Biomedical subjects

Jing Zhao

Publications and source records attributed to Jing Zhao.

178 records · Page 10Linked to original sources

PubMed2002

Axon- or dendrite-predominant outgrowth induced by constituents from Ashwagandha.

We previously reported that the methanol extract of Ashwagandha (roots of Dunal) induced dendrite extension in a human neuroblastoma cell line. In this study, we found that six of the 18 compounds isolated from the methanol extract enhanced neurite outgrowth in human neuroblastoma SH-SY5Y cells. Double immunostaining was performed in rat cortical neurons using antibodies to phosphorylated NF-H as an axonal marker, and to MAP2 as a dendritic marker. In withanolide A-treated cells, the length of NF-H-positive processes was significantly increased compared with vehicle-treated cells, whereas, the length of MAP2-positive processes was increased by withanosides IV and VI. These results suggest that axons are predominantly extended by withanolide A, and dendrites by withanosides IV and VI.

Animals↗

PubMed2002

Large volume hepatic freezing: association with significant release of the cytokines interleukin-6 and tumor necrosis factor a in a rat model.

Although cryotherapy of liver tumors is generally considered a safe procedure, a syndrome of coagulopathy and fatal multiorgan failure has been observed in some patients and is called the cryoshock phenomenon. Our aim was to establish an animal model of this phenomenon and examine the effects of the basic parameters of freezing or cryotherapy on it. A group of 75 female Sprague-Dawley rats were allocated randomly to five groups: (1) sham laparotomy (n = 15); (2) small (25% liver volume) single freeze (n = 15); (3) small (25% liver volume) double freeze (n = 15); (4) large (50% liver volume) single freeze (n = 15); (5) large (50% liver volume) double freeze (n = 15). Blood samples were collected at different postoperative times, and organs were harvested for histopathology. There was a significant release of tumor necrosis factor-a (TNFa) and interleukin 6 (IL-6) following hepatic freezing, which was greatest in group 5. Postoperative serum cytokine levels were significantly associated with hepatocellular injury, as measured by postoperative serum aspartate transaminase (AST) concentrations. Severe hemoglobinuria and renal injury, as demonstrated by the serum creatinine level and the glomerular neutrophil count, were observed and were greatest in group 5. Hepatic cryosurgery is associated with release of IL-6 and TNFa and renal injury in a rat model. It is likely that the cryoshock phenomenon is another form of the systemic inflammatory response syndrome. Based on the results of this study, it is possibly mediated by cytokines released from the frozen liver tissue. We therefore caution against cryotherapy of large tumor volumes.

Animals↗

PubMed2002

Phosphorylation of histone h3 at serine 10 cannot account directly for the detachment of human heterochromatin protein 1gamma from mitotic chromosomes in plant cells.

Heterochromatin protein 1 (HP1) controls heterochromatin formation in animal cells, at least partly through interaction with lysine 9 (Lys-9)-methylated histone H3. We aimed to determine whether a structurally conserved human HP1 protein exhibits conserved heterochromatin localization in plant cells and studied its relation to modified histone H3. We generated transgenic tobacco plants and cycling cells expressing the human HP1gamma fused to green fluorescent protein (GFP) and followed its association with chromatin. Plants expressing GFP-HP1gamma showed no phenotypic perturbations. We found that GFP-HP1gamma is preferentially associated with the transcriptionally "inactive" heterochromatin fraction, a fraction enriched in Lys-9-methylated histone H3. During mitosis GFP-HP1gamma is detached from chromosomes concomitantly with phosphorylation of histone H3 at serine 10 and reassembles as cells exit mitosis. However, this phosphorylation cannot directly account for the dissociation of GFP-HP1gamma from mitotic chromosomes inasmuch as phosphorylation does not interfere with binding to HP1gamma. It is, therefore, possible that phosphorylation at serine 10 creates a "code" that is read by as yet an unknown factor(s), eventually leading to detachment of GFP-HP1gamma from mitotic chromosomes. Together, our results suggest that chromatin organization in plants and animals is conserved, being controlled at least partly by the association of HP1 proteins with methylated histone H3.

Cell Nucleus↗

PubMed2002

[Sleep time of children from 1 month to 5 years of age in Shanghai, an epidemiological study].

