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1.
J Anim Physiol Anim Nutr (Berl) ; 101(2): 284-292, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27272013

RESUMO

Resveratrol has generated interest in cats due to reported health benefits. Cats have low activity of ß-glucuronidase, and we hypothesized they could not form two common resveratrol metabolites, resveratrol-3-O-glucuronide and resveratrol-4'-O-glucuronide. Resveratrol, 3 mg/cat/day, was given orally to intact male (n = 5) and female cats (n = 5) for 4 weeks. A control group (8 intact males) was used for comparison. Plasma and urine were collected weekly and analysed using high-pressure liquid chromatography coupled with tandem mass spectrometry. Resveratrol and resveratrol-3-O-sulphate, but no glucuronide metabolites, were detected in plasma and urine. Median (range 10-90th percentile) plasma resveratrol for control and treatment groups was 0.46 ng/ml (0.02-1.74 ng/ml) and 0.96 ng/ml (0.65-3.21 ng/ml). Median (range) plasma resveratrol-3-O-sulphate for control and treatment groups was 6.32 ng/ml (2.55-10.29 ng/ml) and 11.45 ng/ml (1.47-53.29 ng/ml). Plasma resveratrol differed from control in week 4, while plasma resveratrol-3-O-sulphate was different in all weeks (p < 0.05). Median (range) urine resveratrol for control and treatment groups was 0.28 ng/ml (0.05-1.59 ng/ml) and 19.98 ng/ml (8.44-87.54 ng/ml). Median (range) urine resveratrol-3-O-sulphate for control and treatment groups was 26.71 ng/ml (10.50-75.58 ng/ml) and 108.69 ng/ml (11.83-231.05 ng/ml). All time points for urine resveratrol and resveratrol-3-O-sulphate were significantly different from control (p < 0.05), except for weeks 1, 3 and 4 for resveratrol. The results support our hypothesis that cats are unlikely able to glucuronidate resveratrol, most likely due to a reduction in the activity of ß-glucuronidase.


Assuntos
Gatos/sangue , Gatos/urina , Estilbenos/metabolismo , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Dieta/veterinária , Feminino , Masculino , Resveratrol , Organismos Livres de Patógenos Específicos , Estilbenos/sangue , Estilbenos/urina
3.
J Cell Biol ; 90(1): 108-15, 1981 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-6265473

RESUMO

A defect in mitochondrial protein synthesis has previously been identified in the respiration-deficient Chinese hamster lung fibroblast mutant V79-G7. The present work extends the characterization of this mutant. A more sensitive analysis has shown that mutant mitochondria synthesize all mitochondrially encoded peptides, but in significantly reduced amounts. This difference is also seen when isolated mitochondria are tested for in vitro protein synthesis. To distinguish between a defect in the translational machinery and a defect in the transcription of mitochondrial DNA, we investigated the synthesis of the 16S and 12S mitochondrial rRNA species and found them to be made in normal amounts in G7 mitochondria. These rRNA species appear to be assembled into subunits whose sedimentation behavior is virtually indistinguishable from that of the wild-type subunits. We also examined the consequences of the defect in mitochondrial protein synthesis on mutant cells and their mitochondria-utilizing techniques of electron microscopy, two-dimensional gel electrophoresis and immunochemical analysis. G7 mitochondria have a characteristic ultrastructure distinguished by predominantly tubular cristae, but the overall biochemical composition of mitochondrial membrane and matrix fractions appears essentially unaltered except for the absence of a few characteristic peptides. Specifically, we identify the absence of two mitochondrially encoded subunits of cytochrome c oxidase on two-dimensional gels and demonstrate a drastic reduction of both cytoplasmically and mitochondrially synthesized subunits of enzyme in immunoprecipitates of G7 mitochondria.


