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Biomedical subjects

S Zhao

Publications and source records attributed to S Zhao.

At least 181 records · Page 10Linked to original sources
PubMed2000

Effects of gonadotropin-releasing hormone agonist on the incidence of apoptosis in porcine and human granulosa cells.

Gonadotropin-releasing hormone (GnRH) has been found to be expressed in ovaries of various species and to modulate cell differentiation in ovarian cells. GnRH agonists (GnRHa) are widely used in the stimulation protocols of assisted reproduction. In the present study, the direct effects of a GnRHa on the incidence of apoptosis and sterodogenesis in porcine in human granulosa cells were investigated. Cells were obtained from 6-month-old swine and in vitro fertilization patients, and cultured in minimum essential medium (MEM) supplemented with 5% fetal bovine serum for 24 h. The GnRHa (burserelin acetate) was added to the MEM at various concentrations (0, 5, 50, 500 pg/ml, and 5 ng/ml). The nuclei of granulosa cells were examined by fluorescence microscopy after Hoechst 33258 staining, and the incidence of apoptotic cells was tabulated. The GnRHa directly increased the incidence of apoptosis in both types of granulosa cells. The concentration of GnRHa in clinical use is much higher than the concentration which produced apoptosis in granulosa cells here. The clinical dosage of GnRHa should be reconsidered with regard to its apoptosis-inducing effect.

Animals↗
PubMed2000

Inhibition of nitric oxide synthase activity diminishes the acute effects of relaxin on growth, but not softening, of the cervix in the rat.

Relaxin promotes growth and softening of the cervix during pregnancy in the rat. This study examined the hypothesis that nitric oxide (NO) mediates the effects of relaxin on the rat cervix. To test that hypothesis, N omega-nitro-L-arginine methyl ester (L-NAME) was used to inhibit NO synthase, the enzyme that converts arginine to NO and L-citrulline. Nonpregnant rats were ovariectomized when they were 78 days old (day 1 of treatment). At ovariectomy each animal was fitted with silicon tubing implants containing progesterone (P) and estrogen (E) in doses that provide blood levels similar to those during late pregnancy. Rats were assigned to three treatment groups. The control group OPE (n = 6 rats) received 0.5 ml L-NAME vehicle (PBS) sc at 6-h intervals from 0600 h on day 7 through 1200 h on day 8 and 0.5 ml relaxin vehicle (PBS) sc at 0600 and 1200 h on day 8. Group OPER (n = 6 rats) was treated in the same way as group OPE, except that 20 microg porcine relaxin were administered. Group OPERI (n = 7 rats) was treated in the same way as group OPER, except that L-NAME was administered at a dose of 100 mg/kg x 6 h. Between 1400-1500 h on day 8, the cervices were removed and weighed. Cervical wet weight and extensibility were markedly greater (P < 0.01) in relaxin-treated group OPER rats than in group OPE controls. Treatment with L-NAME diminished relaxin's effects on cervical wet weight, but not cervical extensibility. In conclusion, this study provides evidence that NO contributes to the acute effects of relaxin on the growth, but not the softening, of the rat cervix.

Animals↗
PubMed2000

Cloning and characterization of CIS 1b (cytokine inducible SH2-containing protein 1b), an alternative splicing form of CIS 1 gene.

JAK-STAT pathway is essential in relaying cytokine signals and plays a vital role in cellular responses such as proliferation, differentiation and immunity. Some members of a recently found cytokine-inducible SH2 protein (CIS, =SOCS or SSI) family have proved to have negative effects on modulating JAK-STAT signaling pathway. In the present study, a novel human cDNA (CIS1b) which proved to be a variant of CIS1 gene was isolated by screen human placenta lambda gt11 cDNA library and 5'-rapid amplification of cDNA ends (RACE). Furthermore, the gene structure of CIS1 was determined by comparing the cDNA sequences of CIS1 and CIS1b to the genomic sequence in human chromosome 3p21.3. The expression patterns of CIS1b as well as CIS1 were analysed by Northern blot.

Alternative Splicing↗
PubMed2000

Biases in estimating the effect of cumulative exposure in log-linear models when estimated exposure levels are assigned.

