Biomedical subjects

Lin Li

Publications and source records attributed to Lin Li.

At least 235 records · Page 13Linked to original sources

PubMed2002

Human V gamma 2V delta 2 T cells augment migration-inhibitory factor secretion and counteract the inhibitory effect of glucocorticoids on IL-1 beta and TNF-alpha production.

In immune cells, proinflammatory cytokine gene expression is regulated by glucocorticoids, whereas migration-inhibitory factor (MIF), a pleiotropic cytokine, has the unique property of counteracting the inhibitory effect of glucocorticoids on TNF-alpha and IL-1beta secretion. A few lines of evidence suggest that gammadelta T cells play an important role in immunoregulation. However, it is unknown whether human gammadelta T cells participate in regulating MIF secretion, and how gammadelta T cells, glucocorticoids, and cytokines converge to give a unified physiological response. In this study, we demonstrate that human Vgamma2Vdelta2 T cells augment MIF secretion. Remarkably, these Vgamma2Vdelta2 T cells, functioning similarly to MIF in part, counteracted inhibition of dexamethasone on production of IL-1beta and TNF-alpha. SCID mice reconstituted with human PBMC that were mock depleted of Vdelta2 T cells and repeatedly infected with lethal dose of Escherichia coli had shorter survival time than those reconstituted with PBMC that were depleted of Vdelta2 T cells. Thus, human Vgamma2Vdelta2 T cells are likely to play broad-spectrum roles in immunoregulation and immunopathology by influencing MIF secretion and the immunomodulatory function of glucocorticoids.

Animals↗

PubMed2002

A draft sequence of the rice genome (Oryza sativa L. ssp. indica).

We have produced a draft sequence of the rice genome for the most widely cultivated subspecies in China, Oryza sativa L. ssp. indica, by whole-genome shotgun sequencing. The genome was 466 megabases in size, with an estimated 46,022 to 55,615 genes. Functional coverage in the assembled sequences was 92.0%. About 42.2% of the genome was in exact 20-nucleotide oligomer repeats, and most of the transposons were in the intergenic regions between genes. Although 80.6% of predicted Arabidopsis thaliana genes had a homolog in rice, only 49.4% of predicted rice genes had a homolog in A. thaliana. The large proportion of rice genes with no recognizable homologs is due to a gradient in the GC content of rice coding sequences.

Arabidopsis↗

PubMed2002

Full-length cDNA cloning of human neuroglobin and tissue expression of rat neuroglobin.

Neuroglobin is a recently discovered respiratory, porphyrin-containing protein that is expressed in the brain of mouse and human. However, the full-length cDNA sequence and genomic organization of human neuroglobin have not been reported. In this paper, the full-length cDNA sequence of human neuroglobin was cloned following bioinformatic analysis and the rapid amplification of cDNA ends (RACE) technique. It was shown that the full-length cDNA sequence (GenBank Accession No. AF422796) of human neuroglobin is 1909 bp in size, and the genomic sequence is 8041 bp in size (GenBank Accession No. AF422797). To further study the characterization of this gene, the coding region of rat neuroglobin (GenBank Accession No. AF333245) was cloned by using degeneracy PCR. The result showed high conservation among human, rat, and mouse neuroglobin. Furthermore, it was demonstrated that NGB was extensively expressed in rat brain by using in situ hybridization and the immunohistochemical technique. Transcription of NGB mRNA was shown to be widely distributed throughout the adult rat brain, including cerebral cortex, hippocampus, thalamus, hypothalamus, olfactory bulb, and cerebellum. NGB protein immunoreactive cells were also widely distributed throughout normal adult rat brain, including cerebral cortex, hippocampus, thalamus, hypothalamus, pons, and cerebellum. It could be seen that the NGB-immunopositive signals were in the cytoplasma and processes of the neuron. These data strongly support the notion that neuroglobin is a highly conserved gene in evolution and is very important in the nervous system, possibly related to the oxygen supply of the neuron.

Aging↗

PubMed2002

Comparison of quantitative perfusion imaging using arterial spin labeling at 1.5 and 4.0 Tesla.

High-field arterial spin labeling (ASL) perfusion MRI is appealing because it provides not only increased signal-to-noise ratio (SNR), but also advantages in terms of labeling due to the increased relaxation time T(1) of labeled blood. In the present study, we provide a theoretical framework for the dependence of the ASL signal on the static field strength, followed by experimental validation in which a multislice pulsed ASL (PASL) technique was carried out at 4T and compared with PASL and continuous ASL (CASL) techniques at 1.5T, both in the resting state and during motor activation. The resting-state data showed an SNR ratio of 2.3:1.4:1 in the gray matter and a contrast-to-noise ratio (CNR) of 2.7:1.1:1 between the gray and white matter for the difference perfusion images acquired using 4T PASL, 1.5T CASL, and 1.5T PASL, respectively. However, the functional data acquired using 4T PASL did not show significantly improved sensitivity to motor cortex activation compared with the 1.5T functional data, with reduced fractional perfusion signal change and increased intersubject variability. Possible reasons for these experimental results, including susceptibility effects and physiological noise, are discussed.

