Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 371
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
J Insect Sci ; 14: 110, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25205015

RESUMEN

Non-native plant species can provide native generalist insects, including pests, with novel food and habitats. It is hypothesized that local and landscape-level abundances of non-native plants can affect the population size of generalist insects, although generalists are assumed to be less sensitive to habitat connectivity than specialists. In a heterogeneous landscape in Japan, the relationship between the density of a native pest of rice (Stenotus rubrovittatus (Matsumura) (Heteroptera: Miridae)) and the abundance of Italian ryegrass (Lolium multiflorum Lam. (Poales: Poaceae)), a non-native meadow grass known to facilitate S. rubrovittatus, was analyzed. Statistical analyses of data on bug density, vegetation, and the spatial distribution of fallow fields and meadows dominated by Italian ryegrass, obtained by field surveys, demonstrated that local and landscape-level abundances of Italian ryegrass (the unmowed meadow areas within a few hundred meters of a sampling plot) positively affected bug density before its immigration into rice fields. Our findings suggest that a generalist herbivorous insect that prefers non-native plants responds to spatial availability and connectivity of plant species patches at the metapopulation level. Fragmentation by selective mowing that decreases the total area of source populations and increases the isolation among them would be an effective and environmentally-friendly pest management method.


Asunto(s)
Heterópteros/fisiología , Interacciones Huésped-Parásitos , Lolium/parasitología , Oryza/parasitología , Animales , Ecosistema , Herbivoria , Japón , Dinámica Poblacional
2.
Allergy ; 66(3): 428-33, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21083568

RESUMEN

BACKGROUND: The pathogenesis of chronic spontaneous urticaria (CU) has recently been conceived to be associated with thrombin generation through the extrinsic coagulation pathway. However, little is known about the components of the intrinsic coagulation pathway potentially involved. METHODS: To investigate the whole process of coagulation, both classical coagulation assays and a global coagulation test, the intrinsic coagulation pathway-dependent activated partial thromboplastin time (APTT) clot waveform analysis, were performed using plasma of 36 patients with CU who had various severities. RESULTS: Classical coagulation assays revealed that levels of fibrinogen, D-dimer, and fibrin and fibrinogen degradation products (FDP), and positive rates of soluble fibrin monomer complex (SFMC) were significantly elevated in patients with CU, whereas the elevation of prothrombin fragment 1 + 2 was not statistically significant. On the other hand, all parameters of a global coagulation test, APTT clot waveform analysis, evidently showed a hypercoagulable pattern and were significantly correlated to disease severity of CU. CONCLUSIONS: CU is characterized by elevated blood coagulation potential with involvement of the intrinsic coagulation factors, which may contribute in vivo to the generation of fibrin even by small amounts of thrombin.


Asunto(s)
Coagulación Sanguínea , Urticaria/sangre , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Pruebas de Coagulación Sanguínea , Estudios de Casos y Controles , Niño , Enfermedad Crónica , Humanos , Persona de Mediana Edad , Adulto Joven
3.
Haemophilia ; 17(5): 771-6, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21682824

RESUMEN

Studies conducted in European and North American countries have demonstrated that various factors including races affect the frequency of inhibitor formation in haemophilia patients. The present study was undertaken to analyse factors affecting the incidence of inhibitor formation in Japanese haemophilia A and B patients. Analytical data were retrospectively collected from haemophilia A and B patients born after 1988, the year when monoclonal antibody-purified factor VIII products were first marketed in Japan. Various data were collected from 184 patients (153 cases of haemophilia A; 31 cases of haemophilia B). The sample size of haemophilia B cases was too small to reveal any significant differences between the inhibitor formation group and the inhibitor-free group in any of background variables. For patients with haemophilia A, on the other hand, univariate analysis identified the severity of haemophilia and a positive family history of inhibitor development as risk factors for the formation of inhibitors. In analyses of the clotting factor products used, the incidence of inhibitor formation did not differ significantly between the group treated with plasma-derived products (29.7%) and the group treated with recombinant products (25.0%). When background variables were compared, age was higher in the group treated with plasma-derived products but none of the other background variables differed between the two groups. These results suggest that in Japanese haemophilia patients, the type of clotting factor preparations used for therapy has not influenced the incidence of inhibitor formation.


