Biomedical subjects

Qin Xiao

Publications and source records attributed to Qin Xiao.

8 recordsLinked to original sources

PubMed2026

De novo haplotype-resolved genome assembly of the endemic kiwifruit Actinidia hubeiensis.

The genus Actinidia, which encompasses the widely cultivated kiwifruit, is characterized by its rich species diversity. Wild Actinidia species serve as invaluable germplasm reservoirs for crop improvement. As an important kiwifruit species, Actinidia hubeiensis represents a unique taxonomic group endemic to Hubei Province, contributing valuable genetic diversity to the genus Actinidia. Here, we present a haplotype-resolved genome assembly for A. hubeiensis. The two haplotype assemblies (Hap1 and Hap2) spanned 658.03 Mb (N50 = 23.16 Mb) and 597.19 Mb (N50 = 20.89 Mb), encoding 35,741 and 36,647 high-confidence protein-coding genes, respectively. Based on comprehensive assessments, both haplotypes demonstrated high completeness (BUSCO completeness > 99%), excellent continuity (LAI up to 21.67), low base-error rates (QV > 40), and nearly complete read mapping rates (> 98%). This genome assembly provides crucial genomic resources for the genus, enriching our understanding of kiwifruit biodiversity and offering new insights into the genetic background and evolutionary characteristics of this distinctive species.

Actinidia↗

PubMed2006

Wild-type microglia extend survival in PU.1 knockout mice with familial amyotrophic lateral sclerosis.

The most common inherited form of amyotrophic lateral sclerosis (ALS), a neurodegenerative disease affecting adult motoneurons, is caused by dominant mutations in the ubiquitously expressed Cu(2+)/Zn(2+) superoxide dismutase (SOD1). Recent studies suggest that glia may contribute to motoneuron injury in animal models of familial ALS. To determine whether the expression of mutant SOD1 (mSOD1(G93A)) in CNS microglia contributes to motoneuron injury, PU.1(-/-) mice that are unable to develop myeloid and lymphoid cells received bone marrow transplants resulting in donor-derived microglia. Donor-derived microglia from mice overexpressing mSOD1(G93A), an animal model of familial ALS, transplanted into PU.1(-/-) mice could not induce weakness, motoneuron injury, or an ALS-like disease. To determine whether expression of mSOD1(G93A) in motoneurons and astroglia, as well as microglia, was required to produce motoneuron disease, PU.1(-/-) mice were bred with mSOD1(G93A) mice. In mSOD1(G93A)/PU.1(-/-) mice, wild-type donor-derived microglia slowed motoneuron loss and prolonged disease duration and survival when compared with mice receiving mSOD1(G93A) expressing cells or mSOD1(G93A) mice. In vitro studies confirmed that wild-type microglia were less neurotoxic than similarly cultured mSOD1(G93A) microglia. Compared with wild-type microglia, mSOD1(G93A) microglia produced and released more superoxide and nitrite+nitrate, and induced more neuronal death. These data demonstrate that the expression of mSOD1(G93A) results in activated and neurotoxic microglia, and suggests that the lack of mSOD1(G93A) expression in microglia may contribute to motoneuron protection. This study confirms the importance of microglia as a double-edged sword, and focuses on the importance of targeting microglia to minimize cytotoxicity and maximize neuroprotection in neurodegenerative diseases.

Aging↗

PubMed2006

Protective effects of an anti-inflammatory cytokine, interleukin-4, on motoneuron toxicity induced by activated microglia.

Microglia-mediated cytotoxicity has been implicated in models of neurodegenerative diseases, such as amyotrophic lateral sclerosis, Parkinson's disease and Alzheimer's disease, but few studies have documented how neuroprotective signals might mitigate such cytotoxicity. To explore the neuroprotective mechanism of anti-inflammatory cytokines, we applied interleukin-4 (IL-4) to primary microglial cultures activated by lipopolysaccharide as well as to activated microglia cocultured with primary motoneurons. lipopolysaccharide increased nitric oxide and superoxide (O(2) (.-)) and decreased insulin-like growth factor-1 (IGF-1) release from microglial cultures, and induced motoneuron injury in microglia-motoneuron cocultures. However, lipopolysaccharide had minimal effects on isolated motoneuron cultures. IL-4 interaction with microglial IL-4 receptors suppressed and nitric oxide release, and lessened lipopolysaccharide-induced microglia-mediated motoneuron injury. The extent of nitric oxide suppression correlated directly with the extent of motoneuron survival. Although IL-4 enhanced release of free IGF-1 from microglia in the absence of lipopolysaccharide, it did not enhance free IGF-1 release in the presence of lipopolysaccharide. These data suggest that IL-4 may provide a significant immunomodulatory signal which can protect against microglia-mediated neurotoxicity by suppressing the production and release of free radicals.

Animals↗

PubMed2006

An optimal pooling strategy applied to high-throughput screening for rare marker-free transformants.

