bluuebunny/crossref_metadata_2025 huggingface dataset:
Tenascin C in Stem Cell Niches: Redundant, Permissive or Instructive?
Authors: von Holst Alexander
Published: February 2008

The stem cell niche provides the specialized environment that is able to sustain the lifelong maintenance of stem cells in their discrete locations within organs. The niche is usually composed of several different cell types and a specialized extracellular matrix consisting of many different constituents. Additionally, a variety of growth factors are secreted into the extracellular space and contribute to the functional organization of the niche. Here, I will concentrate on the multimodular extracellular matrix glycoprotein tenascin C (Tnc) and discuss it as an exemplary molecule that is present in several stem cell niches. In spite of its intuitively suggestive presence, it has been difficult to provide functional evidence for the importance of Tnc in the context of stem cells. In the nervous system, the careful analysis of Tnc-deficient mice has revealed that the developmental program neural stem cell pass-through is delayed due to changes in growth factor responsiveness. To gain further insight, we have employed the gene trap technology in neural stem cells to identify potential Tnc target genes. This approach has surfaced 2 interesting candidates that may contribute to a better understanding of the signal(s) elicited by Tnc in neural stem/progenitor cells in the niche.
Association of Dry Tongue to Pyrexia in Long-Term Hospitalized Patients
Authors: Saito Toshiyuki , Oobayashi Kyoko , Shimazaki Yoshihiro , Yamashita Yoshihisa , Iwasa Yasuyuki , Nabeshima Fumikazu , Ikematsu Hideyuki
Published: February 2008

Background: The oral care of hospitalized elderly patients is thought to have a preventive effect on aspiration pneumonia, which is one of the main causes of fever. Although the decreased secretion of saliva is frequently observed in elderly people, no study has examined how a dry oral cavity affects aspiration. Objective: This study was performed to assess the association of dry tongue to pyrexia. As the main outcome measure, pyrexia of hospitalized patients with dry tongue was adjusted for dysphagia and other variables. Methods: We performed a 6-month cohort study on 106 hospitalized patients. Tongue dorsum moisture was measured using a simple method with a membrane filter (L-Salivo®) at baseline examination. Dysphagia and other covariates which could cause fever were also examined. Pyrexia of the subjects during the 6-month study period was analyzed with baseline data of dry tongue adjusted for dysphagia and other variables. Results: Patients with a dry tongue (odds ratio 5.76; 95% confidence interval 1.72–19.30; p = 0.005) and those with severe dysphagia (odds ratio 19.47; 95% confidence interval 5.13–73.88; p < 0.0001) had an increased risk of having ≧2 febrile days in multivariate analysis. Conclusion: The result suggests that a dry tongue dorsum is a significant risk factor for pyrexia, independent of dysphagia. Checking for a dry tongue and dysphagia can be useful for identifying patients who need intensive oral care.
Proportional Analysis of the Pig Renal Parenchyma and Sinus Structures
Authors: Pereira-Sampaio Marco A. , Henry Robert W. , Favorito Luciano A. , Sampaio Francisco J.B.
Published: February 2008

Aims: This study was performed to determine the proportion of the parenchyma and sinus structures of pig kidneys and the distance between the collecting system and the kidney surface. Methods: Forty-one pig kidneys were analyzed. Cavalieri’s principle was used to obtain the volume of the cortex, medulla and sinus, as well the proportions of the arteries, veins and collecting system in the sinus. Results: The volume of the renal parenchyma varied from 129 to 488.4 cm3. The renal cortex was 83.79% and the medulla 16.21%. The collecting system occupied the greatest part of the sinus, ranging from 34.78 to 71.91% of the renal sinus. The collecting system was closer to the dorsal than to the ventral surface in the cranial pole (p < 0.001) and the hilar zone (p < 0.01). The distance from the collecting system to the medial border was shorter than that to the lateral border in the caudal pole (p < 0.001). Conclusion: With this new information about the variation in thickness of the pig renal parenchyma, continued studies using the pig model are needed to support the use of radiofrequency ablation and cryoablation in deep and large renal tumors with a component in the renal sinus.
Influence of Physical Exercise and Food Restriction on the Biomechanical Properties of the Femur of Ageing Male Rats
Authors: Thomsen Jesper Skovhus , Skalicky Monika , Viidik Andrus
Published: February 2008

