Biomedical subjects

Z Qian

Publications and source records attributed to Z Qian.

At least 55 records · Page 3Linked to original sources

PubMed1999

[Purification and specific detection of two major Schistosoma gut-associated circulating antigens, CAA and CCA].

AIM: To investigate the specificity differences of the 2 major gut-associated diagnostic circulating molecules in Schistosoma japonicum infection, CAA and CCA, and to obtain sufficient purified material for setting up a standard series in quantitative determinations. METHODS: Isolation and purification of the two worm fractions from a trichloroacetic acid (TCA) soluble preparation of S. japonicum adult worm antigen (AWAj-TCA) by Mono-Q anion exchange chromatography were performed and the specific reactivity of the eluted fractions by antigen-capture ELISA (specific for CAA or CCA) with reference to affinity purified preparations of S. mansoni CAA and CCA was analysed. RESULTS: By using an ionic strength gradient, CCA was eluted in two major peaks, an unbound fraction CCA-1, and a major bound fraction CCA-2. Two additional minor peaks, CCA-3 and CCA-4, were eluted at higher ionic strengths. CAA was only detected in a bound fraction, partly overlapping with CCA-3. In the CCA-1 and CCA-2 fractions reactivity was only found in the antigen-capture ELISA using anti-CCA McAbs both for capture and detection. The CAA fraction was predominantly found to be positive in the antigen-capture ELISA using anti-CAA McAbs both for capture and detection. However, when using combinations of anti-CCA and anti-CAA McAbs for capture and detection by ELISA this fraction showed some reactivity. CONCLUSION: Two CCA fractions contain molecules which bear at least two CCA-epitopes; while the CAA fraction contains molecules which contain at least two CAA-epitopes, and one CCA-epitope.

Animals↗

PubMed1999

[Detecton of circulating antigen in sera from mice infected with Toxoplasma tachyzoites].

AIM: To explore an assay method for the early diagnosis of Toxoplasma infection. METHODS: Serum samples collected from three groups of mice infected experimentally with different doses of Toxoplasma trophozoites were detected for the presence of Toxoplasma circulating antigen by using fast ELISA. RESULTS: Toxoplasma circulating antigen was detected on days 4, 4 and 3 after infection in light, moderate and heavy infection groups, respectively. CONCLUSION: The level of circulating antigen was in parallel with the duration of infection. The determination of circulating antigen is useful in the early diagnosis of Toxoplasma infection.

Animals↗

PubMed1998

Evidence that the TIM light response is relevant to light-induced phase shifts in Drosophila melanogaster.

Light is a major environmental signal for the entrainment of circadian rhythms. In Drosophila melanogaster, recent experiments suggest that photic information is transduced to the clock through the timeless gene product, TIM. We provide genetic and spectral evidence supporting the relevance of TIM light responses to clock resetting. A missense mutant TIM, TIM-SL, exhibits greater sensitivity to light in both TIM protein disappearance and locomotor activity phase shifting assays. We show that the wavelength dependence of light-induced decreases in TIM levels and that of light-mediated phase shifting are virtually identical. Analysis of dose response of TIM disappearance in a variety of mutant genotypes suggests cell-autonomous light responses that are largely independent of the canonical visual transduction pathway.

Animals↗

PubMed1998

Fas-mediated apoptosis in accelerated graft arteriosclerosis.

Pathological conditions have been recognized where vessel destruction is a prominent feature of the pathogenic process. One such condition consists of the chronic rejection of blood vessels in transplanted solid organs. Accelerated graft arteriosclerosis (AGA) is a multifactorial process characterized by the concentric proliferation of smooth muscle cells (SMCs) within the intima of the vessel wall of transplanted organs. Proliferation of SMCs within the intima corresponds to a response of these cells to injury. In situations like restenosis post-angioplasty, the mechanism of injury: the mechanical disruption of the tunica media, is evident. However, in the case of AGA, the mechanism of injury has remained elusive. In this report, we provide evidence that injury to SMCs in AGA vessels requires an intact Fas pathway. The resulting damage to the tunica media and internal elastic lamina, in turn, might trigger the proliferation of intimal smooth muscle cells that appear to be less sensitive to Fas mediated killing, particularly when supported by a favorable context of inflammatory cytokines and growth factors, as it is the case in AGA. This pathogenic process results in a absolute loss of functional blood vessels that is not being compensated by an efficient angiogenic response.