Assuntos
Mitocôndrias/metabolismo , Biossíntese de Proteínas , Animais , Linhagem Celular , Cricetinae , DNA Mitocondrial/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Fibroblastos , Pulmão , Mitocôndrias/análise , Mitocôndrias/ultraestrutura , Mutação , Proteínas/análise , RNA Ribossômico/biossíntese
4.
Climacteric ; 12(4): 341-51, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19421917

RESUMO

OBJECTIVES: To evaluate the psychometric properties of a scale we constructed to measure menopause-related symptoms in Hispanic and White non-Hispanic women. METHODS: Items were generated from the literature and clinical experiences. Hispanic (n = 123, 51.34 +/- 5.14 years) and White (n = 210, 53.36 +/- 4.80 years) women completed the scale and other instruments used to validate respective constructs. A subgroup of 69 women completed our scale a second time. RESULTS: Following exploratory factor analysis using the entire sample, confirmatory factor analysis was conducted for Hispanic and White women, separately. The same four-factor model (vasomotor, psychological symptoms, relationship(s), and other symptoms) fit data for both ethnic groups. The coefficient alpha for internal consistency was 0.852 and 0.849 for the initial and second administration, respectively, and the test-retest reliability was significant (p < 0.001). There were differences in factor scores among groups with different menopausal status. Factor scores were significantly correlated with scores of a global quality-of-life instrument (p < or = 0.001). CONCLUSIONS: Our study suggests that the scale is appropriate for use for Hispanic and White non-Hispanic women and is capable of detecting differences among women with different menopause-related symptoms. Menopause-related symptoms measured by the scale were correlated with global quality of life.


Assuntos
Menopausa/etnologia , Psicometria/métodos , Escolaridade , Emprego , Feminino , Nível de Saúde , Hispânico ou Latino/psicologia , Fogachos/epidemiologia , Humanos , Renda , Pessoa de Meia-Idade , Psicometria/estatística & dados numéricos , Qualidade de Vida , Reprodutibilidade dos Testes , Inquéritos e Questionários , Sudorese , População Branca/psicologia
5.
Mutagenesis ; 23(6): 423-37, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18678752

RESUMO

A review of risk factors affecting background rates of micronuclei and chromosomal aberration (CA) formation in peripheral blood lymphocytes (PBLs) was undertaken with a view to aiding the interpretation of genotoxicity biomonitoring studies. Both endogenous factors and those due to methodological variation were evaluated. Background variation of other indices of genotoxicity in PBLs (specifically 8-hydroxy-deoxyguanosine and comet assays) were also considered as these data likely reflect overlapping causes of DNA damage and may provide some indicators for future research areas. A number of host risk factors, namely age, gender, smoking, vitamin B(12) and folate status, were identified for which there is strong or sufficient evidence that they impact on background levels of genotoxicity biomarkers. Evaluation of these factors should be routinely included in genotoxicity biomonitoring studies. Although data on the influence of smoking is somewhat inconsistent, because of its known association with cancer and DNA damage, it is also classified as a high-risk factor. A number of other factors were identified for which there is weak or insufficient evidence including alcohol consumption, disease conditions and infections, physical exercise, body mass index and genotype. The review shows that the evaluation of biomonitoring studies of genotoxicity is complex and there is a need to improve study designs by setting an a priori hypothesis, collecting good exposure data and stratifying groups appropriately, using appropriate power calculations before initiating biomonitoring studies, and collecting information on appropriate risk factors. There is a need for further collaborative work and the establishment of centres of excellence on genotoxicity biomonitoring. If these measures are achieved, then it would be possible to use the data from biomonitoring studies in risk assessments to derive risk management measures.


Assuntos
Linfócitos/efeitos dos fármacos , Testes de Mutagenicidade , Mutagênicos/toxicidade , Fatores Etários , Biomarcadores/análise , Monitoramento Ambiental , Identidade de Gênero , Humanos , Incidência , Fatores de Risco
6.
Behav Brain Res ; 331: 54-66, 2017 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-28511979

RESUMO

Rodent spatial memory is commonly tested using the water-maze; however, there is a potential confound of stress on learning in this behavioural paradigm. This is particularly relevant when testing spatial memory in models of neurodegeneration, such as the 3xTg mouse model for Alzheimer's disease. Here, we first confirmed that 3xTgAD mice express fear conditioning and then compared the performance of young and middle-aged mice on short-duration versions of the radial arm water-maze (RAWM) and the minimally stressful T-maze spontaneous alternation task. Our main questions were: (1) does the reliance on stressors in water-maze training mask the true cognitive ability of 3xTgAD mice; and (2) are 3xTgAD mice similarly impaired in water-maze and T-maze protocols. Firstly, male and female 3xTgAD mice displayed intact freezing responses in both contextual and Pavlovian fear conditions. As male 3xTgAD mice displayed relatively enhanced fear responses the remaining tests were performed using only female 3xTgAD and control mice in order to equate for response to stressors. We found that alternation rates after both short and long delays were impaired at both ages in female 3xTgAD mice, indicative of robust spatial working memory deficits. For RAWM, again performance deficits were found in young 3xTgAD mice. As both tasks had similar efficacy at revealing early spatial memory deficits, we suggest that spontaneous behavioural protocols be prioritised over water maze testing in models such the 3xTgAD mouse as the former provide a far less stressful but equally effective alternative.


