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Biomedical subjects

Bing Yu

Publications and source records attributed to Bing Yu.

At least 55 records · Page 3Linked to original sources
PubMed2005

Trunk position in supine of infants born preterm and at term: an assessment using a computerized pressure mat.

PURPOSE: Trunk position may influence motor, cognitive, and social development during infancy and early childhood and has not been quantitatively assessed. The purpose of this study was to assess the trunk positions of infants born at term and preterm in supine using a computerized pressure mat. METHODS: Trunk position was represented as a ratio of head and pelvis to trunk pressure. Eighteen healthy infants born preterm with a mean gestational age of 31.9 weeks (25.0-34.6) and fifteen healthy infants born at term with a mean gestational age of 38.9 weeks (37.3-40.6) were assessed at 38 to 43 weeks gestational age. RESULTS: Infants born at term spent more than two-thirds of the time in either flexed or neutral trunk positions. No significant differences were found between infants born preterm and those born at term in total duration of flexion or extension or in flexion event duration. CONCLUSION: This study provides evidence that infants born preterm may not exhibit greater trunk extension tendencies in supine than infants born at term. Results should be interpreted with caution, however, because of the small sample size and large variability observed within the subject groups. Infants born at less than 30 weeks of gestation may demonstrate greater extension tendencies than those born at more than 30 weeks of gestation.

Case-Control Studies↗
PubMed2005

Effect of fatigue on knee kinetics and kinematics in stop-jump tasks.

BACKGROUND: Altered motor control strategies in landing and jumping maneuvers are a potential mechanism of noncontact anterior cruciate ligament injury. There are biomechanical differences between male and female athletes in the landing phase of stop-jump tasks. Fatigue is a risk factor in musculoskeletal injuries. HYPOTHESIS: Lower extremity muscle fatigue alters the knee kinetics and kinematics during the landing phase of 3 stop-jump tasks and increases an athlete's risk of anterior cruciate ligament injury. STUDY DESIGN: Controlled laboratory study. METHODS: Three-dimensional videography and force plate data were collected for 20 recreational athletes (10 male and 10 female athletes) performing 3 stop-jump tasks before and after completing a fatigue exercise. Knee joint angles and resultant forces and moments were calculated. RESULTS: Both male and female subjects had significantly increased peak proximal tibial anterior shear forces (P = .01), increased valgus moments (P = .03), and decreased knee flexion angles (P = .03) during landings of all 3 stop-jump tasks when fatigued. Fatigue did not significantly affect the peak knee extension moment for male or female athletes. CONCLUSION: Fatigued recreational athletes demonstrate altered motor control strategies, which may increase anterior tibial shear force, strain on the anterior cruciate ligament, and risk of injury for both female and male subjects. CLINIC RELEVANCE: Fatigued athletes may have an increased risk of noncontact anterior cruciate ligament injury.

Adult↗
PubMed2005

[Sorting of packaging cells for retroviral vector carrying green fluorescent gene and viral titer determination].

OBJECTIVE: To develop a method for acquisition of efficient and stable retroviral packaging cells on the basis of fluorescence-activated cell sorting (FACS) technique. METHODS: PA317 cells were transfected by the recombinant retroviral vector pLEGFP via liposome, and the result of transfection was examined using fluorescent microscope. Polyclones and monoclone of the packaging cells were obtained with FACS and identified by PCR and reverse transcriptional PCR (RT-PCR). NIH3T3 cells were used to determine the virus titer in the supernatant. RESULTS: Examination under fluorescence microscope confirmed the success of cell transfection with the retrovirus, and polyclonal and monoclonal cells with efficient and stable expression were obtained after FACS. The inserted EGFP gene fragment could be amplified by PCR from the genomic DNA of the polyclonal and monoclonal cells and by RT-PCR from the retrovirus RNA in the supernatant of monoclonal cell culture and some of the monoclonal cell cultures (6/8). Determination of the virus titer in the cell culture supernatant showed efficient viral production by the cells. CONCLUSION: FACS is an efficient method for obtaining stable retroviral packaging cells.