Adult↗

PubMed2002

HIV/AIDS knowledge and attitudes in Chinese medical professionals and students before and after an informational lecture on HIV/AIDS.

The rapid increase in human immunodeficiency virus (HIV) prevalence and incidence requires that Chinese health professionals mobilize for HIV prevention. The article describes an HIV/acquired immune deficiency syndrome knowledge and attitude assessment administered before and after a lecture. HIV transmission knowledge was good, with 90 percent to 100 percent of participants correctly identifying means of transmission. Prior to and after the lecture, 43 percent and 21 percent, respectively, were unwilling to sit or work with an HIV-infected person. To increase the likelihood of prevention activities' success, HIV knowledge and attitudes of health care personnel in China must be monitored and improved.

Adult↗

PubMed2002

Hyposmotic membrane stretch potentiated muscarinic receptor agonist-induced depolarization of membrane potential in guinea-pig gastric myocytes.

AIM: To investigate the relationship between hyposmotic membrane stretch and muscarinic receptor agonist-induced depolarization of membrane potential in antral gastric circular myocytes of guinea-pig. METHODS: Using whole cell patch-clamp technique recorded membrane potential and current in single gastric myocytes isolated by collagenase. RESULTS: Hyposmotic membrane stretch hyperpolarized membrane potential from -60.0mV+/-1.0mV to -67.9mV+/-1.0mV. TEA (10 mmol/L), a nonselective potassium channel blocker significantly inhibited hyposmotic membrane stretch-induced hyperpolarization. After KCl in the pipette and NaCl in the external solution were replaced by CsCl to block the potassium current, hyposmotic membrane stretch depolarized the membrane potential from -60.0 mV+/-1.0mV to -44.8 mV+/-2.3mV (P<0.05), and atropine (1 micromol/L) inhibited the depolarization of the membrane potential. Muscarinic receptor agonist Carbachol depolarized membrane potential from -60.0mV+/-1.0mV to -50.3 mV+/-0.3mV (P<0.05) and hyposmotic membrane stretch potentiated the depolarization. Carbachol induced muscarinic current (I( cch )) was greatly increased by hyposmotic membrane stretch. CONCLUSION: Hyposmotic membrane stretch potentiated muscarinic receptor agonist-induced depolarization of membrane potential, which is related to hyposmotic membrane stretch-induced increase of muscarinic current.

Animals↗

PubMed2002

[A preliminary study of pentanucleotide repeat polymorphism of apolipoprotein(a) gene in coronary atherosclerotic heart disease].

OBJECTIVE: This study inquired into the relationship between a pentanucleotide repeats(PNR) polymorphism of the apolipoprotein(a)[apo(a)] gene and coronary atherosclerotic heart disease(CHD) in Chinese Han nationality. METHODS: PNR polymorphism of the apo(a) gene from 165 cases of CHD and 153 normal individuals were analyzed by polymerase chain reaction(PCR)-denature polyacrylamide gel electrophoresis-silver stain. RESULTS: The frequencies of (TTTTA)(5/8) genotype (0.188) and (TTTTA)(5) allele (0.115) in CHD group were remarkably higher than those in control group (0.039, 0.026)(P<0.01, P<0.05). CONCLUSION: These findings indicate that the PNR polymorphism of apo(a) is associated with the susceptibility to CHD, which may be involved in the development of CHD.

Aged↗

PubMed2002

[Localization of hepatitis C virus core protein in the nucleus of peripheral blood mononuclear cells of hepatitis C patients].

BACKGROUND: To study the significance of the expression of HCV core protein in PBMC of patients with chronic hepatitis C and to evaluate the relationship between HCV core protein expression and clinical states. METHODS: Identification of HCV protein antigen (Ag) in PBMC of 66 hepatitis C patients by immunohistochemical method and clinical status of the patients with HCV protein positive expression were investigated. In 27 out off 66 patients the HCV RNA and HCV Ag in PBMC were detected with RT-PCR and immunohistochemical method. RESULTS: The HCV Ag (core+NS3) was identified in PBMC in 51 out of 66 patients (77.27%). It was also demonstrated that HCV core protein in nucleus showed strong expression and NS3 protein in cytoplasm showed weak expression. The expression of core protein in nucleus of PBMC were 35.29% in advanced chronic hepatitis patients, which was significantly higher than that from moderate cases (5.88%). CONCLUSIONS: This study suggested that the expression of PMBC-HCV core protein may be related to the clinical state of the patients. The nuclear expression of HCV core protein in PBMC of patients with hepatitis C may be related to the persistence and activity of the chronic hepatitis C virus and play an important role in the pathogenesis of cirrhrosis and hepatocellular carcinoma.

