Biomedical subjects

Q Lin

Publications and source records attributed to Q Lin.

At least 91 records · Page 5Linked to original sources

PubMed2000

Efficacy of vaccines containing rhoptry-associated proteins RAP1 and RAP2 of Plasmodium falciparum in Saimiri boliviensis monkeys.

A vaccine trial was conducted with rhoptry-associated proteins 1 and 2 (RAP1 and RAP2) of Plasmodium falciparum in Saimiri boliviensis monkeys to compare the ability of parasite-derived (PfRAP1 and 2) and recombinant proteins (rRAP1 and 2) to induce protective immune responses and to find adjuvants suitable for use in humans. Eight groups of 6 monkeys each were immunized with parasite-derived or recombinant RAP1 and 2 with Freund's complete adjuvant (FCA) followed by Freund's incomplete adjuvant (FIA), Montanide ISA720 adjuvant, or CRL1005 adjuvant. Recombinant RAP1 and RAP2 were also administered separately, with Montanide ISA720. After 3 immunizations, monkeys were challenged by iv inoculation of 50,000 parasites of the Uganda Palo Alto strain of P. falciparum. Of the animals vaccinated using FCA/FIA, 1 of 6 control monkeys, 3 of 6 immunized with PfRAP1 and 2, and 2 of 6 with rRAP1 and 2 did not require drug treatment. Of the monkeys vaccinated with Montanide ISA720 adjuvant, 0 of the 6 control monkeys, 2 of 6 immunized with RAP1 and 2, 1 of 6 immunized with rRAP1, and 4 of 6 immunized with RAP2 did not require drug treatment. Two of 6 monkeys immunized with PfRAP1 and 2 with CRL1005 did not require treatment. All groups receiving RAP1, RAP2, or both had a significant decrease in initial parasite multiplication rates and there was a significant negative correlation between anti-RAP2 antibody and multiplication rates. Animals were rechallenged with the homologous parasite 126 days after the first challenge. Of the monkeys that did not require drug treatment after the first challenge, none developed detectable parasitemia following rechallenge.

Adjuvants, Immunologic↗

PubMed2000

[Construction, expression and activity test of a reshaping single-chain antibody against human CD3].

Monoclonal antibody (McAb) against human CD3 can adjust human body's immune statement in various ways, so that its clinical potential is highly regarded. In order to overcome the immunogenecity related to the murine McAb, this research effort was focused on constructing a reshaping single-chain antibody(scFv) against human CD3 employing antibody engineering. First, the CDRs of the murine McAb against human CD3 OKT3 was transplanted into the light-chain framework regions (FRs) of human McAb LS1 and the heavy-chain FRs of human McAb Nd respectively, spatial conformation was predicted by computer analysis. Then some particular residues were replaced in FRs basing on the result of conformational prediction to draw out the amino acid sequences of the reshaped VL and VH. The genes were chemically synthesize and inserted into an expression vector pROH80 to construct the reshaping scFv. Inducing the expression of reshaping scFv, the products are mainly as inclusion bodies. The reshaping scFv was expressed in another vector pALM. The inclusion bodies were denatured and then renatured by gel filtration. The renatured products were purified by immobilized metal affinity chromatograph (IMAC). Finally, the antigen-binding activily of the reshaping scFv against human CD3 was testified by the Compelitire in hibilory fluorescenceactivated cell sorting (FACS). The competitive inhibition rate is 18%.

Amino Acid Sequence↗

PubMed2000

[Affect of heredity, disease and environment on the life-span of personage in History Book of Song Dynasty].

The data have been sorted and calculated by statistics for personages' life-span according to surname and Yin-Yang type and disease according to the cause of pattern over 793 personage from the biography of emperor families' and official in feudal times and subjects of the feudal ruler in History Book of Song Dynasty. (1) For there are some genetic diseases causing their earlier death in surname Zhao's, the average value of life-span is shorter than the other surname of Wang, Li, Zhang, Liu and Chen's. Because the average value among those five surnames are not different each other, the character of the distribution of every one's tally with neuter alleles. (2) The average value in a population on a type of mild Yin and Yang is higher than the type of Yang only, P < 0.05. (3) Disease and bad environment are the limiting factors for life. Besides, to rise the resistance ability is an important path way for increasing our life-span. The attribute of a genetic system in Yin or Yang is an objective existence. Influence on life by genetics may vary with various disease and environment, but different disease is controlled genetically. A bad environment may affect life, but neuter environment would be affected the life through attribute of a genetic system in Yin or Yang type indirectly.

