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Biomedical subjects

W Zhou

Publications and source records attributed to W Zhou.

At least 199 records · Page 11Linked to original sources
PubMed1999

[Studies of the mechanism of lowering intraocular pressure on Erycibele alkaloid].

OBJECTIVE: To investigate the molecular pharmacological mechanism of lowering intraocular pressure of Erycibele alkaloid. METHODS: Rabbit pupil diameter was measured by a pupillary ruler in constant illumination and the intraocular pressure (IOP) was measured by pneumatonometer. Iris contracting force was measured in an experiment of isolated rabbit iris. Radioimmune method was used to determine the content of cyclonucleotide. RESULTS: The pD(2) value (the affinity to M-receptors of agonist) of Erycibele alkaloid's miosis is 3.60 +/- 0.15 and its IOP lowering action is 3.49 +/- 0.07. In the isolated iris contracting experiment, its pD(2) value is 6.38 +/- 0.12. M(3) receptor antagonist is the strongest antagonist in inhibiting the miosis, IOP lowering action and isolated iris pupillary contracting action of Erycibele alkaloid. 0.01% Erycibele alkaloid can cause the decrease of cAMP and the increase of cGMP in the aqueous humor. CONCLUSIONS: The effects of miosis and IOP lowering of Erycibele alkaloid are all mediated by M(3) receptor subtype and its signal transductive mechanism is connected with cyclic nucleotide system.

Animals↗
PubMed1999

[Effects of methyl tertiary butyl ether on liver tissue gene expression in rats].

OBJECTIVE: Methyl tertiary butyl ether (MTBE) is a new gasoline additive, with certain carcinogenecity in animal experiments. To study its possible mechanism of carcinogenesis in animals, expression of protooncogene c-myc and functional gene glutathione S-transferase-P (GST-P) in the liver tissues of rats chronically exposed to MTBE was detected. METHODS: Forty male SD rats with body weights of 180 - 200 grams were randomly divided into four groups and gavaged with MTBE dissolved in soybean oil with doses of 1 000, 600, 200 and 0 mg/kg, respectively, once daily and five days a week for 13 weeks. Liver tissues of the animals were frozen quickly in liquid nitrogen and their total RNA extracted with one-step method. The probes of c-myc and GST-P were labeled with digoxin by random primer method, and dots hybridization with RNA was used. RESULTS: Levels of expression of c-myc gene in the liver tissues of rats increased significantly, but not for those of GST-P. CONCLUSION: MTBE can induce the higher expression of c-myc gene, which suggests it can promote cell proliferation-one of possible mechanisms of carcinogenesis in animals.

Animals↗
PubMed1999

[Comparison of subclinical infection rates between vaccinated group with type I inactivated vaccine against hemorrhagic fever and controls].

OBJECTIVE: To compare subclinical infection rate in the vaccinated group with type I inactivated vaccine against hemorrhagic fever with renal syndrome (HFRS) with that in the controls and to understand its enhancement. METHODS: A trial field was selected in Jiande County, Zhejiang Province during July 1974 to November 1997. Paired-sera before and after vaccination were collected from 401 vaccinee and 360 controls, respectively. Serum titer of indirect immunofluorescent IgG antibody (IFAT) against HFRS was detected for each of them, and its cut-off value depended on the distribution of serum antibody titer in the second determination in the controls, which could be used to evaluate subclinical infection before vaccination. RESULTS: There was no significant difference in subclinical infection between those with positive and negative IFAT before vaccination, with different cut-off values for identifying subclinical infection. In both vaccinated and control groups with negative IFA before vaccination, subclinical infection rate was 7.62% in the controls, and 2.17% and 1.63% in the vaccinated ones, with cut-off values of 1:160 and 1:320, respectively, significantly different from that in the former. Subclinical infection rate was 11.38% and 6.78% in the vaccinated ones, as cut-off values of 1:20 and 1:40, respectively, without significant difference from the controls. CONCLUSION: No increase in subclinical infection in the vaccinated group with type I inactivated vaccine against HFRS was found.