Asunto(s)
Coagulantes/inmunología , Factor IX/inmunología , Factor VIII/inmunología , Hemofilia A/inmunología , Hemofilia B/inmunología , Isoanticuerpos/inmunología , Adolescente , Adulto , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/uso terapéutico , Niño , Preescolar , Coagulantes/uso terapéutico , Factor IX/uso terapéutico , Factor VIII/uso terapéutico , Femenino , Hemofilia A/tratamiento farmacológico , Hemofilia B/tratamiento farmacológico , Humanos , Japón , Masculino , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/uso terapéutico , Estudios Retrospectivos , Factores de Riesgo , Adulto Joven
5.
Artículo en Inglés | MEDLINE | ID: mdl-18361106

RESUMEN

A 10-day-old male neonate was admitted with bilious vomiting and gross hematochezia. Peripheral eosinophilia, delayed positive skin prick test to artificial milk, and elevated eosinophil cationic protein levels suggested cow's milk allergy. Fluid infusion with prohibition of oral intake improved the digestive symptoms. Breast-feeding was resumed on hospital day 3 and only casein hydrolysate formula was fed from day 7 onward. Nevertheless, eosinophilia and elevated transaminase levels developed on day 14. Liver dysfunction associated with casein hydrolysate formula was suspected and the infant was transferred to soy formula. Eosinophil counts decreased and transaminase levels were normalized on day 19. A cow's milk protein-specific lymphocyte proliferation test was positive for alpha-casein, beta-lactoglobulin, and bovine serum albumin, indicating sensitization of T cells to cow's milk proteins. These observations suggest that careful attention should be paid to liver dysfunction in non-immunoglobulin E-mediated cow's milk allergy, even when hypoallergenic formula is used.


Asunto(s)
Fórmulas Infantiles , Hepatopatías/etiología , Hipersensibilidad a la Leche/complicaciones , Caseínas/efectos adversos , Eosinofilia/etiología , Humanos , Inmunoglobulina E/sangre , Recién Nacido , Masculino
6.
J Clin Invest ; 87(5): 1862-6, 1991 May.
Artículo en Inglés | MEDLINE | ID: mdl-2022752

RESUMEN

Branched chain alpha-ketoacid dehydrogenase (BCKDH) deficiency results in maple syrup urine disease (MSUD). We examined the molecular basis of familial cases of MSUD by analyzing the activity, subunit structure, mRNA sequence, and genome structure of the affected enzyme. The BCKDH activity in the proband with MSUD was approximately 6% of the normal control level. Immunoblot analysis revealed that the E1 beta subunit of BCKDH was absent and that the E1 alpha subunit of BCKDH was markedly reduced. We amplified the cDNAs of the E1 alpha subunit and the E1 beta subunit of the BCKDH complex obtained from cells of the patient, using the polymerase chain reaction method, then sequenced the amplified cDNAs. The deduced amino acid sequence for the E1 alpha subunit of the patient's cell was normal. An 11-bp deletion was identified in the region that encoded the mitochondrial targeting leader peptide in the E1 beta cDNA. This 11-bp sequence is found in the first exon of the BCKDH-E1 beta gene, as a direct tandem repeat. Amplification of genomic DNA revealed that the consanguineous parents were heterozygous for this mutant allele, and sister and brother of the patient with the disease were homozygous for this mutant allele. This 11-bp deletion mutation caused a change in the reading frame and the mature E1 beta protein was defective. These observations show the biological importance of the E1 beta subunit of BCKDH to maintain normal function of the enzyme activity. The absence of the E1 beta subunit results in instability of the E1 alpha subunit.


Asunto(s)
Deleción Cromosómica , Cetona Oxidorreductasas/genética , Enfermedad de la Orina de Jarabe de Arce/genética , Complejos Multienzimáticos/genética , Señales de Clasificación de Proteína/genética , 3-Metil-2-Oxobutanoato Deshidrogenasa (Lipoamida) , Secuencia de Bases , ADN/análisis , Femenino , Humanos , Immunoblotting , Masculino , Datos de Secuencia Molecular , Mutación , ARN Mensajero/análisis
7.
J Clin Invest ; 92(3): 1555-8, 1993 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8376606

