Biomedical subjects

Ying Li

Publications and source records attributed to Ying Li.

At least 253 records · Page 14Linked to original sources

PubMed2004

Rothia aeria sp. nov., Rhodococcus baikonurensis sp. nov. and Arthrobacter russicus sp. nov., isolated from air in the Russian space laboratory Mir.

Four Gram-positive bacteria, strains A1-17B(T), A1-22(T), A1-3(T) and A1-8, isolated from the air in the Russian space laboratory Mir, were subjected to a polyphasic taxonomic study. Phylogenetic analysis of the bacteria based on their 16S rDNA sequence showed that they belong to the genera Rothia (A1-17B(T)), Rhodococcus (A1-22(T)) and Arthrobacter (A1-3(T) and A1-8). Morphological, physiological, chemotaxonomic and genomic characteristics supported the assignments of these strains to these genera, but they could not be classified as any existing species within each respective genus. 16S rDNA similarity values between strain A1-17B(T) and its neighbours, Rothia dentocariosa genomovar II, Rothia dentocariosa, Rothia mucilaginosa and Rothia nasimurium, were respectively 99.8, 98.0, 96.4 and 95.4 %. Polyphasic taxonomic evidence indicated that strain A1-17B(T) should be categorized together with the unofficially named Rothia dentocariosa genomovar II, but clearly differentiated them from the established species of the genus ROTHIA: Strain A1-22(T) formed a coherent cluster with Rhodococcus erythropolis, Rhodococcus globerulus, Rhodococcus marinonascens and Rhodococcus percolatus in 16S rDNA sequence analysis, but DNA-DNA relatedness values were only 45.5, 35.3, 18.9 and 21.9 %. Strains A1-3(T) and A1-8 shared 99.9 % 16S rDNA sequence similarity, and strain A1-3(T) showed the highest level of 16S rDNA similarity, 96.6 %, to Arthrobacter polychromogenes. Contrasting biochemical characteristics were also identified. Finally, as a result of the polyphasic taxonomic study, three of the strains are proposed as type strains of novel species: Rothia aeria sp. nov. (A1-17B(T)=GTC 867(T)=JCM 11412(T)=DSM 14556(T)), Rhodococcus baikonurensis sp. nov. (A1-22(T)=GTC 1041(T)=JCM 11411(T)=DSM 44587(T)) and Arthrobacter russicus sp. nov. (A1-3(T)=GTC 863(T)=JCM 11414(T)=DSM 14555(T)).

Air Microbiology↗

PubMed2004

Sphingomonas yabuuchiae sp. nov. and Brevundimonas nasdae sp. nov., isolated from the Russian space laboratory Mir.

On the basis of phenotypic and genotypic characteristics and 16S rRNA gene sequence analysis, novel species belonging to the genera Sphingomonas and Brevundimonas were identified from samples taken from the Russian space laboratory Mir. Strain A1-18(T) was isolated from the air. 16S rDNA sequence analysis showed that strain A1-18(T) formed a coherent cluster with Sphingomonas sanguinis, Sphingomonas parapaucimobilis, Sphingomonas paucimobilis and Sphingomonas roseiflava with sequence similarity of 97.5-98.6 %. Similar to other Sphingomonas species, the G+C content was 66.1 mol%, but DNA-DNA hybridization rates at optimal temperatures among these related species were only 24.7-51.7 %. Strain A1-18(T) can be differentiated biochemically from related species. Strain W1-2B(T) was isolated from condensation water. It forms a distinct lineage within the genus Brevundimonas, forming a coherent cluster with Brevundimonas vesicularis, Brevundimonas aurantiaca and Brevundimonas intermedia. 16S rDNA sequence similarities were 98.6-99.5 % and the G+C content was 66.5 mol%, similar to other Brevundimonas species, but DNA-DNA relatedness was only 50.2-54.8 %. Strain W1-2B(T) also showed some differential biochemical properties from its related species. A series of polyphasic taxonomic studies led to the proposal of two novel species, Sphingomonas yabuuchiae sp. nov. (type strain A1-18(T)=GTC 868(T)=JCM 11416(T)=DSM 14562(T)) and Brevundimonas nasdae sp. nov. (type strain W1-2B(T)=GTC 1043(T)=JCM 11415(T)=DSM 14572(T)).

