41 research outputs found
Mechanisms of human telomerase reverse transcriptase (hTERT) regulation: clinical impacts in cancer
Background
Limitless self-renewal is one of the hallmarks of cancer and is attained by telomere maintenance, essentially through telomerase (hTERT) activation. Transcriptional regulation of hTERT is believed to play a major role in telomerase activation in human cancers.
Main body
The dominant interest in telomerase results from its role in cancer. The role of telomeres and telomere maintenance mechanisms is well established as a major driving force in generating chromosomal and genomic instability. Cancer cells have acquired the ability to overcome their fate of senescence via telomere length maintenance mechanisms, mainly by telomerase activation.
hTERT expression is up-regulated in tumors via multiple genetic and epigenetic mechanisms including hTERT amplifications, hTERT structural variants, hTERT promoter mutations and epigenetic modifications through hTERT promoter methylation. Genetic (hTERT promoter mutations) and epigenetic (hTERT promoter methylation and miRNAs) events were shown to have clinical implications in cancers that depend on hTERT activation. Knowing that telomeres are crucial for cellular self-renewal, the mechanisms responsible for telomere maintenance have a crucial role in cancer diseases and might be important oncological biomarkers. Thus, rather than quantifying TERT expression and its correlation with telomerase activation, the discovery and the assessment of the mechanisms responsible for TERT upregulation offers important information that may be used for diagnosis, prognosis, and treatment monitoring in oncology. Furthermore, a better understanding of these mechanisms may promote their translation into effective targeted cancer therapies.
Conclusion
Herein, we reviewed the underlying mechanisms of hTERT regulation, their role in oncogenesis, and the potential clinical applications in telomerase-dependent cancers.info:eu-repo/semantics/publishedVersio
Geoeconomic variations in epidemiology, ventilation management, and outcomes in invasively ventilated intensive care unit patients without acute respiratory distress syndrome: a pooled analysis of four observational studies
Background: Geoeconomic variations in epidemiology, the practice of ventilation, and outcome in invasively ventilated intensive care unit (ICU) patients without acute respiratory distress syndrome (ARDS) remain unexplored. In this analysis we aim to address these gaps using individual patient data of four large observational studies. Methods: In this pooled analysis we harmonised individual patient data from the ERICC, LUNG SAFE, PRoVENT, and PRoVENT-iMiC prospective observational studies, which were conducted from June, 2011, to December, 2018, in 534 ICUs in 54 countries. We used the 2016 World Bank classification to define two geoeconomic regions: middle-income countries (MICs) and high-income countries (HICs). ARDS was defined according to the Berlin criteria. Descriptive statistics were used to compare patients in MICs versus HICs. The primary outcome was the use of low tidal volume ventilation (LTVV) for the first 3 days of mechanical ventilation. Secondary outcomes were key ventilation parameters (tidal volume size, positive end-expiratory pressure, fraction of inspired oxygen, peak pressure, plateau pressure, driving pressure, and respiratory rate), patient characteristics, the risk for and actual development of acute respiratory distress syndrome after the first day of ventilation, duration of ventilation, ICU length of stay, and ICU mortality. Findings: Of the 7608 patients included in the original studies, this analysis included 3852 patients without ARDS, of whom 2345 were from MICs and 1507 were from HICs. Patients in MICs were younger, shorter and with a slightly lower body-mass index, more often had diabetes and active cancer, but less often chronic obstructive pulmonary disease and heart failure than patients from HICs. Sequential organ failure assessment scores were similar in MICs and HICs. Use of LTVV in MICs and HICs was comparable (42\ub74% vs 44\ub72%; absolute difference \u20131\ub769 [\u20139\ub758 to 6\ub711] p=0\ub767; data available in 3174 [82%] of 3852 patients). The median applied positive end expiratory pressure was lower in MICs than in HICs (5 [IQR 5\u20138] vs 6 [5\u20138] cm H2O; p=0\ub70011). ICU mortality was higher in MICs than in HICs (30\ub75% vs 19\ub79%; p=0\ub70004; adjusted effect 16\ub741% [95% CI 9\ub752\u201323\ub752]; p<0\ub70001) and was inversely associated with gross domestic product (adjusted odds ratio for a US$10 000 increase per capita 0\ub780 [95% CI 0\ub775\u20130\ub786]; p<0\ub70001). Interpretation: Despite similar disease severity and ventilation management, ICU mortality in patients without ARDS is higher in MICs than in HICs, with a strong association with country-level economic status. Funding: No funding
Mitochondrial physiology
As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery
Mitochondrial physiology
As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery
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Association of Demographic Factors and Infantile Hemangioma Characteristics with Risk of PHACE Syndrome
