Biomedical subjects

Qi Li

Publications and source records attributed to Qi Li.

At least 109 records · Page 6Linked to original sources

PubMed2004

Oral contraceptive use and risk of diabetes among Chinese women.

Oral contraceptive (OC) use has been associated with alterations in carbohydrate metabolism. We examined the effect of OC use on the risk of diabetes among Chinese women. A nested case-control study was conducted among 57,130 women screened for diabetes at enrollment for the Shanghai Women's Health Study, a population-based cohort study of Chinese women aged 40-70 years in Shanghai, China. Included in this study were 259 women newly diagnosed with diabetes and 2072 age-matched controls (8 controls per case), randomly selected from women who tested negative for urine glucose. Multivariate-adjusted odds ratios (OR) and 95% confidence intervals (CI) were used to measure the strength of the association between OC use and diabetes risk. Overall, OC use was not associated with the risk of diabetes. Stratified analysis by menopausal status revealed a dose-response relationship between the duration of OC use and the risk of diabetes among premenopausal women (p for trend = 0.02), with a 3.2-fold elevated risk observed among those who used OC longer than 1 year. Risk of diabetes diminished with increasing time since last OC use (p = 0.02). Use of intrauterine devices was associated with a reduced risk of diabetes in both pre- and postmenopausal women (OR = 0.67, CI: 0.48-0.93). These findings suggest that recent use (within 5 years) and continued use (>1 year) of OCs may increase the risk of diabetes among Chinese women. However, the attributable risk for diabetes among OC users in the general population, if confirmed by further studies, appears to be small.

Adult↗

PubMed2004

Establishment of an ELISA system for determining soluble LAIR-1 levels in sera of patients with HFRS and kidney transplant.

LAIR-1, the leukocyte-associated Ig-like receptor-1, is a trans-membrane molecule that functions as an inhibitory receptor on natural killer cells, T lymphocytes and monocytes. It has been well known that many trans-membrane receptors can shed from the cell surface and be released into the circulation in soluble form when lymphocytes, endothelials and other immune cells are activated. In many cases, the levels of soluble receptors in the circulation can be used as markers of lymphocyte activation in transplant patients and virus infection patients. To investigate whether LAIR-1 is able to be released into the sera, we developed a sandwich enzyme-linked immunosorbent assay (ELISA) system based on two anti-LAIR-1 monoclonal antibodies (MAb) with different epitope specificities. Using this ELISA, we found that sLAIR-1 existed in the supernatants collected from PMA, PHA or CD3 MAb-stimulated lymphocytes cultures in vitro for the first time. Moreover, we found that LAIR-1 level in serum samples from healthy individuals was 6.2 +/- 3.3 ng/ml, whereas the levels in sera of patients with hemorrhagic fever with renal syndrome (HFRS) and patients 3-7 days after kidney transplant increased to 47.2 +/- 35.9 and 24.4 +/- 16.0 ng/ml, respectively. Furthermore, HFRS patients in oliguric phase showed higher serum sLAIR-1 levels than those in other phases, and transplant patients with rejection showed higher serum sLAIR-1 level than those without rejection. These findings demonstrated that LAIR-1 can be released when lymphocytes are activated, suggesting sLAIR-1 may be used as a predictor for monitoring immune reaction in some virus infections and organ transplants which may be useful in clinical treatment of these diseases.

Animals↗

PubMed2004

Successful auricle replantation via microvascular anastomosis 10 h after complete avulsion.

OBJECTIVE: To report a case of successful total auricle replantation 10 h after complete amputation. MATERIAL AND METHODS: Replantation was achieved by means of microvascular anastomosis and other therapies, and assisted by careful nursing. The patient's auricle was completely cut off with a sharp blade by an assailant, who retained it for 5 h. Having been retrieved, it was then preserved in ice for 5 h. Using microscopy, an artery and vein were found at the confluences of the upper and middle and lower and middle parts of the amputated auricle and head wound, respectively An end-to-end anastomosis was performed on these vessels. After operation, the following treatments were used: drainage; reopening of the drainage channels with a needle: flushing or soaking with heparin sodium solution; controlling infection and coagulation; increasing blood volume: dilating vessels; and special nursing. RESULTS: The replanted auricle survived with a normal contour and a very favorable esthetic appearance. CONCLUSIONS: The neat, uncontaminated wound margins and the fact that the amputated auricle was preserved in ice, even though it had been amputated 10 h before the operation, were prerequisites for successful auricle replantation. The microvascular anastomosis technique played a very important role in the survival of the amputated auricle. The postoperative treatment, observation and nursing were difficult but vital aspects of the procedure. The establishment of an effective venous return was a sign of the survival of the amputated auricle.

