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Using combined data from the Relativistic Heavy Ion and Large Hadron Colliders, we constrain the shear and bulk viscosities of quark-gluon plasma (QGP) at temperatures of â¼150-350 MeV. We use Bayesian inference to translate experimental and theoretical uncertainties into probabilistic constraints for the viscosities. With Bayesian model averaging we propagate an estimate of the model uncertainty generated by the transition from hydrodynamics to hadron transport in the plasma's final evolution stage, providing the most reliable phenomenological constraints to date on the QGP viscosities.
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Following publication of the original article [1], the author report typographical errors in the.
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BACKGROUND: The purpose of this paper is to systematically review the literature with respect to stakeholder views of selection methods for medical school admissions. METHODS: An electronic search of nine databases was conducted between January 2000-July 2014. Two reviewers independently assessed all titles (n = 1017) and retained abstracts (n = 233) for relevance. Methodological quality of quantitative papers was assessed using the MERSQI instrument. The overall quality of evidence in this field was low. Evidence was synthesised in a narrative review. RESULTS: Applicants support interviews, and multiple mini interviews (MMIs). There is emerging evidence that situational judgement tests (SJTs) and selection centres (SCs) are also well regarded, but aptitude tests less so. Selectors endorse the use of interviews in general and in particular MMIs judging them to be fair, relevant and appropriate, with emerging evidence of similarly positive reactions to SCs. Aptitude tests and academic records were valued in decisions of whom to call to interview. Medical students prefer interviews based selection to cognitive aptitude tests. They are unconvinced about the transparency and veracity of written applications. Perceptions of organisational justice, which describe views of fairness in organisational processes, appear to be highly influential on stakeholders' views of the acceptability of selection methods. In particular procedural justice (perceived fairness of selection tools in terms of job relevance and characteristics of the test) and distributive justice (perceived fairness of selection outcomes in terms of equal opportunity and equity), appear to be important considerations when deciding on acceptability of selection methods. There were significant gaps with respect to both key stakeholder groups and the range of selection tools assessed. CONCLUSIONS: Notwithstanding the observed limitations in the quality of research in this field, there appears to be broad concordance of views on the various selection methods, across the diverse stakeholders groups. This review highlights the need for better standards, more appropriate methodologies and for broadening the scope of stakeholder research.
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Critérios de Admissão Escolar , Faculdades de Medicina/normas , Desempenho Acadêmico , Testes de Aptidão , Tomada de Decisões Gerenciais , Docentes de Medicina , Humanos , Entrevistas como Assunto , Julgamento , Reprodutibilidade dos Testes , Estudantes de Medicina/psicologiaRESUMO
BACKGROUND: Several cross-sectional studies have shown an association between exposure to life events and psychological problems in adults with intellectual disability (ID). To establish life events as a risk factor, prospective designs are needed. METHODS: Support staff informants provided data on the psychological problems of 68 adults with ID and their recent exposure to life events. Using data collected on the same sample 3.5 to 4 years earlier, prospective analysis of the relationships between life events exposure and psychological problems over time was explored. RESULTS: Hierarchical linear regression analyses demonstrated a contribution of life events to the prediction of later psychological problems after controlling for earlier psychological problems. Exploratory analyses showed that the relationship between life events and psychological problems might be unidirectional, and non-spurious; remaining present once the impact of other correlates of psychological problems was controlled. CONCLUSIONS: These data offer support for the status of life events (with a negative valence) as a risk factor for psychological problems in adults with ID. To establish life events as a causal risk factor, research is needed to examine the mechanisms via which life events have their impact on psychological well-being.
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Deficiência Intelectual/epidemiologia , Deficiência Intelectual/psicologia , Acontecimentos que Mudam a Vida , Transtornos Mentais/epidemiologia , Transtornos Mentais/psicologia , Adulto , Feminino , Humanos , Modelos Lineares , Estudos Longitudinais , Masculino , Saúde Mental , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de RiscoRESUMO
The physico-chemical quality attributes of meat from broilers with significant differences in growth rate were investigated in this study. Two chicken populations from a random mating broiler control population were established as a slow-growing subpopulation (SG) with an average growth rate of 229 g/wk and a fast-growing subpopulation (FG) with an average growth rate of 319 g/wk. The initial pH at 15 min and final pH after 24 h were higher (P < 0.05) in breast muscle from FG than muscle from the SG population. Muscle from the SG had higher (P < 0.05) L* and b* of 57.0 and 11.2, compared with L* and b* of 55.8 and 10.5 from the FG. Although no difference in a* was observed, hue angle was different (P < 0.05) at 52.7 and 50.4 in FG and SG populations, respectively. Water-holding capacity was 25 to 27% and not different between the populations, but 5-d drip loss at 8.48% was higher (P < 0.05) in the muscle from the SG compared with the FG at 6.44%. Cook yield was higher (P < 0.05) in the FG muscle at 86.92% compared with the SG muscle at 85.96%. There was a positive correlation of +0.20 between pH difference and drip loss only in the FG. Significantly higher (P < 0.05) cook yields were observed in muscle from FG than SG chickens. The lower weight, higher L* value, and lower initial and final pH values in the SG population, coupled with higher drip loss and lower cook yield, likely result from differences in growth rate.
