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Biomedical subjects

Y Qi

Publications and source records attributed to Y Qi.

At least 73 records · Page 4Linked to original sources
PubMed2000

A precolumn derivatization high-performance liquid chromatographic method with improved sensitivity and specificity for the determination of astragaloside IV in Radix Astragali.

A reversed-phase high-performance liquid chromatographic method is developed for the determination of astragaloside (AGS) IV, which is known as the active constituent of Radix Astragali. The method uses precolumn derivatization with benzoyl chloride to form the benzoyl ester of AGS IV quantitatively and is carried out with a wide-ranging concentration (0.004-0.080 mg/mL) of the derivatized AGS IV. The eluent consists of 90% methanol, 4% tetrahydrofuran, 6% water, and 0.2% triethylamine, with vitamin D3 added as the internal standard.

Chromatography, High Pressure Liquid↗
PubMed2000

Chronic alcohol ingestion induces osteoclastogenesis and bone loss through IL-6 in mice.

To investigate the role of IL-6 in alcohol-mediated osteoporosis, we measured a variety of bone remodeling parameters in wild-type (il6(+/+)) or IL-6 gene knockout (il6(-/-)) mice that were fed either control or ethanol liquid diets for 4 months. In the il6(+/+) mice, ethanol ingestion decreased bone mineral density, as determined by dual-energy densitometry; decreased cancellous bone volume and trabecular width and increased trabecular spacing and osteoclast surface, as determined by histomorphometry of the femur; increased urinary deoxypyridinolines, as determined by ELISA; and increased CFU-GM formation and osteoclastogenesis as determined ex vivo in bone marrow cell cultures. In contrast, ethanol ingestion did not alter any of these parameters in the il6(-/-) mice. Ethanol increased receptor activator of NF-kappaB ligand (RANKL) mRNA expression in the bone marrow of il6(+/+) but not il6(-/-) mice. Additionally, ethanol decreased several osteoblastic parameters including osteoblast perimeter and osteoblast culture calcium retention in both il6(+/+) and il6(-/-) mice. These findings demonstrate that ethanol induces bone loss through IL-6. Furthermore, they suggest that IL-6 achieves this effect by inducing RANKL and promoting CFU-GM formation and osteoclastogenesis.

Absorptiometry, Photon↗
PubMed2000

Effect of low water activity on staphylococcal enterotoxin A and B biosynthesis.

Staphylococcus aureus strains FDA 743 (staphylococcal enterotoxin A [SEA]-producing), FDA 778 (staphylococcal enterotoxin B [SEB]-producing), and S6 (SEA- and SEB-producing) were used to examine the effect of low water activity (a(w)) on SEA and SEB biosynthesis. In this report, we show that SEB production is more sensitive to low a(w) than SEA production. We also show that when proline is available as a compatible solute for S. aureus, SEB production is significantly stimulated at low a(w). This stimulatory effect was not observed when other compatible solutes (i.e., glycine betaine or carnitine) were added to low a(w) growth media. Finally, Northern blot analysis revealed that the stimulation of SEB production at low a(w) by added proline occurs at the level of transcription.

Blotting, Northern↗
PubMed2000

Heritability of the blood pressure response to acute ethanol exposure in five inbred strains of mice.

BACKGROUND: Chronic alcohol consumption is a major risk factor for hypertension. There is evidence in humans that the susceptibility to alcohol-related hypertension may vary based on genotype. As a first step in investigating the genetic basis for alcohol-related hypertension, the current study was designed to assess the heritability of the blood pressure response to acute ethanol exposure by using AKR/J (AK), C57BL/6J (B6), DBA/2J (D2), Balb/cJ (Balb), and A/J (A) mice. METHODS: Mean arterial pressure (MAP) was recorded continuously for 24 hr in freely moving mice from an indwelling femoral catheter before we tested the effects of saline or ethanol (2 g/kg ip) on blood pressure. RESULTS: Relative to saline, ethanol caused a pressor response that peaked within 10 min, followed by a decline in MAP. Strain A mice had a significantly greater pressor response to ethanol than other strains and did not show a decline in MAP below baseline. All other strains showed a progressive fall in blood pressure below baseline across the 60 min measurement interval. Heritability was estimated to be 0.62 for the pressor response and 0.64 for the maximal depressor response. Repeated doses of ethanol at 1 hr intervals in A and B6 mice (0, 2, 1.5, 1.5, 1.5 g/kg ip) resulted in a dose-dependent increase in MAP in A mice for the first three doses and a dose-dependent decrease in MAP in B6 mice that was independent of blood ethanol concentrations. CONCLUSION: The results indicate that there is a significant genetic component to the acute blood pressure response to ethanol.

