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Biomedical subjects

Yun Li

Publications and source records attributed to Yun Li.

At least 91 records · Page 5Linked to original sources
PubMed2005

[Association of polymorphism in alpha-adducin gene with antihypertensive effect of Hydrochlorothiazide].

OBJECTIVE: To explore the association between G614T single nuclear polymorphism (SNP) of the alpha-adducin gene and the antihypertensive effect of hydrochlorothiazide (HCTZ) in essential hypertensive (EH) patients. METHODS: Eight hundred twenty nine EH patients were given 12.5 mg HCTZ/d for six weeks. Alpha-adducin gene G614T SNP in the tenth exon was determined by PCR-RFLP in 754 patients with complete records. All the patients were grouped according to TT, GT and GG genotypes. RESULTS: After 6 weeks of HCTZ treatment, the decreases in DBP and MAP of patients carrying 614T allele of alpha-adducin were significantly greater than that of those carrying GG homozygotes (P < 0.05). The decreases in SBP and MAP were significantly greater in patients with the TT genotype as compared with GT or GG genotype (P < 0.05). The effective rate of BP fall by HCTZ was higher in patients with TT genotype than those with GT or GG genotype (P < 0.05). Multivariate stepwise regression analysis showed that the TT genotype and the baseline SBP were the two major predictors affecting the decrease in SBP. CONCLUSION: The present study suggests that the alpha-adducin G614T polymorphism is associated with the antihypertensive effect of HCTZ, which is more effective in patients with TT genotype.

Adult↗
PubMed2004

Insulin-like growth factor-binding protein-3 plays an important role in regulating pharyngeal skeleton and inner ear formation and differentiation.

Insulin-like growth factor-binding protein (IGFBP)-3 is the major insulin-like growth factor (IGF) carrier protein in the bloodstream. IGFBP-3 prolongs the half-life of circulating IGFs and prevents their potential hypoglycemic effect. IGFBP-3 is also expressed in many peripheral tissues in fetal and adult stages. In vitro, IGFBP-3 can inhibit or potentiate IGF actions and even possesses IGF-independent activities, suggesting that local IGFBP-3 may also have paracrine/autocrine function(s). The in vivo function of IGFBP-3, however, is unclear. In this study, we elucidate the developmental role of IGFBP-3 using the zebrafish model. IGFBP-3 mRNA expression is first detected in the migrating cranial neural crest cells and subsequently in pharyngeal arches in zebrafish embryos. IGFBP-3 mRNA is also persistently expressed in the developing inner ears. To determine the role of IGFBP-3 in these tissues, we ablated the IGFBP-3 gene product using morpholino-modified antisense oligonucleotides (MOs). The IGFBP-3 knocked down embryos had delayed pharyngeal skeleton morphogenesis and greatly reduced pharyngeal cartilage differentiation. Knockdown of IGFBP-3 also significantly decreased inner ear size and disrupted hair cell differentiation and semicircular canal formation. Furthermore, reintroduction of a MO-resistant form of IGFBP-3 "rescued" the MO-induced defects. These findings suggest that IGFBP-3 plays an important role in regulating pharyngeal cartilage and inner ear development and growth in zebrafish.

Animals↗
PubMed2004

[Comparison of pharmacokinetics/pharmacodynamics of cefdinir, cefpodoxime proxetil and cefaclor against common bacteria of community acquired infections].