Environment↗

PubMed2000

[Evaluation of autonomic nervous function with heart rate variability and cardiovascular reflex tests in type II diabetes mellitus patients].

OBJECTIVE: To evaluate autonomic nervous function in simple diabetes mellitus patients, diabetic nephropathy(DN) patients and diabetes mellitus patients with accompanying coronary heart disease(DC) by studying heart rate variability (HRV) and cardiovascular reflex tests. METHODS: 57 type II diabetes mellitus patients were divided into 3 groups: 29 of simple diabetes mellitus, 17 of DC, and 11 of DN. The three groups were matched to 15 healthy controls for age, HRV and three cardiovascular reflex tests were performed in all the patients. RESULTS: The overall frequency of abnormal autonomic nervous function in 57 diabetes mellitus patients was 45.6%. All the diabetes mellitus groups especially the DN group were lower than a normal control group in time domain indexes and nonlinear dynamics indexes. As the patterns of R-R interval Poincare plots were concerned, the control group was mainly of comet-shaped pattern, the simple diabetes mellitus group was mainly of torpedo-shaped pattern, while the DN group and the DC group had more irregular patterns. CONCLUSION: Decrease in HRV is an early clinical marker for evolving diabetic autonomic neuropathy. This method may be helpful for evaluating organ dysfunction in diabetes mellitus patients.

Adult↗

PubMed2000

[Study on human leucocyte antigen-DQ region gene polymorphism in cases of habitual abortion with anticardiolipin antibody].

OBJECTIVE: To investigate the relationship between human leucocyte antigen(HLA)-DQ region gene polymorphism and habitual abortion with anticardiolipin antibody(ACL). METHODS: Polymerase chain reaction-restrictive fragment length polymorphism (PCR-RFLP) was used to type HLA-DQA1 and HLA-DQB1 alleles in 30 cases of habitual abortion with anticardiolipin antibody and 90 women with normal pregnancy history. RESULTS: The frequency of DQB1 * 0303 was found to be significantly higher in ACL(+) habitual abortion group (33.3%) than those in normal control group (P < 0.05). Whereas, there was no significant difference found not only in frequency of other DQB1 alleles, but also in frequency of DQA1 alleles and DQA1-DQB1 haplotypes between two groups. CONCLUSION: The results show an association between ACL(+) habitual abortion and HLA-DQB1 * 0303, which suggest DQB1 * 0303 may be susceptible gene to ACL(+) habitual abortion.

Abortion, Habitual↗

PubMed2000

[Retrospective analysis of 266 cases of pregnancy complicated by heart disease].

OBJECTIVE: To investigate the influence of cardiac function of pregnant women on outcome of their pregnancies. METHODS: Clinical data of 266 cases of pregnant women with heart diseases from January, 1993 to March, 1999 were analyzed retrospectively. RESULTS: (1) The highest incidence of cardiac disease with grade I to II of heart function was due to myocarditis, sequelae of myocarditis and abnormal cardiac rhythm (179 cases, 67.29%). The incidence of congenital heart disease is on the second (41 cases, 15.41%) which is higher than that of rheumatic heart disease (28 cases, 10.91%). (2) Grade III and IV cardiac function was mainly related to congenital and rheumatic heart diseases during pregnancy. The rate of grade I/II heart function in pregnant women after heart operations was 95.45%. (3) The incidence of premature delivery, low weight of newborns and perinatal mortality of mother were higher in women with grade III and IV heart function than in those with grade I and II heart function. CONCLUSIONS: The incidence of myocarditis and sequelae of myocarditis is increasing. Pregnancies complicated with congenital and rheumatic heart diseases are still major causes of perinatal morbidity and mortality of mother and baby. Heart operation can obviously improve the heart function. More effective managements should be adopted.

Adult↗

PubMed2000

[Detection of extended-spectrum beta-lactamases and drug sensitivity test in clinical isolates of the family Enterobacteriaceae in Shanghai].

OBJECTIVE: To investigate extended-spectrum beta-lactamases (ESBLs) production in clinical isolates of the family Enterobacteriaceae in Shanghai, and compare the resistant rates of ESBLs-producing strains and non-ESBLs-producing strains to 11 antibiotics. METHODS: Double-disk synergy test was used to detect ESBLs in 1,026 strains of the family Enterobacteriaceae; Kirby-bauer agar diffusion method was used to judge drug sensitivity. RESULTS: 34.31% of strains of the family Enterobacteriaceae were considered ESBLs producers by double-disk synergy test. The prevalences of ESBLs in isolates of Klebsiella pneumoniae, Escherichia coli and Enterobacter cloacae were 37.40%, 30.21% and 41.82% respectively. Except Imipinem and Cefmetazole, the resistant rates of ESBLs-producing strains to other 9 antibiotics were much higher than that of non-ESBLs-producing strains(P < 0.01). The resistant rates of Imipinem to ESBLs-producing strains were the lowest. CONCLUSIONS: The prevalence of ESBLs in clinical isolates of the family Enterobacteriaceae in Shanghai was high; it is necessary for clinical laboratory to detect ESBLs in clinical isolates of the family Enterobacteriaceae routinely. The resistant rates of ESBLs-producing strains to most antibiotics were high. Imipinem and Cefmetazole were the effective antibiotics to infections caused by ESBLs-producing strains.

