐10−4 M), and papaverine (10−4M).

Results: The arteriole constrictor response to NE and the dilator response to hydrogen peroxide, dibutyryl cGMP and cAMP, and papaverine were not different between the dietary groups. Copper deficiency attenuated the ACH‐induced dilation, but the response was restored in the presence of SOD.

Conclusions: The inactivation of cytosolic Cu, Zn‐SOD by restriction of dietary copper results in the depression of NO‐mediated vascular smooth‐muscle relaxation probably by interaction of NO with superoxide.
A System for Culture of Endothelial Cells in 20–50‐μm Branching Tubes
Authors: Frame Mary D.S. , Sarelius Ingrid H.
Published: April 2008

Objective: To construct an in vitro endothelial cell culture system which would mimic the geometry and hemodynamic conditions of the arteriolar microcirculation.

Methods: Using a photolithography technique, semicircular channels (20–50 μm in diameter) were etched in mirror‐image patterns on pairs of borosilicate microscope slide glass. One‐half of each plate pair was predrilled with perfusion port holes at funnel‐shaped fluid entrance regions. The perfusion system was constructed of micropipette glass and Teflon® tubing, and imbedded in Sylgard®. Two types of endothelial cells were grown to confluence within the half‐channels: rabbit lung microvascular endothelial cells (a gift of Dr. M.E. Gerritsen, Miles Inc.) and human umbilical vein endothelial cells. After the cells were confluent, the two mirror images were aligned and clamped together to form a complete branching system of tubes lined with endothelial cells.

Results: This cell culture system can be perfused at physiological flow rates corresponding to wall shear stress values in the range 0.03–48 dyn/cm2. The fluid velocity profiles can be measured in this system by tracking the velocity and flow paths of 0.5‐μm fluorescently labeled microspheres. Endothelial cells which grow within the channel exhibit F‐actin alignment along the long axis of the channel by 3 days after seeding. Scanning electron micrographs indicate that 4 hr after seeding, endothelial cells commonly form cellular projections extending across the half‐channel; by 5 days after seeding, the projections appear to have flattened out along the bottom of the channel.

Conclusions: An in vitro endothelial cell culture system was constructed which mimics the geometry and hemodynamics conditions of resistance arterioles. This system can be used to examine endothelial cell responses to flow and flow gradients under defined and controllable conditions which mimic the arteriolar microcirculation.
Menadione‐Induced Oxidative Stress in Bovine Heart Microvascular Endothelial Cellsa
Authors: KOSSENJANS WILHELM , RYMASZEWSKI ZBIGNIEW , BARANKIEWICZ JERZY , BOBST ALBERT , ASHRAF MUHAMMAD
Published: April 2008

Objective: Oxidative stress from increased production of reactive oxygen species or decreased efficiency of inhibitory and scavenger systems may contribute to vascular injury. In this study, we developed an in vitro model of vascular injury by menadione‐induced oxidative stress in bovine heart microvascular endothelial cells.

Methods: Oxidative stress was induced by exposure to menadione. Superoxide, hydrogen peroxide and hydroxyl radical formation was measured by superoxide dismutase‐inhibitable cytochrome c reduction, the dichlorofluorescin technique and the salicylate method, respectively. Electron paramagnetic‐spin resonance spectroscopy employing 5–5′‐dimethyl‐1‐pyrroline‐N‐oxide for superoxide trapping was used. Endothelial cell cytotoxicity was assessed by lactate dehydrogenase release.

Results: Superoxide and hydroxyl radical were produced in a time‐ and concentration‐dependent fashion. Fluorescence in the presence of dichlorofluorescin confirmed hydrogen peroxide formation. Endothelial cell cytotoxicity became evident after 5 h of menadione treatment at concentrations of 100 μM. 3‐Aminobenzamide, a poly(ADP‐ribose)polymerase inhibitor, and dimethylthiourea, a hydrogen peroxide and hydroxyl radical scavenger, decreased menadione cytotoxicity, whereas deferoxamine, an inhibitor of hydroxyl radical formation, did not.

Conclusions: The results suggest that menadione toxicity is mediated by poly(ADP‐ribose)polymerase activation via hydrogen peroxide formation and that menadione‐treated bovine heart microvessel endothelial cells provide a suitable in vitro model to study oxidative stress in endothelial cells.
Determination of the Magnitude of the Water‐Exclusive Pathway in Cat Skeletal Muscle Microvasculature
Authors: WOLF MATTHEW B.
Published: April 2008

Objective: To measure the magnitude of the water‐exclusive pathway in cat skeletal muscle.

