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1.
Public Health ; 224: 118-122, 2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37757630

RESUMO

OBJECTIVE: Most respiratory virus surveillance relies on medically attended respiratory illness, but an understanding of the true patterns of infection independent of care-seeking behaviour would enhance clinical and public health responses to respiratory virus outbreaks. We evaluated the potential of decedent surveillance by estimating the burden of respiratory virus infection in decedents in a large, urban medical examiner's office. STUDY DESIGN: Observational. METHODS: In 2020-2022, we tested nasopharyngeal swabs from 4121 decedents in Detroit, Michigan for 15 respiratory viruses, including SARS-CoV-2, respiratory syncytial virus, and influenza virus A and B. We analysed infection prevalence over time and by age, sex, race/ethnicity, and manner of death. RESULTS: Of 4113 valid tests, 30.2% were positive for at least one virus, and 6.1% were positive for multiple viruses. All viruses were detected except for influenza A/H1N1 and influenza B. The most prevalent viruses were SARS-CoV-2 (15.7%), rhinovirus (11.2%), and adenovirus (4.9%), which were detected in all months. Most viruses exhibited decreasing prevalence with age, higher prevalence among Black and Hispanic than among White decedents and lower prevalence among deaths from natural causes; SARS-CoV-2 was a notable exception to the patterns by age and manner of death, instead reflecting community trends in catchment counties. CONCLUSIONS: There was high prevalence and diversity of respiratory viruses in decedents entering a large, urban medical examiner's office. Decedent surveillance could offer a clearer picture of the true underlying burden of infection, motivating public health priorities for intervention and vaccine development, and augmenting data for real-time response to respiratory virus outbreaks.

2.
Anim Genet ; 49(6): 520-526, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30311252

RESUMO

The Functional Annotation of ANimal Genomes (FAANG) project aims, through a coordinated international effort, to provide high quality functional annotation of animal genomes with an initial focus on farmed and companion animals. A key goal of the initiative is to ensure high quality and rich supporting metadata to describe the project's animals, specimens, cell cultures and experimental assays. By defining rich sample and experimental metadata standards and promoting best practices in data descriptions, deposition and openness, FAANG champions higher quality and reusability of published datasets. FAANG has established a Data Coordination Centre, which sits at the heart of the Metadata and Data Sharing Committee. It continues to evolve the metadata standards, support submissions and, crucially, create powerful and accessible tools to support deposition and validation of metadata. FAANG conforms to the findable, accessible, interoperable, and reusable (FAIR) data principles, with high quality, open access and functionally interlinked data. In addition to data generated by FAANG members and specific FAANG projects, existing datasets that meet the main-or more permissive legacy-standards are incorporated into a central, focused, functional data resource portal for the entire farmed and companion animal community. Through clear and effective metadata standards, validation and conversion software, combined with promotion of best practices in metadata implementation, FAANG aims to maximise effectiveness and inter-comparability of assay data. This supports the community to create a rich genome-to-phenotype resource and promotes continuing improvements in animal data standards as a whole.


Assuntos
Curadoria de Dados/normas , Genômica , Metadados/normas , Animais , Gado , Animais de Estimação , Software
3.
BMC Genomics ; 17: 407, 2016 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-27230772

RESUMO

BACKGROUND: Indigenous populations of animals have developed unique adaptations to their local environments, which may include factors such as response to thermal stress, drought, pathogens and suboptimal nutrition. The survival and subsequent evolution within these local environments can be the result of both natural and artificial selection driving the acquisition of favorable traits, which over time leave genomic signatures in a population. This study's goals are to characterize genomic diversity and identify selection signatures in chickens from equatorial Africa to identify genomic regions that may confer adaptive advantages of these ecotypes to their environments. RESULTS: Indigenous chickens from Uganda (n = 72) and Rwanda (n = 100), plus Kuroilers (n = 24, an Indian breed imported to Africa), were genotyped using the Axiom® 600 k Chicken Genotyping Array. Indigenous ecotypes were defined based upon location of sampling within Africa. The results revealed the presence of admixture among the Ugandan, Rwandan, and Kuroiler populations. Genes within runs of homozygosity consensus regions are linked to gene ontology (GO) terms related to lipid metabolism, immune functions and stress-mediated responses (FDR < 0.15). The genes within regions of signatures of selection are enriched for GO terms related to health and oxidative stress processes. Key genes in these regions had anti-oxidant, apoptosis, and inflammation functions. CONCLUSIONS: The study suggests that these populations have alleles under selective pressure from their environment, which may aid in adaptation to harsh environments. The correspondence in gene ontology terms connected to stress-mediated processes across the populations could be related to the similarity of environments or an artifact of the detected admixture.


