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1.
Public Health ; 174: 74-82, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31323600

RESUMEN

OBJECTIVES: Tobacco use and alcohol use have their origin in adolescence, and risky use of these substances is amongst the leading preventable causes of morbidity and mortality. Health literacy (HL) encompasses the skills that are decisive to make appropriate health decisions in this context. Given the paucity of evidence on the link between HL and adolescents' health behaviors, the present study examined overall HL and different components of HL and their associations with smoking and alcohol use among 13 to 17-year-old Austrian students. STUDY DESIGN: Data were obtained from a national survey carried out in Austria (N = 4219; 56% females) as part of the Health Behaviour in School-aged Children: World Health Organization (WHO) collaborative cross-national study. METHODS: We tested two structural equation models, one including the overall HL scale as the predictor and one with the three subscales of HL 'finding,' 'understanding and appraising,' and 'applying' health-related information as predictors of smoking and alcohol use. RESULTS: Although overall HL was related to all indicators of adolescents' smoking and drinking, the three HL components had differential effects on these behaviors. The easier it was for the participants to 'understand and appraise' and 'apply' health-related information, the less frequently they had smoked and drunk alcohol and the less was the amount of alcohol they had consumed. Contrarily, the easier it was for the participants to 'find' information, the more they had smoked and drunk alcohol. CONCLUSIONS: Our results indicate that availability of health-related information may be insufficient on its own to prevent or reduce risky substance use. This is of particular importance for the development and improvement of primary prevention programs targeting adolescent populations.


Asunto(s)
Conducta del Adolescente/psicología , Consumo de Bebidas Alcohólicas/epidemiología , Alfabetización en Salud/estadística & datos numéricos , Asunción de Riesgos , Fumar/epidemiología , Adolescente , Austria/epidemiología , Femenino , Humanos , Masculino , Estudiantes/psicología , Estudiantes/estadística & datos numéricos , Encuestas y Cuestionarios
2.
J Helminthol ; 93(6): 681-689, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30149813

RESUMEN

As part of the international joint projects working towards the control of taeniosis/cysticercosis in Asia Pacific, epidemiological studies on Taenia solium cysticercosis have been carried out in high-incidence populations, such as minority groups in Thailand. To assess the epidemiology of cysticercotic infections in pigs in the hill-tribe minority villages (Karen) in Tak province, Thailand, we conducted serological screening and necropsies. The patterns of antibody response to T. solium antigens were then investigated using immunoblot assays. Of the 188 pig serum samples tested for antibody responses to partially purified low-molecular-weight antigens of T. solium cyst fluid, positive responses were detected in 37 samples (19.7%). Based on these results, 16 pigs (10 seropositive and 6 seronegative) were necropsied for investigation of cysticerci and intestinal parasites. All seropositive pigs were coinfected with both T. solium and Taenia hydatigena cysticerci, except one, which was infected with T. hydatigena alone. Three of the six seronegative pigs were confirmed to be infected with T. hydatigena. Pigs infected with T. solium showed much stronger antibody responses than those infected with T. hydatigena. Our results demonstrate the co-occurrence of two swine cysticercoses due to T. solium and T. hydatigena in the studied areas. This study also reveals the importance of direct confirmation of the presence of cysticerci by necropsy after serological screening. In addition to the prevalence of swine cysticercosis in these endemic areas, our findings also reveal potential implications for the development of serological diagnostic assays for swine cysticercosis.


Asunto(s)
Coinfección/veterinaria , Cisticercosis/veterinaria , Enfermedades de los Porcinos/parasitología , Taenia/aislamiento & purificación , Teniasis/veterinaria , Animales , Coinfección/epidemiología , Coinfección/parasitología , Cisticercosis/parasitología , Femenino , Humanos , Masculino , Mianmar/epidemiología , Población Rural , Porcinos , Enfermedades de los Porcinos/epidemiología , Taenia/clasificación , Taenia/genética , Taenia solium/genética , Taenia solium/aislamiento & purificación , Taenia solium/fisiología , Teniasis/parasitología , Tailandia/epidemiología
3.
Trop Biomed ; 34(2): 464-470, 2017 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33593030