Animals↗
PubMed2000

[A comparison of malignant fibrous histiocytoma of head, neck and extremities].

OBJECTIVE: To compare the epidemiology, local and regional invasion and prognosis of head and neck, malignant fibrous histiocytoma (MFH) and extremity MFH. METHODS: Between January 1, 1972 and December 31, 1993, 173 patients with MFH (71 head and neck, 102 extremities and trunk) were referred to the Cancer Hospital for surgical treatment. They were 101 men and 72 women, with age ranging from 13 to 83 years (median: 45 years). The extent of surgery was classified into radical, wide and local resection. RESULTS: For head and neck, local recurrence of MFH after wide resection was 80.4% (37/46), compared with 36.4% (8/22) after radical surgery (P = 0.000). The five-year survival was 50.79% in all the head and neck patients (74.75% in patients free of local recurrence, 37.74% in patients with local recurrence; P = 0.0181), compared with 70.71% in extremity patients (P = 0.0005). Repeated surgery after recurrence of MFH could cure 40.9% of the head and neck patients and 80.7% of the extremity patients. CONCLUSION: Inadequate resection of head and neck MFH in initial surgery is associated with a high incidence of local recurrence, which is always correlated with worse prognosis. Repeated surgery for recurrent head and neck MFH is not as effective as for recurrent extremity MFH. Therefore, we suggest that the initial surgery for head and neck MFH should be as radical as allowed to avoid a possible local recurrence.

Adolescent↗
PubMed2000

[Genetic epidemiologic study of mitochondrial DNA 7445A-->G mutation among non-syndromic deafness in Chinese population].

OBJECTIVE: To study the Mitochondrial DNA 7445A-->G mutation in nonsyndromic deafness patients in Chinese population. METHOD: Polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) were used to screen the mitochondrial DNA 7445A-->G mutation among 128 nonsyndromic deafness individuals from 32 pedigrees, 135 sporadic nonsyndromic deafness patients and 100 normal subjects. RESULT: The 7445A-->G mutation did not appear in the experiment. CONCLUSION: Incidence of the mitochondrial 7445A-->G mutation was lower than that of mtDNA 1555A-->G mutation in nonsyndromic deafness patients in China.

China↗
PubMed2000

[Construction of a novel Bm NPV Bac to Bac system].

A Bi-Shuttle vector Bm-Bacmid was constructed by co-infecting Bm N cells with wild type genomic DNA from BmNPV and Ac-Bacmid DNA. It could not only replicate in E. coli cells as a large plasmid and but also remain infectious when induced into Bm N or Sf9 cells. Recombinant virus rBmHBe was obtained after transposition of a donor plasmid carrying Hepatitis Be antigen gene (HBeAg) into att Tn7, and was demonstrated by Southern blotting. SDS-PAGE analysis showed that HBeAg gene were highly expressed in Bm N cells. By ELISA testing, the highest antigenecity titer of HBeAg protein in cell cultural medium was up to a dilution of 1:32,000. Although HBeAg protein also presented in the Bm N cells the titer was only 1:2000. The HBcAg protein was much fewer than HBeAg (< 1:160) whatever in culture medium and in cells. The results showed that Bm N cells was able to recognize the signal peptide sequence and cut it correctly for HBeAg protein's excreting production.

