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Yi Hu

Publications and source records attributed to Yi Hu.

At least 37 records · Page 2Linked to original sources
PubMed2005

Boro-norleucine as a P1 residue for the design of selective and potent DPP7 inhibitors.

Dipeptide-based inhibitors with C-substituted (alkyl or aminoalkyl) alpha-amino acids in the P2 position and boro-norleucine (boro-Nle) in the P1 position were synthesized. Relative to boro-proline, boro-Nle as a P1 residue was shown able to significantly dial out DPP4, FAP, DPP8, and DPP9 activity. Dab-boro-Nle (4g) proved to be the most selective and potent DPP7 inhibitor with a DPP7 IC50 value of 480 pM.

Boronic Acids↗
PubMed2005

Floral gene resources from basal angiosperms for comparative genomics research.

BACKGROUND: The Floral Genome Project was initiated to bridge the genomic gap between the most broadly studied plant model systems. Arabidopsis and rice, although now completely sequenced and under intensive comparative genomic investigation, are separated by at least 125 million years of evolutionary time, and cannot in isolation provide a comprehensive perspective on structural and functional aspects of flowering plant genome dynamics. Here we discuss new genomic resources available to the scientific community, comprising cDNA libraries and Expressed Sequence Tag (EST) sequences for a suite of phylogenetically basal angiosperms specifically selected to bridge the evolutionary gaps between model plants and provide insights into gene content and genome structure in the earliest flowering plants. RESULTS: Random sequencing of cDNAs from representatives of phylogenetically important eudicot, non-grass monocot, and gymnosperm lineages has so far (as of 12/1/04) generated 70,514 ESTs and 48,170 assembled unigenes. Efficient sorting of EST sequences into putative gene families based on whole Arabidopsis/rice proteome comparison has permitted ready identification of cDNA clones for finished sequencing. Preliminarily, (i) proportions of functional categories among sequenced floral genes seem representative of the entire Arabidopsis transcriptome, (ii) many known floral gene homologues have been captured, and (iii) phylogenetic analyses of ESTs are providing new insights into the process of gene family evolution in relation to the origin and diversification of the angiosperms. CONCLUSION: Initial comparisons illustrate the utility of the EST data sets toward discovery of the basic floral transcriptome. These first findings also afford the opportunity to address a number of conspicuous evolutionary genomic questions, including reproductive organ transcriptome overlap between angiosperms and gymnosperms, genome-wide duplication history, lineage-specific gene duplication and functional divergence, and analyses of adaptive molecular evolution. Since not all genes in the floral transcriptome will be associated with flowering, these EST resources will also be of interest to plant scientists working on other functions, such as photosynthesis, signal transduction, and metabolic pathways.

Biodiversity↗
PubMed2005

Gene discovery in Plasmodium vivax through sequencing of ESTs from mixed blood stages.

Despite the significance of Plasmodium vivax as the most widespread human malaria parasite and a major public health problem, gene expression in this parasite is poorly understood. To accelerate gene discovery and facilitate the annotation phase of the P. vivax genome project, we have undertaken a transcriptome approach to study gene expression in the mixed blood stages of a P. vivax field isolate. Using a cDNA library constructed from purified blood stages, we have obtained single-pass sequences for approximately 21,500 expressed sequence tags (ESTs), the largest number of transcript tags obtained so far for this species. Cluster analysis revealed that the library is highly redundant, resulting in 5407 clusters. Clustered ESTs were searched against public protein databases for functional annotation, and more than one-third showed a significant match, the majority of these to Plasmodium falciparum proteins. The most abundant clusters were to genes encoding ribosomal proteins and proteins involved in metabolism, consistent with the predominance of trophozoites in the field isolate sample. In spite of the scarcity of other parasite stages in the field isolate, we could identify genes that are expressed in rings, schizonts and gametocytes. This study should facilitate our understanding of the gene expression in P. vivax asexual stages and provide valuable data for gene prediction and annotation of the P. vivax genome sequence.

Animals↗
PubMed2005

Expression of floral MADS-box genes in basal angiosperms: implications for the evolution of floral regulators.

