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1.
J Environ Manage ; 304: 114264, 2022 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-34906809

RESUMEN

Enhanced efficiency fertilisers (EEF) may reduce nitrogen (N) losses and improve uptake efficiency through synchronising N release with in-season plant requirements. We hypothesised that EEF formed via matrix encapsulation in biodegradable polymers will improve N use efficiency when compared to conventional urea fertiliser. This hypothesis was investigated for two biodegradable polymer matrices: polyhydroxyalkanoate (PHA), containing 11.6% urea (by mass), and polybutylene-adipate-co-terephthalate (PBAT), containing either 19.4 or 32.7% urea; and two contrasting soil types: sand and clay. Nitrogen availability and form was investigated under leaching conditions (water) with a growth accelerator pot experiment involving a horticultural crop and novel non-destructive three-dimensional scanning to measure in-season biomass development. The PBAT 32.7% formulation enabled greater above ground biomass production at both 50 and 100 kg N ha-1 equivalent application rates compared to conventional urea. For the sandy soil, plant scanning indicated that improved uptake performance with PBAT 32.7% was probably the result of greater N availability after 25 days than for conventional urea. Two of the encapsulated formulations (PHA and PBAT 19.4%) tended to decrease nitrogen leaching losses relative to urea (P < 0.05 for the red clay soil). However, decreased N leaching loss was accompanied by poorer N uptake performance, indicative of N being less available in these biopolymer formulations. A snapshot of nitrous oxide emissions collected during peak nitrate concentration (prior to planting and leaching) suggested that the biopolymers promoted N loss via gaseous emission relative to urea in the sandy soil (P < 0.05), and carbon dioxide emissions data suggested that biopolymer-carbon increased microbial activity (P < 0.1). Controlled testing of N release in water was a poor predictor of biomass production and leaching losses. The diverse behaviours of the tested formulations present the potential to optimise biopolymers and their N loadings by taking into account soil and environmental factors that influence the efficient delivery of N to target crops. The greater N uptake efficiency demonstrated for the PBAT 32.7% formulation confirms our hypothesis that matrix encapsulation can enable better synchronisation of N release with crop requirements and decrease leaching losses.


Asunto(s)
Fertilizantes , Objetivos , Agricultura , Productos Agrícolas , Fertilizantes/análisis , Nitrógeno/análisis , Polímeros , Suelo
2.
Photosynth Res ; 127(2): 161-70, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26031418

RESUMEN

Current effects on climate change and dwindling fossil fuel reserves require new materials and methods to convert solar energy into a viable clean energy source. Recent progress in the direct conversion of light into photocurrent has been well documented using Photosystem I. In plants, PSI consists of a core complex and multiple light-harvesting complexes, denoted LHCI and LHCII. Most of the methods for isolating PSI from plants involve a selective, detergent solubilization from thylakoids followed by sucrose gradient density centrifugation. These processes isolate one variant of PSI with a specific ratio of Chl:P700. In this study, we have developed a simple and potentially scalable method for isolating multiple PSI variants using Hydroxyapatite chromatography, which has been well documented in other Photosystem I isolation protocols. By varying the wash conditions, we show that it is possible to change the Chl:P700 ratios. These different PSI complexes were cast into a PSI-Nafion-osmium polymer film that enabled their photoactivity to be measured. Photocurrent increases nearly 400% between highly washed and untreated solutions based on equal chlorophyll content. Importantly, the mild washing conditions remove peripheral Chl and some LHCI without inhibiting the photochemical activity of PSI as suggested by SDS-PAGE analysis. This result could indicate that more P700 could be loaded per surface area for biohybrid devices. Compared with other PSI isolations, this protocol also allows isolation of multiple PSI variants without loss of photochemical activity.


Asunto(s)
Clorofila/metabolismo , Electricidad , Complejos de Proteína Captadores de Luz/metabolismo , Luz , Complejo de Proteína del Fotosistema I/metabolismo , Spinacia oleracea/metabolismo , Cristalografía por Rayos X , Durapatita/química , Electroquímica , Electroforesis en Gel de Poliacrilamida , Fotoblanqueo , Complejo de Proteína del Fotosistema I/química , Spinacia oleracea/efectos de la radiación
3.
J Evol Biol ; 26(10): 2244-59, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24028472