OBJECTIVE: To compare the pharmacokinetics/pharmacodynamics property of cefdinir, cefpodoxime proxetil and cefaclor against common bacteria of community acquired infections and evaluate the recommended regimens. METHODS: The antibacterial activities of 3 agents against 238 clinical isolates were determined by standard agar dilution test and the pharmacokinetics of these antibiotics in male healthy volunteers were conducted in Latin-square manner. The time over MIC (T > MIC) of serum antibiotic concentrations were calculated with pharmacokinetic equation and MIC. RESULTS: The value of MIC90 s cefdinir against these bacterial strains except penicillin non-sensitive pneumococci were 0.031-1 mg/L. Cefpodoxime held similar antibacterial activity with cefdinir, but was less potent against staphylococci. Cefaclor had much higher MIC values than other two drugs. After oral administration of 250 mg cefaclor, the drug concentration quickly reached peak concentration of 4.95 mg/L +/- 2.41 mg/L and the eliminative half time was 0.69 h +/- 0.6 h; the Tmax, Cmax and T1/2beta of cefdinir and cefpodoxime after oral administration of 100 mg were 2.5 h +/- 0.48 h, 0.81 mg/L +/- 0.19 mg/L, 1.73 h +/- 0.3 h and 2.38 h +/- 0.43 h, 1.12 mg/L +/- 0.28 mg/L, 1.92 h +/- 0.55 h, respectively. T > MIC of cefdinir in thrice daily administration were longer than 40% of medication interval against most of the tested isolates; no T > MIC period was found in cefpodoxime against staphylococci and the T > MICs of cefaclor after 250 mg oral administration were shorter than expected values against most bacteria. CONCLUSION: With powerful antibacterial activity, the T > MICs of cefdinir after 100 mg oral administration can meet with the clinical requirement in most infections; PK/PD value of cefpodoxime proxetil against staphylococci is lower than expectancy and 250 mg cefaclor 3 times daily is not enough to the treatment of common community acquired infections, the regimens of cefpodoxime proxetil and cefclor should be furtherly optimized.

Anti-Bacterial Agents↗
PubMed2004

Utilization of early invasive management strategies for high-risk patients with non-ST-segment elevation acute coronary syndromes: results from the CRUSADE Quality Improvement Initiative.

CONTEXT: The American College of Cardiology/American Heart Association (ACC/AHA) guidelines for the management of non-ST-segment elevation acute coronary syndromes (NSTE ACS) recommend early invasive management for high-risk patients, given the benefits with this approach demonstrated in randomized clinical trials. OBJECTIVES: To determine the use and predictors of early invasive management strategies (cardiac catheterization <48 hours following presentation) in high-risk patients with NSTE ACS and to examine the association of early invasive management with mortality. DESIGN, SETTING, AND PATIENTS: The CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the ACC/AHA Guidelines) Quality Improvement Initiative evaluated care patterns and outcomes for 17,926 high-risk NSTE ACS patients (positive cardiac markers and/or ischemic electrocardiographic changes) based on ACC/AHA guidelines recommendations at 248 US hospitals with catheterization and revascularization facilities between March 2000 and September 2002. MAIN OUTCOME MEASURES: Use of early invasive management within 48 hours of presentation, predictors of early invasive management, and in-hospital mortality. Results Of the 17,926 patients analyzed, 8037 (44.8%) underwent early cardiac catheterization less than 48 hours following presentation. Predictors of early invasive management included cardiology care, younger age, lack of prior or current congestive heart failure, lack of renal insufficiency, ischemic electrocardiographic changes, positive cardiac markers, white race, and male sex. Patients treated with early invasive management were more likely to be treated with medications and interventions recommended by the ACC/AHA guidelines and had a lower risk of in-hospital mortality after adjusting for differences in clinical characteristics and after comparing propensity-matched pairs (2.5% vs 3.7%, P<.001). Conclusions An early invasive management strategy is not utilized in the majority of high-risk patients with NSTE ACS. This strategy appears to be reserved for patients without significant comorbidities and those cared for by cardiologists and is associated with a lower risk of in-hospital mortality.

Aged↗
PubMed2004

Reaction modes and mechanism in indolizine photooxygenation reactions.

