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Biomedical subjects

Yu Zhao

Publications and source records attributed to Yu Zhao.

At least 91 records · Page 5Linked to original sources

Synthesis and biological evaluation of novel compounds related to 1-arylnaphthalene lignans and isoquinolines.

Novel compounds designed as hybrids of 1-arylnaphthalene lignans with isoquinoline alkaloids were prepared and evaluated for their cytotoxicities on human tumor cell lines, such as A549, Hela, PC-3, CNE, BEL-7404, and KB. Some of the synthetic compounds exhibited their IC50 values on selected cell lines at 10(-6) M scale. The preliminary CoMFA molecular-modelling studies of these synthetic analogues were also performed.

Antineoplastic Agents↗

Two new taxoids from Taxus chinensis.

Two new taxoids, 2,20-O-diacetyltaxumairol N (1) and 14beta-hydroxy-10-deacetyl-2-O-debenzoylbacatin III (2), were isolated from the needles and stems of Taxus chinensis. Their structures were determined on the basis of extensive 1D- and 2D-NMR-spectral analysis. Compound 1 showed weak cytotoxicity activity against T-24 (IC50 = 34 microg/ml) and QGY-7701 (IC50 = 22 microg/ml) cancer lines. Compound 2 showed no obvious cytotoxicity activity against T-24 (IC50 > 100 microg/ml) and QGY-7701 (IC50 > 100 microg/ml) cancer lines.

Antineoplastic Agents, Phytogenic↗

Effects of the Chinese herbal formula Shi-Bi-Lin on cytokine release from the human mast cell line.

BACKGROUND: The traditional Chinese herbal formula Cang Er Zi San has been used for the treatment of rhinitis, paranasal sinusitis, and allergic rhinitis for several centuries. However, its therapeutic mechanisms remain largely unclear. OBJECTIVE: To study the effects of Shi-Bi-Lin (SBL), a modified Cang Er Zi San formula, on cytokine release from and expressions in the human mast cell line (HMC-1). METHODS: The HMC-1 was preincubated with different concentrations of SBL extract solution 1 hour before being stimulated with 25 ng/mL of phorbol myristate acetate plus 2.5 x 10(-7)M calcium ionophore A23187 and then further incubated for 6, 12, and 24 hours, respectively. The cell culture supernatants were harvested, and the cytokines of interleukin 4 (IL-4), IL-6, IL-8, and tumor necrosis factor alpha (TNF-alpha) in the supernatants were measured by enzyme-linked immunosorbent assay. Furthermore, the total RNA of the cells was extracted, and the cytokines' messenger RNA expressions were examined using semiquantitative reverse transcriptase-polymerase chain reaction. RESULTS: After different incubation periods at different concentrations, SBL could potently inhibit the cytokines of IL-4 and TNF-alpha and modestly affect IL-6 but not obviously affect IL-8 release from the HMC-1. However, no inhibitory effects were detected on the messenger RNA expressions of these cytokines. CONCLUSIONS: These results demonstrate that SBL could modulate the mast cell-mediated hypersensitivity reaction in allergy. Inhibition of mast cell-derived IL-4 and TNF-alpha might explain the efficacy of SBL in treating allergic disease.

Anti-Allergic Agents↗

Synthesis and biological evaluation of a natural ester sintenin and its synthetic analogues.

Synthesis of 3-(3,4-dimethoxyphenyl)propyl-3-(3,4-dimethoxyphenyl) propanoate (18), a cytotoxic natural ester, was carried out by a convenient synthetic path with a total yield of 49%. Sixteen of its analogues (19-34) were also prepared. Seventeen unsaturated derivatives of 18, compounds 1-17, were also synthesized to examine the structure-activity relationship of this type of ester. All of the synthetic compounds were passed through the cytotoxicity screenings on human tumor cell lines, such as PC-3, Hela, A549, BEL7404, CNE, and KB. Some of the esters exhibited moderate inhibitory effects on these tumor cell lines. The phenolic derivatives exhibited the highest cytotoxicity among these derivatives, while the unsaturated esters were more cytotoxic than the saturated analogues. Some of the compounds also exhibited inhibition on alpha-glucosidase.

Antineoplastic Agents↗

Evaluation of antiviral activity of compounds isolated from Ranunculus sieboldii and Ranunculus sceleratus.