RESUMEN

Floral nectar composition has been explained as an adaptation to factors that are either directly or indirectly related to pollinator attraction. However, it is often unclear whether the sugar composition is a direct adaptation to pollinator preferences. Firstly, the lower osmolality of sucrose solutions means that they evaporate more rapidly than hexose solutions, which might be one reason why sucrose-rich nectar is typically found in flowers with long tubes (adapted to long-tongued pollinators), where it is better protected from evaporation than in open or short-tubed flowers. Secondly, it can be assumed that temperature-dependent evaporation is generally lower during the night than during the day so that selection pressure to secrete nectar with high osmolality (i.e. hexose-rich solutions) is relaxed for night-active flowers pollinated at night. Thirdly, the breeding system may affect selection pressure on nectar traits; that is, for pollinator-independent, self-pollinated plants, a lower selective pressure on nectar traits can be assumed, leading to a higher variability of nectar sugar composition independent of pollinator preferences, nectar accessibility and nectar protection. To analyse the relations between flower tube length, day vs. night pollination and self-pollination, the nectar sugar composition was investigated in 78 European Caryophylloideae (Caryophyllaceae) with different pollination modes (diurnal, nocturnal, self-pollination) using high-performance liquid chromatography (HPLC). All Caryophylleae species (Dianthus and relatives) were found to have nectar with more than 50% sucrose, whereas the sugar composition of Sileneae species (Silene and relatives) ranged from 0% to 98.2%. In the genus Silene, a clear dichotomous distribution of sucrose- and hexose-dominant nectars is evident. We found a positive correlation between the flower tube length and sucrose content in Caryophylloideae, particularly in day-flowering species, using both conventional analyses and phylogenetically independent contrasts.


Asunto(s)
Caryophyllaceae/metabolismo , Néctar de las Plantas/química , Polinización , Caryophyllaceae/anatomía & histología , Caryophyllaceae/clasificación , Cromatografía Líquida de Alta Presión , Ritmo Circadiano , Flores/anatomía & histología , Flores/metabolismo , Fructosa/química , Fructosa/metabolismo , Glucosa/química , Glucosa/metabolismo , Filogenia , Néctar de las Plantas/metabolismo , Sacarosa/química , Sacarosa/metabolismo
4.
Fortschr Neurol Psychiatr ; 78(3): 154-60, 2010 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-20213581

RESUMEN

Angiographic Moyamoya is a rare cerebrovascular disease most frequent in asia. Its characateristics are recurrent ischemic attacks due to progressive occlusion of ICA branches. Angiography reveals fine arterial collateralisation reminding of ascending smoke ("moyamoya" in japanese). Neurosurgical treatment strategies include direct and indirect reanastomosation procedures. Randomised trials for comparison of clinical outcome and long term survival remain missing. A 23 years old female with glycogenosis type IA was first diagnosed bilateral angiographic moyamoya with bilateral proximal stenosis of ICA after transient ischemic attack (TIA). Coincidence of both rare diseases moyamoya and glycogenosis has previously been reported in three cases, so that this metabolic dysfunction presumably is a true risk factor for moyamoya. In our case, excellent angiographic and functional results were achieved by bilateral, consecutive Enzephalo-Duro-Arterio-Myo-Synangiosis (EDAMS).


Asunto(s)
Enfermedad del Almacenamiento de Glucógeno Tipo I/complicaciones , Enfermedad del Almacenamiento de Glucógeno Tipo I/patología , Enfermedad de Moyamoya/complicaciones , Enfermedad de Moyamoya/patología , Procedimientos Neuroquirúrgicos , Procedimientos Quirúrgicos Vasculares , Arteria Carótida Interna/patología , Estenosis Carotídea/patología , Angiografía Cerebral , Femenino , Enfermedad del Almacenamiento de Glucógeno Tipo I/cirugía , Humanos , Ataque Isquémico Transitorio/complicaciones , Ataque Isquémico Transitorio/patología , Angiografía por Resonancia Magnética , Enfermedad de Moyamoya/cirugía , Neovascularización Patológica/patología , Neovascularización Patológica/terapia , Adulto Joven
5.
Cardiovasc Eng Technol ; 11(3): 328-336, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32002814