Assuntos
Doença de Alzheimer/fisiopatologia , Comportamento Animal/fisiologia , Aprendizagem em Labirinto/fisiologia , Transtornos da Memória/fisiopatologia , Memória Espacial/fisiologia , Água , Animais , Modelos Animais de Doenças , Transtornos da Memória/genética , Camundongos Transgênicos
7.
Nature ; 405(6787): 631, 633, 2000 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-10864309
8.
J Nucl Med ; 29(10): 1688-96, 1988 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-3171697

RESUMO

The distribution and kinetics of six human and one murine monoclonal IgM antibodies (MoAb) were studied in BALB/c mice. Labeling was with 111In, 75Se, and 125I. The monomers and pentamers of certain MoAbs were studied. Human distribution studies were also performed. The serum containing [111In]MoAb was obtained from one of the patients 24 hr after administration and injected into mice which were then killed and assayed for 111In distribution. In general, the [75Se] and [111In]MoAbs had distribution and kinetic patterns that were similar while the 125I-labeled MoAbs dehalogenated after 4 hr. Monomers and pentamers had highly similar distributions suggesting that the distribution of IgMs may be based on factors other than molecular size. The murine IgM showed a somewhat different distribution in mice than did human IgMs. Serum from the patient containing [111In]MoAb had a distribution in mice similar to that of the patient with high liver and gastrointestinal uptake. The human imaging indicates that it is possible to target tumor with human IgM MoAbs, but significant problems remain in regard to their clinical use.


Assuntos
Anticorpos Monoclonais , Imunoglobulina M , Radioisótopos de Índio , Radioisótopos do Iodo , Radioisótopos de Selênio , Animais , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Distribuição Tecidual
9.
Am J Cardiol ; 57(6): 441-5, 1986 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-3946262

RESUMO

A portable solid-state recorder-display system was used to measure and analyze heart rate during the waking hours of 3 consecutive days in free-living sedentary normal middle-aged men who were randomized to undergo 3 regimens of physical activity during a 12-week period: low-intensity exercise training at home (n = 21), high-intensity exercise training at home (n = 23) and customary activity (n = 20). This was done to determine whether the system could detect changes in heart rate and, indirectly, in physical activity within the 3 groups. In both training groups the percentage of total recorded time spent within the prescribed high or low heart rate range recorded at 6 or 12 weeks increased significantly (p less than 0.05), whereas control subjects showed no increase above baseline values. Peak oxygen consumption increased by 8% and 17% in men undergoing low- and high-intensity training, whereas in control subjects it did not change. This solid-state system reliably measures prescribed increases in heart rate and provides an indirect measure of physical activity in normal sedentary men undergoing exercise training at home.


Assuntos
Computadores , Frequência Cardíaca , Microcomputadores , Monitorização Fisiológica/métodos , Esforço Físico , Assistência Ambulatorial , Estudos de Avaliação como Assunto , Humanos , Masculino , Pessoa de Meia-Idade , Educação Física e Treinamento , Distribuição Aleatória
10.
Dev Comp Immunol ; 18(1): 33-43, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8050615

