bluuebunny/crossref_metadata_2025 huggingface dataset:
Cdc42 and RhoB Activation Are Required for Mannose Receptor-mediated Phagocytosis by Human Alveolar Macrophages
Authors: Zhang Jianmin , Zhu Jinping , Bu Xia , Cushion Melanie , Kinane T. Bernard , Avraham Hava , Koziel Henry
Published: December 2004

Human alveolar macrophages (AMs) phagocytose Pneumocystis (Pc) organisms predominantly through mannose receptors, although the molecular mechanism mediating this opsonin-independent process is not known. In this study, using AMs from healthy individuals, Pc phagocytosis was associated with focal F-actin polymerization and Cdc42, Rac1, and Rho activation in a time-dependent manner. Phagocytosis was primarily dependent on Cdc42 and RhoB activation (as determined by AM transfection with Cdc42 and RhoB dominant-negative alleles) and mediated predominantly through mannose receptors (as determined by siRNA gene silencing of AM mannose receptors). Pc also promoted PAK-1 phosphorylation, which was also dependent on RhoGTPase activation. HIV infection of AMs (as a model for reduced mannose receptor expression and function) was associated with impaired F-actin polymerization, reduced Cdc42 and Rho activation, and markedly reduced PAK-1 phosphorylation in response to Pc organisms. In healthy AMs, Pc phagocytosis was partially dependent on PAK activation, but dependent on the Rho effector molecule ROCK. These data provide a molecular mechanism for AM mannose receptor-mediated phagocytosis of unopsonized Pc organisms that appears distinct from opsonin-dependent phagocytic receptors. Reduced AM mannose receptor-mediated Cdc42 and Rho activation in the context of HIV infection may represent a mechanism that contributes to the pathogenesis of opportunistic pneumonia.
Interaction of Sla2p's ANTH Domain with PtdIns(4,5)P2Is Important for Actin-dependent Endocytic Internalization
Authors: Sun Yidi , Kaksonen Marko , Madden David T. , Schekman Randy , Drubin David G.
Published: December 2004

A variety of studies have implicated the lipid PtdIns(4,5)P2in endocytic internalization, but how this lipid mediates its effects is not known. The AP180 N-terminal homology (ANTH) domain is a PtdIns(4,5)P2-binding module found in several proteins that participate in receptor-mediated endocytosis. One such protein is yeast Sla2p, a highly conserved actin-binding protein essential for actin organization and endocytic internalization. To better understand how PtdIns(4,5)P2binding regulates actin-dependent endocytosis, we investigated the functions of Sla2p's ANTH domain. A liposome-binding assay revealed that Sla2p binds to PtdIns(4,5)P2specifically through its ANTH domain and identified specific lysine residues required for this interaction. Mutants of Sla2p deficient in PtdIns(4,5)P2binding showed significant defects in cell growth, actin organization, and endocytic internalization. These defects could be rescued by increasing PtdIns(4,5)P2levels in vivo. Strikingly, mutant Sla2p defective in PtdIns(4,5)P2binding localized with the endocytic machinery at the cell cortex, establishing that the ANTH-PtdIns(4,5)P2interaction is not necessary for this association. In contrast, multicolor real-time fluorescence microscopy and particle-tracking analysis demonstrated that PtdIns(4,5)P2binding is required during endocytic internalization. These results demonstrate that the interaction of Sla2p's ANTH domain with PtdIns(4,5)P2plays a key role in regulation of the dynamics of actin-dependent endocytic internalization.
The expression patterns of mRNA‐encoding stem cell factor, internal stem cell factor and c‐kit in the prepubertal and adult porcine ovary
Authors: Brankin V. , Hunter M. G. , Horan T. L. , Armstrong D. G. , Webb R.
Published: December 2004

The receptor, c‐kit, and its ligand, stem cell factor (SCF), are important regulators of ovarian follicle growth and development. The aim of this study was to identify the sites of expression of mRNA for c‐kit and SCF in prepubertal and mature (pregnant and non‐pregnant) animals. Ovaries were recovered from prepubertal animals, non‐pregnant sows and five sows at approximately 3 months of gestation. Ovine SCF and c‐kit DNA were cloned into plasmid vectors to produce RNA probes. Expression of mRNA encoding SCF and c‐kit were detected via in situ hybridization. Both mRNA were detected throughout ovaries from all animals. This study provides evidence that the growth‐factor complex is required throughout follicle development, and also for continued maintenance of the corpus luteum (CL) in the mature animal. SCF mRNA was localized to the granulosa cell layer and was also extensively expressed in endothelial tissue and throughout the CL. c‐kit mRNA was detected in the theca layer, oocytes and also in CL. In conclusion, expression of SCF and c‐kit mRNA in granulosa and theca cells, respectively, indicate an important interaction between somatic cells throughout follicle development and that in the mature animal, SCF and c‐kit potentially have a role in maintaining progesterone secretion by the CL. The observations of continued expression of SCF and c‐kit throughout development suggest that there may be differences in the role of this receptor–ligand complex between large mono‐ vs. poly ovulatory species, such as the pig.
Evaluation of cyclin D1 expression and its subcellular distribution in mouse tissues
Authors: De Falco Maria , Fedele Valentina , De Luca Luca , Penta Roberta , Cottone Giuliano , Cavallotti Ivan , Laforgia Vincenza , De Luca Antonio
Published: December 2004

