bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optical coherence tomography as a novel tool for non‐destructive measurement of the hull thickness of lupin seeds
Authors: Clements J. C. , Zvyagin A. V. , Silva K. K. M. B. D. , Wanner T. , Sampson D. D. , Cowling W. A. 
Published: June 2004

AbstractHull thickness is an important component of seed quality, which effects dehulling ability, feed or food nutritional aspects and cooking times. A breeding objective in Lupinus angustifolius crop improvement is to reduce hull thickness and a rapid screening method is needed to efficiently screen genotypes. Optical coherence tomography (OCT) imaging using infrared illumination at 980 nm was used to compare hull thickness of genotypes of four lupin species. OCT‐derived hull layer thickness correlated highly with actual hull thickness determined by environmental scanning electron microscopy (r = 0.90) and allowed reliable distinction between mutant (thin‐hulled) and parent genotypes of L. angustifolius. The imaging could clearly penetrate lupin seed to a depth of approximately 200 μm. The use of OCT to measure hull thickness has the advantage that it is rapid and non‐destructive and should be very useful in selecting thin hull lines of lupins and other species on a single seed basis in germplasm or progeny from crosses.
EFFECT OF MAGNESIUM ON MECHANICAL PROPERTIES OF PRESSURIZED MESENTERIC SMALL ARTERIES FROM OLD AND ADULT RATS
Authors: Adrian Mark , Laurant Pascal , Berthelot Alain 
Published: May 2004

Summary1. The purpose of the present study was to determine the effects of magnesium (Mg) on the mechanical properties of resistance arteries in adult and old rats.2. Studies were performed in adult (17 weeks) and old (104 weeks) male Wistar rats. The vasodilatory response and the passive mechanical properties of the wall of isolated perfused and pressurized arterial segments of mesenteric small arteries were investigated after Mg and verapamil application, both known for their calcium antagonistic properties.3. Mesenteric resistance arteries from old rats exhibited an outward hypertrophic remodelling, with enlargment of the lumen, thickening of the media and enlarged media cross‐sectional area.4. The vasodilatory response induced by the application of increasing extracellular concentrations of Mg and verapamil was significantly smaller in preconstricted mesenteric arteries of old rats than in those of adult rats.5. Incremental distensibility in response to increasing intravascular pressures did not change. However, the stress–strain curve was shifted to the left in pressurized mesenteric arteries from old rats, indicating arterial wall stiffness. Verapamil (3 µmol/L) did not modify the stress–strain curves in either adult or aged rats. However, Mg (4.8 mmol/L) significantly shifted the curve to the right in mesenteric arteries from adult rats and, to a greater degree, in those from old rats.6. Although Mg‐induced vasodilatation is impaired in aged rats, increased Mg concentration improved the mechanics of pressurized mesenteric resistance arteries. The fact that Mg decreases arterial stiffness in arteries from old rats suggests that Mg has a beneficial effect on age‐related changes to the vascular wall.
NANOMOLAR LEVEL OF OUABAIN INCREASES INTRACELLULAR CALCIUM TO PRODUCE NITRIC OXIDE IN RAT AORTIC ENDOTHELIAL CELLS
Authors: Dong Xian Hui , Komiyama Yutaka , Nishimura Noriko , Masuda Midori , Takahashi Hakuo 
Published: May 2004

