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1.
Osteoporos Int ; 23(7): 1931-8, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22159633

RESUMEN

SUMMARY: The rates of bone mineral density testing for osteoporosis among healthy mid-life women are high, although their osteoporosis or fracture risk is low. To reduce unnecessary testing, we created and evaluated a tool to guide bone density testing based on the woman's age, weight, fracture history, and menopausal status. INTRODUCTION: This study aims to improve case finding of mid-life women with low bone mass on bone mineral density (BMD) assessment. METHODS: Among healthy women aged 40-60 years having their first BMD test, osteoporosis risk factors were assessed by questionnaire and BMD by dual-energy X-ray absorptiometry. The combination of risk factors that best discriminated women with/without low bone mass (T-score ≤ -2.0) was determined from the logistic regression model area under the curve (AUC) and internally validated using bootstrapping. Using the model odds ratios, a clinical prediction rule was created and its discriminative properties assessed and compared with that of the osteoporosis self-assessment tool (OST). Sensitivity analyses examined results for pre-/peri- and post-menopausal women, separately. RESULTS: Of 1,664 women referred for baseline BMD testing, 433 with conditions known to be associated with bone loss were excluded. Of 1,231 eligible women, 944 (77%) participated and 87 (9.2%) had low bone mass (35 pre-/peri- and 52 post-menopausal). Four risk factors for low bone mass were identified and incorporated into a clinical prediction rule. Selecting women for BMD testing with weight of ≤70 kg or any two of age >51, years' post-menopause of ≥1, and history of fragility fracture after age 40 was associated with 93% sensitivity to identify women with low bone mass, compared with 47% sensitivity for an OST score of ≤1 (AUC 0.75 versus OST AUC 0.69, p = 0.04). Results restricted to post-menopausal women were similar. CONCLUSIONS: Among healthy mid-life women receiving a baseline BMD test, few had low bone mass, supporting the need for guidance about testing. A prediction rule with four risk factors had improved sensitivity over the OST. Further validation is warranted.


Asunto(s)
Densidad Ósea/fisiología , Técnicas de Apoyo para la Decisión , Osteoporosis/diagnóstico , Absorciometría de Fotón/métodos , Adulto , Femenino , Humanos , Persona de Mediana Edad , Osteoporosis/etiología , Osteoporosis/fisiopatología , Osteoporosis Posmenopáusica/diagnóstico , Osteoporosis Posmenopáusica/etiología , Osteoporosis Posmenopáusica/fisiopatología , Posmenopausia/fisiología , Valor Predictivo de las Pruebas , Premenopausia/fisiología , Factores de Riesgo , Procedimientos Innecesarios
2.
Osteoarthritis Cartilage ; 19(4): 366-74, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21324369

RESUMEN

OBJECTIVE: To highlight seminal publications in the past year on the topic of non-pharmacologic management of osteoarthritis (OA). DESIGN: A systematic search of the PUBMED and Cochrane databases from September 2009 to September 2010 was conducted to identify articles reporting on studies examining the safety or efficacy of non-pharmacologic therapies in the management of OA. Non-pharmacologic therapies were those considered in the 2008 OARSI OA guidelines. Identified articles were reviewed for quality; those of highest quality and deemed to have greatest potential impact on the management of OA were summarized. RESULTS: The search identified 117 unique articles. Of these, four studies were chosen to highlight. A nested two-stage trial found that traditional Chinese acupuncture (TCA) was not superior to sham acupuncture, but that the providers' style affected both pain reduction and satisfaction with treatment, suggesting that the analgesic benefits of acupuncture may be partially mediated by the acupuncturists' behavior. A systematic review found little evidence of a significant effect for electrostimulation vs sham or no intervention on pain in knee OA. A single-blinded trial of Tai Chi vs attention controls found that 12 weeks of Tai Chi was associated with improvements in symptoms and disability in patients with knee OA. A randomized trial of early ACL reconstructive surgery and rehabilitation vs structured rehabilitation alone in subjects with acute anterior cruciate ligament tears found that, at 24 months following randomization, all study participants had improved, suggesting that a strategy of structured rehabilitation followed acute ACL injury may preclude the need for surgical reconstruction. CONCLUSIONS: High quality studies of the safety and efficacy of non-pharmacologic agents in the management of OA remain challenging due to difficulties with adequate blinding and appropriate selection of attention controls. High quality studies suggest modest, if any, benefit of many non-pharmacologic therapies over attention control or placebo, but a significant impact of both over no intervention at all.