Background: Voluntary running in wheels as well as food reduction increase the life spans of rats. Disparate parameters such as the collagen biomarker of ageing and the development of kidney pathologies are decreased by voluntary exercise. There are few reports on the influence of physical exercise and food restriction on the skeleton of male rats. Most investigations initiated rather short-term interventions in 4- to 5-week-old animals and thus studied more the influence of growth than the influence of ageing on the skeleton. Objective: To compare the effects of physical exercise and food restriction on the biomechanical properties of bone tissue of ageing male rats with the interventions starting at the age of 5 months with the end point at 23 months. This enables the study of the influence of these interventions on the ageing of the skeleton. Methods: Five groups of male Sprague-Dawley rats were used: baseline (BL), voluntarily running in wheels (RW), food restriction to attain pair weight with RW animals (PW), forced running in treadmills (TM), and sedentary controls (SE). The biomechanical properties of femoral neck, diaphysis, and distal metaphysis were measured. Results: While the body weights and fat-free mass increased from BL to SE group, the occiput-sacrum length did not increase and the length of the femur increased marginally. These lengths were slightly retarded in RW and PW groups compared to the SE group. The strength of the distal femoral metaphysis decreased from BL to SE group. This decrease was counteracted by physical exercise (RW and TM groups) as well as by food restriction (PW group). In contrast, the strength of the femoral mid-diaphysis did not differ between BL and SE groups. Conclusions: The distal metaphysis in the male rat femur is more prone to decreasing biomechanical strength than the diaphysis during ageing. Physical exercise, when started at the age of 5 months, when the skeleton has reached its adult size, is somewhat effective in counteracting these changes. There is also some retarding effect of food restriction.
Increased Framingham Coronary Heart Disease Risk Score in Dementia Caregivers Relative to Non-Caregiving Controls
Authors: von Känel Roland , Mausbach Brent T. , Patterson Thomas L. , Dimsdale Joel E. , Aschbacher Kirstin , Mills Paul J. , Ziegler Michael G. , Ancoli-Israel Sonia , Grant Igor
Published: February 2008

Background: Elderly individuals who provide care to a spouse suffering from dementia bear an increased risk of coronary heart disease (CHD). Objective: To test the hypothesis that the Framingham CHD Risk Score would be higher in dementia caregivers relative to non-caregiving controls. Methods: We investigated 64 caregivers providing in-home care for their spouse with Alzheimer’s disease and 41 gender-matched non-caregiving controls. All subjects (mean age 70 ± 8 years, 75% women, 93% Caucasian) had a negative history of CHD and cerebrovascular disease. The original Framingham CHD Risk Score was computed adding up categorical scores for age, blood lipids, blood pressure, diabetes, and smoking with adjustment made for sex. Results: The average CHD risk score was higher in caregivers than in controls even when co-varying for socioeconomic status, health habits, medication, and psychological distress (8.0 ± 2.9 vs. 6.3 ± 3.0 points, p = 0.013). The difference showed a medium effect size (Cohen’s d = 0.57). A relatively higher blood pressure in caregivers than in controls made the greatest contribution to this difference. The probability (area under the receiver operator curve) that a randomly selected caregiver had a greater CHD risk score than a randomly selected non-caregiver was 65.5%. Conclusions: Based on the Framingham CHD Risk Score, the potential to develop overt CHD in the following 10 years was predicted to be greater in dementia caregivers than in non-caregiving controls. The magnitude of the difference in the CHD risk between caregivers and controls appears to be clinically relevant. Clinicians may want to monitor caregiving status as a routine part of standard evaluation of their elderly patients’ cardiovascular risk.
Figure-Ground Separation by Cue Integration
Authors: Tang Xiangyu , von der Malsburg Christoph
Published: February 2008

This letter presents an improved cue integration approach to reliably separate coherent moving objects from their background scene in video sequences. The proposed method uses a probabilistic framework to unify bottom-up and top-down cues in a parallel, “democratic” fashion. The algorithm makes use of a modified Bayes rule where each pixel's posterior probabilities of figure or ground layer assignment are derived from likelihood models of three bottom-up cues and a prior model provided by a top-down cue. Each cue is treated as independent evidence for figure-ground separation. They compete with and complement each other dynamically by adjusting relative weights from frame to frame according to cue quality measured against the overall integration. At the same time, the likelihood or prior models of individual cues adapt toward the integrated result. These mechanisms enable the system to organize under the influence of visual scene structure without manual intervention. A novel contribution here is the incorporation of a top-down cue. It improves the system's robustness and accuracy and helps handle difficult and ambiguous situations, such as abrupt lighting changes or occlusion among multiple objects. Results on various video sequences are demonstrated and discussed. (Video demos are available at http://organic.usc.edu:8376/∼tangx/neco/index.html .)
Analysis of the Interaction Between the Dendritic Conductance Density and Activated Area in Modulating α-Motoneuron EPSP: Statistical Computer Model
Authors: Gradwohl Gideon , Grossman Yoram
Published: February 2008

Five reconstructed α-motoneurons (MNs) are simulated under physiological and morphological realistic parameters. We compare the resulting excitatory postsynaptic potential (EPSP) of models, containing voltage-dependent channels on the dendrites, with the EPSP of a passive MN and an active soma and axon model. In our simulations, we apply three different distribution functions of the voltage-dependent channels on the dendrites: a step function (ST) with uniform spatial dispersion; an exponential decay (ED) function, with proximal to the soma high-density location; and an exponential rise (ER) with distally located conductance density. In all cases, the synaptic inputs are located as a gaussian function on the dendrites. Our simulations lead to eight key observations. (1) The presence of the voltage-dependent channels conductance (gActive) in the dendrites is vital for obtaining EPSP peak boosting. (2) The mean EPSP peaks of the ST, ER, and ED distributions are similar when the ranges of G (total conductance) are equal. (3) EPSP peak increases monotonically when the magnitude of gNa_step (maximal gNa at a particular run) is increased. (4) EPSP kinetics parameters were differentially affected; time integral was decreased monotonically with increased gNa_step, but the rate of rise (the decay time was not analyzed) does not show clear relations. (5) The total G can be elevated by increasing the number of active dendrites; however, only a small active area of the dendritic tree is sufficient to get the maximal boosting. (6) The sometimes large variations in the parameters values for identical G depend on the gNa_step and active dendritic area. (7) High gNa_step in a few dendrites is more efficient in amplifying the EPSP peak than low gNa_step in many dendrites. (8) The EPSP peak is approximately linear with respect to the MNs' RN (input resistance).
Hellish Females: The Strange Woman of Septuagint Proverbs and 4QWiles of the Wicked Woman (4Q184)
Authors: Goff Matthew
Published: February 2008

