Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 201
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Public Health ; 224: 152-158, 2023 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-37797561

RESUMEN

OBJECTIVE: We aimed to determine how municipal subsidies for seasonal influenza vaccines for the elderly affected vaccination coverage and health outcomes and how responses to vaccine prices changed during the COVID-19 pandemic. STUDY DESIGN AND METHODS: This ecological study includes 1245 municipalities in Japan between 2019 and 2020. Fixed-effects regression analysis was performed to evaluate the effect of influenza vaccine cost subsidy for people aged 65 years or older on vaccination coverage, all-cause mortality, and influenza-related mortality. RESULTS: The vaccination rate increased when patients' copayments decreased, and reducing the copayment by 1000 Japanese Yen (JPY) was estimated to increase the vaccination rate by 6.3% (95% confidence interval [CI] 4.5-8.2%) in the adjusted model. When examining the additional effect of a zero price compared to a nearly zero price, we found that a zero price increased the immunization rate by 6.4% (95% CI 1.4-11.5%). The effect of copayment on the increase in vaccination coverage was significantly lower during the pandemic than in the pre-pandemic period. The municipal and prefectural analyses found no association between influenza vaccine copayments and all-cause, influenza, or pneumonia mortality. CONCLUSION: Cost subsidies and the zero-price effect were shown to increase vaccination coverage but were not associated with relevant mortality measures. Although the impact was attenuated under pandemic conditions, cost subsidy effectively increases the vaccination rate.

2.
Phys Rev Lett ; 126(6): 062501, 2021 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-33635678

RESUMEN

In an emulsion-counter hybrid experiment performed at J-PARC, a Ξ^{-} absorption event was observed which decayed into twin single-Λ hypernuclei. Kinematic calculations enabled a unique identification of the reaction process as Ξ^{-}+^{14}N→_{Λ}^{10}Be+_{Λ}^{5}He. For the binding energy of the Ξ^{-} hyperon in the Ξ^{-}-^{14}N system a value of 1.27±0.21 MeV was deduced. The energy level of Ξ^{-} is likely a nuclear 1p state which indicates a weak ΞN-ΛΛ coupling.

3.
J Eur Acad Dermatol Venereol ; 34(10): 2318-2329, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32173916

RESUMEN

BACKGROUND: Previous studies of guselkumab have demonstrated clinical benefits in patients with plaque-type psoriasis, generalized pustular psoriasis, erythrodermic psoriasis and palmoplantar pustulosis (PPP). OBJECTIVE: The aim of this exploratory analysis of a double-blind, multicenter, placebo-controlled, phase 3 study in Japanese patients with PPP was to evaluate the efficacy of guselkumab in the subset of patients with pustulotic arthro-osteitis (PAO). METHODS: Patients were randomized to receive guselkumab 100 or 200 mg at weeks 0, 4, 12 and every 8 weeks, or placebo with cross-over to guselkumab 100 or 200 mg at week 16 (placebo group). Efficacy endpoints were changes from baseline in magnetic resonance imaging (MRI) score, EuroQOL-5 dimensions (EQ-5D) index score, EQ-5D pain/discomfort dimension score and C-reactive protein (CRP, mg/L) level in all PAO patients through week 52. Data from both guselkumab groups were combined and presented as results for a single overall guselkumab group. RESULTS: Among 159 patients with PPP, 66 with PAO were randomized across treatment groups. For patients with MRI data for all regions assessed, the proportion of patients in the guselkumab group with PAO characterized as severe decreased from 23.8% (10/42) at baseline to 5.4% (2/42) at week 52. The mean (SD) change from baseline at week 52 in EQ-5D index score was 0.20 (0.17) among PPP patients with PAO and 0.15 (0.17) among those without PAO in the guselkumab group. Among all PAO patients, the proportions with an EQ-5D pain/discomfort dimension score of no or slight pain/discomfort in the guselkumab group increased from baseline to week 52 [33.3% (7/21) vs. 87.5% (35/40)]. The mean (SD) CRP levels decreased in all PAO patients in the guselkumab group at week 52 compared to baseline [-1.71 (8.16) mg/L]. CONCLUSION: Guselkumab treatment showed beneficial outcomes for PAO signs and symptoms in Japanese patients with PPP.


