Biomedical subjects

J Zhou

Publications and source records attributed to J Zhou.

At least 235 records · Page 13Linked to original sources

PubMed2001

[High efficient expression of recombinant human platelet factor IV in Pichia pastoris].

OBJECTIVE: To express recombinant human platelet factor 4 (PF4) in methanol yeast. METHODS: PF4 cDNA amplified by PCR was cloned into the mating factor alpha (MFalpha) signal sequence, downstream the alcohol oxidase 1 (AOX 1) promoter of the pPIC9 vector. The reconstructed vector was subsequently integrated into the methanol yeast P. pastoris strain GS115. The highly expressing strain was selected and the protein sequences and their biological activities were assayed. RESULTS: The amino acid sequence of rhPF4 was the same as that of natural one. The rhPF4 can neutralize the anticoagulation effect of heparin in a dose-dependent manner. CONCLUSION: The amount of rhPF4 expressed in methanol yeast meets well the scale for manufacturing. The biological activities of the rhPF4 were the same as that of natural PF4.

Cloning, Molecular↗

PubMed2001

[Study on new techniques for genetic diagnosis of deletional alpha-thalassemia].

OBJECTIVE: To develop polymerase chain reaction (PCR) techniques for diagnosis of three commonest deletional alpha-thalassemia determinants in China: - -(SA), - alpha(3.7) and - alpha(4.2). METHOD: Three groups of primers were designed and used to amplify the respective type of the deletional alpha-thalassemia under an optimized PCR condition, followed by agarose gel electrophoresis and EB-stainning. RESULT: Homozygous and heterozygotes, as well as double heterozygous of the 3 commonest deletions were successfully detected and diagnosed by the developed techniques. The results were identical to that from Southern Blot analysis. Forty two cases of alpha-thalassemia were diagnosed by these techniques. CONCLUSION: The 3 PCR-based techniques established by our lab were accurate, simple, and well reproducible for gene diagnosis of the deletional alpha-thalassemia determinants.

DNA Primers↗

PubMed2001

[Establishment and identification of squamous cell lines carcinoma of tongue transferred with anti-sense cyclin A gene].

OBJECTIVE: The aim of this study is to investigate the relationship between cyclin A and cycle regulation of squamous cells carcinoma of tongue, and to provide basis for cancer gene therapy. METHODS: Eukaryocyte expression vector (pAS-A) containing anti-sense and the full-length human cyclin A complementary DNA (cDNA) (1.77 kb) was constructed and was transferred into squamous carcinoma of the tongue cell line (Tca8113) by Lipofect AMINETM introduction. The positive cell clones were selected with G418. Transcription of Neo gene mRNA and cyclin A mRNA were determined by in situ hybridization. The stable expression of anti-sense cyclin A in the Tca8113 cell line was determined using immunohistochemical methods. RESULTS: After G418 selection, cells transferred anti-sense cyclin A were obtained successfully. The positive cells of in situ hybridization of specific-stained Neoprobe were observed in cells transferred eukaryocyte expression vector. The positive cells of in situ hybridization of cyclin A in cells transferred anti-sense cyclin A were significantly fewer than those in cells transferred cyclin A. The positive rate of cyclin A immunohistochemical stain in cells transferred anti-sense cyclin A was significantly lower than that in cells transferred cyclin A. CONCLUSION: Human anti-sense cyclin A gene is stably expressed in the Tca8113 cell lines.

Carcinoma, Squamous Cell↗

PubMed2001

[Research and establishment of the computerized orthodontic and orthopedic prediction system].

OBJECTIVE: The aim of this study was to develop a computerized orthopedics and orthodontics interactive prediction system and verify its reliability. METHODS: 24 cases of Angel II division I patients were selected in the study. All of them had been treated by activator or Frankel functional appliance, and had the satisfied therapy result. Both pre and post-treatment cephalogram of them were used verifying veracity of therapy prediction. RESULTS: All of cephalometric measure items include 11 angle measure items and 14 distance measure items. There were 9 coincidence indicators in angle measure items and 7 in distance measure items. CONCLUSION: The results indicate it is liable and effective to use the computerized orthopedics and orthodontics system for prediction.

Activator Appliances↗

PubMed2001

[Establishment and research of the computerized profile and photo prediction system].

OBJECTIVE: The study aims to develop a lateral oral facial profile and photo prediction system and then to verify its reliability. METHODS: 24 paired lateral cepholagrams in both pre- and post-treatment were selected and analyzed by three soft tissue cephalometric analysis methods in this study. All cases were of the angel II division I malocclusion, and had been successfully treated with the orthopedics therapy by activator or Frankel appliance. Soft tissue profile prediction had been automatically completed, following the hard tissue interactive orthopedics prediction approach in the pretreatment lateral cephalogram, and the predictive results were compared to the same cepholametric analysis in post-treatment cephalogram. RESULTS: There are 19 coincidence indicators in 30 measurements of three soft tissue cephalometric analysis, and 7 in 9 angel measurements, 10 in 18 instance measurements, 2 in 3 instance ratio measurements is consistency, respectively. CONCLUSION: The results indicate that the lateral oral facial profile and photo prediction system is effective in profile prediction.

