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1.
PLoS Comput Biol ; 20(5): e1012058, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38709818

RESUMEN

A challenging goal of neural coding is to characterize the neural representations underlying visual perception. To this end, multi-unit activity (MUA) of macaque visual cortex was recorded in a passive fixation task upon presentation of faces and natural images. We analyzed the relationship between MUA and latent representations of state-of-the-art deep generative models, including the conventional and feature-disentangled representations of generative adversarial networks (GANs) (i.e., z- and w-latents of StyleGAN, respectively) and language-contrastive representations of latent diffusion networks (i.e., CLIP-latents of Stable Diffusion). A mass univariate neural encoding analysis of the latent representations showed that feature-disentangled w representations outperform both z and CLIP representations in explaining neural responses. Further, w-latent features were found to be positioned at the higher end of the complexity gradient which indicates that they capture visual information relevant to high-level neural activity. Subsequently, a multivariate neural decoding analysis of the feature-disentangled representations resulted in state-of-the-art spatiotemporal reconstructions of visual perception. Taken together, our results not only highlight the important role of feature-disentanglement in shaping high-level neural representations underlying visual perception but also serve as an important benchmark for the future of neural coding.


Asunto(s)
Modelos Neurológicos , Corteza Visual , Percepción Visual , Animales , Percepción Visual/fisiología , Corteza Visual/fisiología , Macaca mulatta , Biología Computacional , Redes Neurales de la Computación , Estimulación Luminosa , Masculino , Neuronas/fisiología , Encéfalo/fisiología
2.
Curr Microbiol ; 81(8): 237, 2024 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-38907801

RESUMEN

Toxic cyanobacterial blooms in various water bodies have been given much attention nowadays as they release hazardous substances in the surrounding areas. These toxic planktonic cyanobacteria in shrimp ponds greatly affect the survival of shrimps. Ecuador is the second highest shrimp producing country in the Americas after Brazil; and the shrimp-based economy is under threat due to toxic cyanobacterial blooms in Ecuador shrimp ponds. This study investigated the abundance of different cyanobacteria in the shrimp ponds at the Chone and Jama rivers (in Manabi province) at Ecuadorian pacific coast, focusing on different environmental factors, such as temperature, pH, salinity, and light. Temperature and pH were identified as key factors in influencing the abundance of cyanobacteria, with a significant positive correlation between Raphidiopsis raciborskii and pH. The highest and lowest abundance of cyanobacteria found during the dry season in the shrimp ponds near the Chone and Jama rivers were > 3 × 106 and 1 × 106 Cell.m-3, respectively. The Shannon-Wiener Diversity Index fluctuated between 0.41-1.15 and 0.31-1.15 for shrimp ponds of Chone and Jama rivers, respectively. This variation was linked to changes in salinity and the presence of harmful algal blooms, highlighting the importance of continuous monitoring. Additionally, the study areas showed eutrophic conditions with low diversity, underlining the need for additional spatiotemporal studies and expanded research in both rivers, to better understand these complex phenomena. The findings underscore the importance of continuous monitoring and expanded research in cyanobacteria ecology, with implications for public health and aquatic resource management.


Asunto(s)
Acuicultura , Cianobacterias , Estanques , Ecuador , Cianobacterias/clasificación , Cianobacterias/aislamiento & purificación , Animales , Estanques/microbiología , Humanos , Penaeidae/microbiología , Salinidad , Floraciones de Algas Nocivas , Estaciones del Año , Temperatura
3.
BMC Geriatr ; 23(1): 1, 2023 01 02.
Artículo en Inglés | MEDLINE | ID: mdl-36593448

