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1.
Medicina (B.Aires) ; 77(4): 314-320, ago. 2017. ilus
Article in Spanish | LILACS | ID: biblio-894485

ABSTRACT

La autofagia es un proceso de reciclado de partes de la célula. Como se describe en esta revisión, ocurre naturalmente preservando a las células de la acumulación de toxinas, moléculas y organelas dañadas y además permite los procesos de desarrollo y diferenciación de los tejidos. En el transcurso de la autofagia, el procesamiento de los sustratos a reciclar genera ATP, lo que constituye una fuente alternativa de energía en situaciones de estrés. En este sentido, bajo condiciones hostiles como hipoxia o falta de nutrientes, el proceso puede dispararse de modo exacerbado llevando a la muerte celular. Algunas alteraciones en su funcionamiento pueden involucrar el desarrollo de diversas patologías, tales como el daño hepático, el cáncer y las enfermedades neurodegenerativas.


Autophagy is a process of recycling parts of the cell. As described in this review, it occurs naturally in order to preserve cells from the accumulation of toxins, damaged molecules and organelles, and to allow processes of tissue development and differentiation. In the course of autophagy, the processing of the substrates to be recycled generates ATP, thus providing an alternative source of energy in stress situations. In this sense, under hostile conditions such as hypoxia or lack of nutrients, the autophagy process can be exacerbated leading to cell death. Some alterations in its functioning may involve the development of various pathologies, including liver damage, cancer and neurodegenerative diseases.


Subject(s)
Humans , Autophagy/physiology , Cell Differentiation/physiology , Cell Survival/physiology , Neurodegenerative Diseases/pathology , Energy Metabolism/physiology , Neoplasms/pathology , Cell Hypoxia , Adenosine Triphosphate/metabolism , Neurodegenerative Diseases/physiopathology , Neoplasms/physiopathology
2.
Rev. méd. Chile ; 143(2): 175-182, feb. 2015. tab
Article in Spanish | LILACS | ID: lil-742568

ABSTRACT

Background: In 2007, a Clinical-Case-Portfolio (CCP) was introduced as a new assessment instrument for fourth grade undergraduate medical students. Since then, several changes have been implemented such as reduction on the number of clinical cases, peer review and the introduction of virtual patient to the portfolio. Aim: To describe the virtual patient model incorporated to the CCP and assess the perception of this change and its effects on the performance of undergraduate students. Material and Methods: Virtual patients were implemented based on prototype clinical cases with specific syndromes. Students’ perceptions about CCP before and after the introduction of virtual patients were evaluated using a validated questionnaire that was answered voluntarily and anonymously. Results: Overall perception of CCP significantly improved after the incorporation of virtual patients (97.1 ± 24.9 and 111.3 ± 25.7 points; 57.8 and 66.2% respectively). The same improvements were observed for the domains “Student Learning”, “Organization and Evaluation”, “Teaching Methodology” and “Integration”. In both years, students obtained high grades in CCP evaluations. However CCP grades were not significantly correlated with integrated final grades. Conclusions: The incorporation of virtual patients improved undergraduate students’ perception of CCP.


Subject(s)
Animals , Mice , Apoptosis , Axin Protein/metabolism , Enzyme Activation , Poly(ADP-ribose) Polymerases/metabolism , Protein-Serine-Threonine Kinases/antagonists & inhibitors , Aurora Kinases , Adenosine Triphosphate/metabolism , Apoptosis Inducing Factor/genetics , Apoptosis Inducing Factor/metabolism , Cell Line , Cell Membrane/metabolism , Cell Membrane/physiology , Mitochondria/metabolism , Protein Kinase Inhibitors/pharmacology , RNA Interference , Time-Lapse Imaging
3.
Rev. bras. cir. cardiovasc ; 30(1): 49-54, Jan-Mar/2015. tab
Article in English | LILACS | ID: lil-742891

ABSTRACT

Introduction: Perioperative myocardial infarction adversely affects the prognosis of patients undergoing coronary artery bypass graft and its diagnosis was hampered by numerous difficulties, because the pathophysiology is different from the traditional instability atherosclerotic and the clinical difficulty to be characterized. Objective: To identify the frequency of perioperative myocardial infarction and its outcome in patients undergoing coronary artery bypass graft. Methods: Retrospective cohort study performed in a tertiary hospital specialized in cardiology, from May 01, 2011 to April 30, 2012, which included all records containing coronary artery bypass graft records. To confirm the diagnosis of perioperative myocardial infarction criteria, the Third Universal Definition of Myocardial Infarction was used. Results: We analyzed 116 cases. Perioperative myocardial infarction was diagnosed in 28 patients (24.1%). Number of grafts and use and cardiopulmonary bypass time were associated with this diagnosis and the mean age was significantly higher in this group. The diagnostic criteria elevated troponin I, which was positive in 99.1% of cases regardless of diagnosis of perioperative myocardial infarction. No significant difference was found between length of hospital stay and intensive care unit in patients with and without this complication, however patients with perioperative myocardial infarction progressed with worse left ventricular function and more death cases. Conclusion: The frequency of perioperative myocardial infarction found in this study was considered high and as a consequence the same observed average higher troponin I, more cases of worsening left ventricular function and death. .