Adult↗

PubMed2004

TH1 immune responses to fully MHC mismatched allografts are diminished in the absence of MyD88, a toll-like receptor signal adaptor protein.

Toll-like receptors (TLRs) are innate immune receptors that are critical for recognizing conserved microbial motifs by inducing TH1 immunity. The majority of TLRs utilize the adaptor protein MyD88 for signal transduction, although other adaptors have been recently described. As the role of innate immunity in transplantation is unclear, we examined the importance of the MyD88 pathway in acute rejection of fully MHC-mismatched murine allografts and specifically investigated whether MyD88 signaling is important for DC (dendritic cell) function and TH1 alloimmune responses. Our results demonstrate that acute rejection of both fully allogeneic skin and cardiac allografts occurs in the absence of MyD88. However, priming of naïve recipient T cells by allogeneic DCs and TH1 immune responses were diminished in the absence of MyD88, although TH2 immunity remained intact. Thus, these results demonstrate that MyD88 signaling is important for DC function and TH1 responses during fully MHC-mismatched solid-organ transplantation, although graft rejection occurs independently of MyD88.

Adaptor Proteins, Signal Transducing↗

PubMed2004

CD4+CD25+ regulatory T cells suppress allograft rejection mediated by memory CD8+ T cells via a CD30-dependent mechanism.

CD4(+)CD25(+) regulatory T (Treg) cells suppress naive T cell responses, prevent autoimmunity, and delay allograft rejection. It is not known, however, whether Treg cells suppress allograft rejection mediated by memory T cells, as the latter mount faster and stronger immune responses than their naive counterparts. Here we show that antigen-induced, but not naive, Treg cells suppress allograft rejection mediated by memory CD8(+) T cells. Suppression was allospecific, as Treg cells induced by third-party antigens did not delay allograft rejection. In vivo and in vitro analyses revealed that the apoptosis of allospecific memory CD8(+) T cells is significantly increased in the presence of antigen-induced Treg cells, while their proliferation remains unaffected. Importantly, neither suppression of allograft rejection nor enhanced apoptosis of memory CD8(+) T cells was observed when Treg cells lacked CD30 or when CD30 ligand-CD30 interaction was blocked with anti-CD30 ligand Ab. This study therefore provides direct evidence that pathogenic memory T cells are amenable to suppression in an antigen-specific manner and identifies CD30 as a molecule that is critical for the regulation of memory T cell responses.

Animals↗

PubMed2004

[The influence of TLSFJM on the proportion of Th1/Th2-like cell subsets].

AIM: To explore the influence of TLSF(JM) on the proportion of alloantigen activated Th1 and Th2-like cell subsets. METHODS: TLSF(JM) or IL-4 was added to mixed lymocyte reaction(MLR) system. The influence of TLSF(JM) on the proportion of Th1 and Th2-like cell subsets was analyzed by intracellular immunofluorescence staining and FACS. RESULTS: In the TLSF(JM) group, the proportion of IFN-gamma(+) cells differentiated from activated lymphoblast descended from 49.8% to 43.1%, IL-4(+) cells from 75.4% to 43.7% and IL-6(+) cells from 67.8% to 52.6%. The similar tendency was also observed in the unactivated small lymphocytes. CONCLUSION: TLSF(JM) can inhibit both the Th1 and Th2-like cell subsets, but mainly inhibit the Th2-like cell subset, thereby reducing the proportion of Th2-like cell subsets.

Cell Line, Tumor↗

PubMed2004

[Studies on the changes in the interleukin-13 expression and on activator protein-1 activity in rat pulmonary tissue with acute lung injury induced by endotoxin].

OBJECTIVE: To investigate the changes in plasma level of interleukin-13 (IL-13) and the changes in the pulmonary IL-13 mRNA content and the pulmonary activator protein-1 (AP-1) activity of the rats inflicted with acute lung injury (ALI) induced by lipopolysaccharide (LPS), so as to explore the relationship between IL-13 expression and AP-1 activity. METHODS: One hundred and twenty Wistar rats were employed in the study and were randomly divided into A (2 mg/kg), B (4 mg/kg), C (6 mg/kg) and D (8 mg/kg) groups according to different dosage of LPS administration and a control group (NS group) at each observing time point. The rats were observed at 1, 2, 4 and 6 postburn hours (PBHs) and every 6 rats were deployed in every group and each time points. A model of systemic inflammatory response syndrome-acute lung injury (SIRS-ALI) was replicated in Wistar rats. The plasma content of IL-13 was assayed by enzyme-linked immunosorbent assay (ELISA), and the pulmonary tissue content of IL-13 mRNA and AP-1 activity by reverse transcriptase-polymerase chain reaction (RT-PCR) and electrophoretic mobility shift assays (EMSA). RESULTS: The plasma content of IL-13, pulmonary content of IL-13 mRNA and AP-1 activity increased simultaneously after LPS administration. All the above indices were significantly different statistically between the LPS groups and the control group (P < 0.05 - 0.01). The plasma level of IL-13 and pulmonary tissue mRNA content and AP-1 activity in A, B, C and D groups were increased significantly with peak levels at 2 PBHs. CONCLUSION: The pulmonary AP-1 activity increased with the enhanced expression of IL-13, which was related to the development of SIRS-ALI.