Photooxygenations of 1,2-, 1,3-, and 2,3-di- and 1,2,3-trisubstituted indolizines 1a-1f under different reaction conditions in methanol and acetonitrile have been investigated to establish the general reaction pattern and mechanism in indolizine photooxygenation in view of the influence of the ring substituents and substitution pattern. Photooxygenations of 1-acyl-2-phenylindolizines 1a and 1b and 1,3-dibenzoyl-2-phenylindolizine (1d) are self-sensitized, while those of 1-(p-nitrobenzoyl)-2-phenylindolizine (1c) and 2-phenyl-3-(p-chlorobenzoyl)indolizine (1e) need to be sensitized by rose bengal (RB) or methylene blue (MB). These reactions proceed via a singlet oxygen mechanism yet follow different pathways in methanol and in acetonitrile, with peroxidic zwitterion D (in methanol) and dioxetane E across the indolizine C2-C3 bond (in acetonitrile) as the intervening intermediates. Methanol trapping of the peroxidic zwitterion results in C3-N bond cleavage and pyrrole ring opening to give the corresponding (E)- and (Z)-3-(2-pyridinyl)-3-benzoylpropenoic acid methyl esters (2 and 3) and 4-(2-pyridinyl)-3-phenyl-5-aryl-5-hydroxyfuran-2-one (4) as products in methanol, while O-O bond homolysis of the dioxetane furnishes 3-(2-pyridinyl)-3-benzoyl-2-phenyloxirane-2-carboxaldehyde (6) and 1-(6-methyl-2-pyridinyl)-2-phenylethanedione (5) as products in acetonitrile. 3-Benzoyl-1-indolizinecarboxylic acid methyl ester (1f) is unreactive toward singlet oxygen; however, it could be photooxygenated under electron transfer conditions with 9,10-dicyanoanthracene (DCA) as a sensitizer. This reaction takes place by the combination of the indolizine cation radical with the superoxide anion radical (or molecular oxygen) to give the pyridine ring oxidized methyl 3-benzoyl-5-methoxy-8-hydroxy-1-indolizinecarboxylate (9f), dimethyl 2-(2-pyridinyl)fumarate (8f), and dimethyl 2-(2-pyridinyl)maleate (7f) as products.

Journal Article↗
PubMed2004

Factors affecting increasing radiation dose for mammography in North Carolina from 1997 through 2001: an analysis of Food and Drug Administration annual surveys.

RATIONALE AND OBJECTIVES: To determine which factors affected the increase in average glandular dose recorded at the annual US Food and Drug Administration Mammography Quality Standards Act inspections of mammography equipment in North Carolina from 1997 to 2001. MATERIALS AND METHODS: Average glandular dose, HVL, kVp, ambient light, luminance, equipment age, processing speed, and system speed for every mammography unit at all facilities in the state were collected by state inspectors. A mixed-effect model was used to assess the average changes of glandular dose over time and to identify the factors associated with these changes. RESULTS: There was a statistically significant increase in the average glandular dose in North Carolina in 1999, 2000, and 2001 when compared with the baseline year of 1997. Factors that were statistically significantly linked to this effect were changes in kVp, processing speed, and system speed. CONCLUSION: Average glandular dose for mammography has recently increased in North Carolina. This change is likely caused by changes in screen-film products and processing techniques.

Annual Reports as Topic↗
PubMed2004

Coronavirus-induced demyelination occurs in the absence of CD28 costimulatory signals.

Infection of mice with mouse hepatitis virus (MHV) strain A59 results in acute encephalitis, hepatitis, and chronic demyelinating disease. T lymphocytes play an important role in MHV infection, and costimulatory signals are an important component of T cell function. To elucidate the role of the main costimulatory molecule, CD28, in MHV pathogenesis and demyelination, we examined the kinetics of MHV-A59 infection in CD28 knockout mice. MHV-A59-infected CD28 knockout mice developed acute encephalitis and hepatitis, and the same degree of chronic demyelination as normal C57Bl/6 (B6) mice. Thus, CD28, the costimulatory T cell molecule, is not required for MHV infection and MHV-induced demyelination.

Animals↗
PubMed2004

Expression of matrix metalloproteinases in supraglottic carcinoma and its clinical implication for estimating lymph node metastases.

