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Local Regulation (local + regulation)
Selected AbstractsInefficient Local Regulation of Local ExternalitiesJOURNAL OF PUBLIC ECONOMIC THEORY, Issue 3 2005GREGORY BESHAROV The consequences of commitment failure have been missing from debates about the decentralized regulation of automobile emissions and other sources of local consumption externalities. Even when the direct external effects of such products are limited to a single jurisdiction, the presence of increasing returns-to-scale production causes one jurisdiction's choice of regulatory standard to affect the prices and availability of goods elsewhere. Decentralized regulatory equilibria may be inefficient as a result. Because of a commitment failure, production may be split between standards,and consumers denied the full range of products,when it is efficient to have standards that allow products to be consumed everywhere. Coordination failures may cause similar inefficiencies. The results question the usefulness of the principle of subsidiarity as commonly employed. [source] Local regulation of human breast xenograft models,,JOURNAL OF CELLULAR PHYSIOLOGY, Issue 3 2010Jodie M. Fleming Breast cancer studies implant human cancer cells under the renal capsule, subcutaneously, or orthotopically and often use estrogen supplementation and immune suppressants (etoposide) in xenograft mouse models. However, cell behavior is significantly impacted by signals from the local microenvironment. Therefore, we investigated how the combinatorial effect of the location of injection and procedural differences affected xenograft characteristics. Patient-derived breast cancer cells were injected into mouse abdominal or thoracic mammary glands,±,estrogen and/or etoposide pretreatment. Abdominal xenografts had increased tumor incidence and volume, and decreased latency (P,<,0.001) compared to thoracic tumors. No statistically significant difference in tumor volume was found in abdominal xenografts treated,±,estrogen or etoposide; however, etoposide suppressed tumor volume in thoracic xenografts (P,<,0.02). The combination of estrogen and etoposide significantly decreased tumor incidence in both sites. In addition, mice treated,±,estradiol were injected orthotopically or subcutaneously with well-characterized breast cancer cell lines (MCF7, ZR75-1, MDA MB-231, or MCF10Ca1h). Orthotopic injection increased tumor volume; growth varied with estrogen supplementation. Location also altered methylation status of several breast cancer-related gene promoters. Lastly, vascularization of orthotopic tumors was significantly enhanced compared to subcutaneous tumors. These data suggest that optimal xenograft success occurs with orthotopic abdominal injections and illustrate molecular details of the compelling influence of the local microenvironment on in vivo models. J. Cell. Physiol. 224: 795,806, 2010. Published 2010 Wiley-Liss, Inc. [source] Monastrol, a prototype anti-cancer drug that inhibits a mitotic kinesin, induces rapid bursts of axonal outgrowth from cultured postmitotic neuronsCYTOSKELETON, Issue 1 2004Saad A. Haque Abstract Terminally postmitotic neurons continue to express many of the kinesin-related proteins known to configure microtubules during mitosis. Drugs that inhibit these kinesins are being developed as anti-cancer agents with the hope that they will inhibit proliferation of tumor cells without having adverse effects on the nervous system. The prototype, termed monastrol, inhibits the kinesin known as Eg5, which is essential for maintaining separation of the half-spindles. Eg5 is also highly expressed in neurons, particularly during development. Exposure of cultured sympathetic neurons to monastrol for a few hours increased both the number and the growth rate of the axons. With additional time, the overall lengths of the axons were indistinguishable from controls. Sensory neurons showed a similar short-term increase in axonal growth rate. However, prolonged exposure resulted in shorter axons, suggesting that sensory neurons may be more sensitive to toxic effects of the drug. Nevertheless, the overall health of the cultures was still far more robust than cultures treated with taxol, a drug commonly used for anti-cancer therapy. On the basis of these results, we conclude that Eg5 normally generates forces that oppose axonal growth, presumably by partially suppressing the forward advance of microtubules. We speculate that local regulation of Eg5 could be a means by which neurons coordinate rapid bursts of axonal growth with appropriate environmental cues. The comparatively modest toxic effects on the neurons over time are a hopeful sign for clinicians interested in using anti-Eg5 drugs for cancer therapy. Cell Motil. Cytoskeleton 58:10,16, 2004. © 2004 Wiley-Liss, Inc. [source] Specificity of a new lipid mediator produced by testicular and peritoneal macrophages on steroidogenesisINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 5 2000Lukyanenko Macrophage-derived factor (MDF) is a lipophilic factor produced