bluuebunny/crossref_metadata_2025 huggingface dataset:
Perspectives on Building Consortia Between Libraries and Other Agencies
Authors: Bell Brian , Borek Dian , Richardson Gail , Lewis Walter
Published: April 2006

This article looks at issues surrounding cooperative partnerships between different types of libraries, and between libraries and other organizations. The Ontario School Curriculum Resource (OSCR) and developments in Ontario and Canada are the focus of the article; however, it also provides perspectives on the cooperative experiences that are fundamental to many partnerships. The important benefits as well as the challenges of partnerships are considered, as is the future of cooperative resource sharing.
EDEN: A Web-Based Model for Electronic Document Exchange
Authors: Durno John
Published: April 2006

The advantages of Web-based document exchange between libraries are just beginning to be systematically explored. This article focuses on general considerations in the development of a Web-based model for electronic document exchange (EDE) in the context of the OpenILL Cooperative's EDEN project. These include an overview of the existing document delivery standard (GEDI) and its relationship to emerging models and a discussion of factors being considered in the development of a Web-based protocol, including document exchange format, application event sequencing, metadata, and security.
Closing the 95 Percent Gap: Library Resource Sharing for People with Print Disabilities
Authors: Epp Mary Anne
Published: April 2006

Experts estimate that only 5 percent of the world's publishing output is made accessible in alternate formats for people who cannot use print. While some popular commercial digital audio and textual products are available to people with print disabilities, many people do not have equal access to reading materials and other resources. People who cannot use print due to a visual, physical, neurological, or perceptual disability need libraries to provide the equitable access. Libraries need strategic partnerships, improved public policy, and international agreements to fulfill the promise. Equity laws, union catalogs, new technology, standards for production and resource sharing, postal subsidies, and commercial production of alternate formats have all helped. This article focuses on key elements that affect library resource sharing for people with disabilities in the United States, Canada, and the United Kingdom. Challenges include attitudes, organizational isolation, diversity of alternate formats, nonadherence to standards, inaccessible online services, an uncooperative publishing industry, inconsistent access to equipment, and inadequate training. Recommendations are made to improve the legal framework, develop sharing library communities, and apply universal design principles.
Consortia in Europe: Describing the Various Solutions through Four Country Examples
Authors: Hormia-Poutanen Kristiina , Xenidou-Dervou Claudine , Kupryte Rima , Stange Kari , Kuznetsov Alex V , Woodward Hazel M
Published: April 2006

This article describes and discusses consortia models in Europe. Emphasis is given to those consortia that support content provision and access to electronic information resources in society. Four country cases are introduced as examples of the heterogeneous solutions chosen by the consortia. The main results and impact of the consortia are discussed. International cooperation has played an important role in the development of consortia in Europe. Regional and global collaboration initiatives are also discussed.
The Online Computer Library Center's Open WorldCat Program
Authors: Nilges Chip
Published: April 2006

This article describes the Online Computer Library Center's (OCLC) Open WorldCat program. WorldCat is a worldwide union catalog created and maintained collectively by more than 9,000 member institutions. Open WorldCat seeks to make library collections and services visible and available through popular search engines such as Yahoo! and Google and other heavily used sites on the open Web. In this capacity, Open WorldCat provides an important central connection between the shared information of the library network and the Web. The article describes the history and rationale of the project; explains how Open WorldCat works for information seekers, participating libraries, and partners; and reports on what OCLC has learned from the program to date.
Interconnected and Innovative Libraries: Factors Tying Libraries More Closely Together
Authors: Webster Peter
Published: April 2006

This article considers the many developments in technology and practice that are making libraries more connected and interdependent. It looks at new integrated online services and reviews the increasing importance of both formal and informal standards. Global centralized Web services are discussed. The relationships between information industry companies and libraries are considered. Virtual reference services and far-reaching digitization projects are explored. The article concludes that close cooperation is allowing libraries to take their services to new levels and is key to the continued innovation of those services.
Cervantes y la satira: Clodio el maldiciente en el Persiles
Authors: Cacho Casal Rodrigo
Published: April 2006

El personaje de Clodio, poeta sat�rico y maldiciente del Persiles, encarna los defectos que Cervantes atribu�a a la s�tira. El autor del Quijote atac� constantemente esta modalidad en sus obras, pues para �l representaba la negaci�n de los preceptos b�sicos que deben sustentar la literatura. Clodio funciona como una alegor�a negativa, y su estudio permite aclarar el significado que Cervantes atribu�a a la s�tira y, al mismo tiempo, desvelar los ideales est�ticos y morales que justifican este rechazo.
El boom en Mundo Nuevo : critica literaria, mercado y la guerra de valoraciones
Authors: Draper Susana
Published: April 2006

La revista Mundo Nuevo se pos� en el campo literario con un intelectual diferente al de Casa de las Am�ricas o Marcha, creando una versi�n est�tica de la nueva narrativa. Al publicitarse que la publicaci�n era financiada por la CIA, Rodr�guez Monegal renunci� a la direcci�n y se gener� un �mbito de pol�micas que intentaron redefinir el "boom" literario diferenciando al "cr�tico" del espacio est�tico y del mercado. Este art�culo analiza estas luchas que constituyeron un cap�tulo fundamental de la "guerra fr�a" en relaci�n al "boom" latinoamericano.
A Large Aggregate of Men: Garro, Renan and the Failure of Alliance
Authors: Lund Joshua
Published: April 2006

