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Biomedical subjects

Yu Zhang

Publications and source records attributed to Yu Zhang.

At least 307 records · Page 17Linked to original sources
PubMed2003

[Comparative clinical observation of the short-term bone fusion effect of composite biosynthetic bone and ilium auto-grafting].

OBJECTIVE: To evaluate the short-term bone fusion after implantation of composite biosynthetic bone made of coralline hydroxyapatite composite (CHC) as a substitute for autologous bone grafting. METHODS: A clinical sequential trial was designed and the biosynthetic bone and the patient's ilium were respectively used in the treatment of femoral nonunions and interbody fusion. X-ray examinations were performed 10 weeks after the operations and the bone fusion was graded according to Lane-Sandhu's method. RESULTS: The biosynthetic bone was capable of bone fusion as observed in this experiment. Sequential analysis found that the upper bound was reached when the X-ray examination scores of 15th pairs were transcribed in the chart with 2 pairs of cases dismissed for having the same grade. CONCLUSION: The bone fusion effect of CHC is better than auto-grafting judging from the present observation at 10 weeks after operation.

Adult↗
PubMed2003

[Bulking controls induced by nitrogen insufficiency in yeast system].

The effect of nitrogen addition to salad oil manufacturing wastewater system was studied. The results of batch experiments demonstrated: 1. addition of nitrogen was helpful to improve oil removal, and the oil removal rate was above 90% when COD/N value was between 50/1 and 20/1; 2. addition of nitrogen improved the sludge settleability, which was much better under COD/N value of 50/1 and 20/1. In the continuous experiment, the value of slude volume index(SVI) was between 100 and 200, and the removal rates of oil and COD were above 95% and 90%, respectively when the COD/N ratio was kept at value of 20/1. Nitrogen addition to salad oil manufacturing wastewater system is an effective method for preventing or controlling sludge bulking.

Industrial Waste↗
PubMed2003

[Modified FLAG regimen in the management of refractory acute myeloid leukemia].

OBJECTIVE: To evaluate the therapeutic effect of modified FLAG regimen in the management of refractory acute myeloid leukemia (AML). METHODS: Sixteen patients with refractory AML were divided into two groups. In modified FLAG regimen group (n=10), the patients received fludarabine (Flu, 50 mg/d, VDx5 d) and Ara-c (200 mg/d, VDx5 or 7 d). The regimen for classic FLAG group (n=6) consisted of Flu (50 mg/d, VDx5d), Ara-C (500 or 1,000 mg/d, VDx5d) and G-CSF (300 microg/d, x5 d, subcutaneously injected 4-6 hours before chemotherapy). Each patient received subcutaneous G-CSF (300 microg/d) when the white blood cell count was lower than 1.0x10(9)/L till the condition was corrected. RESULTS: The total complete remission(CR) rate of the 16 patients was 50% (8/16). Seven patients in modified group achieved CR (70%) and only one of the classic group did (17%, P<0.05). Episodes of infections were lower in modified group than in the classic group (50% vs 83%). CONCLUSION: Modified FLAG regimen is more likely than classic FLAG regimen to achieve CR and reduce infections in patients with refractory AML.

Adolescent↗
PubMed2003

[Application of atomic force microscopy in the study of morphology of double minute chromosomes].

Atomic force microscopy (AFM) has many advantages in the study of biological samples, such as the convenient specimen preparation and the high resolution. In the present study, AFM was used to observe the double minute chromosomes (DMs) in mouse methotrexate-resistant cell line 3T3R500. AFM images were obtained by tapping mode, contact mode and later force mode of AFM. DMs were composed of two compact spheres connected with fibers. The number of DMs in the 3T3R500 cells increased with increasing levels of methotrexate (MTX) resistance. The data of the height and the underside diameter of the DMs were also obtained. The details of specimen preparation and scan mode selection of AFM were discussed. Our results show that AFM is a powerful method in the study of DMs.