The ABC model of floral organ identity is based on studies of Arabidopsis and Antirrhinum, both of which are highly derived eudicots. Most of the genes required for the ABC functions in Arabidopsis and Antirrhinum are members of the MADS-box gene family, and their orthologs are present in all major angiosperm lineages. Although the eudicots comprise 75% of all angiosperms, most of the diversity in arrangement and number of floral parts is actually found among basal angiosperm lineages, for which little is known about the genes that control floral development. To investigate the conservation and divergence of expression patterns of floral MADS-box genes in basal angiosperms relative to eudicot model systems, we isolated several floral MADS-box genes and examined their expression patterns in representative species, including Amborella (Amborellaceae), Nuphar (Nymphaeaceae) and Illicium (Austrobaileyales), the successive sister groups to all other extant angiosperms, plus Magnolia and Asimina, members of the large magnoliid clade. Our results from multiple methods (relative-quantitative RT-PCR, real-time PCR and RNA in situ hybridization) revealed that expression patterns of floral MADS-box genes in basal angiosperms are broader than those of their counterparts in eudicots and monocots. In particular, (i) AP1 homologs are generally expressed in all floral organs and leaves, (ii) AP3/PI homologs are generally expressed in all floral organs and (iii) AG homologs are expressed in stamens and carpels of most basal angiosperms, in agreement with the expectations of the ABC model; however, an AG homolog is also expressed in the tepals of Illicium. The broader range of strong expression of AP3/PI homologs is inferred to be the ancestral pattern for all angiosperms and is also consistent with the gradual morphological intergradations often observed between adjacent floral organs in basal angiosperms.

Evolution, Molecular↗
PubMed2005

Subspace algorithms for noise reduction in cochlear implants.

A single-channel algorithm is proposed for noise reduction in cochlear implants. The proposed algorithm is based on subspace principles and projects the noisy speech vector onto "signal" and "noise" subspaces. An estimate of the clean signal is made by retaining only the components in the signal subspace. The performance of the subspace reduction algorithm is evaluated using 14 subjects wearing the Clarion device. Results indicated that the subspace algorithm produced significant improvements in sentence recognition scores compared to the subjects' daily strategy, at least in stationary noise. Further work is needed to extend the subspace algorithm to nonstationary noise environments.

Adult↗
PubMed2005

Comparative genomic analyses in Asparagus.

Garden asparagus (Asparagus officinalis L.) belongs to the monocot family Asparagaceae in the order Asparagales. Onion (Allium cepa L.) and Asparagus officinalis are 2 of the most economically important plants of the core Asparagales, a well supported monophyletic group within the Asparagales. Coding regions in onion have lower GC contents than the grasses. We compared the GC content of 3374 unique expressed sequence tags (ESTs) from A. officinalis with Lycoris longituba and onion (both members of the core Asparagales), Acorus americanus (sister to all other monocots), the grasses, and Arabidopsis. Although ESTs in A. officinalis and Acorus had a higher average GC content than Arabidopsis, Lycoris, and onion, all were clearly lower than the grasses. The Asparagaceae have the smallest nuclear genomes among all plants in the core Asparagales, which typically have huge genomes. Within the Asparagaceae, European Asparagus species have approximately twice the nuclear DNA of that of southern African Asparagus species. We cloned and sequenced 20 genomic amplicons from European A. officinalis and the southern African species Asparagus plumosus and observed no clear evidence for a recent genome doubling in A. officinalis relative to A. plumosus. These results indicate that members of the genus Asparagus with smaller genomes may be useful genomic models for plants in the core Asparagales.

Asparagus Plant↗
PubMed2005

[Predictive value of detection of sentinel lymph nodes on lymphatic metastasis of non-small cell lung cancer].