by rat testicular and peritoneal macrophages that maximally stimulates testosterone production by rat Leydig cells through a steroidogenic acute regulatory protein independent mechanism. The purpose of the present study was to determine whether MDF is also produced by human macrophages, and/or if it acts on human steroidogenic cells. We also studied the tissue-specific functions of MDF by determining if it also acts on steroidogenic cells of the ovary and adrenal glands and, if so, does it require new protein synthesis. It was found that MDF was produced by human peritoneal macrophages, and was capable of stimulating human steroidogenic cells. In terms of tissue specificity, it was found that primary cultures of rat adrenocortical cells respond to MDF with increased secretion of aldosterone and corticosterone, as did rat granulosa cells by producing progesterone. MDF acted in the presence of cycloheximide, indicating that it does not require new protein synthesis. These results indicate that MDF may have significant therapeutic potential and provide a basis for future studies concerning its physiological role in humans. These results further suggest that MDF is not only involved in paracrine regulation of Leydig cells, but also has the potential for the local regulation of steroidogenesis in both granulosa and adrenal cortical cells. [source] Resource variability, aggregation and direct density dependence in an open context: the local regulation of an African elephant populationJOURNAL OF ANIMAL ECOLOGY, Issue 1 2008Simon Chamaillé-Jammes Summary 1An emerging perspective in the study of density dependence is the importance of the spatial and temporal heterogeneity of resources. Although this is well understood in temperate ungulates, few studies have been conducted in tropical environments where both food and water are limiting resources. 2We studied the regulation of one of the world's largest elephant populations in Hwange National Park, Zimbabwe. The study period started in 1986 when the population was released from culling. Using census data we investigated changes in elephant abundance with respect to rainfall and density across the entire park and across waterholes. 3The population more than doubled since culling stopped. The population increased continuously during the first 6 years, and then fluctuated widely at about 30 000 individuals. Immigration processes must have been involved in the increase of the population size. 4Population growth rates were negatively related to previous population density by a convex relationship, and negatively related to the ratio of previous population density on annual rainfall by a linear relationship. However, only this latter model (i.e. assuming a fluctuating carrying capacity related to annual rainfall) produced realistic dynamics. Overall, population decreased during dry years when the elephant density was high. 5During dry years there were fewer waterholes retaining water during the dry season and consequently elephant numbers at waterholes increased, while their aggregation level across waterholes decreased. On the long-run elephant numbers increased only at the less crowded waterholes. 6We suggest that the interaction between population size and the available foraging range determined by the number of active waterholes during the dry season controls the park population. 7Our results emphasize the need to understand how key-resource areas cause resource-based aggregation, which ultimately influences the strength of density dependence. More specifically, this study suggests that climate variability strongly affects local elephant population dynamics through changes in surface-water availability. Finally, as dispersal is likely to be an important driver of the dynamics of this population, our results support views that a metapopulation framework should be endorsed for elephant management in open contexts. [source] Remodeling and Vascular Spaces in BoneJOURNAL OF BONE AND MINERAL RESEARCH, Issue 1 2007Erik Fink Eriksen Abstract In recent years, we have come to appreciate that the close association between bone and vasculature plays a pivotal role in the regulation of bone remodeling and fracture repair. In 2001, Hauge et al. characterized a specialized vascular structure, the bone remodeling compartment (BRC), and showed that the outer lining of this compartment was made up of flattened cells, displaying all the characteristics of lining cells in bone. A decrease in bone turnover leads to a decrease in surfaces covered with remodeling compartments, whereas increased turnover causes an increase. Immunoreactivity for all major osteotropic growth factors and cytokines including osteoprotegerin (OPG) and RANKL has been shown in the cells lining the BRC, which makes the BRC the structure of choice for coupling between resorption and formation. The secretion of these factors inside a confined space separated from the bone marrow would facilitate local regulation of the remodeling process without interference from growth factors secreted by blood cells in the marrow