Adolescent↗
PubMed1999

[A study on immunogenicity and safety of bivalent inactivated vaccine against hemorrhagic fever with renal syndrome].

OBJECTIVE: To study side effects and effectiveness of bivalent inactivated vaccine against hemorrhagic fever with renal syndrome in population of a randomized controlled field trial. METHODS: Serum indirect immunofluorescent antibody in 167 persons and neutralization antibody (types I and II) in 69 persons, who received three-dose vaccine, were determined two weeks after immunization, and side effects in 657 vaccinees were observed within 72 houses after immunization. RESULTS: Serum positive conversion rate of indirect immunofluorescent antibody was 99.04% (166/167) with GMT of 24.51 +/- 2.06. Serum positive conversion rate of neutralization antibody was 100% (69/69), 91.30% (63/69) for types I and 88.41% (61/69) for type II, respectively. GMTs for type I and II neutralization antibody were 18.27 +/- 2.21 and 12.47 +/- 2.16, respectively. Side effects at local site vaccinated of the body and temperature rising could be seen in 1.48% and 0.36% of the vaccinees, respectively. No severe side effect and abnormal reaction was found in vaccinees on the field. CONCLUSION: Immune response to bivalent inactivated vaccine against hemorrhagic fever with renal syndrome was satisfactory with slight side effect.

Adolescent↗
PubMed1999

[PCR for the detection of 16S rRNA gene bacteria].

According to the high conservative region of 16S rRNA gene in bacteria, PCR primers of the broad-range bacteria, gram-positive bacteria and gram-negative bacteria were synthesized to detect 13 bacterium species and (40) clinical specimens. All the tested bacterium species were positive. The lowest concentration of Escherichia Coli detected by serial dilution was 4 CFU.ml-1. The positive rate of PCR (27/40) was higher than that of bacterium culture(18/40). The results indicate that these PCR primers possess high specificity and sensitivity in identifying 16S rRNA gene of bacteria.

Bacteriuria↗
PubMed1999

[Studies on preparation of L-phenylalanine from phenylpyruvic acid by E. coli EP8-10].

E. coli EP8-10 was selected from the soil. It was able to produce the transaminase with high activity when it was cultivated on the medium containing peptone and beef extract. Optimum conditions of enzyme reaction was: phenylpyruvic acid's concentration of 0.3-0.5 mol/L, L-Asptaric acid used as amino donor, pH 8.5 37 degrees C. When phenylpyruvic acid was 0.3 mol/L, 48 g/L L-phenylalanine was produced after 6 h with 97% conversion rate.

Culture Media↗
PubMed1999

[Nucleotide sequence at position -155 to +25 of the 5' flanking region of the angiotensinogen gene of Han people].

OBJECTIVE: To study the polymorphism of 5'-flanking region of angiotensinogen gene and relations to essential hyperfension. METHODS: The nucleotide sequence at position -155 to +25 of the 5'-flanking region in angiotensinogen gene of Han people in Chinese population was identified by applying PCR-single stranded conformational polymorphism(SSCP) and PCR-directed sequencing. RESULTS: (1) The Han people carry an adenylate(A), instead of a cytidylate(C) at position -20 of the 5'-flanking region of AGT gene; (2) A new mutation T-->A at position -46 was detected and A-allele frequencies was similar in both hypertensives and normotensive controls. CONCLUSIONS: The variant T-->A at position -46 of AGT gene was not associated with hypertension, but an adenylate (A) at position -20 of the 5'-flanking region of AGT gene. might be an genetic marker for Hans people.

5' Flanking Region↗
PubMed1999

[Construction of a pufferfish gridded cosmid library].