RESUMEN

A serological survey of pig cysticercosis was conducted in a hill-tribe village at Thai-Myanmar border, Tak province of Thailand in 2012. Sixteen backyard pigs were examined for pig cysticercosis and gastrointestinal helminth infection. In addition to cysticerci of Taenia solium and Taenia hydatigena found outside the gut, nine other helminth species were found in guts: Echinostoma malayanum, Pseudanoplocephala crawfordi, Ascarops dentata, Physocephalus sexalatus, Gnathostoma doloresi, Ascaris suum, Globocephalus sp., Oesophagostomum dentatum and Bourgelatia diducta. The study presents a report for the first time of adult tapeworm, P. crawfordi infection in pigs from Thailand. For medical importance, E. malayanum, P. crawfordi, G. doloresi and A. suum have been confirmed as potentially zoonotic helminths and pigs may act as one of the reservoir hosts for human helminthiases. Pigs of both gender and all ages appeared to be exposed to the parasites equally and did not show any significant difference to these helminth species in richness and total intensity.

4.
J Helminthol ; 88(3): 376-80, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23452760

RESUMEN

Bovine cysticercosis causing damage to the beef industry is closely linked to human taeniasis due to Taenia saginata. In African countries, Taenia spp. from wildlife are also involved as possible sources of infections in livestock. To identify the aetiological agents of bovine cysticercosis in Ethiopia, cysticerci were collected from 41 cattle slaughtered in the eastern and central areas during 2010-2012. A single cysticercus per animal was subjected to the polymerase chain reaction (PCR)-based DNA sequencing of mitochondrial cytochrome c oxidase subunit 1 gene, and the resultant sequence was compared with those of members of the genus Taenia. Although 38 out of 41 cysticerci (92.7%) were identified as T. saginata, three samples (7.3%) showed the hitherto unknown sequences of Taenia sp., which is distantly related to Taenia solium, Taenia arctos and Taenia ovis. Old literatures suggest it to be Taenia hyaenae, but morphological identification of species could not be completed by observing only the larval samples.


Asunto(s)
Enfermedades de los Bovinos/parasitología , Cisticercosis/veterinaria , Variación Genética , Taenia/clasificación , Taenia/genética , Animales , Bovinos , Análisis por Conglomerados , Cisticercosis/parasitología , ADN de Helmintos/genética , ADN Mitocondrial/genética , Complejo IV de Transporte de Electrones/genética , Etiopía , Genotipo , Datos de Secuencia Molecular , Filogenia , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN , Homología de Secuencia , Taenia/aislamiento & purificación
5.
Parasitol Int ; 63(2): 324-6, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24333828

RESUMEN

Cystic echinococcosis (CE) is well known to be an important zoonotic disease and national disease due to the traditional nomadic life style in Mongolia. The present study was carried out to obtain data on the seropositivity to antigen B, in domestic livestock, goats, sheep and cattle, in each province of Mongolia. The seropositivity to antigen B varied by province and ranged from 0% to 25.0% in goats, 0% to 12.5% in sheep, and 0% to 13.3% in cattle. In total, 9.2% of goats, 3.6% of sheep and 5.9% of cattle in Mongolia showed seropositivity.


Asunto(s)
Enfermedades de los Bovinos/parasitología , Equinococosis Hepática/veterinaria , Enfermedades de las Cabras/parasitología , Proteínas del Helminto/inmunología , Lipoproteínas/inmunología , Enfermedades de las Ovejas/parasitología , Animales , Bovinos , Enfermedades de los Bovinos/sangre , Enfermedades de los Bovinos/epidemiología , Equinococosis Hepática/sangre , Equinococosis Hepática/epidemiología , Equinococosis Hepática/inmunología , Enfermedades de las Cabras/sangre , Enfermedades de las Cabras/epidemiología , Cabras , Proteínas del Helminto/sangre , Humanos , Lipoproteínas/sangre , Mongolia/epidemiología , Estudios Seroepidemiológicos , Ovinos , Enfermedades de las Ovejas/sangre , Enfermedades de las Ovejas/epidemiología , Zoonosis
6.
Trop Biomed ; 30(2): 164-73, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23959481

RESUMEN

A 43-year-old Tibetan woman living in northwest Sichuan, China, confirmed to be a taeniasis carrier of Taenia solium was treated with pumpkin seeds combined with Areca nut extract in October 2009. All 20 tapeworms except one without scolex were expelled under good conditions. She was free of secondary cysticercosis within one year follow up. Although the first choice for treatment of taeniasis is still praziquantel, it may often cause serious side effect on asymptomatic cysticercosis cases to suddenly become symptomatic within a half day of the treatment. Therefore, the problems in treatment of taeniasis and/or cysticercosis in Asia are briefly overviewed, since other platyhelminthic diseases including schistosomiasis, opisthorchiasis etc. are more common and praziquantel is strongly recommended for mass treatment of these trematodiases with no idea on the co-infection with eggs of T. solium which cause asymptomatic cysticercosis.