RESUMEN

Platelets exposed to shear stress aggregate in the absence of exogenously added agonists, utilizing distinct platelet membrane receptors and ligands depending upon the level of shear stress applied. Using a modified cone and plate type viscometer, we previously demonstrated that, under low shear stress (18 dyn/cm2), aggregation is mediated by platelet membrane glycoprotein (GP) IIb-IIIa and fibrinogen, whereas aggregation induced by high shear stress (108 dyn/cm2) requires the binding of von Willebrand factor (vWF) to both GPIb-IX and GPIIb-IIIa (Ikeda, Y., M. Handa, K. Kawano, T. Kamata, M. Murata, Y. Araki, H. Anbo, Y. Kawai, K. Watanabe, I. Itagaki, et al. 1991. J. Clin. Invest. 87:1234-1240). Here we report that vWF-dependent aggregation occurs under low shear stress in citrated platelet-rich plasma (PRP) from two types of congenital bleeding disorders, platelet-type von Willebrand disease (vWD) and type IIB vWD, in both of which ristocetin-induced aggregation is known to be heightened. Aggregation induced by low shear stress was enhanced in both types of disorders compared to normal controls, and the enhancement was completely abolished by anti-vWF monoclonal antibody NMC-4, which blocks the GPIb-binding site on vWF. Under high shear stress, the extent of maximal aggregation was not different between controls and the patient groups although maximal aggregation was reached much more quickly in the latter. When citrated PRP was exposed to a gradient of shear stress (6 to 108 dyn/cm2 over a 5-min period), vWF-dependent aggregation, as judged from the inhibitory effect of NMC-4, first occurred at 14 dyn/cm2 in platelet-type vWD and at 10-12 dyn/cm2 in type IIB vWD, as compared with more than 81 +/- 20.1 dyn/cm2 in control platelets. These results suggest that an abnormality in either vWF or GPIb-IX triggers the aggregation-inducing interaction of the two molecules under low shear stress, which might explain the intravascular platelet clumping, that presumably underlies the thrombocytopenia observed in these bleeding disorders.


Asunto(s)
Agregación Plaquetaria , Enfermedades de von Willebrand/sangre , Factor de von Willebrand/metabolismo , Humanos , Reología , Estrés Mecánico , Enfermedades de von Willebrand/clasificación
8.
J Thromb Haemost ; 4(6): 1354-60, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16706982

RESUMEN

Factor (F)V is converted into its active form, FVa, by limited proteolysis. Thrombin-catalyzed activation of FV is essential for its full cofactor activation. Previously, we reported that thrombin was bound to the C2 domain in the light chain of FVIII. As FV has a similar domain structure to FVIII, we focused on the FV C2 domain as a possible binding region for thrombin. Kinetic parameters, measured by surface plasmon resonance, revealed that the K(d) values of anhydro-thrombin for FV, FVa, and the FV C2 domain were 66, 240, and 670 nmol L(-1), respectively. FV activation was increased by approximately 9-fold by the addition of thrombin. In the presence of the FV C2 domain, this increase of the FV activation was inhibited. However, FV activation was not inhibited by the addition of the FVIII C2 domain. FV was cleaved into a 105-kDa heavy chain and a 71/74-kDa light chain by thrombin-catalyzed proteolysis at Arg709, Arg1018 and Arg1545. In the presence of the FV C2 domain, the cleavage was inhibited at all sites. Proteolysis was not affected by the addition of the FVIII C2 domain. These results indicated that the FV C2 domain contains a major binding site for thrombin and that this domain is necessary for the proteolysis at all cleavage sites. Furthermore, the present results also suggested that thrombin has an independent binding site for FV different from that for FVIII.


Asunto(s)
Factor VIII/metabolismo , Factor V/química , Factor V/metabolismo , Factor Va/metabolismo , Trombina/metabolismo , Unión Competitiva , Factor VIII/química , Factor Va/química , Humanos , Cinética , Unión Proteica , Estructura Terciaria de Proteína , Resonancia por Plasmón de Superficie
9.
J Thromb Haemost ; 4(2): 377-84, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16420569

RESUMEN

BACKGROUND: Precise assessment of clotting function is essential for monitoring of hemostatic treatment for hemophilias A and B. MATERIALS AND METHODS: Clot waveform analysis and thrombin generation assays were performed on factor (F) VIII- and FIX-deficient plasmas, which had been reconstituted with known amounts of recombinant FVIII (rFVIII) and affinity-purified FIX respectively. Clot waveforms were assessed qualitatively and quantitatively by measuring the parameters clotting time, maximum coagulation velocity (Min1), and maximum coagulation acceleration (Min2). The thrombin generation assay was also assessed qualitatively and measurements made of time to peak and peak height. RESULTS: Overall results obtained with both assays showed good correlation for both clotting factors confirming that the changes in clotting waveform reflected changes in thrombin generation. Both assays demonstrated a predictable dose response to the addition of FVIII or IX. However, clot waveform analysis was more sensitive than the thrombin generation assay, particularly in detecting very low levels (0-0.1 IU dL(-1)) of both factors. CONCLUSIONS: These data suggest that the application of clot waveform analysis to the routine management of the hemophiliacs could increase our understanding of the clinical significance of low levels of FVIII and FIX that cannot be measured by assays in current use. This may be particularly useful in the management of hemophiliacs with inhibitors or undergoing gene therapy.


