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1.
J Quant Spectrosc Radiat Transf ; 186: 17-39, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32817995

RESUMEN

TEMPO was selected in 2012 by NASA as the first Earth Venture Instrument, for launch between 2018 and 2021. It will measure atmospheric pollution for greater North America from space using ultraviolet and visible spectroscopy. TEMPO observes from Mexico City, Cuba, and the Bahamas to the Canadian oil sands, and from the Atlantic to the Pacific, hourly and at high spatial resolution (~2.1 km N/S×4.4 km E/W at 36.5°N, 100°W). TEMPO provides a tropospheric measurement suite that includes the key elements of tropospheric air pollution chemistry, as well as contributing to carbon cycle knowledge. Measurements are made hourly from geostationary (GEO) orbit, to capture the high variability present in the diurnal cycle of emissions and chemistry that are unobservable from current low-Earth orbit (LEO) satellites that measure once per day. The small product spatial footprint resolves pollution sources at sub-urban scale. Together, this temporal and spatial resolution improves emission inventories, monitors population exposure, and enables effective emission-control strategies. TEMPO takes advantage of a commercial GEO host spacecraft to provide a modest cost mission that measures the spectra required to retrieve ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2), formaldehyde (H2CO), glyoxal (C2H2O2), bromine monoxide (BrO), IO (iodine monoxide),water vapor, aerosols, cloud parameters, ultraviolet radiation, and foliage properties. TEMPO thus measures the major elements, directly or by proxy, in the tropospheric O3 chemistry cycle. Multi-spectral observations provide sensitivity to O3 in the lowermost troposphere, substantially reducing uncertainty in air quality predictions. TEMPO quantifies and tracks the evolution of aerosol loading. It provides these near-real-time air quality products that will be made publicly available. TEMPO will launch at a prime time to be the North American component of the global geostationary constellation of pollution monitoring together with the European Sentinel-4 (S4) and Korean Geostationary Environment Monitoring Spectrometer (GEMS) instruments.

2.
Gen Comp Endocrinol ; 201: 1-7, 2014 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-24681151

RESUMEN

Raising nestlings in a biparental species involves a complex and dynamic interaction of physiology and behavior among a group of organisms. Parents may be predicted to vary their behaviors based not only upon their own state, but also in relation to the states of both offspring and the other parent. In this study we explore the relationships between parental feeding behaviors and family member condition in eastern bluebirds, with a special emphasis on baseline corticosterone, a hormone associated with energy mediation and stress. We found that the overall number of feeding trips made by both male and female parents were positively correlated to the corticosterone levels of nestlings. Maternal, but not paternal, baseline corticosterone levels were positively correlated to nestling baseline corticosterone levels. Additionally, adult males' feeding behavior was positively correlated to adult females' baseline corticosterone levels. These findings suggest a complex interplay between parental behavior and physiological state not only within a given organism, but also across organisms operating within a family unit. In addition, these results provide evidence that paternal and maternal efforts are influenced by related but distinct pressures, and that male and female parenting may be governed differentially even in species with relatively equitable biparental care.


Asunto(s)
Corticosterona/sangre , Conducta Alimentaria/fisiología , Conducta Materna/fisiología , Comportamiento de Nidificación/fisiología , Conducta Paterna/fisiología , Pájaros Cantores/fisiología , Animales , Femenino , Masculino
3.
Int J Sports Med ; 34(1): 81-6, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22930219

RESUMEN

32 postmenopausal women were randomized to a 16-week home-based walking program or control group. Before and after the intervention, each subject completed a graded maximal treadmill test to establish VO(2)max and resting saliva was collected to determine levels of salivary immunoglobulin A. The 16-week walking program resulted in an increase in VO(2)max (+10.4%; p<0.01). Repeated measures ANOVA revealed a marked increase in the resting secretion rate of salivary immunoglobulin A (+37.4%; p<0.05) in the exercise group following training. Independent of study group, both before and after the intervention, the secretion rate of salivary immunoglobulin A ( - 32.3%) and saliva flow rate (- 29.3%) were reduced following acute maximal exercise (p<0.05). Weekly upper respiratory symptomatology logs revealed that the number of incidences of upper respiratory symptoms throughout the intervention period were the same and the duration per incidence (control: 5.3±1.5 days; exercise: 6.3±2.2 days) were similar between study groups. These findings in postmenopausal women support that the secretion rate of salivary immunoglobulin A and saliva flow rate are reduced immediately following maximal exercise. Moreover, a 16-week moderate intense walking program can increase the secretion of salivary immunoglobulin A without affecting upper respiratory symptomatology.