Importance: A 2010 prospective study of 108 infants estimated the incidence of PHACE (posterior fossa malformations, hemangioma, arterial anomalies, cardiac defects, eye anomalies) syndrome to be 31% in children with facial infantile hemangiomas (IHs) of at least 22 cm2. There is little evidence regarding the associations among IH characteristics, demographic characteristics, and risk of PHACE syndrome. Objectives: To evaluate demographic characteristics and comorbidities in a large cohort of patients at risk for PHACE syndrome and assess the clinical features of large head and neck IH that may be associated with a greater risk of a diagnosis of PHACE syndrome. Design, Setting, and Participants: This multicenter, retrospective cohort study assessed all patients with a facial, head, and/or neck IH who were evaluated for PHACE syndrome from August 1, 2009, to December 31, 2014, at 13 pediatric dermatology referral centers across North America. Data analysis was performed from June 15, 2017, to February 29, 2020. Main Outcomes and Measures: The main outcome was presence or absence of PHACE syndrome. Data included age at diagnosis, sex, patterns of IH presentation (including size, segment location, and depth), diagnostic procedures and results, and type and number of associated anomalies. Results: A total of 238 patients (mean [SD] age, 2.96 [4.71] months; 184 [77.3%] female) were included in the analysis; 106 (44.5%) met the criteria for definite (n = 98) or possible (n = 8) PHACE syndrome. A stepwise linear regression model found that a surface area of 25 cm2or greater (odds ratio [OR] 2.99; 95% CI, 1.49-6.02) and involvement of 3 or more locations (OR, 17.96; 95% CI, 6.10-52.85) to be statistically significant risk factors for PHACE syndrome. Involvement of the parotid gland (OR, 0.39; 95% CI, 0.18-0.85) and segment S2 (OR, 0.38; 95% CI, 0.16-0.91) was associated with a lower risk. Race and ethnicity may also be associated with PHACE syndrome risk, although more studies are needed. Conclusions and Relevance: This cohort study further described factors associated with both a higher and lower risk of PHACE syndrome. The presence of multiple anatomical sites and large surface area were associated with greater risk, whereas S2 or parotid IHs were associated with lower, but still potential, risk. These findings can help in counseling families and decision-making regarding evaluation of infants with large head and neck IHs.12 month embargo; published online: 16 June 2021This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Occurrence of Pyemotes sp. on Tuta absoluta (Meyrick)
The aim of this work was to study the population reduction of the tomato leafminer moth, Tuta absoluta (Meyrick), by Pyemotes sp. in the laboratory. The mite became greenish when fed on caterpillars, pupae, and adults of T. absoluta. The caterpillars and adults of T. absoluta were quickly paralyzed by the mite venom. A single T. absoluta could host many Pyemotes sp, physogastric females, which were allowed to grow on the moth. Pyemotes sp. can be a new alternative for the biological control of T. absoluta. However, this possibility must be better understood before it could be recommended, because Pyemotes sp. could also cause dermatitis in the humans.<br>O ácaro Pyemotes sp. (Acari: Pyemotidae) é um parasita de várias espécies de insetos e exibe o processo de fisogastria na reprodução. É registrada a ocorrência de Pyemotes sp. sobre a traça-do-tomateiro, Tuta absoluta (Meyrick), que sofreu redução considerável de suas populações em condições de laboratório. Este ácaro foi observado parasitando larvas, pupas e adultos de T. absoluta e suas fêmeas fisogástricas apresentaram coloração esverdeada. As larvas e adultos de T. absoluta atacados por Pyemotes sp. exibiram paralisia em poucos minutos, devido à injeção de toxinas por parte do ácaro. Observou-se que um único indivíduo de T. absoluta pode suportar muitas fêmeas fisogástricas de Pyemotes sp., permitindo que outra geração do ácaro continuasse a se reproduzir. O ácaro Pyemotes sp. surge como uma possibilidade para o controle biológico de T. absoluta, mas sua utilização deve ser melhor avaliada já que é uma espécie causadora de dermatites em humanos
Dalbavancin in the treatment of different gram-positive infections: a real-life experience
Dalbavancin is a lipoglycopeptide with a very prolonged half-life enabling treatment with a single intravenous administration that has been approved to treat complicated skin and soft-tissue infections. Information on the efficacy and safety of dalbavancin in other situations is very scarce. This retrospective study included adult patients who received at least one dose of dalbavancin between 2016 and 2017 in 29 institutions in Spain. The primary objective was to report the use of dalbavancin in clinical practice, including its efficacy and tolerability. The potential impact of dalbavancin on reducing the length of hospital stay and hospital costs was also evaluated. A total of 69 patients received dalbavancin during the study period (58.0% male; median age 63.5 years). Dalbavancin was used to treat prosthetic joint infection (29.0%), acute bacterial skin and skin-structure infection (21.7%), osteomyelitis (17.4%) and catheter-related bacteraemia (11.6%). These infections were mainly caused by Staphylococcus aureus (27 isolates), coagulase-negative staphylococci (24 isolates) and Enterococcus spp. (11 isolates). All but two patients received previous antibiotics for a median of 18 days. Dalbavancin was administered for a median of 21 days (range 7–168 days), and concomitant antimicrobial therapy was prescribed to 25 patients (36.2%). The overall clinical success rate of dalbavancin was 84.1%. Adverse events, mainly mild in intensity, were reported in nine patients. Overall, dalbavancin was estimated to reduce hospitalisation by 1160 days, with an estimated overall cost reduction of €211 481 (€3064 per patient). Dalbavancin appears to be an effective therapy for many serious Gram-positive infections