Animals↗
PubMed2000

[Production of monoclonal antibodies to broad bean wilt virus and application in virus detection].

Six hybridoma cell lines secretion monoclonal antibodies(MAbs) against broad bean wilt virus(BBWV) were produced by fusing mouse myeloma cells(SP 2/0) with spleen cells from BAL B/c immunized by the BBWV particles. The hybridoma cell lines secreted MAbs stably after cultured in vitro for 3 months or stored in liquid nitrogen and then revived for several times. The titres of ascitic fluids of six MAbs ranged from 1:256,000 to 1:640,000 when measured by indirect ELISA. In agarose gel immunodiffusion test, it showed that the six MAbs represented the same isotype of murine antibodies, IgG1. Six MAbs could detect 4 tested BBWV isolates, but didn't crossreact with other 5 plant viruses. The result of Western blot showed that all the six MAbs can react with the 44.7 kD large coat protein subunit of BBWV. This is the first report of production of MAbs against BBWV.

Animals↗
PubMed2000

[Detection of cucumber mosaic virus subgroup II isolate from tobacco plants in Yunnan province].

One of the spherical virus(designated as CMV-YNb) was isolated form the tobacco plants in Yunnan province. SDS-PAGE showed that this virus contained one polypeptide with molecular weights of 55 kD. The polypeptide was submitted to automated Edman degradation, and found the 10 amino acid sequence of the N-terminus of 55 kD protein shares 100% identity with amino acid sequence of coat protein of CMV-Q, which is belong to CMV Subgroup II. Western blot analysis also showed that this 55 kD protein was serological related to CMV-Q. A 0.9 kb cDNA fragment was amplified by RT-PCR from the RNA template of CMV-YNb with the QCf/QCr primer pair, which was designed according to the CP gene sequence of CMV-Q. The cDNA fragment was then cloned and sequenced. The fragment comprises 865 bp (EMBL accession number: AJ242585), including a 197 bp of 5' intergenic region, 657 bp of CP gene encoding 158 amino acids and a 11 bp of 3' partial non-coding region. Comparison of the nucleotide and amino acid sequences of CMV-YNb CP gene with that of CMV strains belonging to Subgroup II, and that of CMV strains belonging to subgroup I showed 97%-98% and 96%-99%, 75%-76% and 78%-79% identities, respectively. With these data, we made a conclusion that the CMV-YNb is an isolate of CMV Subgroup II.

Amino Acid Sequence↗
PubMed2000

[Pedicled galeal flap in the reconstruction of head and neck tumor defects].

OBJECTIVE: To evaluate the advantage and applications of pedicled galeal flap in head and neck region. METHODS: A consecutive series of 17 patients underwent surgical reconstruction with pedicled galeal flaps after head and neck tumor resection. The defects included nasopharynx, skull base, maxilla, orbital base, oropharynx and oral cavity and the size ranged from 5 cm x 5 cm to 10 cm x 10 cm. The technique for using this flap was described and application was illustrated with 3 case reports. RESULTS: Complete success of galeal flaps for the reconstruction of head and neck defects was achieved in 13 of the 17 cases (76.5%) and partial necrosis was observed in the remaining 4 cases (23.4%). Immediate wound complications occurred in four cases, which resolved spontaneously. Four delayed complications were observed in 4 of 9 survival cases that included trismus (3) and alopecia (1). CONCLUSION: Galeal flap is a thin, pliable and well vascularised reconstruction tissue and is highly reliable. The donor site morbidity is minor. We have found the flap to be useful in the reconstruction of a variety of defects in head and neck, especially in skull base, orbital base, nasopharynx and oropharynx.

Adolescent↗
PubMed2000

[Prevention and management of complications with laparoscopy cholecystectomy].

OBJECTIVE: To prevent the complication of laparoscopy cholecystectomy (LC). METHODS: This text analysed 1,200 cases retrospectively with LC from Feb. 1993 to May. 1998. RESULTS: Three cases with biliferous duct injury, two cases with bile leakage from the stamp of cystic duct, two cases with gallbladder artery injury. CONCLUSIONS: Strict preoperative examination and standard operative procedure can reduce markedly complication of LC.