Summary1. Changes in [Ca2+]i across the cell membrane and/or the sarcoplasmic reticulum regulate endothelial nitric oxide (NO) synthase activity.2. In the present study, we investigated the effect of ouabain, a specific inhibitor of Na+/K+‐ATPase, on NO release and [Ca2+]i movements in cultured rat aortic endothelial cells (RAEC) by monitoring NO production continuously using an NO‐specific real‐time sensor and by measuring the change in [Ca2+]i using a fluorescence microscopic imaging technique with high‐speed wavelength switching. The t½ (half‐time of the decline of [Ca2+]i to basal levels after stimulation with 10 µmol/L bradykinin) was used as an index of [Ca2+]i extrusion.3. A very low concentration of ouabain (10 nmol/L) did not increase the peak of NO production, but decreased the decay of NO release and, accordingly, increased integral NO production by the maximal dose–response concentration induced by bradykinin. The same dose of ouabain affected [Ca2+]i movements across the cell membrane and/or sarcoplasmic reticulum induced by bradykinin with a time‐course similar to that of NO release. Moreover, the t½ was significantly increased.4. Pretreatment of RAEC with Na+‐free solution, an inhibitor of the Na+/Ca2+ exchanger, and nickel chloride hexahydrate prevented the effects induced by bradykinin and ouabain.5. These observations using real‐time recording indicate that a small amount of ouabain contributes to the bradykinin‐stimulated increase of NO production through inhibition of plasma membrane Na+/K+‐ATPase activity and an increase in intracellular Na+ concentrations. The membrane was then depolarized, leading to a decline in the bradykinin‐stimulated increase in [Ca2+]i by forward mode Na+/Ca2+ exchange to prolong the Ca2+ signal time.6. From these results, we suggest that nanomolar levels of ouabain modulate [Ca2+]i movements and NO production in RAEC.
CYTOCHROMES P450 ARE DIFFERENTLY EXPRESSED IN NORMAL AND VARICOSE HUMAN SAPHENOUS VEINS: LINKAGE WITH VARICOSIS
Authors: Bertrand‐Thiebault Céline , Ferrari Luc , Boutherin‐Falson Odile , Kockx Mark , Desquand‐Billiald Stéphanie , Fichelle Jean‐Marc , Nottin Rémi , Renaud Jean‐François , Batt Anne‐Marie , Visvikis Sophie 
Published: May 2004

Summary1. The expression of cytochrome P450 (CYP) enzymes and cyclo‐oxygenases (COX) was investigated in human saphenous veins by reverse transcription–polymerase chain reaction analysis. Non‐varicose veins were obtained from patients undergoing aortocoronary bypass grafting, whereas varicose veins were obtained from patients undergoing stripping removal of varicose saphenous veins.2. In non‐varicose veins, CYP1B1, CYP2C, CYP2E1 and CYP4A11 were detected, whereas CYP2J2, CYP3A5, COX‐1 and COX‐2 were detected almost exclusively in varicose veins. CYP4F2 was not detectable.3. Except for CYP4A11, the levels of individual CYP mRNA were higher in varicose veins than in control veins.4. Smooth muscle cell volume, determined by a colour image‐analysis system, was increased approximately 1.5‐fold in varicose veins.5. Because CYPs and COXs produce various vasoactive compounds, increased expression of these enzymes could be involved in the impairment of vascular tone and may contribute to varicose pathology. Then, CYP or COX modulators may be potentially active in the treatment of chronic venous insufficiency.
CHRONIC DECREASE IN FLOW CONTRIBUTES TO HEART FAILURE‐INDUCED ENDOTHELIAL DYSFUNCTION IN RATS
Authors: Devaux C , Iglarz M , Richard V , Mulder P , Henrion D , Renet S , Henry JP , Thuillez C 
Published: May 2004

Summary1. Chronic heart failure (CHF) impairs endothelium‐dependent, nitric oxide (NO)‐mediated dilation. This decreased dilation may be partly secondary to the chronic decrease in blood flow, but this hypothesis has not yet been tested. Thus, we assessed whether a localized, chronic increase in blood flow in vivo reverses endothelial dysfunction of small arteries in rats with CHF.2. Two months after coronary artery ligation or sham surgery, second‐order side branches of the superior mesenteric artery were ligated in order to obtain persistently elevated blood flow (HF) in the adjacent first‐order side branch compared with normal vessels (NF). One month later, responses to acetylcholine and flow‐mediated vasodilatation (FMD) were assessed in vitro in an arteriograph.3. Chronic heart failure induced a decrease in mesenteric blood flow (374 ± 25 and 305 ± 27 µL/min for sham and CHF, respectively; P < 0.05). Neither CHF nor the chronic increase in flow affected the responses to acetylcholine.4. Chronic heart failure decreased FMD (maximal response in sham and control 34 ± 6 and 13 ± 4%, respectively; P < 0.05). Chronic increases in blood flow did not modify FMD in sham, but restored FMD in CHF rats (28 ± 4%; P < 0.05 vs CHF NF).5. The restored response was abolished by an inhibitor of NO synthesis (NG‐nitro‐l‐arginine). Chronic heart failure did not affect the abundance of mesenteric endothelial NO synthase (eNOS) mRNA.6. A chronic increase in flow significantly increased the abundance of eNOS mRNA in sham rats, but only moderately and non‐significantly in CHF rats.7. Thus, endothelial dysfunction of small arteries in CHF appears to be largely the consequence of the chronic decrease in flow.
ADMINISTRATION OF EXOGENOUS TISSUE PLASMINOGEN ACTIVATOR REDUCES OEDEMA IN MICE LACKING THE TISSUE PLASMINOGEN ACTIVATOR GENE
Authors: Stringer Kathleen A , Dunn John S , Gustafson Daniel L 
Published: May 2004

