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Biomedical subjects

Qi Zhou

Publications and source records attributed to Qi Zhou.

At least 73 records · Page 4Linked to original sources
PubMed2004

Enhanced transfection efficiency of a systemically delivered tumor-targeting immunolipoplex by inclusion of a pH-sensitive histidylated oligolysine peptide.

Successful cancer gene therapy depends on the development of non-toxic, efficient, tumor cell- specific systemic gene delivery systems. Our laboratory has developed a systemically administered, ligand-liposome complex that can effectively and preferentially deliver its therapeutic payload to both primary and metastatic tumors. To further improve the transfection efficiency of this targeting complex, a synthetic pH-sensitive histidylated oligolysine K[K(H)KKK]5-K(H)KKC (HoKC), designed to aid in endosomal escape and condensation of DNA, was included in the complex. The presence of HoKC increased the in vitro transfection efficiency over that of the original complex. Moreover, no increase in cytotoxicity was observed due to the presence of the HoKC peptide. In a DU145 human prostate cancer xenograft tumor model in athymic nude mice, inclusion of the HoKC peptide did not interfere with the tumor targeting specificity of the i.v. administered ligand/liposome/DNA complex. Most importantly, the level of transgene expression was significantly elevated in the tumors, but not in the normal tissue in those animals receiving the complex incorporating HoKC. The in vivo enhancement of transfection efficiency by this modified gene delivery vehicle could lead to a reduction in the number of administrations required for antitumor efficacy.

Animals↗
PubMed2004

Lack of association between the HindIII RFLP of the osteocalcin (BGP) gene and bone mineral density (BMD) in healthy pre- and postmenopausal Chinese women.

In Caucasian populations, the polymorphic restriction endonuclease HindIII marker of the osteocalcin (also known as BGP, for bone Gla protein) gene has recently been reported to be associated with bone mass, a major risk determinant of osteoporosis. In this study, we investigated the relationship between the BGP HindIII polymorphism and bone mineral density (BMD) in 388 premenopausal (31.18 +/- 5.92 years) and 169 postmenopausal (58.90 +/- 6.27 years) Chinese women. The BMD of spine and hip was measured by dual-energy X-ray absorptiometry (DEXA). All the study subjects were genotyped at the HindIII site of the BGP gene by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) detecting methods. The BGP alleles were designated according to the absence ( H) or presence ( h) of the HindIII restriction site. We did not find any significant difference in spine and hip BMD across BGP genotypes in either pre- or postmenopausal women or the combined group. Our result is not consistent with recent reports that the HindIII marker of the BGP gene is associated with osteoporosis. The different findings may reflect inter-population differences in the association (i.e., linkage disequilibrium) of molecular markers with BMD, and indicate the limit of using the HindIII marker of the BGP gene as a genetic marker to discern women susceptible to low BMD and thus osteoporosis in Chinese.

Adolescent↗
PubMed2004

Colonization and persistence of a plant growth-promoting bacterium Pseudomonas fluorescens strain CS85, on roots of cotton seedlings.

Pseudomonas fluorescens CS85, which was previously isolated from the rhizosphere of cotton seedlings, acts as both a plant growth-promoting bacterium and a biocontrol agent against cotton pathogens, including Rhizoctonia solani, Colletotrichum gossypii, Fusarium oxysporum f sp. vasinfectum, and Verticillium dahliae. Strain CS85 was labeled separately with luxAB and gusA. The labeled strains were stably maintained and had high levels of expression of the marker genes, luxAB and gusA, after successive transfers on nonselective medium, long-term preservation, and after recovery from soil. The labeled strains displayed similar biocontrol characteristics (e.g., antibiosis, effects of growth-promotion and disease-control) to the original strain. The labeled strains colonized all surfaces of the young plant root zones, such as roots hairs and lateral roots, although the distribution of the labeled strains on the root surfaces was not uniform. Moreover, the population densities of the labeled strains on the root surface were stably maintained at high levels during the first 2 weeks of plant growth in the native soil, so that about 10(7)-10(8) CFU/g root were detected, then decreased gradually. Nevertheless, approximately 10(6) CFU/g root of the labeled strains were observed on the root surfaces 35 d after planting.

Antibiosis↗
PubMed2004

[Study on the changes of TMJ stress before and after sagittal split ramus osteotomy by 3D finite element method].

