Biomedical subjects

Z Zheng

Publications and source records attributed to Z Zheng.

At least 91 records · Page 5Linked to original sources

PubMed2000

[Abdominoplasty with a combined technique of lipectomy and liposuction].

OBJECTIVE: To evaluate an abdominoplasty technique combined with lipectomy and liposuction. METHODS: Twenty-five patients were undergoing for the abdominoplasty with lipectomy and liposuction in the same operation procedure. A public incision with W-shape was used for the lower abdominal lipectomy, and the upper abdomen was treated with an electronic liposuction technique. After the operation, each patient was followed up for evaluation of the results. RESULT: All of the patients got good contour of the abdomen without obvious complications. The abdominal perimeter was shrunk form 5 cm to 15 cm with over 3 months follow-ups. CONCLUSIONS: The combination of lipectomy and liposuction may be a good and safe method for abdominoplasty. The abdominal flap during the lipectomy could achieve higher survival rate than the traditional technique, due to the less injury on the neurovascular structures sustained by the liposuction procedure.

Abdominal Muscles↗

PubMed2000

[Effect of interaction between water and fertilizer on wheat and maize semiarid region of western Liaoning].

Using 312-D optimum design and quadratic general rotation design, the effect of interaction between water and fertilizer on wheat and maize yields was studied in semiarid region of western Liaoning Province. Reasonable combination of applying N and P fertilizers, irrigation, and mulching corn straws could increase crop yield remarkably, otherwise, it could not only increase cost, but also result in output reduction due to increasing crop stress to water or nutrients. Based on the results of the trials, the effects of the productive factors on crop yield were analyzed. The optimum economical combination of water and fertilizers fitting for local agriculture was put forward, i.e., water 120.2 mm, N 58.5 kg.hm-2, and P2O5 123.0 kg.hm-2 for wheat, and water 173.3 mm, N 256.5 kg.hm-2, P2O5 85.5 kg.hm-2, and straw mulching 8509.5 kg.hm-2 for maize.

Fertilizers↗

PubMed2000

[Flight capacity and facultative migration of cotton bollworm].

The flight capacity of moth cotton bollworm was studied by hanging flight installation. According to the flight rhythm and time, the individuals of population could be differentiated into long, medium, and short flight type. Laboratory stuies on the effect of temperature and food on pre-reproductive period, fecundity and life-span showed that the pre-reproductive period was only 2.13 +/- 0.67 days under 28 degrees C, and food or temperature had no significant effect on pre-reproductive period. The physiological period fitting for migration was quite short, only 1-2 nights. The population sources in Fengxian county, Jiangsu province and Chaoyang city, Liaoning province were studied by analysis of the dissecting of females ovary and the patterns of moth occurrence sequentially. The result indicated that the 2nd and 3rd generation moths in Chaoyang all or partly immigrated from other places, while in Fengxian, there was no migration. The flight capacity and reproductive characteristics of moth cotton bollworm were compared with other migratory or un-migratory species. The facultative migration and potential for migration of this species were discussed.

Animal Feed↗

PubMed2000

CT scanning and arthroscopic evaluation of patellofemoral malalignment.

OBJECTIVE: To determine the pattern of malalignment and the extent of chondral damage, the patellofemoral joint was evaluated by CT scanning and the findings were proved by arthroscopic examination. METHODS: In 20 cases, 40 knees were examined by CT scanning with and without quadriceps contraction in order to differentiate between static and dynamic abnormalities. The CT images were analyzed. The arthroscopic examination was carried out for 27 knees in 20 cases. RESULTS: Ten knees had static patellar lateral subluxation and 16 knees dynamic lateral subluxation. Eleven knees had static patellar lateral tilt, and 7 knees dynamic tilt. All of the 27 knees showed arthroscopic patellar maltracking and chondral damage. CONCLUSIONS: The patellofemoral alignment, affection of quadriceps, and the extent of tight retinaculum may be precisely evaluated by CT measurement and proved by arthroscopic examination.

