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1.
Proc Natl Acad Sci U S A ; 118(52)2021 12 28.
Artículo en Inglés | MEDLINE | ID: mdl-34930833

RESUMEN

In the cell, the conformations of nascent polypeptide chains during translation are modulated by both the ribosome and its associated molecular chaperone, trigger factor. The specific interactions that underlie these modulations, however, are still not known in detail. Here, we combine protein engineering, in-cell and in vitro NMR spectroscopy, and molecular dynamics simulations to explore how proteins interact with the ribosome during their biosynthesis before folding occurs. Our observations of α-synuclein nascent chains in living Escherichia coli cells reveal that ribosome surface interactions dictate the dynamics of emerging disordered polypeptides in the crowded cytosol. We show that specific basic and aromatic motifs drive such interactions and directly compete with trigger factor binding while biasing the direction of the nascent chain during its exit out of the tunnel. These results reveal a structural basis for the functional role of the ribosome as a scaffold with holdase characteristics and explain how handover of the nascent chain to specific auxiliary proteins occurs among a host of other factors in the cytosol.


Asunto(s)
Secuencias de Aminoácidos/genética , Proteínas de Escherichia coli , Péptidos , Isomerasa de Peptidilprolil , Biosíntesis de Proteínas/genética , Escherichia coli/genética , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Humanos , Espectroscopía de Resonancia Magnética , Simulación de Dinámica Molecular , Péptidos/química , Péptidos/genética , Péptidos/metabolismo , Isomerasa de Peptidilprolil/química , Isomerasa de Peptidilprolil/metabolismo , Ingeniería de Proteínas , Pliegue de Proteína , Ribosomas/metabolismo , alfa-Sinucleína/química , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismo
2.
Worldviews Evid Based Nurs ; 19(1): 56-63, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35040245

RESUMEN

BACKGROUND: Cardiac rehabilitation programs (CRP) are effective evidence-based secondary prevention programs that reduce morbidity and mortality in patients with cardiovascular disease (CVD). However, participation remains suboptimal, resulting in under-treatment and greater risk for recurrent cardiac events. Understanding the reasons behind CRP dropout is urgently needed to inform the development of programs that best meet patient needs and support sustained engagement. AIMS: The aim of this study was to identify and understand factors impacting CRP dropout from the patient perspective. METHODS: A qualitative study using semi-structured interviews was undertaken to examine the experience of 23 patients who dropped out of a CRP within a large urban hospital in British Columbia, Canada. Data were coded, analyzed using the constant comparison technique, and organized thematically. RESULTS: Participants described multiple challenges when attempting to complete CRP. Analysis of the data led to the identification of three main categories: (1) challenges living with CVD, (2) perceived advantages and disadvantages of CRP, and (3) unmet needs during CRP. LINKING EVIDENCE TO ACTION: In the practice setting, assessment of readiness to engage in CRP, alongside patient preferences and engagement needs, should be undertaken for maximum CRP uptake and completion. Providing diverse modes of CRP delivery, along with exploring the impact of virtual options as compared to traditional in-person programs, will further advance the CRP evidence and may help address pervasive access barriers.


Asunto(s)
Rehabilitación Cardiaca , Enfermedades Cardiovasculares , Colombia Británica , Rehabilitación Cardiaca/métodos , Humanos , Evaluación del Resultado de la Atención al Paciente , Investigación Cualitativa
3.
Proc Natl Acad Sci U S A ; 115(39): 9744-9749, 2018 09 25.
Artículo en Inglés | MEDLINE | ID: mdl-30201720

RESUMEN

Cotranslational folding (CTF) is a fundamental molecular process that ensures efficient protein biosynthesis and minimizes the formation of misfolded states. However, the complexity of this process makes it extremely challenging to obtain structural characterizations of CTF pathways. Here, we correlate observations of translationally arrested nascent chains with those of a systematic C-terminal truncation strategy. We create a detailed description of chain length-dependent free energy landscapes associated with folding of the FLN5 filamin domain, in isolation and on the ribosome, and thus, quantify a substantial destabilization of the native structure on the ribosome. We identify and characterize two folding intermediates formed in isolation, including a partially folded intermediate associated with the isomerization of a conserved cis proline residue. The slow folding associated with this process raises the prospect that neighboring unfolded domains might accumulate and misfold during biosynthesis. We develop a simple model to quantify the risk of misfolding in this situation and show that catalysis of folding by peptidyl-prolyl isomerases is sufficient to eliminate this hazard.