PURPOSE: To investigate the characteristic changes of the TMJ stress distributions, before and after SSRO for treating the skeletal class III malocclusion, being during centric occlusion. METHODS: CT scan was used to obtain 2-D transverse image of maxilla and mandible. Finite element models were established before and after SSRO. An analysis of the stress, strain, and displacement of TMJ configurations was done by three-finite element method. Paired t test was used to compare the stress before and after operation. RESULTS: The Von Mises stress on TMJ configurations was found to decrease significantly after mandibular set-back SSRO; The maximal and minimal principal stress and maximal displacement were also found to decrease after surgery; The stress of both sides of the TMJ was found to distribute symmetrically. CONCLUSION: Oral and maxillofacial deformity was treated by orthognathics surgery, jaws were repositional that induce the changes of the TMJ stress, the upper and lower further study should be done to determine the stress changes effecting the function and health of TMJ.

Finite Element Analysis↗
PubMed2004

[Summary of 2004 Chinese National Conference on oral and maxillofacial vascular anomalies].

Congenital vascular anomalies have been the subject of much controversy and confusion over the years, many remain to be investigated and resolved. Authorized by the Managing Director Board of Chinese Stomatological Association (CSA), 2004 Chinese National Conference on Oral and Maxillofacial Vascular Anomalies was successfully held on July 15 to 18, 2004 in Shenzhen Grand Hotel. The conference was sponsored by Chinese Society of Oral and Maxillofacial Surgery (CSOMS), and undertaken by the Second People's Hospital of Shenzhen city. Professor ZHANG Zhen-kang, president of CSA, Professor QIU Wei-liu, president of CSOMS and academician of Chinese Academy of Engineers, and Professor LIU Bao-lin, vice president of CSOMS were present and made important speech at the meeting. More than 120 delegates nationwide attended this conference. Through a 3-day of oral presentation and discussion, the terminology, classification, treatment selection and outcome measurement of oral and maxillofacial hemangioma and vascular malformations were concerted among the delegates. Hemangiomas and vascular malformations have been recognized as distinct diseases that exhibit unique properties and behavior that demand an appropriately tailored treatment plan. The classification of Waner and Suen was adopted and different treatment modalities were reviewed and advocated for different lesions. Delegates were most interested in intralesional injection of Pingyangmycin for venous malformations, Krypton laser photodynamic therapy of venular malformations, Nd:YAG laser therapy for deep head and neck venous malformations after surgical exposure of the lesions, as well as "double" embolization of large venous malformations reported by Professor QIN Zhong-ping. The conference witnessed the foundation of the Division of Vascular Anomalies, Chinese Society of Oral and Maxillofacial Surgery.

Arteriovenous Malformations↗
PubMed2004

[The effect of endothelial leukocyte-adhesion molecule-1 on the shape and cytoskeleton of porcine trabecular meshwork cells].

OBJECTIVE: To study the effects of endothelial leukocyte-adhesion molecule-1 (ELAM-1) on the shape and actin cytoskeleton of cultured porcine trabecular meshwork cells (PTCs). METHODS: The cultured PTCs were stimulated by interleukin-1 (IL-1) and conjugated by ELAM-1 antibody or further cross-linked by IgG. Immunocytochemical procedures were used to study the expression of ELAM-1 and FITC-phalloidin was used to stain the actin filaments on PTCs; phase contrast microscope was employed to observe the dynamic changes of cellular shape and the intercellular conjunction and confocal microscope was used to observe the changes of actin and cellular thickness. RESULTS: IL-1 treatment increased the expression of ELAM-1 in PTCs which resulted in enlarged intercellular space in PTCs with more rounded and stereoscopic morphology after specific antibody conjugation or IgG cross linking. In addition, actin filaments became sparse, cellular rigidity decreased, and the cellular thickness increased after these treatments. CONCLUSIONS: Our results demonstrated that IL-1 activated PTCs can express ELAM-1 and interaction of ELAM-1 with specific antibodies and cross linking with IgG, induced a rounding-up of PTCs. This change in cell shape may be due to its action on the actin cytoskeleton.

Actins↗
PubMed2004

Association of estrogen receptor-alpha and vitamin D receptor genotypes with therapeutic response to calcium in postmenopausal Chinese women.

