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1.
Clin Exp Obstet Gynecol ; 40(2): 203-9, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23971238

RESUMO

PURPOSE: To investigate the clinical observations, provider experience, safety, and tolerance of the hysterosalpingo-contrast sonography (HyCoSy) procedure. MATERIALS AND METHODS: A retrospective study design in which data was collected from ninety-six subfertile women who underwent the HyCoSy procedure at the University of Louisville over a 16-month interval. RESULTS: Ninety-six HyCoSy procedures were performed by a single investigator and contained complete records for review. The authors observed significant decreases in the quantities of saline and air utilized per procedure over time (p < 0.0001 and p = 0.0001). Results from the HyCoSy studies were more often non-diagnostic or non-patent in women with a body mass index (BMI) > 30. Reported pain scores did not statistically differ over the course of the study interval. There were no procedure-related complications noted. CONCLUSION: The HyCoSy procedure is a timely and minimally invasive study that can be implemented in an office setting with minimal prior operator experience that improves over time.


Assuntos
Competência Clínica , Histerossalpingografia/métodos , Histerossalpingografia/normas , Infertilidade Feminina/diagnóstico por imagem , Ultrassonografia/métodos , Adulto , Índice de Massa Corporal , Feminino , Doenças dos Genitais Femininos/diagnóstico por imagem , Humanos , Histerossalpingografia/efeitos adversos , Dor , Ultrassonografia/efeitos adversos
2.
J Cell Biol ; 137(4): 881-90, 1997 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-9151690

RESUMO

abnormal spindle, a gene required for normal spindle structure and function in Drosophila melanogaster, lies immediately adjacent the gene tolloid at 96A/B. It encodes a 220-kD polypeptide with a predicted pI of 10.8. The recessive mutant allele asp1 directs the synthesis of a COOH terminally truncated or internally deleted peptide of approximately 124 kD. Wild-type Asp protein copurifies with microtubules and is not released by salt concentrations known to dissociate most other microtubule-associated proteins. The bacterially expressed NH2-terminal 512-amino acid peptide, which has a number of potential phosphorylation sites for p34(cdc2) and MAP kinases, strongly binds to microtubules. The central 579-amino acid segment of the molecule contains one short motif homologous to sequences in a number of actin bundling proteins and a second motif present at the calmodulin binding sites of several proteins. Immunofluorescence studies show that the wild-type Asp protein is localized to the polar regions of the spindle immediately surrounding the centrosome. These findings are discussed in relation to the known spindle abnormalities in asp mutants.


Assuntos
Proteínas de Drosophila , Genes de Insetos , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Fuso Acromático/ultraestrutura , Sequência de Aminoácidos , Animais , Sequência de Bases , Sítios de Ligação , Proteínas de Ligação a Calmodulina/genética , Proteínas de Ligação a Calmodulina/metabolismo , Clonagem Molecular , Drosophila melanogaster , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Dados de Sequência Molecular
3.
Trends Genet ; 7(5): 155-61, 1991 May.
Artigo em Inglês | MEDLINE | ID: mdl-1906209

RESUMO

A physical map of the Drosophila melanogaster genome is being assembled, consisting of ordered overlapping cosmid clones. The map is constructed in steps, separately for each chromosomal division. Gaps in this map are to be bridged with yeast artificial chromosome clones. Hybridization to previously cloned genes and extensive use of in situ hybridization to polytene chromosomes ensure that the cosmid map is firmly anchored to the wealth of available genetic and cytogenetic information. The intention is to make the physical map widely available as part of an overall, integrated genetic resource for the Drosophila research community.


