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1.
Front Physiol ; 14: 1150265, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37057184

RESUMO

In exercise science, the crossover effect denotes that fat oxidation is the primary fuel at rest and during low-intensity exercise with a shift towards an increased reliance on carbohydrate oxidation at moderate to high exercise intensities. This model makes four predictions: First, >50% of energy comes from carbohydrate oxidation at ≥60% of maximum oxygen consumption (VO2max), termed the crossover point. Second, each individual has a maximum fat oxidation capacity (FATMAX) at an exercise intensity lower than the crossover point. FATMAX values are typically 0.3-0.6 g/min. Third, fat oxidation is minimized during exercise ≥85%VO2max, making carbohydrates the predominant energetic substrate during high-intensity exercise, especially at >85%VO2max. Fourth, high-carbohydrate low-fat (HCLF) diets will produce superior exercise performances via maximizing pre-exercise storage of this predominant exercise substrate. In a series of recent publications evaluating the metabolic and performance effects of low-carbohydrate high-fat (LCHF/ketogenic) diet adaptations during exercise of different intensities, we provide findings that challenge this model and these four predictions. First, we show that adaptation to the LCHF diet shifts the crossover point to a higher %VO2max (>80%VO2max) than previously reported. Second, substantially higher FATMAX values (>1.5 g/min) can be measured in athletes adapted to the LCHF diet. Third, endurance athletes exercising at >85%VO2max, whilst performing 6 × 800 m running intervals, measured the highest rates of fat oxidation yet reported in humans. Peak fat oxidation rates measured at 86.4 ± 6.2%VO2max were 1.58 ± 0.33 g/min with 30% of subjects achieving >1.85 g/min. These studies challenge the prevailing doctrine that carbohydrates are the predominant oxidized fuel during high-intensity exercise. We recently found that 30% of middle-aged competitive athletes presented with pre-diabetic glycemic values while on an HCLF diet, which was reversed on LCHF. We speculate that these rapid changes between diet, insulin, glucose homeostasis, and fat oxidation might be linked by diet-induced changes in mitochondrial function and insulin action. Together, we demonstrate evidence that challenges the current crossover concept and demonstrate evidence that a LCHF diet may also reverse features of pre-diabetes and future metabolic disease risk, demonstrating the impact of dietary choice has extended beyond physical performance even in athletic populations.

2.
Rev Sci Instrum ; 91(9): 094701, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33003802

RESUMO

Searches for dark matter axions involve the use of microwave resonant cavities operating in a strong magnetic field. Detector sensitivity is directly related to the cavity quality factor, which is limited, until recently, to the use of non-superconducting metals by the presence of the external magnetic field. In this paper, we present a cavity of novel design whose quality factor is not affected by a magnetic field. It is based on a photonic structure by the use of sapphire rods. The quality factor at cryogenic temperature is in excess of 5 × 105 for a selected mode.

3.
Energy Build ; 229: 110517, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33041474

RESUMO

A great fraction (20-40%) of primary energy is required for building air conditioning, so the use of renewable energy sources is increasing. The geothermal energy for Heating, Ventilating and Air Conditioning (HVAC) systems can be used considering an Earth-to-Air Heat eXchanger (EAHX). This work analyses the performance of an EAHX through a mathematical model (2D), as a function of diameter and length of the air ducts. The problem is solved with finite element method. A case study office building is analyzed. The air conditioning plant is characterized by fan-coil units and primary air; the EAHX is positioned upstream the Air Handling Unit (AHU) to pre-cool/pre-heat the air. The building is virtually placed initially in six Italian cities (different climatic zones according to Italian regulation DPR 412/93) and subsequently in eight worldwide cities according to Köppen climate classification. The following parameters are calculated: air temperature variation and thermal efficiency of the EAHX; the decreasing of cooling and heating capacity of the coils into the AHU. The best results refer to a duct length of 100 m for Ottawa (warm-summer humid continental climate, 65% capacity reduction), the worst ones for Rio de Janeiro (tropical wet and dry climate, maximum 24% reduction).