Methods: The osmotic reflection coefficient (σd) was measured for sucrose, raffinose and cyancobalamine using osmotic transient techniques in the isolated, perfused cat hindlimb preparation at sufficiently high perfusate flows (60–80 ml/min−1 100 g−1) so that solute diffusion was not a factor. Microvascular filtration coefficient values required for the σd determination were measured using the capillary filtration coefficient (CFC) technique at these high flows. With these σd data and macromolecular reflection coefficient data from a previous study, discrete pore‐modeling techniques were used to estimate the magnitude of the water movement through the water‐exclusive pathway.

Results: CFC values increased significantly at very high flows (>80 ml/min−1 100 g−1), but these values were unchanged from control at the lower flows used to measure σd. The σd values for sucrose and raffinose were 0.41 ± 0.03 SE and 0.42 ± 0.03 SE, respectively, in 12 limbs. In the same limbs, the σd for cyancobalamine was 0.52 ± 0.03 SE, which was significantly (p < 0.05) larger, consistent with a larger Stokes‐Einstein radius for this molecule. A 3‐pathway model (small and large pores and a water‐exclusive pathway) was fit to the data. The result was that 41 ± 4% (95% confidence interval) of total water flow makes use of the water‐exclusive pathway in this preparation.

Conclusions: The very high fraction of water flow through the water‐exclusive pathway in cat skeletal muscle suggests that this pathway is of major importance in microvascular water movement under normal conditions. Failure to take this finding into account can lead to inaccuracies in the estimation of parameters for pathways which carry solute.
The Relationship between Scholarly Communication and Science and Technology Studies (STS)
Authors: Park Ji-Hong
Published: April 2008

Several studies of scholarly communication are based on a socio-technical perspective that has its root in science and technology studies (STS). Despite this close connection, the relationship between scholarly communication and STS is not well understood. Given this gap, this article aims to identify a conceptual link between the two fields, beginning with a review of each field and then examining areas of overlap. Findings reflect the fact that one domain of STS is concerned with the content of scientific knowledge; this is known as the sociology of scientific knowledge (SSK). This domain is closely related to the processes of scholarly communication, including publishing, searching, collaborating, citing, and writing. The other domain of STS, which focuses on institutions, norms, evaluations, and innovations, is known as sociology of science (or institutional sociology of science). This area is related to scholarly communication structures. Studies of bibliometric evaluation, relationships among disciplines, and innovation and productivity are examples of this connection.
Surviving Referees' Reports
Authors: Martin Brian
Published: April 2008

Making revisions in response to referees’ comments can be challenging and sometimes discouraging. A pragmatic step-by-step approach can help overcome barriers.
Exploring Darwin's correspondence: some important but lesser known correspondents and projects
Authors: Veak T.
Published: April 2008

This paper explores Darwin's 14,000 plus letters and suggests that in spite of the enormous amount of published material on Darwin and his work, there remains much untapped information in his correspondence. A quantitative analysis of his correspondence reveals that many of Darwin's most important sources and projects have not been researched. I provide examples in two of his correspondents, William B. Tegetmeier and John Scott, who were extremely important to Darwin's work in domestic animal breeding and plant hybrid studies, respectively. In addition, Darwin's work on seed viability and distribution are discussed to illustrate both the extent of his correspondence network and the complexity of his many sub-projects. The appendices suggest avenues for the further research of Darwin's correspondence by correlating the amount of correspondence with the amount of published material on the correspondents.
A matter of perspective: multiple readings of George Gaylord Simpson'sTempo and mode in evolution
Authors: Cain J.
Published: April 2008

The paper examines book reviews produced for George Gaylord Simpson's (1944) Tempo and mode in evolution. This book was one of a series of key American publications in the synthesis period (1930s–1940s) of evolutionary studies. When these reviews are organised by their authors' specialities, patterns in emphasis arise. The patterns raise important questions about reader perspective and the various ways meaning was imposed onto this book. The analytical concept of polyvalence – the idea that within a community of readers, texts come to have multiple meanings and this pluralism leads to different notions of value – provides a useful tool for drawing implications about this case. In particular, an emphasis on polyvalence and multiple perspectives solves a stalemate between conflicting interpretations of the synthesis period. The reviews of Simpson's book show many perspectives were active in the period, yet the main historical interpretations of the period each build from only one of those multiple perspectives. As a result, each necessarily is incomplete. A more satisfactory understanding of the period will need to build on the concept of polyvalence.
Bentham for “beginners and amateurs” and ladies:Handbook of the British flora
Authors: Shteir A. B.
Published: April 2008

