Biomedical subjects

Xinfang Lu

Publications and source records attributed to Xinfang Lu.

5 recordsLinked to original sources

PubMed2007

Proteomic analysis of cervical-vaginal fluid: identification of novel biomarkers for detection of intra-amniotic infection.

Intra-amniotic infection (IAI) is associated with preterm birth and perinatal mortality. To identify potential biomarkers, we performed a comprehensive survey of the cervical-vaginal fluid (CVF) proteome from a primate IAI model utilizing multidimensional protein identification technology (LC/LC-MS/MS) and MALDI-TOF-MS analyses. Analyses of CVF proteome identified 205 unique proteins and differential expression of 27 proteins in controls and IAI samples. Protein expression signatures and immunodetection of specific biomarkers identified can be employed for noninvasive detection of IAI.

Amniotic Fluid↗

PubMed2006

Genotoxicants target distinct molecular networks in neonatal neurons.

BACKGROUND: Exposure of the brain to environmental agents during critical periods of neuronal development is considered a key factor underlying many neurologic disorders. OBJECTIVES: In this study we examined the influence of genotoxicants on cerebellar function during early development by measuring global gene expression changes. METHODS: We measured global gene expression in immature cerebellar neurons (i.e., granule cells) after treatment with two distinct alkylating agents, methylazoxymethanol (MAM) and nitrogen mustard (HN2). Granule cell cultures were treated for 24 hr with MAM (10-1,000 microM) or HN2 (0.1-20 microM) and examined for cell viability, DNA damage, and markers of apoptosis. RESULTS: Neuronal viability was significantly reduced (p < 0.01) at concentrations > 500 microM for MAM and > 1.0 microM for HN2; this correlated with an increase in both DNA damage and markers of apoptosis. Neuronal cultures treated with sublethal concentrations of MAM (100 microM) or HN2 (1.0 microM) were then examined for gene expression using large-scale mouse cDNA microarrays (27,648). Gene expression results revealed that a) global gene expression was predominantly up-regulated by both genotoxicants; b) the number of down-regulated genes was approximately 3-fold greater for HN2 than for MAM; and c) distinct classes of molecules were influenced by MAM (i.e, neuronal differentiation, the stress and immune response, and signal transduction) and HN2 (i.e, protein synthesis and apoptosis). CONCLUSIONS: These studies demonstrate that individual genotoxicants induce distinct gene expression signatures. Further study of these molecular networks may explain the variable response of the developing brain to different types of environmental genotoxicants.

Alkylating Agents↗

PubMed2005

Standardizing global gene expression analysis between laboratories and across platforms.

To facilitate collaborative research efforts between multi-investigator teams using DNA microarrays, we identified sources of error and data variability between laboratories and across microarray platforms, and methods to accommodate this variability. RNA expression data were generated in seven laboratories, which compared two standard RNA samples using 12 microarray platforms. At least two standard microarray types (one spotted, one commercial) were used by all laboratories. Reproducibility for most platforms within any laboratory was typically good, but reproducibility between platforms and across laboratories was generally poor. Reproducibility between laboratories increased markedly when standardized protocols were implemented for RNA labeling, hybridization, microarray processing, data acquisition and data normalization. Reproducibility was highest when analysis was based on biological themes defined by enriched Gene Ontology (GO) categories. These findings indicate that microarray results can be comparable across multiple laboratories, especially when a common platform and set of procedures are used.

Gene Expression Profiling↗

PubMed2002

Biochemical changes in primary culture of skeletal muscle cells following dimethoate exposure.

In order to investigate the cellular mechanism of muscular weakness in the Intermediate Myasthenia Syndrome (IMS) following acute organophosphate poisoning, we studied the cytotoxicity of dimethoate and its effects on the activity of acetylcholine esterase (AChE), Na+-K+-ATPase, succinate dehydrogenase (SDH), and Ca2+-ATPase in primary cultured skeletal muscle cells. The results showed that the activity of AChE was significantly inhibited in a dose and time-dependent manner when cells were exposed to dimethoate for 2 h, but the expression of heat-shock protein (HSP70) in muscle cells was significantly increased in a time-dependent manner following dimethoate exposure. Dimethoate can significantly increase the activity of Na+-K+-ATPase in the mitochondrial and cytoplasm fraction of muscle cells, and inhibit the activity of Ca2+-ATPase. This study suggests that the disruption of intracellular homeostasis and energy metabolism of the muscle cells may play a role in the etiology of IMS.

Acetylcholinesterase↗

PubMed2002

[The polymorphism of delta-aminolevulinic acid dehydratase and genetic susceptibility to lead toxicity in Uighur and Yi population in China].

OBJECTIVE: To investigate the polymorphism of delta-aminolevulinic acid dehydratase(ALAD) and the genetic susceptibility to lead toxicity in Uighur and Yi population in China. METHODS: The ALAD genotypes were determined by PCR and MspI restriction fragment length polymorphism techniques in 214 Uighur individuals from Xinjiang autonomous region and 144 Yi individuals from Yunnan province. The correlation between the polymorphism of ALAD and blood lead levels, and the factors affecting the latter were explored. RESULTS: The frequencies of the allele ALAD1 and ALAD2 in Uighur are 0.91 and 0.09; and in Yi are 0.98 and 0.02 respectively. In Uighur the average blood lead level was (76 +/- 4) microgram/L, and 25.7% individuals with blood lead level > or = 100 micrograms/L. In Yi the average blood lead level was (50 +/- 16) microgram/L, and 6.3% individuals with blood lead level > or = 100 micrograms/L. However, no statistic correlation between the distribution of ALAD alleles and the blood lead level was found in both populations. CONCLUSION: The genetic susceptibility of ALAD polymorphism to lead toxicity may exhibit in a lead dose-dependent manner.

China↗