Air Microbiology↗

PubMed2004

Analyses of peripheral blood mononuclear cells in operational tolerance after pediatric living donor liver transplantation.

Operational tolerance (graft acceptance in an immunosuppression (IS)-free environment) after living-donor liver transplantation (LDLT) could occur by our elective protocol in some patients. There is, nevertheless, no reliable parameter to monitor patients who may discontinue IS without a risk of rejection. To identify such parameters, we systemically phenotyped peripheral blood mononuclear cells from operationally tolerant patients. An increase was observed in the frequency of CD4+CD25high+ cells, B cells and Vdelta1/Vdelta2 gammadeltaT-cells ratio in operationally tolerant patients (Gr-tol; n = 12), compared with those from age-matched volunteers (Gr-vol; n = 24) or patients on IS (Gr-IS; n = 19). The frequency of NK cells was decreased in Gr-tol, compared with those in Gr-IS or Gr-vol. The frequency of NKT cells was decreased after LDLT, compared with that in Gr-vol. Although the contribution of those subsets to the tolerant state remains elusive, the results may provide important clues for reliable indicators of tolerance after LDLT.

Adolescent↗

PubMed2004

Reverse transcriptase activity of hepatitis B virus (HBV) DNA polymerase within core capsid: interaction with deoxynucleoside triphosphates and anti-HBV L-deoxynucleoside analog triphosphates.

The use of L(-)SddC [beta-L-2',3'-dideoxy-3'-thiacytidine (lamivudine, 3TC)] for the treatment of Herpes B virus (HBV) infection is hindered by the emergence of drug-resistance associated with the L526M, L550V, and L526M/M550V mutations of the viral DNA polymerase (DP). The interactions of the anti-HBV compounds 2',3'-dideoxy-2',3'-didehydro-beta-L(-)-5-fluorode-oxycytidine and 2'-fluoro-5-methyl-beta-L-arabinofuranosyluracil triphosphate with HBV DP and its L(-)SddC-associated mutants have not been studied. The e antigen-negative variant of HBV associated with the G1896A mutation in the precore region has a high prevalence. Its effect on HBV DP is unclear. Because HBV DNA synthesis occurs in the nucleocapsid, we examined the kinetics of the reverse transcriptase activity from wild-type (wt) and mutated DPs with the wt or G1896A-mutated RNA template in the nucleocapsid. The effects of this template mutation on the activities of these L-nucleoside triphosphates were also examined. Results indicated that these DP mutations increased the Km values of deoxy-NTPs and decreased the efficiencies (Vmax/Km) of DPs. The additional L526M mutation increased the efficiency of the M550V-mutated DP but no more than that of the L526M-mutated DP. The G1896A mutation had impacts on the interactions between different DPs and deoxy-NTPs, except dCTP. It also had different impacts on the actions of the L-nucleoside triphosphates toward DPs. The L526M and M550V mutations caused a greater decrease in the Vmax using the wt RNA template compared with the G1896A-mutated template. The L526M, M550V, and L526M/M550V mutations caused varying degrees of resistance to the different M-nucleoside triphosphates.

Animals↗

PubMed2004

Negative regulation of prolactin receptor stability and signaling mediated by SCF(beta-TrCP) E3 ubiquitin ligase.

Ubiquitin-dependent degradation of hormone receptors is emerging as a key mechanism that regulates the magnitude and duration of hormonal effects on cells and tissues. The pituitary hormone prolactin (PRL) is involved in regulating cell differentiation, proliferation, and survival. PRL engages its receptor (PRLR) to initiate various signaling cascades, including the phosphorylation and activation of Stat5. We found that PRL promotes interaction between PRLR and the F-box protein beta-TrCP2, which functions as a substrate recognition subunit of the SCF(beta-TrCP) E3 ubiquitin ligase. This interaction requires PRLR phosphorylation and the integrity of serine 349 within a conserved motif, which is similar to conserved motifs present in other substrates of SCF(beta-TrCP). The PRLR(S349A) mutant is resistant to ubiquitination and is more stable than its wild-type counterpart. Phosphorylated PRLR undergoes ubiquitination by SCF(beta-TrCP) in vitro. Knockdown of beta-TrCP expression inhibits the ubiquitination and degradation of PRLR and promotes PRL-dependent phosphorylation of Stat5 as well as Stat5-dependent transcription in cells. Furthermore, the activation of Stat5 and the stimulation of cell growth by PRL are augmented in cells expressing the PRLR(S349A) mutant. These data indicate that PRLR is a novel SCF(beta-TrCP) substrate and implicate beta-TrCP as an important negative regulator of PRL signaling and cellular responses to this hormone.

