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1.
Ann Oncol ; 2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39241963

RESUMEN

BACKGROUND: Epstein-Barr virus-specific cytotoxic T lymphocyte (EBV-CTL) is an autologous adoptive T-cell immunotherapy generated from the blood of individuals and manufactured without genetic modification. In a previous phase II trial of locally recurrent or metastatic nasopharyngeal carcinoma (R/M NPC) patients, first-line gemcitabine and carboplatin (GC) and EBV-CTL combination demonstrated objective antitumor EBV-CTL activity and a favorable safety profile. The present study explored whether this combined first-line chemo-immunotherapy strategy would produce superior clinical efficacy and better quality of life compared with conventional chemotherapy treatment. PATIENTS AND METHODS: This multicenter, randomized, phase III trial evaluated the efficacy and safety of GC followed by EBV-CTL versus GC alone as first-line treatment of R/M NPC patients. Thirty clinical sites in Singapore, Malaysia, Taiwan, Thailand, and the USA were included. Subjects were randomized to first-line GC (four cycles) and EBV-CTL (six cycles) or GC (six cycles) in a 1 : 1 ratio. The primary outcome was overall survival (OS) and secondary outcomes included progression-free survival, objective response rate, clinical benefit rate, quality of life, and safety. CLINICALTRIALS: gov identifier: NCT02578641. RESULTS: A total of 330 subjects with NPC were enrolled. Most subjects in both treatment arms received four or more cycles of chemotherapy and most subjects in the GC + EBV-CTL group received two or more infusions of EBV-CTL. The central Good Manufacturing Practices (GMP) facility produced sufficient EBV-CTL for 94% of GC + EBV-CTL subjects. The median OS was 25.0 months in the GC + EBV-CTL group and 24.9 months in the GC group (hazard ratio = 1.19; 95% confidence interval 0.91-1.56; P = 0.194). Only one subject experienced a grade 2 serious adverse event related to EBV-CTL. CONCLUSIONS: GC + EBV-CTL in subjects with R/M NPC demonstrated a favorable safety profile but no overall improvement in OS versus chemotherapy. This is the largest adoptive T-cell therapy trial reported in solid tumors to date.

2.
Ann Oncol ; 27(12): 2210-2215, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27681866

RESUMEN

BACKGROUND: Treatment with sorafenib, although associated with inhibition of tumour growth and angiogenesis in in vivo studies, leads to up-regulation of pERK. The addition of MEK inhibition could potentially abrogate this effect and potentiate anti-tumour activity. This phase I study investigated the maximum tolerated dose (MTD), safety, tolerability, pharmacokinetics (PK) and biomarker correlates of selumetinib combined with sorafenib in patients with advanced hepatocellular carcinoma (HCC). METHODS: Patients with Child-Pugh (CP) score ≤7 were treated with 400 mg twice daily of sorafenib with escalating doses of selumetinib in a 3 + 3 study design. The dose-limiting toxicity (DLT) evaluation period was 28 days. PK of selumetinib was determined. Angiogenic effect was evaluated with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). RESULTS: Twenty-seven patients of Asian ethnicity were enrolled. The MTD was selumetinib 75 mg daily with sorafenib 400 mg twice daily. DLT included grade 3 transaminitis, diarrhoea and fatigue. Most common treatment-related adverse events at MTD (all grades) were diarrhoea (85%), rash (59%), hypertension (44%), fatigue (30%), anorexia (22%) and hand-foot syndrome (22%). Four patients (15%) had PR and 13 (48%) had SD. PR or SD was observed for ≥6 months in seven patients. The median overall survival was 14.4 months. Selumetinib exposures in combination with sorafenib were comparable to other monotherapy studies. A reduction in permeability-surface area product noted in DCE-MRI with treatment correlated with worse survival outcomes. CONCLUSION: The MTD of selumetinib was 75 mg daily when combined with sorafenib 400 mg twice a day in CP ≤7 HCC. Acceptable adverse events and encouraging anti-tumour activity warrant further evaluation. DCE-MRI findings deserve prospective evaluation. CLINICALTRIALSGOV IDENTIFIER: NCT01029418.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Bencimidazoles/administración & dosificación , Carcinoma Hepatocelular/tratamiento farmacológico , Neoplasias Hepáticas/tratamiento farmacológico , Niacinamida/análogos & derivados , Compuestos de Fenilurea/administración & dosificación , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Bencimidazoles/efectos adversos , Carcinoma Hepatocelular/patología , Supervivencia sin Enfermedad , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/patología , Femenino , Humanos , Estimación de Kaplan-Meier , Neoplasias Hepáticas/patología , Masculino , Dosis Máxima Tolerada , Persona de Mediana Edad , Estadificación de Neoplasias , Niacinamida/administración & dosificación , Niacinamida/efectos adversos , Compuestos de Fenilurea/efectos adversos , Inhibidores de Proteínas Quinasas/administración & dosificación , Inhibidores de Proteínas Quinasas/efectos adversos , Sorafenib
5.
Res Aging ; 45(2): 210-220, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-35466812