Asunto(s)
Ejercicio Físico/fisiología , Inmunoglobulina A Secretora/metabolismo , Posmenopausia , Saliva/inmunología , Análisis de Varianza , Prueba de Esfuerzo , Femenino , Humanos , Incidencia , Persona de Mediana Edad , Oxígeno/metabolismo , Infecciones del Sistema Respiratorio/epidemiología , Factores de Tiempo , Caminata/fisiología
4.
Horm Metab Res ; 43(11): 774-81, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22009372

RESUMEN

We have previously shown that soy protein isolate (SPI) with intact phytoestrogen content prevented obesity-related dysfunction. Recent data have suggested that soy ingredients may act as regulators of adipogenic programming in adipose tissue (AT) and liver. Thus, the current study was undertaken to determine whether the beneficial effects of SPI are linked to changes in adipogenic regulators, such as the Wnt signaling cascade. For this, lean (LZR) and obese Zucker (OZR) rats were provided isocaloric and isonitrogenous diets containing SPI, sodium caseinate, or dairy whey protein for 17 weeks. At termination, SPI increased body weight and total adiposity in rodents, which corresponded with an increase in both adipocyte size and number. Furthermore, markers of inflammation, hypercholesterolemia, and hepatic steatosis were all reduced in OZR rats provided SPI. Transcript abundance of several canonical and noncanonical Wnt signaling intermediates in liver, but not AT, was distinctly modified by SPI. Collectively, these data confirm the protective SPI attenuated obesity-related metabolic dysfunction conceivably through regulation of adipogenic programming, as evident by changes in AT morphology and hepatic Wnt signaling. Collectively, this study confirmed the potential utilization of soy protein and its bioactive ingredients for prevention and treatment of obesity-related comorbidities.


Asunto(s)
Hígado/metabolismo , Obesidad/dietoterapia , Obesidad/metabolismo , Transducción de Señal , Proteínas de Soja/uso terapéutico , Proteínas Wnt/metabolismo , Adipogénesis , Tejido Adiposo Blanco/metabolismo , Tejido Adiposo Blanco/patología , Adiposidad , Animales , Proteína C-Reactiva/análisis , Recuento de Células , Tamaño de la Célula , Epidídimo , Hígado Graso/etiología , Hígado Graso/prevención & control , Regulación de la Expresión Génica , Hipercolesterolemia/etiología , Hipercolesterolemia/prevención & control , Hígado/patología , Masculino , Obesidad/patología , Obesidad/fisiopatología , Tamaño de los Órganos , Distribución Aleatoria , Ratas , Ratas Zucker , Componente Amiloide P Sérico/análisis , Proteínas Wnt/genética
5.
Chronobiol Int ; 38(5): 694-704, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33478260

RESUMEN

Sleep and fatigue-associated symptoms are prominent during chemotherapy. The purpose of this pilot study was to examine bright light effects on sleep disruption, fatigue, daytime sleepiness, depression, and quality of life (QOL) in women with stage I-III breast cancer undergoing chemotherapy. In this 2-group randomized controlled trial (NCT02658708), participants were randomized to receive either blue-green light of 12,000 lux (experimental) or dim red light of 5 lux (control). Light therapy was self-administered using a light visor cap at home. Both groups received 30-minute daily light therapy for 21 consecutive days following the 2nd cycle of chemotherapy. Sleep quality, fatigue, daytime sleepiness, depression, and QOL were self-reported, and nocturnal sleep was monitored by ambulatory polysomnography before the initiation of chemotherapy (baseline) and following the light intervention (posttest). Relative change was assessed at posttest controlling for pretest scores. At posttest, the experimental group self-reported significantly shorter sleep latency than controls (10 vs. 20 min, p = .045) consistent with polysomnography findings (14 vs. 63 min). Polysomnography also revealed longer total sleep time (467 vs. 315 min) and higher sleep efficiency (74% vs. 58%) in experimental vs. controls. Participants receiving bright light experienced a 30% relative decrease in depression, while there was a 24% increase in the controls. The experimental group reported substantially fewer increases in symptom intensity than controls (33% vs. 166%). These findings suggest that bright light likely improved sleep quality and depression and mitigated worsening intensity of symptoms during the first three cycles of chemotherapy. However, features of bright light, e.g., treatment duration, frequency, and timing in relation to chemotherapy treatment require further investigation.