AIM: To investigate the correlation between calcium treatment in postmenopausal women and estrogen receptor-alpha (ER-alpha) Xba I and Pvu II genotype and vitamin D receptor (VDR) Apa I genotype. METHODS: One hundred fifteen postmenopausal Chinese women of Han population were enrolled and treated with calcichew-D3 (1000 mg calcium and 400 U vitamin D3) daily for 1 year. At entry and after 1 year treatment, the bone mineral density (BMD), serum and urinary bone turnover biochemical markers were evaluated. ER-alpha and VDR genotype were analyzed using PCR-restriction fragment length polymorphism. RESULTS: After 1 year of calcium supplementation, a significant increase of BMD and a marked reduction in serum ALP and PTH levels, and a significant increase of serum 25-(OH) vitamin D level were observed (P<0.01 or P<0.05). At entry and after 1 year of treatment, no significant association was found between Xba I, Pvu II, and Apa I genotypes and BMD in L1-4, Neck, and Troch, and all bone turnover marker levels. However, the percentage of change (median, QR) in Neck BMD was significantly different in homozygous XX [-4.14 (from -6.54 to -1.34)] in comparison with Xx [1.72 (from -1.12 to 3.20)] (P<0.001) or xx [1.22 (from -1.74 to 3.06)] Xba I ER-alpha genotype (P=0.001). CONCLUSION: Women with ER-alpha Xba I genotype XX may have a higher risk of relatively fast bone mass loss in femoral neck after menopause and that they may have a poor responsiveness to calcium supplementation. The changes in BMD are not associated with ER-alpha Pvu II genotype and VDR Apa I genotype after 1 year of calcium supplementation.

Aged↗
PubMed2004

[Cloning and expression of the endo-beta-glucanase III cDNA gene from Trichoderma viride AS3.3711].

To study the construction of yeast bioengineering strain which can degrade cellulosic waste, an endo-beta-glucanase III (EG III) cDNA gene of Trichoderma viride AS3.3711 was isolated with RT-PCR protocol. After sequencing it was constructed on S. cerevisiae induceable expression vector pYES2. A L9 (3(4)) orthogonal design was used to optimize yeast sonication assistant transformation. The expression of EG III gene was induced by 2% beta-D-glactose, the transcription and expression of it was detected by Northern blotting and Congo Red method respectively. The endo-beta-glucanase activity was assayed as CMCase activity with CMC-Na as a substrate. The results show that the ORF of EG III was 1254 bp, encoding 418 aa, deducing molecular weight 44.1 x 10(3), group 5 (sonication treat time 60 s, incubate 40 min, SS-DNA 150 microg, heat shock 5 min) was the optimum one of the orthogonal experiment, and EG III transformants can produced clear hydrolysis halos on the Congo-Red-CMC plate. The measure of the enzyme activity show that the expression product can be expressed in active forms and secreted to the medium. The enzyme activity was approached the highest level (0.041 U/mL) when the culture time was 60 h. The optimized enzyme reaction temperature was 50 degrees C and the optimized pH was 5.8.

Cloning, Molecular↗
PubMed2004

[Relationship of msp AI polymorphism in cytochrome P450c 17alpha gene with bone mass and bone size in Shanghai men of Han nationality].

OBJECTIVE: To investigate the relationship of Msp AI polymorphism in the promoter region of cytochrome P450c 17alpha (CYP17) gene with bone mass and bone size in Shanghai men of Han nationality. METHODS: The CYP17 Msp AI genotype was determined by polymerase chain reaction-restriction fragment length polymorphism in 397 unrelated men (324 healthy men, 73 osteoporosis patients) aged 46-80 years of Han nationality in Shanghai. Bone mineral density (BMD), bone mineral content (BMC), and bone cross-section area (CSA) at lumber spine 1-4 and at any sites of proximal femur, including femoral neck, trochanter and Ward's triangle were measured by duel-energy X-ray absorptiometry. RESULTS: Frequency distributions of CYP17 genotype were TC (51.1%), CC (33.8%), and TT (15.1%). The allele frequencies T and C were 40.7% and 59.3%, respectively. Allele frequencies did not deviate from Hardy-Weinberg equilibrium. The frequencies of CYP17 Msp AI genotype did not show difference between osteoporosis cases and healthy controls. In group of all population, or in subgroups of osteoporosis patients and healthy men, CYP17 Msp AI genotype was not significantly associated with BMD, BMC, and CSA at lumber spine 1-4 and at any sites of proximal femur after having been adjusted for age, weight, and height with analysis of covariance. CONCLUSION: Msp AI polymorphism of CYP17 gene is not a genetic factor that influence the variation of bone mass and bone size in Shanghai men of Han nationality.