I offer a new interpretation of Elena Garro's Los recuerdos del porvenir (1963) by reading it as a political critique of the tense relations between class consciousness and national consolidation. To do so, I read her novel against the nation form as theorized by Ernest Renan in his speech, What is a Nation? (1882). I argue that Renan's insufficiently executed turn against race blunts the force of his argument regarding the nation form, a contradiction that Garro's novel highlights. Ultimately, Renan's theory of the nation is based on a kind of consensual alliance that Garro represents as a near impossibility.
The Lessons of San Manuel Bueno, martir
Authors: Mancing Howard
Published: April 2006

Many readers of San Manuel Bueno, m�rtir, the story of a priest who does not believe in the religion he preaches, have equated the character Manuel Bueno with the author Miguel de Unamuno, a serious conceptual error. After a review of criticism and some theoretical considerations, I propose an understanding of the work as an indictment of conservative ideologies that would keep the masses in believing ignorance. Important to my understanding is the role of the narrator: �ngela. The discursive control assumed by this female narrator provides a positive alternative to the negative lesson of the unbelieving priest.
Textualidad y sexualidad en la construccion de la selva: genealogias discursivas en La voragine de Jose Eustasio Rivera
Authors: Mejias-Lopez Alejandro
Published: April 2006

In this essay, I argue that Rivera's novel shows the Amazonian rainforest as a textual corpus, both a repository of writing and a sexualized body overwritten by history. Through the always contradictory and self-parodying narrative of Arturo Cova, La vor�gine traces a genealogy of exploitation and its legitimating discourses from the moment of conquest to the Rubber Boom. Rather than a true representation of the Latin American natural space, La vor�gine seeks to question the very concept of truth, revealing the Amazon as a space always already written by the linguistic violence of modernity, colonialism, and patriarchy
Antidepressants and the Chaotic Brain: Implications for the Respectful Treatment of Selves
Authors: Heinrichs Douglas W
Published: April 2006

Traditional understanding of how psychotropic drugs work emphasize highly specific actions at subcellular levels. This model appears to have implications that seriously conflict with our usual view of human agency and autonomy, raising not just theoretical quandaries but contributing to patient reluctance to utilize these drugs. Furthermore, it discourages both meaningful treatment integration and appreciation of the uniqueness of patients. Through a consideration of antidepressants in particular, this paper argues for a more comprehensive model based on nonlinear dynamics and chaos theory that can be applied across multiple domains. This model yields important suggestions for reconciling perspectives in neuroscience with traditional views of human agency. It also encourages real integration of clinical and research approaches in psychiatry, and further defines the components of respectful treatment of patients.
Lived Time and Psychopathology
Authors: Wyllie Martin
Published: April 2006

Some psychopathologic experiences have as one of their structural aspects the experience of restructured temporality. The general argument is that one of the universal microstructures of experience, namely, lived time offers a particular perspective relevant to certain psychopathologic experiences. Lived time is connected with the experience of the embodied human subject as being driven and directed towards the world in terms of bodily potentiality and capability. The dialectical relationship between the embodied human subject and the world results in a sense of lived time (personal time), a lived time that is intimately synchronized with the time of others (intersubjective time). Some experiences of acute suffering, and in particular acute melancholic suffering, can dramatically alter the temporal microstructure of experience to the extent that personal lived time becomes disordered. Normally, past and future withdraw on their own according with their nature of "not being." The future is characterized as openness to change and movement. The absence of this openness is the closing of the future; without this openness, the future appears static and deterministic. When the future is experienced as static, then one longer has the possibility of "things getting better," nor does one have any possibility of relinquishing or escaping from the past because a static future does not allow openness to change and movement. In short, both past and future become static. With the presence of melancholic suffering and the absence of temporal movement, a sense of hopelessness may arise in the individual because suffering without temporal movement becomes, from the sufferer's perspective, eternal suffering.
The Post-9/11 Public Sphere: Citizen Talk about the 2004 Presidential Debates
Authors: Carlin Diana B. , Schill Dan , Levasseur David G , King Anthony S
Published: April 2006

Citizen discussions of the 2004 presidential election provided an opportunity to examine the state of public discourse in the United States. Prior to 9/11 the public sphere was described by many as being in ill health. This study examines discourse about the 2004 election from discussion groups and online discussion boards after the presidential debates to identify the characteristics of discourse exhibited in the public sphere after 9/11. The examination revealed that both forms of discussion exhibited normative ideals. However, egocentric argument rooted in self-interest and personal examples were prevalent, and a preference for domestic rather than international issues was common. The significance of the research rests in the failure of much discussion, especially online discourse, to meet normative ideals. In the end, the findings provide a means for improving future public discourse.
Barack Obama's Address to the 2004 Democratic National Convention: Trauma, Compromise, Consilience, and the (Im)possibility of Racial Reconciliation
Authors: Frank David A , McPhail Mark Lawrence
Published: April 2006