RESUMEN

This study aimed to examine whether changes in generalized trust (GT) and particularized trust (PT) predict changes in depressive symptoms (CES-D 8), and whether changes in self-rated health (SRH), family support (FS), and life satisfaction (LS) mediate the relationship between changes in the two types of trust and depressive symptoms in Chinese older adults. Structural equation modeling was employed to analyze two-wave data on 3770 participants aged 65 and over. Our results showed that in a context where GT was low and PT was high, an increase in GT was associated with more depressive symptoms, while an increase in PT was associated with fewer depressive symptoms. As such, GT cannot be viewed as protective against depression in older adults in a given context. LS partially mediated the relationship between changes in PT and depressive symptoms. The findings support psychosocial processes rather than health-problem and support pathways.


Asunto(s)
Depresión , Apoyo Familiar , Humanos , Anciano , Depresión/diagnóstico , Confianza , Pueblos del Este de Asia , Satisfacción Personal
6.
Radiography (Lond) ; 29(1): 184-189, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36469993

RESUMEN

INTRODUCTION: The use of computed tomography (CT) in healthcare institutions has increased rapidly in recent years. The Singapore Health Services (SingHealth) cluster of healthcare institutions has taken the first step in establishing a local cluster-wide CT Diagnostic Reference Levels (DRL) in Singapore. CT dose data from each institution were collected through two primary dosimetry metrics: volume CT dose index (CTDIvol measured in mGy) and dose-length product (DLP measured in mGy.cm). METHODS: Data from 19 CT scanners in seven institutions under one of Singapore healthcare cluster were retrospectively collected and analysed. The five common adult CT examinations analysed were CT Brain (non-contrast enhanced), CT Chest (IV contrast enhanced), CT Kidney-Ureter-Bladder (CT KUB, non-contrast enhanced), CT Pulmonary Angiogram (CT PA, IV contrast enhanced) and CT Abdomen-Pelvis (CT AP, IV contrast enhanced, single phase). Median CTDIvol and DLP values for the five CT examinations from each institution were derived, with the cluster DRLs determined as the 75th percentile of the distribution of the institution median dose values. RESULTS: A total of 2413 dose data points were collected over a six-month period from June to November 2020. The cluster CT DRLs for the five CT examinations were determined to be 47 mGy and 820 mGy.cm for CT Brain, 5.4 mGy and 225 mGy.cm for CT Chest, 6.7 mGy and 248 mGy.cm for CT PA, 4.6 mGy and 190 mGy.cm for CT KUB and 6.9 mGy and 349 mGy.cm for CT AP. CONCLUSION: The establishment of the cluster CT DRLs provided individual institutions with a better understanding if their CT doses are unusually high or low, while emphasising that these DRLs are not meant as hard dose limits or constraints to follow strictly.


Asunto(s)
Niveles de Referencia para Diagnóstico , Tomografía Computarizada por Rayos X , Adulto , Humanos , Dosis de Radiación , Estudios Retrospectivos , Singapur , Tomografía Computarizada por Rayos X/métodos , Atención a la Salud
7.
Ann Oncol ; 23(4): 997-1005, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21821548

