181 research outputs found
Evidence for a mitochondrial localization of the retinoblastoma protein
<p>Abstract</p> <p>Background</p> <p>The retinoblastoma protein (Rb) plays a central role in the regulation of cell cycle, differentiation and apoptosis. In cancer cells, ablation of Rb function or its pathway is a consequence of genetic inactivation, viral oncoprotein binding or deregulated hyperphosphorylation. Some recent data suggest that Rb relocation could also account for the regulation of its tumor suppressor activity, as is the case for other tumor suppressor proteins, such as p53.</p> <p>Results</p> <p>In this reported study, we present evidence that a fraction of the total amount of Rb protein can localize to the mitochondria in proliferative cells taken from both rodent and human cells. This result is also supported by the use of Rb siRNAs, which substantially reduced the amount of mitochondrial Rb, and by acellular assays, in which [<sup>35</sup>S]-Methionine-labeled Rb proteins bind strongly to mitochondria isolated from rat liver. Moreover, endogenous Rb is found in an internal compartment of the mitochondria, within the inner-membrane. This is consistent with the protection of Rb from alkaline treatment, which destroys any interaction of proteins that are weakly bound to mitochondria.</p> <p>Conclusion</p> <p>Although a few data regarding an unspecific cytosolic localization of Rb protein have been reported for some tumor cells, our results are the first evidence of a mitochondrial localization of Rb. The mitochondrial localization of Rb is observed in parallel with its classic nuclear location and paves the way for the study of potential as-yet-unknown roles of Rb at this site.</p
Actividad antihelmíntica “in vitro” de extractos acuosos obtenidos a partir de la biomasa comestible de Dichrostachys cinerea (L.) Wight et Arn.
Antecedentes: El empleo de la biomasa comestible de Dichrostachys cinerea constituye una alternativa para la alimentación de rumiantes y para el control de parasitosis en estos animales. Evaluar la actividad antihelmíntica “in vitro” de extractos acuosos obtenidos a partir de las legumbres, rebrotes y hojas de plantas adultas.
Métodos: Con el material vegetal colectado se obtuvieron tres soluciones madre, a partir de éstas se prepararon extractos acuosos mediante infusión, decocción y maceración. Posteriormente los extractos fueron diluidos a diferentes concentraciones (infusión y decocción al 10 % y maceración al 10, 15 y 20 %), para un total de 15 tratamientos (cinco en cada tipo de material vegetal). Se utilizaron además de cuatro controles: dos positivos y dos negativos. Se utilizó como modelo biológico la lombriz de tierra. Para cada tratamiento se empleó una placa de Petri en las que se añadieron 10 mL del extracto en cuestión y seis lombrices. Se midió el tiempo, en minutos, de ocurrencia de parálisis y muerte de las lombrices.
Resultados: El efecto antihelmíntico de la infusión y decocción al 10 % no mostró diferencias significativas entre los tiempos de ocurrencia de la muerte de las lombrices. La obtención de los extractos por maceración propició una mayor extracción de metabolitos secundarios, los cuales son responsables de la actividad antihelmíntica demostrada en el presente estudio.
Conclusiones: Todos los extractos mostraron actividad antihelmíntica “in vitro”. El extracto acuoso obtenido por maceración y diluido al 20 % fue el más efectivo de los tres materiales vegetales estudiados.
