Biomedical subjects

F Zhang

Publications and source records attributed to F Zhang.

At least 217 records · Page 12Linked to original sources

PubMed2000

Detection of human cytomegalovirus pp67 late gene transcripts in cerebrospinal fluid of human immunodeficiency virus type 1-infected patients by nucleic acid sequence-based amplification.

This study examined the clinical correlation between the presence of human cytomegalovirus (HCMV) pp67 mRNA in cerebrospinal fluid (CSF) and active HCMV central nervous system (CNS) disease in patients with human immunodeficiency virus type 1 (HIV-1). In total, 76 CSF specimens collected from 65 HIV-1-positive patients diagnosed with HCMV CNS disease, other non-HCMV-related CNS diseases, or no CNS disease were tested for the presence of HCMV pp67 mRNA using the NucliSens cytomegalovirus (CMV) pp67 assay (Organon Teknika, Durham, N.C.). The results were compared to those of a nested PCR for the detection of HCMV glycoprotein B DNA and to those obtained by viral culture (54 samples). CSF specimens collected from patients without HCMV CNS disease yielded the following results: pp67 assay negative, 62 of 62 specimens; culture negative, 41 of 41 specimens; and PCR negative, 56 of 62 specimens (6 specimens were positive). CSF specimens collected from patients with HCMV CNS disease yielded the following results: pp67 assay positive, 9 of 13 specimens; PCR positive, 13 of 13 specimens; and culture positive, 2 of 13 specimens. After resolution of the discordant results, the following positive and negative predictive values (PPV and NPV, respectively) for the diagnosis of HCMV CNS disease were determined. The PPV for PCR, pp67 assay, and culture were 68.4, 100, and 100%, respectively, and the NPV for PCR, pp67 assay, and culture were 100, 97.0, and 82. 7%, respectively. The sensitivities for DNA PCR, pp67 assay, and culture for the detection of HCMV were 100, 84.6, and 18%, respectively, and the clinical specificities were 90.5, 100, and 100%, respectively. This study indicates that the detection of HCMV pp67 mRNA in CSF has good correlation with active HCMV CNS disease, whereas CSF culture is insensitive and qualitative DNA PCR may detect latent nonreplicating virus in CSF from patients without HCMV CNS disease.

AIDS-Related Opportunistic Infections↗

PubMed2000

Resistance to Friend murine leukemia virus infection conferred by the Fv-4 gene is recessive but appears dominant from the effect of the immune system.

Fv-4 is a mouse gene that dominantly confers resistance to infection with Friend murine leukemia virus (F-MuLV) (S. Suzuki, Jpn. J. Exp. Med. 45:473-478, 1975). However, the resistance caused by Fv-4 is recessive in nude mice, which suggests that immunological effects play important roles in this resistance in vivo (K. Higo, Y. Kubo, Y. Iwatani, T. Ono, M. Maeda, H. Hiai, T. Masuda, K. Kuribayashi, F. Zhang, T. Lamin, A. Adachi, and A. Ishimoto, J. Virol. 71:750-754, 1997). To determine the immunological effect on the resistance in vivo, we infected immunologically immature newborn mice homozygous (Fv-4(r/r)) and heterozygous (Fv-4(r/-)) for Fv-4. Although the Fv-4(r/r) mice showed complete resistance to F-MuLV whether infected neonatally or as adolescents, the Fv-4(r/-) mice showed high sensitivity to viral proliferation and disease induction when infected as newborns but complete resistance when infected as adolescent mice. To confirm the immunological effect on the resistance in adolescent mice with the Fv-4(r/r) and Fv-4(r/-) genotypes, we examined the effect of an immunosuppressant drug, FK506, on the resistance. The mice with the Fv-4(r/r) genotype treated with FK506 still showed resistance, but the mice with the Fv-4(r/-) genotype became highly sensitive to F-MuLV infection. Flow cytometric analysis to detect the Fv-4 gene product showed that the Fv-4 gene product was expressed on the cells from newborn and adolescent mice. The Fv-4 gene product was also detected on the cells from the FK506-treated mice as well as on those from untreated mice. However, a quantitative difference in the gene product between the cells with the Fv-4(r/r) and Fv-4(r/-) genotypes was detected by indirect staining for flow cytometry. These results show that the resistance to F-MuLV infection conferred by the Fv-4 gene is originally recessive, but it looks dominant in adolescent mice mainly because of the effect of the immune system.

Animals↗

PubMed2000

E2F is required to prevent inappropriate S-phase entry of mammalian cells.