RESUMEN

BACKGROUND: Individuals with metastatic Epstein-Barr virus (EBV)-positive nasopharyngeal carcinoma (NPC) continue to have poor outcomes. To evaluate the ability of a dendritic cell (DC) vaccine to target subdominant EBV antigens LMP1 and LMP2 expressed by NPC cells, we vaccinated patients using autologous DCs transduced with an adenovirus encoding a truncated LMP1 (ΔLMP1) and full-length LMP2 (Ad-ΔLMP1-LMP2). MATERIALS AND METHODS: Sixteen subjects with metastatic NPC received Ad-ΔLMP1-LMP2 DC vaccines i.d. biweekly for up to five doses. Toxicity, immune responses and clinical responses were determined. RESULTS: Most patients had extensive disease, with a median of three visceral sites of involvement (range 1-7). No significant toxicity was observed. Ad-ΔLMP1-LMP2 DCs induced delayed type hypersensitivity responses in 9 out of 12 patients, but although these DCs activated LMP1/2-specific T cells in vitro, no such increase in the frequency of peripheral LMP1/2-specific T cells was detected. Three patients had clinical responses including one with partial response (for 7½ months) and two with stable disease (for 6½ and 7½ months). CONCLUSIONS: Ad-ΔLMP1-LMP2 transduced DCs can be successfully generated and safely administered to patients with advanced NPC. Since efficacy was limited, future studies should focus on DC vaccines with greater potency administered to subjects with less tumor burden.


Asunto(s)
Adenoviridae/genética , Vacunas contra el Cáncer/administración & dosificación , Carcinoma/terapia , Células Dendríticas/inmunología , Neoplasias Nasofaríngeas/terapia , Proteínas de la Matriz Viral/inmunología , Adulto , Vacunas contra el Cáncer/efectos adversos , Vacunas contra el Cáncer/inmunología , Carcinoma/mortalidad , Carcinoma/virología , Células Cultivadas , Técnicas de Cocultivo , Células Dendríticas/metabolismo , Células Dendríticas/trasplante , Células Dendríticas/virología , Supervivencia sin Enfermedad , Infecciones por Virus de Epstein-Barr/complicaciones , Femenino , Vectores Genéticos , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/mortalidad , Neoplasias Nasofaríngeas/virología , Eliminación de Secuencia , Resultado del Tratamiento , Proteínas de la Matriz Viral/genética , Proteínas de la Matriz Viral/metabolismo
8.
Ann Oncol ; 22(11): 2516-2522, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21385886

RESUMEN

BACKGROUND: The objective of this study was to assess the safety, maximum tolerated dose (MTD), pharmacokinetics, pharmacodynamics, and preliminary efficacy of SB939, a novel histone deacetylase (HDAC) inhibitor, in patients with advanced solid malignancies. PATIENTS AND METHODS: Dose-escalating cohorts of three to six patients received SB939 orally thrice weekly for 3 weeks in a 4-week cycle. Acetylated histone H3 (acH3) was measured in peripheral blood mononuclear cells (PBMCs). RESULTS: Thirty patients treated at one of five doses (10-80 mg/day) received 79 cycles of SB939 (range, 1-12 cycles). Dose-limiting toxic effects were fatigue, hypokalemia, troponin T elevation, and QTc prolongation. Peak plasma concentration (C(max)) and area under the concentration-time curve extrapolated to infinity increased dose proportionally. The MTD of SB939 was 80 mg/day. The mean elimination half-life and oral clearance of SB939 were 7.2 ± 0.6 h and 53.0 ± 8.5 l/h, respectively, with no substantial accumulation on day 15. An increase in acH3 was observed at hour 3 and correlated with dose and C(max). Stable disease was seen in several tumor types treated at ≥40 mg. HDAC inhibition was consistently observed at 60 mg, the recommended dose. CONCLUSIONS: SB939 can be safely administered at the recommended dose and reaches plasma levels that strongly inhibit HDAC in PBMCs. These data support further efficacy studies of SB939.


Asunto(s)
Bencimidazoles/administración & dosificación , Inhibidores de Histona Desacetilasas/administración & dosificación , Neoplasias/tratamiento farmacológico , Administración Oral , Adulto , Anciano , Bencimidazoles/efectos adversos , Bencimidazoles/farmacocinética , Relación Dosis-Respuesta a Droga , Femenino , Inhibidores de Histona Desacetilasas/efectos adversos , Inhibidores de Histona Desacetilasas/farmacocinética , Histona Desacetilasas/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/enzimología , Neoplasias/metabolismo
9.
J Neurol ; 268(10): 3878-3885, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33830335

