Other Publications (11)
- Journal of Gastroenterology and Hepatology
- Physical Chemistry Chemical Physics : PCCP
- Gaceta Medica De Mexico
- Jornal Brasileiro De Pneumologia : Publicacao Oficial Da Sociedade Brasileira De Pneumologia E Tisilogia
- BMC Neuroscience
- Digestive Endoscopy : Official Journal of the Japan Gastroenterological Endoscopy Society
- Physical Therapy in Sport : Official Journal of the Association of Chartered Physiotherapists in Sports Medicine
- Brain, Behavior, and Immunity
- Ticks and Tick-borne Diseases
- Frontiers in Physiology
Articles by Rafael Barreto in JoVE
The Colon-26 Carcinoma Tumor-bearing Mouse as a Model for the Study of Cancer Cachexia Andrea Bonetto1, Joseph E. Rupert1, Rafael Barreto1, Teresa A. Zimmers1 1Department of Surgery, Simon Cancer Center and IUPUI Center for Cachexia Research, Innovation and Therapy, Indiana University School of Medicine Mice bearing the Colon-26 (C26) carcinoma represent a classical model of cancer cachexia. Progressive muscle wasting occurs in association with tumor growth, over-expression of muscle-specific ubiquitin ligases, and reductions in muscle cross-sectional area. Fat loss is also observed. Cachexia is studied in a time-dependent manner with increasing severity of wasting.
Other articles by Rafael Barreto on PubMed
Oxidative-inflammatory Damage in Cirrhosis: Effect of Vitamin E and a Fermented Papaya Preparation Journal of Gastroenterology and Hepatology. May, 2007 | Pubmed ID: 17444858 Oxidative DNA damage occurs as an early event in hepatitis C virus (HCV) infection and is an indication of the potential for carcinogenesis. The aim of this study was to test a novel antioxidant/immunomodulator in patients with HCV-related cirrhosis.
Combined Monte Carlo and Quantum Mechanics Study of the Solvatochromism of Phenol in Water. The Origin of the Blue Shift of the Lowest Pi-pi* Transition Physical Chemistry Chemical Physics : PCCP. Mar, 2009 | Pubmed ID: 19224040 A combined and sequential use of Monte Carlo simulations and quantum mechanical calculations is made to analyze the spectral shift of the lowest pi-pi* transition of phenol in water. The solute polarization is included using electrostatic embedded calculations at the MP2/aug-cc-pVDZ level giving a dipole moment of 2.25 D, corresponding to an increase of 76% compared to the calculated gas-phase value. Using statistically uncorrelated configurations sampled from the MC simulation, first-principle size-extensive calculations are performed to obtain the solvatochromic shift. Analysis is then made of the origin of the blue shift. Results both at the optimized geometry and in room-temperature liquid water show that hydrogen bonds of water with phenol promote a red shift when phenol is the proton-donor and a blue shift when phenol is the proton-acceptor. In the case of the optimized clusters the calculated shifts are in very good agreement with results obtained from mass-selected free jet expansion experiments. In the liquid case the contribution of the solute-solvent hydrogen bonds partially cancels and the total shift obtained is dominated by the contribution of the outer solvent water molecules. Our best result, including both inner and outer water molecules, is 570 +/- 35 cm(-1), in very good agreement with the small experimental shift of 460 cm(-1) for the absorption maximum.
[Serum Levels of Beta2 Microglobulin and Ultrasensitive C-reactive Protein As Markers of Histological Activity in Ulcerative Colitis] Gaceta Medica De Mexico. Jan-Feb, 2010 | Pubmed ID: 20422932 There is currently increasing interest in research focused on new, non-invasive biochemical markers with better efficacy for evaluating endoscopic activity in patients with inflammatory bowel disease (IBD). In the present study, we determined the diagnostic utility of high sensitive C-reactive protein (hs CRP) and beta2 microglobulin (beta2M) levels and analyzed their correlation with the histological activity of ulcerative colitis (UC).
Smoking Among Patients Hospitalized at a University Hospital in the South of Brazil: Prevalence, Degree of Nicotine Dependence, and Motivational Stage of Change Jornal Brasileiro De Pneumologia : Publicacao Oficial Da Sociedade Brasileira De Pneumologia E Tisilogia. Jan-Feb, 2012 | Pubmed ID: 22407043 To determine the prevalence and profile of smoking among hospitalized patients at a university hospital in the south of Brazil.