OBJECTIVE: Twenty to 30% of clinically node-negative patients with squamous cell carcinoma (SCC) of supraglottic larynx were pathologically confirmed with occult lymph node metastasis after operation. Therefore, preoperative judgment on the neck node metastasis should be very important for making an appropriate surgical plan. The purpose of this study is to explore the role of matrix metalloprotineases (MMPs) in the metastatic potential of supraglottic carcinoma in this regard. STUDY DESIGN: Examination of MMPs expression in supraglottic carcinoma and establishment of the mathematic model for diagnosis of occult lymph node metastases in a prospective manner. METHODS: Thirty-two patients with supraglottic SCC underwent supraglottic horizontal partial laryngectomy and neck dissection, and the samples of primary cancer and the corresponding adjacent non-neoplastic tissues were evaluated for both mRNA and protein expression of MMP-1, MMP-2, MMP-7, MMP-8, MMP-9, and MMP-10 using reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry. In addition, cervical lymph nodes were examined by routine histopathology to determine whether there was any evidences of node metastasis. RT-PCR and immunohistochemical data were analyzed by multivariate logistic regression, and then two mathematical models were established according to the multivariate logistic regression analysis. RESULTS: Among the six kinds of MMPs, both mRNA and protein expression of MMP-2, MMP-7, and MMP-9 were found up-regulated in more than 63% of the tumor tissues as compared with the adjacent non-neoplastic tissues, and this was significantly correlated with lymph node metastasis (all P < .05). Twenty patients, including seven cases with N0, were pathologically confirmed as having cervical lymph node metastasis. Using RT-PCR and immunohistochemical data of MMP-2, MMP-7, and MMP-9, two mathematic models were tested, and their diagnostic efficiencies for lymph node metastasis were 84% and 88%, respectively. CONCLUSION: Expressions of MMP-2, MMP-7, and MMP-9 are up-regulated in supraglottic carcinoma tissues, suggesting that MMPs may be useful in the detection of occult lymph node metastasis but that more research is needed.

Adult↗
PubMed2004

Health-related quality of life among patients with breast cancer receiving zoledronic acid or pamidronate disodium for metastatic bone lesions.

BACKGROUND: Research on individual differences in health-related quality of life (HRQOL) can identify intervention targets and important covariates in analyses of treatment outcomes. OBJECTIVES: The objectives of this study were to describe HRQOL trajectories for women with metastatic breast cancer in a randomized trial of bisphosphonates and to identify characteristics associated with variations in HRQOL. RESEARCH DESIGN: We conducted a prospective quality-of-life study within a randomized, controlled trial. SUBJECTS: We studied women with metastatic breast cancer receiving zoledronic acid or pamidronate disodium to reduce the incidence of skeletal-related events (SREs). MAIN OUTCOME MEASURES: HRQOL was measured at fixed time points during the trial. Individual growth-curve modeling was used to describe longitudinal trajectories and to identify predictors of trajectories. RESULTS: For most domains of HRQOL, the mean trajectory reflected a mild increase, which leveled off later in the trial. Older age and full-time employment were associated with higher baseline HRQOL. Longer time from cancer diagnosis to randomization, lower Eastern Cooperative Oncology Group (ECOG) status (score of 2 ["inactive"]), and a history of SREs were associated with lower baseline HRQOL. Significant differences across geographic regions were observed for all domains. Active ECOG status (score of 0-1) at baseline was predictive of greater increases in all domains of HRQOL except Social/Family Well-Being. Age, geographic region, and time from first bone metastases to randomization were associated with longitudinal changes in some domains. CONCLUSIONS: Women with metastatic breast cancer receiving bisphosphonates for prevention of SREs experienced an overall increase in HRQOL. Variations among women's experiences are explained partly by such characteristics as a history of SREs.

Bone Neoplasms↗
PubMed2004

Coronavirus neurovirulence correlates with the ability of the virus to induce proinflammatory cytokine signals from astrocytes and microglia.

The molecular and cellular basis of coronavirus neurovirulence is poorly understood. Since neurovirulence may be determined at the early stages of infection of the central nervous system (CNS), we hypothesize that it may depend on the ability of the virus to induce proinflammatory signals from brain cells for the recruitment of blood-derived inflammatory cells. To test this hypothesis, we studied the interaction between coronaviruses (mouse hepatitis virus) of different neurovirulences with primary cell cultures of brain immune cells (astrocytes and microglia) and mouse tissues. We found that the level of neurovirulence of the virus correlates with its differential ability to induce proinflammatory cytokines (interleukin 12 [IL-12] p40, tumor necrosis factor alpha, IL-6, IL-15, and IL-1beta) in astrocytes and microglia and in mouse brains and spinal cords. These findings suggest that coronavirus neurovirulence may depend on a novel discriminatory ability of astrocytes and microglia to induce a proinflammatory response in the CNS.