E2F is a family of transcription factors that regulates the cell cycle. It is widely accepted that E2F-mediated transactivation of a set of genes is the critical activity that governs cellular progression through G(1) into S phase. In contrast to this hypothesis, we demonstrate that E2F actually suppresses the onset of S phase in two cell types when the cells are arrested by gamma irradiation. Our findings indicate that in these cells, the critical event triggering progression from G(0)/G(1) arrest into S phase is the release of E2F-mediated transrepression of cell cycle genes, not transactivation by E2F. Furthermore, our data suggest that E2F-mediated transactivation is not necessary for the G(1)/S-phase transition in these cells.

Animals↗

PubMed2000

Angiogenesis and morphogenesis of murine fetal distal lung in an allograft model.

Neovascularization is crucial to lung morphogenesis; however, factors determining vessel growth and formation are poorly understood. The goal of our study was to develop an allograft model that would include maturation of the distal lung, thereby ultimately allowing us to study alveolar development, including microvascular formation. We transplanted 14-day gestational age embryonic mouse lung primordia subcutaneously into the back of nude mice for 3.5-14 days. Lung morphogenesis and neovascularization were evaluated by light microscopy, in situ hybridization, and immunohistochemical techniques. Embryonic 14-day gestational age control lungs had immature structural features consistent with pseudoglandular stage of lung development. In contrast, 14 days after subcutaneous transplantation of a 14-day gestational age lung, the allograft underwent significant structural morphogenesis and neovascularization. This was demonstrated by continued neovascularization and cellular differentiation, resulting in mature alveoli similar to those noted in the 2-day postnatal neonatal lung. Confirmation of maturation of the allograft was provided by progressive type II epithelial cell differentiation as evidenced by enhanced local expression of mRNA for surfactant protein C and a threefold (P < 0.008) increase in vessel formation as determined by immunocytochemical detection of platelet endothelial cell adhesion molecule-1 expression. Using the tyrosine kinase Flk-1 receptor (flk-1) LacZ transgene embryos, we determined that the neovascularization within the allograft was from the committed embryonic lung endothelium. Therefore, we have developed a defined murine allograft model that can be used to study distal lung development, including neovascularization. The model may be useful when used in conjunction with an altered genetic background (knockout or knock in) of the allograft and has the further decided advantage of bypassing placental barriers for introduction of pharmacological agents or DNA directly into the lung itself.

Animals↗

PubMed2000

GAP-43 mediates retinal axon interaction with lateral diencephalon cells during optic tract formation.

GAP-43 is an abundant intracellular growth cone protein that can serve as a PKC substrate and regulate calmodulin availability. In mice with targeted disruption of the GAP-43 gene, retinal ganglion cell (RGC) axons fail to progress normally from the optic chiasm into the optic tracts. The underlying cause is unknown but, in principle, can result from either the disruption of guidance mechanisms that mediate axon exit from the midline chiasm region or defects in growth cone signaling required for entry into the lateral diencephalic wall to form the optic tracts. Results here show that, compared to wild-type RGC axons, GAP-43-deficient axons exhibit reduced growth in the presence of lateral diencephalon cell membranes. Reduced growth is not observed when GAP-43-deficient axons are cultured with optic chiasm, cortical, or dorsal midbrain cells. Lateral diencephalon cell conditioned medium inhibits growth of both wild-type and GAP-43-deficient axons to a similar extent and does not affect GAP-43-deficient axons more so. Removal or transplant replacement of the lateral diencephalon optic tract entry zone in GAP-43-deficient embryo preparations results in robust RGC axon exit from the chiasm. Together these data show that RGC axon exit from the midline region does not require GAP-43 function. Instead, GAP-43 appears to mediate RGC axon interaction with guidance cues in the lateral diencephalic wall, suggesting possible involvement of PKC and calmodulin signaling during optic tract formation.

Animals↗

PubMed2000

The effect of zhu yu hua tan tang on intracranial pressure in case of acute cerebral hemorrhage.

The therapeutic effect of Zhu Yu Hua Tan Tang ([symbol: see text] Decoction for removing blood stasis and resolving phlegm) plus general and modern treatment on acute cerebral hemorrhage in 44 cases, and the pressure-lowering effect of Zhu Yu Hua Tan Tang and mannitol in 20 cases of acute cerebral hemorrhage in the basilar region, and in rabbits with experimental encephaledema induced by injection of olive oil into the common carotid artery were observed in this study. The results showed that Zhu Yu Hua Tan Tang plus general treatment can better improved the conscious state of the patients than western medicine, and it can make the intracranial pressure drop clinically by 40.44%. The intracranial pressure-lowering effect of Zhu Yu Hua Tan Tang, though slow, is smooth and long-lasting without any rebound phenomenon, as compared to those of mannitol. Similar results were found in animal experiments, but the intracranial pressure-lowering amplitude of Zhu Yu Hua Tan Tang was stronger than that of mannitol. The difference between the clinical and experimental results needs to be further studied.