4.
Phys Rev Lett ; 124(17): 171801, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32412290

RESUMO

A ferromagnetic axion haloscope searches for dark matter in the form of axions by exploiting their interaction with electronic spins. It is composed of an axion-to-electromagnetic field transducer coupled to a sensitive rf detector. The former is a photon-magnon hybrid system, and the latter is based on a quantum-limited Josephson parametric amplifier. The hybrid system consists of ten 2.1 mm diameter yttrium iron garnet spheres coupled to a single microwave cavity mode by means of a static magnetic field. Our setup is the most sensitive rf spin magnetometer ever realized. The minimum detectable field is 5.5×10^{-19} T with 9 h integration time, corresponding to a limit on the axion-electron coupling constant g_{aee}≤1.7×10^{-11} at 95% C.L. The scientific run of our haloscope resulted in the best limit on dark matter axions to electron coupling constant in a frequency span of about 120 MHz, corresponding to the axion-mass range 42.4-43.1 µeV. This is also the first apparatus to perform a wide axion-mass scanning by only changing the static magnetic field.

5.
J Robot Surg ; 14(2): 261-269, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31124038

RESUMO

The aim of the study is to report surgical and early functional outcomes of first 100 patients undergoing robot-assisted radical cystectomy (RARC) with totally intracorporeal urinary diversion (ICUD) in a single center. The main surgeon (A.P.) attended a modular training program at a referring center mentored by a worldwide-recognized robotic surgeon (P.W.). The program consisted of: (a) 10 h of theoretical lessons; (b) video session (c) step-by-step in vivo modular training. Each procedure was performed as taught, without any technique variation. Demographics, intra-operative data and post-operative complications, along with early functional outcomes, were recorded for each patient. We retrospectively evaluated the first consecutive 100 patients submitted to RARC with totally ICUD from July 2015 to December 2018. Median age at surgery was 69 years (IQR 60-74). 52 (52%), 32 (32%), and 17 (17%) patients received orthotopic neobladder, ileal conduit and uretero-cutaneostomy, respectively. Median operative time was 410 min. A median number of lymph nodes retrieved were 27 and median estimated blood loss was 240 mL with median hospitalization time of 7 days. All procedures were completed successfully without open conversion. A statistically significant improvement was found in the late (30-90 post-operative days) post-operative complications (p = 0.02) and operative time for urinary derivation. At multivariate logistic regression model ASA score ≥ 3 (OR = 4.2, p = 0.002) and number of lymph nodes retrieved (OR = 1.16, p = 0.02) were found to be predictors of 90-day complications. An adequate modular training is paramount to obtain successful results and reduce the learning curve of RARC, as demonstrated by our experience.


Assuntos
Cistectomia/educação , Cistectomia/métodos , Curva de Aprendizado , Procedimentos Cirúrgicos Robóticos/educação , Procedimentos Cirúrgicos Robóticos/métodos , Derivação Urinária/educação , Derivação Urinária/métodos , Idoso , Feminino , Humanos , Masculino , Resultado do Tratamento , Neoplasias da Bexiga Urinária/cirurgia
6.
J Fish Biol ; 92(3): 804-827, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29537086

RESUMO

Populations of fishes provide valuable services for billions of people, but face diverse and interacting threats that jeopardize their sustainability. Human population growth and intensifying resource use for food, water, energy and goods are compromising fish populations through a variety of mechanisms, including overfishing, habitat degradation and declines in water quality. The important challenges raised by these issues have been recognized and have led to considerable advances over past decades in managing and mitigating threats to fishes worldwide. In this review, we identify the major threats faced by fish populations alongside recent advances that are helping to address these issues. There are very significant efforts worldwide directed towards ensuring a sustainable future for the world's fishes and fisheries and those who rely on them. Although considerable challenges remain, by drawing attention to successful mitigation of threats to fish and fisheries we hope to provide the encouragement and direction that will allow these challenges to be overcome in the future.


