Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
3,160
result(s) for
"Lopes, Pedro"
Sort by:
Single-cell roadmap of human gonadal development
2022
Gonadal development is a complex process that involves sex determination followed by divergent maturation into either testes or ovaries
1
. Historically, limited tissue accessibility, a lack of reliable in vitro models and critical differences between humans and mice have hampered our knowledge of human gonadogenesis, despite its importance in gonadal conditions and infertility. Here, we generated a comprehensive map of first- and second-trimester human gonads using a combination of single-cell and spatial transcriptomics, chromatin accessibility assays and fluorescent microscopy. We extracted human-specific regulatory programmes that control the development of germline and somatic cell lineages by profiling equivalent developmental stages in mice. In both species, we define the somatic cell states present at the time of sex specification, including the bipotent early supporting population that, in males, upregulates the testis-determining factor
SRY
and sPAX8s, a gonadal lineage located at the gonadal–mesonephric interface. In females, we resolve the cellular and molecular events that give rise to the first and second waves of granulosa cells that compartmentalize the developing ovary to modulate germ cell differentiation. In males, we identify human
SIGLEC15
+
and
TREM2
+
fetal testicular macrophages, which signal to somatic cells outside and inside the developing testis cords, respectively. This study provides a comprehensive spatiotemporal map of human and mouse gonadal differentiation, which can guide in vitro gonadogenesis.
This study provides a comprehensive spatiotemporal map of human and mouse gonadal differentiation, using a combination of single-cell and spatial transcriptomics, chromatin accessibility assays and fluorescent microscopy, which can guide in vitro gonadogenesis.
Journal Article
Molecular modeling and dynamics studies with explicit inclusion of electronic polarizability: theory and applications
by
Roux, Benoit
,
MacKerell, Alexander D
,
Lopes, Pedro E. M
in
Alkanes
,
Amoeba
,
Charged particles
2009
A current emphasis in empirical force fields is on the development of potential functions that explicitly treat electronic polarizability. In the present article, the commonly used methodologies for modeling electronic polarization are presented along with an overview of selected application studies. Models presented include induced point-dipoles, classical Drude oscillators, and fluctuating charge methods. The theoretical background of each method is followed by an introduction to extended Lagrangian integrators required for computationally tractable molecular dynamics simulations using polarizable force fields. The remainder of the review focuses on application studies using these methods. Emphasis is placed on water models, for which numerous examples exist, with a more thorough discussion presented on the recently published models associated with the Drude-based CHARMM and the AMOEBA force fields. The utility of polarizable models for the study of ion solvation is then presented followed by an overview of studies of small molecules (e.g., CCl4, alkanes, etc.) and macromolecule (proteins, nucleic acids and lipid bilayers) application studies. The review is written with the goal of providing a general overview of the current status of the field and to facilitate future application and developments.
Journal Article
Patient reported outcomes in oncology: changing perspectives—a systematic review
by
Silveira, Augusta
,
Lopes Ferreira, Pedro
,
Gonçalves, Joaquim
in
Advance directives
,
Cancer
,
Care and treatment
2022
In public health context, oncology is associated with severe negative impact on patients and on their relatives’ quality of life. Over the last decades, survival has remained at 50% worldwide for some tumor locations. Patient reported outcomes (PROs) assessment and, the corresponding use in clinical practice, help establishing patient individualized profiling involving caregivers. The purpose of this systematic review was to examine critical success factors for PROs assessment in daily clinical oncology practice. Additionally, we investigated how PROs collection can change oncology perspectives for patients and caregivers. According to PRISMA guidelines, 83 studies were included in this systematic review, whether related with implementation in daily clinical practice or associated with its use in oncology. PROs assessment gathers multi-professional teams, biomedical and clinical expertise, patients, families and caregivers. Institutional involvement, first line for caregiver’s adherence, team continuous formation, encompassing training and support, design of clear workflows, continuous monitoring, and data analysis are crucial for implementation. PROs measures are decisive in oncology. Several items were improved, including caregiver–patient–physician communication, patient risk groups identification, unmet problems and needs detection, disease course and treatment tracking, prognostic markers, cost-effectiveness measurement and comfort/support provision for both patients and caregivers. Routine assessment and implementation of PROs in clinical practice are a major challenge and a paradigm transformation for future.
