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1.
Climacteric ; 26(6): 550-559, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37673101

RESUMEN

This study aimed to analyze the effects of physical exercise (PE) on bone health in menopausal women through an umbrella review and to assess the quality of systematic reviews (SRs) and meta-analyses (MAs) included. The review was registered in PROSPERO (CRD42020208130) and the Rayyan application was used. The methodological quality of the included studies was evaluated by A MeaSurement Tool to Assess Systematic Reviews (AMSTAR), and Grading of Recommendations Assessment, Development and Evaluation (GRADE) was applied to assess the level of evidence of the results. The results showed that low-intensity jumping exercises with longer sessions proved to be efficient in the hip segment. Swimming requires further investigation, as it showed high heterogeneity. Aerobic and resistance exercises showed inconsistent results, requiring further studies with these modalities of PE. Concurrent training showed improvements in the lumbar spine, femoral neck, Ward's triangle and trochanter. Finally, combined resistance exercises are effective in preserving bone mineral density (BMD) of the femoral neck and lumbar spine in postmenopausal women. In conclusion, jumping exercises were efficient in the hip, while aerobic and resistance exercises are still inconsistent. Concurrent training showed improvements in BMD of the lumbar spine, femoral neck, Ward's triangle and trochanter. Finally, combined resistance protocols are effective in preserving BMD of the femoral neck and lumbar spine in postmenopausal women.


Asunto(s)
Densidad Ósea , Cuello Femoral , Femenino , Humanos , Ejercicio Físico , Vértebras Lumbares , Menopausia , Revisiones Sistemáticas como Asunto , Metaanálisis como Asunto
2.
J Appl Microbiol ; 130(5): 1758-1769, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33090617

RESUMEN

AIMS: The objective of this study was to evaluate the cytotoxic activity of Cronobacter strains isolated from foods (n = 50) and clinical samples (n = 6) in Brazil and genotype selected strains (n = 18) using multi-locus sequence typing (MLST) METHODS AND RESULTS: The cytotoxic activity of C. sakazakii (n = 29), C. dublinensis (n = 13), C. malonaticus (n = 6), C. turicensis (n = 6) and C. muytjensii (n = 2) was screened using Vero, RK13, Hep2c, NCTC clone 929 and BHK-21 cell lines. Selected Cronobacter strains were assigned to C. sakazakii ST 21, C. turicensis ST 252, C. sakazakii ST 647, and three newly assigned STs: C. turicensis STs 738-740. The maximum death caused by non-heat-treated filtrates was 20·4, 86·2, 47·0 and 84·0%, in Vero, RK13, Hep2c and NCTC clone 929 cells, respectively. These were caused by C. sakazakii strains C291 and C292 (ST 494) which had been isolated during neonatal Cronobacter meningitis infection, and C110 (ST 395) isolated from flaxseed flour. Thermal treatment (100°C/20 min) significantly reduced the cytotoxicity activity in NCTC clone 929 and Vero cells (P ≤ 2 × 10-6 ), but not in RK13 (P = 0·12) and Hep2c (P = 0·85), indicating the cytotoxin(s) were probably proteinaceous. Electron microscopy revealed that cytotoxic compounds from C. sakazakii induced several cell death characteristics, including loss of cell-cell contact, microvilli reduction and cellular lysis. Autophagic vacuoles and mitochondrial damage were the most common ultrastructural features observed. CONCLUSIONS: It was concluded that Cronobacter strains, especially C. sakazakii, could produce heat-labile cytotoxic compounds in cell filtrates. SIGNIFICANCE AND IMPACT OF THE STUDY: This study providing insights into the pathogenesis of the Cronobacter genus. Cytotoxins were identified in excreted filtrates of C. sakazakii strains isolated from food and clinical specimens. The presence of Cronobacter strains that can produce cytotoxins in foods can be a potential threat to human health and highlight the need for high levels of hygiene.