Cyclin D1 is a key cell‐cycle regulatory protein required for the cell to progress through G1 to S phase. We have shown by Western blot analysis that cyclin D1 has a wide distribution in adult mouse tissues, with its level of expression being tissue‐dependent. Immunohistochemistry has also shown that cyclin D1 may be present in the cytoplasm, in the nucleus or in both these cell compartments: cytoplasmic staining was observed in both proliferating cells (e.g. kidney, intestine, stomach and salivary gland) and in the non‐dividing cells (the mature neurons of adult brain), while nuclear staining was seen in the neurons of the embryonic nervous system. Immunoelectron microscopy results indicate that, in tissues where cyclin D1 is present in both compartments (e.g. intestinal enterocytes), it may move via nuclear pores from the nucleus to the cytoplasm, and vice versa. The findings as a whole suggest that cyclin D1 may play multiple roles within specific tissues, probably by interacting with different substrates, and that its transit between nuclear and cytoplasmic compartments may help maintain cell homeostasis.
Chronic systemic hypoxia causes intra‐retinal angiogenesis
Authors: Shortt Alex J. , Howell Katherine , O'Brien Colm , McLoughlin Paul
Published: December 2004

Retinal hypoxia occurs in many conditions that cause vascular disease in the eye and is an important stimulus to new vessel formation. However, the adult retina can also become hypoxic when there is systemic hypoxaemia such as occurs in chronic lung diseases, congenital cardiac disease and residence at high altitude. Little is known about the adaptive responses of the retinal vasculature in such circumstances. Previous research in the retinopathy of prematurity model may not apply to the adult tissue given the different mechanisms controlling angiogenesis in developing and mature circulations. We tested the hypothesis that chronic systemic hypoxia leads to angiogenesis in the adult retinal circulation, in the absence of pre‐existing vascular disease. Adult male Sprague–Dawley rats (n = 9) were exposed to a fraction of inspired oxygen of 0.10 for 2 weeks while control animals (n = 10) were exposed to room air. Stereological techniques were used to quantify the vascular volume, endothelial surface area and the total number of branch points of all blood vessels in the superficial retinal vascular plexus. The mean volume and endothelial surface area of these vessels were significantly greater in the hypoxic than in the control group. The mean number of blood vessel branch points was also significantly greater in the hypoxic group. Our findings demonstrate that chronic systemic hypoxia, in the absence of other pathological processes, causes angiogenesis in the adult rat retina and provide an in vivo model for investigating this important process in the adult retina, in particular pathways specific to this tissue.
THE GLOBAL‐LOCAL NEXUS: NGOs AND THE ARTICULATION OF SCALE
Authors: ARTS BAS
Published: December 2004

Non‐Governmental Organisations (NGOs), such as Greenpeace, World Wide Fund for Nature (WWF), Pax Christi, Oxfam and Amnesty International, have become effective political players at different governance levels: local, regional, national and international. In addition, they have contributed to the construction of multi‐level governance practices as well as to a re‐articulation of scale. They have done so, among others, by ‘thinking globally, acting locally’; re‐conceptualising local issues into global ones (and vice versa); bringing local interests to international negotiating tables; and building up ‘glocalised’ networks. In this paper, three cases to illustrate these claims will be presented: (a) the Biodiversity Convention; (b) the human rights regime; and (c) the Forest Stewardship Council (FSC). As a general conclusion, the effects of these non‐state, de‐territorialised and ‘glocalised’ practices on the role and authority of the nation state will be (shortly) assessed. It will be claimed that we do not observe a ‘general retreat of the state’, but issue‐specific re‐definitions of its role and authority.
GLOBAL ‘LIFEWORLDS’ VERSUS LOCAL ‘SYSTEMWORLDS’: HOW FLYING WINEMAKERS PRODUCE GLOBAL WINES IN INTERCONNECTED LOCALES
Authors: LAGENDIJK ARNOUD
Published: December 2004

How do culture and the economy relate in a spatial context? Recent work on the economy‐culture relationship has developed the idea of ‘articulation’. Rather than conceiving culture as a separate factor, as an add‐on to economic analysis, culture and the economy represent interlaced dimensions in economic processes. The economy represents a cultural process, but culture, in turn, is influenced by the evolution of economic practices and concepts, including the advances of economic science. This paper will focus on how this articulated interpretation of the culture‐economy relationship bears on our conceptualisation of the territorial dimension of the economy. The starting point of the discussion is the prevalent emphasis on the region or ‘locale’ as a core site of economic development, set against the background of pervasive globalisation. Responding to recent discussions on Habermas's conceptual pair of ‘systemworld’–‘lifeworld’, an ‘articulated’ perspective on space is presented. One of the key messages is that an analysis of economic processes in space should develop a much richer interpretation of the market, which should be perceived as a culturally and territorially‐rooted institution. Such an interpretation may be inspired by the notion of ‘organised markets’, as well as by the conceptualisation of the economy and economics suggested by actor‐network thinking.
Transcriptional regulation of the humanABOhisto‐blood group genes is dependent on the N box upstream of the proximal promoter
Authors: Kominato Yoshihiko , Hata Yukiko , Matsui Kazuhiro , Takizawa Hisao , Tsukada Jun‐ichi , Nakajima Tamiko , Kaneko Yasushi , Kishi Koichiro
Published: December 2004

BACKGROUND: Our previous studies of the transcriptional regulation of the humanABOgene indicated that negative regulatory elements are present in the sequence just upstream from the proximal promoter. The role of the −275 to −118 region in regulation ofABOgene transcription is further characterized.

