Biomedical subjects

Yi Lin

Publications and source records attributed to Yi Lin.

54 records · Page 3Linked to original sources

PubMed2004

Murine CD45+CD86+ cells isolated from para-aortic lymph nodes in an abortion-prone model.

The present study aims to address whether the analysis of CD45+CD86+ cells isolated from para-aortic lymph nodes (pLNs) is valuable in assessment of the status of local immunity at the murine feto-maternal interface. CBA/J x DBA/2 mice, virgin CBA/J mice, and CBA/J x BALB/c mice were used as an abortion-prone model (group A), nonpregnant controls (group N), and fertile controls (group F), respectively. The percentage of CD45+CD86+ cells in the CD45+ cell group (CD45+CD86+ percentage for short) and the absolute number of these cells were determined by means of flow cytometry (FCM), using mononuclear cells isolated from pLNs collected 5.5, 9.5, and 13.5 days post-coitum (dpc), respectively, and mononuclear cells isolated from placentas 13.5 dpc. To clarify the identity of these CD86+ cells, FCM was also performed with CD3, CD19, and DX5 as specific markers for murine T-cells, B-cells, and NK cells, respectively. Both resorption rate and absolute number of resorptions were significantly higher in group A (29.3%, 1.8+/-1.0) than in group F (4.8%, 0.3+/-0.5, P<0.001, respectively). Similarly, both cell percentage and absolute number of CD45+CD86+ cells in pLNs collected 13.5 dpc were significantly higher in group A than in group F (27.5+/-14.0% versus 12.3+/-7.1%, and 1362+/-687 versus 615+/-353, P=0.001, respectively). The CD45+CD86+ percentage was around 7.5% in nonpregnant CBA/J mice, similar to the 10.6% in CBA/JxDBA/2 mice 5.5 dpc, but had increased dramatically, to 23.9%, by 9.5 dpc (P<0.001 versus nonpregnant mice and P=0.002 versus CBA/JxDBA/2 mice 5.5 dpc), and remained at a higher level (27.5%) until 13.5 dpc. However, this trend was not observed in group F during pregnancy. The increased CD45+CD86+ percentage at day 9.5 of gestation, when resorption begins, may support the assumption that CD45+CD86+ cells play a role in the course of embryo resorption. Lymphocyte phenotypic analysis in the lymph nodes that drain the pregnant uterus may be helpful to assess the status of local immunity at the feto-maternal interface.

Animals↗

PubMed2004

Molecular cloning and sequence analysis of the chitinase gene from Bacillus thuringiensis serovar alesti.

Endogenous chitinase plays a positive role in the pathogenicity of Bacillus thuringiensis to insect pests. The chitinase gene was cloned from B. thuringiensis serovar alesti strain HD-16, and the deduced 676 amino acid sequence showed a high degree of similarity with other Bacillus chitinases. Additionally, the deduced amino acid sequence showed that the protein contained an amino terminus signal peptide and consisted of a catalytic domain, a fibronectin type III domain and a chitin-binding domain. All three domains showed conserved sequences when compared to other bacterial chitinase or cellulase sequences.

Amino Acid Sequence↗

PubMed2004

Mutation analysis of five candidate genes in Chinese patients with hypospadias.

Hypospadias is the displacement of the urethral meatus from the tip of the glans to the ventral side of the phallus. During fetal development, SRY, SOX9, WT1, SRD5A2 and AR are important at different stages in the differentiation and development of the male genital system. Mutations in these genes impair masculinization and may be associated with hypospadias. In order to explore these possibilities, we employed polymerase chain reaction and direct sequencing to analyze the coding regions of these five genes in 90 Chinese hypospadias patients. We found a total of 16 different mutations in SRD5A2, AR and WT1 in 24 of these 90 patients. Seven mutations are novel. No mutation was found in SRY or SOX9. SNP V89L found in SRD5A2 was statistically significant between patients and controls. Our results indicated that mutations in SRD5A2, AR and WT1 were associated with hypospadias. In conclusion, mutations are frequently found in genes that control androgen action and metabolism, but are seldom found in genes active in the early phase of sex determination and differentiation. Mutations in AR, SRD5A2 or WT1 seem to be associated not only with hypospadias but also with micropenis.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗

PubMed2004

[Review and analysis of 283 cases of Kawasaki disease].