Introdução: O infarto do miocárdio perioperatório afeta negativamente o prognóstico dos pacientes submetidos à cirurgia de revascularização do miocárdio e seu diagnóstico esbarra em inúmeras dificuldades, pois a fisiopatologia é diferente da tradicional instabilidade aterosclerótica e o quadro clínico de difícil caracterização. Objetivo: Identificar a frequência de infarto do miocárdio perioperatório e seu desfecho em pacientes submetidos à cirurgia de revascularização do miocárdio. Métodos: Coorte retrospectiva realizada em hospital terciário especializado em cardiologia, de 1 de maio de 2011 a 30 de abril de 2012, que incluiu todos os prontuários contendo registros de cirurgia de revascularização do miocárdio. Para confirmação diagnóstica do infarto do miocárdio perioperatório, foram utilizados os critérios da Third Universal Definition of Myocardial Infarction Resultados: Foram analisados 116 casos. Foi diagnosticado infarto do miocárdio perioperatório em 28 pacientes (24,1%). Número de enxertos e utilização e tempo de circulação extracorpórea foram fatores associados a este diagnóstico e a média de idade foi significativamente mais elevada neste grupo. O critério diagnóstico elevação de troponina I foi positivo em 99,1% dos casos, independentemente do diagnóstico de infarto do miocárdio perioperatório. Não foi encontrada diferença significativa entre tempo de internação hospitalar e em unidade de terapia intensiva nos grupos com e sem esta complicação, porém pacientes com infarto do miocárdio perioperatório evoluíram com pior função ventricular esquerda e mais casos de óbito. Conclusão: A frequência de infarto do miocárdio perioperatório encontrada neste trabalho foi considerada alta e como consequência do mesmo observou-se média mais elevada de troponina I, mais casos de piora da função ventricular esquerda e óbito. .


Subject(s)
Animals , Female , Male , Mice , Cell Death/physiology , Glucose/metabolism , Hypoxia-Ischemia, Brain/metabolism , Neurons/physiology , Oxygen/metabolism , Sex Characteristics , Signal Transduction/physiology , Adenosine Triphosphate/metabolism , Apoptosis Inducing Factor/metabolism , /metabolism , /metabolism , Cerebellum/cytology , Mice, Knockout , Mitochondria/metabolism , Neurons/cytology , Poly(ADP-ribose) Polymerases/genetics , Poly(ADP-ribose) Polymerases/metabolism
4.
Article in English | WPRIM | ID: wpr-19167

ABSTRACT

Cryptosporidium andersoni ATP-binding cassette (CaABC) is an important membrane protein involved in substrate transport across the membrane. In this research, the nucleotide binding domain (NBD) of CaABC gene was amplified by PCR, and the eukaryotic expression vector of pEGFP-C1-CaNBD was reconstructed. Then, the recombinant plasmid of pEGFP-C1-CaNBD was transformed into the mouse intestinal epithelial cells (IECs) to study the iron transportation function of CaABC. The results indicated that NBD region of CaABC gene can significantly elevate the transport efficiency of Ca2+, Mg2+, K+, and HCO3 - in IECs (P<0.05). The significance of this study is to find the ATPase inhibitors for NBD region of CaABC gene and to inhibit ATP binding and nutrient transport of CaABC transporter. Thus, C. andersoni will be killed by inhibition of nutrient uptake. This will open up a new way for treatment of cryptosporidiosis.


Subject(s)
ATP-Binding Cassette Transporters/chemistry , Adenosine Triphosphate/metabolism , Amino Acid Sequence , Animals , Calcium/metabolism , Cloning, Molecular , Cryptosporidiosis/parasitology , Cryptosporidium/chemistry , Humans , Iron/metabolism , Mice , Molecular Sequence Data , Protein Structure, Tertiary , Protozoan Proteins/chemistry , Sequence Alignment
5.
Article in English | WPRIM | ID: wpr-55050

ABSTRACT

When mouse bone marrow-derived macrophages were stimulated with serum amyloid A (SAA), which is a major acute-phase protein, there was strong inhibition of osteoclast formation induced by the receptor activator of nuclear factor kappaB ligand. SAA not only markedly blocked the expression of several osteoclast-associated genes (TNF receptor-associated factor 6 and osteoclast-associated receptor) but also strongly induced the expression of negative regulators (MafB and interferon regulatory factor 8). Moreover, SAA decreased c-fms expression on the cell surface via shedding of the c-fms extracellular domain. SAA also restrained the fusion of osteoclast precursors by blocking intracellular ATP release. This inhibitory response of SAA is not mediated by the well-known SAA receptors (formyl peptide receptor 2, Toll-like receptor 2 (TLR2) or TLR4). These findings provide insight into a novel inhibitory role of SAA in osteoclastogenesis and suggest that SAA is an important endogenous modulator that regulates bone homeostasis.


Subject(s)
Adenosine Triphosphate/metabolism , Animals , Cell Differentiation , Cell Line , Gene Expression Regulation, Developmental , Humans , Macrophages/cytology , Mice , Osteoclasts/cytology , RANK Ligand/metabolism , Receptor, Macrophage Colony-Stimulating Factor/genetics , Receptors, Formyl Peptide/metabolism , Serum Amyloid A Protein/metabolism , Toll-Like Receptor 2/metabolism , Toll-Like Receptor 4/metabolism
6.
Rev. bras. enferm ; 67(6): 965-971, Nov-Dec/2014.
Article in Portuguese | LILACS, BDENF | ID: lil-732819

ABSTRACT

Trata-se de pesquisa qualitativa exploratória, que buscou analisar as representações sociais de mães adolescentes sobre as práticas alimentares do filho no primeiro ano de vida. Teve como sujeitos 10 mães adolescentes, cujos filhos encontravam-se na faixa etária de sete a doze meses de vida. Os dados foram coletados por meio de entrevista semi-estruturada, além da utilização de material visual. A análise seguiu a técnica de análise de conteúdo, apoiando-se no referencial da Teoria das Representações Sociais. Dessa análise, emergiram quatro temas: conflito do amamentar versus consagração do mingau; estabelecendo a alimentação complementar do filho; discurso cristalizado: "danoninho vale mais que um bifinho"; a (in)definição dos hábitos alimentares maternos: implicações para a alimentação infantil. As representações que conduzem as práticas maternas na escolha, preparo e oferta dos alimentos seguem uma lógica particular, onde as adolescentes reinterpretam os discursos técnicos nos termos da sua cultura.