Asunto(s)
Cronobacter/clasificación , Cronobacter/patogenicidad , Microbiología de Alimentos , Meningitis Bacterianas/microbiología , Virulencia , Animales , Brasil , Línea Celular , Supervivencia Celular , Chlorocebus aethiops , Cronobacter/genética , ADN Bacteriano , Infecciones por Enterobacteriaceae/microbiología , Genotipo , Interacciones Huésped-Patógeno , Humanos , Tipificación de Secuencias Multilocus , Células Vero
3.
Genet Mol Res ; 15(4)2016 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-27808379

RESUMEN

The population of Pará (a state in Brazil) has a very characteristic food culture, as a majority of the carbohydrates consumed are obtained from cassava (Manihot esculenta Crantz) derivatives. Tucupi is the boiled juice of cassava roots that plays a major role in the culinary footprint of Pará. Before boiling, this juice is known as manipueira and contains linamarin, a toxic glycoside that can decompose to hydrogen cyanide. In this study, the cytotoxic and genotoxic effects of tucupi on cultured human lymphocytes were assessed using the comet assay and detection of apoptosis and necrosis by differential fluorescent staining with acridine orange-ethidium bromide. Tucupi concentrations (v/v) were determined using the methylthiazole tetrazolium biochemical test. Concentrations of tucupi that presented no genotoxic effects (2, 4, 8, and 16%) were used in our experiments. The results showed that under our study conditions, tucupi exerted no genotoxic effects; however, cytotoxic effects were observed with cell death mainly induced by necrosis. These effects may be related to the presence of hydrogen cyanide in the juice.


Asunto(s)
Bebidas , Calor , Manihot/química , Mutágenos/toxicidad , Raíces de Plantas/química , Adulto , Muerte Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Ensayo Cometa , Daño del ADN , Femenino , Fluorescencia , Humanos , Masculino , Coloración y Etiquetado , Adulto Joven
4.
Genet Mol Res ; 12(4): 4106-15, 2013 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-24114206

RESUMEN

There is a constant search for new cancer treatments that are less aggressive and economically affordable. In this context, natural products extracted from plants, fungi, and microorganisms are of great interest. Pestheic acid, or dihidromaldoxin, is a chlorinated diphenylic ether extracted from the phytopathogenic fungus Pestalotiopsis guepinii (Amphisphaeriaceae). We assessed the cytotoxic, cytostatic, and genotoxic effects of pestheic acid in a gastric adenocarcinoma cell line (PG100). A decrease in clonogenic survival was observed. Pestheic acid also induced significant increases in both micronucleus and nucleoplasmic bridge frequency. However, we did not observe changes in cell cycle kinetics or apoptosis induction. Reactive oxygen species induced by diphenylic ethers may explain the genotoxicity and mutagenicity of pestheic acid. The absence of repair checkpoints that we observed is probably due to the fact that the PG100 cell line lacks the TP53 gene, which is common in gastric cancers. Even though pestheic acid has had a clear cytotoxic effect, the minimal inhibitory concentration was high, which shows that pestheic acid is not an active anticancer compound under these conditions.


Asunto(s)
Antineoplásicos/farmacología , Hidrocarburos Clorados/farmacología , Éteres Fenílicos/farmacología , Adenocarcinoma , Adulto , Apoptosis/efectos de los fármacos , Ascomicetos/química , Puntos de Control del Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Doxorrubicina/farmacología , Humanos , Masculino , Pruebas de Micronúcleos , Neoplasias Gástricas
5.
Phytochem Anal ; 23(5): 529-39, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22323110

RESUMEN

INTRODUCTION: Non-volatile oleoresins from neotropical Burseraceae are traditionally used for craft, technological and medicinal purposes. The crude resin is usually sold in popular markets of the forest communities. Adding value to this rainforest raw material requires establishing its composition. OBJECTIVE: To analyse the resin composition from different Burseraceae species and establish a minimally reproducible profile by gas chromatography, in order to parameterise its quality control. METHODOLOGY: Crude oleoresin samples of 10 Protium and Trattinnickia species and a commercial blend were subjected to hydrodistillation to remove volatile compounds. The chloroform-soluble residues were methylated, analysed by GC-FID (flame ionisation detection), and individual components were identified by analysing their mass fragmentation pattern in GC-MS and comparison with data from the literature. The blend solubility was assayed in 30 non-chlorinated solvents at three different proportions. RESULTS: The resins consisted exclusively of triterpenes, showing a common predominance of four major compounds in all the samples, corresponding to α-amyrin, ß-amyrin, α-amyrenone and ß-amyrenone. This profile was complemented with minor amounts of the tetracyclic ß-elemolic and α-elemolic acids, maniladiol, brein and other oxidised trace compounds. The better solvents for the resin were those chemically bearing more than four carbon atoms, as n-butyl acetate, 2-ethoxyethanol and isopropanol. The crude resin blend sold contained around 10% of insoluble material that was constituted by up to 70% inorganic residues mixed with humic acid derivatives, as attested by ash analysis and IR spectroscopy, respectively. CONCLUSION: The experimental results, complemented by a general inspection of the literature, demonstrated a systematically reproducible triterpene profile in Protium and Trattinnickia species.