Amino Acid Motifs↗

PubMed2004

Trends in prevalence, awareness, treatment and control of hypertension in the middle-aged population of China, 1992-1998.

The objective of this study was to analyze the trends in prevalence, awareness, treatment and control of hypertension in the middle-aged population of China. There were about 1,000 participants each from 13 different study populations that were examined in surveys conducted from 1992-1994 (n=18,746) and in 1998 (n=13,504) in conjunction with the China Multi-Center Study of Cardiovascular Epidemiology. Half the subjects were men and half were women; their ages ranged from 35 to 59 years. Hypertension was defined as systolic blood pressure > or =140 mmHg, diastolic blood pressure > or =90 mmHg, and/or current treatment with antihypertensive medications. Hypertension awareness and treatment were assessed with a standardized questionnaire. Hypertension control was defined as blood pressure measurements of less than 140/90 mmHg. The results showed that 24.0% of participants had hypertension in 1998, an increase of 2.3% from 1992-1994 (p <0.05). The prevalence of hypertension was 25.4% higher in urban than in rural areas, and was higher in men than in women. Among hypertensives, 42.6% were aware of their hypertension (a 5.3% increase compared with 1992-1994, p <0.05), 31.1% were treated (a 3.8% increase, p <0.05), and 6.0% were controlled (a 2.6% increase, p <0.05). The rates of awareness, treatment and control were higher in women than men, and higher in urban than rural areas. For treated hypertensives, the rate of control increased from 12.7% in 1992-1994 to 19.9% in 1998 (p <0.05). These findings indicate that hypertension prevalence is increasing in China. Control rates, while improving, still remain low. This implies that effective public health measures are needed to enhance the awareness, treatment, and control rates in the Chinese population.

Adult↗

PubMed2004

Needs and preferences regarding sex education among Chinese college students: a preliminary study.

CONTEXT: College students are more likely than other student populations to be sexually active. To improve sex education in China among this group, educators must know college students' needs and their preferences for receiving information on sexuality. METHODS: In 2002, students at a large Chinese university completed surveys about their history of school-based sex education and their other sources of information on sexuality. The survey also explored students' preferences for topics to be included in a college-level sex education course, comfort level with receiving information on these topics and views of effective teaching strategies. RESULTS: Before college, 47% of respondents had received no school-based education on sexual behavior; however, all respondents had taken a class covering reproduction, typically beginning in middle school (78%). Reading material, radio, classroom lecture and parents were more popular sources of information among females than among males; friends, the Internet and personal sexual experience were more frequent sources for males than for females. Higher proportions of males than females favored including sex therapy and masturbation in a hypothetical course. In addition, males felt more comfortable than females discussing 11 of 20 subjects; the two genders indicated similar levels of comfort in talking about the other topics. Males and females differed on how best to convey information on sexuality, with females generally favoring private methods, such as reading. CONCLUSIONS: More comprehensive school-based sex education is needed for Chinese youth. When developing and implementing such programs, health educators should consider differences between males' and females' preferred ways for receiving information on sexuality.

Adult↗

PubMed2004

[Retromandibular incision and miniplate rigid fixation for condylar and subcondylar fractures].