This is qualitative research that investigates the social representations of adolescent mothers on child eating habits in the first year of life. Its subjects were 10 adolescent mothers, whose children were aged seven to twelve months. Data were collected through semi-structured interview, besides the use of visual material. The analysis followed the technique of content analysis, relying on the framework of Social Representations Theory. That analysis revealed four themes: the conflict of breastfeeding versus consecration of porridge; establishing complementary feeding of the child; crystallized speech: "yogurt is better than a little steak"; the (un)definition of maternal eating habits: implications for infant feeding. The representations that drive maternal practices in selecting, preparing and offering food follow a particular logic, where adolescents reinterpret technical speeches in terms of their culture.


Esta es una investigación cualitativa que investiga las representaciones sociales de madres adolescentes en las prácticas de alimentación infantil en el primer año de vida. El estudio incluyó a 10 madres adolescentes cuyos hijos tenían entre siete a doce meses. Los datos fueron obtenidos mediante entrevista semiestructurada, además de la utilización de material visual. El análisis se realizó por la técnica de análisis de contenido, basándose en el marco de la teoría de las representaciones sociales. Ese análisis revelo cuatro temas: el conflicto de la lactancia materna frente a la consagración de la papilla; el establecimiento de alimentación complementaria del niño; discurso cristalizado "el yogur es mejor que un filete"; la dieta materna sin definición: implicaciones para la alimentación infantil. Las representaciones que impulsan prácticas maternas en la selección, preparación y oferta de alimentos siguen una lógica particular, donde las adolescentes reinterpretan intervenciones técnicas en términos de su cultura.


Subject(s)
Animals , Guinea Pigs , Hypoxia, Brain/physiopathology , Olfactory Bulb/physiopathology , Ubiquinone/analogs & derivatives , Ubiquinone/pharmacology , Action Potentials/drug effects , Adenosine Triphosphate/metabolism , Barbiturates/pharmacology , Coenzymes , In Vitro Techniques , Olfactory Bulb/drug effects
7.
Rev. bras. cir. cardiovasc ; 29(2): 249-254, Apr-Jun/2014. tab, graf
Article in Portuguese | LILACS | ID: lil-719408

ABSTRACT

O paradoxo do cálcio foi pela primeira vez citado em 1966 por Zimmerman et al. A partir daí, ganhou grande interesse por parte da comunidade científica internacional devido ao fato da ausência do íon cálcio produzir na célula muscular cardíaca dano semelhante à lesão de isquemia-reperfusão. Apesar de não serem conhecidos todos os mecanismos envolvidos no processo da lesão celular no paradoxo do cálcio, a conexão intercelular mantida somente pelo nexus parece ter papel chave na fragmentação celular. A adição de pequenas concentrações de cálcio, bloqueadores de canal de cálcio, hiponatremia ou hipotermia são importantes para evitar que haja lesão celular no momento da reperfusão com soluções com concentração fisiológica de cálcio.


The calcium paradox was first mentioned in 1966 by Zimmerman et al. Thereafter gained great interest from the scientific community due to the fact of the absence of calcium ions in heart muscle cells produce damage similar to ischemia-reperfusion. Although not all known mechanisms involved in cellular injury in the calcium paradox intercellular connection maintained only by nexus seems to have a key role in cellular fragmentation. The addition of small concentrations of calcium, calcium channel blockers, and hyponatraemia hypothermia are important to prevent any cellular damage during reperfusion solutions with physiological concentration of calcium.


Subject(s)
Animals , Humans , Rats , Calcium/metabolism , Heart Injuries/metabolism , Myocytes, Cardiac/metabolism , Adenosine Triphosphate/metabolism , Cell Membrane Permeability , Caffeine/adverse effects , Calcium Channel Blockers/pharmacology , Calcium/administration & dosage , Dinitrophenols/metabolism , Glycocalyx/metabolism , Heart Failure/etiology , Heart Injuries/etiology , Heart Injuries/pathology , Myocardial Reperfusion Injury/metabolism , Myocardium/metabolism , Sodium/physiology , Time Factors
8.
Yonsei Medical Journal ; : 1664-1671, 2014.
Article in English | WPRIM | ID: wpr-180228

ABSTRACT

PURPOSE: To investigate chemosensitivity with an adenosine triphosphate-based chemotherapy response assay in patients with epithelial ovarian or peritoneal cancer according to tumor histology, grade, and disease status. MATERIALS AND METHODS: One hundred specimens were collected during primary or secondary debulking from 67 patients with primary ovarian cancer, 24 patients with recurrent ovarian cancer, 5 patients with primary peritoneal cancer, and 4 patients with recurrent peritoneal cancer; samples were collected between August 2006 and June 2009. Tumor cells were isolated and cultured for 48 hours in media containing chemotherapy. The chemosensitivity index (CI) was calculated as 300 minus the sum of the cell death rate at 0.2x, 1x, and 5x drug concentrations, and the CI values were compared. RESULTS: CI values were obtained from 93 of 100 patients. The most active agents against primary disease were ifosfamide and paclitaxel. For primary serous adenocarcinoma, paclitaxel and irinotecan were the most active, followed by ifosfamide. For clear cell carcinoma, ifosfamide was the most active, followed by paclitaxel and irinotecan. Although not statistically significant, the CIs of cisplatin, carboplatin, paclitaxel, and docetaxel decreased as tumor grade increased. In 14 cases of recurrent disease, paclitaxel was the most active, followed by ifosfamide and cisplatin. CONCLUSION: Ifosfamide and paclitaxel were the most active drugs for primary and recurrent disease. Therefore, we recommend further clinical studies to confirm the efficacy of paclitaxel, ifosfamide, and cisplatin combination chemotherapy for recurrent and primary ovarian cancer.