Gene Expression Regulation, Viral↗
PubMed2005

Construction and co-expression of bicistronic plasmid encoding human WEE1 and stem cell factor.

To protect the hematopoietic stem cells (HSCs) from apoptosis induced by chemotherapy and promote HSC proliferation, bi-functional gene delivery systems are increasingly investigated in gene therapy. In the present study, we constructed a bicistronic vector, pWISG, expressing the anti-apoptotic protein human WEE1 (WEE1Hu) and the fusion protein of the proliferation-stimulating stem cell factor (SCF) and enhanced green fluorescent protein (EGFP) separately with internal ribosome entry site (IRES). We first examined the expression and location of WEE1Hu in Chinese hamster ovary (CHO) cells and showed that WEE1Hu was located in the nucleus, which was confirmed by immunohistochemistry and Western blot. We determined the expression and receptor-binding ability of the SCF-EGFP fusion protein on CD34+ cells, which were proved by reverse transcription polymerase chain reaction (RT-PCR) and flow cytometry, respectively. Furthermore, inhibition of cisplatin-induced apoptosis was observed in CD34+ cells transfected with pWISG, which implies that protection for CD34+ cells was achieved via WEE1Hu and SCF-EGFP. Our study suggests that the introduction of two functional genes via bicistronic vector is more powerful and efficient than single gene therapy.

Animals↗
PubMed2005

[Skeleton reconstruction of oblique facial clefts using mandibular outer table].

OBJECTIVE: This paper presents a new method of skeleton reconstruction for oblique facial clefts using autogenous bone of the mandibular outer table. METHODS: In the operation, the mandibular outer table was harvested through the intraoral approach. Assisted with internal rigid fixation technique, the mandibular outer table was used to reconstruct the naso-orbital framework as inlay or onlay bone graft. RESULTS: From 1993 to 2001, seven cases of oblique facial clefts were repaired with mandibular outer table bone graft. Postoperative follow-up for 6 months to 3 years demonstrated that the grafted bone healed well with the adjacent bones. No obvious bone resorption was observed. The facial appearance was improved greatly. CONCLUSIONS: The mandibular outer table, with similar bone density to the calvarium, is easy to harvest without donor site scar. The method is quite ideal for skeleton reconstruction of oblique facial clefts.

Adolescent↗
PubMed2005

[Analyses of Pont Index of dental crowding patients and normal occlusion people].

OBJECTIVE: The research aimed to analyze the significance of Pont Index in the dental crowding. METHODS: Respectively selected 91 normal occlusion persons and 101 dental crowding patients, measured every item of Pont Index of these two sample groups, and compared the results. RESULTS: The premolar index and molar index of dental crowding patients were obviously bigger than that of normal occlusion, and there was apparent significant difference. There was no significant gender difference of Pont Index either in normal occlusion or dental crowding patients. Whereas there was significant gender difference of premolar arch width and molar arch width in normal occlusion. CONCLUSION: The occurrence of dental crowding is clearly related to Pont Index.

Bicuspid↗
PubMed2005

[Genetic polymorphism analysis of 6 STR loci on the X chromosome in Xi'an Han population].

OBJECTIVE: To investigate the alleles and genotypes frequency of 6 short tandem repeat (STR) loci (DXS8378, DXS7132, DXS6789, DXS101, HPRTB and DXS7423) on the X chromosome in Han population. METHODS: The six X-chromosome STR loci were analyzed by PCR following polyacylamide gel electrophoresis and silver stain. RESULTS: Among 120 females from Xi'an Han population, the number of alleles in the 6 loci (DXS8378, DXS7132, DXS6789, DXS101, HPRTB and DXS7423) were 5, 6, 11, 10, 8, and 4 respectively; the number of genotypes in the 6 loci were 10, 17, 29, 32, 22, and 7 respectively; Exact tests demonstrated genotype frequencies in females had no departure from Hardy-Weinberg equilibrium. CONCLUSION: The six X-chromosome STR loci are appropriate for individual identification, paternity testing involving a female child and for study on related disease.