Bile Ducts↗
PubMed1999

Three amino acid residues determine selective binding of FK506-binding protein 12.6 to the cardiac ryanodine receptor.

FK506-binding protein (FKBP12) has been found to be associated with the skeletal muscle ryanodine receptor (RyR1) (calcium release channel), whereas FKBP12.6, a novel isoform of FKBP, is selectively associated with the cardiac ryanodine receptor (RyR2). For both RyRs, the stoichiometry is 4 FKBP/RyR. Although FKBP12.6 differs from FKBP12 by only 18 of 108 amino acids, FKBP12.6 selectively binds to RyR2 and exchanges with bound FKBP12.6 of RyR2, whereas both FKBP isoforms bind to RyR1 and exchange with bound FKBP12 of RyR1. To assess the amino acid residues of FKBP12.6 that are critical for selective binding to RyR2, the residues of FKBP12.6 that differ with FKBP12 were mutated to the respective residues of FKBP12. RyR2 of cardiac sarcoplasmic reticulum, prelabeled by exchange with [35S]FKBP12.6, was used as assay system for binding/exchange with the mutants. The triple mutant (Q31E/N32D/F59W) of FKBP12.6 was found to lack selective binding to the cardiac RyR2, comparable with that of FKBP12.0. In complementary studies, mutations of FKBP12 to the three critical amino acids of FKBP12.6, conferred selective binding to RyR2. Each of the FKBP12.6 and FKBP12 mutants retained binding to the skeletal muscle RyR1. We conclude that three amino acid residues (Gln31, Asn32, and Phe59) of human FKBP12.6 account for the selective binding to cardiac RyR2.

Amino Acid Sequence↗
PubMed1999

Immunolocalization of beta ig-h3 protein in 5q31-linked corneal dystrophies and normal corneas.

OBJECTIVE: To characterize the relation of the beta ig-h3 protein to the diagnostic corneal deposits in the hereditary corneal dystrophies recently shown to have mutations in the beta ig-h3 gene on chromosome 5q31. METHODS: Corneas with lattice, granular, mixed granular-lattice ("Avellino"), and 2 types of Reis-Bücklers dystrophy were diagnosed by the histochemical and ultrastructural characteristics of their abnormal aggregates. Dystrophic and normal corneas were compared for immunolocalization of beta ig-h3 protein. RESULTS: In normal corneas, immunoreactivity for beta ig-h3 protein was strongest in the Bowman layer, and next strong along stromal interlamellar junctions and attachment sites of collagen to the Descemet membrane. Antibody binding was intense on all dystrophic aggregates, mimicking somewhat the normal protein distribution. Mixed granular-lattice dystrophy had the most variation in beta ig-h3-immunopositive forms. The aggregates in both the "rod-shaped" Reis-Bücklers type and the "curly fiber" Thiel-Behnke type were strongly stained for beta ig-h3 protein, consistent with mutations on the beta ig-h3 gene. CONCLUSIONS: The marked immunopositivity for beta ig-h3 protein in the abnormal deposits in these dystrophies indicates that beta ig-h3 protein is a major component. The variety and quantity of immunopositive forms suggests that they consist primarily of the mutant protein, self-polymerizing and/or incorrectly binding to other corneal components. Variability of forms may relate to both the specific mutation and regional interactions of this protein.

Adult↗
PubMed1999

Inhibitory effects of tachykinin receptor antagonists on thermally induced inflammatory reactions in a rat model.