Asunto(s)
Filaminas/biosíntesis , Humanos , Cinética , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Pliegue de Proteína , Modificación Traduccional de las Proteínas , Deficiencias en la Proteostasis/metabolismo , Ribosomas/metabolismo , Secuencias Repetidas en Tándem , Termodinámica
4.
J Infect Dis ; 218(11): 1739-1745, 2018 10 20.
Artículo en Inglés | MEDLINE | ID: mdl-29931158

RESUMEN

Background: Human papillomavirus (HPV) is a known causative factor in the etiology of cervical cancer. Methods: HPV DNA genotyping was performed in menstrual blood (MB) collected in napkins from patients with cervical intraepithelial neoplasia (CIN), HPV infection and sexually active apparently normal subjects. In the same patient cohort, MB TAP1 I333V and TAP1 D637G gene polymorphisms were examined. Results: The sensitivity, specificity, and positive and negative predictive values of HPV DNA in the detection of CIN or HPV infection were 83% (223 of 268), 98% (131 of 134), 99% (223 of 226), and 74% (131 of 176), respectively. Moreover, HPV DNA was found in 24% (28/118) patients who had loop electrosurgical excision procedure treatment and 0% (0/76) HPV infected or CIN1 patient with proven recovery. On the other hand, the risk of developing high-grade CIN was significantly reduced for AG and GG genotypes compared with AA genotype and for carriers with a G allele compared with those with an A allele for both polymorphisms. Conclusions: MB HPV DNA is a potential noninvasive marker for screening and monitoring of squamous intraepithelial lesion. Together with TAP1 I333V and TAP1 D637G gene polymorphisms, the combined test may be useful for stratifying high-risk patients for better follow-up strategies.


Asunto(s)
Transportador de Casetes de Unión a ATP, Subfamilia B, Miembro 2/genética , Menstruación/sangre , Papillomaviridae/genética , Infecciones por Papillomavirus/diagnóstico , Displasia del Cuello del Útero/diagnóstico , Adulto , ADN Viral/sangre , ADN Viral/genética , Femenino , Marcadores Genéticos/genética , Humanos , Infecciones por Papillomavirus/virología , Polimorfismo de Nucleótido Simple/genética , Displasia del Cuello del Útero/virología
5.
J Biomol NMR ; 63(2): 151-163, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26253948

RESUMEN

The translational diffusion of macromolecules can be examined non-invasively by stimulated echo (STE) NMR experiments to accurately determine their molecular sizes. These measurements can be important probes of intermolecular interactions and protein folding and unfolding, and are crucial in monitoring the integrity of large macromolecular assemblies such as ribosome-nascent chain complexes (RNCs). However, NMR studies of these complexes can be severely constrained by their slow tumbling, low solubility (with maximum concentrations of up to 10 µM), and short lifetimes resulting in weak signal, and therefore continuing improvements in experimental sensitivity are essential. Here we explore the use of the paramagnetic longitudinal relaxation enhancement (PLRE) agent NiDO2A on the sensitivity of (15)N XSTE and SORDID heteronuclear STE experiments, which can be used to monitor the integrity of these unstable complexes. We exploit the dependence of the PLRE effect on the gyromagnetic ratio and electronic relaxation time to accelerate recovery of (1)H magnetization without adversely affecting storage on N z during diffusion delays or introducing significant transverse relaxation line broadening. By applying the longitudinal relaxation-optimized SORDID pulse sequence together with NiDO2A to 70S Escherichia coli ribosomes and RNCs, NMR diffusion sensitivity enhancements of up to 4.5-fold relative to XSTE are achieved, alongside ~1.9-fold improvements in two-dimensional NMR sensitivity, without compromising the sample integrity. We anticipate these results will significantly advance the use of NMR to probe dynamic regions of ribosomes and other large, unstable macromolecular assemblies.