RESUMEN

PURPOSE: Metabolic alterations underlie many pathophysiological conditions, and their understanding is critical for the development of novel therapies. Although the assessment of metabolic changes in vivo has been historically challenging, recent developments in molecular imaging have allowed us to study novel metabolic research concepts directly in the living subject, bringing us closer to patients. However, in many instances, there is need for sensors that are in close proximity to the organ under investigation, for example to study vascular metabolism. METHODS: In this study, we developed and validated a metabolic detection platform directly in the living subject under an inflammatory condition. The signal collected by a scintillating fiber is amplified using a photomultiplier tube and decodified by an in-house tunable analysis platform. For in vivo testing, we based our experiments on the metabolic characteristics of macrophages, cells closely linked to inflammation and avid for glucose and its analog 18F-fluorodeoxyglucose (18F-FDG). The sensor was validated in New Zealand rabbits, in which inflammation was induced by either a) high cholesterol (HC) diet for 16 weeks or b) vascular balloon endothelial denudation followed by HC diet. RESULTS: There was no difference in weight, hemodynamics, blood pressure, or heart rate between the groups. Vascular inflammation was detected by the metabolic sensor (Inflammation: 0.60 ± 0.03 AU vs. control: 0.48 ± 0.03 AU, p = 0.01), even though no significant inflammation/atherosclerosis was detected by intravascular ultrasound, underscoring the high sensitivity of the system. These findings were confirmed by the presence of macrophages on ex vivo aortic tissue staining. CONCLUSION: In this study, we validated a tunable very sensitive metabolic sensor platform that can be used for the detection of vascular metabolism, such as inflammation. This sensor can be used not only for the detection of macrophage activity but, with alternative probes, it could allow the detection of other pathophysiological processes.


Asunto(s)
Aorta/metabolismo , Aortitis/metabolismo , Aterosclerosis/metabolismo , Técnicas Biosensibles , Metabolismo Energético , Fluorodesoxiglucosa F18/metabolismo , Fibras Ópticas , Radiofármacos/metabolismo , Lesiones del Sistema Vascular/metabolismo , Animales , Aorta/lesiones , Aorta/patología , Aortitis/patología , Aterosclerosis/patología , Modelos Animales de Enfermedad , Macrófagos/metabolismo , Macrófagos/patología , Conejos , Reproducibilidad de los Resultados , Procesamiento de Señales Asistido por Computador , Lesiones del Sistema Vascular/patología
6.
Acad Med ; 97(8): 1098, 2022 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-34647918
7.
Circ Res ; 89(1): 71-6, 2001 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-11440980

RESUMEN

Tissue factor (TF) is a low-molecular-weight glycoprotein that initiates the extrinsic clotting cascade and is considered a major regulator of arterial thrombogenicity. TF pathway inhibitor (TFPI) is a major physiological inhibitor of TF-initiated coagulation. The aim of this study was to define the complex interplay between TF and TFPI and the regulation of vascular thrombogenicity in a model of vascular remodeling. To determine the levels and pattern of vascular expression of TF and TFPI associated with vascular remodeling, a murine model of flow cessation was studied. TF activity of the arteries increased after ligation (P<0.05). Quantitative analysis of homogenates of remodeled carotid arteries revealed increased TF expression but unchanged TFPI expression compared with normal carotid arteries, resulting in enhanced TF activity. To determine the potential therapeutic role of TFPI in this thrombogenic state, mice were treated with intravascular adenoviral delivery of either murine TFPI (Ad-mTFPImyc) or a control adenovirus (Ad-DeltaE1). Overexpression of TFPI decreased vascular TF activity compared with viral control (P<0.01). Overexpression of TFPI inhibited neointimal formation (P=0.038), resulting in enhanced luminal area (P=0.001) 4 weeks after flow cessation. In this murine model of vascular remodeling, an imbalance between TF and TFPI expression is generated, resulting in increased TF activity. Overexpression of TFPI in this model inhibits vascular TF activity and results in attenuation of vascular remodeling associated with flow interruption.


Asunto(s)
Arteriosclerosis/etiología , Trombosis de las Arterias Carótidas/etiología , Lipoproteínas/fisiología , Tromboplastina/fisiología , Animales , Arteriosclerosis/metabolismo , Arteriosclerosis/terapia , Trombosis de las Arterias Carótidas/metabolismo , Trombosis de las Arterias Carótidas/terapia , Terapia Genética , Lipoproteínas/genética , Ratones , Ratones Endogámicos C57BL
8.
Leukemia ; 16(12): 2379-87, 2002 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12454742