Assuntos
Ecótipo , Genoma , Genômica , Genótipo , Animais , Galinhas/genética , Biologia Computacional/métodos , Ontologia Genética , Genética Populacional , Genômica/métodos , Técnicas de Genotipagem , Homozigoto , Seleção Genética
4.
BMC Genomics ; 17(1): 812, 2016 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-27760519

RESUMO

BACKGROUND: Analyses of sequence variants of two distinct and highly inbred chicken lines allowed characterization of genomic variation that may be associated with phenotypic differences between breeds. These lines were the Leghorn, the major contributing breed to commercial white-egg production lines, and the Fayoumi, representative of an outbred indigenous and robust breed. Unique within- and between-line genetic diversity was used to define the genetic differences of the two breeds through the use of variant discovery and functional annotation. RESULTS: Downstream fixation test (F ST ) analysis and subsequent gene ontology (GO) enrichment analysis elucidated major differences between the two lines. The genes with high F ST values for both breeds were used to identify enriched gene ontology terms. Over-enriched GO annotations were uncovered for functions indicative of breed-related traits of pathogen resistance and reproductive ability for Fayoumi and Leghorn, respectively. CONCLUSIONS: Variant analysis elucidated GO functions indicative of breed-predominant phenotypes related to genomic variation in the lines, showing a possible link between the genetic variants and breed traits.


Assuntos
Cruzamento , Galinhas/genética , Genômica , Fenótipo , Polimorfismo de Nucleotídeo Único , Animais , Cromossomos , Biologia Computacional/métodos , Variação Genética , Genômica/métodos , Mutação , Reprodutibilidade dos Testes
5.
Science ; 224(4653): 1104-6, 1984 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-6719135

RESUMO

Human metallothioneins are encoded by a complex multigene family. The chromosomal location of these genes has been determined by gel transfer hybridization analysis of the DNA from human-rodent cell hybrids. Chromosome 16 contains a cluster of metallothionein sequences, including two functional metallothionein I genes and a functional metallothionein II gene. The remaining sequences, including a processed pseudogene, are dispersed to at least four other autosomes. The absence of metallothionein sequences from the X chromosome indicates that Menkes' disease, an X-linked disorder of copper metabolism, affects metallothionein expression by a trans-acting mechanism.


Assuntos
Encefalopatias Metabólicas/genética , Mapeamento Cromossômico , Síndrome dos Cabelos Torcidos/genética , Metalotioneína/genética , Animais , Cromossomos Humanos 16-18 , Cobre/metabolismo , Cricetinae , Cricetulus , Humanos , Células Híbridas , Camundongos
6.
Poult Sci ; 88(12): 2610-9, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19903960

RESUMO

Selecting chicken for improved meat production has altered the relative growth of organs in modern broiler lines compared with heritage lines. In this study, we compared the growth and feed efficiency of a heritage line, UIUC, with a modern production line, Ross 708, for 5 wk posthatch. During this period, the BW and feed efficiency of the modern strain was higher than that of the heritage line, indicating that the Ross 708 birds were more efficient than the UIUC birds at converting feed to body mass. The relative growth of the breast, heart, liver, and intestine were also compared during these 5 wk. The breast muscle of the heritage line constituted 9% of the total body mass at 5 wk, whereas in the modern line, the breast muscle was 18% of the total mass of the bird. In contrast, the relative size of the heart decreased after d 14 in the modern line, suggesting that selection for increased breast muscle has translated into relatively less weight of the heart muscle. The liver matured earlier in modern lines, possibly improving nutrient utilization as the birds shift from lipid- to carbohydrate-rich feed. Finally, jejunal and ileal sections of the intestine were 20% longer in the modern line, perhaps allowing for increased nutrient absorption.