RESUMEN

BACKGROUND: Frailty is a physiological condition characterized by a decreased reserve to stressors. In patients with COVID-19, frailty is a risk factor for in-hospital mortality. The aim of this study was to assess the relationship between clinical presentation, analytical and radiological parameters at admission, and clinical outcomes according to frailty, as defined by the Clinical Frailty Scale (CFS), in old people hospitalized with COVID-19. MATERIALS AND METHODS: This retrospective cohort study included people aged 65 years and older and admitted with community-acquired COVID-19 from 3 March 2020 to 31 April 2021. Patients were categorized using the CFS. Primary outcomes were symptoms of COVID-19 prior to admission, mortality, readmission, admission in intensive care unit (ICU), and need for invasive mechanical ventilation. Analysis of clinical symptoms, clinical outcomes, and CFS was performed using multivariable logistic regression, and results were expressed as odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Of the 785 included patients, 326 (41.5%, 95% CI 38.1%-45.0%) were defined as frail (CFS ≥ 5 points): 208 (26.5%, 95% CI 23.5%-29.7%) presented mild-moderate frailty (CFS 5-6 points) and 118 (15.0%, 95% CI 12.7%-17.7%), severe frailty (7-9 points). After adjusting for epidemiological variables (age, gender, residence in a nursing home, and Charlson comorbidity index), frail patients were significantly less likely to present dry cough (OR 0.58, 95% CI 0.40-0.83), myalgia-arthralgia (OR 0.46, 95% CI 0.29-0.75), and anosmia-dysgeusia (OR 0.46, 95% CI 0.23-0.94). Confusion was more common in severely frail patients (OR 3.14; 95% CI 1.64-5.97). After adjusting for epidemiological variables, the risk of in-hospital mortality was higher in frail patients (OR 2.79, 95% CI 1.79-4.25), including both those with mild-moderate frailty (OR 1.98, 95% CI 1.23-3.19) and severe frailty (OR 5.44, 95% CI 3.14-9.42). Readmission was higher in frail patients (OR 2.11, 95% CI 1.07-4.16), but only in mild-moderate frailty (OR 2.35, 95% CI 1.17-4.75).. CONCLUSION: Frail patients presented atypical symptoms (less dry cough, myalgia-arthralgia, and anosmia-dysgeusia, and more confusion). Frailty was an independent predictor for death, regardless of severity, and mild-moderate frailty was associated with readmission.


Asunto(s)
COVID-19 , Fragilidad , Humanos , Anciano , COVID-19/complicaciones , COVID-19/terapia , Fragilidad/diagnóstico , Fragilidad/epidemiología , Tiempo de Internación , Estudios Retrospectivos , Pacientes Internos , Anosmia , Tos , Disgeusia , Mialgia , Anciano Frágil , Evaluación Geriátrica/métodos
4.
J Clin Nurs ; 31(7-8): 958-966, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34245058

RESUMEN

AIMS AND OBJECTIVES: To investigate the possible association between hyponatremia and falls, in a sample of hospitalised adult patients. BACKGROUND: In-hospital falls are a problem of major importance, provoking a significant decline in the quality of life of many patients. Recent studies have identified a relationship between such falls and the presence of hyponatremia. DESIGN: Analytical retrospective observational case-control study. METHODS: The study population consisted of hospitalised patients who had suffered an in-hospital fall during the period 2014-2016. For each case, two controls who had not suffered any such fall were recruited. These cases and controls were matched according to gender, age, hospitalisation unit and date of admission. Study data were obtained from the hospital's record of falls, regarding the patients' socio-demographic factors, physical and psychological conditions and blood levels of sodium, potassium, urea and creatinine. The study is reported in accordance with STrengthening the Reporting of OBservational studies in Epidemiology guidelines. RESULTS: The study sample consisted of 555 patients (185 cases and 370 controls). Hyponatraemia was detected in 57 cases (30.8%). A statistically significant relationship was found between the presence of hyponatraemia and the occurrence of falls: OR = 2.04. Other risk factors for falls were hypercreatinaemia OR 2.49, hyperuraemia OR 1.82, disorientation, need for ambulatory assistance and longer hospital stay. CONCLUSIONS: From the study findings, we conclude that hyponatraemia is a predictor of falls by acute hospitalised patients. Further research is needed on the relationship between hypercreatinaemia, hyperuraemia and falls. RELEVANCE TO CLINICAL PRACTICE: The assessment of risk factors for falls, such as hyponatraemia, can alert us to the possibility of this event occurring and facilitate the implementation of preventive measures. This parameter should be included as a significant new factor in assessment instruments designed to assess the risk of falls, thus enhancing the reliability and diagnostic validity of these instruments.