RESUMEN

Resistance to the antifolate methotrexate (MTX) can cause treatment failure in childhood acute lymphoblastic leukemia (ALL). This may result from defective MTX accumulation due to alterations in the human reduced folate carrier (hRFC) gene. We have identified an hRFC gene point mutation in a transport-defective CCRF-CEM human T-ALL cell line resulting in a lysine to glutamic acid substitution at codon 45 (E45K), which has been identified in other antifolate-resistant sublines (JBC 273:30 189, 1998; JBC 275:30 855, 2000). To characterize the role of this mutation in MTX resistance, transfection experiments were performed using hRFC-null CCRF-CEM cells. E45K transfectants demonstrated an initial rate of MTX influx that was approximately 0.5-fold that of CCRF-CEM cells, despite marked protein overexpression. Cytotoxicity studies revealed partial reversal of MTX and raltitrexed resistance in E45K transfectants, while trimetrexate resistance was significantly increased. Kinetic analysis indicated only minor differences in MTX kinetics between wild-type and E45K hRFCs, however, K(i)s for folic acid and 5-formyltetrahydrofolate were markedly reduced for E45K hRFC. This was paralleled by increased folic acid transport and reduced synthesis of MTX polyglutamates. Collectively, the results demonstrate that expression of E45K hRFC leads to increased MTX resistance due to decreased membrane transport and, secondarily, from alterations in binding affinities and transport of folate substrates. However, despite these findings, we could find no evidence of this mutation in 121 childhood ALL samples, suggesting that it does not contribute to clinical MTX resistance in this disease.


Asunto(s)
Antimetabolitos Antineoplásicos/farmacocinética , Proteínas Portadoras/genética , Resistencia a Antineoplásicos/genética , Leucemia/tratamiento farmacológico , Proteínas de Transporte de Membrana , Metotrexato/farmacocinética , Mutación Puntual , Sustitución de Aminoácidos , Células de la Médula Ósea/patología , Proteínas Portadoras/fisiología , Niño , Ácido Fólico/farmacocinética , Humanos , Cinética , Leucemia/genética , Leucemia/patología , Estructura Terciaria de Proteína , Proteína Portadora de Folato Reducido , Transfección , Células Tumorales Cultivadas
9.
Clin Cancer Res ; 7(11): 3416-22, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11705857

RESUMEN

The presence of sequence variants in the human reduced folate carrier (hRFC) was assessed in leukemia blasts from children with acute lymphoblastic leukemia (ALL) and in normal peripheral blood specimens. A CATG frame shift insertion at position 191 was detected in 10-60% of hRFC transcripts from 10 of 16 ALL specimens, by RFLP analysis and direct sequencing of hRFC cDNAs. In genomic DNAs prepared from 105 leukemia (n = 54) and non-leukemia (n = 51) specimens, PCR amplifications and direct sequencing of exon 3 identified a high-frequency G to A single nucleotide polymorphism at position 80 that resulted in a change of arginine-27 to histidine-27. The allelic frequencies of G/A80 were nearly identical for the non-leukemia (42.2% CGC and 57.8% CAC) and leukemia (40.7% CGC and 59.3% CAC) genomic DNAs. In cDNAs prepared from 10 of these ALL patients, identical allelic frequencies (40 and 60%, respectively) were recorded. In up to 62 genomic DNAs, hRFC-coding exons 4-7 were PCR-amplified and sequenced. A high-abundance C/T696 polymorphism was detected with nearly identical frequencies for both alleles, and a heterozygous C/A1242 sequence variant was identified in two ALL specimens. Both C/T696 and C/A1242 were phenotypically silent. In transport assays with [(3)H]methotrexate and [(3)H]5-formyl tetrahydrofolate, nearly identical uptake rates were measured for the arginine-27- and histidine-27-hRFC proteins expressed in transport-impaired K562 cells. Although there were no significant differences between the kinetic parameters for methotrexate transport for the hRFC forms, minor (approximately 2-fold) differences were measured in the K(i)s for other substrates including Tomudex, 5,10-dideazatetrahydrofolate, GW1843U89, and 10-ethyl-10-deazaaminopterin and for 5-formyl tetrahydrofolate.


Asunto(s)
Proteínas Portadoras/genética , Proteínas de Transporte de Membrana , Polimorfismo de Nucleótido Simple , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Sustitución de Aminoácidos , Linfocitos B/metabolismo , Secuencia de Bases , Transporte Biológico/genética , Niño , Análisis Mutacional de ADN , ADN Complementario/química , ADN Complementario/genética , ADN de Neoplasias/química , ADN de Neoplasias/genética , Frecuencia de los Genes , Humanos , Células K562 , Metotrexato/farmacocinética , Mutagénesis Insercional , Plásmidos/genética , Mutación Puntual , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , ARN Neoplásico/genética , ARN Neoplásico/metabolismo , Proteína Portadora de Folato Reducido , Células Madre/metabolismo , Transfección
10.
Arch Neurol ; 55(8): 1137-9, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9708966