The Strange Woman of Proverbs can be understood as signifying a type of "real" woman who is immoral that the intended male addressees are taught to avoid. This is also the case in Septuagint Proverbs, but the LXX expands her ability to function as a metaphor for abstract ideas. 4Q184 creatively reworks the Strange Woman to describe a female who functions as a general symbol for wickedness. She is associated with Sheol to a greater extent than any figure from Proverbs. In their reception of the Strange Woman, the Septuagint and 4Q184 have interpretative traditions in common, or at least understand her in similar ways.
The Inverse Ocean Modeling System. Part II: Applications
Authors: Muccino J. C. , Luo H. , Arango H. G. , Haidvogel D. , Levin J. C. , Bennett A. F. , Chua B. S. , Egbert G. D. , Cornuelle B. D. , Miller A. J. , Di Lorenzo E. , Moore A. M. , Zaron E. D.
Published: February 2008

The Inverse Ocean Modeling (IOM) System is a modular system for constructing and running weak-constraint four-dimensional variational data assimilation (W4DVAR) for any linear or nonlinear functionally smooth dynamical model and observing array. The IOM has been applied to four ocean models with widely varying characteristics. The Primitive Equations Z-coordinate-Harmonic Analysis of Tides (PEZ-HAT) and the Regional Ocean Modeling System (ROMS) are three-dimensional, primitive equations models while the Advanced Circulation model in 2D (ADCIRC-2D) and Spectral Element Ocean Model in 2D (SEOM-2D) are shallow-water models belonging to the general finite-element family. These models, in conjunction with the IOM, have been used to investigate a wide variety of scientific phenomena including tidal, mesoscale, and wind-driven circulation. In all cases, the assimilation of data using the IOM provides a better estimate of the ocean state than the model alone.
Historical Perspectives on African American Males as Subjects of Education Policy
Authors: Fultz Michael , Brown Anthony
Published: February 2008

The intent of this article is to frame the contemporary policy prescriptions concerning the plight and prospects of African American males in historical perspective. The authors argue that the emergence of African American males as a special subject of educational policy represents a more explicit rendering of a deeply rooted social and educational policy discourse in which African American males figured prominently but seldom as a targeted subject. Selected historical literature in African American education, sociology, and educational policy are reviewed, noting relevant trends over time.
The Impact of Law on African American Males
Authors: Green Preston C.
Published: February 2008

This article analyzes whether federal and state constitutional and statutory provisions sufficiently protect African American male students from racism in public education. The first section explains how structural racism and unconscious racism have worked in tandem to prevent many African American males from experiencing the promise of equal educational opportunity in Brown v. Board of Education (1954). The second section examines the two federal laws that are primarily invoked to protect African Americans from governmental discrimination: (a) the Equal Protection Clause of the Fourteenth Amendment, and (b) Title VI of the Civil Rights Act of 1964. The third section explains whether legal arguments arising from the accountability movement might enable African American males to obtain remedies from the effects of structural and unconscious racism. Three provisions are examined: (a) the No Child Left Behind Act of 2001, (b) state education clauses, and (c) the Due Process Clause of the Fourteenth Amendment.
African American Males in Special Education
Authors: Moore James L. , Henfield Malik S. , Owens Delila
Published: February 2008

Drawing on a larger study, this article is based on the findings of individual interviews and biographical questionnaires conducted with 10 African American males in special education. These students attended two low-performing, urban high schools located in the midwestern part of the United States. Using critical race theory as the theoretical framework, this article focuses on these students' perceptions of school counselors and their attitudes toward school counseling services. Implications, based on the findings, are given to school counselors.
Brown in Black and White—Then and Now
Authors: Hodge Samuel R. , Harrison Louis , Burden Joe W. , Dixson Adrienne D.
Published: February 2008

The U.S. Supreme Court's decision in the Brown v. Board of Education case was used as a point of reference to elaborate on the often divergent realities in education and sport for Black and White Americans. The impetus to integrate sport and the movement to integrate educational institutions in America were two separate yet often paralleled phenomena. It is typically argued that efforts to integrate educational institutions were about ensuring equitable access and opportunity. Less so, due to moral principles, integration in sports was more about winning and generating revenue. Still today, race-related divergences are reflected in education and sport. The intent of this article is to reflect on America's education and sport histories (then) and highlight some present-day realities (now) as associated with the social construct of race, particularly for Black male students and athletes.
Unintended Consequences
Authors: Dancy T. Elon E. , Brown M. Christopher
Published: February 2008