Animals↗
PubMed2003

[Quadruple therapy with CsA, MTX, MMF and ATG for preventing graft-versus-host disease in unrelated donor hematopoietic stem cell transplantation].

OBJECTIVE: To evaluate the efficacy of quadruple therapy with cyclosporine (CsA), methotrexate (MTX), mycophenolate mofetil (MMF) and low-dose antithymocyte globulin (ATG) for graft-versus-host disease (GVHD) prophylaxis in unrelated donor hematopoietic stem cell transplantation (URD-HSCT). METHODS: Thirteen patients with leukemia received URD-HSCT, of whom 11 had HLA genotypes and 2 had mismatch for 1 genetic locus. Another 11 leukemia patients all serologically matched underwent related donor (RD)-HSCT. Total body irradiation (TBI) plus cyclophosphamide (CTX) was adopted in 19 cases and modified BuCY conditioning regimen (hydroxyurea, busulfan, Ara-C, Cyclophosphamide ) in the other 5 cases. All the patients received CsA+MTX protocal for GVHD prophylaxis, and in those undergoing URD-HSCT, additional MMF and low-dose ATG were used. RESULTS: The incidence and severity of regimen-related toxicity differed little between unrelated and related transplantation. Acute GVHD (aGVHD) occurred in 46.2% of the patients undergoing URD- HSCT and in 55.6% of those with RD-HSCT, respectively. Four patients had chronic GVHD (cGVHD), in the 7 ones who could be followed up after URD-HSCT; 6 of the 9 patients with RD-HSCT developed cGVHD postoperatively. One patient with URD-HSCT died of hemorrhagic cystitis and another with RD-HSCT died of cytomegalovirus (CMV) pneumonia. The at one-year disease-free survival rate was 87.5% and 90.9% in patients with unrelated and related transplantation respectively. Significant difference was not noted in the positivity rate of CMV antigen between the patients receiving URD-HSCT or RD-HSCT. CONCLUSION: CsA+MTX in combination with MMF and low-dose ATG may decrease the incidence and severity of aGVHD without increasing transplant-related mortality or CMV infection.

Adolescent↗
PubMed2003

[STI 571 for treating 19 patients with chronic-phase chronic myeloid leukemia].

OBJECTIVE: To compare the therapeutic effects of STI 571 in treating Philadelphia chromosome (Ph)-positive patients with chronic-phase and acceleration phase chronic myeloid leukemia (CML-CP and CML-AP, respectively). METHODS: A total of 19 CML patients with Ph chromosome and/or fluorescence in situ hybridization (FISH)-bcr/abl fusion gene positivity rates over 90% and a median age of 38 years were recruited in this study, 12 of whom had previously failed to respond to interferon-alpha. Five of the 19 patients were in accelerated phase and 14 in chronic phase, 9 of the latter patient group in early stage of CML-CP (within 1 year since diagnosis) and 5 in advanced stage (3-6 years since diagnosis). All the patients were given oral STI 571 at the dose of 300-500 mg/d for a median treatment course of 5 months, and the 5 patients with CML-AP also received homoharringtonine at dose of 1-2 mg/d for an average of 1.5 treatment cycles (7-14 d for a complete treatment cycle). The Ph chromosome and the FISH-bcr/abl were analysed again 3 months after the treatment. RESULTS: STI 571 induced 100% complete hematological remission (CHR) and 79% major cytogenetic responses (MCR) in these patients. The complete cytogenetic remission (CCR) rates of CML-AP patients and CML-CP patients in advanced stage were lower than that of CML- CP patients in early stage (0% and 40% vs 88.9%). CONCLUSION: STI 571 can achieve high rate of CHR and MCR in CML-CP patients, especially in those in early stage of the disease.

Adolescent↗
PubMed2003

[Gene expression of interstitial collagenase MMP-13 in progressive phase of rat liver fibrosis induced by ethanol].