Asunto(s)
Hiponatremia , Accidentes por Caídas/prevención & control , Adulto , Estudios de Casos y Controles , Humanos , Hiponatremia/diagnóstico , Hiponatremia/epidemiología , Hiponatremia/etiología , Calidad de Vida , Reproducibilidad de los Resultados , Estudios Retrospectivos , Factores de Riesgo
5.
Molecules ; 26(21)2021 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-34771079

RESUMEN

The extract of Cardiospermum halicacabum L. (C. halicacabum) obtained from flower, leaf and vine was loaded into modified phospholipid vesicles aiming at obtaining sprayable, biocompatible and effective nasal spray formulations for the treatment of nasopharyngeal diseases. Penetration enhancer-containing vesicles (PEVs) and hyalurosomes were formulated, and stabilized by adding a commercial gelatin from fish (20 mg/mL) or chondroitin sulfate from catshark cartilages (Scyliorhinus canicula, 20 mg/mL). Cryo-TEM images confirmed the formation of spherical vesicles, while photon correlation spectroscopy analysis disclosed the formation of small and negatively-charged vesicles. PEVs were the smaller vesicles (~100 nm) along with gelatin-hyalurosomes (~120 nm), while chondroitin-PEVs and chondroitin-hyalurosomes were larger (~160 nm). Dispersions prepared with chondroitin sulfate were more homogeneous, as the polydispersity index was ~0.15. The in vitro analysis of the droplet size distribution, average velocity module and spray cone angle suggested a good spray-ability and deposition of formulations in the nasal cavity, as the mean diameter of the droplets was in the range recommended by the Food and Drug Administration for nasal targets. The spray plume analysis confirmed the ability of PEVs, gelatin-PEVs, hyalurosomes and gelatin-hyalurosomes to be atomized in fine droplets homogenously distributed in a full cone plume, with an angle ranging from 25 to 30°. Moreover, vesicles were highly biocompatible and capable of protecting the epithelial cells against oxidative damage, thus preventing the inflammatory state.


Asunto(s)
Sulfatos de Condroitina , Gelatina , Liposomas , Rociadores Nasales , Fosfolípidos , Extractos Vegetales/administración & dosificación , Sapindaceae/química , Aerosoles , Antioxidantes/administración & dosificación , Antioxidantes/química , Materiales Biocompatibles/química , Fenómenos Químicos , Composición de Medicamentos , Humanos , Queratinocitos/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Tamaño de la Partícula , Extractos Vegetales/química
6.
J Oral Pathol Med ; 47(10): 938-944, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30067878

RESUMEN

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) is a global public health problem, which increases in prevalence every year. Evidence brings up that small populations of stem cells, the cancer stem cells (CSC), are responsible for tumour initiation, tumorigenesis, progression, and metastasis. These cells play a crucial role in cancer development and treatment response, but the origin of CSCs remains unclear. In this research, we have sequenced the entire exome of the three different groups of cells of primary squamous cell carcinoma tumour from different patients, with the aim to understand their main genetic changes and to elucidate the possible origin of tumour cells and tumour stem cells. MATERIAL AND METHODS: We performed a whole exome sequencing in the germinal line, tumour cells, and CSC ALDH+ samples from four HNSCC patients. An analysis pipeline was used to filter, score, rank, and prioritize candidate variants according to its effect on protein structure and phylogenetic conservation using available information on pathways and protein function databases. RESULTS: Results showed variations in genes involved in oncogenic pathways and shed light on the evolution model of the CSC and tumour cells for each patient in which stem cells (CS) triggered the formation of CSC and these in turn become tumour cells. CONCLUSIONS: These findings support the idea that it is possible to identify in each individual patient if the CS are of tumour origin or vice versa, thus being possible a more personalized treatment.


Asunto(s)
Secuenciación del Exoma , Neoplasias de Cabeza y Cuello/genética , Neoplasias de Cabeza y Cuello/patología , Células Madre Neoplásicas/patología , Carcinoma de Células Escamosas de Cabeza y Cuello/genética , Carcinoma de Células Escamosas de Cabeza y Cuello/patología , Anciano , Carcinogénesis/genética , Transformación Celular Neoplásica/genética , Femenino , Humanos , Pérdida de Heterocigocidad , Masculino , Persona de Mediana Edad , Células Tumorales Cultivadas
7.
Rev Esp Enferm Dig ; 110(8): 531-532, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29900744

RESUMEN

Pneumatosis cystoides intestinalis is characterized by multiple air-filled cysts in the intestine wall. A perforation causes pneumoperitoneum, frequently with minimal clinical affectation and do not require surgery at first in most cases. Recently, some cancer treatments, mainly molecular targeted therapy, have been associated with this complication. For this reason, radiologic findings of intestinal pneumatosis and/or secondary perforation during patient follow-up should be carefully interpreted. The clinical-analytical findings should always be considered. We report a case associated with the use of tyrosine kinase inhibitors in order to illustrate this point.