George Bentham's Handbook of the British flora (1859) had a mixed reception during its publishing history. From motivations that were both botanical and educational, Bentham aimed to write a “popular” book for “beginners and amateurs” rather than a textbook or a Flora for experts, but his book was caught in cross-currents of mid-Victorian science. While some botanists welcomed the accessibility of Bentham's book, others were more critical and dismissive. Because Bentham wrote as an expert, his product was subject to judgment from those who were preoccupied with technical issues and debates. This essay charts the genesis of Bentham's book and studies its reception at a time of considerable change in cultures of natural history. It probably was not possible for Bentham's book to satisfy several quite different contemporary agendas. Recent scholarship about book history, forms of science writing, and sharpening demarcations between “amateurs” and “professionals” can help explain why Bentham's Handbook of the British flora had a category problem.
“Your lordship's most obliged servant”: letters from Louis Fraser to the thirteenth Earl of Derby, 1840 to 1851
Authors: Moore Amberley
Published: April 2008

ABSTRACT: Louis Fraser, sometime curator of the museum of the Zoological Society of London, was described by his contemporaries as a protégé of the 13th Earl of Derby, an “excellent naturalist”, a “zoological traveller” and the author and publisher of Zoologica typica. Published sources provide some information about Fraser but it is not entirely supported by papers in the Public Record Office, Kew, by the minutes of the council meetings of the Zoological Society of London and by Lord Derby's correspondence held at Liverpool and Philadelphia. Fraser corresponded with Lord Derby for eleven years between 1840 and 1851 and his letters to Lord Derby, together with other archives, provide a more accurate and detailed account of this eventful decade of his life, which included his experiences as zoologist on the 1841 naval expedition to the River Niger and his visit to Tunisia in 1846 collecting for Lord Derby about which, hitherto, little has been written.
Birds depicted in a folio of eighteenth century water-colours by Sarah Stone
Authors: Walters Michael
Published: April 2008

ABSTRACT: In 1996 The Natural History Museum purchased a series of original water colour drawings by Sarah Stone of specimens in the Leverian Museum, on many of which descriptions of new species were made by John Latham. The contents of the Leverian Museum were auctioned, the specimens were scattered and most are now lost. Sarah Stone's pictures represent the only surviving evidence of the identity and appearance of these specimens. Some of Latham's descriptions based on Leverian specimens have never been identified with any known species. In the absence of the specimens the Sarah Stone pictures are important for nomenclatural reasons. The purpose of this paper is to identify each picture with its current scientific name, to check if any of the original identifications were erroneous and to see if any of the pictures could be found to represent unknown or extinct species. The Leverian collection contained specimens of species which would not be known to science for up to 50 years or more. It has long been known that the dispersal of the Leverian collection was a tragedy, but the evidence of Sarah Stone's drawings indicates that it was an even greater tragedy than had previously been thought.
“Codex canadiensis”, an early illustrated manuscript of Canadian natural history
Authors: Reeves Henry M. , Gagnon FrançOis-Marc , Houston C. Stuart
Published: April 2008

ABSTRACT: “Codex canadiensis” consists of 79 leaves with 180 illustrations of plants, birds, mammals, fishes, and a few fabulous animals. This manuscript arguably is the most obscure and enigmatic surviving document pertaining to the early natural history of French Canada. It was lost until 1930, when Baron Marc de Villiers first published a facsimile. Two inferior editions later appeared in Canada. The codex was acquired about 1949 by Oklahoma oil baron Thomas Gilcrease and then deposited in the Gilcrease Museum, Tulsa, Oklahoma. Under the direction of one of us (Gagnon), French-Canadian scholars have established the codex's author was Father Louis Nicolas (1634–c. 1678), a Jesuit priest who laboured among tribes along the St Lawrence River and the Great Lakes during 1664–1675. This rejects the previous attribution to Charles Bécard (correctly Bécart), Sieur de Granville. The codex likely was completed in part, if not entirely, after Nicolas' return to France in 1675, and it is closely related to a much larger undated work by Nicolas, “Histoire naturelle des Indes Occidentales”. “Codex canadiensis” is among the most valuable extant manuscripts illustrating the natural history of North America as explored by early European naturalists.
Domestication of the canary, Serinus canaria - the change from green to yellow
Authors: Birkhead T. R. , Schulze-Hagen K. , Kinzelbach R.
Published: April 2008