Nineteen compounds isolated from Ranunculus sieboldii and Ranunculus sceleratus were tested for inhibitory effects on hepatitis B virus (HBV) and Herpes simplex virus type-1 (HSV-1). The results showed that apigenin 4'- O- alpha-rhamnopyranoside, apigenin 7- O- beta-glucopyranosyl-4'- O- alpha-rhamnopyranoside, tricin 7- O- beta-glucopyranoside, tricin, and isoscopoletin possessed inhibitory activity against HBV replication. Protocatechuyl aldehyde exhibited an inhibiting activity on HSV-1 replication. It is therefore suggested that further investigations on these bioactive compounds might be needed to discover and develop new antiviral agents.

Antiviral Agents↗

PKC-induced ERK1/2 interactions and downstream effectors in ovine cerebral arteries.

Both protein kinase C (PKC) and extracellular signal-regulated kinases (ERK1/2) are involved in mediating vascular smooth muscle contraction. We tested the hypotheses that in addition to PKC activation of ERK1/2, by negative feedback ERKs modulate PKC-induced contraction, and that their interactions modulate both thick and thin myofilament pathways. In ovine middle cerebral arteries (MCA), we measured isometric tension and intracellular free calcium concentration ([Ca(2+)](i)) responses to PKC stimulation [phorbol 12,13-dibutyrate (PDBu), 3 x 10(-6) M] in the absence or presence of ERK1/2 inhibition (U-0126, 10(-5) M). After PDBu +/- ERK1/2 inhibition, we also examined by Western immunoblot the levels of total and phosphorylated ERK1/2, caldesmon(Ser789), myosin light chain(20) (MLC(20)), and CPI-17. PDBu induced significant increase in tension in the absence of increased [Ca(2+)](i). PDBu also increased phosphorylated ERK1/2 levels, a response blocked by U-0126. In turn, U-0126 augmented PDBu-induced contractions. PDBu also was associated with significant increases in phosphorylated caldesmon(Ser789) and MLC(20) levels, each of which peaked at 5 to 10 min. PDBu also increased phosphorylated CPI-17 levels, which peaked at 2 to 3 min. Rho kinase inhibition (Y-27632, 3 x 10(-7) M) did not alter PDBu-induced contraction. These results support the idea that PKC activation can increase CPI-17 phosphorylation to decrease myosin light chain phosphatase activity. In turn, this increases MLC(20) phosphorylation in the thick filament pathway and increases Ca(2+) sensitivity. In addition, ERK1/2-dependent phosphorylation of caldesmon(Ser789) was not necessary for PDBu-induced contraction and appears not to be involved in the reversal of caldesmon's inhibitory effect on actin-myosin ATPase.

Animals↗

In vitro antiviral activity of three enantiomeric sesquiterpene lactones from Senecio species against hepatitis B virus.

Three enantiomeric sesquiterpene lactones were isolated under the bioguidance of the suppression of hepatitis B virus (HBV) surface antigen (HBsAg) from Senecio species, a widely distributed Chinese medicinal herb traditionally used for the treatment of hepatitis B, dermatosis and inflammation. The anti-HBV activity of the purified compounds was measured; all of them showed suppressive activity on the expression of HBsAg and HBV e antigen (HBeAg) in the HepG2.2.15 cell line. Real-time quantitative PCR analysis showed that the studied compounds decreased the number of infectious virions released, but did not inhibit the intracellular HBV DNA. The results suggest that enantiomeric sesquiterpene lactones may possess the potential to work synergistically with other antiviral compounds for the treatment of HBV infection.

Antiviral Agents↗

Two new icetexane diterpenoids from Salvia przewalskii.

Two new icetexane diterpenoids, przewalskin C, D (1, 2), together with sixteen known diterpenoids, were isolated from Salvia przewalskii. Eight of known ones (compounds 3, 12-18) were reported firstly from this plant. To the best of our knowledge, it's the first report of icetexane diterpenoids from this plant. The identification and structural elucidation of these compounds were based on 1D- and 2D-NMR spectral data analysis.

Diterpenes↗

[Studies on the chemical constituents in herb of Ranunculus sceleratus].