OBJECTIVE: The aim of the study was to review the cases of Kawasaki Disease (KD) and analyze the clinical features especially their cardiac complications. METHODS: Totally 283 patients with KD were hospitalized from 1992 to 2002. Their clinical features and factors associated with increased risk of coronary artery aneurysms were reviewed. RESULTS: (1) Among the 283 KD patients, 186 were male and 97 were female. The male-female ratio was 1.9:1. Most of them (71%) were younger than 3 years old. Seasonal peak was in spring and summer (from May to Aug). Depending on the criteria of KD, 228 (81%) were diagnosed as typical KD and 55 (19.4%) were atypical KD. All patients had fever, lasting for 6.1 days. The most common clinical features were oral mucosal changes (97.5%) and cervical lymphadenopathy (95.4%), conjunctivitis (91.2%). And changes in the extremities (89.8%) and rash (81.5%) were also noted. (2) Before the treatment, coronary artery abnormalities were seen in 103/279 (36.9%), which occurred within 4 - 30 days of fever onset. Two weeks after intravenous gamma globulin (IVIG) treatment, the new cases of coronary artery abnormalities were 28/211 (13.3%). The prevalence of coronary artery aneurysms (CAA) with KD was 4.7%. The risk factors of CAA were male cases (P < 0.05) and fever lasting longer than 9 days (P < 0.05). Other cardiac abnormalities in acute phase included left atrial and ventricular enlargement (40/279, 14.3%) and changes in ECG (57/274, 20.8%). The pericardial effusions were found in 11 cases (3.9%). CONCLUSIONS: Cardiac complications of KD occurred in the early period of KD. The new cases of coronary artery abnormalities were 13.3% after IVIG treatment. The risk factors of CAA included male cases and fever lasting for longer time.

Child, Preschool↗

PubMed2004

[Pretreatment and resource utilization of industrial effluent with benzoic acid].

Extraction equilibrium of benzoic acid were studied using 20%, 30% and 50% tributyl phosphate (TBP) in kerosene, 1-octanol and toluene as the extractants, to investigate the efficient method of recovering benzoic and acetic acid in the industrial effluent and meeting the requirement of the terminal wastewater treatment. The CODCr value in residual phase and the recovery of benzoic acid in various extractants were measured. The results showed that the recovery of benzoic acid was closed to 100% with 50% TBP/kerosene system, and depended on the polarity of extractant for pure solvent system. The recovery with 1-octanol was equivalent to the one with 30% TBP. The CODCr value in the residual phase depended on the CODCr value from benzoic acid and the solubility of extractant, which does not depend on the benzoic acid concentration in the residue phase apparently, and shown 50% TBP approximately equal to 30% TBP > 1-octanol > 20% TBP > toluene. Meanwhile, the profitable diagram of pretreatment of industrial effluent with benzoic acid was suggested, i.e. firstly, extract benzoic acid with toluene and return the toluene to the benzoic acid reactor, then, extract acetic acid with trialkylphosphine oxide and back-extract the acetic acid with CaO or MgO to produce calcium magnesium acetate.

1-Octanol↗

PubMed2004

Influence of N,N'-diacetyl-L-cystine on D-galactosamine/lipopolysaccharide induced immunological liver failure in mice.

AIM: To study the therapeutic effects of N,N'-diacetyl-L-cystine (DiNAC) on immunological liver failure. METHODS: Serum ALT, AST and T cell subsets in peripheral blood of the experimental animals during the trial period were analyzed by an automatic serum analyzer and a flow cytometer, respectively. The sectioned liver specimens were examined under a light microscope. And 24 h after the injection of Gal/LPS, the survival rate of rats was calculated. RESULTS: DiNAC (50, 200, 800 mg x kg(-1), i.p.) suppressed the elevation of serum levels of ALT and AST, markedly enhanced proliferation and differentiation of T cell subsets (CD4+, CD8+ and Th1, Th2), and improved all the histopathological features. In mice of fulminant hepatic failure (FHF), the survival time significantly prolonged and the survival rate increased 24 h after i.p. DiNAC. These effects were obviously dose-dependent. CONCLUSION: DiNAC on mice with FHF has an inhibitory action which is related to immune mechanism.

Alanine Transaminase↗

PubMed2003

Analytical method for the determination of atrazine and its dealkylated chlorotriazine metabolites in water using SPE sample preparation and GC-MSD analysis.