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Galinhas/crescimento & desenvolvimento , Galinhas/genética , Músculo Esquelético/fisiologia , Animais , Feminino , MasculinoRESUMO
Vitamin D(3) (VD(3) ) is a steroid hormone that regulates bone health and numerous aspects of immune function and may play a role in respiratory health. We hypothesized that T helper type 2 (Th2) disorders, chronic rhinosinusitis with nasal polyps (CRSwNP) and allergic fungal rhinosinusitis (AFRS) would have VD(3) deficiencies, resulting in increased mature dendritic cells (DCs) and bone erosion. We conducted a retrospective study examining VD(3) levels in patients with AFRS (n = 14), CRSwNP (n = 9), chronic rhinosinusitis without nasal polyps (CRSsNP) (n = 20) and cerebrospinal fluid leak repair (non-diseased controls) (n = 14) at time of surgery. Circulating immune cell levels were determined by immunostaining and flow cytometric analysis. Plasma VD(3) and immune regulatory factors (granulocyte-macrophage colony-stimulating factor and prostaglandin E(2) ) were measured by enzyme-linked immunosorbent assay. It was observed that CRSwNP and AFRS demonstrated increased circulating DCs, while chronic rhinosinusitis without nasal polyps displayed increased circulating macrophages. CRSwNP and AFRS were to found to have insufficient levels of VD(3) which correlated inversely with circulating numbers of mature DCs, DC regulatory factors and bone erosion. CRSsNP displayed no change in circulating DC numbers or VD(3) status compared to control, but did display increased numbers of circulating macrophages that was independent of VD(3) status. Lastly, VD(3) deficiency was associated with more severe bone erosion. Taken together, these results suggest support a role for VD(3) as a key player in the immunopathology of CRSwNP and AFRS.
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Fungos/imunologia , Rinite Alérgica Perene/imunologia , Rinite/imunologia , Sinusite/imunologia , Circulação Sanguínea/imunologia , Remodelação Óssea/imunologia , Contagem de Células , Células Cultivadas , Colecalciferol/sangue , Doença Crônica , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Células Dendríticas/patologia , Humanos , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/patologia , Pólipos Nasais , Rinite/sangue , Rinite/fisiopatologia , Rinite Alérgica Perene/sangue , Rinite Alérgica Perene/fisiopatologia , Sinusite/sangue , Sinusite/fisiopatologia , Equilíbrio Th1-Th2RESUMO
Werner's syndrome (WS) is an inherited disease with clinical symptoms resembling premature aging. Early susceptibility to a number of major age-related diseases is a key feature of this disorder. The gene responsible for WS (known as WRN) was identified by positional cloning. The predicted protein is 1432 amino acids in length and shows significant similarity to DNA helicases. Four mutations in WS patients were identified. Two of the mutations are splice-junction mutations, with the predicted result being the exclusion of exons from the final messenger RNA. One of the these mutations, which results in a frameshift and a predicted truncated protein, was found in the homozygous state in 60 percent of Japanese WS patients examined. The other two mutations are nonsense mutations. The identification of a mutated putative helicase as the gene product of the WS gene suggests that defective DNA metabolism is involved in the complex process of aging in WS patients.
