bluuebunny/crossref_metadata_2025_split huggingface dataset:
Leptin But Not Ciliary Neurotrophic Factor (CNTF) Induces Phosphotyrosine Phosphatase-1B Expression in Human Neuronal Cells (SH-SY5Y): Putative Explanation of CNTF Efficacy in Leptin-Resistant State
Authors: Benomar Yacir , Berthou Flavien , Vacher Claire-Marie , Bailleux Virginie , Gertler Arieh , Djiane Jean , Taouis Mohammed 
Published: November 2008

Growing evidences suggest that obesity is associated with hypothalamic leptin resistance, leading to the alteration of food intake control. Alternative treatment using ciliary neurotrophic factor (CNTF) has been suggested because CNTF exerts a leptin-like effect, even in leptin-resistant states, but the mechanisms by which CNTF maintains this effect are not yet understood. Both leptin and CNTF act in the hypothalamus through similar signaling pathways including janus kinase-2/signal transducer and activator of transcription (STAT)-3 pathway. To explore the differences and interactions between leptin and CNTF signaling pathways, differentiated human neuroblastoma cells (SH-SY5Y) were exposed to either leptin or CNTF and then challenged for each cytokine. Leptin pretreatment completely abolished leptin-dependent STAT-3 and ERK 1/2 phosphorylations without affecting CNTF action. The lack of cross-desensitization between leptin and CNTF signaling pathways occurred despite the induction of suppressor of cytokine signaling-3 in response to both cytokines. Interestingly, leptin as well as insulin induced the expression of phosphotyrosine phosphatase (PTP)-1B, whereas CNTF treatment did not affect its expression. In addition, acute leptin treatment but not CNTF induced PTP-1B expression in mouse hypothalamic arcuate nucleus. Furthermore, the overexpression of human PTP-1B in SH-SY5Y cells completely abolished leptin- and insulin-dependent janus kinase-2, STAT-3, and ERK 1/2 phosphorylations, but CNTF action was not altered. Collectively, our results suggest that PTP-1B constitutes a key divergent element between leptin/insulin and CNTF signaling pathways at the neuronal level, which may constitute a possible mechanism that explains the efficacy of CNTF in leptin-resistant states.
Phosphotyrosine phosphatase 1B has a critical role in the onset of neuronal leptin resistance and is unable to inhibit CNTF-dependent signaling pathways in leptin-resistant states.
Importance of Proprotein Convertase Subtilisin/Kexin Type 9 in the Hormonal and Dietary Regulation of Rat Liver Low-Density Lipoprotein Receptors
Authors: Persson Lena , Gälman Cecilia , Angelin Bo , Rudling Mats 
Published: November 2008

Hormonal or dietary challenge can stimulate hepatic low-density lipoprotein receptor (LDLR) expression through posttranscriptional mechanisms. We here tested whether such observations may be due to regulation of proprotein convertase subtilisin/kexin type 9 (PCSK9). Treatment with glucagon resulted in a 2-fold increase in hepatic LDLR protein expression, whereas its mRNA levels were reduced; this occurred simultaneously with a 70% reduction in PCSK9 expression. Insulin treatment resulted in responses opposite to those seen by treatment with glucagon. Furthermore, high-dose ethinylestradiol treatment reduced PCSK9 expression by half. Finally, feeding of rats with dietary cholesterol reduced PCSK9 expression, resulting in an increased number of hepatic LDLRs despite a reduction of LDLR mRNA levels. Regulation of PCSK9 occurred in part through sterol regulatory element binding protein-2, but changes in this cholesterol-controlled transcription factor could not explain all hormonal effects seen. We conclude that the hormonal and dietary regulation of hepatic LDLRs also involves posttranscriptional regulation by PCSK9. The identification of PCSK9 regulation by these various treatments is important in understanding of the physiological function of this protein and points to new targets for therapeutic treatments to increase hepatic LDLR numbers.PCSK9, which reduces LDL-receptors by posttranscriptional mechanisms, is involved in the hormonal stimulation of LDL receptors by glucagon and estrogens.
Static electric field detection and behavioural avoidance in cockroaches
Authors: Newland Philip L. , Hunt Edmund , Sharkh Suleiman M. , Hama Noriyuki , Takahata Masakazu , Jackson Christopher W. 
Published: November 2008

