Search PubMed⌕ Search

Biomedical subjects

Jun Zhao

Publications and source records attributed to Jun Zhao.

At least 109 records · Page 6Linked to original sources
PubMed2003

Metabolic effects of a novel bioartificial liver on serum from severe hepatitis patients: an in vitro study.

OBJECTIVE: To establish a novel bioartificial liver (BAL) consisting of spheroids of porcine hepatocytes in a hollow-fiber bioreactor, and to perform an in vitro study on its metabolic effects on the serum from severe hepatitis B patients. METHODS: Hepatocytes were isolated from pup pigs and cultured as aggregate spheroids through rotation and vibration. Phase-contrast microscopy, transmission electron microscopy, and scanning electron microscopy were used for morphological detection of hepatocyte spheroids. The hepatocyte spheroids were then transferred into the shell of a polysulfone hollow-fiber bioreactor, creating a novel BAL. Diluted serum samples of severe hepatitis B patients were circulated for 3 hours each into the bioreactor, by using an extracorporeal circulatory system. Every half hour, including both before and after perfusion, serum samples were collected to assay total bilirubin (TBIL), total protein (TP), albumin (ALB), and globulin (GLB) concentrations in order to judge the metabolic effects of this novel BAL. RESULTS: Most hepatocytes had formed spheroids with high viability after 24 hours in culture. After 3 hours of perfusion, when compared with the control group, the serum concentration of TBIL in the treatment group decreased significantly (P < 0.01), but the serum concentrations of TP and ALB increased significantly (P < 0.05). CONCLUSIONS: Hepatocytes can be conveniently cultured as aggregate spheroids through a rotation and vibration method. The novel BAL is efficient in removing bilirubin from the serum of severe hepatitis B patients, and in supplying the serum with ALB. Thus, the BAL might provide effective therapy for patients with severe hepatitis B.

Bilirubin↗
PubMed2003

Effects of blocking androgen receptor expression with specific hammerhead ribozyme on in vitro growth of prostate cancer cell line.

OBJECTIVE: To study the possibility of gene therapy for prostate cancer by blocking androgen receptor (AR) gene expression using a specific hammerhead ribozyme (RZ). METHODS: The hammerhead ribozyme expression vector pcDNA-hAR-RZ, specific to AR mRNA, was constructed and transfected into the prostate cancer cell line LNCaP by using lipofectamine. Androgen receptor expression was measured by RT-PCR and immunohistochemical methods. Cellular proliferation activities were assayed using the tetrazolium bromide colorimetry method; cell cycle changes were observed by flow cytometry; and cell apoptosis was detected by the TdT-mediated dUTP-biotin nick end labeling method. RESULTS: One to seven days after transfection with the ribozyme expression vector, AR mRNA expression at molecular and protein levels in LNCaP cells decreased by 32.6% - 40.7% (P < 0.05) and 21.0% - 87.64% (P < 0.05) respectively, and cell proliferation was inhibited by 18.28% - 35.34% (P < 0.05). Meanwhile, the cell cycle was arrested at the G2/M stage, and apoptotic morphological changes occurred with an apoptosis rate of 25.17% (P < 0.01). CONCLUSION: Ribozyme specific against AR mRNA is capable of inhibiting the expression AR and inducing the apoptosis in prostate cancer cells.

Apoptosis↗
PubMed2003

[Cloning and expressing the E2 subunit of pyruvate dehydrogenase complex].

OBJECTIVES: To construct the expression vector of the pyruvate dehydrogenase complex E2 subunit gene (PDC-E2). METHODS: The PDC-E2 gene was amplified from human lymphocytes with RT-PCR, and was cloned into pExSecI vector to induce the PDC-E2 expression. The products were identified with western blot and ELISA. RESULTS: The expression vector pExSecI/PDC-E2 was successfully constructed. The products could be identified by the specific self-antibodies in the sera from the primary biliary cirrhosis patients. CONCLUSION: High efficient expression vector of PDC-E2 lays the foundation for serum assay of primary biliary cirrhosis patients with prokaryotic expressing PDC-E2.

Cloning, Molecular↗
PubMed2003

[Correction of malmaxillomandibular relation with therapeutic complete denture].

