RESUMEN
The accessory subunit of mitochondrial DNA polymerase gamma, POLGbeta, functions as a processivity factor in vitro. Here we show POLGbeta has additional roles in mitochondrial DNA metabolism. Mitochondrial DNA is arranged in nucleoprotein complexes, or nucleoids, which often contain multiple copies of the mitochondrial genome. Gene-silencing of POLGbeta increased nucleoid numbers, whereas over-expression of POLGbeta reduced the number and increased the size of mitochondrial nucleoids. Both increased and decreased expression of POLGbeta altered nucleoid structure and precipitated a marked decrease in 7S DNA molecules, which form short displacement-loops on mitochondrial DNA. Recombinant POLGbeta preferentially bound to plasmids with a short displacement-loop, in contrast to POLGalpha. These findings support the view that the mitochondrial D-loop acts as a protein recruitment centre, and suggest POLGbeta is a key factor in the organization of mitochondrial DNA in multigenomic nucleoprotein complexes.
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ADN Mitocondrial/metabolismo , ADN Polimerasa Dirigida por ADN/metabolismo , Subunidades de Proteína/metabolismo , Línea Celular Tumoral , ADN Polimerasa gamma , ADN Mitocondrial/análisis , ADN Mitocondrial/química , ADN Polimerasa Dirigida por ADN/genética , Humanos , Mitocondrias/enzimología , Mitocondrias/ultraestructura , Inhibidores de la Síntesis del Ácido Nucleico , Nucleoproteínas/metabolismo , Plásmidos/química , Subunidades de Proteína/antagonistas & inhibidores , Subunidades de Proteína/genética , Interferencia de ARNRESUMEN
Elongin A is a transcription elongation factor that increases the overall rate of mRNA chain elongation by RNA polymerase II. To gain more insight into the physiological functions of Elongin A, we generated Elongin A-deficient mice. Elongin A homozygous mutant (Elongin A(-/-)) embryos demonstrated a severely retarded development and died at between days 10.5 and 12.5 of gestation, most likely due to extensive apoptosis. Moreover, mouse embryonic fibroblasts (MEFs) derived from Elongin A(-/-) embryos exhibited not only increased apoptosis but also senescence-like growth defects accompanied by the activation of p38 MAPK and p53. Knockdown of Elongin A in MEFs by RNA interference also dramatically induced the senescent phenotype. A study using inhibitors of p38 MAPK and p53 and the generation of Elongin A-deficient mice with p53-null background suggests that both the p38 MAPK and p53 pathways are responsible for the induction of senescence-like phenotypes, whereas additional signaling pathways appear to be involved in the mediation of apoptosis in Elongin A(-/-) cells. Taken together, our results suggest that Elongin A is required for the transcription of genes essential for early embryonic development and downregulation of its activity is tightly associated with cellular senescence.
Asunto(s)
Apoptosis/genética , Senescencia Celular/genética , Factores de Transcripción/genética , Factores de Elongación Transcripcional/genética , Factores de Elongación Transcripcional/metabolismo , Animales , Elonguina , Femenino , Muerte Fetal/genética , Feto/anomalías , Fibroblastos/citología , Regulación del Desarrollo de la Expresión Génica/genética , Inmunohistoquímica , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Embarazo , Proteína p53 Supresora de Tumor/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
Point mutations in mitochondrial tRNA genes are responsible for individual subgroups of mitochondrial encephalomyopathies. We have recently reported that point mutations in the tRNA(Leu)(UUR) and tRNA(Lys) genes cause a defect in the normal modification at the first nucleotide of the anticodon. As part of a systematic analysis of pathogenic mutant mitochondrial tRNAs, we purified tRNA(Ile) with a point mutation at nucleotide 4269 to determine its nucleotide sequence, including modified nucleotides. We found that, instead of causing a defect in the post-transcriptional modification, a pathogenic point mutation in the mitochondrial tRNA(Ile) reduced the stability of the mutant tRNA molecule, resulting in a low steady-state level of aminoacyl-tRNA. The reduced stability was confirmed by examining the life-span of the mutant tRNA(Ile) both in vitro and in vivo, as well as by monitoring its melting profile. Our finding indicates that the mutant tRNA(Ile) itself is intrinsically unstable.