Asunto(s)
Neoplasias de la Mama , Calidad de Vida , Neoplasias de la Mama/tratamiento farmacológico , Ritmo Circadiano , Depresión/terapia , Fatiga/terapia , Femenino , Humanos , Fototerapia , Proyectos Piloto , Sueño
6.
Sci Total Environ ; 750: 141693, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-32846253

RESUMEN

Extreme rainfall events are predicted to become more frequent with climate change and can have a major bearing on instream solute and pollutant transport in mineralised catchments. The Coledale Beck catchment in north-west England was subject to an extreme rainfall event in December 2015 that equated to a 1 in 200-year event. The catchment contains the UK's first passive metal mine water treatment system, and as such had been subject to intense monitoring of solute dynamics before and after commissioning. Due to this monitoring record, the site provides a unique opportunity to assess the effects of a major storm event on (1) catchment-scale solute transport, and (2) the resilience of the new and novel passive treatment system to extreme events. Monitoring suggests a modest decline in treatment efficiency over time that is not synchronous with the storm event and explained instead by changes in system hydraulic efficiency. There was no apparent flushing of the mine system during the event that could potentially have compromised treatment system performance. Analysis of metal transport in the catchment downstream of the mine suggests relatively subtle changes in instream chemistry with modest but statistically-significant reductions in zinc in the lower catchment irrespective of flow condition after the extreme event, but most parameters of interest show no significant change. Increased export of colloidal iron and aluminium is associated with major landslips in the mid-catchment after the storm and provide fresh sorption sites to attenuate dissolved zinc more rapidly in these locations, corroborated by laboratory experiments utilising site materials to investigate the attenuation/release of metals from stream and terrestrial sediments. The data are important as they show both the resilience of passive mine water treatment systems to extreme events and the importance of catchment-scale monitoring to ensure continued effectiveness of treatment initiatives after major perturbation.

7.
J Exp Med ; 192(10): 1403-14, 2000 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-11085743

RESUMEN

The essential upstream steps in granzyme B-mediated apoptosis remain undefined. Herein, we show that granzyme B triggers the mitochondrial apoptotic pathway through direct cleavage of Bid; however, cleavage of procaspases was stalled when mitochondrial disruption was blocked by Bcl-2. The sensitivity of granzyme B-resistant Bcl-2-overexpressing FDC-P1 cells was restored by coexpression of wild-type Bid, or Bid with a mutation of its caspase-8 cleavage site, and both types of Bid were cleaved. However, Bid with a mutated granzyme B cleavage site remained intact and did not restore apoptosis. Bid with a mutation preventing its interaction with Bcl-2 was cleaved but also failed to restore apoptosis. Rapid Bid cleavage by granzyme B (<2 min) was not delayed by Bcl-2 overexpression. These results clearly placed Bid cleavage upstream of mitochondrial Bcl-2. In granzyme B-treated Jurkat cells, endogenous Bid cleavage and loss of mitochondrial membrane depolarization occurred despite caspase inactivation with z-Val-Ala-Asp-fluoromethylketone or Asp-Glu-Val-Asp-fluoromethylketone. Initial partial processing of procaspase-3 and -8 was observed irrespective of Bcl-2 overexpression; however, later processing was completely abolished by Bcl-2. Overall, our results indicate that mitochondrial perturbation by Bid is necessary to achieve a lethal threshold of caspase activity and cell death due to granzyme B.


Asunto(s)
Apoptosis , Proteínas Portadoras/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Serina Endopeptidasas/metabolismo , Clorometilcetonas de Aminoácidos/farmacología , Animales , Proteína Proapoptótica que Interacciona Mediante Dominios BH3 , Células de la Médula Ósea , Proteínas Portadoras/genética , Caspasas/metabolismo , Células Cultivadas , Activación Enzimática , Granzimas , Humanos , Células Jurkat , Ratones , Mitocondrias/metabolismo , Modelos Biológicos , Procesamiento Proteico-Postraduccional , Proteínas Proto-Oncogénicas c-bcl-2/genética , Transducción de Señal , Receptor fas/metabolismo
8.
Horm Metab Res ; 41(7): 523-30, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19277946