Activator Appliances↗

PubMed2001

[Comparison of the post-operative complication in head-neck malignant neoplasms between aged and pre-aged].

OBJECTIVE: To compare the post-operation complication of head-neck malignant tumor in the aged with pre-aged. METHOD: 80 aged and 92 pre-aged cases of head-neck tumor were performed operation. In the aged group, 26 cases were performed with preoperative radiotherapy and 13 cases with postoperative radiotherapy. In the pre-aged group, 40 cases were performed with preoperative radiotherapy and 6 cases with postoperative radiotherapy. RESULT: The incidence of complication in the aged is higher than that in the pre-aged group. Moreover, the post-surgery complications of tumor in head and neck in the aged preferably appear in the cardiopulmones and urology. In contrast, most of the complication in the pre-aged appears in the incision of operation. CONCLUSION: Prior to surgery, we should clear with the situation of patients, and consequently choose appropriate methods of operation. Age does not play an essential role in the decision of the methods of operation.

Age Factors↗

PubMed2001

[1.4 kb 5' flanking region of class I patatin directs tuber-specific gus expression in potato (Solanum tuberosum L.)].

Binary vectors pPATIs (with partial signal sequence) and pPATI (without signal sequence) were constructed by fusing 1.4 kb 5' flanking regions of Class I patatin gene with GUS. Transient GUS expression was observed in in vitro tuber slices bombarded with pPATI. These constructs were then introduced into potato (cv. Desiree) via Agrobacterium tumefaciens transformation. Transgenic potato plants were confirmed by X-Gluc staining and PCR. Using in vitro tuberization system, GUS activities were assayed by fluorescence. It was shown that, in plants transformed with PATI-GUS, GUS specific activities were about 10-20 fold higher in tubers than in stems. Increased sucrose concentration could not induce PATI-GUS expression, but light enhanced PATI-GUS expression in cultured shoots.

Carboxylic Ester Hydrolases↗

PubMed2001

[Detection of trehalose in transgenic tobacco by HPLC with ELSD].

The E. coli trehase synthalose gene(otsA) was transferred into Nicotiana tabacum mediated by Agrobacterium, but the method for detecting low concentration of trehalose in transgenic plant was not available. The high performance liquid chromatograph(HPLC) with evaporative light-scatting detector(ELSD) using water: methyl cyanide(1:2.6 v/v) as mobile phase was established in this work. An ODS column Zorbax RX-SIL was employed. the trehalose detection limits of ELSD was 5 mg/L. From the linear relationship between the logarithm of trehalose concentration and the logarithm of peak area, it was shown there was 14.7 micrograms.(g FW)-1 in transgenic plant. The data strongly confirmed that trehalose was responsible for the improved stress tolerance of the tobacco.

Chromatography, High Pressure Liquid↗

PubMed2001

[Expression of otsA gene in tobacco and improvement stress tolerance].

The Escherichia coli trehalose-6-phosphate synthase gene(otsA) was engineered under the control of cauliflower mosaic virus regulatory sequences (CaMV35S) for expression in plants. OtsA gene was incorporated into the chromosome DNA by Agrobacterium-mediated transfer and expressed in Nicotiana tabacum. The otsA gene transgenic plant exhibited multiple phenotypic alteration: improved stunted growth and drought tolerance. The detached leaves from the transgenic plant, their water loss slower than that of the controls. Trehalose accumulated in transgenic plant was determined by HPLC suggest that synthesis of the sugar improving plant to stress tolerance.

Gene Expression↗

PubMed2001

[Incompatibility among indigenous plasmids of Sinorhizobium fredii strains and its application for plasmid curing].

The indigenous plasmids of S. frediii HN01 and WWG18 were labeled with Tn5-MobsacB. Those plasmids were cured on TY medium containing 10% sucrose to identify its function. The pSymHN01b of HN01 was transferred into WWG18SR and C361SR. The results of plasmid detection, curing and pot plant experiment revealed that the incompatibility was existed between pSym-HN01b and symbiotic plasmid of WWG18SR or the third plasmid of C361SR. But it was compatible with the nonsymbiotic plasmid of WWG18SR and symbiotic plasmid of C361SR. Using plasmid incompatibility, The symbiotic plasmid of WWG18SR and one nonsymbiotic plasmid of C361SR were eliminated successfully.