RESUMEN

OBJECTIVE: To describe a patient with multifocal cerebral ischemia whose only identified potential risk factors were use of postmenopausal hormone replacement and heterozygosity to factor V Leiden mutation. DESIGN: A case report. SETTING: A tertiary care center. PATIENT: A 51-year-old woman taking hormone replacement (0.625 mg/d of estrogen alternating with 10 mg/d of medroxyprogesterone) presented with a generalized tonic-clonic seizure. She had persistent multifocal non-enhancing lesions on magnetic resonance imaging of the brain. A stereotactic biopsy of the brain performed to exclude gliomatosis cerebri was consistent with cerebral ischemia. An extensive evaluation to uncover the cause of stroke revealed only heterozygosity to factor V Leiden mutation. MAIN OUTCOME AND RESULTS: Hormonal replacement was discontinued and the patient had no recurrent ischemic strokes. CONCLUSIONS: Postmenopausal hormonal replacement may be a risk factor for ischemic stroke in women with the factor V Leiden mutation. Ongoing trials of hormonal replacement provide an opportunity to test this hypothesis.


Asunto(s)
Isquemia Encefálica/complicaciones , Isquemia Encefálica/etiología , Trastornos Cerebrovasculares/etiología , Terapia de Reemplazo de Estrógeno/efectos adversos , Factor V , Mutación , Isquemia Encefálica/inducido químicamente , Isquemia Encefálica/genética , Isquemia Encefálica/patología , Trastornos Cerebrovasculares/genética , Trastornos Cerebrovasculares/patología , Femenino , Humanos , Imagen por Resonancia Magnética , Persona de Mediana Edad , Factores de Riesgo
11.
Neurology ; 44(1): 117-20, 1994 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8290045

RESUMEN

McLeod syndrome is an Xp21-linked Kell blood group variant due to lack of erythrocyte protein Kx with associated RBC membrane dysfunction such as acanthocytosis. A man with this syndrome developed chorea and slight neuropsychological impairment. He had caudate atrophy on cerebral imaging and reduced striatal dopamine D2-receptor binding on single-photon emission computed tomography. Since Xp21 was partly deleted in the patient, the missing gene product (possibly Kx) may be essential for the integrity of the striatum.


Asunto(s)
Encéfalo/fisiopatología , Ligamiento Genético , Sistema del Grupo Sanguíneo de Kell/genética , Cromosoma X , Benzamidas , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Medios de Contraste , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Pirrolidinas , Síndrome , Tomografía Computarizada de Emisión de Fotón Único , Tomografía Computarizada por Rayos X
12.
Neurology ; 41(11): 1836-8, 1991 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1944918

RESUMEN

Anti-acetylcholine receptor (AChR) antibodies in myasthenia gravis (MG) can be quantitated using AChR extracted from the human rhabdomyosarcoma cell line TE671 (AChRTE671) as a practical alternative to AChR from human amputated limbs (AChRAMP). We compared the two antigen preparations using serum samples from different clinical groups of MG patients (n = 112) and various controls (n = 189). With two exceptions, both tests were positive or negative in the same patients. However, in the generalized MG group, the TE671 assay yielded significantly lower titers than the AChRAMP assay.


Asunto(s)
Autoanticuerpos/análisis , Miastenia Gravis/inmunología , Receptores Colinérgicos/inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Línea Celular , Femenino , Humanos , Masculino , Persona de Mediana Edad
13.
Neurology ; 40(2): 273-6, 1990 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-2300248

RESUMEN

We studied motor and psychomotor changes over 1 year after surgery in 7 patients with severe idiopathic Parkinson's disease (PD) who underwent intrastriatal autologous adrenal medulla transplant. Significant clinical improvements were present 1 year after surgery and primarily involved increased quantity of "on" time and increased quality of "off" time: "on" time increased from a mean 60.7% of the waking day to 82.7%, and "off" function improved. In contrast, although "on" function also improved, statistically significant improvement occurred in only 1 measure, the Unified Parkinson's Disease Rating Scale activities of daily living subscale. Medications did not change, and motor fluctuations persisted. Improvement began several weeks after surgery, was maximal at 4 to 6 months, and was sustained thereafter. There was significant group improvement in quality of life measures of sleep and rest, social isolation, and ambulation. One patient had severe, recurrent depression postoperatively. The efficacy of adrenal transplant surgery is not transient, and specific functional improvements can be prolonged.