Journal Article↗

PubMed1998

Yeast Ty1 retrotransposition is stimulated by a synergistic interaction between mutations in chromatin assembly factor I and histone regulatory proteins.

A screen for host mutations which increase the rate of transposition of Ty1 and Ty2 into a chromosomal target was used to identify factors influencing retroelement transposition. The fortuitous presence of a mutation in the CAC3 gene in the strain in which this screen was undertaken enabled us to discover that double mutaions of cac3 and hir3, but neither of the two single mutations, caused a dramatic increase in the rate of retrotransposition. We further showed that this effect was not due to an increase in the overall level of Ty1 mRNA. Two subtle cac3 phenotypes, slight methyl methanesulfonate (MMS) sensitivity and reduction of telomeric silencing, were significantly enhanced in the cac3 hir3 double mutant. In addition, the growth rate of the double mutant was reduced. HIR3 belongs to a class of HIR genes that regulate the transcription of histones, while Cac3p, together with Cac1p and Cac2p, forms chromatin assembly factor I. Other combinations of mutations in cac and hir genes (cac3 hir1, cac3 hir2, and cac2 hir3) also increase Ty transposition and MMS sensitivity and reduce the growth rate. A model explaining the synergistic interaction between cac and hir mutations in terms of alterations in chromatin structure is proposed.

Alleles↗

PubMed1998

[Distribution of transforming growth factor-beta and its receptor in bronchiolo-alveolar cell hyperplasia and bronchiolo-alveolar carcinoma].

The distribution of the three isoforms of transforming growth factor (TGF)-beta (TGF-beta 1, -beta 2, and -beta 3) as well as their signaling receptor, TGF-beta type I receptor (T beta R-I), in bronchiolo-alveolar cell hyperplasia (BAH) and bronchiolo-alveolar carcinoma (BAC) was examined by immunohistochemistry using specific antibodies. The results showed that the expression of one or more TGF-beta subtypes occurred in a large proportion of BAC and BAH tissues. The expression of TGF-beta 1 and TGF-beta 3 was increased in tumor cells compared with hyperplastic cells. BAC with expression of two or three ligands was associated with a higher incidence of lymph node metastasis. These results suggest that hyperplastic cells and cancer cells derived from bronchiolo-alveolar cell can synthesize and secrete TGF-beta isoforms and its receptor T beta R-I which may contribute to the progression of BAC in part.

Adenocarcinoma, Bronchiolo-Alveolar↗

PubMed1998

[Study on mechanism of bushen yugong granule in treating uterine dysgenesia].

OBJECTIVE: To explore the effective mechanism of Bushen Yugong Granule (BSYGG, a Chinese medicine preparation) in treating infertility due to uterine dysgeneia. METHODS: (1) Clinical study: Serum level of sex hormone and endometrial content of estradial receptor (ER) and progesterone receptor (PR) in follicle period of 60 patients (the tested group) were measured and compared before and after treatment, and the data were also compared with those of 70 normal women (the control group). (2) Experimental study: Rats were divided into the control group and 3 tested groups fed with different dose of BSYGG. Pathologic examination of pituitary, ovary and uterus of rats after BSYGG treatment, and serum levels of ER, PR were measured. Also, an estrogen activity experiment was adopted in some young cophorectomized rats. RESULTS: (1) Clinical study, the difference of serum sex hormone levels between the tested and the control group was insignificant. The percentage of patients in tested group with endometrial ER content over ++ was lower than that in the control group (46.9% vs 72.4%) significantly (P < 0.05), after treatment, it arised to 65.4% in test group, the change after treatment was significant (P < 0.05). (2) Experimental study: The number of follicle, weight of uterus and serum E2 level increased significantly after BSYGG treatment. The endometrial content of ER in the control group was 29.25 +/- 17.03%, while in the tested group, it was 67.75 +/- 24.56%-83.00 +/- 9.87% after treatment, the difference between the two groups was significant (P < 0.005). CONCLUSION: BSYGG has an estrogen-like activity, it could increase the endometrial content of ER, enhance the effect of estrogen on uterus and promote the uterine development, so as to elevate the fertilization rate.

