Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 42
Filtrar
1.
Artículo en Inglés | MEDLINE | ID: mdl-37584007

RESUMEN

Background: 1.1.Inflammatory Bowel Disease (IBD) are the manifestation of overzealous dys-regulated immune response in the intestinal tract, directed primarily against the indigenous microbes combined with defective functioning of anti-inflammatory pathways. Finding a trustable lead to predicting de novo Crohn's Disease (CD) prior to performing "pouch surgery", Restorative Proctocolectomy (RPC) with Ileal Pouch-Anal Anastomosis (IPAA) for UC and/or Indeterminate Colitis (IC) is clinically important and remains debatable. De novo CD is a subsequent long-term postoperative complication in IBD patients with Ulcerative Colitis (UC) undergoing IPAA. Herewith we discuss this understanding in laboratory-based basic science research, with its molecular application as a possible corner stone tool for clinical progress and success in the IBD Clinic. Crypt Paneth cell (PCs) secreted enteroendocrine alpha-defensin 5 (DEFA5)" if developed properly is likely to solve diagnostic and prognostic difficulty in IBD Clinics. DEFA5 has shown the ability to differentiate the predominant subtypes of colonic IBD (CC vs. UC) at first endoscopy biopsy, avoiding diagnosis delay prior to colectomy. In addition, DEFA5 accurately circumvents indeterminate colitis (IC) patients into accurate IBD subtype (UC or CC). Further, DEFA5 can be used in selecting CC patients that may have positive outcomes after IPAA surgery [1]. Furthermore, likewise, DEFA5 can predict UC patients likely to have positive or poor outcome, e.g. those patients that are likely to transform/ convert and adhere to de novo Crohn's after IPAA can be picked up in endoscopy biopsy before surgery. Aim: 1.2.To assessed comprehensive state-of-the-art understanding domains on the de novo Crohn's disease subsequent to IPAA surgery for ulcerative colitis. Methods: 1.3.A literature search based on preferred reporting items for over-review and meta-analysis protocols (PRISMA-P) was performed. A comprehensive current search of PubMed, MEDLINE, CINAHL, Embase, Google® search engine and Cochrane Database of collected reviews was performed from January 1990 through December 2018. The search consists of retrospective studies and case reports of reporting postoperative de novo CD incidence and adverse events. Secondary and hand/manual searches of reference lists, other studies cross-indexed by authors, reviews, commentaries, books and meeting abstracts were also performed. Studies were included only if the diagnosis of de novo CD was established clinically and histologically based on inflammation of afferent limb(s) or perianal disease. The search excluded non-English language and non-human studies as well as editorials. Results: 1.4.Published data on de novo CD developing after RPC with IPAA are still limited. A total of three hundred and sixty-five (#365) patients in 13 publications reported de novo CD after a median follow-up of 66 (range: 3-236) months. All patients were diagnosed with clinically active pouch CD during follow-up surveillance after IPAA for UC or IC. A de novo CD diagnosis depended on either inflammation in the mucosa involving the small intestine proximal to the ileal pouch any time after IPAA surgery and/or when perianal complications developed after closure of a temporary diverting loop ileostomy. Successful management is facilitated by co-operation within a multidisciplinary team of gastroenterologists and colorectal surgeons and closely involving the patient in therapeutic decisions. Awareness of symptoms leads to timely consultation, diagnosis, treatment and restoration of intestinal continuity. Conclusion: 1.5.The nature history and risk of de novo CD after IPAA for UC remains debatable. Chronic pouchitis and/or pouch failure often precedes a diagnosis of de novo CD. A successful management is facilitated by a triad cooperation between gastroenterologists, colorectal surgeons and the patient.