Asunto(s)
Pruebas de Coagulación Sanguínea/métodos , Factor IX/análisis , Factor VIII/análisis , Hemofilia A/sangre , Hemofilia B/sangre , Biometría , Pruebas de Coagulación Sanguínea/estadística & datos numéricos , Factor IX/administración & dosificación , Factor VIII/administración & dosificación , Hemofilia A/tratamiento farmacológico , Hemofilia B/tratamiento farmacológico , Humanos , Técnicas In Vitro , Masculino , Tiempo de Tromboplastina Parcial/métodos , Tiempo de Tromboplastina Parcial/estadística & datos numéricos , Proteínas Recombinantes/administración & dosificación , Sensibilidad y Especificidad , Tiempo de Trombina/métodos , Tiempo de Trombina/estadística & datos numéricos
10.
Int J Hematol ; 84(2): 158-65, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16926139

RESUMEN

The safety and efficacy of Kogenate, a recombinant factor VIII (rFVIII) preparation for the treatment of bleeding episodes, were studied in a 123-patient meta-analysis population of previously treated patients (PTPs), including 15 enrolled in the registration Phase III trial (PTP-I group), 93 from the post-marketing special investigation (PTP-II group), and 15 from short-term special investigations in surgery or tooth extraction (SI group). These patients (82 severe, 31 moderate, 9 mild, and 1 unknown), aged 11 months to 72 years, were enrolled in 28 centers in Japan. Blood samples taken at the baseline and at 3, 6, 9, 12, 18, and 24 months after the introduction of Kogenate were evaluated for FVIII inhibitor antibodies, antibodies formed against trace proteins derived from the rFVIII production process, and for general changes in laboratory test results. Mean exposure to Kogenate was 1103 days in PTP-I, 86 days in PTP-II, 27 days in patients in surgery, and 2 days in patients with tooth extraction. Assessment of FVIII inhibitor activity was conducted in 115 of the 123 patients by means of the Bethesda assay. Twelve patients were found to have a low titer of FVIII inhibitor (0.5-3.0 BU/mL) prior to any administration of Kogenate, and 103 were inhibitor-negative at the baseline. Among this latter group, 3 patients (2.9%) tested inhibitor-positive, with titers ranging from 1.2 to 2.1 BU/mL, with 4 patients below 1.0 BU/mL. One patient in the 11 PTPs investigated (PTP-I) developed antibodies against baby hamster kidney protein and mouse immunoglobulin G, but these findings were transient and asymptomatic. Hemostasis was achieved (markedly effective or effective) in 3666 of the 3855 bleeding episodes (95.1%) observed in 108 patients. Only 1 infusion was necessary in 3790 (98.3%) of these episodes. These data indicate that Kogenate is safe and very effective for the treatment of bleeding in PTPs with hemophilia A.


Asunto(s)
Contaminación de Medicamentos , Factor VIII/efectos adversos , Hemofilia A/sangre , Hemorragia/sangre , Adolescente , Adulto , Anciano , Animales , Autoanticuerpos/sangre , Autoanticuerpos/inmunología , Inhibidores de Factor de Coagulación Sanguínea/sangre , Inhibidores de Factor de Coagulación Sanguínea/inmunología , Niño , Preescolar , Ensayos Clínicos Fase II como Asunto , Ensayos Clínicos Fase III como Asunto , Cricetinae , Perros , Factor VIII/administración & dosificación , Factor VIII/inmunología , Estudios de Seguimiento , Hemofilia A/tratamiento farmacológico , Hemofilia A/inmunología , Hemorragia/tratamiento farmacológico , Hemorragia/inmunología , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Lactante , Persona de Mediana Edad , Factores de Tiempo
11.
Cancer Res ; 45(11 Pt 2): 5867-71, 1985 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-4053057

RESUMEN

3-Hydroxyamino-1-methyl-5H-pyrido[4,3-b]indole (N-OH-Trp-P-2) is a direct-acting mutagenic compound derived by metabolic activation from 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), a strongly mutagenic carcinogen. The action of N-OH-Trp-P-2 on DNA in vitro was investigated. N-OH-Trp-P-2 inactivated Bacillus subtilis transforming DNA and produced single-strand cuts in a supercoiled circular DNA (phi X174RFI) under neutral conditions. When mouse FM3A cells in culture were treated with a noncytotoxic dose of N-OH-Trp-P-2 and then the cellular DNA was examined by the alkaline elution technique, chain cleavages of the DNA were observed. Cysteamine inhibited the spontaneous degradation of N-OH-Trp-P-2 and enhanced the covalent binding of [3H]N-OH-Trp-P-2 to DNA. This finding offered an explanation for the previously observed enhancement of Trp-P-2 mutagenicity by cysteamine. In contrast cysteamine inhibited the N-OH-Trp-P-2-mediated inactivation of B. subtilis DNA as well as the strand cleavage in phi X174RFI DNA. The cleavage in phi X174RFI DNA was also inhibited by catalase. These observations indicate that the mutagenicity and DNA-cleaving activity of N-OH-Trp-P-2 are distinct from each other, that the inactivation of transforming DNA was caused mainly by strand cleavage, and that the DNA cleavage was probably caused by active oxygen radicals produced in the oxidative degradation of N-OH-Trp-P-2.