Asunto(s)
Osteoartritis/terapia , Acupuntura , Anciano , Ejercicio Físico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Osteoartritis/rehabilitación , Manejo del Dolor , Satisfacción del Paciente , Especialidad de Fisioterapia , Taichi Chuan , Estimulación Eléctrica Transcutánea del Nervio
3.
Phys Chem Chem Phys ; 13(32): 14302-10, 2011 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-21695318

RESUMEN

Responsive monolayers are key building blocks for future applications in organic and molecular electronics in particular because they hold potential for tuning the physico-chemical properties of interfaces, including their energetics. Here we study a photochromic SAM based on a conjugated azobenzene derivative and its influence on the gold work function (Φ(Au)) when chemisorbed on its surface. In particular we show that the Φ(Au) can be modulated with external stimuli by controlling the azobenzene trans/cis isomerization process. This phenomenon is characterized experimentally by four different techniques, kelvin probe, kelvin probe force microscopy, electroabsorption spectroscopy and ultraviolet photoelectron spectroscopy. The use of different techniques implies exposing the SAM to different measurement conditions and different preparation methods, which, remarkably, do not alter the observed work function change (Φ(trans)-Φ(cis)). Theoretical calculations provided a complementary insight crucial to attain a deeper knowledge on the origin of the work function photo-modulation.


Asunto(s)
Compuestos Azo/química , Oro/química , Membranas Artificiales , Teoría Cuántica , Compuestos Azo/síntesis química , Estructura Molecular , Tamaño de la Partícula , Procesos Fotoquímicos , Estereoisomerismo , Propiedades de Superficie
4.
Genetics ; 180(1): 27-39, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18723894

RESUMEN

The molecular mechanisms mediating eukaryotic replication termination and pausing remain largely unknown. Here we present the molecular characterization of Rtf1 that mediates site-specific replication termination at the polar Schizosaccharomyces pombe barrier RTS1. We show that Rtf1 possesses two chimeric myb/SANT domains: one is able to interact with the repeated motifs encoded by the RTS1 element as well as the elements enhancer region, while the other shows only a weak DNA binding activity. In addition we show that the C-terminal tail of Rtf1 mediates self-interaction, and deletion of this tail has a dominant phenotype. Finally, we identify a point mutation in Rtf1 domain I that converts the RTS1 element into a replication barrier of the opposite polarity. Together our data establish that multiple protein DNA and protein-protein interactions between Rtf1 molecules and both the repeated motifs and the enhancer region of RTS1 are required for site-specific termination at the RTS1 element.


Asunto(s)
Replicación del ADN , Elementos de Facilitación Genéticos , Proteínas de Saccharomyces cerevisiae/genética , Schizosaccharomyces/genética , Proteína de Unión a TATA-Box/genética , Secuencias de Aminoácidos , Secuencia de Aminoácidos , ADN/química , ADN Ribosómico/química , Proteínas Fúngicas/química , Modelos Genéticos , Datos de Secuencia Molecular , Mutación Puntual , Estructura Terciaria de Proteína , Homología de Secuencia de Aminoácido , Técnicas del Sistema de Dos Híbridos
5.
Mol Vis ; 14: 2190-203, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-19052649