OBJECTIVE: To isolate and determine the chemical constituents from Ranunculus sceleratus. METHOD: Six compounds were isolated and purified by extraction and different kinds of column chromatography. The structures were determined on the basis of extensive spectral analysis such as EI-MS, 1H-NMR, 13C-NMR, DEPT and NOEDS. RESULT: The structures were elucidated as stigmasta-4-ene-3,6-dione I, stigmasterol II, isoscopoletin III, scoparone IV, protocatechuic aldehyde V and protocatechuic acid VI, respectively. CONCLUSION: Compound I, III, IV, V and VI were isolated from R. genus for the first time.

Benzaldehydes↗

[Complications of successively double autologous hemopoietic stem cell transplants].

In order to get clinical information about safety and feasibility of successively double autologous hemopoietic stem cell transplants (SD-AHSCT) in malignant hematological disease patients, the complications and hematological reconstitution after SD-AHSCT in 20 patients were analyzed retrospectively. 20 patients with hematologic malignancies received autologous peripheral blood stem/progenitor cell transplantation at the first transplant, and then were given autologous bone marrow transplantation as the second transplant at 4-10 months. The results showed that all the patients tolerated mobilization and collection of peripheral blood stem/progenitor cells as well as bone marrow collection. All the patients got enough hematological stem/progenitor cells for SD-AHSCT and achieved hematological reconstitution after SD-AHSCT. The speed of hematological reconstitution was positively correlated with the transfused quantity of hematological stem/progenitor cells (r = 0.968). The hematological reconstitution after the first autologous hemopoietic stem cell transplant (AHSCT) was earlier than that of the second (P < 0.05). There was no statistical difference between the first and the second AHSCT for the incidence of skin or mucous membrane bleeding (P > 0.05). No patients occurred massive hemorrhage during SD-AHSCT. The quantity of platelet transfusion in the second AHSCT was larger than that in the first AHSCT (P < 0.01). The incidence of oral ulcer in the first AHSCT was significantly higher than that in the second (P < 0.01). No statistical difference between the first and the second AHSCT was there in infectious sites, infectious pathogens and infection incidence (P > 0.10). All the complications were improved or cured, and no patients died of SD-AHSCT complications. In conclusion, SD-AHSCT is safe and feasible, and worthy to be further popularized.

Adolescent↗

[The immunohistochemical observations of NOS in the nasal mucosa of allergic rhinitis animal model of guinea pigs].

OBJECTIVE: To study the immunoreactivity and distribution of both iNOS and eNOS isoforms, and observe the effect of desloratadine on them. METHOD: The guinea pigs were sensitized and challenged followed by harvest of their nasal tissue for immunohistochemical staining. The slides images were semiquantitatively analyzed and compared with the desloratadine treated group and negative control group. RESULT: Both iNOS and eNOS were positively stained in each group. The immunoreactivity of iNOS had no significant difference between groups (P > 0.05), but eNOS had stronger immunoreactivity in the model group and the desloratadine treated group when compared with the negative control group (P < 0.01 and P < 0.05). In addition to the distribution area of iNOS, eNOS was also positive stained in the goblet cells. Desloratadine had no influence on iNOS and eNOS immunoreactivity. CONCLUSION: eNOS might play a more important role than iNOS in regulating the NO level of the nasal tissue of the guinea pigs suffered from allergic rhinitis, and desloratadine had no involvement in regulating the expression of iNOS and eNOS.

Animals↗

[Establishment of a modified intranasally ovalbumin induced animal model of allergic rhinitis].