The nexus between educational attainment and collegiate perceptions for African American male undergraduates after Brown v. Board of Education et al.'s are explored in this study. Terenzini Transitions to College interview protocol was used to assess participants' precollege, in-class, and out-of-class experiences in college. A sample of eight African American men representing diverse socioeconomic backgrounds and precollege experiences was interviewed to gauge their sensemaking in two different collegiate contexts. Trustworthiness techniques support the following emergent themes in this study: (a) socially diverse experiences matter; (b) participants' manhood and behavior are shaped differently in different collegiate contexts; and (c) faculty-to-student interaction matters. The implications of these findings and the in-class and out-of-class experiences of African American men in higher education are discussed.
Realizing the Intended Outcomes of Brown
Authors: Harper Shaun R.
Published: February 2008

Equitable access to social mobility and advancement through education were among the intended outcomes of the Brown v. Board of Education case and related legislation. Despite this, scholars have illuminated the ways in which colleges, universities, and schools continually disadvantage African American male students. Although the evidence overwhelmingly confirms that many of the goals and promises of Brown remain unfulfilled, a different perspective is offered in this article. Specifically, ways in which high-achieving African American male undergraduates gain, negotiate, and benefit from access to powerful social networks on predominantly White campuses are presented herein. Findings from interviews with 32 high achievers at six large public research universities show a clear nexus between campus leadership, active out-of-class engagement, and the acquisition of social capital. The ways in which the participants leveraged their access to social networks and activated their social capital for goal actualization during and immediately after college are also discussed.
Black Political Economy in the 21st Century
Authors: Tauheed Linwood F.
Published: February 2008

In The Crisis of the Negro Intellectual, Harold Cruse challenged Black intellectuals, and Black economists in particular, to a “studied creation” of new economic forms not limited by the ideologies of capitalism or Marxism. Using the term new institutionalism, Cruse saw this as “a new and dynamic synthesis” of “politics, economics, and culture.” He argued that “the initial ideas . . . must emanate from the minds of an advanced type of Negro intelligentsia, or they will not emerge.” In this article, the author takes the position that Cruse's insightful critique continues to be valid, but meeting the challenge requires the development of a Methodology of Black political economy more robust than the current choices. The author proposes a methodological framework, “critical institutionalism”; a plan for use of the proposed Methodology; and an assessment of how Black Studies programs might develop scholar-activists proficient at negotiating the territories between ideology, Methodology, theory, and practice.
Examining the Interaction Among Likelihood to Sexually Harass, Ratee Attractiveness, and Job Performance
Authors: Lee Jo Ann , Welbourne Jennifer L. , Hoke Wesley A. , Beggs Joyce
Published: February 2008

The present work examines whether a rater's likelihood to sexually harass (LSH) moderates the effects of employee attractiveness, gender type of job, and explicit performance information on performance appraisals of female subordinates. A mixed design was used with rater LSH (high vs. medium vs. low) as a between-subjects variable; ratee attractiveness (high vs. low), ratee actual performance level (high vs. low), and job type (disc jockey vs. secretary vs. security guard) were within-subjects variables. A total of 92 male undergraduates completed Pryor's LSH Scale, read 12 written performance scenarios (with employee photographs), and rated performance of described female employees. Interactions between LSH with attractiveness and performance were found.
Entrepreneurs' Social Skills and New Venture Performance: Mediating Mechanisms and Cultural Generality
Authors: Baron Robert A. , Jintong Tang
Published: February 2008

This research seeks to extend previous findings concerning the relationship between entrepreneurs' social skills and new venture performance. Two potential mediators of such effects (entrepreneurs' success in obtaining information and essential resources) were investigated, and data were collected in a culture not included in previous studies (China). Results indicate that several social skills (e.g., social perception, expressiveness) are significantly related to measures of new venture performance and that these effects are indeed mediated by the two proposed mediating variables. Implications of these findings for efforts to understand how micro-level variables influence macro-level measures of new venture performance are discussed.
Information behaviour meets social capital: a conceptual model
Authors: Widén-Wulff Gunilla , Ek Stefan , Ginman Mariam , Perttilä Reija , Södergård Pia , Tötterman Anna-Karin
Published: February 2008

Much research has been done on the favourable influence of social environment and social networks on knowledge production. The aim of this article is to design a theoretical framework where both information behaviour (IB) research and social capital (SC) research are integrated. Integrating these areas is seen as an advantage when focusing on the social construction of knowledge, and a model is proposed to illuminate sources and consequences of social capital and knowledge sharing. This framework will function as a basis on which to build when the authors proceed with a number of empirical studies involving the university context, social networks of the unemployed, and virtual networks of young people.
Israeli Image Repair
Authors: Handley Robert L.
Published: February 2008

When Israeli citizens commit terrorist attacks against other Israeli citizens, they problematize the dominant Western news narrative that says that Palestinians commit terrorist attacks against Israelis who respond in self-defense. The citizen-terrorist also wrecks the image boundaries of “terrorist” and “citizen,” because citizens are normally victims of terrorism. This study scrutinizes how elite U.S. print reporters covered three different terrorist attacks committed by Israeli citizens against Israeli citizens. Two attacks were carried out by Arab Israelis and one was carried out by an Israeli Jew. In all three cases, reporters managed to repair the image of the “citizen” by suggesting that terrorism came from the West Bank, not Israel. However, reporters repaired the image of the Jewish Israeli but not did repair the Arab Israeli image. By restoring the dominant images of Jew-as-victim and Arab-as-aggressor, reporters managed to re-invoke the narrative that Arabs attack Israelis.
Mental Health Disorders and Functioning of Women in Domestic Violence Shelters
Authors: Helfrich Christine A. , Fujiura Glenn T. , Rutkowski-Kmitta Violet
Published: February 2008

