Search PubMed⌕ Search

Biomedical subjects

Peng Zhang

Publications and source records attributed to Peng Zhang.

At least 181 records · Page 10Linked to original sources
PubMed2004

[Clinical effects of preoperative chemotherapy for Wilms tumor].

OBJECTIVE: To evaluate the effects of preoperative chemotherapy for Wilms' tumor. METHODS: Thirty-five surgically treated cases of Wilms tumor were retrospectively analyzed, 27 of which received preoperative chemotherapy. RESULTS: After chemotherapy, the tumor volume reduced obviously in 17 cases and adverse effects of the chemotherapeutic agents occurred in 15 cases. Subsequent operation was performed in all the patients, of whom 1 died during the operation, 4 had delayed healing of the incisions and 5 still had decreased leucocytes. CONCLUSIONS: Chemotherapy before the operation for Wilms tumor can effectively reduce the complications of the operation. Appropriate chemotherapy protocol and vigorous conservative drug therapy help prevent the occurrence of adverse effects and complications of the chemotherapy.

Adolescent↗
PubMed2004

[Reversal effect of tetrandrine in combination with droloxifene on cell line K562/A02 and its correlation with inducted apoptosis].

To study the correlation of the reversal effect of tetrandrine (Tet) in combination with droloxifene (DRL) on multidrug resistant cell line K562/A02 and induction apoptosis, the apoptosis of K562 cells and K562/A02 cells after the treatment of Tet and DRL alone or their combination was detected by flow cytometry (FCM). The results showed 0.62 microg/ml Tet and 1.94 microg/ml DRL alone could induce apoptosis of K562 cells in time-dependent manner after culture for 48 hours. Neither Tet at 0.62 microg/ml nor DRL at 1.94 microg/ml alone could induce apoptosis of K562/A02 cells, but in the combination of them two induced apoptosis of few K562/A02 cells in culture for 72 hours. In conclusion, the mechanism of Tet and DRL reversing multidrug resistance has no correlation with the apoptosis of K562/A02 cells.

Alkaloids↗
PubMed2004

[Experimental study on effect of erzhi tiangui recipe on quality of oocyte in mice].

OBJECTIVE: To observe the effect of Erzhi Tiangui recipe (ETR) on quality of oocyte in the process of external fertilization and embryo-transplantation. METHODS: Eighty mice were randomly divided into 4 groups, Group A treated with ETR plus human menopausal gonadotropin (HMG), Group B with ETR, Group C with HMG and Group D with normal saline. Ovulation test and cleavage test were conducted to observe the effect of treatment on quality of oocytes. RESULTS: The difference on ovulation number between Group A and C was insignificant, but the difference in comparison between the two groups was significant in aspects of oocyte morphological scoring, fertilization rate and cleavage rate (P<0.05). CONCLUSION: ETR could play its effect synergistically with Western medicine, and raise the quality of oocytes.

Animals↗
PubMed2004

[Generation of T cell-mediated antitumor response in vitro by autologous dendritic cells pulsed with tumor lysates in patients with non-small cell lung cancer].

OBJECTIVE: To investigate whether dendritic cells pulsed with whole tumor lysates (WTL) could in vitro elicit antitumor T cell responses in patients with non-small-cell lung cancer (NSCLC). METHODS: Monocyte-derived immature DCs (imDCs) generated in the presence of human recombinant granulocyte-macrophage colony stimulating factor and interleukin-4 from peripheral blood mononuclear cell of NSCLC patients, and then were induced to mature by pulsing autologous WTL (DCs/WTL) or by the addition of TNF-alpha(TNF/DCs). FACS and MLR assay were used to monitor their phenotypic changes and capacity to stimulate allogeneic and autologous T cell proliferation. DCs/WTL activated with TNF-alpha (* DCs/WTL) were cocultured in vitro with autologous T cells for eliciting antitumor CTLs. T cell mediated antitumor responses were measured by IFN-gamma enzyme-linked immunospot (ELISPOT) assay for WTL-specific IFN-gamma releasing T cells and by lactate dehydrogenase release (LDH) assay for lysis of autologous tumor cells, respectively. RESULTS: When monocytes-derived imDCs from the patients with NSCLC (n = 10) were pulsed with autologous WTL for a day at 30 microg total protein of WTL per 10(6) DCs/ml, this led to up-regulation of CD1a, CD83 and CD86 as well as HLA-DR, and also led to marked stimulation of allogeneic T cell proliferating activity, which was comparable to that of TNF/DCs. However, their capacity of stimulating autologous T cell proliferation in vitro was significantly more potent than those of TNF/DCs (P < 0.05). The numbers of WTL-specific IFN-gamma releasing T cells in 1/3 cultures after one week exposure to * DCs/WTL was increased significantly compared with those pulsing with TNF/DCs plus IL-2 or IL-2 alone (P = 0.05). T cells derived by priming of non-adherent PBMCs with * DCs/WTL after 14 days in vitro stimulation were significantly more responsive to autologous tumor cells compared with LAK (n = 3, P < 0.05), but its cytotoxicity against K562 cells was also comparable to LAK cells. CONCLUSION: Monocyte-derived DCs from NSCLC patients could serve as functional APC. The * DCs/WTL may effectively elicit T cell-mediated antitumor response in vitro and enhance NK killing activity.