RESUMEN

OBJECTIVE: Niemann Pick disease type C (NPC) is a rare progressive neurovisceral lysosomal disorder caused by autosomal recessive mutations in the NPC1 or NPC2 genes. 18F-fluorodeoxyglucose (FDG) is a positron-emitting glucose analogue for non-invasive imaging of brain metabolism. FDG PET is commonly used for dementia imaging but its specific application to NPC is rarely described. METHODS: This is a retrospective study of all baseline brain FDG PET performed for NPC patients. Images were assessed using a normal database statistical comparison of metabolic changes expressed in standard deviations and three-dimensional Stereotactic Surface Projection maps. Typical hypometabolic patterns in NPC were identified. We further investigated any correlation between the degree of regional brain hypometabolism and the Iturriaga clinical severity scale. RESULTS: Brain FDG PET images of 14 adolescent-adult NPC patients were analysed, with mean age of 35 years. We found significant frontal lobe hypometabolism in 12 patients (86%), thalamic hypometabolism in eight patients (57%) and variable parietal lobe hypometabolism in 13 patients (93%). Hypometabolic changes were usually bilateral and symmetric. Ten out of 13 ataxic patients showed cerebellar or thalamic hypometabolism (sensitivity 77%, specificity 100%). Linear regression analysis showed frontal lobe hypometabolism to have the best correlation with the Iturriaga clinical scale (R2 = 0.439; p = 0.01). CONCLUSIONS: We found bilateral symmetric hypometabolism of the frontal lobes, thalami and parietal lobes (especially posterior cingulate gyrus) to be typical of adolescent-adult NPC. Ataxia was commonly associated with cerebellar or thalamic hypometabolism. Frontal lobe hypometabolism showed the best inverse correlation with clinical severity.


Asunto(s)
Fluorodesoxiglucosa F18 , Enfermedad de Niemann-Pick Tipo C , Adolescente , Adulto , Encéfalo/diagnóstico por imagen , Humanos , Enfermedad de Niemann-Pick Tipo C/diagnóstico por imagen , Tomografía de Emisión de Positrones , Estudios Retrospectivos
10.
Br J Cancer ; 102(6): 981-6, 2010 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-20160718

RESUMEN

BACKGROUND: Molecularly targeted agents with anti-angiogenic activity, including bevacizumab, have demonstrated clinical activity in patients with advanced/metastatic hepatocellular carcinoma (HCC). This multicentre phase II study involving patients from several Asian countries sought to evaluate the safety and efficacy of bevacizumab plus capecitabine in this population. METHODS: Histologically proven/clinically diagnosed advanced HCC patients received bevacizumab 7.5 mg kg(-1) on day 1 and capecitabine 800 mg m(-2) twice daily on days 1-14 every 3 weeks as first-line therapy. RESULTS: A total of 45 patients were enrolled; 44 (96%) had extrahepatic metastasis and/or major vessel invasion and 30 (67%) had hepatitis B. No grade 3/4 haematological toxicity occurred. Treatment-related grade 3/4 non-haematological toxicities included diarrhoea (n=2, 4%), nausea/vomiting (n=1, 2%), gastrointestinal bleeding (n=4, 9%) and hand-foot syndrome (n=4, 9%). The overall response rate (RECIST) was 9% and the disease control rate was 52%. Overall, median progression-free survival (PFS) and overall survival (OS) were 2.7 and 5.9 months, respectively. Median PFS and OS were 3.6 and 8.2 months, respectively, for Cancer of the Liver Italian Programme (CLIP) score < or =3 patients, and 1.4 and 3.3 months, respectively, for CLIP score 4 patients. CONCLUSION: The bevacizumab-capecitabine combination shows good tolerability and modest anti-tumour activity in patients with advanced HCC.


Asunto(s)
Anticuerpos Monoclonales/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma Hepatocelular/tratamiento farmacológico , Desoxicitidina/análogos & derivados , Fluorouracilo/análogos & derivados , Neoplasias Hepáticas/tratamiento farmacológico , Adulto , Anciano , Anticuerpos Monoclonales/efectos adversos , Anticuerpos Monoclonales Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Bevacizumab , Capecitabina , Carcinoma Hepatocelular/mortalidad , Carcinoma Hepatocelular/patología , Desoxicitidina/administración & dosificación , Desoxicitidina/efectos adversos , Progresión de la Enfermedad , Femenino , Fluorouracilo/administración & dosificación , Fluorouracilo/efectos adversos , Humanos , Neoplasias Hepáticas/mortalidad , Neoplasias Hepáticas/patología , Masculino , Persona de Mediana Edad , Terapia Neoadyuvante , Estadificación de Neoplasias , Análisis de Supervivencia , Resultado del Tratamiento , Adulto Joven
11.
Science ; 272(5258): 109-12, 1996 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-8600518