Asunto(s)
Resonancia Magnética Nuclear Biomolecular , Ribosomas/química , Sustancias Macromoleculares/química , Resonancia Magnética Nuclear Biomolecular/métodos , Proteínas/química , Subunidades Ribosómicas/química
6.
J Electrocardiol ; 48(5): 803-8, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26206742

RESUMEN

BACKGROUND: The persistence of ST segment depression in recovery signifies a strongly positive exercise treadmill test (ETT). However, it is unclear if early recovery of ST segments portends a similar prognosis. We sought to determine if persistence of ST depression into recovery correlates with ischemic burden based on myocardial perfusion imaging (MPI). METHODS: This was a retrospective analysis of 853 consecutive patients referred for exercise MPI at a tertiary academic center over a 24-month period. Patients were stratified into three groups based on the results of the ETT: normal (negative ETT), persistence (positive ETT with >1mm ST segment depression at 1minute in recovery) and early normalization (positive ETT with <1mm ST segment depression at 1minute in recovery). Summed stress scores (SSSs) were calculated then for each patient, while the coronary anatomy was reported for the subset of patients who received coronary angiograms. RESULTS: A total of 513 patients had a negative ETT, 235 patients met criteria for early normalization, while 105 patients met criteria for persistence. The persistence group had a significantly greater SSS (8.48±7.77) than both the early normalization (4.34±4.98, p<0.001) and normal (4.47±5.31, p<0.001) groups. The SSSs of the early normalization and normal groups were not statistically different and met the prespecified non-inferiority margin (mean difference 0.12, -0.66=lower 95% CI, p<0.001). Among the 87 patients who underwent an angiogram, significant three-vessel or left main disease was seen in 39.3% of the persistence group compared with 5.9% of normal and 7.4% of early normalization groups. CONCLUSION: Among patients with an electrically positive ETT, recovery of ST segment depression within 1minute was associated with a lower SSS than patients with persistence of ST depression beyond 1minute. Furthermore, early ST segment recovery conferred a similar SSS to patients with a negative ETT. These results suggest that among patients evaluated for chest pain with a positive ETT, early recovery of the ST segment during recovery is associated with a significantly less ischemic burden on subsequent MPI and thus may represent a false positive finding in exercise treadmill testing.


Asunto(s)
Angiografía Coronaria/métodos , Electrocardiografía/métodos , Prueba de Esfuerzo/métodos , Isquemia Miocárdica/diagnóstico , Isquemia Miocárdica/epidemiología , Colombia Británica/epidemiología , Angiografía Coronaria/estadística & datos numéricos , Electrocardiografía/estadística & datos numéricos , Prueba de Esfuerzo/estadística & datos numéricos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
7.
Lung ; 192(2): 297-303, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24469113

RESUMEN

BACKGROUND: The impact of obstructive sleep apnea (OSA) on the development of atherosclerotic cardiovascular disease (CVD) in the absence of overt CVD or risk factors is unclear. Our purpose was to assess whether patients with OSA without overt CVD or risk factors have subclinical atherosclerosis as evaluated by carotid intima medial thickness (CIMT) compared to matched controls. METHODS: We measured CIMT in patients >40 years old, who underwent polysomnography for suspected OSA and did not have a history of CVD or risk factors (smoking, hypertension, diabetes, hyperlipidemia). OSA severity was classified according to apnea-hypopnea index. Serum levels of high-sensitivity C-reactive protein, fibrinogen, and lipids were assessed and relationships with OSA severity explored. CIMT measurements from patients with OSA were compared those of to age-, gender-, and BMI-matched controls from a community-based cohort without known CVD or OSA. RESULTS: Fifty-one patients were studied. Of these, patients with severe OSA had an increased CIMT compared to patients without OSA, but the relationship was not significant after controlling for age (p = 0.10). However, 37 patients had OSA and were matched to 105 controls. CIMT was significantly increased in OSA patients versus controls (0.77 vs. 0.68 mm, p = 0.03). The difference between patients and controls was greater for patients with severe OSA (0.83 vs. 0.71 mm) than for patients with mild-to-moderate OSA (0.71 vs. 0.67 mm). CONCLUSIONS: Patients with OSA but without a history of or risk factors for CVD have increased CIMT compared to a BMI-, age-, and gender-matched cohort. This provides evidence that OSA is an independent risk factor for the development of CVD.