Adult↗

PubMed2000

[Long-term therapeutic effects of extended radical resection and radical resection of cancer of cardia and stomach fundus].

OBJECTIVE: To study the best range of radical resection in the treatment of cancer of the cardia and fundus of stomach. METHODS: 418 patients with cancer of the cardia and fundus of stomach underwent radical resection. Of them 192 were treated by extended radical resection (extended group), and 226 by radical resection (radical group). The 5-year and 10-year survival rates were followed up and compared in the two groups. RESULTS: Analysis failed to demonstrate significant difference between the two operations for TNM stage I and II (P > 0.05). For stage III, however, the 5-year and 10-year survival rates in the extended group increased by 14.2% and 15.9% as compared with those in the radical group (P < 0.05). The two groups survival rates were similar for stage IV (P > 0.05). CONCLUSIONS: To completely clean the lymph nodes of splenic hilus and artery and improve long-term survival rate, extended radical resection including spleen and body and tail of the pancreas should be recommended for stage III patients with cancer of the cardia and fundus of stomach when their serosa was involved or lymph node metastasis took place.

Cardia↗

PubMed2000

[Effect of kidney tonifying and circulation promoting compound on transcription of T-cell apoptosis related Fas and FasL genes in aged rats].

OBJECTIVE: To probe the molecular mechanism for down-regulation of T-cell apoptosis by Kidney tonifying compound (KTC) in aged rats. METHODS: GAPDH was used as an internal control gene, and semi-quantitative analysis of the transcription of Fas and FasL genes was performed by using RNase protection assay. RESULTS: The Fas/GAPDH and FasL/GAPDH optical density (OD) ratios was 0.81 +/- 0.17 and 0.84 +/- 0.12 in the aged control group, and 0.36 +/- 0.16 and 0.26 +/- 0.12 in the young control group, the difference between the two groups was significant. In the circulation promoting group, the parameters were 0.99 +/- 0.36 and 0.94 +/- 0.33 which were not significantly different as compared with those in the aged control group (P > 0.05). In the two Kidney tonifying groups, the Fas/GAPDH OD ratio was 0.78 +/- 0.11 and 0.78 +/- 0.20, respectively, and no significant difference was observed as compared with those in the aged control group. However the FasL/GAPDH OD ratios in the two kidney tonifying group were 0.71 +/- 0.21 and 0.68 +/- 0.15, which were lower than those in the aged control group (P < 0.01). CONCLUSION: The negative regulation of FasL gene expression may be one of the molecular mechanisms of KTC in down-regulating excessive apoptosis of T-cell in aged rats.

Aging↗

PubMed2000

[Activities of superoxide dismutase in Xanthomonas oryzae pv. oryzae and its induction].

The activities of superoxide dismutase(SOD) in Xanthomonas oryzae pv. oryzae were determined to demonstrate the correlation of SOD activities with the bacterial virulence. In liquid culture, SOD activities of the tested strains reached the maxima at the end of lag phase and then declined. The virulent strain PXO99A showed higher SOD activities than the avirulent strain PXO99A (pBUavr Xa10.F1). Analysis on the subcellular location indicated that SOD activities detected from the cytoplasm and periplasm were over 70% and 20%-30% of the total, respectively. Treatment of the bacterial culture for 1 h with exogenous O2- at concentration of 50-800 mumol/L induced SOD activities of both the strains. The treatment with 200 mumol/L resulted in the highest SOD activities. The effect of exogenous O2- on SOD induction was more significant in 12 h-culture than in 24 h-culture, and more notable for the virulent strain PXO99A. The treatment with exogenous O2- resulted in significantly decreased survival rate off both the strains. The decreases of survival rate were greater in 24 h-culture than in 12 h-culture, and more significantly for the virulent strain than for the avirulent one.

Oryza↗

PubMed2000

[Study on the mechanism of hemocompatibility of titanium oxide films].