Subject(s)
Adenocarcinoma, Clear Cell/drug therapy , Adenosine Triphosphate/metabolism , Adult , Aged , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Camptothecin/administration & dosage , Carboplatin/therapeutic use , Cisplatin/administration & dosage , Drug Resistance, Neoplasm , Drug Screening Assays, Antitumor/methods , Female , Humans , Ifosfamide/administration & dosage , Middle Aged , Neoplasm Recurrence, Local/drug therapy , Neoplasms, Glandular and Epithelial/drug therapy , Ovarian Neoplasms/drug therapy , Paclitaxel/therapeutic use , Peritoneal Neoplasms/drug therapy , Predictive Value of Tests , Sensitivity and Specificity , Taxoids/administration & dosage
9.
Int. braz. j. urol ; 39(2): 276-285, Mar-Apr/2013. tab, graf
Article in English | LILACS | ID: lil-676272

ABSTRACT

Purpose Evidence shows that adenosine triphosphate (ATP) is involved in the transmission of multiple chronic pain via P2X7 receptor. This study was to investigate the P2X7 and microglial cells in the chronic prostatitis pain. Materials and Methods Rats were divided into control group and chronic prostatitis group (n = 24 per group). A chronic prostatitis animal model was established by injecting complete Freund's adjuvant (CFA) to the prostate of rats, and the thermal withdrawal latency (TWL) was detected on days 0, 4, 12 and 24 (n = 6 at each time point in each group). Animals were sacrificed and the pathological examination of the prostate, detection of mRNA expression of P2X7 and ionized calcium binding adaptor molecule 1 (IBA-1) and measurement of content of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in the dorsal horn of L5-S2 spinal cord were performed on days 0, 4, 12 and 24. In addition, the content of TNF-α and IL-1β in the dorsal horn of L5-S2 spinal cord was measured after intrathecal injection of inhibitors of microglial cells and/or P2X7 for 5 days. Results The chronic prostatitis was confirmed by pathological examination. The expression of P2X7 and IBA-1 and the content of TNF-α and IL-1β in rats with chronic prostatitis were significantly higher than those in the control group. On day 4, the expressions of pro-inflammatory cytokines became to increase, reaching a maximal level on day 12 and started to reduce on day 24, but remained higher than that in the control group. Following suppression of microglial cells and P2X7 receptor, the secretion of TNF-α and IL-1β was markedly reduced. Conclusion In chronic prostatitis pain, the microglial cells and P2X7 receptor are activated resulting in the increased expression of TNF-α and IL-1β in the L5-S2 spinal cord, which might attribute to the maintenance and intensification of pain in chronic prostatitis. .


Subject(s)
Animals , Male , Rats , Microglia/cytology , Microglia/metabolism , Prostate/metabolism , Prostatitis/metabolism , /physiology , Adenosine Triphosphate/metabolism , Calcium-Binding Proteins/metabolism , Chronic Pain/metabolism , Interleukin-1beta/metabolism , Microfilament Proteins/metabolism , Pain Measurement , Prostate/pathology , Prostatitis/pathology , Random Allocation , Reverse Transcriptase Polymerase Chain Reaction , RNA, Messenger/analysis , Spinal Cord/metabolism , Tumor Necrosis Factor-alpha
10.
Rev. bras. ter. intensiva ; 25(1): 49-55, jan.-mar. 2013. tab
Article in Portuguese | LILACS | ID: lil-673367

ABSTRACT

Evidências recentes sugerem que o balanço proteico negativo secundário à doença grave se associa ao aumento de morbidade. A perda da proteína corporal total é inevitável nesse cenário, mesmo com uma abordagem nutricional agressiva, e resulta, principalmente, do catabolismo da fibra muscular esquelética. O principal mecanismo bioquímico e metabólico envolvido nesse processo é o sistema ubiquitina-proteassoma, que, paradoxalmente, consome a adenosina trifosfatocomo fonte energética e motriz. É possível que a neutralidade do balanço proteico nessas instâncias clínicas, seja tão importante na melhora dos desfechos quanto atingir a meta calórica estimada ou medida pela calorimetria indireta. Estudos recentes apontam a utilização de concentrações mais elevadas de proteínas na terapia nutricional do paciente grave como importante para um impacto positivo na mortalidade. A proposta deste trabalho foi revisar alguns princípios da terapia nutricional relativos ao metabolismo proteico, sinalizar para as principais assertivas das diretrizes das sociedades especializadas e comentar estudos recentes, que abordam a questão em tela, sob a visão crítica da experiência clínica dos autores.