Asunto(s)
Burseraceae/química , Extractos Vegetales/química , Resinas de Plantas/química , Destilación/métodos , Cromatografía de Gases y Espectrometría de Masas , Metilación , Estructura Molecular , Peso Molecular , Ácido Oleanólico/análogos & derivados , Ácido Oleanólico/química , Ácido Oleanólico/aislamiento & purificación , Extractos Vegetales/análisis , Control de Calidad , Reproducibilidad de los Resultados , Resinas de Plantas/análisis , Solubilidad , Solventes/química , América del Sur , Triterpenos/análisis , Triterpenos/química , Compuestos Orgánicos Volátiles/química
6.
Heliyon ; 7(8): e07816, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34423146

RESUMEN

Natural products have been used in the treatment of illnesses throughout the history of humankind. Exploitation of bioactive compounds from natural sources can aid in the discovery of new drugs, provide the scaffold of new medicines. In the face of challenging diseases, such as the COVID-19 pandemic, for which there was no effective treatment, nature could offer insights as to novel therapeutic options for control measures. However, the environmental impact and supply chain of bioactive production must be carefully evaluated to ensure the detrimental effects will not outweigh the potential benefits gained. History has already proven that highly bioactive compounds can be rare and not suitable for medicinal exploitation; therefore, the sustainability must be accessed before expensive, time-demanding, and large trials can be initialized. A sustainable option to readily produce a phytotherapy with minimal environmental stress is the use of agro-industry wastes, a by-product produced in high quantities. In this review we evaluate the sustainability issues associated with the production of phytotherapy as a readily available tool for pandemic control.

7.
Genet Mol Res ; 7(3): 872-82, 2008 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-18949706

RESUMEN

Trypanosoma cruzi is the epidemiological agent of Chagas' disease, affecting most of Central and South America, constituting a significant health and socio-economic problem. The parasite has a metabolism largely based on the consumption of amino acids, which participate in a diversity of metabolic pathways, leading to many crucial compounds for the survival of this parasite. Study of its enzymes has the potential to disclose new therapeutic targets and foster the development of new drugs. In this study, we employed computational approaches to reconstruct in silico the amino acid metabolic pathways of T. cruzi, aiming to link genomic information with functional information. For that, protein sequences from 570 EC classes belonging to 25 different pathways in general amino acid metabolism were downloaded from KEGG. A subset of 471 EC classes had at least one sequence deposited. Clustering of the proteins belonging to each EC class was performed using a similarity-based approach implemented in the tool AnEnPi. Reconstruction of the metabolic pathways comprising the amino acid metabolism of T. cruzi was performed by analyzing the output of BLASTP, using as query the dataset of predicted proteins of T. cruzi against all sequences of each individual cluster. This approach allowed us to identify 764 T. cruzi proteins probably involved in the metabolism of amino acids as well as the identification of several putative cases of analogy. Furthermore, we were able to identify several enzymatic activities of T. cruzi that were not previously included in KEGG.


Asunto(s)
Aminoácidos/metabolismo , Biología Computacional/métodos , Redes y Vías Metabólicas , Trypanosoma cruzi/metabolismo , Aminoácidos/genética , Animales , Proteínas Protozoarias/genética , Proteínas Protozoarias/metabolismo , Trypanosoma cruzi/genética
8.
Clin Exp Med ; 6(1): 33-7, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16550342

RESUMEN

Very satisfactory results have been obtained with the treatment of sickle cell anaemia with hydroxyurea (HU), an antineoplastic drug. This is because it significantly increases the levels of foetal haemoglobin. Nevertheless, inadequate dosages or prolonged treatment with this pharmaceutical can provoke cytotoxicity or genotoxicity, increasing the risk of neoplasia. We monitored patients under treatment with HU for possible mutagenic effects, through cytogenetic tests (mitotic index and chromosome aberrations) for one year. Checking at two-month intervals, the cytotoxic effect was not evident. There was no evidence of genotoxicity under the conditions of our experiment. However individuals treated with HU should be constantly monitored, as an absence of genotoxicity could be transitory; the mitotic index should also be observed, as an indicator of cytotoxicity.