OBJECTIVES: Exposure-response trends in occupational studies of chronic disease are often modeled via log-linear models with cumulative exposure as the metric of interest. Exposure levels for most subjects are often unknown, but can be estimated by assigning known job-specific mean exposure levels from a sample of workers to all workers. Such assignment results in (nondifferential) measurement error of the Berkson type, which does not bias the estimate of exposure effect in linear models but can result in substantial bias in log-linear models with dichotomous outcomes. This bias was explored in estimated exposure-response trends using cumulative exposure. METHODS: Simulations were conducted under the assumptions that (i) exposure level is assigned to all workers based on the job-specific means from a sample of workers, (ii) exposure level and duration are log-normal, (iii) the true exposure-response model is log-linear for cumulative exposure, (iv) the disease is rare, and (v) the variance of job-specific exposure level increases with its job-specific mean. Results Assignment of job-specific mean exposure levels from a sample of workers causes an upward bias in the estimated exposure-response trend when there is little variance in the duration of exposure but causes a downward bias when duration has a large variance. This bias can be substantial (eg, 30-50%). CONCLUSIONS: Berkson errors in exposure result in little bias in estimating exposure-response trends when the standard deviation of duration is approximately equal to its mean, which is common in many occupational studies. No bias occurs when the variance of exposure level is constant across jobs, but such conditions are probably uncommon.

Humans↗
PubMed2000

Analysis of DNA-ploidy using laser scanning cytometer in brain tumors and its clinical application.

There have been few reports on investigation of the cell kinetics of brain tumors using a laser scanning cytometer (LSC). We compared DNA analysis using a flow cytometer (FCM) with that by LSC using established cell lines of brain tumors, and we demonstrated the similarity of both analytical results. The DNA-index (DI) and proliferating index (PI) of various brain tumors were determined, and the results showed that these indices reflected the malignancy of the tumors. The DI values were higher for astrocytoma grade IV than for astrocytoma grade II, frequently showing an aneuploid pattern. The determination of DNA-ploidy using LSC, together with cryopathological diagnosis, was considered to be useful for deciding the area to be resected for glioma perioperatively and to be worth applying clinically.

Brain Neoplasms↗
PubMed2000

[Establishment and application of Z-HL16C cell line].

OBJECTIVE: Human embryonic lung fibroblasts at 8th passage was presented to us by the Institute of Virology. At its 16th passage,under the culture condition of our laboratory, the lung fibroblasts changed into epithelial like cells. We attempted to establish a cell line and applied it for virus isolation. METHODS: The cells were continuously passaged, cloned, the cell morphology, growth capacity and chromosome number were determined. RESULTS: The cell size appeared uniform, cell boundary was distinct, the cell recovery rate after frozen storing was above 90%. The cell replicated permanently and now it has been passaged 136 times. The chromosome number has changed from 46 to 110. We named this cell line the ZHL16C. It proved to be sensitive to these viruses tested: enteroviruses (Polio, Cox, Echo), influenza viruses, parainfluenza viruses, adenoviruses, measles virus, herpes simplex and herpes zoster viruses, cytomegalovirus, rubella virus and respiratory syncytial virus. When using Z-HL16C cell to isolate virus from 29 adenovirus swab samples collected from 29 soldiers with epidemic high fever in a new military, adenovirus type 3,7 coxsackie virus types B1, B5, B5, B5, B5 were isolated. CONCLUSIONS: The cell line HL16C has been stably established, it has a broad spectrum in sensitivity for viruses.

Cell Culture Techniques↗
PubMed2000

[Pot experiment on effect of clipping at seedling stage on spring wheat].

Pot experiment on the compensatory effects of spring wheat(Triticum aestivum) at different clipping intensities (simulating herbivory) at seedling stage (three leaves) was conducted in semiarid region of Gansu Province. Under two conditions of 60% and 90% of field water-holding capacity, spring wheat growth was stimulated by clipping at seedling stage, resulting in overcompensation in biological and economic yields, and with more compensation for heavy clipping than light clipping. The overcompensation of the spring wheat was at the cost of more water consumption.

Plant Development↗
PubMed2000

[Medium selection and compounding of environmental eco-engineering through making use of life rubbish to produce carpet turf].

Through making use of life rubbish as medium and choosing several materials with high feasibility as compound materials to produce carpet turf, the medium selection and compounding were carried out, and the growth effect of several kinds of turfgrass on each compound medium, its pH value and water stress function were also studied. Sawdust could raise the drought-resistant capacity of turfgrass by strengthening the water-retaining capacity of medium, and promote turfgrass growth. Plant ash showed a strong basicity, and when it made up 25% of medium, the pH value of the medium could be over 9. Fine river sand could improve the ventilating capacity of medium, but if mixed too much, it would decrease its nutritional level. It is suggested that the performance of compound mediums differed greatly with compound materials. Synthesizing each index studied showed that among all compounding mediums sawdust had a significantly positive effect, and had a broad application value.

Ecosystem↗
PubMed2000

[Effect of different watering and fertilization on N utilization efficiency].

The comprehensive effects of the timing of watering and N and K fertilization(D), amount of irrigated water(W), and application rates of chemical N and K fertilizers, and farm manure(M) were studied by the design of orthogonal regression rotation with five factors and five levels under dry greenhouse condition. The N utilization efficiency of potato was in order of N > W > D > M > K. Under different application rates of W, N, K and M, the N utilization efficiency was significantly increased with optimum timing of watering and fertilization. When the application rate was low, the timing should be earlier, while it was high, the timing should be later. High application rates of W and N resulted in the best interaction effect, with 57.83% of N utilization efficiency; moderater W and N or low W and N had 29.17-40.99% of efficiency; and high W and low N or low W and high N resulted in the lowest efficiency, with 22.87% and 22.51%, respectively.

