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1.
Eat Disord ; 32(2): 212-222, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38186089

RESUMO

Non-purging compensatory behaviors (NPCB; e.g. driven exercise, fasting, other extreme behaviors) are a subcategory of compensatory behaviors typically characterized as infrequent and less severe. Limited prior research has studied NPCB despite their increasing prevalence among adults with binge-spectrum eating disorders (B-ED). More research is needed to understand the types of NPCB present among B-ED and the association between NPCB, clinical severity, and treatment outcomes. Secondary analyses were conducted among 155 adults with B-ED in cognitive-behavioral (CBT)-based clinical trials. At baseline and post-treatment, clinical interviews of eating pathology assessed binge eating frequency, purging compensatory behavior frequency, and global eating pathology. The following NPCB were also assessed: driven exercise, 24-h fasting, 8+ waking hours of compensatory fasting, chewing and spitting, and other extreme weight control behaviors. Participants engaging in NPCB reported higher global eating pathology than those not engaging in NPCB. Frequency of chewing and spitting and 24-h fasting significantly decreased over treatment. Engagement in NPCB at baseline did not predict CBT outcomes. The current study highlights the prevalence and clinical severity of NPCB in B-ED but offers promising results regarding the potential for CBT to improve these behaviors. More research is needed on other extreme weight control behaviors reported qualitatively in our sample and on the maintenance of improvements in non-purging behaviors after CBT.


Assuntos
Transtorno da Compulsão Alimentar , Bulimia , Transtornos da Alimentação e da Ingestão de Alimentos , Adulto , Humanos , Transtorno da Compulsão Alimentar/terapia , Resultado do Tratamento , Bulimia/terapia , Jejum
2.
Science ; 223(4642): 1293-6, 1984 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-6322299

RESUMO

Human T-cell leukemia-lymphoma virus (HTLV) is a human C-type retrovirus that can transform T lymphocytes in vitro and is associated with certain T-cell neoplasms. Recent data suggest that, in the United States, patients with acquired immunodeficiency syndrome (AIDS), homosexual men with lymphadenopathy, and hemophiliacs have had significant exposure rates to HTLV, whereas matched and unmatched control American subjects have rarely been exposed to this agent. In the present experiments, T cells specifically reactive against HTLV were propagated from a patient whose HTLV-bearing lymphoma was in remission. The T cells were cloned in the presence of the virus and an HTLV-specific cytotoxic T-cell clone was isolated. This clone was infected and transformed by the virus, with one copy of an HTLV-I provirus being integrated into the genome. This T-cell clone did not exhibit the normal dependence on T-cell growth factor (interleukin-2) and proliferated spontaneously in vitro. Exposure of the clone to HTLV-bearing, autologous tumor cells specifically inhibited its proliferation and resulted in its death. These results may have implications for HTLV-associated inhibition of T-cell responses.


Assuntos
Transformação Celular Neoplásica , Transformação Celular Viral , Deltaretrovirus/fisiologia , Linfócitos T Citotóxicos/microbiologia , Síndrome da Imunodeficiência Adquirida/etiologia , Divisão Celular/efeitos dos fármacos , Sobrevivência Celular , Células Clonais , Efeito Citopatogênico Viral , Citotoxicidade Imunológica , Deltaretrovirus/genética , Deltaretrovirus/imunologia , Genes Virais , Hemofilia A , Homossexualidade , Humanos , Interleucina-2/farmacologia , Recombinação Genética , Linfócitos T Citotóxicos/imunologia
3.
Science ; 261(5120): 438-46, 1993 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-8332909