OBJECTIVE: To assess the age specific sleep time among children 1 month to 5 years of age in Shanghai, China, and to identify the related factors. METHODS: A questionnaire survey was conducted among the parents of 3 266 children 1 month to 5 years of age, randomly selected in five urban districts of Shanghai in August and September of 1999 and 2000, with a response rate of 97.83%. RESULTS: The total sleep time among children less than 48 months of age in Shanghai was less than that among children the same age in Western countries. The factors related to children's inadequacy of total time included parental insufficient sleep time, children's difficult temperament parental presence at sleep onset of children, and cosleeping. CONCLUSIONS: The total sleep time among children at tender age in Shanghai is on the low side. The main influencing factor of insufficiency of sleep time among children is the family environmental factor, especially parental improper response to children's sleep behaviors.

Age Factors↗

PubMed2002

Echogenicity of liver metastases from colorectal carcinoma is an independent prognostic factor in patients treated with regional chemotherapy.

BACKGROUND: Echogenicity of liver metastases was found to be a predictive biologic factor influencing long-term outcome after curative liver resection. The current analysis focuses on the influence of echogenicity on survival in patients treated with intraarterial chemotherapy for unresectable colorectal carcinoma liver metastases. METHODS: A retrospective analysis of prospectively collected data at the Department of Surgery at the University of New South Wales-affiliated St. George Hospital was performed. Two hundred twelve consecutive patients with unresectable hepatic metastases from colorectal carcinoma treated between May 1992 and September 2000 were analyzed. Echogenicity of metastases was measured intraoperatively using a 5 MHz probe. Overall survival difference was compared between hyper- and hypoechoic metastases on an intention-to-treat basis. RESULTS: At a median followup of 15.1 months, 47 patients (22%) were alive and 165 (78%) had died. A significant survival benefit was observed in patients having hyperechoic lesions (median survival 16.2 months, 95% confidence interval [CI] 13.9-18.5) compared to hypoechoic lesions (median survival 11.6 months, 95% CI 8-15.2), P < 0.01. Other prognostic factors were differentiation of the primary tumor (P < 0.02), percentage hepatic replacement (P < 0.05) and carcinoembryonic antigen decrease (P < 0.03). Echogenicity was identified as an independent prognostic factor in multivariate analysis (P < 0.009). CONCLUSIONS: Echogenicity is an important prognostic survival parameter.

Adult↗

PubMed2002

Lentiviral vectors for delivery of genes into neonatal and adult ventricular cardiac myocytes in vitro and in vivo.

Vectors based on lentiviruses such as human immunodeficiency virus (HIV) type-1 have many advantages for gene therapy, including the ability to infect non-dividing cells, long-term transgene expression and the absence of induction of an inflammatory/immune response. This study was initiated to determine whether lentiviruses would efficiently transfer genes to both neonatal and adult cardiac cells in culture and, by direct injection, to the heart in vivo. A three-plasmid expression system, including a packaging defective helper construct, a plasmid coding for a heterologous (VSV-G) envelope protein and a vector construct harboring reporter genes - E-GFP (enhanced green fluorescent protein) and puro (puromycin-resistance protein) was used to generate pseudotyped HIV-1 particles by transient transfection of human embryonic kidney 293T cells. We demonstrated efficient gene transfer into neonatal and adult cardiac myocytes in vitro and identified conditions in which virtually 100 % of cultured neonatal and 70 % of adult cardiac myocytes express the reporter gene. Transduction of adult cardiac myocytes with high titre lentiviral vectors did not affect the cell number, morphology or viability compared to untransduced cells. We delivered HIV-1-based vectors to the intact heart by direct injection. Hearts transduced with pseudotyped HIV-1 vectors showed levels of transgene expression comparable to that achieved by adenovirus vectors. This study demonstrates for the first time that lentivirus-based vectors can successfully transduce adult cardiomyocytes both in vitro and in vivo, and opens up the prospect of lentivirus-based vectors becoming an important gene delivery system in the cardiovascular field.

Adult↗

PubMed2002

A-type natriuretic peptide receptor in the spontaneously hypertensive rat kidney.