Recent evidence suggests that a negative protein balance secondary to severe disease is associated with increased morbidity. A loss of total body protein is inevitable in this scenario, even with an aggressive nutritional approach, primarily due to the catabolism of skeletal muscle fibers. The ubiquitin-proteasome system is the primary metabolic and biochemical mechanism involved in this process; paradoxically, this system consumes adenosine triphosphate as its energy source. It is possible that a neutral protein balance in these clinical situations is important for improving outcomes and achieving the caloric goals estimated or measured by indirect calorimetry. Recent studies have suggested that the use of higher protein concentrations in nutritional therapy for critically ill patients may help to reduce mortality. The purpose of this study was to review some of the nutrition therapy principles related to protein metabolism, evaluate the main assertions of the guidelines of specialty societies and review the recent studies that address these issues using critical insights from the authors' clinical experience.


Subject(s)
Humans , Nutritional Requirements , Nutritional Support/methods , Proteins/metabolism , Adenosine Triphosphate/metabolism , Calorimetry, Indirect , Critical Illness , Practice Guidelines as Topic , Proteasome Endopeptidase Complex/metabolism , Proteins/administration & dosage , Ubiquitin/metabolism
11.
Article in English | WPRIM | ID: wpr-188339

ABSTRACT

To quantify the reduction in workload during intra-aortic balloon pump (IABP) therapy, indirect parameters are used, such as the mean arterial pressure during diastole, product of heart rate and peak systolic pressure, and pressure-volume area. Therefore, we investigated the cardiac energy consumption during IABP therapy using a cardiac electromechanics model. We incorporated an IABP function into a previously developed electromechanical model of the ventricle with a lumped model of the circulatory system and investigated the cardiac energy consumption at different IABP inflation volumes. When the IABP was used at inflation level 5, the cardiac output and stroke volume increased 11%, the ejection fraction increased 21%, the stroke work decreased 1%, the mean arterial pressure increased 10%, and the ATP consumption decreased 12%. These results show that although the ATP consumption is decreased significantly, stroke work is decreased only slightly, which indicates that the IABP helps the failed ventricle to pump blood efficiently.


Subject(s)
Adenosine Triphosphate/metabolism , Arterial Pressure , Cardiac Output , Heart Failure/pathology , Heart Rate , Humans , Intra-Aortic Balloon Pumping , Models, Theoretical , Stroke Volume , Ventricular Function, Left
12.
Braz. j. med. biol. res ; 45(12): 1135-1140, Dec. 2012. ilus, tab
Article in English | LILACS | ID: lil-659653

ABSTRACT

Azospirillum brasilense is a diazotroph that associates with important agricultural crops and thus has potential to be a nitrogen biofertilizer. The A. brasilense transcription regulator NifA, which seems to be constitutively expressed, activates the transcription of nitrogen fixation genes. It has been suggested that the nitrogen status-signaling protein GlnB regulates NifA activity by direct interaction with the NifA N-terminal GAF domain, preventing the inhibitory effect of this domain under conditions of nitrogen fixation. In the present study, we show that an N-terminal truncated form of NifA no longer required GlnB for activity and lost regulation by ammonium. On the other hand, in trans co-expression of the N-terminal GAF domain inhibited the N-truncated protein in response to fixed nitrogen levels. We also used pull-down assays to show in vitro interaction between the purified N-terminal GAF domain of NifA and the GlnB protein. The results showed that A. brasilense GlnB interacts directly with the NifA N-terminal domain and this interaction is dependent on the presence of ATP and 2-oxoglutarate.


Subject(s)
Adenosine Triphosphate/metabolism , Azospirillum brasilense/enzymology , Bacterial Proteins/metabolism , Ketoglutaric Acids/metabolism , Transcription Factors/metabolism , beta-Galactosidase/metabolism , Azospirillum brasilense/metabolism , Genetic Vectors , Plasmids
13.
Braz. j. med. biol. res ; 45(6): 482-487, June 2012. ilus, tab
Article in English | LILACS | ID: lil-622776

ABSTRACT

This study explored the reduction of adenosine triphosphate (ATP) levels in L-02 hepatocytes by hexavalent chromium (Cr(VI)) using chi-square analysis. Cells were treated with 2, 4, 8, 16, or 32 μM Cr(VI) for 12, 24, or 36 h. Methyl thiazolyl tetrazolium (MTT) experiments and measurements of intracellular ATP levels were performed by spectrophotometry or bioluminescence assays following Cr(VI) treatment. The chi-square test was used to determine the difference between cell survival rate and ATP levels. For the chi-square analysis, the results of the MTT or ATP experiments were transformed into a relative ratio with respect to the control (%). The relative ATP levels increased at 12 h, decreased at 24 h, and increased slightly again at 36 h following 4, 8, 16, 32 μM Cr(VI) treatment, corresponding to a "V-shaped" curve. Furthermore, the results of the chi-square analysis demonstrated a significant difference of the ATP level in the 32-μM Cr(VI) group (P < 0.05). The results suggest that the chi-square test can be applied to analyze the interference effects of Cr(VI) on ATP levels in L-02 hepatocytes. The decreased ATP levels at 24 h indicated disruption of mitochondrial energy metabolism and the slight increase of ATP levels at 36 h indicated partial recovery of mitochondrial function or activated glycolysis in L-02 hepatocytes.