Assuntos
Conservação dos Recursos Naturais/métodos , Pesqueiros , Peixes/fisiologia , Animais , Ecossistema , Peixes/crescimento & desenvolvimento , Dinâmica Populacional , Qualidade da Água
7.
Int. braz. j. urol ; 44(1): 63-68, Jan.-Feb. 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-892940

RESUMO

ABSTRACT Objectives The aim of our study is to present early outcomes of our series of retroperitoneal-RAPN (Robot Assisted Partial Nephrectomy). Materials and methods From September 2010 until December 2015, we performed 81 RAPN procedures (44 at left kidney and 37 at right). Average size was 3cm (1-9). Average PADUA score 7.1 (5-10). Average surgical time (overall and only robot time), ischemia time, blood loss, pathological stage, complications and hospital stay have been recorded. Results All of the cases were completed successfully without any operative complication or surgical conversion. Average surgical time was 177 minutes (75-340). Operative time was 145 minutes (80-300), overall blood loss was 142cc (60-310cc). In 30 cases the pedicle was late clamped with an average ischemia time of 4 minutes (2-7). None of the patient had positive surgical margins at definitive histology (49pT1a, 12pT1b, 3pT2a, 2pT3a). Hospital stay was 3 days (2-7). Conclusions The retroperitoneal robotic partial nephrectomy approach is safe and allows treatment of even quite complex tumors. It also combines the already well known advantages guaranteed by the da Vinci® robotic surgical system, with the advantages of the retroperitoneoscopic approach.


Assuntos
Humanos , Masculino , Feminino , Espaço Retroperitoneal/cirurgia , Procedimentos Cirúrgicos Robóticos/métodos , Neoplasias Renais/cirurgia , Nefrectomia/métodos , Resultado do Tratamento , Pessoa de Meia-Idade
8.
Int Braz J Urol ; 44(1): 63-68, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29211396

RESUMO

OBJECTIVES: The aim of our study is to present early outcomes of our series of retroperitoneal-RAPN (Robot Assisted Partial Nephrectomy). MATERIALS AND METHODS: From September 2010 until December 2015, we performed 81 RAPN procedures (44 at left kidney and 37 at right). Average size was 3cm (1-9). Average PADUA score 7.1 (5-10). Average surgical time (overall and only robot time), ischemia time, blood loss, pathological stage, complications and hospital stay have been recorded. RESULTS: All of the cases were completed successfully without any operative complication or surgical conversion. Average surgical time was 177 minutes (75-340). Operative time was 145 minutes (80-300), overall blood loss was 142cc (60-310cc). In 30 cases the pedicle was late clamped with an average ischemia time of 4 minutes (2-7). None of the patient had positive surgical margins at definitive histology (49pT1a, 12pT1b, 3pT2a, 2pT3a). Hospital stay was 3 days (2-7). CONCLUSIONS: The retroperitoneal robotic partial nephrectomy approach is safe and allows treatment of even quite complex tumors. It also combines the already well known advantages guaranteed by the da Vinci® robotic surgical system, with the advantages of the retroperitoneoscopic approach.


Assuntos
Neoplasias Renais/cirurgia , Nefrectomia/métodos , Espaço Retroperitoneal/cirurgia , Procedimentos Cirúrgicos Robóticos/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
9.
Sci Rep ; 6: 38557, 2016 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-27934898

RESUMO

While Abrikosov vortices repel each other and form a uniform vortex lattice in bulk type-II superconductors, strong confinement potential profoundly affects their spatial distribution eventually leading to vortex cluster formation. The confinement could be induced by the geometric boundaries in mesoscopic-size superconductors or by the spatial modulation of the magnetic field in superconductor/ferromagnet (S/F) hybrids. Here we study the vortex confinement in S/F thin film heterostructures and we observe that vortex clusters appear near magnetization inhomogeneities in the ferromagnet, called bifurcations. We use magnetic force microscopy to image magnetic bifurcations and superconducting vortices, while high resolution scanning tunneling microscopy is used to obtain detailed information of the local electronic density of states outside and inside the vortex cluster. We find an intervortex spacing at the bifurcation shorter than the one predicted for the same superconductor in a uniform magnetic field equal to the thermodynamical upper critical field Hc2. This result is due to a local enhanced stray field and a competition between vortex-vortex repulsion and Lorentz force. Our findings suggest that special magnetic topologies could result in S/F hybrids that support superconductivity even when locally the vortex density exceeds the thermodynamic critical threshold value beyond which the superconductivity is destroyed.