Asunto(s)
Anemia de Células Falciformes/tratamiento farmacológico , Antidrepanocíticos/uso terapéutico , Aberraciones Cromosómicas , Hidroxiurea/uso terapéutico , Índice Mitótico , Adolescente , Adulto , Anemia de Células Falciformes/genética , Estudios de Casos y Controles , Niño , Femenino , Humanos , Masculino , Pruebas de Mutagenicidad
9.
Tissue Cell ; 37(5): 413-22, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16140351

RESUMEN

The morphophysiological changes that occur during oocyte primary growth in Serrasalmus spilopleura were studied using ultrastructural cytochemical techniques. In the previtellogenic oocytes endoplasmic reticulum components, Golgi complex cisternae and vesicles, lysosomes, multivesicular bodies and some electron-dense vesicles react to acid phosphatase (AcPase) detection. The endoplasmic reticulum components, Golgi complex cisternae and vesicles also react to osmium tetroxide and potassium iodide impregnation (KI). These structures, except for the Golgi complex cisternae, are strongly contrasted by osmium tetroxide and zinc iodide impregnation (ZIO). Some electron-dense vesicles are ZIO-stained, while microvesicles in the multivesicular bodies and other large isolated cytoplasmic vesicles are contrasted by KI. At primary oocyte growth, the activity of the endomembranous system and the proliferation of membranous organelles are intense. The biosynthetic pathway of the lysosomal proteins such as acid phosphatase, involves the endoplasmic reticulum, Golgi complex, vesicles with inactive hydrolytic enzymes and, finally, the lysosomes. The oocyte endomembranous system have reduction capacity and are involved in the metabolism of rich in SH groups.


Asunto(s)
Peces/anatomía & histología , Peces/fisiología , Oocitos/ultraestructura , Folículo Ovárico/ultraestructura , Fosfatasa Ácida/análisis , Animales , Retículo Endoplásmico/ultraestructura , Femenino , Aparato de Golgi/ultraestructura , Oocitos/química , Oocitos/crecimiento & desarrollo , Tetróxido de Osmio , Fijación del Tejido/métodos
10.
Am J Trop Med Hyg ; 42(5): 429-40, 1990 May.
Artículo en Inglés | MEDLINE | ID: mdl-2111098

RESUMEN

The association between infection with Trypanosoma cruzi and the development of electrocardiographic alterations and mortality was studied longitudinally for 9 years in a population residing in an endemic area in Castro Alves, Bahia, Brazil. Annual censuses were begun in 1973. At 3 year intervals from 1974 to 1983, the population was examined serologically and subjected to electrocardiography using standardized techniques. Of 1,751 individuals registered during the 10 censuses, 1,541 (88%) were examined serologically at least once. Of 747 individuals in constant residence and originally seronegative, 24 were seropositive upon subsequent evaluation, giving a seroconversion rate of 4.92/1,000 person-years (PY). The overall rate of development of an abnormal ECG was 25.7/1,000 PY for seropositive individuals and 12.5/1,000 PY for seronegative individuals, a relative risk of 2. The 10-14-year-old seropositive group had the highest risk of developing ECG abnormalities (24.1/1,000 PY, relative risk = 3.5). The age-adjusted mortality rate of seropositive individuals was slightly higher than for seronegative individuals (8.9 vs. 7.8/1,000 PY). In sero-positive individuals, mortality was strongly associated with the presence of ventricular conduction defects and arrhythmias. Ventricular conduction defects appeared most frequently in younger individuals. Older individuals presented the highest risk of development of frequent and multifocal extrasystoles.