Aged↗

PubMed2000

Efficacy and effect of SI17 therapy on pancreatic polypeptide in vascular and tension-type headache.

BACKGROUND AND PURPOSE: Vascular and tension-type headache is most commonly encountered, and SI17 therapy has been tested to treat headache with good results. The efficacy of SI17 therapy for vascular and tension-type headache was compared and the effect of SI17 therapy on pancreatic polypeptide (PP) was studied. MATERIALS AND METHODS: 29 cases of vascular headache (20 cases in acute attack during the trial) and 27 cases of tension-type headache (19 cases in acute attack) were enrolled in the study. Plasma PP level before and 4th day after treatment was measured by radioimmunoassay. RESULTS: SI17 therapy is better for the treatment of vascular headache. Vascular headache with higher PP level and tension-type headache with normal PP level had good therapeutic results. CONCLUSION: The clinical efficacy is better for vascular headache with the increase of vagus tension and for tension-type headache with normal vagus tension.

Acupuncture Points↗

PubMed2000

[A quantitative analysis of IL-6 mRNA expression of peripheral blood monocyte cell in patients with chronic hepatitis B].

OBJECTIVE: To investigate the relationship of interleukin-6 (IL-6) mRNA expression with the immunopathogenesis and viral clearance. METHODS: The serum IL-6 level of patients with chronic hepatitis B (CHB) were detected by ELISA and quantitatively the IL-6 mRNA expression of peripheral blood monocyte cell (PBMC) in patients with CHB were analysed by competitive RT-PCR-ELISA. RESULTS: Serum level of IL-6 in patients with CHB was significantly increased. Both expression rates of IL-6 mRNA target fragment in control and in patients with CHB were 41.7% (5/12) and 82.1% (23/28) respectively. The quantitative ELISA of production of RT-PCR showed the copies of IL-6 mRNA in 5 cases of control were 1 000 to 10 000 (the mean log copies was 3.65), while the copies of IL-6 mRNA in 23 cases of patients were all more then 10 000 (the mean log copies was 4.40). CONCLUSION: This study shows that the increased level of IL-6 may play some role in hepatitis B infection, the increased serum level of IL-6 is related to the enhanced expression of IL-6 mRNA of PBMC.

Adult↗

PubMed2000

[Three-dimensional reconstruction of experimental fibrotic liver tissue and effect of herbal compound on it].

OBJECTIVE: To observe the three-dimensional structure of fibrotic liver tissue and the effect of herbal compound 861 (Cpd861) on it. METHODS: Experimental rat liver fibrosis was induced by human albumin. Liver biopsy specimens were stained with Masson trichrome staining and liver fibrosis was divided into 6 stages. Three-dimensional structure of fibrotic and Cpd861 treated liver tissue were observed by computer aided three-dimensional reconstruction with serial slices. RESULTS: The fibrous septa of fibrotic liver were continuous and wide, the sinusoids were sparsely, irregularly distributed and dilated. After treatment with Cpd861, the fibrous septa were much less than that of without treatment. The sinusoids were more regular and arranged in radius to central veins. CONCLUSION: Observed three-dimensionally, experimental rat liver fibrosis can be inhibited and reversed by herbal compound.

Animals↗

PubMed2000

[Treatment of superior vena cava syndrome in cancer patients with intravascular stent and local thrombolysis].

OBJECTIVE: To study the therapentic efficacy of using intravascular stent and local thrombolysis for superior vena cava syndrome(SVCS) in cancer patients. METHODS: Among 26 cancer patients with SVCS there were 17 cases of lung cancer with mediastinal lymphnode metastases, 5 cases of malignant mediastinal tumor, 2 cases of non-Hodgkin's lymphomas, 2 cases of esophageal carcinoma with mediastinal lymphnode metastases. Through femoral vein, a catheter with side holes was introduced up to the superior vena cava. Following local dripping of urokinase for 20-40 min, the obstructed region was distended with the inflated balloon and then a self-expanding stent was put in the inflated region. RESULTS: The procedure was successful in 24 patients, but failed in 2 cases because the guide wire could not pass through the obstructed region. In 3 patients with superior vena cava stenosis of 10 cm in length, two stents were used. In the other 21 patients, 1 stent was adequate. Local thrombolytic treatment was given in 24 patients before the angioplastic balloon was inflated. The vena caval pressure at the distal end of the stenotic lesion dropped from 21.23 +/- 1.80 mm Hg before treatment to 5.33 +/- 0.98 mm Hg after treatment. The difference was statistically significant. Collateral veins were no longer filled by contrast after treatment. The caliber of the supericar vena cava restored to normal and its outline was smooth. The symptoms of SVCS subsided after treatment in 2-3 days. CONCLUSION: Intravascular, self-expandable stent combined with local thrombolysis is a micro-invasive and effective method of treatment for cancer patients with superior vena cava syndrome.