Summary1. It has recently become apparent that tissue plasminogen activator (tPA) modulates inflammation in diseases such as rheumatoid arthritis (RA) and acute respiratory distress syndrome (ARDS).2. We have shown previously that tPA has anti‐inflammatory activity in in vivo models of oedema or inflammation.3. The present study investigated the ability of exogenous recombinant tPA (rtPA) to reduce carrageenan‐mediated oedema in mice lacking the tPA gene, testing the hypothesis that rtPA treatment may be beneficial in diseases such as RA and ARDS in which there is a paucity of endogenous tPA.4. Knockout mice deficient in the tPA gene and matching wild‐type mice received an intraplantar injection (25 µL) of carrageenan (1.5%, w/v) following either vehicle (sterile water for injection) or tPA (12 mg/kg).5. Footpad oedema was measured, an oedema index was calculated and tissue myeloperoxidase (MPO) activity was determined. Mean oedema indices were higher in untreated tPA (–/–) mice than untreated wild‐type mice. Pretreatment with rtPA in either tPA (–/–) or wild‐type mice reduced the mean measured peak footpad oedema index by 63 and 48%, respectively. Tissue MPO activity was not different between treatment groups.6. We conclude that exogenous rtPA has the ability to reduce acute oedema without altering neutrophil infiltration into the site of injury in both tPA (–/–) and wild‐type mice and that endogenous tPA may participate in the inflammatory process, as evidenced by higher oedema indices in untreated tPA (–/–) mice. These data provide support for the potential clinical utility of exogenous rtPA in the treatment of inflammatory diseases, such as RA and ARDS, in which there is a paucity of tPA.
ACTIVATION OF RENAL CALCIUM AND WATER EXCRETION BY NOVEL PHYSIOLOGICAL AND PHARMACOLOGICAL ACTIVATORS OF THE CALCIUM‐SENSING RECEPTOR
Authors: Conigrave Arthur D , Lok Hiu Chuen 
Published: May 2004

Summary1. Activated Ca2+‐sensing receptors (CaR) play key roles in the regulation of whole‐body calcium metabolism by inhibiting the secretion of the key calcitropic hormone parathyroid hormone and promoting urinary calcium excretion.2. We have now examined the effects of intravenous administration of novel calcium receptor activators on renal function in anaesthetized female Wistar rats.3. The type II calcimimetic NPS R‐467 and the CaR‐active amino acids l‐Phe and l‐Ala, which act at distinct binding sites on the receptor, all activated urinary flow rate, calcium and osmolar excretion and suppressed urinary osmolality.4. The effects of l‐Phe and NPS R‐467 on urine flow rate and calcium excretion were stereoselective, consistent with the idea that these effects were mediated by calcium‐sensing receptors.5. However, d‐Phe also suppressed urinary osmolality and promoted osmolar excretion, possibly by exceeding the transport maximum in the proximal tubule.6. The data indicate that novel activators of CaR, including l‐amino acids at physiologically relevant serum concentrations, play a significant role in the regulation of urinary calcium and water excretion.
NEURAL CONTROL OF RENAL MEDULLARY PERFUSION
Authors: Eppel Gabriela A , Malpas Simon C , Denton Kate M , Evans Roger G 
Published: May 2004

Summary1. There is strong evidence that the renal medullary circulation plays a key role in long‐term blood pressure control. This, and evidence implicating sympathetic overactivity in development of hypertension, provides the need for understanding how sympathetic nerves affect medullary blood flow (MBF).2. The precise vascular elements that regulate MBF under physiological conditions are unknown, but likely include the outer medullary portions of descending vasa recta and afferent and efferent arterioles of juxtamedullary glomeruli, all of which receive dense sympathetic innervation.3. Many early studies of the impact of sympathetic drive on MBF were flawed, both because of the methods used for measuring MBF and because single and often intense neural stimuli were tested.4. Recent studies have established that MBF is less sensitive than cortical blood flow (CBF) to electrical renal nerve stimulation, particularly at low stimulus intensities. Indeed, MBF appears to be refractory to increases in endogenous renal sympathetic nerve activity within the physiological range in all but the most extreme cases.5. Multiple mechanisms appear to operate in concert to blunt the impact of sympathetic drive on MBF, including counter‐regulatory roles of nitric oxide and perhaps even paradoxical angiotensin II‐induced vasodilatation. Regional differences in the geometry of glomerular arterioles are also likely to predispose MBF to be less sensitive than CBF to any given vasoconstrictor stimulus.6. Failure of these mechanisms would promote reductions in MBF in response to physiological activation of the renal nerves, which could, in turn, lead to salt and water retention and hypertension.
BRIEF EXPOSURE TO ETHANOL AUGMENTS VASCULAR CONTRACTILITY IN HUMAN CHORIONIC PLATE ARTERIES
Authors: Hong Eun Hui , Kang Na Young , Kim Jee Ahn , Koo Tae Bon , Kang Bong‐Seok , Kim In Kyeom 
Published: May 2004