Assuntos
Galinhas/crescimento & desenvolvimento , Galinhas/genética , Seleção Genética , Animais , Peso Corporal , Cruzamento , Coração/crescimento & desenvolvimento , Intestinos/crescimento & desenvolvimento , Masculino , Músculo Esquelético/crescimento & desenvolvimento
7.
J Pharmacol Exp Ther ; 325(2): 681-90, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18287214

RESUMO

We have recently proposed the hypothesis that inhibition of the cyclic nucleotide phosphodiesterase (PDE) 10A may represent a new pharmacological approach to the treatment of schizophrenia (Curr Opin Invest Drug 8:54-59, 2007). PDE10A is highly expressed in the medium spiny neurons of the mammalian striatum (Brain Res 985:113-126, 2003; J Histochem Cytochem 54:1205-1213, 2006; Neuroscience 139:597-607, 2006), where the enzyme is hypothesized to regulate both cAMP and cGMP signaling cascades to impact early signal processing in the corticostriatothalamic circuit (Neuropharmacology 51:374-385, 2006; Neuropharmacology 51:386-396, 2006). Our current understanding of the physiological role of PDE10A and the therapeutic utility of PDE10A inhibitors derives in part from studies with papaverine, the only pharmacological tool for this target extensively profiled to date. However, this agent has significant limitations in this regard, namely, relatively poor potency and selectivity and a very short exposure half-life after systemic administration. In the present report, we describe the discovery of a new class of PDE10A inhibitors exemplified by TP-10 (2-{4-[-pyridin-4-yl-1-(2,2,2-trifluoro-ethyl)-1H-pyrazol-3-yl]-phenoxymethyl}-quinoline succinic acid), an agent with greatly improved potency, selectivity, and pharmaceutical properties. These new pharmacological tools enabled studies that provide further evidence that inhibition of PDE10A represents an important new target for the treatment of schizophrenia and related disorders of basal ganglia function.


Assuntos
Inibidores de Fosfodiesterase/farmacologia , Diester Fosfórico Hidrolases/fisiologia , Pirazóis/farmacologia , Quinolinas/farmacologia , Esquizofrenia/tratamento farmacológico , Animais , Comportamento Animal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , AMP Cíclico/metabolismo , GMP Cíclico/metabolismo , Dopamina/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Atividade Motora/efeitos dos fármacos , Inibidores de Fosfodiesterase/sangue , Inibidores de Fosfodiesterase/farmacocinética , Diester Fosfórico Hidrolases/genética , Ratos , Ratos Endogâmicos F344 , Proteínas Recombinantes/antagonistas & inibidores , Proteínas Recombinantes/genética , Reflexo de Sobressalto/efeitos dos fármacos , Esquizofrenia/metabolismo , Esquizofrenia/fisiopatologia
9.
Forensic Sci Int ; 264: 63-9, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27032615

RESUMO

Microbially mediated mechanisms of human decomposition begin immediately after death, and are a driving force for the conversion of a once living organism to a resource of energy and nutrients. Little is known about post-mortem microbiology in cadavers, particularly the community structure of microflora residing within the cadaver and the dynamics of these communities during decomposition. Recent work suggests these bacterial communities undergo taxa turnover and shifts in community composition throughout the post-mortem interval. In this paper we describe how the microbiome of a living host changes and transmigrates within the body after death thus linking the microbiome of a living individual to post-mortem microbiome changes. These differences in the human post-mortem from the ante-mortem microbiome have demonstrated promise as evidence in death investigations. We investigated the post-mortem structure and function dynamics of Staphylococcus aureus and Clostridium perfringens after intranasal inoculation in the animal model Mus musculus L. (mouse) to identify how transmigration of bacterial species can potentially aid in post-mortem interval estimations. S. aureus was tracked using in vivo and in vitro imaging to determine colonization routes associated with different physiological events of host decomposition, while C. perfringens was tracked using culture-based techniques. Samples were collected at discrete time intervals associated with various physiological events and host decomposition beginning at 1h and ending at 60 days post-mortem. Results suggest that S. aureus reaches its highest concentration at 5-7 days post-mortem then begins to rapidly decrease and is undetectable by culture on day 30. The ability to track these organisms as they move in to once considered sterile space may be useful for sampling during autopsy to aid in determining post-mortem interval range estimations, cause of death, and origins associated with the geographic location of human remains during death investigations.