A method is reported for the determination of atrazine and its dealkylated chlorotriazine metabolites in ground, surface, and deionized water. Water samples are adjusted to pH 3-4 prior to loading onto two SPE cartridges in series: C-18 and C-18/cation exchange mixed-mode polymeric phases. The analytes are eluted from each of the two cartridges separately, and the pooled and concentrated fraction is analyzed using gas chromatography-mass selective detection in the selected ion monitoring mode. The lower limit of method validation is 0.10 micrograms/L (ppb) for 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine), 2-amino-4-chloro-6-(isopropylamino)-s-triazine (G-30033, deethylatrazine), 2-amino-4-chloro-6-(ethylamino)-s-triazine (G-28279, deisopropylatrazine), and 2,4-diamino-6-chloro-s-triazine (G-28273, didealkyatrazine). The overall mean procedural recoveries (and standard deviations) are 96 (6.9), 96 (5.5), 95 (6.8), and 100% (10%) for atrazine, G-30033, G-28279, and G-28273, respectively (n = 49). The method validation study was conducted under U.S. EPA FIFRA Good Laboratory Practice Guidelines 40 CFR 160. The reported procedure accounts for residues of G-28273 in water.

Atrazine↗

PubMed2003

Immune response in mice inoculated with plasmid DNAs containing multiple-epitopes of foot-and-mouth disease virus.

This paper focuses on the development of candidate DNA vaccine encoding antigenic epitopes of type O foot-and-mouth disease virus (FMDV). A series of plasmids encoding different combinations of B cell epitopes and a T cell epitope were constructed and characterized by inoculating BALB/c mice. The specific antibodies were only detectable in the mice inoculated with plasmids encoding the T cell epitope and B cell epitopes from sites 5 and 1, within which site 5 includes residues 135-167 of VP1 and site 1 includes 141-160 region (G-H loop) and carboxyl terminus of VP1. Stronger cellular immune responses were also observed in these mice using T cell proliferation assay.

Animals↗

PubMed2003

Resistance function of rice lipid transfer protein LTP110.

Plant lipid transfer proteins (LTPs) are a class of proteins whose functions are still unknown. Some are proposed to have antimicrobial activities. To understand whether LTP110, a rice LTP that we previously identified from rice leaves, plays a role in the protection function against some serious rice pathogens, we investigated the antifungal and antibacterial properties of LTP110. A cDNA sequence, encoding the mature peptide of LTP110, was cloned into the Impact-CN prokaryotic expression system. The purified protein was used for an in vitro inhibition test against rice pathogens, Pyricularia oryzae and Xanthomonas oryzae. The results showed that LTP110 inhibited the germination of Pyricularia oryzae spores, and its inhibitory activity decreased in the presence of a divalent cation. This suggests that the antifungal activity is affected by ions in the media; LTP110 only slightly inhibited the growth of Xanthomonas oryzae. However, the addition of LTP110 to cultured Chinese hamster ovarian cells did not retard growth, suggesting that the toxicity of LTP110 is only restricted to some cell types. Its antimicrobial activity is potentially due to interactions between LTP and microbe-specific structures.

Amino Acid Sequence↗

PubMed2003

Nitric oxide-induced inhibition of aortic smooth muscle cell motility: role of PTP-PEST and adaptor proteins p130cas and Crk.

Vascular injury increases nitric oxide (NO) levels, and this effect may play a counterregulatory role in neointima formation, by decreasing vascular smooth muscle cell motility. However, the mechanisms underlying this effect are not well established. We tested the hypothesis that NO decreases cell motility by increasing the activity of a protein tyrosine phosphatase (PTP), PTP-PEST, in cultured rat aortic smooth muscle cells. Two NO donors increased the activity of PTP-PEST. A cGMP analog mimicked the effect of NO, whereas a guanyl cyclase inhibitor blocked it, indicating that elevated cGMP is both necessary and sufficient to induce PTP-PEST activity. Overexpression of wild-type PTP-PEST induced antimotogenesis, whereas expression of dominant negative PTP-PEST blocked the antimotogenic effect of NO, indicating that increased PTP-PEST activity is both sufficient and necessary to explain the effect of NO. Overexpression of PTP-PEST mimicked NO-induced dephosphorylation of adapter protein p130cas, whereas dominant negative PTP-PEST blocked the effect of NO, indicating that upregulation of PTP-PEST is both necessary and sufficient to explain NO-induced p130cas dephosphorylation. Expression of a substrate domain-deleted p130cas decreased motogenesis, whereas overexpression of wild-type p130cas blocked the antimotogenic effect of NO, indicating the functional importance of p130cas dephosphorylation. NO induced dissociation of the Cas-Crk complex, an effect that was mimicked by overexpression of PTP-PEST and opposed by expression of dominant negative PTP-PEST. Our results indicate that NO decreases aortic smooth muscle cell motility via a cGMP-mediated mechanism, involving upregulation of PTP-PEST, in turn inducing dephosphorylation of p130cas, and likely involving Cas-Crk dissociation as a downstream event.