OBJECTIVE: The purpose of this study is to evaluate the effect of therapeutic complete denture in rectifying malmaxillomandibular relation of complete. METHODS: 11 patients were treated with therapeutic complete denture, of which the maxillary premolars and molars were artificial ceramic teeth and mandibular premolar and molar region was just like a splint. The changes before and after the treatment were recorded by mandibular kinesiograph(MKG). The effect was evaluated by self-control comparison. RESULTS: After rectifying, the concentration of the closing locus end position evidently increased, the symmetry of mandible motion significantly improved, CRO-ICO three-dimensional slide range decreased and moreover, the teeth had even and stable contact during sliding. CONCLUSION: The temporary therapeutic complete denture had a fair effect in rectifying malmaxil-lomandibular relation of edentulous patients.

Aged↗
PubMed2003

[Construction, expression and functional characterization of disulfide-stabilized anti-hepatocarcinoma single chain Fv fused with truncated Pseudomonas exotoxin].

AIM: To prepare fusion protein of disulfide-stabilized anti-hepatocarcinoma single chain Fv(dsFv)and truncated Pseudomonas exotoxin(PE38). METHODS: The gene encoding the fusion protein was cloned into the prokaryotic expression vector pTIG which was then transformed into E.coli origami(DE3). The expressed product was purified through Ni-NTA agarose affinity chromatography column. The cytotoxicity of the purified dsFv-PE38 was detected by MTT colorimetry. RESULTS: The immunotoxin dsFv PE38 was expressed in E.coli origami(DE3) in a soluble form, which accounted for nearly 21% of the total bacterial soluble proteins. The results of cytotoxic assay showed that the dsFv-PE38 could specifically kill hepatocarcinoma cells, while spared the normal hepatic cells. CONCLUSION: The immunotoxin dsFv-PE38 may have some potential value in the treatment of hepatocarcinoma.

ADP Ribose Transferases↗
PubMed2002

Crystal structure of the cytoskeleton-associated protein glycine-rich (CAP-Gly) domain.

Cytoskeleton-associated proteins (CAPs) are involved in the organization of microtubules and transportation of vesicles and organelles along the cytoskeletal network. A conserved motif, CAP-Gly, has been identified in a number of CAPs, including CLIP-170 and dynactins. The crystal structure of the CAP-Gly domain of Caenorhabditis elegans F53F4.3 protein, solved by single wavelength sulfur-anomalous phasing, revealed a novel protein fold containing three beta-sheets. The most conserved sequence, GKNDG, is located in two consecutive sharp turns on the surface, forming the entrance to a groove. Residues in the groove are highly conserved as measured from the information content of the aligned sequences. The C-terminal tail of another molecule in the crystal is bound in this groove.

Amino Acid Sequence↗
PubMed2002

Effects of intestinal survival surgery on systemic and mucosal immune responses in SIV-infected rhesus macaques.

Evaluation of cellular immunity in the intestinal lamina propria of rhesus macaques has been used previously to assess protective immunity against mucosal simian immunodeficiency virus (SIV) challenges. As this technique requires survival surgery to obtain jejunal tissue, effects of surgical stress on the immune system were investigated. SIV-specific immune responses, including IgG and IgA binding antibodies in sera and mucosal secretions, IgG and IgA secreting cells in peripheral blood, IgG neutralizing antibodies, T-cell proliferative responses, and interferon-gamma secretion by peripheral blood mononuclear cells, were evaluated pre- and post-surgery in macaques immunized with adenovirus-SIV recombinant vaccines and SIV envelope protein and in SIV-infected macaques. No differences in these immune parameters were observed in SIV-naïve, immunized macaques or healthy SIV-infected macaques with regard to surgery. A dramatic increase in total IgA antibody level following surgery in the rectal secretions of one SIV-infected macaque that was rapidly progressing to AIDS and failed to recover from surgery was attributed to an abscess that developed at the intestinal site. To date, nearly 30 other macaques have undergone the intestinal survival surgery, some on more than one occasion, without experiencing any clinical difficulty. Overall, our results suggest that in healthy macaques, intestinal resection survival surgery can be conducted safely. Further, the method can be used to reliably sample the intestinal mucosa without major or persistent impact on humoral or cellular immune responses.

Animals↗
PubMed2002

ATP-induced endothelium-independent enhancement of lymphatic vasomotion in guinea-pig mesentery involves P2X and P2Y receptors.