RESUMO

The three-dimensional solution structure of a complex between the DNA binding domain of the chicken erythroid transcription factor GATA-1 and its cognate DNA site has been determined with multidimensional heteronuclear magnetic resonance spectroscopy. The DNA binding domain consists of a core which contains a zinc coordinated by four cysteines and a carboxyl-terminal tail. The core is composed of two irregular antiparallel beta sheets and an alpha helix, followed by a long loop that leads into the carboxyl-terminal tail. The amino-terminal part of the core, including the helix, is similar in structure, although not in sequence, to the amino-terminal zinc module of the glucocorticoid receptor DNA binding domain. In the other regions, the structures of these two DNA binding domains are entirely different. The DNA target site in contact with the protein spans eight base pairs. The helix and the loop connecting the two antiparallel beta sheets interact with the major groove of the DNA. The carboxyl-terminal tail, which is an essential determinant of specific binding, wraps around into the minor groove. The complex resembles a hand holding a rope with the palm and fingers representing the protein core and the thumb, the carboxyl-terminal tail. The specific interactions between GATA-1 and DNA in the major groove are mainly hydrophobic in nature, which accounts for the preponderance of thymines in the target site. A large number of interactions are observed with the phosphate backbone.


Assuntos
Proteínas de Ligação a DNA/química , Fatores de Transcrição/química , Sequência de Aminoácidos , Animais , Sequência de Bases , Sítios de Ligação , Galinhas , Fatores de Ligação de DNA Eritroide Específicos , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Dados de Sequência Molecular , Conformação Proteica , Estrutura Terciária de Proteína , Dedos de Zinco
4.
J Clin Invest ; 74(1): 56-62, 1984 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-6330177

RESUMO

Cell lines were established from the peripheral blood of two patients with adult T cell leukemia. In contrast to our previous experience, where all such lines expressed T cell markers, these two cell lines expressed B cell antigens and Ig light chains (kappa on CF-2, lambda on HS). Human T cell lymphoma proviral (HTLV) sequences were demonstrated in both cell lines. Since only a portion of the cells in culture expressed Ig light chains, experiments were carried out to exclude the possibility that the cultures were not a mixture of B and T or non-B cells. Cells that expressed kappa- or lambda-light chains were separated by cell sorting from kappa- or lambda-negative cells and replaced in culture. Light chain negative cells reexpressed light chains after time in culture. After 5-azacytidine treatment of the cell lines, all cells expressed Ig light chains. These studies show that the human retrovirus HTLV, which has been demonstrated to be associated with certain T cell malignancies, can infect B cells or B cell precursors.


Assuntos
Linfócitos B/imunologia , Leucemia/imunologia , Linfoma/imunologia , Linfócitos T/imunologia , Adulto , Antígenos de Neoplasias/análise , Antígenos de Superfície/análise , Linhagem Celular , Transformação Celular Neoplásica , Enzimas de Restrição do DNA , DNA de Neoplasias/genética , Citometria de Fluxo , Humanos , Cadeias Leves de Imunoglobulina/análise , Cadeias kappa de Imunoglobulina/análise , Leucemia/genética , Linfoma/genética , Hibridização de Ácido Nucleico
5.
Mol Cell Biol ; 9(5): 2228-32, 1989 May.
Artigo em Inglês | MEDLINE | ID: mdl-2747649

RESUMO

Molecular genetic analysis of a number of vertebrate erythroid cell-specific genes has identified at least two types of cis-acting regulatory sequences which control the complex developmental pattern of gene expression during erythroid cell maturation. Tissue-specific cellular enhancers have been identified 3' to three erythroid cell-specific genes, and additional regulatory elements have been identified in the promoters of many erythroid genes. We show that the histone H5 enhancer, like the adult beta-globin enhancer, is involved in mediating the developmental induction of histone H5 mRNA as erythroid cells mature. We also describe the preliminary characterization of a tissue-specific regulatory element within the 5' region of the H5 locus and describe investigations of the interaction between this element and the histone H5 enhancer in mediating histone H5 regulation.