Assuntos
Mapeamento Cromossômico , Drosophila melanogaster/genética , Animais , Clonagem Molecular , Cosmídeos , Cromossomo X
4.
Mol Cell Biol ; 5(7): 1591-600, 1985 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-4022008

RESUMO

The multigene family which codes for the mouse major urinary proteins consists of about 35 genes. Most of these are members of two distinct groups, group 1 and group 2. The group 1 and group 2 genes are organized in head-to-head pairs within 12 to 15 remarkably uniform chromosomal units or domains about 45 kilobase pairs (kb) in size. The 45-kb units are located on chromosome 4, and many of them are adjacent to each other. We propose that the 45-kb unit is a unit both of organization and of evolutionary change. In this study the homologies within the unit were observed by examining, in an electron microscope, heteroduplex and foldback structures made from cloned major urinary protein genes. These show that the 45-kb unit is a gigantic imperfect palindrome. Each arm of the palindrome contains two regions of inverted symmetry of 9.5 and 4.5 kb separated by a 3-kb nonsymmetrical region. We argue that the nonsymmetrical regions arose by a series of deletion events in the two arms of the palindrome. The center of the 45-kb unit is an 8-kb sequence without inverted symmetry flanked by the 9.5-kb regions, which contain the 4-kb genes and their immediate 5' and 3' flanking regions. The junction between adjacent 45-kb units is a 2- to 4-kb sequence without inverted symmetry flanked by the 4.5-kb regions. Some of the 45-kb units are arranged as direct tandem repeats. Others appear to be in inverted orientation with respect to a neighboring unit. Cloned major urinary protein genes show few incidences of the repetitive elements B1, B2, R, and MIF. Two elements, a B1 and an R, may be a constant feature of the 45-kb units. If so, in those cases in which the units are in tandem array, both of these elements will occur with a 45-kb periodicity. A comparison of corresponding parts of different 45-kb units shows that they differ because of a number of deletion or insertion events, particularly in the regions 3' to the genes.


Assuntos
Proteínas/genética , Animais , Sequência de Bases , Clonagem Molecular , Genes , Camundongos , Hibridização de Ácido Nucleico , Sequências Repetitivas de Ácido Nucleico
5.
Int J Radiat Biol ; 82(11): 781-92, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17148262

RESUMO

PURPOSE: To examine the wavelength dependence of cellular responses in human melanocytes and human melanoma cells exposed to ultraviolet radiation (UVR). MATERIALS AND METHODS: Primary human melanocytes and G361 human melanoma cells were exposed to ultraviolet-C (UVC), ultraviolet-B (UVB), or ultraviolet-A (UVA) radiation. Dose-response relationships for clonal cell survival were assessed, and flow cytometry was used to monitor cell cycle distributions for up to one week post-irradiation. Chromosomal aberrations were scored in exposed and unexposed melanoma cells. RESULTS: G361 melanoma cells were more sensitive than melanocytes to killing by UVB and UVC radiation. This difference in sensitivity between cell types was much less marked following UVA irradiation. The melanoma cells showed a sustained, dose-dependent G2/M block following exposure with all wavelengths; in addition, transit through S phase was slowed following UVA irradiation. There was no apparent block to G1 cells entering S phase at any wavelength. Melanocytes, on the other hand, showed a marked G1 arrest, particularly following UVA irradiation. Cytogenetic results showed a dose-dependent increase in chromatid-type aberrations, mostly gaps, breaks and exchanges, in exposed melanoma cells. CONCLUSION: These results show that G361 malignant melanoma cells have lost the ability to regulate the cell cycle at the G1/S checkpoint and are more sensitive than melanocytes to cell killing by UVC and UVB but not UVA radiation. Similarly, exposure of these melanoma cells to UVC and UVB, and to a much lesser extent UVA, induced chromatid aberrations. UVA nevertheless induced strong cell cycle delays in both cell types, indicating that UVA exposure can significantly affect genome metabolism.