Asunto(s)
Mitocondrias/genética , Mitocondrias/patología , Encefalomiopatías Mitocondriales/genética , Mutación Puntual/genética , Estabilidad del ARN , ARN de Transferencia de Isoleucina/genética , Acilación , Anticodón/genética , Secuencia de Bases , Extractos Celulares , Etidio/farmacología , Semivida , Células HeLa , Humanos , Mitocondrias/efectos de los fármacos , Encefalomiopatías Mitocondriales/patología , Datos de Secuencia Molecular , Desnaturalización de Ácido Nucleico , Procesamiento Postranscripcional del ARN , ARN de Transferencia de Isoleucina/biosíntesis , ARN de Transferencia de Isoleucina/metabolismo , Análisis de Secuencia de ARN , Temperatura , Transcripción Genética/efectos de los fármacosRESUMEN
It has been found that insulin-like growth factor I (IGF-I) exerts cytoprotection against Abeta amyloid-induced neuronal cell death. Deposits of Abeta amyloid are one of the pathological hallmarks of Alzheimer's disease (AD). Here, we examined whether IGF-I exerts protective activity against cell death induced by a familial AD (FAD)-linked mutant of amyloid precursor protein (APP), and we found that IGF-I protected cells from toxicity of FAD-associated V642I mutant of APP in multiple cell systems. IGFBP-3 blocked this action of IGF-I, but not of des(1-3)IGF-I, which was as active as IGF-I in the presence of IGFBP-3. The data also demonstrated that the IGF-I receptor (IGF-IR) mediates the protective activity of IGF-I. The antagonizing function of the IGF-I/IGF-IR system against V642I-APP, which is further antagonized by IGFBP-3, provides a molecular clue to the understanding of AD pathophysiology and to the establishment of potential therapy for AD.
Asunto(s)
Precursor de Proteína beta-Amiloide/metabolismo , Apoptosis/efectos de los fármacos , Factor I del Crecimiento Similar a la Insulina/metabolismo , Receptor IGF Tipo 1/metabolismo , Sustitución de Aminoácidos , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/farmacología , Animales , Anticuerpos/farmacología , Línea Celular , Relación Dosis-Respuesta a Droga , Humanos , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/metabolismo , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/farmacología , Factor I del Crecimiento Similar a la Insulina/antagonistas & inhibidores , Factor I del Crecimiento Similar a la Insulina/farmacología , Ratones , Mutagénesis Sitio-Dirigida , Fragmentos de Péptidos/farmacología , Unión Proteica/efectos de los fármacos , Unión Proteica/fisiología , ARN Mensajero/metabolismo , Receptor IGF Tipo 1/antagonistas & inhibidores , Receptor IGF Tipo 1/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Linfocitos T/citología , Linfocitos T/metabolismo , TransfecciónRESUMEN
Using a yeast two-hybrid method, we searched for amyloid precursor protein (APP)-interacting molecules by screening mouse and human brain libraries. In addition to known interacting proteins containing a phosphotyrosine-interaction-domain (PID)-Fe65, Fe65L, Fe65L2, X11, and mDab1, we identified, as a novel APP-interacting molecule, a PID-containing isoform of mouse JNK-interacting protein-1 (JIP-1b) and its human homolog IB1, the established scaffold proteins for JNK. The APP amino acids Tyr(682), Asn(684), and Tyr(687) in the G(681)YENPTY(687) region were all essential for APP/JIP-1b interaction, but neither Tyr(653) nor Thr(668) was necessary. APP-interacting ability was specific for this additional isoform containing PID and was shared by both human and mouse homologs. JIP-1b expressed by mammalian cells was efficiently precipitated by the cytoplasmic domain of APP in the extreme Gly(681)-Asn(695) domain-dependent manner. Reciprocally, both full-length wild-type and familial Alzheimer's disease mutant APPs were precipitated by PID-containing JIP constructs. Antibodies raised against the N and C termini of JIP-1b coprecipitated JIP-1b and wild-type or mutant APP in non-neuronal and neuronal cells. Moreover, human JNK1beta1 formed a complex with APP in a JIP-1b-dependent manner. Confocal microscopic examination demonstrated that APP and JIP-1b share similar subcellular localization in transfected cells. These data indicate that JIP-1b/IB1 scaffolds APP with JNK, providing a novel insight into the role of the JNK scaffold protein as an interface of APP with intracellular functional molecules.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales , Enfermedad de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Proteínas Portadoras/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Proteínas Nucleares/metabolismo , Transactivadores/metabolismo , Secuencias de Aminoácidos/fisiología , Sustitución de Aminoácidos , Animales , Encéfalo/metabolismo , Proteínas Portadoras/genética , Biblioteca de Genes , Humanos , Proteínas Quinasas JNK Activadas por Mitógenos , Ratones , Ratones Endogámicos ICR , Mutagénesis Sitio-Dirigida , Proteínas del Tejido Nervioso/metabolismo , Proteínas Nucleares/genética , Fosfotirosina/metabolismo , Unión Proteica/fisiología , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Estructura Terciaria de Proteína/genética , Estructura Terciaria de Proteína/fisiología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Relación Estructura-Actividad , Transactivadores/genética , Técnicas del Sistema de Dos HíbridosRESUMEN
