bluuebunny/crossref_metadata_2025_split huggingface dataset:
Decrease in Tumor Apparent Permeability‐Surface Area Product to a MRI Macromolecular Contrast Medium Following Angiogenesis Inhibition with Correlations to Cytotoxic Drug Accumulation
Authors: DALDRUP‐LINK HEIKE E. , OKUHATA YOSHITAKA , WOLFE ALLAN , SRIVASTAV SUDESK , ØIE SVEN , FERRARA NAPOLEONE , COHEN ROBERT L. , SHAMES DAVID M. , BRASCH ROBERT C. 
Published: June 2004

ABSTRACTBackground: New strategies for cancer therapy include the combination of angiogenesis inhibitors with cytotoxins. However, angiogenesis inhibitors may alter tumor microvessel structure and transendothelial permeability thereby reducing tumoral delivery of cytotoxic agents. The aim of this study was to estimate quantitatively the apparent permeability‐surface area product (KPS) in tumors to a macromolecular contrast medium (MMCM), to follow changes in KPS induced by antibodies to vascular endothelial growth factor (anti‐VEGF), and to correlate the findings with tumor accumulation of cisplatin, a highly protein‐bound cytotoxin, and 5‐fluorouracil (5‐FU), a small unbound cytotoxin.Methods: Dynamic MRI enhanced with a MMCM (albumin‐(Gd‐DTPA)30) was analyzed using a two‐compartment tumor tissue model (plasma and interstitial water) to quantitatively estimate KPS. These estimates of KPS were correlated with cytotoxic drug accumulations in the tumors.Results: Anti‐VEGF treatment reduced KPS to MMCM in tumor tissue from 0.013 mL h−1 cm−3 (n = 9) at baseline to 0.003 mL h−1 cm−3 (n = 9) 24 h later (p < .05). The KPS values correlated significantly (r2 = .78; p < .0001) with the tumor cisplatin accumulation. No correlation (r2 = .001; p = .89) was found between KPS and tumor accumulation of the substantially smaller 5‐FU molecule.Conclusions: MMCM‐enhanced MRI can be used to detect and estimate changes in KPS to this contrast agent following a single dose of anti‐VEGF antibody. The decline in KPS induced by this inhibitor of angiogenesis is associated with reduced tumor concentration of a protein‐bound cytotoxin, similar in molecular weight to the contrast agent. MRI assays of microvascular status as performed here may be useful to clinically monitor responses to anti‐angiogenesis drugs and to optimize the choice and timing of cytotoxic drug administration.
Effect of Venous Air Embolization on Pulmonary Microvascular Protein Permeability
Authors: STEWART RANDOLPH H. , ALLEN STEVEN J. , QUICK CHRISTOPHER M. , ROHN DOUGLAS A. , COX CHARLES S. , LAINE GLEN A. 
Published: June 2004

ABSTRACTObjective:An increase in pulmonary lymph flow and lymph protein clearance following pulmonary air embolization has been interpreted as evidence of increased pulmonary microvascular permeability. The authors hypothesized that air embolization does not alter the pulmonary microvascular permeability to protein and that this could be demonstrated by determining the effect of air embolization on the pulmonary solvent drag reflection coefficient (σf).Methods:Anesthetized dogs were instrumented with left atrial balloon‐tipped catheters, pulmonary lymphatic cannulae, and inferior vena caval catheters. Values were determined for pulmonary lymph flow (QL) and the lymph‐to‐plasma protein concentration ratio (CL/CP) at baseline, after CL/CP was decreased to a filtration independent value by raising left atrial pressure via progressive balloon inflation and after 2 h of air embolization into the inferior vena cava with continued left atrial hypertension.Results:QL increased and CL/CP decreased to a filtration‐independent value following induction of left atrial hypertension. Air embolization induced during left atrial hypertension resulted in no significant change in CL/CP. The authors were unable to demonstrate that σf changed following pulmonary air embolization.Conclusions:Utilizing the washdown technique, the authors could not find any evidence that pulmonary microvascular protein permeability is altered by air embolization.
Independence of Connexin Expression and Vasomotor Conduction from Sympathetic Innervation in Hamster Feed Arteries
Authors: LOOFT‐WILSON ROBIN C. , HAUG SARA J. , NEUFER P. DARRELL , SEGAL STEVEN S. 
Published: June 2004