Renal NPR-A binding characteristics was examined in SHR. Renal ANP binding sites of NPR-A showed a lower maximal binding capacity and higher affinity in SHR than in WKY at all intrarenal sites. Despite the lower B(max) in SHR, both ANP(1-28) and ANP(5-25) stimulate similar or greater cGMP production in isolated glomeruli. Studies on guanylate cyclase from glomerular and papillary membranes have reported an increased basal and stimulated guanylate cyclase activity in SHR. The present study provides further evidences for altered NPR-A receptors in SHR kidney, which might act as a negative feedback in response to hypertension.

Animals↗

PubMed2002

Altered eosinophil levels as a result of viral infection in asthma exacerbation in childhood.

Respiratory viral infection is known to be a significant cause of asthma exacerbation. Eosinophils have been considered to play an important role in the pathogenesis of virus-induced asthma exacerbations. To determine how often asthma exacerbation is caused by virus infections and to examine the relationship between eosinophilia and asthma episode, we investigated 64 children who experienced asthma attacks between October 1999 and March 2000. We used rapid enzyme immunoassays to detect antigens of respiratory syncytial virus (RSV), influenza A virus, and adenovirus in nasopharyngeal secretions (NPS) of these children, and enumerated eosinophils in the blood and NPS. We detected RSV in 27% and influenza A virus in 17% of the patients. No adenovirus infection or RSV/influenza A co-infection was detected. RSV-infected children were younger (3.85 +/- 0.83 years old) than influenza A virus-infected patients (5.23 +/- 1.34 years old). Eighty-two per cent of patients in the RSV group and 36% of patients in the influenza A virus group had moderate-to-severe asthma episodes (p < 0.05). In RSV-infected children, the eosinophil counts in NPS were higher in the 'severe' group, and younger patients had a greater number of eosinophils in their NPS than older patients (p < 0.05). These trends were not found in influenza A virus patients. In conclusion, our results indicate that, compared with influenza A virus-induced asthma attacks, RSV infection had a higher probability of being associated with asthma exacerbation in infants and younger children and induced attacks of greater severity. The increase in the number of eosinophils in the NPS of RSV-infected children may be responsible, in part, for these differences.

Antigens, Viral↗

PubMed2002

Withanolide derivatives from the roots of Withania somnifera and their neurite outgrowth activities.

Five new withanolide derivatives (1, 9-12) were isolated from the roots of Withania somnifera together with fourteen known compounds (2-8, 13-19). On the basis of spectroscopic and physiochemical evidence, compounds 1 and 9-12 were determined to be (20S,22R)-3 alpha,6 alpha-epoxy-4 beta,5 beta,27-trihydroxy-1-oxowitha-24-enolide (1), 27-O-beta-D-glucopyranosylpubesenolide 3-O-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranoside (withanoside VIII, 9), 27-O-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosylpubesenolide 3-O-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranoside (withanoside IX, 10), 27-O-beta-D-glucopyranosylpubesenolide 3-O-beta-D-glucopyranoside (withanoside X, 11), and (20R,22R)-1 alpha,3 beta,20,27-tetrahydroxywitha-5,24-dienolide 3-O-beta-D-glucopyranoside (withanoside XI, 12). Of the isolated compounds, 1, withanolide A (2), (20S,22R)-4 beta,5 beta,6 alpha,27-tetrahydroxy-1-oxowitha-2,24-dienolide (6), withanoside IV (14), withanoside VI (15) and coagulin Q (16) showed significant neurite outgrowth activity at a concentration of 1 microM on a human neuroblastoma SH-SY5Y cell line.

Disaccharides↗

PubMed2002

Over-expression of LPTS-L in hepatocellular carcinoma cell line SMMC-7721 induces crisis.

AIM: To evaluate the function of the longer transcripts LPTS-L in hepatocellular carcinoma cell line SMMC-7721. METHODS: SMMC-7721 cells were transfected with LPTS-L expression construct and stably transfected cells were selected by G418. Multiple single clones formed and were checked for their phenotype. In the study of the effect on telomerase activity of LPTS-L in vitro, GST-LPTS-L fusion protein was expressed in E.coli and purified by glutathione-agarose column. Telomeric repeat amplification protocol (TRAP) assays were performed to study the influence of telomerase activity in SMMC-7721 cells. RESULTS: Over-expression of LPTS-L induced SMMC-7721 cells into crisis. LPTS-L could inhibit the telomerase activity in SMMC-7721 cells in vitro. CONCLUSION: LPTS-L is a potent telomerase inhibitor. Over-expression of LPTS-L can induce hepatoma cells into crisis due to the reduction of telomerase activity.