Assuntos
Histonas/genética , Transcrição Gênica , Animais , Galinhas , Deleção Cromossômica , Elementos Facilitadores Genéticos , Eritrócitos/metabolismo , Eritropoese , Regulação da Expressão Gênica , Mutação , Regiões Promotoras Genéticas
6.
Mol Cell Biol ; 6(5): 1751-9, 1986 May.
Artigo em Inglês | MEDLINE | ID: mdl-2878364

RESUMO

A library of recombinant bacteriophage was prepared from ts167 avian erythroblastosis virus-transformed erythroid precursor cells (HD6), and integrated proviruses from three distinct genomic loci were isolated. A subclone of one of these proviruses (pAEV1) was shown to confer temperature-sensitive release from transformation of erythroid precursor cells in vitro. The predicted amino acid sequence of the v-erbB polypeptide from the mutant had a single amino acid change when compared with the wild-type parental virus. When the wild-type amino acid was introduced into the temperature-sensitive avian erythroblastosis virus provirus in pAEV1, all erythroid clones produced in vitro were phenotypically wild type. The mutation is a change from a histidine to an aspartic acid in the temperature-sensitive v-erbB polypeptide. It is located in the center of the tyrosine-specific protein kinase domain and corresponds to amino acid position 826 of the human epidermal growth factor receptor sequence.


Assuntos
Alpharetrovirus/genética , Vírus da Leucose Aviária/genética , Transformação Celular Neoplásica , Eritroblastos/citologia , Genes Virais , Proteínas Virais/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Células Cultivadas , Embrião de Galinha , Clonagem Molecular , Fibroblastos/citologia , Mutação , Hibridização de Ácido Nucleico , Proteínas Oncogênicas v-erbB , Fenótipo , Transfecção
7.
Mol Cell Biol ; 16(5): 2238-47, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8628290

RESUMO

GATA-1, a transcription factor essential for the development of the erythroid lineage, contains two adjacent highly conserved zinc finger motifs. The carboxy-terminal finger is necessary and sufficient for specific binding to the consensus GATA recognition sequence: mutant proteins containing only the amino-terminal finger do not bind. Here we identify a DNA sequence (GATApal) for which the GATA-1 amino-terminal finger makes a critical contribution to the strength of binding. The site occurs in the GATA-1 gene promoters of chickens, mice, and humans but occurs very infrequently in other vertebrate genes known to be regulated by GATA proteins. GATApal is a palindromic site composed of one complete [(A/T)GATA(A/G)] and one partial (GAT) canonical motif. Deletion of the partial motif changes the site to a normal GATA site and also reduces by as much as eightfold the activity of the GATA-1 promoter in an erythroid precursor cell. We propose that GATApal is important for positive regulation of GATA-1 expression in erythroid cells.


Assuntos
Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Sequências Reguladoras de Ácido Nucleico , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Dedos de Zinco , Sequência de Aminoácidos , Animais , Sequência de Bases , Núcleo Celular/metabolismo , Células Cultivadas , Galinhas , Sequência Consenso , Proteínas de Ligação a DNA/química , Fatores de Ligação de DNA Eritroide Específicos , Fator de Transcrição GATA1 , Globinas/genética , Células-Tronco Hematopoéticas/metabolismo , Humanos , Cinética , Camundongos , Dados de Sequência Molecular , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/metabolismo , Homologia de Sequência do Ácido Nucleico , Fatores de Transcrição/química , Transfecção , Vertebrados
8.
Mol Cell Biol ; 4(5): 890-7, 1984 May.
Artigo em Inglês | MEDLINE | ID: mdl-6328275

RESUMO

B-cell lines established from two individuals with T-cell acute lymphocytic leukemia (T-ALL) express HLA-DR antigens, whereas the isogenic T-cells do not. The lack of expression correlates with a lack of detectable HLA-DR mRNA. All of the DR alpha DNA sequences detected by a cloned DR alpha cDNA probe are contained in a BglII fragment which varies slightly in size (4.0 to 4.8 kilobases) from one individual to another. In DNA from the T-cells not expressing DR alpha mRNA, all of the potential HpaII sites within the BglII fragment appeared to be methylated. In contrast, at least some of these sites were not methylated in DNA from the B-cells expressing high levels of DR alpha mRNA. Treatment of these T-cells with 5-azacytidine resulted in the induction of DR surface antigen expression, the appearance of DR alpha mRNA, and the partial demethylation of the DR alpha DNA sequences. T-cell lines established from human T-cell leukemia-lymphoma virus associated T-cell neoplasias, in contrast to the T-cell acute lymphocytic leukemia cell lines, expressed both DR antigens and DR alpha mRNA; the HpaII sites within the BglII fragment of DR alpha DNA of these human T-cell leukemia-lymphoma virus-positive T-cell lines were in all cases at least partially unmethylated. Uncultured peripheral blood T-cells from human T-cell leukemia-lymphoma virus-infected individuals expressed DR antigens at a low level, and the DR alpha locus was partially unmethylated. After 48 h in culture, DR antigen expression was substantially increased, but no significant changes were observed in methylation of the DR alpha locus or in the amount of DR mRNA which was present. This suggests that expression of DR antigens also can be modulated post-transcriptionally.