The two authors of this article offer alternative readings of Barack Obama's July 27, 2004, address to the 2004 Democratic National Convention (DNC) as an experiment in interracial collaborative rhetorical criticism, one in which they "write together separately." David A. Frank judges Obama's speech a prophetic effort advancing the cause of racial healing. Mark Lawrence McPhail finds Obama's speech, particularly when it is compared to Reverend Al Sharpton's DNC speech of July 28, 2004, an old vision of racelessness. Despite their different readings of Obama's address, both authors conclude that rhetorical scholars have an important role to play in cultivating a climate of racial reconciliation.
To Form a More Perfect Union: Bill Clinton and the Art of Deliberation
Authors: Murphy John M
Published: April 2006

This essay examines former president Bill Clinton's speech to the 2004 Democratic National Convention. It argues that Clinton crafted a collective agency for his audience. He did so through his emphasis on the choices offered to the audience; the symbolic charge of this speech, in turn, rests in Clinton's ability to weave those choices into a coherent model of deliberation, one presented and enacted by the speaker. His address constitutes the people as the key actor in U.S. history, evaluating the nominees in light of communal wisdom. Such strategies, I argue, offer one path toward a more vibrant political culture.
"You Know Where I Stand": Moral Framing of the War on Terrorism and the Iraq War in the 2004 Presidential Campaign
Authors: Spielvogel Christian
Published: April 2006

Many pundits assumed that an allegiance to "moral values" associated with social issues such as same-sex marriage enabled George W. Bush to narrowly defeat John F. Kerry in the 2004 presidential election campaign. In this essay, I argue that both candidates produced surprisingly little explicit discourse on the moral issues in and of themselves, but rather, in distinct ways, relied upon the moral framing of the "war on terrorism" and the situation in Iraq as a battle between "good and evil" in their day-to-day political discourse. I argue that Bush employed this rhetorical frame to politically and morally cloak the war in Iraq under a larger war on terror and, in this way, produced a hegemonic expression, test, and affirmation of conservative morality. Although John Kerry successfully questioned the validity of Bush's policy framing of the Iraq war as part of the war on terror, he continued to reason within the orthodox moral frame created by Bush in the wake of September 11, 2001. Consequently, Kerry did not critique the conservative moral foundations upon which Bush's policy frame rested nor did he affix an alternative liberal moral worldview to his own discourse on Iraq.
Fascism and Philosophy: The Case of Actualism
Authors: Fogu Claudio
Published: April 2006

From the mid 1980s and for over two decades studies of fascist ideology conducted in the wake of the linguistic turn have delivered a transformed picture of the fascist phenomenon, all but reversing the refusal of an earlier generation of scholars to even grant fascism the status of ideology. Lately, however, a direct challenge to the cultural historiography of fascism has come from intellectual historians such as Martin Jay and Richard Wolin, who have traced the ideological roots of the 'linguistic turn' itself to thinkers associated with fascism, and, through them, all the way to a supposed anti-Enlightenment tradition dating back to the French post-revolutionary period. Seeking to respond to this challenge, this essay seeks to highlight the key role played by the Great War in fostering the ideological coalescence of fascism and in characterizing the confrontation that intellectuals on both the left and the right engaged with it.
The article focuses on the figure of Giovanni Gentile, best known as a neo-idealist philosopher, author of a systemic post-Hegelian philosophical system called attualismo (actualism), and Italian fascism's prime ideologue. Examining Gentile's war-time writings I argue that the development of actualism towards a systemic conflation of politics and philosophy should be seen as the result of Gentile's response to the Italian experience of the Great War culminating in the elaboration of a fully modernist philosophy of history in his seminal essay entitled "Politica e filosofia" (1918). Arguing that the Italian victory in the Great War had proven that all "history belongs to the present" of consciousness and is therefore "entirely immanent in the act of its construction," Gentile called for a new political subject that would orient itself towards this actualist vision of historical action, representation and consciousness. Fascism responded to that call organizing its vision of history around actualist principles.
French Catholic Traditionalism and the Specter of Reactionary Politics
Authors: Stoekl Allan
Published: April 2006

In this article I first sketch out what I think remains the importance and continued appeal of the traditionalist response to Catholic (Vatican II) reform, particularly in light of rising French anxiety concerning the role of religion in civil society. This conservative tendency in French Catholic thought is represented most forcefully by followers of Mgr. Marcel Lefebvre. Lefebrvre's positions involve not only a return to pre-Vatican II practices—the Latin Mass, hierarchical social relations within the Church, etc.—but, more important, a larger rejection of lay society and an implicit (and at times explicit) return to a belief that religious authority and civil authority are or should be one and the same. This rejection of secular society very much puts the traditionalists in league with certain right-wing political parties.
My second goal in this article is to sketch out the ways in which the traditionalist church may very well be headed toward reconciliation with the Vatican, subsequent to the election of Pope Benedict XVI, whose position on ecumenism might tend to be somewhat different from that of John Paul II. If this is the case, the mainstream, post-Vatican II church might indeed find itself, willy nilly, drifting distinctly to the right, if only because anti-ecumenical positions inevitably will lead to anti-republican, if not frankly reactionary, political positions.
Caveolin-1 Expression Is Associated with Plaque Formation in Hypercholesterolemic Rabbits
Authors: Lin Wei-Wen , Lin Yu-Chun , Chang Ti-Yu , Tsai Shu-Huai , Ho Hon-Chun , Chen Ying-Tsung , Yang Vivian C.
Published: April 2006