Assuntos
Melanócitos/efeitos da radiação , Melanoma/etiologia , Neoplasias Induzidas por Radiação/etiologia , Raios Ultravioleta , Animais , Células CHO , Ciclo Celular/efeitos da radiação , Sobrevivência Celular/efeitos da radiação , Transformação Celular Neoplásica , Células Cultivadas , Aberrações Cromossômicas , Cricetinae , Dano ao DNA , Relação Dose-Resposta à Radiação , Humanos , Melanócitos/citologia , Melanoma/genética , Melanoma/patologia
6.
Genetics ; 156(2): 711-21, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11014818

RESUMO

The mutagen-sensitive-101 (mus101) gene of Drosophila melanogaster was first identified 25 years ago through mutations conferring larval hypersensitivity to DNA-damaging agents. Other alleles of mus101 causing different phenotypes were later isolated: a female sterile allele results in a defect in a tissue-specific form of DNA synthesis (chorion gene amplification) and lethal alleles cause mitotic chromosome instability that can be observed genetically and cytologically. The latter phenotype presents as a striking failure of mitotic chromosomes of larval neuroblasts to undergo condensation of pericentric heterochromatic regions, as we show for a newly described mutant carrying lethal allele mus101(lcd). To gain further insight into the function of the Mus101 protein we have molecularly cloned the gene using a positional cloning strategy. We report here that mus101 encodes a member of the BRCT (BRCA1 C terminus) domain superfamily of proteins implicated in DNA repair and cell cycle checkpoint control. Mus101, which contains seven BRCT domains distributed throughout its length, is most similar to human TopBP1, a protein identified through its in vitro association with DNA topoisomerase IIbeta. Mus101 also shares sequence similarity with the fission yeast Rad4/Cut5 protein required for repair, replication, and checkpoint control, suggesting that the two proteins may be functional homologs.


Assuntos
Proteína BRCA1/genética , Proteínas de Ciclo Celular/genética , Mapeamento Cromossômico , Reparo do DNA/genética , Replicação do DNA/genética , Proteínas de Drosophila , Drosophila melanogaster/genética , Genes de Insetos , Genes Letais , Heterocromatina/genética , Sequência de Aminoácidos , Animais , Proteína BRCA1/química , Proteínas de Ciclo Celular/química , Feminino , Genes BRCA1 , Infertilidade Feminina/genética , Proteínas de Insetos/química , Proteínas de Insetos/genética , Larva , Masculino , Dados de Sequência Molecular , Mutagênese , Fenótipo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Cromossomo X
7.
Genetics ; 139(4): 1631-47, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7789765

RESUMO

A physical map of the euchromatic X chromosome of Drosophila melanogaster has been constructed by assembling contiguous arrays of cosmids that were selected by screening a library with DNA isolated from microamplified chromosomal divisions. This map, consisting of 893 cosmids, covers approximately 64% of the euchromatic part of the chromosome. In addition, 568 sequence tagged sites (STS), in aggregate representing 120 kb of sequenced DNA, were derived from selected cosmids. Most of these STSs, spaced at an average distance of approximately 35 kb along the euchromatic region of the chromosome, represent DNA tags that can be used as entry points to the fruitfly genome. Furthermore, 42 genes have been placed on the physical map, either through the hybridization of specific probes to the cosmids or through the fact that they were represented among the STSs. These provide a link between the physical and the genetic maps of D. melanogaster. Nine novel genes have been tentatively identified in Drosophila on the basis of matches between STS sequences and sequences from other species.


Assuntos
Mapeamento Cromossômico , Cosmídeos , Drosophila melanogaster/genética , Sitios de Sequências Rotuladas , Cromossomo X , Sequência de Aminoácidos , Animais , Sequência de Bases , DNA , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos
8.
Genetics ; 147(4): 1697-722, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9409831

RESUMO

We have established a collection of 2460 lethal or semi-lethal mutant lines using a procedure thought to insert single P elements into vital genes on the third chromosome of Drosophila melanogaster. More than 1200 randomly selected lines were examined by in situ hybridization and 90% found to contain single insertions at sites that mark 89% of all lettered subdivisions of the Bridges' map. A set of chromosomal deficiencies that collectively uncover approximately 25% of the euchromatin of chromosome 3 reveal lethal mutations in 468 lines corresponding to 145 complementation groups. We undertook a detailed analysis of the cytogenetic interval 86E-87F and identified 87 P-element-induced mutations falling into 38 complementation groups, 16 of which correspond to previously known genes. Twenty-one of these 38 complementation groups have at least one allele that has a P-element insertion at a position consistent with the cytogenetics of the locus. We have rescued P elements and flanking chromosomal sequences from the 86E-87F region in 35 lines with either lethal or genetically silent P insertions, and used these as probes to identify cosmids and P1 clones from the Drosophila genome projects. This has tied together the physical and genetic maps and has linked 44 previously identified cosmid contigs into seven "super-contigs" that span the interval. STS data for sequences flanking one side of the P-element insertions in 49 lines has identified insertions in the alphagamma element at 87C, two known transposable elements, and the open reading frames of seven putative single copy genes. These correspond to five known genes in this interval, and two genes identified by the homology of their predicted products to known proteins from other organisms.