Asunto(s)
Antineoplásicos/efectos adversos , Neumatosis Cistoide Intestinal/complicaciones , Neumoperitoneo/etiología , Inhibidores de Proteínas Quinasas/efectos adversos , Pirimidinas/efectos adversos , Sulfonamidas/efectos adversos , Anciano , Antineoplásicos/uso terapéutico , Carcinoma de Células Renales/complicaciones , Carcinoma de Células Renales/tratamiento farmacológico , Humanos , Indazoles , Neoplasias Renales/complicaciones , Neoplasias Renales/tratamiento farmacológico , Masculino , Neumatosis Cistoide Intestinal/diagnóstico por imagen , Neumoperitoneo/diagnóstico por imagen , Neumoperitoneo/terapia , Inhibidores de Proteínas Quinasas/uso terapéutico , Pirimidinas/uso terapéutico , Sulfonamidas/uso terapéutico , Tomografía Computarizada por Rayos X
8.
JTCVS Open ; 17: 306-319, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38420534

RESUMEN

Objective: The impact of conduit dimensions and location of esophagogastric anastomosis on long-term quality of life after esophagectomy remains unexplored. We investigated the association of these parameters with surgical outcomes and patient-reported quality of life at least 18 months after esophagectomy. Methods: We identified all patients who underwent esophagectomy for cancer from 2018 to 2020 in our institution. We reviewed each patient's initial postoperative computed tomography scan measuring the gastric conduit's greatest width (centimeters), linear staple line length (centimeters), and relative location of esophagogastric anastomosis (vertebra). Quality of life was ascertained using patient-reported outcome measures. Perioperative complications, length of stay, and mortality were collected. Multivariate regressions were performed. Results: Our study revealed that a more proximal anastomosis was linked to an increased risk of pulmonary complications, a lower recurrence rate, and greater long-term insomnia. Increased maximum intrathoracic conduit width was significantly associated with trouble enjoying meals and reflux long term after esophagectomy. A longer conduit stapled line correlated with fewer issues related to insomnia, improved appetite, less dysphagia, and significantly enhanced "social," "role," and "physical'" aspects of the patient's long-term quality of life. Conclusions: The dimensions of the gastric conduit and the height of the anastomosis may be independently associated with outcomes and long-term quality of life after esophagectomy for cancer.

9.
Elife ; 132024 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-38386406

RESUMEN

Blindness affects millions of people around the world. A promising solution to restoring a form of vision for some individuals are cortical visual prostheses, which bypass part of the impaired visual pathway by converting camera input to electrical stimulation of the visual system. The artificially induced visual percept (a pattern of localized light flashes, or 'phosphenes') has limited resolution, and a great portion of the field's research is devoted to optimizing the efficacy, efficiency, and practical usefulness of the encoding of visual information. A commonly exploited method is non-invasive functional evaluation in sighted subjects or with computational models by using simulated prosthetic vision (SPV) pipelines. An important challenge in this approach is to balance enhanced perceptual realism, biologically plausibility, and real-time performance in the simulation of cortical prosthetic vision. We present a biologically plausible, PyTorch-based phosphene simulator that can run in real-time and uses differentiable operations to allow for gradient-based computational optimization of phosphene encoding models. The simulator integrates a wide range of clinical results with neurophysiological evidence in humans and non-human primates. The pipeline includes a model of the retinotopic organization and cortical magnification of the visual cortex. Moreover, the quantitative effects of stimulation parameters and temporal dynamics on phosphene characteristics are incorporated. Our results demonstrate the simulator's suitability for both computational applications such as end-to-end deep learning-based prosthetic vision optimization as well as behavioral experiments. The modular and open-source software provides a flexible simulation framework for computational, clinical, and behavioral neuroscientists working on visual neuroprosthetics.