OBJECTIVES: To demonstrate the gene expression of MMP-13 in the progressive phase of ethanol-induced experimental liver fibrosis in rats. METHODS: 34 SD rats were randomized into two groups. The rats in experimental group (n=24) were given ethanol (44%, 7g/kg) every day, and the rats in control group (n=10) were given equality normal saline. Liver samples were harvested from experimental rats at the 4th, 12th and 24th weeks respectively. The dynamic expression of MMP-13 mRNA was assayed by semi-quantity reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: In normal rat liver, a faint band of MMP-13 mRNA was observed by RT-PCR (0.24+/-0.41). The gene expression of MMP-13 increased in the livers of rats treated with ethanol for 4 weeks (0.62+/-0.54), but it was not considered statistically, when compared with that in normal rats livers. And the livers from 12-week-treated rats showed a markedly MMP-13 mRNA expression (1.65+/-0.47, t=-4.363, P<0.01). Once the fibrosis became prominent (24 weeks), a faint band of MMP-13 mRNA was observed (0.39+/-0.25). CONCLUSION: MMP-13 participates in the degradation of newly-formed matrix in the early phase of rat liver fibrosis induced by ethanol, but it expresses in a distinct time frame

Animals↗
PubMed2003

[Effect of modified FLAG regimen therapy on 33 patients with relapsed/refractory leukemia].

BACKGROUND & OBJECTIVE: The hematological complete remission (CR) rate of the FLAG regimen [fludarabine and cytarabine (Ara-C) and granulocyte-colony stimulating factor] for relapsed and refractory acute non- lymphocytic leukemia (ANLL) was 50-64%. The aim of this study was to investigate the modified FLAG regimen (Ara-C reduced to 200 mg per day intravenous injection for 5 to 7 days, and the patients were not administrated G-CSF before fludarabine and Ara-C) to examine whether it can achieve the same effectiveness and minor side effects. METHODS: Of 33 patients with acute leukemia, there were 16 cases with ANLL, 12 cases with refractory acute lymphocytic leukemia (ALL) and 5 cases with relapsed ALL, respectively. All patients received fludarabine (Flu) 30 mg/m(2)/d intravenous injection for 5 days. And every patient received simultaneously Flu in combination with Ara-C intravenously for 5-7 days, 18 cases with Ara-C at a dose of 200 mg per day, 5 cases with Ara-c 500 mg/d and 10 cases with Ara-c 1000 mg/d, respectively. One course consisted of 7 days. ALL patients and the patients received Ara-C at a dose of 200 mg per day were not treated with G-CSF before chemotherapy. ALL patients received vincristine at a dose of 2 mg/w for 2 times and prednisone 60-80 mg/d for 14 days. Of these 33 patients, the cases with white blood cell(WBC) counts less than 1.0 x 10(9)/L were treated with G-CSF at a dose of 300 microg/d subcutaneously until WBC counts were more than 3.0 x 10(9)/L. All patient were examined for bone marrow after every course. RESULTS: The CR rate of 16 patients with refractory ANLL was 56.3%, whereas the CR rate of 12 cases with refractory ALL was 17% (P< 0.01). The CR rate of the patients with refractory ANLL who received Ara-C 200 mg/d was higher than those with refractory ANLL receiving Ara-C at the medial doses (70% versus 33%, P >0.05). The average durations of WBC< 0.6 x 10(9)/L and platelet< 15.6 x 10(9)/L were 5 days and 4.3 days, respectively. Infection rate of the patients receiving Ara-C 200 mg/d was significantly lower than those receiving Ara-C at the medial doses (58% versus 87.5%,P< 0.05). CONCLUSION: The CR rate of modified FLAG regimen is higher than classic FLAG, whereas the infection rate of the former is lower than the latter.

Adolescent↗
PubMed2003

[Medical image elastic registration smoothed by unconstrained optimized thin-plate spline].

Elastic registration of medical image is an important subject in medical image processing. Previous work has concentrated on selecting the corresponding landmarks manually and then using thin-plate spline interpolating to gain the elastic transformation. However, the landmarks extraction is always prone to error, which will influence the registration results. Localizing the landmarks manually is also difficult and time-consuming. We the optimization theory to improve the thin-plate spline interpolation, and based on it, used an automatic method to extract the landmarks. Combining these two steps, we have proposed an automatic, exact and robust registration method and have gained satisfactory registration results.