PURPOSE: To report the method and effects of anatomical reduction by retro-mandibular incision and miniplate rigid fixation for condylar and subcondylar fractures. METHODS: Twenty-four condylar neck and subcondylar fractures including 18 unilateral and 6 bilateral in 24 consecutive patients were studied. The fractures were approached by retromandibular incision and miniplate rigid fixation. Postoperative follow up was 3 to 6 months. The treatment results were evaluated including occlusion,joint functions as well as radiographic assessment of condylar changes. RESULTS: The average mouth opening deviation was 6.2mm before operation, which reduced to 1.4mm 3 months after surgical treatment,3 patients had malocclusion,2 had facial nerve damages. CONCLUSION: Miniplate rigid fixation by retromandibular incision based on anatomical reduction is an effective procedure in treating severely displaced and dislocated neck of condyle and subcondylar fractures.

Adult↗

PubMed2004

[The association between infection of Epstein-Barr virus and chronic periodontitis].

OBJECTIVE: To investigate the relationship between Epstein-Barr virus (EBV) infection and chronic periodontitis. METHODS: In 62 chronic periodontitis patients, subgingival plaque samples were collected from active periodontitis site, quiescent periodontitis site, and initial gingivitis sites of each subject. The nested polymerase chain reaction (nested-PCR) was used to determine the presence of EBV. RESULTS: The EBV was detected in 58.0% of the samples from active periodontitis sites, which was significantly higher than that from quiescent periodontitis sites (58.0% vs 22.6%, P < 0.01) and from initial gingivitis sites (58.0% vs 19.4%, P < 0.01). CONCLUSION: The results suggest that EBV infection is associated with the activity of chronic periodontitis.

Adult↗

PubMed2004

[Role of leptin during childhood growth and development].

Leptin, the peptide hormone product of the ob gene, regulates food intake and energy expenditure at the hypothalamic level. Leptin is a trigger for puberty onset in rodents, as a metabolism signals to link reproductive function to the nutritional status, and has a similar effect in childhood growth and development.

Body Weight↗

PubMed2004

Study on aqueous two-phase systems of the mixture SDS/CTAB surfactants.

The phenomenon of two dilute aqueous phases composed of sodium dodecylsulfate (SDS) and cetyl trimethyl ammonium bromide (CTAB) was investigated under various conditions such as concentrations and molar ratios of the two surfactants, the addition of sodium chloride and temperature. Vesicles formation was found in the both phases by TEM image.

Cetrimonium↗

PubMed2004

[Effect of copper pollution on seedling growth and activate oxygen metabolism of Trifolium pratense].

The effect of copper (Cu) pollution on the seedling growth and activate oxygen metabolism of Trifolium pratense was studied by water cultivation experiments. The results showed that under low concentration of Cu (< 10 mg.L-1), the growth of Trifolium pratense seedlings could be improved, their fresh/dry weight and the contents of soluble protein and chlorophylls in leaves increased slightly, the MDA content of leaf cells decreased, the activities of SOD, CAT and POD in the activate oxygen metabolism system slightly increased, and the balance of protective enzyme system was hold. However, with the increase of Cu concentration (10-100 mg.L-1), there existed an obvious negative effect on the growth of Trifolium pratense seedlings. The seedlings under high concentrations of Cu were shorter and smaller, their fibrous roots were shorter and fewer, and their fresh/dry weight and the contents of soluble protein and chlorophylls in leaves decreased drastically. With the increase of Cu concentration, the membrane penetration, electric conductivity and MDA content of leaf cells increased. Furthermore, the activate oxygen metabolism system was destroyed, the balance of protective enzyme system was broken, the activities of SOD and CAT decreased by 26.67% and 71.31%, respectively, while the POD activity increased by 10.6 times.

Catalase↗

PubMed2004

[Effects of dietary calcium on the blood glucose, blood lipid and hormone of rat fed a high fat diet].

