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1.
J Pers Assess ; : 1-9, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38489487

RESUMEN

Shedding light on the validity of sentence completion test (SCT) verbal defensiveness as an index of defensive behavior, the current two-part study examined the relationship between psychological threat and verbal defensiveness among military security and mission-critical team candidates using SCTs. Our study showed that as the threatening nature of SCT stems increased, defensive responses also increased, substantiating the link between psychological threat and defensive behavior. In addition, expert ratings of stem content revealed moderately strong relationships with defensive responses across two different SCTs, irrespective of their structural characteristics. In contrast to previous studies using total verbal defensiveness scores, we examined specific defensive response types and their associations with stem threat ratings, finding that omissions, denial, and comments about the test were linked to stem threat levels. Lastly, our study extends the application of the SCT verbal defensiveness index beyond specialized personnel selection, finding no significant differences in verbal defensiveness based on gender or military status. Overall, these findings contribute to a comprehensive understanding of defensive behavior and its contextual variations.

2.
J Pharm Sci ; 112(12): 2965-2980, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37741455

RESUMEN

Antibody-drug conjugates unite the specificity and long circulation time of an antibody with the toxicity of a chemical cytostatic or otherwise active drug using appropriate chemical linkers to reduce systemic toxicity and increase therapeutic index. This combination of a large biological molecule and a small molecule creates an increase in complexity. Multiple production processes are required to produce the native antibody, the drug and the linker, followed by conjugation of afore mentioned entities to form the final antibody-drug conjugate. The connected processes further increase the number of points of control, resulting in necessity of additional specifications and intensified analytical characterization. By combining scientific understanding of the production processes with risk-based approaches, quality can be demonstrated at those points where control is required and redundant comparability studies, specifications or product characterization are avoided. Over the product development lifecycle, this will allow process qualification to focus on those areas critical to quality and prevent redundant studies. The structure of the module 3 common technical document for an ADC needs to reflect each of the production processes and the combined overall approach to quality. Historically, regulatory authorities have provided varied expectations on its structure. This paper provides an overview of essential information to be included and shows that multiple approaches work as long as adequate cross-referencing is included.


Asunto(s)
Inmunoconjugados , Inmunoconjugados/química , Anticuerpos Monoclonales/química
3.
EMBO Rep ; 24(9): e56562, 2023 09 06.
Artículo en Inglés | MEDLINE | ID: mdl-37492931

RESUMEN

Cochlear hair cell loss is a leading cause of deafness in humans. Neighboring supporting cells have some capacity to regenerate hair cells. However, their regenerative potential sharply declines as supporting cells undergo maturation (postnatal day 5 in mice). We recently reported that reactivation of the RNA-binding protein LIN28B restores the hair cell-regenerative potential of P5 cochlear supporting cells. Here, we identify the LIN28B target Trim71 as a novel and equally potent enhancer of supporting cell plasticity. TRIM71 is a critical regulator of stem cell behavior and cell reprogramming; however, its role in cell regeneration is poorly understood. Employing an organoid-based assay, we show that TRIM71 re-expression increases the mitotic and hair cell-forming potential of P5 cochlear supporting cells by facilitating their de-differentiation into progenitor-like cells. Our mechanistic work indicates that TRIM71's RNA-binding activity is essential for such ability, and our transcriptomic analysis identifies gene modules that are linked to TRIM71 and LIN28B-mediated supporting cell reprogramming. Furthermore, our study uncovers that the TRIM71-LIN28B target Hmga2 is essential for supporting cell self-renewal and hair cell formation.


Asunto(s)
Cóclea , Células Ciliadas Auditivas , Animales , Humanos , Ratones , Diferenciación Celular/genética , Cóclea/metabolismo , Perfilación de la Expresión Génica , Células Ciliadas Auditivas/metabolismo , Células Madre/metabolismo , Proteínas de Motivos Tripartitos/genética , Ubiquitina-Proteína Ligasas/metabolismo
4.
Methods Mol Biol ; 2676: 117-129, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37277628

RESUMEN

Phage display facilitates the evolution of peptides and proteins for affinity selection against targets, but it is mostly limited to the chemical diversity provided by the naturally encoded amino acids. The combination of phage display with genetic code expansion allows the incorporation of noncanonical amino acids (ncAAs) into proteins expressed on the phage. In this method, we describe incorporation of one or two ncAAs in a single-chain fragment variable (scFv) antibody in response to amber or quadruplet codon. We take advantage of the pyrrolysyl-tRNA synthetase/tRNA pair to incorporate a lysine derivative and an orthogonal tyrosyl-tRNA synthetase/tRNA pair to incorporate a phenylalanine derivative. The encoding of novel chemical functionalities and building blocks in proteins displayed on phage provides the foundation for further phage display applications in fields such as imaging, protein targeting, and the production of new materials.