BACKGROUND & OBJECTIVE: The metastasis status of regional lymph node is an important prognostic factor of non-small cell lung cancer (NSCLC). Sentinel lymph node (SLN) mapping and biopsy is a quick and high efficient technique to intraoperatively detect occult micrometastatic disease, however, its application in NSCLC is immature. This study was designed to investigate the feasibility of detecting SLN in patients with NSCLC during radical surgery, and to evaluate its accuracy of predicting metastasis status of regional lymph node. METHODS: Fifty patients with NSCLC underwent SLN detection. During radical operation, 4 ml of 1% isosulfan blue was injected into the lung tissue around the tumor at 3, 6, 9, and 12 o'clock sites. Location and number of blue dyed SLNs were recorded, and compared with pathologic results to calculate the accuracy and false negative rate of SLN detection. RESULTS: Blue dyed SLNs were seen in 33 patients with a detection rate of 66.0%. SLNs located in N1 lymph node of 24 patients (72.7%), in N2 lymph node of 6 patients (18.2%), in both N1 and N2 lymph nodes of 3 patients (9.1%). Approved by pathology, the accuracy of SLN detection was 87.9% (29/33), the sensibility was 73.3% (11/15), the false negative rate was 26.7% (4/15). CONCLUSION: SLN detection is valuable for predicting hilar and mediastinal lymph nodes metastases in NSCLC.

Adult↗
PubMed2005

[Altered expression of the HSD17B4 gene in esophageal squamous cell carcinoma and loss of heterozygosity analysis].

OBJECTIVE: To investigate the alteration of the gene HSD17B4 in esophageal squamous cell carcinoma and its potential significance. METHODS: The mRNA expression and loss of heterozygosity (LOH) of HSD17B4 in 40 primary esophageal tumors were detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and microsatellite analysis with the intragenic marker D5S1384 of the gene. RESULTS: The frequencies of allelic loss of D5S1384 and the rate of down-regulation of gene HSD17B4 were 46.2% and 62.5%, respectively. CONCLUSION: HSD17B4 may be a candidate tumor suppressor gene associated with esophageal squamous cell carcinoma.

17-Hydroxysteroid Dehydrogenases↗
PubMed2005

[Expression of tick-borne encephalitis virus prM-E protein in insect cells and studies on its antigenicity].

BACKGROUND: To express the prM-E protein in Sf9 cells, and lay a basis for further study on the function of the viral proteins and development of specific diagnostic reagents. METHODS: The recombinant prM-E protein of tick-borne encephalitis virus was expressed in insect cell Sf9 by RT-PCR amplification of prM-E gene, construction of donor plasmid of Bac-to-Bac baculovirus expression system, homologous recombination of donor plasmid with bacmid DNA at the site of Tn7 and transfection of insect cell Sf9. RESULTS: Recombinant subviral particles, about 30 nm in diameter, consisting of prM-E were observed by electron microscope in the supernatant of infected cells, which indicated that infected cells released virus-like particles (VLPs) into the culture medium. The results of Western-blot and the indirect immunofluorescence assay (IFA) showed that the recombinant proteins retained antigenic and conformational structures similar to those of native virus proteins. Using the recombinant prM-E as antigens to detect samples of patient sera by ELISA and IFA, all of 16 sera from patients with tick-borne encephalitis were positive and all of 6 sera from other patients were negative. CONCLUSION: The prM-E protein expressed in insect cells retains good antigenicity.

Animals↗
PubMed2005

[Application of endoscopic ultrasonography to preoperative clinical staging of esophageal cancer].

BACKGROUND & OBJECTIVE: Preoperative clinical staging is the key to choose ideal therapy plan for esophageal cancer. Endoscopic ultrasonography (EUS), an accuracy diagnostic technique for TN staging of esophageal cancer, is used commonly in foreign countries, but seldom in China. This study was to evaluate the application of EUS to preoperative clinical staging of esophageal cancer. METHODS: A total of 72 patients were examined preoperatively with EUS, and staged according to UICC (1997) TNM staging system. The EUS findings were compared with surgical pathologic findings. RESULTS: The accuracy rates of T staging and N staging by EUS were 80.6% (58/72) and 88.9% (64/72), respectively. The accuracy rates of T staging were 50.0% (2/4) for T0, 75.0% (3/4) for T1, 70.6% (12/17) for T2, 90.0% (36/40) for T3, and 71.4% (5/7) for T4; those of N staging were 92.3% (36/39) for N0 and 84.8% (28/33) for N1, of which the accuracy rates of diagnosing mediastinum and abdomen lymph node metastases were 90.0% and 64.5%. The staging results by EUS were significantly accordant with those by surgical pathology: T staging, association coefficient = 0.687, P < 0.001; N staging, association coefficient = 0.878, P < 0.001. Twenty-two cases were staged incorrectly, including 14 cases of T staging, of which 8 cases were due to not distinguishing T2 and T3 correctly, and 8 cases of N staging, of which 5 cases were due to not distinguishing lymphadenitis and metastatic lymph nodes correctly. CONCLUSIONS: The accuracy rate of EUS is high for preoperative staging of esophageal carcinoma, especially for T3 and mediastinum lymph node. Distinguishing T2 and T3, lymphadenitis and metastatic lymph nodes correctly and diagnosing abdomen lymph node metastasis can improve the diagnosis accuracy rate of EUS.