RESUMEN

Saturated fatty acids (SFAs) are known to induce inflammation and insulin resistance in adipocytes through toll-like receptor-4 (Tlr4) signaling, but the mechanisms are not well delineated. Furthermore, the potential roles of Tlr2 and the c-Jun N-terminal kinase (JNK) in inflammation in adipocytes have not been investigated. We demonstrated that palmitate, lipopolysaccharide (LPS), and the toll-like receptor-2 (Tlr2) agonist, zymosan A (ZymA), induced insulin resistance in a time- and dose-dependent manner in 3T3-L1 adipocytes. Corresponding with the reduction of insulin sensitivity was an increased expression of IL-6, as well as activation of the proinflammatory transcription factors, nuclear factor kappa B, and activator protein-1. Reactive oxygen species (ROS) accumulation was also observed in palmitate and Tlr agonist treated adipocytes. The JNK inhibitor, SP600125, attenuated insulin resistance mediated by SFA and Tlr agonists, which corresponded with a diminished proinflammatory response and reduced ROS accumulation. Collectively, these results demonstrated Tlr2 involvement in adipocyte inflammation and therefore implicated the receptor as a potential target for SFA. Moreover, activation of JNK also appeared to be essential to Tlr2-, as well as Tlr4-induced insulin resistance and oxidative stress.


Asunto(s)
Adipocitos/inmunología , Resistencia a la Insulina , MAP Quinasa Quinasa 4/metabolismo , Estrés Oxidativo/efectos de los fármacos , Palmitatos/farmacología , Receptor Toll-Like 2/inmunología , Receptor Toll-Like 4/inmunología , Células 3T3 , Adipocitos/efectos de los fármacos , Adipocitos/metabolismo , Animales , Expresión Génica/efectos de los fármacos , MAP Quinasa Quinasa 4/genética , Ratones , Transducción de Señal/efectos de los fármacos , Receptor Toll-Like 2/genética , Receptor Toll-Like 4/genética
9.
J Clin Invest ; 80(4): 998-1008, 1987 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-2443540

RESUMEN

We have segregated DR1+ individuals into two categories according to whether or not their class II+ cells stimulated T lymphocyte clones specific for or restricted to DR1. In a majority of cases (87%), failure to stimulate was a property of cells having the B14;DR1 haplotype and/or nonclassical 21-hydroxylase deficiency. Absence of clonal proliferation could not be explained by release of an intercellular suppressor factor or by stimulator cell absorption of interleukin 2. Homozygous cells inheriting both stimulatory (DR1n) and nonstimulatory (DR1x) haplotypes did not successfully mediate clonal expansion, implying that a trans acting factor operates intracellularly to modify both DR1 alleles or their products. Other DR alleles did not appear to be affected as evidence by normal proliferative responses of T lymphocyte clones restricted to DR2 or DR7 and stimulated by DR1x,2 and DR1x,7 cells, respectively. By two-dimensional gel analysis, we have further identified a 50-kD surface glycoprotein contained in anti-DR immunoprecipitates of DR1x, but not DR1n or non-DR1 cellular lysates. This 50-kD structure had antigenic and peptide identity to DR alpha and beta chains but was resistant to dissociation under conditions that normally separate DR alpha and beta (8 M urea plus 5% 2-mercaptoethanol); boiling in sodium dodecyl sulfate was required to segregate the component polypeptides of the 50-kD heterodimer. We postulate that a product of a novel combinatorial association between constitutive chains of DR may interfere with or compete for normal T cell receptor recognition of DR1 as both an alloantigen and a restricting element. We further propose that gene abnormalities within the class III region of a haplotype associated with nonclassical 21-hydroxylase deficiency may extend into the DR subregion of the major histocompatibility complex with consequent aberrations in DR1 presentation.


Asunto(s)
Hiperplasia Suprarrenal Congénita , Genes MHC Clase II , Antígenos HLA-D/análisis , Antígenos HLA-DR/análisis , Esteroide Hidroxilasas/deficiencia , Alelos , Electroforesis en Gel de Poliacrilamida , Epítopos/análisis , Epítopos/genética , Femenino , Regulación de la Expresión Génica , Ligamiento Genético , Antígeno HLA-DR1 , Haploidia , Humanos , Masculino , Peso Molecular , Mapeo Peptídico , Fenotipo , Propiedades de Superficie
10.
Can J Gastroenterol ; 21(11): 753-5, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18026580

RESUMEN

Malakoplakia is a rare inflammatory condition seen in transplant patients. There are two previously reported cases of malakoplakia involving the gastrointestinal tract in liver transplant patients. The present paper reports a case of colonic malakoplakia in a 58-year-old woman, a liver transplant recipient who was receiving immunosuppressive drugs. She presented with chronic diarrhea while on tacrolimus. There was no history of antecedent infection. Colonoscopy showed patchy mucosal edema, but no discrete yellow plaques or nodules. The diagnosis was made by colon biopsies, which showed chronic inflammation with many histiocytes containing Michaelis-Gutmann bodies. Although rare, malakoplakia is one of many potential causes of diarrhea in a transplant patient. The present case indicates that malakoplakia may be associated with chronic diarrhea, even if there are no macroscopic lesions seen during colonoscopy.