OBJECTIVE: To observe the early and late symptomatic, pathological and immunological changes in an intranasal ovalbumin-induced animal model of allergic rhinitis in guinea pigs. METHODS: Guinea pigs were intranasally sensitized with ovalbumin absorbed on aluminum hydroxide and after 5 days' interval, they were challenged with 1% ovalbumin solution once every 3 days for total 11 times. Two control groups were studied in parallel, the positive treatment control group was treated with antihistamine and the negative control group was sham-sensitized and sham-challenged. Typical symptoms of allergic rhinitis, such as sneezing, nasal scratching, nasal blockage and rhinorrhea were evaluated. Passive cutaneous anaphylaxis reaction (PCA) was performed to measure the levels of IgG1 and IgE. Eosinophils infiltration and goblet cells in nasal mucosa were observed. In addition, the level of histamine and the number of total leukocytes and eosinophils in the nasal lavage fluid were also measured. RESULTS: In the model group, symptoms of sneezing, nasal scratching, nasal blockage and rhinorrhea were induced after ovalbumin challenge. The respiratory rate (RR), which reflected the resistance of upper airway, showed a biphasic change. In the PCA test, IgG1 and IgE levels increased after challenges. Eosinophil infiltration in nasal mucosa was more obvious in active groups in comparison to with the negative control group (P < 0.05 or < 0.01). The histamine, total leucocytes and eosinophils levels in nasal lavage fluid also showed higher in the model group (P < 0.05 or < 0.01). The antihistamine treated animals were also induced out above changes but modest compared with the model group (P < 0.05 or < 0.01). The negative control showed few of above changes with significant difference (P < 0.05 or < 0.01). CONCLUSIONS: Our results implied that the modified animal model of allergic rhinitis was capable of showing satisfactory symptomatic and pathophysiological changes in allergic rhinitis. It showed a biphasic nasal blockage with shorter establishment duration. The model also had good treatment reaction to antihistamine. The animal model we introduced may be useful in the study of allergic rhinitis.

Administration, Intranasal↗

[Reoperative treatment of lumbar disc herniation].

OBJECTIVE: To explore the causes, methods and outcomes of reoperative treatment after lumbar disc surgery. METHODS: Nine hundred and twenty eight patients with lumbar disc herniation were treated surgically from January 1995 to January 2004, of whom 43 patients (4.6%) underwent reoperation due to persistent pain or recurrence of symptoms. Forty patients were followed up from 3 months to 84 months (mean 30 months). RESULTS: According to Macnab's criteria, outcomes were excellent in 11 cases (27.5%), good in 16 cases (40%), fair in 8 cases (20%), and poor in 5 cases (12.5%). CONCLUSIONS: The major causes of reoperation after lumbar disc surgery included incomplete removal of herniating discs and recurrent disc herniation of primary interspace, secondary lumbar canal stenosis, and adhesion of nerve roots. Prior to primary surgical treatment of lumbar disc herniation, operative indications must be strictly accurate, surgical methods should be correctly selected, and improved and refined surgical skills should be guaranteed. Satisfactory outcomes can be gained with reoperation for patients who still requiring treatment.

Diskectomy↗

[Effects of FLAG regimen in treatment of refractory or relapsed acute myeloid leukemia].

In order to evaluate the effects of FLAG regimen in treatment of refractory and relapsed acute myeloid leukemia (AML), 27 patients with refractory or relapsed acute myeloid leukemia (10 refractory AML patients, 17 relapsed AML patients) were treated with FLAG regimen. The results show that the rate of complete remission was 48.2% (13/27), the rate of partial remission was 14.8% (4/27), and the overall response rate was 63.0%. Main toxicities were gastrointestinal side effectes, myelosupression and neutropenia. It is concluded that FLAG regimen can be employed in treatment of the refractory or relapsed patients who were not respond to other regimen, and the regiment was safe.

Adolescent↗

Surgical treatment of scoliosis caused by neurofibromatosis type 1.

OBJECTIVE: To retrospectively analyze the relationship between curve types and clinical results in surgical treatment of scoliosis in patients with neurofibromatosis type 1 (NF-1). METHODS: Forty-five patients with scoliosis resulting from NF-1 were treated surgically from 1984 to 2002. Mean age at operation was 14.2 years. There were 6 nondystrophic curves and 39 dystrophic curves depended on their radiographic features. According to their apical vertebrae location, the dystrophic curves were divided into three subgroups: thoracic curve (apical vertebra at T8 or above), thoracolumbar curve (apical vertebra below T8 and above L1), and lumber curve (apical vertebra at L1 and below). Posterior spine fusion, combined anterior and posterior spine fusion were administrated based on the type and location of the curves. Mean follow-up was 6.8 years. Clinical and radiological manifestations were investigated and results were assessed. RESULTS: Three patients with muscle weakness of low extremities recovered entirely. Two patients with dystrophic lumbar curve maintained their low back pain the same as preoperatively. The mean coronal and sagittal Cobb's angle in nondystrophic curves was 80.3 degrees and 61.7 degrees before operation, 30.7 degrees and 36.9 degrees after operation, and 32.9 degrees and 42.1 degrees at follow-up, respectively. In dystrophic thoracic curves, preoperative Cobb's angle in coronal and sagittal plane was 96.5 degrees and 79.8 degrees, postoperative 49.3 degrees and 41.7 degrees, follow-up 54.1 degrees and 45.3 degres, respectively. In thoracolumbar curves, preoperative Cobb's angle in coronal and sagittal plane was 75.0 degrees and 47.5 degrees, postoperative 31.2 degrees and 22.8 degrees, follow-up 37.5 degrees and 27.8 degrees, respectively. In lumbar curves preoperative Cobb's angle in coronal plane was 55.3 degrees, postoperative 19.3 degrees, and follow-up 32.1 degrees. Six patients with dystrophic curves had his or her curve deteriorated more than 10 degrees at follow-up. Three of them were in the thoracic subgroup and their kyphosis was larger than 95 degrees, and three in lumbar subgroup. Hardware failure occurred in 3 cases. Six patients had 7 revision procedures totally. CONCLUSIONS: Posterior spinal fusion is effective for most dystrophic thoracic curves in patients whose kyphosis is less than 95 degrees. Combined anterior and posterior spinal fusion is stronger recommended for patients whose kyphosis is larger than 95 degrees and those whose apical vertebra is located below T8. Patients should be informed that repeated spine fusion might be necessary even after combined anterior and posterior spine fusion.