Caveolin-1, the major structural protein of caveolae, is present in several cell types known to play a role in the development of atherosclerosis. In this study, the distribution and expression of caveolin-1 in the arterial walls were studied in hypercholesterolemic rabbits. Immunohistochemical results indicated that the staining intensity of caveolin-1 reached a high level in the arterial intima at 5 weeks after high-cholesterol-diet treatment and decreased to a very low level at 8 weeks when atheromatous plaques appeared. Western blot analysis showed that in rabbits fed a high-cholesterol diet for 5 weeks, the expression of caveolin-1 reached its highest level and then decreased from 8 to 12 weeks. The proliferative activity of smooth muscle cells (SMCs) decreased to the lowest level at 5 weeks and then increased at 8 and 12 weeks. Nitric oxide synthase activity gradually decreased in animals fed a high-cholesterol diet throughout the experiment. These studies demonstrate that the change in abundance of caveolin-1 is associated with SMC proliferation in the formation of atheromatous plaque after hypercholesterolemia insult.
Altered Expression of Ezrin in Esophageal Squamous Cell Carcinoma
Authors: Zeng Hongmei , Xu Liyan , Xiao Dawei , Zhang Haihua , Wu Xianying , Zheng Ruiming , Li Qiaoshan , Niu Yongdong , Shen Zhongying , Li Enmin
Published: April 2006

Ezrin is a membrane-cytoskeletal linker belonging to the ezrin-radixin-moesin (ERM) family and has been suggested to be involved in tumorigenesis. In this study we investigated ezrin expression pattern in normal esophageal mucosa and esophageal squamous cell carcinoma (ESCC) and the correlation with clinical characteristics. Immunohistochemical staining showed a tendency for ezrin to translocate from membrane to cytoplasm in the progression from normal epithelium to invasive carcinoma of the esophagus. By Western blot, we found that ezrin expression was downregulated in 13 ESCC specimens and upregulated in 36 others. Moreover, quantitative real-time RT-PCR demonstrated that ezrin mRNA level in normal esophageal mucosa was 3.60 ± 3.60 times that in ESCC ( p<0.001). Proliferating cell nuclear antigen (PCNA) expression level was higher in ezrin downregulated group compared with that in ezrin upregulated group ( p<0.05). However, there was no significant association between ezrin expression and clinical characteristics. The results suggested that the localization of ezrin by immunohistochemistry may be useful in the diagnosis of ESCC, and ezrin may play a suppressive role in the tumorgenesis of ESCC.
Estimation and Application of Biological Variation of Urinary δ-Aminolevulinic Acid and Porphobilinogen in Healthy Individuals and in Patients with Acute Intermittent Porphyria
Authors: Aarsand Aasne K , Petersen Per Hyltoft , Sandberg Sverre
Published: April 2006

Background: Diagnosis of an attack of acute intermittent porphyria (AIP) is based on the demonstration of increased concentrations of porphobilinogen (PBG) and δ-aminolevulinic acid (ALA) in urine, but many AIP patients also have high baseline concentrations in remission. The aim of this study was to estimate the biological variations of ALA, PBG, and porphyrins in healthy individuals and AIP patients to improve interpretation of test results.

Methods: Fifteen healthy individuals and 15 AIP patients were included, and biological variations were calculated based on urine samples collected weekly for 10 consecutive weeks. For the AIP patients, long-term variations were also estimated based on 7 samples collected through a 2-year period.

Results: The porphyrin variances were inhomogeneously distributed; biological variations of porphyrins were therefore not calculated. The within-subject biological variations of ALA and PBG were 16%–20% in the short-term settings and for PBG, 25% in the long-term setting, giving reference change values of ∼50% and 70%, respectively. The probability of detecting a 100% real change in PBG was 97% in the short-term setting and 80% in the long-term setting.

Conclusions: In an AIP patient, a 2-fold increase in PBG, independent of the baseline concentration, will be detected with a probability >80% and is most likely related to the patient’s disease and not caused only by analytical and biological variation. When PBG is used in the assessment of AIP-related symptoms, both the PBG concentration in remission and the length of time since the previous sample must be considered.
Different Roles for Amygdala Central Nucleus and Substantia Innominata in the Surprise-Induced Enhancement of Learning
Authors: Holland Peter C. , Gallagher Michela
Published: April 2006