In this paper a study on the facts affecting blood compatibility of titanium oxide films synthesized by ion beam assisted deposition is presented, and the mechanism of blood compatibility is discussed. We think that the blood compatibility is determined by surface energy and work function of the film. The protein adsorption is determined by surface energy. An area with a range of values of polar and dispersion components of surface energies, where good protein adsorption property will exhibit, was defined. That is, more human serum albumin (HSA) and less human fibrinogen (HFG) will be adsorbed in this area. Work function is also an important factor to influence blood compatibility. Low work function can inhibit the decomposition of HFG and improve thromboresistance.

Adsorption↗

PubMed1999

Immortalization of human prostate epithelial cells by HPV 16 E6/E7 open reading frames.

BACKGROUND: The exact pathogenesis for prostate cancer is not known. Progress made in prostate cancer research has been slow, largely due to the lack of suitable in vitro models. Here, we report our work on the immortalization of a human prostate epithelial cell line and show that it can be used as a model to study prostate tumorigenesis. METHODS: Replication-defective retrovirus harboring the human papillomavirus (HPV) type 16 E6 and E7 open reading frames was used to infect primary human prostate epithelial cells. Polymerase chain reaction, followed by Southern hybridization for the HPV 16 E6/E7, Western blot for prostatic acid phosphatase, telomeric repeat amplification protocol assay for telomerase activity, two-dimensional gels for cytokeratins, and cytogenetic analysis were undertaken to characterized the infected cells. RESULTS: The retrovirus-infected cell line, HPr-1, continued to grow in culture for more than 80 successive passages. Normal primary cells failed to proliferate after passage 6. HPr-1 cells bore close resemblance to normal primary prostate epithelial cells, both morphologically and biochemically. However, they possessed telomerase activity and proliferated indefinitely. Cytogenetic analysis of HPr-1 cells revealed a human male karyotype with clonal abnormalities and the appearance of multiple double minutes. CONCLUSIONS: The HPr-1 cells expressed prostatic acid phosphatase and cytokeratins K8 and K18, proving that they were prostate epithelial cells. They were benign in nude mice tumor formation and soft agar colony formation assay. The HPr-1 cell line is an in vitro representation of early prostate neoplastic progression.

Acid Phosphatase↗

PubMed1999

Regulation of the expression of MHC class I and II by class II transactivator (CIITA) in hematopoietic cells.

In order to develop an effective immunotherapy for hematological malignancies, we investigated the applicability of class II transactivator (CIITA), which had been demonstrated to regulate the expression of MHC class II (MHC-II) by assembling the transcription factors of MHC-II molecules, for immunotherapy by potentiating the antigenicity of tumour cells by inducing MHC expression. First, 32 hematopoietic cell lines were analysed for the expression of HLA-DR, CIITA, RFX5 or HLA-ABC. Fourteen cell lines were positive and 18 were negative for HLA-DR. All the 14 HLA-DR positive cell lines were demonstrated to express CIITA mRNA by RT-PCR. On the other hand, in all the 18 HLA-DR negative cell lines, the expression of CIITA was not demonstrated. RFX5, which is one of the transcription factors of MHC-II, was expressed ubiquitously in all 32 cell lines. Three cell lines out of 23 hematopoietic cell lines examined were negative for HLA-ABC, and all three of these cell lines were negative for both HLA-DR and CIITA expression. Furthermore, CIITA cDNA was transfected into K562 cells, which were negative for HLA-ABC, -DR and -DQ, but positive for HLA-DP. The transfection rendered HLA-DR negative to positive and increased the expression level of HLA-DP, but HLA-DQ remained negative. In addition to HLA-DR, HLA-ABC was also induced to express by the transfection of CIITA gene. The present study demonstrated that the expression of HLA-DR in hematopoietic cells is regulated in subordination to CIITA and the expression of HLA-DR (and HLA-ABC in K562) is induced by transfection with the CIITA gene. These findings revealed the applicability of CIITA in potentiating anti-tumour immunity of HLA-DR negative tumour cells for immunotherapy of hematological malignancies.

