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Biomedical subjects

Jun Li

Publications and source records attributed to Jun Li.

At least 541 records · Page 30Linked to original sources
PubMed2003

[Association between AvaII exon 13 polymorphism at the LDL receptor gene different and serum lipid levels in normotensives and essential hypertensives in Shanghai].

OBJECTIVE: To investigate the AvaII polymorphism of low density lipoprotein receptor gene in both health and essential hypertension populations, and to evaluate the association of AvaII polymorphism with level of blood lipid. METHODS: Using polymerase chain reaction (PCR), AvaII polymorphism was studied in 109 health individuals and 319 patients with essential hypertension. RESULTS: There were three kinds of genotype: (+/+), (+/-), (-/-). The frequencies of the three genotypes were shown as follows: (+/+) 0.9%, (+/-) 27.5%, (-/-) 71.6% in health population and (+/+) 1.2%, (+/-) 33.9%, (-/-) 64.9% in essential hypertension population, respectively. The frequencies of the two alleles were shown as follows: (+) 14.7%, (-) 85.3% in health population, (+) 18.2%, (-) 81.8% in essential hypertension population and (+) 17.3%, (-) 82.7% in the community, respectively. In male essential hypertension cases, the genotypes were associated with serum TC and LDL-C level in the following order: (-/-) < (+/-) (P < 0.05). In women and healthy population, there was a similar trend but not statistically significant (P > 0.05). CONCLUSIONS: A significant association was found between the common variation of LDL-R gene and serum TC and LDL-C levels. (+) Allele was associated with elevated level of serum TC and LDL-C, but (-) allele was associated with a low level of serum TC and LDL-C. The frequencies of (-) allele in both group were related to serum low level TC while LDL-C was much higher than that reported in the western countries. These data indicated that genetic factors which resistant to hypercholesterolemia in Chinese people were different from those findings in West while might be one of the reasons to explain why that serum TC level in Chinese was lower than people in the western countries.

Adult↗
PubMed2003

[Pioglitazone, a peroxisome proliferators-activated receptor gamma ligand, inhibits dimethylhydrazine (DMH) induced aberrant crypt foci in rats].

OBJECTIVE: To investigate the chemopreventive effects of pioglitazone (exogenous PPAR gamma ligand) on rat colon aberrant crypt foci, a rat carcinogenesis model induced by dimethylhydrazine (DMH), and to compare pioglitazone with sulindac (a NSAID). METHODS: Thirty-two, 8-week-old, female Sprague-Dawley rats were randomly divided into four groups (n = 8 each). Group 1 rats were injected with DMH alone (120 mg.kg-1, single subcutaneous injection). Group 2 rats were injected with saline alone. Group 3 rats were pre-treated with sulindac (320 mg.kg-1) for 7 days before DMH initiation. Group 4 rats were treated with pioglitazone (100 mg.kg-1). The animals were killed at the end of the experiment (week 5) and the colons were stained with methylene blue. The aberrant crypt foci (ACF) of the colonic mucosa were assessed. RESULTS: In Group 1 rats (DMH only), the average numbers of ACF/colon and AC/colon were (182 +/- 93) and (263 +/- 198), respectively. In Group 2 (saline group) rats, no ACF were found. In Group 3 (sulindac group) rats, the average numbers of ACF/colon and AC/colon were (91 +/- 49) and (140 +/- 69), respectively. Both of them were decreased significantly compared with the values in Group 1 (P < 0.01 and P < 0.05). In Group 4 (pioglitazone group) rats, the average numbers of ACF/colon and AC/colon were (97 +/- 23) and (148 +/- 31), respectively. Both of them were decreased significantly compared with the values in Group 1 (P < 0.01 and P < 0.05). No difference was found in the values of Group 3 and Group 4. CONCLUSION: These results suggest that pioglitazone have chemopreventive effects against rat colon carcinogenesis induced by DMH, whose effect is similar to that of sulindac.

1,2-Dimethylhydrazine↗
PubMed2003

[Cloning and sequence analysis of Eg95 cDNA from different stages of Echinococcus granulosus in Xinjiang].