1. The present study has investigated mechanisms underlying ATP-induced endothelium-independent enhancement of vasomotion in guinea-pig mesenteric lymphatic vessels. 2. Lymphatic vasomotion, vessel tone and smooth muscle [Ca(2+)](i) showed similar ATP concentration-response curves. 3. ATP, at 0.1 mM, caused a biphasic increase in tonic [Ca(2+)](i) and superimposed vasomotion-associated Ca(2+) transients. All ATP-induced [Ca(2+)](i) changes were abolished by incubating the smooth muscle with suramin (0.1 mM). 4. alpha,beta-MeATP (0.1 mM) and UTP (0.1 mM) caused similar changes in [Ca(2+)](i) but the responses to these agonists were smaller than to ATP. 5. The actions of alpha,beta-MeATP (0.1 mM) were inhibited by suramin (0.1 mM) and PPADS (30 micro M) but not by reactive blue 2 (30 micro M). 6. In the presence of alpha,beta-MeATP (0.1 mM), the increases in tonic [Ca(2+)](i) and vasomotion-associated Ca(2+) transients induced by ATP (0.1 mM) were inhibited by U73122 (5 micro M), CPA (20 micro M) and heparin, whereas U73343 (5 micro M) and pre-treatment with PTx (100 ng ml(-1)) had no significant effects. 7. Depletion of the intracellular stores with CPA (20 micro M) caused an increase in [Ca(2+)](i), which was not blocked by desensitization of P(2X) receptors with alpha,beta-MeATP. 8. The data indicate that ATP, at relatively high concentrations increases lymphatic smooth muscle [Ca(2+)](i) and vasomotion through activation of P(2X1) and P(2Y2) purinoceptors present on lymphatic smooth muscle. The increase in [Ca(2+)](i) is likely to result from Ca(2+) release from inositol-1,4,5-trisphosphate-sensitive stores as well as Ca(2+) influx through store-operated channels and P(2X)-gated channels.

Adenosine Triphosphate↗
PubMed2002

Potent, persistent cellular immune responses elicited by sequential immunization of rhesus macaques with Ad5 host range mutant recombinants encoding SIV Rev and SIV Nef.

Vaccines incorporating multiple HIV components should elicit broad immunity and protection against a spectrum of HIV strains. Early regulatory and accessory gene products are attractive candidates for such vaccines. Here, immunogenicity studies on SIV Rev and Nef expressed in replication competent Adenovirus type 5 host range mutant vectors (Ad5hr) are summarized. Interferon-gamma (IFN-gamma)-secreting cells in response to Env and Rev peptides were enumerated by ELISPOT after two sequential immunizations of 55 macaques with Ad5hr-SIVenv/rev. Responses to SIV Nef were assessed in 16 macaques also immunized with Ad5hr-SIVnef. Potent cellular immunity to both Rev and Nef was induced following the second Ad-recombinant immunization and persisted for at least 30 weeks. Persistent cellular immunity to SIV Env was also seen, with a mean of 700 IFN-gamma-secreting cells per million PBMC. Rev and Env responses were positively correlated. While greater responses to early gene products occur in natural infection, as immunogens Rev and Nef elicited the same number of IFN-gamma secreting cells as Env, after adjusting for differences in protein size. The same percentage of macaques also responded to Rev, Nef, and Env: 59, 63, and 64%, respectively. Overall, Ad5hrSIVenv/rev and -SIVnef were highly effective immunogens. Their contribution to protective efficacy will be addressed in future studies.

AIDS Vaccines↗
PubMed2002

Two putative BIN2 substrates are nuclear components of brassinosteroid signaling.

GSK3 is a highly conserved kinase that negatively regulates many cellular processes by phosphorylating a variety of protein substrates. BIN2 is a GSK3-like kinase in Arabidopsis that functions as a negative regulator of brassinosteroid (BR) signaling. It was proposed that BR signals, perceived by a membrane BR receptor complex that contains the leucine (Leu)-rich repeat receptor-like kinase BRI1, inactivate BIN2 to relieve its inhibitory effect on unknown downstream BR-signaling components. Using a yeast (Saccharomyces cerevisiae) two-hybrid approach, we discovered a potential BIN2 substrate that is identical to a recently identified BR-signaling protein, BES1. BES1 and its closest homolog, BZR1, which was also uncovered as a potential BR-signaling protein, display specific interactions with BIN2 in yeast. Both BES1 and BZR1 contain many copies of a conserved GSK3 phosphorylation site and can be phosphorylated by BIN2 in vitro via a novel GSK3 phosphorylation mechanism that is independent of a priming phosphorylation or a scaffold protein. Five independent bes1 alleles containing the same proline-233-Leu mutation were identified as semidominant suppressors of two different bri1 mutations. Over-expression of the wild-type BZR1 gene partially complemented bin2/+ mutants and resulted in a BRI1 overexpression phenotype in a BIN2(+) background, whereas overexpression of a mutated BZR1 gene containing the corresponding proline-234-Leu mutation rescued a weak bri1 mutation and led to a bes1-like phenotype. Confocal microscopic analysis indicated that both BES1 and BZR1 proteins were mainly localized in the nucleus. We propose that BES1/BZR1 are two nuclear components of BR signaling that are negatively regulated by BIN2 through a phosphorylation-initiated process.