RESUMO

A major route of signal transduction in mammalian lymphocytes is the phosphatidyl inositol (PI) pathway. As previously demonstrated in the channel catfish, and confirmed in the present work with the red drum, modulators of the PI pathway such as phorbol ester and calcium ionophore acted synergistically to stimulate proliferation of teleost peripheral blood leukocytes (PBL). Red drum PBL also proliferated strongly in response to phorbol ester alone, at doses which were not mitogenic for catfish PBL. Cell depletion studies suggested that macrophage-derived cytokines probably played a role in supporting the mitogenic response to phorbol ester alone. Dose titration studies with a panel of kinase inhibitors suggested that mitogenic and synergistic doses of phorbol ester primarily targeted an enzyme activity similar to protein kinase C (PKC). However, in the same inhibitor studies, the target enzyme was insensitive to staurosporine, suggesting the involvement of an unusual form of PKC. Similarly, cell proliferation stimulated by phorbol ester was suppressed, but not eliminated by a calcium channel blocker Verapamil. Thus, while the synergistic action of phorbol ester and calcium ionophore appeared to be mediated by a PI pathway, these studies have suggested that PKC isoforms and membrane ion pumps unique to the lower vertebrates may participate in regulation of the cell cycle.


Assuntos
Bass/anatomia & histologia , Bass/sangue , Leucócitos/citologia , Leucócitos/metabolismo , Proteína Quinase C/metabolismo , Sulfonamidas , 1-(5-Isoquinolinasulfonil)-2-Metilpiperazina , Alcaloides , Animais , Benzofenantridinas , Calcimicina/farmacologia , Cálcio/sangue , Divisão Celular/efeitos dos fármacos , Técnicas In Vitro , Isoquinolinas/farmacologia , Leucócitos/efeitos dos fármacos , Linfócitos/citologia , Linfócitos/efeitos dos fármacos , Monócitos/efeitos dos fármacos , Fenantridinas/farmacologia , Fosfatidilinositóis/sangue , Piperazinas/farmacologia , Proteína Quinase C/antagonistas & inibidores , Transdução de Sinais , Acetato de Tetradecanoilforbol/farmacologia
11.
Dev Comp Immunol ; 23(3): 221-30, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10402209

RESUMO

In mammalian B lymphocytes, engagement of the B cell antigen receptor (BCR) activates several parallel intracellular signaling pathways which ultimately lead to expression of differentiated functions such as cell proliferation and antibody production or to cellular apoptosis. BCR engagement stimulates the classical mitogen activated protein kinase (MAPK) pathway, also called the extracellular-related kinase (ERK) pathway, resulting in activation of the signature terminal enzyme in the pathway, MAPK (or ERK). BCR signaling also activates the phosphatidyl inositol pathway and its key enzyme protein kinase C (PKC). To investigate the ERK pathway in cells of the teleost immune system, peripheral blood leukocytes from red drum or channel catfish were treated with PKC activators or antibodies which crosslink the BCR. Proteins were identified in both red drum and catfish B cells that resembled mammalian ERKs in molecular weight and in their possessing a distinctive pTEpY dual phosphorylation site. BCR-mediated activation of these presumptive teleost ERKs depended in part (red drum) or in total (catfish) on PKC. To our knowledge this represents the first report of a functional MAPK kinase pathway in teleost fish.


Assuntos
Linfócitos B/metabolismo , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Proteínas Quinases Ativadas por Mitógeno , Receptores de Antígenos de Linfócitos B/metabolismo , Animais , Ativação Enzimática , Peixes , Ictaluridae , Camundongos , Proteína Quinase 3 Ativada por Mitógeno , Proteína Quinase 6 Ativada por Mitógeno , Proteína Quinase C/metabolismo , Transdução de Sinais
12.
AIDS Res Hum Retroviruses ; 8(2): 269-75, 1992 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1540412

RESUMO

To quantitate the amount of human immunodeficiency virus type 1 (HIV-1) DNA in peripheral blood mononuclear cells (PBMC) of 78 infected individuals, we have developed a polymerase chain reaction (PCR) assay that is both quantitative and sensitive. Quantitation was based on incorporation of a 32P end-labelled primer (SK39) in the PCR reaction and on comparison after electrophoresis with known amounts of HIV DNA. A linear relationship was obtained between the natural logarithms of the radioactive counts detected and the number of HIV-1 DNA copies (10-1000 copies) from the standard DNA. HIV copy numbers from patient samples were then extrapolated from the standard curves. This sensitive and reproducible method was compared with virus isolation which is a semiquantitative evaluation of viral burden. HIV DNA levels correlated with virus isolation, i.e., high viral burden (100-1000 HIV copies) were found in most samples from which virus was isolated after only 7 days in culture; low viral burden (less than 100 HIV copies) was observed in samples from which virus was isolated after 14 to 21 days in culture. These estimates of viral burden were then compared with the clinical stage of the individuals.