Asunto(s)
Médula Suprarrenal/trasplante , Cuerpo Estriado/cirugía , Enfermedad de Parkinson/cirugía , Desempeño Psicomotor , Actividades Cotidianas , Análisis de Varianza , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Pruebas Neuropsicológicas , Enfermedad de Parkinson/fisiopatología , Enfermedad de Parkinson/psicología , Calidad de Vida , Trasplante Autólogo
14.
Int J Radiat Oncol Biol Phys ; 13(12): 1807-13, 1987 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-3679917

RESUMEN

Forty-four patients with predominantly inoperable or recurrent head and neck cancers were treated with combined chemotherapy (CT) and radiation therapy (RT) in a Phase I/II study. CT and RT were combined in a concomitant fashion to take advantage of radiosensitizing properties of the chemotherapeutic agents. Each treatment cycle consisted of cisplatin 60 mg/M2 on day 1, 5-FU infusion at a dose of 800 mg/M2 per day continuously for 5 days and RT at 200 cGy per day, days 1 through 5. The treatment cycle was repeated every 2 weeks for 7 cycles in patients treated curatively and for 2 to 6 cycles in patients treated palliatively due to prior radiation therapy or the presence of metastatic disease. Regional control was achieved in 98% of the patients. Regional control has persisted in 87% of the patients treated curatively with a minimum follow-up of 24 months. Distant failure occurred in 23% of this group. Actuarial survival of 2 years for the curative group is 66%. Concomitant combination of radiation with radiation potentiating chemotherapeutic agents shows promise of increase in local control.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Neoplasias de Cabeza y Cuello/terapia , Cisplatino/administración & dosificación , Terapia Combinada , Esquema de Medicación , Evaluación de Medicamentos , Fluorouracilo/administración & dosificación , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Neoplasias de Cabeza y Cuello/radioterapia , Humanos , Metástasis de la Neoplasia , Estudios Prospectivos
15.
Int J Radiat Oncol Biol Phys ; 30(1): 49-53, 1994 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-8083128

RESUMEN

PURPOSE: Multicentric cancer is present in a large proportion of mastectomies performed as treatment of breast cancer; it has been considered a contraindication to breast conservation. METHODS AND MATERIALS: We reviewed the records of our patients with Stage I or II breast cancer treated with breast conserving surgery and radiation therapy over a 13-year period. Twenty-seven patients had two or more nodules of grossly visible cancer separated by histologically normal breast tissue. All patients had grossly negative margins of excision; however, four patients had microscopically positive margins. Nine patients had positive axillary nodes. All patients received radiation therapy to the breast postoperatively, with a median dose of 50.4 Gy in 28 fractions; 11 patients also received a boost dose of 6-20 Gy to the tumor bed. Eleven patients were given adjuvant chemotherapy and one patient was given adjuvant tamoxifen. RESULTS: With a median follow-up of 53 months, only one patient has relapsed in the breast (3.7%); that patient relapsed in multiple distant sites at the same time. Three patients have died of disseminated disease; the actuarial survival and disease-free survival rates at 4 years are 89%. CONCLUSION: Breast conservation may be considered for patients with multicentric breast cancer discovered at the time of histologic examination. For patients with multicentric disease detected prior to surgery, breast conserving therapy may be appropriate as long as: (1) all clinically and radiographically apparent abnormalities are removed, (2) clear margins of resection are achieved, and (3) there is no extensive intraductal component.


Asunto(s)
Neoplasias de la Mama/cirugía , Mastectomía Segmentaria , Neoplasias Primarias Secundarias/cirugía , Adulto , Anciano , Neoplasias de la Mama/patología , Neoplasias de la Mama/radioterapia , Terapia Combinada , Contraindicaciones , Femenino , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Invasividad Neoplásica , Neoplasias Primarias Secundarias/patología , Neoplasias Primarias Secundarias/radioterapia
16.
J Med Chem ; 43(10): 2079-81, 2000 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-10821720

RESUMEN

Partially hydrogenated derivatives of the new heterocyclic ring systems benz[d]indolo[2,3-g]azecine and bisindolo[3,2-d][2, 3-g]azecine were synthesized starting from lactones and amines via the described synthetic methods. In binding assays with rat striatal receptors, 7-methyl-6,7,8,9,14,15-hexahydro-5H-benz[d]indolo[2, 3-g]azecine (LE 300) proved to be of high affinity for the D(1) binding site (K(i) = 0.08 nmol for displacement of [(3)H]SCH23390), being superior in this assay to standards such as butaclamol and SCH23390. This compound was characterized as a dopamine antagonist by conditioned avoidance response test with mice. Thus, LE 300 represents the lead of a new class of dopamine antagonists for future investigations.