RESUMEN

PURPOSE: Degenerative retinal diseases are characterized by inflammation and microglial activation. The nonpsychoactive cannabinoid, cannabidiol (CBD), is an anti-inflammatory in models of diabetes and glaucoma. However, the cellular and molecular mechanisms are largely unknown. We tested the hypothesis that retinal inflammation and microglia activation are initiated and sustained by oxidative stress and p38 mitogen-activated protein kinase (MAPK) activation, and that CBD reduces inflammation by blocking these processes. METHODS: Microglial cells were isolated from retinas of newborn rats. Tumor necrosis factor (TNF)-alpha levels were estimated with ELISA. Nitric oxide (NO) was determined with a NO analyzer. Superoxide anion levels were determined by the chemiluminescence of luminol derivative. Reactive oxygen species (ROS) was estimated by measuring the cellular oxidation products of 2', 7'-dichlorofluorescin diacetate. RESULTS: In retinal microglial cells, treatment with lipopolysaccharide (LPS) induced immediate NADPH oxidase-generated ROS. This was followed by p38 MAPK activation and resulted in a time-dependent increase in TNF-alpha production. At a later phase, LPS induced NO, ROS, and p38 MAPK activation that peaked at 2-6 h and was accompanied by morphological change of microglia. Treatment with 1 microM CBD inhibited ROS formation and p38 MAPK activation, NO and TNF-alpha formation, and maintained cell morphology. In addition, LPS-treated rat retinas showed an accumulation of macrophages and activated microglia, significant levels of ROS and nitrotyrosine, activation of p38 MAPK, and neuronal apoptosis. These effects were blocked by treatment with 5 mg/kg CBD. CONCLUSIONS: Retinal inflammation and degeneration in uveitis are caused by oxidative stress. CBD exerts anti-inflammatory and neuroprotective effects by a mechanism that involves blocking oxidative stress and activation of p38 MAPK and microglia.


Asunto(s)
Cannabidiol/farmacología , Endotoxinas/farmacología , Fármacos Neuroprotectores/farmacología , Uveítis/inducido químicamente , Uveítis/enzimología , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Animales , Muerte Celular/efectos de los fármacos , Activación Enzimática/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Lipopolisacáridos/farmacología , Macrófagos/enzimología , Macrófagos/patología , Masculino , Microglía/efectos de los fármacos , Microglía/enzimología , Microglía/patología , Modelos Biológicos , NADPH Oxidasas/antagonistas & inhibidores , NADPH Oxidasas/metabolismo , Óxido Nítrico/metabolismo , Estrés Oxidativo/efectos de los fármacos , Ácido Peroxinitroso/metabolismo , Ratas , Ratas Sprague-Dawley , Retina/efectos de los fármacos , Retina/enzimología , Retina/patología , Superóxidos/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo
6.
Leukemia ; 31(12): 2702-2708, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-28663577

RESUMEN

Myelodysplastic syndromes (MDS) represent a heterogeneous group of hematological clonal disorders. Here, we have tested the bone marrow (BM) cells from 38 MDS patients covering all risk groups in two immunodeficient mouse models: NSG and NSG-S. Our data show comparable level of engraftment in both models. The level of engraftment was patient specific with no correlation to any specific MDS risk group. Furthermore, the co-injection of mesenchymal stromal cells (MSCs) did not improve the level of engraftment. Finally, we have developed an in vitro two-dimensional co-culture system as an alternative tool to in vivo. Using our in vitro system, we have been able to co-culture CD34+ cells from MDS patient BM on auto- and/or allogeneic MSCs over 4 weeks with a fold expansion of up to 600 times. More importantly, these expanded cells conserved their MDS clonal architecture as well as genomic integrity.