Asunto(s)
Trasplante de Hígado/efectos adversos , Malacoplasia/diagnóstico , Malacoplasia/etiología , Diarrea/etiología , Femenino , Humanos , Inmunosupresores/efectos adversos , Persona de Mediana Edad , Tacrolimus/efectos adversos
11.
Poult Sci ; 95(11): 2624-2632, 2016 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-27143762

RESUMEN

This study examined the ability of flax-based ingredients to attenuate nonalcoholic fatty liver disease ( NAFLD: ) in aged laying hens-a novel and more physiologically relevant model of human disease. Our results showed only hens supplemented with whole flaxseed ( WFX: ) reduced steatosis and hepatocellular ballooning. Serum AST was also reduced in hens provided WFX and defatted flaxseed meal ( DFM: ). Hepatic ω-3 PUFA enrichment was improved with supplementation of WFX, DFM, and flaxseed oil ( FXO: ). However, this effect was more evident in the WFX group. In contrast, transcript abundance of genes linked to NAFLD were predominantly modified with FXO supplementation. Taken together, our data indicate a potential synergistic relationship between the fatty acid and lignan content in flaxseed which attenuated the progression of NAFLD in aged laying hens. Although more research is necessary, these findings demonstrate the potential use of whole flaxseed for the treatment and prevention of NAFLD in humans.


Asunto(s)
Dieta , Lino/metabolismo , Enfermedad del Hígado Graso no Alcohólico/dietoterapia , Alimentación Animal/análisis , Animales , Pollos/fisiología , Modelos Animales de Enfermedad , Femenino , Lino/química , Enfermedad del Hígado Graso no Alcohólico/etiología , Distribución Aleatoria , Semillas/química
12.
J Neuroendocrinol ; 28(12)2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27805753

RESUMEN

Dehydroepiandrosterone (DHEA) is a testosterone/oestrogen precursor and known modulator of vertebrate aggression. Male song sparrows (Melospiza melodia morphna) show high aggression during breeding and nonbreeding life-history stages when circulating DHEA levels are high, and low aggression during molt when DHEA levels are low. We previously showed that androgen receptor and aromatase mRNA expression are higher during breeding and/or nonbreeding in brain regions associated with reproductive and aggressive behaviour, although the potential role of DHEA in mediating these seasonal changes remained unclear. In the present study, nonbreeding male song sparrows were captured and held in the laboratory under short days (8 : 16 h light/dark cycle) and implanted with s.c. DHEA-filled or empty (control) implants for 14 days. DHEA implants increased aggression in a laboratory-based simulated territorial intrusion. Brains of DHEA-implanted birds showed higher aromatase mRNA expression in the preoptic area (POA) and higher androgen receptor mRNA expression in the periventricular nucleus of the medial striatum (pvMSt) and ventromedial nucleus of the hypothalamus. The DHEA-induced increases in aromatase expression in the POA and androgen receptor expression in the pvMSt are consistent with previously reported seasonal increases in these markers associated with naturally elevated DHEA levels. This suggests that DHEA facilitates seasonal increases in aggression in nonbreeding male song sparrows by up-regulating steroid signalling/synthesis machinery in a brain region-specific fashion.


Asunto(s)
Agresión/fisiología , Aromatasa/metabolismo , Proteínas Aviares/fisiología , Encéfalo/fisiología , Deshidroepiandrosterona/fisiología , Receptores Androgénicos/metabolismo , Gorriones/fisiología , Animales , Masculino , ARN Mensajero/metabolismo
13.
Cell Death Differ ; 7(10): 973-83, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11279544