Algorithms↗
PubMed2003

Anatomically accurate individual face modeling.

This paper presents a new 3D face model of a specific person constructed from the anatomical perspective. By exploiting the laser range data, a 3D facial mesh precisely representing the skin geometry is reconstructed. Based on the geometric facial mesh, we develop a deformable multi-layer skin model. It takes into account the nonlinear stress-strain relationship and dynamically simulates the non-homogenous behavior of the real skin. The face model also incorporates a set of anatomically-motivated facial muscle actuators and underlying skull structure. Lagrangian mechanics governs the facial motion dynamics, dictating the dynamic deformation of facial skin in response to the muscle contraction.

Biomechanical Phenomena↗
PubMed2003

[Effect of tea polyphenol on liver fibrosis in rats and related mechanism].

OBJECTIVE: To investigate the effect of tea polyphenol (TP)'s on liver fibrosis in rats and its possible mechanism. METHOD: Rats were divided into 5 groups, 4 groups of which were stomach perfused with alcohol resulting in alcoholic liver fibrosis, and 3 groups of which were stomach perfused with TP simultaneously. Another group was normal control one. Histological change of rat liver was investigated and quantitative analysis was made in 24 weeks, and rat liver anti-oxidation index and serum endotoxin were determined at the same time. RESULT: Liver fibrosis in TP group was slight, and anti-oxidize index and endotoxin level were markedly improved in comparison with those of alcohol groups. CONCLUSION: Tea polyphenol can protect hepatocytes from fibrosis. Its mechanism is possibly due to cleaning up overfull lipid per-oxidation and reducing the level of endotoxin.

Animals↗
PubMed2002

Sequence and analysis of rice chromosome 4.

Rice is the principal food for over half of the population of the world. With its genome size of 430 megabase pairs (Mb), the cultivated rice species Oryza sativa is a model plant for genome research. Here we report the sequence analysis of chromosome 4 of O. sativa, one of the first two rice chromosomes to be sequenced completely. The finished sequence spans 34.6 Mb and represents 97.3% of the chromosome. In addition, we report the longest known sequence for a plant centromere, a completely sequenced contig of 1.16 Mb corresponding to the centromeric region of chromosome 4. We predict 4,658 protein coding genes and 70 transfer RNA genes. A total of 1,681 predicted genes match available unique rice expressed sequence tags. Transposable elements have a pronounced bias towards the euchromatic regions, indicating a close correlation of their distributions to genes along the chromosome. Comparative genome analysis between cultivated rice subspecies shows that there is an overall syntenic relationship between the chromosomes and divergence at the level of single-nucleotide polymorphisms and insertions and deletions. By contrast, there is little conservation in gene order between rice and Arabidopsis.

Arabidopsis↗
PubMed2002

Molecular cloning and characterization of CT120, a novel membrane-associated gene involved in amino acid transport and glutathione metabolism.

Within the minimum LOH region on chromosome 17p13.3 deleted in hepatocellular carcinoma, a novel human plasma membrane-associated gene, named CT120, was isolated from a human kidney cDNA library using electronical cloning and RACE. The novel gene CT120 consists of 2145bp and encodes a protein with 257 amino acids. Database search revealed that homologs of CT120 exist in different organisms from plant to animal kingdoms, which suggests that CT120 is a highly conserved gene during biological evolution. Different expression patterns of CT120 were observed in many different human normal tissues and in various human tumor cell lines. Transcript of CT120 was not detectable in normal lung tissue, but was abundant in SPC-A-1 (human epithelial-like lung adenocarcinoma) cell line, suggesting that CT120 may be involved in lung cancer development. Subcellular localization analysis showed that CT120 is a novel membrane-associated protein. CT120 can interact with SLC3A2 (member 2 of solute carrier family 3) and GGTL3B (isoform of gamma-glutamyltranspeptidase-like 3) in eukaryotic cells by yeast two-hybrid screen and co-immunoprecipitation assay, which suggested that CT120 may assume very essential physiological functions involved in amino acid transport and glutathione metabolism.

