1,113 research outputs found
Administration of bisphosphonate for hypercalcemia associated with oral cancer
BACKGROUND: The efficacy of treating hypercalcemia with bisphosphonate (BP) in patients with advanced oral cancer has not been fully investigated. This retrospective study evaluated the clinical course of hypercalcemic patients with and without BP treatment. METHODS: Sixteen hypercalcemic patients, most of whom had uncontrollable locoregional lesions and lung metastases, were studied. Nine patients had been given BP, and the rest had not. RESULTS: There were significant differences in age and serum ALT between the BP-treated and -untreated groups. The first administration of BP effectively and safely decreased the serum calcium level, but repeated administrations were less effective. Although the patients treated with BP survived significantly longer than the untreated subjects, the difference of the median was only about 2 weeks. CONCLUSION: The occurrence of hypercalcemia in oral cancer patients apparently implies an extremely poor prognosis, and long-term survival cannot be expected, even with BP treatment
Genetic and Other Contributions to Alcohol Intake in Rhesus Macaques ( Macaca mulatta )
The etiology of alcoholism and alcohol abuse, like many other complex diseases, is heterogeneous and multifactorial. Numerous studies demonstrate a genetic contribution to variation in the expression of alcohol-related disorders in humans. Over the past decade, nonhuman primates have emerged as a valuable model for some aspects of human alcohol abuse because of their phylogenetic proximity to humans. Long-term, longitudinal studies of rhesus macaques ( Macaca mulatta ) have provided much insight into environmental influences, especially early life experiences, on alcohol consumption and behavior patterns that characterize alcohol intake later in life. It is not known, however, whether there is a genetic component as well to the variation seen in alcohol consumption in rhesus macaques. A significant genetic component to variation in alcohol consumption in rhesus macaques would show for the first time that like humans, for nonhuman primates additive genetic influences are important. Moreover, their use as a model for alcohol-related disorders in humans would have even greater relevance and utility for designing experiments incorporating the expanding molecular genetics field, and allow researchers to investigate the interaction among the known environmental influences and various genotypes. Methods : In this study, we investigate factors contributing to variation in alcohol consumption of 156 rhesus macaques collected over 10 years when subjects were adolescent in age, belonging to a single extended pedigree, with each cohort receiving identical early rearing backgrounds and subsequent treatments. To measure alcohol consumption each animal was provided unfettered simultaneous access both to an aspartame-sweetened 8.4% (v/v) alcohol-water solution, the aspartame-sweetened vehicle, and to water for 1 hour each day during the early afternoon between 13:00 and 15:00 in their home cages for a period of 5 to 7 weeks. We use multiple regression to identify factors that significantly affect alcohol consumption among these animals and a maximum likelihood program (ASReml) that, controlling for the significant factors, estimates the genetic contribution to the variance in alcohol consumption. Results : Multiple regression analysis identified test cohort and rearing environment as contributing to 57 and 2%, respectively, of the total variance in alcohol consumption. Of the remaining 41% of the variance about half (19.8%) was attributable to additive genetic effects using a maximum likelihood program. Conclusion : This study demonstrates that, as in humans, there are additive genetic factors that contribute to variation in alcohol consumption in rhesus macaques, with other nongenetic factors accounting for substantial portions of the variance in alcohol consumption, Our findings show the presence of an additive genetic component and suggest the potential utility of the nonhuman primate as a molecular genetics tool for understanding alcohol abuse and alcoholism.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66182/1/j.1530-0277.2006.00044.x.pd
Purposeful selection of variables in logistic regression
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Thermal Adaptation and Diversity in Tropical Ecosystems: Evidence from Cicadas (Hemiptera, Cicadidae)
The latitudinal gradient in species diversity is a central problem in ecology. Expeditions covering approximately 16°54′ of longitude and 21°4′ of latitude and eight Argentine phytogeographic regions provided thermal adaptation data for 64 species of cicadas. We test whether species diversity relates to the diversity of thermal environments within a habitat. There are general patterns of the thermal response values decreasing in cooler floristic provinces and decreasing maximum potential temperature within a habitat except in tropical forest ecosystems. Vertical stratification of the plant communities leads to stratification in species using specific layers of the habitat. There is a decrease in thermal tolerances in species from the understory communities in comparison to middle level or canopy fauna. The understory Herrera umbraphila Sanborn & Heath is the first diurnally active cicada identified as a thermoconforming species. The body temperature for activity in H. umbraphila is less than and significantly different from active body temperatures of all other studied species regardless of habitat affiliation. These data suggest that variability in thermal niches within the heterogeneous plant community of the tropical forest environments permits species diversification as species adapt their physiology to function more efficiently at temperatures different from their potential competitors
Plasmodium berghei Hsp90 contains a natural immunogenic I-A<sup>b</sup>-restricted antigen common to rodent and human Plasmodium species
Thorough understanding of the role of CD4 T cells in immunity can be greatly assisted by the study of responses to defined specificities. This requires knowledge of Plasmodium-derived immunogenic epitopes, of which only a few have been identified, especially for the mouse C57BL/6 background. We recently developed a TCR transgenic mouse line, termed PbT-II, that produces CD4+ T cells specific for an MHC class II (I-Ab)-restricted Plasmodium epitope and is responsive to both sporozoites and blood-stage P. berghei. Here, we identify a peptide within the P. berghei heat shock protein 90 as the cognate epitope recognised by PbT-II cells. We show that C57BL/6 mice infected with P. berghei blood-stage induce an endogenous CD4 T cell response specific for this epitope, indicating cells of similar specificity to PbT-II cells are present in the naïve repertoire. Adoptive transfer of in vitro activated TH1-, or particularly TH2-polarised PbT-II cells improved control of P. berghei parasitemia in C57BL/6 mice and drastically reduced the onset of experimental cerebral malaria. Our results identify a versatile, potentially protective MHC-II restricted epitope useful for exploration of CD4 T cell-mediated immunity and vaccination strategies against malaria
Does thermoregulatory behavior maximize reproductive fitness of natural isolates of Caenorhabditis elegans?