Recent studies have proposed that activation of the sensory nervous system after thermal injury induces the release of vasoactive neuropeptides, including tachykinins which contribute to the local inflammatory reaction as well as to the nociceptive transmission at the spinal cord level. Effects of the tachykinins substance P and neurokinin A are mediated by the neurokinin 1 and 2 (NK1, NK2) receptors. The aim of the present study was to investigate the modulatory role of NK1 and NK2 antagonists on edema formation, and on hindpaw withdrawal latency to experimentally asses nociception. Thermal injury was inflicted on the anaesthetized rat by dipping the right hindpaw into hot water at 60 degrees C for 20 s. The amount of edema formation was calculated by measuring the hindpaw volume with a plethysmograph before and during 420 min after scalding. In other studies scalding was inflicted under brief anesthesia, and hindpaw withdrawal latencies (HWL) to mechanical stimulation were recorded before injury and at 180 min after. The effect on edemic reactions of rats treated locally with NK1 and NK2 receptor antagonist were studied, as well as the effect of the same compounds on HWL after intrathecal injection. Scalding induced a progressive edema formation which was reduced significantly in rats treated with local injection of 100 nmol of NK1 and NK2 antagonists 45 min after the injury. The thermally induced inflammation was followed by significant decrease of the latency of hindpaw withdrawal response to mechanical stimulation. Intrathecal injection of 30 nmol of the same drugs 180 min after scalding was followed by significant increase in HWL. The results indicate that SP and NKA contribute to the inflammatory reactions after thermal injury and that the tachykinin receptor antagonists possess the ability to reduce both the local edemic reaction as well as the nociceptive transmission at the spinal cord level.

Animals↗
PubMed1999

Nucleotide sequence of a 5892 base pairs fragment of the LsMNPV genome and phylogenetic analysis of LsMNPV.

A 5892 bp fragment of Leucania separata multiple nuclear polyhederosis virus (LsMNPV) containing gp37, 39 k genes and another four ORFs was sequenced in this article. According to regulatory elements on 5' uncoding sequences, the ORF4 and ORF1 are probably two novel baculovirus genes, and the ORF4 probably also is a new early-late gene. The possible functions about GP37 and 39 K proteins were explored. The homology of GP37 protein among LsMNPV and 8 other insect virus was compared. The evolutional position of LsMNPV is also estimated based on the homology of gp37 genes. The structure and its homology of several genes in LsMNPV prove that LsMNPV is far related with other baculovirus and has an exceptional genome organization.

Amino Acid Sequence↗
PubMed1999

Treatment of an autoimmune disease with "classical" T cell veto: a proposal.

Immune responses protect against infectious diseases and cancers. In normal circumstances, the immune system is tolerant to self. However, under certain conditions this tolerance is broken. The immune system attacks otherwise normal tissue. An autoimmune disease ensues. Strategies are now being sought that remove the pathogenic T cells without affecting other immune functions. "Classical" veto has been described as an immune suppressive mechanism able to remove T cells in a highly specific and effective manner. The present article briefly reviews the current knowledge on the development of autoreactive T cells and their regulation in the periphery. It describes "classical" veto, its mechanisms, and its novel applications. Finally, it argues that "classical" veto can be adapted to treat an autoimmune disease, such as type I diabetes mellitus.

Autoimmune Diseases↗
PubMed1999

Capture ElISA and in vitro cell binding assay for the detection of antibodies to human papillomavirus type 6b virus-like particles in patients with anogenital warts.

To investigate human papillomavirus (HPV) virus-like particle (VLP)-specific antibody responses among anogenital warts patients, a VLP-based capture ELISA was established. Twenty-six percent (35/134) of control subjects and 50.0% (39/78) of patients with current anogenital warts showed IgG seropositivity to HPV 6b VLPs. HPV 6b VLP-specific antibody responses recognised native VLPs only, and had no cross-reaction with HPV type 16 VLPs. No differences in reactivity were observed between L1 and L1 + L2 VLPs, suggesting that L2 contributes little to the total immunogenicity of the papillomavirus virion. A VLP-cell binding assay was also established. Some sera from patients with anogenital warts specifically inhibited VLP binding to the surface of epithelial cells, suggesting that these antibodies might be functionally neutralising. These data show that serological responses to HPV 6b VLPs were induced among some but not all patients with anogenital warts, and give a proportional estimate of infection in the community.

Adolescent↗