Asunto(s)
Enfermedades de las Arterias Carótidas/diagnóstico , Enfermedades de las Arterias Carótidas/etiología , Grosor Intima-Media Carotídeo , Apnea Obstructiva del Sueño/complicaciones , Adulto , Enfermedades Asintomáticas , Estudios de Casos y Controles , Estudios de Cohortes , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Medición de Riesgo , Factores de Riesgo , Índice de Severidad de la Enfermedad , Apnea Obstructiva del Sueño/diagnóstico
8.
Vasc Med ; 18(1): 13-8, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23263153

RESUMEN

The aim of this study was to assess the association between peripheral arterial tonometry (PAT) and two more traditional measures of endothelial function - flow-mediated dilation (FMD) and its hyperemic stimulus, hyperemic peak velocity time integral (VTI). We related three vascular function measures (natural log transformed PAT, FMD, and VTI) from 304 patients (mean age 48.9 ± 12.5 years), including 105 with coronary artery disease (CAD). Using linear regression, we studied the relationships between lnPAT, FMD, and VTI, and compared differences in these parameters in those with and without CAD. Although FMD and lnPAT both had a correlation with VTI (Pearson's r = 0.119, p = 0.039 and r = 0.167, p = 0.004, respectively), lnPAT had no correlation with FMD (r = -0.0471, p = 0.414). lnPAT was also lower in patients with CAD compared to controls (mean 0.51 ± 0.19 versus 0.65 ± 0.26, respectively, p < 0.0001). In multivariate analysis, VTI remained associated with lnPAT (standardized ß = 0.1369, p = 0.04). Among this group of subjects with and without CAD, lnPAT was found to be unrelated to FMD but correlated with VTI. This would suggest that lnPAT is a measure of microvascular function. Although it is unrelated to FMD, lnPAT is decreased in patients with pre-existing cardiovascular disease. Further studies are required to determine if this can be used clinically as a tool for cardiac risk stratification and prediction of CAD.


Asunto(s)
Arterias/fisiopatología , Enfermedades Cardiovasculares/fisiopatología , Endotelio Vascular/fisiopatología , Adulto , Femenino , Humanos , Masculino , Manometría , Persona de Mediana Edad
9.
Materials (Basel) ; 16(4)2023 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-36837013

RESUMEN

An AA6061 aluminum alloy tube was fabricated by compacting machining chips via thermomechanical consolidation, including hot pressing and hot extrusion. The microstructure evolution and formation of oxide particles were investigated in correlation to tensile mechanical properties. It was found that fine Al/Mg oxide particles were formed due to the fracture of oxide layers on the chips and the reaction between Mg and Al2O3 during hot extrusion. The oxide particles inhibited the growth of recrystallized α-Al grains, leading to the formation of a microstructure consisting of coarse elongated grains with sizes of 420 µm and fine equiaxed grains with sizes of 10 µm. After T6 heat treatment, a microstructure with finer grains (grain sizes: 34 µm) formed due to further recrystallization induced by residual strain. The tensile mechanical properties testing results indicated that a good combination of strength (296 MPa) and ductility (7.6%) was achieved in the T6 heat treated samples, which were likely attributed to the high-quality inter-chip bonding, as well as the fine oxide particles which were small enough that further crack nucleation and growth around them were inhibited during tensile deformation. For the purpose of comparison, the microstructure and mechanical properties of the as-extruded and T6 heat treated samples produced by hot extrusion of the cast ingot of AA6061 aluminum alloy were also investigated. The lower tensile strength of solid-state recycled tube sample might be associated with the consumption of Mg atoms by the oxidation reaction, leading to the lower density of ß″ precipitates in precipitation strengthening.