Adult↗

PubMed1998

[Comparative observation on the efficacy of several test/probe systems for detecting schistosome circulating antigen].

AIM: To compare the efficacy of 5 test/probe systems for the detecting of schistosomal circulation antigen (SCA) in sera from infected rabbits. METHODS: Nine rabbits were infected with monosexual cercariae (either male or female), 7 rabbits were infected with bisexual cercariae as controls. Blood samples were collected periodically post infection (p.i). 15 rabbits were infected each with 250 bisexual cercaria and divided into 3 groups, 2 groups were treated with allyl thiourea (295-590 mg/kg) from 19 d or 46 d respectively, to inhibit their egg formation. One untreated group was used as control. Blood samples were collected weekly until 8 wk post infection. SCA detecting methods include (1) dot-ELISA/McAb anti-surface membrane antigen of adult worms (8SE4), (2) dot-ELISA/McAb anti-CCA (3D10), (3) Sandwich dot-ELISA/McAb anti-egg antigen (MG2), (4) Sandwich-ELISA/McAb anti-egg antigen (2H10), (5) Sandwich-ELISA/McAb anti-CAA (1B10). RESULTS: Using method (1) all of the 18 rabbits infected with monosexual cercariae were negative. Using method (2) only 1 rabbit harboured 133 male worms showed positive. Using method (5) no SCA were detected in sera from female cercariae-infected rabbits but 3 out of 9 male cercariae-infected rabbits showed positive reaction. SCA detecting results from rabbits treated with allyl thiourea: both method (1) and (3) showed negative in rabbits treated from 19 d (p.i.) but all gave positive reaction in 6-7 wk in rabbits treated from 46 d (p.i.). There were all negative detected by using method (4) and all positive at 6 wk (p.i.) detected by method (5) in rabbits of 3 groups whether treated or non-treated. CONCLUSION: Various test/probe systems have different efficacy in detecting SCA but (5) of the methods (1)(2) tests/probe systems could not detect SCA in rabbits with single female cercariae infection. From the egg formation inhibition study, the SCA detected by McAb 8SE4 dot-ELISA might be related to egg maturation. Whether the surface membrane antigen of adult worm has common antigenic component with egg antigen remains to be studied.

Animals↗

PubMed1998

[Study on invasibility and multiplication of Toxoplasma strains with different virulence toward Vero-cells].

AIM: To investigate the pathogenic mechanisms of Toxoplasma strains with different virulence. METHODS: Tachyzoites from 3 strains, Viz. RH, B36 and Fukaya strains, were challenged to in vitro cultivated Vero-cells. Systematic examinations on the earliest invasion time, the invasion rate and intracellular multiplication were performed under different cultivation conditions. RESULTS: The tachyzoites of all the 3 strains invaded the host cells within a short period after inoculation. Invasion rates were all increased along with the prolonged duration of infection. The intracellular multiplication was found to be most active in RH strain, moderate in B36, and comparatively slow in Fukaya strains. Using purified tachyzoites freed from host debris and proteins and adding sufficient FCS in the medium may facilitate the invasion and subsequent multiplication of the parasite. CONCLUSION: Strain differences in pathogenicity to the host may be correlated to the genetically predetermined multiplication capabilities of the parasites after being invaded to the host cell, and that environmental factors may give certain impact on the invasibility of the parasite.

Animals↗

PubMed1998

[Correlation between the dose and the anti-Toxoplasma effect of activated mouse macrophages induced by IFN-gamma and the synergism between IFN-gamma and TNF-alpha].

