bluuebunny/crossref_metadata_2025 huggingface dataset:
Transmural cardiac strains in the lateral wall of the ovine left ventricle
Authors: Cheng Allen , Langer Frank , Rodriguez Filiberto , Criscione John C. , Daughters George T. , Miller D. Craig , Ingels Neil B.
Published: December 2004

The constant-volume property of contracting cardiac muscle has been invoked in models of heart wall mechanics that predict that systolic subendocardial left ventricular (LV) wall thickening must significantly exceed subepicardial thickening. To examine this prediction, we implanted arrays of radiopaque markers to measure lateral equatorial wall transmural strains and global and regional LV geometry in seven sheep and studied the four-dimensional dynamics of these arrays using biplane videofluoroscopy (60 Hz) in anesthetized intact animals 1 and 8 wk after surgery. A transmural gradient of systolic lateral wall thickening was observed at 1 wk ( P = 0.009; linear regression) but was no longer present at 8 wk ( P = 0.243). Referenced to end diastole, group mean (±SD) end-systolic radial subepicardial, midwall, and subendocardial wall thickening strains were, respectively, 0.08 ± 0.08, 0.14 ± 0.08, and 0.22 ± 0.12 at 1 wk and 0.19 ± 0.07 ( P = 0.02; 1 vs. 8 wk), 0.20 ± 0.04, and 0.23 ± 0.07 at 8 wk. With the exception of an 8-ml (7%) increase in end-diastolic volume ( P = 0.04) from 1 to 8 wk, LV shape and hemodynamics were otherwise unchanged. We conclude that equivalent hemodynamics can be generated by the left ventricle with or without a transmural gradient of systolic wall thickening in this region; thus such a gradient is unlikely to be a fundamental property of the contracting LV myocardium. We discuss some implications of these findings regarding mechanisms involved in systolic wall thickening.
Myocardial oxygenation and adenosine release in isolated guinea pig hearts during changes in contractility
Authors: Ejike J. Chiaka , Arakaki Lorilee S. L. , Beard Daniel A. , Ciesielski Wayne A. , Feigl Eric O. , Schenkman Kenneth A.
Published: December 2004

Previous work from this laboratory using near-infrared optical spectroscopy of myoglobin has shown that ∼20% of the myocardium is hypoxic in buffer-perfused hearts that are perfused with fully oxygenated buffer at 37°C. The present study was undertaken to determine cardiac myoglobin saturation in buffer-perfused hearts when cardiac contractility was increased with epinephrine and decreased during cardiac arrest with KCl. Infusion of epinephrine to achieve a doubling of contractility, as measured by left ventricular maximum pressure change over time (dP/d t), resulted in a decrease in mean myoglobin saturation from 79% at baseline to 65% and a decrease in coronary venous oxygen tension from 155 mmHg at baseline to 85 mmHg. Cardiac arrest with KCl increased mean myoglobin saturation to 100% and coronary venous oxygen tension to 390 mmHg. A previously developed computer model of oxygen transport in the myocardium was used to calculate the probability distribution of intracellular oxygen tension and the hypoxic fraction of the myocardium with an oxygen tension below 0.5 mmHg. The hypoxic fraction of the myocardium was ∼15% at baseline, increased to ∼30% during epinephrine infusion, and fell to ∼0% during cardiac arrest. The coronary venous adenosine concentration changed in parallel with the hypoxic fraction of the myocardium during epinephrine and KCl. It is concluded that catecholamine stimulation of buffer-perfused hearts increases hypoxia in the myocardium and that the increase in venous adenosine concentration is a reflection of the larger hypoxic fraction of myocardium that is releasing adenosine.
Erythrocytes of humans with cystic fibrosis fail to stimulate nitric oxide synthesis in isolated rabbit lungs
Authors: Liang Griffith , Stephenson Alan H. , Lonigro Andrew J. , Sprague Randy S.
Published: December 2004

Erythrocytes (red blood cells) of either rabbits or healthy humans are required to demonstrate the participation of nitric oxide (NO) in the regulation of pulmonary vascular resistance in the isolated rabbit lung. The property of the erythrocyte that is responsible for the stimulation of NO synthesis was reported to be the ability to release ATP in response to physiological stimuli, including deformation. Moreover, a signal transduction pathway that relates mechanical deformation of erythrocytes to ATP release has been described, and the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) is a component, i.e., erythrocytes of individuals with CF do not release ATP in response to deformation. Here, we investigated the hypothesis that, in contrast to those of healthy humans, erythrocytes of humans with CF fail to stimulate endogenous NO synthesis in the isolated rabbit lung. We report that CFTR is a component of the membranes of both rabbit and human erythrocytes. The addition of the NO synthase inhibitor Nω-nitro-l-arginine methyl ester (l-NAME, 100 μM) produced increases in vascular resistance in isolated rabbit lungs perfused with physiological salt solution (PSS) containing erythrocytes of healthy humans, but l-NAME was without effect when the lungs were perfused with PSS alone or PSS containing erythrocytes of CF patients. These results provide support for the hypothesis that, in CF, a defect in ATP release from erythrocytes could lead to decreased endogenous pulmonary NO synthesis and contribute to pulmonary hypertension.
Alginate plasma expander maintains perfusion and plasma viscosity during extreme hemodilution
Authors: Cabrales Pedro , Tsai Amy G. , Intaglietta Marcos
Published: December 2004