Antigens, CD1↗
PubMed2004

[The influence of combined supplementation of glutamine and recombinant human growth hormone on the protein metabolism in severely burned patients].

OBJECTIVE: To investigate the influence of combined supplementation of glutamine (Gln) and recombinant human growth hormone (rhGH) on the protein metabolism in severely burned patients. METHODS: Sixty severely burned patients were enrolled in the study and were randomly divided into control (C, n = 20) and Gln with rhGH (Gln + rhGH, n = 20) groups. The patients in C group received glycine as the placebo, while those in Gln group took Gln orally in dose of 0.5 g kg(-1) d(-1) during 1-14 postburn days (PBDs). For the patients in Gln + rhGH group rhGH was administered subcutaneously in dose of 0.2 U kg(-1) d(-1) in addition to glutamine in same dosage beginning on the 7 PBD for 7 days. The plasma Gln concentration in the 3 groups of patients was determined on the 1st, 7th and 14th PBD and the plasma albumin level was determined on 14th and 21st PBD. The wound healing rate of the patients within 30 PBSs and the total hospital stay days were recorded. RESULTS: The plasma Gln concentration in Gln + rhGH group of patients was evidently higher than that in C group after 7 PBD[(452.28 +/- 21.72) micromol/L vs(325.12 +/- 25.34) micromol/L, P < 0.05]. The plasma albumin level in Gln + rhGH group was obviously higher than that in C and Gln groups on the 21st PBD (P < 0.05). The wound healing rate in Gln + rhGH group was evidently higher than that in Gln and C groups on the 30th PBD (P < 0.05). The total hospital stay days in Gln + rhGH group were obviously less than that in C and Gln groups (P < 0.05 or 0.01). CONCLUSION: Combined administration of Gln and rhGH could be beneficial to the elevation of plasma Gln level in severely burned patients and the systemic protein synthesis was therefore enhanced and the wound healing rate was improved.

Adult↗
PubMed2004

Neither the tumor necrosis factor alpha-308 A/G polymorphism nor the alpha2-macroglobulin polymorphism was associated with late-onset Alzheimer's disease in the Chinese population.

Late-onset Alzheimer's disease (LOAD) is the most common cause of dementia in the elderly. It is a complex and genetically heterogeneous disorder. Epidemiological studies demonstrated that nonsteroidal anti-inflammatory drugs could prevent or delay the onset of LOAD suggesting inflammation may be involved in AD. Tumor necrosis factor (TNF) is a potent immunomodulator and it might increase the production of amyloid beta(Abeta), which makes it an appropriate AD candidate gene. Alpha2 macroglobulin (A2M) is a serum protease inhibitor and a major low-density lipoprotein receptor-related protein (LRP) ligand. It can bind Abeta and mediate its clearance and degradation, suggesting it might be another AD candidate gene. In the present study, we analyzed the a 5 bp Ins/Del polymorphism of A2M gene (A2M-2), TNF alpha-308 A/G polymorphism and apolipoprotein E (APOE) polymorphisms of 67 sporadic late-onset AD patients and 142 normal elderly controls in the Chinese population. Our data showed that the APOE epsilon4 allele frequency in AD was significantly higher than that in the normal controls (chi2 = 11.66, P < 0.01) neither the frequencies of genotypes nor alleles of the TNF alpha-308 A/G and A2M polymorphisms were significantly different between AD and controls,suggesting the two polymorphisms were not risk factors to LOAD in Chinese.

Aged↗
PubMed2004

[Identification and analysis of F2 stable population derived from the cross of triploid x diploid in rice].

Polyploid strain 149-B, that was generated naturally from a rice twin-seedling population SAR-2, has been determined as triploid (2n = 36). It was then used as the female parent crossing with a normal diploid variety SH R363. From its F2 generation we obtained a genetic-stable population. To prove the uniformity of such a population, SSR markers were used to survey the F2 individual plants. The results showed that F2 individuals carried only one parental molecular marker at each polymorphic locus, and their genotypes were identical with F1 progeny. Based on the above experiments, we consider that this F2 population is definitely an early-generation stable population. Meanwhile, we discussed the possible mechanism of the special phenomenon as well.