Asunto(s)
Carbolinas/toxicidad , ADN , Mutágenos , Animales , Carbolinas/metabolismo , Carcinógenos/metabolismo , ADN/metabolismo , Ratones
12.
Cancer Res ; 49(4): 915-9, 1989 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-2563234

RESUMEN

The mechanism of the cytotoxic action of 2-chlorodeoxyadenosine in mouse FM3A cells was investigated. Imbalance of the dNTP pools occurred within 3 h of treatment with 20 microM 2-chlorodeoxyadenosine; the dATP and dGTP pools were depleted and the dTTP pool increased. 2-Chlorodeoxyadenosine added to the culture medium broke mature DNA strands, giving fragments of 100-200 kilobase pairs as found by orthogonal-field-alternation gel electrophoresis. DNA strand breaks, measured by this technique, were observed in the treated cells about 12 h after the addition. The cells also lost viability at about 12 h. Breaks in the single and double strands of DNA, as measured by alkaline and neutral filter elution, became evident 18 h after treatment with 20 microM 2-chlorodeoxyadenosine; there were as many single-strand breaks as would be caused by 130 rads of gamma-ray irradiation. Double-strand breaks were equivalent to those caused by 2180 rads of gamma-ray irradiation. Comparison of the ratio of single- and double-strand breaks caused by 2-chlorodeoxyadenosine to that following radiation suggested that 2-chlorodeoxyadenosine broke only double strands. Cycloheximide inhibited the breakage of DNA double strands and the cell death caused by this compound. Flow cytometric studies of cytostasis brought about by 2-chlorodeoxyadenosine in FM3A cells showed that cells accumulated in the earlier part of the S phase. 2-Chlorodeoxyadenosine decreased DNA synthesis more than RNA or protein synthesis. The breaks in double strands of DNA were probably important in the cell death caused by 2-chlorodeoxyadenosine. The intracellular dNTP imbalance may trigger these events.


Asunto(s)
Supervivencia Celular/efectos de los fármacos , Daño del ADN , Desoxiadenosinas/análogos & derivados , Desoxirribonucleótidos/metabolismo , Animales , Línea Celular , Cladribina , Cicloheximida/farmacología , Desoxiadenosinas/farmacología , Cinética , Ratones
13.
Biochim Biophys Acta ; 883(2): 277-83, 1986 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-3091080

RESUMEN

The location of ferrochelatase in bovine heart mitochondria has been studied. When the mitochondria were fractionated into Complexes I, II and III, ferrochelatase activity was only found in Complex I. Complex I also showed heme synthesis from ferric ion in the presence of NADH as an electron donor. Immunoblot experiments confirmed the presence of ferrochelatase in Complex I, but not in Complexes II or III. Some phospholipids, including phosphatidylserine and cardiolipin, stimulated NADH-dependent heme synthesis from ferric ion. When purified ferrochelatase was incubated with the low molecular weight form of NADH dehydrogenase prepared from Complex I, heme synthesis from ferric ion occurred by the addition of NADH. FMN markedly elevated the synthesis. These results indicate that ferrous ion is produced by NADH oxidation in Complex I and is then utilized for heme synthesis by ferrochelatase.


Asunto(s)
Ferroquelatasa/metabolismo , Liasas/metabolismo , Mitocondrias Cardíacas/enzimología , Quinona Reductasas/metabolismo , Animales , Cardiolipinas/metabolismo , Bovinos , Mononucleótido de Flavina/farmacología , Hemo/biosíntesis , Técnicas de Inmunoadsorción , NAD/metabolismo , NAD(P)H Deshidrogenasa (Quinona) , Oxidación-Reducción , Fosfatidilserinas/metabolismo
14.
Biochim Biophys Acta ; 1544(1-2): 267-77, 2001 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-11341935