Summary1. Heavy alcohol consumption has been known as a risk factor for hypertension, although the mechanism by which alcohol intake causes hypertension remains elusive.2. We tested the hypothesis that brief exposure to ethanol augments vascular contractility through the stress response in human chorionic plate arteries.3. Human chorionic plate arteries were mounted in organ baths and exposed to 5% ethanol for 15, 30 or 45 min.4. Brief exposure for 45 min, but not 15 min, not only augmented contractility to KCl and 5‐hydroxytryptamine 5 h after the end of exposure, but also increased the expression of heat shock protein (HSP) 70 in the tissues.5. Reverse transcription–polymerase chain reaction showed gradual increases of hsp70 mRNA expression, but not heat shock cognate 70 (hsc70), hsp90α or glucose regulatory protein 78 (grp78) mRNA expression, in an exposure time‐dependent manner 3 h after the end of exposure.6. These results indicate that ethanol augments vascular contractility through the stress response.
EFFECTS OF RILMENIDINE ON PROXIMAL TUBULAR FLUID ABSORPTION IN RATS
Authors: Jovanovska Valentina , Eitle Eveline , Harris Peter J 
Published: May 2004

Summary1. The antihypertensive agent rilmenidine has threefold higher affinity for I1 imidazoline receptors compared with α2‐adrenoceptors and acts on the central nervous system by reducing sympathetic activity and in the kidney by inhibiting Na+/H+ exchange activity.2. In the present study, we examined: (i) the effects of luminal and peritubular administration of rilmenidine on fluid absorption in superficial proximal tubules; and (ii) the nature of the receptors involved in mediating the action of this drug in the presence of specific antagonists (efaroxan, idazoxan and 2‐methoxy‐idazoxan). Studies were performed in anaesthetized Sprague‐Dawley rats using shrinking split‐drop micropuncture.3. Luminal administration of rilmenidine (10−5 and 10−13 mol/L) inhibited proximal tubular fluid absorption. Peritubular rilmenidine at 10−12 and 10−13 mol/L also inhibited fluid uptake, whereas rilmenidine at 10−11 mol/L had a significant stimulatory action.4. In the presence of the I2 > I1/α2‐adrenoceptor antagonist idazoxan (10−5 mol/L), luminal rilmenidine (10−5 mol/L) stimulated fluid absorption. Stimulation of fluid uptake was also observed when rilmenidine (10−5 mol/L) and the I1 imidazoline receptor antagonist efaroxan (10−5 mol/L) were added together in the luminal fluid. Luminal administration of the selective α2‐adrenoceptor antagonist 2‐methoxy‐idazoxan (10−5 mol/L) resulted in significant attenuation of the inhibitory action of luminal rilmenidine (10−5 mol/L). This indicates that both I1 imidazoline receptors and α2‐adrenoceptors are involved in the luminal actions of rilmenidine.5. The effects of luminal and peritubular administration of α‐methylnoradrenaline (an α2‐adrenoceptor agonist) were compared with those of rilmenidine. Luminal α‐methylnoradrenaline, at higher concentrations (10−7 and 10−5 mol/L), inhibited fluid absorption, as was seen with peritubular rilmenidine, but, in contrast with rilmenidine, no stimulatory action was observed. Peritubular α‐methylnoradrenaline inhibited fluid uptake at higher concentrations (10−5 and 10−7 mol/L), whereas rilmenidine at these concentrations had no effect. The differences in the concentration‐dependent responses for rilmenidine and α‐methylnoradrenaline indicate that both imidazoline receptors and α2‐adrenoceptors are involved in the actions of these compounds on proximal fluid uptake.
ANTI‐APOPTOTIC EFFECT OF ATORVASTATIN, A 3‐HYDROXY‐3‐METHYLGLUTARYL COENZYME A REDUCTASE INHIBITOR, ON CARDIAC MYOCYTES THROUGH PROTEIN KINASE C ACTIVATION
Authors: Tanaka Koichi , Honda Masaaki , Takabatake Toshikazu 
Published: May 2004