Extreme hemodilution was performed in the hamster chamber window model using 6% Dextran 70, lowering systemic hematocrit by 60%. Animals were subsequently divided into three groups and hemodiluted to a hematocrit of 11% using 6% Dextran 70, 6% Dextran 500, and a 4% Dextran 70 + 0.7% alginate solution ( n = 6 each group). Final plasma viscosities were 1.4 ± 0.2, 2.2 ± 0.1, and 2.7 ± 0.2 cp, respectively, ( P < 0.05, high viscosity vs. low viscosity). Blood viscosities were 2.1 ± 0.2, 2.9 ± 0.4, and 3.9 ± 0.3 cp, respectively. The lowest blood and plasma viscosity group had a significantly lower functional capillary density, 37 ± 16%, whereas the two high-viscosity solutions were 71 ± 15% and 76 ± 12% ( P < 0.05, high viscosity vs. low viscosity), respectively. Arteriolar and venular flow in the Dextran 500 and alginate groups was higher than baseline (i.e., normal nontreated animals), whereas the low-viscosity group showed a reduction in flow. These microvascular changes were paralleled by changes in base excess, which was negative for the Dextran 70 group and positive for the other groups. However, tissue Po2 was uniformly low for all groups (average of 1.4 mmHg). Calculation of tissue oxygen consumption in the window chamber based on the microvascular data, flow, and intravascular Po2 showed that only the alginate + Dextran 70 solution-exchanged animals returned to baseline oxygen consumption, whereas the other groups were lower than baseline ( P < 0.05). These results show that hemodilution performed with high-viscosity plasma expanders yields systemic arterial pressures and functional capillary densities that are significantly higher ( P < 0.05) than those obtained with 6% Dextran 70, a fluid whose viscosity is similar to that of plasma. A condition for obtaining these results is that the oncotic pressure of the plasma expander be titrated to near normal, so that autotransfusion of fluid from the tissue into the vascular compartment does not reduce the effects of increasing plasma viscosity and increased shear stress on the microvascular wall.
Role of gustatory thalamus in anticipation and comparison of rewards over time in rats
Authors: Schroy Pearl Lee , Wheeler Robert A. , Davidson Collin , Scalera Giuseppe , Twining Robert C. , Grigson Patricia S.
Published: December 2004

Rats reduce intake of a palatable saccharin solution when it is followed by access to a preferred sucrose solution. This phenomenon, referred to as an anticipatory contrast effect (ACE), is thought to occur because the value of the saccharin conditioned stimulus pales in comparison to the highly rewarding sucrose unconditioned stimulus expected in the near future. Although relatively little is known about the underlying neural substrates, lesions of the gustatory thalamus fully disrupt the phenomenon (Reilly S, Bornovalova M, and Trifunovic R. Behav Neurosci 118: 365–376, 2004; Reilly S and Pritchard TC. Behav Neurosci 110: 746–759, 1996). The present set of experiments revisited this issue to determine the nature of this deficit. Rats with bilateral ibotenic acid lesions of the gustatory thalamus were given 3-min access to 0.15% saccharin and, after a 0-s or 5-min interval, were given 3-min access to either the same saccharin solution or a highly preferred 1.0 M sucrose solution. In experiment 1, ACE testing began with the 5-min interstimulus interval (ISI) and then switched to the 0-s ISI. For experiment 2, the order of ISI testing was reversed. The results show that axon-sparing, neurotoxic lesions of the gustatory thalamus prevent ACEs with a 0-s ISI and lead to a reversal (i.e., a reinforcement effect) with a 5-min ISI. Together, the results suggest that the lesion leads to a specific reward comparison deficit, whereby the rats fail to compare the value of an available reward with the memory of a preferred reward that is anticipated in the near future.
Hypoxic pulmonary vasoconstriction
Authors: Moudgil Rohit , Michelakis Evangelos D. , Archer Stephen L.
Published: December 2004

Humans encounter hypoxia throughout their lives. This occurs by destiny in utero, through disease, and by desire, in our quest for altitude. Hypoxic pulmonary vasoconstriction (HPV) is a widely conserved, homeostatic, vasomotor response of resistance pulmonary arteries to alveolar hypoxia. HPV mediates ventilation-perfusion matching and, by reducing shunt fraction, optimizes systemic Po2. HPV is intrinsic to the lung, and, although modulated by the endothelium, the core mechanism is in the smooth muscle cell (SMC). The Redox Theory for the mechanism of HPV proposes the coordinated action of a redox sensor (the proximal mitochondrial electron transport chain) that generates a diffusible mediator [a reactive O2species (ROS)] that regulates an effector protein [voltage-gated potassium (Kv) and calcium channels]. A similar mechanism for regulating O2uptake/distribution is partially recapitulated in simpler organisms and in the other specialized mammalian O2-sensitive tissues, including the carotid body and ductus arteriosus. Inhibition of O2-sensitive Kvchannels, particularly Kv1.5 and Kv2.1, depolarizes pulmonary artery SMCs, activating voltage-gated Ca2+channels and causing Ca2+influx and vasoconstriction. Downstream of this pathway, there is important regulation of the contractile apparatus' sensitivity to calcium by rho kinase. Controversy remains as to whether hypoxia decreases or increases ROS and which electron transport chain complex generates the ROS (I and/or III). Possible roles for cyclic adenosine diphosphate ribose and an unidentified endothelial constricting factor are also proposed by some groups. Modulation of HPV has therapeutic relevance to cor pulmonale, high-altitude pulmonary edema, and sleep apnea. HPV is clinically exploited in single-lung anesthesia, and its mechanisms intersect with those of pulmonary arterial hypertension.
State Reaction to Globalization, a Class Centered Analysis: The Case of Barbados and Trinidad and Tobago
Authors: Ramsaran Dave
Published: December 2004