Adenocarcinoma↗
PubMed2004

Versatile protein biotinylation strategies for potential high-throughput proteomics.

We present intein-mediated approaches for efficient biotinylation of proteins site-specifically. The reactive C-terminal thioester generated from intein-assisted protein splicing (either in vitro or in live cells) served as an attractive and exclusive site for attaching cysteine-containing biotin. Using these novel biotinylation strategies, we were able to efficiently biotinylate many proteins from different biological sources in a potentially high-throughput, high-content fashion. Some of these proteins were subsequently immobilized, in a very simple manner, onto different avidin-functionalized solid surfaces for applications such as protein microarray and surface plasmon resonance (SPR) spectroscopy, highlighting the numerous advantages of using biotin over other tags (e.g., GST, His-tag, etc.) as the method of choice in protein purification/immobilization. In addition, our intein-mediated strategies provided critical advantages over other protein biotinylation strategies in a number of ways. For the first time, we also successfully demonstrated that intein-mediated protein biotinylation proceeded adequately inside both bacterial and mammalian living cells, as well as in a cell-free protein synthesis system. Taken together, our results indicate the versatility of these intein-mediated strategies for potential high-throughput proteomics applications. They may also serve as useful tools for various biochemical and biophysical studies of proteins both in vitro and in vivo.

Biotinylation↗
PubMed2004

The GAOLAOZHUANGREN1 gene encodes a putative glycosyltransferase that is critical for normal development and carbohydrate metabolism.

Glycosyltransferases are enzymes that catalyze the attachment of a sugar molecule to specific acceptor molecules. These enzymes have been shown to play important roles in a number of biological processes. Whereas a large number of putative glycosyltransferase genes have been identified by genomic sequencing, the functions of most of these genes are unknown. Here we report the characterization of an Arabidopsis mutant, designated gaolaozhuangren1 (glz1), which is allelic to parvus characterized recently. The glz1 mutant exhibited a reduced plant stature, reduced size of organs in the shoot and dark-green leaves, indicating an important role of GLZ1 gene in normal development. The earliest GLZ1 expression appears at the shoot apical region of 4-d-old seedlings, which coincides with the onset of the glz1 morphological phenotypes. GLZ1 is expressed in a tissue-specific and developmentally regulated manner, predominantly in the stem and silique, and moderately in the flower. GLZ1 expression is strong in the midrib of rosette and cauline leaves; however, its expression was not detectable in the midrib of the cotyledon. Further analyses revealed that carbohydrate composition and distribution were aberrant in the glz1 mutant. These, together with the GLZ1 expression pattern, suggest a requirement for the GLZ1 function in normal sink-source transition during plant development.

Arabidopsis↗
PubMed2004

Recent advances in gel-based proteome profiling techniques.

This review focuses on recent developments in gel-based proteomics techniques. By combining traditional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and two-dimensional gel electrophoretic techniques with recent advances in protein labeling using different classes of molecules (i.e., fluorescent dyes, chemical probes, radioisotopes), new technologies have been developed that allow for high-throughput studies of proteins at the whole-proteome scale.

Electrophoresis, Gel, Two-Dimensional↗
PubMed2004

[Shrinkage of resected specimens of esophageal carcinoma].