Asunto(s)
Antihelmínticos/administración & dosificación , Extractos Vegetales/administración & dosificación , Taenia solium/efectos de los fármacos , Teniasis/tratamiento farmacológico , Adulto , Animales , Areca/química , China , Cucurbita/química , Femenino , Humanos , Praziquantel/administración & dosificación , Semillas/química , Teniasis/parasitología
7.
Parasitol Res ; 110(6): 2247-54, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22173453

RESUMEN

Kudoa ogawai n. sp. (Myxozoa; Multivalvulida) is described from the trunk muscle of Pacific barrelfish Hyperoglyphe japonica caught in Japan. Oval to ellipsoidal cysts, white to yellowish in colour, 1-2 mm in size, were filled with numerous spores having four polar capsules. Spores were stellate with rounded peripheral edges in apical view, and garlic shaped with four prominent apical projections in side view. Average (range) spore size was 13.3 (12.0-14.2) µm in width and 9.0 (8.3-9.7) µm in length. The spore dimensions and the apical projections of K. ogawai n. sp. were clearly distinguishable from the other muscle-infecting species. Molecular analyses of 18S rDNA and 28S rDNA sequences showed that K. ogawai n. sp. is closely related to Kudo iwatai and Kudoa hemiscylli (95% and 92% genetic similarity, respectively), but the present species is morphologically distinct from the two species. Phylogenetic analysis of 18S and 28S rDNA placed K. ogawai n. sp. sister to all Kudoa spp. available in GenBank.


Asunto(s)
Enfermedades de los Peces/parasitología , Músculos/parasitología , Myxozoa/clasificación , Myxozoa/aislamiento & purificación , Enfermedades Parasitarias en Animales/parasitología , Perciformes/parasitología , Animales , Análisis por Conglomerados , ADN Ribosómico/química , ADN Ribosómico/genética , Japón , Microscopía , Datos de Secuencia Molecular , Myxozoa/anatomía & histología , Myxozoa/genética , Filogenia , ARN Ribosómico 18S/genética , ARN Ribosómico 28S/genética , Análisis de Secuencia de ADN , Esporas/citología
8.
J Helminthol ; 86(4): 391-4, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21929841

RESUMEN

A case of cystic echinococcosis (CE) in a domestic cat is described from Saint Petersburg, Russia. Ultrasonography showed numerous cysts with hyperechoic walls and anechoic contents within the cat's abdominal cavity. Molecular identification based on mitochondrial DNA genes indicated that the causative agent was Echinococcus granulosus sensu stricto (G1 strain). This is the first report of CE in a cat caused by E. granulosus sensu stricto with molecular confirmation.


Asunto(s)
Enfermedades de los Gatos/diagnóstico , Enfermedades de los Gatos/patología , Equinococosis/veterinaria , Echinococcus granulosus/aislamiento & purificación , Abdomen/diagnóstico por imagen , Abdomen/patología , Animales , Enfermedades de los Gatos/parasitología , Gatos , ADN Mitocondrial/química , ADN Mitocondrial/genética , Equinococosis/diagnóstico , Equinococosis/parasitología , Equinococosis/patología , Femenino , Datos de Secuencia Molecular , Federación de Rusia , Análisis de Secuencia de ADN , Ultrasonografía
9.
Transpl Infect Dis ; 13(3): 318-23, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20804536

RESUMEN

Cytomegalovirus (CMV) reinfection of seropositive individuals has been associated with adverse outcomes in organ transplantation and is a frequent cause of congenital infection. Previously we demonstrated that mismatching of CMV glycoprotein H (gH) serotypes was associated with CMV disease after renal transplantation. Because the antigen domain 2 (AD2) epitope of glycoprotein B (gB) is conserved among CMV isolates and is one of the known targets of neutralizing antibodies, in this study we investigated whether antibodies against the epitope contribute to protection from CMV reinfection in renal transplantation, irrespective of gH serological matching. For this purpose, the gB and gH serology and clinical outcomes were analyzed retrospectively for 77 transplant recipients in the donor positive/recipient positive setting, who were managed by preemptive strategy. We found that there was a good negative correlation between the numbers of antigenemia-positive cells and the levels of antibodies against gB AD2 in the CMV-gH antibody matched group, but not in the CMV-gH antibody mismatched group. None of the recipients with antibodies against both gB AD2 and strain-specific epitopes of gH have experienced CMV disease during 6 month after transplantation, while 28% of those who lacked either/both antibody response needed preemptive therapy. Because the outcome was statistically significant, antibodies against gB AD2 can be a useful indicator to predict emergence of CMV disease for preemptive therapy, in addition to antibodies against the mismatched gH types.