This study investigates the presence of mental health symptoms and disorders reported by 74 women in a domestic violence shelter and the impact of those symptoms on function in work, school, and social encounters. Findings are compared to estimates of U.S. women generally, based on a national sample of over 65,000 women drawn from the 1995 National Health Interview Survey. The sheltered sample presents significantly higher rates of mental conditions and functional impairments affecting their work, school, and social functioning. These women are also less educated and poorer and use more health services than the U.S. population. Mental health conditions must be identified in shelters to improve functioning and facilitate independence from abusers.
Police Response to Domestic Violence
Authors: Perez Trujillo Monica , Ross Stuart
Published: February 2008

Assessing and responding to risk are key elements in how police respond to domestic violence. However, relatively little is known about the way police make judgments about the risks associated with domestic violence and how these judgments influence their actions. This study examines police decisions about risk in domestic violence incidents when using a risk assessment instrument. Based on a sample of 501 risk assessments completed by police in Australia, this study shows that a limited number of items on the risk assessment instrument are important in police officers' decisions about risk. Statistical analyses show that the victim's level of fear contributes to police officers' judgment on the level of risk and their decisions on which risk management strategy should be used. These findings suggest that research on police responses to domestic violence needs to pay greater attention to situational dynamics and the task requirements of risk-based decision making.
The Saga of ISAGA
Authors: Klabbers Jan H. G.
Published: February 2008

This article sketches the emergence of gaming and simulation associations in the 1960s and 1970s with a particular interest in ISAGA, the International Simulation and Gaming Association. It elaborates on the prospects to shape a meta-science of design, constituted by communities of practice and nourished by communities of observers. It is partly a transdisciplinary review on gaming and simulation methodology and partly an elaboration of current methodological questions. One reason for taking a dual position relates to the fact that members of gaming and simulation associations represent two distinct branches of science: the design and analytical sciences. The basic idea of the design sciences is to build and assess artifacts. The scientific method of the analytical sciences aims at developing and testing theories. Each pays attention to different notions of causality and different criteria for success.
Role-play and language socialization among bilingual Korean children in the United States
Authors: Yun Seongwon
Published: February 2008

This article examines children's role-play within the framework of language socialization, as well as the relations between (a) utterances made by young bilingual Korean children within the role-play frame and (b) metacommunicative utterances about the play. It analyzes the language features that children use to set up the context of role-play and explores the relationships of the children who participate in the process of role-play socialization. Data analysis includes thematically and pragmatically related sequences of naturally occurring interactions during lunch time and play time in a Korean Baptist church in the United States and play time at some of the children's homes. Results indicate that bilingual children socialize themselves and jointly construct their identities through role-play in the communities of practice using specific features of language such as metacommunicative verbs, deictics, and code-switching.
It's all About the Money: Chris and Pat Compare Salaries
Authors: Renard Monika K.
Published: February 2008

Can you name 20 influences on pay that could cause a difference in earnings between two ostensibly equal employees? This short, involving exercise can be used to illustrate the numerous influences that affect how employees' pay is determined, for example, education, experience required for the job, supply and demand, company size, seniority, and merit. It identifies and clarifies three major categories of influences—internal consistency, external competitiveness, and individual contribution—that affect pay decisions and pay policies. The exercise stimulates students' thinking about pay issues and sets the stage for a discussion of effective compensation decisions.
Bone marrow–derived mesenchymal stem cells facilitate engineering of long-lasting functional vasculature
Authors: Au Patrick , Tam Joshua , Fukumura Dai , Jain Rakesh K.
Published: February 2008

Vascular tissue engineering requires a ready source of endothelial cells and perivascular cells. Here, we evaluated human bone marrow–derived mesenchymal stem cells (hMSCs) for use as vascular progenitor cells in tissue engineering and regenerative medicine. hMSCs expressed a panel of smooth muscle markers in vitro including the cardiac/smooth muscle–specific transcription coactivator, myocardin. Cell-cell contact between endothelial cells and hMSCs up-regulated the transcription of myocardin. hMSCs efficiently stabilized nascent blood vessels in vivo by functioning as perivascular precursor cells. The engineered blood vessels derived from human umbilical cord vein endothelial cells and hMSCs remained stable and functional for more than 130 days in vivo. On the other hand, we could not detect differentiation of hMSCs to endothelial cells in vitro, and hMSCs by themselves could not form conduit for blood flow in vivo. Similar to normal perivascular cells, hMSC-derived perivascular cells contracted in response to endothelin-1 in vivo. In conclusion, hMSCs are perivascular cell precursors and may serve as an attractive source of cells for use in vascular tissue engineering and for the study of perivascular cell differentiation.
Identification of the Otopetrin Domain, a conserved domain in vertebrate otopetrins and invertebrate otopetrin-like family members
Authors: Hughes Inna , Binkley Jonathan , Hurle Belen , Green Eric D ,   NISC Comparative Sequencing Program, Sidow Arend , Ornitz David M
Published: February 2008

Background

Otopetrin 1 (Otop1) encodes a multi-transmembrane domain protein with no homology to known transporters, channels, exchangers, or receptors. Otop1 is necessary for the formation of otoconia and otoliths, calcium carbonate biominerals within the inner ear of mammals and teleost fish that are required for the detection of linear acceleration and gravity. Vertebrate Otop1 and its paralogues Otop2 and Otop3 define a new gene family with homology to the invertebrate Domain of Unknown Function 270 genes (DUF270; pfam03189).