Assuntos
Linfócitos B/imunologia , DNA de Neoplasias/genética , Genes MHC da Classe II , Antígenos de Histocompatibilidade Classe II/análise , Linfócitos T/imunologia , Adulto , Antígenos de Superfície/análise , Linhagem Celular , Transformação Celular Viral , Antígenos HLA-DR , Herpesvirus Humano 4/imunologia , Humanos , Leucemia/imunologia , Linfoma/imunologia , Metilação , Hibridização de Ácido Nucleico
9.
Mol Cell Biol ; 20(2): 713-23, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10611250

RESUMO

A region located at kbp -3.9 to -2.6 5' to the first hematopoietic exon of the GATA-1 gene is necessary to recapitulate gene expression in both the primitive and definitive erythroid lineages. In transfection analyses, this region activated reporter gene expression from an artificial promoter in a position- and orientation-independent manner, indicating that the region functions as the GATA-1 gene hematopoietic enhancer (G1HE). However, when analyzed in transgenic embryos in vivo, G1HE activity was orientation dependent and also required the presence of the endogenous GATA-1 gene hematopoietic promoter. To define the boundaries of G1HE, a series of deletion constructs were prepared and tested in transfection and transgenic mice analyses. We show that G1HE contains a 149-bp core region which is critical for GATA-1 gene expression in both primitive and definitive erythroid cells but that expression in megakaryocytes requires the core plus additional sequences from G1HE. This core region contains one GATA, one GAT, and two E boxes. Mutational analyses revealed that only the GATA box is critical for gene-regulatory activity. Importantly, G1HE was active in SCL(-/-) embryos. These results thus demonstrate the presence of a critical network of GATA factors and GATA binding sites that controls the expression of this gene.


Assuntos
Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Elementos Facilitadores Genéticos/genética , Proteínas Proto-Oncogênicas , Elementos de Resposta/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ativação Transcricional/genética , Animais , Sequência de Bases , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Sítios de Ligação , Linhagem da Célula , Sequência Consenso/genética , Sondas de DNA , Proteínas de Ligação a DNA/fisiologia , Eritrócitos/citologia , Eritrócitos/metabolismo , Fatores de Ligação de DNA Eritroide Específicos , Fator de Transcrição GATA1 , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/metabolismo , Humanos , Células K562 , Megacariócitos/citologia , Megacariócitos/metabolismo , Camundongos , Camundongos Transgênicos , Dados de Sequência Molecular , Regiões Promotoras Genéticas/genética , Deleção de Sequência/genética , Proteína 1 de Leucemia Linfocítica Aguda de Células T , Saco Vitelino/embriologia , Saco Vitelino/metabolismo
10.
Mol Endocrinol ; 9(9): 1135-46, 1995 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7491106

RESUMO

GATA-1 is a DNA-binding protein that regulates transcription of erythroid-specific genes and is required for the formation of mature erythroid cells. We show here that the GATA-1 hormone response-like element (GHRE) within the first intron of the gene functions as an inhibitory element in chicken erythroid precursor cells, as revealed by expression studies with mutants of the minimal GATA-1 promoter. We identify in these precursor cells the relevant proteins that interact with GHRE as a heterodimer of the thyroid hormone receptor alpha and the chicken ovalbumin upstream promoter transcription factor. Our results indicate that this novel complex can negatively regulate the GATA-1 promoter and suggest that GATA-1 can overcome this inhibitory action. We provide evidence that the viral gene product, v-erb A, can also reduce GATA-1 promoter activity through the GHRE site.