Asunto(s)
Fosfenos , Prótesis Visuales , Animales , Humanos , Simulación por Computador , Programas Informáticos , Ceguera/terapia
10.
Curr Opin Microbiol ; 78: 102432, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38325247

RESUMEN

Cyanobacteria evolved the oxygenic photosynthesis to generate organic matter from CO2 and sunlight, and they were responsible for the production of oxygen in the Earth's atmosphere. This made them a model for photosynthetic organisms, since they are easier to study than higher plants. Early studies suggested that only a minority among cyanobacteria might assimilate organic compounds, being considered mostly autotrophic for decades. However, compelling evidence from marine and freshwater cyanobacteria, including toxic strains, in the laboratory and in the field, has been obtained in the last decades: by using physiological and omics approaches, mixotrophy has been found to be a more widespread feature than initially believed. Furthermore, dominant clades of marine cyanobacteria can take up organic compounds, and mixotrophy is critical for their survival in deep waters with very low light. Hence, mixotrophy seems to be an essential trait in the metabolism of most cyanobacteria, which can be exploited for biotechnological purposes.


Asunto(s)
Cianobacterias , Cianobacterias/genética , Cianobacterias/metabolismo , Fotosíntesis/fisiología , Atmósfera , Oxígeno/metabolismo
11.
Clin Genitourin Cancer ; 21(6): e485-e494, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37453915

RESUMEN

Locally advanced prostate cancer comprises approximately 20% of new prostate cancer diagnoses. For these patients, international guidelines recommend treatment with radiotherapy (RT) to the prostate in combination with long-term (2-3 years) androgen deprivation therapy (ADT), or radical prostatectomy in combination with extended pelvic lymph node dissection (PLND) as another treatment option for selected patients as part of multimodal therapy. Improvements in overall survival with docetaxel or an androgen receptor signaling inhibitor have been achieved in patients with metastatic castration sensitive or castration resistant prostate cancer. However, the role of systemic therapy combinations for high risk and/or unfavorable prostate cancer is unclear. In this context, the aim of this review is to assess the current evidence for systemic treatment combinations as part of primary definitive therapy in patients with high-risk localized prostate cancer.


Asunto(s)
Neoplasias de la Próstata , Masculino , Humanos , Neoplasias de la Próstata/patología , Antagonistas de Andrógenos/uso terapéutico , Docetaxel , Terapia Combinada
12.
Biochim Biophys Acta Bioenerg ; 1864(2): 148954, 2023 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-36563737

RESUMEN

The marine cyanobacterium Prochlorococcus is one of the main primary producers on Earth, which can take up glucose by using the high affinity, multiphasic transporter GlcH. We report here the overexpression of glcH from Prochlorococcus marinus strain SS120 in Escherichia coli. Modeling studies of GlcH using the homologous MelB melibiose transporter from Salmonella enterica serovar Typhimurium showed high conservation at the overall fold. We observed that an important structural interaction, mediated by a strong hydrogen bond between D8 and R141, is conserved in Prochlorococcus, although the corresponding amino acids in MelB from Salmonella are different. Biased docking studies suggested that when glucose reaches the pocket of the transporter and interacts with D8 and R141, the hydrogen bond network in which these residues are involved could be disrupted, favoring a conformational change with the subsequent translocation of the glucose molecule towards the cytoplasmic region of the pmGlcH structure. Based on these theoretical predictions and on the conservation of N117 and W348 in other MelB structures, D8, N117, R141 and W348 were mutated to glycine residues. Their key role in glucose transport was evaluated by glucose uptake assays. N117G and W348G mutations led to 17 % decrease in glucose uptake, while D8G and R141G decreased the glucose transport by 66 % and 92 % respectively. Overall, our studies provide insights into the Prochlorococcus 3D-structure of GlcH, paving the way for further analysis to understand the features which are involved in the high affinity and multiphasic kinetics of this transporter.