OBJECTIVE: To study expression and sequence differences of Echinococcus granulosus 95(Eg95) antigen cDNA from different stages of protoscolex, oncosphere and adult worm of E. granulosus from Xinjiang Uighur Aut. Reg. METHODS: In accordance with the sequence of Eg95 antigen cDNA, the primers of Eg95 were designed. Eg95 antigen cDNAs were amplified by PCR from protoscolex, oncosphere and adult worm cDNA libraries of E. granulosus, respectively and were cloned into pUCm-T plasmid, and sequenced. The sequences were analyzed by DNAman and GenBank/BLAST biosoftware. RESULTS: PCR results showed that Eg95 antigen cDNA was amplified from three stages of E. granulosus cDNA libraries. Sequencing analysis indicated that the Eg95 cDNA length was 402 bp, same as the reported data in GenBank. CONCLUSION: The Eg95 antigen cDNA was expressed in the different life-cycle stages of E. granulosus in Xinjiang and there was no nucleic acid sequence difference of Eg95 antigen among the protoscolex, oncosphere and adult worm of E. granulosus.

Animals↗
PubMed2003

[Adsorbent effect of activated carbon on small molecular uremic toxin and its influence factors].

OBJECTIVE: To analyze the adsorbent effect of activated carbon on uremic toxin and its influence factors. METHODS: Uremic toxins (urea, creatinine and uric acid) were dissolved in the distilled water to obtain uremic toxic solution. Activated carbon was added to the solution, and the concentrations of uremic toxins were measured at different time spots. To determine the influence factors, some possible related materials, such as bile, amino acid, Ringer's, solution of glucose, HCl or NaOH respectively were added simultaneously. RESULTS: The concentrations of toxins in uremic toxic solution decreased 5 min after adding the activated carbon. The concentration of urea was the lowest at 30 min, but it increased after 50 min; while the concentrations of creatinine and uric acid reached the lowest level from 10 to 30 min after adding the activated carbon, and maintained at the same level after that. The bile, amino acid, electrolyte, glucose and pH value did not influence the adsorption of uric acid significantly, but they influenced the adsorption of urea and creatinine. Bile and amino acid influenced the concentration of urea remarkably, following glucose, NaOH and HCl. The effect of pH 2.0 solution on the creatinine concentration was the most significant, following glucose. CONCLUSION: Activated carbon has adsorptive effect on uremic toxins, but its adsorptive effect decreases as time goes on. Bile, glucose, amino acid, NaOH and HCl can affect the adsorptive effect of activated carbon on uremic toxins to some extent.

Adsorption↗
PubMed2003

Application of Neomysis awatschensis as a standard marine toxicity test organism in China.

The small mysid crustacean Neomysis awatschensis was collected in the west coast of Jiaozhou Bay, Qingdao, China in 1992 and acclimated and cultured in laboratory conditions since then. Standard acute toxicity tests using 4-6 d juvenile mysids of this species were conducted and the results were compared with Mysidopsis bahia, a standard toxicity test organism used in the US in terms of their sensitivities to reference toxins, as well as their taxonomy, morphology and geographic distributions. Because of its wide distribution along the Chinese coast, similar sensitivity to pollutants as M. bahia, short life history, small size and the ease of handling, this study intended to use N. awatschensis as one of the standard marine organisms for toxicity testing in China. The species were applied to acute toxicity evaluations of drilling fluid and its additives, organotin TPT and toxic algae, and to chronic (life cycle) toxicity assays of organotin TPT and a toxic dinofalgellate Alexandrium tamarense, respectively. Using N. awatschensis as a standard toxicity testing organism in marine pollution assessment in China is suggested.

Animal Experimentation↗
PubMed2003

[An analysis on the cost of hypertensive outpatient in the community hospital in Shanghai].