10.
Nat Chem ; 14(10): 1165-1173, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35927328

RESUMEN

Co-translational folding is crucial to ensure the production of biologically active proteins. The ribosome can alter the folding pathways of nascent polypeptide chains, yet a structural understanding remains largely inaccessible experimentally. We have developed site-specific labelling of nascent chains to detect and measure, using 19F nuclear magnetic resonance (NMR) spectroscopy, multiple states accessed by an immunoglobulin-like domain within a tandem repeat protein during biosynthesis. By examining ribosomes arrested at different stages during translation of this common structural motif, we observe highly broadened NMR resonances attributable to two previously unidentified intermediates, which are stably populated across a wide folding transition. Using molecular dynamics simulations and corroborated by cryo-electron microscopy, we obtain models of these partially folded states, enabling experimental verification of a ribosome-binding site that contributes to their high stabilities. We thus demonstrate a mechanism by which the ribosome could thermodynamically regulate folding and other co-translational processes.


Asunto(s)
Pliegue de Proteína , Ribosomas , Microscopía por Crioelectrón , Péptidos/metabolismo , Biosíntesis de Proteínas , Proteínas/química , Ribosomas/química
11.
Nat Commun ; 13(1): 4243, 2022 07 22.
Artículo en Inglés | MEDLINE | ID: mdl-35869078

RESUMEN

Co-translational folding is a fundamental process for the efficient biosynthesis of nascent polypeptides that emerge through the ribosome exit tunnel. To understand how this process is modulated by the shape and surface of the narrow tunnel, we have rationally engineered three exit tunnel protein loops (uL22, uL23 and uL24) of the 70S ribosome by CRISPR/Cas9 gene editing, and studied the co-translational folding of an immunoglobulin-like filamin domain (FLN5). Our thermodynamics measurements employing 19F/15N/methyl-TROSY NMR spectroscopy together with cryo-EM and molecular dynamics simulations reveal how the variations in the lengths of the loops present across species exert their distinct effects on the free energy of FLN5 folding. A concerted interplay of the uL23 and uL24 loops is sufficient to alter co-translational folding energetics, which we highlight by the opposite folding outcomes resulting from their extensions. These subtle modulations occur through a combination of the steric effects relating to the shape of the tunnel, the dynamic interactions between the ribosome surface and the unfolded nascent chain, and its altered exit pathway within the vestibule. These results illustrate the role of the exit tunnel structure in co-translational folding, and provide principles for how to remodel it to elicit a desired folding outcome.


Asunto(s)
Pliegue de Proteína , Ribosomas , Simulación de Dinámica Molecular , Biosíntesis de Proteínas , Proteínas/metabolismo , Ribosomas/metabolismo , Termodinámica
12.
Acta Obstet Gynecol Scand ; 90(9): 1005-9, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21623741

RESUMEN

OBJECTIVE: To assess the knowledge on commercial cord blood banking (CCBB) among pregnant women. DESIGN: Cross-sectional survey. Setting. Antenatal clinics of two major public maternity units in Hong Kong. POPULATION: Pregnant women. METHODS: Self-administered questionnaire. MAIN OUTCOME MEASURES: The survey explored knowledge about the use of self-stored umbilical cord blood (UCB) stem cells and attitude towards CCBB. RESULTS: Of the 2,000 women recruited, 1 866 (93.3%) completed the questionnaire. The majority (78.2%) had no idea that there was the chance of using self-stored stem cells. Moreover, most of the respondents were unclear about which diseases other than leukemia are amenable to treatment with UCB stem cells in general. Only 20.3% of women knew that stem cells are available from the Red Cross in case their children need hematopoietic cell transplantation. CONCLUSIONS: The results of this study revealed inadequate knowledge on UCB stem cell banking and its applications among most of our pregnant women. The government and clinicians should combine efforts to provide accurate information on utilization of UCB stem cells during antenatal care.


Asunto(s)
Bancos de Sangre , Comprensión , Sangre Fetal , Conocimiento , Mujeres Embarazadas , Trasplante de Células Madre de Sangre del Cordón Umbilical , Estudios Transversales , Recolección de Datos , Femenino , Hong Kong , Humanos , Embarazo , Encuestas y Cuestionarios
13.
Comput Intell Neurosci ; 2021: 6679661, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33959157

RESUMEN

E-mail systems and online social media platforms are ideal places for news dissemination, but a serious problem is the spread of fraudulent news headlines. The previous method of detecting fraudulent news headlines was mainly laborious manual review. While the total number of news headlines goes as high as 1.48 million, manual review becomes practically infeasible. For news headline text data, attention mechanism has powerful processing capability. In this paper, we propose the models based on LSTM and attention layer, which fit the context of news headlines efficiently and can detect fraudulent news headlines quickly and accurately. Based on multi-head attention mechanism eschewing recurrent unit and reducing sequential computation, we build Mini-Transformer Deep Learning model to further improve the classification performance.