Alleles↗
PubMed2005

[Surgical management of craniomaxillofacial fibrous dysplasia].

OBJECTIVE: To explore the method to obtain good aesthetic and functional results in surgical management of craniomaxillofacial fibrous dysplasia and correct the grotesque deformity. METHODS: According to the type of the lesions, different excision and reconstruction methods were used. RESULTS: 19 cases (4 monostotic cases and 15 polyostotic cases) were surgically treated. The period of follow-up range from 9 months to 5 years, all patients obtained satisfactory aesthetic and functional results. No relapse happened during follow up. CONCLUSIONS: Based on modern craniomaxillofacial techniques and computer aided design, extensive radical excision and craniomaxillofacial skeleton reconstruction could be safely accomplished, and the better results were obtained, both aestheticly and functionally.

Adolescent↗
PubMed2005

[Analysis of recombinant erythropoietin and its tryptic digest by capillary electrophoresis and capillary electrophoresis-electrospray ionization-mass spectrometry using capillary coated with 6,6-ionene].

The microheterogeneity of recombinant human erythropoietin (rhEPO) was analyzed by capillary electrophoresis (CE) using a capillary coated with 6,6-ionene. The applicability of a volatile electrolyte for fast analysis of tryptic fragments of rhEPO with online CE-electrospray ionization-mass spectrometry (ESI-MS) was investigated, resulting in a reproducible separation of eleven rhEPO tryptic fragments within 22 min under the following conditions: running buffer 300 mmol/L acetic acid-ammonium acetate (HAc-NH4Ac), pH 4.80, separation voltage -15 kV and capillary temperature 25 degrees C. The proposed method is rapid and effective, and can be used for the structural analysis of related proteins.

Electrophoresis, Capillary↗
PubMed2005

Allele distribution of five X-chromosome short tandem repeat loci in Ewenke population of north China.

OBJECTIVE: To study the allele genetic polymorphism of five short tandem repeat (STR) loci on X-chromosome in Ewenke population of north China and to provide basic data for forensic identification. METHODS: Genomic DNA was extracted from EDTA-whole blood of Ewenke population by Chelex-100. The DNA samples were amplified by PCR and were analyzed by polyacrylamide gel electrophoresis and silver staining. The sequence length variations of DXS6799, DXS8378, DXS101, HPRTB, and DXS6789 loci on X-chromosome in 98 unrelated Ewenke individuals were investigated. RESULTS: All five loci analyzed showed high polymorphism and genetic stability. The data of the five X-chromosome STR loci in Ewenke ethnic group of China was in accordance with Hardy-Weinberg equilibrium by Chi-square test. CONCLUSION: Allele polymorphism of five X-chromosome STR loci can be used as a genetic marker for forensic identification and population genetic research.

Asian People↗
PubMed2004

Cytotoxicity of HSVtk and hrTNF-alpha fusion genes with IRES in treatment of gastric cancer.

The efficacy of the suicide gene therapy by using the herpes simplex virus thymidine kinase/ganciclovir (HSVtk/GCV) system for the treatment of cancer is limited because of the insufficient gene transfer and the low killing activity. To enhance the antitumor activity, we probed into whether recombinant ritroviral expression vector PLXSN expressing both HSVtk and TNF-alpha genes could potentiate the destruction of SGC7901. The PL(tk-TNF-alpha)SN harboring HSVtk and TNF-alpha genes in sequence was constructed with a bicistronic unit including the internal ribosomal entry site, the recombinant retroviruses were transferred into SGC7901 cells by lipofectamine, and pEGFP and Western blot analysis were used to detect the expression of fusion genes in transfected SGC7901 cells, and then apoptosis of the transfected cells were detected by using the TdT-mediated dUTP nick end labeling, flow cytometric analysis and transmission electron microscopy. In vitro study, the transfected gastric cancer cells were maintained in the GCV-contained medium, to assay the cell killing effect and bystander effect. In vivo experiments, retroviral serum plasmids were transfected into tumor-bearing nude mice, to observe the changes of tumor volumes and survival of the mice. In vitro there was no significant difference of cell survival rate between the three groups. However, in vivo results showed that tk/GCV, tk-TNF-alpha/GCV and TNF-alpha could inhibit the tumor growth, and the obvious anti-tumor effect was shown in tk-TNF-alpha/GCV group, and TNF-alpha obviously enhanced the anti-tumor effect in vivo. The pathologic examination showed necrosis of the cancer in the treated groups.

