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Biomedical subjects

Qi Zhou

Publications and source records attributed to Qi Zhou.

At least 91 records · Page 5Linked to original sources
PubMed2003

Estrogen receptor alpha gene polymorphisms and peak bone density in Chinese nuclear families.

PBD is an important determinant of osteoporotic fractures. Few studies were performed to search for genes underlying PBD variation in Chinese populations. We tested linkage and/or association of the estrogen receptor alpha gene polymorphism with PBD in 401 Chinese nuclear families. This study suggests the ER-alpha gene may have some minor effects on PBM variation in the Chinese population. Low peak bone density (PBD) in adulthood is an important determinant of osteoporotic fractures in the elderly. PBD variation is mainly regulated by genetic factors. Extensive molecular genetics studies have been performed to search for genes underlying PBD variation, largely in whites. Few studies were performed in Chinese populations. In this study, we simultaneously test linkage and/or association of the estrogen receptor alpha (ER-alpha) gene polymorphism with PBD in 401 Chinese nuclear families (both parents plus their female children) of 1260 subjects, with the 458 children generally between 20 and 40 years of age. All the subjects were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) at polymorphic PvuII and XbaI sites inside the ER-alpha gene. Bone mineral density was measured at the lumbar spine (L1-L4) and hip (femoral neck, trochanter, and intertrochanteric region). Raw bone mineral density values were adjusted by age, height, and weight as covariates. We detected marginally significant results for within-family association (transmission disequilibrium; p = 0.054) between the spine bone mineral density variation and the ER-alpha XbaI genotypes. For the hip bone mineral density variation, significant (p < 0.05) linkage results were generally found for the two intragenic markers. Analyses of the haplotypes defined by the two markers confer further evidence for linkage of the ER-alpha with the hip PBD variation. In conclusion, this study suggests that the ER-alpha gene may have minor effects on PBD variation in our Chinese population.

Asian People↗
PubMed2003

Expression of p27, cyclin E and cyclin A in hepatocellular carcinoma and its clinical significance.

AIM: To investigate the expression of p27, cyclin E and cyclin A in hepatocellular carcinoma (HCC) and its potential clinical significance. METHODS: Expression of p27, cyclin E and cyclin A in 45 HCC specimens and 30 adjacent noncancerous lesions obtained from 45 patients during surgery was examined by immunohistochemical SABC assay. The diameter of tumor ranged from 1 cm to 19 cm (d< or =5 cm, 9 samples; 5 cm 10 cm, 17 samples). The tumors were graded according to the criteria described by Edmondson-Steiner: well-differentiated HCC group (Grade I+II), 26 samples; poorly-differentiated HCC group (Grade III+IV), 19 samples. According to the clinical-pathologic features, 19 samples were poorly encapsulated, 15 samples had portal invasion of cancer, 11 samples had extrahepatic metastasis, and 12 samples had intrahepatic metastasis. All of the samples were classified as the invasive and metastatic group, while the remaining was classified as the non-invasive and non- metastatic group. RESULTS: The average labeling index (LI) of p27 in HCC lesions was significantly higher than that in adjacent noncancerous lesions (45.87+/-14.21 vs 33.77+/-12.92, t=3.745, P<0.001). The LI of p27 was associated with differentiation, invasiveness and metastasis of the tumors (34.46+/-12.29 vs 52.80+/-11.36, t=5.17; 41.42+/-12.86 vs 51.44+/-14.10, t=2.48; P<0.05). Cyclin E was overexpressed in 16 cases (35.6%) while cyclin A was overexpressed in 21 cases (46.7%) in HCC lesions. No overexpression of cyclin E or cyclin A could be observed in adjacent non-carcinoma lesions and normal liver tissues. The overexpressions of cyclin E and cyclin A were correlated with differentiation, tumor thrombus, invasiveness and metastasis (P<0.05). Expression of cyclin E was significantly correlated with expression of cyclin A (r=0.329, P<0.05). The LI of p27 was significantly decreased in cyclin E, cyclin A positive groups (40.33+/-11.91 vs 49.50+/-13.76, t=3.05; 38.86+/-11.19 vs 52.57+/-12.62, t=3.89; P<0.05). CONCLUSION: p27, cyclin E, cyclin A play cooperative roles in HCC tumorigenesis, differentiation, invasiveness and metastasis. Detection of their expression may be helpful in prediction of tumor progression.

Adult↗
PubMed2003

[Study on nitrogen removal treating agriculture wastewater in subsurface constructed wetland].