Asunto(s)
Proteínas Facilitadoras del Transporte de la Glucosa , Prochlorococcus , Proteínas Facilitadoras del Transporte de la Glucosa/genética , Proteínas Facilitadoras del Transporte de la Glucosa/metabolismo , Prochlorococcus/genética , Prochlorococcus/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Mutagénesis , Escherichia coli/genética , Glucosa/metabolismo
13.
Colloids Surf B Biointerfaces ; 209(Pt 2): 112170, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34740093

RESUMEN

Natural nasal spray formulations were prepared by using Zingiber officinalis (Z. officinalis) extract and citral synergically loaded into specifically designed phospholipid vesicles. Phospholipid vesicles were selected according to their stabilizing effect on the nasal mucosal barrier, and their effectiveness was further potentiated by the co-loading of Z. officinalis extract as antioxidant and anti-inflammatory agent, and citral as antibacterial molecule. Cryo-TEM images confirmed the formation of morphologically homogeneous and small vesicles, sized around 100 nm, negatively charged (-44 mV) and highly biocompatible (viability ≥100%) as detected by using epithelial cells. The analysis of size distribution of sprayed droplets, average velocity module and spray cone angle suggested a good aptitude of the vesicles to be nebulized and their effective deposition in the nasal cavity. Moreover, vesicles were effectively capable of inhibiting some nasal pathogenic bacteria (i.e. Streptococcus pyogenes, Staphylococcus aureus, Escherichia coli) and to protect the epithelial cells against oxidative damage. The formulations are natural and safe, and all of them have shown promising technological and biological properties suggesting their possible application in the nasal cavity for the treatment of congestions and non-allergic rhinitis.


Asunto(s)
Antioxidantes , Fosfolípidos , Monoterpenos Acíclicos , Extractos Vegetales/farmacología
14.
Front Oncol ; 12: 891886, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35912190

RESUMEN

Background: Intermediate-risk prostate cancer (PCa) is usually treated by a combination of external beam radiation therapy (EBRT) and a short course of androgen deprivation therapy (ADT). ADT is associated with multiple side effects, including weight gain, loss of libido, and hot flashes. In contrast, anti-androgen monotherapy is generally better tolerated in spite of higher rates of gynecomastia. Objective: This study assessed the effectiveness of enzalutamide monotherapy combined with hypofractionated EBRT (Hypo-EBRT) for treating intermediate risk prostate cancer. Method: This trial was a multicenter, open-label phase II study of 6 months of enzalutamide monotherapy combined with Hypo-EBRT for intermediate-risk prostate cancer. Hypo-EBRT was initiated 8-12 weeks after initiating enzalutamide. The primary endpoint was PSA decline >80% measured at the 25th week of enzalutamide administration. Secondary end-points included assessment of toxicity, changes in anthropomorphic body measurements, sexual hormones, and metabolic changes. Results: Sixty-two patients were included in the study from January 2018 to February 2020. A PSA decline of >80% was observed in all evaluable patients at the end of enzalutamide treatment and 92% achieved PSA values under 0.1 ngr/ml. All patients remain in PSA response (<80% reduction of the initial values) 6 months after the end of enzalutamide treatment. The most frequent adverse events were hypertension, asthenia, and gynecomastia. There were no significant changes in bone density, body mass index (BMI), or patient-reported outcomes (PROs). Conclusion: Enzalutamide monotherapy is very effective along with hEBRT in reducing PSA levels for patients with intermediate-risk prostate cancer. Longer follow-up is needed to confirm the potential use of this combination in future randomized trials.

15.
Microbiol Spectr ; 10(4): e0018722, 2022 08 31.
Artículo en Inglés | MEDLINE | ID: mdl-35852322

RESUMEN

Marine Synechococcus, together with Prochlorococcus, contribute to a significant proportion of the primary production on Earth. The spatial distribution of these two groups of marine picocyanobacteria depends on different factors such as nutrient availability and temperature. Some Synechococcus ecotypes thrive in mesotrophic and moderately oligotrophic waters, where they exploit both oxidized and reduced forms of nitrogen. Here, we present a comprehensive study, which includes transcriptomic and proteomic analyses of the response of Synechococcus sp. strain WH7803 to nanomolar concentrations of nitrate, compared to micromolar ammonium or nitrogen starvation. We found that Synechococcus has a specific response to a nanomolar nitrate concentration that differs from the response shown under nitrogen starvation or the presence of standard concentrations of either ammonium or nitrate. This fact suggests that the particular response to the uptake of nanomolar concentrations of nitrate could be an evolutionary advantage for marine Synechococcus against Prochlorococcus in the natural environment. IMPORTANCE Marine Synechococcus are a very abundant group of photosynthetic organisms on our planet. Previous studies have shown blooms of these organisms when nanomolar concentrations of nitrate become available. We have assessed the effect of nanomolar nitrate concentrations by studying the transcriptome and proteome of Synechococcus sp. WH7803, together with some physiological parameters. We found evidence that Synechococcus sp. strain WH7803 does sense and react to nanomolar concentrations of nitrate, suggesting the occurrence of specific adaptive mechanisms to allow their utilization. Thus, very low concentrations of nitrate in the ocean seem to be a significant nitrogen source for marine picocyanobacteria.