Asunto(s)
Osteítis , Psoriasis , Anticuerpos Monoclonales Humanizados , Método Doble Ciego , Humanos , Japón , Psoriasis/tratamiento farmacológico , Índice de Severidad de la Enfermedad
5.
J Evol Biol ; 28(3): 590-600, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25615872

RESUMEN

Floral scents are among the key signals used by pollinators to navigate to specific flowers. Thus, evolutionary changes in scents should have strong impacts on plant diversification, although scent-mediated plant speciation through pollinator shifts has rarely been demonstrated, despite being likely. To examine whether and how scent-mediated plant speciation may have occurred, we investigated the Asimitellaria plant lineage using multidisciplinary approaches including pollinator observations, chemical analyses of the floral scents, electroantennographic analyses and behavioural bioassays with the pollinators. We also performed phylogenetically independent contrast analyses of the pollinator/floral scent associations. First, we confirmed that the pairs of the sympatric, cross-fertile Asimitellaria species in three study sites consistently attract different pollinators, namely long-tongued and short-tongued fungus gnats. We also found that a stereoisomeric set of floral volatiles, the lilac aldehydes, could be responsible for the pollinator specificity. This is because the compounds consistently elicited responses in the antennae of the long-tongued fungus gnats and had contrasting effects on the two pollinators, that is triggering the nectaring behaviour of long-tongued fungus gnats while repelling short-tongued fungus gnats in a laboratory experiment. Moreover, we discovered that volatile composition repeatedly switched in Asimitellaria between species adapted to long-tongued and short-tongued fungus gnats. Collectively, our results support the idea that recurrent scent-mediated speciation has taken place in the Asimitellaria-fungus gnat system.


Asunto(s)
Flores/química , Polinización , Saxifragaceae/química , Animales , Antenas de Artrópodos/fisiología , Dípteros , Electrofisiología/métodos , Femenino , Masculino , Filogenia , Simpatría , Compuestos Orgánicos Volátiles/análisis , Compuestos Orgánicos Volátiles/química
6.
Immunogenetics ; 66(12): 737-42, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25186068

RESUMEN

The serum collectin mannose-binding lectin (MBL) plays a major role in innate immunity by activation of the lectin complement pathway or by acting as an opsonin. The serum levels of human and animal MBL are associated with susceptibility to a wide range of infections, and the variation of MBL in serum is genetically determined. In the chicken, 14 single nucleotide polymorphisms (SNPs) have so far been found in the MBL promoter region. In this study, the transcription activity of a 670-bp promoter region covering all 14 SNPs from the four MBL promoter alleles A1 to A4 was assessed using a dual-luciferase assay. Of the analysed alleles, A1 showed the highest transcription activity although this allele is frequently found in chickens with low MBL mRNA expression.


Asunto(s)
Alelos , Pollos/genética , Lectina de Unión a Manosa/genética , Regiones Promotoras Genéticas , Transcripción Genética , Animales , Expresión Génica , Orden Génico , Genes Reporteros , Lectina de Unión a Manosa/sangre , Polimorfismo de Nucleótido Simple
7.
Am J Transplant ; 13(7): 1655-64, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23750800