Acute Disease↗

PubMed1999

Homeotic gene expression in the wild-type and a homeotic mutant of the moth Manduca sexta.

Antibodies were used to examine the expression patterns of Antennapedia (Antp), Ultrabithorax (Ubx), Ubx and abdominal-A combined (Ubx/abd-A), and Distalless (Dll) in the embryos of the moth Manduca sexta. We found that the spatial and temporal pattern of Antp expression in Manduca was correlated with the anterior migration of two patches of epithelium that include the anterior-most tracheal pits, and with the development of functional spiracles. Ubx expression showed an intricate pattern which suggests complex regulation during development. Throughout Manduca embryogenesis the expression of Ubx/Abd-A and Dll was similar to that reported for other insects. However, there was no apparent reduction in Ubx/Abd-A expression in the Manduca abdominal proleg primordia that expressed Dll. The expression of these four proteins was also examined in embryos of the Manduca homozygous homeotic mutant Octopod (Octo). The Octo mutation results in the transformation of A1 and A2 in the anterior direction, with homeotic legs appearing on A1 and occasionally A2. Our results suggest that in Octo animals there is a reduction in the level of Ubx protein expression throughout its domain. Based on homeotic gene expression in wild-type and mutant Manduca and in other insects, we discuss potential roles of homeotic genes in insect morphological evolution.

Amino Acid Sequence↗

PubMed1999

Downregulation and abnormal expression of E-cadherin and beta-catenin in nasopharyngeal carcinoma: close association with advanced disease stage and lymph node metastasis.

Nasopharyngeal carcinoma (NPC) is predominantly of the undifferentiated histological subtype. Histological differentiation is of limited prognostic significance in NPC. Recent studies have suggested that downregulation of the cadherin-catenin cell adhesion complex may play a crucial role in the initial stage of cancer invasion and metastasis and is associated with poor prognosis in human cancers. Expression of E-cadherin has not been reported previously in NPC, and its prognostic value in NPC is unknown. The purpose of this study was to examine the expression pattern of E-cadherin and its associated partner, beta-catenin, in NPC and their possible applications as prognostic markers to predict the clinical outcome of NPC. Expression of the E-cadherin and beta-catenin was examined by immunohistochemical methods in 74 cases of primary NPC and 17 of their corresponding lymph node metastases. Normal nasopharyngeal epithelium showed strong and homogeneous immunocytochemical staining of E-cadherin and beta-catenin at the cell membranes and intercellular junctions. In contrast, primary NPC showed variable and heterogeneous staining patterns of E-cadherin and beta-catenin. Loss of membranous E-cadherin expression was significantly associated with advanced stages of diseases (P<.001). Eighty percent to ninety percent of NPC in stages IV and V (Ho's staging), respectively, showed a reduced (<35%) membranous staining of E-cadherin compared with normal nasopharyngeal epithelium. Expression of beta-catenin also was downregulated in advanced NPC. Ninety percent to one hundred percent of NPC in stages IV and V (Ho's staging) expressed a reduction (<35%) of imnmunocytochemical staining of beta-catenin. The expression pattern of beta-catenin staining was strongly associated with the expression of E-cadherin (P<.001). Unlike E-cadherin, nuclear staining of beta-catenin expression was observed in some of the primary NPC and lymph node metastasis. Reduced expression of E-cadherin and beta-catenin expression was associated with a shorter survival of NPC patients (P<.001). In advanced NPC patients (stages IV and V), a significant difference in survival was observed in tumors with higher or lower levels of E-cadherin expression (P=.0224, log-rank test). These observations suggests that expression of E-cadherin and beta-catenin may have prognostic values in NPC patients.

Adult↗

PubMed1999

Co-cultivation of CD4+ and CD8+ human T-cells leads to the appearance of CD4 cells expressing CD8 through de novo synthesis of the CD8 alpha-subunit.