Results

Multi-species comparison of the predicted primary sequences and predicted secondary structures of 62 vertebrate otopetrin, and arthropod and nematode DUF270 proteins, has established that the genes encoding these proteins constitute a single family that we renamed the Otopetrin Domain Protein (ODP) gene family. Signature features of ODP proteins are three "Otopetrin Domains" that are highly conserved between vertebrates, arthropods and nematodes, and a highly constrained predicted loop structure.

Conclusion

Our studies suggest a refined topologic model for ODP insertion into the lipid bilayer of 12 transmembrane domains, and highlight conserved amino-acid residues that will aid in the biochemical examination of ODP family function. The high degree of sequence and structural similarity of the ODP proteins may suggest a conserved role in the intracellular trafficking of calcium and the formation of biominerals.
Transcriptomic dissection of tongue squamous cell carcinoma
Authors: Ye Hui , Yu Tianwei , Temam Stephane , Ziober Barry L , Wang Jianguang , Schwartz Joel L , Mao Li , Wong David T , Zhou Xiaofeng
Published: February 2008

Background

The head and neck/oral squamous cell carcinoma (HNOSCC) is a diverse group of cancers, which develop from many different anatomic sites and are associated with different risk factors and genetic characteristics. The oral tongue squamous cell carcinoma (OTSCC) is one of the most common types of HNOSCC. It is significantly more aggressive than other forms of HNOSCC, in terms of local invasion and spread. In this study, we aim to identify specific transcriptomic signatures that associated with OTSCC.

Results

Genome-wide transcriptomic profiles were obtained for 53 primary OTSCCs and 22 matching normal tissues. Genes that exhibit statistically significant differences in expression between OTSCCs and normal were identified. These include up-regulated genes (MMP1, MMP10, MMP3, MMP12, PTHLH, INHBA, LAMC2, IL8, KRT17, COL1A2, IFI6, ISG15, PLAU, GREM1, MMP9, IFI44, CXCL1), and down-regulated genes (KRT4, MAL, CRNN, SCEL, CRISP3, SPINK5, CLCA4, ADH1B, P11, TGM3, RHCG, PPP1R3C, CEACAM7, HPGD, CFD, ABCA8, CLU, CYP3A5). The expressional difference of IL8 and MMP9 were further validated by real-time quantitative RT-PCR and immunohistochemistry. The Gene Ontology analysis suggested a number of altered biological processes in OTSCCs, including enhancements in phosphate transport, collagen catabolism, I-kappaB kinase/NF-kappaB signaling cascade, extracellular matrix organization and biogenesis, chemotaxis, as well as suppressions of superoxide release, hydrogen peroxide metabolism, cellular response to hydrogen peroxide, keratinization, and keratinocyte differentiation in OTSCCs.

Conclusion

In summary, our study provided a transcriptomic signature for OTSCC that may lead to a diagnosis or screen tool and provide the foundation for further functional validation of these specific candidate genes for OTSCC.
Viability of impacted bone allografts under metal mesh at the calcar in revision surgery of the hip
Authors: Buttaro M. , Araujo G. S. , Araujo E. S. , Comba F. , Piccaluga F.
Published: February 2008

Metal meshes are used in revision surgery of the hip to contain impacted bone grafts in cases with cortical or calcar defects in order to provide rotational stability to the stem. However, the viability of bone allografts under these metal meshes has been uncertain.

We describe the histological appearances of biopsies obtained from impacted bone allografts to the calcar contained by a metal mesh in two femoral reconstructions which needed further surgery at 24 and 33 months after the revision procedure.

A line of osteoid and viable new bone was observed on the surface of necrotic trabeculae. Active bone marrow between these trabeculae showed necrotic areas in some medullary spaces with reparative fibrous tissue and isolated reactive lymphocytes. This is interpreted as reparative changes after revascularisation of the cancellous allografts.

These pathological findings are similar to those reported in allografts contained by cortical host bone and support the hypothesis that incorporation of morcellised bone under metal meshes is not affected by these devices.
The use of ultrasound in acquisition of the anterior pelvic plane in computer-assisted total hip replacement
Authors: Parratte S. , Kilian P. , Pauly V. , Champsaur P. , Argenson J.-N. A.
Published: February 2008

We have evaluated in vitro the accuracy of percutaneous and ultrasound registration as measured in terms of errors in rotation and version relative to the bony anterior pelvic plane in computer-assisted total hip replacement, and analysed the intra- and inter-observer reliability of manual or ultrasound registration.