Assuntos
Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica , Hormônios/farmacologia , Regiões Promotoras Genéticas , Sequências Reguladoras de Ácido Nucleico , Fatores de Transcrição/genética , Animais , Sequência de Bases , Sítios de Ligação , Ligação Competitiva , Fator I de Transcrição COUP , Galinhas/genética , DNA/química , DNA/metabolismo , Proteínas de Ligação a DNA/imunologia , Proteínas de Ligação a DNA/fisiologia , Células Precursoras Eritroides/metabolismo , Fatores de Ligação de DNA Eritroide Específicos , Íntrons , Dados de Sequência Molecular , Mutagênese , Receptores dos Hormônios Tireóideos/imunologia , Receptores dos Hormônios Tireóideos/fisiologia , Fatores de Transcrição/imunologia , Fatores de Transcrição/fisiologia , Transfecção , Tri-Iodotironina/farmacologia
11.
J Med Chem ; 35(15): 2843-55, 1992 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-1495015

RESUMO

The echinocandins are a well-known class of lipopeptides characterized by their potent antifungal activity against Candida species. The mechanism of action of the echinocandins is generally thought to be the inhibition of beta-1,3-glucan synthesis, an important structural component in the cell wall of Candida species. Extensive structure-activity studies on the fatty acid side chain of echinocandin B (1) led to the preparation of the clinical candidate cilofungin (4). However, little is known about the cyclic peptide. We now report the preparation, by solid-phase synthesis, of a series of simplified analogs of cilofungin in which the unusual amino acids found in the echinocandins were replaced with more readily accessible natural amino acids. The solid-phase approach to the total synthesis of these analogs allowed us to conveniently explore structural modifications that could not be accomplished by chemical modification of the natural product. The simplest analog 5 showed no biological activity. Structural complexity was then returned to the system in a systematic fashion so as to reapproach the original cilofungin structure. Antifungal activity and the inhibition of beta-1,3-glucan synthesis were monitored at each step of the process, thereby revealing the basic structure-activity relationships of the amino acids and the minimal structural requirements for biological activity in the echinocandin ring system. The results suggests that the 3-hydroxy-4-methylproline residue enhances activity but the L-homotyrosine residue is crucial for both antifungal activity and the inhibition of beta-1,3-glucan synthesis.


Assuntos
Antifúngicos/síntese química , Peptídeos Cíclicos , beta-Glucanas , Sequência de Aminoácidos , Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Equinocandinas , Glucanos/biossíntese , Dados de Sequência Molecular , Peptídeos/síntese química , Peptídeos/farmacologia , Relação Estrutura-Atividade
12.
Can J Public Health ; 86(6): 402-7, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-8932480

RESUMO

Rates and correlates of problems associated with the use of alcohol are reported from the 1993 General Social Survey in Canada. Approximately 1 in 11 drinkers (9.2%) reported that drinking has had an adverse effect on his or her social life, physical health, happiness, home life or marriage, work, or finances in the past year. The most commonly reported problems concerned physical health (5.1%), and financial position (4.7%). Approximately one in eight drinkers (12.9%) had driven a car within an hour after consuming two or more drinks in the previous year. Furthermore, more than two of every five respondents reported that they had experienced some problem due to other people's drinking. In a multivariate analysis, age, marital status, gender, religious attendance and employment status were the strongest predictors of problem drinking. The number of heavy drinking occasions is a stronger predictor of drinking problems than is overall level of consumption.