10.
J Nutr Health Aging ; 20(8): 841-844, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27709233

RESUMO

OBJECTIVE: Apolipoprotein E4 (APOE4) genotype has been implicated as a moderating factor in cognitive function studies. Although prior studies have suggested that vitamin C is associated with better cognitive function in elders, link between the two has been mixed. Limited data exist as to whether the APOE4 genotype influences these associations. Therefore, this study sought to determine whether the association between vitamin C and cognition in a rural community dwelling cohort differs by the APOE4 genotype. DESIGN AND PARTICIPANTS: Data were analyzed on 582 participants (n=183 men; n=399 women) from a rural community-based cohort. Cognition was assessed using the Repeatable Battery for the Assessment of Neuropsychological Status and The Executive Interview. APOE genotyping was ascertained by standard methods. The relation between vitamin C supplementation and cognition were analyzed first with ANOVA and then ANCOVA with age, gender, education as covariates. Analyses were initially run in the full sample and then split by APOE4 presence (yes/no). RESULTS: Overall, Vitamin C supplementation was associated with significantly better immediate memory (p=0.04), visuospatial skills (p=0.002), language (p=0.01), and global cognitive functioning (p=0.006). Among APOE4 non-carriers, vitamin C supplementation was positively associated with immediate memory (F[1,392] =6.7, p=0.01), visuospatial skills (F[1,391]=10.6, p=0.001), language (F[1,392]=13.0, p<0.001), attention (F[1,386]=7.9, p=0.005, and global cognition (F[1,382]=11.0, p=0.001. However, there was no significant link between vitamin C supplementation and cognition among APOE4 carriers. CONCLUSION: Vitamin C supplementation was found to be positively associated with cognition among this rural-dwelling community-based sample; however, the associations appeared to differ by APOE4 status. These data may suggest that targeted genotype-specific cognitive enhancement studies are needed to clarify the potential benefits of vitamin C supplementation.


Assuntos
Apolipoproteína E4/uso terapêutico , Ácido Ascórbico/uso terapêutico , Idoso , Apolipoproteína E4/genética , Ácido Ascórbico/administração & dosagem , Cognição , Feminino , Genótipo , Humanos , Masculino , População Rural
11.
Cell Death Dis ; 6: e1823, 2015 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-26181203

RESUMO

The ErbB tyrosine kinase receptor family has been shown to have an important role in tumorigenesis, and the expression of its receptor members is frequently deregulated in many types of solid tumors. Various drugs targeting these receptors have been approved for cancer treatment. Particularly, in breast cancer, anti-Her2/EGFR molecules represent the standard therapy for Her2-positive malignancies. However, in a number of cases, the tumor relapses or progresses thus suggesting that not all cancer cells have been targeted. One possibility is that a subset of cells capable of regenerating the tumor, such as cancer stem cells (CSCs), may not respond to these therapeutic agents. Accumulating evidences indicate that miR-205-5p is significantly downregulated in breast tumors compared with normal breast tissue and acts as a tumor suppressor directly targeting oncogenes such as Zeb1 and ErbB3. In this study, we report that miR-205-5p is highly expressed in BCSCs and represses directly ERBB2 and indirectly EGFR leading to resistance to targeted therapy. Furthermore, we show that miR-205-5p directly regulates the expression of p63 which is in turn involved in the EGFR expression suggesting a miR-205/p63/EGFR regulation.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Receptores ErbB/genética , MicroRNAs/genética , Receptor ErbB-2/genética , Fatores de Transcrição/genética , Proteínas Supressoras de Tumor/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Receptores ErbB/biossíntese , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Lapatinib , MicroRNAs/biossíntese , Terapia de Alvo Molecular , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Quinazolinas/administração & dosagem , Receptor ErbB-2/biossíntese , Fatores de Transcrição/biossíntese , Trastuzumab/administração & dosagem , Proteínas Supressoras de Tumor/biossíntese
12.
PLoS One ; 10(6): e0127407, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26061868