An optimal pooling system, called Accurate and Fast Target Screening, has been developed for high-throughput identifying the rare marker-free transformants. This system can identify targets between 10- and 100-fold more efficiently than analysis of individual samples. By calculating the efficiency for different proportions of targets and the optimal group size in a worst case scenario, we are able to estimate an upper limit for the number of tests that are required. The application of this system to determine the transgene in an artificially constructed population of transgenic and non-transgenic wheat lines successfully identified the 10 positive samples located randomly with 990 negative samples using only 92 PCR reactions. The same approach was also applied to determine transgene expression by SDS-PAGE of seed proteins. This system gives unambiguous positive or negative results and should facilitate marker-free transformation.

Algorithms↗

PubMed2006

Comparison of headspace and direct single-drop microextraction and headspace solid-phase microextraction for the measurement of volatile sulfur compounds in beer and beverage by gas chromatography with flame photometric detection.

Three approaches based on headspace single-drop microextraction (HS-SDME), direct single-drop microextraction (Direct-SDME), and headspace solid-phase microextraction (HS-SPME), have been compared for analyzing volatile sulphur compounds (VSCs) in beer and beverage. Procedures and performance of the three methods have been contrasted through the determination of extraction efficiencies, precision, linearity and limits of detection. The overall process of HS-SDME and HS-SPME was applied to GC-FPD determination of five VSCs in beer and beverage.

Beer↗

PubMed2006

[Disequilibrium linkage between the polymorphism in exons 2, 3 and 4 of the MICA gene and HLA-B antigen of patient with ankylosing spondylitis].

OBJECTIVE: To investigate the association between the exons 2 to 4 of the MICA gene and ankylosing spondylitis (AS). METHODS: By PCR-SSOP, DNA samples from 56 AS patients and 112 random healthy individuals, as normal control were genotyped to analyse the polymorphism in exons 2, 3, 4 of the MICA alleles. RESULTS: MICA*008 was dominant in MICA allele,accounted for 32.14% and 30.36% in AS patients and normal controls respectively. The frequency of MICA*007 was significantly increased in AS patients, when compared with normal controls (chi-square=10.18, P<0.05, RR=2.50). No difference was found in the other MICA alleles. The haplotype analysis revealed that there were the strong linkage disequilibrium between MICA and HLA-B of AS patients, and normal controls. There was a difference in MICA*007-B27 between two groups (chi-square=18.46, P<0.05, RR=7.47). Both HLA-B27 and MICA*007 were strongly associated with AS. Stratified analysis showed that HLA-B27 was significantly relative to AS,while it was not found between MICA*007 and AS. CONCLUSION: The increased frequency of MICA alleles may be due to its strong linkage disequilibrium with HLA-B27.

Alleles↗

PubMed2004

Activated microglia initiate motor neuron injury by a nitric oxide and glutamate-mediated mechanism.

Recent studies suggest that motor neuron (MN) death may be non-cell autonomous, with cell injury mediated by interactions involving non-neuronal cells, such as microglia and astrocytes. To help define these interactions, we used primary MN cultures to investigate the effects of microglia activated by lipopolysaccharide or IgG immune complexes from patients with amyotrophic lateral sclerosis. Following activation, microglia induced MN injury, which was prevented by a microglial iNOS inhibitor as well as by catalase or glutathione. Glutamate was also required since inhibition of the MN AMPA/kainate receptor by CNQX prevented the toxic effects of activated microglia. Peroxynitrite and glutamate were synergistic in producing MN injury. Their toxic effects were also blocked by CNQX and prevented by calcium removal from the media. The addition of astrocytes to cocultures of MN and activated microglia prevented MN injury by removing glutamate from the media. The protective effects could be reversed by inhibiting astrocytic glutamate transport with dihydrokainic acid or pretreating astrocytes with H2O2. Astrocytic glutamate uptake was also decreased by activated microglia or by added peroxynitrite. These data suggest that free radicals released from activated microglia may initiate MN injury by increasing the susceptibility of the MN AMPA/kainate receptor to the toxic effects of glutamate.

Amino Acid Transport System X-AG↗

PubMed2004

[Gleason histologic grading of prostate carcinoma in relation to serum PSA, PSA in situ and immunohistochemical expression of 34 beta E12 and P504S].

OBJECTIVE: To study the Gleason histologic grading of prostate carcinoma in relation to the serum prostate-specific antigen (PSA) level and the PSA in situ of the tumor, and the immunohistochemical staining of basal cell-specific cytokertain(34 beta E12) and alpha-Methylacyl-CoA racemase(P504S) of the tumor. METHODS: The serum PSA levels were measured in 40 cases of prostate carcinoma. The Gleason histologic grading was based on histopathologic examination of the tumors, and the immunohistochemical staining including PSA in situ (35 cases), 34 beta E12(12 cases) and P504S(10 cases) was examined. RESULTS: The higher the Gleason histologic grading of prostate carcinoma, the higher the serum PSA level(P < 0.01), and the weaker the positive reaction of the immunohistochemical staining of PSA of the tumor(P < 0.05). And the tumor cells displayed positive reaction for P504S and negative for 34 beta E12. CONCLUSION: The Gleason histologic grading of prostate carcinoma is positively related to the serum PSA level and negatively to PSA in situ of the tumor immunohistochemically. It is important to use immunohistochemical staining for 34 beta E12 and P504S in the pathologic diagnosis of prostate carcinoma.

Aged↗