Assuntos
Alcoolismo/complicações , Nível de Saúde , Qualidade de Vida , Adolescente , Adulto , Idoso , Alcoolismo/epidemiologia , Alcoolismo/psicologia , Condução de Veículo , Canadá/epidemiologia , Feminino , Inquéritos Epidemiológicos , Humanos , Renda , Masculino , Pessoa de Meia-Idade , Análise Multivariada
13.
Can J Public Health ; 86(6): 397-401, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-8932479

RESUMO

Rates and correlates of alcohol use are reported from the 1993 General Social Survey, a household telephone survey of 10,385 Canadians carried out by Statistics Canada. Continuing a recent trend, alcohol use has declined. The portrait of the Canadian who is most likely to drink and drink heavily is that of a young adult male who is not married, relatively well-off, and rarely or never attends religious services. In a multivariate analysis of the combined impact of sociodemographic factors on drinking and drinking levels, it was found that the frequency of religious attendance and age were the strongest predictors of current drinking. Gender was the strongest predictor of volume of alcohol consumption, while religious attendance, age, marital status and employment status were also significant predictors.


Assuntos
Consumo de Bebidas Alcoólicas/epidemiologia , Alcoolismo/epidemiologia , Adolescente , Adulto , Distribuição por Idade , Idoso , Alcoolismo/etiologia , Canadá/epidemiologia , Feminino , Inquéritos Epidemiológicos , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Religião , Fatores de Risco , Fatores Socioeconômicos
14.
Poult Sci ; 56(3): 979-84, 1977 May.
Artigo em Inglês | MEDLINE | ID: mdl-605069

RESUMO

The anticoccidial activity of lasalocid, monensin, and roxarsone, alone and in combination, was evaluated against eleven Eimeria tenella recent field isolates. Lasalocid was used at 0.0075. 0.01, and 0.0125% activity drug in feed; monensin at 0.0099 and 0.0121%; and roxarsone at 0.005%. Further studies with lasalocid 0.0075%, monensin 0.0099% and roxarsone 0.005 and 0.0025% combinations were carried out against three E. tenella field isolates selected from the aforementioned strains. Lasalocid and monensin each exhibited a high degree of anticoccidial activity at all concentrations tested. Lasalocid and monensin fed in combination with roxarsone showed, in addition to high anticoccidial activity a further reduction in gross lesions and oocysts production, more pronounced at 0.005% level of roxarsone than at 0.0025%, compared to either medication alone or the roxarsone combinations. These positive effects were noted with all strains tested. The practical aspects of these findings are discussed.


Assuntos
Antibacterianos/administração & dosagem , Arsenicais/administração & dosagem , Galinhas , Coccidiose/veterinária , Furanos/administração & dosagem , Lasalocida/administração & dosagem , Monensin/administração & dosagem , Doenças das Aves Domésticas/tratamento farmacológico , Roxarsona/administração & dosagem , Administração Oral , Ração Animal , Animais , Coccidiose/tratamento farmacológico , Coccidiose/parasitologia , Combinação de Medicamentos , Fezes/parasitologia , Feminino , Lasalocida/uso terapêutico , Masculino , Monensin/uso terapêutico , Doenças das Aves Domésticas/parasitologia , Roxarsona/uso terapêutico
15.
Poult Sci ; 59(2): 268-73, 1980 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7413556

RESUMO

Lasalocid at the concentration of .0075% (68 g/ton) with and without roxarsone 45.4 g/ton was fed in combination with the growth promotants bacitracin methylene disalicylate 200 g/ton, bambermycins 2 g/ton, lincomycin 4 g/ton, nosiheptide 2.5 g/ton, zinc bacitracin 200 g/ton g/ton, and virginiamycin 20 g/ton exhibited a high degree of anticoccidial activity against mixed Eimeria infection in chickens in 9 day challenged battery trials. In these short term challenge trials chicks fed lasalocid, and the lasalocid growth promotant combinations, performed significantly better (P < .05) for growth and anticoccidial efficacy than those fed the growth promotants alone, and the infected, unmedicated controls. In almost all instances, the lasalocid-roxarsone-antibiotic combinations allowed for numerical increases in gains, improvement in feed conversion, and numerical decreases in lesions (in some cases, statistically significant (P < .05) over chicks fed lasalocid alone and/or the lasalocid antibiotic combination. The growth promotants did not interfere with the anticoccidial activity of lasalocid. The growth promotants fed alone exhibited no anticoccidial activity. However, when roxarsone was combined with the antibiotics, the combination resulted in numerically improved performance, reduced mortality, and in most instances, statistically significant decreases in lesions (P .05) over the infected, unmedicated control.