space. The BRC creates an environment where cells inside the structure are exposed to denuded bone, which may enable direct cellular interactions with integrins and other matrix factors known to regulate osteoclast/osteoblast activity. However, the denuded bone surface inside the BRC also constitutes an ideal environment for the seeding of bone metastases, known to have high affinity for bone matrix. Reduction in BRC space brought about by antiresorptive therapies such as bisphosphonates reduce the number of skeletal events in advanced cancer, whereas an increase in BRC space induced by remodeling activators like PTH may increase the bone metastatic burden. The BRC has only been characterized in detail in trabecular bone; there is, however, evidence that a similar structure may exist in cortical bone, but further characterization is needed. [source] ECONOMIC FUNDAMENTALS IN LOCAL HOUSING MARKETS: EVIDENCE FROM U.S. METROPOLITAN REGIONSJOURNAL OF REGIONAL SCIENCE, Issue 3 2006Min Hwang ABSTRACT This paper investigates the effects of national and regional economic conditions on outcomes in the single-family housing market: housing prices, vacancies, and residential construction activity. Our three-equation model confirms the importance of changes in regional economic conditions, income, and employment on local housing markets. The results also provide the first detailed evidence on the importance of vacancies in the owner-occupied housing market on housing prices and supplier activities. The results also document the importance of variations in materials, labor and capital costs, and regulation in affecting new supply. Simulation exercises, using standard impulse response models, document the lags in market responses to exogenous shocks and the variations arising from differences in local parameters. The results also suggest the importance of local regulation in affecting the pattern of market responses to regional income shocks. [source] Expression of morphogenic genes in mature ovarian and testicular tissues: Potential stem-cell niche markers and patterning factorsMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 2 2006Kristian R. von Schalburg Abstract Morphogens are developmental regulators that modulate different tissue patterning, proliferation, differentiation, or remodeling processes in embryonic and adult tissues. Morphogens may also evoke specific regulatory programs in stem cells. Some of the morphogens involved in these processes have been characterized, while others remain unidentified. A microarray containing 3,557 salmonid cDNAs was used to compare the transcriptomes of rainbow trout precocious ovary at three different stages during second year (June, August, and October) with a reference (June normal ovary) transcriptome. During this study, we detected morphogen transcript hybridizations to salmonid elements and the study was enlarged to investigate these activities in various developmental stages of both ovary and testis. Genes from diverse development regulator families such as Anterior gradient-2, BMP, Epimorphin, Flightless, Frizzled, Notch, Tiarin, Twisted gastrulation, and Wnt were demonstrated to be expressed in the adult trout gonads. In mice or rats, expression of mammalian bmp-4, epimorphin, flightless, twisted gastrulation, and GW112 transcripts were localized to cell types isolated from the developed ovary and testis. Comparisons of salmonid and mammalian morphogens at the amino acid residue level show high similarities, suggesting functional conservation. This report provides evidence for local regulation by various morphogens and their potential to control distinct programs of gene expression in the gametes and their accessory cells during gametogenesis. Mol. Reprod. Dev. © 2005 Wiley-Liss, Inc. [source] Calcium sensing and cell signaling processes in the local regulation of osteoclastic bone resorptionBIOLOGICAL REVIEWS, Issue 1 2004Mone Zaidi ABSTRACT The skeletal matrix in terrestrial vertebrates undergoes continual cycles of removal and replacement in the processes of bone growth, repair and remodeling. The osteoclast is uniquely important in bone resorption and thus is implicated in the pathogenesis of clinically important bone and joint diseases. Activated osteoclasts form a resorptive hemivacuole with the bone surface into which they release both acid and osteoclastic lysosomal hydrolases. This article reviews cell physiological studies of the local mechanisms that regulate the resorptive process. These used in vitro methods for the isolation, culture and direct study of the properties of neonatal rat osteoclasts. They demonstrated that both local microvascular agents and products of the bone resorptive process such as ambient Ca2+ could complement longer-range systemic regulatory mechanisms such as those that might be exerted through calcitonin (CT). Thus elevated extracellular [Ca2+], or applications of surrogate divalent cation agonists for Ca2+, inhibited bone resorptive activity and produced parallel increases in cytosolic [Ca2+], cell retraction and longer-term