Animals↗
PubMed2004

[Simplified gonadorelin stimulation test in diagnosis of precocious puberty].

OBJECTIVE: To assess the diagnostic value of the simplified gonadorelin stimulation test for precocious puberty. METHODS: Two hundred and ninety-two girls with signs of advanced breast development received the gonadorelin stimulation test. According to the result of gonadorelin stimulation test, the girls were divided into 3 groups: 151 with central precocious puberty (CPP),119 with premature thelarche (PT) and 22 with peripheral precocious puberty (PPP). RESULTS: LH or FSH levels at 15 min, 30 min, 60 min in PPP group were not significantly different (P>0.05). Those were significantly different in PT group (P<0.01). The highest levels of LH were at 30 min and the highest levels of FSH were at 60 min. LH or FSH levels at 15 min, 30 min, 60 min in CPP group were significantly different (P<0.01) with the highest levels at 30 min. The ratio of basal LH and FSH >0.2 had a diagnostic sensitivity of 48.3 % and specificity of 69.7%. Taking the LH/FSH ratio >0.9 at 15 min, 30 min, 60 min as cut-off value, the diagnostic sensitivity was 80.1%, 68.9% and 38.4%, and the specificity was 90.8%, 96.6% and 69.7%, respectively. CONCLUSION: The LH/FSH ratio>0.9 at 15 min after gonadorelin stimulation test can be used as a cut-off value to differentiate CPP from PT and blood sample at 60 min were not necessary.

Child↗
PubMed2004

[Partial remove of mastoid tip in open-ended tympanoplasty or mastoidetomy].

OBJECTIVE: To summarize the effect of partial remove of mastoid tip in open-ended tympanoplasty or simple redical mastoidectomy. METHOD: Ten cases of cholesteatoma otitis media were treated with simple redical mastoidectomy. Thirty-four cases were treated with open-ended tympanoplasty. The mastoid tip were partial removed in all cases. RESULT: The volume of mastoid cavity became small after operation. The follow up time was 3 months. The dry ear rate was 97.6% (43 cases). After 1 years follow up there wasn't recurrence of cholesteatoma. CONCLUSION: The technique of partial remove of mastoid tip effective in open-ended tympanoplasty or simple redical mastoidectomy. We believe that in order to destry death cavity, shorten dry ear time and decrease recurrence it is very necessary.

Adolescent↗
PubMed2004

[Clinical diagnostic value for nasal bone fracture by three-dimensional reconstruction of spiral CT].

OBJECTIVE: To evaluate the value of three-dimensional reconstruction of spiral CT in diagnosing nasal bone fracture. METHOD: Forty-six patients with nasal bone fracture were scanned transverselly and reconstructed with three-dimensional software by GE Lightspeed Plus Multiple Slices Scaner. RESULT: Nine cases (19.6%) show false negative with X-ray examination. There were 35 cases (76%) of simple nasal bone fracture and 16 cases (34.8%) compound fracture. CONCLUSION: There is important significance for diagnosing nasal bone fracture by three-dimensional reconstruction at present of spiral CT.

Adolescent↗
PubMed2004

[Identification and analysis of F2 stable population derived from the cross of triploid x diploid in rice].

Polyploid strain 149-B, that was generated naturally from a rice twin-seedling population SAR-2, has been determined as triploid (2n = 36). It was then used as the female parent crossing with a normal diploid variety SH R363. From its F2 generation we obtained a genetic-stable population. To prove the uniformity of such a population, SSR markers were used to survey the F2 individual plants. The results showed that F2 individuals carried only one parental molecular marker at each polymorphic locus, and their genotypes were identical with F1 progeny. Based on the above experiments, we consider that this F2 population is definitely an early-generation stable population. Meanwhile, we discussed the possible mechanism of the special phenomenon as well.