Within most modern learning theories, the discrepancy between expected and obtained outcomes (“prediction error” or “surprise”) is a critical determinant of the acquisition of learned associations. The results of studies from many laboratories show that the surprising omission of an expected event may enhance attention to stimuli that remain present, such that subsequent learning about those stimuli is enhanced. A series of reports from our laboratories demonstrated that these surprise-induced enhancements of stimulus associability depend on circuitry that includes the amygdala central nucleus (CeA), the cholinergic neurons in the sublenticular substantia innominata/nucleus basalis magnocellularis (SI/nBM), as well as certain cortical projections of these latter neurons. In this study, we found very different roles for CeA and SI/nBM in surprise-induced enhancements of stimulus associability. In four experiments that used transient inactivation techniques, we found that surprise-induced enhancement of subsequent learning about a stimulus depended on intact CeA function at the time of surprise but not when more rapid learning was subsequently expressed. In contrast, normal SI/nBM function was critical to the expression of enhanced learning but was not necessary when surprise was induced. These data suggest that these two components of the so-called “extended amygdala” serve distinct roles in the encoding and retrieval of information used in modulating attention to stimuli in associative learning. Additional circuitry linking these brain regions may also be important in the maintenance of that information.
Inclusion Body Formation and Neurodegeneration Are Parkin Independent in a Mouse Model of α-Synucleinopathy
Authors: von Coelln Rainer , Thomas Bobby , Andrabi Shaida A. , Lim Kah Leong , Savitt Joseph M. , Saffary Roya , Stirling Wanda , Bruno Kristy , Hess Ellen J. , Lee Michael K. , Dawson Valina L. , Dawson Ted M.
Published: April 2006

Mutations in the genes coding for α-synuclein and parkin cause autosomal-dominant and autosomal-recessive forms of Parkinson's disease (PD), respectively. α-Synuclein is a major component of Lewy bodies, the proteinaceous cytoplasmic inclusions that are the pathological hallmark of idiopathic PD. Lewy bodies appear to be absent in cases of familial PD associated with mutated forms of parkin. Parkin is an ubiquitin E3 ligase, and it may be involved in the processing and/or degradation of α-synuclein, as well as in the formation of Lewy bodies. Here we report the behavioral, biochemical, and histochemical characterization of double-mutant mice overexpressing mutant human A53T α-synuclein on a parkin null background. We find that the absence of parkin does not have an impact on the onset and progression of the lethal phenotype induced by overexpression of human A53T α-synuclein. Furthermore, all major behavioral, biochemical, and morphological characteristics of A53T α-synuclein-overexpressing mice are not altered in parkin null α-synuclein-overexpressing double-mutant mice. Our results demonstrate that mutant α-synuclein induces neurodegeneration independent of parkin-mediated ubiquitin E3 ligase activity in nondopaminergic systems and suggest that PD caused by α-synuclein and parkin mutations may occur via independent mechanisms.
Neural Variability in Premotor Cortex Provides a Signature of Motor Preparation
Authors: Churchland Mark M. , Yu Byron M. , Ryu Stephen I. , Santhanam Gopal , Shenoy Krishna V.
Published: April 2006

We present experiments and analyses designed to test the idea that firing rates in premotor cortex become optimized during motor preparation, approaching their ideal values over time. We measured the across-trial variability of neural responses in dorsal premotor cortex of three monkeys performing a delayed-reach task. Such variability was initially high, but declined after target onset, and was maintained at a rough plateau during the delay. An additional decline was observed after the go cue. Between target onset and movement onset, variability declined by an average of 34%. This decline in variability was observed even when mean firing rate changed little. We hypothesize that this effect is related to the progress of motor preparation. In this interpretation, firing rates are initially variable across trials but are brought, over time, to their “appropriate” values, becoming consistent in the process. Consistent with this hypothesis, reaction times were longer if the go cue was presented shortly after target onset, when variability was still high, and were shorter if the go cue was presented well after target onset, when variability had fallen to its plateau. A similar effect was observed for the natural variability in reaction time: longer (shorter) reaction times tended to occur on trials in which firing rates were more (less) variable. These results reveal a remarkable degree of temporal structure in the variability of cortical neurons. The relationship with reaction time argues that the changes in variability approximately track the progress of motor preparation.
Amphetamine Exposure Enhances Habit Formation
Authors: Nelson Andrew , Killcross Simon
Published: April 2006

Performance of instrumental actions in rats is initially sensitive to postconditioning changes in reward value, but after more extended training, behavior comes to be controlled by stimulus–response (S-R) habits that are no longer goal directed. To examine whether sensitization of dopaminergic systems leads to a more rapid transition from action–outcome processes to S-R habits, we examined performance of amphetamine-sensitized rats in an instrumental devaluation task. Animals were either sensitized (7 d, 2 mg/kg/d) before training (experiment 1) or sensitized between training and testing (experiment 2). Rats were trained to press a lever for a reward (three sessions) and were then given a test of goal sensitivity by devaluation of the instrumental outcome before testing in extinction. Control animals showed selective sensitivity to devaluation of the instrumental outcome. However, amphetamine sensitization administered before training caused the animals’ responding to persist despite the changed value of the reinforcer. This deficit resulted from an inability to use representations of the outcome to guide behavior, because a reacquisition test confirmed that all of the animals had acquired an aversion to the reinforcer. In experiment 2, post-training sensitization did not disrupt normal goal-directed behavior. These findings indicate that amphetamine sensitization leads to a rapid progression from goal-directed to habit-based responding but does not affect the performance of established goal-directed actions.
Regulation of the neuroendocrine reproductive axis by kisspeptin-GPR54 signaling
Authors: Smith Jeremy T , Clifton Donald K , Steiner Robert A
Published: April 2006