SUMMARYElectric fields are pervasively present in the environment and occur both as a result of man-made activities and through natural occurrence. We have analysed the behaviour of cockroaches to static electric fields and determined the physiological mechanisms that underlie their behavioural responses. The behaviour of animals in response to electric fields was tested using a Y-choice chamber with an electric field generated in one arm of the chamber. Locomotory behaviour and avoidance were affected by the magnitude of the electric fields with up to 85% of individuals avoiding the charged arm when the static electric field at the entrance to the arm was above 8–10 kV m–1. Electric fields were found to cause a deflection of the antennae but when the antennae were surgically ablated, the ability of cockroaches to avoid electric fields was abolished. Fixation of various joints of the antennae indicated that hair plate sensory receptors at the base of the scape were primarily responsible for the detection of electric fields, and when antennal movements about the head–scape joint were prevented cockroaches failed to avoid electric fields. To overcome the technical problem of not being able to carry out electrophysiological analysis in the presence of electric fields, we developed a procedure using magnetic fields combined with the application of iron particles to the antennae to deflect the antennae and analyse the role of thoracic interneurones in signalling this deflection. The avoidance of electric fields in the context of high voltage power lines is discussed.
Plasticity in a cerebellar-like structure: suppressing reafference during episodic behaviors
Authors: Zhang Zhi , Bodznick David 
Published: November 2008

SUMMARY
Detection of relevant sensory signals requires the filtering out of irrelevant noise, including noise created by the animal's own movements(reafference). This is accomplished in the electrosense of little skates(Raja erinacea) by an adaptive filter in the cerebellar-like electrosensory nucleus (dorsal nucleus) in the medulla. We have shown that electrosensory inputs reliably coupled to the regularly recurring movements of breathing over time are eliminated selectively in the principal neurons(ascending efferent neurons, AENs) by a cancellation signal that is a negative of the reafference and is supplied by a parallel fiber system. Similarly,electrosensory inputs repeatedly linked to passive fin movements are eliminated suggesting that the filter also functions in relation to other behaviors besides breathing. To determine whether this adaptive filter can eliminate reafference created by brief and infrequent episodic behaviors like swimming in skates, we initiated a series of coupling tests in which an external electrosensory stimulus was coupled to short bouts of either parallel fiber stimulation or passive fin movements, and then measured the ability of AENs to generate a cancellation signal. Following five brief coupling periods(30–60 s) separated by long rest periods (1–9 min), 38.5% of the AENs developed a cancellation signal when the coupling was to parallel fiber stimulation, and 73% when the coupling was to passive fin movement. We demonstrate that the cancellation signals can be developed incrementally,persist for at least a 3 h rest period without reinforcement, and are extinguished within minutes when the association of sensory stimulus and fin movement or parallel fiber stimulation no longer exists. The results indicate that the adaptive filter has the properties necessary to cancel reafference associated with even brief and infrequent behaviors.
Changes in pulmonary blood flow do not affect gas exchange during intermittent ventilation in resting turtles
Authors: Wang Tobias , Hicks James W. 
Published: November 2008