Crosses, Genetic↗
PubMed2004

[Histopathological research and immunofluorescence of AVND virus infection in cultured scallop Chlamys farreri].

The naturally infected scallops Chlamys farreri sampled during mass mortality in summer of 2003 was detected by means of histopathological and MAb-based immunofluorescence assay (IFA). The results of histological examination demonstrated that a series of histopathological changes including cell swelling, basophilic increase, disorder, partial sloughing and excessive sloughing were always observed in epithelia of many different organs, e.g. mantle, gills, stomach, intestine and kidney. Additionally, the infected tissues were applied for in situ detection of the "acute virus necrobiotic disease" (AVND) virus by means of specific MAb-based IFA, and the result demonstrated that this pathological changes or lesions were perfectly coincident with the positive cells (fluorescencing cells) . The positive cells were denser in some local area of epithelia, and exhibited serious pathological lesions, which would reveal the roles of this virus in pathogenesis and further confirm that the AVND virus is the main causative agent of mass mortalities among cultured scallop Chlamys farreri farmed in northern coast of China.

Animals↗
PubMed2003

Ca2+-dependent redox modulation of SERCA 2b by ERp57.

We demonstrated previously that calreticulin (CRT) interacts with the lumenal COOH-terminal sequence of sarco endoplasmic reticulum (ER) calcium ATPase (SERCA) 2b to inhibit Ca2+ oscillations. Work from other laboratories demonstrated that CRT also interacts with the ER oxidoreductase, ER protein 57 (also known as ER-60, GRP58; ERp57) during folding of nascent glycoproteins. In this paper, we demonstrate that ERp57 overexpression reduces the frequency of Ca2+ oscillations enhanced by SERCA 2b. In contrast, overexpression of SERCA 2b mutants defective in cysteines located in intralumenal loop 4 (L4) increase Ca2+ oscillation frequency. In vitro, we demonstrate a Ca2+-dependent and -specific interaction between ERp57 and L4. Interestingly, ERp57 does not affect the activity of SERCA 2a or SERCA 2b mutants lacking the CRT binding site. Overexpression of CRT domains that disrupt the interaction of CRT with ERp57 behave as dominant negatives in the Ca2+ oscillation assay. Our results suggest that ERp57 modulates the redox state of ER facing thiols in SERCA 2b in a Ca2+-dependent manner, providing dynamic control of ER Ca2+ homeostasis.

Animals↗
PubMed2003

Complete sequence and molecular characterization of pNB101, a rolling-circle replicating plasmid from the haloalkaliphilic archaeon Natronobacterium sp. strain AS7091.

A new plasmid was isolated from the haloalkaliphilic archaeon, Natronobacterium sp. strain AS7091 and named pNB101. Sequence analysis revealed that pNB101 consists of 2,538 bp, in which three major open reading frames (ORF1, ORF2, and ORF3) were identified in the same strand. The ORF1 encodes a putative replication (Rep) protein with three typical motifs (I, II, and III) found in rolling-circle (RC) replicating plasmids. The putative double-stranded origin (DSO) and single-stranded origin (SSO) were detected within ORF3 and downstream of ORF1, respectively. S1 nuclease digestion and Southern blot analysis demonstrated the existence of the single-stranded DNA (ssDNA) intermediate from pNB101, which corresponds to the leading strand in RC replication and was further confirmed by strand-specific RNA probes. A single transcript for ORF1 ( rep) was detected by Northern blotting, and the 5' end of this transcript was determined by primer extension. Both results indicate that the three motifs (I-III) are located at the very end of the N-terminal of this Rep protein. Northern blot analysis also revealed that the ORF3 was transcribed at a very high level, which may play an important role in plasmid replication because the putative DSO is located in this gene. Together, our results indicate that pNB101, the first plasmid isolated from haloalkaliphilic Archaea, represents a novel RC-replicating plasmid.

Amino Acid Sequence↗