STUDY DESIGN AND METHODS: Transient transfection experiments into various cells were performed with luciferase reporter plasmids carryingABOupstream sequences, and electrophoretic mobility shift assay was carried out with a nuclear extract prepared from the human gastric cancer KATOIII cells.

RESULTS: It is shown that the −202 to −118 region is involved in the negative regulation ofABOgene transcription in all cell lines examined. Transient transfection experiments in KATOIII cells with a reporter plasmid carrying mutated N box at −196 to −191 demonstrate that the N box is a negative regulatory element in the −202 to −118 sequence. Electrophoretic mobility shift assays indicate that the N box binds with a nuclear factor from KATOIII cells.

CONCLUSION: These results indicate that repression of transcription from theABOproximal promoter is partially dependent upon the N box. Therefore, reduced binding of the protein with the N box might play a direct role inABOgene expression.
Good and poor mobilizing patients differ in mobilized CD34+ cell adhesion molecule profiles
Authors: Ford Clyde D. , Greenwood Jay , Anderson Jeffrey , Handrahan Diana , Petersen Finn Bo
Published: December 2004

BACKGROUND:  Alterations in expression of adhesion molecules are important in the trafficking of hematopoietic progenitors and probably in the mobilization process. Relatively little and conflicting data are currently available on the differences in expression between good and poor mobilizing patients.

STUDY DESIGN AND METHODS:  In this study, the expression of eight adhesion molecules on the collected CD34+ cells from 36 patients undergoing mobilization was determined.

RESULTS:  Good mobilizing patients, defined as those who collected their target in one apheresis procedure, had significantly fewer cells that expressed CD11a (LFA‐1) and CD54 (ICAM‐1) and borderline fewer that expressed CD11c, CD49d (VLA‐4), and CD49d (VLA‐5). No differences were detected in CD11b (Mac‐1), CD15s (sLex), or CD62L (L‐selectin). Linear regression analysis identified number of prior chemotherapy courses and expression of CD11a (LFA‐1) as independent predictive factors for mobilization efficiency. Good and poor mobilizing patients had approximately the same number of total CD34+ cells collected and little difference in times to engraftment.

CONCLUSIONS:  CD11a (LFA‐1) expression inversely correlates with mobilization efficiency. Elucidation of the mechanism(s) underlying these observations will require further study.
Epitheliotrophic capacity of a growth factor preparation produced from platelet concentrates on corneal epithelial cells: a potential agent for the treatment of ocular surface defects?
Authors: Hartwig Dirk , Harloff Susanne , Liu Lei , Schlenke Peter , Wedel Thilo , Geerling Gerd
Published: December 2004

BACKGROUND:  Topical application of serum eye drops has been reported to accelerate healing of persistent ocular surface defects. It is supposed that growth factors in serum support the wound healing process. Platelets (PLTs) are rich in growth factors and easily available as PLT concentrates (PCs) from blood banks. Therefore, growth factor preparations from PCs may serve as a new and superior therapeutic agent for such defects.

STUDY DESIGN AND METHODS:  After thrombin stimulation for growth factor release, the cell‐free supernatant (PLT releasate) of washed PCs (n = 8) was analyzed for epitheliotrophic factors and its wound healing capacity in comparison to serum (n = 8). Human corneal epithelial cells were used as a model to investigate cell growth, migration, and differentiation in response to both blood products.

RESULTS:  PLT releasate contains more epithelial growth factor, PLT‐derived growth factor, and transforming growth factor‐β, but less hepatocyte growth factor, fibronectin, and vitamins. Cell growth was significantly better in response to PLT releasate. Migration and differentiation were slightly better supported by serum.

CONCLUSION:  Possibly owing to its high content of growth factors, PLT releasate has a distinct superior effect on cell growth. Stimulation of migration and differentiation was slightly inferior but still acceptable. PLT releasate could therefore be a novel treatment option for ocular surface defects.
Detection of free hepatitis C virus core antigen by enzyme‐linked immunosorbent assay is not suitable for screening of granulocyte colony‐stimulating factor‐mobilized hematopoietic progenitor donors
Authors: Lozano María L. , Candela María J. , Cano Horacio , Zuazu Isabel , Vicente Vicente
Published: December 2004

BACKGROUND:  Recent studies have shown that hepatitis C virus (HCV) can be detected in peripheral blood mononuclear cells of patients who are negative for the presence of anti‐HCV and serum HCV RNA. The aim of the study was to evaluate the prevalence of HCV viremia in granulocyte colony‐stimulating factor (G–CSF) mobilized peripheral blood progenitor cell (PBPC) donors by the use of a free HCV core antigen enzyme‐linked immunosorbent assay (ELISA).

STUDY DESIGN AND METHODS:  A total of 28 samples from consecutive PBPC donors that were mobilized with G–CSF, and 13 samples from patients presenting with leukocytosis of greater than 20 × 109 per L from other causes, were tested by a free HCV core antigen ELISA. Positive samples were confirmed by use of neutralization assays. The specificity of the assay was studied in 48,911 healthy blood donors negative for the presence of anti‐HCV.