RESUMEN

L-Amino acid oxidase (LAO, EC 1.4.3.2) is widely distributed in snake venom, and induces apoptosis in vascular endothelial cells, causing prolonged bleeding from vessel walls at bite sites. The effect of snake venom LAOs on platelet function is controversial. Further, we have little information on their structural characterization. We purified M (mamushi)-LAO, a single-chain glycoprotein with a molecular mass of 60 kDa and a pI of 4.9, from Agkistrodon halys blomhoffii (Japanese mamushi) venom, and determined the N-terminal and several internal amino acid sequences of this enzyme. Molecular cloning based on these data was conducted to elucidate its full-length cDNA structure (2192 nucleotides), which includes a putative 18 amino acid residue signal peptide and a 504 residue mature subunit. The predicted M-LAO translation product shares 87.3% identity with that of Crotalus adamanteus (Southeastern diamondback rattlesnake) LAO. M-LAO, up to a final concentration of 2.6 microM, inhibited both agonist- and shear stress-induced platelet aggregation (SIPA) dose-dependently. In agonist-induced platelet aggregation, M-LAO predominantly inhibited the second aggregation, but with a marginal inhibition of the first. In SIPA, the inhibition was more dramatic under low-shear stress than high-shear stress, and was enhanced by the presence of L-leucine, a substrate of this enzyme. Catalase, a H2O2 scavenger, totally quenched such enhancement. These results suggest that M-LAO inhibits the interaction between activated platelet integrin alphaIIb/beta3 and fibrinogen through the continuous generation of H2O2, and may contribute to prolonged bleeding from the vessels at snake bite sites.


Asunto(s)
Aminoácido Oxidorreductasas/química , Inhibidores de Agregación Plaquetaria/química , Agkistrodon , Aminoácido Oxidorreductasas/genética , Secuencia de Aminoácidos , Animales , ADN Complementario , Humanos , L-Aminoácido Oxidasa , Datos de Secuencia Molecular , Agregación Plaquetaria/efectos de los fármacos , Conformación Proteica , Homología de Secuencia de Aminoácido
15.
Clin Nephrol ; 64(5): 329-36, 2005 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-16312259

RESUMEN

AIM: Thin basement membrane disease (TBMD) is characterized histologically by diffuse thinning of glomerular basement membrane (GBM). Although recent genetic analysis has shown that TBMD might be included within type IV collagen disorders, conventional immunohistochemical studies demonstrated normal labeling of type IV collagen alpha chains in the GBM. We have, however, successfully used confocal laser scanning microscopy to demonstrate a significantly reduced signal of type IV collagen alpha5 chain (alpha5(IV)) along capillary walls in TBMD. In order to further understand the association of type IV collagen with TBMD, we used immunoelectron microscopy to examine renal biopsies from 6 children with TBMD and six control children with minimal change nephrotic syndrome. METHODS: Ultrathin sections of LR gold resin were incubated with a rat monoclonal antibody against human alpha1(IV), alpha2(IV), alpha3(IV), alpha4(IV) alpha5(IV) or alpha6(IV) followed by colloidal gold conjugated goat anti-rat IgG. After taking electron micrographs, the labeling was quantitatively evaluated in the area occupied by the segments of basement membrane. The basement membrane was divided into three equal segments viz. subepithelial side, central portion and subendothelial side. RESULTS: In control subjects, the number of gold particles for alpha1(IV) or alpha2(IV) was significantly greater in the subendothelial side and central portion than in the subepithelial side of the GBM, whilst alpha3(IV), alpha4(IV) or alpha5(IV) labeling was significantly more prominent in the central portion compared to the subepithelial and subendothelial side of the GBM. TBMD samples showed a similar distribution pattern except that the subepithelial side and central portion of the GBM had a significantly reduced amount of alpha5(IV) antigen compared to control subjects. CONCLUSION: This is the first report demonstrating a diminished labeling intensity of alpha5(IV) in the central portion and subepithelial side of the GBM in renal biopsy specimens from patients with TBMD. These findings suggest that an abnormality of alpha5(IV) might possibly be associated with the pathogenesis of TBMD.


Asunto(s)
Colágeno Tipo IV/análisis , Membrana Basal Glomerular/química , Enfermedades Renales/patología , Adolescente , Niño , Femenino , Humanos , Enfermedades Renales/genética , Masculino , Microscopía Inmunoelectrónica , Linaje
16.
Transplant Proc ; 37(2): 1131-3, 2005 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15848646