2.
Artículo en Inglés | MEDLINE | ID: mdl-37615012

RESUMEN

Introduction: 1.1.Inflammatory Bowel Disease (IBD) is recklessly evolving worldwide as incautious disaster, especially in developing nations as a regional duplicitous emergence disease. It has come to light that adaptive Western culture, rapid urbanization lifestyle in the developing nations has been seen to be associated with this increasing trend incidence. Apparent unclassified strategic challenge assessment of how key trends and uncertainties might lead the world over the next decades to help developing nations and plan for the long term. Healthcare professionals are faced with limited resource and unequipped laboratories for IBD diagnostics, prognostics and monitoring management. Limited knowledge on IBD among developing nation's physician's/healthcare providers is painstaking and indisputable challenge. With the emergence of advanced communications technology, the internet offers diverse, substantial, easily accessible, and educational resources that are more time- and cost-efficient than conventional modes of knowledge acquisition. An On-Line Web-Based Resources about IBD, as a guide would greatly assist health professionals and patients. Methods: 1.2.We performed a literature search according to PRISMA-P (preferred reporting items for review and meta-analysis and searches in PubMed (MEDLINE database) to identify and select peer-reviewed articles allied to web-based educational accoutrements for IBD. Results: 1.3.In developing nations, locally trained physicians have limited knowledge on IBD. Mostly, IBD is not included in their training Core Curriculum and research in this field/area is limited in these countries. The healthcare approaches, both at the primary care and referral levels, many times lack the essential regular clinical guidance and laboratory evaluation assessments needs for monitoring patients. Moreover, increasing treatment costs impose additional burden on the healthcare systems. Expensive pharmacological biosimilar and biologic agents/drugs, new treatment targets, and new quality indicators in patient health quality of life and care are significant challenge in addition to early manifestations of IBD are likely to be missed at most health institutions. Conclusion: 1.4.We herewith summarize an on-line web-based e-learning guide for IBD-related educational resources to assist physicians, healthcare personnel and patients worldwide, especially in the developing nations where the epidemiological monitoring studies are limited, due to a lack of medical surveillance systems and reliable and unified registries and databases.

3.
J Parasitol ; 104(3): 289-291, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29373074

RESUMEN

Gizzard helminths were examined in 100 (50 adult, 50 juvenile) female northern pintails ( Anas acuta). Sixty-three individual helminths, representing 5 species ( Amidostomum acutum, Echinuria uncinata, Epomidiostomum uncinatum, Streptocara crassicauda, and Gastrotaenia cygni) were found. Twenty-seven northern pintails were infected with 1-3 helminth species and averaged 1.4 species. Overall, A. acutum and G. cygni were the most prevalent and abundant species (20%, n = 31 and 10%, n = 25, respectively), followed by S. crassicauda (5%, n = 5), E. uncinata (1%, n = 1), and E. uncinatum (1%, n = 1). Intensity of infection for A. acutum, E. uncinata, E. uncinatum, S. crassicauda, and G. cygni was 1.6 ± 0.3 [SE], 1.0 ± 0, 1.0 ± 0, 1.0 ± 0, and 2.5 ± 0.6, respectively. Our findings represent new information about gizzard helminth infections in northern pintails wintering along the Texas coast.


Asunto(s)
Enfermedades de las Aves/parasitología , Patos/parasitología , Molleja de las Aves/parasitología , Helmintiasis Animal/parasitología , Migración Animal , Animales , Enfermedades de las Aves/epidemiología , Cestodos/aislamiento & purificación , Femenino , Helmintiasis Animal/epidemiología , Estaciones del Año , Spirurina/aislamiento & purificación , Texas/epidemiología , Trichostrongyloidea/aislamiento & purificación
4.
Oncogene ; 36(10): 1364-1373, 2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-27869166

RESUMEN

EZH2 is crucial for the progression of prostate cancer (PCa) and castration-resistant prostate cancer (CRPC) through upregulation and activation of progenitor genes, as well as androgen receptor (AR)-target genes. However, the mechanisms by which EZH2 is regulated in PCa and CRPC remain elusive. Here we report that EZH2 is post-transcriptionally regulated by SKP2 in vitro in cultured cells and in vivo in mouse models. We observed aberrant upregulation of Skp2, Ezh2 and histone H3 lysine 27 trimethylation (H3K27me3) in both Pten null mouse embryonic fibroblasts (MEFs) and Pten null mouse prostate tissues. Loss of Skp2 resulted in a striking decrease of Ezh2 levels in Pten/Trp53 double-null MEFs and in prostate tumors of Pten/Trp53 double-null mutant mice. SKP2 knockdown decreased EZH2 levels in human PCa cells through upregulation of TRAF6-mediated and lysine(K) 63-linked ubiquitination of EZH2 for degradation. Ectopic expression of TRAF6 promoted the K63-linked ubiquitination of EZH2 to decrease EZH2 and H3K27me3 levels in PCa cells. In contrast, TRAF6 knockdown resulted in a reduced EZH2 ubiquitination with an increase of EZH2 and H3K27me3 levels in PCa cells. Furthermore, the catalytically dead mutant TRAF6 C70A abolished the TRAF6-mediated polyubiquitination of recombinant human EZH2 in vitro. Most importantly, a concurrent elevation of Skp2 and Ezh2 was found in CRPC tumors of Pten/Trp53 mutant mice, and expression levels of SKP2 and EZH2 were positively correlated in human PCa specimens. Taken together, our findings revealed a novel mechanism on EZH2 ubiquitination and an important signaling network of SKP2-TRAF6-EZH2/H3K27me3, and targeting SKP2-EZH2 pathway may be a promising therapeutic strategy for CRPC treatment.