RESUMEN

The engineered Fc-nonbinding (crystallizable fragment-nonbinding) CD3 antibody has lower mitogenicity and a precise therapeutic window for disease remission in patients with type 1 diabetes. Before anti-CD3 can be considered for use in transplantation, the most effective timing of treatment relative to transplantation needs to be elucidated. In this study anti-CD3F(ab')2 fragments or saline were administered intravenously for 5 consecutive days (early: d1-3 or delayed: d3-7) to mice transplanted with a cardiac allograft (H2(b)-to-H2(k); d0). Survival of allografts was prolonged in mice treated with the early protocol (MST = 48 days), but most were rejected by d100. In contrast, in mice treated with the delayed protocol allografts continued to survive long term. The delayed protocol significantly inhibited donor alloreactivity at d30 as compared to the early protocol. A marked increase in Foxp3(+) T cells (50.3 ± 1.6%) infiltrating the allografts in mice treated with the delayed protocol was observed (p < 0.0001 vs. early (24.9 ± 2.1%)) at d10; a finding that was maintained in the accepted cardiac allografts at d100. We conclude that the timing of treatment with anti-CD3 therapy is critical for inducing long-term graft survival. Delaying administration effectively inhibits the alloreactivity and promotes the dominance of intragraft Foxp3(+) T cells allowing long-term graft acceptance.


Asunto(s)
Anticuerpos Monoclonales Humanizados/uso terapéutico , Complejo CD3/efectos de los fármacos , Linfocitos T CD4-Positivos/inmunología , Factores de Transcripción Forkhead/inmunología , Rechazo de Injerto/prevención & control , Supervivencia de Injerto/efectos de los fármacos , Trasplante de Corazón/inmunología , Proteínas Represoras/inmunología , Animales , Complejo CD3/inmunología , Linfocitos T CD4-Positivos/efectos de los fármacos , Linfocitos T CD4-Positivos/patología , Células Cultivadas , Modelos Animales de Enfermedad , Ensayo de Immunospot Ligado a Enzimas , Femenino , Citometría de Flujo , Estudios de Seguimiento , Factores de Transcripción Forkhead/efectos de los fármacos , Rechazo de Injerto/inmunología , Rechazo de Injerto/patología , Supervivencia de Injerto/inmunología , Trasplante de Corazón/patología , Inmunohistoquímica , Terapia de Inmunosupresión/métodos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Ratones Transgénicos , Proteínas Represoras/efectos de los fármacos , Factores de Tiempo , Trasplante Homólogo
9.
Tissue Antigens ; 76(4): 334-5, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20579314

RESUMEN

Human leukocyte antigen B-*15:180 is a B*08/B*15 recombinant allele similar to B*15:29 with substitutions positions at 97, 292, 538, 539.


Asunto(s)
Alelos , Antígenos HLA-B/genética , Proteínas Recombinantes/genética , Secuencia de Bases , Antígeno HLA-B15 , Humanos , Datos de Secuencia Molecular , Alineación de Secuencia
10.
Bull World Health Organ ; 88(11): 854-60, 2010 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-21076567

RESUMEN

OBJECTIVE: To determine whether a cash-for-work programme during the annual food insecurity period in Bangladesh improved nutritional status in poor rural women and children. METHODS: The panel study involved a random sample of 895 households from over 50,000 enrolled in a cash-for-work programme between September and December 2007 and 921 similar control households. The height, weight and mid-upper arm circumference of one woman and child aged less than 5 years from each household were measured at baseline and at the end of the study (mean time: 10 weeks). Women reported 7-day household food expenditure and consumption on both occasions. Changes in parameters were compared between the two groups. FINDINGS: At baseline, no significant difference existed between the groups. By the study end, the difference in mean mid-upper arm circumference between women in the intervention and control groups had widened by 2.29 mm and the difference in mean weight, by 0.88 kg. Among children, the difference in means between the two groups had also widened in favour of the intervention group for: height (0.08 cm; P<0.05), weight (0.22 kg; P<0.001), mid-upper arm circumference (1.41 mm; P<0.001) and z-scores for height-for-age (0.02; P<0.001), weight-for-age (0.17; P<0.001), weight-for-height (0.23; P<0.001) and mid-upper arm circumference (0.12; P<0.001). Intervention households spent more on food and consumed more protein-rich food at the end of the study. CONCLUSION: The cash-for-work programme led to greater household food expenditure and consumption and women's and children's nutritional status improved.