The Kiss1 gene codes for a family of peptides that act as endogenous ligands for the G protein-coupled receptor GPR54. Spontaneous mutations or targeted deletions of GPR54 in man and mice produce hypogonadotropic hypogonadism and infertility. Centrally administered kisspeptins stimulate gonadotropin secretion by acting directly on GnRH neurons. Sex steroids regulate the expression of KiSS-1 mRNA in the brain through direct action on KiSS-1 neurons. In the arcuate nucleus (Arc), sex steroids inhibit the expression of KiSS-1, suggesting that these neurons serve as a conduit for the negative feedback regulation of gonadotropin secretion. In the anteroventral periventricular nucleus (AVPV), sex steroids induce the expression of KiSS-1, implying that KiSS-1 neurons in this region may have a role in the preovulatory LH surge (in the female) or sexual behavior (in the male).
Localization and steroid regulation of prostaglandin E2 receptor protein expression in ovine cervix
Authors: Schmitz Thomas , Levine Brian A , Nathanielsz Peter W
Published: April 2006

Although prostaglandin E2 (PGE2) has been identified as a central mediator of the cervical ripening process, the mechanisms responsible for PGE2 ripening are still poorly understood, partly because of the lack of information concerning the precise cellular localization and regulation of PGE2 (EP) receptors in the cervix. To provide new insights into the mechanisms of cervical ripening, we used indirect immunofluorescence to localize cervical EP receptor protein expression in ovariectomized ewes and examined the effect of administration of progesterone or estradiol. EP receptors were widely distributed in cervical blood vessels, epithelium of the cervical canal, circular and longitudinal muscles, and stroma. Estradiol replacement decreased EP1 and EP3 receptor protein in blood vessel media (by 23 and 31% respectively, P < 0.05) and decreased EP1 receptor protein expression in the longitudinal muscle layer (by 27%, P < 0.05). Stromal EP1 and EP3 receptor protein expression was also reduced by estradiol (by 29 and 20% respectively, P < 0.05). Progesterone replacement had no significant effect on EP receptor protein expression. The arterial changes would favor PGE2-induced vasodilatation, subsequent edema and leukocyte infiltration during the cervical ripening process whereas the muscular alterations would facilitate smooth muscle relaxation and cervical dilatation. Furthermore, estradiol provoked perinuclear localization of EP3 receptor protein in the longitudinal muscle layer. This latter result suggests that cellular EP receptor localization is regulated by estradiol and that PGE2 may also control smooth muscle contraction and regulate ovine cervical dilatation in an intracrine manner via EP3 receptors.
Glycosylation dependent cell adhesion molecule 1-like protein and l-selectin expression in sheep interplacentomal and placentomal endometrium
Authors: Muniz Jésus J , Joyce Margaret M , Taylor James D , Burghardt James R , Burghardt Robert C , Johnson Greg A
Published: April 2006

Glycosylation dependent cell adhesion molecule 1 (GlyCAM-1), a mucin component of sheep histotroph produced by glandular epithelium (GE) during early pregnancy, is hypothesized to function in implantation. However, GlyCAM-1 is present in uterine tissues subsequent to implantation suggesting additional functions of this l-selectin-binding ligand. This study focused on uterine GlyCAM-1 expression during placentome development in sheep. Western blot analysis of day 50 pregnant sheep identified 45, 40, and 25 kDa bands in interplacentomal endometrium, 40 and 25 kDa bands in placentomes, and 80 and 40 kDa bands in chorioallantois. The GlyCAM-1 proteins in interplacentomal regions were comparable to those detected in day 15–19 pregnant sheep, however, the 80 kDa form was unique to chorioallantois, and the absence of the 45 kDa GlyCAM-1 in placentomes indicated differences between interplacentomal and placentomal endometrium. Immunofluorescence identified GlyCAM-1 in lumenal epithelium (LE), stromal fibroblasts, and vascular smooth muscle cells. To better define its cellular distribution, GlyCAM-1 was co-localized with either epithelium-specific cytokeratin, smooth muscle-specific alpha-smooth muscle actin (α SMA), or stromal-specific vimentin. In interplacentomal endometrium, GlyCAM-1 co-localized with cytokeratin in LE but not in GE. GlyCAM-1 did not co-localize with α SMA, and was localized in the extracellular matrix of vimentin-positive stroma. In placentomes, GlyCAM-1 did not co-localize with cytokeratin, but did co-localize with α SMA and vimentin. Thus, in contrast to interplacentomal regions, GlyCAM-1 in placentomes was predominantly localized in vasculature rather than epithelial cells. Further, leukocytes expressing L-selectin were localized to the endothelial surface of GlyCAM-1-expressing vessels within placentomes. These data suggest that GlyCAM-1 assumes distinct functions in compartment-specific regions of the sheep uterus.
Improved development by Taxol pretreatment after vitrification of in vitro matured porcine oocytes
Authors: Shi Wen-Qing , Zhu Shi-En , Zhang Dong , Wang Wei-Hua , Tang Guo-Liang , Hou Yun-Peng , Tian Shu-Jun
Published: April 2006