Assuntos
Alelos , Mapeamento Cromossômico , Elementos de DNA Transponíveis , Drosophila melanogaster/genética , Genes de Insetos , Animais , Sequência de Bases , DNA Complementar , Feminino , Genes Letais , Masculino , Mutagênese Insercional , Mapeamento por Restrição
9.
Gene ; 195(2): 187-93, 1997 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-9305763

RESUMO

Complementation analysis had suggested that the Drosophila melanogaster genome contains approximately 5000 genes, but it is now generally accepted that the actual number is several times as high. We report here an analysis of 1788 anonymous sequence tagged sites (STSs) from the European Drosophila Genome Project (EDGP), totalling 463 kb. The data reveal a substantial number of previously undescribed potential genes, amounting to 6.1% of the number of Drosophila genes already in the sequence databases.


Assuntos
Drosophila melanogaster/genética , Genes de Insetos , Sitios de Sequências Rotuladas , Sequência de Aminoácidos , Animais , Mapeamento Cromossômico , Genoma , Dados de Sequência Molecular , Família Multigênica , Alinhamento de Sequência , Análise de Sequência de DNA/métodos
10.
FEBS Lett ; 467(2-3): 337-40, 2000 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-10675565

RESUMO

gamma-Glutamylcysteine synthetase (GCS) catalyses a critical, rate-limiting step in glutathione synthesis. In this study we describe the isolation and characterisation of a GCS cDNA (pDmGCS4.3. 3) from Drosophila melanogaster by functional complementation of a Saccharomyces cerevisiae gsh1 mutant. Expression of pDmGCS4.3.3 in the yeast mutant partially restored glutathione levels and conferred resistance to methylglyoxal. The pDmGCS4.3.3 cDNA was found to be approx. 4.6 kb in length, containing a 2 kb fragment encoding an open reading frame with a high degree of deduced amino acid sequence identity with previously reported GCS sequences. In situ hybridisation revealed that the Drosophila GCS gene maps to 7D6-9 on the X chromosome.


Assuntos
Drosophila melanogaster/genética , Glutamato-Cisteína Ligase/genética , Sequência de Aminoácidos , Animais , Mapeamento Cromossômico , Clonagem Molecular , DNA Complementar/química , Drosophila melanogaster/enzimologia , Teste de Complementação Genética , Glutationa/biossíntese , Dados de Sequência Molecular , Mutação , Filogenia , Plasmídeos , Saccharomyces cerevisiae/genética , Alinhamento de Sequência
11.
Am J Med ; 89(6): 757-60, 1990 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2252044

RESUMO

PURPOSE: Patients with chest pain but without angiographic evidence of significant atherosclerotic coronary artery disease (CAD) are often found to have other medical or psychiatric disorders, including mitral valve prolapse, panic disorder (PD), and major depressive disorder (MDD). The purpose of this study was to determine the degree of comorbidity between MDD/PD and mitral valve prolapse in a group of patients with non-CAD chest pain. PATIENTS AND METHODS: Patients referred for cardiac catheterization and coronary angiography for suspected CAD who were 70 years of age or younger and without other significant medical illnesses or cardiac complications were eligible for study. The first 100 patients who agreed to a psychiatric diagnostic interview were recruited. RESULTS: Forty-eight of the 100 patients were found to be without significant CAD. Forty-two percent of these patients, compared to 19% of the patients with significant CAD, were found to have either MDD, PD, or both. Eighty percent of the patients without CAD who had mitral valve prolapse also had either MDD or PD (p less than 0.006). CONCLUSIONS: The finding that mitral valve prolapse was significantly associated with MDD/PD has implications for the diagnosis and treatment of patients with non-CAD chest pain, and may explain why these patients complain of symptoms.