This paper seeks to compare the reactions of two states to the process of globalization: (1) Barbados and (2) Trinidad and Tobago. The major contention is that state reaction to the process of globalization is not necessarily in defense of the population who elect governments to office, but rather their response is dependent on the type of economic elites within the nation-state, and the extent to which the social formation allows national elites to couch their interest in nationalist terms. The major hypothesis advanced is that the more the economic elites stand to benefit from the process of globalization, the more they will urge the state to push ahead with the process of globalization, even if it has negative consequences for the population. On the other hand, the more the economic elite stand to lose in terms of material well-being, the more they will urge the state to resist the process, making their argument in nationalist terms. This diminishes the state’s ability to transform the society and reduce inequality. A combination of content analysis of the major daily newspapers in each country in 2002 as well as interviews with key informants provides the data for this study.
Beyond Ethnicity: The Global Comparative Analysis of Ethnic Conflict
Authors: Fenton Steve
Published: December 2004

Conflicts that are reported as being between ethnic groups are often described as “ethnic conflicts.” The implication is that such conflicts belong to a general type of ethnic conflict with certain repeated and predictable features. This type of conflict is seen as being motivated by ethnic sentiments, as being grounded in deeply set hatreds, and as being virtually inescapable. By applying the epithet “ethnic,” it is as if the conflict were already explained. However, there are many reasons to be suspicious of these implications. Ethnic groups presently embroiled in fierce conflict may have been, at a previous point in time, peacefully co-existent. Frequently, the very lines of ethnic difference become blurred through intermarriage and cultural change. Therefore, in order to understand conflict described as “ethnic” we need to uncover the reasons why (in a given conflict situation) there is heightened awareness of ethnic difference. Then we need to explain what I have termed “the conditions of ethnicity,” that is, the external conditions which lead to severe conflict; and those external circumstances that make it likely that the conflict will follow lines of ethnic differentiation. Two of these conditions are the strength of the state system and the ability of the state to manage ethnic conflict.
Language Policy and Ethnic Tensions in Quebec and Latvia
Authors: Schmid Carol , Zepa Brigita , Snipe Arta
Published: December 2004

This article traces the factors that led to the adoption of the Charter of the French Language in Quebec in 1977 and the Latvian Language Law in 1999. Concerns for the French language in Quebec in the 1960s and 1970s, the Latvian language in the Soviet Union in the late 1980s, and in the Latvian state in the 1990s were ignited by some of the same demographic and assimilative forces in the two societies. Demographic factors included a decline in the birth rate, lower socioeconomic status, and a fear of minoritization in their own respective territories. Schools in English in Quebec and schools in Russian in Latvia attracted most immigrants. To counter these trends, language policies were drafted restricting access to English and Russian languages in schools, on commercial signs, in legislative bodies, and in municipal, public, and para-public administration. Looking for a model to change these conditions, Latvia based a significant part of its language law on the Quebec Charter of the French Language. Significant controversies erupted in both societies with the passage of restrictive language legislation. While the laws have helped to reverse the position of the French and Latvian languages, they have not solved the delicate balance between linguistic communal rights and individual rights.
What’s It Worth to You? The Questionable Value of Instrumentalist Approaches to Ethnic Identification
Authors: Hempel Lynn
Published: December 2004

The assertion that material interests underlie ethnic identification is central to instrumentalist approaches to ethnicity. However, recent approaches—circumstantialism and constructivism—refine instrumentalism, addressing posited shortcomings, including an examination of the contexts and conditions in which interests and identities are expressed and constructed. Nevertheless, these later approaches explicitly or implicitly reproduce instrumentalism’s basic material premise. Using survey data from the multiethnic country of Mauritius, I examine this premise by exploring the relationship between economic instrumentalism and ethnic identification within and across ethnic groups. I find limited support for an instrumentalist approach to ethnic identification as this approach explains only a modest amount of variance in ethnic identification and is insufficient for explaining the significant differences that emerge in the relationship between economic instrumentalism and ethnic identification across ethnic groups. Consequently, it is argued that current instrumentalist approaches provide a deficient account of ethnic identification and related group processes.
Globalization and Africa's Regional and Local Responses
Authors: Massamba Guy , Kariuki Samuel M. , Ndegwa Stephen N.
Published: December 2004

As a response to globalization, the New Partnership for Africa's Development (NEPAD) is indicative of a new awareness among African leaders that they must respond in ways that create empowering opportunities for African societies to benefit from, rather than be victims of, globalization. Following a review of Africa's responses to previous epochs of globalization, we examine the relevance of leadership given the dismal record of past development efforts and given the hard choices pressed upon African societies by the dynamics of current globalization. We assert that the NEPAD can be transformative if it does not limit its efforts to institutional restructuring and governance but, in addition, becomes a coda for effective leadership. Finally, we highlight the limits and frustrations faced by post-apartheid South Africa—where the state has fully embraced global economic imperatives but must also confront the socioeconomic needs of its apartheid-scarred constituencies, as evident from local resistances.
Globalization from Below: AIDWA, Foreign Funding, and Gendering Anti-Violence Campaigns
Authors: Armstrong Elisabeth
Published: December 2004

Social movements and nongovernmental organizations (NGOs) fight on the frontlines of neoliberal development policies, for their constituencies and for their own survival. These groups’ proximity to neoliberalism, through their funding sources and decision-making structures, has come under increasing scrutiny marked by the critical description of their “NGOization.” This globalization from below into the fabric of grassroots resistance marks an important site of departure for one national women’s organization, the All India Democratic Women’s Association (AIDWA). Member-sustained and independent from outside donor funding, but deeply marked by World Bank/International Monetary Fund development demands, AIDWA sheds light on those organizational forms that refuse to compromise their goals even as they recognize changing political conditions. This paper looks at their analysis and politics to combat violence against women, an approach that never wholly leaves its local battles against domestic violence even as it directly implicates neoliberal capitalism in women’s intimate relationships with violence.
Religion and Development Revisited: Comparing Islam and Christianity With Reference to the Case of Iran
Authors: Alamdari Kazem
Published: December 2004