Subject(s)
Animals , Humans , Adenosine Triphosphate/metabolism , Carcinogens, Environmental/toxicity , Chromium/toxicity , Hepatocytes/drug effects , Analysis of Variance , Adenosine Triphosphate/chemistry , Cell Culture Techniques , Chi-Square Distribution , China , Coloring Agents , Cell Survival/drug effects , Hepatocytes/metabolism , Mitochondria, Liver/metabolism , Tetrazolium Salts , Thiazoles
14.
Mem. Inst. Oswaldo Cruz ; 107(2): 170-177, Mar. 2012. graf
Article in English | LILACS | ID: lil-617061

ABSTRACT

Trichomonas vaginalis is a parasite of the human urogenital tract that causes trichomonosis, the most prevalent non-viral sexually transmitted disease. Ectonucleoside triphosphate diphosphohydrolase (NTPDase) family members, which hydrolyse extracellular ATP and ADP and ecto-5′-nucleotidase, which hydrolyses AMP, have been characterised in T. vaginalis. For trichomonad culture, the growth medium is supplemented with 10 percent serum, which is an important source of nutrients, such as adenosine. Here, we investigated the ATP metabolism of T. vaginalis trophozoites from long-term cultures and clinical isolates under limited bovine serum conditions (1 percent serum). The specific enzymatic activities were expressed as nmol inorganic phosphate (Pi) released/min/mg protein, the gene expression patterns were determined by reverse transcriptase-polymerase chain reaction, the extracellular adenine nucleotide hydrolysis was analysed by high performance liquid chromatography and the cell cycle analysis was assessed by flow cytometry. Serum limitation led to the profound activation of NTPDase and ecto-5'-nucleotidase activities. Furthermore, the levels of NTPDase A and B transcripts increased and extracellular ATP metabolism was activated, which led to enhanced ATP hydrolysis and the formation of ADP and AMP. Moreover, the cell cycle was arrested at the G0/G1 stage, which suggested adenosine uptake. Our data suggest that under conditions of serum limitation, NTPDase and ecto-5'-nucleotidase play a role in providing the adenosine required for T. vaginalis growth and that this process contributes to the establishment of parasitism.


Subject(s)
Animals , Cattle , Female , Humans , /metabolism , Adenosine Triphosphate/metabolism , Antigens, CD/metabolism , Apyrase/metabolism , Trichomonas vaginalis/enzymology , Cell Cycle , Chromatography, High Pressure Liquid , Flow Cytometry , Reverse Transcriptase Polymerase Chain Reaction
15.
Article in English | WPRIM | ID: wpr-202334

ABSTRACT

Bisphenol A (BPA) has been reported to possess hepatic toxicity. We investigated the hypothesis that BPA, below the no observed adverse effect level (NOAEL), can induce hepatic damage and mitochondrial dysfunction by increasing oxidative stress in the liver. Two doses of BPA, 0.05 and 1.2 mg/kg body weight/day, were administered intraperitoneally for 5 days to mice. Both treatments impaired the structure of the hepatic mitochondria, although oxygen consumption rate and expression of the respiratory complex decreased only at the higher dose. The hepatic levels of malondialdehyde (MDA), a naturally occurring product of lipid peroxidation, increased, while the expression of glutathione peroxidase 3 (GPx3) decreased, after BPA treatment. The expression levels of proinflammatory cytokines such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) also increased. In HepG2 cells, 10 or 100 nM of BPA also decreased the oxygen consumption rate, ATP production, and the mitochondrial membrane potential. In conclusion, doses of BPA below the NOAEL induce mitochondrial dysfunction in the liver, and this is associated with an increase in oxidative stress and inflammation.


Subject(s)
Adenosine Triphosphate/metabolism , Animals , Glutathione Peroxidase/metabolism , Hep G2 Cells , Humans , Inflammation/chemically induced , Injections, Intraperitoneal , Interleukin-6/metabolism , Lipid Peroxidation/drug effects , Liver/drug effects , Male , Malondialdehyde/metabolism , Membrane Potential, Mitochondrial/drug effects , Mice , Mice, Inbred C57BL , Mitochondria/drug effects , Oxidative Stress/drug effects , Oxygen Consumption/drug effects , Phenols/toxicity , Tumor Necrosis Factor-alpha/metabolism
16.
Arq. bras. cardiol ; 95(2): 264-273, ago. 2010. graf
Article in Portuguese | LILACS | ID: lil-557836

ABSTRACT

FUNDAMENTO: Anormalidades do metabolismo miocárdico têm sido observadas em pacientes com insuficiência cardíaca de diferentes etiologias. A espectroscopia por ressonância magnética (ERM) com fósforo 31 é uma técnica não invasiva que permite a detecção de alterações metabólicas miocárdicas. OBJETIVO: Determinar o metabolismo de repouso dos fosfatos de alta energia em pacientes portadores de doença de Chagas (DC) pela ERM com fósforo 31. MÉTODOS: Foram estudados 39 pacientes com DC, sendo 23 com função ventricular preservada (Grupo FP) e 16 com disfunção ventricular (Grupo DV), avaliados pela ecodopplercardiografia. A ERM da região anterosseptal foi realizada nos 39 pacientes e em 8 indivíduos normais (Grupo C), por meio de um aparelho Phillips de 1,5 Tesla, obtendo-se a relação fosfocreatina/trifosfato de adenosina beta (PCr/β-ATP) miocárdicos. RESULTADOS: Os níveis cardíacos de PCr/β-ATP estavam reduzidos no Grupo DV em relação ao Grupo FP, e estes apresentaram níveis reduzidos em relação ao Grupo C (Grupo DV: 0,89 ± 0,31 vs Grupo FP: 1,47 ± 0,34 vs Grupo C: 1,88 ± 0,08, p < 0,001). Houve correlação entre a fração de ejeção do ventrículo esquerdo e a PCr/β-ATP nos 39 pacientes estudados (r = 0,64, p < 0,001). Os pacientes em classe funcional I (n = 22) apresentaram PCr/β-ATP de 1,45 ± 0,35, e aqueles em classes funcionais II e III (n = 17), PCr/β-ATP de 0,94 ± 0,36 (p < 0,001). CONCLUSÃO: A ERM permitiu detectar de forma não invasiva alterações no metabolismo energético em pacientes com DC, mesmo sem disfunção sistólica; tais alterações estavam relacionadas com a gravidade do comprometimento cardíaco.