Aged↗
PubMed2003

Nuclear transfer: progress and quandaries.

Cloning mammals by nuclear transfer is a powerful technique that is quickly advancing the development of genetically defined animal models. However, the overall efficiency of nuclear transfer is still very low and several hurdles remain before the power of this technique will be fully harnessed. Among these hurdles include an incomplete understanding of biologic processes that control epigenetic reprogramming of the donor genome following nuclear transfer. Incomplete epigenetic reprogramming is considered the major cause of the developmental failure of cloned embryos and is frequently associated with the disregulation of specific genes. At present, little is known about the developmental mechanism of reconstructed embryos. Therefore, screening strategies to design nuclear transfer protocols that will mimic the epigenetic remodeling occurring in normal embryos and identifying molecular parameters that can assess the developmental potential of pre-implantation embryos are becoming increasingly important. A crucial need at present is to understand the molecular events required for efficient reprogramming of donor genomes after nuclear transfer. This knowledge will help to identify the molecular basis of developmental defects seen in cloned embryos and provide methods for circumventing such problems associated with cloning the future application of this technology.

Animals↗
PubMed2003

Parathyroid hormone gene with bone phenotypes in Chinese.

Osteoporosis is a common disorder afflicting old people. The parathyroid hormone (PTH) gene is involved in bone remodeling and calcium homeostasis, and has been considered as an important candidate gene for osteoporosis. In this study, we simultaneously tested linkage and/or association of PTH gene with bone mineral density (BMD) and bone mineral content (BMC), two important risk factors for osteoporosis. A sample of 1263 subjects from 402 Chinese nuclear families was used. The families are composed of both parents and at least one healthy daughter aged from 20 to 45 years. All the subjects were genotyped at the polymorphic BstBI site inside the intron 2 of the PTH gene (a nucleotide substitution of G to A at the position +3244). BMD and BMC were measured at the lumbar spine and the hip region via dual-energy X-ray absorptiometry (DXA). Using QTDT (quantitative trait transmission disequilibrium test), we did not find significant results for association or linkage between the PTH gene and BMD or BMC variation at the spine or hip. Our data do not support the PTH gene as a quantitative trait locus (QTL) underlying the bone phenotypic variation in the Chinese population.

Adult↗
PubMed2003

Developmental capacity of ferret embryos by nuclear transfer using G0/G1-phase fetal fibroblasts.

With the ultimate goal of establishing experimental protocols necessary for cloning ferrets, the present study has established parameters for the reconstruction of ferret embryos by nuclear transfer (NT) using G0/G1-phase donor fetal fibroblasts. Cumulus-oocyte complexes were harvested from superovulated ferrets and cultured in maturation medium for 24 h. Matured oocytes were then enucleated and injected with the fibroblast nuclei derived from 14-16-h serum-starved cells. Reconstructed embryos were then activated by a combination of electric pulses and chemical stimulations. Subsequently, the reconstructed and activated embryos were either cultured in vitro or transferred to pseudopregnant ferrets to evaluate their developmental capacity in vitro and in vivo. Our results demonstrated that 56.3% of reconstructed embryos (n = 187) cleaved, while 26.0% and 17.6% developed to morula and blastocyst phases in vitro, respectively. The blastocysts derived from NT embryos demonstrated normal morphology by differentially staining as compared to normal blastocysts developed in vivo following fertilization. In vivo developmental studies at 21 days posttransplantation demonstrated 8.8% of reconstructed embryos (n = 91) implanted into the uterine lining of recipients, while 3.3% formed fetuses. However, reconstructed embryos (n = 387) failed to develop to term (42 days). These results demonstrate donor nuclei of G0/G1-phase fetal fibroblast cells can be reprogrammed to support the development of reconstructed ferret embryos in vitro and in vivo; however, a significant third-trimester block occurs preventing full-term development.

Animals↗
PubMed2003

Polymorphisms of four bone mineral density candidate genes in Chinese populations and comparison with other populations of different ethnicity.