RESUMEN

The molecular pathways responsible for apoptosis in response to granzyme B have remained unresolved. Here we present data supporting the notion that granzyme B-mediated cell death is largely dependent on a pathway that is inhibitable by Bcl-2 or its viral analog BHRF1. We used a panel of stably transfected FDC-P1 mouse myeloid cell lines to show that overexpression of functional, wild-type Bcl-2 or BHRF1 rescued cells from granzyme B-mediated apoptosis, whereas mutated (Gly145-->Glu) Bcl-2, or wild-type Bcl-2 directed to the plasma membrane conferred no protection. Overexpression of Bcl-2 resulted in inhibition of multiple parameters of apoptosis in response to purified perforin and granzyme B, including DNA fragmentation, changes in light scatter profile indicating cell shrinkage and increased refractivity, loss of mitochondrial membrane potential and inhibited colony formation in clonogenic assays. Nevertheless, when exposed to cytotoxic lymphocytes, FDC-P1 and YAC-1 cells overexpressing Bcl-2 remained susceptible to death imparted by cytolytic granules, irrespective of whether the granules contained granzyme B. Thus, alternative granzyme B-independent pathways can be activated by intact lymphocytes to overcome Bcl-2-like inhibitors of apoptosis, enabling CTLs to overcome potential viral blocks to granzyme B-mediated cell death.


Asunto(s)
Apoptosis/inmunología , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Serina Endopeptidasas/metabolismo , Linfocitos T Citotóxicos/citología , Proteínas Virales/metabolismo , Animales , Expresión Génica/fisiología , Granzimas , Humanos , Células Jurkat , Leucemia Mieloide , Linfoma , Ratones , Ratones Endogámicos C57BL , Mitocondrias/enzimología , Proteínas Proto-Oncogénicas c-bcl-2/genética , Linfocitos T Citotóxicos/metabolismo , Transfección , Células Tumorales Cultivadas
14.
Diabetes ; 27(2): 102-7, 1978 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-624438

RESUMEN

Hemoglobin A1c (HbA1c) is a glycosylated derivative of hemoglobin and is one of a family of derivatives whose concentrations are elevated in patients with diabetes mellitus. Published methods for the measurement of HbA1c are relatively tedious and require modest amounts of blood. A high-performance liquid chromatographic (HPLC) method for the determination of HbA1c is presented. The method is rapid (20 minutes), precise (coefficient of variation of 5-10 per cent), uses small amounts of sample (3 microliter.), can be automated. A sample preparation technique using filtration was developed that shortened and simplified preparation of venous blood and allowed use of capillary samples. HbA1c was measured by this method in three age-stratified groups of controls and a group of insulin-requiring juvenile diabetics. There was clear separation of HbA1c values between all normals (5.9 +/- 1.3, 5.6 +/- 0.7, 7.1 +/- 0.9 per cent) and the diabetics (12.1 +/- 2.4 per cent). Use of this method can facilitate large-scale clinical investigations and permit biochemical investigations of the metabolism and formation of hemoglobin A1c where small sample sizes are necessary.


Asunto(s)
Hemoglobinas/aislamiento & purificación , Adolescente , Adulto , Factores de Edad , Niño , Preescolar , Cromatografía Líquida de Alta Presión/métodos , Diabetes Mellitus/sangre , Diabetes Mellitus Tipo 1/sangre , Glicósidos/aislamiento & purificación , Humanos , Persona de Mediana Edad
15.
J Mol Biol ; 265(5): 541-52, 1997 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-9048947

RESUMEN

Mge1, a GrpE-related protein in the mitochondrial matrix of the budding yeast Saccharomyces cerevisiae, is required for translocation of precursor proteins into mitochondria. The effect of Mge1 on nucleotide release from Ssc1, an Hsp70 of the mitochondrial matrix, was analyzed. The release of both ATP and ADP from Ssc1 was stimulated in the presence of Mge1, therefore we conclude that Mge1 functions as a nucleotide release factor for Ssc1. Mge1 bound stably to Ssc1 in vitro; this interaction was resistant to high concentrations of salt but was disrupted by the addition of ATP. ADP was much less effective in releasing Mge1 from Ssc1 whereas ATP gamma S and AMPPNP could not disrupt the Ssc1/Mge1 complex. Ssc1-3, a temperature sensitive SSC1 mutant protein, did not form a detectable complex with Mge1. Consistent with the lack of a detectable interaction, Mge1 did not stimulate nucleotide release from Ssc1-3. A conserved loop structure on the surface of the ATPase domain of DnaK has been implicated in its interaction with GrpE. Since the single amino acid change in Ssc1-3 lies very close to the analogous loop in Ssc1, the role of this loop in the Ssc1:Mge1 interaction was investigated. Deletion of the loop abolished the physical and functional interaction of Ssc1 with Mge1, suggesting that the loop in Ssc1 is also important for the Ssc1:Mge1 interaction. Two mutants with single amino acid changes within the loop did not eliminate the stable binding of Mge1, yet the binding of Mge1 did not stimulate the release of nucleotides from the mutant SSC1 proteins. We propose that the loop region of Ssc1 is important for the physical interaction between Mge1 and Ssc1, and for generation of a conformational change necessary for Mge1-induced nucleotide release.