RESUMO

The Warburg effect and tumor hypoxia underlie a unique cancer metabolic phenotype characterized by glucose dependency and aerobic fermentation. We previously showed that two non-toxic metabolic therapies - the ketogenic diet with concurrent hyperbaric oxygen (KD+HBOT) and dietary ketone supplementation - could increase survival time in the VM-M3 mouse model of metastatic cancer. We hypothesized that combining these therapies could provide an even greater therapeutic benefit in this model. Mice receiving the combination therapy demonstrated a marked reduction in tumor growth rate and metastatic spread, and lived twice as long as control animals. To further understand the effects of these metabolic therapies, we characterized the effects of high glucose (control), low glucose (LG), ketone supplementation (ßHB), hyperbaric oxygen (HBOT), or combination therapy (LG+ßHB+HBOT) on VM-M3 cells. Individually and combined, these metabolic therapies significantly decreased VM-M3 cell proliferation and viability. HBOT, alone or in combination with LG and ßHB, increased ROS production in VM-M3 cells. This study strongly supports further investigation into this metabolic therapy as a potential non-toxic treatment for late-stage metastatic cancers.


Assuntos
Dieta Cetogênica , Oxigenoterapia Hiperbárica , Cetonas/administração & dosagem , Metástase Neoplásica/terapia , Neoplasias Experimentais/patologia , Animais , Camundongos
13.
Opt Lett ; 40(4): 653-6, 2015 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-25680173

RESUMO

We report the experimental demonstration of two coupled laser cavities via self-imaging interference in a multimode waveguide. The coupling is optimized by considering images formed by two coherent phase-delayed signals at the input of a 3×3 splitter. As a result, the complex transfer coefficients of the coupling element can be chosen to increase the mode selectivity of the coupled system. A demonstration is given by the successful fabrication of a tunable laser with a side-mode suppression ratio (SMSR) up to 40 dB and a 6.5 nm tuning range. The laser delivers milliwatts of output power to a lensed fiber and is fully compatible with processes supporting vertically-etched sidewalls.

14.
Urol Int ; 94(3): 262-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25171377

RESUMO

OBJECTIVES: To identify the predictive variables affecting the outcome after radical surgery for bladder cancer by a newer statistical methodology, i.e. nonparametric combination (NPC). METHODS: A multicenter study enrolled 1,312 patients who had undergone radical cystectomy for bladder cancer in 11 Italian oncological centers from January 1982 to December 2002. A statistical analysis of their medical history and diagnostic, pathological and postoperative variables was performed using a NPC test. The patients were included in a comprehensive database with medical history and clinical and pathological data. Five-year survival was used as the dependent variable, and p values were corrected for multiplicity using a closed testing procedure. The newer nonparametric approach was used to evaluate the prognostic importance of the variables. All of the analyses were performed using routines developed in MATLAB© and the significance level was set at α = 0.05. RESULTS: A significant prognostic predictive value (p < 0.01) for tumor clinical staging, hydronephrosis, tumor pathological staging, grading, presence of concomitant carcinoma in situ, regional lymph node involvement, corpora cavernosa invasion, microvascular invasion, lymphatic invasion and prostatic stroma involvement was found. CONCLUSIONS: The NPC test could handle any type of variable (categorical and quantitative) and take into account the multivariate relation among variables. This newer methodology offers a significant contribution in biomedical studies with several endpoints and is recommended in presence of non-normal data and missing values, as well as solving high-dimensional data and problems relating to small sample sizes.