ABSTRACTObjective: Vasomotor responses can travel along the wall of resistance microvessels by two distinct mechanisms: cell‐to‐cell conduction through gap junctions or the release of neurotransmitter along perivascular nerves. It is unknown whether vascular innervation influences the expression of connexin molecules which comprise gap junctions, or the conduction of vasomotor responses. In feed arteries of the hamster retractor muscle (RFA), the authors tested whether sympathetic denervation would alter the expression of connexin isoforms and the conduction of vasomotor responses.Methods: Using intact vessels with sympathetic innervation and those 7–8 days following denervation surgery, mRNA expression was quantified using real‐time PCR, cellular localization of Cx protein was characterized using immunohistochemistry, and vasomotor responses to dilator and constrictor stimuli were evaluated in isolated pressurized RFA.Results: Connexin protein localization and mRNA expression were similar between innervated and denervated vessels. mRNA levels were Cx43 = Cx37 > Cx45 ≫ Cx40. Vasodilation to acetylcholine conducted ≥2000 μ m along innervated and denervated vessels, as did the biphasic conduction of vasoconstriction and vasodilation in response to KCl. Vasoconstriction to phenylephrine conducted < 500 μ m and was attenuated (p < .05) in denervated vessels.Conclusions: The profile of connexin expression and the conduction of vasomotor responses are largely independent of sympathetic innervation in feed arteries of the hamster retractor muscle (RFA).
Nitric Oxide Measurements in Rat Mesentery Reveal Disrupted Venulo‐Arteriolar Communication in Diabetes
Authors: NELLORE KAVITHA , HARRIS NORMAN R. 
Published: June 2004

ABSTRACTObjective: Arteriolar tone is partially controlled by diffusing mediators released by closely paired venules and is reported to depend on venular shear and venular leukocyte adherence. In healthy rat mesentery, venule‐initiated arteriolar dilation and consequent enhanced capillary flow appear to be tightly regulated by nitric oxide (NO). In contrast, diabetes inhibits NO‐dependent vasodilation and is associated with dysfunctional microcirculation. The objective of this study was to investigate venule‐dependent NO in diabetes.Methods: Arteriolar and venular wall concentrations of NO were measured in control and diabetic (streptozotocin‐induced) rat mesentery with fluorescent diaminofluorescein‐2‐diacetate (DAF‐2‐DA); tissue NO was measured with DAF‐2. Venular leukocyte adherence and microvascular shear rates were also measured.Results: Microvascular NO in diabetic rats was found to be significantly lower (< 50%) than in controls. In normal rats, arteriolar NO demonstrated a positive correlation with venular NO and venular shear, and a negative correlation with venular leukocyte adherence. Diabetes eliminated all these correlations. No correlation was present between arteriolar NO and arteriolar shear in either normal or diabetic rats.Conclusions: Arteriolar NO appears to be enhanced by venular shear in normal but not in diabetic rats. This dysfunction could contribute to poor capillary perfusion in diabetes.
Contribution of Active Membrane Processes to Conducted Hyperpolarization in Arterioles of Hamster Cheek Pouch
Authors: CRANE GLENIS J. , NEILD TIMOTHY O. , SEGAL STEVEN S. 
Published: June 2004