OBJECTIVE: To study the cost of the hypertensive outpatients. METHODS: The study randomly selected 460 insured patients with hypertension and investigated their cost on each case in the out-patient department through 2002, based on the electronic system of medical insurance. RESULTS: As a whole, the distribution of hypertensive outpatient expenditure takes on the positively skewed, with the median of 1 567.9 Yuan RMB. With the increase of age, the average expenses in each age group increased accordingly. In the study, the average number of outpatient attendances per patient was 19.5, the average expenses per visit was 115.4 Yuan RMB. In age groups 40 - 49 and 50 - 59, expenses of outpatient in male and female groups are obviously different in 2002 (Wilcoxon W(40 - 49) = 36, P(40 - 49) = 0.037; Wilcoxon W(50 - 59) = 374, P(50 - 59) = 0.023), as well as the number of out-patients (Wilcoxon W(40 - 49) = 52.5, P(40 - 49) = 0.007; Wilcoxon W(50 - 59) = 379, P(50 - 59) = 0.028). When considering the factors of gender and age at one time, the outpatient expenditures in the male group were significantly different between the different age groups (chi(2) = 22.3, P < 0.001), as well as the number of outpatients (chi(2) = 25.4, P < 0.001). In addition, the expenditure of drugs, which took a large proportion of the total expenditure of hypertensive outpatients (about 83.6 percent), was divided into three parts according to the degree of correlation with hypertension: direct expenses related to the with disease, the indirect expenses and the irrespective. The proportions of each part were 19.9 percent, 32.3 percent and 47.8 percent respectively. CONCLUSION: When economic evaluation of community prevention is carried out, the cost and cost-benefit analysis based on the analysis of outpatient expenditure and the proportion of expenses on hypertension should be taken into account. Additionally, to provide appropriate mode of medicare, to impact the behaviors and expenditure of patients, and to provide low-cost but good effective drug are also essential and important factors.

Adult↗
PubMed2003

[Quality of life of patients with arthritis in China].

OBJECTIVE: To evaluate the quality of life of arthritis patients in China. METHODS: Patients (n = 1 344) were selected by stratified random sampling according to the economic conditions and the ranking of hospitals, and asked to complete the arthritic self-reported questionnaire of quality of life. RESULTS: The scores of quality of life were not different between male arthritis and female arthritis in different age groups (P > 0.05). The lower scores of quality of life were reported more often among the women older than 65 years. Those of lower educational level and lower income got fewer scores. Compared to the married and unmarried patients, the divorcees and those who were bereft of their spouses gained low scores (t = 9.310, P = 0.001). Among different occupation groups, the labors and farmers also got lower scores than others (P < 0.05). On the other hand, if the arthritis with better physical conditions, it was more possible that the scores were higher, but to pressed pain index, there were no different scores shown between the second and third grade (mean difference = 4.910, P = 0.765), and to joint swell index, there are no different scores between either the 0 and 1 grade (mean difference = 16.308, P = 0.079) or the 2 and 3 grade (mean difference = 6.643, P = 0.533). CONCLUSION: To improve the quality of life of all arthritis patients, enhancing the quality of medical technology and enriching the medical knowledge are evidently necessary. However, it is also important to prefect social security system, to improve the country education and pay attention to life of elderly in order to improve the quality of life of all arthritis patients.

Adult↗
PubMed2003

[Suppression of corneal neovascularization by conditioned culture medium of human amniotic membrane].