Amino Acid Sequence↗
PubMed2002

Quantitative study of macroscopic quantum tunneling in a dc SQUID: a system with two degrees of freedom.

To test whether the theory of macroscopic quantum tunneling (MQT) is applicable to systems with 2 degrees of freedom, we experimentally investigated the switching current distribution of a dc SQUID. Using sample parameters determined from measurements at T=4.2 K, we are able to make quantitative comparison to the theories from 8 mK to 4.2 K. The excellent agreement between the data and the MQT theory demonstrates that tunneling from the zero-voltage state of the dc SQUID is well described by the quantum mechanics.

Journal Article↗
PubMed2002

Abnormal spine morphology and enhanced LTP in LIMK-1 knockout mice.

In vitro studies indicate a role for the LIM kinase family in the regulation of cofilin phosphorylation and actin dynamics. In addition, abnormal expression of LIMK-1 is associated with Williams syndrome, a mental disorder with profound deficits in visuospatial cognition. However, the in vivo function of this family of kinases remains elusive. Using LIMK-1 knockout mice, we demonstrate a significant role for LIMK-1 in vivo in regulating cofilin and the actin cytoskeleton. Furthermore, we show that the knockout mice exhibited significant abnormalities in spine morphology and in synaptic function, including enhanced hippocampal long-term potentiation. The knockout mice also showed altered fear responses and spatial learning. These results indicate that LIMK-1 plays a critical role in dendritic spine morphogenesis and brain function.

Actin Cytoskeleton↗
PubMed2002

Vitamin E succinate inhibits the function of androgen receptor and the expression of prostate-specific antigen in prostate cancer cells.

Although epidemiological evidence indicates that a daily supplement of vitamin E may reduce the risk of prostate cancer, the detailed mechanism underlying this effect remains unclear. Here we demonstrate that alpha-tocopheryl succinate (VES) can suppress the expression of prostate-specific antigen (PSA), a marker for the progression of prostate cancer. VES can also suppress androgen receptor (AR) expression by means of transcriptional and posttranscriptional modulation, but not ligand binding, nuclear translocation, or AR dimerization. This VES-mediated inhibition of AR is selective because VES does not repress the expression of other nuclear receptors. Cell growth studies further show that VES inhibits the growth of prostate cancer LNCaP cells. In contrast, hydroxyflutamide (HF), an antiandrogen currently used to treat prostate cancer patients, only slightly inhibits LNCaP cell growth. Interestingly, simultaneous addition of HF and VES results in a more significant inhibition of LNCaP cell growth. Moreover, selenomethionine (SM), a prostate cancer treatment adjuvant, shows an inhibitory effect on LNCaP cell growth, yet has no effect on the AR/PSA pathway. Together, our data indicate that VES may suppress androgen/AR-mediated cell growth and PSA expression by inhibiting AR expression at both the transcription and translation levels. This previously undescribed mechanism may explain how VES inhibits the growth of prostate cancer cells and help us to establish new therapeutic concepts for the prevention and treatment of prostate cancer.

Androgen Receptor Antagonists↗
PubMed2002

Tetrakis[(4-aminopyridinio)acetato-kappa O]diaquamanganese(II) diperchlorate.

In the centrosymmetric title complex, [Mn(C(7)H(8)N(2)O(2))(4)(H(2)O)(2)](ClO(4))(2), the Mn(II) ion is in an octahedral environment, with the equatorial plane being defined by the O atoms of four monodentate carboxylate groups, and the octahedron being completed by two trans-coordinated water molecules. There are intramolecular hydrogen bonds between the coordinated water molecules and the non-coordinated O atoms of the carboxylate groups. Hydrogen bonds between the amino groups and the carboxylate groups of neighbouring molecules generate a layered hydrogen-bonded network.

Aminopyridines↗