Adolescent↗

[The effect of desloratadine on the TXB2 and leukotrienes levels in the nasal lavage fluid of allergic rhinitis animal model].

OBJECTIVE: To observe the thromboxane (TX)B2 and cysteinyl leukotrienes (LTs) levels in the nasal lavage fluid of allergic rhinitis model and to observe the effect of desloratadine on the mediators. METHOD: In the positive control group, 8-12 week old male or female guinea pigs were intranasal sensitized and challenged with ovalbumin solution. The antihistamine treatment group was treated with desloratadine and the negative control group was sham-sensitized and sham-challenged. The nasal lavage fluid of each group was collected 5 hours after challenge and the levels of TXB2 and LTs in the nasal lavage fluid were measured. RESULT: In the positive control group, the TXB2 and LTs levels were the highest of the three groups and the desloratadine treated group had lower level (P < 0.05 and P < 0.01). The negative control showed the lowest level. CONCLUSION: Our study demonstrated that in this model of allergic rhinitis, the levels of TXB2 and LTs in nasal lavage fluid increased dominantly after allergen challenge and desloratadine could inhibit the release of TXB2 and LTs, which implied that the therapeutic mechanism of desloratadine might contribute to the inhibitory effect on TXB2 and LTs production or release in allergic rhinitis subjects.

Animals↗

[The treatment of sinusitis in patients with nasopharyngeal carcinoma after radiotherapy and the relative factors].

OBJECTIVE: To explore the surgery way on sinusitis with nasopharyngeal carcinoma (NPC) caused by radiotherapy and the relative factors. METHOD: Forty-five cases of NPC patients with sinusitis caused by radiotherapy were treated by endoscopic sinus surgery in our department from 1998 to 2003. There were 24 males and 21 females, ranging in age from 34 to 45 years old. The clinical data of the patients were analysed retrospectively. RESULT: All the patients were followed up for a period of 1 to 4 years after operation. 22 cases (48.9%) were cured, 18 cases (40%) were improved, but the other 5 cases (11.1%) were no effective. No serious complications and tumor recurrence occurred. CONCLUSION: The incidence of sinusitis in patients with NPC after radiotherapy is very high which interferes the effect of radiotherapy on NPC. Endoscopic sinus surgery is an effective method to open sinus ostium. It is feasible and favorable.

Adult↗

The growth characteristics and ginsenosides isolation of suspension-cultured crown gall of Panax quinquefolium.

The growth characteristics and ginsenosides isolation of the suspension-cultured crown gall of Panax quinquefolium were studied. The result showed that the maximum biomass of cultures was 18.6 g/L (dry weight) and the content of ginsenosides reached its maximum level of 620.4 mg/L on the 27th day. The utilization rates of sugar, phosphorus, nitrogen in NH4+ and nitrogen in NO3- were 91.8%, 100%, 81% and 97%, respectively. Four compounds were isolated from the suspension-cultured crown gall and their structures were elucidated as pseudoginsenoside F11 (I), ginsenoside Rd (II), ginsenoside Rb1 (llI) and ginsenoside Rb3 (IV).

Culture Media↗