Fluoxetine Prevents Development of an Early Stress-related Molecular Signature in the Rat Infralimbic Medial Prefrontal Cortex. Implications for Depression? BMC Neuroscience. Oct, 2012 | Pubmed ID: 23075086 Psychological stress, particularly in chronic form, can lead to mood and cognitive dysfunction and is a major risk factor in the development of depressive states. How stress affects the brain to cause psychopathologies is incompletely understood. We sought to characterise potential depression related mechanisms by analysing gene expression and molecular pathways in the infralimbic medial prefrontal cortex (ILmPFC), following a repeated psychological stress paradigm. The ILmPFC is thought to be involved in the processing of emotionally contextual information and in orchestrating the related autonomic responses, and it is one of the brain regions implicated in both stress responses and depression.
Efficacy and Tolerability of Low-volume (2 L) Versus Single- (4 L) Versus Split-dose (2 L + 2 L) Polyethylene Glycol Bowel Preparation for Colonoscopy: Randomized Clinical Trial Digestive Endoscopy : Official Journal of the Japan Gastroenterological Endoscopy Society. Nov, 2014 | Pubmed ID: 24645966 To compare the efficacy and tolerability of a low-volume (2-L) polyethylene glycol (PEG) regimen for colonoscopy compared to single (4-L) or split-dose (2-L + 2-L) regimens.
Normative Data of Frontal Plane Patellar Alignment in Athletes Physical Therapy in Sport : Official Journal of the Association of Chartered Physiotherapists in Sports Medicine. May, 2015 | Pubmed ID: 25534038 The objective of this study was to provide normative data of frontal plane patellar alignment according to McConnell and Arno angles, verify the association between theses angles and identify the presence of patellar rotation in different sports.
Chemotherapy-related Cachexia is Associated with Mitochondrial Depletion and the Activation of ERK1/2 and P38 MAPKs Oncotarget. Jul, 2016 | Pubmed ID: 27259276 Cachexia affects the majority of cancer patients, with currently no effective treatments. Cachexia is defined by increased fatigue and loss of muscle function resulting from muscle and fat depletion. Previous studies suggest that chemotherapy may contribute to cachexia, although the causes responsible for this association are not clear. The purpose of this study was to investigate the mechanism(s) associated with chemotherapy-related effects on body composition and muscle function. Normal mice were administered chemotherapy regimens used for the treatment of colorectal cancer, such as Folfox (5-FU, leucovorin, oxaliplatin) or Folfiri (5-FU, leucovorin, irinotecan) for 5 weeks. The animals that received chemotherapy exhibited concurrent loss of muscle mass and muscle weakness. Consistently with previous findings, muscle wasting was associated with up-regulation of ERK1/2 and p38 MAPKs. No changes in ubiquitin-dependent proteolysis or in the expression of TGFβ-family members were detected. Further, marked decreases in mitochondrial content, associated with abnormalities at the sarcomeric level and with increase in the number of glycolytic fibers were observed in the muscle of mice receiving chemotherapy. Finally, ACVR2B/Fc or PD98059 prevented Folfiri-associated ERK1/2 activation and myofiber atrophy in C2C12 cultures. Our findings demonstrate that chemotherapy promotes MAPK-dependent muscle atrophy as well as mitochondrial depletion and alterations of the sarcomeric units. Therefore, these findings suggest that chemotherapy potentially plays a causative role in the occurrence of muscle loss and weakness. Moreover, the present observations provide a strong rationale for testing ACVR2B/Fc or MEK1 inhibitors in combination with anticancer drugs as novel strategies aimed at preventing chemotherapy-associated muscle atrophy.
Effects of Immune Activation During Early or Late Gestation on Schizophrenia-related Behaviour in Adult Rat Offspring Brain, Behavior, and Immunity. Jul, 2016 | Pubmed ID: 27423491 Maternal exposure to infectious agents during gestation has been identified as a significant risk factor for schizophrenia. Using a mouse model, past work has demonstrated that the gestational timing of the immune-activating event can impact the behavioural phenotype and expression of dopaminergic and glutamatergic neurotransmission markers in the offspring. In order to determine the inter-species generality of this effect to rats, another commonly used model species, the current study investigated the impact of a viral mimetic Poly (I:C) at either an early (gestational day 10) or late (gestational day 19) time-point on schizophrenia-related behaviour and neurotransmitter receptor expression in rat offspring. Exposure to Poly (I:C) in late, but not early, gestation resulted in transient impairments in working memory. In addition, male rats exposed to maternal immune activation (MIA) in either early or late gestation exhibited sensorimotor gating deficits. Conversely, neither early nor late MIA exposure altered locomotor responses to MK-801 or amphetamine. In addition, increased dopamine 1 receptor mRNA levels were found in the nucleus accumbens of male rats exposed to early gestational MIA. The findings from this study diverge somewhat from previous findings in mice with MIA exposure, which were often found to exhibit a more comprehensive spectrum of schizophrenia-like phenotypes in both males and females, indicating potential differences in the neurodevelopmental vulnerability to MIA exposure in the rat with regards to schizophrenia related changes.