Four clinicians were asked to perform registration of the landmarks of the anterior pelvic plane on two cadavers. Registration was performed under four different conditions of acquisition. Errors in rotation were not significant. Version errors were significant with percutaneous methods (16.2°; p < 0.001 and 19.25° with surgical draping; p < 0.001), but not with the ultrasound acquisition (6.2°, p = 0.13). Intra-observer repeatability was achieved for all the methods. Inter-observer analysis showed acceptable agreement in the sagittal but not in the frontal plane.

Ultrasound acquisition of the anterior pelvic plane was more reliable in vitro than the cutaneous digitisation currently used.
Orthopaedic thromboprophylaxis
Authors: Warwick D. , Dahl O. E. , Fisher W. D.
Published: February 2008

Thromboprophylaxis remains a controversial subject. A vast amount of epidemiological and trial data about venous thromboembolism has been published over the past 40 years. These data have been distilled and synthesised into guidelines designed to help the practitioner translate this extensive research into ‘evidence-based’ advice.

Guidelines should, in theory, benefit patient care by ensuring that every patient routinely receives the best prophylaxis; without guidelines, it is argued, patients may fail to receive treatment or be exposed to protocols which are ineffective, dangerous or expensive.

Guidelines, however, have not been welcomed or applied universally. In the United States, orthopaedic surgeons have published their concerns about the thromboprophylaxis guidelines prepared by the American College of Chest Physicians. In Britain, controversy persists with many surgeons unconvinced of the risk/benefit, cost/benefit or practicality of thromboprophylaxis. The extended remit of the recent National Institute of Clinical Excellence thromboprophylaxis guidelines has been challenged.

The reasons for this disquiet are addressed in this paper and particular emphasis is placed on how clinically-acceptable guidelines could be developed and applied.
Efavirenz-Induced Hypersensitivity Reaction Manifesting in Rash and Hepatitis in a Latino Male
Authors: Leung Jennifer M , O'Brien John G , Wong Hing Ka , Winslow Dean L
Published: February 2008

Objective:

To report a case of hypersensitivity manifesting in a rash, fever, and life-threatening hepatitis in a patient initiated on efavirenz therapy.

Case Summary:

A 30-year-old Latino male newly diagnosed with HIV was started on efavirenz-based highly active antiretroviral therapy (HAART) using tenofovir 300 mg, emtricitabine 200 mg, and efavirenz 600 mg once daily. Eleven days after beginning therapy, he developed a hypersensitivity reaction manifesting in rash and fever preceding severe drug-induced hepatitis. Liver enzyme peak values were aspartate transaminase 3410 U/L and alanine transaminase 2132 U/L. Hepatitis resolved with discontinuation of the HAART. The patient was rechallenged with tenofovir and emtricitabine one year later; no adverse reactions occurred.

Discussion:

The Naranjo probability scale demonstrated a probable relationship between this adverse reaction and efavirenz. A MEDLINE search (2004 to September 2007) revealed 2 cases of rash preceding hepatitis with the initiation of efavirenz. Both cases were in women; there were no prior reported cases of efavirenz hypersensitivity in men. Although the mechanism of this reaction is unknown, a few factors may have contributed to this reaction. The half-life and the auto-induction of efavirenz may explain the continued rise in liver enzymes and severe hepatitis that continued to occur once the drug was discontinued. Another cause that may have contributed is the metabolism of the medication. CYP2B6 is responsible for almost 90% of the clearance of efavirenz. Data from a recent pharmacokinetic study showed that efavirenz concentrations were higher in both black and Latino patients when compared with those of white patients. In addition, it is highly probable that this patient's liver function was impaired when transaminase levels peaked, resulting in decreased clearance of efavirenz.

Conclusions:

Although such a hypersensitivity reaction is rare, efavirenz is the most probable cause of the erythematous maculopapular rash and acute hepatitis in this patient. Monitoring of liver function in patients who present with a rash following initiation of efavirenz-based HAART is recommended. In addition, clinicians should exercise caution in patients presenting with rash, fever, and increased liver enzymes (>3 times the upper limit of normal or patient baseline). It is strongly recommended that efavirenz therapy be withheld in such cases and reevaluated once liver enzyme levels stabilize.
Chronic Fluoxetine Stimulates Maturation and Synaptic Plasticity of Adult-Born Hippocampal Granule Cells
Authors: Wang Jing-Wen , David Denis J. , Monckton James E. , Battaglia Fortunato , Hen René
Published: February 2008

Chronic treatments with selective serotonin reuptake inhibitors (SSRIs) have been shown to increase hippocampal neurogenesis. However, it is not known whether SSRIs impact the maturation and functional integration of newborn neurons. Here we examined the effects of subchronic and chronic fluoxetine on the structural and physiological properties of young granule cells. Our results show that doublecortin-positive immature neurons displayed increased dendritic arborization after chronic fluoxetine treatment. In addition, chronic but not subchronic fluoxetine elicited a decrease in the number of newborn neurons expressing immature markers and a corresponding increase in those expressing mature markers. These results suggest that chronic fluoxetine accelerates the maturation of immature neurons. We also investigated the effects of fluoxetine on a form of neurogenesis-dependent long-term potentiation (LTP) in the dentate gyrus. This form of LTP was enhanced by chronic fluoxetine, and ablation of neurogenesis with x-irradiation completely blocked the effects of chronic fluoxetine on LTP. Finally, we demonstrated that the behavioral effect of fluoxetine in the novelty-suppressed feeding test requires chronic administration and is blocked by x-irradiation. These results show that the effects of fluoxetine on LTP and behavior both require neurogenesis and follow a similar delayed time course. The effects of chronic fluoxetine on the maturation and functional properties of young neurons may therefore be necessary for its anxiolytic/antidepressant activity and contribute to its delayed onset of therapeutic efficacy.
Stimulus-Specific Adaptations in the Gaze Control System of the Barn Owl
Authors: Reches Amit , Gutfreund Yoram
Published: February 2008