RESUMEN

Metabolic liver disease can be cured by orthotopic liver transplantation. Some successful cases of whole or partial liver transplantation have been reported. Because liver function in these recipients is normal save for the production of the responsive metabolic factor, auxiliary partial orthotopic liver transplantation (APOLT) may produce a benefit. However, no experimental model of APOLT for metabolic liver diseases has been reported. We established a canine APOLT model to evaluate the clinical feasibility and efficacy of APOLT to cure hemophilia. The donor normal beagle dog was used to establish an APOLT model. A left lobe partial liver graft taken from the donor was orthotopically transplanted to the recipient after resection of the native left lobe preserving the native right lobe. Recipients showed no atrophy and comparable blood flow in both the graft and the native liver at the time of exploration after APOLT. Thus, APOLT was performed from a normal donor to a recipient with hemophilia A. In this recipient, blood factor VIII activity markedly increased after APOLT and was maintained for 7 weeks. No episode of bleeding was seen during the observation. In conclusion, a canine APOLT model was successfully established as evidenced by sustained production of factor VIII in a hemophilia recipient. These findings suggest the clinical feasibility and efficacy of APOLT for metabolic liver diseases.


Asunto(s)
Factor VIII/análisis , Hemofilia A/cirugía , Trasplante de Hígado/métodos , Animales , Bilirrubina/sangre , Biomarcadores/sangre , Modelos Animales de Enfermedad , Perros , Estudios de Factibilidad , Supervivencia de Injerto , Trasplante de Hígado/fisiología , Masculino , Trasplante Homólogo
17.
J Invest Dermatol ; 86(4): 449-53, 1986 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-3755739

RESUMEN

The relative antioxidant efficacy, in vitro, of several antibiotics was examined by studying their effects on the generation of reactive oxygen species (ROS) using zymosan-stimulated polymorphonuclear leukocytes (PMNL) and the cell-free, xanthine-xanthine oxidase system. The species investigated are superoxide radical anion (O2-.), hydrogen peroxide (H2O2), and hydroxyl radical (OH.). Three tetracyclines (tetracycline HCl, oxytetracycline HCl, and minocycline HCl), erythromycin, cephalexin, penicillin G, chloramphenicol, and streptomycin were used as test drugs. At concentrations comparable to therapeutic blood levels, tetracycline HCl, oxytetracycline HCl, minocycline HCl, and erythromycin inhibited some of the ROS production by PMNL. In the xanthine-xanthine oxidase system, only minocycline HCl suppressed the H2O2 level. Cephalexin, penicillin G, chloramphenicol, and streptomycin did not affect any of the ROS examined at the concentrations tested. The capacity of some of these agents to inhibit ROS generation by PMNL may account, in part, for their efficacy in inflammatory skin diseases such as acne vulgaris. The antioxidant effect of these antibiotics does not stem from their capability to scavenge ROS, but originates rather from their effect on PMNL cell function directly with resultant anti-inflammatory effects on the inflammatory processes.


Asunto(s)
Antioxidantes/farmacología , Neutrófilos/efectos de los fármacos , Oxígeno/biosíntesis , Tetraciclinas/farmacología , Radicales Libres , Humanos , Técnicas In Vitro , Minociclina/farmacología , Neutrófilos/metabolismo , Oxitetraciclina/farmacología , Tetraciclina/farmacología , Xantina Oxidasa , Xantinas
18.
J Invest Dermatol ; 111(6): 1189-92, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9856838

RESUMEN

IgG antibodies to a cleavage product of alpha-fodrin (120 kDa alpha-fodrin) have recently been identified as organ-specific autoantibodies in primary Sjögren's syndrome. In this study, we examined seroreactivity of mothers and infants with neonatal lupus erythematosus (NLE) to a recombinant NH2-terminal protein (120 kDa alpha-fodrin) of human alpha-fodrin. Serum samples were collected during the perinatal period in seven pregnancies of five mothers delivering offspring with NLE. Anti-120 kDa alpha-fodrin antibodies were identified by immunoblotting in six of seven perinatal maternal sera of offspring with NLE: one of two congenital heart block offspring and all five offspring with cutaneous NLE. These antibodies were placentally transmitted to infants. One of the five mothers had primary Sjögren's syndrome, and four were asymptomatic. One asymptomatic mother did not demonstrate anti-120 kDa alpha-fodrin activity at the time of the first delivery of a congenital heart block infant, but was found to be positive at the time of subsequent delivery of a second child with cutaneous NLE. We propose that maternal antibodies to 120 kDa alpha-fodrin may be an additional serologic marker for the risk of NLE in anti-Ro/SS-A positive women.