RESULTS:  The free HCV core antigen assay showed a 46.4 percent positivity in PBPC donors mobilized with G–CSF and 61.5 percent in patients exhibiting leukocytosis in the absence of G–CSF treatment. All the samples were found to be false‐positive samples, and those related with growth factor treatment did not react when G–CSF was discontinued. Overall specificity by the test in freshly collected blood donor specimens was 99.62 percent.

CONCLUSION:  Data indicate that the free HCV core antigen ELISA is not a valid test in diagnosing HCV infection in G–CSF‐treated PBPC donors. Moreover, false‐positive results of this test on blood donors might be indicative of elevated white blood cell numbers. The low specificity of this assay in the PBPC mobilization setting suggests that molecular assays should be the test of choice in the screening of G–CSF‐treated donors.
Securing U.S. Energy in a Changing World
Authors: Verrastro Frank A. , Placke James A. , Hegburg Alan S.
Published: December 2004

The following is an edited transcript of the thirty‐sixth in a series of Capitol Hill conferences convened by the Middle East Policy Council. The meeting was held on September 17, 2004, in the Russell Senate Office Building with Chas. W. Freeman, Jr., moderating. See http://www.mepc.org/public_asp/forums_chcs/37.asp for slides accompanying Mr. Verrastro's remarks.
The Israeli Disengagement Initiative
Authors: Golan Galia
Published: December 2004

Dr. Golan is professor, emerita, in the department of political science at the Hebrew University of Jerusalem and professor of government at the Interdisciplinary Center, Herzliya.
Stepping Stones to Permanent Employment in the Public Service
Authors: Tunny Gene , Mangan John
Published: December 2004

Abstract.  Labour force transitions are investigated using a longitudinal database covering staff movements in the Queensland public service. The database covers those who have entered the public service through traditional recruitment methods as well as those who have entered through temporary and casual appointments. The analysis is based on a new methodology of cumulative incidence function testing and competing risks regression analysis. Interest is centred on entry by non‐standard employees and their subsequent transition through the public service. It was found that non‐standard employment can be a stepping stone to permanent employment but only for about one in four new non‐standard employees.
How prevalent is smoking and nicotine dependence in primary care in Germany?
Authors: Hoch Eva , Muehlig Stephan , Höfler Michael , Lieb Roselind , Wittchen Hans‐Ulrich
Published: December 2004

Aims  Identifying, diagnosing and reducing nicotine use, dependence and related morbidity are considered key responsibilities of primary care physicians. Little is known, however, about the magnitude of the problem in primary care and the extent of treatment in Germany. This paper reports on (1) life‐time and point prevalences of smoking and nicotine dependence among unselected consecutive German primary care attendees; (2) associations of smoking status with socio‐demographic features and (3) rates of doctors’ recognition and treatment patterns.

Design  Data came from the Smoking and Nicotine Dependence Awareness and Screening Study (SNICAS), a nationally representative two‐stage epidemiological point prevalence study (stage I: prestudy characterization of a nation‐wide sample of 889 primary care doctors; stage II: target day assessment of 28 707 unselected consecutive patients).

Results  (1) Of all primary care attendees, 71% reported having ever used a tobacco product (life‐time regular smokers 51%; life‐time occasional smokers 21.5%.). Point prevalence (4 weeks) of smoking was considerably lower (occasional use 4.7%, regular use 24.9%). The rate of DSM‐IV nicotine dependence (13.9%) was highest among the youngest age groups. (2) Rates of regular and dependent smokers decreased markedly with age, mainly as a result of the steadily increasing numbers of male ex‐smokers and low numbers of older female life‐time ever smokers. Young age, unemployment, being single, divorced, widowed or separated from the partner were associated with higher rates of smoking or nicotine dependence. (3) In about 25% of patients, primary care doctors failed to recognize the patient's current smoking and/or nicotine dependence. Case recognition was highest for nicotine dependence (76%). Among recognized cases, 56% had ever received any kind of advice or counselling about quitting; yet only 12% had ever participated in any smoking cessation programme.

Conclusions  Beyond the confirmation of the well‐established finding of a high prevalence of smokers in primary care, this paper demonstrates (1) considerable point prevalence of DSM‐IV nicotine dependence (14%); (2) that it is noteworthy, however, that the rates are not higher than those in community samples; and (3) a considerable variation by age group with highest rates among the young (22–31%), but considerably lower rates among subjects aged 50 and above (16% to 0.9% in the oldest). This substantial association with age seems to be due mainly to the low smoking rates in older women and the increasing numbers of successful, particularly male, quitters from 40 years onwards. Recognition of primary care patients’ smoking status by primary‐care practitioners was moderate, and the frequency of past and current primary care interventions was low. These findings call for systematic investigation into barriers that impede the implementation of smoking cessation interventions in primary care settings.
Land‐use trends in Endemic Bird Areas: global expansion of agriculture in areas of high conservation value
Authors: Scharlemann Jörn P. W. , Green Rhys E. , Balmford Andrew
Published: December 2004