OBJECTIVE: To explore the effects of dietary calcium on the blood glucose, blood lipid and hormone of Wistar rats fed high fat diet. METHODS: 54 male Wistar rats were randomly divided into 6 groups: A group was fed basic diet (0.5% calcium), B group was fed high fat and low calcium diet (0.08% calcium), C group was fed a high fat and normal calcium diet (0.5% calcium), D and E group was fed a high fat and high calcium diet (1% and 1.5% calcium respectively), F group was fed high fat and high calcium diet (1.5% calcium) supplemented with vitamin D(600IU%). After 9 weeks, blood glucose, blood lipid and serum insulin, leptin, thyroid hormone, growth hormone, neuropeptide Y (NPY) were measured. RESULTS: Compared with those of C group, the body weight and body fat content decreased significantly in other groups, so did the serum cholesterol and triglyceride, but there was no significant difference among all the groups in high density lipoprotein (P > 0.05). The blood glucose and serum insulin in C group increased and compared with that of C group, the insulin in E group decreased significantly (P < 0.05), the serum FT3 in D, E, F groups increased significantly (P < 0.05) and the plasma NPY in E, F groups decreased significantly. There was no significant difference among all the groups in the level of serum growth hormone (P > 0.05). CONCLUSION: Dietary reduced serum cholesterol and triglyceride, improved hyperinsulinemia, decreased plasma NPY and increased serum FT3, thereby inhibited the obesity induced by high fat diet.

Animals↗

PubMed2004

[Trends in prevalence, awareness, treatment and control of hypertension in middle-aged Chinese population].

OBJECTIVE: To analyze the trends in prevalence, awareness, treatment, control of hypertension among middle-aged Chinese. METHODS: The study comprised two cross-sectional surveys including urban and rural residents, manual workers, farmers and fishermen in different southern and northern parts of China. There were 13 populations under research with comparable data. 18 746 (in 1992 - 1994) and 13 504 (in 1998) participants, aged 35 through 59 years, equal number of men and women, were examined in each of the surveys, on blood pressure measurement, in 1992 - 1994 and in 1998. Hypertension was defined as systolic pressure >/= 140 mm Hg, and/or diastolic pressure >/= 90 mm Hg, and/or reported treatment with antihypertensive medications. Awareness and treatment on hypertension were assessed with standardized questions. Hypertension control was defined as measured blood pressure of less than 140/90 mm Hg. Awareness, treatment and control of hypertension were standardized according to the WHO world standard population. RESULTS: In 1998, 24.0% of participants had hypertension, an increase of 2.3% from 1992 - 1994. Prevalence of hypertension was higher in urban area (25.4%), increasing with age, and higher in men among the younger groups and lower in women among the older groups. Overall, in 1998, 42.6% were aware of their hypertensive status (increase of 5.3%), 31.3% were treated (increase of 3.8%), and the rate under control was 6.0% (increase of 2.6%). The rates of awareness, treatment and control, which tended to increase with age except those aged above 55 years, which were higher in urban areas and women compared with rural areas and men. For people with treated hypertension, the rates of those under control were ranged from 12.7% in 1992 - 1994, to 19.9% in 1998. CONCLUSION: Prevalence of hypertension was increasing in China, while the rates of control, although improving, continued to be low. This implied that effective public measures needed to be developed to enhance the awareness and rates of treatment.

Adult↗

PubMed2004

[The effect of vitreous surgery combined with intraocular lens implantation in proliferative diabetic retinopathy].

PURPOSE: To evaluate the effecting and complications of the vitreous surgery combined with intraocular lens implantation in proliferative diabetic retinopathy. METHODS: Forty-one eyes of 38 cases of proliferative diabetic retinopathy complicated with serious cataract were treated with phacoemulsification, pars plan vitctomy, peeling, photocoagulation, intraocular lens implantation and gas tampanade. Preoperative and postoperative visual acuity, anterior segment by slit lamp, fundus fluorescein angiography and surgery complications were analyzed. RESULTS: Average follow-up was 9 months. The visual acuity was improved in 36 eyes. The anterior response of operation was slight. The complications included cornea edema in 1 eye, high intraocular press in 1 eye, rubeosis in 1 eye and retinal detachment in 1 eye. CONCLUSIONS: The vitreous surgery combined with intraocular lens implantation was an effective operation for proliferative diabetic retinopathy with serious cataract.

Adult↗

PubMed2004

[Role of leptin in development of peripubertal boys].