Journal Article
An emergency system for monitoring pulse oximetry, peak expiratory flow, and body temperature of patients with COVID-19 at home: Development and preliminary application
by
Borguezan, Bruno Max
,
Melo, Pedro Lopes de
,
Milagres, Lucimar Gonçalves
in
Adult
,
Analysis
,
Asthma
2021
COVID-19 is characterized by a rapid change in the patient's condition, with major changes occurring over a few days. We aimed to develop and evaluate an emergency system for monitoring patients with COVID-19, which may be useful in hospitals where more severe patients stay in their homes.
The system consists of the home-based patient unit, which is set up around the patient and the hospital unit, which enables the medical staff to telemonitor the patient's condition and help to send medical recommendations. The home unit allows the data transmission from the patient to the hospital, which is performed using a cell phone application. The hospital unit includes a virtual instrument developed in LabVIEW® environment that can provide a real-time monitoring of the oxygen saturation (SpO2), beats per minute (BPM), body temperature (BT), and peak expiratory flow (PEF). Abnormal events may be fast and automatically identified. After the design details are described, the system is validated by a 30-day home monitoring study in 12 controls and 12 patients with COVID-19 presenting asymptomatic to mild disease. Patients presented reduced SpO2 (p<0.0001) and increased BPM values (p<0.0001). Three patients (25%) presented PEF values between 50 and 80% of the predicted. Three of the 12 monitored patients presented events of desaturation (SpO2<92%). The experimental results were in close agreement with the involved pathophysiology, providing clear evidence that the proposed system can be a useful tool for the remote monitoring of patients with COVID-19.
An emergency system for home monitoring of patients with COVID-19 was developed in the current study. The proposed system allowed us to quickly respond to early abnormalities in these patients. This system may contribute to conserving hospital resources for those most in need while simultaneously enabling early recognition of patients under acute deterioration, requiring urgent assessment.
Journal Article
Risk factors for hospital death in conditions needing palliative care: Nationwide population-based death certificate study
2018
Background: Most people would prefer to die at home as opposed to hospital; therefore, understanding mortality patterns by place of death is essential for health resources allocation. Aim: We examined trends and risk factors for hospital death in conditions needing palliative care in a country without integrated palliative care. Design: This is a death certificate study. We examined factors associated with hospital death using logistic regression. Setting/participants: All adults (1,045,381) who died between 2003 and 2012 in Portugal were included. We identified conditions needing palliative care from main causes of death: cancer, heart/cerebrovascular, renal, liver, respiratory and neurodegenerative diseases, dementia/Alzheimer's/senility and HIV/AIDS. Results: Conditions needing palliative care were responsible for 70.7% deaths (N = 738,566, median age 80); heart and cerebrovascular diseases (43.9%) and cancer (32.2%) accounted for most. There was a trend towards hospital death (standardised percentage: 56.3% in 2003, 66.7% in 2012; adjusted odds ratio: 1.04, 95% confidence interval: 1.04-1.04). Hospital death risk was higher for those aged 18-39 years (3.46, 3.25-3.69 vs aged 90+), decreasing linearly with age; lower in dementia/Alzheimer's/senility versus cancer (0.13, 0.13-0.13); and higher for the married and in HIV/AIDS (3.31, 3.00-3.66). Effects of gender, working status, weekday and month of death, hospital beds availability, urbanisation level and deprivation were small. Conclusion: The upward hospital death trend and fact that being married are risk factors for hospital death suggest that a reliance on hospitals may coexist with a tradition of extended family support. The sustainability of this model needs to be assessed within the global transition pattern in where people die.