Assuntos
Arsenicais/administração & dosagem , Coccidiose/veterinária , Lasalocida/administração & dosagem , Doenças das Aves Domésticas/tratamento farmacológico , Roxarsona/administração & dosagem , Animais , Galinhas , Coccidiose/tratamento farmacológico , Quimioterapia Combinada
16.
Radiat Res ; 177(1): 44-51, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22029841

RESUMO

In the present study survival responses were determined in cells with differing radiosensitivity, specifically primary fibroblast (AG0-1522B), human breast cancer (MDA-MB-231), human prostate cancer (DU-145) and human glioma (T98G) cells, after exposure to modulated radiation fields delivered by shielding 50% of the tissue culture flask. A significant decrease (P < 0.05) in cell survival was observed in the shielded area, outside the primary treatment field (out-of-field), that was lower than predicted when compared to uniform exposures fitted to the linear-quadratic model. Cellular radiosensitivity was demonstrated to be an important factor in the level of response for both the in- and out-of-field regions. These responses were shown to be dependent on secretion-mediated intercellular communication, because inhibition of cellular secreted factors between the in- and out-of-field regions abrogated the response. Out-of-field cell survival was shown to increase after pretreatment of cells with agents known to inhibit factors involved in mediating radiation-induced bystander signaling (aminoguanidine, DMSO or cPTIO). These data illustrate a significant decrease in survival out-of-field, dependent upon intercellular communication, in several cell lines with varying radiosensitivity after exposure to a modulated radiation field. This study provides further evidence for the importance of intercellular signaling in modulated exposures, where dose gradients are present, and may inform the refinement of established radiobiological models to facilitate the optimization of advanced radiotherapy treatment plans.


Assuntos
Sobrevivência Celular/efeitos da radiação , Comunicação Celular/efeitos da radiação , Linhagem Celular Tumoral , Humanos , Tolerância a Radiação , Raios X
18.
Am J Physiol ; 242(5): F436-46, 1982 May.
Artigo em Inglês | MEDLINE | ID: mdl-7081433

RESUMO

The permselectivity of the postglomerular capillary wall was studied by performing pulse-injection multiple indicator-dilution experiments on dog kidneys in vivo, using simultaneous injection of T1824-labeled albumin (plasma reference), creatinine (extracellular reference), and one or two radioactively labeled indicators: raffinose (595 dalton), vitamin B12 (1,357 dalton), or inulin (approximately 5,000 dalton). The urine transit patterns superimposed for all these except albumin, suggesting equal permeability for these molecular weight markers at the level of the glomerular filtration barrier. But the renal vein mean transit times progressively decreased. Therefore, their apparent interstitial volumes of distribution decrease with increasing molecular weight. This could be due to several factors acting singly or in combination: reduced capillary permeability in the postglomerular microcirculation; restricted diffusion in the postglomerular interstitium; or excluded volume effects. Evidence suggested that the effect was due to a combination of permeability and exclusion volume effects. To assess the validity of this assumption, the barrier-limited model was compared with the experimental data. The results were analyzed (both hydropenic and mannitol-diuretic dogs) and best fits calculated using two independent parameters, permeability and excluded volume. For permeability (X10(-4) cm/s, mean +/- SD) the range of values was always greater than or equal to 15 for creatinine and raffinose, and greater than or equal to 12 for B12. The permeability for inulin was 6.9 +/- 1.4. When interstitial volume excluded was expressed as percentage of the volume available to creatine, the excluded volume was negligible for raffinose and B12 but 12 +/- 5% for inulin. During mannitol diuresis the permeability for creatinine and raffinose remained high, but the values tended to decrease for B12. The permeability of inulin decreased to 2.9 +/- 0.09. Mannitol diuresis increased the excluded volume of inulin but did not alter the creatinine, raffinose, or B12 value.