Fertilizers↗
PubMed2000

[Mycorrhizal research on nitrogen-fixing plants].

Advances in mycorrhizal research on nitrogen-fixing plants were introduced. The universality of mycorrhizal formation in nitrogen fixing plants, the reciprocal promotion effect of symbiosis, and the application prospect of mycorrhizal techniques under stressed conditions were summarized and reviewed. The mechanism of enhancing nitrogen fixation of N-fixing plants by mycorrhizal fungi in symbiosis was preliminary discussed.

Fungi↗
PubMed2000

Magnetic susceptibility of Dy-DTPA-BMA to reperfused myocardial infarction in an excised dog heart model: evidence of viable myocardium.

OBJECTIVE: To assess the effects of Dy-DTPA-BMA (sprodiamide) on ex-vivo MR imaging of reperfused acute myocardial infarction. METHODS: Eighteen dogs were subjected to 2-hour coronary artery occlusion followed by 24-hour reperfusion. Dysprosium-chelate (Dy-DTPA-BMA) was injected into 16 dogs. Twenty minutes before their sacrifice. Two dogs did not receive the contrast medium and were used as controls. Excised hearts were imaged on T2-weighted spin-echo sequence (T2W SE) and T2*-weighted gradient recalled echo sequence (T2*W GRE), then sectioned and double-perfused for planimetric comparison. RESULTS: Dy-DTPA-BMA induced myocardial signal loss was detected on T2W SE and on T2*W GRE images. The signal loss was observed at the subendocardial location of the myocardial wall inducing an apparent enlargement of the left ventricle cavity and a thinning appearance of the anterior myocardial wall. CONCLUSIONS: Myocyte necrosis diminishes the potency of dysprosium to cause MR imaging signal intensity loss in reperfused myocardial infarction. Pre-infarcted myocardium with potentially reversible viability may be responsible for the effect of the contrast medium.

Animals↗
PubMed2000

Identification of a mutation hotspot in exon 8 of Wilson disease gene by cycle sequencing.

OBJECTIVE: To screen for mutation hotspot of Wilson disease (WD) gene in Chinese population. METHODS: Cycle sequencing was used to detect mutation in exon 8 of WD gene in 30 patients with Wilson disease. RESULTS: The same missense mutation, Arg779Leu, was identified in 14 WD patients, four of whom were homozygous and the other heterozygous for this mutation. The frequency of this mutation in Chinese patients was 30%. CONCLUSION: The codon 779 (CCG-->CTG) of exon 8 of WD gene was one of mutation hotspots in Chinese.

Adenosine Triphosphatases↗
PubMed2000

[Expression of telomerase and its RNA in nasopharyngeal carcinoma].

OBJECTIVE: To study the activity of telomerase and the expression of its RNA in nasopharyneal carcinoma (NPC) and HNE1 cell lines of NPC. METHODS: Telomerase activity was detected with telomeric repeat amplification protocol (TRAP) PCR ELISA kit in 41 cases of NPC, 14 cases of tissues adjacent to the carcinoma, and 19 cases of chronic nasopharyngitis, HNE1 cell lines of NPC, HL60 cell lines of leukemia, TUL1 cell lines of lung cancer, as well as three other kinds of normal control cells. The sensitivity and specificity of telomerase assay were also analyzed. Moreover, the expression of human telomerase RNA (hTR) was studied in 27 cases of NPC, 19 cases of adjacent nasopharyngeal tissues, and 17 cases of control groups by RT-nested PCR. RESULTS: The telomerase activity was found increased in NPC and in tissues adjacent to NPC with absorbance value (A value) of 1.15 U +/- 0.78 U and 1.04 U +/- 0.67 U respectively, compared with chronic nasopharyngitis (A = 0.18 U +/- 0.09 U). In NPC with cervical lymphnodes involvement the telomerase activity (A = 1.25 U +/- 0.79 U) was higher than in those without involvement (A = 1.02 U +/- 0.71 U), P < 0.05. The telomerase activity was also observed in HNE1 cell lines (A = 1.26 U +/- 0.97 U) and in other two kinds of cancer cell lines, but not in the three kinds of normal control cells. By contrast, no significant difference was seen in the expression of hTR among the three nasopharyngeal biopsy groups (P > 0.05). Finally, the sensitivity of telomerase assay was high (at an amount of 10(2) HNE1 cells), and the specificity was also high (after inactivation by heat or RNase, the telomerase activity was very low). CONCLUSIONS: A high frequency of telomerase activity is commonly seen in NPC, adjacent nasopharyngeal tissues, and HNE1 cell lines and is closely associated with NPC with cervical lymphnodes involvement. Both sensitivity and specificity of the telomerase assay are high. However, owing to the fact that the expression of hTR has no obvious difference between NPC and normal tissues and does not always correspond with the telomerase activity, it would be better to do TRAP as well as hTR assays for the activity and expression in assessing the carcinogenesis of NPC. So, more intensive study on the role of hTR in the carcinogenesis of NPC and on the exact relationship between hTR and telomerase is needed.