To explain the level of difference between Muslim societies and the West, many refer to religious sources as if Christianity caused modern development; and Islam all present misfortunes. This paper challenges this common view of religious determinism arguing that rather than Christianity or Islam per se, it is the variation in social, historical, and ecological conditions that led to the persistence of integration of religion and state hence underdevelopment in many Muslim countries. Neither the realm of Islam was always behind nor was the land of Christianity always at the forefront. Major characteristics such as violence and sexism have been common in Islam and Christianity as well as other religions. That Islam emerged in violence and Christianity against state violence does not represent the entire history of these religions. Jihad in Islam and Crusade in Christianity justify massive violence in favor of their interests. Despite violent resistance of the church against modern reforms, Western societies succeeded in achieving a new civilization and forced the church into its domain of faith, rituals, and moral responsibilities, while Muslim societies have not succeeded yet in achieving similar developments needed to reform Islam. Consequently, unlike the West, religion in Muslim societies still continues to play its traditional roles, including exertion of political power that prevents structural and institutional changes and, most notably, the recognition of individuals’ rights needed for modernity. Religious reforms, including separation from the state as a requirement for modern development and democracy in the Muslim world, must begin with multidimensional societal changes with the engagement of the global community.
Cytokines link osteoblasts and inflammation: microarray analysis of interleukin-17- and TNF-α-induced genes in bone cells
Authors: Shen Fang , Ruddy Matthew J , Plamondon Pascale , Gaffen Sarah L
Published: December 2004

The novel cytokine interleukin (IL)-17 has been implicated in many infectious and autoimmune settings, especially rheumatoid arthritis. Consistent with its proinflammatory effects on bone, osteoblast cells are highly responsive to IL-17, particularly in combination with other inflammatory cytokines. To better understand the spectrum of activities controlled by IL-17, we globally profiled genes regulated by IL-17 and tumor necrosis factor α (TNF-α) in the preosteoblast cell line MC3T3-E1. Using Affymetrix microarrays, 80–90 genes were up-regulated, and 19–50 genes were down-regulated with IL-17 and TNF-α as compared with TNF-α alone. These included proinflammatory chemokines and cytokines, inflammatory genes, transcriptional regulators, bone-remodeling genes, signal transducers, cytoskeletal genes, genes involved in apoptosis, and several unknown or unclassified genes. The CXC family chemokines were most dramatically induced by IL-17 and TNF-α, confirming the role of IL-17 as a potent mediator of inflammation and neutrophil recruitment. Several transcription factor-related genes involved in inflammatory gene expression were also enhanced, including molecule possessing ankyrin repeats induced by lipopolysaccharide/inhibitor of κBζ (MAIL/κBζ), CCAAT/enhancer-binding protein δ (C/EBPδ), and C/EBPβ. We also identified the acute-phase gene lipocalin-2 (LCN2/24p3) as a novel IL-17 target, which is regulated synergistically by TNF-α and IL-17 at the level of its promoter. A similar but not identical pattern of genes was induced by IL-17 and TNF-α in ST2 bone marrow stromal cells and murine embryonic fibroblasts. This study provides a profile of genes regulated by IL-17 and TNF-α in osteoblasts and suggests that in bone, the major function of IL-17 is to cooperate and/or synergize with other cytokines to amplify inflammation.
Seismic Damage to Segmented Buried Pipe
Authors: O'Rourke Michael , Deyoe Erik
Published: December 2004

A fragility relation for buried segmented pipe subject to either the wave propagation or permanent ground deformation (PGD) hazard is presented. In the past, relations to estimate wave propagation damage to buried segmented pipe frequently use peak particle velocity (Vmax) to characterize the seismic hazard. For example, in 1993, O'Rourke and Ayala developed an empirical relation between damage (quantified by repairs per kilometer of pipe) and Vmax using data from four U.S. and two Mexican events. Existing fragility relations for PGD typically characterize the hazard by the amount of permanent ground movement. It is shown herein that for statistically reliable data, differences in estimated wave propagation repair rates become much smaller when the seismic shaking is characterized by ground strain as opposed to Vmax. Furthermore, damage rates for PGD are shown to be consistent with those for wave propagation when the PGD hazard is similarly characterized by ground strain. The combined wave propagation and PGD relation is quite consistent for four orders of magnitude of ground strain.
Estimating Inelastic Displacements for Design: Extended Pile-Shaft-Supported Bridge Structures
Authors: Hutchinson T. C. , Chai Y. H. , Boulanger R. W. , Idriss I. M.
Published: December 2004

Accurate estimation of inelastic displacements is important for the evaluation of the seismic performance of structures with desired ductile response. In this paper, nonlinear dynamic analyses results from a companion numerical study investigating the response of ductile-designed bridge structures, were compared with a commonly applied inelastic displacement estimation approach and an alternative approach. The extended pile-shaft-supported bridge structures considered are susceptible to amplified response under long-period velocity pulses, and hence an evaluation of design methods for estimating inelastic displacement demands is warranted. In this case, force-reduction–displacement-ductility–period (R−μΔ−T) relations and a mean spectral displacement approach are investigated. The alternative approach estimates inelastic displacement demand using the mean elastic spectral displacement between two spectral periods that are important for the structure's response. Results support the conceptual merits of using the mean spectral displacement method, indicating that the approach is capable of reducing the uncertainty in predicting inelastic displacement demands for the types of structures considered when subjected to near-fault ground motions.
The Development of Anticipatory Smiling
Authors: Venezia Meaghan , Messinger Daniel S. , Thorp Danielle , Mundy Peter
Published: December 2004