Multiple Resistance to Acaricides in Field Populations of Rhipicephalus Microplus from Rio Grande Do Sul State, Southern Brazil Ticks and Tick-borne Diseases. Sep, 2016 | Pubmed ID: 27717758 Acaricide resistance is a major obstacle to the control of Rhipicephalus microplus. Historically, the indiscriminate use of chemical compounds has contributed to the selection of populations resistant to different classes of acaricides. Therefore, multiple acaricide resistance is an important threat to the chemical control of the cattle tick. To investigate the occurrence and extent of multiple resistance to acaricides in Southern Brazil we performed larval tests with cypermethrin, chlorpyriphos, amitraz, fipronil and ivermectin on 104 cattle tick field samples from different ranches in Rio Grande do Sul, between the years 2013 and 2015. Adult immersion tests with a commercial formulation mixture of chlorpyriphos and cypermethrin were performed on 75 samples. Four levels of resistance were established according to the mortality of larvae: Level I: mortality between 82% and 95%; Level II: mortality between 57% and 82%; Level III: mortality between 25% and 57%; and Level IV: mortality lower than 25%. Resistance to cypermethrin was detected in 98.08% of the samples evaluated, mostly at resistance level IV. The frequency of samples resistant to amitraz, chlorpyriphos, ivermectin and fipronil was 76.92%, 60.58%, 60.58% and 53.85% respectively. Multiple resistance to three or more compounds was found in 78.85% of the samples. The results obtained in this study are alarming and reveal a new scenario for the challenge of tick control using chemicals. This is an issue of high importance to cattle production systems where this tick is responsible for a high economic impact.
Cancer and Chemotherapy Contribute to Muscle Loss by Activating Common Signaling Pathways Frontiers in Physiology. 2016 | Pubmed ID: 27807421 Cachexia represents one of the primary complications of colorectal cancer due to its effects on depletion of muscle and fat. Evidence suggests that chemotherapeutic regimens, such as Folfiri, contribute to cachexia-related symptoms. The purpose of the present study was to investigate the cachexia signature in different conditions associated with severe muscle wasting, namely Colon-26 (C26) and Folfiri-associated cachexia. Using a quantitative LC-MS/MS approach, we identified significant changes in 386 proteins in the quadriceps muscle of Folfiri-treated mice, and 269 proteins differentially expressed in the C26 hosts (p < 0.05; -1.5 ≥ fold change ≥ +1.5). Comparative analysis isolated 240 proteins that were modulated in common, with a large majority (218) that were down-regulated in both experimental settings. Interestingly, metabolic (47.08%) and structural (21.25%) proteins were the most represented. Pathway analysis revealed mitochondrial dysfunctions in both experimental conditions, also consistent with reduced expression of mediators of mitochondrial fusion (OPA-1, mitofusin-2), fission (DRP-1) and biogenesis (Cytochrome C, PGC-1α). Alterations of oxidative phosphorylation within the TCA cycle, fatty acid metabolism, and Ca(2+) signaling were also detected. Overall, the proteomic signature in the presence of both chemotherapy and cancer suggests the activation of mechanisms associated with movement disorders, necrosis, muscle cell death, muscle weakness and muscle damage. Conversely, this is consistent with the inhibition of pathways that regulate nucleotide and fatty acid metabolism, synthesis of ATP, muscle and heart function, as well as ROS scavenging. Interestingly, strong up-regulation of pro-inflammatory acute-phase proteins and a more coordinated modulation of mitochondrial and lipidic metabolisms were observed in the muscle of the C26 hosts that were different from the Folfiri-treated animals. In conclusion, our results suggest that both cancer and chemotherapy contribute to muscle loss by activating common signaling pathways. These data support the undertaking of combination strategies that aim to both counteract tumor growth and reduce chemotherapy side effects.