The appearance of a population of dual-staining CD4+CD8+ cells in human T-lymphocyte cultures has been reported by various authors, including our own observation that they are always seen in simple phytohaemagglutinin-stimulated cultures from several different donors. The purpose of the present study was to investigate factors involved in the dual-staining (DS) phenotype, and to clarify some apparent inconsistencies between published observations. Our findings can be summarised as follows. 1. A population of DS CD4+CD8+ cells always appears in PHA-stimulated T-cell cultures if they contain both CD4 and CD8 subsets. The incidence of DS cells is related to PHA concentration, but other factors are involved since DS cells are not seen in PHA-stimulated cultures of purified CD4+ or CD8+ cells. Stimulation with PHA is not a prerequisite since very similar results are seen with ConA. 2. Direct physical contact between CD4+ and CD8+ cells is required for the appearance of the DS phenotype; soluble factors alone, including IL-4, appear nor to be responsible. 3. The DS phenotype in these conditions is always CD4+ cells weakly expressing CD8 and is a consequence of de novo synthesis of the CD8alpha molecule by the CD4+ cells.

Apoptosis↗

PubMed1999

Stimulation of benzyladenine-induced in vitro shoot organogenesis and endogenous proline in melon (Cucumis melo L.) by fish protein hydrolysates in combination with proline analogues.

A previous study demonstrated that proline is beneficial for improving melon in vitro shoot organogenesis. A natural source of proline and proline precursors can be obtained from fish protein hydrolysates (FPH), a byproduct of the fishery industry. Proline analogues azetidine-2-carboxylate and hydroxyproline in combination with standardized FPH were used to stimulate proline synthesis and benzyladenine-induced shoot organogenesis by exploiting the proposed proline-linked pentose phosphate pathway (PPP). In the presence of elevated levels of endogenous proline, potential stimulation of cytokinins and auxin may occur via the PPP and shikimate pathways, respectively. Treatments with FPH singly and in combination with the above proline analogues significantly increased the endogenous proline content and the extent of differentiation, suggesting that in vitro organogenesis is closely linked to proline synthesis, strengthening the hypothesis that purine metabolism via the proline-linked PPP may be important for organogenesis. Thioproline addition resulted in increased proline levels but without corresponding stimulation of organogenesis. This study also provides potential use of fishery waste for value-added application in plant micropropagation industry.

Adenine↗

PubMed1999

Preparation and characterization of new electrocardiogram electrodes.

A new generation of electrocardiogram (ECG) electrodes have been fabricated and superficially modified by a special controlled precorrosion process. The electrodes have been characterized by scanning electron microscopy (SEM), resistance-capacitance measurements (RCM) and simulated defibrillation recovery (SDR). The resulting surface of the Sn alloys was rough, and, consequently, a large active surface area was available. As a result, a higher electrocardiogram electrode performance, including low alternating current (a.c.) impedance, excellent time stability and improved SDR, was achieved. Such new design can surely find important future applications in clinical diagnosis.

Journal Article↗

PubMed1999

Generation of bcr-abl specific cytotoxic T-lymphocytes by using dendritic cells pulsed with bcr-abl (b3a2) peptide: its applicability for donor leukocyte transfusions in marrow grafted CML patients.