When do infants begin to communicate positive affect about physical objects to their social partners? We examined developmental changes in the timing of smiles during episodes of initiating joint attention that involved an infant gazing between an object and a social partner. Twenty‐six typically developing infants were observed at 8, 10, and 12 months during the Early Social‐Communication Scales, a semistructured assessment for eliciting initiating joint attention and related behaviors. The proportion of infant smiling during initiating joint attention episodes did not change with age, but there was a change in the timing of the smiles. The likelihood of infants smiling at an object and then gazing at the experimenter while smiling (anticipatory smiling) increased between 8 and 10 months and remained stable between 10 and 12 months. The increase in the number of infants who smiled at an object and then made eye contact suggests a developing ability to communicate positive affect about an object.
Long‐Term Memory for an Emotional Interpersonal Interaction Occurring at 5 Months of Age
Authors: Bornstein Marc H. , Arterberry Martha E. , Mash Clay
Published: December 2004

We examined infants' long‐term retention of a single unique emotional experience into early childhood. Twenty‐month‐olds who had participated in a still‐face procedure at 5 months (experience group) fixated the face of the person who had instigated the still face significantly less than the faces of 2 other novel persons. Control 20‐month‐olds (no‐experience group) looked longer overall and fixated the target person equally or more than the 2 novel persons. In short, children who interacted with a stranger in the laboratory under both natural and anomalous social conditions just once when they were infants apparently retained a specific memory of that person and the experience into toddlerhood.
On Specifying Specificity: Facial Expressions at 4 Months
Authors: Bennett David S. , Bendersky Margaret , Lewis Michael
Published: December 2004

Izard (2004/this issue) clarifies the position of differential emotions theory by proposing a distinction between hard and soft versions of event‐emotion expression relations. We concur that the best design to examine situational specificity in facial expressions is one that utilizes multiple stimulus situations assessed over multiple occasions and ages. However, the problem of how to identify, a priori, a family of stimulus situations remains. We offer an example from our own recent work demonstrating how facial expressions and physiological indexes may converge to indicate the presence of a meaningful family of stimulus situations. Specifically, we found evidence for a family of frustrating, goal‐blocking events that elicited expressions and cortisol responses indicative of anger at 4 months. Yet, individual differences exist in that these situations also elicited expressions and cortisol changes indicative of sadness. Identification of a more comprehensive set of such situations throughout infancy will allow researchers to more systematically examine the degree to which situational specificity of emotions is present.
Role of PROP1 in Pituitary Gland Growth
Authors: Ward Robert D. , Raetzman Lori T. , Suh Hoonkyo , Stone Brandon M. , Nasonkin Igor O. , Camper Sally A.
Published: December 2004

Mutations in the PROP1 transcription factor gene lead to reduced production of thyrotropin, GH, prolactin, and gonadotropins as well as to pituitary hypoplasia in adult humans and mice. Some PROP1-deficient patients initially exhibit pituitary hyperplasia that resolves to hypoplasia. To understand this feature and to explore the mechanism whereby PROP1 regulates anterior pituitary gland growth, we carried out longitudinal studies in normal and Prop1-deficient dwarf mice from early embryogenesis through adulthood, examining the volume of Rathke’s pouch and its derivatives, the position and number of dividing cells, the rate of apoptosis, and cell migration by pulse labeling. The results suggest that anterior pituitary progenitors normally leave the perilumenal region of Rathke’s pouch and migrate to form the anterior lobe as they differentiate. Some of the cells that seed the anterior lobe during organogenesis have proliferative potential, supporting the expansion of the anterior lobe after birth. Prop1-deficient fetal pituitaries are dysmorphic because mutant cells are retained in the perilumenal area and fail to differentiate. After birth, mutant pituitaries exhibit enhanced apoptosis and reduced proliferation, apparently because the mutant anterior lobe is not seeded with progenitors. These studies suggest a mechanism for Prop1 action and an explanation for some of the clinical findings in human patients.
Tetranuclear Mo2Rh2 Complexes Obtained from Reactions between Triple Cubane-Type Oxide Cluster [(Cp*Rh)4Mo4O16] (Cp* = η5-C5(CH3)5) and Methanethiol: [{Cp*Rh(μ-SCH3)3MoO2}2(μ-O)] and [{Cp*Rh(μ-SCH3)3MoO}2(μ-X)(μ-Y)] (X, Y = O and X = O, Y = S). Synthesis, X-Ray Structures, and Dynamic Behavior in Nonaqueous Media
Authors: Xi Rimo , Wang Bateer , Abe Masaaki , Ozawa Yoshiki , Kinoshita Isamu , Isobe Kiyoshi
Published: December 2004

A new series of linear-type Mo2Rh2 tetranuclear complexes, [{Cp*RhIII(μ-SCH3)3MoVIO2}2(μ-O)] (1), [{Cp*RhIII(μ-SCH3)3MoVO}2(μ-O)2] (2), and [{Cp*RhIII(μ-SCH3)3MoVO}2(μ-O)(μ-S)] (3), has been prepared from reactions of the triple cubane-type oxide cluster [(Cp*Rh)4Mo4O16]·2H2O with CH3SH. These tetranuclear complexes have been characterized by elemental analysis, infrared, electronic, and 1H, 13C, and 17O NMR spectroscopies as well as X-ray analysis.