AIM: To find out the dose dependence of the anti-Toxoplasma effect induced by IFN-gamma and to determine the possible synergistic activity between TNF-alpha and IFN-gamma. METHODS: The in vitro effect of cultivated mouse peritoneal macrophages activated by IFN-gamma alone or IFN-gamma combined with different doses of TNF-alpha on the intracellular tachyzoites of RH strains and the nitric oxide (NO) level in the culture medium supernatant were simultaneously determined. RESULTS: With the increase in the dose of IFN-gamma, the anti-Toxoplasma effect was augmented and the NO level was enhanced. At 24 hours after tachyzoite invasion, a significant reversed correlation was demonstrated between the NO level and the number of intracellular parasites. CONCLUSION: The anti-Toxoplasma effect of macrophages activated by IFN-gamma appears to be dose-dependent and TNF-alpha acts synergitically with IFN-gamma in the activation of macrophages. The production of reactive NO could be an important effector in the IFN-gamma primed anti-Toxoplasma action.

Animals↗

PubMed1998

[Studies on fermentation conditions of cytokinin produced by rhizobia strain 4012a].

The conditions of cytokinin fermentation of the rhizobia strain 4012a were detected by the ELISA. The results indicated that the optimal medium for cytokinin production by strain 4012a was composed of glucose 10 g/L, (NH4)2SO4 1.0, K2HPO4.3H2O 0.6, MgSO4.7H2O 0.1, CaCl2.2H2O 0.4, FeCl3.6H2O 0.04, Na2MoO4.2H2O 0.1 mg/L, calcium pantothenate 100 micrograms/L, adenine 200 mg/L. When strain 4012a was grown in 250 ml flask containing 50 ml of the medium on the rotary shaker (150 r/min) at 27 degrees C for 96 h, the yield of CTK 908 micrograms/L culture solution was obtained. It displayed bioactivity kinetin equivalents (KE) 1 mg/L medium with the radish cotyledon expansion test.

Culture Media↗

PubMed1998

Complement contributes to the rejection of complete and class I major histocompatibility complex--incompatible cardiac allografts.

BACKGROUND: We have demonstrated previously that the terminal complement component C6 contributes to the acute rejection of ACI cardiac allografts by PVG recipients. ACI rats differ from PVG rats at major and minor histocompatibility antigens and ACI cardiac allografts stimulate vigorous alloantibody responses in PVG rats. We have now bred the C6 deficiency onto four PVG congenic rat strains to determine the effects of C6 on cardiac allograft survival across individual donor-recipient major histocompatibility complex (MHC) disparities. METHODS: Hearts from C6-deficient PVG.1A (RT1a) donors were transplanted heterotopically to fully MHC-incompatible C6-sufficient and C6-deficient PVG.1L (RT1(1)) recipients, as well as from C6-deficient PVG.R8 (RT1.AaBu) donors to MHC class I incompatible C6-sufficient and C6-deficient PVG. 1U (RT1.AuBu) recipients. RESULTS: Hearts from PVG.1A (C6-) female donors were rejected acutely (7 to 9 days; n = 5) by fully MHC disparate female PVG.1L (C6+) recipients, but they survived significantly longer in female PVG.1L (C6-) recipients (13 to >50 days; n = 6). Slightly better survival resulted in male PVG.1L (C6-) heart transplant recipients of male PVG.1A (C6-) hearts (19 to >50 days [n = 5] vs 6 to 9 days for C6+ male PVG.1L recipients [n = 10]). The C6 deficiency had an even greater effect in PVG.1U recipients of class I MHC disparate PVG.R8 hearts (>50 day survival in C6- PVG.1U recipients [n = 5] vs 6 to 7 days in C6+ recipients [n = 8]). The cardiac allografts elicited similarly vigorous immunoglobulin M and G alloantibody responses in the C6- and C6+ recipients as measured by flow cytometry. At the time of acute rejection, the hearts in the C6+ recipients demonstrated extensive vascular endothelial destruction. In contrast, rejection of hearts by C6- recipients was characterized by endothelialitis, but there was little destruction of the endothelium and limited proliferation of smooth muscle cells in the intima. CONCLUSIONS: These results demonstrate that the terminal complement component C6 can contribute to the rejection of class I or complete MHC-incompatible hearts in rats that have been characterized as "high" alloantibody responders.