Asunto(s)
Cardiomiopatía Chagásica/epidemiología , Enfermedad de Chagas/epidemiología , Población Rural , Adolescente , Adulto , Anciano , Animales , Anticuerpos Antiprotozoarios/análisis , Brasil/epidemiología , Cardiomiopatía Chagásica/mortalidad , Cardiomiopatía Chagásica/fisiopatología , Enfermedad de Chagas/mortalidad , Enfermedad de Chagas/fisiopatología , Niño , Preescolar , Electrocardiografía , Femenino , Humanos , Lactante , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Prevalencia , Estudios Prospectivos , Trypanosoma cruzi/inmunología
11.
Am J Trop Med Hyg ; 59(5): 736-40, 1998 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9840590

RESUMEN

The northeastern highlands of Brazil are endemic for several tropical diseases, especially American trypanosomiasis (Chagas' disease) and schistosomiasis. Twenty years ago, we measured the seroprevalence of protozoan diseases in Santo Inácio, a village of approximately 1,000 inhabitants located 1,000 m above sea level. We detected small numbers of sera with antibodies against Trypanosoma cruzi and Toxoplasma gondii, and the area had a low prevalence both of American trypanosomiasis (3.54%) and toxoplasmosis (27.43%) compared with nearby Brazilian areas. This was attributed to a specific triatomine vector and local housing conditions. Twenty years later, we again determined the prevalences of both diseases and compared these results with those from Iraquara, a larger town with the same ethnic and social background but with a higher prevalence of rural activities. The incidence of Chagas' disease in San Inácio showed the same low level, i.e., 3.78% (5 of 132) with only adult males affected in contrast with Iraquara, which had an incidence of 34.5%, but a low prevalence of only one of 22 among children up to 14 years of age. Santo Inácio maintained a low (25.8%) seroprevalence for toxoplasmosis. Housewives presented a higher incidence of toxoplasmosis during both periods, probably due to related risk factors. Cats were found less frequently in Santo Inácio than in Iraquara, which showed an incidence of 65.5% seropositivity for Toxoplasma gondii. These results suggest that the environmental conditions of Santo Inácio were preserved after 20 years, with a low incidence of these selected protozoan diseases.


Asunto(s)
Enfermedad de Chagas/epidemiología , Toxoplasmosis/epidemiología , Adolescente , Adulto , Animales , Anticuerpos Antibacterianos/sangre , Anticuerpos Antiprotozoarios/sangre , Proteínas Bacterianas , Brasil/epidemiología , Gatos , Enfermedad de Chagas/inmunología , Niño , Femenino , Estudios de Seguimiento , Humanos , Masculino , Factores de Riesgo , Estudios Seroepidemiológicos , Infecciones Estreptocócicas/epidemiología , Infecciones Estreptocócicas/inmunología , Streptococcus/inmunología , Estreptolisinas/inmunología , Factores de Tiempo , Toxoplasma/inmunología , Toxoplasmosis/inmunología , Trypanosoma cruzi/inmunología
12.
Am J Trop Med Hyg ; 25(4): 552-62, 1976 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-822736

RESUMEN

The prevalence rates and household distribution of seroreactivity to Trypanosoma cruzi by complement fixation (CF) and indirect immunofluorescent antibody methods were determined in a population of 1,087 persons living in a rural area endemic for Chagas' disease in northeast Brazil. There was a gradual rise in the rate of seropositivity to 60% by age 20. Between ages 20 and 55 the prevalence rate remained at about 60%, but declined thereafter. The decline in the older age groups was not accompanied by a fall in geometric mean titer, suggesting that the decline might better be explained by an increased mortality among those seropositive than by a decrease in CF reactivity associated with age. There was variation in the rates of seropositivity in children among the geographic subunits, but the rates among adults were fairly uniform. Household clustering of seropositivity was demonstrated when both household size and age distribution were taken into account. The presence of a seropositive child less than 5 years of age was a good indicator of a household with a high rate of seropositivity; screening for young seropositive children might be a useful tool to locate high risk households. Seropositive children in households where the mother was seropositive but the father seronegative were significantly younger than seropositive children in households where the father was seropositive but the mother seronegative even though the age distribution and the overall rate of seropositivity in both groups of children were similar; thus, conversion to seropositivity earlier in life in children of seropositive mothers may not be due solely to increased exposure, but may indicate that the immunologic response in such children differed from that of children from seronegative mothers.