Complex 1 crystallizes in the monoclinic space group P21/n (No. 14) with a = 15.348(3), b = 14.059(3), c = 17.879(3) Å, β = 107.11(2)°, V = 3690(1) Å3, and Z = 4. Complex 2 crystallizes in the monoclinic space group C2/c (No. 15) with a = 25.334(4), b = 21.271(2), c = 17.831(3) Å, β = 129.70(5)°, V = 7393(2) Å3, and Z = 8. Complex 3 crystallizes in the orthorhombic space group Pcab (No. 61) with a = 16.902(3), b = 26.631(3), c = 16.855(2) Å, V = 7587(3) Å3, and Z = 8. Complex 1 involves a nearly linear “O2MoVI(μ-O)MoVIO2” framework, to which two Cp*RhIII units are linked by μ-SCH3 ligands. Complexes 2 and 3 have an analogous tetranuclear MoV2RhIII2 structure in which the MoV and RhIII atoms are bridged by three μ-SCH3 ligands. Complex 2 contains a doubly-bridged “OMoV(μ-O)2MoVO” framework with an Mo–Mo distance of 2.564(1) Å, while 3 contains a “OMoV(μ-O)(μ-S)MoVO” framework with an Mo–Mo distance of 2.666(1) Å. Complexes 2 and 3 retain the tetranuclear structure but are fluxional in solution. The fluxional behaviors are due to intramolecular rotations of the “Cp*Rh(μ-SCH3)” moieties on the trigonal planes of the octahedral Mo centers. Line-shape analyses of variable-temperature 1H NMR spectra measured in C6D5Cl yield activation parameters of ΔH‡ = +80.2 kJ mol−1, ΔS‡ = +22.1 J K−1 mol−1, and ΔG‡298 K = +73.6 kJ mol−1 for the rotation in 2 and ΔH‡ = +76.8 kJ mol−1, ΔS‡ = +21.1 J K−1 mol−1, and ΔG‡298 K = +70.5 kJ mol−1 for that in 3.
Interaction of Iodine with Aza-18-crown-6 and Aza-12-crown-4. Kinetic and Spectrophotometric Studies in Chloroform and 1,2-Dichloroethane Solutions
Authors: Hasani Masoumeh , Shamsipur Mojtaba
Published: December 2004

Interactions of 1,4,7,10,13-pentaoxa-16-azacyclooctadecane (aza-18-crown-6) and 1,4,7-trioxa-10-azacyclododecane (aza-12-crown-4) with iodine have been investigated spectrophotometrically in chloroform and 1,2-dichloroethane solutions. The observed time dependence of the charge-transfer band and subsequent formation of I3− in solution were related to the slow transformation of the initially formed 1 : 1 macrocycle·I2 outer complex to an inner electron donor–acceptor (EDA) complex, followed by fast reaction of the inner complex with iodine to form a triiodide ion, as follows:

The pseudo-first-order rate constants at various temperatures for the transformation process were evaluated from the absorbance-time data. The activation parameters (Ea, ΔH‡, and ΔS‡) for the transformation were obtained from the temperature dependence of the rate constants. The stoichiometry and formation constants of the resulting EDA complexes have also been determined. The influences of both the azacrowns’ structure and the solvent properties on the kinetics and stability of the resulting charge-transfer complexes are discussed.
59Co Nuclear Quadrupole Interaction in Crystalline Δ-Tris[trans-(1R,2R)-1,2-diaminocyclohexane]cobalt(III) Chloride Trihydrate
Authors: Ueda Takahiro , Nakamura Nobuo , Iida Masayasu
Published: December 2004

The lineshape of 59Co NMR was measured on solid [Co(chxn)3]3+ (chxn = trans-(1R,2R)-1,2-diaminocyclohexane) at the Larmor frequencies of 47 and 96 MHz. The 59Co nuclear quadrupole coupling constant and the asymmetry parameter of the electric field gradient were determined to be 7.50 MHz and 0.75, respectively. These values correspond to a very small distortion of the complex cation in the crystal.
Growth of Barium Chlorapatite Crystals from a Sodium Chloride Flux
Authors: Oishi Shuji , Michiba Noriyuki , Ishizawa Nobuo , Rendon-Angeles Juan Carlos , Yanagisawa Kazumichi
Published: December 2004

Large and well-formed crystals of barium chlorapatite [Ba5Cl(PO4)3] were grown for the first time from a sodium chloride flux. The solubility of Ba5Cl(PO4)3 in NaCl increased with increasing temperature, reaching about 1.9 mol% solubility at 1100 °C. The crystal growth of Ba5Cl(PO4)3 was conducted by heating a mixture of solute and flux at 1100 °C for 10 h, and then cooling to 500 °C at a rate of 5 °C h−1. Colorless and transparent prismatic crystals with lengths of up to 12 mm and widths of 3 mm were grown from high-temperature solutions containing 0.4—2.2 mol% solute. The most suitable solute content for the growth of prismatic crystals was 1.2 mol%. The prismatic crystals were bounded by the {} and {} faces. The aspect ratios were in the region of 1.1 to 4.8. Needle crystals with lengths of up to 4 mm and widths of 60 μm were obtained during every growth run. The needle crystals were elongated in the <0001> directions, with aspect ratios ranging from 43 to 56. The major constituents were almost homogeneously distributed in the prismatic and needle crystals.
9,10-Dicyanoanthracene-Photosensitized Elimination of 1,1′-Binaphthalene from Dinaphthyl Methylphosphonate and Trinaphthyl Phosphate through the Termolecular Interaction in the Singlet Excited State
Authors: Nakamura Mitsunobu , Miki Masamichi , Majima Tetsuro
Published: December 2004