Asunto(s)
Compuestos de Amonio , Prochlorococcus , Synechococcus , Nitratos , Nitrógeno , Proteómica , Agua de Mar
16.
Front Med (Lausanne) ; 9: 874307, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35872778

RESUMEN

Background: Autopsies can shed light on the pathogenesis of new and emerging diseases. Aim: To describe needle core necropsy findings of the lung, heart, and liver in decedents with COVID-19. Material: Cross-sectional study of needle core necropsies in patients who died with virologically confirmed COVID-19. Histopathological analyses were performed, and clinical data and patient course evaluated. Results: Chest core necropsies were performed in 71 decedents with a median age of 81 years (range 52-97); 47 (65.3%) were men. The median interval from symptoms onset to death was 17.5 days (range 1-84). Samples of lung (n = 62, 87.3%), heart (n = 48, 67.6%) and liver (n = 39, 54.9%) were obtained. Fifty-one lung samples (82.3%) were abnormal: 19 (30.6%) showed proliferative diffuse alveolar damage (DAD), 12 (19.4%) presented exudative DAD, and 10 (16.1%) exhibited proliferative plus exudative DAD. Of the 46 lung samples tested for SARS-CoV-19 by RT-PCR, 39 (84.8%) were positive. DAD was associated with premortem values of lactate dehydrogenase of 400 U/L or higher [adjusted odds ratio (AOR) 21.73; 95% confidence interval (CI) 3.22-146] and treatment with tocilizumab (AOR 6.91; 95% CI 1.14-41.7). Proliferative DAD was associated with an onset-to-death interval of over 15 days (AOR 7.85, 95% CI 1.29-47.80). Twenty-three of the 48 (47.9%) heart samples were abnormal: all showed fiber hypertrophy, while 9 (18.8%) presented fibrosis. Of the liver samples, 29/39 (74.4%) were abnormal, due to steatosis (n = 12, 30.8%), cholestasis (n = 6, 15.4%) and lobular central necrosis (n = 5, 12.8%). Conclusion: Proliferative DAD was the main finding on lung core needle necropsy in people who died from COVID-19; this finding was related to a longer disease course. Changes in the liver and heart were common.

17.
Annu Int Conf IEEE Eng Med Biol Soc ; 2021: 3378-3381, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34891964

RESUMEN

Retinal models are needed to simulate the translation of visual percepts to Retinal Ganglion Cells (RGCs) neural spike trains, through which visual information is transmitted to the brain. Restoring vision through neural prostheses motivates the development of accurate retinal models. We integrate biologically-inspired image features to RGC models. We trained Linear-Nonlinear models using response data from biological retinae. We show that augmenting raw image input with retina-inspired image features leads to performance improvements: in a smaller (30sec. of retina recordings) set integration of features leads to improved models in approximately $\frac{2}{3}$ of the modeled RGCS; in a larger (4min. recording) we show that utilizing Spike Triggered Average analysis to localize RGCs in input images and extract features in a cell-based manner leads to improved models in all (except two) of the modeled RGCs.


Asunto(s)
Retina , Células Ganglionares de la Retina , Visión Ocular
18.
Annu Int Conf IEEE Eng Med Biol Soc ; 2021: 4293-4296, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34892171