Adult↗

PubMed2000

Ebselen protection against hydrogen peroxide-induced cytotoxicity and DNA damage in HL-60 cells.

AIM: To study the protective effect of ebselen (Ebs) on hydrogen peroxide (H2O2)-induced cytotoxicity and DNA damage in human leukemia cell line HL-60. METHODS: The inhibitory effect of H2O2 on cell growth was determined using the tetrazolium dye colorimetric test, and the lipid peroxidation was estimated by malondialdehyde (MDA) formation. DNA damage was detected using single cell gel electrophoresis, and intracellular reactive oxygen species (ROS) formation was measured using a fluorescent probe, 2',7'-dichlorofluorescin diacetate (DCFH-DA). RESULTS: H2O2 (100 mumol.L-1) suppressed the growth of HL-60 cells and the addition of Ebs (1-20 mumol.L-1) reduced the suppression in a concentration-dependent manner. Furthermore, Ebs also displayed a concentration-dependent reduction of MDA formation in H2O2-treated cells, at the concentration of 20 mumol.L-1 the inhibitory rate was 56.4%. Ebs was able to reduce the ROS formation and DNA damage caused by H2O2 in a concentration-dependent manner. CONCLUSION: Ebs has a strong protective ability against the cytotoxicity and DNA damage caused by reactive oxygen species (ROS).

Antioxidants↗

PubMed2000

[Relation of venous drainage and inadequate circulation in the rat pedicled TRAM flap model].

OBJECTIVE: To evaluate the circulatory characteristics of the TRAM flap because the vascular supply to lateral portion of the conventional TRAM (zone 4) occasionally may become compromised resulting in necrosis of fat tissue or requiring segmental excision of the poor perfused tissue. METHODS: In this study, we designed a rat pedicled TRAM flap model with either inadequate arterial or venous circulation. The skin paddle was photographed and the survival areas were measured on the tenth postoperative day. RESULTS: The results showed that the group with poor arterial inflow of the flap, which resulted from ligation of the superior deep epigastric artery, exhibited skin necrosis in zone 1 and 2. Venous stasis due to selective ligation of the venous pedicle resulted in necroses of a major area in the lateral part of the flap, especially in zone 4. However, venous stasis may be alleviated by an additional cutaneous venous return system. CONCLUSIONS: Our results demonstrated that conventional rat TRAM flap with poor arterial inflow differs from that with venous stasis in terms of manifestations and extent of inadequate circulation. Necrosis of the lateral portion of human TRAM flaps may therefore be attributed to problems of venous stasis. Such problems might then be ameliorated by creating an additional cutaneous venous return system.

Abdominal Muscles↗

PubMed2000

[Effect of foliar leaching on growth and mineral nutrition of maize under NaCl stress].

The impact of foliar leaching on growth and mineral nutrition maize under NaCl stress was investigated. The results showed that there was no difference in biomass between leaching and control treatments under low NaCl stress (0 and 50 mmol.L-1), but under high NaCl stress (100 and 200 mmol.L-1), the biomass of leaching treatment was higher, with a better at pH 3.5 than at pH 7.0. The shoot K+ content in leaching treatments was higher than that of control under no NaCl stress, but lower under 200 mmol.L-1 NaCl stress. Shoot Na+ content of leaching treatments was lower than that of control under high NaCl stress, and shoot Ca2+ and Mg2+ contents of leaching treatments were higher under no NaCl stress. Root K+, Na+, Ca2+ and Mg2+ content and relative water content of leaching treatments had no significant changes, compared with those of control. It was suggested that foliar leaching could alleviate harmful degree of maize under serious salt stress, which was related with the decrease of shoot Na+ content by foliar leaching.

Minerals↗

PubMed2000

[Dynamics of soil P pool in a long-term fertilizing experiment of wheat-maize rotation. I. Crop yield effect of fertilizer P and dynamics of soil total P and inorganic P].