9,10-Dicyanoanthracene (DCA) photosensitized intramolecular binaphthalene elimination of dinaphthyl methylphosphonates and trinaphthyl phosphates occurred through an exciplex between the singlet excited DCA (1DCA*) and the naphthyl group of dinaphthyl methylphosphonate and trinaphthyl phosphates in tetrahydrofuran, 1,4-dioxane, and benzene. Diethyl mononaphthyl phosphates also formed an exciplex with 1DCA*, while no reaction occurred. The binaphthalene elimination occurs via the intramolecular quenching of the exciplex by the second naphthyl group of dinaphthyl methylphosphonate or trinaphthyl phosphate, while the exciplex between the mononaphthyl phosphate and 1DCA* decays to give the starting compounds. The lifetime of the exciplex between the trinaphthyl phosphate and 1DCA* was shorter than that between the mononaphthyl phosphate and 1DCA*. The termolecular interaction (teraromatic groups interaction) of 1DCA* and two naphthyl groups of dinaphthyl methylphosphonate or trinaphthyl phosphate is suggested by the emission observation of the termolecular interaction of two naphthyl groups of trinaphthyl phosphate and 1,4-dicyanobenzene in the singlet excited state during the quenching of the intramolecular excimer of dinaphthyl methylphosphonate or trinaphthyl phosphates by 1,4-dicyanobenzene. The O–P(O)–O spacer is necessary for the binaphthalene elimination during the termolecular interaction in the singlet excited state.
Thermochemical Treatment of Radiata Pine (Pinus radiata) Bark with Hydrogen Peroxide Solutions at Temperatures Higher than 100 °C
Authors: Inoue Seiichi , Ogi Tomoko , Yazaki Yoshi
Published: December 2004

Radiata pine bark was treated with 0—15% hydrogen peroxide (H2O2) solutions at temperatures higher than 100 °C, and fractionated into water soluble, insoluble, and gas fractions. The distribution of these fractions was calculated on the basis of weight and carbon content, and compared with the aim of finding the optimum conditions for efficiently obtaining water-soluble materials for producing wood adhesives. The yield of water-soluble materials was significantly dependent on the temperature and the concentration of H2O2 solution. The highest yields of water-soluble materials (47.4 and 47.9% on the basis of weight and carbon content, respectively) were obtained with 15% H2O2 solution at 120 °C. The yield increased with increasing temperature up to 120 °C and then decreased at higher temperatures. Under the latter conditions, gases such as CO2 and CO were generated. When the bark was treated with 15% H2O2 solution at 140 °C, an exothermic reaction took place and 47.4% of the carbon of the bark was converted into gases. At the same time, most of the H2O2 was decomposed. The water-soluble fraction mainly consisted of low molecular weight acidic components, which are degaradated and oxygenated products of lignin and polyflavanoids. This bark solubilization process consists of very complicated combinations of various reactions. Many organic compounds, other than acids, might be present in the water-soluble fraction. The water-insoluble material is the oxygenated cellulose compound.
Photoionization and Ion Pair Formation of N,N-Diethyl-p-phenylenediamine in Various Polar Solvents
Authors: Hirata Yoshinori , Kawashima Osamu
Published: December 2004

By using transient absorption and photoconductivity measurement techniques, we have investigated the photoionization process of N,N-diethyl-p-phenylenediamine in various polar solvents. Significant excitation wavelength and excitation intensity effects were observed in alcoholic solvents. The slowly rising component of the photoconductivity in hundreds of nanoseconds or longer time scale is ascribed to the dissociation of the monophotonically produced ion pairs. In addition, a photoconductivity signal that has almost the same duration as the excitation laser pulse and is due to the geminate pair formed via the two-photon ionization is clearly observed with the 248-nm excitation. On the other hand, the biphotonic process was negligible with the 351-nm excitation in ethanol and 1-propanol. The monophotonically formed long-lived ion pair did not contribute to the conductivity. The long lifetime of the ion pair indicates that not only the Coulombic interaction but also the exciplex-like specific interaction is important.
The Photovoltaic Mechanism of a Polythiophene/Perylene Pigment Two-Layer Solar Cell
Authors: Nakamura Jun-ichi , Suzuki Shinji , Takahashi Kohshin , Yokoe Chiho , Murata Kazuhiko
Published: December 2004

The energy conversion efficiency of a two-layer organic solar cell consisting of a perylene pigment (PV) and regioregular polythiophene polymer (P3DT) was 0.99% under illumination with simulated solar light (AM 1.5–100 mW cm−2). The photovoltaic mechanism is discussed on the basis of the ionization potential of the component materials. The photoinduced hole-transfer from PV to P3DT quickly occurred at the PV/P3DT interface because of the large free energy change of 1.2 eV, then the subsequent charge separation efficiently proceeded, resulting in a large short-circuit photocurrent of 6.5 mA cm−2. On the other hand, the open-circuit photovoltage was only 0.42 V because the LUMO level of PV is close to the HOMO level of P3DT. The difference between the LUMO and the HOMO can be attributed to the open-circuit photovoltage.
Electron-Transfer Kinetics of Nitroxide Radicals as an Electrode-Active Material
Authors: Suga Takeo , Pu Yong-Jin , Oyaizu Kenichi , Nishide Hiroyuki
Published: December 2004

The electron-transfer rate constants of nitroxide derivatives, 4-(N-t-butyl-N-oxylamino)-t-butylbenzene, 4-(N-t-butyl-N-oxylamino)methoxybenzene, and 2,2,6,6-tetramethylpiperidinyl-N-oxyl, were investigated by electrochemical methods, which demonstrated that these radicals can potentially be used as a high power-rate electrode-active material due to their fast electron-transfer process.
A New Synthetic Method for Dipeptides Containing α,β-Didehydroamino Acids Utilizing an α-Tosylglycine Residue
Authors: Shiraishi Yohsuke , Yamauchi Hiroshi , Takamura Takashi , Kinoshita Hideki
Published: December 2004

