RESUMEN
The intense inhomogeneous magnetic fields acting on the diamagnetic materials naturally present in cells can generate strong magnetic forces. We have developed a superconducting magnet platform with large gradient high magnetic field (LG-HMF), which can produce three magnetic force fields of -1360, 0, and 1312 T(2)/m, and three corresponding apparent gravity levels, namely 0, 1, and 2-g for diamagnetic materials. In this study, the effects of different magnetic force fields on osteoblast-like cells (MG-63 and MC3T3-E1) viability, microtubule actin crosslinking factor 1 (MACF1) expression and its association with cytoskeleton were investigated. Results showed that cell viability increased to different degrees after exposure to 0 or 1-g conditions for 24 h, but it decreased by about 30% under 2-g conditions compared with control conditions. An increase in MACF1 expression at the RNA or protein level was observed in osteoblast-like cells under the magnetic force field of -1360 T(2)/m (0-g) relative to 1312 T(2)/m (2-g). Under control conditions, anti-MACF1 staining was scattered in the cytoplasm and partially colocalized with actin filaments (AFs) or microtubules (MTs) in the majority of osteoblast-like cells. Under 0-g conditions, MACF1 labeling was concentrated at perinuclear region and colocalization was not apparent. The patterns of anti-MACF1 labeling on MTs varied with MTs' changing under LG-HMF environment. In conclusion, LG-HMF affects osteoblast-like cell viability, MACF1 distribution, expression, and its association with cytoskeleton to some extent.
Asunto(s)
Actinas/metabolismo , Citoesqueleto/metabolismo , Citoesqueleto/efectos de la radiación , Proteínas de Microfilamentos/metabolismo , Microtúbulos/metabolismo , Microtúbulos/efectos de la radiación , Osteoblastos/metabolismo , Animales , Línea Celular , Relación Dosis-Respuesta en la Radiación , Campos Electromagnéticos , Ratones , Osteoblastos/efectos de la radiación , Dosis de RadiaciónRESUMEN
OBJECTIVE: To develop a pair of diagnostic PCR primers for Cryptosporidium parvum. METHODS: A species-specific gene fragment of C. parvum was obtained through RAPD analysis. After the fragment was isolated, purified, cloned and sequenced, a pair of primers FF was designed and synthesised based on the sequence. With the primers, the anticipated fragment in size of 603 bp was amplified by PCR from 2 American strains and 4 Chinese strains of C. parvum. The samples of 35 rabbits feces and 55 human feces were detected by PCR with primers FF and 021, the latter was a species-specific diagnostic primer reported by Morgan. RESULTS: All six strains amplified by the primers FF showed same detection rate with 021. Sensitivity test indicated that DNA of 1 oocyst per gram of feces could be detected by the PCR. CONCLUSION: The primers FF showed high specificity and sensitivity, and can be used for diagnosing Crytosporidium parvum infection.