RESUMEN

Ultraviolet light (UV)-induced DNA damage can be repaired by DNA photolyase in a light-dependent manner. Two types of photolyase are known, one specific for cyclobutane pyrimidine dimers (CPD photolyase) and another specific for pyrimidine (6-4) pyrimidone photoproducts[(6-4)photolyase]. In contrast to the CPD photolyase, which has been detected in a wide variety of organisms, the (6-4)photolyase has been found only in Drosophila melanogaster. In the present study a gene encoding the Drosophila(6-4)photolyase ws cloned, and the deduced amino acid sequence of the product was found to be similar to the CPD photolyase and to the blue-light photoreceptor of plants. A homolog of the Drosophila (6-4)photolyase gene was also cloned from human cells.


Asunto(s)
Desoxirribodipirimidina Fotoliasa/química , Drosophila melanogaster/enzimología , Células Fotorreceptoras de Invertebrados/química , Proteínas de Plantas/química , Secuencia de Aminoácidos , Animales , Clonación Molecular , Reparación del ADN , ADN Complementario/genética , Desoxirribodipirimidina Fotoliasa/genética , Desoxirribodipirimidina Fotoliasa/metabolismo , Drosophila melanogaster/genética , Flavina-Adenina Dinucleótido/metabolismo , Genes de Insecto , Humanos , Luz , Datos de Secuencia Molecular , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Alineación de Secuencia , Rayos Ultravioleta
12.
Mol Imaging Biol ; 10(1): 48-53, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-17994266

RESUMEN

PURPOSE: To assess the contribution of concurrent low-dose, noncontrast CT in the assessment of the malignant potential of incidental focal 2-deoxy-2-[F-18]fluoro-D-glucose (FDG)-avid colonic lesions on positron emission tomography/computed tomography (PET/CT). PROCEDURES: Routine FDG-PET/CT scans were reviewed for identification of focal FDG-avid colon lesions, and the CT component was independently reviewed for an anatomical lesion and malignant potential based on CT criteria. Clinical, endoscopic, and histopathology follow-up was obtained. RESULTS: A total of 85/2,916 (3%) oncology FDG-PET/CT scans had incidental focal colon lesions. Clinical and/or endoscopic follow-up was available in 83/85 (98%) patients. Focal, corresponding CT lesions were found in 44/83 (53%) patients, but features of malignancy were not assessable. Of the 44 patients with a final diagnosis, 32/44 (73%) were FDG-PET/CT true positives; 5/44 (11%) were false positives; and 7/44 (16%) had inconclusive FDG-PET/CT findings. CONCLUSIONS: Concurrent low-dose, noncontrast CT improves localization, but does not provide independent information on the malignant potential of incidental focal colonic activity on FDG-PET/CT.


Asunto(s)
Enfermedades del Colon/diagnóstico , Medios de Contraste/metabolismo , Fluorodesoxiglucosa F18 , Hallazgos Incidentales , Tomografía de Emisión de Positrones , Tomografía Computarizada por Rayos X , Endoscopía , Reacciones Falso Positivas , Estudios de Seguimiento , Humanos
13.
Int J Infect Dis ; 77: 34-39, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30292892

RESUMEN

OBJECTIVE: The objective of this study was to evaluate the effects of earlier intervention by an antimicrobial stewardship team (AST) on antimicrobial use, antimicrobial resistance rates, and the clinical outcomes, without changing the weekly intervention schedule. METHODS: A retrospective study was conducted at Fukuoka University Hospital between April 2013 and March 2016. The effects were compared among three study periods (SP): SP1 (patients receiving anti-methicillin-resistant Staphylococcus aureus agents and carbapenems for ≥14 days), SP2 (patients receiving specific antimicrobials for ≥14 days), and SP3 (patients receiving specific antimicrobials regardless of the duration of treatment). RESULTS: The timing of AST intervention was shortened from an average of 15.5days after administration in SP1 to 4.2 days in SP3. The antimicrobial use density (AUD) of carbapenems and piperacillin-tazobactam decreased significantly (SP2 vs. SP3, p<0.05), and the costs of specific antimicrobials decreased (SP1, US$ 1080000; SP2, US$ 944000; SP3, US$ 763000). The rates of carbapenem resistance among Pseudomonas aeruginosa isolates showed a significant reduction from 16.2% in SP2 to 8.7% in SP3 (p<0.05). The mortality rate and length of stay did not change during the study period. CONCLUSIONS: Earlier intervention by an AST could contribute to the proper use of antimicrobials without adversely affecting patient outcomes.