SUMMARYThe breathing pattern of many different air-breathing vertebrates,including lungfish, anuran amphibians, turtles, crocodiles and snakes, is characterized by brief periods of lung ventilation interspersed among apnoeas of variable duration. These intermittent ventilatory cycles are associated with characteristic increases in pulmonary blood flow and tachycardia. In animals with central vascular shunts, the rise in pulmonary blood flow during ventilation is associated with the development of left-to-right (L–R)cardiac shunt (pulmonary recirculation of oxygenated blood returning from the lungs). By contrast, a large net right-to-left (R–L) shunt (pulmonary bypass) normally prevails during apnoea. The cardio–respiratory interaction and the changes in cardiac shunting have been suggested to improve pulmonary gas exchange but the benefits of L–R shunting on pulmonary gas transport have not been studied experimentally. The present study measured pulmonary gas exchange in fully recovered, freely diving turtles, where changes in pulmonary blood flow were prevented by partial occlusion of the pulmonary artery. Prevention of L–R shunt during ventilation did not impair CO2 excretion and overall, oxygen uptake and CO2excretion did not correlate with changes in pulmonary blood flow. We conclude that increases in pulmonary blood flow associated with ventilation are not required to maintain resting rates of oxygen uptake and CO2excretion in resting animals.
Weight and nutrition affect pre-mRNA splicing of a muscle gene associated with performance, energetics and life history
Authors: Marden James H. , Fescemyer Howard W. , Saastamoinen Marjo , MacFarland Suzanne P. , Vera J. Cristobal , Frilander Mikko J. , Hanski Ilkka 
Published: November 2008

SUMMARYA fundamental feature of gene expression in multicellular organisms is the production of distinct transcripts from single genes by alternative splicing(AS), which amplifies protein and functional diversity. In spite of the likely consequences for organismal biology, little is known about how AS varies among individuals or responds to body condition, environmental variation or extracellular signals in general. Here we show that evolutionarily conserved AS of troponin-t in flight muscle of adult moths responds in a quantitative fashion to experimental manipulation of larval nutrition and adult body weight. Troponin-t (Tnt) isoform composition is known to affect muscle force and power output in other animals, and is shown here to be associated with the thorax mass-specific rate of energy consumption during flight. Loading of adults with external weights for 5 days caused an AS response nearly identical to equal increases in actual body weight. In addition, there were effects of larval feeding history on adult Tntisoform composition that were independent of body weight, with moths from poorer larval feeding regimes producing isoform profiles associated with reduced muscle performance and energy consumption rate. Thus, Tntisoform composition in striated muscle is responsive to both weight-sensing and nutrition-sensing mechanisms, with consequent effects on function. In free-living butterflies, Tnt isoform composition was also associated with activity level and very strongly with the rate of egg production. Overall, these results show that AS of a muscle gene responds in a quantitative fashion to whole-organism variables, which apparently serves to coordinate muscle strength and energy expenditure with body condition and life history.
Regionally Specified Human Neural Progenitor Cells Derived from the Mesencephalon and Forebrain Undergo Increased Neurogenesis Following Overexpression of ASCL1
Authors: Kim Hyun-Jung , McMillan Erin , Han Fabin , Svendsen Clive N. 
Published: November 2008

Abstract
Human neural progenitor cells (hNPC) derived from the developing brain can be expanded in culture and subsequently differentiated into neurons and glia. They provide an interesting source of tissue for both modeling brain development and developing future cellular replacement therapies. It is becoming clear that hNPC are regionally and temporally specified depending on which brain region they were isolated from and its developmental stage. We show here that hNPC derived from the developing cortex (hNPCCTX) and ventral midbrain (hNPCVM) have similar morphological characteristics and express the progenitor cell marker nestin. However, hNPCCTX cultures were highly proliferative and produced large numbers of neurons, whereas hNPCVM divided slowly and produced fewer neurons but more astrocytes. Microarray analysis revealed a similar expression pattern for some stemness markers between the two growing cultures, overlaid with a regionally specific profile that identified some important differentially expressed neurogenic transcription factors. By overexpressing one of these, the transcription factor ASCL1, we were able to regain neurogenesis from hNPCVM cultures, which produced larger neurons with more neurites than hNPCCTX but no fully mature dopamine neurons. Thus, hNPC are regionally specified and can be induced to undergo neurogenesis following genetic manipulation. Although this restores neuronal production with a region-specific phenotype, it does not restore full neurochemical maturation, which may require additional factors.
Motivational and cultural correlates of second language acquisition
Authors: Yu Baohua , Watkins David A. 
Published: November 2008