Permeation of several redox species through a cell membrane of a single algal protoplast (radius 100 microns) was investigated by amperometry with a Pt microdisk electrode (disk radius, 6.5 microns) located near the membrane. The redox current observed at the microelectrode decreased as the microelectrode approached the cell membrane since the membrane acted as a barrier for diffusion of redox species from bulk to the microelectrode. Permeability coefficient (Pm) of the protoplast membrane was determined by the quantitative analysis of the variation of the redox current with microelectrode-membrane distance using digital simulation. The Pm values for Fe(CN)6(4-), Fe(CN)6(3-), Co(phen)3(2+), ferrocenyl methanol(FMA) and p-hydroquinone(QH2) were < or = 1.0 x 10(-4), < or = 1.0 x 10(-4), 1.0 x 10(-3), 5.0 x 10(-3) and 2.0 x 10(-2) cm/s, respectively. Using these Pm values, the concentration changes inside a model cell and chloroplast were theoretically calculated.
Asunto(s)
Permeabilidad de la Membrana Celular , Chlorophyta , Electrofisiología , Microelectrodos , Oxidación-Reducción , ProtoplastosRESUMEN
PURPOSE: The majority of lung carcinoma patients requiring resection have smoking habits prior to surgical treatment, and the correlation of smoking with postoperative complications is well known. However, few studies have investigated the correlation between long-term survival and cigarette smoking in patients with primary, resected lung carcinoma. We analyzed the relationship between clinical factors, including cigarette smoking before surgery, and 10-year survival in stage I non-small-cell lung carcinoma (NSCLC). PATIENTS AND METHODS: Cigarette smoking habit and other factors influencing either the overall survival or the disease-specific survival rates of patients with stage I primary, resected NSCLC were evaluated according to the Cox proportional hazards model using a total of 369 patients with stage I-NSCLC. RESULTS: Comparison of the cause of death in patients with 30 or more pack-years and patients with less than 30 pack-years showed significant differences in the prevalence of recurrent disease and onset of nonmalignant disease. Multivariate analysis demonstrated significant correlations between overall survival and age and pack-years. Disease-specific survival showed significant correlations with age, tumor classification, and visceral pleural invasion. CONCLUSION: Smoking pack-years is an important clinical prognostic factor in evaluating overall long-term survival in patients with stage I primary, resected NSCLC.
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Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Neoplasias Pulmonares/mortalidad , Fumar/efectos adversos , Anciano , Anciano de 80 o más Años , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico , Carcinoma de Pulmón de Células no Pequeñas/cirugía , Femenino , Humanos , Japón/epidemiología , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/cirugía , Masculino , Persona de Mediana Edad , Análisis Multivariante , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Fumar/mortalidad , Tasa de SupervivenciaRESUMEN
Elevated expression levels of matrix metalloproteinase (MMP)-2 and MMP-9 have been implicated as playing important roles in tumor invasion and metastasis in various tissues. We investigated the relationship between circulating plasma MMP-9, its expression in tumor samples, and other clinical features in patients with non-small cell lung cancer (NSCLC). A series of 73 patients (45 men and 28 women) who underwent surgery for NSCLC was used in this study. Preoperative plasma concentrations of MMP-9 were examined using a one-step sandwich enzyme immunoassay. Expression levels of MMP-2, MMP-9, tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 were measured in 24 tumor samples by immunohistochemistry. The plasma concentration of MMP-9 in NSCLC patients (71.0 +/- 60.2 ng/ml) was significantly elevated compared to that of healthy volunteers (P < 0.0001). MMP-9 concentrations were elevated in 33 of 73 cases (45.2%), compared with a cutoff value of the mean +/- 2 SD in healthy volunteers. There were statistically significant differences in MMP-9 concentration in adenocarcinoma versus squamous cell carcinoma (P = 0.014) and adenocarcinoma versus large cell carcinoma (P = 0.014). Five of 24 patients (20.8%) had positive immunohistochemical MMP staining of the tumor cell cytoplasm, and two cases had positive staining in the surrounding stromal cells. Plasma MMP-9 concentrations were elevated in 45.2% of NSCLC patients; however, this elevation did not seem to correlate with MMP-9 production by cancer and stromal cells. We concluded that the MMP-9 ELISA could be a beneficial adjunct for assessing the tumor burden of NSCLC, especially for types of squamous cell carcinoma and large cell carcinoma.