Assuntos
Translocação Bacteriana/fisiologia , Clostridium perfringens/fisiologia , Mudanças Depois da Morte , Staphylococcus aureus/fisiologia , Animais , Contagem de Colônia Microbiana , Fluorescência , Patologia Legal , Camundongos Pelados , Modelos Animais , Imagem Corporal Total
10.
Transl Psychiatry ; 6(9): e901, 2016 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-27676442

RESUMO

Duchenne muscular dystrophy is caused by mutations in the DYSTROPHIN gene. Although primarily associated with muscle wasting, a significant portion of patients (approximately 25%) are also diagnosed with autism spectrum disorder. We describe social behavioral deficits in dystrophin-deficient mice and present evidence of cerebellar deficits in cGMP production. We demonstrate therapeutic potential for selective inhibitors of the cGMP-specific PDE5A and PDE9A enzymes to restore social behaviors in dystrophin-deficient mice.

11.
Gene ; 24(1): 137-46, 1983 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-6414888

RESUMO

We have isolated two metallothionein (MT) cDNA clones copied from the RNA of cadmium-resistant monkey kidney cells. The complete DNA sequences of these clones show that they encode two distinct MTs. One clone appears to represent monkey MT-II, as shown by its close homology to the human MT-II sequence, whereas the second may correspond to monkey MT-I or a related variant metallothionein. Conserved sequences were identified in both the 5' and 3' untranslated regions of these clones.


Assuntos
Metalotioneína/genética , RNA Mensageiro/genética , Animais , Sequência de Bases , Evolução Biológica , Linhagem Celular , Clonagem Molecular , DNA/genética , Genes , Haplorrinos/genética , Biossíntese de Proteínas
12.
Gene ; 82(2): 269-80, 1989 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-2511079

RESUMO

We have determined the complete sequence and structure of a second myosin I heavy-chain gene from Acanthamoeba castellanii. This gene, which we have named MIL, spans approx. 6kb, is split by 17 introns, encodes a 1147-aa polypeptide, and is transcribed in log-phase cells. The positions of six of the introns are conserved relative to a vertebrate muscle myosin gene. Similar to the previously characterized MIB heavy-chain gene, the deduced MIL heavy-chain aa sequence reveals a 125-kDa protein composed of a myosin globular head domain joined to a novel, approx. 50-kDa C-terminal domain that is rich in glycine, proline and alanine residues. There are differences, however, between MIL and MIB in the sequence organization of their unconventional C-terminal domains. We conclude from this and other data that Acanthamoeba express at least three myosin I heavy-chain isoforms: MIL, plus MIA and MIB, whose purifications have been published previously. Amoeba genomic DNA blots probed with a short, highly conserved sequence whose position is transposed between MIB and MIL indicate that the Acanthamoeba myosin I heavy-chain gene family may actually contain as many as six genes. Finally, we compared the myosin I sequences with those of two related proteins, Drosophila NinaC and the bovine myosin I-like protein, and found that a portion of the unconventional C-terminal domains of the amoeba myosins I and the bovine protein appear to be related.