The present study investigates the relationships among motivational factors, cultural correlates and second language proficiency. The participants, from both Western and Asian backgrounds, were learning Chinese at university level in the People’s Republic of China. 115 students (35 Western students and 80 Asian students) ranging from beginning to advanced levels of proficiency were surveyed.
The results of the study indicated that the degree of integrativeness into Chinese culture and motivation was significantly and positively related to Chinese language proficiency, while language anxiety was significantly and negatively correlated to such proficiency. However instrumental orientation was found to have no statistically significant relationship with such proficiency. Multiple regression analysis indicated that integrativeness and gender were major variables predicting Chinese language proficiency. Significant differences between Western and Asian student groups were found in terms of motivational variables and Chinese language proficiency. Compared with the Asian student group, the Western student group tended to perform better in spoken Chinese proficiency as evaluated by their teachers and seemed to have higher levels of motivation and integrativeness but lower levels of instrumental orientation and language anxiety. Recommendations are made to enhance motivation and second language acquisition.
The Effects of Failing to Include Hard-to-Reach Respondents in Longitudinal Surveys
Authors: Odierna Donna H. , Schmidt Laura A. 
Published: November 2008

Objectives. We sought to determine whether failure to locate hard-to-reach respondents in longitudinal studies causes biased and inaccurate study results. Methods. We performed a nonresponse simulation in a survey of 498 low-income women who received cash aid in a California county. Our simulation was based on a previously published analysis that found that women without children who applied for General Assistance experienced more violence than did women with children who applied for Temporary Assistance to Needy Families. We compared hard-to-reach respondents whom we reinterviewed only after extended follow-up effort 12 months after baseline with other respondents. We then removed these hard-to-reach respondents from our analysis. Results. Other than having a greater prevalence of substance dependence (14% vs 6%), there were no significant differences between hard- and easy-to-reach respondents. However, excluding the hard to reach would have decreased response rates from 89% to 71% and nullified the findings, a result that did not stem primarily from reduced statistical power. Conclusions. The effects of failure to retain hard-to-reach respondents are not predicable based on respondent characteristics. Retention of these respondents should be a priority in public health research.
Terrorism-Related Fear and Avoidance Behavior in a Multiethnic Urban Population
Authors: Eisenman David P. , Glik Deborah , Ong Michael , Zhou Qiong , Tseng Chi-Hong , Long Anna , Fielding Jonathan , Asch Steven 
Published: November 2008

Objectives. We sought to determine whether groups traditionally most vulnerable to disasters would be more likely than would be others to perceive population-level risk as high (as measured by the estimated color-coded alert level) would worry more about terrorism, and would avoid activities because of terrorism concerns.Methods. We conducted a random digit dial survey of the Los Angeles County population October 2004 through January 2005 in 6 languages. We asked respondents what color alert level the country was under, how often they worry about terrorist attacks, and how often they avoid activities because of terrorism. Multivariate regression modeled correlates of worry and avoidance, including mental illness, disability, demographic factors, and estimated color-coded alert level.Results. Persons who are mentally ill, those who are disabled, African Americans, Latinos, Chinese Americans, Korean Americans, and non-US citizens were more likely to perceive population-level risk as high, as measured by the estimated color-coded alert level. These groups also reported more worry and avoidance behaviors because of concerns about terrorism.Conclusions. Vulnerable populations experience a disproportionate burden of the psychosocial impact of terrorism threats and our national response. Further studies should investigate the specific behaviors affected and further elucidate disparities in the disaster burden associated with terrorism and terrorism policies.
Community Influences on Young People's Sexual Behavior in 3 African Countries
Authors: Stephenson Rob 
Published: November 2008