OBJECTIVE: Pufferfish is a newly-established model organism in human genome research, which has been demonstrated its unique advantages in comparative genomics. Construction of a genomic library of pufferfish is the prerequisite to any studies of its genome. METHODS: Genomic DNA from Fugu rubripes, a species distribute only in Japan and China seas, was used to construct a library in a novel cosmid vector, named sCOGH2, which contains an exon-trapping cassette. RESULTS: This library is composed of 57,600 clones gridded in 60,096-well cell culture plates, one clone each well. The average size of the inserts is around 35 kb. It provides 99.2% probability to find any unique DNA fragment of pufferfish in this library. The clones of this library can survive after more than 10 times freeze-thaw, also demonstrating high stability in propagation. The clones shone highly positive signals when hybridized with the pufferfish genomic DNA. CONCLUSIONS: The library accords with qualitative demands of a cosmid library.

Animals↗
PubMed1999

An experimental study on homoharringtonine liposome and glaucoma filtration surgery.

PURPOSE: To observe the inhibitory action of homoharringtonine liposome during the healing process of wounds in the filtering sites. METHODS: Posterior sclerectomies were performed in 14 rabbits. Postoperatively one eye of each rabbit received subconjunctival injections of HH liposome and fellow eye received saline injection in a randomized masked fashion. RESULTS: Fourteen days after operation the IOP of experimental eyes reduced significantly (P < 0.01) as compared with the controlled eyes, and the number of remaining filtering blebs increased noticeably (P < 0.05). Pathohistological examination revealed that the number of fibroblasts per square micron in the filtering sites and the thickness of the scars in the center of the filtering sites of the experimental eyes were less than those of the controlled eyes. No serious ocular toxic and side effects were found. CONCLUSION: This experiment suggest that homoharringtonine liposome can markedly inhibit the scar formation of filtering sites after glaucoma filtering surgery, promote the formation of filtering blebs, and provide an experimental evidence for its clinical use in future.

Animals↗
PubMed1999

[Pathogenesis and clinical classification of the malignant glaucoma].

PURPOSE: To study the pathogenesis of the malignant glaucoma and the basis for the clinical classification of malignant glaucoma. METHODS: Twelve eyes with malignant glaucoma were examed by ultrasound biomicroscopy (UBM), type A and type B ocular ultrasounographer and other clinical ophthalmic tests and diagnostic therapy. The ocular anatomic structures of all 12 eyes were compared with those of the fellow eyes. RESULTS: Ciliary block were confirmed in four of the twelve eyes (33.3%) with malignant glaucoma while the narrow and small anterior segment were found in the fellow eyes by UBM. Iris lens disphragm anterior displacement were found in the other eight of the twelve eyes (76.6%) and their ciliary bodies were deformed passively. The ciliary bodies and anterior segment of the fellow eyes of these eight eyes were anatomically normal. Diagnostic surgery was performed in seven of the twelve eyes and six cases with fluid existing in the vitreous cavity were identified. CONCLUSION: According to our study, we suggest to classify malignant glaucoma into two tyges. One is ciliary block, which caused by ciliary block and concerned with the narrow and small structure of the anterior segment of eye. The other is lens iris block, which caused by iris lens diaphragm anterior displacement. Both types have the same pathophysiologic characteristics, such as, shallow anterior chamber, posterior chamber disappearance and aqueous humor misdirection to the vitreous cavity. But their pathogengesis may not be completely same.

Adult↗
PubMed1999

[The application of modularity design in the pulse oximeter].

This paper presents a thought of modularity design and application in our pulse oximeter and its hardware and software composition of the function board, the application can improve the reliability of the instrument greatly and make it easy to expand its function.

Equipment Design↗
PubMed1999

[Construction of adenovirus 4 vector with deletion of 78.9-86 mu fragment and express of beta-galactosidase gene].