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/enzimología , Colagenasas/sangre , Neoplasias Pulmonares/enzimología , Anciano , Anciano de 80 o más Años , Colagenasas/metabolismo , Femenino , Gelatinasas/sangre , Gelatinasas/metabolismo , Humanos , Técnicas para Inmunoenzimas , Inmunohistoquímica , Masculino , Metaloproteinasa 2 de la Matriz , Metaloproteinasa 9 de la Matriz , Metaloendopeptidasas/sangre , Metaloendopeptidasas/metabolismo , Persona de Mediana Edad , Inhibidor Tisular de Metaloproteinasa-1/sangre , Inhibidor Tisular de Metaloproteinasa-1/metabolismo , Inhibidor Tisular de Metaloproteinasa-2/sangre , Inhibidor Tisular de Metaloproteinasa-2/metabolismoRESUMEN
Intraocular controlled drug release is one way to facilitate drug efficacy and decrease side effects that occur with systemic administration. Vitreoretinal drug delivery with the biodegradable scleral plug has been investigated. The scleral plug, which is made of biodegradable polymers and drugs, can be implanted at the pars plana using a simple procedure, and it gradually releases effective doses of drugs with polymer biodegradation for several months. The release profiles of the drugs were dependent on the kind of polymers used, their molecular weights, and the amount of drug in the plug. The plugs are effective for treating vitreoretinal diseases such as proliferative vitreoretinopathy. The implantation site was replaced with connective tissue. Electroretinography and histologic studies revealed little retinal toxicity. This implantable scleral plug was supposed to be advantageous for diseases such as cytomegalovirus retinitis that respond to repeated intravitreal injections and for vitreoretinal disorders that require vitrectomy.
Asunto(s)
Sistemas de Liberación de Medicamentos , Oftalmopatías/tratamiento farmacológico , Enfermedades de la Retina/tratamiento farmacológico , Esclerótica/metabolismo , Cuerpo Vítreo , Animales , Biodegradación Ambiental , Retinitis por Citomegalovirus/tratamiento farmacológico , Ganciclovir/administración & dosificación , Humanos , Ácido Láctico/administración & dosificación , Ácido Poliglicólico/administración & dosificación , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Polímeros/administración & dosificación , Solubilidad , Vitreorretinopatía Proliferativa/tratamiento farmacológicoRESUMEN
Subfoveal choroidal neovascularization (CNV) causes significant visual loss, especially in patients with age-related macular degeneration (AMD). Several pharmaceutical treatments that use anti-angiogenic agents have been tried to inhibit the activity of CNV experimentally and clinically. In general, however, systemically administered drugs may reach not only targeted tissues but also other tissues, resulting in unwanted side effects. Also, to maintain therapeutic levels of the drugs in targeted tissues, frequent administration for an extended period of time is required. To solve these problems, drug delivery systems targeted to the CNV are being developed. Anatomic characteristics of CNV tissues resemble those of tumor vasculature, exhibiting enhanced permeability and retention effect. Drug targeting to CNV may be feasible in the same manner as it is to tumors. In this review, we describe two approaches of drug targeting to CNV: passive targeting and active targeting.
Asunto(s)
Neovascularización Coroidal/tratamiento farmacológico , Sistemas de Liberación de Medicamentos , Animales , Anticuerpos Monoclonales/uso terapéutico , Antígenos CD , Ciclohexanos , Endoglina , Humanos , Inmunoconjugados/uso terapéutico , O-(Cloroacetilcarbamoil) Fumagilol , Permeabilidad , Alcohol Polivinílico/administración & dosificación , Receptores de Superficie Celular , Sesquiterpenos/administración & dosificación , Molécula 1 de Adhesión Celular Vascular/análisis , Molécula 1 de Adhesión Celular Vascular/inmunologíaRESUMEN
A mitochondrial tRNA(Lys) gene mutation at nucleotide position 8344 is responsible for the myoclonus epilepsy associated with ragged-red fibers (MERRF) subgroup of mitochondrial encephalomyopathies. Here, we show that normally modified uridine at the anticodon wobble position remains unmodified in the purified mutant tRNA(Lys). We have reported a similar modification defect at the same position in two mutant mitochondrial tRNAs(Leu)(UUR) in another subgroup, mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS), indicating this defect is common in the two kinds of tRNA molecules with the respective mutations of the two major mitochondrial encephalomyopathies. We therefore suggest the defect in the anticodon is responsible, through the translational process, for the pathogenesis of mitochondrial diseases.