Asunto(s)
Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/metabolismo , Proteínas Quinasas Asociadas a Fase-S/genética , Factor 6 Asociado a Receptor de TNF/metabolismo , Animales , Línea Celular Tumoral , Modelos Animales de Enfermedad , Técnicas de Inactivación de Genes , Histonas/metabolismo , Humanos , Lisina/metabolismo , Masculino , Ratones , Fosfohidrolasa PTEN/genética , Fosfohidrolasa PTEN/metabolismo , Próstata/metabolismo , Neoplasias de la Próstata/patología , Estabilidad Proteica , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Ubiquitinación
5.
Leukemia ; 30(4): 800-11, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26621337

RESUMEN

Natural killer (NK) cells are key components of the innate immune system, providing potent antitumor immunity. Here, we show that the tumor growth factor-ß (TGF-ß)/SMAD signaling pathway is an important mechanism for NK cell immune evasion in childhood B-acute lymphoblastic leukemia (ALL). We characterized NK cells in 50 consecutive children with B-ALL at diagnosis, end induction and during maintenance therapy compared with age-matched controls. ALL-NK cells at diagnosis had an inhibitory phenotype associated with impaired function, most notably interferon-γ production and cytotoxicity. By maintenance therapy, these phenotypic and functional abnormalities partially normalized; however, cytotoxicity against autologous blasts remained impaired. We identified ALL-derived TGF-ß1 to be an important mediator of leukemia-induced NK cell dysfunction. The TGF-ß/SMAD signaling pathway was constitutively activated in ALL-NK cells at diagnosis and end induction when compared with healthy controls and patients during maintenance therapy. Culture of ALL blasts with healthy NK cells induced NK dysfunction and an inhibitory phenotype, mediated by activation of the TGF-ß/SMAD signaling pathway, and abrogated by blocking TGF-ß. These data indicate that by regulating the TGF-ß/SMAD pathway, ALL blasts induce changes in NK cells to evade innate immune surveillance, thus highlighting the importance of developing novel therapies to target this inhibitory pathway and restore antileukemic cytotoxicity.


Asunto(s)
Citotoxicidad Inmunológica/inmunología , Evasión Inmune/inmunología , Células Asesinas Naturales/inmunología , Leucemia-Linfoma Linfoblástico de Células Precursoras B/inmunología , Proteínas Smad/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Adolescente , Adulto , Estudios de Casos y Controles , Niño , Preescolar , Femenino , Citometría de Flujo , Estudios de Seguimiento , Humanos , Lactante , Células Asesinas Naturales/metabolismo , Células Asesinas Naturales/patología , Masculino , Fosforilación , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patología , Transducción de Señal , Células Tumorales Cultivadas , Microambiente Tumoral/inmunología
6.
Nucl Med Biol ; 41(3): 276-81, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24533987