5' Untranslated Regions↗
PubMed2004

[The biological characteristics of a mucoid Pseudomonas aeruginosa strain with a newly discovered mutation of mucA gene].

OBJECTIVE: To compare the mucA gene sequence, biofilm formation, growth rate and antibiotic resistance of a mucoid Pseudomonas aeruginosa strain 'PA17' with those of the nonmucoid strain PAOI. METHODS: The mucA genes of PA17 and PAOI were amplified and the PCR products were sequenced. Biofilm was established and detected with scanning electron microscope 8 h, 24 h, 3 d and 6 d later. Clones counting method was used to compare the growth curves of PA17 and PAOI. International standard plate dilution method was used to detect the susceptibility of common antibiotics for PA17 and PAOI in vitro. RESULTS: There was a 166-333 deletion mutation in mucA gene of PA17. The biofilm formation rate and growth rate of PA17 were noticeably lower than those of PAOI. The antibiotic resistance profile of PA17 was identical to that of PAOI. CONCLUSION: A mucoid Pseudomonas aeruginosa with a new type of mutation of mucA gene is discovered. The biologic characteristics of this strain are different from those of the mucoid Pseudomonas aeruginosa strain reported previously, which may be related with the newly discovered mutation of mucA gene.

Amino Acid Sequence↗
PubMed2004

Immediate effects of a knee brace with a constraint to knee extension on knee kinematics and ground reaction forces in a stop-jump task.

BACKGROUND: A small knee flexion angle in landing tasks was identified as a possible risk factor for noncontact anterior cruciate ligament injuries that are common in sports. HYPOTHESIS: A specially designed knee brace with a constraint to knee extension would significantly increase the knee flexion angle at the landing of athletic tasks preceded with horizontal movement components, such as stop-jump tasks. STUDY DESIGN: Repeated measure design for brace effects. METHODS: Three-dimensional videographic and force plate data were collected for 10 male and 10 female recreational athletes performing a stop-jump task with and without the specially designed brace. Knee flexion angle at landing, maximum knee flexion angle, and peak ground reaction forces during the stance phase of the stop-jump task were determined for each subject with and without the knee brace. RESULTS: The knee brace decreased the knee flexion angle at the landing by 5 degrees for both genders but did not significantly affect the peak ground reaction forces during the landing. CONCLUSIONS: The specially designed knee brace may be a useful device in the prevention and rehabilitation of noncontact anterior cruciate ligament injuries in sports.

Adolescent↗
PubMed2004

A polymorphism in the poliovirus receptor gene differs in motor neuron disease.

Poliovirus has been implicated in the etiology of sporadic motor neuron disease. DNA polymorphisms in the poliovirus receptor gene (PVR) are associated with persistent poliovirus infection in cell culture. PVR DNA polymorphisms were therefore studied in 110 cases of amyotrophic lateral sclerosis, 30 cases of progressive muscular atrophy (a disorder of lower motor neurons) and 280 normal controls. In exon 2 of PVR the heterozygous Ala67Thr change was detected in 20.0% of progressive muscular atrophy, 11.8% of amyotrophic lateral sclerosis and 6.8% of control subjects. The frequency of the polymorphism was significantly higher in patients with progressive muscular atrophy than in controls. Differences in the poliovirus receptor gene may result in slowly progressive viral cytopathic effects that lead to lower motor neuron forms of motor neuron disease.