Asunto(s)
Aminoacil-ARNt Sintetasas , Bacteriófagos , Aminoácidos/química , Lisina/metabolismo , Codón , ARN de Transferencia/genética , Bacteriófagos/genética , Bacteriófagos/metabolismo , Aminoacil-ARNt Sintetasas/metabolismo
5.
bioRxiv ; 2023 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-36711735

RESUMEN

Cochlear hair cell loss is a leading cause of deafness in humans. Neighboring supporting cells have some capacity to regenerate hair cells. However, their regenerative potential sharply declines as supporting cells undergo maturation (postnatal day 5 in mice). We recently reported that reactivation of the RNA-binding protein LIN28B restores the hair cell-regenerative potential of P5 cochlear supporting cells. Here, we identify the LIN28B target Trim71 as a novel and equally potent enhancer of supporting cell plasticity. TRIM71 is a critical regulator of stem cell behavior and cell reprogramming, however, its role in cell regeneration is poorly understood. Employing an organoid-based assay, we show that TRIM71 reactivation increases the mitotic and hair cell-forming potential of P5 cochlear supporting cells by facilitating their de-differentiation into progenitor-like cells. Our mechanistic work indicates that TRIM71’s RNA-binding activity is essential for such ability, and our transcriptomic analysis identifies gene modules that are linked to TRIM71 and LIN28B-mediated supporting cell reprogramming. Furthermore, our study uncovers that the TRIM71-LIN28B target Hmga2 is essential for supporting cell self-renewal and hair cell formation.

6.
J Sch Health ; 92(10): 959-967, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35871529

RESUMEN

BACKGROUND: Recess provides many physical, mental, and social benefits for students; however, the most recent systematic review examining the benefits of recess was conducted over a decade ago. The purpose of this paper was to determine the current benefits of school recess by conducting an updated systematic review of the literature. METHODS: Multiple databases were systematically examined to find articles fitting the following inclusionary criteria: (a) school recess, (b) all schooling before college, and (c) recess benefits of any kind. Research was limited to literature published between June 2009 and July 2020. RESULTS: Nine studies were included in this review. The majority of studies examined elementary-aged students. Seven studies were conducted in the United States, and 2 studies were conducted internationally. Recess provided school-aged children academic and cognitive benefits, behavioral and emotional benefits, physical benefits, and social benefits. IMPLICATIONS FOR SCHOOL HEALTH POLICY, PRACTICE, AND EQUITY: Providing recess for all school levels positively impacts the whole child; there was no literature implicating negative impacts of recess. CONCLUSIONS: Schools can improve overall student health and belonging by redesigning and/or implementing daily recess.


Asunto(s)
Instituciones Académicas , Estudiantes , Anciano , Niño , Política de Salud , Humanos , Estudiantes/psicología , Estados Unidos
7.
Sci Adv ; 8(6): eabj7651, 2022 02 11.
Artículo en Inglés | MEDLINE | ID: mdl-35148175

RESUMEN

Hair cell (HC) loss within the inner ear cochlea is a leading cause for deafness in humans. Before the onset of hearing, immature supporting cells (SCs) in neonatal mice have some limited capacity for HC regeneration. Here, we show that in organoid culture, transient activation of the progenitor-specific RNA binding protein LIN28B and Activin antagonist follistatin (FST) enhances regenerative competence of maturing/mature cochlear SCs by reprogramming them into progenitor-like cells. Transcriptome profiling and mechanistic studies reveal that LIN28B drives SC reprogramming, while FST is required to counterbalance hyperactivation of transforming growth factor-ß-type signaling by LIN28B. Last, we show that LIN28B and FST coactivation enhances spontaneous cochlear HC regeneration in neonatal mice and that LIN28B may be part of an endogenous repair mechanism that primes SCs for HC regeneration. These findings indicate that SC dedifferentiation is critical for HC regeneration and identify LIN28B and FST as main regulators.