Hepatitis C Antigens↗

PubMed2002

Phylogenetic position of Chinese endemic Drosophila curviceps species subgroup in the Drosophila immigrans group.

In order to investigate the phylogenetic position of Chinese endemic Drosophila curviceps species subgroup within the D. immigrans group on DNA molecular level, the ITS1 region of ribosomal DNA and part of Adh gene for 12 species represented all the five subgroups in D. immigrans group were sequenced. Molecular phylogenetic trees were constructed by using parsimony and neighbor-joining methods based on ITS1, Adh and combined sequences. In the molecular trees, species of the D. curviceps subgroup cluster together, strongly supporting establishment of a separating subgroup suggested in an initial morphologic study. This subgroup is the sister taxa of the D. quadrilineata subgroup. They are the younger subgroups, splitting about 3.4 Mya. The D. hypocausta subgroup is located at the base of the molecular tree, diverged first in this group about 9.2 Mya. Taking the geographic distribution into account, we can conclude that D. curviceps subgroup originated from tropic zones, agreeing with the previous morphologic and biogeographic suggestions. The position of D. neohypocausta was also discussed in this report and it seems that it is closer to the D. immigrans subgroup than to the D. hypocausta subgroup.

Alcohol Dehydrogenase↗

PubMed2002

Samarium-153-EDTMP bone uptake rate and its relation to therapeutic effect.

OBJECTIVE: To evaluate the measurement of Samarium-153 ethylenediaminetetramethylene phosphonic acid ((153)Sm-EDTMP) bone uptake rate using whole-body scintigraphy and analyze the relationship between bone uptake rate and therapeutic effect. METHODS: Sixty-six patients with painful bony metastases from prostate (n = 15), lung (n = 20), breast (n= 18), nasopharyngeal carcinoma (NPC) (n=5), colon (n=2), kidney (n=2) and unknown cause (n=4) carcinoma were examined with whole-body scintigraphy 10 min and 5 h post administration of (153)Sm-EDTMP. Bone uptake rate was then calculated. (1 ) Complete response (CR): disappearance of > 2 metastases, Karnofsky Performance Score (KPS) increase > 20, moderate or complete remission of bone pain 7 d post injection of (153)Sm-EDTMP. (2) Partial response (PR): disappearance of 1-2 metastases, KPS increase 10-20, moderate remission of bone pain in 3 wk. (3) Non-response (NR): no disappearance or shrinkage of metastases, KPS increase < 10, no or slight remission of bone pain. RESULTS: The range of bone uptake rate in 66 patients was 31 .9% - 86.6% (mean = 56. 0%). The bone uptake rate in the CR group (17 cases, 25.7%), PR group (24 cases, 36.4%), and NR group (25 cases, 37.9%) was 52.4% - 86.6% (mean = 68.7%), 43.7% - 70.4% (mean = 58.3%), and 31.9%- 51 .5% (mean = 41 . 0%) respectively. Statistical analysis showed that there was a significant difference between the CR and PR groups ( t = 4.258, P = 0.001 ) as well as between PR and NR groups ( t = 8.48,P = 0.001 ). CONCLUSIONS: Using a simple and reliable whole-body scintigraphic technique to calculate prospectively the bone uptake rate, we have, for the first time in China, reported the relationship between bone uptake rate and therapeutic effect. This allows nuclear medicine physicians to calculate a safe and effective dose of (153)Sm-EDTMPin individual patients to palliate bone cancer pain without myelotoxicity.

Bone Neoplasms↗

PubMed2002

Identification of Streptococcus species and Haemophilus influenzae by direct sequencing of PCR products from 16S-23SrDNA intergenic spacer regions.

OBJECTIVE: To set up a rapid and simple method for identificating bacteria by 16S-23SrDNA intergenic spacer regions (ISRs). METHODS: Polymorphic products of PCR from ISRs were selected on agarose gel and sequenced directly using purified fragments by excising the gel without cloning. Nucleotide sequences were compared with GenBank databases and analyzed by DNAMAN program. RESULTS: There was only a single product in streptococcus genus after PCR amplification of 16S-23SrDNA ISRs. Five streptococcal species were obtained from 7 strains of streptococcus. Two major amplicons were consistently generated for 8 strains of Haemophilus influenzae (H. influenzae). The sequence data showed that they all belonged to H. influenzae type b on GenBank databases. CONCLUSION: PCR and direct sequencing of 16S-23SrDNA ISRs were very successful methods for bacterial species identification.