Asunto(s)
Conducta Alimentaria , Abastecimiento de Alimentos/estadística & datos numéricos , Estado Nutricional , Evaluación de Programas y Proyectos de Salud/economía , Recompensa , Población Rural/estadística & datos numéricos , Bangladesh , Índice de Masa Corporal , Niño , Protección a la Infancia/estadística & datos numéricos , Preescolar , Femenino , Abastecimiento de Alimentos/economía , Humanos , Masculino , Análisis Multivariante , Encuestas Nutricionales , Evaluación de Programas y Proyectos de Salud/estadística & datos numéricos , Análisis de Regresión , Bienestar Social/economía , Bienestar Social/estadística & datos numéricos , Salud de la Mujer
11.
Am J Transplant ; 9(8): 1732-41, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19519810

RESUMEN

Blockade of CD40-CD154 signaling pathway is an attractive strategy to induce potent immunosuppression and tolerance in organ transplantation. Due to its strong immunosuppressive effect shown in nonhuman primate experiments, anti-CD154 monoclonal antibodies (mAbs) have been tried in clinical settings, but it was interrupted by unexpected thromboembolic complications. Thus, inhibition of the counter molecule, CD40, has remained an alternative approach. In the previous preliminary study, we have shown that 4D11, a novel fully human anti-CD40 mAb, has a fairly potent immunosuppressive effect on kidney allograft in nonhuman primates. In this study, we aimed to confirm the efficacy and untoward events of the 2-week induction and 180-day maintenance 4D11 treatments. In both, 4D11 significantly suppressed T-cell-mediated alloimmune responses and prolonged allograft survival. Addition of weekly 4D11 administration after the induction treatment further enhanced graft survival. Complete inhibition of both donor-specific Ab and anti-4D11 Ab productions was obtained only with higher-dose maintenance therapy. No serious side effect including thromboembolic complications was noted except for a transient reduction of hematocrit in one animal, and decrease of peripheral B-cell counts in all. These results indicate that the 4D11 appears to be a promising candidate for immunosuppression in clinical organ transplantation.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Antígenos CD40/inmunología , Rechazo de Injerto/prevención & control , Trasplante de Riñón/inmunología , Animales , Anticuerpos Monoclonales/sangre , Anticuerpos Monoclonales/inmunología , Antígenos CD40/antagonistas & inhibidores , Ligando de CD40/antagonistas & inhibidores , Ligando de CD40/inmunología , Rechazo de Injerto/inmunología , Humanos , Terapia de Inmunosupresión , Inmunosupresores/uso terapéutico , Macaca fascicularis , Masculino , Modelos Animales , Transducción de Señal/inmunología
14.
Transplant Proc ; 51(3): 676-683, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30979450

RESUMEN

OBJECTIVES: Living donor kidney transplant relieves the disease burden of patients with end-stage renal disease but may shorten donor life expectancy; however, their quality of life (QOL) is preserved. Nevertheless, the magnitude of the net gain of this procedure is unknown. We evaluated the QOL of both donors and recipients concurrently and calculated the net utility gain. METHODS: We recruited 210 subjects who visited the kidney transplantation clinic of a university hospital. Subjects were asked to complete the 5-level EQ-5D-based questionnaire, and patient characteristics were extracted from their medical records. We performed multivariate tobit models analysis to evaluate the QOL change caused by transplant surgery and subsequently ran computational simulations to determine the net utility gains of donors and recipients. We also performed sensitivity analyses. RESULTS: After excluding 16 answers with missing data, we analyzed 203 answers in total. After the transplant surgery, recipients gained 0.07 in utility value while donors lost 0.04. In the net utility analysis, we found that the quality-adjusted life years gained ranged from 7.2 to 7.8 in the most favorable case observed in the combination of middle-aged recipients and elderly donors. Assuming no utility discount, the most favorable combination was that with older donors and younger recipients. CONCLUSIONS: These findings indicated that the QOL improvement in recipients was larger than the loss among donors. When calculating the net utilities, a combination of middle-aged recipients and elderly donors yielded the largest net utility, but this was likely derived from assumption in the discount of QOL.