Assuntos
Cistectomia/métodos , Avaliação de Resultados da Assistência ao Paciente , Estatística como Assunto , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células de Transição/cirurgia , Interpretação Estatística de Dados , Feminino , Humanos , Hidronefrose/complicações , Itália , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estadiamento de Neoplasias , Valor Preditivo dos Testes , Prognóstico , Próstata/patologia , Estudos Retrospectivos , Estatísticas não Paramétricas , Neoplasias da Bexiga Urinária/cirurgia
15.
Diabetes Obes Metab ; 17(2): 136-44, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25298165

RESUMO

AIMS: To evaluate glucose-lowering treatment strategies with linagliptin and metformin in people with newly diagnosed type 2 diabetes and marked hyperglycaemia, a prevalent population for which few dedicated studies of oral antidiabetes drugs have been conducted. METHODS: A total of 316 patients, with type 2 diabetes diagnosed for ≤12 months and with glycated haemoglobin (HbA1c) concentration in the range 8.5-12.0%, were randomized 1:1 to double-blind, free-combination treatment with linagliptin 5 mg once daily and metformin twice daily (uptitrated to 2000 mg/day maximum) or to linagliptin monotherapy. The primary endpoint was change in HbA1c concentration from baseline at week 24 (per-protocol completers' cohort: n = 245). RESULTS: The mean (standard deviation) age and HbA1c at baseline were 48.8 (11.0) years and 9.8 (1.1)%, respectively. At week 24, the mean ± standard error (s.e.) HbA1c decreased from baseline by -2.8 ± 0.1% with linagliptin/metformin and -2.0 ± 0.1% with linagliptin; a treatment difference of -0.8% (95% confidence interval -1.1 to -0.5; p <0.0001). Similar results were observed in a sensitivity analysis based on intent-to-treat principles: adjusted mean ± s.e. changes in HbA1c of -2.7 ± 0.1% and -1.8 ± 0.1%, respectively; treatment difference of -0.9% (95% CI -1.3 to -0.6; p <0.0001). A treatment response of HbA1c <7.0% was achieved by 61 and 40% of patients in the linagliptin/metformin and linagliptin groups, respectively. Few patients experienced drug-related adverse events (8.8 and 5.7% of patients in the linagliptin/metformin and linagliptin groups, respectively). Hypoglycaemia occurred in 1.9 and 3.2% of patients in the linagliptin/metformin and linagliptin groups, respectively (no severe episodes). Body weight decreased significantly with the combination therapy (-1.3 kg between-group difference; p =0.0033). CONCLUSIONS: Linagliptin in initial combination with metformin in patients with newly diagnosed type 2 diabetes and marked hyperglycaemia, an understudied group, elicited significant improvements in glycaemic control with a low incidence of hypoglycaemia, weight gain or other adverse effects. These results support early combination treatment strategies and suggest that newly diagnosed patients with marked hyperglycaemia may be effectively managed with oral, non-insulin therapy.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores da Dipeptidil Peptidase IV/administração & dosagem , Hiperglicemia/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Metformina/administração & dosagem , Purinas/administração & dosagem , Quinazolinas/administração & dosagem , Glicemia/efeitos dos fármacos , Diabetes Mellitus Tipo 2/sangue , Método Duplo-Cego , Esquema de Medicação , Quimioterapia Combinada , Hemoglobinas Glicadas/efeitos dos fármacos , Humanos , Hiperglicemia/sangue , Cooperação Internacional , Linagliptina , Resultado do Tratamento
16.
Cell Death Dis ; 5: e1336, 2014 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-25032859

RESUMO

A number of studies suggest that cancer stem cells are essential for tumour growth, and failure to target these cells can result in tumour relapse. As this population of cells has been shown to be resistant to radiation and chemotherapy, it is essential to understand their biology and identify new therapeutic approaches. Targeting cancer metabolism is a potential alternative strategy to counteract tumour growth and recurrence. Here we applied a proteomic and targeted metabolomic analysis in order to point out the main metabolic differences between breast cancer cells grown as spheres and thus enriched in cancer stem cells were compared with the same cells grown in adherent differentiating conditions. This integrated approach allowed us to identify a metabolic phenotype associated with the stem-like condition and shows that breast cancer stem cells (BCSCs) shift from mitochondrial oxidative phosphorylation towards fermentative glycolysis. Functional validation of proteomic and metabolic data provide evidences for increased activities of key enzymes of anaerobic glucose fate such as pyruvate kinase M2 isoform, lactate dehydrogenase and glucose 6-phopshate dehydrogenase in cancer stem cells as well as different redox status. Moreover, we show that treatment with 2-deoxyglucose, a well known inhibitor of glycolysis, inhibits BCSC proliferation when used alone and shows a synergic effect when used in combination with doxorubicin. In conclusion, we suggest that inhibition of glycolysis may be a potentially effective strategy to target BCSCs.