Base Sequence↗

PubMed2002

Intracellular calcium was involved in muscarinic currents increased by hypoosmotic membrane stretch in gastric myocytes of guinea pig.

AIM: To investigate the role of intracellular calcium in muscarinic currents increased by hypoosmotic membrane stretch in gastric antral circular myocytes of the guinea pig. METHODS: The whole cell patch-clamp technique was used, and the myocytes were isolated by collagenase. Cells were swelled by hypoosmotic solution (200 Osmmol/kg). RESULTS: The hypoosmotic membrane stretch markedly increased carbachol-induced muscarinic currents (ICCh). The ICCh and the increase of ICCh were completely blocked by quinidine 3 micromol/L, a specific muscarinic current blocker. In external calcium-free solution hypoosmotic membrane stretch could not increase ICCh, but in the presence of nicadipine 5 micromol/L, a L-type calcium channel blocker or gadolinium chloride 100 nmol/L, a stretch-activated cation channel blocker, the ICCh was still increased by hypoosmotic membrane stretch. When both nicardipine and gadolinium chloride were added into external solution, ICCh were not increased by hypoosmotic membrane stretch any more. Ryanodine, a calcium-induced calcium release (CICR) agonist completely blocked hypoosmotic membrane stretch-induced increase of ICCh. CONCLUSION: Hypoosmotic membrane stretch increased ICCh and the increment was related to influx of external calcium and CICR.

Animals↗

PubMed2002

Inhibition of 6A8 alpha-mannosidase causes oncosis-like death of BJAB cells.

To study relationships between glycosylation and cell survival we used a human alpha-mannosidase, 6A8, recently discovered in our laboratory. We found that glycosylation of BJAB cells was modified when cells were transduced with a fragment of antisense 6A8 cDNA, which resulted in an inhibition of 6A8 alpha-mannosidase expression. In comparison to wild type, mock- or sense 6A8-tansduced cells, the antisense 6A8-transduced cells showed increased cell death in culture. The dying cells were characterized by cell and nucleus swelling, membrane blebbing, organelle dilation and membrane breaking at the blebbing sites. They did not have apoptotic bodies. Annexin-V staining and DNA fragmentation assays also showed no evidence of apoptosis in these cells. This data implied that BJAB cells underwent an oncosis-like cell death upon transduction with a fragment of antisense 6A8 cDNA, which inhibited 6A8 alpha-mannosidase expression and therefore modified glycosylation of proteins shown by Con A binding test. These data imply that 6A8 alpha-mannosidase plays an important role in preventing oncosis-like death in BJAB cells. The possible mechanism of cell death by oncosis was discussed.

Cell Death↗

PubMed2002

Clinical comparison of the selective serotonin3 antagonists ramosetron and granisetron in treating acute chemotherapy-induced emesis, nausea and anorexia.

OBJECTIVE: The efficacies of the selective 5-hydroxytryptamine3 (5-HT3) antagonists--ramosetron (0.3 mg) and granisetron (3 mg) in treating acute chemotherapy-induced digestive system dysunction were compared. METHODS: A total of 111 patients were enrolled in a single-blind, randomised crossover study; with data from 98 were used to assess efficacy and data from 110 to assess the safety profile. Ramosetron or granisetron was given intraveneously 15 min befire chemotherpy. RESULTS: The ability of ramosetron to prevent emesis, nausea and anorexia was similar to granisetron during the first 6 h following the administration of chemotherapy, ciplatin or doxorubicin. However, during the first 24 h after chemotherapy, significant differences between ramosetron and granisetron appeared: emetic episode (P = 0.068), nausea (P = 0.006), and anorexia (P = 0.048) remained lower in ramosetron-treated patients. The safety profile of ramosetron was similar to that of granisetron and adverse events in both groups were generally mild and transient. CONCLUSION: Ramosetron is more potent and longer-lasting than granisetron in preventing chemotherapy-induced digestive disturbances.

Adolescent↗

PubMed2002

[Repopulation with exogenous mitochondria in the cell].