Asunto(s)
ATPasas Transportadoras de Calcio , Proteínas Portadoras/metabolismo , Proteínas Fúngicas/metabolismo , Proteínas HSP70 de Choque Térmico/metabolismo , Proteínas de Choque Térmico , Proteínas de Transporte de Membrana , Chaperonas Moleculares/metabolismo , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Nucleótidos de Adenina/metabolismo , Secuencia de Bases , Sitios de Unión , Proteínas Portadoras/química , Secuencia Conservada , Cartilla de ADN/genética , Proteínas Fúngicas/química , Proteínas HSP70 de Choque Térmico/química , Mitocondrias/metabolismo , Proteínas de Transporte de Membrana Mitocondrial , Chaperonas Moleculares/química , Chaperonas Moleculares/genética , Estructura Molecular , Mutagénesis Sitio-Dirigida , Unión Proteica , Saccharomyces cerevisiae/genética
16.
J Leukoc Biol ; 70(1): 18-29, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11435481

RESUMEN

Cytotoxic lymphocytes largely comprise CD8(+) cytotoxic T cells and natural killer cells and form the major defense of higher organisms against virus-infected and transformed cells. A key function of cytotoxic lymphocytes is to detect and eliminate potentially harmful cells by inducing them to undergo apoptosis. This is achieved through two principal pathways, both of which require direct but transient contact between the killer cell and its target. The first, involving ligation of TNF receptor-like molecules such as Fas/CD95 by their cognate ligands, results in mobilization of conventional, programmed cell-death pathways centered on activation of pro-apoptotic caspases. This review concentrates on the second pathway, in which the toxic contents of secretory vesicles of the cytotoxic lymphocyte are secreted toward the target cell, and some toxins penetrate into the target cell cytoplasm and nucleus. In addition to invoking a powerful stimulus to caspase activation, this "granule-exocytosis mechanism" provides a variety of additional strategies for overcoming inhibitors of the caspase cascade that may be elaborated by viruses. The key molecular players in this process are the pore-forming protein perforin and a family of granule-bound serine proteases or granzymes. The molecular functions of perforin and granzymes are under intense investigation in many laboratories including our own, and recent advances will be discussed. In addition, this review discusses the evidence pointing to the importance of perforin and granzyme function in pathophysiological situations as diverse as infection with intracellular pathogens, graft versus host disease, susceptibility to transplantable and spontaneous malignancies, lymphoid homeostasis, and the tendency to auto-immune diseases.


Asunto(s)
Antígenos de Diferenciación de Linfocitos T/fisiología , Proteínas de Unión al Calcio/fisiología , Quimiocinas/fisiología , Glicoproteínas de Membrana/fisiología , Ribonucleoproteínas/fisiología , Animales , Antígenos de Diferenciación de Linfocitos T/inmunología , Antígenos de Diferenciación de Linfocitos T/metabolismo , Proteínas de Unión al Calcio/inmunología , Proteínas de Unión al Calcio/metabolismo , Calreticulina , Quimiocinas/inmunología , Quimiocinas/metabolismo , Gránulos Citoplasmáticos/inmunología , Gránulos Citoplasmáticos/metabolismo , Humanos , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/metabolismo , Glicoproteínas de Membrana/inmunología , Glicoproteínas de Membrana/metabolismo , Perforina , Proteínas Citotóxicas Formadoras de Poros , Ribonucleoproteínas/inmunología , Ribonucleoproteínas/metabolismo , Linfocitos T Citotóxicos/inmunología , Linfocitos T Citotóxicos/metabolismo
17.
Arch Intern Med ; 153(18): 2113-7, 1993 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-8379802

RESUMEN

BACKGROUND: Many studies reporting the frequency of breast cancer screening have been based only on physician and patient surveys or on data from quality assurance studies and do not assess the reliability of information obtained from these various sources. METHODS: To obtain more complete data we studied mammography performed in a 3-year period, 1988 through 1991, in 24 nonacademic primary care group practices by both auditing the medical records and obtaining questionnaire responses from 1819 women aged 53 to 62 years and from their 98 physicians in the nonmetropolitan Midwest. RESULTS: Medical record data indicated that mammography was performed in all 3 years in 16.7%, in at least two of 3 years in 49.8%, and in at least one of 3 years in 81.7% of women. While patient reports of a family history of breast cancer, health insurance coverage for mammography, and greater annual household income were each significant predictors, a patient report that a clinic staff member had discussed mammography was the strongest predictor of greater frequency of mammography. CONCLUSIONS: In this study of self-selected physicians and their patients, record-documented mammographic examinations were considerably more frequent than has been reported in some studies, but occurred at rates consistent with quality assurance data for the region. These data suggest that clinic staff initiatives with screening mammography have a large impact.