Assuntos
Acanthamoeba/genética , Genes , Miosinas/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Bovinos/genética , Drosophila melanogaster/genética , Dados de Sequência Molecular , Homologia de Sequência do Ácido Nucleico , Especificidade da Espécie
13.
J Comp Neurol ; 309(1): 17-26, 1991 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-1910054

RESUMO

An antibody directed against the alpha(o) subunit of bovine brain G(o) (R4) was used to identify a Drosophila retinal protein which may be the analogue of vertebrate transducin. The immunoreactivity appears predominantly in the retinal and occellar rhabdomeres. On a Western blot, the antibody recognizes a 41 kDa protein that is present in the heads of yellow white flies, but not in the heads of eyeless mutant flies, eyes absent. This protein is not recognized by an antibody raised against Drosophila alpha(o). Antibody R4 intensely stains rhabdomeres and, to a lesser extent, the neuropil of the central nervous system in tissue sections of adult flies. Antibody to Drosophila alpha(o) stains the neuropil of the central nervous system, but does not stain rhabdomeres. In developing flies, faint immunoreactivity appears in the retinal rhabdomeres at about 70% of the time through pupal development and increases to its apparent adult maximal level about 1 day after eclosion. Tissue sections from a phototransduction mutant, norp A, have retinal immunoreactivity at normal levels up to about 1 week after eclosion, but by 2 weeks, immunoreactivity has largely disappeared. This disappearance parallels the degeneration of the retina in norp A mutants. In Drosophila and other invertebrates, light activates a phospholipase C in the retina. The identification of a protein in Drosophila rhabdomeres with an antibody raised against a mammalian G protein alpha subunit thought to be involved in phospholipase C activation suggests that there may be common structural features between the putative Drosophila transducin and alpha(o). The identification of regions common to mammalian alpha(o) and Drosophila transducin may then provide clues to the structural requirements for PLC activation.


Assuntos
Proteínas de Ligação ao GTP/imunologia , Proteínas/análise , Retina/citologia , Animais , Anticorpos , Western Blotting , Bovinos , Drosophila , Imuno-Histoquímica , Proteínas/imunologia
14.
Neuropsychopharmacology ; 15(2): 116-24, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8840347

RESUMO

(+/-)3,4-Methylenedioxymethamphetamine (MDMA) releases dopamine and serotonin in vivo and stimulates locomotor activity. Previous work demonstrated that MDMA-stimulated dopamine release could be reduced by the selective 5-HT2A receptor antagonist [R-(+)-a- (2,3-dimethoxyphenyl)-1-[2-(4-fluorophenylethyl)]-4-piperidinem ethanol] (MDL 100,907). In the present study MDL 100,907 significantly reduced MDMA-stimulated locomotion without affecting basal levels of locomotion. Other agents with 5-HT2A antagonist activity (ritanserin, clozapine, MDL 28,133A, or methiothepin), as well as agents that block 5-HT1A-(propranolol), D2-(haloperidol), or D1 receptors (SCH 23390) also reduced MDMA-stimulated locomotion. Intraventricularly administered 5,7-dihydroxytryptamine decreased regional 5-HT levels and attenuated MDMA-stimulated locomotion. These data support the conclusion that serotonin released onto 5-HT2A receptors contributes to MDMA-stimulated locomotion and suggest that MDMA-stimulated locomotion may be useful as an in vivo behavioral measure of 5-HT2A antagonism. The data also support previous reports of contributions of 5-HT1A, D1 and D2 receptors to MDMA-stimulated locomotion. A preliminary time-course analysis indicating time-dependent contributions of different receptors to MDMA-stimulated locomotion suggests the potential utility of this model for characterizing potential atypical antipsychotic compounds.


Assuntos
Fluorbenzenos/farmacologia , Atividade Motora/efeitos dos fármacos , N-Metil-3,4-Metilenodioxianfetamina/antagonistas & inibidores , Piperidinas/farmacologia , Serotoninérgicos/farmacologia , Antagonistas da Serotonina/farmacologia , 5,7-Di-Hidroxitriptamina/farmacologia , Animais , Química Encefálica/efeitos dos fármacos , Clozapina/farmacologia , Antagonistas de Dopamina/farmacologia , Masculino , Metiotepina/farmacologia , N-Metil-3,4-Metilenodioxianfetamina/farmacologia , Terminações Pré-Sinápticas/efeitos dos fármacos , Terminações Pré-Sinápticas/metabolismo , Ratos , Receptores de Neurotransmissores/efeitos dos fármacos , Ritanserina/farmacologia , Serotonina/metabolismo , Estimulação Química
15.
Neuropharmacology ; 25(3): 249-55, 1986 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2871513