To create human mitochondrial DNA (mtDNA)-transferred cells as cell model of mitochondria defects-related diseases, platelet of normal young and old subjects were isolated as donor of mtDNA, then fused with mtDNA-depleted cells (rho0 cells) under induction of PEG1500. Auxtrophy test, cytochrome c oxidase activity assay and PCR amplification of mtDNA were done to confirm the transferring of mtDNA. Cell clones were visible in the medium 10 to 15 days after fusion, which grew well in medium lacking uridine, had positive COX activity and contained objective fragment of mtDNA by PCR, opposite to rho0 cells. Transferring of mtDNA to rho0 cells was identified, and mtDNA-transferred cell models were successfully created.

Adult↗

PubMed2002

[The morphology observation, mechanics intensity test and genetic analysis of brittle culm mutant bcm581-1 in rice].

A rice brittle culm mutant bcm581-1 which derived from the Ds transposone transformation population was found, but the mutant was identified that it was not to be induced by Ds transposone insertion through PCR. The examination of the vascular bundle and cortical fibre cells in culm under the light and electron microscope showed that, the number of cortical vascular bundle of mutant was much more, the hollow among the cortical vascular bundle was deeper, and the cell walls of cortical fibre cells were thinner than the normal. The test of culm mechanics intensity showed that the load, elongation, strain, and stress of bcm581-1 were 5-9 times lower than normal. The moisture content and the wide fibre content of culm were test, the former was 3.5% higher, but the latter was 8.12% lower than normal. The analysis of genetic segregation in F2 and F1B1 population indicated that the brittle culm mutant was controlled by one recessive gene.

Biomechanical Phenomena↗

PubMed2001

Second cysteine-rich domain of Dickkopf-2 activates canonical Wnt signaling pathway via LRP-6 independently of dishevelled.

Recent evidence suggests that members of the Dickkopf (Dkk) family can directly bind to LDL-related protein (LRP)-6, resulting in inhibition of Wnt-activated signaling. To further characterize the interactions between Dkk and LRP proteins, conditioned media containing individually conserved cysteine-rich domains of Dkk-1 and Dkk-2 were prepared. Although full-length Dkk-1 and Dkk-2 and the second cysteine-rich domains of both Dkk molecules inhibited Wnt-3a-induced activation of lymphoid enhancing factor (LEF)-1, a downstream target of the canonical pathway, we found that the second cysteine-rich domain of Dkk-2 (Dkk-2C2) was able to stimulate the canonical pathway when LRP-6 was ectopically expressed in NIH3T3 cells. This effect of Dkk-2C2 could be blocked by a monoclonal antibody specific to the second YWTD repeat domain of LRP-5/6, suggesting that Dkk-2C2 acts via LRP-6. We also showed that while both Axin and the DIX domain of Dishevelled (Dvl) could inhibit Dkk-2C2-induced activation of LEF-1, the DEP domain of Dvl, which inhibited Wnt-induced activation of LEF-1, failed to inhibit the activation of LEF-1 by Dkk-2C2 or by an activated form of LRP-5, LRPC2. In addition, glycogen synthase kinase-3 beta, a potent inhibitor for both Dvl and Wnt, also failed to inhibit LRPC2 or Dkk-2C2. Furthermore, knocking-down the expression of Dvl molecules by short interfering RNAs specific to Dvl inhibited Wnt-induced, but not LRPC2-induced, activation of LEF-1. All the evidence indicates that Dkk-2C2 signals through LRP proteins, which does not require Dvl, while Wnt protein may employ both Dvl, presumably through Fz, and LRP to achieve more efficient signal transduction.

3T3 Cells↗

PubMed1999

Effect of apolipoprotein E gene Hha I restricting fragment length polymorphism on serum lipids in cholecystolithiasis.

AIM:To investigate the role of apolipoprotein E (apoE) polymorphism in the lithogenesis of gallstone and the hereditary pathogenesis of the disease.METHODS: Polymerase chain reaction (PCR) was used to study apoE phenotypes and allele frequencies in patients with gallstones and control, and the fasting serum lipids of subjects were also measured by enzymatic methods.RESULTS:The levels of triglyceride (TG) and very low density lipoprotein cholesterol (VLDL-C) were much higher in E(2/3) patients than that in E(2/3) control. E(3/3) patients were accompanied with remarkably low levels of high density lipoprotein cholesterol (HDL-C) and its subforms.But in E(3/4) patients there were only slight changes in levels of VLDL-C and low density lipoprotein cholesterol (LDL-C).CONCLUSION:Different apoE phenotype patients with gallstones have different cheracteristics of dyslipidemia and the average level of serum lipids in patients with gallstones are higher than subjects without gallstones in the same apoE gene phenotype.epsilon2 allele is possibly one of the dangerous factors in the lithogenesis of cholecystolithiasis.

Journal Article↗