Asunto(s)
Trasplante de Riñón/métodos , Trasplante de Riñón/psicología , Donadores Vivos/psicología , Calidad de Vida , Adulto , Anciano , Femenino , Humanos , Fallo Renal Crónico/epidemiología , Fallo Renal Crónico/etiología , Masculino , Persona de Mediana Edad , Encuestas y Cuestionarios , Obtención de Tejidos y Órganos
15.
Am J Transplant ; 8(1): 250-2, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18093277

RESUMEN

In order to obviate a small-for-size graft syndrome (SFSGS), a portacaval (PC) shunt had been considered in a case of adult-to-adult living donor liver transplantation (AA-LDLT). In a recent AA-LDLT case, we adopted the PC shunt to resolve SFSGS; however, graft atrophy was observed in the late period of LDLT, thereby resulting in liver dysfunction. Due to the surgical closure of the PC shunt at 11 months post-LDLT, the graft regenerated gradually and resulted in the recovery of the liver function. This experience indicates that the portacaval shunt would overcome SFSGS in the early period of LDLT, while it would cause the graft atrophy and the graft dysfunction in the late period of LDLT.


Asunto(s)
Trasplante de Hígado , Hígado/patología , Donadores Vivos , Derivación Portocava Quirúrgica , Adulto , Atrofia , Femenino , Humanos , Hígado/fisiopatología , Pruebas de Función Hepática , Trasplante de Hígado/efectos adversos , Trasplante de Hígado/patología , Masculino , Tamaño de los Órganos , Derivación Portocava Quirúrgica/efectos adversos , Síndrome
16.
Eur J Surg Oncol ; 33(6): 783-9, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17408910

RESUMEN

AIMS: To determine whether prostate cancer screening strategies with re-screening interval determined by individual baseline prostate-specific antigen values are cost-effective. METHODS: Based on the results of an actual contemporary screening program, we established Markov decision analytic models of prostate cancer screening with personalized re-screening interval strategies using cutoff baseline PSA levels for biennial screening as well as a model of uniformly annual or biennial screening. These strategies were compared in terms of cumulative incidence of early cancer and cost-effectiveness. RESULTS: Early cancer detection rates were similar among all strategies. Personalized strategies were more cost-effective compared to uniform screening strategies. If all participants with negative PSA results uniformly omit annual screening, it would be more costly but less effective (dominated). Contrary, annual screening for all participants would cost too much. These results were robust throughout sensitivity analysis incorporating every assumption in the models. CONCLUSIONS: This study adds important evidence that personalized rescreening strategies based on individual baseline PSA have advantages of cost-effectiveness against conventional uniform strategies.


Asunto(s)
Tamizaje Masivo/estadística & datos numéricos , Antígeno Prostático Específico/análisis , Neoplasias de la Próstata/diagnóstico , Anciano , Análisis Costo-Beneficio , Técnicas de Apoyo para la Decisión , Árboles de Decisión , Diagnóstico Precoz , Humanos , Masculino , Cadenas de Markov , Tamizaje Masivo/economía , Persona de Mediana Edad , Neoplasias de la Próstata/economía , Años de Vida Ajustados por Calidad de Vida , Sensibilidad y Especificidad , Factores de Tiempo
17.
J Mass Spectrom ; 52(2): 78-93, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-27935159