Asunto(s)
Anticodón , Síndrome MERRF/genética , Miopatías Mitocondriales/genética , Mutación , ARN de Transferencia de Lisina/genética , Línea Celular , Células HeLa , Humanos , Síndrome MELAS/genética , Mitocondrias/metabolismo , Mutación Puntual , ARN de Transferencia de Leucina/genética , ARN de Transferencia de Lisina/aislamiento & purificación , Uridina/metabolismoRESUMEN
The topographical organization and ultrastructural features of the intralaminar thalamic nuclei (ITN) projections to the globus pallidus (GP) were studied using the biotinylated dextran amine (BDA) anterograde tracing method in the rat. To assess the functional association of BDA injection sites in the ITN, the known topographical organization of the ITN-neostriatal (Str) projections and calcium binding protein (CaBP) immunostaining patterns of the Str and GP were used. BDA injection in the lateral part of the lateral parafascicular nucleus and the caudal part of the central lateral nucleus labeled fibers and boutons mainly in the dorsolateral sensorimotor territory of the Str and the middle territories of the GP. BDA injection in the medial part of the lateral parafascicular nucleus and the central lateral nucleus labeled mainly the middle association territory of the Str and the border and the caudomedial territories of the GP. BDA injection in the medial parafascicular nucleus and the central medial nucleus labeled mainly the medial limbic territory of the Str. The medial parafascicular nucleus projected to the medial-most region of the GP, while the central medial nucleus projection to the GP was very sparse. Electron microscopic observations indicated that BDA-labeled boutons form asymmetric synapses mainly on 0.5-2.0 microm diameter dendritic shafts in the GP. The boutons were small but had a relatively long active zone. The present observations together with the known topographical organization of striatopallidal projections indicated that the ITN-GP projections were topographically organized in parallel to the ITN-Str projections. Thus, each part of the ITN projecting to the sensorimotor, the association, and the limbic territories of the Str also projects to the corresponding functional territories of the GP.
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Biotina/análogos & derivados , Biotina/análisis , Dextranos/análisis , Globo Pálido/química , Núcleos Talámicos/química , Animales , Colorantes Fluorescentes/análisis , Globo Pálido/fisiología , Globo Pálido/ultraestructura , Vías Nerviosas/química , Vías Nerviosas/fisiología , Vías Nerviosas/ultraestructura , Ratas , Ratas Sprague-Dawley , Núcleos Talámicos/fisiología , Núcleos Talámicos/ultraestructuraRESUMEN
UNLABELLED: We retrospectively evaluated the usefulness of PET with 11C-methionine (methionine PET) for the diagnosis of lymph node metastases in patients with lung cancer. METHODS: Methionine PET and CT were performed before surgical intervention in 41 patients with primary lung cancer. We evaluated individual lymph nodes by methionine PET along with corresponding CT images. The 11C-methionine accumulation of lymph nodes was assessed semiquantitatively by analysis of the tumor-to-muscle ratio (TMR) and was compared with CT and histological diagnoses. RESULTS: A total of 126 lymph nodes, 36 of which were histologically diagnosed as metastatic, were assessed by CT and methionine PET. The TMR in metastatic lymph nodes (n = 36) was 5.15+/-1.69, whereas that of nonmetastatic lymph nodes (n = 90) was 2.91+/-0.76; this difference was significant (P < 0.0001). The most adequate TMR cutoff value for diagnosis of metastasis based on the results of receiver operating characteristic curve analysis was 4.1. The positive and negative predictive values, sensitivity, specificity, and accuracy of methionine PET were 79.5%, 94.3%, 86.1%, 91.1%, and 89.7%, respectively, and were superior to those of CT (57.6%, P = 0.04; 81.7%, P = 0.008; 52.8%, P = 0.002; 84.4%, NS; and 75.4%, P = 0.002, respectively). All positive nodes that were shown to be true-positive by CT, and 12 of 17 false-negatives on CT were correctly diagnosed by PET. Ten of 14 lymph nodes that were false-positive on CT were also correctly diagnosed by PET. CONCLUSION: Methionine PET appears to be superior to CT for the diagnosis of lymph node metastasis in lung cancer patients. The high negative predictive value of methionine PET suggests that cases in which lymph nodes are enlarged on CT with negative PET analysis may be diagnosed as negative for metastasis.