Crosses, Genetic↗
PubMed2004

[Study on large-scale CD34+ cell enrichment using immunomagnetic isolation apparatus].

In order to find a method suitable for purifying large amount of CD34(+) cells, from 5 cases who accepted autologous peripheral blood stem cell transplantation, CD34(+) cells were collected and enriched by using Isolex 300i (Nexell). Phenotypes were detected by flow cytometry and the biological viability were assayed by the colony-forming experiments and cell expansion experiment in vitro. The results showed that the number of mononuclear cells first collected was about (3.5 - 6.0) x 10(10) and (0.55 - 1.2)% of cells were CD34 positive. The number of positive production was about (2.0 - 3.0) x 10(8); the CD34(+) cells purity was (75 - 85)% and the yield was (40 - 65)%. The CD34(+) cells of positive production could expand up to 2 - 3 times when cultured with SCF + IL3 + FL + TPO + EPO in vitro. The results of colony-forming experiments demonstrated that the CD34(+) cells collected has enough colony-forming ability. All results showed the enriched CD34(+) cells with biological viability. In conclusion, the CD34(+) immunomagnetic isolation apparatus Isolex300i is suitable to clinical application for a large amount of CD34(+) cell enrichment.

Antigens, CD34↗
PubMed2003

Cadmium sulfide nanocrystals via two-step hydrothermal process in microemulsions: synthesis and characterization.

CdS nanocrystals with an average diameter of 16 nm were synthesized in the CTAB/n-C(5)H(11)OH/n-C(6)H(14)/water quaternary microemulsions by a two-step hydrothermal process at 90 and 130 degrees C. The reaction of carbamide and carbon disulfide was employed as the sulfur source for the preparation of CdS nanocrystals. The resulting crystals were characterized with powder X-ray diffraction, transmission electron microscopy, UV-vis absorption spectroscopy, and photoluminescence spectroscopy. A unique core/shell structure of CdS nanocrystals was suggested for the explanation of the interesting phenomenon.

Journal Article↗
PubMed2003

Association study between late-onset Alzheimer's disease and the transferrin gene polymorphisms in Chinese.

To investigate the possible involvement of the transferrin (TF) gene polymorphism in the manifestation of Alzheimer's disease (AD), we analyzed the TF and apolipoprotein E (APOE) genotypes of 67 sporadic late-onset AD patients and 131 normal elderly controls in the Chinese population. Our data showed that the TF C1 homozygosity carriers had an increased risk of AD in subjects > or =75 years of age, showing that homozygosity for the TF C1 allele was associated with an approximately three-fold increased risk (OR=3.57, 95% CI, 1.24-10.27, P=0.014). No synergic effects were found between the APOE epsilon 4 allele and TF gene polymorphisms.

Age Factors↗
PubMed2003

Two cassava promoters related to vascular expression and storage root formation.

Cassava ( Manihot esculenta Crantz) storage roots, organs accumulating large amounts of starch, develop from primary roots via secondary growth. The availability of promoters related to storage-root formation is a prerequisite for engineering root traits in cassava. Two cDNAs, c15 and c54, were identified from a storage-root cDNA library of cassava MCol1505 via differential screening. The transcripts of c15 and c54 were detected in storage roots but not in leaves by Northern analysis. Homology analysis of the deduced amino acid sequences showed that C15 is likely to be related to cytochrome P450 proteins, which are involved in the oxidative degradation of various compounds, while C54 may be related to Pt2L4, a cassava glutamic acid-rich protein. The promoter regions of c15 and c54 were isolated from the corresponding clones in a cassava genomic library. A 1,465-bp promoter fragment ( p15/1.5) of c15 and a 1,081-bp promoter region ( p54/1.0) of c54 were translationally fused to the uidA reporter gene, and introduced into cassava and Arabidopsis thaliana (L.) Heynh. The expression patterns of p15/1.5::uidA and p54/1.0::uidA in transgenic plants showed that both promoters are predominantly active in phloem, cambium and xylem vessels of vascular tissues from leaves, stems, and root systems. More importantly, strong beta-glucuronidase activity was also detected in the starch-rich parenchyma cells of transgenic storage roots. Our results demonstrate that the two promoters are related to vascular expression and secondary growth of storage roots in cassava.

Amino Acid Sequence↗
PubMed2003

Different evolutionary patterns between young duplicate genes in the human genome.