inhibition of enzyme release in isolated rat osteoclasts. These changes showed specificity, inactivation, and voltage-dependent properties that implicated a cell surface Ca2+ receptor (CaR) sensitive to millimolar extracellular [Ca2+]. Pharmacological, biophysical and immunochemical evidence implicated a ryanodine-receptor (RyR) type II isoform in this process and localized it to a unique, surface membrane site, with an outward-facing channel-forming domain. Such a surface RyR might function either directly or indirectly in the process of extracellular [Ca2+] sensing and in turn be modulated by cyclic adenosine diphosphate ribose (cADPr) produced by the ADP-ribosyl cyclase, CD38. The review finishes by speculating about possible detailed models for these transduction events and their possible interactions with other systemic mechanisms involved in Ca2+ homeostasis as well as the possible role of the RyR-based signaling mechanisms in longer-term cell regulatory processes. [source] An optimal adaptive design to address local regulations in global clinical trials,PHARMACEUTICAL STATISTICS: THE JOURNAL OF APPLIED STATISTICS IN THE PHARMACEUTICAL INDUSTRY, Issue 3 2010Xiaolong Luo Abstract After multi-regional clinical trials (MRCTs) have demonstrated overall significant effects, evaluation for a region-specific effect is often important. Recent guidance (see, e.g. 1) from regulatory authorities regarding evaluation for possible country-specific effects has led to research on statistical designs that incorporate such evaluations in MRCTs. These statistical designs are intended to use the MRCTs to address the requirements for global registration of a medicinal product. Adding a regional requirement could change the probability for declaring positive effect for the region when there is indeed no treatment difference as well as when there is in fact a true difference within the region. In this paper, we first quantify those probability structures based on the guidance issued by the Ministry of Health, Labour and Welfare (MHLW) of Japan. An adaptive design is proposed to consider those probabilities and to optimize the efficiency for regional objectives. This two-stage approach incorporates comprehensive global objectives into an integrated study design and may mitigate the need for a separate local bridging study. A procedure is used to optimize region-specific enrollment based on an objective function. The overall sample size requirement is assessed. We will use simulation analyses to illustrate the performance of the proposed study design. Copyright © 2010 John Wiley & Sons, Ltd. [source] Who Will Consent to Emergency Treatment Trials for Subarachnoid Hemorrhage?ACADEMIC EMERGENCY MEDICINE, Issue 4 2009Angela Del Giudice MD Abstract Objectives:, Aneurysmal subarachnoid hemorrhage (SAH) is a devastating disorder that still requires much clinical study. However, the decision to participate in a randomized clinical trial, particularly a neuroemergency trial, is a complex one. The purposes of this survey were to determine who would participate in a randomized clinical trial that intended to examine transfusion practices after SAH, to identify who could serve as potential proxy decision-makers, and to find which patient characteristics were associated with the decision to participate. Methods:, This was a cross-sectional study using a self-administered questionnaire, composed of a brief description of the proposed trial followed by questions about participation using a 5-point Likert scale. Information sought included potential decision-maker, demographic data, setting and reason for current health care access, and personal or family history of neurologic injury. Results:, Nine-hundred five subjects were enrolled during emergency department (ED) visits, office visits, hospital admissions, or online, during a 1-month period: 63% were women and 46% were white. Nonneurologic problems were the leading reason (90%) for health care access, but 45% had a personal or family history of neurologic injury. Overall, 54% (95% confidence interval [CI] = 51% to 57%) of subjects stated they would definitely or probably consent to participate. No subject characteristics were associated with this decision: age (p = 0.28), sex (p = 0.16), race/ethnicity (p = 0.07), education (p = 0.44), religion (p = 0.42), clinical setting (p = 0.14), reason for visit (p = 0.58), and/or history of neurologic injury (p = 0.33). The vast majority (88%) identified a family member as the proxy decision-maker, again without differences among groups. Conclusions:, Greater than half of respondents stated they would participate in a proposed emergency treatment trial for SAH. Our survey suggests that the decision to participate is highly individualized, because no demographic, pathologic, historical, or access-related predictors of choice were found. Educational materials designed for this type of trial would need to be broad-based. Family members should be considered as proxy decision-makers where permitted by federal and local regulations. [source] | |||||||||||||