Asunto(s)
Células de la Médula Ósea/patología , Síndromes Mielodisplásicos/patología , Animales , Biomarcadores , Trasplante de Médula Ósea , Aberraciones Cromosómicas , Modelos Animales de Enfermedad , Femenino , Expresión Génica , Genes Reporteros , Xenoinjertos , Humanos , Inmunofenotipificación , Masculino , Células Madre Mesenquimatosas , Ratones , Ratones Noqueados , Síndromes Mielodisplásicos/diagnóstico , Síndromes Mielodisplásicos/genética , Síndromes Mielodisplásicos/metabolismo
7.
Oncogene ; 9(10): 2935-42, 1994 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7916148

RESUMEN

Reduced expression of the tissue transglutaminase in both murine and human tumours has been consistently associated with tumour growth and progression. To investigate the functional effects of transglutaminase expression we have transfected a constitutive human tissue transglutaminase expression construct into a highly malignant hamster fibrosarcoma cell line Met B. Met B clones expressing the exogenous tissue transglutaminase exhibited a reduced incidence of primary tumour formation and an increased adherence to tissue culture plastic and fibronectin coated surfaces when compared to transfected and non transfected control cells. Transglutaminase transfected clones exhibited no significant differences in their growth rates measured in vitro, cell morphology or levels of spontaneous apoptosis measured by the determination of detergent insoluble apoptotic envelopes. The data demonstrates a suppressive effect of tissue transglutaminase on tumour growth and confirms its importance in the phenotypic changes associated with the cancer process.


Asunto(s)
Fibrosarcoma/enzimología , Transglutaminasas/genética , Animales , Apoptosis , Adhesión Celular , División Celular/genética , Clonación Molecular , Cricetinae , Dipéptidos/metabolismo , Fibrosarcoma/patología , Humanos , Ratones , Transfección
8.
Br J Ophthalmol ; 89(11): 1453-7, 2005 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-16234452

RESUMEN

BACKGROUND/AIM: Acrylic lens size and shape may influence the rate of posterior capsule opacification (PCO) and need for Nd:YAG capsulotomy. The aim of this study is to compare the Nd:YAG capsulotomy rate of the three piece acrylic/PMMA AcrySof MA series lens with the one piece acrylic AcrySof SA series lens. METHODS: 434 eyes of 329 patients who had cataract extraction and implantation of one of four types of intraocular lenses (IOLs) were evaluated for rate of Nd:YAG capsulotomy. 176 eyes received the acrylic AcrySof MA30AC IOL, 71 eyes the acrylic AcrySof MA60AC IOL, 45 eyes the acrylic AcrySof SA30AL IOL, and 142 eyes the acrylic AcrySof SA60AT IOL. RESULTS: The rates of Nd:YAG capsulotomy with the three piece IOL (MA30AC/MA60AC) and the one piece IOL (SA30AL/SA60AT) were 1.2% and 2.1% at 6 months, 2.8% and 5.9% at 12 months, and 3.6% and 7.5% at 24 months, respectively. The incidence of Nd:YAG capsulotomy was higher in patients who received the one piece IOL (p=0.01, log rank test). There was no difference in Nd:YAG capsulotomy rates when comparing lens optic size, age, sex, history of pars plana vitrectomy, and diabetes mellitus. CONCLUSIONS: This study shows a greater incidence of Nd:YAG capsulotomy in patients who receive one piece acrylic AcrySof lenses when compared to those who receive three piece acrylic AcrySof lenses.


Asunto(s)
Catarata/etiología , Terapia por Láser , Cápsula del Cristalino/cirugía , Lentes Intraoculares/efectos adversos , Resinas Acrílicas , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Diseño de Prótesis , Recurrencia , Reoperación/instrumentación , Análisis de Supervivencia
9.
Leukemia ; 29(9): 1928-38, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25943179

