Biomedical subjects

Jianghua Chen

Publications and source records attributed to Jianghua Chen.

5 recordsLinked to original sources

PubMed2006

Angelica stimulates proliferation of murine bone marrow mononuclear cells by the MAPK pathway.

Murine bone marrow mononuclear cells (MNC) were isolated and co-incubated with Angelica to investigate its effects on bone marrow cells and the underlying mechanism of action. Angelica stimulates MNC proliferation as determined by the 3-(4, 5-dimethythiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Our results also suggest that the mechanism of action involves the phosphorylation of ERK1/2 and P38, two key proteins in the MAPK pathway. MAPK inhibitors, PD 98059 and SB 203580, block MNC proliferation caused by Angelica. Taken together, our results show that Angelica induces the proliferation of murine MNC by activating ERK1/2 and P38 MAPK proteins.

Angelica sinensis↗

PubMed2006

Control of petal shape and floral zygomorphy in Lotus japonicus.

Zygomorphic flowers, with bilateral (dorsoventral) symmetry, are considered to have evolved several times independently in flowering plants. In Antirrhinum majus, floral dorsoventral symmetry depends on the activity of two TCP-box genes, CYCLOIDEA (CYC) and DICHOTOMA (DICH). To examine whether the same molecular mechanism of floral asymmetry operates in the distantly related Rosid clade of eudicots, in which asymmetric flowers are thought to have evolved independently, we investigated the function of a CYC homologue LjCYC2 in a papilionoid legume, Lotus japonicus. We showed a role for LjCYC2 in establishing dorsal identity by altering its expression in transgenic plants and analyzing its mutant allele squared standard 1 (squ1). Furthermore, we identified a lateralizing factor, Keeled wings in Lotus 1 (Kew1), which plays a key role in the control of lateral petal identity, and found LjCYC2 interacted with Kew1, resulting in a double mutant that bore all petals with ventralized identity to some extents. Thus, we demonstrate that CYC homologues have been independently recruited as determinants of petal identities along the dorsoventral axis in two distant lineages of flowering plants, suggesting a common molecular origin for the mechanisms controlling floral zygomorphy.

Alleles↗

PubMed2005

A putative CENTRORADIALIS/TERMINAL FLOWER 1-like gene, Ljcen1, plays a role in phase transition in Lotus japonicus.

CENTRORADIALIS/TERMINAL FLOWER 1 (CEN/TFL1) genes play an important role in the phase transition of plant flowering. Here we characterized the expression pattern of a CEN/TFL1-like gene, Ljcen1, from Lotus japonicus. Sequence analysis revealed that Ljcen1 shared 67-76% identity to its homologs from a variety of plant species. Ljcen1 transcripts could be detected at the young root tip and reproductive shoot apical meristem of L. japonicus. RNA in situ hybridization analysis revealed that Ljcen1 was continuously expressed in the sub-domain of the primary inflorescence meristem and transiently expressed in the secondary inflorescence meristem. The ectopic expression of Ljcen1 in Arabidopsis driven by double CaMV 35S promoter delayed the flowering. These results suggested that Ljcen1 gene was involved in a conserved CEN/TFL1 pathway that functions in phase transition of shoot apical meristem in L. japonicus.

Amino Acid Sequence↗

PubMed2005

Fast DNA translocation through a solid-state nanopore.

We report experiments and modeling of translocation of double-strand DNA through a siliconoxide nanopore. Long DNA molecules with different lengths ranging from 6500 to 97000 base pairs have been electrophoretically driven through a 10 nm pore. We observe a power-law caling of the translocation time with the length, with an exponent of 1.27. This nonlinear scaling is strikingly different from the well-studied linear behavior observed in similar experiments performed on protein pores. We present a theoretical model where hydrodynamic drag on the ection of the polymer outside the pore is the dominant force counteracting the electrical driving force. We show that this applies to our experiments, and we derive a power-law scaling with an exponent of 1.22, in good agreement with the data.

Computer Simulation↗

PubMed2003

Impact of acute rejection episodes on long-term renal allograft survival.

OBJECTIVE: To assess the impact of the number, and time of acute rejection (AR) and outcome of anti-rejection therapy on the long-term survival of renal allografts and the relative risk factors. METHODS: The Kaplan-Meier analysis and log-rank test were used to calculate the survival rates of patients and grafts in no acute rejection group (NAR, 895 patients), 1 rejection episode group (1AR, 183), 2 and more than 2 rejection episodes group (2AR, 17), acute rejection group [AR (1AR + 2AR), 200], early acute rejection group (within 90 days after transplantation, EAR, 125), late acute rejection group (91 days later, LAR, 58), completely AR reversed group (CAR, 105), and incompletely AR reversed group (IAR, 68). The relative risk factors were analyzed by the Cox proportional hazards regression. RESULTS: The 5- and 10-year survival rates of renal allografts were 75.4% and 17.1% in AR and 93.2% and 86.5% in the NAR group (P < 0.0001). The long-term graft survival was much lower in the 2AR group than in the NAR or 1AR groups (P < 0.0001 and P = 0.002, respectively). It was similar in either the NAR or CAR groups (P = 0.31), but it was significantly lower (P < 0.0001) in the IAR group. Multivariate Cox regression analysis revealed that the outcome of anti-rejection therapy is an important risk factor affecting the long-term survival of allografts. CONCLUSIONS: AR is significantly associated with poor long-term survival of renal allografts. But the long-term graft survival of patients with one acute rejection but completely reversed is not significantly different from that of patients without acute rejection.

Adolescent↗