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Cromossomos Humanos Par 8/genética , Clonagem Molecular , DNA Helicases/genética , Mutação , Síndrome de Werner/genética , Envelhecimento/genética , Sequência de Aminoácidos , Sequência de Bases , Mapeamento Cromossômico , Códon de Terminação , DNA/metabolismo , DNA Helicases/química , DNA Complementar/genética , Suscetibilidade a Doenças , Exodesoxirribonucleases , Éxons/genética , Feminino , Mutação da Fase de Leitura , Heterozigoto , Homozigoto , Humanos , Masculino , Dados de Sequência Molecular , Neoplasias/etiologia , Neoplasias/genética , RecQ Helicases , Alinhamento de Sequência , Helicase da Síndrome de WernerRESUMO
This article discusses the role and responsibilities of the registered nurse in providing first aid in challenging environments, such as crowded nightclubs. Basic assistance for common emergencies, including substance misuse, wounds, choking and anaphylaxis, are discussed. This article emphasises the importance of risk assessment and reminds readers of the need to maintain personal safety.
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Primeiros Socorros/métodos , Obstrução das Vias Respiratórias/enfermagem , Anafilaxia/enfermagem , Primeiros Socorros/enfermagem , Humanos , Hiperventilação/enfermagem , Medição de Risco , Transtornos Relacionados ao Uso de Substâncias/enfermagem , Ferimentos e Lesões/enfermagemRESUMO
This article, the first in an eight-part series, discusses the importance of a considered, responsible approach to first aid. The article describes the challenges of working outside one's clinical environment and describes the legal background to undertaking first aid.
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Primeiros Socorros , Papel do Profissional de Enfermagem , HumanosRESUMO
Nodulation (nod) gene expression in Rhizobium meliloti requires plant inducers and the activating protein product of the nodD gene. We have examined three genes in R. meliloti which have nodD activity and sequence homology. These three nodD genes are designated nodD1, nodD2 and nodD3, and have distinctive properties. The nodD1 gene product activates expression of the nodABC operon, as measured by a nodC-lacZ fusion or by transcript analysis, in the presence of crude seed or plant wash or the inducer, luteolin. The nodD3 gene product can cause a high basal (uninduced) level of nodC-lacZ expression and nodABC transcripts which is relatively unaffected by inducers. The effect of nodD3 is dependent on the presence of another gene, syrM (symbiotic regulator). By primer extension analysis we determined that the transcription start site is the same for nodD1 plus luteolin or nodD3-syrM mediated expression of nodA and nodH mRNAs. syrM also enhances the expression of another symbiotically important trait, production of extracellular polysaccharide. This regulatory effect of syrM requires locus syrA, which is linked to nodD3 and syrM. The syrM-syrA mediated increase in polysaccharide production requires at least some of the previously identified exo genes and may be a parallel regulatory event to the syrM-nodD3 control of nod promoters.
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Regulação da Expressão Gênica , Genes Bacterianos , Família Multigênica , Rhizobium/genética , Western Blotting , Expectorantes , Flavonoides , Luteolina , Mutação , Plasmídeos , Homologia de Sequência do Ácido Nucleico , Transcrição GênicaRESUMO
The early steps of symbiotic nodule formation by Rhizobium on plants require coordinate expression of several nod gene operons, which is accomplished by the activating protein NodD. Three different NodD proteins are encoded by Sym plasmid genes in Rhizobium meliloti, the alfalfa symbiont. NodD1 and NodD2 activate nod operons when Rhizobium is exposed to host plant inducers. The third, NodD3, is an inducer-independent activator of nod operons. We previously observed that nodD3 carried on a multicopy plasmid required another closely linked gene, syrM, for constitutive nod operon expression. Here, we show that syrM activates expression of the nodD3 gene, and that nodD3 activates expression of syrM. The two genes constitute a self-amplifying positive regulatory circuit in both cultured Rhizobium and cells within the symbiotic nodule. We find little effect of plant inducers on the circuit or on expression of nodD3 carried on pSyma. This regulatory circuit may be important for regulation of nod genes within the developing nodule.
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Proteínas de Bactérias/genética , Proteínas de Ligação a DNA , Regulação Bacteriana da Expressão Gênica , Genes Bacterianos , Fixação de Nitrogênio/genética , Sinorhizobium meliloti/genética , Transativadores , Proteínas de Bactérias/biossíntese , Flavonoides/farmacologia , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Luteolina , Proteínas Recombinantes de Fusão/biossínteseRESUMO
We have established the DNA sequence and analyzed the transcription and translation products of a series of putative nodulation (nod) genes in Rhizobium meliloti strain 1021. Four loci have been designated nodF, nodE, nodG and nodH. The correlation of transposon insertion positions with phenotypes and open reading frames was confirmed by sequencing the insertion junctions of the transposons. The protein products of these nod genes were visualized by in vitro expression of cloned DNA segments in a R. meliloti transcription-translation system. In addition, the sequence for nodG was substantiated by creating translational fusions in all three reading frames at several points in the sequence; the resulting fusions were expressed in vitro in both E. coli and R. meliloti transcription-translation systems. A DNA segment bearing several open reading frames downstream of nodG corresponds to the putative nod gene mutated in strain nod-216. The transcription start sites of nodF and nodH were mapped by primer extension of RNA from cells induced with the plant flavone, luteolin. Initiation of transcription occurs approximately 25 bp downstream from the conserved sequence designated the "nod box," suggesting that this conserved sequence acts as an upstream regulator of inducible nod gene expression. Its distance from the transcription start site is more suggestive of an activator binding site rather than an RNA polymerase binding site.