The reaction of peptides containing an N-Boc- or N-Z-α-tosylglycine residue at the N-terminus with a variety of excess nitro compounds under basic conditions to give the nitro compound-adducts in good yields, followed by the elimination of nitrous acid from the adducts to afford the corresponding dipeptide containing α,β-didehydroamino acids with (Z)-configuration predominantly. Treatment of the same starting materials with aldehydes in the presence of base and tributylphosphine also gave a dipeptide containing α,β-didehydroamino acids with high (Z)-selectivity in satisfactory yields. The present method can be successfully applied to the synthesis of a protected leucine enkephalin analog.
Synthesis and Stereochemistry of N-Phenyl-N-9-triptycylhydroxylamine Derivatives and Related Compounds
Authors: Agawa Chiharu , Otsuka Keiko , Minoura Mao , Mazaki Yasuhiro , Yamamoto Gaku
Published: December 2004

During the course of attempts at synthesis of N-phenyl-N-9-triptycylhydroxylamine (1), we found that the reaction of N-9-triptycylhydroxylamine (5) with benzenediazonium-2-carboxylate afforded 3-(2-carboxyphenyl)-1-(9-triptycyl)triazene 1-oxide (6), the structure of which was confirmed by X-ray crystallography. Oxidation of N-(9-triptycyl)aniline (4) with mCPBA gave phenyl 9-triptycyl nitroxide (7) and N-(9-triptycyl)-1,4-benzoquinonimine (8) in small yields. Reduction of 7 with phenylhydrazine gave 1, and O-ethylation of 1 gave O-ethyl-N-phenyl-N-9-triptycylhydroxylamine (2). Results of X-ray crystallography for compounds 2, 4, 7, and 8 and results of dynamic NMR studies for 1, 2, and 8 are presented. In compound 8, Tp–N rotation and C=N topomerization took place on the NMR timescale at high temperatures above 60 °C, and the energy barriers to both processes were obtained. In compounds 1 and 2, dynamic NMR behavior was observed at very low temperatures below ca. −50 °C, and the energy barriers to the respective processes could not be determined except for those related to “Ph-passing”.
A Water-Soluble Phospholipid Polymer as a New Biocompatible Synthetic DNA Carrier
Authors: Sakaki Shujiro , Tsuchida Mamoru , Iwasaki Yasuhiko , Ishihara Kazuhiko
Published: December 2004

The purpose of this work was the preparation of a water-soluble DNA complex with a biocompatible phospholipid polymer for delivering DNA into a target cell. The phospholipid polymer, poly[2-methacryloyloxyethyl phosphorylcholine (MPC)-co-2-aminoethyl methacrylate (AEMA)] (poly(MPC-co-AEMA)), was synthesized and the functions of poly(MPC-co-AEMA) as a DNA carrier were compared with those of a conventional cationic DNA carrier such as poly(l-lysine). We investigated the toxicity of these polymers and the water solubility, structures, and nuclease resistance of the associated DNA/polymer complexes. An evaluation of toxicity in a colony forming test using Chinese hamster fibroblast cells (V-79 cells) indicated that the toxicity of poly(MPC-co-AEMA) is about 40% of that of poly(l-lysine). In the case of a salmon sperm DNA/poly(l-lysine) complex, a water-insoluble precipitate formed. In contrast, the DNA/poly(MPC-co-AEMA) complex was completely water-soluble. Although the DNA/poly(l-lysine) complex did not provide a CD spectrum, the DNA/poly(MPC-co-AEMA) complex did. DNase I hardly degraded the DNA in the DNA/poly(MPC-co-AEMA) complex. To demonstrate the transient expression of β-galactosidase, a plasmid DNA/poly(MPC-co-AEMA) complex was incubated with V-79 cells with chloroquine treatment. Under a phase-contrast microscope after 5-bromo-4-chloro-3-indolyl-β-d-galactopyranoside (X-gal) staining, more stained cells due to the transient expression of β-galactosidase were observed in a sample with the poly(MPC-co-AEMA) complex than in a sample with the poly(l-lysine) complex. From these results came the following conclusions: poly(MPC-co-AEMA) is a useful water-soluble polymer that can form a complex with DNA, and DNA/poly(MPC-co-AEMA) has good potential for DNA delivery into cells.
Free Energy Perturbation Studies on Enantiomeric Discrimination of Pyridino-18-Crown-6 Ethers
Authors: Hwang Sungu , Lee One-Sun , Chung Doo Soo
Published: December 2004

We performed FEP and MD simulations on enantiomeric complexes of seven 18-crown-6 ether compounds and a chiral protonated amine to obtain the free energy differences, and to elucidate the mechanism responsible for enantioselectivity. The FEP calculation reproduced the experimental enantioselectivity quite well. We partitioned the binding free energy in solution into the binding free energy in the gas phase and the solvation energy, and discussed the results. In the MD simulations, the detailed motion of host–guest complexes was monitored.
Carrier Mobility of Discotic Lamellar Mesophases of 5,10,15,20-Tetrakis(4-n-pentadecylphenyl)porphyrin
Authors: Monobe Hirosato , Mima Shoji , Shimizu Yo
Published: December 2004

The carrier mobility of discotic lamellar mesophases was evaluated by Time-of-Flight (TOF) method for mesogenic 5,10,15,20-tetrakis(4-n-pentadecylphenyl)porphyrin and was found to be in the order of 10−4 cm2 V−1 s−1. In spite of the higher order of molecular orientation in the lamellar mesophases, it is comparable with that of hexagonal disordered columnar mesophase. This is the first report of charged carrier mobility of a discotic lamellar mesophase.
A Ruthenium(II)-Pyridylamine Complex Showing a Fluxional Intramolecular π–π Interaction
Authors: Kojima Takahiko , Hayashi Ken-ichi , Matsuda Yoshihisa
Published: December 2004

A novel ruthenium(II) complex having 2-naphthoylamide groups attached to TPA (tris(2-pyridylmethyl)amine) was synthesized and characterized; the 2-naphthoylamide arms exhibited fractional behavior of intramolecular π–π interaction.