Journal Article
XAI Systems Evaluation: A Review of Human and Computer-Centred Methods
by
Oliveira, Tiago
,
Silva, Eduardo
,
Braga, Cristiana
in
computer-centred
,
evaluation methods
,
explainable artificial intelligence
2022
The lack of transparency of powerful Machine Learning systems paired with their growth in popularity over the last decade led to the emergence of the eXplainable Artificial Intelligence (XAI) field. Instead of focusing solely on obtaining highly performing models, researchers also develop explanation techniques that help better understand the system’s reasoning for a particular output. An explainable system can be designed, developed, and evaluated from different perspectives, which enables researchers from different disciplines to work together on this topic. However, the multidisciplinary nature of XAI systems creates new challenges for condensing and structuring adequate methodologies to design and evaluate such systems. This paper presents a survey of Human-centred and Computer-centred methods to evaluate XAI systems. We propose a new taxonomy to categorize XAI evaluation methods more clearly and intuitively. This categorization gathers knowledge from different disciplines and organizes the evaluation methods according to a set of categories that represent key properties of XAI systems. Possible ways to use the proposed taxonomy in the design and evaluation of XAI systems are also discussed, alongside with some concluding remarks and future directions of research.
Journal Article
Smoothness and long time existence for solutions of the Cahn–Hilliard equation on manifolds with conical singularities
2022
We consider the Cahn–Hilliard equation on manifolds with conical singularities. For appropriate initial data we show that the solution exists in the maximal Lq -regularity space for all times and becomes instantaneously smooth in space and time, where the maximal Lq -regularity is obtained in the sense of Mellin–Sobolev spaces. Moreover, we provide precise information concerning the asymptotic behavior of the solution close to the conical tips in terms of the local geometry.
Journal Article
Measuring lung water adds prognostic value in heart failure patients undergoing cardiac magnetic resonance
2021
To assess whether a simplified cardiac magnetic resonance (CMR)–derived lung water density (LWD) quantification predicted major events in Heart Failure (HF). Single-centre retrospective study of consecutive HF patients with left ventricular ejection fraction (LVEF) < 50% who underwent CMR. All measurements were performed on HASTE sequences in a parasagittal plane at the right midclavicular line. LWD was determined by the lung-to-liver signal ratio multiplied by 0.7. A cohort of 102 controls was used to derive the LWD upper limit of normal (21.2%). The primary endpoint was a composite of time to all-cause death or HF hospitalization. Overall, 290 patients (mean age 64 ± 12 years) were included. LWD measurements took on average 35 ± 4 s, with good inter-observer reproducibility. LWD was increased in 65 (22.4%) patients, who were more symptomatic (NYHA ≥ III 29.2 vs. 1.8%;
p
= 0.017) and had higher NT-proBNP levels [1973 (IQR: 809–3766) vs. 802 (IQR: 355–2157 pg/mL);
p
< 0.001]. During a median follow-up of 21 months, 20 patients died and 40 had ≥ 1 HF hospitalization. In multivariate analysis, NYHA (III–IV vs. I–II; HR: 2.40; 95%-CI: 1.30–4.43;
p
= 0.005), LVEF (HR per 1%: 0.97; 95%-CI: 0.94–0.99;
p
= 0.031), serum creatinine (HR per 1 mg/dL: 2.51; 95%-CI: 1.36–4.61;
p
= 0.003) and LWD (HR per 1%: 1.07; 95%-CI: 1.02–1.12;
p
= 0.007) were independent predictors of the primary endpoint. These findings were mainly driven by an association between LWD and HF hospitalization (
p
= 0.026). A CMR-derived LWD quantification was independently associated with an increased HF hospitalization risk in HF patients with LVEF < 50%. LWD is a simple, reproducible and straightforward measurement, with prognostic value in HF.
Journal Article
Cardiac magnetic resonance patterns of left ventricular remodeling in patients with severe aortic stenosis referred to surgical aortic valve replacement
2024
Left ventricular (LV) hypertrophy is a common finding in patients with severe aortic stenosis (AS). Cardiac magnetic resonance (CMR) is the gold-standard technique to evaluate LV remodeling. Our aim was to assess the prevalence and describe the patterns of LV adaptation in AS patients before and after surgical aortic valve replacement (AVR). Prospective study of 130 consecutive patients (71y [IQR 68–77y], 48% men) with severe AS, referred for surgical AVR. Patterns of LV remodeling were assessed by CMR. Besides normal LV ventricular structure, four other patterns were considered: concentric remodeling, concentric hypertrophy, eccentric hypertrophy, and adverse remodeling. At baseline CMR study: mean LV indexed mass: 81.8 ± 26.7 g/m
2
; mean end-diastolic LV indexed volume: 85.7 ± 23.1 mL/m
2
and median geometric remodeling ratio: 0.96 g/mL [IQR 0.82–1.08 g/mL]. LV hypertrophy occurred in 49% of subjects (concentric 44%; eccentric 5%). Both normal LV structure and concentric remodeling had a prevalence of 25% among the cohort; one patient had an adverse remodeling pattern. Asymmetric LV wall thickening was present in 55% of the patients, with predominant septal involvement. AVR was performed in 119 patients. At 3–6 months after AVR, LV remodeling changed to: normal ventricular geometry in 60%, concentric remodeling in 27%, concentric hypertrophy in 10%, eccentric hypertrophy in 3% and adverse remodeling (one patient). Indexes of AS severity, LV systolic and diastolic function and NT-proBNP were significantly different among the distinct patterns of remodeling. Several distinct patterns of LV remodelling beyond concentric hypertrophy occur in patients with classical severe AS. Asymmetric hypertrophy is a common finding and LV response after AVR is diverse.