Animals↗

PubMed1998

Changes in assortative mating: the impact of age and education, 1970-1990.

Data from the U.S. Census and Current Population Survey are used to examine trends in the propensity to marry or to cohabit by the age and educational attainment of potential partners. Marriage rates declined sharply across all age and educational combinations between 1970 and 1980 and declined more sharply for less-educated persons between 1980 and 1990. The rise in cohabitation compensated somewhat for the decline in marriage rates, but the compensation was unequally spread among age and educational combinations. Highly educated men were more likely, and highly educated women were no more or less likely, to marry than to co-habit with less-educated partners in 1970 and 1980. By 1990, however, educational assortative-mating patterns between these two types of unions were similar. In 1990, marriages and cohabitations involving women who were better educated than their partners were more common than those involving women who were less educated than their partners. In addition, men and women in their early 20s tend to have partners better educated than themselves, but persons in their 30s tend to cross the less-than-high-school/more-than-high-school educational barrier when partners differ in educational attainment.

Adolescent↗

PubMed1997

Amyotrophic lateral sclerosis and occupational exposure to electromagnetic fields.

In an hypothesis-generating case-control study of amyotrophic lateral sclerosis, lifetime occupational histories were obtained. The patients (n = 28) were clinic based. The occupational exposure of interest in this report is electromagnetic fields (EMFs). This is the first and so far the only exposure analyzed in this study. Occupational exposure up to 2 years prior to estimated disease symptom onset was used for construction of exposure indices for cases. Controls (n = 32) were blood and nonblood relatives of cases. Occupational exposure for controls was through the same age as exposure for the corresponding cases. Twenty (71%) cases and 28 (88%) controls had at least 20 years of work experience covering the exposure period. The occupational history and task data were used to classify blindly each occupation for each subject as having high, medium/high, medium, medium/low, or low EMF exposure, based primarily on data from an earlier and unrelated study designed to obtain occupational EMF exposure information on workers in "electrical" and "nonelectrical" jobs. By using the length of time each subject spent in each occupation through the exposure period, two indices of exposure were constructed: total occupational exposure (E1) and average occupational exposure (E2). For cases and controls with at least 20 years of work experience, the odds ratio (OR) for exposure at the 75th percentile of the E1 case exposure data relative to minimum exposure was 7.5 (P < 0.02; 95% CI, 1.4-38.1) and the corresponding OR for E2 was 5.5 (P < 0.02; 95% CI, 1.3-22.5). For all cases and controls, the ORs were 2.5 (P < 0.1; 95% CI, 0.9-8.1) for E1 and 2.3 (P = 0.12; 95% CI, 0.8-6.6) for E2. This study should be considered an hypothesis-generating study. Larger studies, using incident cases and improved exposure assessment, should be undertaken.

Adult↗

PubMed1997

Percutaneous implantation of non-small-cell lung carcinoma: technique and observations.

RATIONALE AND OBJECTIVES: The authors performed this study to determine whether intrathoracic inoculation of non-small-cell lung carcinoma with fluoroscopic guidance would provide for more accurate implantation. MATERIALS AND METHODS: A tumor cell inoculum (2 x 10(6) cells per 0.15 mL) was injected percutaneously under fluoroscopic guidance at the posterior midaxillary line in 22 athymic nude mice. The mice underwent imaging with a mammographic unit at 3, 5, and 8 weeks after implantation. The mice were sacrificed at 8 weeks, and autopsy was performed to determine tumor yield. RESULTS: The use of a percutaneous technique under fluoroscopic guidance greatly facilitated the accurate implantation of xenografts. Tumor growth was seen at radiography in 18 of the 22 (82%) mice at 8 weeks. Necropsy revealed a 100% tumor yield. Histologic examination confirmed adenocarcinoma of the lung. The average number of tumors found in the lung parenchyma was 1.05 +/- 0.35; the average number of tumors found in the mediastinum was 0.59 +/- 0.67. The average tumor weight was 389 mg +/- 64.3. The average tumor size was 300 mm3 +/- 66.23. CONCLUSION: With fluoroscopic guidance, percutaneous implantation of tumor cells in athymic nude mice is simple and effective.