Dendritic cells (DC), the most potent 'professional' antigen-presenting cells, hold promise for improving the immunotherapy of cancer. In this study, we investigated the ability of normal donor DC pulsed ex vivo with 12 mer bcr-abl (b3a2) peptide to generate b3a2-specific autologous or HLA-identical sibling donor's cytotoxic T-lymphocytes (CTL). DC that were grown from normal peripheral blood adherent cells or purified DC precursors in the presence of GM-CSF and IL-4, were pulsed with b3a2-peptide then were induced to become mature and functional cells by the addition of TNF-alpha. These peptide-pulsed mature DC elicited a potent b3a2-specific CTL response in vitro. The b3a2-peptide pulsed DC-primed peripheral blood lymphocytes (PBL) displayed significantly higher cytotoxic activity compared with peptide non-pulsed DC-primed PBL against target cells, which are b3a2 positive marrow cells derived from HLA-identical sibling chronic myelogenous leukemia (CML) patient, or peptide-pulsed autologous macrophages (P < 0.001). In addition, the b3a2 peptide-pulsed DC-primed and non-pulsed DC-primed PBL showed no cytotoxic response against peptide non-pulsed autologous macrophages. These findings revealed that normal donor PBL pre-immunized with b3a2-peptide pulsed autologous DC could increase the graft-versus-leukemia effect without exaggerating graft-versus-host-disease. Both CD8+ and CD4+ T lymphocytes were shown to be involved in the effector cell populations. The b3a2 peptide-pulsed DC-primed T cells were significantly superior in their production of GM-CSF and TNF-alpha compared with peptide non-pulsed DC-primed T cells. These intriguing preclinical results imply the feasibility of developing b3a2 peptide-DC based protocol for in vitro sensitization of normal donor leukocytes before donor leukocyte transfusions for patients with CML, who relapsed after HLA-matched sibling bone marrow transplantation.

Blood Donors↗

PubMed1999

Lack of drug interaction between omeprazole, lansoprazole, pantoprazole and theophylline.

AIMS: Theophylline is a model substrate of cytochrome P4501A2. The ability of the proton pump inhibitors (PPI) omeprazole, lansoprazole and pantoprazole to induce cytochrome P4501A2 has not yet been unequivocally resolved. The aim of this comprehensive study was to compare directly the effect of the three PPI on the absorption and disposition of theophylline. METHODS: Twenty healthy, nonsmoking, male and female volunteers (extensive metabolisers of cytochrome P4502C19 and Helicobacter pylori negative) participated in a randomized, double-blind, four-period, placebo-controlled crossover study. In each of the four periods they received either omeprazole (40 mg), lansoprazole (60 mg), pantoprazole (80 mg) or placebo once daily for 10 days. Sustained release theophylline (350 mg twice daily) was coadministered from day 8-10. Pharmacokinetics of theophylline as well as of all three PPI were determined at steady-state (day 10). RESULTS: In all periods, point estimates and 90% confidence intervals of the area under the concentration-time curves (AUC), maximum steady-state concentrations and peak-trough fluctuations of theophylline were not altered by PPI pretreatment and met the required limits for bioequivalence. Point estimates (90% confidence intervals) of the AUC ratios of theophylline plus PPI to theophylline alone were 0.92 (0.87-0.97), 0.90 (0.85-0.95) and 1.00 (0.95-1.06) for omeprazole, lansoprazole and pantoprazole, respectively. CONCLUSIONS: Concomitant intake of omeprazole, lansoprazole or pantoprazole at high therapeutic doses does not affect the absorption and disposition of theophylline.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed1999

Recombinant fusion protein and DNA vaccines against foot and mouth disease virus infection in guinea pig and swine.

In this study, we provide evidence that a recombinant fusion protein containing beta-galactosidase and a tandem repeat peptide of immunogenic dominant epitope of foot-and-mouth disease virus (FMDV) VP1 protein elicits high levels of neutralizing antibody and protects both guinea pigs and swine against infection. Vaccination with this fusion protein induced a FMDV-specific proliferative T-cell response and a neutralizing antibody response. The immunized guinea pigs and swine were protected against FMD type O virus infection. Two DNA plasmids expressing genes of foot-and-mouth disease were constructed. Both plasmids pBO1 and pCO1 contain a signal sequence of the swine immunoglobulin G (IgG) gene and fusion protein gene of pXZ84. The signal sequence and fusion protein gene were under the control of a metallothionein promoter in the case of the pBO1 plasmid and under the control of a cytomegalovirus immediate early promoter in the case of pCO1 plasmid. When pBO1 and pCO1 were inoculated intramuscularly into guinea pigs, both plasmids elicited a neutralizing antibody response and spleen cell proliferation increased following stimulation with FMDV antigen, but animals were not protected from viral challenge.

Animals↗