Asunto(s)
Antiinfecciosos/uso terapéutico , Programas de Optimización del Uso de los Antimicrobianos , Antiinfecciosos/economía , Carbapenémicos/economía , Carbapenémicos/uso terapéutico , Daptomicina/uso terapéutico , Farmacorresistencia Microbiana , Fluoroquinolonas/uso terapéutico , Humanos , Linezolid/uso terapéutico , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Combinación Piperacilina y Tazobactam/economía , Combinación Piperacilina y Tazobactam/uso terapéutico , Pseudomonas aeruginosa/efectos de los fármacos , Estudios Retrospectivos , Teicoplanina/uso terapéutico , Factores de Tiempo , Resultado del Tratamiento , Vancomicina/uso terapéutico
14.
Nucleic Acids Res ; 28(22): 4540-3, 2000 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-11071943

RESUMEN

Hjc resolvase is an archaeal enzyme involved in homologous DNA recombination at the Holliday junction intermediate. However, the structure and the catalytic mechanism of the enzyme have not yet been identified. We performed database searching using the amino acid sequence of the enzyme from Pyrococcus furiosus as a query. We detected 59 amino acid sequences showing weak but significant sequence similarity to the Hjc resolvase. The detected sequences included DPN:II, HAE:II and Vsr endonuclease, which belong to the type II restriction endonuclease family. In addition, a highly conserved region was identified from a multiple alignment of the detected sequences, which was similar to an active site of the type II restriction endonucleases. We substituted three conserved amino acid residues in the highly conserved region of the Hjc resolvase with Ala residues. The amino acid replacements inactivated the enzyme. The experimental study, together with the results of the database searching, suggests that the Hjc resolvase is a distantly related member of the type II restriction endonuclease family. In addition, the results of our database searches suggested that the members of the RecB domain superfamily are evolutionarily related to the type II restriction endonuclease family.


Asunto(s)
Desoxirribonucleasas de Localización Especificada Tipo II/genética , Endodesoxirribonucleasas/genética , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Proteínas Arqueales/genética , Bases de Datos Factuales , Desoxirribonucleasas de Localización Especificada Tipo II/metabolismo , Endodesoxirribonucleasas/metabolismo , Resolvasas de Unión Holliday , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Mutación , Unión Proteica , Pyrococcus furiosus/enzimología , Pyrococcus furiosus/genética , Alineación de Secuencia , Homología de Secuencia de Aminoácido
15.
Nucleic Acids Res ; 28(12): 2353-62, 2000 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-10871367

RESUMEN

Photolyase is a DNA repair enzyme that reverses UV-induced photoproducts in DNA in a light-dependent manner. Recently, photolyase homologs were identified in higher eukaryotes. These homologs, termed crypto-chromes, function as blue light photoreceptors or regulators of circadian rhythm. In contrast, most bacteria have only a single photolyase or photolyase-like gene. Unlike other microbes, the chromosome of the cyanobacterium SYNECHOCYSTIS: sp. PCC6803 contains two ORFs (slr0854 and sll1629) with high similarities to photolyases. We have characterized both genes. The slr0854 gene product exhibited specific, light-dependent repair activity for a cyclo-butane pyrimidine dimer (CPD), whereas the sll1629 gene product lacks measurable affinity for DNA in vitro. Disruption of either slr0854 or sll1629 had little or no effect on the growth rate of the cyanobacterium. A mutant lacking the slr0854 gene showed severe UV sensitivity, in contrast to a mutant lacking sll1629. Phylogenetic analysis showed that sll1629 is more closely related to the cryptochromes than photolyases. We conclude that sll1629 is a bacterial cryptochrome. To our knowledge, this is the first description of a bacterial cryptochrome.