Acute appearance of fatty acids in human plasma – a comparative study between polar-lipid rich oil from the microalgae Nannochloropsis oculata and krill oil in healthy young males
Tolerance to the Neuron-Specific Paraneoplastic HuD Antigen
Experiments dating back to the 1940's have led to the hypothesis that the brain is an immunologically privileged site, shielding its antigens from immune recognition. The paraneoplastic Hu syndrome provides a powerful paradigm for addressing this hypothesis; it is believed to develop because small cell lung cancers (SCLC) express the neuron-specific Hu protein. This leads to an Hu-specific tumor immune response that can develop into an autoimmune attack against neurons, presumably when immune privilege in the brain is breached. Interestingly, all SCLC express the onconeural HuD antigen, and clinically useful tumor immune responses can be detected in up to 20% of patients, yet the paraneoplastic neurologic syndrome is extremely rare. We found that HuD-specific CD8+ T cells are normally present in the mouse T cell repertoire, but are not expanded upon immunization, although they can be detected after in vitro expansion. In contrast, HuD-specific T cells could be directly activated in HuD null mice, without the need for in vitro expansion. Taken together, these results demonstrate robust tolerance to the neuronal HuD antigen in vivo, and suggest a re-evaluation of the current concept of immune privilege in the brain
Behaviour and Physiology: The Thermal Strategy of Leatherback Turtles
Background: Adult leatherback turtles (Dermochelys coriacea) exhibit thermal gradients between their bodies and the environment of $8uC in sub-polar waters and #4uC in the tropics. There has been no direct evidence for thermoregulation in leatherbacks although modelling and morphological studies have given an indication of how thermoregulation may be achieved. Methodology/Principal Findings: We show for the first time that leatherbacks are indeed capable of thermoregulation from studies on juvenile leatherbacks of 16 and 37 kg. In cold water (, 25uC), flipper stroke frequency increased, heat loss through the plastron, carapace and flippers was minimized, and a positive thermal gradient of up to 2.3uC was maintained between body and environment. In warm water (25 – 31uC), turtles were inactive and heat loss through their plastron, carapace and flippers increased. The thermal gradient was minimized (0.5uC). Using a scaling model, we estimate that a 300 kg adult leatherback is able to maintain a maximum thermal gradient of 18.2uC in cold sub-polar waters. Conclusions/Significance: In juvenile leatherbacks, heat gain is controlled behaviourally by increasing activity while heat flux is regulated physiologically, presumably by regulation of blood flow distribution. Hence, harnessing physiology and behaviour allows leatherbacks to keep warm while foraging in cold sub-polar waters and to prevent overheating in
Australians’ views on carbon pricing before and after the 2013 federal election
As climate policies change through the legislative process, public attitudes towards them may change as well. Therefore, it is important to assess how people accept and support controversial climate policies as the policies change over time. Policy acceptance is a positive evaluation of, or attitude towards, an existing policy; policy support adds an active behavioural component1, 3. Acceptance does not necessarily lead to support. We conducted a national survey of Australian residents to investigate acceptance of, and support for, the Australian carbon pricing policy before and after the 2013 federal election, and how perceptions of the policy, economic ideology, and voting behaviour affect acceptance and support. We found acceptance and support were stable across the election period, which was surprising given that climate policy was highly contentious during the election. Policy acceptance was higher than policy support at both times and acceptance was a necessary but insufficient condition of support. We conclude that acceptance is an important process through which perceptions of the policy and economic ideology influence support. Therefore, future climate policy research needs to distinguish between acceptance and support to better understand this process, and to better measure these concepts
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