ABSTRACT: New information on the domestication of the canary, Serinus canaria, shows that the process by which the wild-type canary was transformed by artificial selection into a pure yellow one occurred earlier than previously thought. Previous studies suggest that selective breeding occurred in Germany, that the first birds with any yellow plumage appeared around 1610, and that the first all yellow birds appeared around 1677. We describe an Italian painting from the 1490s showing completely yellow birds that may be canaries. This suggests selective breeding of canaries may have occurred in Italy before this date. We also report some information from Conrad Gessner who, in 1555, described a specific type of partially yellow canary from Italy. Gessner stated these specially bred birds were transported to Germany, which is where we know selective breeding continued. Paintings in the unpublished encyclopaedia of the German cleric, Marcus zum Lamm, from around 1580 show partially yellow canaries and a crested canary. A painting from around 1657 by the German artist Johann Walter shows what is probably an all yellow canary.
Edward Heron-Allen FRS (1861–1943): a review of his scientific career, with an annotated bibliography of his foraminiferal publications
Authors: Hodgkinson Richard L. , Whittaker John E.
Published: April 2008

ABSTRACT: In spite of his many other interests, Edward Heron-Allen also worked for nearly 50 years as a scientist on minute shelled protists, called foraminifera, much of it in an unpaid, unofficial capacity at The Natural History Museum, London, and notably in collaboration with Arthur Earland. During this career he published more than 70 papers and obtained several fellowships, culminating in 1919 in his election to the Royal Society. Subsequently, he bequeathed his foraminiferal collections and fine library to the Museum, and both are housed today in a room named in his honour. In this paper, for the first time, an assessment of his scientific accomplishments is given, together with a full annotated bibliography of his publications held in the Heron-Allen Library. This is part of a project to produce a bibliography of his complete publications, recently initiated by the Heron-Allen Society.
A bibliography for John Bachman
Authors: Waddell G.
Published: April 2008

John Bachman (1790–1874) was co-author with John James Audubon of The viviparous quadrupeds of North America (1842–1848). His other major books were The doctrine of the unity of the human race examined on the principles of science (1850) and A defense of Luther and the Reformation (1853). He wrote approximately 70 articles on topics ranging from religion to natural history including scientifi c methodology, wild plants, variation in domesticated plants and animals, hybrids, agriculture, bird migration and animal markings.
Ships employed in Arctic ice: Discoverys past, 1602 to 1876
Authors: Savours Ann
Published: April 2008

This paper looks back to the predecessors of Captain Robert Falcon Scott's Discovery, which was built for the National Antarctic Expedition 1901–1904. The period covered is 1602 to 1876. An account is given of the exploring voyages of those ships named Discovery which sailed to the Arctic, including those of George Waymouth, Henry Hudson, William Baffin, James Knight, Christopher Middleton, James Cook, George Vancouver and Sir George Nares. In addition brief mention is made of several ships owned by the East India Company, also named Discovery, which sailed in lower latitudes.
DiscoveryInvestigations: an early attempt at ecologically sustainable development?
Authors: Marsden Rosalind
Published: April 2008

This paper aims to pay tribute to the work of three people, Sidney Frederick Harmer, Ernest Rowland Darnley and Stanley Wells Kemp who followed and amplified the ideas put forward by Jens Andreas Mørch in attempts to preserve the whaling industry and learn all there was to know about whales and their environment. Both Harmer and Kemp were keen taxonomists and diligent collectors of everything biological. Their approach, which was to reject nothing and to investigate everything as it might be useful one day, led to one of the largest oceanographic investigations of the first half of the twentieth century. They also provided part of the origins of both the British Antarctic Survey and the National Oceanography Centre, Southampton.
FromDiscoveryto discovery: the hydrology of the Southern Ocean, 1885–1937
Authors: Mills Eric L.
Published: April 2008

The work at sea of George Deacon on the RRS William Scoresby and RRS Discovery II between 1927 and 1937 resulted in the publication of “The hydrology of the Southern Ocean” (1937) and a description of the Southern Ocean and the names of its water masses that are still in use. Deacon's interpretations were publicized by Sverdrup, Johnson and Fleming in the text The oceans (1942), but their origin is in earlier work, mainly German, between 1898 and 1922, in which Gerhard Schott, Erich von Drygalski, Alfred Merz, and Georg Wüst, and especially Wilhelm Brennecke, added significantly to knowledge of the meridional circulation of the Atlantic Ocean. Deacon's great contribution was to systematize the physical oceanography of the Southern Ocean and to show that it was part of a global system.