Animals↗

PubMed2003

Protection of tree shrews by pVAX-PS DNA vaccine against HBV infection.

The immunological protection of pVAX-PS, a DNA vaccine, was assessed in the tree shrews model. pVAX-PS was constructed by inserting the gene encoding the middle (pre-S2 plus S) envelope protein of HBV into a plasmid vector pVAX1. Tree shrews (Tupaia belangeri chinenesis) were experimentally infected with human HBV by inoculation with human serum positive for HBV markers. DNA vaccination-induced seroconversion and antibody to HBV surface antigen (anti-HBs) were analyzed by ELISA, and protective effects elicited by pVAX-PS vaccination against subsequent HBV challenge were evaluated by detection of HBV seromarkers and observation of hepatic lesions in HBV-infected tree shrews. The results shown that anti-HBs were detectable in serum at week 2 after pVAX-PS vaccination and peaked at week 4, and immunization with pVAX-PS decreased the positive conversion rate of HBV seromarkers and relieved hepatic lesions in tree shrews challenged with HBV. These results indicated that pVAX-PS immunization could induce remarkable humoral immune response and prevent the experimental tree shrews from infection of HBV.

Animals↗

PubMed2002

Hot-fluid annealing for crystalline titanium dioxide nanoparticles in stable suspension.

Titanium dioxide (TiO(2)) nanoparticles were synthesized by controlled hydrolysis of titanium alkoxide in reverse micelles in a hydrocarbon solvent. Upon annealing in situ in the presence of the micelles at temperatures considerably lower than those required for the traditional calcination treatment in the solid state, the TiO(2) nanoparticles became highly crystalline but still maintained the same physical parameters and remained in a stable suspension. Thus, the method has allowed the preparation of crystalline TiO(2) nanoparticles that are monodispersed in the same way as they are initially produced in the microemulsion. Effects of the fluid properties on the crystallization of nanoparticles are discussed.

Journal Article↗

PubMed2002

NO attenuates insulin signaling and motility in aortic smooth muscle cells via protein tyrosine phosphatase 1B-mediated mechanism.

OBJECTIVE: Hyperinsulinemia is a significant risk factor for the pathogenesis of vascular disease. Protein tyrosine phosphatase 1B (PTP1B) has been recognized as a modulator of insulin signaling in nonvascular cells, and we have recently reported that NO increases the activity of PTP1B in rat vascular smooth muscle cells. In the present study, we tested the hypothesis that NO attenuates insulin-stimulated cell motility via a PTP1B-mediated mechanism involving downregulation of insulin signal transduction. METHODS AND RESULTS: Treatment of primary aortic smooth muscle cells from newborn rats with the NO donor S-nitroso-N-acetylpenicillamine reduced cell motility, tyrosine phosphorylation levels of insulin receptor beta subunit and insulin receptor substrate-1, and extracellular signal-regulated kinase activity. Overexpression of wild-type PTP1B via an adenoviral vector blocked the capacity of insulin to stimulate cell motility and insulin receptor phosphorylation, whereas expression of a dominant-negative mutant of PTP1B attenuated the capacity of NO to decrease cell motility. CONCLUSIONS: Our findings indicate that activation of PTP1B is necessary and sufficient to account for the capacity of NO to decrease insulin-stimulated signal transduction and cell motility in cultured aortic smooth muscle cells. The results could explain the capacity of NO to oppose neointima formation in states of hyperinsulinemia.

Animals↗

PubMed2002

Use of blood outgrowth endothelial cells for gene therapy for hemophilia A.

A culture of human blood outgrowth endothelial cells (BOECs) was established from a sample of peripheral blood and was transfected using a nonviral plasmid carrying complementary DNA for modified human coagulation factor VIII (B domain deleted and replaced with green fluorescence protein). BOECs were then chemically selected, expanded, cryopreserved, and re-expanded in culture. Stably transfected BOECs were administered intravenously daily for 3 days to NOD/SCID mice at 4 cell dose levels (from 5 x 10(4) to 40 x 10(4) cells per injection). In 156 days of observation, mice showed levels of human FVIII that increased with cell dose and time. Mice in all cell dose groups achieved therapeutic levels (more than 10 ng/mL) of human FVIII, and mice in the 3 highest dose groups acquired levels that were normal (100-200 ng/mL) or even above the normal range (highest observed value, 1174 ng/mL). These levels indicate that the BOECs expanded in vivo after administration. When the mice were killed, it was found that BOEC accumulated only in bone marrow and spleen and that these cells retained endothelial phenotype and transgene expression. Cell doses used here would make scale-up to humans feasible. Thus, the use of engineered autologous BOECs, which here resulted in sustained and therapeutic levels of FVIII, may comprise an effective therapeutic strategy for use in gene therapy for hemophilia A.