RESUMEN

Bone marrow (BM) genetic abnormalities in myelodysplastic syndrome (MDS) have provided important biological and prognostic information; however, frequent BM sampling in older patients has been associated with significant morbidity. Utilizing single-nucleotide polymorphism array (SNP-A) and targeted gene sequencing (TGS) of 24 frequently mutated genes in MDS, we assessed the concordance of genetic abnormalities in BM and peripheral blood (PB) samples concurrently from 201 MDS patients. SNP-A karyotype in BM was abnormal in 108 (54%) and normal in 93 (46%) patients, with 95% (190/201) having an identical PB karyotype. The median copy number (CN) for deletions was significantly lower in BM (CN:1.4 (1-1.9)) than in PB (CN:1.5 (1-1.95), P<0.001). Using TGS, 71% (130/183) patients had BM somatic mutations with 95% (124/130) having identical mutations in PB. The mutant allele burden was lower in PB (median 27% (1-96%)) compared with BM (median 29% (1-100%); P=0.14) with no significant difference in the number, types of mutations or World Health Organization subtype. In all patients with discordant SNP (n=11) and mutation (n=6) profiles between BM and PB, shared abnormalities were always present irrespective of treatment status. Overall, 86% of patients had a clonal aberration with 95% having identical SNP-A karyotype and mutations in PB, thus enabling frequent assessment of response to treatment and disease evolution especially in patients with fibrotic or hypocellular marrows.


Asunto(s)
Células Sanguíneas/metabolismo , Células de la Médula Ósea/metabolismo , Aberraciones Cromosómicas , Genómica , Síndromes Mielodisplásicos/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Células Sanguíneas/patología , Médula Ósea/patología , Células de la Médula Ósea/patología , Estudios de Cohortes , Variaciones en el Número de Copia de ADN , Análisis Mutacional de ADN , Femenino , Estudios de Asociación Genética , Humanos , Cariotipo , Masculino , Persona de Mediana Edad , Mutación , Síndromes Mielodisplásicos/diagnóstico , Síndromes Mielodisplásicos/patología , Polimorfismo de Nucleótido Simple , Adulto Joven
10.
Oncogene ; 34(14): 1843-52, 2015 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-24814516

RESUMEN

Cancer stem cells or tumour-propagating cells (TPCs) have been identified for a number of cancers, but data pertaining to their existence in lymphoma so far remain elusive. We show for the first time that a small subset of cells purified from human anaplastic lymphoma kinase (ALK)-positive and -negative, anaplastic large cell lymphoma cell lines and primary patient tumours using the side population (SP) technique have serial tumour-propagating capacity both in vitro and in vivo; they give rise to both themselves and the bulk tumour population as well as supporting growth of the latter through the production of soluble factors. In vivo serial dilution assays utilising a variety of model systems inclusive of human cell lines, primary human tumours and nucleophosmin (NPM)-ALK-induced murine tumours demonstrate the TPC frequency to vary from as many as 1/54 to 1/1336 tumour cells. In addition, the SP cells express higher levels of pluripotency-associated transcription factors and are enriched for a gene expression profile consistent with early thymic progenitors. Finally, our data show that the SP cells express higher levels of the NPM-ALK oncogene and are sensitive to an ALK inhibitor.


Asunto(s)
Linfoma Anaplásico de Células Grandes/patología , Proteínas Nucleares/metabolismo , Proteínas Tirosina Quinasas Receptoras/metabolismo , Células de Población Lateral/citología , Células de Población Lateral/metabolismo , Adulto , Anciano de 80 o más Años , Quinasa de Linfoma Anaplásico , Animales , Antineoplásicos Fitogénicos/farmacología , Apoptosis , Línea Celular Tumoral , Proliferación Celular , Supervivencia Celular , Niño , Preescolar , Crizotinib , Etopósido/farmacología , Femenino , Perfilación de la Expresión Génica , Humanos , Linfoma Anaplásico de Células Grandes/genética , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad , Células Madre Neoplásicas/citología , Nucleofosmina , Células Madre Pluripotentes/citología , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-kit/biosíntesis , Pirazoles/farmacología , Piridinas/farmacología , Proteínas Tirosina Quinasas Receptoras/antagonistas & inhibidores , Transducción de Señal
11.
FEBS Lett ; 311(2): 174-8, 1992 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-1356831