OBJECTIVE: To construct a human adenovirus type 4(Ad4) vector with partial deletion at E3 region (78.9-86 mu). METHODS: Ad4 DNA was extracted from purified virus cultured in WI-38 cells. The essential fragment(71.3-100 mu) covering Ad4 E3 region was cloned and partial deletion of E3 region of this clone has been performed, generating plasmid pAd4 delta KS. Furthermore, a beta-galactosidase (beta-gal) gene flanked by CMV early promoter and SV40 poly A signal was inserted into pAd4 delta KS, resulting in pAd4c beta. This plasmid was cotransfected with Ad4 DNA, Bcl I A fragments into 293 cells, producing a non-defective recombinant Ad4 virus encoding B-gal. RESULT: The results showed that the constructed recombinant virus could efficiently express the foreign gene, beta-gal. CONCLUSION: Ad4 vector with a deletion of E3 region can be explored as a live vaccine for prevention of human infectious diseases.

Adenovirus E3 Proteins↗
PubMed1999

[Optimization of productivity of Epstein-Barr virus membrane antigen in baculovirus infected insect cells].

OBJECTIVE: To probe factors influencing the expression level of in insect cells. METHODS: Insect cells at different growth phases and in different culture media were infected with recombinant baculovirus carrying EBV-MA gene, where the membrane anchor sequence was deleted. The expression level of EBV-MA was detected by immunodots assay and scanner analysis. RESULTS: Cells at the early exponential phase yielded more expressed recombinant EBV-MA than those at the late exponential and stationary phases. Infected cells supplemented with fresh medium at various phases of growth resulted in improved productivity of EBV-MA. Further experiments revealed that replacing fresh medium prior to infection and supplementing a mixture of glucose and glutamine after infection, the productivity could be improved dramatically. Comparing the productivity of EBV-MA expressed in sf9 cells with that in sf21 cells, no obvious difference was found. CONCLUSION: Consumption of nutrients and accumulation of metabolites in cell culture media were the important factors influencing the productivity of EBV-MA in insect cells.

Animals↗
PubMed1999

[Monitoring and elimination of sulfur dioxide and nitrogen dioxide by passive sampling method].

The concentration of atmospheric pollutants, sulfur dioxide and nitrogen dioxide, were monitored by passive sampler with spectrophotometric determination method. The results were compared with active sampling method. It was found that the two methods got the same results. The adsorption of sulfur dioxide and nitrogen dioxide by sorbent-saturated filter paper was also studied.

Air Pollutants↗
PubMed1999

[Determination of sulfur dioxide by fluorometric analysis].

A method to determine the concentration of atmospheric pollutant, sulfur dioxide, was studied by fluorophotometric method. The composition and concentration of reaction solution were optimized. This method can be developed to be a fibre optic fluorometric method for routine monitoring.

Air Pollutants↗
PubMed1998

Transgenic mice demonstrate a testis-specific promoter for lactate dehydrogenase, LDHC.

The mammalian genome encodes a family of lactate dehydrogenase (LDH) isozymes. Two of these, ldha and ldhb, are expressed ubiquitously. The ldhc gene is active only in the germinal epithelium during spermatogenesis. In our analysis of ldhc gene regulation, we found that a 60-base pair promoter sequence was sufficient for testis-specific expression in an in vitro transcription assay. To confirm these findings, a genomic fragment containing 100 base pairs overlapping the transcription start site was isolated and linked to the Escherichia coli lacZ gene. We report that this genomic fragment drives testis-specific expression in transgenic mice. We conclude that transcription of the transgene and possibly of the endogenous ldhc gene is restricted to leptotene/pachytene primary spermatocytes.

Animals↗
PubMed1998

Mixed-backbone oligonucleotides as second-generation antisense agents with reduced phosphorothioate-related side effects.

Mixed-backbone oligonucleotides containing alternative phosphorothioate and phosphodiester linkages in the 2'-O-methylribonucleosides segment show increased affinity with complementary targets, increased stability towards nucleases in vitro and in vivo, and reduced phosphorothioate-related prolongation of partial thromboplastin time compared to phosphorothioate oligodeoxynucleotides, thereby providing antisense agents with reduced side effects.

Drug Stability↗