Asunto(s)
Reprogramación Celular , Folistatina , Animales , Reprogramación Celular/genética , Cóclea/metabolismo , Folistatina/genética , Folistatina/metabolismo , Células Ciliadas Auditivas/metabolismo , Ratones , Regeneración/genética
8.
J Am Chem Soc ; 143(12): 4600-4606, 2021 03 31.
Artículo en Inglés | MEDLINE | ID: mdl-33750116

RESUMEN

Discovering molecules that regulate closely related protein isoforms is challenging, and in many cases the consequences of isoform-specific pharmacological regulation remains unknown. RAF isoforms are commonly mutated oncogenes that serve as effector kinases in MAP kinase signaling. BRAF/CRAF heterodimers are believed to be the primary RAF signaling species, and many RAF inhibitors lead to a "paradoxical activation" of RAF kinase activity through transactivation of the CRAF protomer; this leads to resistance mechanisms and secondary tumors. It has been hypothesized that CRAF-selective inhibition might bypass paradoxical activation, but no CRAF-selective inhibitor has been reported and the consequences of pharmacologically inhibiting CRAF have remained unknown. Here, we use bio-orthogonal ligand tethering (BOLT) to selectively target inhibitors to CRAF. Our results suggest that selective CRAF inhibition promotes paradoxical activation and exemplify how BOLT may be used to triage potential targets for drug discovery before any target-selective small molecules are known.


Asunto(s)
Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas B-raf/antagonistas & inhibidores , Línea Celular Tumoral , Humanos , Modelos Moleculares , Estructura Molecular , Inhibidores de Proteínas Quinasas/química , Proteínas Proto-Oncogénicas B-raf/metabolismo , Transducción de Señal/efectos de los fármacos
9.
Nat Methods ; 18(3): 240-241, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33637971
10.
Nat Commun ; 11(1): 4825, 2020 09 24.
Artículo en Inglés | MEDLINE | ID: mdl-32973178

RESUMEN

Short regulatory RNA molecules underpin gene expression and govern cellular state and physiology. To establish an alternative layer of control over these processes, we generated chimeric regulatory RNAs that interact reversibly and light-dependently with the light-oxygen-voltage photoreceptor PAL. By harnessing this interaction, the function of micro RNAs (miRs) and short hairpin (sh) RNAs in mammalian cells can be regulated in a spatiotemporally precise manner. The underlying strategy is generic and can be adapted to near-arbitrary target sequences. Owing to full genetic encodability, it establishes optoribogenetic control of cell state and physiology. The method stands to facilitate the non-invasive, reversible and spatiotemporally resolved study of regulatory RNAs and protein function in cellular and organismal environments.


Asunto(s)
Expresión Génica , Células Fotorreceptoras/metabolismo , ARN/metabolismo , Animales , Células HEK293 , Humanos , MicroARNs/metabolismo , ARN/genética , ARN Interferente Pequeño
11.
Neuron ; 103(3): 412-422.e4, 2019 08 07.
Artículo en Inglés | MEDLINE | ID: mdl-31221560

RESUMEN

Selective synaptic and axonal degeneration are critical aspects of both brain development and neurodegenerative disease. Inhibition of caspase signaling in neurons is a potential therapeutic strategy for neurodegenerative disease, but no neuron-specific modulators of caspase signaling have been described. Using a mass spectrometry approach, we discovered that RUFY3, a neuronally enriched protein, is essential for caspase-mediated degeneration of TRKA+ sensory axons in vitro and in vivo. Deletion of Rufy3 protects axons from degeneration, even in the presence of activated CASP3 that is competent to cleave endogenous substrates. Dephosphorylation of RUFY3 at residue S34 appears required for axon degeneration, providing a potential mechanism for neurons to locally control caspase-driven degeneration. Neuronally enriched RUFY3 thus provides an entry point for understanding non-apoptotic functions of CASP3 and a potential target to modulate caspase signaling specifically in neurons for neurodegenerative disease.


Asunto(s)
Axones/patología , Degeneración Nerviosa/patología , Proteínas del Tejido Nervioso/fisiología , Animales , Axones/enzimología , Caspasa 3/fisiología , Células Cultivadas , Proteínas del Citoesqueleto , Activación Enzimática , Ganglios Espinales/citología , Ganglios Espinales/embriología , Ratones , Ratones Noqueados , Degeneración Nerviosa/enzimología , Proteínas del Tejido Nervioso/química , Proteínas del Tejido Nervioso/deficiencia , Fosforilación , Procesamiento Proteico-Postraduccional , Receptor trkA/fisiología , Células Receptoras Sensoriales/fisiología , Relación Estructura-Actividad
12.
J Strength Cond Res ; 33(8): 2251-2261, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29621114

RESUMEN

Kocher, MH, Oba, Y, Kimura, IF, Stickley, CD, Morgan, CF, and Hetzler, RK. Allometric grip strength norms for American children. J Strength Cond Res 33(8): 2251-2261, 2019-To develop normative data from a large cohort of American school children (ages 6-18) for unscaled and allometrically scaled handgrip strength data that are uninfluenced by body size (body mass [BM] and stature [Ht]). Data (age, handgrip strength, BM, and Ht) were collected from the 2011-2012 and 2013-2014 National Health and Nutrition Examination Survey databases, resulting in 4,665 cases (2,384 boys and 2,281 girls). Multiple log-linear regressions were used to determine allometric exponents for BM and Ht separately for each age and sex to satisfy the common exponent and group difference principles described by Vanderburgh. Appropriateness of the allometric model was assessed through regression diagnostics, including normality and homoscedasticity of residuals. Allometrically scaled, ratio-scaled, and unscaled grip strength were then correlated with BM and Ht to examine the effectiveness of the procedure in controlling for body size. The data did not allow for development of a common exponent across age and sex that did not violate the common exponent and group difference principles. Correlations between allometrically scaled handgrip strength with BM and Ht were not significant (p ≤ 0.479) and approached zero, unlike correlations of unscaled handgrip strength with BM and Ht (p < 0.001 for all), indicating that allometric scaling was successful in removing the influence of body size. Allometric scaling handgrip strength by age and sex effectively controls for body size (Ht and BM) and perhaps maturation (Ht). The allometric exponents and normative values developed can be used to compare handgrip strength within age and sex while controlling for body size.


Asunto(s)
Fuerza de la Mano/fisiología , Adolescente , Factores de Edad , Androstanoles , Estatura , Índice de Masa Corporal , Niño , Femenino , Humanos , Modelos Lineales , Masculino , Encuestas Nutricionales , Estándares de Referencia , Factores Sexuales , Estados Unidos
13.
Physiol Behav ; 194: 137-143, 2018 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-29752975

RESUMEN

Numerous studies have examined the effects of captivity survival training on psychological and physiological function in trainees. In the present study we shifted the focus to instructors, and measured the effects that the delivery of training exerts on their levels of stress and performance. Because instructors are called upon to perform difficult duties (e.g., mock interrogations) under extreme conditions, we hypothesized that significant increases in psychological and physiological indices of stress would occur due to training. In addition, as part of their job tasking, the instructors conducted courses in consecutive weeks. This offered a unique and ecologically valid opportunity to assess carryover of stress from one week to the next. We hypothesized stress levels would be higher in the second than the first week of training. Our first hypothesis was supported: Delivering training was associated with impairments in mood, fatigue, and sleep, as well as a reduction in the ratio of testosterone/cortisol level in blood. Our second hypothesis was largely not supported as a 3-day break separating consecutive courses appeared sufficient for restoring psychological and physiological function. Our results demonstrate that although the delivery of training exerts negative effects on instructors' levels of stress, the 3-day recovery period separating consecutive courses is sufficient to return psychological and physiological function to baseline levels.


Asunto(s)
Afecto , Cognición , Fatiga , Hidrocortisona/sangre , Estrés Laboral/psicología , Sueño , Testosterona/sangre , Adulto , Femenino , Humanos , Masculino , Personal Militar/psicología , Estrés Laboral/sangre , Sobrevida/psicología , Enseñanza/psicología , Adulto Joven
14.
Perspect Psychol Sci ; 12(6): 927-955, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28934559

RESUMEN

Proponents of "enhanced interrogation techniques" in the United States have claimed that such methods are necessary for obtaining information from uncooperative terrorism subjects. In the present article, we offer an informed, academic perspective on such claims. Psychological theory and research shows that harsh interrogation methods are ineffective. First, they are likely to increase resistance by the subject rather than facilitate cooperation. Second, the threatening and adversarial nature of harsh interrogation is often inimical to the goal of facilitating the retrieval of information from memory and therefore reduces the likelihood that a subject will provide reports that are extensive, detailed, and accurate. Third, harsh interrogation methods make lie detection difficult. Analyzing speech content and eliciting verifiable details are the most reliable cues to assessing credibility; however, to elicit such cues subjects must be encouraged to provide extensive narratives, something that does not occur in harsh interrogations. Evidence is accumulating for the effectiveness of rapport-based information-gathering approaches as an alternative to harsh interrogations. Such approaches promote cooperation, enhance recall of relevant and reliable information, and facilitate assessments of credibility. Given the available evidence that torture is ineffective, why might some laypersons, policymakers, and interrogation personnel support the use of torture? We conclude our review by offering a psychological perspective on this important question.


Asunto(s)
Comunicación , Modelos Psicológicos , Decepción , Humanos , Relaciones Interpersonales , Memoria , Tortura
15.
Cell Chem Biol ; 24(10): 1250-1258.e4, 2017 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-28919041

RESUMEN

To dissect the cellular roles of individual kinases, it is useful to design tools for their selective activation. We describe the engineering of a split-cAbl kinase (sKin-Abl) that is rapidly activated in cells with rapamycin and allows temporal, dose, and compartmentalization control. Our design strategy involves an empirical screen in mammalian cells and identification of split site in the N lobe. This split site leads to complete loss of activity, which can be restored upon small-molecule-induced dimerization in cells. Remarkably, the split site is transportable to the related Src Tyr kinase and the distantly related Ser/Thr kinase, AKT, suggesting broader applications to kinases. To quantify the fold induction of phosphotyrosine (pTyr) modification, we employed quantitative proteomics, NeuCode SILAC. We identified a number of known Abl substrates, including autophosphorylation sites and novel pTyr targets, 432 pTyr sites in total. We believe that this split-kinase technology will be useful for direct activation of protein kinases in cells.


Asunto(s)
Ingeniería de Proteínas , Proteínas Proto-Oncogénicas c-abl/metabolismo , Activación Enzimática/efectos de los fármacos , Células HEK293 , Humanos , Fosforilación , Fosfotirosina/metabolismo , Proteínas Proto-Oncogénicas c-abl/genética , Sirolimus/farmacología , Familia-src Quinasas/genética
16.
Int J Psychophysiol ; 117: 37-47, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28400246

RESUMEN

In the Canadian Armed Forces (CAF), Conduct After Capture (CAC) training is a 4-day captivity survival course during which soldiers are exposed to increasing stress, and evaluated on their ability to accomplish military objectives. We hypothesized that: (a) compared to baseline, CAC training would cause significant, reversible perturbations in measures of psychological functioning and serum and salivary stress hormone levels relevant to models of stress hardiness and vulnerability; and (b) deviations from baseline would be maximal at the time point of most intense stress during training. CAF personnel were assessed at baseline, twice during training (immediately prior to a less challenging interrogation role-play scenario and again following another much more intense interrogation role-play scenario), and after completion of training. At each occasion, mood, fatigue, dissociation, PTSD symptoms, short-term and working memory, and salivary cortisol and dehydroepiandrosterone (DHEA) were assessed. As predicted, scores on all measures were degraded during CAC but recovered after completion of training, and almost all measures were most degraded at the more intense interrogation role-play scenario. Unexpectedly, memory performance was unaffected by training, suggesting that a short duration of intense stress might be insufficient for degrading it. Another unexpected finding was that mood assessed prior to training predicted successful completion of training, which bears important practical implications for increasing the success rate of training in similar environments. These results demonstrate that despite its relative brevity, CAC training nevertheless induces significant but reversible effects on psychological and physiological function-necessary preconditions for stress inoculation training.


Asunto(s)
Afecto/fisiología , Trastornos de Combate/metabolismo , Trastornos de Combate/fisiopatología , Fatiga/fisiopatología , Memoria a Corto Plazo/fisiología , Personal Militar , Trastornos por Estrés Postraumático/metabolismo , Trastornos por Estrés Postraumático/fisiopatología , Adulto , Ansiedad/fisiopatología , Deshidroepiandrosterona/metabolismo , Trastornos Disociativos/fisiopatología , Femenino , Humanos , Hidrocortisona/metabolismo , Masculino , Persona de Mediana Edad , Personal Militar/educación , Adulto Joven
17.
J Strength Cond Res ; 31(10): 2794-2807, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28195935

RESUMEN

The purpose of the study was to determine allometric exponents for scaling grip strength in children that effectively control for body mass (BM) and stature (Ht) and to develop normative grip strength data for Hawaiian children. One thousand, four hundred thirty-seven students (754 boys) from a rural community in Hawaii participated in this 5-year study, resulting in 2,567 data points. Handgrip strength, BM, and Ht were collected every year. Multiple log-linear regression was used to determine allometric exponents for BM and Ht. Appropriateness of the allometric model was assessed through regression diagnostics, including normality of residuals and homoscedasticity. Allometrically scaled, ratio-scaled, and unscaled grip strength were then correlated with BM and Ht to examine the effectiveness of the procedure in controlling for body size. Allometric exponents for BM and Ht were calculated separately for each age group of boys and girls to satisfy the common exponent and group difference principles described by Vanderburgh. Unscaled grip strength had moderate to strong positive correlations with BM and Ht (p ≤ 0.05 for all) for all age groups. Ratio-scaled handgrip strength had significant moderate to strong negative correlations with BM (p ≤ 0.05 for all) and, to a lesser extent, Ht (p ≤ 0.05 for 8- to 12-year-old boys; p ≤ 0.05 for 8- to 12- and 14-year-old girls). Correlations between allometrically scaled handgrip strength and BM and Ht were not significant and approached zero. This study was the first to allometrically scale handgrip strength for BM and Ht in Hawaiian children. Allometric scaling applied to grip strength provides a useful expression of grip strength free of the confounding influence of body size.


Asunto(s)
Fuerza de la Mano/fisiología , Nativos de Hawái y Otras Islas del Pacífico , Adolescente , Factores de Edad , Estatura , Índice de Masa Corporal , Niño , Estudios Transversales , Femenino , Hawaii , Humanos , Modelos Lineales , Masculino , Análisis de Regresión , Factores Sexuales
18.
PDA J Pharm Sci Technol ; 71(2): 127-135, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-27789804

RESUMEN

Concentration determination is an important method of protein characterization required in the development of protein therapeutics. There are many known methods for determining the concentration of a protein solution, but the easiest to implement in a manufacturing setting is absorption spectroscopy in the ultraviolet region. For typical proteins composed of the standard amino acids, absorption at wavelengths near 280 nm is due to the three amino acid chromophores tryptophan, tyrosine, and phenylalanine in addition to a contribution from disulfide bonds. According to the Beer-Lambert law, absorbance is proportional to concentration and path length, with the proportionality constant being the extinction coefficient. Typically the extinction coefficient of proteins is experimentally determined by measuring a solution absorbance then experimentally determining the concentration, a measurement with some inherent variability depending on the method used. In this study, extinction coefficients were calculated based on the measured absorbance of model compounds of the four amino acid chromophores. These calculated values for an unfolded protein were then compared with an experimental concentration determination based on enzymatic digestion of proteins. The experimentally determined extinction coefficient for the native proteins was consistently found to be 1.05 times the calculated value for the unfolded proteins for a wide range of proteins with good accuracy and precision under well-controlled experimental conditions. The value of 1.05 times the calculated value was termed the predicted extinction coefficient. Statistical analysis shows that the differences between predicted and experimentally determined coefficients are scattered randomly, indicating no systematic bias between the values among the proteins measured. The predicted extinction coefficient was found to be accurate and not subject to the inherent variability of experimental methods. We propose the use of a predicted extinction coefficient for determining the protein concentration of therapeutic proteins starting from early development through the lifecycle of the product.LAY ABSTRACT: Knowing the concentration of a protein in a pharmaceutical solution is important to the drug's development and posology. There are many ways to determine the concentration, but the easiest one to use in a testing lab employs absorption spectroscopy. Absorbance of ultraviolet light by a protein solution is proportional to its concentration and path length; the proportionality constant is the extinction coefficient. The extinction coefficient of a protein therapeutic is usually determined experimentally during early product development and has some inherent method variability. In this study, extinction coefficients of several proteins were calculated based on the measured absorbance of model compounds. These calculated values for an unfolded protein were then compared with experimental concentration determinations based on enzymatic digestion of the proteins. The experimentally determined extinction coefficient for the native protein was 1.05 times the calculated value for the unfolded protein with good accuracy and precision under controlled experimental conditions, so the value of 1.05 times the calculated coefficient was called the predicted extinction coefficient. Comparison of predicted and measured extinction coefficients indicated that the predicted value was very close to the experimentally determined values for the proteins. The predicted extinction coefficient was accurate and removed the variability inherent in experimental methods.