Summary1. Pleiotropic effects of statins, which are independent of lipid lowering, have been reported. In the present study, we examined the effect of a statin on apoptosis of adult rat cultured cardiac myocytes. We used the protein kinase C (PKC) inhibitors staurosporine (1 µmol/L), chelerythrine (10 µmol/L) and rottlerin (5 µmol/L) to induce myocyte apoptosis. The effect of atorvastatin (10−7 g/mL), a statin, on myocyte apoptosis induced by these PKC inhibitors was examined.2. All these PKC inhibitors markedly increased the percentage of terminal deoxyribonucleotidyl transferase‐mediated dUTP–digoxigenin nick end‐labeling (TUNEL)‐positive myocytes. This increase was significantly suppressed by atorvastatin treatment. Both chelerythrine and rottlerin induced subcellular translocation of PKCδ and elevated caspase‐3 activity in myocytes. The changes in the subcellular distribution of PKCδ and caspase‐3 activity induced by these PKC inhibitors were suppressed by atorvastatin treatment.3. The results of the present study suggest that the inhibitory effect of atorvastatin on apoptosis of adult rat cardiac myocytes induced by the PKC inhibitors is through activation of PKCδ pathway.
Switching Order Statistics through Random Power Contractions
Authors: WesoŁowski Jacek , Ahsanullah Mohammad 
Published: June 2004

SummaryThis paper investigates a new random contraction scheme which complements the length‐biasing and convolution contraction schemes considered in the literature. A random power contraction is used with order statistics, leading to new and elegant characterizations of the power distribution. In view of Rossberg's counter‐example of a non‐exponential law with exponentially distributed spacings of order statistics, possibly the most appealing consequence of the result is a characterization of the exponential distribution via an independent exponential shift of order statistics.
The Narrative Approach in Art Education: A Case Study
Authors: Esser‐Hall Gabriele , Rankin Jeff , Ndita Dumile Johannes 
Published: June 2004

AbstractThis case study takes as its focus the work of the Fine Art graduate Dumile Johannes Ndita, who visually narrates his experience of life in contemporary South Africa. The artist graduated from Border Technikon, East London, an institution which teaches the narrative approach. It is the aim of the authors to illustrate how this method enables students to transfer lived experience into image. The three voices in this paper come from different backgrounds. The artist will explain the meaning of his drawings, the teacher will give background information on the community and culture in which he himself and the artist operate and outline teaching methods. Students taught by this method create work that has impact and meaning beyond the confines of the art school. To argue this point, the theoretician will add her voice and reflect on meta‐narratives presented in Dumile Johannes Ndita's drawings. Intricate inter‐textual patterns, shared and interconnecting institutional narratives tie our individual voices to those of the wider community and culture of present‐day South Africa and beyond.
The Assessment of GCSE Art: Criterion‐Referencing and Cognitive Abilities
Authors: Rayment Trevor , Britton Brian 
Published: June 2004

AbstractIn this paper Cognitive Abilities Test scores are compared directly with moderated GCSE scores awarded to the same group of pupils. For ease of interpretation the comparisons are presented in a graphical form. Whilst some provisional and tentative conclusions are drawn about the reliability of GCSE art, questions are raised about the general validity of criterion‐referenced assessment in this area.
Open Minds and a Sense of Adventure: How Teachers of Art & Design Approach Technology
Authors: Wood Joyce 
Published: June 2004

AbstractHow does the use of technology in Art and Design differ from its use in other subjects? What uses do art teachers make that might seem noteworthy to their colleagues in other subject areas? And are there respects in which ICT affects art teaching uniquely?The following report is drawn from two national, qualitative studies, carried out over four years and involving over two hundred skilled computer users in the UK teaching force [1]. The studies explored good practice in use of ICT in twelve separate curriculum subjects. Research addressed the following questions:How does ICT help teachers convey the central concepts of their subjects? What can be learned with the aid of ICT that might not be learned as readily in any other way?The study found that each curriculum subject uses ICT distinctively, has singular hardware requirements and is treated differently in terms of resourcing and access.