Anti-Bacterial Agents↗

PubMed2000

[An investigation on risk factors of cerebral arteriosclerosis].

OBJECTIVE: To investigate the risk factors of cerebral arteriosclerosis (CAS) in the special population--the old cadre in organizations affiliated directly under Fujian Province. METHODS: The investigation was carried out according to the case control method of epidemiology and conditional logistic regression model was used. RESULTS: Multivariate analysis showed that CAS was closely related with the clinostatic systolic blood pressure (CSBP, OR: 2.13), triglyceride (TG, OR: 2.08), diabetes mellitus (OR: 1.31), glycosylated hemoglobin (OR: 1.16), recall of portrait characteristic (OR: 0.89), Kidney-Deficiency Syndrome (OR: 1.54) and Yin-Deficiency with Yang-Excess Syndrome (OR: 1.59). And there was a quantity-effect relationship between CSBP, TG and CAS. CONCLUSION: CSBP is the most important risk factor of CAS in the special population of the old cadre, and the TCM Syndromes of Kidney-Deficiency and Yin-Deficiency with Yang-Excess are also independent risk factors of CAS.

Aged↗

PubMed2000

[Clinical study on hemorrheologic changes for metastatic state of gastric cancer and its relationship with syndrome-type in traditional Chinese medicine].

OBJECTIVE: To explore the hemorrheologic changes of gastric cancer in various stages, and the relationship between different phases and Syndrome-types. METHODS: Sixty-three gastric cancer patients and 30 healthy controls matching in sex and age were studied. According to the phases of tumor and the differentiation standards of deficiency and excess syndrome in TCM, the patients were divided into 6 groups: Non-metastasis (NM), lymphnode metastasis (LM), distant metastasis (DM) groups, and Deficiency (D), Excess (E), mixed deficiency and excess (DE) groups. The hemorrheology criteria including whole blood viscosity (BV), plasma viscosity (PV), hematocrit (HCT), fibrinogen (Fib), platelet count (PC), platelet aggregation rate (PAR) were measured. RESULTS: The value of BV, PV, Fib, PC and PAR in gastric cancer groups were higher significantly (P < 0.05, P < 0.01) than those in the healthy control group, but BV, PV in the LM and DM groups were higher than those in the healthy control group significantly (P < 0.05), while difference between NM group and the healthy control group was insignificant (P > 0.05). Hypercoagulability state presented in all the three Syndrome Type groups of gastric cancer patients, but the difference in some criteria between D and E group were significant (P < 0.05, P < 0.01); and DE groups was greatly higher than D and E groups in high-shear BV, Fib and PC (P < 0.05, P < 0.01). CONCLUSION: The value of BV, PV Fib, PC and PAR could be regarded as good referential parameters in reflecting the condition of evil excess.

Adult↗

PubMed2000

[Changes of endometrial macrophages and nature kill cells during luteal phase and early pregnancy].

OBJECTIVE: To investigate the effect of endometrial microenvironment on pregnancy. METHODS: The number of macrophage and nature kill (NK) cells in decidua and endometrium were determined in 19 cases of early pregnancy and 11 non-pregnant women respectively by cytometric analysis. RESULTS: The percentages of macrophages (leukocyte antigen molecules CD14 positive) and NK cells (CD56 positive) were significantly increased in decidua of first trimester as compared with those in luteal endometrium (P < 0.01). The number of CD(56)(+)CD(16)(-) subset of NK cells increased significantly during early pregnancy. While the number of CD(56)(+)CD(16)(+) subset did not change. CONCLUSION: The endometrial macrophages and NK cells may be involved in the mechanism of the fetal protective immune reaction during pregnancy.

Adult↗

PubMed2000

[Effect of sodium nitroprusside on the spontaneous and induced responses of rat spinal cord dorsal horn neurons].