RESUMEN

INTRODUCTION: An approach to radioimmunotherapy (RIT) of metastatic melanoma is the targeting of melanin pigment with monoclonal antibodies (mAbs) to melanin radiolabeled with therapeutic radionuclides. The proof of principle experiments were performed using a melanin-binding antibody 6D2 of IgM isotype radiolabeled with a ß emitter (188)Re and demonstrated the inhibition of tumor growth. In this study we investigated the efficacy of 6D2 antibody radiolabeled with two other longer lived ß emitters (90)Y and (166)Ho in treatment of experimental melanoma, with the objective to find a possible correlation between the efficacy and half-life of the radioisotopes which possess high energy ß (E(max)>1.5 MeV) emission properties. METHODS: 6D2 was radiolabeled with longer lived ß emitters (90)Y and (166)Ho in treatment of experimental melanoma in A2058 melanoma tumor-bearing nude mice. The immunoreactivity of the radiolabeled 6D2 mAb, its in vitro binding to the MNT1 human melanoma cells, the biodistribution and therapy in A2058 human melanoma bearing nude mice as well as dosimetry calculations were performed. RESULTS: When labeled with the longer lived (90)Y radionuclide, the 6D2 mAb did not produce any therapeutic effect in tumor bearing mice while the reduction of the tumor growth by (166)Ho-6D2 was very similar to the previously reported therapy results for (188)Re-6D2. In addition, (166)Ho-labeled mAb produced the therapeutic effect on the tumor without any toxic effects while the administration of the (90)Y-labeled radioconjugate was toxic to mice with no appreciable anti-tumor effect. CONCLUSIONS: (166)Ho-labeled mAb to melanin produced some therapeutic effect on the tumor without any toxic effects while the administration of the (90)Y-labeled radioconjugate was toxic to mice with no appreciable anti-tumor effect. We concluded that the serum half-life of the 6D2 carrier antibody matched well the physical half-life of (166)Ho to deliver the tumoricidal absorbed dose to the tumor. Further investigation of this radionuclide for RIT of melanoma is warranted.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Holmio , Melanoma Experimental/radioterapia , Radioinmunoterapia/métodos , Animales , Anticuerpos Monoclonales/sangre , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/farmacocinética , Línea Celular Tumoral , Estabilidad de Medicamentos , Femenino , Semivida , Humanos , Melanoma Experimental/patología , Ratones , Ratones Desnudos , Ácido Pentético/química , Distribución Tisular , Radioisótopos de Itrio
7.
Phys Occup Ther Pediatr ; 33(4): 453-66, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23387981

RESUMEN

PURPOSE: To present an algorithm with accompanying treatment parameters for the management of congenital muscular torticollis (CMT) based on the best available literature. METHODS: A systematic search of PubMed, MEDLINE, CINHAL, and Cochrane databases was conducted to identify evidence to guide the conservative management of CMT. RESULTS: An evidence-based algorithm was created based on three prognostic factors that influence treatment duration and outcome, including a sternocleidomastoid fibrotic mass, passive range of motion rotation deficit, and age at initiation of treatment. Preliminary treatment parameter recommendations for clinic and home programming accompany the algorithm. CONCLUSION: Use of the proposed evidence-based algorithm with accompanying preliminary treatment parameter recommendations may improve consistency of care and outcomes for infants with CMT. While a higher level of evidence supports the three prognostic factors utilized in the algorithm, research gaps continue to exist with regards to treatment parameters.


Asunto(s)
Algoritmos , Músculo Esquelético/patología , Rango del Movimiento Articular , Tortícolis/congénito , Factores de Edad , Medicina Basada en la Evidencia , Humanos , Lactante , Modalidades de Fisioterapia , Tortícolis/patología , Tortícolis/fisiopatología , Tortícolis/terapia
8.
Mol Psychiatry ; 18(9): 1006-17, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23089634

RESUMEN

Endogenous glucocorticoids are essential for mobilizing energy resources, restraining inflammatory responses and coordinating behavior to an immune challenge. Impaired glucocorticoid receptor (GR) function has been associated with impaired metabolic processes, enhanced inflammation and exaggerated sickness and depressive-like behaviors. To discern the molecular mechanisms underlying GR regulation of physiologic and behavioral responses to a systemic immune challenge, GR(dim) mice, in which absent GR dimerization leads to impaired GR-DNA-binding-dependent mechanisms but intact GR protein-protein interactions, were administered low-dose lipopolysaccharide (LPS). GR(dim)-LPS mice exhibited elevated and prolonged levels of plasma corticosterone (CORT), interleukin (IL)-6 and IL-10 (but not plasma tumor necrosis factor-α (TNFα)), enhanced early expression of brain TNFα, IL-1ß and IL-6 mRNA levels, and impaired later central TNFα mRNA expression. Exaggerated sickness behavior (lethargy, piloerection, ptosis) in the GR(dim)-LPS mice was associated with increased early brain proinflammatory cytokine expression and late plasma CORT levels, but decreased late brain TNFα expression. GR(dim)-LPS mice also exhibited sustained locomotor impairment in the open field, body weight loss and metabolic alterations measured by indirect calorimetry, as well as impaired thermoregulation. Taken together, these data indicate that GR dimerization-dependent DNA-binding mechanisms differentially regulate systemic and central cytokine expression in a cytokine- and time-specific manner, and are essential for the proper regulation and recovery of multiple physiologic responses to low-dose endotoxin. Moreover, these results support the concept that GR protein-protein interactions are not sufficient for glucocorticoids to exert their full anti-inflammatory effects and suggest that glucocorticoid responses limited to GR monomer-mediated transcriptional effects could predispose individuals to prolonged behavioral and metabolic sequelae of an enhanced inflammatory state.