Asunto(s)
Radioisótopos de Carbono , Neoplasias Pulmonares/diagnóstico por imagen , Metionina , Tomografía Computarizada de Emisión , Femenino , Humanos , Neoplasias Pulmonares/patología , Ganglios Linfáticos/diagnóstico por imagen , Metástasis Linfática , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Curva ROC , Radiofármacos , Estudios Retrospectivos , Sensibilidad y Especificidad , Tomografía Computarizada por Rayos XRESUMEN
PURPOSE: Active drug targeting mediated by monoclonal antibodies (mAbs) of vascular endothelial cells in tumors is a new concept in cancer therapy. Integrin alphavbeta3 has been reported to be strongly expressed in vascular endothelial cells of surgically excised choroidal neovascular membranes and is thought to be a potential antigen for mAb-mediated drug targeting of choroidal neovascularization (CNV). The objective of this study was to evaluate the efficacy of drug targeting mediated by anti-integrin alphavbeta3 mAbs in a laser-induced CNV rat model. METHODS: The mitomycin C (MMC)-dextran (MMCD) conjugate was synthesized with a carbodiimide-catalyzed reaction. The mAb was conjugated with MMCD (MMCD-mAb). To evaluate the feasibility of mAb-mediated drug targeting in vitro, we investigated the effect of the immunoconjugates involving dextran-binding MMC on the proliferation of human umbilical vein endothelial cells (HUVECs). CNV was induced by laser photocoagulation in male Brown Norway rats. Immunolocalization of integrin alphavbeta3 in CNV lesions was assessed immunohistochemically with the anti-von Willebrand factor antibody as an endothelial cell marker. Intravenous administration of saline (n = 7), 1 mg/day mAb (n = 7), 100 microg/kg per day free MMC (n = 7), MMCD with irrelevant Ab (n = 7), unconjugated MMCD with unconjugated mAb (MMCD+mAb; n = 7), or MMCD with mAb (MMCD-mAb; n = 8) containing an equal amount of free MMC, was performed daily for 3 days from day 14 after CNV induction. CNV was assessed by fluorescein angiography 2 weeks after treatment. Fluorescein leakage was scored on a four-grade scale. The animals were killed 2 weeks after treatment, and the lesions were evaluated histologically. RESULTS: The inhibition of immunoconjugates on the proliferation of HUVECs was enhanced specifically by the mediatory effect of the mAb. Endothelial cells demonstrated strong immunoreactivity of integrin alphavbeta3 in the CNV. In the vehicle-treated group, fluorescein leakage equal to that before treatment was observed 2 weeks after treatment, with an average score of 2.00 +/- 0.17 (mean +/- SEM). MMCD-mAb significantly inhibited the development of CNV in rats (P < 0.01). Moreover, the thickness of the lesions was significantly reduced in the MMCD-mAb-treated group (P < 0.01). CONCLUSIONS: Immunoconjugates effectively inhibited progression of CNV in this model. The results suggest that mAb-mediated drug targeting may be beneficial in the treatment of CNV.