Animals↗

PubMed2002

Functionalized carbon nanotubes: properties and applications.

Carbon nanotubes can be functionalized via amidation and esterification of the nanotube-bound carboxylic acids. The solubility of these functionalized carbon nanotubes makes it possible to characterize and study the properties of carbon nanotubes using solution-based techniques. Representative results concerning the solubility, dispersion, defunctionalization, and optical properties of the functionalized carbon nanotubes are presented. Several examples for the use of functionalized carbon nanotubes in the fabrication of polymeric carbon nanocomposites, the probing of nanotube-molecule interactions, and the conjugation with biological species are highlighted and discussed.

Animals↗

PubMed2002

Functionalization of carbon nanotubes with bovine serum albumin in homogeneous aqueous solution.

Single-walled (SWNTs) and multiple-walled (MWNTs) carbon nanotubes were solubilized via the esterification of nanotube-bound carboxylic acids by oligomeric polyethylene glycol compounds. The water-soluble samples were used as starting materials in reactions with bovine serum albumin (BSA) protein in ambient aqueous solutions. The reaction conditions were designed for thermodynamically favorable transformation from ester to amide linkages, yielding SWNT-BSA and MWNT-BSA conjugates. The results show that the use of soluble starting nanotube materials in an indirect functionalization method represents a valuable approach to the biomodification of carbon nanotubes.

Esterification↗

PubMed2002

[Expression, purification and function of rice nonspecific lipid transfer protein].

Plant nonspecific lipid transfer protein(nsLTP) is a class of protein which has in vitro lipid transferring activity between biomembranes. In order to study the antimicrobial function of rice nonspecific lipid transfer protein, a gene LTP110 encoding rice nsLTP was cloned into ThioFusion expression vector pET32a (+) and expressed in host strain Bl21(DE3)trxB-. After induction by IPTG at 30 degrees C for 5 h, the fusion protein thio-LTP110 was in large amount produced. The expressed protein was purified by Ni2(+)-chelating Sepharose fast flow column, then digested by enterokinase. By passing through nickel affinity column again, the cleavage product, LTP110, was obtained. CD spectrum scanning from 185 nm to 250 nm showed that the recombinant protein LTP110 had similar secondary structure with the nsLTP purified from rice etiolated seedlings. Activity determination by fluorescent lipid P-96 showed that it had lipid binding activity. Microbial inhibition test results revealed that LTP110 deterred germination of the spores of rice pathogen P. oryzae, showing it might be involved in plant microbial resistance function. Therefore, it has the potential to be used in plant transgene engineering to improve plant resistance.

Antifungal Agents↗

PubMed2002

[Comparison of effects of three chemotherapy regimens for advanced non-small cell lung cancer].

BACKGROUND & OBJECTIVE: The platinum-combination chemotherapy has been proved to be benefit to the patients with advanced non-small cell lung cancer (NSCLC), but the suitable regimen of chemotherapy has been much debated during the last decade. This study was designed to compare MIP regimen [mitomycin + ifosfamid + cisplatin], TP regimen [Taxol + cisplatin], and DP regimen [docetaxel + cisplatin] and to evaluate the efficacy of the three regimens in patients with advanced NSCLC. METHODS: Ninety-two patients were enrolled in this study, 32 for MIP, 30 for TP, and 30 for DP. The characteristics of patients were comparable except there were more stage IV patients and second chemotherapy patients in DP group. RESULTS: For MIP, TP, and DP groups, the objective response rates were 43.8%, 40%, and 46.7%, respectively; the median duration of survival were 11, 10, and 12 months respectively; the 1 year survival rate were 46%, 40%, and 50%, respectively. The major toxicities were bone marrow suppression, nausea, vomiting, and alopecia. CONCLUSIONS: MIP, TP, and DP regimens are effective and safe chemotherapy protocols for the treatment of advanced NSCLC patients.

Antineoplastic Combined Chemotherapy Protocols↗