ABSTRACTObjective: Conduction of vasodilation triggered by acetylcholine (ACh) in arteriolar networks reflects hyperpolarization and its spread from cell to cell along the vessel wall. The amplitude and distance of the vasomotor response appear greater than can be explained by simple passive decay of the electrical signal. The authors tested the hypothesis that the conduction of hyperpolarization involves active membrane processes as the signal travels along the arteriolar wall.Methods: Intracellular recordings of membrane potential were made from either the smooth muscle or endothelial cell layer of arterioles of the hamster cheek pouch in vivo. Acetylcholine was delivered onto an arteriole using microiontophoresis at defined distances from the recording site, and transient hyperpolarizations were recorded. The area enclosed by the transients (voltage × time integral below baseline) was measured and compared to the area expected if the hyperpolarization was spreading passively.Results:In 11 of 15 recordings from smooth muscle and 5 of 7 from endothelium, areas of the transients were larger than expected for purely passive spread of the electrical signal.Conclusions: Conduction of hyperpolarization is enhanced by active membrane processes as the signal travels along the arteriolar wall. Signal augmentation will promote blood flow to tissue regions from which hyperpolarization of arterioles originates.
Functional Link Between ETB Receptors and eNOS Maintain Tissue Oxygenation in the Normal Liver
Authors: PAXIAN MARKUS , KELLER STEVE A. , BAVEJA RAJIV , KORNESZCZUK KATARZYNA , HUYNH TOAN T. , CLEMENS MARK G. 
Published: June 2004

ABSTRACTObjective: Endothelins and their receptors play a crucial role in regulating liver microcirculation in pathophysiological conditions. The authors investigated the functional significance of the coupling of ETB receptors and eNOS in maintaining regional perfusion and tissue oxygenation in the normal liver.Methods: The effect of endothelin‐1 or the ETB agonist IRL1620 on oxygen consumption was determined in isolated perfused liver and isolated hepatocytes. Oxygen delivery to the liver tissue was determined in vivo. Following eNOS or iNOS blockade, either ET‐1 or IRL1620 was infused via the portal vein. Hepatic tissue oxygenation, redox state, and microcirculation were investigated by intravital microscopy. Injury was estimated by serum LDH.Results: Although IRL1620 and endothelin‐1 increased oxygen consumption in isolated hepatocytes, in intact liver, endothelin decreased oxygen consumption while IRL1620 produced no change. In vivo, ETB stimulation modestly altered hepatic tissue PO2, redox potential, and microcirculation. eNOS inhibition and ETB activation dramatically reduced microcirculatory blood flow, oxygen supply, and increased LDH release. Inhibition of iNOS resulted in small but not significant changes in these parameters. Concomitant ETA/ETB receptor activation increased microcirculatory failure and decreased tissue oxygen even without NOS inhibition. In contrast, hepatocellular injury was significantly increased following eNOS inhibition.Conclusions: Coupling between ETB receptor stimulation and eNOS activation decreases sinusoidal constriction and plays a functionally important role in maintaining microcirculation and tissue oxygenation in the normal liver.
From private to public: Alba de Céspedes' agony column in 1950s Italy
Authors: Morris Penny 
Published: June 2004

SummaryA unique, if problematical, historical source for the study of the ‘private sphere’, the problem page has, as yet, been the subject of little serious attention. This article initially considers the problem page in general terms, and with particular reference to 1950s Italy, a time when a notable feature of the changing patterns of cultural consumption was the emergence and upsurge in popularity of the weekly magazine. The rest of the paper is devoted to an analysis of best-selling author Alba de Céspedes' agony column, ‘Dalla parte di lei’, published in the magazine Epoca. The article shows that the column provides intriguing insights into the state of family and marriage during a time of transition. It discusses the idea of the agony column as a commodity, but also highlights de Céspedes' aim of providing a kind of compendium of lay morals, arguing that any attempt to provide an alternative to the Catholic Church, and the prevailing conservative attitudes of the time, was a matter of careful negotiation.
Natural mothers: teaching morals and parent-craft in Italy, 1945–60
Authors: Bernini Stefania 
Published: June 2004

SummaryAt the end of the Second World War, politicians and social observers apprehensively considered the condition of the family and its destiny and role in post-war Italy. As well as informing political discourses and sociological examinations, the family became a privileged terrain for medical and psychological enquiry, with particular attention given to parenthood and the maternal role of women. The article explores the role played by religious and medical authorities in shaping narratives of parental responsibilities during the post-war years. The interplay of biology and morality in medical discourse and Catholic teaching is discussed in the context of debates about motherhood and the management of childbirth. Particular attention is given to discussions about the use of pain relief in labour and the reception by Italian Catholic gynaecologists of the so-called ‘natural childbirth method’, advocated during the post-war period by a number of European and American practitioners.
The redefinition of gender roles and family structures among Istrian peasant families in Trieste, 1954–64
Authors: Nemec Gloria 
Published: June 2004