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The development of cancer is the result of a series of molecular changes occurring in the cell. These events lead to changes in the expression level of numerous genes that result in different phenotypic characteristics of tumors. In this report we describe the assembly and utilization of a 5766 member cDNA microarray to study the differences in gene expression between normal and neoplastic human ovarian tissues. Several genes that may have biological relevance in the process of ovarian carcinogenesis have been identified through this approach. Analyzing the results of microarray hybridizations may provides new leads for tumor diagnosis and intervention.
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Regulação Neoplásica da Expressão Gênica/genética , Genes Neoplásicos/genética , Neoplasias Ovarianas/genética , Clonagem Molecular , DNA Complementar/genética , Etiquetas de Sequências Expressas , Feminino , Proteínas Ligadas por GPI , Humanos , Glicoproteínas de Membrana/genética , Mesotelina , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase , RNA Mensageiro/genética , DNA Polimerase Dirigida por RNA/genética , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
The present study was designed to determine whether normolipidemic male squirrel monkeys (Saimiri sciureus) exhibit low density lipoprotein (LDL) heterogeneity similar to that observed in humans and if present, whether LDL subfractions are altered by consumption of low vs. high dose ethanol (EtOH). Primates were divided into three groups designated control, low, and high EtOH and fed isocaloric liquid diets containing 0%, 12% and 24% of calories as EtOH, respectively, for 6 months. The 12% EtOH caloric level resulted in a modest, non-significant increase in high density lipoprotein (HDL) cholesterol and no change in LDL cholesterol or plasma apolipoprotein B (apo B), while the 24% dose produced significant elevations in plasma, LDL and HDL cholesterol and apo B. Using a single-spin density gradient ultracentrifugation procedure developed for humans, three distinct LDL subclasses designated LDL1a (d = 1.031 g/ml), LDL1b (d = 1.038 g/ml) and LDL 2 (d = 1.046 g/ml) were isolated from all three treatment groups. Monkey LDL subfractions were nearly identical to very light, light and heavy LDL subspecies isolated from human plasma in terms of their: (1) isopycnic densities following ultracentrifugation; (2) co-migration as single bands with beta-electrophoretic mobility in cellulose acetate and agarose electrophoretic gels; (3) size-dependent migration pattern in polyacrylamide gradient electrophoretic gels; (4) co-migration as a single band corresponding to apo B-100, following SDS polyacrylamide gel electrophoresis; and (5) decrease in total cholesterol/protein ratios with increasing LDL subclass density. Although there were no treatment differences in LDL particle size, within each treatment group, mean particle size for each LDL subfraction was significantly different from every other subfraction. Low (12%) dose alcohol had no effect on LDL subfraction mass relative to controls while high alcohol consumption resulted in marked increases in all lipid (except triglyceride) and protein of the larger, buoyant LDL subspecies (LDL1a and LDL1b). Moreover, the best correlation between plasma apo B and LDL subfraction total mass was demonstrated with LDL1b (r = 0.735). Since neither the lipid nor the protein concentration of the small, dense, purportedly more atherogenic, LDL2 changed with the 24% EtOH dose, we propose that the LDL subfraction alterations associated with high alcohol intake in squirrel monkeys (increased LDL1a, increased LDL1b, LDL2 no effect) may represent a compensatory response to modulate the overall atherogenic lipoprotein profile associated with elevations in total LDL cholesterol and plasma apolipoprotein B.