Studies on polymorphisms of candidate genes and their association with bone mineral density (BMD) have been reported in many populations, but few have been reported in Chinese populations. We investigated polymorphisms of the following five commonly used markers of four prominent BMD candidate genes with the purpose of identifying useful genetic markers for osteoporosis genetic research in Chinese: the Sp1 and RsaI polymorphisms of the collagen type 1 alpha l (Col1a1) gene, the -174G/C promoter polymorphism of the interleukin 6 (IL-6) gene, the Asn363Ser polymorphism of the glucocorticoid receptor (GR) gene, and the T --> C polymorphism in intron 5 of the transforming growth factor beta(1) (TGF-beta(1)) gene. We evaluated these polymorphisms using PCR-RFLP in samples of at least 124 random individuals. We compared the polymorphisms of these five markers with other populations using the chi(2) test and Fisher's exact two-tailed test. For the RsaI polymorphism, only three heterozygotes but no variant homozygote were identified. For the -174G/C polymorphic site, only one GC heterozygote and no CC homozygote were found. Alleles s, Ser, and A(1) at the Sp1, Asn363Ser, and T --> C marker sites that have been found to be polymorphic in other populations were not found in Chinese. Significant differences of allele and genotype frequency distributions were observed at these polymorphisms ( P < 0.001) after comparing with other populations. Our results suggest that variant alleles of the five markers are absent or too rare to be useful genetic makers in Chinese, despite the fact that they have been commonly used as polymorphic markers in osteoporosis genetic research in other populations.

Base Sequence↗
PubMed2003

Heat shock proteins in mammalian development.

Mammalian development follows a defined but adjustable program, depending on the plasticity of embryonic cells 'response to environmental changes. Heat shock proteins (Hsp) are integral part of this developmental program and gene targeting experiments have started to unravel developmental processes, which exhibit specific requirements for Hsps (e.g. Hsp70.2 for spermatogenesis). In the present paper, we will review available data on Hsp function and discuss the roles of heat shock factors (HSF), their major regulators, in mammalian development.

Animals↗
PubMed2003

A real-time and dynamic biological information retrieval and analysis system (BIRAS).

The aim of this study is to design a biological information retrieval and analysis system (BIRAS) based on the Internet. Using the specific network protocol, BIRAS system could send and receive information from the Entrez search and retrieval system maintained by National Center for Biotechnology Information (NCBI) in USA. The literatures, nucleotide sequence, protein sequences, and other resources according to the user-defined term could then be retrieved and sent to the user by pop up message or by E-mail informing automatically using BIRAS system. All the information retrieving and analyzing processes are done in real-time. As a robust system for intelligently and dynamically retrieving and analyzing on the user-defined information, it is believed that BIRAS would be extensively used to retrieve specific information from large amount of biological databases in now days. The program is available on request from the corresponding author.

Animals↗
PubMed2003

Antidepressant use: concordance between self-report and claims records.

BACKGROUND: Researchers need valid methods to assess whether patients are taking their antidepressant medications. Two important sources of data on drug exposure are patients' self-reports and pharmacy claims. OBJECTIVE: To compare self-report and claims data for antidepressant exposure. RESEARCH DESIGN: Cross-sectional analysis. SUBJECTS: This study comprised 422 contemporaneous self-report and claims data points obtained from 164 unique patients in a longitudinal depression study in which patients completed up to five surveys during an 18-month period. MEASURES: For the self-report measure, the following question was asked: Do you now take any prescription medicines for depression? Using claims data, patients were considered to be using an antidepressant if they had filled at least one antidepressant prescription in the 90 days before survey dates. RESULTS: Self-report and claims agreed in 85% (358/422) of cases, with a kappa of 0.69. Eighty-eight percent (56/64) of discrepant cases using other study data sources was resolved. Reasons for discrepancies included the use of medications for conditions other than depression (32/64), recent AD discontinuations (6/64), samples usage (3/64), and low-frequency/PRN use (7/64). CONCLUSIONS: Self-report and claims showed good concordance, but they reflect different truths. Self-report identifies medications intended primarily for the treatment of depressive disorders, whereas claims data identify use of medicines with antidepressant effects. Our assessment of discordant cases showed self-report to be more valid than claims to assess current antidepressant use for depression therapy.

Adolescent↗