This study was designed to examine the effect of Taxol pretreatment on vitrification of porcine oocytes matured in vitro by an open pulled straw (OPS) method. In the first experiment, the effect of Taxol pretreatment and fluorescein diacetate (FDA) staining on parthenogenetic development of oocytes was evaluated. In the second experiment, viability, microtubule organization and embryo development of oocytes were assessed after oocytes were exposed to vitrification/warming solutions or after vitrification with or without Taxol pretreatment. The results showed that Taxol pretreatment and/or FDA staining did not negatively influence the oocyte’s developmental competence after parthenogenetic activation. After being exposed to vitrification/warming solutions, the survival rate (83.3%) of the oocytes was significantly (P < 0.05) reduced as compared with that in the control (100%). Vitrification/warming procedures further reduced the survival rates of oocytes regardless of oocytes being treated with (62.1%) or without (53.8%) Taxol. The proportions of oocytes with normal spindle configuration were significantly reduced after the oocytes were exposed to vitrification/warming solutions (38.5%) or after vitrification with (10.3%) or without (4.1%) Taxol pretreatment as compared with that in control (76.8%). The rates of two-cell-stage (5.6–53.2%) embryos at 48 h and blastocysts (0–3.8%) at 144 h after activation were significantly reduced after exposure to vitrification/warming solutions or after vitrification as compared with control (90.9% and 26.6% respectively). However, the proportion of vitrified oocytes developed to two-cell stage was significantly higher when oocytes were pretreated with (24.3%) than without (5.6%) Taxol. These results indicate that pretreatment of oocytes with Taxol before vitrification helps to reduce the damage induced by vitrification and is a potential way to improve the development of vitrified porcine oocytes.
Relationships of changes in B-mode echotexture and colour-Doppler signals in the wall of the preovulatory follicle to changes in systemic oestradiol concentrations and the effects of human chorionic gonadotrophin in mares
Authors: Gastal E L , Gastal M O , Ginther O J
Published: April 2006

A duplex grey-scale and colour-Doppler ultrasound instrument was used to study the changes in the wall of the preovulatory follicle in mares. When the follicle reached ≥35 mm (hour 0), mares were randomized into control (n = 16) and human chorionic gonadotropin (hCG)-treated (n = 16) groups. The hCG treatment was given at hour 0. Scanning was done every 12 h until hour 36, every hour between hours 36 and 48, and every 12 h thereafter until ovulation. Blood was sampled every 12 h for oestradiol assay. During the period 0–24 h post-treatment, oestradiol concentrations decreased in the hCG group and increased in the controls (significant interaction). During the period 0–36 h post-treatment, thickness and echogenicity of the granulosa increased in the hCG group but not in the controls. During the period 36 to 12 h before ovulation, granulosa and colour-Doppler end-points increased in the control and hCG groups (hour effects), while oestradiol was decreasing in both groups. The prominence and percentage of follicle circumference with an anechoic band peripheral to the granulosa and colour-Doppler signals in the follicle wall, indicating arterial blood flow, decreased during the period 4 to 1 h before ovulation (hour effects). Results indicated that the ultrasonographic changes of the wall of the preovulatory follicle were not associated temporally with changes in oestradiol concentrations and prominence of an anechoic band, and colour-Doppler signals decreased during the few hours before ovulation. The hypothesis that the latter portion of the ovulatory LH surge has a negative effect on systemic oestradiol was supported by the immediate decrease in oestradiol concentrations when hCG was injected.
Suppressed expression of genes involved in transcription and translation in in vitro compared with in vivo cultured bovine embryos
Authors: Corcoran D , Fair T , Park S , Rizos D , Patel O V , Smith G W , Coussens P M , Ireland J J , Boland M P , Evans A C O , Lonergan P
Published: April 2006

In vivo-derived bovine embryos are of higher quality than those derived in vitro. Many of the differences in quality can be related to culture environment-induced changes in mRNA abundance. The aim of this study was to identify a range of mRNA transcripts that are differentially expressed between bovine blastocysts derived from in vitro versus in vivo culture. Microarray (BOTL5) comparison between in vivo- and in vitro-cultured bovine blastocysts identified 384 genes and expressed sequence tags (ESTs) that were differentially expressed; 85% of these were down-regulated in in vitro cultured blastocysts, showing a much reduced overall level of mRNA expression in in vitro- compared with in vivo-cultured blastocysts. Relative expression of 16 out of 23 (70%) differentially expressed genes (according to P value) were verified in new pools of in vivo- and in vitro-cultured blastocysts, using quantitative real-time PCR. Most (10 out of 16) are involved in transcription and translation events, suggesting that the reason why in vitro-derived embryos are of inferior quality compared with in vivo-derived embryos is due to a deficiency of the machinery associated with transcription and translation.
Fertility of mice receiving vitrified adult mouse ovaries
Authors: Hani Toshio , Tachibe Takanori , Shingai Saburo , Kamada Nobuo , Ueda Otoya , Jishage Kou-ichi
Published: April 2006