Asunto(s)
Anticuerpos/análisis , Enfermedad de Chagas/epidemiología , Trypanosoma cruzi/inmunología , Adolescente , Adulto , Anciano , Brasil , Enfermedad de Chagas/inmunología , Niño , Preescolar , Pruebas de Fijación del Complemento , Femenino , Técnica del Anticuerpo Fluorescente , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad
13.
J Hum Hypertens ; 16 Suppl 1: S7-S10, 2002 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11986884

RESUMEN

PREVALENCE: Mean values for prevalence of hypertension in 18 selected populations, varied between 15.7% (BP > or = 95 mm Hg) and 27.7% (BP > or = 90 mm Hg). In three Mall surveys in Salvador (n = 5093 volunteers), prevalence mean value was 33.7% (JNC VI criteria), being influenced by age (5.5 to 17.8% and 41.0 to 54.9% for the 25-34 and 55-59 year old age groups, respectively) and socioeconomic class (24.7 and 39.6% for the highest and lowest social class, respectively, OR = 0.50 (0.26-0.95, P = 0.023). The national prevalence by the Ministry of Health is 20%. MORTALITY AND MORBIDITY: Mortality as a consequence of morbidity has increased, with stroke being a leading cause of death (11.3% of total deaths, 10.1% of all deaths in the 20-59 year-old age group, and 33.9% of cardiovascular deaths in Brazilian Capitals, 1994)Cardiovascular risk factors: At comparable age groups, prevalence of other major cardiovascular risk factors are: smoking approximately 27%, total cholesterol > or =200 mg/dl approximately 32.5%, glucose intolerance approximately 8.0%, diabetes approximately 7.5%, BMI 25-29 approximately 29.1%, BMI > or = 30 approximately 9.6%, and physical inactivity approximately 92%. AWARENESS, TREATMENT, AND CONTROL: Data are very scarce. In the total Mall population (n = 4613) in Salvador, a high blood pressure was present in 24.4% of those who either denied hypertension or ignored blood pressure. Of those who reported to be hypertensives, only 34.5% had their blood pressure <140/90 mm Hg. In a national inquiry including 2519 physicians, 88% would start treatment with drug monotherapy, diuretics (53%), and angiotensin-converting enzyme inhibitor (ACEI) (24%). If blood pressure control is not achieved, 55% will combine with another drug (diuretic + ACEI (46%) or + beta-blocker (24%)), and 33% will increase the dosage. Nonpharmacological treatment would be prescribed for every patient by 17% of the physicians, while 62% would prescribe it for 25% of their patients. Adhesion is better for pharmacological (60%) than for nonpharmacological treatment (8%). FINAL REMARKS: Three Consensus Documents (the most recent in 1998), the creation of the Department of Hypertension Leagues, the Fighting Hypertension National Day, the Confederation of Hypertensive Patients Associations, and the very recent launch of the National Plan for Reorganization of Hypertension and Diabetes Care are some measures being taken in a joint effort of the Ministry of Health and the Brazilian Societies of Cardiology, Hypertension and Nephrology, to strengthen and improve the fight against hypertension.


Asunto(s)
Hipertensión/epidemiología , Adulto , Brasil/epidemiología , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/etiología , Enfermedades Cardiovasculares/prevención & control , Humanos , Hipertensión/complicaciones , Hipertensión/prevención & control , Incidencia , Persona de Mediana Edad , Prevalencia , Factores de Riesgo
14.
Med Sci Sports Exerc ; 23(11): 1289-96, 1991 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1766346

RESUMEN

The purpose of this study was to investigate the possible existence of systematic differences between moment-length properties of the rectus femoris muscle of cyclists/speed skaters and runners. In cycling/speed skating the rectus femoris is used at a shorter length than in running because of the pronounced flexion at the hip joint. It was speculated that using the rectus femoris chronically at different lengths would result in different moment-length relations for the two groups of athletes. Moment-length relations of rectus femoris muscles were determined using an adaptation of procedures outlined in the literature. Four subjects in each group performed 13 isometric knee extensions on a Cybex II dynamometer in each of three testing sessions. Knee and hip angles were varied in a systematic way to allow the determination of moment-length relations over a wide range of normal rectus femoris lengths. It was found that cyclists tended to be stronger at short compared with long rectus femoris lengths, whereas the opposite was true for runners. This finding may be associated with an adaptation of the rectus femoris muscle to the requirements of cycling and running or may show an inherited difference in the muscles of the athletes that existed before they became involved in their respective sports. The data of this study do not allow us to distinguish between these two possible factors.