Asunto(s)
Neoplasias de la Mama/prevención & control , Medicina Familiar y Comunitaria , Práctica de Grupo , Mamografía/estadística & datos numéricos , Tamizaje Masivo/estadística & datos numéricos , Medicina Familiar y Comunitaria/estadística & datos numéricos , Femenino , Práctica de Grupo/estadística & datos numéricos , Investigación sobre Servicios de Salud/métodos , Humanos , Auditoría Médica , Persona de Mediana Edad , Medio Oeste de Estados Unidos , Estudios Retrospectivos , Factores Socioeconómicos , Encuestas y Cuestionarios
18.
J Clin Endocrinol Metab ; 47(3): 578-80, 1978 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-263311

RESUMEN

Hemoglobin A1c concentration (HbA1c) was compared to the plasma glucose responses at 1 and 2 h of an oral glucose tolerance test (OGTT) in 63 subjects preselected because of postprandial hyperglycemia. HbA1c concentrations were correlated with 1- and 2-hour plasma glucose responses during the OGTT (r = 0.776 and 0.8602, respectively). The OGTT responses were diabetic-like in 21, indeterminate in 15, and normal in 27 subjects. HbA1c values were within normal limits in all subjects who had a normal or indeterminate OGTT response and in 10 out of 21 with a diabetic OGTT. The 2-h OGTT response among the 10 diabetic responders with normal HbA1c was 200 +/- 31 mg/100 ml (mean +/- SD), while that of the 11 diabetic responders with elevated HbA1c was 352 +/- 122 mg/100 ml. All subjects with an elevated HbA1c had a 2-h plasma glucose above 228 mg/100 ml, whereas only 7% of subjects with a normal HbA1c had a 2-h glucose above this value. It is concluded that only about half of the patients currently diagnosed as having mild or chemical diabetes by OGTT have elevated HbA1c and that an elevated HbA1c is usually associated with 2-h OGTT levels above 228 mg/100 mg.


Asunto(s)
Diabetes Mellitus/diagnóstico , Hemoglobina Glucada/análisis , Glucemia/análisis , Técnicas de Laboratorio Clínico , Prueba de Tolerancia a la Glucosa , Humanos , Valores de Referencia
19.
Neurology ; 29(5): 636-43, 1979 May.
Artículo en Inglés | MEDLINE | ID: mdl-571561

RESUMEN

The response to a standardized exercise test was investigated in 12 volunteers and 13 patients with aches, cramps, and pains. In men, creatine kinase (CK) levels peaked (up to 1600 mU per milliliter) between 10 and 20 hours after exercise. High levels of blood lactate during exercise were related to the intensity of work and to high levels of CK after exercise. The patients could be divided into several groups: (1) those with no change in blood metabolites (psychogenic); (2) those with a disproportionate rise in CK (metabolic myopathies); (3) those with a disproportionate rise of lactate (mitochondrial abnormalities); and (4) in one patient with exercise-related pains, subnormal elevation of fatty acid levels. The correlation of changes in blood lactate, CK, and fatty acids may be useful, whereas an isolated measurement, even if outside the normal range, is often meaningless.


Asunto(s)
Enfermedades Neuromusculares/diagnóstico , Esfuerzo Físico , Adulto , Creatina Quinasa/metabolismo , Ácidos Grasos no Esterificados/sangre , Femenino , Humanos , Lactatos/sangre , Masculino , Enfermedades Neuromusculares/enzimología , Oxígeno/sangre
20.
Neurology ; 29(6): 902-4, 1979 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-572017

RESUMEN

The effect of 2 hours of exercise on the serum creatine kinase (CK) level was investigated in 11 men and 9 women. The mean increase of CK 24 hours after exercise was significantly greater in men. The relative lack of CK elevation in women may: (1) indicate that female muscle is less susceptible to damage by adverse factors; and (2) explain discrepancies in previous reports.


Asunto(s)
Creatina Quinasa/sangre , Esfuerzo Físico , Ácidos Grasos no Esterificados/sangre , Femenino , Humanos , Lactatos/sangre , Masculino , Piruvatos/sangre , Factores Sexuales
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