Asunto(s)
Anticuerpos Antivirales/sangre , Antígenos Virales/inmunología , Infecciones por Citomegalovirus/inmunología , Epítopos/inmunología , Trasplante de Riñón/efectos adversos , Proteínas del Envoltorio Viral/inmunología , Anticuerpos Antivirales/inmunología , Antígenos Virales/química , Citomegalovirus/clasificación , Citomegalovirus/inmunología , Infecciones por Citomegalovirus/virología , Epítopos/genética , Humanos , Trasplante de Riñón/inmunología , Serotipificación , Especificidad de la Especie , Donantes de Tejidos , Proteínas del Envoltorio Viral/química
10.
Biosystems ; 81(2): 165-77, 2005 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15946790

RESUMEN

We address the controversial hot question concerning the validity of the loose coupling versus the lever-arm theories in the actomyosin dynamics by re-interpreting and extending the phenomenological washboard potential model proposed by some of us in a previous paper. In this new model a Brownian motion harnessing thermal energy is assumed to co-exist with the deterministic swing of the lever-arm, to yield an excellent fit of the set of data obtained by some of us on the sliding of Myosin II heads on immobilized actin filaments under various load conditions. Our theoretical arguments are complemented by accurate numerical simulations, and the robustness of the model is tested via different choices of parameters and potential profiles.


Asunto(s)
Actomiosina/química , Miosina Tipo II/química , Actinas/química , Adenosina Trifosfato/química , Biofisica/métodos , Hidrólisis , Modelos Estadísticos , Miosinas/química , Distribución Normal , Estrés Mecánico
11.
Clin Nephrol ; 58(3): 224-30, 2002 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12356193

RESUMEN

A 23-year-old man was admitted with macrohematuria and systemic edema appearing after an acute upper respiratory tract infection. He had been diagnosed 6 years earlier with IgA nephropathy (IgA-N). On admission, hypertension, nephrotic syndrome and hypocomplementemia were evident together with a high titer of anti-streptokinase (ASK). Renal biopsy showed severe glomerular mesangial proliferation, segmental endocapillary proliferation and crescent formation. Immunofluorescence microscopy (IF) showed strong deposition of C3 and reduced deposition of IgA. Electron microscopy showed a so-called "hump" on the epithelial side of the glomerular basement membrane. These features were consistent with post-streptococcal acute glomerulonephritis (PSAGN) superimposed on IgA-N. Following 2 weeks of observation, blood pressure, C3 level and ASK titer returned to normal ranges, although nephrotic syndrome was still evident, which necessitated oral prednisolone (30 mg/day) therapy. Another biopsy taken 2 months later demonstrated regression of endocapillary proliferation and IF showed decreased deposition of C3. Immunohistochemical staining of the specimen taken on admission revealed the presence of numerous T cells and macrophages in the interstitium. Macrophages were also seen in the glomerular tuft. Many interstitial infiltrating cells were positive for interferon-gamma, but their number diminished after treatment. Our findings suggest that PSAGN complicating pre-existing IgA-N activates cellular immunity and augments renal tissue injury.


Asunto(s)
Glomerulonefritis por IGA/complicaciones , Glomerulonefritis/etiología , Riñón/patología , Adulto , Diagnóstico Diferencial , Glomerulonefritis/patología , Glomerulonefritis por IGA/patología , Humanos , Masculino , Microscopía Fluorescente , Infecciones Estreptocócicas/complicaciones
13.
Science ; 294(5543): 864-7, 2001 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-11679673

RESUMEN

Single-molecule imaging techniques were used to reveal the binding of individual cyclic adenosine 3',5'-monophosphate molecules to heterotrimeric guanine nucleotide-binding protein coupled receptors on the surface of living Dictyostelium discoideum cells. The binding sites were uniformly distributed and diffused rapidly in the plane of the membrane. The probabilities of individual association and dissociation events were greater for receptors at the anterior end of the cell. Agonist-induced receptor phosphorylation had little effect on any of the monitored properties, whereas G protein coupling influenced the binding kinetics. These observations illustrate the dynamic properties of receptors involved in gradient sensing and suggest that these may be polarized in chemotactic cells.