Acute Lung Injury↗

PubMed2004

[Expression of matrix metalloproteinase-2,9 in hypopharyngeal carcinoma and its relationship with lymphatic metastasis].

OBJECTIVE: To study the relationship between matrix metalloproteinase-2,9 (MMP-2,9) and the biology behavior, lymphatic metastasis of hypopharyngeal carcinoma by investigating the expression of MMP-2,9. METHOD: Two-step immunohistochemical method was used to examine the expression of monoclona antibody in hypopharyngeal carcinoma tissues. RESULT: It was found that the positive rate of MMP-2 in 32 hypopharyngeal carcinoma tissues was 53.12% (17/32),and the positive rate of MMP-9 was 59.38% (19/32). The difference of the expression in tumor tissue and normal mucosa beside the tumor was significant. The positive rate in those carcinoma with cervical lymph node metastasis was much higher than that in cases without cervical lymph node metastasis. And there was no significant difference found in the expression of MMP-2 and MMP-9. CONCLUSION: MMP-2 and MMP-9 may relate with the lymph node metastasis in hypopharyngeal carcinoma.

Adult↗

PubMed2004

A patient-controlled journal for an electronic medical record: issues and challenges.

Partners Healthcare System, Boston, MA, has developed a patient Web portal that features a patient-controlled electronic "journal" to allow patients to interact with their physician's electronic medical record. Patients can view and respond to health reminders, critique electronic chart information maintained by their doctor's office, enter additional clinical information, and prepare information summaries before an office visit. Creating shared information resources to support a collaborative care model required analysis of the business, architectural, and workflow requirements of the patient-controlled clinical portal and the physician-controlled electronic medical record system. In this paper we describe the challenges in aligning the two systems and serving the different user groups. Coupling the Patient Gateway system, serving over 8700 patients of 90 physicians as of September, 2003, with the Longitudinal Medical Record system, serving over 4000 physicians, has required a clear definition of user goals and workflow, well-defined interfaces, and careful consideration of system assumptions to succeed.

Ambulatory Care Information Systems↗

PubMed2004

[Studies on the expression of mRNA of anti- and pro-inflammatory cytokines in acute lung injury induced by lipopolysaccharide in rat].

OBJECTIVE: To study the role of pro-inflammatory cytokines including tumor necrosis factor-alpha(TNF-alpha), interleukin-1beta(IL-1beta), IL-6, and anti-inflammatory cytokines including IL-4, IL-10, and IL-13 in acute lung injury(ALI). METHODS: Reverse transcription-polymerase chain reaction(RT-PCR) were used to assess the expressions of mRNA of TNF-alpha, IL-1beta, IL-6, IL-4, IL-10 and IL-13 in the lung tissue after lipopolysaccharide challenge. RESULTS: The expression of TNF-alpha mRNA was seen to peak at 1 hour and IL-6 mRNA at 4 hours in lung tissue after the challenge. The highest expression of mRNA of other cytokines, such as IL-1beta, IL-4, IL-10 and IL-13 in lung tissue appeared 2 hours after LPS-induced lung injury. CONCLUSION: TNF-alpha is an early presenting cytokine in ALI, and IL-6 may play an important role in delayed development of ALI. The over-expression of anti-inflammatory cytokines IL-4, IL-10 and IL-13 may act as promoters rather than protectors in amplification of inflammatory process.

Acute Lung Injury↗

PubMed2004

[Changes and significance of TNF, sIL-2R, IL-6, IL-4 and IFN-gamma levels in plasma from the patients with hemorrhagic fever with renal syndrome].