The present study was performed on anesthetized and paralyzed Wistar rats. Extracellular recordings were made from the lumbar enlargement of the spinal cord using carbon filament electrodes. NO donor sodium nitroprusside (SNP) was locally microdialyzed to the spinal cord, and effects of NO on spontaneous response and the responses induced by mechanical stimulation of the hind-foot were observed. After dialyzing for 10~20 min, SNP at a concentration of 1 micromol/L increased the induced responses to innocuous mechanical stimulation and decreased those to noxoius mechanical stimulation. The induced responses to both innocuous and noxious mechanical stimulations were all decreased after dialyzing the same dose of SNP for 20~30 min. The decrease was shown within 7~15 min dialysis when SNP was used at a concentration of 20 micromol/L. SNP at both concentrations of 1 and 20 micromol/L increased spontaneous spikes of the recorded spinal units. These effects were shown preferentially in deep units. The data suggest that in the deeper neurons of the spinal cord NO of different concentrations has different effects on transmission of nociceptive and nonnociceptive signals induced by mechanical stimulation, and No is involved in the antinociception in spinal neurons and facilitates their spontaneous activity.

Animals↗

PubMed2000

[Establishment of ELISA for measuring phenytoin in serum].

OBJECTIVE: To develop a solid phase, competitive enzyme immunoassay for the measurement of serum phenytoin. METHODS: The chemical modified phenytoin combined with human serum albumin and then conjugated with horseradish peroxidase (HRP) to produce the enzyme labeled phenytoin (DPH-HSA-HRP). The anti-phenytoin antibody was prepared in this lab. RESULTS: The working range and sensitivity of this method were 2.9-30 micrograms/ml and 2.87 micrograms/ml respectively. The intra-assay coefficient of variation (CV) was 3.3%-10.2% (n = 15) and inter-assay CV was 5.1%-13.2%. The recovery of this method was 90%-96%. No significant interference was observed with phenobarbital, primidone, carbamazepine, and valproic acid. The new assay method was compared with HPLC method. A linear regression analysis yielded a slope of 1.03, an intercept 1.38 and a correlation coefficient 0.97. CONCLUSIONS: This solid phase enzyme immunoassay for serum phenytoin appears to be simple, precise, and accurate. It may be readily adopted in clinical laboratory for therapeutic monitoring of phenytoin level in serum.

Chromatography, High Pressure Liquid↗

PubMed2000

[CD45-gating for flow cytometric immunophenotyping of leukemia].

OBJECTIVE: To establish a reliable and rapid multiparameter flow cytometric approach for leukemia immunophenotyping. METHODS: Leukemia blast cells which exhibit a character of low CD45 expression and low side scatter density are easily recognized by "CD45-SSC gating", we measured 46 patients and 3 normal persons of immunophenotyping by this gating method as well as traditional forwardscatter-side scatter (FSC-SSC) gating method. RESULTS: 5 of 46 immunophenotypic results from "FSC-SSC gating" showed false diagnosis, which were corrected by "CD45-SSC gating". Further, immunophenotypic mapping of 46 different acute leukemia were obtained by "CD45-SSC gating" and three-color staining, The expression of related antigen could be readily observed. CONCLUSIONS: "CD45-SSC gating" is a reliable and easy method to subclassify leukemia. Three-color staining, which is able to analyze the expression among two related antigens, not only be helpful in leukemia diagnosis but also contribute to study the occurrence, development and prognosis of diseases.

Adolescent↗

PubMed1999

Studies of a putative ice-binding motif in winter flounder skin-type anti-freeze polypeptide.

Winter flounder contains two distinct anti-freeze protein isoforms, which are the liver-type extracellular anti-freeze proteins and the skin-type intracellular anti-freeze protein. The skin-type anti-freeze proteins exhibit lower anti-freeze activities than the liver-type isoforms and this might be due to their lacking complete ice-binding motifs. One of the skin-type anti-freeze proteins, skin-type anti-freeze protein-3, does contain putative overlapping ice-binding motifs with the sequences '-K-DT-' and '-DT-K-'. Synthetic anti-freezes containing 0-3 repeats of the '-DT-K-' motif were tested for stability and activity. Loss of the single '-DT-K-' of skin-type anti-freeze protein-3 increases the anti-freeze activity and increasing the number of motifs to two or three lowers the activity. The decrease in activity with an increasing frequency of the motif correlates with a decrease in the helical content of these peptides at 0 degrees C.

Animals↗

PubMed1999

Pollution monitoring of three rivers passing through Fuzhou City, People's Republic of China.