Asunto(s)
Quimiotaxis , AMP Cíclico/metabolismo , Dictyostelium/fisiología , Proteínas de Unión al GTP Heterotriméricas/metabolismo , Receptores de AMP Cíclico/metabolismo , Transducción de Señal , Animales , Carbocianinas/metabolismo , Membrana Celular/metabolismo , Dictyostelium/citología , Dictyostelium/genética , Dictyostelium/metabolismo , Difusión , Guanosina Difosfato/farmacología , Guanosina Trifosfato/farmacología , Proteínas de Unión al GTP Heterotriméricas/genética , Cinética , Microscopía Fluorescente , Mutación , Fosforilación , Seudópodos/metabolismo
14.
Biophys J ; 81(5): 2838-50, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11606295

RESUMEN

The motility of single one-headed kinesin molecules (K351 and K340), which were truncated fragments of Drosophila two-headed kinesin, has been tested using total internal reflection fluorescence microscopy. One-headed kinesin fragments moved continuously along the microtubules. The maximum distance traveled until the fragments dissociated from the microtubules for both K351 and K340 was approximately 600 nm. This value is considerably larger than the space resolution of the measurement system (SD approximately 30 nm). Although the movements of the fragments fluctuated in forward and backward directions, statistical analysis showed that the average movements for both K340 and K351 were toward the plus end of the microtubules, i.e., forward direction. When BDTC (a 1.3-S subunit of Propionibacterium shermanii transcarboxylase, which binds weakly to a microtubule), was fused to the tail (C-terminus) of K351, its movement was enhanced, smooth, and unidirectional, similar to that of the two-headed kinesin fragment, K411. However, the travel distance and velocity of K351BDTC molecules were approximately 3-fold smaller than that of K411. These observations suggest that a single kinesin head has basal motility, but coordination between the two heads is necessary for stabilizing the basal motility for the normal level of kinesin processivity.


Asunto(s)
Adenosina Trifosfatasas/metabolismo , Transferasas de Carboxilo y Carbamoilo/metabolismo , Cinesinas/metabolismo , Microtúbulos/metabolismo , Fragmentos de Péptidos/metabolismo , Secuencia de Aminoácidos , Animales , Drosophila , Datos de Secuencia Molecular , Movimiento/fisiología , Propionibacterium
16.
Am J Physiol Renal Physiol ; 281(3): F513-21, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11502600

RESUMEN

Unilateral ureteral obstruction (UUO) leads to interstitial fibrosis of the obstructed kidney, and transforming growth factor-beta1 (TGF-beta1) is thought to play an important role in this process. Although increased TGF-beta1 mRNA expression in the obstructed kidney has been demonstrated, the source of the increased TGF-beta1 remains to be elucidated. To determine the precise localization of TGF-beta1 in the obstructed kidney, we examined TGF-beta1 mRNA expression using in situ hybridization and competitive RT-PCR in rats with UUO. In situ hybridization demonstrated that TGF-beta1 mRNA expression was preferentially increased in tubular epithelial cells and to a lesser degree in infiltrating macrophages in obstructed kidneys. Quantitative analysis using competitive RT-PCR in microdissected nephron segments revealed that levels of TGF-beta1 mRNA in obstructed kidneys relative to control kidneys increased significantly in proximal tubules, thick ascending limbs of Henle, and distal convoluted tubules, whereas those in glomeruli and collecting ducts did not change significantly. Of the tubular segments, the proximal tubules appeared to predominantly contribute to increased TGF-beta1 mRNA. Our findings suggest that renal tubules, particularly proximal tubules, are the main contributors to increased TGF-beta1 mRNA expression in obstructed kidneys and to the subsequent interstitial fibrosis.