RESUMEN

Studies were undertaken on a highly metastatic hamster fibrosarcoma cell line with a view to assessing whether cells entering into apoptosis, measured by counting the number of transglutaminase mediated detergent insoluble envelopes, has any synchrony with a particular phase of the cell cycle. A double exposure of thymidine was used to block cells in early S-phase. Flow cytometry in combination with [3H]thymidine incorporation into DNA was used to assess the degree of synchrony and progression through the different phases of cell cycle. The apoptotic index was found to be at its maximum in mid-S-phase. Measurement of transglutaminase activity in each phase of the cell cycle indicated that the specific activity was also at its greatest during mid S-phase. The level of enzyme was relatively unchanged throughout the cell cycle indicating that the regulation of transglutaminase activity occurs primarily through effects on catalytic activity rather than enzyme synthesis.


Asunto(s)
Apoptosis , Ciclo Celular , Transglutaminasas/metabolismo , Animales , Cricetinae , ADN/biosíntesis , Interfase , Fase S , Células Tumorales Cultivadas
12.
FEBS Lett ; 370(1-2): 27-31, 1995 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-7649299

RESUMEN

Tissue transglutaminase (tTgase) is a GTP-binding Ca(2+)-dependent enzyme which catalyses the post-translational modification of proteins via epsilon(gamma-glutamyl) lysine bridges. Recent evidence suggests that the GTP-binding activity of tTgase may be important in intracellular signaling thus explaining some of the diverse suggested roles for the enzyme. In the following work a malignant hamster fibrosarcoma (Met B) has been stably transfected with both the full length tTgase cDNA (wild type) and a mutant form of the cDNA whereby the active site cysteine (Cys 277) has been replaced by serine. Expression of this mutant cDNA leads to a protein with GTP binding activity which is deficient of protein crosslinking activity. When synchronised into S-phase and allowed to progress through the cell cycle tTgase transfected clones (both mutant and wild type), when compared to transfected controls, show a delayed progression from S-phase to G2/M when analysed by flow cytometry which appears to be elicited by the G-protein activity of the tTgase.


Asunto(s)
Ciclo Celular , Proteínas de Unión al GTP/metabolismo , Procesamiento Proteico-Postraduccional , Transglutaminasas/metabolismo , Animales , Sitios de Unión , Western Blotting , División Celular , Cricetinae , Cisteína , ADN/biosíntesis , Fibrosarcoma , Proteínas de Unión al GTP/análisis , Proteínas de Unión al GTP/biosíntesis , Homeostasis , Humanos , Mutagénesis Sitio-Dirigida , Mutación Puntual , Proteínas Recombinantes/análisis , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/metabolismo , Serina , Transfección , Transglutaminasas/análisis , Transglutaminasas/biosíntesis , Células Tumorales Cultivadas
13.
Tumori ; 74(5): 579-83, 1988 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-3217993

RESUMEN

Thirty pretreated patients with progressive and measurable solid tumors (24/30 patients) or myeloproliferative diseases (6/30 patients) were given mitoxantrone at the dose of 5 mg/m2/day in 250 ml normal saline over 30 minutes infusion for 3 consecutive days every 3 weeks. A total of 104 cycles were administered, median 3 for each patient. 39/104 cycles were delayed for a median of 9 days (from 2 to 59 days) because of myelodepression grade I to III (median I); no infection or bleeding was observed. Grade I to II alopecia was recorded in 16 patients. Chronic cardiac toxicity was observed in one patient previously treated with adriamycin. Mitoxantrone at the studied dose schedule in heavily pretreated subjects was well tolerated every 3 to 4 weeks. In 25/30 patients evaluable for response, one patient had a PR, another had 25% reduction (both patients previously treated) and eleven patients obtained disease stability. This effectiveness, 1 PR, 1 MR, 11 disease stability, is not negligible when it is considered that mitoxantrone was the seventh median line of therapy and the fifth median antiblastic drug.