Asunto(s)
Cianobacterias/genética , ADN Bacteriano/efectos de la radiación , Desoxirribodipirimidina Fotoliasa/genética , Proteínas de Drosophila , Proteínas del Ojo , Flavoproteínas/genética , Células Fotorreceptoras de Invertebrados , Rayos Ultravioleta , Secuencia de Bases , Criptocromos , Cianobacterias/crecimiento & desarrollo , Cianobacterias/efectos de la radiación , Reparación del ADN , ADN Bacteriano/genética , Oscuridad , Genes Bacterianos , Luz , Datos de Secuencia Molecular , Filogenia , Receptores Acoplados a Proteínas G
16.
Cancer Res ; 61(9): 3704-11, 2001 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-11325842

RESUMEN

DNA vaccination that can induce both cellular and humoral immune responses has become an attractive immunization strategy against cancer and infection. Dendritic cells (DCs) play a critical role in the induction of immune responses by DNA vaccination. However, a major problem of DNA vaccination is its limited potency, because only a very limited fraction of injected DNA molecules are taken up by DCS: In this study, we describe a novel DNA vaccination strategy to enhance uptake and presentation of antigens by DCS: Specifically, we developed a DNA vaccine based upon expression of a model hepatitis B virus (HBV) e antigen fused to an IgG Fc fragment. After vaccination, the DNA are taken up by cells that produce and secrete the antigen-Fc fusion proteins. The secreted fusion proteins, in addition to inducing B cells, are efficiently captured and processed by DCs via receptor-mediated endocytosis and then presented to the MHC class II and as -I (cross-priming). The results of this study demonstrate that broad enhancement of antigen-specific CD4+ helper, CD8+ cytotoxic T-cell, and B-cell responses can be achieved by this DNA vaccination strategy. Thus, the strategy capable of inducing all arms of the adaptive immunity may provide a novel, generic design for the development of therapeutic and preventive DNA vaccines.


Asunto(s)
Células Dendríticas/inmunología , Inmunoterapia Activa/métodos , Inmunoterapia Adoptiva/métodos , Vacunas de ADN/inmunología , Animales , Formación de Anticuerpos/inmunología , Presentación de Antígeno/inmunología , Linfocitos B/inmunología , Técnicas de Cocultivo , Femenino , Antígenos e de la Hepatitis B/genética , Antígenos e de la Hepatitis B/inmunología , Fragmentos de Inmunoglobulinas/genética , Fragmentos de Inmunoglobulinas/inmunología , Inmunoglobulina G/genética , Inmunoglobulina G/inmunología , Activación de Linfocitos/inmunología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Receptores de IgG/genética , Receptores de IgG/inmunología , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/inmunología , Linfocitos T Citotóxicos/inmunología , Células TH1/inmunología
17.
Genetics ; 154(4): 1451-61, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10747044

RESUMEN

To identify Schizosaccharomyces pombe genes involved in recombination repair, we identified seven mutants that were hypersensitive to both methyl methanesulfonate (MMS) and gamma-rays and that contained mutations that caused synthetic lethality when combined with a rad2 mutation. One of the mutants was used to clone the corresponding gene from a genomic library by complementation of the MMS-sensitive phenotype. The gene obtained encodes a protein of 354 amino acids whose sequence is 32% identical to that of the Rad57 protein of Saccharomyces cerevisiae. An rhp57 (RAD57 homolog of S. pombe) deletion strain was more sensitive to MMS, UV, and gamma-rays than the wild-type strain and showed a reduction in the frequency of mitotic homologous recombination. The MMS sensitivity was more severe at lower temperature and was suppressed by the presence of a multicopy plasmid bearing the rhp51 gene. An rhp51 rhp57 double mutant was as sensitive to UV and gamma-rays as an rhp51 single mutant, indicating that rhp51 function is epistatic to that of rhp57. These characteristics of the rhp57 mutants are very similar to those of S. cerevisiae rad57 mutants. Phylogenetic analysis suggests that Rhp57 and Rad57 are evolutionarily closest to human Xrcc3 of the RecA/Rad51 family of proteins.