The impacts of humans on biodiversity tend to be exacerbated by the coincidence of human settlement with areas of high biological value, as demonstrated by regional, continental and global analyses. We present a global analysis, intersecting Endemic Bird Areas (EBAs) with fine‐scale data on changes in agricultural land use for the past 300 years and for four scenarios projecting land use up to 2050. The proportion of land in agricultural use is currently greater in EBAs than in the rest of the world (42.0% vs. 37.0%, respectively), has been historically (in 1700: 9.1% vs. 5.7%, through to 1900: 43.4% vs. 32.1%) and looks set to remain so in the future (44.6–56.1% vs. 37.0–43.2%; depending on scenario). However, the future course of agricultural expansion is more scenario‐dependent in EBAs than in the rest of the world, indicating that development policies have considerable potential to either ease or exacerbate the disproportionate impact of agriculture on areas of highest biological value.
Photosynthesis, carboxylation and leaf nitrogen responses of 16 species to elevated pCO2 across four free‐air CO2 enrichment experiments in forest, grassland and desert
Authors: Ellsworth David S. , Reich Peter B. , Naumburg Elke S. , Koch George W. , Kubiske Mark E. , Smith Stan D.
Published: December 2004

The magnitude of changes in carboxylation capacity in dominant plant species under long‐term elevated CO2 exposure (elevated pCa) directly impacts ecosystem CO2 assimilation from the atmosphere. We analyzed field CO2 response curves of 16 C3 species of different plant growth forms in favorable growth conditions in four free‐air CO2 enrichment (FACE) experiments in a pine and deciduous forest, a grassland and a desert. Among species and across herb, tree and shrub growth forms there were significant enhancements in CO2 assimilation (A) by +40±5% in elevated pCa (49.5–57.1 Pa), although there were also significant reductions in photosynthetic capacity in elevated pCa in some species. Photosynthesis at a common pCa (Aa) was significantly reduced in five species growing under elevated pCa, while leaf carboxylation capacity (Vcmax) was significantly reduced by elevated pCa in seven species (change of −19±3% among these species) across different growth forms and FACE sites. Adjustments in Vcmax with elevated pCa were associated with changes in leaf N among species, and occurred in species with the highest leaf N. Elevated pCa treatment did not affect the mass‐based relationships between A or Vcmax and N, which differed among herbs, trees and shrubs. Thus, effects of elevated pCa on leaf C assimilation and carboxylation capacity occurred largely through changes in leaf N, rather than through elevated pCa effects on the relationships themselves. Maintenance of leaf carboxylation capacity among species in elevated pCa at these sites depends on maintenance of canopy N stocks, with leaf N depletion associated with photosynthetic capacity adjustments. Since CO2 responses can only be measured experimentally on a small number of species, understanding elevated CO2 effects on canopy Nm and Na will greatly contribute to an ability to model responses of leaf photosynthesis to atmospheric CO2 in different species and plant growth forms.
Canopy recovery after drought dieback in holm‐oak Mediterranean forests of Catalonia (NE Spain)
Authors: Lloret Francisco , Siscart Daniel , Dalmases Carles
Published: December 2004

Climate change is likely to produce more frequent and longer droughts in the Mediterranean region, like that of 1994, which produced important changes in theQuercus ilexforests, with up to 76% of the trees showing complete canopy dieback. At the landscape level, a mosaic of responses to the drought was observed, linked to the distribution of lithological substrates. Damage to the dominant tree species (Q. ilex)and the most common understorey shrub (Erica arborea) was more noticeable on the compact substrates (breccia) than on the fissured ones (schist). This result was consistent with observations documenting deeper root penetration in schist than in breccia materials, allowing the plants growing on fissured substrates to use water from deeper soil levels. Smaller plants were more vulnerable to drought than larger plants in the trees, but not in the shrubs. Overall,Q. ilexwas more affected thanE. arborea. The resilience of the system was evaluated from the canopy recovery 1 year after the episode. Stump and crown resprouting was fairly extensive, but the damage pattern in relation to substrate, plant size, and species remained similar. The effect of recurrent drought episodes was studied on vegetation patches ofQ. ilexlocated on mountain slopes and surrounded by bare rock. We observed that plants that resprouted weakly after a previous drought in 1985 were more likely to die or to produce poor regeneration in 1995 than plants that had resprouted vigorously. Vegetation patches located on the lower part of the slope were also less damaged than patches situated uphill. The study provides evidence of relevant changes in forest canopy as a consequence of extreme climate events. The distribution of this effect across the landscape is mediated by lithological substrate, causing patchy patterns. The results also support the hypothesis that recurrent droughts can produce a progressive loss of resilience, by depleting the ability of surviving plants to regenerate.
Protandry, sexual selection and climate change
Authors: MØller Anders Pape
Published: December 2004