The Tradescantia-micronucleus (Trad-MCN) bioassay was used to determine the pollution levels of three rivers passing through Fuzhou city. Results indicate that all three rivers are polluted but at different levels. They are ranked as follows: Antai River > Baima River > Jinan River. Positive results were obtained when full strengths of the water samples were used to treat the plant cuttings when compared with the negative control (tap water) group. Negative responses were obtained when the Baima and Jinan river water was diluted to 50% but not for the sample from the Antai river. Micronuclei frequencies of the Antai river group were higher than the positive control using the Ping-Yang antibiotic drug (Huapei Drug Manufacturer) at 0.2 microg/ml concentration.

Anti-Bacterial Agents↗

PubMed1999

Activation of the Cdc42-associated tyrosine kinase-2 (ACK-2) by cell adhesion via integrin beta1.

Activated Cdc42-associated kinase-2 (ACK-2) is a non-receptor tyrosine kinase that appears to be a highly specific target for the Rho-related GTP-binding protein Cdc42. In order to understand better how ACK-2 activity is regulated in cells, we have expressed epitope-tagged forms of this tyrosine kinase in COS-7 and NIH3T3 cells. We find that ACK-2 can be activated by cell adhesion in a Cdc42-dependent manner. However, unlike the focal adhesion kinase, which also is activated by cell adhesion, the activation of ACK-2 is F-actin-independent and does not require cell spreading. In addition, overexpression of ACK-2 in COS-7 cells did not result in the stimulation of extracellular signal-regulated kinase activity but rather activated the c-Jun kinase. Both anti-integrin beta1 antibody and RGD peptides inhibited the activation of ACK-2 by cell adhesion. In addition, ACK-2 was co-immunoprecipitated with integrin beta1. Overall, these findings suggest that ACK-2 interacts with integrin complexes and mediates cell adhesion signals in a Cdc42-dependent manner.

Antibodies↗

PubMed1999

Ligand selectivity of the peroxisome proliferator-activated receptor alpha.

Peroxisome proliferator-activated receptors (PPAR alpha, beta, and gamma) are nuclear hormone receptors that play critical roles in regulating lipid metabolism. It is well established that PPARs are the targets for the hypolipidemic synthetic compounds known as peroxisome proliferators, and it has been proposed that various long-chain fatty acids and metabolites of arachidonic acid serve as the physiological ligands that activate these receptors in vivo. However, a persistent problem is that reported values of the equilibrium dissociation constants (Kds) of complexes of PPARs with these ligands are in the micromolar range, at least an order of magnitude higher than the physiological concentrations of the ligands. Thus, the identity of the endogenous ligands for PPAR remains unclear. Here we report on a fluorescence-based method for investigating the interactions of PPAR with ligands. It is shown that the synthetic fluorescent long-chain fatty acid trans-parinaric acid binds to PPARalpha with high affinity and can be used as a probe to monitor protein-ligand interactions by the receptor. Measurements of Kds characterizing the interactions of PPARalpha with various ligands revealed that PPARalpha interacts with unsaturated C:18 fatty acids, with arachidonic acid, and with the leukotriene LTB4 with affinities in the nanomolar range. These data demonstrate the utility of the optical method in examining the ligand-selectivity of PPARs, and resolve a long-standing uncertainty in understanding how the activities of these receptors are regulated in vivo.

Animals↗

PubMed1999

Molecular evolution of type 1 serine/threonine protein phosphatases.

Type 1 serine/threonine protein phosphatases (PP1s) play key roles in many cellular processes. To understand the evolutionary relationships among PP1s from various kingdoms and to provide a valid basis to evaluate the structure-function relationships of these phosphatases, 44 PP1 sequences were aligned, revealing a high sequence similarity among PP1 homologs. About one-third of the total amino acids are conserved in all the sequences studied. Most of these conserved amino acids are located within a 270-amino-acid core region. They include most sites critical to the activity and regulation of PP1s based on three-dimensional structural studies of mammalian PP1s. Positional variation analysis using a sliding window approach revealed two variable blocks in the 270-amino-acid core region. The major variable block corresponds to a subdomain composed of three alpha-helices (alphaG, alphaH, and alphaI) and three beta-sheets (beta7, beta8, and beta9). Phylogenetic analyses suggested that plant and animal PP1s form distinct monophyletic groups. The plant PP1 family contains several subgroups that may be older than the monocot-dicot divergence. In the animal PP1 family, different vertebrate isoforms appear to form distinct subgroups. Relative substitution rate studies indicated that plant PP1s are more diverse than animal PP1s, with an average substitution rate 1.5 times as large as that of animal PP1s. The possible involvement of PP1s in the establishment of multicellularity is discussed.

Amino Acid Sequence↗