OBJECTIVE: To investigate the effects of the conditioned culture medium (CCM) of human amniotic membrane (AM) on corneal neovascularization (CNV) induced by basic fibroblast growth factor (bFGF) in mice. METHODS: AM (with epithelium side up) was cultured in EGM basic medium for 3 days, and the CCM was collected. The CCM consisted of three groups: control (EGM only), AM with epithelium (AM) and AM without epithelium (De-AM). Corneal neovascularization was induced in mice by using micropocket assay with Hydron polymer pellets containing 100 ng bFGF. Migration and proliferation of human umbilical cord vein endothelial cells (HUVEC) were measured in Boyden chambers and by CyQUANT fluorescence binding assay, respectively. The levels of tissue inhibitors of metalloproteinase 1 and 2 (TIMP-1, TIMP-2) in the CCM were determined by ELISA assay. RESULTS: CNV induced by bFGF was significantly suppressed by the CCM of amniotic membrane. When CCM was applied as an eyedrop 4 times a day for 7 days, the area of CNV was (2.48 +/- 0.76) mm(2), (0.64 +/- 0.52) mm(2) and (1.96 +/- 0.65) mm(2) in control, AM and De-AM groups, respectively. The migration and proliferation of HUVEC were strongly inhibited by the CCM of AM with epithelium, while the De-AM had no effect on the migration of HUVEC cells. A high level of TIMP-2 was found in AM group, but not in De-AM group. There were no differences in the amount of TIMP-1 in medium among these three groups. CONCLUSIONS: CCM of amniotic membrane significantly suppresses the CNV induced by bFGF. One of the mechanisms of CCM-mediated suppression is that a high level of TIMP-2 protein is secreted or released into the CCM by AM, which can inhibit the migration and growth of vascular endothelial cells.

Amnion↗
PubMed2003

[Subjective evaluation of acoustic changes before and after restoration with complete denture].

OBJECTIVE: To evaluate clinic adaptive effect of speech articulation of patients before and after restoration with complete denture. METHODS: Before and after patient's restoration at the beginning and then at 1 week, 2 weeks, 4 weeks and 8 weeks, the patient's self-judgement and the measurement of Chinese intelligibility by speech pathologist were used to analyse the regularity of speech articulation of edentulous patients restored with complete denture. RESULTS: At the beginning, the patients in two groups all felt uncomfortable of using denture. After one week, patients using metal base denture adapted well, but patients using plastic base denture needed 2 weeks to adapt. The data of Chinese intelligibility showed significant difference between two groups after using denture 1 week (P<0.05). In metal base group, there was significant difference before and after using denture a week (P<0.01). The plastic base group showed this change after two weeks. CONCLUSION: Patient's phonetic function recovered quickly when the thickness of the base reduced and palatal rugae of the denture base restored. The chinese intelligibility of them was better.

Adaptation, Physiological↗
PubMed2002

Spectroscopic and oxidation-reduction properties of Rhodobacter capsulatus cytochrome c1 and its M183K and M183H variants.

Two variants of the cytochrome c1 component of the Rhodobacter capsulatus cytochrome bc1 complex, in which Met183 (an axial heme ligand) was replaced by lysine (M183K) or histidine (M183H), have been analyzed. Electron paramagnetic resonance (EPR) and magnetic circular dichroism (MCD) spectra of the intact complex indicate that the histidine/methionine heme ligation of the wild-type cytochrome is replaced by histidine/lysine ligation in M183K and histidine/histidine ligation in M183H. Variable amounts of histidine/histidine axial heme ligation were also detected in purified wild-type cytochrome c1 and its M183K variant, suggesting that a histidine outside the CSACH heme-binding domain can be recruited as an alternative ligand. Oxidation-reduction titrations of the heme in purified cytochrome c1 revealed multiple redox forms. Titrations of the purified cytochrome carried out in the oxidative or reductive direction differ. In contrast, titrations of cytochrome c1 in the intact bc1 complex and in a subcomplex missing the Rieske iron-sulfur protein were fully reversible. An Em7 value of -330 mV was measured for the single disulfide bond in cytochrome c1. The origins of heme redox heterogeneity, and of the differences between reductive and oxidative heme titrations, are discussed in terms of conformational changes and the role of the disulfide in maintaining the native structure of cytochrome c1.

Amino Acid Substitution↗
PubMed2002

Thermodynamic product retrieval methodology and validation for NAST-I.