Asunto(s)
Antagonistas de Dopamina/síntesis química , Indoles/síntesis química , Animales , Reacción de Prevención/efectos de los fármacos , Benzazepinas/metabolismo , Benzazepinas/farmacología , Unión Competitiva , Butaclamol/farmacología , Cuerpo Estriado/metabolismo , Antagonistas de Dopamina/metabolismo , Antagonistas de Dopamina/farmacología , Indoles/metabolismo , Indoles/farmacología , Ratones , Conformación Molecular , Ratas , Receptores de Dopamina D1/metabolismo , Porcinos
17.
Am J Cardiol ; 67(5): 381-6, 1991 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-1994662

RESUMEN

The Holter tapes of 61 patients (46 men, mean age +/- standard deviation 65 +/- 11 years) with sudden cardiac death while being monitored were analyzed. Thirty-eight patients were known to have coronary artery disease, 5 had cardiomyopathy, and 7 had aortic valve disease. Etiology remained unknown in 11 patients. Mean New York Heart Association functional class was 2.5 +/- 0.7. Thirty patients had received antiarrhythmic drugs and 32 had received digitalis. Sudden death occurred at rest in 73%. In the hours before death, repetitive ventricular arrhythmias were found in 50 patients (82%), with atrial fibrillation in 34%. Patients with bradyarrhythmic death (18%) had less complex ventricular activity compared to patients with tachyarrhythmic death (p less than 0.01). Lethal arrhythmias--monomorphic ventricular tachycardia, polymorphic ventricular tachycardia, torsades de pointes, primary ventricular fibrillation, and 1:1 conducting atrial tachycardia--were found in 26 (43%), 15 (25%), 5 (8%), 3 (5%), and 1 patient, respectively. The coupling interval of the final ventricular tachycardia correlated inversely with the initial frequency of ventricular tachycardia (p less than 0.05). For patients with tachyarrhythmic death, an increase of heart rate within the last 3 hours was noted (83 vs 89 beats/min, p less than 0.05). Ventricular premature complexes and the proportion of patients with greater than 2 couplets and greater than 2 triplets increased significantly only within the last hour before death.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Arritmias Cardíacas/complicaciones , Muerte Súbita/etiología , Electrocardiografía Ambulatoria , Anciano , Arritmias Cardíacas/epidemiología , Fibrilación Atrial/complicaciones , Muerte Súbita/epidemiología , Femenino , Paro Cardíaco/epidemiología , Paro Cardíaco/etiología , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Procesamiento de Señales Asistido por Computador , Taquicardia/complicaciones , Factores de Tiempo
18.
Biochem Pharmacol ; 61(6): 665-75, 2001 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-11266651

RESUMEN

Severe impairment of methotrexate membrane transport in methotrexate-resistant K562 (K500E) cells was characterized by a nearly complete loss of reduced folate carrier (RFC) transcripts and RFC protein. As determined by 5'-rapid amplification of cDNA ends (5'-RACE), approximately 93% of the RFC transcripts in wild-type cells contained the KS43 5'-untranslated region transcribed from the RFC-B promoter. KS43 transcripts decreased > 90% in K500E cells. The basal and full-length RFC-B promoters were more active (3- and 2-fold, respectively) in directing transcription of a luciferase reporter gene in K500E than in wild-type cells. Treatment with a demethylating agent, 5-aza-2'-deoxycytidine, or with a histone deacetylase inhibitor, trichostatin A, did not increase the levels of RFC transcripts in K500E cells. No differences in RFC gene structure were detected between the lines on Southern blots; however, the RFC signals were decreased approximately 60% in K500E cells. DNA sequences were identical between the lines for the RFC coding region and the two 5'-non-coding exons and their respective promoters. Spectral karyotype analysis and fluorescence in situ hybridization in wild-type cells showed two normal chromosome 21 copies and one or two marker chromosomes, each with an RFC signal. In K500E cells, the RFC gene locus was no longer localized to a normal chromosome 21 (at 21q22.2), and a single RFC signal was associated with a small metacentric chromosome, characterized by a 21/22 translocation. Our results suggest that loss of RFC transcripts in K500E cells is unrelated to changes in the levels of critical transcription factors, or to differences in the extent of RFC promoter methylation or core histone deacetylation. Rather, this phenotype is due to the loss of one or more RFC alleles, and to a translocation of the remaining RFC allele with the formation of a 21/22 fusion chromosome.