Adult↗
PubMed2004

Molecular characterisation of neonatal cardiac hypertrophy and its regression.

Neonatal cardiac hypertrophy associated with diabetic pregnancy is transient and regresses naturally, but is associated with increased morbidity and mortality. This study was undertaken to analyse the changes in expression of 5 cardiac genes, including atrial natriuretic peptide, alpha- and beta-myosin heavy chain, and cardiac and skeletal alpha-actin genes, using a rat neonatal model, in which cardiac hypertrophy was induced via maternal diabetes. In the hypertrophied left ventricle of neonates from diabetic mothers, the levels of mRNA from all the above genes except skeletal alpha-actin were increased by between 1.8- and 12-fold compared with the controls at birth (p < 0.05). In the first 28 days, the level of mRNA for alpha-myosin heavy chain increased slightly, while that for atrial natriuretic peptide and beta-myosin heavy chain decreased continuously similar to the controls, but at a significantly faster rate. No significant difference between the two groups of neonates was observed in all 5 genes after 1 month, indicating complete regression. Expression of 5 cardiac genes in the neonatal cardiac hypertrophy was characterised in both hypertrophic and regressive phases. Hypertrophic regression provides a unique model for the testing of new drugs or genetic modifying factors in cardiac hypertrophy.

Actins↗
PubMed2004

Challenges for clinical genetic DNA testing.

DNA testing was first used in the late 1970s. Today, the indications for a DNA test have expanded to include predicting the development of genetic disorders, screening populations, confirming clinical diagnoses, prenatal testing and DNA testing to individualize medical treatment. Apart from the wide range of indications, the next few years will see a great expansion in the number of DNA tests. This will be driven by information generated from the Human Genome Project. Improved technology will make DNA testing more accessible. In this climate, the challenges will be considerable, particularly in relation to education. The avoidance of ethical, legal and social dilemmas will require informed and wise input from professionals and the community.

Computational Biology↗
PubMed2004

[Study on clinical efficacy and mechanism of xiaoyan zhixue capsule in treating menorrhagia caused by intrauterine device].

OBJECTIVE: To observe the efficacy of Xiaoyan Zhixue Capsule (XYZXC) in treating uterus abnormal menorrhagia caused by intrauterine device (IUD) and to study its mechanism. METHODS: IUD users with menorrhagia were randomly divided into two groups, the XYZXC treated group and adrenosoem (AC-17) control group. Endometrial tissue of XYZXC treated group before and after treatment were taken out to observe its morphologic change with optic and electronic microscope. Animal experiment was done to observe the effect of XYZXC in eliminating inflammation of patierts, and the relevant parameters were monitored. RESULTS: Clinical efficacy: (1) Total effective rate of the treated group was 90.3%, that of control group was 43.5%, comparison between them showed significant difference (P<0.01). (2) Morphological examination of endometrial tissue showed the inflammation in the treated group abated after treatment with the contractible function of helicine artery strengthened. Experimental study showed: (1) The auricular swelling of mice was inhibited by 40.5% in the treated group, the effect was equivalent to that of hydrocortisone (46.9%). (2) Compared with the control group, the plasma 6-keto-PGF1alpha and D-Dimer level in the treated group were markedly lower, and TXB2/6-keto-PGF1alpha ratio and plasma endothelin level were markedly higher (P<0.05 or P<0.01). ET contents in large dosage TCM group was significantly raised (P<0.05). (3) XYZXC could increase amplitude of contraction of the uterus smooth muscle as well as the uterus activity in rats in vivo. CONCLUSION: XYZXC has obvious anti-inflammatory and hemostatic effects, it has marked effect in treating IUD caused pre- and post-menstruation menorrhagia, the possible mechanism may be: (1) Modulating the synthesis of prostaglandin; (2) Antagonizing the IUD caused fibrinolytic hyperfunction; (3) Promoting the synthesis of ET; (4) Increasing the contractility and activity of uterus smooth muscle.

Adult↗