SummaryFrom 1942 to the late 1950s, about 240,000 Italians fled from Istria and Dalmatia, territories included in the new Yugoslav Federal Republic. The last movement of population took place after the London Memorandum in 1954, when the portion of territory closest to Italy (‘Zone B’) was given to Yugoslavia. About 40,000 Italians took part in this last exodus, and most of them were peasants wishing to settle in Trieste. The article describes the adaptation of social behaviours and gender roles among Istrian peasants as they faced new urban realities and modernization in the exodus. Oral sources, personal memoirs, literature and other documents are used to reconstruct the process by which rural communities moved from pre-war stability to change and transformation as they integrated within urban society in Trieste. In this process, gender and familial roles were significantly affected and redefined.
The Italian family from the 1960s to the present
Authors: Saraceno Chiara 
Published: June 2004

SummaryThe family in Italy lies at the centre of an apparent paradox. On the one hand, it appears stronger in its traditional form based on marriage and on intergenerational solidarity than in most European countries. The normal way of living for couples is marriage, marriage instability is lower than the European average, and births out of wedlock are scarce. On the other hand, with its low fertility and long permanence of children in their parents’ household, Italy appears to be a country where the forming of new families and the reproduction of families is most difficult. This article explores the reasons for this paradox, many of which lie in the persistent gender division of labour and in the lack of supportive family policies. At the same time the article shows that despite the apparent stability of the family many changes are under way, some of them dating back to the early 1960s: not only because of fertility decline, but also due to women's changing patterns of behaviour and expectations.
Making connections: family and relatedness in clinics of assisted conception in Italy
Authors: Bonaccorso Monica 
Published: June 2004

SummaryThis article explores contemporary notions of Italian kinship—procreation, the family, biological and social relatedness—as they are shaped by programmes of gamete donation (these are programmes that require the use of third-party egg and semen to achieve conception). The research was carried out in Italian clinics of assisted conception and presents the views of heterosexual couples suffering from impaired infertility. The overall material reveals the power of kinship as a cultural form.
Resolving the departures of observed results from the Ideal Free Distribution with simple random movements
Authors: Jackson A. L. , Humphries S. , Ruxton G. D. 
Published: June 2004

Summary

The Ideal Free Distribution (IFD) is one of the most widely applied theoretical concepts in ecology. Many experimental tests of the IFD incorporating unequal competitors have revealed three consistent departures of observed results from those predicted by the theory. Specifically these are: (1) the full range of predicted equilibria are rarely realized; (2) under‐matching of individuals to resource inputs; and (3) continued movement of individuals after equilibrium is reached.
It has been suggested previously that a model including simple random movements can explain simultaneously all three of these departures. The acceptance of this theory has been hindered by arguments about model construction relating to the timing of events and whether an analytical or individual‐based model is more appropriate.
Here we present the first internally consistent and biologically realistic model of the IFD incorporating random non‐IFD movements (movements made at a rate independent of intake rates). We use this model to confirm that random movements alone can explain all three of the observed departures from the IFD. Furthermore, it is not necessary to have any detailed a priori knowledge about the motivation behind the non‐IFD movements, in order to predict their consequences. We expect non‐IFD movements to be widespread in animal systems, and so warrant further experimental consideration and investigation.
Lifetime reproductive success in relation to morphology in the house sparrowPasser domesticus
Authors: Jensen Henrik , SÆther Bernt‐Erik , Ringsby Thor Harald , Tufto Jarle , Griffith Simon C. , Ellegren Hans 
Published: June 2004