Asunto(s)
Ciclismo , Pierna/fisiología , Músculos/fisiología , Carrera , Patinación , Adaptación Fisiológica , Adulto , Fenómenos Biomecánicos , Femenino , Humanos , Articulación de la Rodilla/fisiología , Pierna/anatomía & histología , Masculino , Músculos/anatomía & histología , Rango del Movimiento Articular
15.
J Biomech ; 26(8): 945-53, 1993 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8349719

RESUMEN

The purpose of this study was to gain an insight into the mechanisms of force sharing among muscles in a functional group. Tendon force measurements were obtained simultaneously from gastrocnemius, soleus, and plantaris muscles of 10 cats during a variety of different locomotor tasks using strain gauge based force transducers. In particular, tendon forces were measured for conditions where movement speed was altered systematically, and where movement speed was kept constant but external resistance to walking was varied systematically. The results show that forces in the gastrocnemius and plantaris tendons increase with increasing intensities of movement, independent of intensity being altered by varying speed or external resistance. In contrast, peak soleus forces, on an average, remained nearly the same for all conditions; however, substantial modulations in soleus force were observed for consecutive stride cycles. These results suggest that soleus forces are not limited by peripheral (contractile) conditions but by central mechanisms and, further, that these central mechanisms depend on speed of movement and resistance to movement.


Asunto(s)
Tendón Calcáneo/fisiología , Miembro Posterior/fisiología , Músculos/fisiología , Tendones/fisiología , Animales , Fenómenos Biomecánicos , Gatos , Electrodos Implantados , Electromiografía/instrumentación , Locomoción/fisiología , Masculino , Movimiento , Estrés Mecánico , Tarso Animal/fisiología , Transductores , Caminata/fisiología
16.
Tissue Cell ; 33(3): 241-8, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11469537

RESUMEN

The ultrastructural characteristics of the organelles present in Serrasalmus spilopleura oogonia and oocytes undergoing primary growth were described in detail, considering its role in the nuclear and cytoplasmic metabolic processes that occur in these cell types. Even though these cells do not significantly differ from those similar to them that are found in other teleost groups, the analysis of their ultrastructure makes available new data on the reproductive biology of Characiformes.


Asunto(s)
Peces/fisiología , Oocitos/ultraestructura , Oogénesis/fisiología , Animales , División Celular/fisiología , Femenino , Microscopía Electrónica , Oocitos/citología
17.
J Electromyogr Kinesiol ; 8(3): 147-55, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9678149

RESUMEN

The purpose of this study was to revisit the electromyographical (EMG)-force relationship of dynamically contracting muscles using direct measurements of EMG and force in cat hindlimb muscles during locomotion. EMG signals were recorded from the plantaris muscle using bipolar indwelling wire electrodes, and the corresponding forces were measured using a tendon force transducer. Force-time histories of cat plantaris muscle were predicted by estimating selected force parameters from EMG and timing parameters, and then constructing two smoothly fitting quintic spline functions from the estimated force parameters. The force predictions did not contain information on force-length or force-velocity properties of the cat plantaris and did not use instantaneous contractile conditions as input. It was found that two smoothly fitting quintic spline functions provided the required properties to approximate plantaris force-time histories accurately, and approximations of the force-time histories using EMG and timing parameters as input for the quintic splines were good. The root mean square errors (RMS) of the predicted compared to the actual plantaris forces were smaller than corresponding results reported in the literature, even though the prediction model did not require the force-length-velocity properties or the instantaneous contractile conditions of the target muscles as input. From the results obtained in this study, it appears that force-time histories of the cat plantaris muscle during locomotion can be predicted adequately from information obtained using EMG and video records, without information on either the force-length and force-velocity properties, or the instantaneous contractile conditions of the muscle.