Assuntos
DNA Viral/análise , Soropositividade para HIV/microbiologia , HIV-1/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Soropositividade para HIV/patologia , Hospitais Militares , Humanos , Contagem de Leucócitos , Militares , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
13.
Environ Health Perspect ; 104(10): 1102-6, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8930553

RESUMO

Although fish in natural populations may carry high body burdens of both organic and inorganic mercury, the effects of this divalent metal on such lower vertebrates is poorly understood. In this report, inorganic mercury in the form of mercuric chloride (HgCl2) is shown to produce both high-dose inhibition and low-dose activation of leukocytes in a marine teleost fish, Sciaenops ocellatus. Concentrations of inorganic mercury > or = 10 microM suppressed DNA synthesis and induced rapid influx of radiolabeled calcium, as well as tyrosine phosphorylation of numerous cellular proteins. Lower concentrations (0.1-1 microM) of HgCl2 that activated cell growth also induced a slow sustained rise in intracellular calcium in cells loaded with the calcium indicator dye fura-2, but did not produce detectable tyrosine phosphorylation of leukocyte proteins. These studies support the possibility that subtoxic doses of HgCl2 may inappropriately activate teleost leukocytes, potentially altering the processes that regulate the magnitude and specificity of the fish immune response to environmental pathogens.


Assuntos
Peixes/imunologia , Leucócitos/efeitos dos fármacos , Cloreto de Mercúrio/toxicidade , Animais , Cálcio/metabolismo , Células Cultivadas , Relação Dose-Resposta a Droga , Humanos , Leucócitos/imunologia , Ativação Linfocitária/efeitos dos fármacos , Fosforilação , Tirosina/metabolismo
14.
Opt Express ; 1(10): 284-92, 1997 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-19373414

RESUMO

For a dilute, interacting Bose gas of magnetically-trapped atoms at temperatures below the critical temperature T0 for Bose-Einstein condensation, we determine the second-order coherence function g (2) (r1 ; r2) within the framework of a finite-temperature quantum field theory. We show that, because of the different spatial distributions of condensate and thermal atoms in the trap, g (2) (r1 ; r2) does not depend on jr1 r2j alone. This means that the experimental determinations of g (2) reported to date give only its spatial average. Such an average may underestimate the degree of coherence attainable in an atom laser by judicious engineering of the output coupler.

15.
Invest Radiol ; 23 Suppl 1: S281-5, 1988 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-3058632

RESUMO

The preclinical and clinical trial experience with ferrioxamine (S-FDF; Salutar, Inc.) as a contrast agent for magnetic resonance imaging (MRI) is summarized. The results in 44 patients or subjects show that the drug is safe and well tolerated when given intravenously. In certain conditions, early results show that the use of this contrast agent provides more information than can be obtained with MRI alone.


Assuntos
Meios de Contraste , Desferroxamina , Compostos Férricos , Quelantes de Ferro , Imageamento por Ressonância Magnética , Adulto , Animais , Cães , Avaliação de Medicamentos , Avaliação Pré-Clínica de Medicamentos , Gadolínio DTPA , Humanos , Masculino , Camundongos , Estudos Multicêntricos como Assunto , Compostos Organometálicos , Ácido Pentético
16.
Phys Rev Lett ; 85(23): 4844-7, 2000 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-11102132

RESUMO

We present a finite temperature field theory for collective excitations of trapped Bose condensates which includes the dynamics of the thermal cloud. In spherical traps we show that excitations couple strongly to a small number of modes, giving resonance structure in their frequency spectra. Where possible, we derive energy shifts and lifetimes of excitations. For the l = 0 mode we show that the simple picture of a decay rate fails, which should be observable in suitable experiments. It also suggests a possible explanation for the anomalous behavior of the m = 0 mode observed in anisotropic traps.