Adenocarcinoma↗

PubMed1997

Nucleolar and nuclear localization properties of a herpesvirus bZIP oncoprotein, MEQ.

Marek's disease virus (MDV) is one of the most oncogenic herpesviruses and induces T lymphomas in chickens within weeks after infection. Only a limited number of viral transcripts are detected in MDV tumor samples and cell lines. One of the major transcripts encodes MEQ, a 339-amino-acid bZIP protein which is homologous to the Jun/Fos family of transcription factors. The C-terminal half of MEQ contains proline-rich repeats and, when fused to the DNA-binding domain of a yeast transcription factor, Gal4 (residues 1 to 147), exhibits transactivation function. MEQ can dimerize with itself and with c-Jun. The MEQ-c-Jun heterodimers bind to an AP-1-like enhancer within the MEQ promoter region with greater affinity than do homodimers of either protein, and they transactivate MEQ expression. Here we show that MEQ is expressed in the nucleus but, interestingly, with a predominant fraction in the nucleoli and coiled bodies. This makes MEQ the first bZIP protein to be identified in the nucleoli. MEQ contains two stretches of basic residues, designated basic region 1 (BR1) and basic region 2 (BR2). Using a series of deletion mutants, we have mapped the primary nuclear localization signal (NLS) and the sole nucleolar localization signal (NoLS) to the BR2 region. BR1 was shown to provide an auxiliary signal in nuclear translocation. To demonstrate that BR2 is an authentic NoLS, BR2 was fused to cytoplasmic v-Raf (delta gag) kinase. The BR2-Raf fusion protein was observed to migrate into the nucleoplasm and the nucleolus. The BR2 region can be further divided into two long arginine-lysine stretches, BR2N and BR2C, which are separated by the five amino acids Asn-Arg-Asp-Ala-Ala (NRDAA). We provide evidence that the requirement for nuclear translocation is less stringent than that for nucleolar translocation, as either BR2N or BR2C alone is sufficient to translocate the cytoplasmic v-Raf (delta gag) into the nucleus, but only in combination can they translocate v-Raf (delta gag) into the nucleolus. Our studies demonstrate that MEQ is both a nuclear and nucleolar protein, adding MEQ to the growing list of transactivators which localize to the nucleolus.

Amino Acid Sequence↗

PubMed1997

[Clinical analysis of huge intraocular foreign body extraction in seventeen cases].

OBJECTIVE: To discuss the definition of huge intraocular foreign body (IOFB), the selection of operation and the improvement of cure rate. METHODS: (1) The foreign body was localized by X-ray, and extracted through sclera; (2) direct localization by indirect ophthalmoscope; (3) extraction of IOFB in combination with pars plana vitrectomy (PPV); (4) extraction through anterior chamber. RESULTS: The IOFBs were extracted successfully in all cases. The foreign bodies of 13 eyes were extracted in combination with PPV (72.2%, secondary enucleation with coral porous hydroxyapatite implantation was performed on one case later), and extracted through sclera in 5 eyes. Post-operative visual acuity was improved in 6 eyes, not changed in 9 eyes and decreased in 3 eyes. CONCLUSION: IOFB extraction in combination with PPV is less damaging, accurate and safe, that reduces the complications and enhances the cure rate. It is worth to popularize.

Adolescent↗

PubMed1997

[Melatonin inhibits TRH-stimulating prolactin gene expression of anterior pituitary cells in newborn rat in vitro].

OBJECTIVE AND METHODS: This work was to investigate whether melatonin (MEL) plays a role in the gene expression of prolactin (PRL), by the Method of in situ hybridyzation. RESULTS: Our results indicated that, at a higher concentration, MEL not only inhibits TRH (thyrotropin releasing hormone) stimulating PRL gene expression of anterior pituitary cell in newborn rat, but also exerts a direct inhibitory effect on PRL gene expression in vitro. CONCLUSION: These results suggest that MEL may be a regulator of PRL synthesis and secreting in vivo.

Animals↗