Asunto(s)
Electromiografía , Contracción Muscular/fisiología , Músculo Esquelético/fisiología , Algoritmos , Animales , Gatos , Electrodos Implantados , Electromiografía/instrumentación , Predicción , Miembro Posterior/fisiología , Locomoción/fisiología , Modelos Biológicos , Procesamiento de Señales Asistido por Computador , Estrés Mecánico , Tendones/fisiología , Factores de Tiempo , Transductores , Grabación de Cinta de Video
18.
Braz J Med Biol Res ; 30(10): 1187-90, 1997 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9496436

RESUMEN

Rotaviruses and reoviruses are involved in human and animal diseases. It is known that both viruses penetrate the gastrointestinal tract but their interaction with phagocytic cells is unknown. To study this interaction, peritoneal resident phagocytic cells were used and rotavirus and reovirus replication in peritoneal phagocytic cells was observed. However, rotavirus replication in these cells led to the production of defective particles since MA-104 cells inoculated with rotavirus phagocytic cell lysate did not show any evidence of virus replication. On the basis of these results, we suggest that, although reovirus dissemination may be helped by these phagocytic cells, these cells may control rotavirus infection and probably contribute to the prevention of its dissemination.


Asunto(s)
Peritoneo/citología , Fagocitos/virología , Reoviridae/fisiología , Rotavirus/fisiología , Animales , Sistema Digestivo/virología , Ratones
19.
Braz J Med Biol Res ; 31(5): 671-4, 1998 May.
Artículo en Inglés | MEDLINE | ID: mdl-9698773

RESUMEN

In order to evaluate the use of a Western blot methodology for the diagnosis of infectious bursal disease virus (IBDV) infection, chickens were experimentally infected with IBDV strains and tested for the presence of viral antigens and antibodies by a blocking Western blot test (bWB). The viral proteins obtained from the bursa of Fabricius (BF) were transferred to a nitrocellulose membrane after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and the chicken sera obtained by heart puncture were used for the detection of these proteins. In order to eliminate nonspecific reactions, we used a rabbit anti-chicken serum (blocking tool). By the use of the bWB test, two distinct viral proteins of 43-kDa (VP2) and 32-kDa (VP3) were detected. We suggest the use of this methodology for the detection of IBDV infection in animals suspected of having IBDV reinfection and a chronic subclinical form of the disease. With the use of the rabbit anti-chicken sera for blocking, this method is practical, sensitive and less time consuming.


Asunto(s)
Infecciones por Birnaviridae/diagnóstico , Pollos/virología , Virus de la Enfermedad Infecciosa de la Bolsa/aislamiento & purificación , Enfermedades de las Aves de Corral/diagnóstico , Animales , Anticuerpos Antivirales/aislamiento & purificación , Antígenos Virales/aislamiento & purificación , Western Blotting , Virus de la Enfermedad Infecciosa de la Bolsa/inmunología , Proteínas de la Matriz Viral/aislamiento & purificación
20.
Braz J Med Biol Res ; 37(12): 1831-8, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15558189

RESUMEN

Gastric cancer is the second most frequent type of neoplasia and also the second most important cause of death in the world. Virtually all the established cell lines of gastric neoplasia were developed in Asian countries, and western countries have contributed very little to this area. In the present study we describe the establishment of the cell line ACP01 and characterize it cytogenetically by means of in vitro immortalization. Cells were transformed from an intestinal-type gastric adenocarcinoma (T4N2M0) originating from a 48-year-old male patient. This is the first gastric adenocarcinoma cell line established in Brazil. The most powerful application of the cell line ACP01 is in the assessment of cytotoxicity. Solid tumor cell lines from different origins have been treated with several conventional and investigational anticancer drugs. The ACP01 cell line is triploid, grows as a single, non-organized layer, similar to fibroblasts, with focus formation, heterogeneous division, and a cell cycle of approximately 40 h. Chromosome 8 trisomy, present in 60% of the cells, was the most frequent cytogenetic alteration. These data lead us to propose a multifactorial triggering of gastric cancer which evolves over multiple stages involving progressive genetic changes and clonal expansion.


Asunto(s)
Adenocarcinoma/genética , Línea Celular Tumoral , Análisis Citogenético/métodos , Neoplasias Gástricas/genética , Adenocarcinoma/patología , Línea Celular Tumoral/patología , Cromosomas Humanos Par 8 , Células Clonales , Criopreservación , Humanos , Cariotipificación , Masculino , Persona de Mediana Edad , Neoplasias Gástricas/patología , Trisomía/genética , Trisomía/patología
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