Objectives. I examined the role of community-level factors in the reporting of risky sexual behaviors among young people aged 15 to 24 years in 3 African countries with varying HIV prevalence rates.Methods. I analyzed demographic and health survey data from Burkina Faso, Ghana, and Zambia during the period 2001 through 2003 to identify individual, household, and community factors associated with reports of risky sexual behaviors.Results. The mechanisms through which the community environment shaped sexual behaviors varied among young men and young women. Community demographic profiles were not associated with reports of risky sexual behavior among young women but were influential in shaping the behavior of young men. Prevailing economic conditions and the behaviors and attitudes of adults in the community were strong influences on young people's sexual behaviors.Conclusions. These results provide strong support for a focus on community-level influences as an intervention point for behavioral change. Such interventions, however, should recognize specific cultural settings and the different pathways through which the community can shape the sexual behaviors of young men and women.
The Interaction of Sexual Identity With Sexual Behavior and Its Influence on HIV Risk Among Latino Men: Results of a Community Survey in Northern San Diego County, California
Authors: Zellner Jennifer A. , Martínez-Donate Ana P. , Sañudo Fernando , Fernández-Cerdeño Araceli , Sipan Carol L. , Hovell Melbourne F. , Carrillo Héctor 
Published: November 2008

Objectives. We examined the sexual behavior, sexual identities, and HIV risk factors of a community sample of Latino men to inform efforts to reduce Latinos' HIV risk. Methods. In 2005 and 2006, 680 Latino men in San Diego County, California, in randomly selected, targeted community venues, completed an anonymous, self-administered survey. Results. Most (92.3%) respondents self-identified as heterosexual, with 2.2%, 4.9%, and 0.6% self-identifying as bisexual, gay, or other orientation, respectively. Overall, 4.8% of heterosexually identified men had a lifetime history of anal intercourse with other men. Compared with behaviorally heterosexual men, heterosexually identified men who had sex with both men and women were more likely to have had a sexually transmitted infection, to have unprotected sexual intercourse with female partners, and to report having sex while under the influence of alcohol or other drugs. Bisexually identified men who had sex with men and women did not differ from behaviorally heterosexual men in these risk factors. Conclusions. Latino men who have a heterosexual identity and bisexual practices are at greater risk of HIV infection, and efforts to reduce HIV risk among Latinos should target this group.
The Scientific Basis for Law as a Public Health Tool
Authors: Moulton Anthony D. , Mercer Shawna L. , Popovic Tanja , Briss Peter A. , Goodman Richard A. , Thombley Melisa L. , Hahn Robert A. , Fox Daniel M. 
Published: November 2008

Systematic reviews are generating valuable scientific knowledge about the impact of public health laws, but this knowledge is not readily accessible to policy makers. We identified 65 systematic reviews of studies on the effectiveness of 52 public health laws: 27 of those laws were found effective, 23 had insufficient evidence to judge effectiveness, 1 was harmful, and 1 was found to be ineffective. This is a valuable, scientific foundation—that uses the highest relevant standard of evidence—for the role of law as a public health tool. Additional primary studies and systematic reviews are needed to address significant gaps in knowledge about the laws’ public health impact, as are energetic, sustained initiatives to make the findings available to public policy makers.
Effects of Alcohol Tax Increases on Alcohol-Related Disease Mortality in Alaska: Time-Series Analyses From 1976 to 2004
Authors: Wagenaar Alexander C. , Maldonado-Molina Mildred M. , Wagenaar Bradley H. 
Published: November 2008

Objective. We evaluated the effects of tax increases on alcoholic beverages in 1983 and 2002 on alcohol-related disease mortality in Alaska.Methods. We used a quasi-experimental design with quarterly measures of mortality from 1976 though 2004, and we included other states for comparison. Our statistical approach combined an autoregressive integrated moving average model with structural parameters in interrupted time-series models.Results. We observed statistically significant reductions in the numbers and rates of deaths caused by alcohol-related disease beginning immediately after the 1983 and 2002 alcohol tax increases in Alaska. In terms of effect size, the reductions were –29% (Cohen's d = –0.57) and –11% (Cohen's d = –0.52) for the 2 tax increases. Statistical tests of temporary-effect models versus long-term-effect models showed little dissipation of the effect over time.Conclusions. Increases in alcohol excise tax rates were associated with immediate and sustained reductions in alcohol-related disease mortality in Alaska. Reductions in mortality occurred after 2 tax increases almost 20 years apart. Taxing alcoholic beverages is an effective public health strategy for reducing the burden of alcohol-related disease.