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Etanol/farmacologia , Lipoproteínas LDL/efeitos dos fármacos , Animais , Apolipoproteínas B/sangue , Apolipoproteínas B/efeitos dos fármacos , Centrifugação Isopícnica , HDL-Colesterol/sangue , HDL-Colesterol/efeitos dos fármacos , LDL-Colesterol/sangue , LDL-Colesterol/efeitos dos fármacos , Eletroforese em Gel de Poliacrilamida , Etanol/administração & dosagem , Lipoproteínas LDL/sangue , Lipoproteínas LDL/classificação , Masculino , SaimiriRESUMO
The time course of lipoprotein changes during ethanol (EtOH) consumption followed by abstinence was examined in 3 groups of male squirrel monkeys: 1) controls fed isocaloric liquid diet; 2) low EtOH monkeys given liquid diet with vodka substituted isocalorically for carbohydrate at 12% of calories; and 3) high EtOH animals fed diet plus vodka at 24% of calories. After 2 weeks, high EtOH monkeys showed significant elevations in total plasma cholesterol which continued to increase at 4 weeks and then declined at 8 weeks. These elevations were the result of increases in both low density (LDL)- and high density lipoprotein (HDL)-cholesterol. Low EtOH monkeys had a modest increase in total cholesterol throughout 8 weeks which was attributed to increments in HDL-cholesterol alone. During abstinence, total, HDL- and LDL-cholesterol concentrations decreased rapidly in the high EtOH group and were similar to control values after 4 days. HDL-cholesterol showed a more gradual decline in animals fed 12% EtOH while LDL-cholesterol remained low and not significantly different from controls. Liver function tests were normal for all animals. Our results indicate that low-dose EtOH favors a coronary protective lipoprotein profile (increases HDL, decreases LDL) in squirrel monkeys while the higher alcohol regimen causes both favorable and unfavorable alterations in plasma lipids which quickly revert to control levels during abstinence.
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Etanol/administração & dosagem , Lipoproteínas HDL/sangue , Lipoproteínas LDL/sangue , Animais , Colesterol/sangue , Masculino , Saimiri , Triglicerídeos/sangueRESUMO
The effect of drinking pattern on plasma lipoproteins and body weight was examined in three groups of squirrel monkeys: (1) controls fed isocaloric liquid diet; (2) regular drinkers given liquid diet containing ethanol (EtOH) substituted isocalorically for carbohydrate at 12% of calories daily; and (3) binge drinkers fed 6% EtOH calories daily for a four-day period followed by three days of 20% EtOH to mimic a weekend bout drinking cycle. The number of calories offered per day was the same for all groups, and the average weekly EtOH consumption (12% calories) was identical for the two alcohol treatments. The entire study lasted six months. There were no significant differences in plasma cholesterol, triglyceride or liver function tests. Regular drinkers had the highest high density lipoprotein2/high density lipoprotein3 (HDL2/HDL3) protein and apolipoprotein A-I/B ratios of any group and exhibited a significant elevation in the molar plasma lecithin:cholesterol acyltransferase (LCAT) rate (nmol/min/ml). Binge drinking produced a selective increase in low density lipoprotein (LDL) cholesterol and apolipoprotein B, and a depression in the fractional LCAT rate (% esterified/min). During the course of the study, controls ate 92% of their diet while the alcohol groups each consumed 95% of the liquid diet. Despite this difference, body weight and Quetelet index (weight/height2) decreased progressively in the order controls greater than regular drinkers greater than binge drinkers. Results from our study indicate that moderate, regular daily consumption of EtOH at 12% of calories causes a modest reduction in body weight and produces a coronary protective lipoprotein profile (increases HDL2/HDL3, increases apolipoprotein A-I/B, low LDL cholesterol). By contrast, when this same average weekly dose is concentrated in a binge cycle, unfavorable alterations in lipoprotein composition (increases LDL cholesterol, increases apolipoprotein B) and metabolism (decreases LCAT activity) occur along with weight loss and depletion of body fat. These studies point to the value of the squirrel monkey model in evaluating both favorable and pathophysiological effects of chronic EtOH intake.
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Consumo de Bebidas Alcoólicas , Peso Corporal/efeitos dos fármacos , Lipoproteínas/sangue , Animais , Apolipoproteínas/sangue , Constituição Corporal , Ingestão de Energia , Etanol/sangue , Etanol/farmacologia , Lipoproteínas HDL/sangue , Masculino , Fosfatidilcolina-Esterol O-Aciltransferase/sangue , SaimiriRESUMO
Several commonly used scintigraphic methods of GFR measurement were evaluated. Forty-three adult patients with a wide range of ages and renal function were studied. The two-sample plasma method of Russell and the urinary method of Jackson were the most accurate methods overall. The one-sample plasma method of Russell, the volume of distribution method of Fawdry, and a terminal slope method were less reliable, especially at low (0-60 ml/min) GFRs. The renal uptake method of Gates correlated poorly to the standards at all GFR levels even when corrected for body surface area or blood volume. The Russell two point and Jackson urinary GFR's can be used as complementary techniques and are recommended as primary methods of scintigraphic GFR determination.