BACKGROUND & OBJECTIVE: There are some kinds of shrinkage in resected specimens of esophageal carcinoma; however,there were few reports on its regularity. This study was designed to investigate the degree of shrinkage in resected specimens of esophageal carcinoma. METHODS: Specimens of seventy patients with esophageal squamous cell carcinoma who underwent resections in Cancer Center, Sun Yat-Sen University were collected. The length of the upper margin,the tumor,and the lower margin were measured with a ruler during operation before the esophagus was removed (in situ). After the esophagus was removed, the specimens were cut longitudinally on the side opposite the tumor, then the length of the upper margin, the tumor, and the lower margin were measured again without retraction. After 48 h fixation of 10% formalin (fixed), the length of the upper margin, the tumor, and the lower margin were measured again. RESULTS: After resection,the shrinkage rates of the upper margin, the tumor,and the lower margin were (40.71+/-10.02)%,(83.59+/-16.57)%, and (58.41+/-12.03)% of their in situ length; after 48 h fixation of 10% formalin, the shrinkage rates of the upper margin,the tumor, and the lower margin were (40.06+/-10.50)%, (80.92+/-15.88)%, and (54.83+/-11.29)% of their in situ length (P< 0.05). CONCLUSION: The specimens of esophageal carcinoma shrink remarkably after removed and after formalin fixation.

Esophageal Neoplasms↗
PubMed2004

[Primary central nervous system lymphoma: a report of 28 patients].

OBJECTIVE: To evaluate the clinical characteristics, reasonable mode of treatment and prognostic factors in patients with primary central nervous system lymphoma (PCNSL). METHODS: Twenty-eight patients with PCNSL treated from 1989 to 2002 were retrospectively reviewed. The clinical characteristics, results of treatment and prognostic factors were analyzed by SPSS10.0 statistic software. RESULTS: Of 28 patients, 18 men and 10 women with a median age of 52 years. The median survival time was 2 years (range 6 months-6 years). The 5-year survival rate was 21.4%. Nineteen patients had single-locus lesion and 9 multi-locus lesion, 78.6% of the patients were diagnosed as having B-cell origin, its main type being diffuse large cell lymphoma. According to international working formulation (WF), moderate-grade of histopathology was observed in 57.7% (15/28). Cox regression analysis revealed that single- or multi-locus lesion was only independent prognostic factor (P = 0.0417). Combined chemotherapy showed significant efficacy for those patients who had lesion of B-cell origin, high grade or multi-locus lesion, and the efficacy of irregular chemotherapy was better than that of regular chemotherapy. CONCLUSION: Primary central nervous system lymphoma has a special prognostic factor. Chemotherapy plays a very important role in comprehensive treatment, irregular chemotherapy should be adopted as a regular treatment.

Adolescent↗
PubMed2004

[Health seeking behavior and access to health care among patients with chronic cough diagnosed by county general hospitals in northern parts of Jiangsu province].

OBJECTIVE: To analyze the impact of socioeconomic and demographic factors on health-seeking behavior among patients with long-term chronic cough. METHODS: 310 patients with chronic cough, identified in two county general hospitals from the study sites were involved in a cross-sectional study. Questionnaire and personal interview were used for data collection. Binary logistic regression, Kaplan-Meier method and Cox analysis were applied in multivariate analysis to identify and quantify the impact of individual factors regarding the delay of reaching primary health care provider and the choice of health facility selection. RESULTS: Delay caused by patients themselves showed a difference between the counties with or without the programes. Occupation and medical insurance were associated with patients' health-seeking behavior. Patients under 18 years old had an earlier chance to access the health facility (RR = 1.90, 95% CI: 1.27 - 2.84), and choosing the general hospital as their first preference when seeking healthcare (RR = 2.06, 95% CI: 1.12 - 3.80). Patients with medical insurance were more likely to seek health care service in the general hospitals (RR = 1.64, 95% CI: 1.35 - 2.10). Only 2.5% of the patients with cough longer than two weeks had received sputum smear tests in the general hospitals. CONCLUSION: Occupation, medical insurance had great importance to the health seeking behaviors of patients with chronic cough which had not been viewed as an 'on-the-alert' symptom to be included in the tuberculosis control programs at the general hospitals either in the Programmed or Non-programmed counties in Jiangsu province.

Adolescent↗