Cryopreservation of the ovaries is a useful technology for preservation of germ cells from experimental animals, because if the female founder is infertile or has mutated mitochondrial DNA, preservation of female germ cells is necessary. Although it is possible to cryopreserve immature mouse ovaries with a high degree of viability by vitrification with a mixture of several cryoprotectants, the viability of cryopreserved adult mouse ovaries is still unknown. Here, we investigated the viability of mouse ovaries at various ages after cryopreservation by vitrification techniques. Donor ovaries were collected from 10-day-, 4-week-, 10-week- and 7-month-old, female, nulliparous, green fluorescence protein (GFP)-transgenic mice and cryopreserved by vitrification. The vitrified-warmed ovaries were orthotopically transplanted to 4- or 10-week-old mice. GFP-positive pups were obtained in all experimental groups. In the 4-week-old recipients, the percentages of GFP-positive pups among the total pups from recipients transplanted with ovaries of 10-day-, 4-week-, 10-week- and 7-month-old donors were 44%, 9%, 12% and 4% respectively. In the 10-week-old recipients, the percentages of GFP-positive pups among the total pups from recipients transplanted with ovaries of 10-day-, 4-week-, 10-week- and 7-month-old donors were 36%, 16%, 2% and 9% respectively. Furthermore, GFP-positive pups also were obtained from recipients transplanted with ovaries of donors without normal estrous cyclicity. Our results indicate that cryopreservation of mouse ovaries by vitrification is a useful method for the preservation of female germ cells from mice of various ages.
Reciprocal expression of 17α-hydroxylase-C17,20-lyase and aromatase cytochrome P450 during bovine trophoblast differentiation: a two-cell system drives placental oestrogen synthesis
Authors: Schuler G , Özalp G R , Hoffmann B , Harada N , Browne P , Conley A J
Published: April 2006

No definitive information is yet available on the steroidogenic capacity of the two morphologically distinct cell types forming the bovine trophoblast, the uninucleated trophoblast cells (UTCs) and the trophoblast giant cells (TGCs). Hence, in order to localise 17α-hydroxylase-C17,20-lyase (P450c17) on a cellular level and to monitor its expression as a function of gestational age, placentomes from pregnant (days 80–284; n = 19), prepartal (days 273–282; 24–36 h prior to the onset of labour; n = 3) and parturient cows (n = 5) were immunostained for P450c17 using an antiserum against the recombinant bovine enzyme. At all stages investigated, P450c17 was exclusively found in the UTCs of chorionic villi (CV), where staining was ubiquitous between days 80 and 160, but was largely restricted to primary CV and the branching sites of secondary CV between days 160 and 240. Thereafter, a distinct ubiquitous staining reoccurred in the UTCs of all CV in late pregnant, prepartal and parturient animals. Using an antiserum against human aromatase cytochrome P450 (P450arom), specific cytoplasmic staining was observed in TGCs. In placentomes from pregnant cows, staining intensity was higher in mature compared with immature TGCs and was more pronounced in the trophoblast covering big stem villi compared with the trophoblast at other sites of the villous tree. In placentomes of a parturient cow, specific staining was only found in mature TGCs that survived the normal, but substantial, prepartal decline in TGC numbers. These results clearly showed that bovine UTCs and TGCs exhibit different steroidogenic capacities, constituting a ‘two-cell’ organisation for oestrogen synthesis. P450c17 expression appears to be quickly down-regulated and P450arom is up-regulated when UTCs enter the TGC differentiation pathway.
A case-control study on the association of idiopathic recurrent pregnancy loss with autoantibodies against β2-glycoprotein I and annexin V
Authors: Zammiti Walid , Mtiraoui Nabil , Kallel Choumous , Mercier Eric , Almawi Wassim Y , Mahjoub Touhami
Published: April 2006

Whereas antiphospholipid antibodies (aPL) are associated with thrombotic events and recurrent spontaneous abortion (RSA), the contribution of anti-β2 glycoprotein 1 (β2GP1) and anti-annexin V antibodies as risk factors for RSA remain poorly understood. We investigated anti-β2-GPI and anti-annexin V IgM and IgG antibodies as potential risk factors for RSA in 200 women with more than three consecutive idiopathic RSA, and 200 age-matched, healthy, parous women. Pearson’s chi squared test analysis showed that while anti-β2-GPI IgG (P = 0.416) and IgM (P = 0.72) were comparable between patients and controls, elevated anti-annexin V IgG (P = 0.006), but not IgM (P = 0.084), was more pronounced in patients. Higher frequencies of elevated IgG-only (P = 0.005), but not IgM-only (P = 1.000; OR = 6.66), anti-annexin V antibodies were noted among patients. Multinomial regression analysis showed that body-mass index (overweight and obesity; P = 0.008), education status (P < 0.001) and anti-β2-GPI IgM (P = 0.033), but not IgG (P = 0.723), were associated with early abortion, while anti-β2-GPI IgG (P = 0.030) and anti-annexin V IgG (P = 0.004) were associated with late RSA. For combined early-late RSA, the only variable selected was education status (P < 0.001), and neither anti-annexin V nor anti-β2-GPI IgM and IgG was associated with early-late RSA. Accordingly, anti-annexin V and anti-β2-GPI should be regarded as independent risk markers of RSA.