Biomedical subjects

R Huang

Publications and source records attributed to R Huang.

203 records · Page 12Linked to original sources

PubMedDate not supplied

Chromone glycosides from Knoxia corymbosa.

Four new chromone glycosides, corymbosins K1-K4 (3-6), together with two known compounds, noreugenin (1) and undulatoside A (2), were isolated from the whole plant of Knoxiacorymbosa (Rubiaceae). The structures of the new compounds were established through extensive NMR or X-ray spectroscopic analysis as 7-O-beta-D-allopyranosyl-5-hydroxy-2-methylchromone (corymbosin K1, 3), 7-O-beta-D-6-acetylglucopyranosyl-5-hydroxy-2-methylchromone (corymbosin K2, 4), 7-O-[6-O-(4-O-trans-caffeoyl-beta-D-allopyranosyl)]-beta-D-glucopyranosyl-5-hydroxy-2-methylchromone (corymbosin K3, 5) and 7-O-[6-O-(4-O-trans-feruloyl-beta-D-allopyranosyl)]-beta-D-glucopyranosyl-5-hydroxy-2- methylchromone (corymbosin K4, 6). Compounds 2-5 were subjected to test their immunomodulatory activity invitro.

Animals↗

PubMedDate not supplied

Biochemical and molecular markers in renal cell carcinoma: an update and future prospects.

Cancer is a big problem in the developed world as well as in developing countries. Renal cell carcinoma (RCC) accounts for approximately 3% of adult malignancies and 90-95% of neoplasms arising from the kidney. RCC is more common in men than in women (2:1), and it most often occurs in patients between the ages of 50-70 years. In all cancers the cancerous cells release particular kind of proteins (called tumour markers) and blood tests are used to detect the presence of these markers. These tumour markers nowadays are an area of interest for oncologists who search for a possible solution in the detection and treatment of RCC. Different kinds of biochemical and molecular markers such as ferritin, MN/CA9, apoptotic index, p53, IL-2, gamma-enolase, CD44, CD95, chromosome instability and loss of heterozygosity have been tested in RCC, but so far no marker fulfils one or the other criteria to be considered as an ideal marker for RCC. This review gives basic and updated information about the different kinds of biomarkers studied in RCC and about the role implementation of genomics and proteomics in RCC.

Adult↗

PubMedDate not supplied

c-fos expression as a marker of central cardiovascular neurons.

Immunohistochemical detection of Fos, the protein product of the immediate-early gene c-fos, was evaluated as a functional marker of central neurons sensitive to a change of blood pressure/blood volume. Controlled hemorrhage and infusion of the hypotensive agent nitroprusside or hydralazine induced the appearance of Fos-immunoreactivity (Fos-IR) in several prominent groups of central neurons: the piriform cortex, bed nucleus of the stria terminalis, islands of Calleja, subfornical organ, central nucleus of the amygdala, parabrachial nucleus, supraoptic and paraventricular nuclei, pontine A5, locus ceruleus, ventrolateral medulla, the nucleus of the solitary tract, area postrema, and intermediolateral cell column in the spinal cord. Elevation of blood pressure by infusion of phenylephrine caused the appearance of Fos-IR in fewer groups of neurons: the bed nucleus of the stria terminalis, central nucleus of the amygdala, parabrachial nucleus, the nucleus of the solitary tract and area postrema. The differential distribution of Fos neurons in hypotensive versus hypertensive animals underscores the potential application of Fos as a metabolic marker in identifying a network of neurons responding to a specific cardiovascular challenge. Further, simultaneous characterization of the transmitter phenotype of Fos-containing neurons offers an additional advantage of this method over other conventional tract-tracing techniques.

Animals↗

PubMedDate not supplied

Measurement of mRNA expression for a variety of cytokines and its receptors in bone marrows of patients with myelodysplastic syndromes.

BACKGROUND: Myelodysplastic syndromes (MDS) are a group of disorders characterized by ineffective and dysplastic haemopoiesis. Previous studies in the lab have shown extensive apoptosis and high levels of transforming growth factor (TGF-beta) and tumor necrosis factor (TNF-alpha) in the stromal layer of MDS bone marrow. The current study focuses on the cytokines expressed in the bone marrow parenchymal cells. MATERIALS AND METHODS: Bone marrow aspirate from 5 normal donors and 26 patients with myelodysplastic syndromes were examined for mRNA expression of tumor necrosis factor alpha (TNF-alpha), macrophage colony stimulating factor (M-CSF), Flt-3 Ligand (Flt-3L), Flt-3 receptor(Flt-3 rec), interleukin 1 beta (IL 1 beta) and interleukin 1 receptor antagonist (IL-1 ra). RESULTS: Comparison of 26 MDS marrows with 5 normals showed a significantly higher value for Flt-3 rec and IL 1 beta (p = 0.031 and p = 0.031) in the former, while only Flt-1 beta rec was considerably higher (p = 0.016) in newly diagnosed patients. In previously diagnosed group, Flt-3 rec (p = 0.001), TNF-alpha (p = 0.04) and IL-1 beta (p = 0.016) were higher than normal while there was no statistically significant difference in the newly versus previously diagnosed MDS cases: CONCLUSION: mRNA expression of all six cytokines measured were considerably higher in MDS when compared to normal and that these levels tend to increase with disease duration. The precise source of these cytokines as well as their role in MDS pathogenesis remains to be determined, but this study confirms our previous reports that there is no dearth of cytokines in these bizarre myelosuppressive states.

Adult↗

PubMedDate not supplied

[Molecular evolution of AdoMet synthetase by DNA recombination with a novel separate-mixing method].

We describe a new approach to in vitro DNA recombination termed Separate-Mixing method in this study. The reaction process of this method consists of two stages: at the first stage the reaction was implemented in two parallel teams, which generated random recombination by template-switching of growing polynucleotides from primers in the presence of unidirectional single-stranded DNA fragments used as templates, and then both teams were mixed together for further extension and recombination of DNA sequences at the second stage. Because of the particular strategy, the reaction process was also accompanied by the other two processes of DNA shuffling and StEP simultaneously. Two AdoMet synthetase genes sam2 from Saccharomyces cerevisiae and metK from Escherichia coli, which have only 56% homology on the DNA level were used for recombination with Separate-Mixing method. DNA recombination was available after a single round of reaction. With sequencing of 10 randomly selected recombinants, no unshuffled parental clone was found, and also no unexpected insertion, deletion or rearrangement was detected. An evolved gene sam' was obtained after screen and selection, which could obviously increase the accumulation of AdoMet in S. cerevisiae.

Directed Molecular Evolution↗