Assuntos
Neoplasias da Mama/metabolismo , Desoxiglucose/metabolismo , Glicólise , Células-Tronco Neoplásicas/metabolismo , Neoplasias da Mama/enzimologia , Linhagem Celular Tumoral , Feminino , Humanos , L-Lactato Desidrogenase/metabolismo , Células-Tronco Neoplásicas/enzimologia , Fosforilação Oxidativa , Piruvato Quinase/metabolismo
17.
Diabet Med ; 31(12): 1505-14, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24824197

RESUMO

AIMS: To investigate the efficacy and safety of the dipeptidyl peptidase-4 inhibitor linagliptin in patients with Type 2 diabetes mellitus inadequately controlled by a combination of metformin and pioglitazone. METHODS: This was a multi-centre, phase 3, randomized, double-blind, placebo-controlled study comparing linagliptin 5 mg once daily (n = 183) and placebo (n = 89) as add-on to metformin and pioglitazone. The primary endpoint was the change from baseline in glycated haemoglobin (HbA1c ) after 24 weeks. RESULTS: The placebo-corrected adjusted mean (se) change in HbA1c from baseline to 24 weeks was -6 (1) mmol/mol [-0.57 (0.13)%] (P < 0.0001). In patients with baseline HbA1c ≥ 53 mmol/mol (7.0%), 32.4% of patients in the linagliptin group and 13.8% in the placebo group achieved HbA1c < 53 mmol/mol (7.0%) (odds ratio 2.94; P = 0.0033). The placebo-corrected adjusted mean (se) change from baseline in fasting plasma glucose at week 24 was -0.57 (0.26) mmol/l [-10.4 (4.7) mg/dl] (P = 0.0280). The incidence of serious adverse events was 2.2% with linagliptin and 3.4% with placebo. Investigator-defined hypoglycaemia occurred in 5.5% of the linagliptin group and 5.6% of the placebo group. No meaningful changes in mean body weight were noted for either group. CONCLUSIONS: Linagliptin as add-on therapy to metformin and pioglitazone produced significant and clinically meaningful improvements in glycaemic control, without an additional risk of hypoglycaemia or weight gain (Clinical Trials Registry No: NCT 00996658).


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Metformina/uso terapêutico , Purinas/uso terapêutico , Quinazolinas/uso terapêutico , Tiazolidinedionas/uso terapêutico , Adulto , Idoso , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Hipoglicemia/induzido quimicamente , Linagliptina , Masculino , Pessoa de Meia-Idade , Pioglitazona , Falha de Tratamento , Resultado do Tratamento , Aumento de Peso
18.
Int J Cancer ; 135(7): 1711-20, 2014 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-24615175

RESUMO

Cancer cells express an abnormal metabolism characterized by increased glucose consumption owing to genetic mutations and mitochondrial dysfunction. Previous studies indicate that unlike healthy tissues, cancer cells are unable to effectively use ketone bodies for energy. Furthermore, ketones inhibit the proliferation and viability of cultured tumor cells. As the Warburg effect is especially prominent in metastatic cells, we hypothesized that dietary ketone supplementation would inhibit metastatic cancer progression in vivo. Proliferation and viability were measured in the highly metastatic VM-M3 cells cultured in the presence and absence of ß-hydroxybutyrate (ßHB). Adult male inbred VM mice were implanted subcutaneously with firefly luciferase-tagged syngeneic VM-M3 cells. Mice were fed a standard diet supplemented with either 1,3-butanediol (BD) or a ketone ester (KE), which are metabolized to the ketone bodies ßHB and acetoacetate. Tumor growth was monitored by in vivo bioluminescent imaging. Survival time, tumor growth rate, blood glucose, blood ßHB and body weight were measured throughout the survival study. Ketone supplementation decreased proliferation and viability of the VM-M3 cells grown in vitro, even in the presence of high glucose. Dietary ketone supplementation with BD and KE prolonged survival in VM-M3 mice with systemic metastatic cancer by 51 and 69%, respectively (p < 0.05). Ketone administration elicited anticancer effects in vitro and in vivo independent of glucose levels or calorie restriction. The use of supplemental ketone precursors as a cancer treatment should be further investigated in animal models to determine potential for future clinical use.