The National Polar-Orbiting Operational Environmental Satellite System (NPOESS) Airborne Sounder Testbed (NAST) consists of two passive collocated cross-track scanning instruments, an infrared interferometer (NAST-I) and a microwave radiometer (NAST-M), that fly onboard high-altitude aircraft such as the NASA ER-2 at an altitude near 20 km. NAST-I provides relatively high spectral resolution (0.25-cm(-1)) measurements in the 645-2700-cm(-1) spectral region with moderate spatial resolution (a linear resolution equal to 13% of the aircraft altitude at nadir) cross-track scanning. We report the methodology for retrieval of atmospheric temperature and composition profiles from NAST-I radiance spectra. The profiles were determined by use of a statistical eigenvector regression algorithm and improved, as needed, by use of a nonlinear physical retrieval algorithm. Several field campaigns conducted under varied meteorological conditions have provided the data needed to verify the accuracy of the spectral radiance, the retrieval algorithm, and the scanning capabilities of this instrumentation. Retrieval examples are presented to demonstrate the ability to reveal fine-scale horizontal features with relatively high vertical resolution.

Journal Article↗
PubMed2002

Encapsulation of an 86-kDa assembly intermediate inside the cavities of GroEL and its single-ring variant SR1 by GroES.

We described previously that during the assembly of the alpha(2)beta(2) heterotetramer of human mitochondrial branched-chain alpha-ketoacid dehydrogenase (BCKD), chaperonins GroEL/GroES interact with the kinetically trapped heterodimeric (alphabeta) intermediate to facilitate conversion of the latter to the native BCKD heterotetramer. Here, we show that the 86-kDa heterodimeric intermediate possesses a native-like conformation as judged by its binding to a fluorescent probe 1-anilino-8-naphthalenesulfonate. This large heterodimeric intermediate is accommodated as an entity inside cavities of GroEL and its single-ring variant SR1 and is encapsulated by GroES as indicated by the resistance of the heterodimer to tryptic digestion. The SR1-alphabeta-GroES complex is isolated as a stable single species by gel filtration in the presence of Mg-ATP. In contrast, an unfolded BCKD fusion protein of similar size, which also resides in the GroEL or SR1 cavity, is too large to be capped by GroES. The cis-capping mechanism is consistent with the high level of BCKD activity recovered with the GroEL-alphabeta complex, GroES, and Mg-ATP. The 86-kDa native-like heterodimeric intermediate in the BCKD assembly pathway represents the largest protein substrate known to fit inside the GroEL cis cavity underneath GroES, which significantly exceeds the current size limit of 57 kDa established for unfolded proteins.

3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)↗
PubMed2002

Ultrasound-modulated optical tomography of biological tissue by use of contrast of laser speckles.

Ultrasound-modulated optical tomography based on the measurement of laser-speckle contrast was investigated. An ultrasonic beam was focused into a biological-tissue sample to modulate the laser light passing through the ultrasonic column inside the tissue. The contrast of the speckle pattern formed by the transmitted light was found to depend on the ultrasonic modulation and could be used for imaging. Variation in the speckle contrast reflected optical inhomogeneity in the tissue. With this technique, two-dimensional images of biological-tissue samples of as much as 25 mm thick were successfully obtained with a low-power laser. The technique was experimentally compared with speckle-contrast-based, purely optical imaging and with parallel-detection imaging techniques, and the advantages over each were demonstrated.

Animals↗
PubMed2002

Hop is an unusual homeobox gene that modulates cardiac development.

Hop is a small, divergent homeodomain protein that lacks certain conserved residues required for DNA binding. Hop gene expression initiates early in cardiogenesis and continues in cardiomyocytes throughout embryonic and postnatal development. Genetic and biochemical data indicate that Hop functions directly downstream of Nkx2-5. Inactivation of Hop in mice by homologous recombination results in a partially penetrant embryonic lethal phenotype with severe developmental cardiac defects involving the myocardium. Inhibition of Hop activity in zebrafish embryos likewise disrupts cardiac development and results in severely impaired cardiac function. Hop physically interacts with serum response factor (SRF) and inhibits activation of SRF-dependent transcription by inhibiting SRF binding to DNA. Hop encodes an unusual homeodomain protein that modulates SRF-dependent cardiac-specific gene expression and cardiac development.

3T3 Cells↗