Carcinoma, Hepatocellular↗

PubMed2001

Preparation and Defluorination Performance of Activated Cerium(IV) Oxide/SiMCM-41 Adsorbent in Water.

By using the wetness impregnation-coprecipitation method, a new adsorbent, cerium(IV) oxide coated on SiMCM-41 ((Ce)SiMCM-41), was prepared for removal of fluoride ions from water. Factors investigated were number of impregnations, Ce/Si ratios, concentrations of F(-) ions, pH values, and calcination temperatures. The dynamics, isotherms, and mechanism of adsorption of F(-) ions were discussed. Copyright 2001 Academic Press.

Journal Article↗

PubMed1999

Differential and Tissue-specific Expression of Mitochondrial Elongation Factor Tu and Ts during Development.

The mitochondrial elongation factors Tu and Ts (EF-Tu(mt) and EF-Ts(mt)) are nuclear gene-encoded mitochondrial proteins and play important roles in growth and development. We prepared antibodies against EF-Tu(mt) and EF-Ts(mt) using purified recombinant EF-Tu(mt) and EF-Ts(mt). Western analysis indicates EF-Tu(mt) and EF-Ts(mt) are expressed differently in various tissues. Their expression in heart and liver increased during development and reached plateau at maturation. Expression of EF-Tu(mt) and EF-Ts(mt) exhi-bited similar tissue-specificity and changed synchronically during development. These results suggest that expression levels of EF-Tu(mt) and EF-Ts(mt) may be regulated by a similar mechanism related to the metabolic state of the cells.

Journal Article↗

PubMed1998

Quantification of Outer-Sphere Macrochelate Formation in the Ternary cis-Diammine-Platinum(II)-Bis-2'-deoxyguanosine 5'-Monophosphate Complex, cis-(NH(3))(2)Pt(dGMP)(2)(2)(-), and Formation of Quaternary Mixed Metal Ion Species with Magnesium(II), Copper(II), or Zinc(II) in Aqueous Solution.

The acid-base properties of cis-(NH(3))(2)Pt(dG)(2)(2)(-), where both dG(2)(-) (=2'-deoxyguanosine 5'-monophosphate) are N7-coordinated to the same Pt(II) [the complex is abbreviated as Pt(dG)(2)(2)(-)], are summarized [on the basis of potentiometric pH titration data from B. Song et al. (Metal-Based Drugs 1996, 3, 131-141)] and a micro acidity constant scheme is developed which allows quantification of the intrinsic acidity of the two P(O)(2)(OH)(-) groups present in this ternary complex (I = 0.1 M, NaNO(3); 25 degrees C). On the basis of comparisons with the corresponding acid-base properties of cis-(NH(3))(2)Pt(dCMP.H-N3)(2) [(dCMP.H)(-) = phosphate-monoprotonated 2'-deoxycytidine 5'-monophosphate] it is concluded that intramolecular, outer-sphere macrochelates form via Pt(NH(3)).O(3)P hydrogen bonds. The formation degree of these macrochelates is quantified; it amounts in aqueous solution in each case (in its lower limit) to about 40% for the various possibilities which exist for the formation of these chelates in the cis-(NH(3))(2)Pt(dG)(2) complexes. The stability constants of the mixed metal ion complexes, M[Pt(H;dG)(dG)](+) and M[Pt(dG)(2)], were also determined via potentiometric pH titrations. On the basis of previous measurements with simple phosphate monoesters and phosphonate derivatives, i.e., R-PO(3)(2)(-) with R being a noncoordinating residue (Sigel, H.; et al., Helv. Chim. Acta 1992, 75, 2634-2656), it is shown that the stability of the two mixed metal ion complexes is largely governed by the basicity of the phosphate groups (as quantified via the mentioned microconstants) indicating that the effect of the N7-bound Pt(II) on the phosphate-metal ion binding properties is relatively small. These results suggest that, e.g., a metal ion bound to a nucleobase residue in a nucleotide or in a nucleic acid affects only slightly the metal ion binding capabilities of its phosphate residue or its phosphate backbone.

Journal Article↗

PubMedDate not supplied

Lentiviral vectors.