Asunto(s)
Dimerización , Conducta de Enfermedad/efectos de los fármacos , Inflamación/inducido químicamente , Lipopolisacáridos/toxicidad , Receptores de Glucocorticoides/metabolismo , Animales , Temperatura Corporal/efectos de los fármacos , Peso Corporal/efectos de los fármacos , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Dióxido de Carbono , Corticosterona/sangre , Citocinas/sangre , Regulación de la Expresión Génica/efectos de los fármacos , Masculino , Ratones , Actividad Motora/efectos de los fármacos , Consumo de Oxígeno/efectos de los fármacos , ARN Mensajero/metabolismo , Telemetría , Factores de Tiempo
9.
Appl Radiat Isot ; 70(11): 2602-7, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22940414

RESUMEN

Cross sections for (223,)(225)Ra, (225)Ac and (227)Th production by the proton bombardment of natural thorium targets were measured at proton energies below 200 MeV. Our measurements are in good agreement with previously published data and offer a complete excitation function for (223,)(225)Ra in the energy range above 90 MeV. Comparison of theoretical predictions with the experimental data shows reasonable-to-good agreement. Results indicate that accelerator-based production of (225)Ac and (223)Ra below 200 MeV is a viable production method.


Asunto(s)
Actinio , Radio (Elemento) , Torio/efectos de la radiación , Actinio/química , Protones , Radio (Elemento)/química , Espectrometría gamma
10.
Appl Radiat Isot ; 70(11): 2590-5, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22944532

RESUMEN

Cross sections for the formation of (225,227)Ac, (223,225)Ra, and (227)Th via the proton bombardment of natural thorium targets were measured at a nominal proton energy of 800 MeV. No earlier experimental cross section data for the production of (223,225)Ra, (227)Ac and (227)Th by this method were found in the literature. A comparison of theoretical predictions with the experimental data shows agreement within a factor of two. Results indicate that accelerator-based production of (225)Ac and (223)Ra is a viable production method.


Asunto(s)
Actinio , Radio (Elemento) , Torio/efectos de la radiación , Actinio/química , Braquiterapia , Protones , Radio (Elemento)/química
11.
Curr Radiopharm ; 5(3): 264-70, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22697482

RESUMEN

Positron emission tomography (PET) of slower biological processes calls for the use of longer lived positron emitting radioisotopes. Beyond radionuclide production considerations, practicality and rapidity of subsequent labeling chemistry further limits the selection of radioisotopes with potentially favorable nuclear properties. One additional limitation is the availability of PET radiotracers at the point-of-care with appropriate on-site production methodologies or robust radionuclide generator systems. The positron emitter (72)As (half-life 26 h) is generated via decay of (72)Se (half-life 8.5 d); this pair comprises and excellent generator system for clinical availability of a longer lived PET isotope. Many (72)Se/As generator systems have been introduced utilizing the rich interplay of Se(IV)/Se(VI) and As(III) /As(V) chemical behavior. This paper describes available generator concepts, and briefly outlines some current arsenic labeling methodologies for the introduction of radioarsenic into biomolecules.


Asunto(s)
Arsénico/aislamiento & purificación , Tomografía de Emisión de Positrones/instrumentación , Radioisótopos/aislamiento & purificación , Generadores de Radionúclidos , Radiofármacos/aislamiento & purificación , Quelantes , Semivida , Humanos , Medicina Nuclear , Radiofármacos/síntesis química
12.
Appl Radiat Isot ; 70(4): 595-601, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22326368

RESUMEN

Selenium-72 production by the proton bombardment of a natural NaBr target has been successfully demonstrated at the Los Alamos National Laboratory Isotope Production Facility (LANL-IPF). Arsenic-72 (half life 26 h) is a medium-lived positron emitting radionuclide with the major advantage of being formed as the daughter of another "generator" radioisotope (Se-72, 8.5 d). A (72)Se/(72)As generator would be the preferred mechanism for clinical utilization of (72)As for positron emission tomography (PET). No portable (72)Se/(72)As generator system has been demonstrated for convenient, repeated (72)As elution ("milking"). In this work, we describe (72)Se production and recovery from irradiated NaBr targets using a 100 MeV proton beam. We also introduce an (72)As generator principle based on (72)Se chelation followed by liquid-liquid extraction, which will be transferred to a solid-phase sorption/elution system.