Asunto(s)
Medios de Comunicación Sociales , Humanos
14.
Nat Commun ; 12(1): 6447, 2021 11 08.
Artículo en Inglés | MEDLINE | ID: mdl-34750347

RESUMEN

During biosynthesis, proteins can begin folding co-translationally to acquire their biologically-active structures. Folding, however, is an imperfect process and in many cases misfolding results in disease. Less is understood of how misfolding begins during biosynthesis. The human protein, alpha-1-antitrypsin (AAT) folds under kinetic control via a folding intermediate; its pathological variants readily form self-associated polymers at the site of synthesis, leading to alpha-1-antitrypsin deficiency. We observe that AAT nascent polypeptides stall during their biosynthesis, resulting in full-length nascent chains that remain bound to ribosome, forming a persistent ribosome-nascent chain complex (RNC) prior to release. We analyse the structure of these RNCs, which reveals compacted, partially-folded co-translational folding intermediates possessing molten-globule characteristics. We find that the highly-polymerogenic mutant, Z AAT, forms a distinct co-translational folding intermediate relative to wild-type. Its very modest structural differences suggests that the ribosome uniquely tempers the impact of deleterious mutations during nascent chain emergence. Following nascent chain release however, these co-translational folding intermediates guide post-translational folding outcomes thus suggesting that Z's misfolding is initiated from co-translational structure. Our findings demonstrate that co-translational folding intermediates drive how some proteins fold under kinetic control, and may thus also serve as tractable therapeutic targets for human disease.


Asunto(s)
Biosíntesis de Proteínas , Pliegue de Proteína , Ribosomas/metabolismo , Deficiencia de alfa 1-Antitripsina/metabolismo , alfa 1-Antitripsina/química , Algoritmos , Secuencia de Aminoácidos , Animales , Western Blotting , Dicroismo Circular , Endopeptidasa K/metabolismo , Humanos , Cinética , Péptidos/química , Péptidos/genética , Péptidos/metabolismo , Procesamiento Proteico-Postraduccional , Conejos , Reticulocitos/citología , Reticulocitos/metabolismo , alfa 1-Antitripsina/genética , alfa 1-Antitripsina/metabolismo , Deficiencia de alfa 1-Antitripsina/genética
15.
Nat Chem ; 13(12): 1214-1220, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34650236

RESUMEN

Most proteins begin to fold during biosynthesis on the ribosome. It has been suggested that interactions between the emerging polypeptide and the ribosome surface might allow the ribosome itself to modulate co-translational folding. Here we combine protein engineering and NMR spectroscopy to characterize a series of interactions between the ribosome surface and unfolded nascent chains of the immunoglobulin-like FLN5 filamin domain. The strongest interactions are found for a C-terminal segment that is essential for folding, and we demonstrate quantitative agreement between the strength of this interaction and the energetics of the co-translational folding process itself. Mutations in this region that reduce the extent of binding result in a shift in the co-translational folding equilibrium towards the native state. Our results therefore demonstrate that a competition between folding and binding provides a simple, dynamic mechanism for the modulation of co-translational folding by the ribosome.


Asunto(s)
Filaminas/metabolismo , Pliegue de Proteína , Ribosomas/metabolismo , Secuencia de Aminoácidos , Filaminas/genética , Simulación de Dinámica Molecular , Mutación , Resonancia Magnética Nuclear Biomolecular , Unión Proteica , Biosíntesis de Proteínas
16.
Circ Heart Fail ; 14(1): e007073, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33464959