Vectors based on lentiviruses have reached a state of development such that clinical studies using these agents as gene delivery vehicles have now begun. They have particular advantages for certain in vitro and in vivo applications especially the unique capability of integrating genetic material into the genome of non-dividing cells. Their rapid progress into clinical use reflects in part the huge body of knowledge which has accumulated about HIV in the last 20 years. Despite this, many aspects of viral assembly on which the success of these vectors depends are rather poorly understood. Sufficient is known however to be able to produce a safe and reproducible high titre vector preparation for effective transduction of growth-arrested tissues such as neural tissue, muscle and liver.

Genetic Therapy↗

PubMedDate not supplied

Effects of novel safrole oxide derivatives, 1-propyl-3-(3,4-methylenedioxyphenyl)-2-propanol and 1-isopropoxy-3-(3,4-methylenedioxyphenyl)-2-propanol, on apoptosis induced by deprivation of survival factors in vascular endothelial cells.

Two safrole oxide derivatives, 1-propoxy-3-(3,4-methylenedioxyphenyl)-2-propanol (FOD) and 1-isopropoxy-3-(3,4-methylenedioxyphenyl)-2-propanol (GOD), were newly synthesized as promoters of apoptosis in vascular endothelial cells. The purpose of this study was to investigate the effects of these two safrole oxide derivatives on cell growth and apoptosis induced by deprivation of survival factors (serum and fibroblast growth factors, aFGF and bFGF) in vascular endothelial cells (VECs). MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium) method, agarose gel electrophoresis, laser scanning confocal microscopy, flow cytometry (FCM), and immunofluorescence assay were used. The cells deprived of FGF and serum were exposed to FOD or GOD 30 to 90 mg x L(-1) for 24 h, cell growth was suppressed (p < .05), whereas detachment and DNA fragmentation of these cells were promoted (p < .01). When the cells were treated with FOD 90 mg x L(-) for 24 h, apoptosis rate was 14.99% (p < .01). There were more cells in G2-M phase and less cells in S phase. At 90 mg x L(-1) concentration, GOD blocked 77.03%of the cells at G0-G1 phase., P53 level in VEC exposed to FOD or GOD was increased (p < .01). The data suggested that FOD and GOD might promote apoptosis of VEC by affect the cell cycle distribution, whereas P53 was involved in this pathway.

Apoptosis↗

PubMedDate not supplied

Randomised double blind placebo control study of adjuvant treatment with the metalloproteinase inhibitor, Marimastat in patients with inoperable colorectal hepatic metastases: significant survival advantage in patients with musculoskeletal side-effects.

BACKGROUND: A double blind placebo RCT of adjuvant treatment of the matrix metalloproteinase inhibitor, Marimastat, in patients with unresectable colorectal liver metastases showed no significant effect on survival. There was a statistically significant survival advantage for the marimastat-treated patients with musculoskeletal-side effects, (p = 0. < 000). AIM: To assess the effect of adjuvant Marimastat in patients with inoperable colorectal liver metastases (CRCLM). PATIENTS AND METHODS: Patients (n = 121) with CRCLM, stratified by treatments for their liver disease status prior to randomization, received adjuvant oral Marimastat treatment 10 mg b.d. or placebo for up to two years. RESULTS: Prognostic indicators such as number and size of hepatic lesions and percentage of liver replacement were well distributed between the treatment (57) and placebo (64) groups. There was no significant overall survival advantage for MARIMASTAT TREATMENT: 388 days, 95% CI, 277-499 and placebo 410 days, 95% CI 306-514, (p = 0.5) log rank. Musculoskeletal symptoms in hands, wrists and/or shoulders developed in 35 out of 57 Marimastat-treated patients. Median survival for 35 patients with musculoskeletal symptoms was 619 days, 95% CI, 360-878 days vs 184 days, 95% CI, 77-291, (p = 0.000 log rank) for 22 patients without symptoms. Musculoskeletal symptoms developed within three months of study treatment in 28 out of 35 (80%) patients. CONCLUSION: Increased survival in Marimastat-treated patients with musculoskeletal symptoms suggests that these may be biological evidence of tissue effect with resulting importance for dose optimisation of Marimastat. This should now be studied in the other randomized control trials of Marimastat.

Aged↗