RESUMO

The results reported here indicate that treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) caused significant changes in the dopamine-synthesizing enzyme, tyrosine hydroxylase. The authors examined the effects of two doses of MPTP on the activities of tyrosine hydroxylase (TH) and tryptophan hydroxylase (TPH) in the striatum, and also the time-course of these effects. Rats received an intraperitoneal loading dose, followed by a 24-hr infusion of MPTP (total doses of 21 or 42 mg) from subcutaneously-implanted osmotic pumps. Seven days after treatment, the activity of tyrosine hydroxylase was decreased by MPTP (42 mg); however, the activity of tryptophan hydroxylase was not affected. In time-course experiments, the activity of tyrosine hydroxylase was maximally reduced at 3 and 7 days after treatment with MPTP (42 mg). The activity of tryptophan hydroxylase did not significantly change at any time-point. Concurrent administration of haloperidol (HALO; 2 mg/kg, 4 doses) with MPTP significantly enhanced the depression of the activity of tyrosine hydroxylase in the striatum caused by MPTP, while treatment with haloperidol alone had no such effect. Concentrations of dopamine in the striatum were maximally decreased to approx. 50% of control in animals treated with haloperidol and MPTP (42 mg), whereas treatment with MPTP alone decreased concentrations of dopamine to approx. 70% of control.


Assuntos
Corpo Estriado/enzimologia , Neurotoxinas/farmacologia , Piridinas/farmacologia , Triptofano Hidroxilase/antagonistas & inibidores , Tirosina 3-Mono-Oxigenase/antagonistas & inibidores , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina , Ácido 3,4-Di-Hidroxifenilacético/metabolismo , Animais , Corpo Estriado/metabolismo , Dopamina/metabolismo , Haloperidol/farmacologia , Ácido Homovanílico/metabolismo , Cinética , Masculino , Ratos , Ratos Endogâmicos
16.
Cancer Lett ; 72(1-2): 103-10, 1993 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-8402566

RESUMO

The purpose of this investigation was to establish a dose response for the effects of dietary phenethyl isothiocyanate (PEITC) on N-nitrosomethylbenzylamine (NMBA)-induced esophageal tumorigenesis and DNA methylation. Groups of 13-27 rats were randomly assigned to AIN-76A diets containing 0, 0.325, 0.75, 1.5 or 3.0 mumol PEITC/g. Two weeks later, rats were administered NMBA subcutaneously at a dose of 0.5 mg/kg once a week for 15 weeks. Animals were maintained on control or experimental diets for an additional 8 weeks and were terminated at week 25 of the experiment. No significant effects on weight gain or food intake were noted for any of the experimental diets when compared with control values. Animals receiving only NMBA developed 9.3 +/- 0.9 tumors/rat, with an incidence of 100%. Dietary PEITC at concentrations of 0.75, 1.5 and 3.0 mumol/g inhibited NMBA-induced esophageal tumor multiplicity by 39%, 90% and 100%, respectively. Esophageal tumor incidence in these groups was reduced by 0%, 40% and 100%, respectively. The 0.325 mumol/g PEITC diet did not significantly affect NMBA-induced esophageal tumorigenesis. These results indicate that the minimum inhibitory dietary concentration of PEITC is between 0.325 and 0.75 mumol/g. Groups of 20 rats were assigned to diets containing 0-3.0 mumol PEITC/g for two weeks as described above, and then sacrificed 24 hours after administration of [3H-methyl]NMBA. The esophageal DNA was isolated, purified, hydrolyzed, and analyzed by HPLC. PEITC inhibited DNA methylation in a dose-dependent manner, as was found in the tumor bioassay. The inhibition of tumor incidence was highly correlated with the percentage inhibition of either 7-methylguanine or O6-methylguanine. These latter results suggest that the inhibitory activity of PEITC in this model is manifested, at least in part, during the functional equivalent of tumor initiation.