13.
Mol Hum Reprod ; 16(4): 241-50, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20086006

RESUMEN

A homozygous missense mutation, C566T, in the follicle stimulation hormone receptor (FSHR) gene has been linked to premature ovarian failure. The disease leads to infertility in a normal karyotype female with an elevated follicle stimulating hormone (FSH) and decreased serum estrogen level. Female mice carrying mutated FSHR gene, called follitropin receptor knockout (FORKO), display similar phenotype and are sterile because of a folliculogenesis block at a primary stage. We investigated the effects of bilateral intra-ovarian injection of an adenovirus expressing a normal copy of human FSHR on the reproductive system of 6-10 weeks female FORKO mice. Ad-LacZ was injected directly into each ovary of the control group. Animals were sacrificed at 2, 4, 8 and 12 weeks post-injection and tissues collected for evaluation. Treated mice showed estrogenic changes in daily vaginal smear whereas control animals remained fixated in the diestrus stage. Histological evaluation showed on average 26 +/- 4 follicles/ovary in treated group with 8 +/- 2 follicles at the antral stage compared with only 5 +/- 2 with zero follicles at antral stage in Ad-LacZ control mice. There was no significant change in serum level of progesterone, however, estrogen level increased 2-3-fold (P < 0.02) and FSH decreased by up to 50% (P < 0.04) in treated animals. FSHR mRNA was detected in the ovaries of the treated group. In conclusion, intra-ovarian injection of an adenovirus expressing human FSHR gene is able to restore FSH responsiveness and reinitiate ovarian folliculogenesis as well as resume estrogen production in female FORKO mice. Ad-LacZ injections indicate the absence of systemic viral dissemination or germ line transmission of adenovirus DNA to offspring.


Asunto(s)
Terapia Genética , Insuficiencia Ovárica Primaria/genética , Insuficiencia Ovárica Primaria/terapia , Receptores de HFE/genética , Receptores de HFE/metabolismo , Adenoviridae/genética , Animales , Femenino , Vectores Genéticos/genética , Humanos , Ratones , Ratones Noqueados , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
14.
Arch Environ Contam Toxicol ; 53(4): 662-6, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17571203

RESUMEN

The blue-winged teal (Anas discors L.), an abundant waterfowl species in North America, winters primarily in Mexico, Central America, and South America. Its transcontinental migratory behavior provides the opportunity to examine contaminant acquisition across a diverse biogeographic landscape that has varied environmental regulations and wildlife laws. We determined concentrations of arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), and selenium (Se) in liver samples of blue-winged teal migrating through southern Texas during autumn 1998 (n = 47) and spring 1999 (n = 46). Concentrations for As (range 0.006 to 0.22 microg/g wet weight [ww]), Cd (range 0.007 to 8.14 microg/g ww), and Pb (range 0.012 to 1.79 microg/g ww) were at background levels for birds, whereas Cu (8.1 to 227.3 microg/g ww) and Se (0.36 to 5.07 microg/g ww) were increased in several individuals. All 24 hatch-year (HY) blue-winged teal had detectable levels of Cd, Cu, Pb, and Se, and eight had detectable levels of As. A seasonal effect was found for Cd, in which the mean Cd concentration in autumn was lower (p < 0.015) than in spring. Comparisons between autumn-collected HY and autumn-collected after-hatch-year (AHY) blue-winged teal found the mean concentration of Cd was higher (p < 0.001) in AHY birds. A seasonal effect occurred for Cu, in which the mean concentration was higher (p < 0.001) in autumn than in spring. Comparisons between seasons using only AHY blue-winged teal found that the mean concentration of Cu was higher (p < 0.001) in autumn than in spring. No sex effects (p > 0.05) were found for the five elements examined. Results indicated that blue-winged teal were acquiring all five elements; that HY blue-winged teal were exposed to these elements in North America; and that increased Se concentrations in 15% of the 93-bird sample were at levels known to cause impairment in birds.