Assuntos
Dor no Peito/etiologia , Transtorno Depressivo/epidemiologia , Prolapso da Valva Mitral/epidemiologia , Pânico , Transtornos Fóbicos/epidemiologia , Cateterismo Cardíaco , Comorbidade , Angiografia Coronária , Doença das Coronárias/diagnóstico , Doença das Coronárias/diagnóstico por imagem , Transtorno Depressivo/complicações , Transtorno Depressivo/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prolapso da Valva Mitral/complicações , Prolapso da Valva Mitral/diagnóstico , Transtornos Fóbicos/complicações , Transtornos Fóbicos/diagnóstico
12.
J Med Chem ; 36(9): 1262-71, 1993 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-8487263

RESUMO

Three homologous series of 3,5-dialkoxy-4-hydroxybenzylamines were prepared and tested (1) as peroxyl radical scavengers in homogeneous aqueous solution, (2) as inhibitors of iron-dependent peroxidation of rabbit brain vesicular membrane lipids, and (3) as cytoprotective agents using primary cultures of rat hippocampal neurons exposed to hydrogen peroxide. The structural requirements for efficient radical trapping in homogeneous solution differed from those for effective lipid peroxidation inhibition: In homogeneous solution a kinetic preference existed for smaller, less sterically encumbered substituents flanking the reactive phenolic hydroxyl group. Lipid peroxidation inhibition, on the other hand, required longer more lipophilic substituents. Consequently, a lipophilic alkoxyl substituent at C3 and a small substituent at C5 appeared optimal for efficient radical scavenging activity in both lipid and homogeneous solution. Maximal cytoprotection of rat hippocampal neurons exposed to hydrogen peroxide was also associated with more lipophilic derivatives although substituent length and substituent bulk may represent independent parameters for relating structure and efficacy in this system.


Assuntos
Antioxidantes/síntese química , Benzilaminas/síntese química , Sequestradores de Radicais Livres , Peroxidação de Lipídeos/efeitos dos fármacos , Animais , Antioxidantes/farmacologia , Benzilaminas/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Encéfalo/metabolismo , Hipocampo/efeitos dos fármacos , Peróxido de Hidrogênio/farmacologia , Ferro/farmacologia , Masculino , Lipídeos de Membrana/metabolismo , Neurônios/efeitos dos fármacos , Peróxidos , Coelhos , Ratos , Ratos Sprague-Dawley , Relação Estrutura-Atividade
13.
Am J Cardiol ; 76(8): 562-4, 1995 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-7677077

RESUMO

Decreased heart rate (HR) variability is an independent risk factor for mortality in cardiac populations. Clinical depression has also been associated with adverse outcomes in patients with coronary artery disease (CAD). This study tests the hypothesis that depressed patients with CAD have decreased HR variability compared with nondepressed CAD patients. Nineteen patients with angiographically documented CAD and either major or minor depression were compared with a sample of nondepressed CAD patients according to age, sex, and smoking status. All patients underwent 24-hour Holter monitoring, and the standard deviation of all normal-to-normal intervals was used as the primary index of HR variability. HR variability was significantly lower in depressed than nondepressed patients (90 +/- 35 vs 117 +/- 26 ms; p < or = 0.01), even after adjusting for relevant covariates. Thus, decreased HR variability may help explain the increased risk for cardiac mortality and morbidity in depressed CAD patients.