The effects of long-term applying fertilizer P and manure on the pools of soil total P and inorganic P and the crop yield in rotation of winter wheat-summer maize-->spring maize were studied. The results showed that the pool of soil total P and inorganic P were increased by applying fertilizer P and manure, and the phosphorus mostly accumulated in soil was inorganic P. The critical amounts of fertilizer P (P2O5) for balancing soil P were 94.7 kg.hm-2 to winter wheat-summer maize and 51.5 kg.hm-2 to spring maize. Based on regression equations, the application rates of fertilizer P (P2O5) for economic optimum and highest yields were 135.8 and 149.8 kg.hm-2 to winter wheat-summer maize, and 88.6 and 95.9 kg.hm-2 to spring maize, respectively.

China↗

PubMed2000

[Dynamics of soil P pool in a long-term fertilizing experiment of wheat-maize rotation. II. Dynamics of soil Olsen-P and inorganic P].

Studies on the dynamics of soil Olsen-P and different form inorganic P in the long-term fertilizing experiment of winter wheat-summer maize-->spring maize rotation showed that the contents of Olsen-P and inorganic P were changed by the accumulation and consumption of P in soil. In P0 treatments, Olsen-P decreased gradually, and then, trended to the critical level. When fertilizing amount was basically equal to the intake by crops, the balance of Olsen-P was dynamically maintained. The contents of Olsen-P and inorganic P were enhanced, when applied P was larger than the P intake by crops. The major contents of residual inorganic P were Ca2-P and Ca8-P, both accounting for 52.3% of total inorganic P in average, and Ca8-P accounting for 78.3%. Al-P and Fe-P accounted for 26.1%, and O-P and Ca10-P accounted for 20.4% of total inorganic P. The availability of fertilizer P was obviously increased by long-term applying fertilizer P together with manure, compared with applying fertilizer P alone.

China↗

PubMed2000

[Effect of AM fungi on water and nutrition status of corn plants under salt stress].

Under NaCl stress, the dry matter production of corn plants inoculated with or without arbuscular mycorrhizal (AM) fungus (Glomus mosseae) was decreased, but the decrement for non-mycorrhizal plants was 10% higher than that for mycorrhizal ones. Under salt stress condition, the dry weights of root system and aboveground part of mycorrhizal corn and its leaf water potential were higher than those of non-mycorrhizal corn, while the proline content of mycorrhizal corn was less than that of non-mycorrhizal corn. The contribution of hypha to P uptake of plants decreased from 45.3% to 42.6%, while the effect of AM fungi on plant growth increased from 30.9% to 63.5% under salt stress condition. The above-mentioned results indicated that the mechanism that AM fungi enhance the salt-resistance of corn is related with the improvements of water and P nutrition conditions. Meanwhile, it was found whether under salt stress or not, the ratio of P accumulation of root system to aboveground part of mycorrhizal corn was higher than that of non-mycorrhizal corn, indicating that the infection of AM fungi changed the P distribution pattern in plant bodies, which is beneficial to increase the salt-resistance of plants.

Ecosystem↗

PubMed2000

[Expression and prognostic significance of multidrug resistance associated protein (MRP) gene in non-small cell lung cancer by in situ hybridization].

OBJECTIVE: To study the effect of MRP gene overexpression on prognosis of patients with non-small cell lung cancer (NSCLC). METHODS: Paraffin-embedded tissues from 47 cases of NSCLC who had undergone radical tumor resection were examined for expression of MRP gene mRNA by in situ hybridization using labelled digoxigenin probes combined with immunohistochemistry. All the patients were retrospectively followed-up. RESULTS: All of the 47 lung cancer specimens were found to have overexpression of MRP mRNA. It was significantly correlated with patients' survival period, response to chemotherapy, recurrence and mestastases after surgery, but was not correlated with histology, tumor size, node status, TNM stage, degree of differentiation, age and sex. CONCLUSION: Overexpression of MRP gene is a marker of prognostic significance in patients with NSCLC.

Adult↗

PubMed2000

[Pulmonary embolism due to deep venous thrombosis of extremities].

OBJECTIVE: To study the relationship between pulmonary embolism and deep venous thrombosis of extremities. METHODS: The authors conducted a retrospective analysis of 100 patients with deep venous thrombosis to analyse the occurrence of pulmonary embolism during 1996 to and 1998 in their hospital. RESULTS: In the 100 patients with deep venous thrombosis, the complication of pulmonary embolism was 45%, fatal pulmonary embolism was 4%. CONCLUSION: The complication of pulmonary embolism in the patients with deep venous thrombosis frequently occurred and medical professionals should pay attention to them.

Adult↗