OBJECTIVES: To study the role of leptin in the development boys during their puberty and its relationship with insulin (INS), growth hormone (GH), estradiol (E2) and testosterone (T). METHODS: One hundred and fifty boys with simple obese aged 7 to 17 years, 150 normal healthy boys and 150 boys with malnutrition matched for age (+/- 3 months) and height (+/- 2 cm) were selected. Serum levels of leptin, INS, GH, E2 and T were measured for them. RESULTS: Serum level of leptin in obese group was significantly higher than that in normal group, and that in normal group was significantly higher than that in malnourished group. In the all three groups, serum level of leptin increased with age first until peak value, then began to decrease, with peak value of 6.96 microg/L at ages of 10-11 y in obese group, 10.25 microg/L at ages of 11-12 y in normal group and 5.08 microg/L at ages of 11-12 y in malnourished group. Serum level of leptin increased steadily from Tanner stages G1 to G2, then began to decrease steadily in G2 to G4. Serum level of leptin increased again in stage G5. Serum level of INS in boys increased steadily with age from 7 to 17 years old. Serum levels of GH, T and E2 in boys began to increase since 10-11 years old. Serum level of leptin positively correlated with serum level of INS and negatively correlated with serum levels of GH and T, but not correlated with serum level of E2. CONCLUSIONS: Leptin may promote pubertal development of boys, but not the determinant factor in triggering and maintaining their pubertal development. Re-increase in level of leptin during stage G5 could inhibit secretion of GH, and signalize the end of puberty in boys.

Adolescent↗

PubMed2004

[A study on the factors influencing insulin resistance in children and adolescents].

OBJECTIVE: To explore the factors influencing insulin resistance in children with different nutritional status during pubertal development. METHODS: Three hundred children with simple obese aged 7 to 17 years, and 300 normal healthy children and 300 children with malnutrition, matched for age (+/- 3 months) and height (+/- 2 cm), were selected. Fasting serum levels of leptin, insulin, glucose, total cholesterol (TC), triglycerides (TG), low density lipoprotein-cholesterol (LDL-C) and high density lipoprotein-cholesterol (HDL-C) were measured for them. RESULTS: Levels of fasting serum insulin in obese children, except for boys at Tanner stage I and girls at Tanner stage II, were higher than those in normal and malnutrition children (P < 0.01). Average serum level of leptin in obese boys and girls at varied Tanner stages was higher than that in normal children, and higher in normal children than that in children with malnutrition (P<0.01). Serum level of TG in obese children [(1.53 +/- 0.13) mmol/L] was higher than that in normal ones [(1.12 +/- 0.10) mmol/L] and in children with malnutrition [(1.03 +/- 0.09) mmol/L]. There was no significant difference in levels of fasting blood glucose and other blood lipids between the three groups of children. Insulin sensitivity decreased with pubertal development and its index reversely correlated with Tanner stage and serum level of leptin (r=-0.27 and -0.36, respectively, P<0.01). CONCLUSION: Obesity (BMI), serum level of leptin and pubertal development were independent risk factors for insulin resistance in children aged 7 to 17 years.

Adolescent↗

PubMed2004

[Feasibility of telephone screening interview in a validity and reliability study of telephone interview to assess dietary intake in Beijing, Shanghai and Hong Kong].

OBJECTIVE: To understand the feasibility of telephone interviews to achieve recruitment of subjects to assess the validity and reliability of the telephone interview in eliciting dietary intake. METHODS: A multi-phase study was conducted in Beijing, Shanghai and Hong Kong in 2002. RESULTS: Three hundred eligible women aged from 20 to 49 years old were recruited in those cities. In the screening interview, 2462 random telephone numbers were dialed with 95% of dials completed within 5 times of attempts. The average number of dial for the completion was two calls, the rates of completion and refusal conversion were not improved remarkably by the increase of calls although some calling attempts reached 20 times. Regarding the processing of the sampling pools in those three cities, Beijing had a lower efficiency rate but a satisfactory completion rate, Shanghai was good in both indicators, and Hong Kong had a good efficiency rate but lower completion rate. The overall telephone screening interview completion rate was 42%, with Hong Kong having the lowest rate (32%) compared with Beijing and Shanghai (47% and 50%, respectively, P < 0.001). CONCLUSION: The telephone interview method could successfully reach the target of urban Chinese women and earn their cooperation with a satisfactory completion rate.

Adult↗