Asunto(s)
Nefronas/fisiopatología , ARN Mensajero/análisis , Transcripción Genética , Factor de Crecimiento Transformador beta/genética , Obstrucción Ureteral/genética , Obstrucción Ureteral/fisiopatología , Animales , Modelos Animales de Enfermedad , Hibridación in Situ , Macrófagos/fisiología , Masculino , Nefronas/citología , Nefronas/patología , Ratas , Ratas Sprague-Dawley , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Obstrucción Ureteral/patología , Urotelio/citología , Urotelio/patología , Urotelio/fisiopatología
17.
J Leukoc Biol ; 70(3): 413-21, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11527991

RESUMEN

To assess the role of bone marrow in the pathogenesis of rheumatoid arthritis (RA), we examined the capacity of CD34(+) cells from bone marrow to generate fibroblast-like type B synoviocytes. CD34(+) cells from the bone marrow of 22 RA patients differentiated into cells with fibroblast-like morphology, which expressed prolyl 4-hydroxylase, in the presence of stem cell factor (SCF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and tumor necrosis factor alpha (TNF-alpha), much more effectively than CD34(+) cells from bone marrow of 15 control subjects (10 patients with osteoarthritis and 5 healthy individuals). The generation of fibroblast-like cells was not at all observed in cultures with SCF, GM-CSF, and interleukin 4 (IL-4) with or without TNF-alpha. Generation of fibroblast-like cells was correlated with matrix metalloproteinase (MMP)-1 levels in culture supernatants. Thus, MMP-1 levels were significantly higher in TNF-alpha-stimulated cultures of bone marrow CD34(+) cells from patients with RA than in those from the control group. These results indicate that bone marrow CD34(+) cells from patients with RA have abnormal capacities to respond to TNF-alpha and to differentiate into fibroblast-like cells producing MMP-1, suggesting that bone marrow CD34(+) progenitor cells might generate type B synoviocytes and thus could play an important role in the pathogenesis of RA.


Asunto(s)
Antígenos CD34/análisis , Artritis Reumatoide/etiología , Células de la Médula Ósea/citología , Fibroblastos/citología , Adulto , Anciano , Artritis Reumatoide/enzimología , Artritis Reumatoide/patología , Células de la Médula Ósea/química , Células de la Médula Ósea/efectos de los fármacos , Diferenciación Celular , Células Cultivadas , Femenino , Fibroblastos/enzimología , Factor Estimulante de Colonias de Granulocitos y Macrófagos/farmacología , Humanos , Masculino , Metaloproteinasa 1 de la Matriz/biosíntesis , Persona de Mediana Edad , Procolágeno-Prolina Dioxigenasa/biosíntesis , Factor de Células Madre/farmacología , Células Madre/química , Células Madre/citología , Células Madre/efectos de los fármacos , Membrana Sinovial/citología , Factor de Necrosis Tumoral alfa/farmacología
18.
Trends Biochem Sci ; 26(7): 438-44, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11440856

RESUMEN

In recent years, the rapid development and progress of single-molecule detection techniques have opened up a new era of biological research. The advantage of single-molecule studies is that data are not obscured by the ensemble-averaged measurements inherent in classical biochemical experiments. These techniques are shedding light on the dynamic and mechanistic properties of molecular machines, both in vivo and in vitro. This review summarizes the single-molecule experiments that have been designed to investigate molecular motors, enzyme reactions, protein dynamics, DNA transcription and cell signaling.


Asunto(s)
Biotecnología/instrumentación , Biotecnología/métodos , ADN/ultraestructura , Cinesinas/química , Transcripción Genética , Actinas/química , Adenosina Trifosfatasas/metabolismo , Animales , Humanos , Canales Iónicos/química , Microscopía Fluorescente , Modelos Biológicos , Miosinas/química , Transducción de Señal
19.
Trends Biotechnol ; 19(6): 211-6, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11356282

RESUMEN

The development of nanomanipulation techniques has given investigators the ability to manipulate single biomolecules and to record mechanical events of biomolecules at the single molecule level. The techniques were developed to elucidate the mechanism of molecular motors. We can directly monitor the unitary process of the mechanical work and the energy conversion processes by combining these techniques with the single molecule imaging techniques. Our results strongly suggest that the sliding movement of the actomyosin motor is driven by Brownian movement. Other groups have reported data that are more consistent with the lever arm model. These methods and imaging techniques enable us to monitor the behavior of biomolecules at work and will be applied to other molecular machines.


Asunto(s)
Micromanipulación/métodos , Biología Molecular/métodos , Miosinas/fisiología , Citoesqueleto de Actina/fisiología , Actinas/fisiología , Adenosina Trifosfato/metabolismo , Fenómenos Biomecánicos , Dineínas/fisiología , Cinesinas/fisiología , Rayos Láser , Microtúbulos/metabolismo
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