Asunto(s)
Lupus Eritematoso Sistémico/inmunología , Autoanticuerpos/sangre , Autoantígenos/aislamiento & purificación , Sitios de Unión de Anticuerpos , Proteínas Portadoras/genética , Proteínas Portadoras/inmunología , ADN Complementario/genética , Femenino , Humanos , Inmunoglobulina G/inmunología , Recién Nacido , Lupus Eritematoso Cutáneo/inmunología , Proteínas de Microfilamentos/genética , Proteínas de Microfilamentos/inmunología , Madres , Proteínas Recombinantes/inmunología , Síndrome de Sjögren/inmunología
19.
J Invest Dermatol ; 108(6): 881-5, 1997 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9182815

RESUMEN

Neonatal lupus erythematosus (NLE) is an antibody-mediated disorder of infants characterized by two major clinical manifestations; cutaneous lupus lesions and congenital heart block (CHB). The disease is associated with placentally transferred maternal anti-Ro/SSA and/or La/SSB antibodies. There is a tendency for the same disease expression to occur within a sibship. To reveal a possible association of class II MHC genes with maternal anti-Ro/SSA autoimmune responses and neonatal outcomes in NLE with a relatively homogeneous ethnic background, haplotype, and allele distributions were analyzed based on the PCR-RFLP results in 26 Japanese anti-Ro/SSA-positive mothers from three groups defined by neonatal outcomes. The results were as follows: (i) maternal HLA-DR5 haplotype DRB1*1101-DQA1*0501-DQB1*0301 and individual class II alleles making up this haplotype were significantly associated with neonatal cutaneous lupus but not CHB. Conversely, maternal HLA-DQB1*0602 carried on HLA-DR2 haplotypes was associated with CHB but not cutaneous NLE; (ii) HLA-DQA1 alleles with glutamine at position 34 of the first domain, which have reportedly been associated with the autoimmune responses to Ro/SSA antigens in other ethnic groups, were increased in the mothers of infants with cutaneous involvement; and (iii) there was no particular class II HLA profile that distinguished the disease manifestations in infants. These findings suggest that specific maternal MHC class II genes might correlate with specific neonatal outcomes in NLE.


Asunto(s)
Anticuerpos Antinucleares/análisis , Antígenos HLA-DQ/análisis , Antígenos HLA-DR/análisis , Lupus Eritematoso Cutáneo/inmunología , Resultado del Embarazo , Embarazo/inmunología , Adulto , Alelos , Aminoácidos/análisis , Anticuerpos Antinucleares/sangre , Autoinmunidad , Causalidad , Femenino , Frecuencia de los Genes , Antígenos HLA-DQ/genética , Antígenos HLA-DR/genética , Haplotipos , Bloqueo Cardíaco/congénito , Bloqueo Cardíaco/epidemiología , Bloqueo Cardíaco/inmunología , Humanos , Incidencia , Recién Nacido , Lupus Eritematoso Cutáneo/epidemiología , Lupus Eritematoso Cutáneo/patología , Intercambio Materno-Fetal , Persona de Mediana Edad , Piel/química , Piel/patología
20.
Arch Neurol ; 58(11): 1914-8, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11709003

RESUMEN

OBJECTIVE: To report a case of familial amyloid polyneuropathy homozygous for the amyloidogenic transthyretin (ATTR) Val30Met gene with motor-dominant sensorimotor polyneuropathy and unusual sural nerve pathological findings. METHODS: Mass spectrometry analysis and polymerase chain reaction-restricting fragment length polymorphism were performed. A right sural nerve biopsy specimen was obtained for histological investigation. SETTING: Academic medical center. RESULTS: A 56-year-old Japanese man living in a local town (Nakajima, Japan) in Ishikawa Prefecture, a nonendemic area of type I familial amyloidotic polyneuropathy, had vitreous amyloidosis, motor-dominant sensorimotor polyneuropathy, erectile dysfunction, and urinary incontinence. He had neither orthostatic hypotension nor indolent diarrhea. Restriction enzyme analysis with EcoT22 I of amplified DNA and mass spectrometry analysis revealed homozygosity for ATTR Val30Met. Of 8 family members, 5 were evaluated and found to be heterozygous for ATTR Val30Met; a family history found no relative with the similar neurologic disorders. The sural nerve biopsy specimen showed focal edema and an amyloid deposit in the subperineural tissue, associated with moderate loss of myelinated and unmyelinated fibers. CONCLUSIONS: In addition to the findings characteristic of homozygosity for ATTR Val30Met such as vitreous amyloidosis and relatively less autonomic involvements, this case had the unique findings of motor-dominant sensorimotor polyneuropathy and unusual sural nerve biopsy specimen results.


Asunto(s)
Neuropatías Amiloides Familiares/genética , Prealbúmina/genética , Nervio Sural/patología , Neuropatías Amiloides Familiares/patología , Humanos , Masculino , Espectrometría de Masas , Persona de Mediana Edad , Linaje , Reacción en Cadena de la Polimerasa
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA