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1.
Cell ; 169(6): 1066-1077.e10, 2017 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-28575670

RESUMEN

Centrosomes are non-membrane-bound compartments that nucleate microtubule arrays. They consist of nanometer-scale centrioles surrounded by a micron-scale, dynamic assembly of protein called the pericentriolar material (PCM). To study how PCM forms a spherical compartment that nucleates microtubules, we reconstituted PCM-dependent microtubule nucleation in vitro using recombinant C. elegans proteins. We found that macromolecular crowding drives assembly of the key PCM scaffold protein SPD-5 into spherical condensates that morphologically and dynamically resemble in vivo PCM. These SPD-5 condensates recruited the microtubule polymerase ZYG-9 (XMAP215 homolog) and the microtubule-stabilizing protein TPXL-1 (TPX2 homolog). Together, these three proteins concentrated tubulin ∼4-fold over background, which was sufficient to reconstitute nucleation of microtubule asters in vitro. Our results suggest that in vivo PCM is a selective phase that organizes microtubule arrays through localized concentration of tubulin by microtubule effector proteins.


Asunto(s)
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Proteínas de Ciclo Celular/metabolismo , Centrosoma/química , Microtúbulos/metabolismo , Tubulina (Proteína)/metabolismo , Animales , Caenorhabditis elegans/citología , Proteínas Portadoras/metabolismo , Centrosoma/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo
2.
Sensors (Basel) ; 24(17)2024 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-39275598

RESUMEN

We aimed to conduct a biophysical comparison of angular (Biorower) and linear (Concept2) rowing ergometers across a wide spectrum of exercise intensities. Sixteen (eleven male) skilled rowers, aged 29.8 ± 8.6 and 23.6 ± 1.5 years, with international competitive experience, performed 7 × 3 min bouts with 30 W increments and 60 s intervals, plus 1 min of all-out rowing on both machines with 48 h in between. The ventilatory and kinematical variables were measured breath-by-breath using a telemetric portable gas analyzer and determined using a full-body markerless system, respectively. Similar values of oxygen uptake were observed between ergometers across all intensity domains (e.g., 60.36 ± 8.40 vs. 58.14 ± 7.55 mL/min/kg for the Biorower and Concept2 at severe intensity). The rowing rate was higher on the Biorower vs. Concept2 at heavy and severe intensities (27.88 ± 3.22 vs. 25.69 ± 1.99 and 30.63 ± 3.18 vs. 28.94 ± 2.29). Other differences in kinematics were observed across all intensity domains, particularly in the thorax angle at the finish (e.g., 19.44 ± 4.49 vs. 27.51 ± 7.59° for the Biorower compared to Concep2 at heavy intensity), likely due to closer alignment of the Biorower with an on-water rowing technique. The overall perceived effort was lower on the Biorower when compared to the Concept2 (14.38 ± 1.76 vs. 15.88 ± 1.88). Rowers presented similar cardiorespiratory function on both rowing ergometers, while important biomechanical differences were observed, possibly due to the Biorower's closer alignment with an on-water rowing technique.


Asunto(s)
Ergometría , Ejercicio Físico , Consumo de Oxígeno , Deportes Acuáticos , Humanos , Masculino , Adulto , Ergometría/métodos , Ergometría/instrumentación , Deportes Acuáticos/fisiología , Ejercicio Físico/fisiología , Adulto Joven , Femenino , Consumo de Oxígeno/fisiología , Fenómenos Biomecánicos/fisiología
3.
Int J Sports Med ; 44(14): 1043-1048, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36452984

RESUMEN

Empirical observations support that the addition of a plastic strip - also known as Randall foils - on the top edge of a rowing blade improves rowing efficiency during the cycle propulsive phase. The aim of the current study was to analyze the effect of using big blades with and without Randall foils on rowing performance. Twenty experienced rowers performed two 90 s tethered rowing bouts (with and without Randall foils) to assess their impact on force production and physiologic variables. All tests were randomized and a repeated measure design was used to compare experimental conditions. Higher values of peak and mean peak forces (479.4±134.7 vs. 423.2±153.0, d=0.83 and 376.5±101.4 vs. 337.1±113.3 N, d=0.68), peak oxygen uptake (47.9±7.5 vs. 45.3±7.3 mL∙kg-1∙min-1, d=0.19), peak blood lactate concentration (7.9±1.6 vs. 6.9±1.7 mmol∙L-1, d=0.16), blood lactate increasing speed (0.08±0.01 vs. 0.07±0.06 [(mmol·L-1)·s-1], d=0.27) and lactic anaerobic energy (27.4±7.9 vs. 23.4±8.1 kJ, d=0.23) were found for big blades with vs. without Randall foils, p<0.05. The current data suggest that the Randall foils can positively affect rowing performance.


Asunto(s)
Deportes Acuáticos , Humanos , Lactatos , Consumo de Oxígeno
4.
Sensors (Basel) ; 23(13)2023 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-37447682

RESUMEN

In recent years, there has been an exponential increase in the number of devices developed to measure or estimate physical exercise. However, before these devices can be used in a practical and research environment, it is necessary to determine their validity and reliability. The purpose of this study is to test the validity and reliability of a load cell sensor-based device (LC) for measuring the peak force (PFr) and the rate of force development (RFD) during the isometric mid-thigh pull (IMTP) test, using a force plate (FP) as the gold standard. Forty-two undergraduate sport science students (male and female) participated in this study. In a single session, they performed three repetitions of the IMTP test, being tested simultaneously with an LC device and a Kistler force platform (FP). The PFr and RFD data were obtained from the force-time curve of the FP and compared with the LC data, provided automatically by the software of the device (Smart Traction device©). The mean difference between the results obtained by the LC device and the gold-standard equipment (FP) was not significantly different (p > 0.05), for both PFr and RFD, which suggests the validity of the ST results. Bland-Altman analysis showed a small mean difference in PFr = 1.69 N, upper bound = 47.88 N, and lower bound = -51.27 N. RFD showed that the mean difference was -5.27 N/s, upper limit = 44.36 N/s, and lower limit = -54.91 N/s. Our results suggest that the LC device can be used in the assessment of the isometric-mid-thigh-pull test as a valid and reliable tool. It is recommended that this device's users consider these research results before putting the ST into clinical practice.


Asunto(s)
Fuerza Muscular , Muslo , Humanos , Masculino , Femenino , Reproducibilidad de los Resultados , Contracción Isométrica , Prueba de Esfuerzo/métodos
5.
Molecules ; 28(16)2023 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-37630416

RESUMEN

Complexes of lanthanide ions, such as Eu(III) (red light emission) and Tb(III) (green light emission), with proper ligands can be highly luminescent and color-tunable, also attaining yellow and orange emission under UV radiation. The ligands employed in this work were poly(sodium acrylate), working as polymeric matrix, and 1,10-phenanthroline, taking advantage of its antenna effect. Possibilities of color display were further enhanced by incorporating a cationic polyfluorene with blue emission. This strategy allowed for obtaining cyan and magenta, besides the aforementioned colors. Uncoated cellulose paper was impregnated with the resulting luminescent inks, observing a strong hypsochromic shift in excitation wavelength upon drying. Hence, while a cheap UV-A lamp sufficed to reveal the polyfluorene's blue emission, shorter wavelengths were necessary to visualize the emission due to lanthanide ions as well. The capacity to reveal, with UV-C radiation, a full-color image that remains invisible under natural light is undoubtedly useful for anti-counterfeiting applications. Furthermore, both lanthanide ion complexes and polyfluorenes were shown to have their luminescence quenched by Cu(II) ions and nitroarenes, respectively.

6.
J Phys Chem A ; 126(10): 1660-1665, 2022 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-35258305

RESUMEN

Metal-deficient polysulfides have been argued for a long time to be responsible for the low kinetics of chalcopyrite leaching to extract copper. It has been shown that chalcopyrite surfaces are the source of sulfur that is oxidized to form polysulfides and elemental sulfur. Electronic structure calculations were performed for HxSnx-2 (x = 0, 1, 2 and n = 1...20), aiming to understand the effect of the pH on the growing chains and the formation of elemental sulfur. The estimated pKa1 of the H2Sn polysulfides converges from 4.2 (n = 3) to 3.4 (n ≥ 8), and the estimated pKa2 converges from 7.6 (n = 3) to 4.1 (n ≥ 8). The initial steps of the formation of polysulfide chains are more favored for protonated species. The elemental sulfur formation due to the decomposition of polysulfides to form smaller chains is mostly favored for protonated species with n smaller than 12. For larger chains, the decomposition is thermodynamically favored for polysulfides with any degree of protonation. The consequences of these results to the understanding of the mechanism of the chalcopyrite leaching process are discussed with the focus on the pH effect and the formation of elemental sulfur.

7.
Sensors (Basel) ; 22(4)2022 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-35214515

RESUMEN

The study aimed to investigate the magnitude and shape of the forces applied on the foot rest, foot strap, and paddle. Thirteen elite male kayakers participated in this study and performed a 2-min test simulating 500 m race pace in a kayak ergometer. Forces applied by the kayakers on the paddle, foot rest, and foot strap were measured with load cells and recorded by an electronic measuring system. The magnitude of the peak forces applied on the foot rest (left: 543.27 ± 85.93; right: 524.39 ± 88.36) approximately doubled the ones applied on the paddle (left: 236.37 ± 19.32; right: 243.92 ± 28.89). The forces on the foot strap were similar in magnitude to the paddle forces (left: 240.09 ± 74.92; right: 231.05 ± 52.01). A positive correlation was found between the peak forces applied on the foot rest and paddle on the same side (p < 0.001). When comparing the best and worst kayakers' performance, the best showed greater forces magnitudes and synchronization of the peak forces. Analyses of the force-time curves, including not only the forces applied by the kayaker on the paddle but also the ones applied on the foot rest and strap, should be considered relevant in terms of technique analyses.


Asunto(s)
Deportes Acuáticos , Animales , Fenómenos Biomecánicos , Ergometría , Masculino , Navíos
8.
Exp Eye Res ; 204: 108458, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33493475

RESUMEN

Peripheral ulcerative keratitis (PUK) is a progressive peripheral thinning of the corneal stroma caused by proinflammatory mediators' release from corneal limbal vasculitis. The clinical presentation is an epithelial defect with a crescent-shaped stromal inflammation. Its exact pathophysiologic mechanisms of PUK remain partially understood, but the overall understanding of the fundamental processes that mediate and effect corneal immunity has continued to expand over the past 25 years. The unique anatomical and physiological characteristics of the periphery in relation to collagen bundles and peripheral corneal vascular arch contribute to the occurrence of this type of ulcer in this region, in addition to the concentration of complement and immunoglobulins. There is a relevant participation of the adjacent conjunctiva. Both cell-mediated immunity and humoral immunity are implicated in the pathogenesis of PUK, and the postulated mechanisms are autoimmune reactions to corneal antigens, deposition of circulating immune complexes and hypersensitivity reactions to foreign antigens. These immunocomplexes are deposited in limbic vessels resulting in the activation of the classical pathway of the complement system and, consequently, in the chemotaxis of inflammatory cells and in the release of several pro-inflammatory cytokines, which allow the production and release of matrix metalloproteinases. The release of inflammatory cytokines by infiltrating cells may induce keratocyte activation, which could then generate more release of a variety of cytokines, such as the neutrophil calgranulin C, thus facilitating an autoimmune response to the protein and precipitating an antibody- and cell-mediated hyperimmune reaction in the peripheral cornea.


Asunto(s)
Úlcera de la Córnea/inmunología , Inmunidad Celular/fisiología , Inmunidad Humoral/fisiología , Autoinmunidad , Sustancia Propia/patología , Úlcera de la Córnea/diagnóstico , Úlcera de la Córnea/fisiopatología , Humanos , Limbo de la Córnea/patología , Vasculitis/patología
9.
Brain Behav Immun ; 95: 462-476, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33964434

RESUMEN

Physically active individuals are less likely to develop chronic pain, and physical exercise is an established strategy to control inflammatory diseases. Here, we hypothesized that 1) peripheral pro-inflammatory macrophages phenotype contribute to predisposition of the musculoskeletal to chronic pain, and that 2) activation of PPARγ receptors, modulation of macrophage phenotypes and cytokines through physical exercise would prevent persistent muscle pain. We tested these hypotheses using swimming exercise, pharmacological and immunochemical techniques in a rodent model of persistent muscle hyperalgesia. Swimming prevented the persistent mechanical muscle hyperalgesia most likely through activation of PPARγ receptors, as well as activation of PPARγ receptors by 15d-PGJ2 and depletion of muscle macrophages in sedentary animals. Acute and persistent muscle hyperalgesia were characterized by an increase in pro-inflammatory macrophages phenotype, and swimming and the 15d-PGJ2 prevented this increase and increased anti-inflammatory macrophages phenotype. Finally, IL-1ß concentration in muscle increased in the acute phase, which was also prevented by PPARγ receptors activation through swimming. Besides, swimming increased muscle concentration of IL-10 in both acute and chronic phases, but only in the persistent phase through PPARγ receptors. Our findings suggest physical exercise activates PPARγ receptors and increases anti-inflammatory responses in the muscle tissue by modulating macrophages phenotypes and cytokines, thereby preventing the establishment of persistent muscle hyperalgesia. These results further highlight the potential of physical exercise to prevent chronic muscle pain.


Asunto(s)
Hiperalgesia , Macrófagos , Músculos/metabolismo , PPAR gamma , Condicionamiento Físico Animal , Animales , Citocinas , Masculino , Ratones , Fenotipo , Prostaglandina D2/análogos & derivados
10.
J Cell Sci ; 132(4)2018 11 09.
Artículo en Inglés | MEDLINE | ID: mdl-30237222

RESUMEN

The centrosome is an important microtubule-organising centre (MTOC) in animal cells. It consists of two barrel-shaped structures, the centrioles, surrounded by the pericentriolar material (PCM), which nucleates microtubules. Centrosomes can form close to an existing structure (canonical duplication) or de novo How centrosomes form de novo is not known. The master driver of centrosome biogenesis, PLK4, is critical for the recruitment of several centriole components. Here, we investigate the beginning of centrosome biogenesis, taking advantage of Xenopus egg extracts, where PLK4 can induce de novo MTOC formation ( Eckerdt et al., 2011; Zitouni et al., 2016). Surprisingly, we observe that in vitro, PLK4 can self-assemble into condensates that recruit α- and ß-tubulins. In Xenopus extracts, PLK4 assemblies additionally recruit STIL, a substrate of PLK4, and the microtubule nucleator γ-tubulin, forming acentriolar MTOCs de novo The assembly of these robust microtubule asters is independent of dynein, similar to what is found for centrosomes. We suggest a new mechanism of action for PLK4, where it forms a self-organising catalytic scaffold that recruits centriole components, PCM factors and α- and ß-tubulins, leading to MTOC formation.This article has an associated First Person interview with the first author of the paper.


Asunto(s)
Proteínas de Ciclo Celular/metabolismo , Proteínas Asociadas a Microtúbulos/metabolismo , Centro Organizador de los Microtúbulos/metabolismo , Microtúbulos/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas de Xenopus/metabolismo , Animales , Centriolos/metabolismo , Centrosoma/metabolismo , Dineínas/metabolismo , Huso Acromático/metabolismo , Xenopus laevis/metabolismo
11.
Purinergic Signal ; 16(3): 403-414, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32766958

RESUMEN

This study aimed to evaluate whether the development and/or maintenance of chronic-latent muscle hyperalgesia is modulated by P2X3 receptors. We also evaluate the expression of P2X3 receptors and PKCε of dorsal root ganglions during these processes. A mouse model of chronic-latent muscle hyperalgesia, induced by carrageenan and evidenced by PGE2, was used. Mechanical muscle hyperalgesia was measured by Randall-Selitto analgesimeter. The involvement of P2X3 receptors was analyzed by using the selective P2X3 receptors antagonist A-317491 by intramuscular or intrathecal injections. Expression of P2X3 and PKCε in dorsal root ganglion (L4-S1) were evaluated by Western blotting. Intrathecal blockade of P2X3 receptors previously to carrageenan prevented the development and maintenance of acute and chronic-latent muscle hyperalgesia, while intramuscular blockade of P2X3 receptors previously to carrageenan only reduced the acute muscle hyperalgesia and had no effect on chronic-latent muscle hyperalgesia. Intrathecal, but not intramuscular, blockade of P2X3 receptors immediately before PGE2, in animals previously sensitized by carrageenan, reversed the chronic-latent muscle hyperalgesia. There was an increase in total and phosphorylated PKCε 48 h after the beginning of acute muscle hyperalgesia, and in P2X3 receptors at the period of chronic muscle hyperalgesia. P2X3 receptors expressed on spinal cord dorsal horn contribute to transition from acute to chronic muscle pain. We also suggest an interaction of PKCε and P2X3 receptors in this process. Therefore, we point out P2X3 receptors of the spinal cord dorsal horn as a pharmacological target to prevent the development or reverse the chronic muscle pain conditions.


Asunto(s)
Dolor Agudo/metabolismo , Dolor Crónico/metabolismo , Músculo Esquelético/metabolismo , Mialgia/metabolismo , Receptores Purinérgicos P2X3/metabolismo , Animales , Progresión de la Enfermedad , Ganglios Espinales/efectos de los fármacos , Ganglios Espinales/metabolismo , Masculino , Ratones , Músculo Esquelético/efectos de los fármacos , Umbral del Dolor/efectos de los fármacos , Fenoles/farmacología , Compuestos Policíclicos/farmacología , Antagonistas del Receptor Purinérgico P2X/farmacología
12.
Int Ophthalmol ; 38(1): 251-256, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28478533

RESUMEN

PURPOSE: To evaluate the relationship between glaucoma diagnosis and the nailfold capillaroscopy pattern in patients with systemic sclerosis. METHODS: An observational study in a cohort of patients with SSc was conducted. Patients with at least one nailfold videocapillaroscopy and one ophthalmology examination at the same year were included. Data collected were: age, sex; type of systemic sclerosis according to the degree of skin impairment, self-reported ethnicity, disease duration, current use and dosage of systemic corticosteroid, current use and dosage of bosentan®, intraocular pressure, central corneal thickness, diagnosis of glaucoma and capillaroscopy pattern. RESULTS: Thirty-one patients with systemic sclerosis were enrolled, 23% had glaucoma. There was no statistically significant association between glaucoma diagnosis and the capillaroscopic pattern (p = 0.86). There was also no significant difference (p = 0.66) regarding intraocular pressure between patients with mild (13.9 ± 3.8 mmHg) and severe capillaroscopic pattern (14.4 ± 2.8 mmHg). The odds ratio of glaucoma for severe capillaroscopic pattern compared to mild was 1.6 (95% confidence interval: 0.3-9.5). CONCLUSION: Up to 23% of patients with SSc have glaucoma. The high prevalence of glaucoma in SSc suggests a possible systemic vascular disturbance as the cause. However, there seems to be no significant association between the capillaroscopy pattern and glaucoma in systemic sclerosis. Further research is required to improve the understanding of glaucoma in the context of systemic sclerosis.


Asunto(s)
Capilares/diagnóstico por imagen , Glaucoma/etiología , Angioscopía Microscópica/métodos , Medición de Riesgo/métodos , Esclerodermia Sistémica/complicaciones , Adulto , Anciano , Brasil/epidemiología , Progresión de la Enfermedad , Femenino , Glaucoma/diagnóstico , Glaucoma/epidemiología , Humanos , Presión Intraocular , Masculino , Persona de Mediana Edad , Uñas/irrigación sanguínea , Proyectos Piloto , Prevalencia , Esclerodermia Sistémica/diagnóstico , Tonometría Ocular/métodos
13.
Eye Contact Lens ; 41(3): 141-4, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25794330

RESUMEN

Corneal involvement in patients with systemic inflammatory disorders may be sight threatening, and it may be associated with a life-threatening disease. Significant systemic inflammatory diseases in this context are autoimmune connective tissue diseases, systemic autoimmune dermatological disorders, and autoimmune diseases of the lacrimal system. Keratoconjunctivitis sicca is usually the most common ocular finding in these patients. Peripheral ulcerative keratitis is a rare condition usually associated with increased ocular morbidity and also mortality, as it might act as an indicator of a more widespread vasculitis. Corneal biomechanical properties may also be altered in connective tissue diseases. Although recent studies suggest that the risk for corneal complications after ocular surgery in patients with quiescent autoimmune disease is minimal, caution is still recommended, as the knowledge about the corneal wound-healing process and the corneal biomechanical properties in these patients is not yet fully understood. This article reviews corneal abnormalities and characteristics in the setting of systemic inflammatory diseases.


Asunto(s)
Enfermedades de la Córnea/patología , Síndrome de Respuesta Inflamatoria Sistémica/patología , Humanos , Queratitis/patología
14.
J Appl Biomech ; 31(4): 258-63, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25838207

RESUMEN

In sprint kayaking the role that paddling technique plays in optimizing paddle forces and resultant kayak kinematics is still unclear. The aim of this study was to analyze the magnitude and shape of the paddle force-time curve at different stroke rates, and their implications for kayak performance. Ten elite kayak paddlers (5 males and 5 females) were analyzed while performing 2000-m on-water trials, at 4 different paces (60, 80, and 100 strokes per minute, and race pace). The paddle and kayak were instrumented with strain gauges and accelerometers, respectively. For both sexes, the force-time curves were characterized at training pace by having a bell shape and at race pace by a first small peak, followed by a small decrease in force and then followed by a main plateau. The force profile, represented by the mean force/peak force ratio, became more rectangular with increasing stroke rate (F[3,40] = 7.87, P < .01). To obtain a rectangular shape to maximize performance, kayak paddlers should seek a stronger water phase with a rapid increase in force immediately after blade entry, and a quick exit before the force dropping far below the maximum force. This pattern should be sought when training at race pace and in competition.


Asunto(s)
Brazo/fisiología , Rendimiento Atlético/fisiología , Navíos , Deportes/fisiología , Aceleración , Adulto , Fenómenos Biomecánicos , Femenino , Humanos , Masculino , Equipo Deportivo , Análisis y Desempeño de Tareas
15.
Adv Drug Deliv Rev ; 207: 115197, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38342240

RESUMEN

Skin cancer is a heterogeneous disease that can be divided into two main groups, melanoma and nonmelanoma skin cancers. Conventional therapies for skin cancer have numerous systemic side effects and a high recurrence rate. Topical treatment is an alternative approach, but drug permeability remains a challenge. Therefore, nanocarriers appear as important nanotechnology tools that reduces both the side effects and improves clinical outcomes. This is why they are attracting growing interest. In this review, scientific articles on the use of nanocarriers for the topical treatment of skin cancer were collected. Despite the promising results of the presented nanocarriers and considering that some of them are already on the market, there is an urgent need for investment in the development of manufacturing methods, as well as of suitable toxicological and regulatory evaluations, since the conventional methods currently used to develop these nanocarriers-based products are more time-consuming and expensive than conventional products.


Asunto(s)
Absorción Cutánea , Neoplasias Cutáneas , Humanos , Administración Tópica , Nanotecnología , Neoplasias Cutáneas/tratamiento farmacológico , Portadores de Fármacos/metabolismo , Piel/metabolismo
16.
Sports Biomech ; : 1-10, 2024 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-38238912

RESUMEN

Rowing performance depends on the design and building materials used for competition. Recently, attempting to improve rowing performance, the Randall foil has been attached to the top edge of a rowing Big blade, making it spoon shaped. The current study aimed to analyse the differences between Big blades with and without Randall foils in force-related variables. Nineteen rowers performed two bouts of 90 s at maximal effort tethered rowing and differences were found in cycle average peak force (4.33 ± 1.46 vs. 5.26 ± 1.57 N/kg), propulsive cycle average time (1.79 ± 0.38 vs. 1.52 ± 0.24 N/kg.s) and rate of force development (8.79 ± 4.75 vs. 12.07 ± 4.60 N/kg/s) for Big blades with and without foils (respectively). Differences were also observed between the middle (4.79 ± 1.21 vs. 4.08 ± 1.48 N/kg) and final phases (4.86 ± 1.45 vs. 4.04 ± 1.47 N/kg) of the rowing effort for the cycle average peak force of Big blades with and without Randall foils. Data suggest a positive effect of these foils on the force-time curve profile. Future studies should focus on testing its influence on free on-water rowing.

17.
bioRxiv ; 2024 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-39229100

RESUMEN

Parkinson's Disease (PD) is a multisystem disorder in which dysregulated neuroimmune crosstalk and inflammatory relay via the gut-blood-brain axis have been implicated in PD pathogenesis. Although alterations in circulating inflammatory cytokines and reactive oxygen species (ROS) have been associated with PD, no biomarkers have been identified that predict clinical progression or disease outcome. Gastrointestinal (GI) dysfunction, which involves perturbation of the underlying immune system, is an early and often-overlooked symptom that affects up to 80% of individuals living with PD. Interestingly, 50-70% of individuals with inflammatory bowel disease (IBD), a GI condition that has been epidemiologically linked to PD, display chronic illness-induced anemia - which drives toxic accumulation of iron in the gut. Ferroptotic (or iron loaded) cells have small and dysmorphic mitochondria-suggesting that mitochondrial dysfunction is a consequence of iron accumulation. In pro-inflammatory environments, iron accumulates in immune cells, suggesting a possible connection and/or synergy between iron dysregulation and immune cell dysfunction. Peripheral blood mononuclear cells (PBMCs) recapitulate certain PD-associated neuropathological and inflammatory signatures and can act as communicating messengers in the gut-brain axis. Additionally, this communication can be modulated by several environmental factors; specifically, our data further support existing literature demonstrating a role for non-steroidal anti-inflammatory drugs (NSAIDs) in modulating immune transcriptional states in inflamed individuals. A mechanism linking chronic gut inflammation to iron dysregulation and mitochondrial function within peripheral immune cells has yet to be identified in conferring risk for PD. To that end, we isolated PBMCs and simultaneously evaluated their directed transcriptome and bioenergetic status, to investigate if iron dysregulation and mitochondrial sensitization are linked in individuals living with PD or IBD because of chronic underlying remittent immune activation. We have identified shared features of peripheral inflammation and immunometabolism in individuals living with IBD or PD that may contribute to the epidemiological association reported between IBD and risk for PD.

18.
J Cell Biol ; 223(4)2024 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-38456967

RESUMEN

The outermost layer of centrosomes, called pericentriolar material (PCM), organizes microtubules for mitotic spindle assembly. The molecular interactions that enable PCM to assemble and resist external forces are poorly understood. Here, we use crosslinking mass spectrometry (XL-MS) to analyze PLK-1-potentiated multimerization of SPD-5, the main PCM scaffold protein in C. elegans. In the unassembled state, SPD-5 exhibits numerous intramolecular crosslinks that are eliminated after phosphorylation by PLK-1. Thus, phosphorylation induces a structural opening of SPD-5 that primes it for assembly. Multimerization of SPD-5 is driven by interactions between multiple dispersed coiled-coil domains. Structural analyses of a phosphorylated region (PReM) in SPD-5 revealed a helical hairpin that dimerizes to form a tetrameric coiled-coil. Mutations within this structure and other interacting regions cause PCM assembly defects that are partly rescued by eliminating microtubule-mediated forces, revealing that PCM assembly and strength are interdependent. We propose that PCM size and strength emerge from specific, multivalent coiled-coil interactions between SPD-5 proteins.


Asunto(s)
Caenorhabditis elegans , Proteínas de Ciclo Celular , Centrosoma , Quinasa Tipo Polo 1 , Animales , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Ciclo Celular/metabolismo , Centrosoma/metabolismo , Microtúbulos/genética , Microtúbulos/metabolismo , Quinasa Tipo Polo 1/metabolismo
19.
Cien Saude Colet ; 29(3): e10202023, 2024 Mar.
Artículo en Portugués, Inglés | MEDLINE | ID: mdl-38451652

RESUMEN

This ecological, time-trend study examined rates of homicide against women residing in Brazil, by state and race/colour, from 2016 to 2020, by performing. Multiple analysis by regression model on longitudinal data. During the study period, 20,405 homicides of women were recorded in Brazil. Standardised homicides rates were higher among black women (6.1/100,000) than among white women (3.4/100,000). From 2016 to 2020, rates decreased 25.2%, from 4.7 deaths per 100,000 women in 2016 to 3.5 in 2020, with a statistically significant downward trend among both black and white women. Statistically significant inverse relationships were found between female homicide rates and HDI, illiteracy rate and proportion of ill-defined causes. The average homicide rate decreased in 2019 and 2020, as compared with 2016. Despite the decreasing time trend in homicide rates for both black and white women, they differed substantially by race, with worse outcomes for black women.


O objetivo deste estudo é avaliar as taxas de homicídios contra mulheres residentes no Brasil, segundo unidades da federação e raça/cor, no período de 2016 a 2020. Trata-se de um estudo ecológico de tendência temporal. Foi realizada análise múltipla adotando-se modelo de regressão para dados longitudinais. No período, ocorreram no Brasil 20.405 homicídios de mulheres e as taxas padronizadas mostraram que as mulheres negras (6,1/100.000) apresentaram as maiores taxas, em comparação às brancas (3,4/100.000). O Brasil apresentou queda de 25,2% de 2016 a 2020. A taxa de homicídio variou de 4,7 mortes por 100 mil mulheres em 2016 para 3,5 em 2020, mas a tendência decrescente e estatisticamente significante foi observada nas taxas de mulheres negras e brancas. As variáveis IDH, taxa de analfabetismo e proporção de causas mal definidas apresentaram uma relação inversa e estatisticamente significante com as taxas de homicídio de mulheres. Nos anos de 2019 e 2020 houve uma diminuição da taxa média de homicídio em relação ao ano de 2016. Apesar do decrescimento na evolução temporal das taxas para negras e brancas, houve diferenças raciais importantes nos homicídios de mulheres, com piores resultados para as mulheres negras.


Asunto(s)
Población Negra , Homicidio , Femenino , Humanos , Brasil/epidemiología , Grupos Raciales , Etnicidad
20.
Cancer Med ; 13(8): e7179, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38650577

RESUMEN

BACKGROUND: Sleep disorders are often complained by cancer patients and can last years after the end of therapies, leading to different negative consequences. Non-pharmacological strategies such as exercise interventions may be considered to counteract this phenomenon. The literature supports the beneficial effects of aerobic training (AT), while evidence on resistance training (RT) is scarce. Accordingly, our systematic review aims to investigate the potential novel effect of RT on sleep outcomes in cancer survivors. METHODS: The literature search was conducted on MEDLINE (Pubmed), Web of Science, Scopus, and Cochrane Central Register of Controlled Trials databases, including only randomized controlled trials (RCTs). The screening procedure was conducted using the web-based software COVIDENCE. Sleep outcomes assessed through self-reported questionnaires or objective sleep measurements were extracted from RCTs recruiting cancer survivors of any age and gender, on or off treatment. The risk of bias (RoB) for each study was assessed using the Cochrane RoB 2 tool for RCTs. Meta-analytic syntheses were performed on sleep quality and insomnia. RESULTS: A total of 21 studies were included in the review. Considering the mean percentage differences of all studies combined, promising positive results were found after combined aerobic and resistance exercise program (COMB) for sleep quality (-19%) and sleep disturbance (-17.3%). The meta-analysis results showed significant improvement for both sleep quality and insomnia (d = 0.28, SE: 0.11, Z = 2.51, p < 0.01, 95% CI: 0.07-0.49 and d = 0.43, SE: 0.20, Z = 2.18, p = 0.029, 95% CI: 0.07-0.49, respectively). CONCLUSION: RT interventions of 60 minutes per session, performed 2-3 times a week for 12 weeks, with exercise intensity ranging from 60% to 80% of one-repetition maximum can be administered to cancer survivors, aiming to improve sleep outcomes.


Asunto(s)
Supervivientes de Cáncer , Neoplasias , Ensayos Clínicos Controlados Aleatorios como Asunto , Entrenamiento de Fuerza , Calidad del Sueño , Humanos , Entrenamiento de Fuerza/métodos , Neoplasias/complicaciones , Neoplasias/terapia , Trastornos del Sueño-Vigilia/terapia , Trastornos del Sueño-Vigilia/etiología , Trastornos del Inicio y del Mantenimiento del Sueño/terapia , Trastornos del Inicio y del Mantenimiento del Sueño/etiología , Masculino , Femenino
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