AIM: To explore the changes of TNF, sIL-2R, IL-6, IL-4 and IFN-gamma levels in plasma from patients with hemorrhagic fever with renal syndrome(HFRS) and analyze the correlation between these cytokine levels and alanine aminotransferase(ALT) level in sera from the patients. METHODS: The cytokine levels were measured by double mAb sandwich ELISA. An automatic biochemical detector(RA-1000) was employed to determine the ALT level. RESULTS: Levels of TNF, IL-6, IL-4, IFN-gamma and sIL-2R in plasma from the patients were(95.82+/-12.04), (362.46+/-141.26), (17.76+/-3.52), (116.18+/-19.80) ng/L and (898 820+/-127 200) U/L, respectively. These cytokines in plasma from healthy donors were (17.89+/-1.68), (43.81+/-18.08), (4.86+/-1.14), (7.57+/-2.41) ng/L and (66 730+/-29 690) U/L, respectively. The cytokine levels of the patients were notably higher than those of the healthy donors.(P<0.01). At the same time, the average ALT level in sera from the patients was 4.4 fold of that from the healthy donors. Statistical analysis showed that levels of TNF, sIL-2R, IL-6 and IFN-gamma were positively correlated with ALT level, respectively. CONCLUSION: The HFRS patients have a significant increase in both cytokines (TNF, sIL-2R, IL-6 and IFN-gamma) and ALT levels. And there is a positive correlation between those cytokine and ALT levels, suggesting that the liver injury during HTNV infection may be related to the elevation of above cytokine levels.

Adult↗

PubMed2004

[Effects of water managements on soil nematode communities in a paddy field].

This paper studied the effect of water managements on the abundance, trophic groups and community composition of soil nematodes in a paddy field in the Lower Reaches of Liaohe Plain at the depths of 0-10 cm, 10-20 cm and 20-30 cm during rice (Oryza sativa L.) growth season. The total number of nematodes at 0-10 cm soil depth was lower in percolation-controlling treatments than in control during pre-tillage and yellow ripeness stage. No significant difference was found in the total number of nematodes at 10-20 cm soil depth during the study period, but significant difference was observed in 20-30 cm soil depth during pre-tillage and yellow ripeness stage. Sixteen families and 22 genera were observed, and Plectus, Tylenchus and Monhystera were the dominant genera. Plectus and Tylenchus were sensitive to different water managements. Significant difference was found in the number of bacterivores at 0-10 cm soil depth during pre-tillage and yellow ripeness stage in percolation-controlling treatments, which exhibited a similar trend with the total number of nematodes. Bacterivores and plant-parasites were the most abundant trophic groups in all plots and at all soil depths during the study period, averaging 60.8% and 33.8% of the nematode communities, respectively, and omnivores-predators were the least abundant groups.

Animals↗

PubMed2004

[Phonation assessment of voice restoration after laryngectomy].

OBJECTIVE: To take an objective phonation assessment for the patients who have taken the tracheo-esophageal (TE) shunt procedure after total laryngectomy. METHOD: Twenty-four patients after TE shunt procedure were selected as TE group. Esophageal speakers after total laryngectomy and normal subjects were considered as controls. All the subjects of three groups took part in the voice acoustic assessment and MPT measurement. Twenty TE speakers took part in intra-tracheal pressure measurement. TE speakers and esophageal speakers participated in the electronic laryngoscope examination. RESULT: There were no significant differences between TE group and esophageal group in every acoustic parameters, but there were very remarkable differences between TE group and normal subjects in jitter, shimmer, harmonics to noise ratio and normalized noise energy. The pressure of TE speakers for comfortable /a/ is (2.86 +/- 0.69) kPa. The pharyno-esophageal segment vibrated regularly in most alaryngeal speakers and shapes of neo-glottis of most alaryngeal speakers were circular. CONCLUSION: Acoustic parameters of TE speakers were similar to those of esophageal speakers, but the tone of TE speakers was more similar to the normal controls. Speaking of the patients after the TE shunt procedure is laborsaving.

Aged↗

PubMed2003

9.1C3 is identical to LAIR-1, which is expressed on hematopoietic progenitors.