BACKGROUND: Following gene duplication, two duplicate genes may experience relaxed functional constraints or acquire different mutations, and may also diverge in function. Whether the two copies will evolve in different patterns remains unclear, however, because previous studies have reached conflicting conclusions. In order to resolve this issue, by providing a general picture, we studied 250 independent pairs of young duplicate genes from the whole human genome. RESULTS: We showed that nearly 60% of the young duplicate gene pairs have evolved at the amino-acid level at significantly different rates from each other. More than 25% of these gene pairs also showed significantly different ratios of nonsynonymous to synonymous rates (Ka/Ks ratios). Moreover, duplicate pairs with different rates of amino-acid substitution also tend to differ in the Ka/Ks ratio, with the fast-evolving copy tending to have a slightly higher Ks than the slow-evolving one. Lastly, a substantial portion of fast-evolving copies have accumulated amino-acid substitutions evenly across the protein sequences, whereas most of the slow-evolving copies exhibit uneven substitution patterns. CONCLUSIONS: Our results suggest that duplicate genes tend to evolve in different patterns following the duplication event. One copy evolves faster than the other and accumulates amino-acid substitutions evenly across the sequence, whereas the other copy evolves more slowly and accumulates amino-acid substitutions unevenly across the sequence. Such different evolutionary patterns may be largely due to different functional constraints on the two copies.

Amino Acid Substitution↗
PubMed2003

[Cardioprotective effects of diltiazem infusion in the perioperative period in patients undergoing coronary artery bypass grafting with extracorporeal circulation].

OBJECTIVE: To evaluate the cardioprotective effects of intravenous diltiazem infusion perioperatively in patients undergoing coronary artery bypass grafting (CABG) under extracorporeal circulation. METHODS: Forty patients undergoing CABG were divided into 2 groups of 20 patients according to the operation date: experimental group in which infusion of diltiazem (0.1 mg/kg/h) was given starting from the onset of extracorporeal circulation until 24 h after the aortic cross-clamping, and blank control group. The relative hemodynamic parameters were recorded for 48 hours. RESULTS: (1) 4 approximately 24 hours after the aortic cross-clamping the heart rates of the experimental group was 98 +/- 18 approximately 96 +/- 13 times/min, significantly lower than those of the control group (111 +/- 16 approximately 105 +/- 14 times/min, P<0.05); the values of rate-pressure product (RPP) of the experimental group were 13.0 +/- 3.7 approximately 11.7 +/- 3.0 mm Hg/min/10(3), significantly lower than those of the control group (14.1 +/- 1.9 approximately 5.8 +/- 3.6 approximately mm Hg/min/10(3), P<0.05) (2) The postoperative peak value of creatine kinase (CK) was not significantly different between these 2 groups. The postoperative peak value of creatine kinase-MB (CK-MB) in the experimental group was 83 +/- 33 IU/L, significantly lower than that in the control group (105 +/- 20 IU/L, P<0.05) and postoperative peak value of cardiac troponin-T (cTNT) was 0.38 +/- 0.21 IU/L, significantly lower than that in the control group (0.83 +/- 0.20 IU/L, P<0.05). The values of CK, CK-MB, and cardiac troponin TC (cTNT) of the patients with coronary vasospasm in the experimental group were all significantly lower than those of the patients with coronary vasospasm in the control group. (3) The average number of arrhythmic events per hour was lower in diltiazem group, and the average number of ventricular premature contraction per hour was significantly lower during the period of ST segment depression in particular. CONCLUSION: Perioperative intravenous diltiazem infusion provides significant cardioprotective effect in patients undergoing CABG.

Arrhythmias, Cardiac↗
PubMed2003

Optical masks prepared by using a liquid-crystal light valve for light-induced photorefractive waveguides.

The optical mask prepared by using a LCLV (liquid-crystal light valve) are first proposed for light-induced photoreactive waveguides in photorefractive materials. Employing this technique, various waveguide structures can be fabricated, e.g., Y- or multiple-branches waveguides, fiber-like waveguides, and Mach-Zehnder-like switches, and even whole optical circuits may be formed. A Y-branches waveguide and a fiber-like waveguide were demonstrated in a LiNbO3:Fe crystal. Several technical problems, such as intensities, resolutions, writing speed, and so on, were also discussed in detail. Using a LCLV with a fast response and a writing beam with a high intensity, the waveguide structures may be changed in real time.

Journal Article↗
PubMed2003

X-ray studies of the structure and electronic behavior of alkanethiolate-capped gold nanoparticles: the interplay of size and surface effects.

We report a study of the structure and electronic properties of a series of thiol-capped Au nanoparticles (NP) of nominal sizes of 1.6, 2.4, and 4.0 nm. Transmission electron microscopy, x-ray powder diffraction, x-ray absorption fine structure, and x-ray photoemission spectroscopy have been used to investigate the size-dependent systematics of lattice contraction and charge redistribution of these NPs. It is found that the lattice contracts and the d charge at the Au atom site depletes relative to bulk Au as the size of the NP decreases. The implication of these observations is discussed in terms of the interplay of quantum-size and surface effect.

Journal Article↗