BACKGROUND: Abnormalities in myocardial metabolism have been observed in patients with heart failure of different etiologies. Magnetic resonance spectroscopy (MRS) with phosphorus-31 is a noninvasive technique that allows detection of myocardial metabolic changes. OBJECTIVE: To determine the resting metabolism of high-energy phosphates in patients with Chagas' disease (CD) by MRS with phosphorus-31. METHODS: We studied 39 patients with CD, 23 with preserved ventricular function (PF Group) and 16 with ventricular dysfunction (VD Group), assessed by Doppler echocardiography. MRS of the anterosseptal region was performed in 39 patients and 8 normal subjects (C Group) through a Phillips 1.5 Tesla device, obtaining the phosphocreatine/beta-adenosine triphosphate myocardial ratio (PCr/β-ATP). RESULTS: The levels of cardiac PCr/β-ATP were reduced in VD Group in relation to PF Group, and the latter presented reduced levels compared to C Group (VD Group: 0.89 ± 0.31 vs PF Group: 1.47 ± 0.34 vs C Group: 1.88 ± 0.08, p < 0.001). A correlation was found between left ventricular ejection fraction and PCr/β-ATP in 39 patients (r = 0.64, p < 0.001). Patients under functional class I (n = 22) presented PCr/β-ATP of 1.45 ± 0.35, and those in functional classes II and III (n = 17), PCr/β-ATP of 0.94 ± 0.36 (p < 0.001). CONCLUSION: The 31-phosphorus MRS was able to detect non-invasively changes in the rest energy metabolism of patients with Chagas' disease, with and without systolic dysfunction. These changes were related to the severity of heart impairment.


Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Chagas Cardiomyopathy/diagnosis , Energy Metabolism/physiology , Magnetic Resonance Spectroscopy , Phosphates/metabolism , Phosphorus , Ventricular Function/physiology , Adenosine Triphosphate/metabolism , Cardiomyopathy, Dilated/complications , Chagas Cardiomyopathy/metabolism , Chagas Disease/metabolism , Heart Failure/etiology , Myocardium/metabolism , Prospective Studies , Severity of Illness Index
17.
Article in English | WPRIM | ID: wpr-188019

ABSTRACT

Ischemia and reperfusion (I/R) injury is a major cause of hepatic failure after liver surgery, but no method could monitor or predict it real-time during surgery. We measured bioelectrical impedance (BEI) and cell viability to assess the usefulness of BEI during I/R in rat liver. A 70% partial liver ischemia model was used. BEI was measured at various frequencies. Adenosine triphosphate (ATP) content, and palmitic acid oxidation rate were measured, and histological changes were observed in order to quantify liver cell viability. BEI changed significantly during ischemia at low frequency. In the ischemia group, BEI increased gradually during 60 min of ischemia and had a tendency to plateau thereafter. The ATP content decreased below 20% of the baseline level. In the I/R group, BEI recovered to near baseline level. After 24 hr of reperfusion, the ATP contents decreased to below 50% in 30, 60 and 120 min of ischemia and the palmitic acid metabolic rates decreased to 91%, 78%, and 74%, respectively, compared with normal liver. BEI may be a good tool for monitoring I/R during liver surgery. The liver is relatively tolerant to ischemia, however after reperfusion, liver cells may be damaged depending upon the duration of ischemia.


Subject(s)
Adenosine Triphosphate/metabolism , Animals , Cell Survival , Electric Impedance , Energy Metabolism , Ischemia/metabolism , Liver/metabolism , Male , Palmitates/metabolism , Rats , Rats, Sprague-Dawley , Reperfusion , Reperfusion Injury/metabolism
18.
Caracas; s.n; jun. 2009. 226 p. ^c30 cmtab, graf. (Ift4872009574449).
Thesis in Spanish | LILACS, LIVECS | ID: biblio-1179274

ABSTRACT

El presente trabajo involucra el estudio del sistema purinérgico mediante la purinérgico mediante la purificación y la caracterización bioquimica de la ecto-enzima E-NPP3 soluble, la cual modula la activación de los receptores purinérgicos mediante la hidrólisis de los nucleótidos extracelulares. La purificación de esta enzima, expresada en la línea celular CHO-K1, requirió el empleo de diferentes columnas cromatográficas; comprobándose la pureza, mediante la determinación de la actividad enzimática, la cuantificación de las proteínas y la detección de dicha enzima. Los resultados de la caracterización de la E-NPP3 indican que presentan un ph óptimo alcalino y que su actividad depende de la la concentración de los iones calcio y magnesio: mientras que el imidazol y el DDT ejercen acciones inhibidoras sobre su actividad. La purificación de la enzima E-NPP3 soluble representa un primer paso para futuros estudios que permitan su cristalización lo cual, constituirá una herramienta en la elaboración de agonistas y antagonistas selectivos o de anticuerpos monoclonales contra dicha enzima, útiles en el diagnóstico o el tratamiento de condiciones patológicas como el cáncer de colon y la colangiocarcinoma. Adicionalmente, teniendo en cuenta que se ha demostrado la disminución de la expresión de las ecto-nucleotidasas en el uroepitelio de pacientes que padecen cistitis intersticial; el presente trabajo comprende también, el desarrollo de un modelo de órgano aislado, la vejiga urinaria del ratón, para el estudio de la secreción de ATP desde las células uroepiteliales. Dicho modelo permitió demostrar, mediante estudios electrofisiológicos y el uso de diferentes fármacos, la contriución de los receptores purinérgicos sobre la actividad eléctrica del nervio pélvico cuando la vejiga es sometida a distensión mecánica gradual; sugiriendo la importancia de estos receptores en la transducción mecanosensorial de dicho órgano y permitiendo inferir la posible interrelación con los receptores de vaniloides en la detección de los estímulos sensoriales por parte del uroepitelio