Assuntos
Anticarcinógenos/farmacologia , DNA de Neoplasias/efeitos dos fármacos , Dimetilnitrosamina/análogos & derivados , Neoplasias Esofágicas/prevenção & controle , Isotiocianatos/farmacologia , Animais , DNA de Neoplasias/metabolismo , Dieta , Dimetilnitrosamina/antagonistas & inibidores , Dimetilnitrosamina/toxicidade , Relação Dose-Resposta a Droga , Neoplasias Esofágicas/induzido quimicamente , Neoplasias Esofágicas/metabolismo , Masculino , Metilação/efeitos dos fármacos , Ratos , Ratos Endogâmicos F344
17.
Biochem Pharmacol ; 36(23): 4095-102, 1987 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-2891359

RESUMO

The psychotomimetic agent, methylenedioxymethamphetamine, produced a rapid, persistent and dose-dependent reduction in cortical tryptophan hydroxylase activity when administered acutely to rats. This effect did not occur in vitro and did not require N-demethylase activity in the whole animal. Kinetic analysis revealed the loss of enzyme activity to be due to an alteration in Vmax with no change in the affinity of the enzyme for either its cofactor or substrate. Coadministration of the serotonin (5-HT) uptake inhibitor, citalopram, only partially antagonized the loss of tryptophan hydroxylase activity 3 hr after methylenedioxymethamphetamine, but completely prevented the loss of cortical 5-HT. Recovery of enzyme activity did occur by 1 week if the neurotoxic effect of methylenedioxymethamphetamine was blocked by fluoxetine. The effect of methylenedioxymethamphetamine on 5-HT synthesis was not affected by pretreatment with alpha-methyl-p-tyrosine, reserpine or yohimbine. Ketanserine and methiothepin, 5-HT receptor antagonists, did partially block the methylenedioxymethamphetamine-induced loss of tryptophan hydroxylase activity, suggesting a possible role for neurotransmitter release in the acute effects of the drug on enzyme activity.


Assuntos
3,4-Metilenodioxianfetamina/farmacologia , Anfetaminas/farmacologia , Córtex Cerebral/enzimologia , Triptofano Hidroxilase/antagonistas & inibidores , 3,4-Metilenodioxianfetamina/análogos & derivados , Animais , Córtex Cerebral/efeitos dos fármacos , Citalopram , Relação Dose-Resposta a Droga , Fluoxetina/farmacologia , Ketanserina/farmacologia , Cinética , Masculino , Metiotepina/farmacologia , N-Metil-3,4-Metilenodioxianfetamina , Butóxido de Piperonila/farmacologia , Propilaminas/farmacologia , Ratos , Ratos Endogâmicos , Serotonina/biossíntese , Antagonistas da Serotonina/farmacologia
18.
Biochem Pharmacol ; 36(5): 747-55, 1987 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-2881549

RESUMO

A single high dose of methylenedioxymethamphetamine, a psychedelic agent, produced a rapid and persistent depletion of striatal indoles similar to that observed following administration of the serotonergic neurotoxin p-chloroamphetamine. The drug had little effect on dopaminergic variables. Like p-chloroamphetamine, methylenedioxymethamphetamine was found to be a relatively selective agent for inducing [3H]serotonin release in vitro. The serotonin uptake inhibitor, citalopram, blocked both [3H]serotonin release in vitro and striatal serotonin depletion in vivo, indicating that both processes were carrier dependent. In vivo comparisons of the stereoisomers of methylenedioxymethamphetamine indicated two phases of serotonin depletion similar to those reported for p-chloroamphetamine. Although both the (+)- and (-)-stereoisomers produced an acute (3 hr) decrease in striatal indoles, the long-term effects of the drug showed stereoselectivity in that the (+)-enantiomer produced the most dramatic serotonin depletion. Comparison of the effects of the stereoisomers of methylenedioxymethamphetamine and its n-desmethyl analog, methylenedioxyamphetamine, on [3H]serotonin and [3H]dopamine release in vitro showed the (+)-enantiomer of both drugs to be the more potent releasing agent. In spite of its reported lack of hallucinogenic activity, (+)methylenedioxyamphetamine was found to be of a potency similar to that of (+)methylenedioxymethamphetamine in inducing [3H]serotonin release in vitro. The results are discussed in terms of the neurochemical similarities between methylenedioxymethamphetamine and p-chloroamphetamine as well as the proposed role of serotonin release in the behavioral effects of methylenedioxymethamphetamine.