Amino Acid Sequence↗
PubMed2002

[Treatment of severe viral hepatitis with artificial liver support system].

BACKGROUND: To investigate the method and therapeutic efficacy of artificial liver support system (ALSS) in treatment of severe viral hepatitis. METHODS: A total of 83 patients including 66 with severe viral hepatitis were treated with ALSS using Baxter-550 artificial kidney and Biologic-DT system. RESULTS: The levels of mean bilirubin, ALT, AST, BUN, Cr and endotoxin was significantly decreased after the treatment. Of the 66 patients?with severe viral hepatitis, 31(47.0%) had improvement in symptoms and 35 (53.0%) died or left hospital. In the control group,50(27.6%) out of the 181 had improvement in symptoms and 131(72.4%) died or left hospital. CONCLUSIONS: ALSS could exert certain therapeutic effects on severe viral hepatitis.

Adult↗
PubMed2002

[Diagnosis and treatment of metachronous multiple primary lung cancer].

BACKGROUND & OBJECTIVE: There is much controversy on the diagnosis and treatment of metachronous multiple primary lung cancer (MMPLC). Until now, there is no absolutely accurate diagnostic criteria. This study was designed to discuss its diagnosis, and to compare the survival rates after different therapeutic modalities. METHODS: The clinical features of 44 patients with MMPLC admitted to our hospital since 1961 were analyzed retrospectively. RESULTS: There were 44 patients in this series, which accounted for 0.39% of all patients with lung cancer treated in our hospital. As to the initial cancer and the repeated cancer, they shared the same pathological type in 23 patients, and located on the same side of the lung in 12 patients. Twenty-four patients received operations, including 12 curative patients. The postoperative morbidity and mortality were 33.3% and 8.3%, respectively. The other 20 patients received radiotherapy or/and chemotherapy. The 5-year survival rates of operative group, curative operative group, and non-operative group were 20.8%, 33.4%, and 10.0%, respectively. CONCLUSIONS: Comprehensive consideration of clinical features may lead to a rational diagnosis and treatment strategy, 5-year survival rate of the operative group, especially the curative group, is significantly higher than that of the non-operative group. The repeated operation, especially the second operation on the same side of the lung, should be performed at the qualified institutes and by the experienced doctors.

Adult↗
PubMed2002

[Synthesis and insecticidal activity of the novel hydroxylbenzenedisulfonanilides compounds].

AIM: To synthesize novel derivatives of hydroxylbenzenedisulfonanilide with high insecticidal activity against the Fasciola hepatica. METHODS: o-(m-, p-) Chlorphenol were used to synthesize the title compounds by sulphonation and nucleiphilic-substitution reaction. The uncoupling activity (insecticidal activity) of these compounds were tested by determining the influence on mitochondrial respiration control ratio (RCR) and the variation of inorganic phosphate in oxidative phosphorylation (delta Pi). RESULTS: Compounds 1-14 are new compounds. The structures of the compounds were determined by IR, HNMR and elemental analysis. Most new compounds have relatively high uncoupling activities, especially compounds 3, 5, 6 and 9. CONCLUSION: Compounds 3, 5, 6 and 9 will become novel fasciolicides and are worth further studying.

Anilides↗
PubMed2002

[Chromosome localization of the dentinogenesis imperfecta type II locus].

OBJECTIVE: To investigate the linkage between dentinogenesis imperfecta type II and chromosome 4q21 in a Tianjin-Tanggu family of the Hui nationality. METHODS: Blood samples were collected from 13 family members. DNAs were analyzed with 8 STRP markers (D4S2915, D4S2932, GATA62A11, D4S2409, DSP STRP, SPP1 STRP, D4S1563, D4S1544) using fluorescence-based PCR. The linkage between eight markers on chromosome 4q21 and dentinogenesis imperfecta type II locus was tested respectively by lod score analysis. RESULTS: Genotype and haplotype were acquired. Genetic linkage analysis demonstrated the maximum lod score of eight STRPs were all larger than zero, in which five of them were larger than 1. CONCLUSION: The locus of dentinogenesis imperfecta type II in Chinese family is located on human chromosome 4q21, which indicated that the locus of Chinese Hui nationality should be the same as that of other reported European or American family.

Chromosome Mapping↗
PubMed2002

[Effects of laser in situ keratomileusis (LASIK) retreatment on the central corneal endothelium and retina and optic nerve].