Protandry refers to the earlier appearance of males before females at sites of reproduction. Sexual selection has been hypothesized to give rise to sex differences in benefits and costs of early arrival, thereby selecting for earlier appearance by the sex subject to more intense sexual selection. If sexual selection is more intense, there is a greater premium on early arrival among individuals of the chosen sex because of direct selection for earlier arrival. This hypothesis leads to the prediction that changes in the costs and benefits of early arrival related to changes in environmental conditions should particularly affect the sex that arrives first and hence the degree of protandry. I tested this hypothesis using the Barn SwallowHirundo rustica. During 1971–2003, the degree of protandry increased significantly in a Danish population because males advanced arrival date while females did not. This earlier arrival by males compared with females was correlated with a significant increase by over 1.2 standard deviations in the length of the outermost tail feathers of males, a secondary sexual character, suggesting direct selection on both protandry and the secondary sexual character. Environmental conditions during spring migration in Northern Africa, as reflected by the normalized difference vegetation index, have deteriorated since 1984, resulting in increased mortality among males during spring migration, but not among females, and this deterioration of climatic conditions was positively correlated with an increasing degree of protandry. Likewise, an increase in April temperatures at the breeding grounds during recent decades is positively correlated with increased protandry, apparently because males can arrive earlier without increasing the fitness cost of early arrival. Local population size did not predict changes in arrival date. These findings suggest that rapid changes in climate can cause a change in degree of protandry and secondary sexual characters.
Carbon flow in an upland grassland: effect of liming on the flux of recently photosynthesized carbon to rhizosphere soil
Authors: Ignacio Rangel‐Castro J. , Prosser Jim I. , Scrimgeour Charlie M. , Smith Pete , Ostle Nick , Ineson Phil , Meharg Andy , Killham Ken
Published: December 2004

The effect of liming on the flow of recently photosynthesized carbon to rhizosphere soil was studied using 13CO2 pulse labelling, in an upland grassland ecosystem in Scotland. The use of 13C enabled detection, in the field, of the effect of a 4‐year liming period of selected soil plots on C allocation from plant biomass to soil, in comparison with unlimed plots. Photosynthetic rates and carbon turnover were higher in plants grown in limed soils than in those from unlimed plots. Higher δ13C‰ values were detected in shoots from limed plants than in those from unlimed plants in samples clipped within 15 days of the end of pulse labelling. Analysis of the aboveground plant production corresponding to the 4‐year period of liming indicated that the standing biomass was higher in plots that received lime. Lower δ13C‰ values in limed roots compared with unlimed roots were found, whereas no significant difference was detected between soil samples. Extrapolation of our results indicated that more C has been lost through the soil than has been gained via photosynthetic assimilation because of pasture liming in Scotland during the period 1990–1998. However, the uncertainty associated with such extrapolation based on this single study is high and these estimates are provided only to set our findings in the broader context of national soil carbon emissions.
Gill histopathology of wild marine fish in Tasmania: potential interactions with gill health of cultured Atlantic salmon, Salmo salar L.
Authors: Nowak B F , Dawson D , Basson L , Deveney M , Powell M D
Published: December 2004

This study surveyed conditions in the gills of wild marine fish in Tasmania to determine potential interactions between wild and cultured fish. Wild marine fish of 12 species were captured from three Atlantic salmon farm sites and three reference sites around Tasmania. The survey concentrated on three species, red cod, Pseudophycis bachus, sand flathead, Platycephalus bassensis, and jack mackerel, Trachurus declivus. Seventy‐six per cent of salmon pens contained wild fish species. The number of species found in a pen ranged from one to nine and the number of individuals ranged from one to 23. Trichodinids were prevalent and occurred on seven of the 13 species examined. Trichodina occurred on the gills of all but one specimen of red cod. Monogenean gill flukes were observed on all three major species sampled and were abundant on sand flathead. Other parasites and conditions observed in the survey included metacercariae of digenean trematodes, epitheliocystis and cysts of unknown origin. Infestations of trichodinids on red cod and monogenean gill flukes on sand flathead were significantly more intense at farm sites than at reference sites. Atlantic salmon sampled at the same time from the farms were only affected by amoebic gill disease and isopods.
Characterization of two membrane‐associated protease genes obtained from screening out‐membrane protein genes ofFlavobacterium columnareG4
Authors: Xie H X , Nie P , Sun B J
Published: December 2004

In order to identify genes encoding the outer membrane proteins (OMPs) of the myxobacterFlavobacterium columnareG4, the expression library of the bacterium was screened by using rabbit antisera developed against its OMPs. Positive colonies ofEscherichia coliM15 containing fragments encoding the bacterial OMPs were selected for cloning the relevant genes by genomic walking methods. Two genes encoding a membrane‐associated zinc metalloprotease and prolyl oligopeptidase are reported in this paper. The membrane‐associated zinc metalloprotease gene (map) is 1800 bp in length, coding for 449 amino acids (aa). Despite the presence of a conserved motif HEXXH for all metalloproteases, the special HEXXH ∼ 32 aa ∼ E motif of theF. columnareG4Map and its low level of identity with other reported zinc‐containing metalloproteases may imply that the membrane‐associated zinc metalloprotease ofF. columnareG4represents a new family of zincins. The gene encoding prolyl oligopeptidase (Pop), a serine proteinase, is 2352 bp in length, coding for 649 aa. Sequence homology analysis revealed that the Pop is also novel as it has <50% identity with other reported prolyl oligopeptidase family proteins. The present study represents the first to employ anti‐fish bacterial OMP sera to screen genes of membrane‐associated proteases of fish pathogenic bacteria, and to provide necessary information for the examination of the role of the two genes in the infection and pathogenesis ofF. columnare.
Relationship between Prenatal Survival Rate at 70 days of Gestation and Morphometric Parameters of Vagina, Uterus and Placenta in Gilts
Authors: Vianna WL , Pinese ME , de Campos Rosseto A , Bombonato PP , Rodrigues PHM , de Sant'Anna Moretti A
Published: December 2004