Assuntos
Apoptose , Neoplasias Encefálicas/mortalidade , Proliferação de Células , Suplementos Nutricionais , Cetonas/administração & dosagem , Animais , Glicemia/análise , Peso Corporal , Neoplasias Encefálicas/dietoterapia , Neoplasias Encefálicas/secundário , Humanos , Medições Luminescentes , Masculino , Camundongos , Taxa de Sobrevida , Células Tumorais Cultivadas
19.
Perfusion ; 28(6): 496-503, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23670806

RESUMO

Myocardial protection during cardiac surgery can be accomplished by different cardioplegic solutions. The aim of this study was to assess myocardial damage after heart valve surgery performed with myocardial protection of a single dose of Celsior cardioplegia or with repeated cold blood cardioplegia. After the stratification of 139 valvular patients by means of matching according to cross-clamp and cardiopulmonary bypass time, 32 patients were retained for comparison (16 patients received Celsior and 16 patients received cold blood cardioplegia). Creatine kinase-MB (CK-MB) and cardiac troponin I (cTnI) release were evaluated until six days after the operation. Pre-operative characteristics were similar in both groups. In the Celsior group, CK-MB and cTnI values were significantly higher from the first up to the sixth post-operative day. Peak cTnI values were 19.4 ± 13.4 and 9.7 ± 7 ng/mL (p=0.01) in the Celsior and the Cold Blood group, respectively. Peak CK-MB values were 79.6 ± 58.8 and 45.9 ± 20.6 U/L (p=0.07) in the Celsior and the Cold Blood group, respectively. Cold blood cardioplegia reduces perioperative myocardial damage compared to the Celsior solution in elective cardiac valve operations.


Assuntos
Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Procedimentos Cirúrgicos Cardíacos/métodos , Soluções Cardioplégicas/administração & dosagem , Parada Cardíaca Induzida/métodos , Coração/efeitos dos fármacos , Miocárdio/patologia , Temperatura Baixa , Dissacarídeos/administração & dosagem , Eletrólitos/administração & dosagem , Feminino , Glutamatos/administração & dosagem , Glutationa/administração & dosagem , Histidina/administração & dosagem , Humanos , Masculino , Manitol/administração & dosagem , Pessoa de Meia-Idade , Estudos Retrospectivos
20.
Urol Int ; 90(2): 191-4, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23147255

RESUMO

OBJECTIVE: It was the aim of this study to evaluate the accuracy of the measurement of tumor size comparing the objective size with that measured by preoperative cystoscopy, by preoperative ultrasound (US) and with the diameter described by the operator before the transurethral resection. PATIENTS AND METHODS: This study included 100 patients with bladder papillary endoscopic features of single or multiple neoplasms who were candidates for transurethral resection. The sizes of the same neoplasms measured during preoperative cystoscopy, preoperative US and described by the operator before the transurethral resection were evaluated. A statistical analysis of the errors of measurement was performed if compared with an objective measurement done with an ureteral catheter. RESULTS: The statistical analysis of the data shows that there are no substantial differences between the objective and subjective measurement, and therefore, the measurements reported by individual operators are reliable. On the contrary, the diameters given by preoperative cystoscopy and US differ significantly from the objective measurement. CONCLUSIONS: This study shows that the most reliable measurement is the subjective measurement made directly by the urologist in the operating room.


Assuntos
Cistoscopia/instrumentação , Ultrassonografia/métodos , Neoplasias da Bexiga Urinária/diagnóstico , Neoplasias da Bexiga Urinária/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Cistoscopia/métodos , Endoscopia/métodos , Humanos , Pessoa de Meia-Idade , Variações Dependentes do Observador , Probabilidade , Prognóstico , Reprodutibilidade dos Testes , Uretra/cirurgia , Neoplasias da Bexiga Urinária/patologia
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