RESUMEN

BACKGROUND: International task force statements advocate telehealth programs to promote health-related quality of life for patients with chronic heart failure (CHF). To that end, we evaluated the efficacy and usability of an automated e-counseling program. METHODS: This Canadian multi-site double-blind randomized trial assessed whether usual care plus either internet-based e-counseling (motivational and cognitive-behavioral tools for CHF self-care) or e-based conventional CHF self-care education (e-UC) improved 12-month Kansas City Cardiomyopathy Questionnaire Overall Summary (KCCQ-OS). Secondary outcomes included program engagement (total logon weeks, logons, and logon hours), total CHF self-care behaviors, diet (fruit and vegetable servings), 6-minute walk test, and 4-day step count. The association between program engagement and health-related quality of life was assessed using KCCQ-OS tertiles. RESULTS: We enrolled 231 patients, median age =59.5 years, 22% female, and elevated median KCCQ-OS=83.0 (interquartile range, 68-93). KCCQ-OS increase ≥5 points was not more prevalent for e-counseling, n=29 (29.6%) versus e-UC, n=32 (34.0%), P=0.51. E-Counseling versus e-UC increased total logon weeks (P=0.02), logon hours (P=0.001), and logons (P<0.001). Only e-counseling showed a positive association between 12-month KCCQ-OS tertile and logon weeks (P=0.04) and logon hours (P=0.004). E-Counseling increased CHF self-care behavior and diet but not 6-minute walk test or 4-day step count. CONCLUSIONS: The primary KCCQ-OS end point was negative for this trial. Only e-counseling showed a positive association between program engagement and 12-month KCCQ-OS tertile, and it improved CHF self-care behavior and diet. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01864369.


Asunto(s)
Terapia Cognitivo-Conductual/métodos , Dieta , Asesoramiento a Distancia/métodos , Insuficiencia Cardíaca/rehabilitación , Intervención basada en la Internet , Entrevista Motivacional/métodos , Autocuidado , Anciano , Método Doble Ciego , Femenino , Insuficiencia Cardíaca/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Motivación , Medición de Resultados Informados por el Paciente , Encuestas y Cuestionarios , Resultado del Tratamiento , Prueba de Paso
17.
J Clin Microbiol ; 48(3): 709-13, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20089764

RESUMEN

The Papanicolaou test generates pain and embarrassment, and cytology screening has limited sensitivity for detection of cervical neoplasia. These factors urge the use of another screening test that can overcome these limitations. We explore a completely noninvasive method using detection of human papillomavirus (HPV) DNA in women's menstrual blood (MB). The participants were divided into 3 cohorts: (i) 235 patients with cervical intraepithelial neoplasia 3 (CIN 3) (n = 48), CIN 2 (n = 60), CIN 1 (n = 58), or condyloma acuminatum (CAC) (n = 69) before treatment or remission; (ii) from the first cohort of patients, 108 CIN 3 or CIN 2 patients after treatment and 62 CIN 1 or CAC patients after remission; and (iii) 323 apparently normal subjects (ANS) without any cervical disease. The HPV genotypes of the infected patients were confirmed by direct sequencing. Quantitative real-time PCR (QRT-PCR) was used to measure the MB HPV16 load for 15 infected patients. Results showed that the sensitivity, specificity, and positive and negative predictive values for detection of MB HPV DNA in samples from patients with CIN or CAC were 82.8%, 93.1%, 90.0%, and 87.9%, respectively. Moreover, MB HPV DNA was found in samples from 22.2% of CIN 3 or CIN 2 patients after treatment, 0.0% of CIN 1 or CAC patients after remission, and 8.1% of ANS, 4 of whom were found to have CIN 1 or CAC. Furthermore, QRT-PCR showed that the normalized MB HPV16 DNA copy numbers in samples from patients with CIN 1 to CIN 3 were significantly increased. These preliminary results suggested that MB HPV DNA is a potential noninvasive marker for these premalignant cervical diseases.


Asunto(s)
Sangre/virología , Condiloma Acuminado/virología , ADN Viral/aislamiento & purificación , Menstruación/sangre , Papillomaviridae/aislamiento & purificación , Infecciones por Papillomavirus/virología , Displasia del Cuello del Útero/virología , Adolescente , Adulto , ADN Viral/química , ADN Viral/genética , Femenino , Genotipo , Humanos , Persona de Mediana Edad , Papillomaviridae/clasificación , Papillomaviridae/genética , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad , Análisis de Secuencia de ADN , Adulto Joven
18.
J Lipids ; 2020: 3491764, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32099678