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Taxa de Filtração Glomerular , Compostos de Organotecnécio , Ácido Pentético , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Avaliação como Assunto , Feminino , Humanos , Rim/diagnóstico por imagem , Rim/fisiologia , Rim/fisiopatologia , Masculino , Métodos , Pessoa de Meia-Idade , Cintilografia , Valores de Referência , Pentetato de Tecnécio Tc 99mRESUMO
Long-term (18-month) consumption of high-dose ethanol ([EtOH] 24% of total calories) by squirrel monkeys results in marked elevations in plasma antiatherogenic high-density lipoprotein (HDL) cholesterol and apolipoprotein (apo) A-1, and atherogenic low-density lipoprotein (LDL) cholesterol and apo B. In an effort to determine whether alterations in lipoprotein turnover could explain the above findings, 131I-HDL apo A-1 and 125I-LDL apo B were injected into EtOH and control animals, following which in-vivo catabolic and production rates were determined. For both lipoproteins, synthetic rates were unaltered, while fractional catabolic rates (FCR) were significantly reduced in EtOH monkeys. Results from this study implicate EtOH-induced changes in hepatic metabolism as the basis for delayed lipoprotein clearance and hence elevated plasma apolipoprotein levels.
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Etanol/administração & dosagem , Lipoproteínas/sangue , Consumo de Bebidas Alcoólicas/sangue , Animais , Apolipoproteína A-I/análise , Apolipoproteína A-I/metabolismo , Apolipoproteínas B/análise , Apolipoproteínas B/metabolismo , Peso Corporal , Lipoproteínas HDL/sangue , Lipoproteínas LDL/sangue , Masculino , Saimiri , Triglicerídeos/sangue , gama-Glutamiltransferase/sangueRESUMO
BACKGROUND: The phenotypic characteristics that allow some tumor cells to metastasize have not been fully identified. The production and/or response of tumor cells to various growth factors have been shown to distinguish cells of differing metastatic potentials. OBJECTIVES: To determine (1) whether rat hepatocellular carcinoma cell lines produce interleukin-6 (IL-6) and (2) whether production of IL-6 correlates with either metastatic potential or tumorigenicity. METHODS: The clonal cell lines 1682.C.2.9.L0 (poorly metastatic) and 1682.C.2.9.L10 (highly metastatic) were selected from a parental hepatocellular carcinoma induced in ACI rats by feeding an ethionine-containing diet and adapted to growth in vitro. RESULTS: Both cell lines resulted in primary tumors with equal frequency and developed a 40-mm nodule in a similar period time, when an inoculum of 5 X 10(6) cells was injected subcutaneously; however, only L10 cells metastasized to the lung. These cell lines did not demonstrate differential expression of several antigens noted to correlate with metastatic potential, including CD44 variant glycoprotein, p53, transferrin receptor, and E-cadherin. In contrast, L0 cells produced less than 10 U of IL-6 per milliliter in culture (as determined by bioassay using 7TD1 cells), whereas L10 cells released more than 95 U of this cytokine per milliliter under identical culture conditions (P<.01, Student's t test). In addition, serum concentrations of IL-6 were elevated in animals bearing L10-induced primary tumors but not in those with L0-induced tumors of comparable mass. Exogenous addition of IL-6 to both tumor cell lines had no effect on the rate of growth in vitro, supporting the similar the tumorigenic potentials observed in vivo. CONCLUSION: Excess IL-6 production appears to identify cells with metastatic potential and does not appear to be essential to the establishment of a primary tumor.
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Interleucina-6/biossíntese , Neoplasias Hepáticas Experimentais/metabolismo , Neoplasias Hepáticas Experimentais/patologia , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Animais , Linhagem Celular/efeitos dos fármacos , Células Clonais/efeitos dos fármacos , Interleucina-6/farmacologia , Masculino , Metástase Neoplásica , Ratos , Ratos EndogâmicosRESUMO
This paper uses a general queuing-theoretic model to derive more appropriate measures of hospital quality, such as turn-away probabilities and patient's expected waiting time, than have been used in recent empirical work [e.g., Joskow (1980)].