Asunto(s)
Mitoxantrona/uso terapéutico , Neoplasias/tratamiento farmacológico , Adulto , Anciano , Médula Ósea/efectos de los fármacos , Evaluación de Medicamentos , Femenino , Corazón/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Mitoxantrona/efectos adversos
14.
Radiat Prot Dosimetry ; 93(1): 11-7, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11548321

RESUMEN

A new thermoluminescence glow curve deconvolution (GCD) function is introduced which accurately describes first order thermoluminescence (TL) curves. The new GCD function is found to be accurate for first order TL peaks with a wide variety of the values of the TL kinetic parameters E and s. The 3-parameter Weibull probability function is used with the function variables being the maximum peak intensity (Im), the temperature of the maximum peak intensity (Tm) and the Weibull width parameter b. An analytical expression is derived from which the activation energy E can be calculated as a function of Tm and the Weibull width parameter b. The accuracy of the Weibull fit was tested using the ten reference glow curves of the GLOCANIN intercomparison program and the Weibull distribution was found to be highly effective in describing both single and complex TL glow curves. The goodness of fit of the Weibull function is described by the Figure of Merit (FOM) which is found to be of comparable accuracy to the best FOM values of the GLOCANIN program. The FOM values are also comparable to the FOM values obtained using the recently published GCD functions of Kitis et al. It is found that the TL kinetic analysis of complex first-order TL glow curves can be performed with high accuracy and speed by using commercially available software packages.


Asunto(s)
Dosimetría Termoluminiscente , Simulación por Computador , Mediciones Luminiscentes , Modelos Teóricos , Dosimetría Termoluminiscente/instrumentación , Dosimetría Termoluminiscente/métodos
15.
Khirurgiia (Mosk) ; (7): 15-8, 1989 Jul.
Artículo en Ruso | MEDLINE | ID: mdl-2796184

RESUMEN

The article analyses the results of the diagnosis and surgical treatment of obstructive jaundice caused by benign diseases in 279 patients. Cholelithiasis was the cause of obstructive jaundice in 82.4% of patients; in 30.3% of cases the clinical symptomatology of the disease was atypical due to which the patients were at first placed erroneously in hospitals for infectious diseases. Endoscopic methods of examination proved to be most informative: the informativeness of ERP was 91%, that of combined laparoscopy--98.5%. Choledochoduodenostomy is the operation of choice in choledocholithiasis, and double drainage after O.B. Milonov--in combination of obstructive choledocholithiasis with papillostenosis.


Asunto(s)
Colecistitis/complicaciones , Colelitiasis/complicaciones , Colestasis/cirugía , Adulto , Anciano , Colestasis/diagnóstico , Colestasis/etiología , Drenaje , Femenino , Humanos , Masculino , Persona de Mediana Edad
17.
18.
Vet Comp Oncol ; 7(2): 92-105, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19453363

RESUMEN

This study employed proteomic and bioinformatic approaches to identify serum biomarkers in canine lymphoma patients. Chilled serum samples derived from non-lymphoma (n = 92) and lymphoma (n = 87) patients were shipped from first opinion veterinary practices, subjected to ion exchange chromatography and analysed by surface-enhanced laser desorption ionization mass spectrometry. Nineteen serum protein peaks were identified between the two groups as being significantly different (P < 0.05) based upon their normalized ion intensities. Two biomarkers were identified that were capable of differentiating lymphoma and non-lymphoma patients. Analysis of the test data provided a positive predictive value (PPV) of 82%. A clinical follow-up study was carried out on 96 canine patients suspected of having lymphoma. Evaluation of this data gave a specificity value of 91%, sensitivity of 75%, PPV of 80% and negative predictive value of 88%. In conclusion, the expression pattern of two serum biomarkers has enabled serum samples to be classified into either lymphoma or non-lymphoma categories.