Asunto(s)
Anticuerpos Monoclonales/administración & dosificación , Neovascularización Coroidal/tratamiento farmacológico , Dextranos/administración & dosificación , Sistemas de Liberación de Medicamentos/métodos , Mitomicina/administración & dosificación , Receptores de Vitronectina/inmunología , Animales , Anticuerpos Monoclonales/farmacología , Permeabilidad Capilar , División Celular/efectos de los fármacos , Células Cultivadas , Coroides/irrigación sanguínea , Coroides/metabolismo , Coroides/patología , Neovascularización Coroidal/diagnóstico , Neovascularización Coroidal/metabolismo , Dextranos/farmacología , Endotelio Vascular/efectos de los fármacos , Fluoresceína/metabolismo , Angiografía con Fluoresceína , Humanos , Inmunoconjugados/administración & dosificación , Inmunoconjugados/farmacología , Masculino , Mitomicina/farmacología , Modelos Animales , Ratas , Ratas Endogámicas BN , Venas Umbilicales/citologíaRESUMEN
PURPOSE: The conjugation of drugs with water-soluble polymers such as poly(vinyl alcohol) (PVA) tends to prolong the half-life of drugs and facilitate the accumulation of drugs in tissues involving neovascularization. The purpose of this study was to evaluate the effect of TNP-470-PVA conjugate on the proliferation of endothelial cells in vitro and on experimental choroidal neovascularization (CNV) in vivo. METHODS: TNP-470 was conjugated in PVA by a dimethylaminopyridine-catalyzed reaction. The effects of TNP-470-PVA and free TNP-470 on the proliferation of human umbilical vein endothelial cells (HUVECs) and bovine retinal pigment epithelial cells (BRPECs) were evaluated by the tetrazolium-based colorimetric assay (XTT assay). Experimental CNV was induced by subretinal injection of gelatin microspheres containing basic fibroblast growth factor, into rabbits. Thirty rabbits were intravenously treated either with TNP-470-PVA (n = 8), free TNP470 (n = 5), free PVA (n = 5), or saline (n = 12) daily for 3 days, 2 weeks after implantation of gelatin microspheres. Fluorescein angiography was performed to detect the area with CNV, and the evaluation was made by computerized measurement of digital images. These eyes were also examined histologically. To observe the accumulation of conjugate, 3 rabbits with CNV received rhodamine B isothiocyanate-binding PVA (RITC-PVA), and the lesion was studied 24 hours later by fluorescein microscopy. RESULTS: The TNP-470-PVA inhibited the growth of HUVECs, similar to that of free TNP-470. The BRPECs were less sensitive to TNP-470-PVA than were the HUVECs. TNP-470-PVA significantly inhibited the progression of CNV in rabbits (P = 0.001). Histologic studies at 4 weeks after treatment demonstrated that the degree of vascular formation and the number of vascular endothelial cells in the subretinal membrane of the eyes treated with TNP-470-PVA were less than those of the control eyes. RITC-PVA remained in the area with CNV 24 hours after administration. CONCLUSIONS: These results suggest that TNP-470-PVA inhibited the proliferation of HUVECs more sensitively than that of BRPECs, and the targeted delivery of TNP-470-PVA may have potential as a treatment modality for CNV.
Asunto(s)
Neovascularización Coroidal/tratamiento farmacológico , Sistemas de Liberación de Medicamentos , Endotelio Vascular/efectos de los fármacos , Epitelio Pigmentado Ocular/efectos de los fármacos , Alcohol Polivinílico/administración & dosificación , Sesquiterpenos/administración & dosificación , Animales , Bovinos , División Celular/efectos de los fármacos , Células Cultivadas , Neovascularización Coroidal/patología , Ciclohexanos , Endotelio Vascular/citología , Angiografía con Fluoresceína , Humanos , Inyecciones Intravenosas , Microscopía Fluorescente , Microesferas , O-(Cloroacetilcarbamoil) Fumagilol , Epitelio Pigmentado Ocular/citología , Alcohol Polivinílico/farmacología , Conejos , Rodaminas , Sesquiterpenos/farmacología , SolubilidadRESUMEN
PURPOSE: Radiation therapy has been used to treat choroidal neovascularization (CNV) in patients with age-related macular degeneration. The in vivo effect of applying focal x-ray irradiation to the eye of rabbits with experimental CNV was investigated. METHODS: CNV was induced in the rabbit eyes by subretinal implantation of gelatin hydrogel microspheres impregnated with basic fibroblast growth factor. Three weeks after implantation, 17 of 34 eyes with CNV lesions accompanied by fluorescein leakage were irradiated with a single dose of 20 Gy; the other 17 eyes were not irradiated and served as the controls. The eyes were examined before irradiation and 1, 2, and 4 weeks after irradiation, by indirect ophthalmoscopy and fluorescein angiography. The degree of a decreasing amount of fluorescein leakage from the CNV lesions after irradiation was graded using a computerized image analysis system and was compared in the irradiated and nonirradiated eyes. These eyes were also examined histologically and immunohistochemically. RESULTS: Fluorescein leakage from the CNV lesions had significantly decreased in the eyes irradiated with 20 Gy compared with the control eyes, throughout the study period (P < 0.05). Histologic and immunohistochemical studies at 4 weeks after irradiation demonstrated that the degree of vascular formation and the number of vascular endothelial cells in the subretinal membrane of the irradiated eyes were less than those of the control eyes. CONCLUSIONS: Focal x-ray irradiation at the ocular region effectively reduced experimental CNV activity. These results support the possibility that radiation therapy may be beneficial in treating CNV.