Assuntos
Doença das Coronárias/fisiopatologia , Depressão/fisiopatologia , Transtorno Depressivo/fisiopatologia , Frequência Cardíaca , Idoso , Análise de Variância , Distribuição de Qui-Quadrado , Doença das Coronárias/diagnóstico , Doença das Coronárias/psicologia , Depressão/diagnóstico , Depressão/psicologia , Transtorno Depressivo/diagnóstico , Transtorno Depressivo/psicologia , Eletrocardiografia Ambulatorial , Feminino , Humanos , Entrevista Psicológica , Masculino , Pessoa de Meia-Idade , Psicofisiologia , Fatores de Risco
15.
Int J Radiat Biol ; 75(5): 647-54, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10374947

RESUMO

PURPOSE: To investigate whether exposure to magnetic fields can affect the rate of RNA synthesis, a broad measure of cellular activity. MATERIALS AND METHODS: Normal human fibroblasts were exposed to 50 Hz magnetic fields at a range of flux densities between 2 microT and 20 mT. The rate of synthesis of total RNA was determined by following the incorporation of [3H]uridine into macromolecular material. In addition, polyadenylated RNA was isolated and used to estimate the rate of synthesis of mRNA. RESULTS: Incorporation of [3H]uridine into both total and messenger RNA increased progressively throughout the 5 h exposure period in all cells. However, magnetic field exposure had no detectable effect on the rate of synthesis of either total or messenger RNA when compared with controls. CONCLUSIONS: These findings indicate that under the conditions examined, gross transcription rates are not affected by exposure to power frequency magnetic fields. Taken together with previous data, this suggests that if magnetic fields do alter cellular activity, the effect is likely to be extremely subtle.


Assuntos
Magnetismo , RNA Mensageiro/biossíntese , Células Cultivadas , Fibroblastos/metabolismo , Humanos , Uridina/metabolismo
16.
Int J Radiat Biol ; 62(2): 211-9, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1355515

RESUMO

Pregnant CD1 mice were exposed on various gestational or postnatal days to 1 Gy of 250 kV X-rays. Ten adult, male offspring from each exposure condition were tested in a radial arm maze. Compared to sham-exposed control mice, acquisition of spatial information was unimpaired in animals exposed on gestational days 13 or 15, or on postnatal day 10, but animals exposed on gestational day 18 or postnatal day 1 showed sustained deficits in acquisition. These results appear consistent with the known time-course for the proliferation and migration of the dentate granule cells of the hippocampus in the mouse, and are discussed in relation to the dependence on hippocampal integrity of the acquisition and use of spatial information. The results suggest that comparable deficits in mental function might be expected in humans similarly exposed to ionizing radiation during periods of proliferation and migration of the dentate granule cells.


Assuntos
Período Crítico Psicológico , Feto/efeitos da radiação , Memória/fisiologia , Efeitos Tardios da Exposição Pré-Natal , Percepção Espacial/fisiologia , Animais , Animais Recém-Nascidos , Feminino , Hipocampo/fisiologia , Hipocampo/efeitos da radiação , Masculino , Memória/efeitos da radiação , Camundongos , Gravidez , Percepção Espacial/efeitos da radiação
17.
Int J Radiat Biol ; 65(5): 611-8, 1994 May.
Artigo em Inglês | MEDLINE | ID: mdl-7910199

RESUMO

Pregnant CD1 mice were exposed on gestational day 18 to 250 kV X-rays at 0.1, 0.25, 0.35 and 0.5 Gy. The performances of 10 adult male offspring from each exposure condition were investigated on a spatial discrimination learning task in a radial arm maze. An impairment in the performance of this task was found which showed a correlation with dose. Compared with sham exposed control mice, performance was not significantly affected with irradiation at 0.1 Gy and was slightly but non-significantly reduced at 0.25 Gy. Irradiation at 0.35 Gy caused a significant impairment in performance, and exposure at 0.5 Gy resulted in a still larger impairment. The overall association between dose and behavioural impairment was best described by a linear relationship without a threshold, although at doses lower than about 0.25 Gy any impairment would appear to be too small to be detectable.