Asunto(s)
Proteínas Sanguíneas/análisis , Enfermedades de los Perros/sangre , Linfoma/veterinaria , Proteómica , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/veterinaria , Factores de Edad , Animales , Biomarcadores de Tumor , Estudios de Casos y Controles , Diagnóstico Diferencial , Perros , Linfoma/sangre , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad
19.
Br J Ophthalmol ; 93(2): 191-7, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19019928

RESUMEN

AIM: To analyse cases of recurrent ectasia in donor corneas after penetrating keratoplasty (PK) for keratoconus. METHODS: Data on 25 patients (36 eyes) with recurrent ectasia were retrospectively analysed in this study. The main outcome measures were time to development of recurrent ectasia after first PK for keratoconus, change in keratometric sphere and astigmatism between final suture removal and development of recurrent ectasia, status of regrafts for recurrent ectasia, and histopathology of grafts excised for recurrent ectasia. RESULTS: The age at first PK was 32.6 (SD 8.5) years, and ectasia developed 21.9 (7.0) years after PK. The mean keratometric sphere and cylinder increased by 4.2 D and 3.0 D, respectively, between final suture removal and diagnosis of recurrent ectasia. Ectasia was often preceded by thinning without bulging of the recipient stroma at the graft-host junction. Fifteen eyes (13 patients) were regrafted for recurrent ectasia, and histopathology of the excised grafts showed changes characteristic of keratoconus in the donor tissue in all cases. Two regrafts (two eyes of one patient) developed ectasia again, with one eye requiring a third PK to improve vision. CONCLUSIONS: Recurrent ectasia was diagnosed on average two decades after PK. Ectatic changes were often bilateral and occasionally recurred after regrafting, suggesting that host cellular and/or biochemical factors may be responsible. Repeat PK for recurrent ectasia is successful in the intermediate term.


Asunto(s)
Queratocono/cirugía , Queratoplastia Penetrante , Adulto , Astigmatismo/etiología , Córnea/patología , Dilatación Patológica/etiología , Femenino , Humanos , Queratocono/patología , Masculino , Persona de Mediana Edad , Recurrencia , Reoperación , Estudios Retrospectivos , Resultado del Tratamiento , Adulto Joven
20.
Cancer Immunol Immunother ; 48(7): 374-81, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10501850

RESUMEN

Progress towards developing vaccines that can stimulate an immune response against growing tumours has involved the identification of the protein antigens associated with a given tumour type. Epitope mapping of tumour antigens for HLA class I- and class II-restricted binding motifs followed by immunization with these peptides has induced protective immunity in murine models against cancers expressing the antigen. MHC class I molecules presenting the appropriate peptides are necessary to provide the specific signals for recognition and killing by cytotoxic T cells (CTL). The principle mechanism of tumour escape is the loss, downregulation or alteration of HLA profiles that may render the target cell resistant to CTL lysis, even if the cell expresses the appropriate tumour antigen. In human tumours HLA loss may be as high as 50%, inferring that a reduction in protein levels might offer a survival advantage to the tumour cells. Alternatively, MHC loss may render tumour cells susceptible to natural killer cell-mediated lysis because they are known to act as ligands for killer inhibitory receptors (KIRs). We review the molecular features of MHC class I and class II antigens and discuss how surface MHC expression may be regulated upon cellular transformation. In addition, selective loss of MHC molecules may alter target tumour cell susceptibility to lymphocyte killing. The development of clinical immunotherapy will need to consider not only the expression of relevant CTL target MHC proteins, but also HLA inhibitory to NK and T cells.


Asunto(s)
Antígenos de Histocompatibilidad Clase II/biosíntesis , Antígenos de Histocompatibilidad Clase I/biosíntesis , Complejo Mayor de Histocompatibilidad/inmunología , Neoplasias/inmunología , Presentación de Antígeno/inmunología , Membrana Celular/inmunología , Membrana Celular/metabolismo , Transformación Celular Neoplásica/inmunología , Antígenos de Histocompatibilidad Clase I/inmunología , Antígenos de Histocompatibilidad Clase II/inmunología , Humanos , Células Asesinas Naturales/inmunología , Relación Estructura-Actividad , Linfocitos T/inmunología
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