RESUMEN

Correct sequences are prerequisite for quality control of therapeutic oligonucleotides. However, there is no definitive method available for determining sequences of highly modified therapeutic RNAs, and thereby, most of the oligonucleotides have been used clinically without direct sequence determination. In this study, we developed a novel sequencing method called 'hydrophobic tag sequencing'. Highly modified oligonucleotides are sequenced by partially digesting oligonucleotides conjugated with a 5'-hydrophobic tag, followed by liquid chromatography-mass spectrometry analysis. 5'-Hydrophobic tag-printed fragments (5'-tag degradates) can be separated in order of their molecular masses from tag-free oligonucleotides by reversed-phase liquid chromatography. As models for the sequencing, the anti-VEGF aptamer (Macugen) and the highly modified 38-mer RNA sequences were analyzed under blind conditions. Most nucleotides were identified from the molecular weight of hydrophobic 5'-tag degradates calculated from monoisotopic mass in simple full mass data. When monoisotopic mass could not be assigned, the nucleotide was estimated using the molecular weight of the most abundant mass. The sequences of Macugen and 38-mer RNA perfectly matched the theoretical sequences. The hydrophobic tag sequencing worked well to obtain simple full mass data, resulting in accurate and clear sequencing. The present study provides for the first time a de novo sequencing technology for highly modified RNAs and contributes to quality control of therapeutic oligonucleotides. Copyright © 2016 John Wiley & Sons, Ltd.


Asunto(s)
Oligonucleótidos/análisis , Aptámeros de Nucleótidos/análisis , Secuencia de Bases , Cromatografía Líquida de Alta Presión , Cromatografía de Fase Inversa , Interacciones Hidrofóbicas e Hidrofílicas , Peso Molecular , Espectrometría de Masa por Ionización de Electrospray , Factor A de Crecimiento Endotelial Vascular/antagonistas & inhibidores
18.
Cancer Res ; 42(8): 3142-7, 1982 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-7046918

RESUMEN

A monoclonal antibody, F11, was produced against a tumor-associated antigen from the spent medium of the M14 human malignant melanoma cell line which was grown continuously in serum-free medium. Ouchterlony double-diffusion study revealed that the F11 monoclonal antibody is an immunoglobulin G1. The F11 monoclonal antibody reacted positively with seven of eight (88%) melanoma, five of five (100%) carcinoma, zero to five normal, and zero of two lymphoblastoid cell lines by indirect immunofluorescence test. Also, by indirect immunofluorescence test, F11 monoclonal antibody reacted with cryostat sections from four of five (80%) melanomas, six of seven (86%) carcinomas, zero of one benign nevus, and zero of two benign breast diseases. By the indirect avidin:biotin:peroxidase complex immunoperoxidase method, the F11 monoclonal antibody reacted positively with cryostat sections from five of five (100%) melanomas, five of five (100%) breast cancers, two of two (100%) colon cancers, zero of one benign nevus, and zero of one Hodgkin's disease spleen. Thus, the tumor-associated antigen that the F11 monoclonal antibody recognizes appears to be expressed by melanomas and carcinomas, hence the designation melanoma-carcinoma-associated antigen. Microscopic observations disclosed that the melanoma-carcinoma-associated antigen is present in the cytoplasm, on the membrane of melanoma and carcinoma cells, and in the lumen of glandular structures of breast and colon carcinomas. The molecular weight of the melanoma-carcinoma-associated antigen in spent medium from the M14 CEM cell line is 100,000 as determined by sodium dodecyl sulfate:polyacrylamide gel electrophoretic analysis of indirect immunoprecipitates obtained with the F11 monoclonal antibody.