Conjugation, Genetic↗

PubMed2001

[Effect of cadmium on the phagocytic function of polymorphonuclear leukocyte in mice tested by chemiluminescence of whole blood].

The effect of cadmium chloride on the immunological toxicity of polymorphonuclear leukocyte (PMN) and on lipid peroxidation in liver were measured by using the chemiluminesence of whole blood and thiobarbituric acid (TBA) method. The results showed that 0.1 and 10 mmol/L of cadmium chloride could accelerate the chemiluminesence of whole blood in vitro, but 1000 mmol/L of cadmium chloride inhibit the chemiluminesence. Two hours after the injection of cadmium chloride through caudal vein, chemiluminesence of whole blood was induced obviously at the dose of cadmium 1 and 100 micrograms/kg BW in vivo, but the chemiluminesence was inhibited at the dose of 500 and 1000 micrograms/kg BW. At the dose of 1 microgram/kg BW, the peroxidation of liver lipids was induced. The results suggested that cadmium at low concentration accelerated the immunity of PMN, while high concentration was toxic to PMN, cadmium at low concentration could accelerate the phagocytic function of phagocytes. Phagocytosis brings about excessive active oxygen in organism and intensifies the action of active oxygen on the lipid peroxidation in tissue cells, at last, results in organic oxidation injury.

Animals↗

PubMed2001

[Pharmacokinetics of site-specific delivery of dexamethasone-dextran prodrug in rat gastrointestinal tract].

AIM: To explore whether dexamethasone-dextran (260,000) has the characteristics of site-specific delivery in rat gastrointestinal tract. METHODS: Dexamethasone prodrug and dexamethasone were administered to rat ig at the dose of 5 mumol.kg-1. The distribution of dexamethasone in the contents and mucosa of different parts of the rat GI tract at different time intervals and its concentration in plasma were determined by HPLC. RESULTS: Dexamethasone was mainly released in the cecum and colon contents and mucosa after oral administration of dexamethasone prodrug. The absorption was reduced significantly. The peak time of the drug in plasma was 8.1 h, and the peak concentration was 32 micrograms.L-1. However, free dexamethasone was found mainly in the contents and mucosa of the stomach, proximal and distal small intestine. The peak time of the drug in plasma was 2.2 h, and the peak concentration was 2120 micrograms.L-1. CONCLUSION: Dexamethasone can be specifically delivered to the large intestine by using dexamethasone-dextran (260,000). It appears that the prodrug has a potential in the treatment of inflammatory bowel disease.

Animals↗

PubMed2001

Regulating effects of vascular endothelial growth factor and ANG II on frog's pericardial stomata, mesothelium and angiogenesis.

OBJECTIVE: To observe the regulating effects of vascular endothelial growth factor (VEGF) and angiotensin II (ANG II) on the frog's pericardium, lymphatic stomata and angiogenesis so as to reveal their effects and mechanism on the mesothelial permeability, lymphatic stoma regulation and myocardial hypertrophy. METHODS: VEGF and ANG II were injected into the frog's peritoneal cavity so as to examine the changes of the pericardial stromata by using transmission electron microscopy, scanning electron microscopy and computerized imaging analysis. RESULTS: Scattered distributed pericardial stomata were found on the parietal pericardium of the frog with a few sinusoid mesothelial cells, whose blood supply was directly from the cardiac chambers flowing into the trabecular spaces of the myocardium (because there are no blood vessels in the myocardium of the frog). The average diameters of the pericardial stomata in VEGF and ANG II groups were 1. 50 microm and 1.79 microm respectively, which were much larger than those in the control group (0.72 microm, P < 0.01); the average distribution densities of the stomata were 8. 25/0.1 mm2 and 12.80/0.1 mm2 in VEGF and ANG II groups, which were also much higher than those in the control group (3.57/0.1 mm2, P < 0.01); the sinusoid areas in VEGF and ANG II groups were 2442.95 microm2/0.1 mm2 and 2121.79 microm2/0.1 mm2, which were larger than that in the control group (995.08 microm2/0.1 mm2 , P < 0.01); no angiogenesis was found in the frogs of the experimental groups. CONCLUSIONS: VEGF and ANG II could strongly regulate the pericardial stomata by increasing their numbers and openings with larger diameters and higher distribution density. They could also increase the sinusoid areas with the result of the higher permeability of the pericardium, which clearly indicated that VEGF and ANG II could speed up the material transfer of the pericardial cavity and play an important role in preventing myocardial interstitial edema. Yet there was no strong evidence to show the angiogenesis in the myocardium.

Angiotensin II↗

PubMed2001

Relation between alkaline phosphatase in gingigval crevicular fluid of implant teeth and the curing result.