Asunto(s)
Aminoácidos/análisis , Química Farmacéutica/métodos , Proteínas/análisis , Absorción Fisicoquímica , Aminoácidos/química , Química Farmacéutica/instrumentación , Valor Predictivo de las Pruebas , Conformación Proteica , Proteínas/química , Sensibilidad y Especificidad , Espectrofotometría Ultravioleta
19.
PLoS Comput Biol ; 12(8): e1005069, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27517607

RESUMEN

In fast-transcribing prokaryotic genes, such as an rrn gene in Escherichia coli, many RNA polymerases (RNAPs) transcribe the DNA simultaneously. Active elongation of RNAPs is often interrupted by pauses, which has been observed to cause RNAP traffic jams; yet some studies indicate that elongation seems to be faster in the presence of multiple RNAPs than elongation by a single RNAP. We propose that an interaction between RNAPs via the torque produced by RNAP motion on helically twisted DNA can explain this apparent paradox. We have incorporated the torque mechanism into a stochastic model and simulated transcription both with and without torque. Simulation results illustrate that the torque causes shorter pause durations and fewer collisions between polymerases. Our results suggest that the torsional interaction of RNAPs is an important mechanism in maintaining fast transcription times, and that transcription should be viewed as a cooperative group effort by multiple polymerases.


Asunto(s)
ARN Polimerasas Dirigidas por ADN/genética , Modelos Teóricos , Transcripción Genética/genética , Algoritmos , Biología Computacional , Simulación por Computador , ADN Bacteriano/genética , ADN Bacteriano/metabolismo , ADN Bacteriano/fisiología , ARN Polimerasas Dirigidas por ADN/metabolismo , ARN Polimerasas Dirigidas por ADN/fisiología , Escherichia coli/genética , Escherichia coli/metabolismo , Procesos Estocásticos , Torque , Transcripción Genética/fisiología
20.
PLoS One ; 11(7): e0156278, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27391240

RESUMEN

Can the onset of PTSD symptoms and depression be predicted by personality factors and thought control strategies? A logical explanation for the different mental health outcomes of individuals exposed to trauma would seem to be personality factors and thought control strategies. Trauma exposure is necessary but not sufficient for the development of PTSD. To this end, we assess the role of personality traits and coping styles in PTSD vulnerability among Israeli and Palestinian students amid conflict. We also determine whether gender and exposure level to trauma impact the likelihood of the onset of PTSD symptoms. Five questionnaires assess previous trauma, PTSD symptoms, demographics, personality factors and thought control strategies, which are analyzed using path analysis. Findings show that the importance of personality factors and thought control strategies in predicting vulnerability increases in the face of political violence: the higher stress, the more important the roles of personality and thought control strategies. Thought control strategies associated with introverted and less emotionally stable personality-types correlate positively with higher levels of PTSD symptoms and depression, particularly among Palestinians. By extension, because mental health is key to reducing violence in the region, PTSD reduction in conflict zones warrants rethinking.


Asunto(s)
Personalidad , Trastornos por Estrés Postraumático/psicología , Violencia/psicología , Guerra , Adaptación Psicológica , Adulto , Árabes , Depresión/complicaciones , Emociones , Femenino , Humanos , Israel , Masculino , Trastornos de la Personalidad , Factores de Riesgo , Encuestas y Cuestionarios , Adulto Joven
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