Journal Article
Evasion of Immune Surveillance in Low Oxygen Environments Enhances Candida albicans Virulence
2018
Successful human colonizers have evolved mechanisms to bypass immune surveillance. Infiltration of PMNs to the site of infection led to the generation of a low oxygen niche. Exposure to low oxygen levels induced fungal cell wall masking, which in turn hindered pathogen sensing and antifungal responses by PMNs. The cell wall masking effect was prolonged by increasing lactate amounts produced by neutrophil metabolism under oxygen deprivation. In an invertebrate infection model, C. albicans was able to kill infected C. elegans nematodes within 2 days under low oxygen conditions, whereas the majority of uninfected controls and infected worms under normoxic conditions survived. These results suggest that C. albicans benefited from low oxygen niches to increase virulence. The interplay of C. albicans with innate immune cells under these conditions contributed to the overall outcome of infection. Adaption to low oxygen levels was in addition beneficial for C. albicans by reducing susceptibility to selected antifungal drugs. Hence, immunomodulation of host cells under low oxygen conditions could provide a valuable approach to improve current antifungal therapies. Microbial colonizers of humans have evolved to adapt to environmental cues and to sense nutrient availability. Oxygen is a constantly changing environmental parameter in different host tissues and in different types of infection. We describe how Candida albicans , an opportunistic fungal pathogen, can modulate the host response under hypoxia and anoxia. We found that high infiltration of polymorphonuclear leukocytes (PMNs) to the site of infection contributes to a low oxygen milieu in a murine subdermal abscess. A persistent hypoxic environment did not affect viability or metabolism of PMNs. Under oxygen deprivation, however, infection with C. albicans disturbed specific PMN responses. PMNs were not able to efficiently phagocytose, produce ROS, or release extracellular DNA traps. Failure to launch an adequate response was caused by C. albicans cell wall masking of β-glucan upon exposure to low oxygen levels which hindered PAMP sensing by Dectin-1 on the surfaces of PMNs. This in turn contributed to immune evasion and enhanced fungal survival. The cell wall masking effect is prolonged by the accumulation of lactate produced by PMNs under low oxygen conditions. Finally, adaptation to oxygen deprivation increased virulence of C. albicans which we demonstrated using a Caenorhabditis elegans infection model. IMPORTANCE Successful human colonizers have evolved mechanisms to bypass immune surveillance. Infiltration of PMNs to the site of infection led to the generation of a low oxygen niche. Exposure to low oxygen levels induced fungal cell wall masking, which in turn hindered pathogen sensing and antifungal responses by PMNs. The cell wall masking effect was prolonged by increasing lactate amounts produced by neutrophil metabolism under oxygen deprivation. In an invertebrate infection model, C. albicans was able to kill infected C. elegans nematodes within 2 days under low oxygen conditions, whereas the majority of uninfected controls and infected worms under normoxic conditions survived. These results suggest that C. albicans benefited from low oxygen niches to increase virulence. The interplay of C. albicans with innate immune cells under these conditions contributed to the overall outcome of infection. Adaption to low oxygen levels was in addition beneficial for C. albicans by reducing susceptibility to selected antifungal drugs. Hence, immunomodulation of host cells under low oxygen conditions could provide a valuable approach to improve current antifungal therapies.
Journal Article