Adult↗
PubMed2000

[The induction of transforming growth factor-beta 1 in reparative process of mouse experimental alveolar bone defect].

OBJECTIVE: To study the induction of transforming growth factor-beta 1(TGF-beta 1) in reparative process of mouse experimental alveolar bone defect. METHODS: Alveolar bone defect were made in 20 mice at 1/1 region. In twelve mice (experimental group), the defect was filled with gelatin sponge infiltrated by TGF-beta 1 solution; in eight mice (control group), the defect was filled with gelatin sponge. The peripheral tissue coating alveolar bone defect was harvested for histopathologic study after 1 week, 2 weeks and 1 month, 3 months. RESULTS: The main histopathologic changes were: 1. experimental group: inflammatory cell infiltration (1W); inflammatory cell disappearance, fibroblast and capillary tachyauxesis, osteoid tissue and small amount neoformative bone tissue appearance (2 W); fibrous tissue decrease, neoformative bone tissue enlarging and maturity(1-3 M). 2. Control group; inflammatory cell infiltration (1W); inflammatory cell disappearance, fibroblast and capillary tachyauxesis (2W); osteoblast appearance around bone defect (1M); small amount neoformative bone tissue around bone defect. CONCLUSION: TGF-beta 1 can induce alveolar bone regeneration.

Alveolar Process↗
PubMed2000

[The clinical and biochemical manifestations of Fanconi syndrome: a report of 42 cases].

OBJECTIVE: To recognize the etiologies, clinical, and biochemical manifestations of Fanconi syndnome (FS). METHODS: 42 patients with FS were analyzed retrospectively. RESULTS: 21 cases were idiopathic in 42 (50%) cases, and the other 21 (50%) cases were acquired (sjogren's 5, and interstitial nephritie 8). The patients were characterized by proximal renal tubular acidosis (n = 41) and multiple renal tubular transport dysfunctions, including hypokalemia (n = 21), hypophorphatemia (n = 29), hypourecemia (n = 19), renal glucosuria (n = 38), aminoaciduria (n = 36), low-molecular-weight proteinuria (n = 21). The clinical manifestations commonly presented with muscle weakness, polydipsia, polyuria and renal bone diseases. 18 patients presented with impaired renal function. Renal pathohistological studied in 14 patients showed renal tubulointerstitial changes of different degrees in all cases, and glomerular changes in 4. CONCLUSIONS: The etiology of FS is various and secondary FS is not uncommon. FS usually present proxmal RTA and renal tubulointerstitial lesions in pathology.

Acidosis, Renal Tubular↗
PubMed2000

[Significance of amnioinfusion and amniotic fluid exchange under continuous internal fetal heart rate monitoring for management of fetal distress during labor].

OBJECTIVE: To discuss the significance of amnioinfusion and amniotic fluid exchange under continuous internal fetal heart rate (FHR) monitoring for management of fetal distress during labor. METHODS: 136 cases with frequent variable deceleration (VD) and meconium stained amniotic fluid during labor were divided into two groups: the study group (68 cases) and the control group (68 cases). The former were treated by amnioinfusion and amniotic fluid exchange, while oxygen inhalation, change of body position, and intravenous infusion for the control group. RESULTS: In the study group, VD disappeared or relieved in 62 cases obviously, and the efficacy rate reached 91.2% (62/68). 48 cases with II degree meconium stained amniotic fluid were treated by amniotic fluid exchange, amniotic fluid became clear or turned to I degree stained in 39 cases. In the control group, VD relieved in 20 cases, the efficacy rate was 19.4%, significantly lower than that of the study group (P < 0.01). In the study group, cesarean section rate was 14.7% neonatal asphyxia 7.4% while they were 47.1% and 48.5% in the control group respectively (P < 0.01; P < 0.01). Neonatal pneumonia caused by meconium aspiration occurred in 13 cases, meconium aspiration syndrome (MAS) 8 cases, with 5 newborns died in the control group, while there was no neonatal death in the study group. There was no significant difference on puerperal morbidity between the 2 groups (P > 0.05). CONCLUSIONS: Amnioinfusion and AF exchange during labor are one of the effective treatment methods for fetal distress and prevention for MAS.

Adult↗