Contents

Swine uterine capacity affects litter size, and it could be used as a selection parameter of reproductive performance. Although there are some controversial results, evidences show that the catheter penetration length is positively correlated with litter size, and it could be used as a tool for predicting selection methods. The aim of this study was to determine whether there is any association between the prenatal survival rate and placental size at 70 days of gestation, the vaginal length [catheter penetration length during artificial insemination (AI)] and the uterine capacity in a homogeneous group of gilts. Sixty‐six commercial‐line gilts in pre‐pubertal phase had their oestrus induced by hormonal treatment [600 UI of Equine Chorionic Gonadtrophin (eCG) i.m. and after a 72‐h period 5 mg of luteinizing hormone (LH) i.m.], but only 40 gilts showed cyclicity after induction. The AI catheter penetration length was tested on these 40 gilts at the moment of AI using a calibrated AI catheter. Four gilts returned to oestrus and the other 36 were killed at around day 69 of pregnancy. The uterine length and weight showed a significant and positive correlation with the prenatal survival rate (p < 0.05). The catheter penetration length was unable to predict the conceptus survival rate on 70 days of gestation; however, the uterine size influenced the survival rate positively. The mean placental area was positively correlated with the mean placental weight (p < 0.0001), and both with the mean foetal weight (p < 0.0001 and p < 0.001, respectively). The analysis of the results obtained showed that neither did the catheter penetration length measurement during AI, nor the prenatal survival rate on day 70 of pregnancy predict the uterine capacity, but the uterine and placental size had a significant influence on the prenatal survival and foetus weight, respectively.
Production of Lambs After the Transfer of Fresh and Cryopreserved in vitro Produced Embryos from Prepubertal Lamb Oocytes and Unsorted and Sex‐sorted Frozen‐thawed Spermatozoa
Authors: Morton KM , Catt SL , Hollinshead FK , Maxwell WMC , Evans G
Published: December 2004

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Cumulus‐oocyte complexes from hormone‐stimulated 3–4‐week‐old (n = 43) and 6–7‐week‐old (n = 12) prepubertal lambs were matured in vitro and incubated with unsorted, or X‐ or Y‐spermatozoa separated with a high‐speed cell sorter (SX MoFlo®) frozen‐thawed. Presumptive zygotes were then cultured to the blastocyst stage, and transferred to recipients fresh or after cryopreservation (frozen). Oocyte cleavage was higher (p < 0.05) with unsorted (515/926, 55.6%) than X‐ or Y‐spermatozoa (261/672, 38.8% and 229/651, 35.2%, respectively) and blastocyst formation (% zygotes) by Day 9 of in vitro culture was lower (p < 0.05) for X‐ (102/261, 39.1%) than unsorted spermatozoa (249/515, 48.3%), but did not differ between Y‐spermatozoa (103/229, 45.0%) and unsorted spermatozoa, or between X‐ and Y‐spermatozoa (p > 0.05). For fresh embryos, survival to term was 50.0% (3/6) for unsorted, 0.0% (0/6) for X‐ and 16.7% (1/6) for Y‐spermatozoa‐derived embryos (p > 0.05), and for frozen embryos was 4.0% (2/50) for unsorted, 9.1% (2/22) for X‐ and 2.9% (1/34) Y‐spermatozoa‐derived embryos (p > 0.05). Of the two lambs born from X‐spermatozoa‐derived embryos, one was female (50%), and from the two Y‐spermatozoa‐derived lambs, both were male (100%), demonstrating that lambs can be produced after the transfer of fresh and cryopreserved IVP embryos derived from prepubertal lamb oocytes and frozen‐thawed sex‐sorted sperm.
Lack of association between occult hepatitis B virus DNA viral load and aminotransferase levels in patients with hepatitis C virus‐related chronic liver disease
Authors: FUJIWARA KEI , TANAKA YASUHITO , ORITO ETSURO , OHNO TOMOYOSHI , KATO TAKANOBU , SUGAUCHI FUMINAKA , SUZUKI SEIJI , HATTORI YUKO , SAKURAI MAYUMI , HASEGAWA IZUMI , OZASA TAKASHI , KANIE FUTOSHI , KANO HIDEYUKI , UEDA RYUZO , MIZOKAMI MASASHI
Published: December 2004

Background and Aim:  Occult hepatitis B virus (HBV) infection in hepatitis C virus (HCV)‐infected patients might enhance the severity of chronic liver disease (CLD). To elucidate the correlation between occult HBV infection and the clinical course of HCV‐related CLD, we evaluated whether the fluctuation of occult HBV‐DNA directly affects the serum alanine aminotransferase (ALT) level.

Methods:  Forty‐one patients with HCV‐related CLD who received regular outpatient treatment and 42 age‐, sex‐, and antibody to hepatitis B core antigen positivity‐matched healthy volunteers were enrolled. Serum HBV‐DNA was quantitatively detected using real‐time detection polymerase chain reaction (RTD–PCR). Serial serum samples in three patients were measured for HBV‐DNA, ALT and HCV core antigen.

Results:  Hepatitis B virus DNA was amplified in eight of the HCV‐related CLD patients (19.5%), which was significantly higher than that of healthy volunteers (2.4%). No significant difference between the genotype 1 HCV‐related CLD group and the genotype 2 group was found. Based on the analyses using serial serum samples, the elevation of HBV‐DNA did not occur before the ALT flares, but occurred at the same time or after the ALT flares.