Asunto(s)
Arsénico/análisis , Aves/metabolismo , Cadmio/análisis , Cobre/análisis , Monitoreo del Ambiente/métodos , Contaminantes Ambientales/análisis , Plomo/análisis , Selenio/análisis , Factores de Edad , Animales , Emigración e Inmigración , Femenino , Masculino , Estaciones del Año , Caracteres Sexuales
16.
Semin Oncol Nurs ; 10(1): 28-41, 1994 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8165376

RESUMEN

Patients receiving allogeneic bone marrow transplant experience multiple complications. Specifically, infection, renal complications, VOD, and GVHD can produce life-threatening toxicity. Many of the treatments cause further compromise of major organs. Astute nursing assessment and prompt interventions can decrease the severity experienced by the patient. Each of these complications requires ongoing study to develop new therapies for management.


Asunto(s)
Lesión Renal Aguda/etiología , Infecciones Bacterianas/etiología , Trasplante de Médula Ósea/efectos adversos , Enfermedad Injerto contra Huésped/fisiopatología , Enfermedad Veno-Oclusiva Hepática/etiología , Lesión Renal Aguda/fisiopatología , Infecciones Bacterianas/fisiopatología , Enfermedad Injerto contra Huésped/epidemiología , Enfermedad Injerto contra Huésped/enfermería , Enfermedad Veno-Oclusiva Hepática/terapia , Humanos , Terapia de Inmunosupresión , Factores de Riesgo
18.
Science ; 247(4945): 946-8, 1990 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-2305262

RESUMEN

Bacterial MerR proteins are dimeric DNA-binding proteins that mediate the Hg(II)-dependent induction of mercury resistance operons. Site-directed mutagenesis of the Bacillus sp. RC607 MerR protein reveals that three of four Cys residues per monomer are required for Hg(II) binding at the single high-affinity binding site. Inactive mutant homodimers can exchange subunits to form heterodimers active for Hg(II) binding. Studies of a heterodimer retaining only three of eight cysteine residues per dimer reveal that Cys79 in one subunit and Cys114 and Cys123 in the second subunit are necessary and sufficient for high-affinity Hg(II) binding in an asymmetric, subunit bridging coordination complex.


Asunto(s)
Bacillus/análisis , Proteínas Bacterianas/metabolismo , Proteínas de Unión al ADN/metabolismo , Mercurio/metabolismo , Secuencia de Aminoácidos , Bacillus/genética , Proteínas Bacterianas/genética , Secuencia de Bases , Sitios de Unión , Cationes , Proteínas de Unión al ADN/genética , Sustancias Macromoleculares , Datos de Secuencia Molecular , Mutación , Relación Estructura-Actividad
19.
Gene ; 85(1): 1-13, 1989 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-2695392

RESUMEN

The RsrI endonuclease, a type-II restriction endonuclease (ENase) found in Rhodobacter sphaeroides, is an isoschizomer of the EcoRI ENase. A clone containing an 11-kb BamHI fragment was isolated from an R. sphaeroides genomic DNA library by hybridization with synthetic oligodeoxyribonucleotide probes based on the N-terminal amino acid (aa) sequence of RsrI. Extracts of E. coli containing a subclone of the 11-kb fragment display RsrI activity. Nucleotide sequence analysis reveals an 831-bp open reading frame encoding a polypeptide of 277 aa. A 50% identity exists within a 266-aa overlap between the deduced aa sequences of RsrI and EcoRI. Regions of 75-100% aa sequence identity correspond to key structural and functional regions of EcoRI. The type-II ENases have many common properties, and a common origin might have been expected. Nevertheless, this is the first demonstration of aa sequence similarity between ENases produced by different organisms.


Asunto(s)
Desoxirribonucleasa EcoRI/genética , Escherichia coli/genética , Rhodobacter sphaeroides/genética , Metiltransferasa de ADN de Sitio Específico (Adenina Especifica)/genética , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , Codón/genética , Escherichia coli/enzimología , Datos de Secuencia Molecular , Sondas de Oligonucleótidos , Plásmidos , Rhodobacter sphaeroides/enzimología , Homología de Secuencia de Ácido Nucleico
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...