Asunto(s)
Azacitidina/análogos & derivados , Proteínas Portadoras/genética , Eliminación de Gen , Regulación Neoplásica de la Expresión Génica , Leucemia Eritroblástica Aguda/genética , Proteínas de la Membrana , Proteínas de Transporte de Membrana , Translocación Genética , Regiones no Traducidas 5'/genética , Antimetabolitos Antineoplásicos/farmacocinética , Antimetabolitos Antineoplásicos/farmacología , Azacitidina/farmacología , Transporte Biológico , Proteínas Portadoras/biosíntesis , Metilación de ADN , Decitabina , Resistencia a Antineoplásicos/genética , Genes Reporteros , Histonas/metabolismo , Humanos , Ácidos Hidroxámicos/farmacología , Hibridación Fluorescente in Situ , Células K562 , Cariotipificación , Metotrexato/farmacocinética , Metotrexato/farmacología , Regiones Promotoras Genéticas/fisiología , ARN Mensajero/biosíntesis , Proteína Portadora de Folato Reducido , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
19.
J Thorac Cardiovasc Surg ; 85(3): 337-45, 1983 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-6827842

RESUMEN

The association of adenocarcinoma with Barrett's esophagus stimulated a review of our experience to study the clinical presentation, pathology, and results of management. Nineteen patients (15 men and four women) satisfied the criteria of primary adenocarcinoma arising in columnar epithelium in the esophagus. The majority had dysphagia (95%) and weight loss (63%). Nearly three fourths of the patients also had a history of hiatus hernia or esophagitis. Diagnosis was confirmed preoperatively in all by endoscopic biopsy and/or cytologic study. Potentially curative resection was performed in 15 patients and palliative procedures in four. Fourteen patients had advanced (Stage III) disease and only five had Stage I or II disease. Multicentric disease within the esophagus was found in seven patients. Postoperative complications included empyema, hemothorax, and pneumonia (one case each). The only postoperative death resulted from complications of previously undetected brain metastases. The median survival of the 15 patients having resection for cure is 12 months. Four are alive, one with disease at 46 months and three free of disease at 19, 87, and 93 months. All four patients undergoing palliative procedures died within 8 months. The study demonstrates that multifocal presentation of the tumor is common in this group of patients and that long-term survival is possible when early tumors are managed aggressively.


Asunto(s)
Adenocarcinoma/etiología , Esófago de Barrett/complicaciones , Enfermedades del Esófago/complicaciones , Neoplasias Esofágicas/etiología , Análisis Actuarial , Adenocarcinoma/patología , Adenocarcinoma/cirugía , Adulto , Anciano , Neoplasias Esofágicas/patología , Neoplasias Esofágicas/cirugía , Esófago/cirugía , Femenino , Gastrectomía , Humanos , Masculino , Neoplasias del Mediastino/secundario , Persona de Mediana Edad , Estadificación de Neoplasias , Complicaciones Posoperatorias/etiología
20.
Surgery ; 114(4): 799-805; discussion 804-5, 1993 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8211697

RESUMEN

BACKGROUND: The role of hepatic resection for noncolorectal gastrointestinal malignancies involving the liver is not well defined. To address this issue we studied our experience with resection of liver tumors arising from primary gastric malignancies. METHODS: A retrospective study of 195 patients who underwent a total of 207 liver resections identified 12 patients with primary gastric cancer who underwent 16 resections for liver involvement. There were 10 adenocarcinomas and two leiomyosarcomas. We examined the type of hepatic surgery, the status of residual disease, and the primary histologic findings. Morbidity, mortality, and actual survival rates were recorded. RESULTS: Thirty-day operative mortality was 8.3% (1 of 12). Hospital mortality was 25% (3 of 12). Operative morbidity occurred in three of nine survivors (33%). Synchronous en bloc resection (n = 3) of stomach and liver for adenocarcinoma produced two long-term survivors (no evidence of disease for 10 and 13 years). Mean survival after synchronous discontinuous resection (n = 4) was 8 months (range, 2 to 17 months). Metachronous resection for adenocarcinoma (n = 3) produced one long-term survivor (74 months), and one patient with recurrent leiomyosarcoma underwent a total of five liver resections and survived 64 months. CONCLUSIONS: For adenocarcinoma, en bloc resection of contiguous liver involvement produced long-term survivors. Synchronous resection of discontinuous metastases did not. Metachronous resection of isolated disease and multiple resections of recurrent isolated disease may have value in carefully selected patients.


Asunto(s)
Neoplasias Hepáticas/secundario , Neoplasias Hepáticas/cirugía , Hígado/cirugía , Neoplasias Gástricas/patología , Adenocarcinoma/mortalidad , Adenocarcinoma/secundario , Adenocarcinoma/cirugía , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Leiomiosarcoma/mortalidad , Leiomiosarcoma/secundario , Leiomiosarcoma/cirugía , Neoplasias Hepáticas/mortalidad , Masculino , Persona de Mediana Edad , Reoperación , Análisis de Supervivencia
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