Asunto(s)
Anticuerpos Monoclonales , Antígenos de Neoplasias/aislamiento & purificación , Carcinoma/inmunología , Melanoma/inmunología , Animales , Línea Celular , Medios de Cultivo , Técnica del Anticuerpo Fluorescente , Humanos , Hibridomas/inmunología , Técnicas para Inmunoenzimas , Linfocitos/inmunología , Ratones , Ratones Endogámicos BALB C , Peso Molecular
19.
Biochim Biophys Acta ; 1107(1): 61-9, 1992 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-1616926

RESUMEN

A study of the effects of alkyl glycosides incorporated into synthetic liposomes with respect to their stability, their in vivo distribution in Ehrlich solid tumor-bearing mice and their in vitro interaction with liver cells was undertaken. The synthetic liposomes were prepared from N,N-didodecyl-N alpha-[6-(trimethylammonio)hexanoyl]-L-alaninamide bromide (N+C5Ala2C12) and labeled with 99mTc. n-Dodecyl glucoside (DG) and n-dodecyl sucrose (DS) were used as alkyl glycosides. The stability was hardly changed by incorporation of alkyl glycosides into the liposomes in saline and serum. The uptake of DG- and DS-modified N+C5Ala2C12 liposomes decreased in liver and spleen compared with that of unmodified N+C5Ala2C12 liposomes, resulting in an increase in blood and other tissues such as tumor, duodenum and kidney, where the DS-modified N+C5Ala2C12 liposomes had a marked tendency. It was observed with electron micrographs that the size of N+C5Ala2C12 liposomes became small by incorporation of alkyl glycoside. The smaller N+C5Ala2C12 liposomes were found to result in the lower uptake in liver. The interaction of the liposomes with liver cells in vitro indicated that both DG- and DS-modified liposomes had a low affinity for liver cells compared with the unmodified liposomes and the extent of interaction of the DS-modified liposomes was weaker than that of the DG-modified liposomes.


Asunto(s)
Carcinoma de Ehrlich/metabolismo , Glicósidos/farmacocinética , Liposomas/farmacocinética , Alquilación , Animales , Células Cultivadas , Portadores de Fármacos , Glucósidos/metabolismo , Cinética , Hígado/citología , Hígado/metabolismo , Masculino , Ratones , Sistema Mononuclear Fagocítico/metabolismo , Cloruro de Sodio , Sacarosa/metabolismo , Distribución Tisular
20.
Free Radic Biol Med ; 22(6): 1029-35, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-9034242

RESUMEN

The functional changes in macrophages (Mphi) following exposure to a high dose (6 Gy) of gamma-rays in vitro were investigated. Resident peritoneal Mphi obtained from C57BL/6 mice were irradiated with gamma-rays (137Cs, 0.3 Gy/min). High-dose irradiation enhanced nitric oxide (NO) production from Mphi treated with interferon-gamma and their cytotoxic activity. The enhancement of NO production by irradiation was attributed to high levels of expression of the inducible nitric oxide synthase. Furthermore, the participation of reactive oxygen intermediates in NO production was examined. Nitric oxide production was not enhanced by treatment with the membrane-oxidizing agent tert-butyl hydroperoxide or the hypoxanthine/xanthine oxidase superoxide (O2.-)-generating system. On the other hand, NO production was enhanced by treatment with a low dose of hydrogen peroxide (H2O2), which can diffuse passively through the cell membrane and can be converted into hydroxyl radicals (HO.) that cause DNA breaks. In addition, treatment with low-dose actinomycin D, which induces DNA strand breaks, enhanced NO production, but hydroxyurea, which stops DNA replication without DNA strand breaks, had no such effect. These findings suggest that DNA strand breaks caused by hydroxyl radicals formed inside the cells by gamma-irradiation, or strand breaks caused directly by radiation, plays an important role in the enhancement of NO production, but peroxidation of cell membranes has little effect.


Asunto(s)
Macrófagos Peritoneales/metabolismo , Macrófagos Peritoneales/efectos de la radiación , Óxido Nítrico/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Animales , Citotoxicidad Inmunológica , Inducción Enzimática , Rayos gamma , Peróxido de Hidrógeno/farmacología , Interferón gamma/farmacología , Leucemia L1210 , Lipopolisacáridos/farmacología , Macrófagos Peritoneales/efectos de los fármacos , Sarcoma de Mastocitos , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Óxido Nítrico Sintasa/biosíntesis
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA