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1.
Rev Esp Quimioter ; 33(6): 466-484, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33070578

RESUMO

The high transmissibility of SARS-CoV-2 before and shortly after the onset of symptoms suggests that only diagnosing and isolating symptomatic patients may not be sufficient to interrupt the spread of infection; therefore, public health measures such as personal distancing are also necessary. Additionally, it will be important to detect the newly infected individuals who remain asymptomatic, which may account for 50% or more of the cases. Molecular techniques are the "gold standard" for the diagnosis of SARS-CoV-2 infection. However, the massive use of these techniques has generated some problems. On the one hand, the scarcity of resources (analyzers, fungibles and reagents), and on the other the delay in the notification of results. These two facts translate into a lag in the application of isolation measures among cases and contacts, which favors the spread of the infection. Antigen detection tests are also direct diagnostic methods, with the advantage of obtaining the result in a few minutes and at the very "pointof-care". Furthermore, the simplicity and low cost of these tests allow them to be repeated on successive days in certain clinical settings. The sensitivity of antigen tests is generally lower than that of nucleic acid tests, although their specificity is comparable. Antigenic tests have been shown to be more valid in the days around the onset of symptoms, when the viral load in the nasopharynx is higher. Having a rapid and real-time viral detection assay such as the antigen test has been shown to be more useful to control the spread of the infection than more sensitive tests, but with greater cost and response time, such as in case of molecular tests. The main health institutions such as the WHO, the CDC and the Ministry of Health of the Government of Spain propose the use of antigenic tests in a wide variety of strategies to respond to the pandemic. This document aims to support physicians involved in the care of patients with suspected SC2 infection, in the context of a growing incidence in Spain since September 2020, which already represents the second pandemic wave of COVID-19.


Assuntos
Antígenos Virais/sangue , Teste Sorológico para COVID-19/métodos , COVID-19/diagnóstico , Consenso , Pandemias , SARS-CoV-2/imunologia , Doença Aguda , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Algoritmos , COVID-19/epidemiologia , COVID-19/mortalidade , COVID-19/transmissão , Teste de Ácido Nucleico para COVID-19/normas , Teste Sorológico para COVID-19/normas , Criança , Pré-Escolar , Busca de Comunicante , Emergências , Feminino , Humanos , Incidência , Lactente , Masculino , Pessoa de Meia-Idade , Nasofaringe/virologia , Sensibilidade e Especificidade , Espanha/epidemiologia , Manejo de Espécimes/métodos , Manejo de Espécimes/normas , Adulto Jovem
2.
Bone Marrow Transplant ; 50(5): 727-33, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25730191

RESUMO

This prospective study aimed to investigate the influence of pretransplant serum ferritin levels on the outcomes of allogeneic hematopoietic SCT (HSCT). In total, 190 patients with acute leukemia or myelodysplastic syndrome were consecutively enrolled. The patients were divided into two groups: low-ferritin group (<1000 ng/mL) and high-ferritin group (⩾1000 ng/mL). The primary end point was the cumulative incidence of infection within 100 days after HSCT, which was similar between the two groups: bloodstream infection, 35 vs 38%, P=0.65; bacterial infection, 44 vs 41%, P=0.68; and fungal infection, 6 vs 8%, P=0.71. The 1-year adjusted probability of OS of the high-ferritin group was significantly lower than that of the low-ferritin group (76 vs 63%, P=0.017). Using receiver operating characteristic curve, the threshold of pretransplant serum ferritin levels for bloodstream infection was 1400 ng/mL; the threshold for OS, EFS and non-relapse mortality was 1349 ng/mL. In conclusion, pretransplant serum ferritin levels of ⩾1000 ng/mL did not influence the incidence of infection but adversely affected OS after HSCT. A higher threshold of pretransplant serum ferritin levels may predict HSCT outcomes.


Assuntos
Infecções Bacterianas , Ferritinas/sangue , Neoplasias Hematológicas , Transplante de Células-Tronco Hematopoéticas , Micoses , Período Pré-Operatório , Adulto , Idoso , Aloenxertos , Infecções Bacterianas/sangue , Infecções Bacterianas/mortalidade , Intervalo Livre de Doença , Feminino , Seguimentos , Neoplasias Hematológicas/sangue , Neoplasias Hematológicas/mortalidade , Neoplasias Hematológicas/terapia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Micoses/sangue , Micoses/mortalidade , Estudos Prospectivos , Taxa de Sobrevida
3.
Appl Biochem Biotechnol ; 174(3): 926-35, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25201210

RESUMO

We have fabricated an immunosensor based on carbon nanotubes and chitosan (CNT-CH) composite for detection of low density lipoprotein (LDL) molecules via electrochemical impedance technique. The CNT-CH composite deposited on indium tin oxide (ITO)-coated glass electrode has been used to covalently interact with anti-apolipoprotein B (antibody: AAB) via a co-entrapment method. The biofunctionalization of AAB on carboxylated CNT-CH surface has been confirmed by Fourier transform infrared spectroscopic and electron microscopic studies. The covalent functionalization of antibody on transducer surface reveals higher stability and reproducibility of the fabricated immunosensor. Electrochemical properties of the AAB/CNT-CH/ITO electrode have been investigated using cyclic voltammetric and impedimetric techniques. The impedimetric response of the AAB/CNT-CH/ITO immunoelectrode shows a high sensitivity of 0.953 Ω/(mg/dL)/cm(2) in a detection range of 0-120 mg/dL and low detection limit of 12.5 mg/dL with a regression coefficient of 0.996. The observed low value of association constant (0.34 M(-1)s(-1)) indicates high affinity of AAB/CNT-CH/ITO immunoelectrode towards LDL molecules. This fabricated immunosensor allows quantitative estimation of LDL concentration with distinguishable variation in the impedance signal.


Assuntos
Técnicas Biossensoriais , Quitosana/química , Lipoproteínas LDL/isolamento & purificação , Nanotubos de Carbono/química , Eletroquímica , Humanos , Limite de Detecção , Espectroscopia de Infravermelho com Transformada de Fourier , Compostos de Estanho/química
4.
Phys Rev Lett ; 108(18): 186803, 2012 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-22681102

RESUMO

The sequence of prominent fractional quantum Hall states up to ν=5/11 around ν=1/2 in a high-mobility two-dimensional electron system confined at oxide heterointerface (ZnO) is analyzed in terms of the composite fermion model. The temperature dependence of R(xx) oscillations around ν=1/2 yields an estimation of the composite fermion effective mass, which increases linearly with the magnetic field. This mass is of similar value to an enhanced electron effective mass, which in itself arises from strong electron interaction. The energy gaps of fractional states and the temperature dependence of R(xx) at ν=1/2 point to large residual interactions between composite fermions.

5.
Bone Marrow Transplant ; 47(1): 95-100, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21358690

RESUMO

To evaluate the incidence and risk factors for secondary solid tumors in Japan after allogeneic hematopoietic SCT (allo-HSCT), 2062 patients who had received allo-HSCT between 1984 and 2005 were retrospectively analyzed. Twenty-eight patients who developed 30 solid tumors were identified a median of 5.6 years after transplantation. The risk for developing tumors was 2.16-fold higher than that of the age- and sex-adjusted general population. The cumulative incidence of solid tumors at 10 years after allo-HSCT was 2.4%. The risk was significantly higher for tumors of the skin, oral cavity and esophagus (standard incidental ratio 40.23, 35.25 and 10.73, respectively). No increase in gastric, colon or lung cancer, despite being the most prevalent neoplasm in the Japanese, was observed. In multivariate analysis, occurrence of chronic GVHD and malignant lymphoma as a primary disease was associated with a higher risk for developing solid tumors. Eighteen patients are still alive, and their 5-year probability of survival since diagnosis of solid tumors is 59.7%. Our data suggest that the incidence and risk factors of secondary solid tumors in Japanese allo-HSCT recipients are comparable to those reported in Western countries and emphasize that the early detection of solid tumors has a crucial role in improving OS.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Linfoma/epidemiologia , Linfoma/terapia , Segunda Neoplasia Primária/epidemiologia , Adolescente , Adulto , Idoso , Criança , Doença Crônica , Feminino , Doença Enxerto-Hospedeiro/epidemiologia , Humanos , Incidência , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Transplante Homólogo
6.
Bone Marrow Transplant ; 46(3): 379-84, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20577219

RESUMO

We retrospectively investigated air-leak syndrome (ALS), including pneumothorax and mediastinal/s.c. emphysema, following allogeneic hematopoietic SCT. Eighteen patients (1.2%) developed ALS among 1515 undergoing SCT between 1994 and 2005 at the nine hospitals participating in the Kanto Study Group on Cell Therapy. The median onset of ALS was at 575 days (range: 105-1766) after SCT and 14 patients (77.8%) had experienced late onset noninfectious pulmonary complications (LONIPC) before ALS. Chronic GVHD (cGVHD) was the strongest risk factor for ALS (odds ratio 13.5, P=0.013 by multivariate analysis). Repeat SCT, male sex and age <38 years at the time of transplantation were also significant risk factors for ALS. Patients with ALS had a significantly worse survival rate than those without ALS (61.5 vs 14.9% at 3 years; P=0.000). The main cause of death was respiratory complications in 8 of the 18 patients. In conclusion, ALS is a rare complication of SCT that is more likely to occur in relatively young male patients with cGVHD and/or LONIPC. It is possible that better understanding and treatment of LONIPC may lead to prevention of ALS.


Assuntos
Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Enfisema Mediastínico/etiologia , Pneumotórax/etiologia , Adolescente , Adulto , Feminino , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Condicionamento Pré-Transplante/efeitos adversos , Condicionamento Pré-Transplante/métodos , Adulto Jovem
7.
Phys Rev Lett ; 103(5): 057204, 2009 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-19792531

RESUMO

The anomalous Hall effect (AHE) has been studied for epitaxial films of Eu(1-x)La(x)TiO(3), in which band filling can be controlled by doping x without undesired changes in magnetization. This system has a simple band structure near the conduction band bottom, which makes it possible to design the AHE. As expected, the anomalous Hall resistivity shows a nonmonotonic change as a function of the carrier density accompanied with the sign reversal around n=2.4 x 10(20) cm(-3). This opens a possibility to control the AHE by devising the material, structure, and doping level.

8.
Nucleosides Nucleotides Nucleic Acids ; 23(8-9): 1127-9, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15571215

RESUMO

The liquid chromatography-mass spectrometry (LC-MS) following on from the two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) technique was applied for the analysis of proteins in a renal stone found in a hyperuricemic patient. This technique was sensitive enough to detect small quantities of proteins even in a renal stone.


Assuntos
Hiperuricemia/patologia , Cálculos Renais/metabolismo , Protrombina/biossíntese , Sialoglicoproteínas/biossíntese , Absorção , Sequência de Aminoácidos , Cromatografia Líquida/métodos , Eletroforese em Gel Bidimensional , Humanos , Masculino , Espectrometria de Massas/métodos , Pessoa de Meia-Idade , Dados de Sequência Molecular , Osteopontina , Protrombina/análise , Sialoglicoproteínas/análise , Espectrometria de Massas por Ionização por Electrospray
9.
Ther Apher ; 6(6): 413-8, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12460403

RESUMO

As a source of hematopoietic stem cells for transplantation, the use of peripheral blood stem cells (PBSCs) has become routine and comparable to that of the use of bone marrow. Recently, elderly patients with hematological malignancies also have been allowed to receive minitransplantations with nonmyeloablative conditioning regimens under sufficient PBSC infusion. As a result of these minitransplantations, elderly donors have been chosen increasingly from the siblings of elderly patients. We analyzed factors influencing the condition of CD34+ cells in the first days of collection in 49 healthy donors from July 1995 to January 2001. The median dose of recombinant human granulocyte colony-stimulating factor was 8 microg/kg/day (range 8 - 10) over 3 days. The target number of CD34+ cells used in this study was > or = 3 x 10(6) cells/kg of recipient body weight. The median apheresis volume was 12 L. Except for one 60 year old man, we obtained an adequate number of stem cells. In the regression analysis, a negative correlation was seen between donor age and the number of CD34+ cells/kg of recipient body weight per 12 L volume (Y = aX + b; a = -0.07507; b = 6.629996; r = -0.50985; p = 0.000252). Significantly higher apheresis results were obtained in donors younger than 45 years compared with donors 45 years old and older (p < 0.0227). There were no correlations among the number of CD34+ cells, donor body weight, and the number of leukocytes in peripheral blood on the first day of apheresis.


Assuntos
Remoção de Componentes Sanguíneos , Doadores de Sangue , Mobilização de Células-Tronco Hematopoéticas , Transplante de Células-Tronco de Sangue Periférico , Adolescente , Adulto , Fatores Etários , Antígenos CD34/análise , Criança , Feminino , Filgrastim , Citometria de Fluxo , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Humanos , Lenograstim , Contagem de Leucócitos , Masculino , Proteínas Recombinantes/administração & dosagem
10.
Acta Crystallogr B ; 57(Pt 4): 458-65, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11468371

RESUMO

The structure of pseudohexagonal-type InFe(1--x--4 delta)Ti(x+3 delta)O(3+x/2) (x = 0.61, delta = 0.04), indium iron titanium oxide, was refined on the basis of a four-dimensional superspace group. The crystal has a compositely modulated structure consisting of two orthorhombic subsystems mutually incommensurate in b. The first subsystem InFe(1-x-4 delta)Ti(x+3 delta)O(2) has a delafossite structure with lattice parameters a = 5.835 (3), b(1) = 3.349 (1) and c = 12.082 (7) A. The second subsystem with b(2) = 2.568 (6) A consists of O atoms. The superspace group of the overall structure is Ccmm(1, 1.305, 0)s00, which can be converted to Amam(0, 0, 0.305)0s0 (No. 63.8). Refinement on 1105 unique reflections converged to R = 0.0303 and wR = 0.0325 with 63 structural parameters. The structure of the first subsystem is the alternate stacking of an edge-shared InO(6) octahedral layer and an Fe/Ti triangle-lattice plane along c. A sheet of O atoms in the second subsystem is also extending on the Fe/Ti plane, where displacive modulation of atoms is prominent.

11.
Acta Crystallogr B ; 57(Pt 4): 449-57, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11468370

RESUMO

The crystal structure of a layered compound Sc(2)B(1.1)C(3.2), scandium boride carbide (M(r) = 140.43), has been re-refined as a commensurate composite crystal using 1795 single-crystal X-ray diffraction intensities with I > 2 sigma(I) collected by Shi, Leithe-Jasper, Bourgeois, Bando & Tanaka [(1999), J. Solid State Chem. 148, 442--449]. The crystal is composed of two layered subsystem structures, i.e. Sc--C--Sc sandwiches and graphite-like layers of the composition B(1/3)C(2/3). The structure refinement was performed in a five-dimensional formalism based on the trigonal superspace group P3m1(p00)(0p0)0m0. The unit cell and other crystal data are a = b = 3.387 (1), c = 6.703 (2) A, V = 66.59 (1) A(3), sigma(1) = (9/7 0 0), sigma(2) = (0 9/7 0), Z = 1, D(x) = 3.501 Mg m(-3). Two different three-dimensional sections through the superspace were analyzed, corresponding to two different superstructure models, one with P3m1 and the other with P3m1. A random distribution of B and C was assumed in the graphite-like layer and 41 structural parameters were introduced. R(F)/wR(F) were 0.0533/0.0482 and 0.0524/0.0476, respectively, for the first and second models. Although the difference between these R(F) or wR(F) values was too fine to exclude one of the models definitely, the advantages of using a superspace group were obvious. It not only brought about better convergence of refinement cycles by virtue of fewer parameters, but also gave an insight into the problem of symmetry of the superstructure.

12.
Anal Sci ; 17(2): 301-5, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11990545

RESUMO

As an attempt to elucidate the factor(s) responsible for the poor performance of a copper(II)-phthalocyanine aminopropylsilica gels (CU-PCSD) column for HPLC, the silanol and/or amino groups remaining on Cu-PCSD were endcapped with trimethylchlorosilane (TMCS) or N-trimethylsilylimidazole (TMSI). The trimethylsilylated Cu-PCS(D)S (Cu-PCSD-TMCS and -TMSI) were investigated concerning their performance as an HPLC-stationary phase in the separation of pi-electron-rich polyaromatic hydrocarbons (PAHs), such as mutagenic anthracene and pyrene. As a result, trimethylsilylation with TMSI, which reacts only with silanol-groups, was not effective to improve the column efficiency. In contrast, trimethylsilylation by TMCS, which reacts with both the silanol- and amino-groups, improved the theoretical plate numbers (N) for PAHs separation with the Cu-PCS(D) column, indicating that the low N values on the Cu-PCSD column were caused by electrostatic interactions between PAHs and the remaining amino-groups on Cu-PCS(D). Furthermore, the retention data of mutagenic heterocyclic amines (HCAs) indicated that the remaining amino groups interact with the polar groups of HCAs.

15.
Nitric Oxide ; 4(5): 505-15, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11020339

RESUMO

We have hypothesized that one aspect of the antitumor activity of curcumin (diferuloylmethane) during the promotion stage of mammary gland tumorigenesis may be linked to reduction of free radicals (Inano et al., Carcinogenesis, 20: 1011-1018, 1999). Nitric oxide (NO) has been found to inflict damage on important biomolecules, and the overproduction of NO in diseases may be implicated in carcinogenesis and tumor progression. We have reported that the presence of three isoforms of nitric oxide synthases (NOS) and NO generation in the mammary gland correlate with the mammary gland development and mammary carcinogenesis. We, therefore, investigated the inhibitory activity of curcumin for the production of NO in rat mammary glands by using an organ culture system to validate the effectiveness and usefulness of curcumin in the pathophysiology of the mammary gland. A diced mammary gland (approximately 3 mm cubes) from the inguinal part of a female Wistar-MS rat treated with estradiol and progesterone was cultured with 2 ml of 5% FCS/DMEM in the presence or absence of LPS (0.5 microg/ml) for 2-3 days. Curcumin ( approximately 100 microM) was added at the same time to the LPS-treated cultures. In some experiments, curcumin was added to the culture after the LPS had been washed out. The NO production was significantly increased (by almost 20-fold compared to the control) by the addition of LPS to the culture system. This enhancement of NO production by LPS was reduced to 76 and to 56% by addition of 30 and 100 microM curcumin, respectively, to the culture. When LPS was eliminated from the culture after prestimulation for 1 day, the production of NO by the mammary gland dropped off, although some NO was still detectable. Curcumin did not further inhibit the production of NO by the prestimulated mammary gland after the elimination of LPS from the culture. The inducible nitric oxide synthase (iNOS, 122 kDa) and endothelial nitric oxide synthase (eNOS, 152 kDa) isoforms were detected in the mammary gland extracts at the end of the organ culture. The quantity of iNOS was apparently increased in the gland treated with LPS, while the eNOS expression was clearly diminished. Curcumin (100 microM) obviously suppressed the iNOS expression in the mammary glands cultured with LPS, and a recovery in the eNOS expression was observed. On the other hand, curcumin exhibited scavenging activity for the NO released from N-ethyl-2-(1-ethyl-2-hydroxy-2-nitrosohydrazino)-ethanamine (NOC 12), a NO donor compound, in the coincubation mixture. These results indicate that curcumin has the ability to inhibit iNOS induction by LPS in the mammary gland and to scavenge NO radicals, which might explain, at least partly, its therapeutic properties in inflammation of the mammary gland.


Assuntos
Curcumina/farmacologia , Glândulas Mamárias Animais/efeitos dos fármacos , Glândulas Mamárias Animais/metabolismo , Óxido Nítrico/metabolismo , Animais , Antineoplásicos/farmacologia , Feminino , Sequestradores de Radicais Livres/farmacologia , Immunoblotting , Isoenzimas/metabolismo , Lipopolissacarídeos/farmacologia , Glândulas Mamárias Animais/enzimologia , Óxido Nítrico Sintase/metabolismo , Óxido Nítrico Sintase Tipo II , Compostos Nitrosos/metabolismo , Técnicas de Cultura de Órgãos , Ratos , Ratos Wistar
16.
Carcinogenesis ; 21(10): 1835-41, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11023541

RESUMO

This investigation evaluated the preventive effect of curcumin on radiation-induced tumor initiation in rat mammary glands. Fifty-four female rats were mated and then divided into two groups at day 11 of pregnancy. As the control group, 27 rats were fed a basal diet during the experimental period. As the experimental group, 27 rats were fed a diet containing 1% curcumin between day 11 of pregnancy and parturition (day 23 of pregnancy). All rats of both groups received whole body irradiation with 1.5 Gy gamma-rays from a (60)Co source at day 20 of pregnancy and were then implanted with a diethylstilbestrol pellet 1 month after weaning. A high incidence (70.3%) of mammary tumorigenesis was observed in the control group. The tumor incidence (18.5%) was significantly reduced in the rats fed curcumin during the initiation stage. The appearance of the first palpable tumor was delayed by 6 months in the curcumin-fed group and the average latent period until the appearance of mammary tumors was 2.5 months longer in the curcumin-fed group than in the control group. By histological examination, the proportion of adenocarcinoma (16.7%) in total tumors in the curcumin-fed rats was found to be decreased to half that (32.1%) in the control group. Compared with the control rats, the body weight of rats in the experimental group was decreased slightly by administration of the curcumin diet from day 11 of pregnancy, in spite of a similar intake of diet, but had recovered to the level of the control by the end of the experiment. At the time of irradiation, curcumin did not have any effect on organ weight or on the development and differentiation of mammary glands of pregnant rats. In addition, the serum concentrations of fatty acids, thiobarbituric acid-reactive substances and ovarian and pituitary hormones, except LH, remained at the control level. Also, no change in litter size and body weight of pups born from curcumin-fed rats indicated no toxicity of curcumin. These results suggest that curcumin does not have any side-effects and is an effective agent for chemoprevention acting at the radiation-induced initiation stage of mammary tumorigenesis.


Assuntos
Anticarcinógenos/uso terapêutico , Curcumina/uso terapêutico , Neoplasias Mamárias Experimentais/prevenção & controle , Neoplasias Induzidas por Radiação/prevenção & controle , Animais , Peso Corporal/efeitos dos fármacos , Peso Corporal/efeitos da radiação , Dieta , Estradiol/sangue , Ácidos Graxos/sangue , Feminino , Masculino , Glândulas Mamárias Animais/efeitos dos fármacos , Glândulas Mamárias Animais/patologia , Glândulas Mamárias Animais/efeitos da radiação , Neoplasias Mamárias Experimentais/etiologia , Gravidez , Progesterona/sangue , Ratos , Ratos Wistar , Receptores de Estrogênio/metabolismo , Irradiação Corporal Total/efeitos adversos
17.
Phys Rev Lett ; 84(17): 3942-5, 2000 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-11019245

RESUMO

To probe the nature of the even-fraction quantum Hall system, we have investigated the low-lying excitation spectrum by exact diagonalization for finite systems. We have found (i) a striking one-to-one correspondence (i.e., a shell structure) between the spectrum and those for free (composite) fermions, (ii) a surprisingly straight scaling plot for the excitation energy that gives a zero gap (metal) in the thermodynamic limit, (iii) the effective mass evaluated from the scaling becoming heavier for nu = 1/2,1/4,1/6, but (iv) some deviations from the single-mode or the Hartree-Fock composite fermion approximation.

18.
Int J Radiat Biol ; 76(8): 1113-20, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10947124

RESUMO

PURPOSE: This investigation evaluated the inhibitory effect of S-2-(3-aminopropylamino)-ethylphosphorothioic acid (WR-2721) against the initiation of mammary tumourigenesis by irradiation, and the antipromotion activity of tamoxifen in the development of radiation-initiated mammary tumours. MATERIALS AND METHODS: Lactating rats were injected with WR-2721 and then irradiated with gamma-rays (1.5 Gy) at day 21 of lactation. The rats were divided into three groups 1 month after irradiation and were implanted with a pellet either of cholesterol as an inert control, diethylstilbestrol (DES) as a tumour-promoting agent, or DES combined with tamoxifen. For the control experiments, non-irradiated and irradiated rats receiving saline instead of WR-2721 were treated with a pellet by the same procedures. RESULTS: The highest incidence (85%) for tumourigenesis of mammary glands was observed in the irradiated rats that had been previously injected with saline following treatment with DES Administration of WR-2721 prior to the irradiation significantly decreased the incidence of mammary tumours to 52.2%. The treatment with DES pellets combined with tamoxifen in the irradiated rats previously injected with saline also markedly suppressed the incidence of mammary tumours even further to 4.4%. Also, the development of mammary tumours was completely prevented in the rats treated with WR-2721 prior to irradiation and then implanted with DES pellets combined with tamoxifen. CONCLUSIONS: These results suggest that the administration of WR-2721 prior to irradiation has an inhibitory effect on the initiation phase, resulting in a partial reduction of mammary tumour development, and that the combination of WR-2721 at the initiation phase with tamoxifen at the promotion phase is quite effective in preventing mammary tumourigenesis induced by radiation.


Assuntos
Amifostina/administração & dosagem , Antineoplásicos Hormonais/administração & dosagem , Neoplasias Mamárias Experimentais/etiologia , Neoplasias Mamárias Experimentais/prevenção & controle , Neoplasias Induzidas por Radiação/prevenção & controle , Protetores contra Radiação/administração & dosagem , Tamoxifeno/administração & dosagem , Animais , Quimioterapia Combinada , Feminino , Ratos , Ratos Wistar
19.
Carcinogenesis ; 21(5): 1043-50, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10783331

RESUMO

Oral contraceptives are used among women worldwide, and radiation is being used increasingly for diagnosis or therapy. We have investigated the effects of contraceptive steroids on the risk of mammary tumors initiated by radiation. Virgin rats received whole-body irradiation with 2.6 Gy gamma-rays 1 month after the administration of low- or high-dose pellets of contraceptive steroids, such as 17alpha-ethinylestradiol (EE(2)) combined with 19-norethisterone (NET). The high-dose pellet was removed 1 month after irradiation, but administration of the low-dose pellet was continued for up to 1 year. The incidence (33.3%) of mammary tumors initiated with radiation was not modified by the long-term administration of the low-dose pellets. However, the incidence (58. 3%) was increased significantly by the irradiation during administration of the high-dose pellets, but no significant difference in the proportion of adenocarcinoma and fibroadenoma was observed. Meanwhile, parous rats were irradiated with 2.6 Gy gamma-rays at weaning, a period of greater susceptibility to radiation, and then were implanted with the low-dose pellets 1 month later. The highest incidence (90%) of mammary tumors was detected in the parous rats. The proportion of adenocarcinomas in the parous irradiated rats increased significantly on treatment with the low-dose pellets. The results suggest that administration of the high-dose pellets of EE(2)-NET, but not of the low-dose pellets, enhances susceptibility to the initiation by gamma-rays of mammary tumors in virgin rats, and that the low-dose pellets act as a tumor promoter in the mammary glands of parous rats irradiated at weaning.


Assuntos
Anticoncepcionais Orais Hormonais/efeitos adversos , Etinilestradiol/efeitos adversos , Neoplasias Mamárias Experimentais/induzido quimicamente , Noretindrona/efeitos adversos , Animais , Relação Dose-Resposta a Droga , Feminino , Humanos , Neoplasias Mamárias Experimentais/patologia , Hormônios Hipofisários/sangue , Ratos , Ratos Wistar
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