OBJECTIVE: To discover the relation between alkaline phosphatase (ALP) in gingival crevicular fluid (GCF) of implant teeth and the curing results. METHODS: We measured the ALP level in GCF among 56 cases of implant teeth which included 2 failed cases, 5 cases with bad oral hygiene and gingivitis, and compared it with that in the normal group composed of 10 persons. RESULTS: The ALP levels in normal group and success implant group showed no difference. The ALP levels in normal group and success with gingivitis group showed obvious difference. The ALP levels of the 2 failed cases are the highest of all. CONCLUSIONS: The ALP level in GCF is an important index in evaluating the curing result of the implant teeth.

Adult↗

PubMed2001

[Relation between alkaline phosphatase in gingival crevicular fluid of implant and the curing result].

OBJECTIVE: To investigate the relation between alkaline phosphatase (ALP) in gingival crevicular fluid (GCF) and prognosis. METHODS: We measured the alkaline phosphatase in gingival crevicular fluid among 56 cases of implant tooth which included 2 failed cases, 5 cases in bad oral hygiene and with gingivitis, compared with the normal group consisted of 10 healthy persons. RESULTS: The difference of ALP level between normal group and success implant group is not significant, but between normal group and success with gingivitis group is significant(P < 0.05). The ALP level of 2 failed cases are highest (because of few failed cases, no statistics was done). CONCLUSIONS: The ALP level in GCF is supposed to be an important index in evaluating the result of the implant.

Adult↗

PubMed2001

[Analysis on the trace element and amino acid content in xinjiang 6 series Rhodiola L. plant].

Trace elements Na, K, Mg, Ca, Mn, Fe, Cu, Zn, Se and 20 kinds of amino acid in Xinjiang 6 series of Rhodiola's root and rootstalk were measured. The result shows that contents of 9 kinds of trace elements in them are different. They contain from 8 to 18 kinds amino acid, and also contain from 3 to 7 kinds of indispensable amino acid respectively. Rhodiola rosea L. contains most kinds of amino acid among six kinds of Rhodiola L. in Xingjiang, and contents of trace elements in it are also moderate, so it is fittest to be a nutrious chinese traditional and herbal drug of six kinds of Rhodiola L. in Xingjiang.

Amino Acids↗

PubMed2001

[Determination of sulfamethoxazole in compound sulfamethoxazole tablet by first derivative ratio spectrometry].

The first derivative ratio spectrometry is used for the determination of sulfamethoxazole in compound sulfamethoxazole tablet. According to the first derivative ratio spectrum of sulfamethoxazole, peak-zero method is applied for the determination at 251 nm. There is a good linear correlation between the first derivative ratio spectrum value and concentration (1-15 micrograms.mL-1) for the method that can eliminate the disturbance of trimethoprim, and no difference while comparing the method with pharmacopoeia method (P > 0.05).

Spectrophotometry, Ultraviolet↗

PubMed2000

Corticosterone inhibits generation of long-term potentiation in rat hippocampal slice: involvement of brain-derived neurotrophic factor.

In the present study, the effect of corticosterone (CORT) on the generation of long-term potentiation (LTP) and its underlying mechanism involving neurotrophin gene expression in CA1 synapses of rat hippocampal slice were examined. Our experimental results showed incubation of hippocampal slice with CORT for 3 h had no effect on either the slope or amplitude of excitatory postsynaptic potentials (EPSP) evoked in hippocampal CA1 pyramidal dentrites, indicating no marked change in basal synaptic transmission. However, when tetanic stimulation (100 pulses, 100 Hz) was delivered to the Schaffer collateral pathway, CORT application significantly attenuated the tetanus-induced increases of both EPSP slope and amplitude, demonstrating an inhibitory effect of CORT on LTP generation. In addition, CORT treatment significantly reduced both slope and amplitude ratios of the second evoked EPSP to the first one when paired-pulse facilitation (PPF) was established at different interpulse intervals from 20 to 40 ms, suggesting that a presynaptic mechanism may be involved in CORT-induced hippocampal synaptic plasticity. Reverse-transcription polymerase chain reaction (RT-PCR) analysis showed that CORT-treated hippocampal CA1 cells underwent a significant decrease in the expression of mRNA for nerve growth factor-beta (NGF-beta) and brain-derived neurotrophic factor (BDNF), but not for neurotrophin-3 (NT-3) compared with those in control. Moreover, BDNF co-applied with CORT significantly antagonized CORT-induced deficit in PPF. Taken together, the present results suggest that CORT-induced inhibition of LTP may be, at least to some extent, mediated by a presynaptic mechanism and decrease in the BDNF expression in rat hippocampal CA1 cells induced by CORT may partially account for this presynaptic mechanism.

Animals↗