Asunto(s)
Neovascularización Coroidal/radioterapia , Modelos Animales de Enfermedad , Animales , Neovascularización Coroidal/metabolismo , Neovascularización Coroidal/patología , Femenino , Angiografía con Fluoresceína , Fondo de Ojo , Procesamiento de Imagen Asistido por Computador , Técnicas para Inmunoenzimas , Queratinas/metabolismo , Macrófagos/patología , Masculino , Oftalmoscopía , Molécula-1 de Adhesión Celular Endotelial de Plaqueta/metabolismo , Conejos , Terapia por Rayos XRESUMEN
To determine the efficacy of fast neutron (FN) for the treatment of non-small cell lung cancer, 112 patients with histologically proven adenocarcinoma or squamous cell carcinoma at a limited stage were studied to evaluate local control and survival, after treatment with either FNs or photons alone. The local control rate of adenocarcinoma in FN-treated patients attained 50%, which was significantly higher than that (<10%) of squamous cell carcinoma in FN-treated patients or that of both histological types of carcinoma in patients treated with photons alone. In accordance with this, the 5-year survival rate for the FN-treated patients with adenocarcinoma was significantly higher than that for FN-treated patients with squamous cell carcinoma or that for photon-treated patients with both histological types of disease. The present study clearly suggests the usefulness of FN in the treatment of adenocarcinoma of the lung, though it was a non-randomized trial.
RESUMEN
The previous scleral implant composed of poly(D, L-lactide-co-glycolide) with ganciclovir (GCV) had some disadvantages such as the second burst in the late phase of release. In this study, the GCV release rate from scleral implants was modified by blending poly(D,L-lactide) (PLA) of two different molecular weights. The scleral implants were prepared by blending PLA-70000 (molecular weight: 70000) and PLA-5000 (molecular weight: 5000) or PLA-130000 (molecular weight: 130000) and PLA-5000 at weight ratios of 100/0, 95/5, 90/10, 80/20, and 0/100. In vitro release tests were performed in 0.1 M phosphate-buffered solution (pH 7.4) at 37 degrees C. An increase in the blended amount of PLA-5000 clearly accelerated the GCV release and the onset of the second burst in the late phase of release tended to delay. The two implants both prepared at a blend ratio of 80/20 successfully prevented the second burst and the GCV release profiles followed the pseudozero-order kinetics after the initial burst as resulting from a diffusional mechanism following Higuchi's equation. Duration of the sustained GCV release could be controlled by changing the blending ratio of high and low molecular weight PLA. The 25% GCV-loaded scleral implants composed of PLA-70000 and PLA-5000 with a blending ratio of 80/20 were implanted in pigmented rabbit eyes. The GCV concentrations in the vitreous after implantation of PLA-70000/PLA-5000 scleral implant with a blending ratio of 80/20 were maintained in the range of effective level for 6 months without a significant burst. Our results suggest that the blended implants are promising for the intraocular controlled drug delivery over a period of several months to one year to treat cytomegalovirus retinitis.
Asunto(s)
Antivirales/administración & dosificación , Retinitis por Citomegalovirus/tratamiento farmacológico , Implantes de Medicamentos , Ganciclovir/administración & dosificación , Animales , Preparaciones de Acción Retardada , Ganciclovir/química , Ganciclovir/farmacocinética , Conejos , Cuerpo Vítreo/metabolismoRESUMEN
An 11-year-old boy had posterior lens capsule rupture resulting from a nonpenetrating (blunt trauma) injury to the eye. A rapidly developing cataract required pars plana lensectomy. This report suggests that posterior capsule rupture may occur secondary to blunt trauma and progressive cataract formation after posterior capsule rupture may require surgery soon after the injury.
Asunto(s)
Catarata/etiología , Lesiones Oculares/complicaciones , Cápsula del Cristalino/lesiones , Heridas no Penetrantes/complicaciones , Extracción de Catarata , Niño , Humanos , Presión Intraocular , Subluxación del Cristalino/etiología , Masculino , Rotura , Agudeza VisualRESUMEN
We report a patient with broad anterior synechias and corneal endothelial damage. The patient had chronic iritis and cataracts secondary to chronic iritis in both eyes. Because the right eye had broad anterior synechias and severe corneal endothelial damage, extracapsular cataract extraction and intraocular lens implantation were performed through the basal iris. Good postoperative visual acuity was obtained. The cornea showed little trauma from the surgery and remained clear 36 months postoperatively.