RESUMEN

Challenges in the field of retinal prostheses motivate the development of retinal models to accurately simulate Retinal Ganglion Cells (RGCs) responses. The goal of retinal prostheses is to enable blind individuals to solve complex, reallife visual tasks. In this paper, we introduce the functional assessment (FA) of retinal models, which describes the concept of evaluating the performance of retinal models on visual understanding tasks. We present a machine learning method for FA: we feed traditional machine learning classifiers with RGC responses generated by retinal models, to solve object and digit recognition tasks (CIFAR-10, MNIST, Fashion MNIST, Imagenette). We examined critical FA aspects, including how the performance of FA depends on the task, how to optimally feed RGC responses to the classifiers and how the number of output neurons correlates with the model's accuracy. To increase the number of output neurons, we manipulated input images - by splitting and then feeding them to the retinal model and we found that image splitting does not significantly improve the model's accuracy. We also show that differences in the structure of datasets result in largely divergent performance of the retinal model (MNIST and Fashion MNIST exceeded 80% accuracy, while CIFAR-10 and Imagenette achieved ∼40%). Furthermore, retinal models which perform better in standard evaluation, i.e. more accurately predict RGC response, perform better in FA as well. However, unlike standard evaluation, FA results can be straightforwardly interpreted in the context of comparing the quality of visual perception.


Asunto(s)
Retina , Prótesis Visuales , Humanos , Aprendizaje Automático , Células Ganglionares de la Retina , Visión Ocular
19.
Antioxidants (Basel) ; 10(7)2021 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-34356342

RESUMEN

A total green nanotechnological nasal spray has been manufactured and proposed as an alternative treatment of rhinitis and rhinosinusitis. It was obtained by combining the strengthening effect of liposomes on barrier function, the hydrating and lubricating properties of sodium hyaluronan and the anti-inflammatory and antioxidant activities of the extract of Zingiber officinalis. To this purpose, the extract was loaded in special phospholipid vesicles immobilized with hyaluronic acid (hyalurosomes), which were further enriched with glycerol in the water phase. Liposomes and glycerosomes were prepared as well and used as reference. Vesicles were oligolamellar and multicompartment, as confirmed by cryogenic transmission electron microscopy (cryo-TEM) observation, small in size (~140 nm) and negatively charged (~-23 mV). Spray characteristics were evaluated by using the Spraytec® and instant images, from which the plume angle was measured. The range of the droplet size distribution and the narrow spray angle obtained suggest a good nebulization and a possible local deposition in the nasal cavity. In vitro studies performed by using human keratinocytes confirmed the high biocompatibility of vesicles and their ability to effectively counteract oxidative damage on cells induced by hydrogen peroxide. The overall collected data suggest that our vesicles are suitable as nasal spray.

20.
J Clin Invest ; 131(23)2021 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-34665780

RESUMEN

BACKGROUNDA long-held goal of vision therapy is to transfer information directly to the visual cortex of blind individuals, thereby restoring a rudimentary form of sight. However, no clinically available cortical visual prosthesis yet exists.METHODSWe implanted an intracortical microelectrode array consisting of 96 electrodes in the visual cortex of a 57-year-old person with complete blindness for a 6-month period. We measured thresholds and the characteristics of the visual percepts elicited by intracortical microstimulation.RESULTSImplantation and subsequent explantation of intracortical microelectrodes were carried out without complications. The mean stimulation threshold for single electrodes was 66.8 ± 36.5 µA. We consistently obtained high-quality recordings from visually deprived neurons and the stimulation parameters remained stable over time. Simultaneous stimulation via multiple electrodes was associated with a significant reduction in thresholds (P < 0.001, ANOVA) and evoked discriminable phosphene percepts, allowing the blind participant to identify some letters and recognize object boundaries.CONCLUSIONSOur results demonstrate the safety and efficacy of chronic intracortical microstimulation via a large number of electrodes in human visual cortex, showing its high potential for restoring functional vision in the blind.TRIAL REGISTRATIONClinicalTrials.gov identifier NCT02983370.FUNDINGThe Spanish Ministerio de Ciencia Innovación y Universidades, the Generalitat Valenciana (Spain), the Europan Union's Horizon 2020 programme, the Bidons Egara Research Chair of the University Miguel Hernández (Spain), and the John Moran Eye Center of the University of Utah.


Asunto(s)
Ceguera/cirugía , Microelectrodos , Lóbulo Occipital/fisiopatología , Enfermedades del Nervio Óptico/cirugía , Percepción Visual , Prótesis Visuales , Estimulación Eléctrica/métodos , Electrodos Implantados , Femenino , Humanos , Persona de Mediana Edad , Lóbulo Occipital/cirugía , Fosfenos , Retina/fisiología , Resultado del Tratamiento , Visión Ocular , Corteza Visual/fisiopatología , Corteza Visual/cirugía
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