Subject(s)
Animals , Mice , Pyrophosphatases/metabolism , Urinary Bladder/cytology , Adenosine Triphosphate/metabolism , Receptors, Purinergic/metabolism , Phosphoric Diester Hydrolases/metabolism , Epithelial Cells/metabolism , Pyrophosphatases/chemistry , Cell Line , Receptors, Purinergic/chemistry , Cholangiocarcinoma/diagnosis , Phosphoric Diester Hydrolases/chemistry , Cystitis, Interstitial/enzymology , Models, Animal , DDT/adverse effects
19.
Indian J Biochem Biophys ; 2009 Feb; 46(1): 86-92
Article in English | IMSEAR | ID: sea-26312

ABSTRACT

The recent upsurge of antimony (Sb) resistance is a major impediment to successful chemotherapy of visceral leishmaniasis (VL). Mechanisms involved in antimony resistance have demonstrated an upregulation of drug efflux pumps; however, the biological role drug efflux pumps in clinical isolates remains to be substantiated. Thus, in this study, the functionality of drug efflux pumps was measured in promastigotes and axenic amastigotes isolated from VL patients, who were either Sb-sensitive (AG83, 2001 and MC9) or resistant (NS2, 41 and GE1) using rhodamine123 as a substrate for multidrug resistant (MDR) pumps and calcein as a substrate for multidrug resistance-associated proteins (MRP) respectively; their specificity was confirmed using established blockers. Sb-resistant (Sb-R) isolates accumulated higher amounts of R123, as compared to Sb-sensitive (Sb-S) isolates. Verapamil, a MDR inhibitor failed to alter R123 accumulation, suggesting absence of classical MDR activity. In Sb-R isolates, both promastigotes and axenic amastigotes accumulated significantly lower amounts of calcein than Sb-S isolates and probenecid, an established pan MRP blocker, marginally increased calcein accumulation. Depletion of ATP dramatically increased calcein accumulation primarily in Sb-R isolates, indicating existence of a MRP-like pump, which was more active in Sb-R isolates. In conclusion, our data suggested that overfunctioning of a MRP-like pump contributed towards generation of Sb-R phenotype in L. donovani field isolates.


Subject(s)
ATP-Binding Cassette Transporters/metabolism , Adenosine Triphosphate/metabolism , Animals , Antimony/pharmacology , Antiprotozoal Agents/pharmacology , Drug Resistance, Multiple , Fluoresceins/metabolism , Humans , Leishmania donovani/drug effects , Leishmania donovani/metabolism , Leishmaniasis, Visceral/drug therapy , Leishmaniasis, Visceral/parasitology , Leishmaniasis, Visceral/physiopathology , Multidrug Resistance-Associated Proteins/antagonists & inhibitors , Multidrug Resistance-Associated Proteins/metabolism , Ofloxacin/pharmacology , Probenecid/pharmacology , Protozoan Proteins/metabolism , Rhodamine 123/metabolism , Verapamil/pharmacology
20.
Yonsei Medical Journal ; : 697-703, 2009.
Article in English | WPRIM | ID: wpr-222144

ABSTRACT

PURPOSE: Adenosine triphosphate-based chemotherapy response assay (ATP-CRA) is a well-documented and validated technology that can individualize chemotherapy for patients with lung, stomach, or breast cancer. This study explored the feasibility of ATP-CRA as a chemosensitivity test in patients with colorectal cancer. MATERIALS AND METHODS: A total of 118 patients who underwent surgical resection for colorectal adenocarcinoma were analyzed for chemosensitivity to 6 anticancer drugs using ATP-CRA. We calculated the cell death rate (CDR) by measuring intracellular ATP levels of drug-exposed cells and untreated controls. RESULTS: Interpretable results were available for 85.5% (118/138) of patients. The mean coefficient of variation for triplicate ATP measurements was 9.2%. The highest CDR was observed in irinotecan (34.0%) and the lowest CDR in etoposide (21.0%). Paclitaxel had the broadest range of CDR (0-86.7%) and 5-FU had the narrowest range of CDR (0-56.8%). The overall highest responsiveness was seen most prevalently in irinotecan (24.7%, 23/93 patients). Irinotecan had the greatest responsiveness in patients with well differentiated and moderately differentiated carcinoma. CONCLUSION: Our study suggests that ATP-CRA could be used to identify patients with colorectal cancer who might benefit from treatment with a specific chemotherapeutic agent.


Subject(s)
Adenocarcinoma/drug therapy , Adenosine Triphosphate/metabolism , Adult , Aged , Aged, 80 and over , Antineoplastic Agents/pharmacology , Colorectal Neoplasms/drug therapy , Drug Screening Assays, Antitumor/methods , Female , Humans , Precision Medicine , Male , Middle Aged , Tumor Cells, Cultured
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