Palabras clave: helmintos, hojas, legumbres, marabú, rebrotes (Fuente: AIMS
USE OF ANTIFUNGAL SAPONIN SC-2 OF SOLANUM CHRYSOTRICHUM FOR THE TREATMENT OF VULVOVAGINAL CANDIDIASIS: IN VITRO STUDIES AND CLINICAL EXPERIENCES
Saponin SC-2 from Solanum chrysotrichum showed antifungal activity, demonstrated in vitro, which inhibited the growth of dermatophytes, and in vivo, to be effective in the treatment against tinea pedis and pityriasis capitis. Fungistatic and fungicidal activity of saponin SC-2 on Candida albicans and other Candida species, fluconazole and ketoconazole resistaent strains was demostrated. SC-2-associated ultrastructural alterations in several Candida species were observed. An exploratory clinical, randomized, double-blind, and controlled ketoconazole study of ketoconazole was conducted with the aim of assessing the effectiveness and tolerability of an herbal medicinal product containing SC-2, on women with Vulvovaginal candidiasis (VVC). The results exhibited a percentage of therapeutic clinical effectiveness similar to that of ketoconazole (X2, p ≥0.30), but obtained a smaller percentage of mycological effectiveness, and 100% tolerability. In conclusion, saponin SC-2 possesses fungicidale and fungistatic activity on Candida albicans and other multi resistant Candida species, causes morphological changes and fungal death, and it is an alternative therapy for the treatment of VVC
Dental erosive wear and salivary flow rate in physically active young adults
Background
Little attention has been directed towards identifying the relationship between physical exercise, dental erosive wear and salivary secretion. The study aimed i) to describe the prevalence and severity of dental erosive wear among a group of physically active young adults, ii) to describe the patterns of dietary consumption and lifestyle among these individuals and iii) to study possible effect of exercise on salivary flow rate.
Methods
Young members (age range 18-32 years) of a fitness-centre were invited to participate in the study. Inclusion criteria were healthy young adults training hard at least twice a week. A non-exercising comparison group was selected from an ongoing study among 18-year-olds. Two hundred and twenty participants accepted an intraoral examination and completed a questionnaire. Seventy of the exercising participants provided saliva samples. The examination was performed at the fitness-centre or at a dental clinic (comparison group), using tested erosive wear system (VEDE). Saliva sampling (unstimulated and stimulated) was performed before and after exercise. Occlusal surfaces of the first molars in both jaws and the labial and palatal surfaces of the upper incisors and canines were selected as index teeth.
Results
Dental erosive wear was registered in 64% of the exercising participants, more often in the older age group, and in 20% of the comparison group. Enamel lesions were most observed in the upper central incisors (33%); dentine lesions in lower first molar (27%). One fourth of the participants had erosive wear into dentine, significantly more in males than in females (p = 0.047). More participants with erosive wear had decreased salivary flow during exercise compared with the non-erosion group (p < 0.01). The stimulated salivary flow rate was in the lower rage (≤ 1 ml/min) among more than one third of the participants, and more erosive lesions were registered than in subjects with higher flow rates (p < 0.01).
Conclusion
The study showed that a high proportion of physically active young adults have erosive lesions and indicate that hard exercise and decreased stimulated salivary flow rate may be associated with such wear
Using Electronic Health Records to Facilitate Precision Psychiatry
The use of clinical prediction models to produce individualised risk estimates can facilitate the implementation of precision psychiatry. As a source of data from large, clinically representative patient samples, electronic health records (EHRs) provide a platform to develop and validate clinical prediction models, as well as potentially implementing them in routine clinical care. The present review describes promising use cases for the application of precision psychiatry to EHR data and considers their performance in terms of discrimination (ability to separate individuals with and without the outcome) and calibration (extent to which predicted risk estimates correspond to observed outcomes), as well as their potential clinical utility (weighing benefits and costs associated with the model compared to different approaches across different assumptions of the number-needed-to-test). We review four externally validated clinical prediction models designed to predict, respectively: psychosis onset, psychotic relapse, cardiometabolic morbidity, and suicide risk. We then discuss the prospects for clinically implementing these models, and the potential added value of integrating data from evidence syntheses, standardised psychometric assessments, and biological data into EHRs. Clinical prediction models can utilise routinely collected EHR data in an innovative way, representing a unique opportunity to inform real-world clinical decision making. Combining data from other sources (e.g. meta-analyses) or enhancing EHR data with information from research studies (clinical and biomarker data) may enhance our abilities to improve performance of clinical prediction models. [Abstract copyright: Copyright © 2024. Published by Elsevier Inc.
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
Report of the Snowmass 2021 Topical Group on Lattice Gauge Theory
Lattice gauge theory continues to be a powerful theoretical and computational
approach to simulating strongly interacting quantum field theories, whose
applications permeate almost all disciplines of modern-day research in
High-Energy Physics. Whether it is to enable precision quark- and lepton-flavor
physics, to uncover signals of new physics in nucleons and nuclei, to elucidate
hadron structure and spectrum, to serve as a numerical laboratory to reach
beyond the Standard Model, or to invent and improve state-of-the-art
computational paradigms, the lattice-gauge-theory program is in a prime
position to impact the course of developments and enhance discovery potential
of a vibrant experimental program in High-Energy Physics over the coming
decade. This projection is based on abundant successful results that have
emerged using lattice gauge theory over the years: on continued improvement in
theoretical frameworks and algorithmic suits; on the forthcoming transition
into the exascale era of high-performance computing; and on a skillful,
dedicated, and organized community of lattice gauge theorists in the U.S. and
worldwide. The prospects of this effort in pushing the frontiers of research in
High-Energy Physics have recently been studied within the U.S. decadal Particle
Physics Planning Exercise (Snowmass 2021), and the conclusions are summarized
in this Topical Report.Comment: 57 pages, 1 figure. Submitted to the Proceedings of the US Community
Study on the Future of Particle Physics (Snowmass 2021). Topical Group Report
for TF05 - Lattice Gauge Theor
Asynchronous Carbon Sink Saturation in African and Amazonian Tropical Forests
Structurally intact tropical forests sequestered ~50% of global terrestrial carbon uptake over the 1990s and early 2000s, removing ~15% of anthropogenic CO2 emissions(1-3). Climate-driven vegetation models typically predict that this tropical forest ‘carbon sink’ will continue for decades(4,5). Here, we assess trends in the carbon sink using 244 structurally intact African tropical forests spanning 11 countries, we compare them with 321 published plots from Amazonia and investigate the underlying drivers of the trends. The carbon sink in live aboveground biomass in intact African tropical forests has been stable for the three decades to 2015, at 0.66 Mg C ha-1 yr-1 (95% CI:0.53-0.79), in contrast to the long-term decline in Amazonian forests(6). Thus, the carbon sink responses of Earth’s two largest expanses of tropical forest have diverged. The difference is largely driven by carbon losses from tree mortality, with no detectable multi-decadal trend in Africa and a long-term increase in Amazonia. Both continents show increasing tree growth, consistent with the expected net effect of rising atmospheric CO2 and air temperature(7-9). Despite the past stability of the African carbon sink, our data suggest a post-2010 increase in carbon losses, delayed compared to Amazonia, indicating asynchronous carbon sink saturation on the two continents. A statistical model including CO2, temperature, drought and forest dynamics accounts for the observed trends and indicates a long-term future decline in the African sink, while the Amazonian sink continues to rapidly weaken. Overall, the uptake of carbon into Earth’s intact tropical forests peaked in the 1990s. Given that the global terrestrial carbon sink is increasing in size, observations indicating greater recent carbon uptake into the Northern hemisphere landmass(10) reinforce our conclusion that the intact tropical forest carbon sink has already saturated. This tropical forest sink saturation and ongoing decline has consequences for policies to stabilise Earth’s climate
Chronic Activation of γ2 AMPK Induces Obesity and Reduces β Cell Function.
Despite significant advances in our understanding of the biology determining systemic energy homeostasis, the treatment of obesity remains a medical challenge. Activation of AMP-activated protein kinase (AMPK) has been proposed as an attractive strategy for the treatment of obesity and its complications. AMPK is a conserved, ubiquitously expressed, heterotrimeric serine/threonine kinase whose short-term activation has multiple beneficial metabolic effects. Whether these translate into long-term benefits for obesity and its complications is unknown. Here, we observe that mice with chronic AMPK activation, resulting from mutation of the AMPK γ2 subunit, exhibit ghrelin signaling-dependent hyperphagia, obesity, and impaired pancreatic islet insulin secretion. Humans bearing the homologous mutation manifest a congruent phenotype. Our studies highlight that long-term AMPK activation throughout all tissues can have adverse metabolic consequences, with implications for pharmacological strategies seeking to chronically activate AMPK systemically to treat metabolic disease
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