Nitrogen removal in subsurface constructed wetland treating agriculture non-pointed wastewater was studied in pilot-scale. The experimental results showed that the removal rates of TN increases with HRT increasing. The removal rates of TN achieved 60% in macrophyte bed system when the nominal hydraulic retention time was 5 days. Removal of TN followed first-order plug flow kinetics. Rate constant of Non-plant bed, Phragmitas communis bed and Zizania caduciflora bed was 0.14, 0.26 and 0.20 d-1 respectively. Denitrification was the main removal mechanism of total nitrogen, the amount of TN that can be removed by harvesting were above 15% compared to the loading into constructed wetland system.

Agriculture↗
PubMed2003

[Association of Apa I polymorphism of vitamin D receptor gene with bone mass in men].

OBJECTIVE: To investigate the association of Apa I polymorphism in vitamin D receptor (VDR) gene with bone mass in men. METHODS: The VDR Apa I genotype was determined by PCR-restriction fragment length polymorphism (RFLP) in 388 unrelated healthy men aged 46-80 years of Han nationality in Shanghai city. Bone mineral density (BMD) and bone mineral content (BMC) at lumber spine 1-4 (L1-4) and at any sites of proximal femur including to femoral neck (Neck), trochanter (Troch) and Ward's striangle (Ward's) were measured by duel-energy X-ray absorptiometry. RESULTS: Frequencies distribution of VDR Apa I genotype were aa for 48.1%, Aa for 44.2% and AA 7.7%. The allele frequencies of Apa I polymorphism were in Hardy-Weinberg equilibrium. No significant association was found between Apa I genotype and BMD or BMC in group of all population or in subgroup of men below 60 years. In men above 60 years, the significant association was found between VDR Apa I genotype and BMD or BMC at L1-4, Neck and Ward's (P < 0.05, P < 0.01) and compared with Aa and aa genotype, AA genotype had significantly higher mean BMD and BMC at L1-4, Neck and Ward's (P < 0.05, P < 0.01). But Apa I genotype is not associated with BMD and BMC at Troch. CONCLUSIONS: Apa I polymorphism is associated with bone mass in men above 60 years, and AA genotype has higher bone mass. Apa I polymorphism in VDR gene possibly influence loss of trabecular and cortical bone mass in old men.

Age Factors↗
PubMed2003

[Phosphorus removal of agriculture wastewater through subsurface constructed wetland].

Phosphorus removal in subsurface constructed wetland treating agriculture non-pointed wastewater was studied in pilot-scale. The experimental results showed that the removal rates of TP increased with HRT increasing when the nominal hydraulic retention time was less than 5 days. The pH decreased distinctly when the retention time was too longer in the batch and sequence style, it may bring on a lower removel rate of TP. The amount of TP that can be removed by harvesting were about 15.8% and 9.5% compared to the total quantity of removing in Phragmitas communis and zizania caduciflora constructed system respectively. Temperature impacted on the removel of TP, the removel rate of TP decreased 30% in the winter compared to summuer.

Agriculture↗
PubMed2002

Nuclear transfer technologies: between successes and doubts.

Cloning of mammals by nuclear transfer can lead to the birth of healthy adult animals but more often compromises the development of the reconstructed embryos. A high incidence of fetal and postnatal losses has been observed in several species, revealing the existence of long-lasting effects induced by the nuclear transfer procedures. Remodeling of donor chromatin by the recipient cytoplasm after nuclear transfer is frequently associated with the deregulation of specific genes, and recent observations point to the potential importance of time-dependent DNA methylation events in the occurrence of these alterations. Screening strategies to design nuclear transfer procedures that would mimic the epigenetic remodeling occurring in normal embryos are being designed, and improvement in the efficiency of procedures could imply a pre-conditioning of donor cells. Early mammalian development appears to be rather tolerant to epigenetic abnormalities, raising the possibility that even a fully functional reprogrammed genome may have been subjected to some epigenetic alterations. Bringing nuclear transfer to routine practice requires greater knowledge and understanding of the basic biological processes underlying epigenetic controls of nuclear activities. An important issue at present is to limit the production of those aberrant phenotypes that may result in significant insult to the nature and welfare of animals.

Animals↗
PubMed2002

Comparative study on the characterization of antisera of anti-aflatoxin B1 from rabbit and laying hen.