OBJECTIVE: To investigate the effects of laser in situ keratomileusis (LASIK) on the corneal endothelium, retina and optic nerve for correcting residual myopia caused by undercorrection or regression. METHODS: The pre- and post-operative values of central corneal endothelium and electrophysiological functions of retina and optic nerve were analyzed respectively in 23 eyes of 18 patients who received LASIK retreatment. The endothelium checked by contact specular microscopy was analyzed for central cell density (CCD), coefficient of cell variation in size and hexagonality preoperatively and 1, 4, 12 weeks after the operation. The amplitude and latency of P(100) in standard pattern visual evoked potentials (P-VEPs), that of a, b waves of different reactions in flash electroretinograms (F-ERGs) and also the total amplitude of oscillatory potentials (OPs) were evaluated preoperatively and 2, 12 weeks after the operation. RESULTS: The mean CCD decreased significantly (3.94%) one week after the operation (P < 0.01). The change was negatively correlated with the thickness of residual untreated posterior cornea (r = -0.719, P < 0.01) and not significantly correlated with the amount of laser pulse (r = 0.371, P > 0.05). There was no significant difference between preoperative and either 4 or 12 week postoperative CCD (P > 0.05). No significant differences in mean coefficient variation and hexagonality were found between preoperative and postoperative values in the follow up (P > 0.05). Examination of electrophysiological function showed that the amplitude of P(100) increased and the latency of P(100) decreased 2 and 12 weeks postoperatively. The significant changes were only at spatial frequency 34' in the P-VEPs test (P < 0.05). In F-ERGs test, there was no significant change in amplitude, latency of a, b waves or total amplitude of OPs between pre-operative and either 2 or 12 week post-operative values (P > 0.05). CONCLUSIONS: Retreatment after LASIK may cause a reversible reduction of CCD with no morphological changes in a short period (1 week) after the operation. It was not absolutely safe for corneal endothelium when the thickness of residual untreated basal cornea approaches to 200 micro m. These results show that the operation seems not to cause functional impairment in the retina and optic nerve. And it also can improve the quality of vision for some degrees.

Adult↗
PubMed2002

[Studies on the chemical constituents in root of Rheum rhizastachyum].

OBJECTIVE: To investigate the chemical constituents from the root and rhizome of Rheum rhizastachyum. METHOD: The compounds were isolated by column chromatography on silica gel, Sephadex LH-20, MCI-gel CHP-20P separately and their structures were elucidated by chemical and spectral technology. RESULT: Six compounds were isolated and identified as chrysophanol, emodin, gallic acid, sucrose, 1-O-beta-D-glucopyranosyl-chrysophanols, 1-O-beta-D-glucopyranosyl-emodin. CONCLUSION: All the compounds were obtained from this plant for the first time.

Anthraquinones↗
PubMedDate not supplied

Preclinical acute toxicity studies and dosimetry estimates of the novel sigma-1 receptor radiotracer, [18F]SFE.

[(18)F]1-(2-Fluoroethyl)-4-[(4-cyanophenoxy)methyl]piperidine ([(18)F]SFE) is a novel, selective, high-affinity sigma-1 receptor radioligand that has been preclinically well characterized in rodents. To support an investigational new drug (IND) application for the first evaluation of [(18)F]SFE in humans, single-organ and whole-body radiation adsorbed doses associated with [(18)F]SFE injection were estimated from rat distribution data. In addition, single- and multiple-dose toxicity studies were conducted in rabbits and in dogs. Multiple-dose toxicity studies in rabbits and single-dose toxicity studies in beagles suggest at least a 100-fold safety margin for humans studies at a mass dose limit of 4.0 mug per intravenous injection, based on the combined no observable adverse effect levels (NOAEL, mg/m(2)) measured in these species. Radiation dosimetry estimates obtained from rat biodistribution analyses of [(18)F]SFE suggest that most tissues would receive about 0.010-0.020 mGy/MBq, while the adrenal glands, brain, bone, liver, lungs, and spleen would receive slightly higher doses (0.024-0.044 mGy/MBq). The adrenal glands were identified as the critical organ, because they received the highest adsorbed radiation dose. The total exposure resulting from a 5 mCi administration of [(18)F]SFE is well below the FDA-defined limits for yearly cumulative and per-study exposures to research participants. These combined results support the expectation that [(18)F]SFE will be safe for use in human positron emission tomography (PET) imaging studies with the administration of 5 mCi and a mass dose equal to or less than 4.0 mug SFE per injection.

Animals↗