Abrupt orientation to novel stimuli is a critical, memory-dependent task performed by the brain. In the present study, we examined two gaze control centers of the barn owl: the optic tectum (OT) and the arcopallium gaze fields (AGFs). Responses of neurons to long sequences of dichotic sound bursts comprised of two sounds differing in the probability of appearance were analyzed. We report that auditory neurons in the OT and in the AGFs tend to respond stronger to rarely presented sounds (novel sounds) than to the same sounds when presented frequently. This history-dependent phenomenon, known as stimulus-specific adaptation (SSA), was demonstrated for rare sound frequencies, binaural localization cues [interaural time difference (ITD) and level difference (ILD)] and sound amplitudes. The manifestation of SSA in such a variety of independent acoustic features, in the midbrain and in the forebrain, supports the notion that SSA is involved in sensory memory and novelty detection. To track the origin of SSA, we analyzed responses of neurons in the external nucleus of the inferior colliculus (ICX; the source of auditory input to the OT) to similar sequences of sound bursts. Neurons in the ICX responded stronger to rare sound frequencies, but did not respond differently to rare ITDs, ILDs, or sound amplitudes. We hypothesize that part of the SSA reported here is computed in high-level networks, giving rise to novelty signals that modulate tectal responses in a context-dependent manner.
Endocannabinoid Signaling Mediates Cocaine-Induced Inhibitory Synaptic Plasticity in Midbrain Dopamine Neurons
Authors: Pan Bin , Hillard Cecilia J. , Liu Qing-song
Published: February 2008

Drugs that increase GABA levels in the brain reduce cocaine seeking in rodents and humans, suggesting that GABAergic inhibition regulates cocaine-seeking behavior. We previously reported that repeated cocaine exposurein vivofacilitates long-term potentiation by reducing the strength of GABAergic inhibition in dopamine neurons of the ventral tegmental area (VTA). Selective blockade of cocaine-induced reduction of GABAergic inhibition in the VTA might diminish cocaine-induced aberrant synaptic plasticity and addictive behavior. Here, we investigated the mechanism for cocaine-induced reduction of GABAergic inhibition. We show that a pathophysiologically relevant concentration of cocaine enables a normally ineffective stimulus to induce long-term depression (LTD) of IPSCs (I-LTD) in VTA dopamine neurons of midbrain slices. Activation of D2dopamine receptors and group I metabotropic glutamate receptors and subsequent recruitment of endocannabinoid signaling are required for I-LTD induction. We further demonstrate thatin vivopretreatment with antagonists to these receptors blocks cocaine-induced reduction of GABAergic inhibition and that repeated cocaine exposurein vivooccludes the subsequent induction of I-LTDex vivo. Together, these results suggest that repeated cocaine exposure reduces the strength of GABAergic inhibition in dopamine neurons by inducing I-LTD-like modificationin vivo.
Acid Sensing Ion Channels in Dorsal Spinal Cord Neurons
Authors: Baron Anne , Voilley Nicolas , Lazdunski Michel , Lingueglia Eric
Published: February 2008

Acid-sensing ion channels (ASICs) are broadly expressed in the CNS, including the spinal cord. However, very little is known about the properties of ASICs in spinal cord neurons compared with brain. We show here that ASIC1a and ASIC2a are the most abundant ASICs in mouse adult spinal cord and are coexpressed by most neurons throughout all the laminas. ASIC currents in cultured embryonic day 14 mouse dorsal spinal neurons mainly flow through homomeric ASIC1a (34% of neurons) and heteromeric ASIC1a plus 2a channels at a ratio of 2:1 (83% of neurons). ASIC2b only has a minor contribution to these currents. The two channel subtypes show different active pH ranges and different inactivation and reactivation kinetics supporting complementary functional properties. One striking property of native dorsal spinal neuron currents and recombinant currents is the pH dependence of the reactivation process. A light sustained acidosis induces a threefold slow-down of the homomeric ASIC1a (from pH 7.4 to pH 7.3) and heteromeric ASIC1a plus 2a (from pH 7.4 to pH 7.2) current reactivation (T0.5increasing from 5.77 to 16.84 s and from 0.98 to 3.2 s, respectively), whereas a larger acidosis to pH 6.6 induces a 32-fold slow-down of the ASIC1a plus 2a current reactivation (T0.5values increasing to 31.30 s). The pH dependence of ASIC channel reactivation is likely to modulate neuronal excitability associated with repetitive firing in response to extracellular pH oscillations, which can be induced, for example, by intense synaptic activity of central neurons.