Conclusions:  The prevalence of occult HBV infection of HCV‐related CLD is significantly higher than that of control. Occult HBV infection has no influence on ALT flares among patients with HCV‐related CLD.
An enigmatic eye: the histology of the tuatara pineal complex
Authors: Ung Casey Y‐J , Molteno Anthony CB
Published: December 2004

Aim:To examine the histology of the tuatara pineal complex and to compare findings wtih those of Dendy. Some reptiles have an anatomically sophisticated pineal complex with a median pineal eye, a paraphysis and a pineal sac. In comparison, the human pineal gland is simple and homogenous and thought to be a phylogenetic relic. It is now considered a neuroendocrine gland the function of which is still not fully understood. Its simple anatomical structure is in contrast to its biochemical complexity; its secretions (the most studied being melatonin) modifying the function of the adeno‐ and neurohypophysis, thyroid and parathyroids, adrenal cortex and medulla, endocrine pancreas and the gonads.

Methods:Histological sections of the brain of a neonatal tuatara were studied by light microscopy.

Results:The histological findings of the pineal eye demonstrated a cornea‐like structure, rudimentary lens and simple retina. The adjacent paraphysis was a large, multisaccular organ and the pineal sac a very large saccular organ with a poorly differentiated retina.

Conclusion:The pineal eye of the tuatara has a remarkably eye‐like structure with photoreceptors that in other reptiles have been shown to exhibit photoreceptive capabilities. The paraphysis appeared to have a secretory function that is as yet undetermined, while the pineal sac had the appearance of a poorly differentiated retina. Thus it appears that the complex biochemistry of the human pineal gland is reflected in the complex anatomical structure of this primitive reptile.
Application of physical principles in the development of tonometry
Authors: Stuckey Gordon C
Published: December 2004

A review of the development of applanation tonometry is undertaken from the perspective of the physical principles involved. Original articles that have contributed to this process are discussed. The result of this endeavour leads to a conclusion that corneal thinning procedures have no effect on original intraocular pressure. Also concluded is a methodology that would allow the direct measurement of original intraocular pressure.
Developments in the management of uveal melanoma
Authors: Damato Bertil
Published: December 2004

Uveal melanomas threaten visual loss, enucleation, and death from metastatic disease. Most patients present because of symptoms, but failures of detection and diagnosis still occur commonly. Treatments aimed at avoiding enucleation include: plaque, proton beam or stereotactic radiotherapy; trans‐scleral or trans‐retinal local resection; and transpupillary thermotherapy. Increasingly, different modalities are being used in combination. The ocular outcomes are related to tumour size, location, spread and cell type. Metastatic disease occurs in many patients and is related to factors such as tumour dimensions, ciliary body involvement, cell type, extravascular matrix patterns and cytogenetics. Abnormalities related to chromosomes 3, 6 and 8 are strongly related to tumour behaviour, for the first time enabling survival probability to be estimated with a high degree of reliability in an individual patient. This enables high‐risk individuals to be targeted for screening while providing reassurance to those with a minimal chance of developing metastatic disease. Such targeting would allow selection of patients for adjuvant systemic therapy, should a suitable treatment become available, and would also facilitate the evaluation of such treatment by increasing the statistical power of any randomized prospective study. The high mortality in patients with monosomy 3 melanoma suggests that in these patients ocular treatment is only palliative. Cytogenetic studies suggest that some melanomas may never develop any metastatic potential and if these impressions are confirmed by further studies, then in these patients the main priority of treatment would be to conserve vision.
Transiently higher release probability during critical period at thalamocortical synapses in the mouse barrel cortex: relevance to differential short‐term plasticity of AMPA and NMDA EPSCs and possible involvement of silent synapses
Authors: Yanagisawa Takufumi , Tsumoto Tadaharu , Kimura Fumitaka
Published: December 2004

Thalamocortical connections undergo remarkable plasticity during the critical period and mounting evidence serves to demonstrate that the activation of silent synapses at postsynaptic sites is an important underlying mechanism in this process. However, relatively little is known about the nature of the presynaptic properties. In the present study, we examined the release probability (Pr) of thalamocortical synaptic terminals on a layer IV neuron in the developing mouse barrel cortex. Using the conventional paired‐pulse ratio (PPR) method, both AMPA and NMDA receptor‐mediated PPR were observed during development. We found that the NMDA PPR increased gradually (thus, a reduction in Pr) from postnatal day (P)4 to P22 but, unexpectedly, the AMPA PPR exhibited a simultaneous decrease. We then used an additional method for assessing release probability, the observation of a progressive block of NMDA receptor‐mediated EPSCs using MK‐801. With this method, we were able to identify two classes of terminals with high or low probabilities of release. Interestingly, the higher release showed a reduction in probability during the critical period, consistent with the NMDA PPR results. We confirmed that the discrepancy between the NMDA and the AMPA PPR results was due to the existence of silent, or NMDA‐only, synapses, as suggested in previous literature. By analysing the correlation between the NMDA or AMPA PPR and the PPR discrepancy, we discuss the hypothesis that the terminals with transiently higher probability of release were found preferentially on silent synapses. Our results suggest that these presynaptic sites may also have an active role in plasticity by working concomitantly with postsynaptic sites during the critical period.