Assuntos
Permeabilidade Capilar , Modelos Biológicos , Circulação Renal , Animais , Creatinina , Cães , Feminino , Inulina , Masculino , Peso Molecular , Rafinose , Vitamina B 12
19.
Fed Proc ; 41(14): 3054-60, 1982 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-6754459

RESUMO

This paper describes the application of the pulse injection, multiple indicator dilution method to the study of cellular uptake in the kidney in vivo. By using the uptake of sugars and amino acids as specific examples, a rationale is provided that outlines the use of the technique in distinguishing luminal compared to antiluminal uptake. The site of cellular uptake processes cannot be localized by using a whole-organ approach such as the indicator dilution method; nevertheless, for sugars the correlation between in vivo studies and vesicle uptake measurements carried out with purified brush border and antiluminal membrane fractions confirms that the indicator dilution experiments reflect events that are occurring at the level of the proximal tubule in dog kidney. Because of the heterogeneity of tubular flow and substrate concentration profiles along the length of the nephron, it is difficult to use in vivo methods for carrying out kinetic studies on substrate uptake at the luminal surface. By contrast, a strong argument is made that uptake at the contraluminal surface of the proximal tubule can be optimally studied by using the single-pass indicator dilution method. The particular advantages are that the orientation of the basolateral membrane is known and also that uptake fluxes can be measured over short periods of time, i.e., less than 5 s. As an experimental example, uptake of glutamine in the kidney is discussed, and by a combination of indicator dilution methodology and arteriovenous extraction measurements combined with computer simulation and mathematical modeling, an approach is developed for the purposes of deriving unidirectional substrate fluxes at opposing nephron surfaces.


Assuntos
Rim/metabolismo , Animais , Creatina/metabolismo , Cães , Fucose/metabolismo , Glucose/metabolismo , Técnicas de Diluição do Indicador , Rim/irrigação sanguínea , Túbulos Renais/metabolismo , Taxa de Depuração Metabólica , Albumina Sérica/metabolismo
20.
Fed Proc ; 43(2): 171-9, 1984 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-6692936

RESUMO

The multiple-indicator dilution technique (MIDT) was used to study glomerular and postglomerular permselectivity to neutral dextran molecular weight markers in anesthetized dogs undergoing mannitol diuresis. Renal vein and urine outflow curves were obtained after an intraarterial pulse injection of 125I-labeled albumin (plasma reference), creatinine (extracellular reference), [14C]inulin, and chromatographically homogeneous 3H-labeled neutral dextrans. The urine recovery data reflect solute losses across the glomerulus. The renal vein outflow curves contain information about both glomerular and postglomerular extraction. For dextrans less than 13,500 daltons the urine transit pattern was superimposed on the glomerular markers creatinine and inulin. Relative to 125I-labeled albumin, the renal vein recoveries for creatinine, inulin, and dextrans (less than 13,500 daltons) were all equal. The renal vein mean transit time (tdextran) was greater than talbumin and less than tcreatinine. With increasing dextran size, tdextran progressively decreased. Eventually for dextrans greater than 15,500 daltons, tdextran became equal to talbumin in the renal vein, whereas urine recovery relative to inulin decreased with increasing size. Urine recovery of 3H-labeled dextran (ED) relative to inulin (Ei) provided a measure of unidirectional fractional glomerular extraction (ED/Ei). Constant infusion fractional clearance measurement of the same dextrans [U/P)D/(U/P)i) was found to equal ED/Ei obtained from the MIDT. Within the autoregulatory range of glomerular filtration, ED/Ei was invariant with reduction in renal plasma flow. Therefore, under the experimental conditions employed in the present study, diffusion across the glomerulus was negligible relative to convection. This permitted estimation of the reflection coefficients for the series of neutral dextrans. Postglomerular extraction was markedly flow dependent, which implies a major diffusion limitation. Application of a barrier-limited distributed model permitted quantitation of postglomerular capillary permeability coefficients for neutral markers of less than 5000 daltons.


Assuntos
Permeabilidade Capilar , Rim/irrigação sanguínea , Glomérulos Renais/irrigação sanguínea , Glomérulos Renais/metabolismo , Taxa de Depuração Metabólica , Peso Molecular , Relação Estrutura-Atividade
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