RESUMEN

Lipoprotein(a) [Lp(a)], aka "Lp little a", was discovered in the 1960s in the lab of the Norwegian physician Kåre Berg. Since then, we have greatly improved our knowledge of lipids and cardiovascular disease (CVD). Lp(a) is an enigmatic class of lipoprotein that is exclusively formed in the liver and comprises two main components, a single copy of apolipoprotein (apo) B-100 (apo-B100) tethered to a single copy of a protein denoted as apolipoprotein(a) apo(a). Plasma levels of Lp(a) increase soon after birth to a steady concentration within a few months of life. In adults, Lp(a) levels range widely from <2 to 2500 mg/L. Evidence that elevated Lp(a) levels >300 mg/L contribute to CVD is significant. The improvement of isoform-independent assays, together with the insight from epidemiologic studies, meta-analyses, genome-wide association studies, and Mendelian randomization studies, has established Lp(a) as the single most common independent genetically inherited causal risk factor for CVD. This breakthrough elevated Lp(a) from a biomarker of atherosclerotic risk to a target of therapy. With the emergence of promising second-generation antisense therapy, we hope that we can answer the question of whether Lp(a) is ready for prime-time clinic use. In this review, we present an update on the metabolism, pathophysiology, and current/future medical interventions for high levels of Lp(a).

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BMC Clin Pharmacol ; 8: 10, 2008 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-18957124

RESUMEN

BACKGROUND: Prior studies suggested low density lipoprotein particle (LDLP) size is a predictor of atherosclerosis. Knowledge of effects of lipid lowering drugs on lipoprotein subclasses is useful. We treated subjects with hyperlipidemia sequentially with statins and fibrates, the 2 main classes of lipid lowering therapy and studied changes in NMR lipoprotein subclasses. METHODS: 35 subjects (21 males; 60 +/- 12 y) were enrolled in a crossover study. Subjects had baseline lipid profile & apoB. Lipoprotein subclasses, particle numbers and diameters were assessed with NMR spectroscopy. Subjects were randomized to simvastatin 20 mg or fenofibrate 200 mg. Repeat testing was done at 12 weeks. After 6 week washout, subjects were started on alternate drug for 12 weeks with pre/post tests. RESULTS: Both therapies resulted in expected changes in lipids and apoB. Decreases in total cholesterol, LDL and apoB were greater with simvastatin. Fenofibrate led to small increase in HDL. Both therapies decreased LDLP. Reduction in LDLP was greater with simvastatin (32%, p < .001) compared to fenofibrate (17%; p = .036 vs pre; p = .027 vs simvastatin end). Fenofibrate resulted in 17% rise in large LDLP (p = .06 vs pre) and 32% drop in small LDLP (p = .007 vs pre). Simvastatin led to decrease in both LDLP fractions (19% large LDLP; p = .001 vs fenofibrate end; 34% small LDLP, p = .019 vs pre). With fenofibrate, LDLP size increased from 20.4 nm to 20.8 nm (p = .037). There was no change in LDLP size with simvastatin. There was 18% increase in HDL particle number (HDLP) with fenofibrate (p = .05). There were no changes in HDLP with simvastatin. There were no changes in HDLP size with either drug. Pre- and post-therapy LDLP/HDLP ratio was similar with fenofibrate but was reduced by simvastatin (p = .045). CONCLUSION: Simvastatin reduced LDLP across all subclasses with no effect on size. Simvastatin had no effect on HDLP. Fenofibrate had weak effect on LDLP number but increased LDLP size by raising large LDLP and reducing small LDLP. Fenofibrate had weak effect on HDLP number with no change in size. Importantly, net atherogenic to antiatherogenic lipoprotein ratio (LDLP/HDLP) was reduced by simvastatin but not by fenofibrate.


Asunto(s)
Ácido Clofíbrico/uso terapéutico , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Lipoproteínas/sangre , Simvastatina/uso terapéutico , Anciano , Ácido Clofíbrico/farmacología , Estudios Cruzados , Femenino , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Lipoproteínas/clasificación , Masculino , Persona de Mediana Edad , Resonancia Magnética Nuclear Biomolecular , Tamaño de la Partícula , Placebos , Estudios Prospectivos , Simvastatina/farmacología
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