17.
Arch Surg ; 120(8): 918-21, 1985 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-4015382

RESUMO

Patch repair of the thoracic aorta using prosthetic graft material in neonates and infants has been advocated, but long-term results have not confirmed that the residual aorta grows. In this study five piglets had portions of aortic tissue excised, ranging from 38% to 72% of the aortic wall. Each pig underwent patch angioplasty repair of the thoracic aorta with prosthetic graft material. Piglets achieved full growth at approximately six months. Aortic catheterization and contrast angiography were done in each animal before it was killed. Growth and histologic study of the aorta was documented at postmortem examination. There were no blood pressure gradients at rest or with isoproterenol hydrochloride (Isuprel)-epinephrine challenge in four of the five piglets. In one animal that underwent a 72% resection of the aortic circumference, a 20-mm gradient was present at rest. It was concluded that the thoracic aorta in piglets will grow adequately to allow patch grafting of up to 70% of the aortic circumference.


Assuntos
Aorta Torácica/crescimento & desenvolvimento , Prótese Vascular , Animais , Animais Recém-Nascidos/crescimento & desenvolvimento , Aorta Torácica/diagnóstico por imagem , Aorta Torácica/cirurgia , Circulação Colateral , Radiografia , Suínos
18.
Science ; 269(5221): 182-3, 1995 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-17789844
19.
Magn Reson Imaging ; 2(4): 307-14, 1984.
Artigo em Inglês | MEDLINE | ID: mdl-6530933

RESUMO

Mn+2 (as MnCl2) was administered to rabbits intravenously and orally (a route of administration which based upon our previous experiments in rats promises to give selective hepatobiliary enhancement with less systemic toxicity). Nuclear magnetic relaxation dispersion or T1 (NMRD) was performed on selected tissues (heart, liver, kidney, serum, and bile) in both animal groups to examine possible qualitative and semiquantitative differences in T1 relaxation at equivalent sacrifice times. One animal was given an oral dose of MnCl2 (620 micromoles/kg) and imaged sequentially (T1 weighted sequence, .12T) for 30 minutes. The NMRD curves for organ tissues show an increase in relaxation efficacy in the 10-20MHz range characteristic of Mn-macromolecular complexes and are similar irrespective of the route of administration. The lack of increased relaxation enhancement for bile in this frequency range reflects cleavage of this complex upon excretion. Decreased overall relaxation in the liver is observed when oral Mn+2 is compared to IV Mn+2 due to the small fraction of administered dose that is absorbed. However, the images document a significant increase in the intensity of liver signal after the oral dose. We suspect this dose may ultimately be adjusted downward to give selective hepatobiliary effects.


Assuntos
Cloretos , Espectroscopia de Ressonância Magnética , Compostos de Manganês , Manganês , Administração Oral , Animais , Bile , Sangue , Coração/anatomia & histologia , Aumento da Imagem/métodos , Rim/anatomia & histologia , Fígado/anatomia & histologia , Manganês/administração & dosagem , Coelhos , Ratos , Ratos Endogâmicos , Fatores de Tempo , Distribuição Tecidual
20.
Magn Reson Imaging ; 3(1): 65-71, 1985.
Artigo em Inglês | MEDLINE | ID: mdl-3999938

RESUMO

Gd2O3 particles (less than 2 microns) in suspension were evaluated as a potential contrast agent for liver-spleen imaging with magnetic resonance. The agent was administered IV to rabbits in doses ranging from 10 to 120 mumol/kg and the tissues removed after sacrifice for in vitro T1 and T2 analysis. The temporal response was determined in liver and spleen samples of rabbits given a fixed dose (60 mumol/kg) and sacrificed at intervals from 15 min to 60 hr later. Documentation of the subanatomic location of Gd2O3 particles in tissue was accomplished by electron microscopy and x-ray dispersion microanalysis. T1 weighted images were obtained at 0.12T on a prototype resistive scanner. The liver, spleen, and lung relaxation times are very responsive to Gd2O3 IV and the effect is dose related. A peak effect is observed between 3-7 hr after injection and relaxation times may normalize by 60 hr. By electron microscopic and x-ray analysis, Gd2O3 is most prominently found in the hepatic and splenic sinusoids. The images show marked enhancement of liver and splenic tissues, aiding in the clear delineation of these tissues from neighboring structures.


Assuntos
Meios de Contraste , Gadolínio , Fígado/anatomia & histologia , Espectroscopia de Ressonância Magnética , Baço/anatomia & histologia , Animais , Gadolínio/metabolismo , Coelhos , Distribuição Tecidual
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