Polyclonal antisera specific for aflatoxin B1 (AFB1) were developed in rabbits and laying hens immunized with AFB1 conjugated to bovine serum albumin (AFB1-BSA). During the immunization schedule, AFB1-specific antisera from rabbits started to obviously be secreted after 60 days of the first AFB1-BSA injection, reached to a peak at day 120, and started to go down at day 135; while in regard to laying hens, antibodies began to largely be produced at day 90, arrived to a peak at day 135, and began to go down at day 165. The rabbits consistently produced anti-AFB1 antisera in 2-fold higher amounts than the laying hens during the antisera production process. But rabbits' and laying hens' antisera to AFB1 were found not to be apparently different in cross-reaction with aflatoxin analogs. Both rabbits' and laying hens' antisera could be used as immunological reagents for detecting AFB1 in agricultural commodities.

Aflatoxin B1↗
PubMed2002

Calcium supplement and bone medication use in a US Medicare health maintenance organization.

This study was conducted to determine the prevalence of the use of calcium supplements and of prescription medications to prevent or treat osteoporosis in men and women in a large New England Medicare Health Maintenance Organization (HMO). A two-page diet, medication use and medical history questionnaire was sent to a random sample of 9000 out of 82 985 members and 2932 (32.6%) responded. Over 97% of the participants were Caucasian and 64.7% were female. The mean ages of the men and women were 74.4+/-5.8 and 74.6+/-6.2 years, respectively. Sixty-nine percent of the men and 59% of the women consumed two or fewer servings of dairy foods per day. Calcium supplement use was more prevalent among the women than the men (66.8% vs 24.9%, p<0.001). Men and women with higher dairy food intakes were more likely to take calcium supplements than were those with lower dairy intakes. Prescription bone medications (including bisphosphonates, raloxifene and calcitonin) were used currently by 17.5% of the women and 2.3% of the men ( p<0.001). An additional 16.2% of the women currently took estrogen. Among the women, bone medication use did not change with age but estrogen use declined with increasing age. Among women age 80+ years, 15.6% used bone medications and 4.9% took estrogen. According to a national survey, more than half the US Caucasian female population over age 80 years has bone density low enough to warrant treatment under current guidelines. Based on the results of this survey, many elderly men and women may benefit from increased utilization of calcium supplements and bone-active medications.

Aged↗
PubMed2002

Antioxidative effects of lovastatin in cultured human endothelial cells.

The effects of lovastatin on glutathione peroxidase activity, hydrogen peroxide consumption, [3H]cholesterol uptake and [14C]acetate incorporation were investigated in cultured human endothelial cells. Treatment of endothelial cells with lovastatin in a medium without serum for 4 hr significantly increased both glutathione peroxidase activity and hydrogen peroxide consumption. This treatment also significantly inhibited cholesterol synthesis and cholesterol esterification. However, lovastatin stimulated cholesterol uptake by the cells. These alterations produced by lovastatin continued up to 24 hr. When serum was present in the culture medium, only decreased cholesterol synthesis and esterification were detected. We suggest that the in vitro antioxidative ability of lovastatin resulted, in part at least, from its activating effect on glutathione peroxidase, its stimulative effect on the ability of endothelial cell to scavenge H(2)O(2), and its hypolipidemic effect.

Journal Article↗
PubMed2002

Chromatin as a regulative architecture of the early developmental functions of mammalian embryos after fertilization or nuclear transfer.

Nuclear transfer of a somatic nucleus into an enucleated oocyte has demonstrated in several mammalian species that the chromatin of a differentiated nucleus can be reprogrammed so as to be able to direct the full development of the reconstructed embryo. This review focus on the timing of the early events that allow the return of somatic chromatin to a totipotent state. Our understanding of the modifications associated with chromatin remodeling is limited by the low amount of biological material available in mammals at early developmental stages and the fact that very few genetic studies have been conducted with nuclear transfer embryos. However, the importance of several factors such as the covalent modifications of DNA through the methylation of CpG dinucleotides, the exchange of histones through a reorganized nuclear membrane, and the interaction between cytoplasmic oocyte components and nuclear complexes in the context of nuclear transfer is becoming clear. A better characterization of the changes in somatic chromatin after nuclear transfer and the identification of oocyte factors or structures that govern the formation of a functional nucleus will help us to understand the relationship between chromatin structure and cellular totipotency.

Acetylation↗
PubMed2002

Novel approaches and hurdles to somatic cloning in cattle.

The overall efficiency of somatic cloning in cattle is still low. Many factors are necessary for successful birth of live offspring. Among them, the source of donor cells reveals the importance of the donor genotype but also the influence of the cell line itself. The cell cycle stage has been intensively investigated, and recent results indicate that, in cattle, the G0 stage of the donor nuclei is not a prerequisite for reprogramming, as highly proliferating cultured fibroblasts also result in live offspring after nuclear transfer. A technical approach using direct microinjection of fibroblast nuclei, instead of fusion of the whole cell, has proved to result in high in vitro development rates in cattle. However, full-term development of somatic cloned embryos is still limited by long-lasting effects and a high incidence of losses at periimplantation time (as well as in late gestation and around calving).