Assuntos
3,4-Metilenodioxianfetamina/farmacologia , Anfetaminas/farmacologia , Corpo Estriado/efeitos dos fármacos , Dopamina/metabolismo , Serotonina/metabolismo , 3,4-Metilenodioxianfetamina/análogos & derivados , Animais , Citalopram , Corpo Estriado/metabolismo , Técnicas In Vitro , Masculino , N-Metil-3,4-Metilenodioxianfetamina , Propilaminas/farmacologia , Ratos , Ratos Endogâmicos , Estereoisomerismo , p-Cloroanfetamina/farmacologia
19.
Biochem Pharmacol ; 37(18): 3477-84, 1988 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-2458731

RESUMO

Repeated injections (s.c.) of methamphetamine (METH) were administered to normal and ascorbic acid-deficient (scorbutic) guinea pigs to assess a potential role for ascorbic acid in the METH-induced effects in central monoaminergic systems. The ascorbic acid-deficient condition differentially influenced the METH-induced responses of dopaminergic and serotonergic variables in the striatum: drug-induced changes in dopaminergic variables were identical in normal and scorbutic animals; METH-induced decreases in serotonergic variables [tryptophan hydroxylase activity, serotonin (5-HT) and 5-hydroxyindoleacetic acid concentrations], however, were prevented in scorbutic animals. The scorbutic condition did not alter significantly the distribution of METH in the brain, nor were striatal concentrations of dopamine (DA) or 5-HT affected. In vitro, ascorbic acid increased significantly DA-mediated [3H]5-HT release from striatal slices, thus suggesting a potential role for ascorbate in DA-mediated actions of METH on serotonergic systems. Although supplemental ascorbate failed to restore the METH-induced serotonergic effects in scorbutic guinea pigs, these data suggest that, in a normal animal, the effects of multiple injections of METH, on serotonergic systems, involve ascorbic acid.


Assuntos
Deficiência de Ácido Ascórbico/metabolismo , Encéfalo/efeitos dos fármacos , Metanfetamina/farmacologia , Receptores Dopaminérgicos/efeitos dos fármacos , Receptores de Serotonina/efeitos dos fármacos , Anfetamina/análise , Animais , Corpo Estriado/análise , Feminino , Cobaias , Ácido Hidroxi-Indolacético/análise , Metanfetamina/análise , Serotonina/análise , Triptofano Hidroxilase/análise
20.
Biochem Pharmacol ; 34(17): 3161-6, 1985 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-2412564

RESUMO

The results reported herein strongly suggest that increased dopaminergic and not increased serotonergic activity is responsible for methamphetamine-induced increases in the nigral concentration of substance P-like immunoreactivity (SPLI). Thus, treatment of rats with the specific dopamine (DA) uptake blockers amfonelic acid (AFA) and nomifensine caused elevations in the SPLI levels within the substantia nigra similar to that of methamphetamine (METH). In contrast, the specific serotonin uptake blockers citalopram and chlorimipramine were without significant effects on this substance P (SP) system. Additional studies revealed that the mechanisms whereby the DA uptake blockers and METH influence the striatonigral SP pathway are likely different. Specifically, AFA, unlike METH, altered the SP system without causing changes in the monoaminergic synthesizing enzymes tyrosine and tryptophan hydroxylase; in addition, pretreatment with reserpine abolished the AFA effect on nigral SPLI but did not interfere with METH-mediated changes in the SP system.


Assuntos
Dopamina/fisiologia , Substância P/metabolismo , Substância Negra/metabolismo , Animais , Citalopram , Clomipramina/farmacologia , Corpo Estriado/metabolismo , Masculino , Metanfetamina/farmacologia , Ácido Nalidíxico/análogos & derivados , Naftiridinas/farmacologia , Nomifensina/farmacologia , Propilaminas/farmacologia , Radioimunoensaio , Ratos , Ratos Endogâmicos , Reserpina/farmacologia , Serotonina/fisiologia
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