Asunto(s)
Reparación del ADN , Proteínas de Unión al ADN/genética , Proteínas Fúngicas/genética , Recombinación Genética/genética , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Schizosaccharomyces/genética , Adenosina Trifosfatasas , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , Enzimas Reparadoras del ADN , ADN de Hongos , Genes Letales , Humanos , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Fenotipo , Filogenia , Homología de Secuencia de Aminoácido
18.
J Leukoc Biol ; 53(3): 256-63, 1993 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8454949

RESUMEN

The relationship between activated neutrophils and end-organ injury in endotoxemia was studied. The function of peripheral blood neutrophils (PMNs) in rabbits with the generalized Shwartzman reaction (GSR) was compared to that of PMNs rabbits receiving a single injection of endotoxin. The following results were obtained: (1) PMNs from rabbits with the GSR demonstrated enhanced adherence to endothelial cells and increased mitochondrial ATP production; (2) the GSR did not enhance chemotaxis and oxygen radical production of PMNs; (3) a single injection of endotoxin did not cause necrosis of visceral organs; (4) in vitro detachment of endothelial cells by PMNs was increased in rabbits with the GSR; (5) in vivo administration of monoclonal antibody (mAb) against CD11b/CD18 (Mac-1) suppressed the increase in PMN adherence; and (6) hemorrhagic necrosis did not occur when mAb to Mac-1 was injected. Thus, enhanced adherence of PMNs to endothelial cells appears to play a key role in endotoxin-induced end-organ injuries in this animal model.


Asunto(s)
Endotoxinas/farmacología , Neutrófilos/fisiología , Fenómeno de Shwartzman/fisiopatología , Animales , Anticuerpos Monoclonales/farmacología , Adhesión Celular , Quimiotaxis de Leucocito , Endotelio/citología , Inyecciones Intravenosas , Hígado/patología , Mediciones Luminiscentes , Pulmón/patología , Neutrófilos/citología , Neutrófilos/efectos de los fármacos , Conejos , Fenómeno de Shwartzman/patología , Sales de Tetrazolio , Tiazoles
19.
Radiat Prot Dosimetry ; 117(1-3): 111-5, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16461486

RESUMEN

Interventional cardiac procedures can be complex and involve extensive use of low dose rate fluoroscopy and high dose rate in image acquisition mode; hence, staff may receive significant radiation exposure. Radiation exposure to operators was assessed in 173 procedures. Fluoroscopy time, number of acquired images and dose-area product were recorded and occupational dose assessed with thermoluminescence dosemeters. The effective dose to the operator was compared with relevant literature data: values found were generally lower than those reported for other interventional cardiology laboratories. This is probably because of the strict radiation protection policy in our centre. Higher effective doses were found for defibrillator implantation and percutaneous transluminal coronary angiography procedures; for other cardiac procedures, effective dose was lower. Yearly extrapolated occupational doses to cardiologists are lower than the regulatory dose limit and in the lower band of doses reported in the literature.


Asunto(s)
Cardiología/métodos , Angiografía Coronaria/métodos , Electrofisiología/métodos , Fluoroscopía/métodos , Exposición Profesional , Protección Radiológica/métodos , Radiografía Intervencional/métodos , Algoritmos , Desfibriladores , Hemodinámica , Humanos , Dosis de Radiación , Monitoreo de Radiación/métodos
20.
Radiat Prot Dosimetry ; 117(1-3): 247-50, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16461491

RESUMEN

Interventional cardiology procedures can involve high doses to patients and, in particular, to patients' skin, the tissue at greatest risk of deterministic injuries. The evaluation of skin dose from interventional procedures is recommended, but difficult because of the amount of different X-ray fields and projections used in a procedure. For this reason, a retrospective follow-up study has been developed to identify skin injuries in patients submitted to one or more cardiac interventions in the Udine hospital between 1998 and 2002. Seventy-eight patients with a cumulative dose-area product >300 Gy cm2 were selected from 3332 patients, who underwent 5039 procedures. In this group the maximum skin dose was 6.7 Gy. The clinical follow-up, performed using the LENT-SOMA methodology, has not detected skin injuries and this result allows a frequency to be estimated for skin injuries in patients undergoing repeated cardiac procedures of <3 x 10(-4) in our centre.


Asunto(s)
Cardiología/métodos , Traumatismos por Radiación/diagnóstico , Radiodermatitis/diagnóstico , Radiología Intervencionista/métodos , Piel/lesiones , Piel/efectos de la radiación , Anciano , Algoritmos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dosis de Radiación , Protección Radiológica , Estudios Retrospectivos , Factores de Tiempo , Rayos X
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