Animals↗
PubMed2002

Intervention and follow-up on human esophageal precancerous lesions in Henan, northern China, a high-incidence area for esophageal cancer.

BACKGROUND: Esophageal cancer (EC) remains a leading cause of cancer-related deaths in Linzhou (formerly Linxian) and Huixian of Henan province, northern China, which has been well recognized as the highest incidence area for EC. The lack of useful chemoprevention agents and early detection methods is the key factors for stable EC incidence in these areas. Human esophageal carcinogensis has been considered as a multistep progressive process. The natural history for EC, however is not very clear. METHODS: Follow-up studies with linear repeated biopsies and histopathological examination were performed on 778 subjects from Linzhou and Huixian. Of these subjects, 578 subjects were followed for 11 years (1989-2000), 400 subjects with different severity of esophageal precancerous lesions were randomly divided into 2 groups for intervention studies with calcium and decaffeinated green tea (DGT). Each group included 200 subjects (100 subjects for treatment, and 100 subjects for placebo). In calcium group, each subject received an oral supplementation of 1,200 mg of calcium daily for 11 months. In DGT group, each subject received 5 mg of DGT daily for 12 months. In placebo group, each subject received placebo pill for 11 months (calcium group) and 12 month (DGT group). At the entry and the end of the trial, esophageal biopsy specimens were taken at the middle and the lower thirds of the esophagus and from macroscopic lesions, if only, of each subject. RESULTS: DGT trail did not show apparent difference between the treatment and placebo group in alleviating the esophageal precancerous lesions and abnormal cell proliferation. For the calcium intervention study, after 11 years' follow-up, 10 subjects had developed into cancers in the calcium group (10%, 8 EC and 2 GCA), and 8 subjects developed into EC in the placebo group (8%). All these patients were diagnosed at very early stage of cancer (symptom-free). Of the 578 subjects, 25 (18 males and 7 females) had developed into EC (n = 23, 4.3%) and gastric cardia cancer (GCA, n = 2, 0.3%), during the 11 years' follow-up. The mean time of cancer development (from entry of the follow-up study to the cancer detection) was 5.0 +/- 2.9 years (males) and 4.7 +/- 3.2 years (females). Of the 25 patients with EC and GCA, 11 were from the 387 followed subjects with "normal" histomorphology of biopsy at the entry of the follow-up study (3%, 11/387), 2 were from the subjects with basal cell hyperplasia, grade I (BCH I, 2%, 2/94), 7 from the subjects with BCH grade II (BCH II, 10%, 7/72), and 5 from BCH III and dysplasia (20%, 5/25). CONCLUSIONS: DGT trail was not shown to have beneficial effects in alleviating esophageal precancerous lesions and abnormal cell proliferation patterns. Calcium supplementation did not produce apparent long-term effects on EC. BCH II could be considered as precancerous lesions of EC. The quantitative histopathological analysis in terms of number of proliferating basal cell layers is of importance in determining the high-risk subjects for EC and evaluating the intervention results. Follow-up studies with repeated endoscopic biopsies are the powerful strategy for early detection and mortality control of EC and GAC in the high incidence area.

Adult↗
PubMed2002

Effect of low magnesium concentration and cholestane-3beta, 5alpha, 6beta-triol on levels of LDL receptor in cultured fibroblasts.

We investigated the level of low density lipoprotein receptors (LDLR) in fibroblasts upon treatment with low magnesium and/or cholestane-3beta, 5alpha, 6beta-triol (TriolC). After 72 h of incubation with low magnesium at a level of 188 micromol or lower, the LDLR levels, determined with immunoblotting analysis, were significantly reduced in the cultured cells. TriolC at a level of 1 microg/ml or higher also decreased LDLR level. However, no further decrease of LDLR level was detected in the cells treated with low magnesium plus TriolC at a level of 0.1 microg/ml, compared with the LDLR level from the cells treated with low magnesium only. Our results showed that both low magnesium concentration and TriolC reduced the LDLR level, but the reducing effect was not accentuated when both were present in the culture medium.