SummaryIn this study we relate variation in lifetime reproductive success (LRS) of male and female house sparrowsPasser domesticusto morphological characteristics.Our analyses demonstrated no sex‐specific difference in the distribution ofLRS. The variance inLRSwas influenced mainly by variation in individual annual reproductive success, and to a lesser extent by variation in individual lifespan.Phenotypic traits explained a significant proportion of the variation inLRSin males, but not in females. The effect of male morphology onLRSoperated mainly through an effect on the number of recruiting daughters.The size of the patch of black feathers on the chest of males (badge size) and male bill length were both positively associated withLRS. Lifespan and bill length were positively related and reproductive success increased with badge size. In females, number of recruiting daughters was positively related to bill length, body mass and body condition index due to the positive effect of these traits on annual production of daughters.These results indicate that identifying factors causing the large individual variation inLRS, which is likely to be closely related to fitness, will be important to understand microevolutionary processes in this metapopulation, and hence their demographic feedbacks.
Lack of homeward orientation and increased mobility result in high emigration rates from low‐quality fragments in a dune wolf spider
Authors: Bonte Dries , Lens Luc , Maelfait Jean‐Pierre 
Published: June 2004

Summary

Mobility and emigration were investigated for the wolf spider Pardosa monticola in grey dune fragments from two high‐density and one low‐density population, where population density was related to patch quality. Pitfall trapping was applied in combination with absolute density estimates by means of quadrat sampling. Orientation behaviour was additionally observed in the high‐ and low‐density patches during two periods in the adult life‐phase (mating and reproduction period). Dune grassland is the core habitat; moss dominated vegetation is the matrix in which dispersal occurs.
Our field experiments confirm the hypothesis that increased activities of a dune wolf spider in a low‐density habitat result in higher emigration rates.
The diffusive emigration rates, which are higher close to the patch border, and mobility within the patch are higher in the low‐density population. In the low‐density patch, females are even more active than males and emigrate in the same proportions as males.
Both males and females were not able to orientate and perform homeward movements during the spring period, in which vegetation height is more or less equal in the core habitat (grassland) and the matrix (moss dune). In June, no homeward orientation was observed in the habitat patch with low quality and low densities (low vegetation height). In the high‐density patch, females but not males were able to perform homeward orientation behaviour at distances close to the pronounced border between grassland and moss dune. At distances of 3 m, females also orientated randomly.
The pattern of differentiated homeward orientation behaviour indicates that it results from visual perception of high contrast borders by the females but not by the males or by sex‐differentiated motivation to return to the core habitat.
Increased emigration rates as a result of higher spider mobility together with the absence of visual orientation towards the patch border suggest the presence of an Allee effect in low‐density patches.
Fish abundance with no fishing: predictions based on macroecological theory
Authors: Jennings Simon , Blanchard Julia L. 
Published: June 2004

SummaryFishing changes the structure of fish communities and the relative impacts of fishing are assessed usefully against a baseline. A comparable baseline in all regions is fish community structure in the absence of fishing.The structure of unexploited communities cannot always be predicted from historical data because fisheries exploitation usually precedes scientific investigation and non‐fisheries impacts, such as climate change, modify ecosystems over time.We propose a method, based on macroecological theory, to predict the abundance and size‐structure of an unexploited fish community from a theoretical abundance–body mass relationship (size spectrum).We apply the method in the intensively fished North Sea and compare the predicted structure of the unexploited fish community with contemporary community data.We suggest that the current biomass of large fishes weighing 4–16 kg and 16–66 kg, respectively, is 97·4% and 99·2% lower than in the absence of fisheries exploitation. The results suggest that depletion of large fishes due to fisheries exploitation exceeds that described in many short‐term studies.Biomass of the contemporary North Sea fish community (defined as all fishes with body mass 64 g−66 kg) is 38% lower than predicted in the absence of exploitation, while the mean turnover time is almost twice as fast (falls from 3·5 to 1·9 years) and 70% less primary production is required to sustain it.The increased turnover time of the fish community will lead to greater interannual instability in biomass and production, complicating management action and increasing the sensitivity of populations to environmental change.This size‐based method based on macroecological theory may provide a powerful new tool for setting ecosystem indicator reference levels, comparing fishing impacts in different ecosystems and for assessing the relative impacts of fishing and climate change.