Assuntos
Comportamento Animal/efeitos da radiação , Memória/efeitos da radiação , Efeitos Tardios da Exposição Pré-Natal , Comportamento Espacial , Animais , Relação Dose-Resposta à Radiação , Feminino , Aprendizagem/efeitos da radiação , Masculino , Camundongos , Camundongos Endogâmicos , Modelos Biológicos , Gravidez , Irradiação Corporal Total
18.
Int J Radiat Biol ; 75(1): 121-7, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9972799

RESUMO

PURPOSE: To investigate the behavioural effects of prenatal irradiation on different days of gestation on the performance of two learning tasks by adult mice. MATERIALS AND METHODS: CD1 mice were exposed in utero to 1 Gy of 250 kV X-rays on gestational days 13, 15 or 18. Other animals were sham-exposed. Male mice were tested as adults in a radial arm maze on two learning tasks considered dependent upon either spatial memory or visual associative memory. RESULTS: Performance of the animals on the tasks was a function of the day on which exposure occurred. Compared with sham-exposed animals, exposure on day 18 produced a highly significant deficit in performance on the spatial task, and a small improvement in the visually cued task. Exposure on day 15 produced no deficit in performance on the spatial task, but a highly significant deficit in the cued task. Exposure on day 13 produced no significant deficits on either task. CONCLUSIONS: These differential effects on performance appear to be consistent with radiation-induced insult to different memory systems within the developing mouse brain. These and further studies will help provide better estimates of the risks of radiation at different times during gestation on cognitive function in humans.


Assuntos
Comportamento Animal/efeitos da radiação , Aprendizagem/efeitos da radiação , Efeitos Tardios da Exposição Pré-Natal , Animais , Encéfalo/efeitos da radiação , Desenvolvimento Embrionário e Fetal/efeitos da radiação , Feminino , Masculino , Camundongos , Gravidez
19.
Int J Radiat Biol ; 69(4): 503-11, 1996 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8627133

RESUMO

Interest in the potential adverse biological effects of exposure to power-frequency magnetic fields has centred on the possibility that these fields may influence tumour promotion, possibly by increasing the rate of cell proliferation. In order to investigate whether exposure to magnetic fields can indeed affect the rate of cell proliferation, normal human fibroblasts were serum starved overnight and then exposed to 50 Hz magnetic fields in a purpose-built facility. The rate of DNA synthesis was taken as a measure of cell proliferation, and was determined by following the incorporation of [3H]-thymidine into macromolecular material. The rate of DNA synthesis in exposed cells was compared with that in control cultures maintained in a standard CO2 incubator where they were exposed to background magnetic fields of < 200 nT. Positive controls were maintained in the same CO2 incubator, but were treated with human recombinant fibroblast growth factor to check that the cells were responsive to growth stimuli. Magnetic fields at 50 Hz and at a range of flux densities between 20 microT and 20 mT had no detectable effect on the rate of DNA synthesis by cells exposed for up to 30 h.


Assuntos
DNA/biossíntese , Campos Eletromagnéticos , Células Cultivadas , Fibroblastos/metabolismo , Humanos , Timidina/metabolismo
20.
Int J Radiat Biol ; 58(4): 713-23, 1990 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1976731

RESUMO

Some epidemiological studies have drawn attention to a possible association between exposure to extremely low-frequency (ELF) electromagnetic fields and the development of acute myeloid leukaemia (AML) in adults. At present there is no experimental evidence for such an association. We have investigated the acute effects of power frequency magnetic fields on haemopoiesis in CBA/H mice known to be susceptible to the induction of AML after exposure to ionizing radiation. Up to 19 days after exposure to 50 Hz fields at 20 mT for 7 days no significant effects on peripheral blood characteristics were observed. Assays of the bone marrow stem cells and myelomonocytic progenitor cells also failed to reveal significant effects. Our experiments cannot, however, rule out subtle effects on cell population dynamics, and further investigations, including long-term studies, are required to establish the extent to which ELF magnetic fields might affect the haemopoietic system.


Assuntos
Campos Eletromagnéticos , Hematopoese , Animais , Hematócrito , Contagem de Leucócitos , Masculino , Camundongos , Camundongos Endogâmicos CBA
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