The leukocyte-associated Ig-like receptor-1 (LAIR-1) is a negative regulator of natural killer (NK) cells, its encoding gene belonging to the leukocyte receptor complex (LRC). Antibody to LAIR-1 can inhibit Ab-induced redirected lysis and TNF-alpha release of effector cells. LAIR-1 contains 2 immunoreceptor tyrosine-based inhibitory motifs (ITIM) in its cytoplasmic region that have been shown to bind constitutively and presumably regulate the tyrosine phosphatase SHP-1 in hematopoietic cells. SHP-1 mutation in mice results in abnormal lymphoproliferation, suggesting that LAIR-1 may also be implicated in regulating hematopoiesis. Here we investigated a monoclonal antibody, 9.1C3, against a NK cell antigen previously described as inducing increased colony formation in in vitro assays of human bone marrow cells. We found that 9.1C3 was expressed on CD34 positive hematopoietic progenitors for the first time. In functional assays, 9.1C3 MAb was able to inhibit Ab-induced redirected lysis and TNF-alpha secretion of NK cells. We proved that 9.1C3 is identical to LAIR-1, based on the fact that not only the antigen precipitated by 9.1C3 MAb was of 40kDa but also 9.1C3 MAb bound specifically to LAIR-1 cDNA transfected COS7 cells as well as recognized LAIR-1 fusion protein in ELISA. This finding provided the first evidence that LAIR-1 expresses on hematopoietic progenitor, implicating its role in the regulation of hematopoiesis at early stage.

Animals↗

PubMed2003

Crystallization and preliminary crystallographic studies of Escherichia coli CcmG/DsbE protein.

CcmG/DsbE is a typical thiol/disulfide oxidoreductase, exhibiting a specific reducing activity in a highly oxidizing environment, and is involved in electron transfer during the maturation of c-type cytochromes. Escherichia coli CcmG/DsbE (residues 19-185) has been crystallized using the hanging-drop vapour-diffusion technique. The crystals belong to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 35.48, b = 48.52, c = 84.78 A. X-ray data have been collected to 1.9 A resolution.

Crystallization↗

PubMed2003

Measurements of elastic constants in thin films of colossal magnetoresistance material.

Measurements of elastic constants of strained 200 and 400 nm thin films, as well as unstrained samples, of the colossal magnetoresistance (CMR) material La0.67Ca0.33MnO3 are presented. Since the peak resistance temperature of a strained CMR film decreases as the film thickness decreases, it is of interest to see if features in the elastic constants, reflecting structural or magnetic changes, follow the peak resistance temperature. It is observed that features in the elastic constants appear not only at the peak resistance temperatures of the CMR samples, but also at a temperature about 17 K higher. A new technique, thin-film resonant ultrasound spectroscopy, was used to make the measurements.

Journal Article↗

PubMed2003

Study of protein-protein interactions by fluorescence of tryptophan analogs: application to immunoglobulin G binding domain of streptococcal protein G.

The protein-protein interaction system often contains many fluorophores that may significantly interfere with the quantitative determination of the binding abilities. To solve this perplexing problem, we biosynthetically incorporated the two tryptophan analogs, 5-hydroxytryptophan and 7-azatryptophan, into the immunoglobulin G (IgG) binding domain of streptococcal protein G (PGBD). The exclusive excitation and novel fluorescence changes in both the intensity and anisotropy are beneficial to reporting the details of the interactions between PGBD and the IgG fragments and enable assessment of the binding abilities. The dissociation constants are estimated to be 0.28 microM for the binding of human Fc and 8.0 microM for mouse Fc. The results clearly demonstrate that labeling of tryptophan analogs has very little effect on the binding abilities and is broadly applicable to quantitatively studying protein-protein interactions in a whole biomolecular complex.

Bacterial Proteins↗

PubMed2003

Prevalence of BK virus and JC virus in peripheral blood leukocytes and normal arterial walls in healthy individuals in China.

Several studies have demonstrated that BK virus (BKV) and JC virus (JCV) establish latent infection in peripheral blood leukocytes (PBLs) of healthy individuals; however, the main populations studied are European. In this study, the prevalence of BKV and JCV DNA in PBLs from healthy adult individuals and umbilical cord blood from newborn children in China was detected by semi-nested polymerase chain reaction (snPCR) followed by restriction enzyme analysis. The results suggest that the healthy adult Chinese population harbors BKV and JCV DNA in peripheral leukocytes. Overall, the prevalence of BKV and JCV DNA in PBLs of healthy adult individuals was 42.1% and 7.8%, respectively. The overall prevalence of BKV DNA was significantly higher than that of JCV DNA. None of the umbilical cord blood samples from newborn children were positive for BKV and JCV DNA. To understand further the target tissues involved in establishment of BKV and JCV latency in healthy individuals, the presence of DNA from both viruses was detected in normal arterial wall samples from 20 young trauma victims by the same method used for leukocyte DNA. BKV DNA was detected alone in 20% of samples tested; JCV DNA was not detected alone in any of the samples. DNA from both viruses was found in 5% of samples. This is the first report to show that normal arterial walls of healthy individuals may be another target site of latency for BKV and JCV.

Adolescent↗