Cells, Cultured↗
PubMed2001

[A Simplified Method for Cryopreservation of Peripheral Blood Stem Cells]

To simplify the traditional method for cryopreservation of peripheral blood stem cells(PBSCs) at -196 degrees C with rate-controlled freezing with 10% dimethyl sulfoxide(DMSO), the simplified method was carried out by freezing the cells to -80 degrees C in low-temperature freezer with the combination of 5% DMSO, 3% hydroxyethyl starch(HES) and 4% human serum albumin(HSA) as cryoprotectant. PBSCs were cryopreserved by different methods. Cell viability and recovery rate of mononuclear cells (MNC), CFU-GM and CD34(+) cells were compared. It was observed that the higher MNC and CFU-GM recovery rates were achieved and without agglutination with the simplified method. It was also found with this simplified method, satisfactory recovery rates of CFU-GM and CD34(+) cells could be obtained when PBSCs were preserved at -80 degrees C as long as 24 months. There was no difference observed in parameters of cryopreserved PBSCs thawed at 37 degrees C and 20 degrees C. After the cells being exposed to 5% DMSO at room temperature for 1 hour, the cell viability decreased from 93.2% to 84.5%, however, the CFU-GM recovery rate was not decreased. It is concluded that the simplified cryopreservation technique is better and simpler than the traditional crypreservation method, will be useful for institutions without rate-controlled freezing facility. Moreover, this method diminishes the amount of DMSO infused into patients, thus decreasing its toxicity.

Journal Article↗
PubMed1998

Apoptosis and its relationship with cell proliferation, p53, Waf1p21, bcl-2 and c-myc in esophageal carcinogenesis studied with a high-risk population in northern China.

AIM:To determine the extent of apoptosis and its possible relationship with the changes of p53, Waflp21, bcl-2, and c-myc at different stages of esophageal carcinogenesis.METHODS:Two hundred and forty-one esophageal biopsy samples from symptom-free subjects and 38 surgically resected esophageal carcinoma tissues from a high-risk population for esophageal cancer in Henan, China were used in this study.Apoptotic cells and apoptotic bodies were identified by well-established morphological criteria. The extent of apoptosis and its possible relationship with the rate of cell proliferation (PCNA) and changes of p53, Waf1p21, bcl-2,and c-myc were analyzed in samples with esophageal precancerous and cancerous lesions.RESULTS:The apoptotic cells, identified morphologically, were located in the same proliferative compartment of hyperproliferative cell population in the esophageal epithelia as the cells immunostaining-positive for p53, bcl-2, c-myc and PCNA.The apoptotic indices (total number of apoptotic cells and apoptotic bodies per mm(2) of the tissue section) were low in the normal epithelia,and increased significantly as the lesions progressed from BCH to DYS and to SCC.The extent of apoptosis correlated well with the cell proliferation indices based on PCNA. The total number of positive cells for p53 stain was much higher than that of apoptotic cells. No difference in apoptotic indices was found between p53-positive and p53-negative samples. Waf1p21-positive cells resided in cell layers were higher in number than p53 and PCNA-positive cells. The number of immunostaining positive cells for Waflp21 increased slightly from normal to BCH,but decreased in DYS and SCC. Positive staining samples for bcl-2 and c-myc increased as the lesions progressed from BCH to DYS and to SCC. No apparent correlation between apoptosis and Waf1p21, bcl-2 or c-myc expression was observed.CONCLUSION:The extent of apoptosis was low in normal esophageal epithelium and increased as the lesions progressed. The apoptotic cells were located in the same hyperproliferative cell compartment as cells immunostaining-positive for p53, bcl-2,c-myc and PCNA,but no apparent correlation between apoptosis and these parameters was observed,possibly due to the complexities of molecular changes in esophageal carcinogenesis.

Journal Article↗
PubMed1998

Comparative studies on epithelial lesions at gastric cardia and pyloric antrum in subjects from a high incidence area for esophageal cancer in Henan, China.

AIM:To investigate the pathogenesis of gastric cardia and the distal part of stomach cancer and to further characterize the histopathogenesis model for gastric cardia cancer from the high-risk population for esophageal cancer.METHODS:Mass survey with endoscopic mucosa biopsy and histopathological examination were carried out on 226 subjects aged above 30 years. Three biopsies were collected one each from the middle part of the esophagus, the gastric cardia and the pyloric antrum. The biopsy tissue was fixed with 85% alcohol and paraffin-embedded.RESULTS:The incidence of intestinal metaplasia and dysplasia at gastric cardia epithelium was higher than that at the pyloric antrum from the subjects in the same area. And there were high incidences of both esophageal and gastric cardia cancer, but a low incidence of gastric cancer at the distal part of the stomach.CONCLUSION:There might be different etiology and pathogenesis of gastric cardia and pyloric cancer at the distal part of the stomach.

Journal Article↗